Initial commit

module/jni/libcxx/test/std/strings/basic.string/allocator_mismatch.verify.cpp

@@ -0,0 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+//   The container's value type must be the same as the allocator's value type
+
+#include <string>
+
+std::basic_string<char, std::char_traits<char>, std::allocator<int> > s; // expected-error@*:* {{Allocator::value_type must be same type as value_type}}

module/jni/libcxx/test/std/strings/basic.string/char.bad.verify.cpp

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+//   ... manipulating sequences of any non-array trivial standard-layout types.
+
+#include <string>
+#include "test_traits.h"
+
+struct NotTrivial {
+    NotTrivial() : value(3) {}
+    int value;
+};
+
+struct NotStandardLayout {
+public:
+    NotStandardLayout() : one(1), two(2) {}
+    int sum() const { return one + two; } // silences "unused field 'two' warning"
+    int one;
+private:
+    int two;
+};
+
+void f() {
+    {
+        // array
+        typedef char C[3];
+        static_assert(std::is_array<C>::value, "");
+        std::basic_string<C, test_traits<C> > s;
+        // expected-error-re@string:* {{{{(static_assert|static assertion)}} failed{{.*}}Character type of basic_string must not be an array}}
+    }
+
+    {
+        // not trivial
+        static_assert(!std::is_trivial<NotTrivial>::value, "");
+        std::basic_string<NotTrivial, test_traits<NotTrivial> > s;
+        // expected-error-re@string:* {{{{(static_assert|static assertion)}} failed{{.*}}Character type of basic_string must be trivial}}
+    }
+
+    {
+        // not standard layout
+        static_assert(!std::is_standard_layout<NotStandardLayout>::value, "");
+        std::basic_string<NotStandardLayout, test_traits<NotStandardLayout> > s;
+        // expected-error-re@string:* {{{{(static_assert|static assertion)}} failed{{.*}}Character type of basic_string must be standard-layout}}
+    }
+}

module/jni/libcxx/test/std/strings/basic.string/range_concept_conformance.compile.pass.cpp

@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// string
+
+#include <string>
+
+#include <concepts>
+#include <ranges>
+
+
+
+static_assert(std::same_as<std::ranges::iterator_t<std::string>, std::string::iterator>);
+static_assert(std::ranges::common_range<std::string>);
+static_assert(std::ranges::random_access_range<std::string>);
+static_assert(std::ranges::contiguous_range<std::string>);
+static_assert(!std::ranges::view<std::string>);
+static_assert(std::ranges::sized_range<std::string>);
+static_assert(!std::ranges::borrowed_range<std::string>);
+static_assert(std::ranges::viewable_range<std::string>);
+
+static_assert(std::same_as<std::ranges::iterator_t<std::string const>, std::string::const_iterator>);
+static_assert(std::ranges::common_range<std::string const>);
+static_assert(std::ranges::random_access_range<std::string const>);
+static_assert(std::ranges::contiguous_range<std::string const>);
+static_assert(!std::ranges::view<std::string const>);
+static_assert(std::ranges::sized_range<std::string const>);
+static_assert(!std::ranges::borrowed_range<std::string const>);
+static_assert(!std::ranges::viewable_range<std::string const>);

module/jni/libcxx/test/std/strings/basic.string/string.access/at.pass.cpp

@@ -0,0 +1,88 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_reference at(size_type pos) const; // constexpr since C++20
+//       reference at(size_type pos); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "min_allocator.h"
+
+#include "test_macros.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type pos)
+{
+    const S& cs = s;
+    if (pos < s.size())
+    {
+        assert(s.at(pos) == s[pos]);
+        assert(cs.at(pos) == cs[pos]);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            TEST_IGNORE_NODISCARD s.at(pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos >= s.size());
+        }
+        try
+        {
+            TEST_IGNORE_NODISCARD cs.at(pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos >= s.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 0);
+    test(S("123"), 0);
+    test(S("123"), 1);
+    test(S("123"), 2);
+    test(S("123"), 3);
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 0);
+    test(S("123"), 0);
+    test(S("123"), 1);
+    test(S("123"), 2);
+    test(S("123"), 3);
+  }
+#endif
+
+    return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.access/back.pass.cpp

@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const charT& back() const; // constexpr since C++20
+//       charT& back(); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s.back()), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs.back()), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s.back());
+    LIBCPP_ASSERT_NOEXCEPT(   cs.back());
+    assert(&cs.back() == &cs[cs.size()-1]);
+    assert(&s.back() == &s[cs.size()-1]);
+    s.back() = typename S::value_type('z');
+    assert(s.back() == typename S::value_type('z'));
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S("1"));
+    test(S("1234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S("1"));
+    test(S("1234567890123456789012345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.access/front.pass.cpp

@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const charT& front() const; // constexpr since C++20
+//       charT& front(); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s.front()), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs.front()), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s.front());
+    LIBCPP_ASSERT_NOEXCEPT(   cs.front());
+    assert(&cs.front() == &cs[0]);
+    assert(&s.front() == &s[0]);
+    s.front() = typename S::value_type('z');
+    assert(s.front() == typename S::value_type('z'));
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S("1"));
+    test(S("1234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S("1"));
+    test(S("1234567890123456789012345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.access/index.pass.cpp

@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_reference operator[](size_type pos) const; // constexpr since C++20
+//       reference operator[](size_type pos); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    S s("0123456789");
+    const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s[0]), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s[0]);
+    LIBCPP_ASSERT_NOEXCEPT(   cs[0]);
+    for (S::size_type i = 0; i < cs.size(); ++i)
+    {
+        assert(s[i] == static_cast<char>('0' + i));
+        assert(cs[i] == s[i]);
+    }
+    assert(cs[cs.size()] == '\0');
+    const S s2 = S();
+    assert(s2[0] == '\0');
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s("0123456789");
+    const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s[0]), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s[0]);
+    LIBCPP_ASSERT_NOEXCEPT(   cs[0]);
+    for (S::size_type i = 0; i < cs.size(); ++i)
+    {
+        assert(s[i] == static_cast<char>('0' + i));
+        assert(cs[i] == s[i]);
+    }
+    assert(cs[cs.size()] == '\0');
+    const S s2 = S();
+    assert(s2[0] == '\0');
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/capacity.pass.cpp

@@ -0,0 +1,75 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// size_type capacity() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+#include "test_macros.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, test_allocator_statistics& alloc_stats)
+{
+    alloc_stats.throw_after = 0;
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    try
+#endif
+    {
+        while (s.size() < s.capacity())
+            s.push_back(typename S::value_type());
+        assert(s.size() == s.capacity());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    catch (...)
+    {
+        assert(false);
+    }
+#endif
+    alloc_stats.throw_after = INT_MAX;
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    test_allocator_statistics alloc_stats;
+    typedef std::basic_string<char, std::char_traits<char>, test_allocator<char> > S;
+    S s((test_allocator<char>(&alloc_stats)));
+    test(s, alloc_stats);
+    s.assign(10, 'a');
+    s.erase(5);
+    test(s, alloc_stats);
+    s.assign(100, 'a');
+    s.erase(50);
+    test(s, alloc_stats);
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s;
+    assert(s.capacity() > 0);
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/clear.pass.cpp

@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void clear(); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    s.clear();
+    assert(s.size() == 0);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    S s;
+    test(s);
+
+    s.assign(10, 'a');
+    s.erase(5);
+    test(s);
+
+    s.assign(100, 'a');
+    s.erase(50);
+    test(s);
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s;
+    test(s);
+
+    s.assign(10, 'a');
+    s.erase(5);
+    test(s);
+
+    s.assign(100, 'a');
+    s.erase(50);
+    test(s);
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/empty.pass.cpp

@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// bool empty() const noexcept; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    ASSERT_NOEXCEPT(s.empty());
+    assert(s.empty() == (s.size() == 0));
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/empty.verify.cpp

@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// class deque
+
+// bool empty() const noexcept; // constexpr since C++20
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+#include <string>
+
+#include "test_macros.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  std::string c;
+  c.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/length.pass.cpp

@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// size_type length() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    assert(s.length() == s.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/max_size.pass.cpp

@@ -0,0 +1,95 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: no-exceptions
+// <string>
+
+// size_type max_size() const; // constexpr since C++20
+
+// NOTE: asan and msan will fail for one of two reasons
+// 1. If allocator_may_return_null=0 then they will fail because the allocation
+//    returns null.
+// 2. If allocator_may_return_null=1 then they will fail because the allocation
+//    is too large to succeed.
+// UNSUPPORTED: sanitizer-new-delete
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test1(const S& s)
+{
+    S s2(s);
+    const size_t sz = s2.max_size() - 1;
+    try { s2.resize(sz, 'x'); }
+    catch ( const std::bad_alloc & ) { return ; }
+    assert ( s2.size() ==  sz );
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test2(const S& s)
+{
+    S s2(s);
+    const size_t sz = s2.max_size();
+    try { s2.resize(sz, 'x'); }
+    catch ( const std::bad_alloc & ) { return ; }
+    assert ( s.size() ==  sz );
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    assert(s.max_size() >= s.size());
+    test1(s);
+    test2(s);
+}
+
+void test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#endif
+}
+
+#if TEST_STD_VER > 17
+constexpr bool test_constexpr() {
+  std::string str;
+
+  size_t size = str.max_size();
+  assert(size > 0);
+
+  return true;
+}
+#endif
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  test_constexpr();
+  static_assert(test_constexpr());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/over_max_size.pass.cpp

@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: no-exceptions
+// XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11}}
+
+// Prior to http://llvm.org/D123580, there was a bug with how the max_size()
+// was calculated. That was inlined into some functions in the dylib, which leads
+// to failures when running this test against an older system dylib.
+// XFAIL: use_system_cxx_lib && target=arm64-apple-macosx{{11.0|12.0}}
+
+// <string>
+
+// size_type max_size() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+#include <stdexcept>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+void
+test(const S& s)
+{
+    assert(s.max_size() >= s.size());
+    S s2(s);
+    const size_t sz = s2.max_size() + 1;
+    try { s2.resize(sz, 'x'); }
+    catch ( const std::length_error & ) { return ; }
+    assert ( false );
+}
+
+bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+    test(S("12345678901234567890123456789012345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/reserve.deprecated_in_cxx20.verify.cpp

@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void reserve(); // Deprecated in C++20
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+#include <string>
+
+int main(int, char**)
+{
+    std::string s;
+    s.reserve(); // expected-warning {{'reserve' is deprecated}}
+    return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp

@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void reserve(); // Deprecated in C++20.
+
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+void
+test(typename S::size_type min_cap, typename S::size_type erased_index)
+{
+    S s(min_cap, 'a');
+    s.erase(erased_index);
+    assert(s.size() == erased_index);
+    assert(s.capacity() >= min_cap); // Check that we really have at least this capacity.
+
+    typename S::size_type old_cap = s.capacity();
+    S s0 = s;
+    s.reserve();
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == s0);
+    assert(s.capacity() <= old_cap);
+    assert(s.capacity() >= s.size());
+}
+
+bool test() {
+    {
+    typedef std::string S;
+    {
+    test<S>(0, 0);
+    test<S>(10, 5);
+    test<S>(100, 50);
+    }
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    {
+    test<S>(0, 0);
+    test<S>(10, 5);
+    test<S>(100, 50);
+    }
+    }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/reserve_size.pass.cpp

@@ -0,0 +1,112 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void reserve(size_type res_arg); // constexpr since C++20
+
+// This test relies on https://llvm.org/PR45368 being fixed, which isn't in
+// older Apple dylibs
+// XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx{{10.9|10.10|10.11|10.12|10.13|10.14|10.15|11.0}}
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(typename S::size_type min_cap, typename S::size_type erased_index, typename S::size_type res_arg)
+{
+    S s(min_cap, 'a');
+    s.erase(erased_index);
+    assert(s.size() == erased_index);
+    assert(s.capacity() >= min_cap); // Check that we really have at least this capacity.
+
+#if TEST_STD_VER > 17
+    typename S::size_type old_cap = s.capacity();
+#endif
+    S s0 = s;
+    if (res_arg <= s.max_size())
+    {
+        s.reserve(res_arg);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == s0);
+        assert(s.capacity() >= res_arg);
+        assert(s.capacity() >= s.size());
+#if TEST_STD_VER > 17
+        assert(s.capacity() >= old_cap); // reserve never shrinks as of P0966 (C++20)
+#endif
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.reserve(res_arg);
+            LIBCPP_ASSERT(s.__invariants());
+            assert(false);
+        }
+        catch (std::length_error&)
+        {
+            assert(res_arg > s.max_size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    {
+      test<S>(0, 0, 5);
+      test<S>(0, 0, 10);
+      test<S>(0, 0, 50);
+    }
+    {
+      test<S>(100, 50, 5);
+      test<S>(100, 50, 10);
+      test<S>(100, 50, 50);
+      test<S>(100, 50, 100);
+      test<S>(100, 50, 1000);
+      test<S>(100, 50, S::npos);
+    }
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    {
+      test<S>(0, 0, 5);
+      test<S>(0, 0, 10);
+      test<S>(0, 0, 50);
+    }
+    {
+      test<S>(100, 50, 5);
+      test<S>(100, 50, 10);
+      test<S>(100, 50, 50);
+      test<S>(100, 50, 100);
+      test<S>(100, 50, 1000);
+      test<S>(100, 50, S::npos);
+    }
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/resize_and_overwrite.pass.cpp

@@ -0,0 +1,103 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <string>
+
+// template<class Operation>
+// void resize_and_overwrite(size_type n, Operation op)
+
+#include <algorithm>
+#include <cassert>
+#include <string>
+
+#include "make_string.h"
+#include "test_macros.h"
+
+template <class S>
+constexpr void test_appending(size_t k, size_t N, size_t new_capacity) {
+  assert(N > k);
+  assert(new_capacity >= N);
+  auto s = S(k, 'a');
+  s.resize_and_overwrite(new_capacity, [&](auto* p, auto n) {
+    assert(n == new_capacity);
+    LIBCPP_ASSERT(s.size() == new_capacity);
+    LIBCPP_ASSERT(s.begin().base() == p);
+    assert(std::all_of(p, p + k, [](const auto ch) { return ch == 'a'; }));
+    std::fill(p + k, p + n, 'b');
+    p[n] = 'c'; // will be overwritten
+    return N;
+  });
+  const S expected = S(k, 'a') + S(N - k, 'b');
+  assert(s == expected);
+  assert(s.c_str()[N] == '\0');
+}
+
+template <class S>
+constexpr void test_truncating(size_t o, size_t N) {
+  assert(N < o);
+  auto s = S(o, 'a');
+  s.resize_and_overwrite(N, [&](auto* p, auto n) {
+    assert(n == N);
+    LIBCPP_ASSERT(s.size() == n);
+    LIBCPP_ASSERT(s.begin().base() == p);
+    assert(std::all_of(p, p + n, [](auto ch) { return ch == 'a'; }));
+    p[n - 1] = 'b';
+    p[n] = 'c'; // will be overwritten
+    return n;
+  });
+  const S expected = S(N - 1, 'a') + S(1, 'b');
+  assert(s == expected);
+  assert(s.c_str()[N] == '\0');
+}
+
+template <class CharT>
+constexpr bool test() {
+  using S = std::basic_string<CharT>;
+  test_appending<S>(10, 15, 15);
+  test_appending<S>(10, 15, 20);
+  test_appending<S>(10, 40, 40);
+  test_appending<S>(10, 40, 50);
+  test_appending<S>(30, 35, 35);
+  test_appending<S>(30, 35, 45);
+  test_appending<S>(10, 15, 30);
+  test_truncating<S>(15, 10);
+  test_truncating<S>(40, 35);
+  test_truncating<S>(40, 10);
+
+  return true;
+}
+
+void test_value_categories() {
+  std::string s;
+  s.resize_and_overwrite(10, [](char*&&, size_t&&) { return 0; });
+  s.resize_and_overwrite(10, [](char* const&, const size_t&) { return 0; });
+  struct RefQualified {
+    int operator()(char*, size_t) && { return 0; }
+  };
+  s.resize_and_overwrite(10, RefQualified{});
+}
+
+int main(int, char**) {
+  test<char>();
+  test<char8_t>();
+  test<char16_t>();
+  test<char32_t>();
+
+  static_assert(test<char>());
+  static_assert(test<char8_t>());
+  static_assert(test<char16_t>());
+  static_assert(test<char32_t>());
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+  test<wchar_t>();
+  static_assert(test<wchar_t>());
+#endif
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/resize_size.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void resize(size_type n); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type n, S expected)
+{
+    if (n <= s.max_size())
+    {
+        s.resize(n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.resize(n);
+            assert(false);
+        }
+        catch (std::length_error&)
+        {
+            assert(n > s.max_size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 0, S());
+    test(S(), 1, S(1, '\0'));
+    test(S(), 10, S(10, '\0'));
+    test(S(), 100, S(100, '\0'));
+    test(S("12345"), 0, S());
+    test(S("12345"), 2, S("12"));
+    test(S("12345"), 5, S("12345"));
+    test(S("12345"), 15, S("12345\0\0\0\0\0\0\0\0\0\0", 15));
+    test(S("12345678901234567890123456789012345678901234567890"), 0, S());
+    test(S("12345678901234567890123456789012345678901234567890"), 10,
+         S("1234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 50,
+         S("12345678901234567890123456789012345678901234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 60,
+         S("12345678901234567890123456789012345678901234567890\0\0\0\0\0\0\0\0\0\0", 60));
+    test(S(), S::npos, S("not going to happen"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 0, S());
+    test(S(), 1, S(1, '\0'));
+    test(S(), 10, S(10, '\0'));
+    test(S(), 100, S(100, '\0'));
+    test(S("12345"), 0, S());
+    test(S("12345"), 2, S("12"));
+    test(S("12345"), 5, S("12345"));
+    test(S("12345"), 15, S("12345\0\0\0\0\0\0\0\0\0\0", 15));
+    test(S("12345678901234567890123456789012345678901234567890"), 0, S());
+    test(S("12345678901234567890123456789012345678901234567890"), 10,
+         S("1234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 50,
+         S("12345678901234567890123456789012345678901234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 60,
+         S("12345678901234567890123456789012345678901234567890\0\0\0\0\0\0\0\0\0\0", 60));
+    test(S(), S::npos, S("not going to happen"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/resize_size_char.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void resize(size_type n, charT c); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type n, typename S::value_type c, S expected)
+{
+    if (n <= s.max_size())
+    {
+        s.resize(n, c);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.resize(n, c);
+            assert(false);
+        }
+        catch (std::length_error&)
+        {
+            assert(n > s.max_size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 0, 'a', S());
+    test(S(), 1, 'a', S("a"));
+    test(S(), 10, 'a', S(10, 'a'));
+    test(S(), 100, 'a', S(100, 'a'));
+    test(S("12345"), 0, 'a', S());
+    test(S("12345"), 2, 'a', S("12"));
+    test(S("12345"), 5, 'a', S("12345"));
+    test(S("12345"), 15, 'a', S("12345aaaaaaaaaa"));
+    test(S("12345678901234567890123456789012345678901234567890"), 0, 'a', S());
+    test(S("12345678901234567890123456789012345678901234567890"), 10, 'a',
+         S("1234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 50, 'a',
+         S("12345678901234567890123456789012345678901234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 60, 'a',
+         S("12345678901234567890123456789012345678901234567890aaaaaaaaaa"));
+    test(S(), S::npos, 'a', S("not going to happen"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 0, 'a', S());
+    test(S(), 1, 'a', S("a"));
+    test(S(), 10, 'a', S(10, 'a'));
+    test(S(), 100, 'a', S(100, 'a'));
+    test(S("12345"), 0, 'a', S());
+    test(S("12345"), 2, 'a', S("12"));
+    test(S("12345"), 5, 'a', S("12345"));
+    test(S("12345"), 15, 'a', S("12345aaaaaaaaaa"));
+    test(S("12345678901234567890123456789012345678901234567890"), 0, 'a', S());
+    test(S("12345678901234567890123456789012345678901234567890"), 10, 'a',
+         S("1234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 50, 'a',
+         S("12345678901234567890123456789012345678901234567890"));
+    test(S("12345678901234567890123456789012345678901234567890"), 60, 'a',
+         S("12345678901234567890123456789012345678901234567890aaaaaaaaaa"));
+    test(S(), S::npos, 'a', S("not going to happen"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/shrink_to_fit.explicit_instantiation.sh.cpp

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// This test checks that we can explicitly instantiate std::string with a custom
+// character type and traits and then use `shrink_to_fit`. In particular, this is
+// a regression test for the bug that was reported at https://stackoverflow.com/q/69520633/627587
+// and https://seedcentral.apple.com/sm/feedback_collector/radar/85053279.
+
+// RUN: %{cxx} %{flags} %{compile_flags} %s %{link_flags} -DTU1 -c -o %t.tu1.o
+// RUN: %{cxx} %{flags} %{compile_flags} %s %{link_flags} -DTU2 -c -o %t.tu2.o
+// RUN: %{cxx} %{flags} %t.tu1.o %t.tu2.o %{link_flags} -o %t.exe
+
+// UNSUPPORTED: no-localization
+
+#include <cstdint>
+#include <ios>
+#include <string>
+
+typedef std::uint16_t char16;
+
+struct string16_char_traits {
+  typedef char16 char_type;
+  typedef int int_type;
+
+  typedef std::streamoff off_type;
+  typedef std::mbstate_t state_type;
+  typedef std::fpos<state_type> pos_type;
+
+  static void assign(char_type&, const char_type&) { }
+  static bool eq(const char_type&, const char_type&) { return false; }
+  static bool lt(const char_type&, const char_type&) { return false; }
+  static int compare(const char_type*, const char_type*, size_t) { return 0; }
+  static size_t length(const char_type*) { return 0; }
+  static const char_type* find(const char_type*, size_t, const char_type&) { return nullptr; }
+  static char_type* move(char_type*, const char_type*, size_t) { return nullptr; }
+  static char_type* copy(char_type*, const char_type*, size_t) { return nullptr; }
+  static char_type* assign(char_type*, size_t, char_type) { return nullptr; }
+  static int_type not_eof(const int_type&) { return 0; }
+  static char_type to_char_type(const int_type&) { return char_type(); }
+  static int_type to_int_type(const char_type&) { return int_type(); }
+  static bool eq_int_type(const int_type&, const int_type&) { return false; }
+  static int_type eof() { return int_type(); }
+};
+
+#if defined(TU1)
+template class std::basic_string<char16, string16_char_traits>;
+#else
+extern template class std::basic_string<char16, string16_char_traits>;
+
+int main() {
+    std::basic_string<char16, string16_char_traits> s;
+    s.shrink_to_fit();
+}
+#endif

module/jni/libcxx/test/std/strings/basic.string/string.capacity/shrink_to_fit.pass.cpp

@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void shrink_to_fit(); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    typename S::size_type old_cap = s.capacity();
+    S s0 = s;
+    s.shrink_to_fit();
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == s0);
+    assert(s.capacity() <= old_cap);
+    assert(s.capacity() >= s.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    S s;
+    test(s);
+
+    s.assign(10, 'a');
+    s.erase(5);
+    test(s);
+
+    s.assign(100, 'a');
+    s.erase(50);
+    test(s);
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s;
+    test(s);
+
+    s.assign(10, 'a');
+    s.erase(5);
+    test(s);
+
+    s.assign(100, 'a');
+    s.erase(50);
+    test(s);
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.capacity/size.pass.cpp

@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// size_type size() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s, typename S::size_type c)
+{
+    assert(s.size() == c);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 0);
+    test(S("123"), 3);
+    test(S("12345678901234567890123456789012345678901234567890"), 50);
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 0);
+    test(S("123"), 3);
+    test(S("12345678901234567890123456789012345678901234567890"), 50);
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/T_size_size.pass.cpp

@@ -0,0 +1,196 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class _Tp>
+//   basic_string(const _Tp& __t, size_type __pos, size_type __n,
+//                const allocator_type& __a = allocator_type()); // constexpr since C++20
+//
+//  Mostly we're testing string_view here
+
+#include <string>
+#include <string_view>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(SV sv, std::size_t pos, std::size_t n)
+{
+    typedef typename S::traits_type T;
+    typedef typename S::allocator_type A;
+    typedef typename S::size_type Size;
+    if (pos <= sv.size())
+    {
+        S s2(sv, static_cast<Size>(pos), static_cast<Size>(n));
+        LIBCPP_ASSERT(s2.__invariants());
+        assert(pos <= sv.size());
+        std::size_t rlen = std::min(sv.size() - pos, n);
+        assert(s2.size() == rlen);
+        assert(T::compare(s2.data(), sv.data() + pos, rlen) == 0);
+        assert(s2.get_allocator() == A());
+        assert(s2.capacity() >= s2.size());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            S s2(sv, static_cast<Size>(pos), static_cast<Size>(n));
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(SV sv, std::size_t pos, std::size_t n, const typename S::allocator_type& a)
+{
+    typedef typename S::traits_type T;
+    typedef typename S::size_type Size;
+    if (pos <= sv.size())
+    {
+        S s2(sv, static_cast<Size>(pos), static_cast<Size>(n), a);
+        LIBCPP_ASSERT(s2.__invariants());
+        assert(pos <= sv.size());
+        std::size_t rlen = std::min(sv.size() - pos, n);
+        assert(s2.size() == rlen);
+        assert(T::compare(s2.data(), sv.data() + pos, rlen) == 0);
+        assert(s2.get_allocator() == a);
+        assert(s2.capacity() >= s2.size());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            S s2(sv, static_cast<Size>(pos), static_cast<Size>(n), a);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    typedef std::basic_string     <char, std::char_traits<char>, A> S;
+
+    test<S,SV>(SV(), 0, 0);
+    test<S,SV>(SV(), 0, 1);
+    test<S,SV>(SV(), 1, 0);
+    test<S,SV>(SV(), 1, 1);
+    test<S,SV>(SV(), 1, 2);
+    test<S,SV>(SV("1"), 0, 0);
+    test<S,SV>(SV("1"), 0, 1);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50,   0);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50,   1);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50,  10);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 100);
+
+    test<S,SV>(SV(), 0, 0, A(4));
+    test<S,SV>(SV(), 0, 1, A(4));
+    test<S,SV>(SV(), 1, 0, A(4));
+    test<S,SV>(SV(), 1, 1, A(4));
+    test<S,SV>(SV(), 1, 2, A(4));
+    test<S,SV>(SV("1"), 0, 0, A(6));
+    test<S,SV>(SV("1"), 0, 1, A(6));
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50,   0, A(8));
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50,   1, A(8));
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50,  10, A(8));
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 100, A(8));
+  }
+
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    typedef std::basic_string     <char, std::char_traits<char>, A> S;
+
+    test<S,SV>(SV(), 0, 0);
+    test<S,SV>(SV(), 0, 1);
+    test<S,SV>(SV(), 1, 0);
+    test<S,SV>(SV(), 1, 1);
+    test<S,SV>(SV(), 1, 2);
+    test<S,SV>(SV("1"), 0, 0);
+    test<S,SV>(SV("1"), 0, 1);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 0);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 1);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 10);
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 100);
+
+    test<S,SV>(SV(), 0, 0, A());
+    test<S,SV>(SV(), 0, 1, A());
+    test<S,SV>(SV(), 1, 0, A());
+    test<S,SV>(SV(), 1, 1, A());
+    test<S,SV>(SV(), 1, 2, A());
+    test<S,SV>(SV("1"), 0, 0, A());
+    test<S,SV>(SV("1"), 0, 1, A());
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 0, A());
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 1, A());
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 10, A());
+    test<S,SV>(SV("1234567890123456789012345678901234567890123456789012345678901234567890"), 50, 100, A());
+  }
+#endif
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    S s = "ABCD";
+    SV sv = "EFGH";
+    char arr[] = "IJKL";
+
+    S s1("CDEF", 4);    // calls ctor(const char *, len)
+    assert(s1 == "CDEF");
+
+    S s2("QRST", 0, 3); // calls ctor(string("QRST", pos, len)
+    assert(s2 == "QRS");
+
+    S s3(sv, 0, std::string::npos);   // calls ctor(T, pos, npos)
+    assert(s3 == sv);
+
+    S s4(sv, 0, 3);   // calls ctor(T, pos, len)
+    assert(s4 == "EFG");
+
+    S s5(arr, 0, 2);     // calls ctor(const char *, len)
+    assert(s5 == "IJ");
+
+    S s6(arr, 0);     // calls ctor(const char *, len)
+    assert(s6 == "");
+
+    S s7(s.data(), 2);     // calls ctor(const char *, len)
+    assert(s7 == "AB");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/alloc.pass.cpp

@@ -0,0 +1,106 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// explicit basic_string(const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test()
+{
+    {
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S()) == noexcept(typename S::allocator_type())), "" );
+#endif
+    S s;
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s.data());
+    assert(s.size() == 0);
+    assert(s.capacity() >= s.size());
+    assert(s.get_allocator() == typename S::allocator_type());
+    }
+    {
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{typename S::allocator_type{}})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S(typename S::allocator_type())) == std::is_nothrow_copy_constructible<typename S::allocator_type>::value), "" );
+#endif
+    S s(typename S::allocator_type(5));
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s.data());
+    assert(s.size() == 0);
+    assert(s.capacity() >= s.size());
+    assert(s.get_allocator() == typename S::allocator_type(5));
+    }
+}
+
+#if TEST_STD_VER >= 11
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test2()
+{
+    {
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S()) == noexcept(typename S::allocator_type())), "" );
+#endif
+    S s;
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s.data());
+    assert(s.size() == 0);
+    assert(s.capacity() >= s.size());
+    assert(s.get_allocator() == typename S::allocator_type());
+    }
+    {
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{typename S::allocator_type{}})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S(typename S::allocator_type())) == std::is_nothrow_copy_constructible<typename S::allocator_type>::value), "" );
+#endif
+    S s(typename S::allocator_type{});
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s.data());
+    assert(s.size() == 0);
+    assert(s.capacity() >= s.size());
+    assert(s.get_allocator() == typename S::allocator_type());
+    }
+}
+
+#endif
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  test<std::basic_string<char, std::char_traits<char>, test_allocator<char> > >();
+#if TEST_STD_VER >= 11
+  test2<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
+  test2<std::basic_string<char, std::char_traits<char>, explicit_allocator<char> > >();
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/brace_assignment.pass.cpp

@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   operator=(basic_string<charT,traits,Allocator>&& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  // Test that assignment from {} and {ptr, len} are allowed and are not
+  // ambiguous.
+  {
+    std::string s = "hello world";
+    s = {};
+    assert(s.empty());
+  }
+  {
+    std::string s = "hello world";
+    s = {"abc", 2};
+    assert(s == "ab");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/char_assignment.pass.cpp

@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& operator=(charT c); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s1, typename S::value_type s2)
+{
+    typedef typename S::traits_type T;
+    s1 = s2;
+    LIBCPP_ASSERT(s1.__invariants());
+    assert(s1.size() == 1);
+    assert(T::eq(s1[0], s2));
+    assert(s1.capacity() >= s1.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 'a');
+    test(S("1"), 'a');
+    test(S("123456789"), 'a');
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"), 'a');
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 'a');
+    test(S("1"), 'a');
+    test(S("123456789"), 'a');
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"), 'a');
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/copy.pass.cpp

@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string(const basic_string<charT,traits,Allocator>& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s1)
+{
+    S s2 = s1;
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2 == s1);
+    assert(s2.capacity() >= s2.size());
+    assert(s2.get_allocator() == s1.get_allocator());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    test(S(A(3)));
+    test(S("1", A(5)));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    test(S(A{}));
+    test(S("1", A()));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/copy_alloc.pass.cpp

@@ -0,0 +1,142 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string(const basic_string& str, const Allocator& alloc); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+#ifndef TEST_HAS_NO_EXCEPTIONS
+struct alloc_imp {
+    bool active;
+
+    TEST_CONSTEXPR alloc_imp() : active(true) {}
+
+    template <class T>
+    T* allocate(std::size_t n)
+    {
+        if (active)
+            return static_cast<T*>(std::malloc(n * sizeof(T)));
+        else
+            throw std::bad_alloc();
+    }
+
+    template <class T>
+    void deallocate(T* p, std::size_t) { std::free(p); }
+    void activate  ()                  { active = true; }
+    void deactivate()                  { active = false; }
+};
+
+template <class T>
+struct poca_alloc {
+    typedef T value_type;
+    typedef std::true_type propagate_on_container_copy_assignment;
+
+    alloc_imp *imp;
+
+    TEST_CONSTEXPR poca_alloc(alloc_imp *imp_) : imp (imp_) {}
+
+    template <class U>
+    TEST_CONSTEXPR poca_alloc(const poca_alloc<U>& other) : imp(other.imp) {}
+
+    T*   allocate  (std::size_t n)       { return imp->allocate<T>(n);}
+    void deallocate(T* p, std::size_t n) { imp->deallocate(p, n); }
+};
+
+template <typename T, typename U>
+bool operator==(const poca_alloc<T>& lhs, const poca_alloc<U>& rhs)
+{
+    return lhs.imp == rhs.imp;
+}
+
+template <typename T, typename U>
+bool operator!=(const poca_alloc<T>& lhs, const poca_alloc<U>& rhs)
+{
+    return lhs.imp != rhs.imp;
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void test_assign(S &s1, const S& s2)
+{
+    try { s1 = s2; }
+    catch ( std::bad_alloc &) { return; }
+    assert(false);
+}
+#endif
+
+
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s1, const typename S::allocator_type& a)
+{
+    S s2(s1, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2 == s1);
+    assert(s2.capacity() >= s2.size());
+    assert(s2.get_allocator() == a);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    test(S(), A(3));
+    test(S("1"), A(5));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"), A(7));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    test(S(), A());
+    test(S("1"), A());
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"), A());
+  }
+
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  if (!TEST_IS_CONSTANT_EVALUATED) {
+    typedef poca_alloc<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    const char * p1 = "This is my first string";
+    const char * p2 = "This is my second string";
+
+    alloc_imp imp1;
+    alloc_imp imp2;
+    S s1(p1, A(&imp1));
+    S s2(p2, A(&imp2));
+
+    assert(s1 == p1);
+    assert(s2 == p2);
+
+    imp2.deactivate();
+    test_assign(s1, s2);
+    assert(s1 == p1);
+    assert(s2 == p2);
+  }
+#endif
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/copy_assignment.pass.cpp

@@ -0,0 +1,90 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   operator=(const basic_string<charT,traits,Allocator>& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s1, const S& s2)
+{
+    s1 = s2;
+    LIBCPP_ASSERT(s1.__invariants());
+    assert(s1 == s2);
+    assert(s1.capacity() >= s1.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S());
+    test(S("1"), S());
+    test(S(), S("1"));
+    test(S("1"), S("2"));
+    test(S("1"), S("2"));
+
+    test(S(),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("123456789"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S());
+    test(S("1"), S());
+    test(S(), S("1"));
+    test(S("1"), S("2"));
+    test(S("1"), S("2"));
+
+    test(S(),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("123456789"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+  }
+#endif
+
+#if TEST_STD_VER > 3
+  {   // LWG 2946
+    std::string s;
+    s = {"abc", 1};
+    assert(s.size() == 1);
+    assert(s == "a");
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/default.pass.cpp

@@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string() noexcept(is_nothrow_default_constructible<allocator_type>::value); // constexpr since C++20
+
+#include <cassert>
+#include <string>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+
+#if TEST_STD_VER >= 11
+// Test the noexcept specification, which is a conforming extension
+LIBCPP_STATIC_ASSERT(std::is_nothrow_default_constructible<std::string>::value, "");
+LIBCPP_STATIC_ASSERT(std::is_nothrow_default_constructible<
+                     std::basic_string<char, std::char_traits<char>, test_allocator<char>>>::value, "");
+LIBCPP_STATIC_ASSERT(!std::is_nothrow_default_constructible<
+                     std::basic_string<char, std::char_traits<char>, limited_allocator<char, 10>>>::value, "");
+#endif
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  std::string str;
+  assert(str.empty());
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/dtor.pass.cpp

@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// ~basic_string() // implied noexcept; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+
+template <class T>
+struct throwing_alloc
+{
+    typedef T value_type;
+    throwing_alloc(const throwing_alloc&);
+    T *allocate(size_t);
+    ~throwing_alloc() noexcept(false);
+};
+
+// Test that it's possible to take the address of basic_string's destructors
+// by creating globals which will register their destructors with cxa_atexit.
+std::string s;
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+std::wstring ws;
+#endif
+
+static_assert(std::is_nothrow_destructible<std::string>::value, "");
+static_assert(std::is_nothrow_destructible<
+                std::basic_string<char, std::char_traits<char>, test_allocator<char>>>::value, "");
+LIBCPP_STATIC_ASSERT(!std::is_nothrow_destructible<
+                     std::basic_string<char, std::char_traits<char>, throwing_alloc<char>>>::value, "");
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  test_allocator_statistics alloc_stats;
+  {
+    std::basic_string<char, std::char_traits<char>, test_allocator<char>> str2((test_allocator<char>(&alloc_stats)));
+    str2 = "long long string so no SSO";
+    assert(alloc_stats.alloc_count == 1);
+  }
+  assert(alloc_stats.alloc_count == 0);
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/implicit_deduction_guides.pass.cpp

@@ -0,0 +1,379 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <string>
+
+// Test that the constructors offered by std::basic_string are formulated
+// so they're compatible with implicit deduction guides.
+
+#include <string>
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "test_iterators.h"
+#include "constexpr_char_traits.h"
+
+template <class T, class Alloc = std::allocator<T>>
+using BStr = std::basic_string<T, std::char_traits<T>, Alloc>;
+
+// Overloads
+//  using A = Allocator;
+//  using BS = basic_string
+//  using BSV = basic_string_view
+// ---------------
+// (1)  basic_string() - NOT TESTED
+// (2)  basic_string(A const&) - BROKEN
+// (3)  basic_string(size_type, CharT, const A& = A())
+// (4)  basic_string(BS const&, size_type, A const& = A())
+// (5)  basic_string(BS const&, size_type, size_type, A const& = A())
+// (6)  basic_string(const CharT*, size_type, A const& = A())
+// (7)  basic_string(const CharT*, A const& = A())
+// (8)  basic_string(InputIt, InputIt, A const& = A()) - BROKEN
+// (9)  basic_string(BS const&)
+// (10) basic_string(BS const&, A const&)
+// (11) basic_string(BS&&)
+// (12) basic_string(BS&&, A const&)
+// (13) basic_string(initializer_list<CharT>, A const& = A())
+// (14) basic_string(BSV, A const& = A())
+// (15) basic_string(const T&, size_type, size_type, A const& = A())
+TEST_CONSTEXPR_CXX20 bool test() {
+
+  using TestSizeT = test_allocator<char>::size_type;
+  { // Testing (1)
+    // Nothing to do. Cannot deduce without any arguments.
+  }
+  { // Testing (2)
+    // This overload isn't compatible with implicit deduction guides as
+    // specified in the standard.
+    // const test_allocator<char> alloc{};
+    // std::basic_string s(alloc);
+  }
+  { // Testing (3) w/o allocator
+    std::basic_string s(6ull, 'a');
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "aaaaaa");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::basic_string w(2ull, L'b');
+    ASSERT_SAME_TYPE(decltype(w), std::wstring);
+    assert(w == L"bb");
+#endif
+  }
+  { // Testing (3) w/ allocator
+    std::basic_string s(6ull, 'a', test_allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), BStr<char,test_allocator<char>>);
+    assert(s == "aaaaaa");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::basic_string w(2ull, L'b', test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), BStr<wchar_t, test_allocator<wchar_t>>);
+    assert(w == L"bb");
+#endif
+  }
+  { // Testing (4) w/o allocator
+    const std::string sin("abc");
+    std::basic_string s(sin, (size_t)1);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "bc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    const WStr win(L"abcdef");
+    std::basic_string w(win, (TestSizeT)3);
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"def");
+#endif
+  }
+  { // Testing (4) w/ allocator
+    const std::string sin("abc");
+    std::basic_string s(sin, (size_t)1, std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "bc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    const WStr win(L"abcdef");
+    std::basic_string w(win, (TestSizeT)3, test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"def");
+#endif
+  }
+  { // Testing (5) w/o allocator
+    const std::string sin("abc");
+    std::basic_string s(sin, (size_t)1, (size_t)3);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "bc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    const WStr win(L"abcdef");
+    std::basic_string w(win, (TestSizeT)2, (TestSizeT)3);
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"cde");
+#endif
+  }
+  { // Testing (5) w/ allocator
+    const std::string sin("abc");
+    std::basic_string s(sin, (size_t)1, (size_t)3, std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "bc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    const WStr win(L"abcdef");
+    std::basic_string w(win, (TestSizeT)2, (TestSizeT)3, test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"cde");
+#endif
+  }
+  { // Testing (6) w/o allocator
+    std::basic_string s("abc", (size_t)2);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "ab");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::basic_string w(L"abcdef", (size_t)3);
+    ASSERT_SAME_TYPE(decltype(w), std::wstring);
+    assert(w == L"abc");
+#endif
+  }
+  { // Testing (6) w/ allocator
+    std::basic_string s("abc", (size_t)2, std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "ab");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  std::char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    std::basic_string w(L"abcdef", (TestSizeT)3, test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"abc");
+#endif
+  }
+  { // Testing (7) w/o allocator
+    std::basic_string s("abc");
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::basic_string w(L"abcdef");
+    ASSERT_SAME_TYPE(decltype(w), std::wstring);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (7) w/ allocator
+    std::basic_string s("abc", std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  std::char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    std::basic_string w(L"abcdef", test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // (8) w/o allocator
+    using It = cpp17_input_iterator<const char*>;
+    const char* input = "abcdef";
+    std::basic_string s(It(input), It(input + 3), std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+  }
+  { // (8) w/ allocator
+    {
+      using Expect = std::basic_string<char, std::char_traits<char>, test_allocator<char>>;
+      using It = cpp17_input_iterator<const char*>;
+      const char* input = "abcdef";
+      std::basic_string s(It(input), It(input + 3), test_allocator<char>{});
+      ASSERT_SAME_TYPE(decltype(s), Expect);
+      assert(s == "abc");
+    }
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    {
+      using ExpectW = std::basic_string<wchar_t, std::char_traits<wchar_t>, test_allocator<wchar_t>>;
+      using It = cpp17_input_iterator<const wchar_t*>;
+      const wchar_t* input = L"abcdef";
+      std::basic_string s(It(input), It(input + 3), test_allocator<wchar_t>{});
+      ASSERT_SAME_TYPE(decltype(s), ExpectW);
+      assert(s == L"abc");
+    }
+#endif
+  }
+  { // Testing (9)
+    const std::string sin("abc");
+    std::basic_string s(sin);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    const WStr win(L"abcdef");
+    std::basic_string w(win);
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (10)
+    const std::string sin("abc");
+    std::basic_string s(sin, std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    const WStr win(L"abcdef");
+    std::basic_string w(win, test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (11)
+    std::string sin("abc");
+    std::basic_string s(std::move(sin));
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    WStr win(L"abcdef");
+    std::basic_string w(std::move(win));
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (12)
+    std::string sin("abc");
+    std::basic_string s(std::move(sin), std::allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using WStr = std::basic_string<wchar_t,
+                                  constexpr_char_traits<wchar_t>,
+                                  test_allocator<wchar_t>>;
+    WStr win(L"abcdef");
+    std::basic_string w(std::move(win), test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), WStr);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (13) w/o allocator
+    std::basic_string s({'a', 'b', 'c'});
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::basic_string w({L'a', L'b', L'c'});
+    ASSERT_SAME_TYPE(decltype(w), std::wstring);
+    assert(w == L"abc");
+#endif
+  }
+  { // Testing (13) w/ allocator
+    std::basic_string s({'a', 'b', 'c'}, test_allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), BStr<char, test_allocator<char>>);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::basic_string w({L'a', L'b', L'c'}, test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), BStr<wchar_t, test_allocator<wchar_t>>);
+    assert(w == L"abc");
+#endif
+  }
+  { // Testing (14) w/o allocator
+    std::string_view sv("abc");
+    std::basic_string s(sv);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using Expect = std::basic_string<wchar_t, constexpr_char_traits<wchar_t>>;
+    std::basic_string_view<wchar_t, constexpr_char_traits<wchar_t>> BSV(L"abcdef");
+    std::basic_string w(BSV);
+    ASSERT_SAME_TYPE(decltype(w), Expect);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (14) w/ allocator
+    using ExpectS = std::basic_string<char, std::char_traits<char>, test_allocator<char>>;
+    std::string_view sv("abc");
+    std::basic_string s(sv, test_allocator<char>{});
+    ASSERT_SAME_TYPE(decltype(s), ExpectS);
+    assert(s == "abc");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using ExpectW = std::basic_string<wchar_t, constexpr_char_traits<wchar_t>,
+                                      test_allocator<wchar_t>>;
+    std::basic_string_view<wchar_t, constexpr_char_traits<wchar_t>> BSV(L"abcdef");
+    std::basic_string w(BSV, test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(w), ExpectW);
+    assert(w == L"abcdef");
+#endif
+  }
+  { // Testing (15) w/o allocator
+    std::string s0("abc");
+    std::basic_string s(s0, 1, 1);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "b");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    std::wstring w0(L"abcdef");
+    std::basic_string w(w0, 2, 2);
+    ASSERT_SAME_TYPE(decltype(w), std::wstring);
+    assert(w == L"cd");
+#endif
+  }
+  { // Testing (15) w/ allocator
+    using ExpectS = std::basic_string<char, std::char_traits<char>, test_allocator<char>>;
+    ExpectS s0("abc");
+    std::basic_string s(s0, 1, 1, test_allocator<char>{4});
+    ASSERT_SAME_TYPE(decltype(s), ExpectS);
+    assert(s == "b");
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    using ExpectW = std::basic_string<wchar_t, std::char_traits<wchar_t>, test_allocator<wchar_t>>;
+    ExpectW w0(L"abcdef");
+    std::basic_string w(w0, 2, 2, test_allocator<wchar_t>{6});
+    ASSERT_SAME_TYPE(decltype(w), ExpectW);
+    assert(w == L"cd");
+#endif
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/initializer_list.pass.cpp

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string(initializer_list<charT> il, const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string s = {'a', 'b', 'c'};
+    assert(s == "abc");
+  }
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+  {
+    std::wstring s;
+    s = {L'a', L'b', L'c'};
+    assert(s == L"abc");
+  }
+#endif
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s = {'a', 'b', 'c'};
+    assert(s == "abc");
+  }
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+  {
+    typedef std::basic_string<wchar_t, std::char_traits<wchar_t>, min_allocator<wchar_t>> S;
+    S s;
+    s = {L'a', L'b', L'c'};
+    assert(s == L"abc");
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/initializer_list_assignment.pass.cpp

@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string& operator=(initializer_list<charT> il); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string s;
+    s = {'a', 'b', 'c'};
+    assert(s == "abc");
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s;
+    s = {'a', 'b', 'c'};
+    assert(s == "abc");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/iter_alloc.pass.cpp

@@ -0,0 +1,145 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class InputIterator>
+//   basic_string(InputIterator begin, InputIterator end,
+//   const Allocator& a = Allocator()); // constexpr since C++20
+
+
+#include <string>
+#include <iterator>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "test_iterators.h"
+#include "min_allocator.h"
+
+template <class It>
+TEST_CONSTEXPR_CXX20 void
+test(It first, It last)
+{
+    typedef typename std::iterator_traits<It>::value_type charT;
+    typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+    typedef typename S::allocator_type A;
+    S s2(first, last);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == static_cast<std::size_t>(std::distance(first, last)));
+    unsigned i = 0;
+    for (It it = first; it != last;) {
+        assert(s2[i] == *it);
+        ++it;
+        ++i;
+    }
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+}
+
+template <class It, class A>
+TEST_CONSTEXPR_CXX20 void
+test(It first, It last, const A& a)
+{
+    typedef typename std::iterator_traits<It>::value_type charT;
+    typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+    S s2(first, last, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == static_cast<std::size_t>(std::distance(first, last)));
+    unsigned i = 0;
+    for (It it = first; it != last;) {
+        assert(s2[i] == *it);
+        ++it;
+        ++i;
+    }
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    const char* s = "12345678901234567890123456789012345678901234567890";
+
+    test(s, s);
+    test(s, s, A(2));
+
+    test(s, s+1);
+    test(s, s+1, A(2));
+
+    test(s, s+10);
+    test(s, s+10, A(2));
+
+    test(s, s+50);
+    test(s, s+50, A(2));
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), A(2));
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), A(2));
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), A(2));
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+50));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+50), A(2));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+    const char* s = "12345678901234567890123456789012345678901234567890";
+
+    test(s, s);
+    test(s, s, A());
+
+    test(s, s+1);
+    test(s, s+1, A());
+
+    test(s, s+10);
+    test(s, s+10, A());
+
+    test(s, s+50);
+    test(s, s+50, A());
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), A());
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), A());
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), A());
+
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+50));
+    test(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+50), A());
+  }
+#endif
+  {
+      static_assert((!std::is_constructible<std::string, std::string,
+                                            std::string>::value),
+                    "");
+      static_assert(
+          (!std::is_constructible<std::string, std::string, std::string,
+                                  std::allocator<char> >::value),
+          "");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/iter_alloc_deduction.pass.cpp

@@ -0,0 +1,115 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++03, c++11, c++14
+
+// template<class InputIterator,
+//      class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
+//  basic_string(InputIterator, InputIterator, Allocator = Allocator())
+//    -> basic_string<typename iterator_traits<InputIterator>::value_type,
+//                 char_traits<typename iterator_traits<InputIterator>::value_type>,
+//                 Allocator>; // constexpr since C++20
+//
+//  The deduction guide shall not participate in overload resolution if InputIterator
+//  is a type that does not qualify as an input iterator, or if Allocator is a type
+//  that does not qualify as an allocator.
+
+#include <cassert>
+#include <cstddef>
+#include <iterator>
+#include <string>
+#include <type_traits>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+class NotAnIterator {};
+using NotAnInputIterator = std::back_insert_iterator<std::basic_string<char16_t>>;
+
+template <typename T>
+struct NotAnAllocator { typedef T value_type; };
+
+template <class Iter, class Alloc, class = void>
+struct CanDeduce : std::false_type { };
+
+template <class Iter, class Alloc>
+struct CanDeduce<Iter, Alloc, decltype((void)
+  std::basic_string{std::declval<Iter>(), std::declval<Iter>(), std::declval<Alloc>()}
+)> : std::true_type { };
+
+static_assert( CanDeduce<int*, std::allocator<int>>::value);
+static_assert(!CanDeduce<NotAnIterator, std::allocator<char>>::value);
+static_assert(!CanDeduce<NotAnInputIterator, std::allocator<char16_t>>::value);
+static_assert(!CanDeduce<wchar_t const*, NotAnAllocator<wchar_t>>::value);
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    const char* s = "12345678901234";
+    std::basic_string s1(s, s+10);  // Can't use {} here
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == 10);
+    assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
+  }
+  {
+    const char* s = "12345678901234";
+    std::basic_string s1{s, s+10, std::allocator<char>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == 10);
+    assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
+  }
+  {
+    const wchar_t* s = L"12345678901234";
+    std::basic_string s1{s, s+10, test_allocator<wchar_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      wchar_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<wchar_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   test_allocator<wchar_t>>, "");
+    assert(s1.size() == 10);
+    assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
+  }
+  {
+    const char16_t* s = u"12345678901234";
+    std::basic_string s1{s, s+10, min_allocator<char16_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char16_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char16_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char16_t>>, "");
+    assert(s1.size() == 10);
+    assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
+  }
+  {
+    const char32_t* s = U"12345678901234";
+    std::basic_string s1{s, s+10, explicit_allocator<char32_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                        char32_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,      std::char_traits<char32_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type, explicit_allocator<char32_t>>, "");
+    assert(s1.size() == 10);
+    assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/move.pass.cpp

@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string(basic_string<charT,traits,Allocator>&& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s0)
+{
+    S s1 = s0;
+    S s2 = std::move(s0);
+    LIBCPP_ASSERT(s2.__invariants());
+    LIBCPP_ASSERT(s0.__invariants());
+    assert(s2 == s1);
+    assert(s2.capacity() >= s2.size());
+    assert(s2.get_allocator() == s1.get_allocator());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    test(S(A(3)));
+    test(S("1", A(5)));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)));
+  }
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    test(S(A{}));
+    test(S("1", A()));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()));
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/move_alloc.pass.cpp

@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string(basic_string&& str, const Allocator& alloc); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s0, const typename S::allocator_type& a)
+{
+    S s1 = s0;
+    S s2(std::move(s0), a);
+    LIBCPP_ASSERT(s2.__invariants());
+    LIBCPP_ASSERT(s0.__invariants());
+    assert(s2 == s1);
+    assert(s2.capacity() >= s2.size());
+    assert(s2.get_allocator() == a);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  test_allocator_statistics alloc_stats;
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S()) == std::is_nothrow_move_constructible<A>::value), "" );
+#endif
+    test(S(), A(3, &alloc_stats));
+    test(S("1"), A(5, &alloc_stats));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"), A(7, &alloc_stats));
+  }
+
+    int alloc_count = alloc_stats.alloc_count;
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S()) == std::is_nothrow_move_constructible<A>::value), "" );
+#endif
+    S s1 ( "Twas brillig, and the slivy toves did gyre and gymbal in the wabe", A(&alloc_stats));
+    S s2 (std::move(s1), A(1, &alloc_stats));
+  }
+    assert ( alloc_stats.alloc_count == alloc_count );
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+#if TEST_STD_VER > 14
+    static_assert((noexcept(S{})), "" );
+#elif TEST_STD_VER >= 11
+    static_assert((noexcept(S()) == std::is_nothrow_move_constructible<A>::value), "" );
+#endif
+    test(S(), A());
+    test(S("1"), A());
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"), A());
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/move_assign_noexcept.pass.cpp

@@ -0,0 +1,107 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string& operator=(basic_string&& c)
+//     noexcept(
+//         allocator_traits<allocator_type>::propagate_on_container_move_assignment::value ||
+//         allocator_traits<allocator_type>::is_always_equal::value); // C++17, constexpr since C++20
+//
+//  before C++17, we use the conforming extension
+//     noexcept(
+//         allocator_type::propagate_on_container_move_assignment::value &&
+//         is_nothrow_move_assignable<allocator_type>::value); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+
+template <class T>
+struct some_alloc
+{
+    typedef T value_type;
+    some_alloc(const some_alloc&);
+    T *allocate(size_t);
+};
+
+template <class T>
+struct some_alloc2
+{
+    typedef T value_type;
+
+    some_alloc2() {}
+    some_alloc2(const some_alloc2&);
+    T *allocate(size_t);
+    void deallocate(void*, unsigned) {}
+
+    typedef std::false_type propagate_on_container_move_assignment;
+    typedef std::true_type is_always_equal;
+};
+
+template <class T>
+struct some_alloc3
+{
+    typedef T value_type;
+
+    some_alloc3() {}
+    some_alloc3(const some_alloc3&);
+    T *allocate(size_t);
+    void deallocate(void*, unsigned) {}
+
+    typedef std::false_type propagate_on_container_move_assignment;
+    typedef std::false_type is_always_equal;
+};
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string C;
+    static_assert(std::is_nothrow_move_assignable<C>::value, "");
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;
+    static_assert(!std::is_nothrow_move_assignable<C>::value, "");
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
+#if TEST_STD_VER > 14
+    // if the allocators are always equal, then the move assignment can be noexcept
+    static_assert( std::is_nothrow_move_assignable<C>::value, "");
+#else
+      static_assert(!std::is_nothrow_move_assignable<C>::value, "");
+#endif
+  }
+#if TEST_STD_VER > 14
+  {
+    //  POCMA is false, always equal
+    typedef std::basic_string<char, std::char_traits<char>, some_alloc2<char>> C;
+    static_assert( std::is_nothrow_move_assignable<C>::value, "");
+  }
+  {
+    //  POCMA is false, not always equal
+    typedef std::basic_string<char, std::char_traits<char>, some_alloc3<char>> C;
+    static_assert(!std::is_nothrow_move_assignable<C>::value, "");
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/move_assignment.pass.cpp

@@ -0,0 +1,84 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   operator=(basic_string<charT,traits,Allocator>&& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s1, S s2)
+{
+    S s0 = s2;
+    s1 = std::move(s2);
+    LIBCPP_ASSERT(s1.__invariants());
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s1 == s0);
+    assert(s1.capacity() >= s1.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S());
+    test(S("1"), S());
+    test(S(), S("1"));
+    test(S("1"), S("2"));
+    test(S("1"), S("2"));
+
+    test(S(),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("123456789"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S());
+    test(S("1"), S());
+    test(S(), S("1"));
+    test(S("1"), S("2"));
+    test(S("1"), S("2"));
+
+    test(S(),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("123456789"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/move_noexcept.pass.cpp

@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string(basic_string&&)
+//        noexcept(is_nothrow_move_constructible<allocator_type>::value); // constexpr since C++20
+
+// This tests a conforming extension
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+
+int main(int, char**)
+{
+    {
+        typedef std::string C;
+        static_assert(std::is_nothrow_move_constructible<C>::value, "");
+    }
+    {
+        typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;
+        static_assert(std::is_nothrow_move_constructible<C>::value, "");
+    }
+    {
+        typedef std::basic_string<char, std::char_traits<char>, limited_allocator<char, 10>> C;
+#if TEST_STD_VER <= 14
+        static_assert(!std::is_nothrow_move_constructible<C>::value, "");
+#else
+        static_assert( std::is_nothrow_move_constructible<C>::value, "");
+#endif
+    }
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/nullptr.compile.pass.cpp

@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <string>
+
+// basic_string(nullptr_t) = delete; // C++2b
+// basic_string& operator=(nullptr_t) = delete; // C++2b
+
+#include <string>
+#include <type_traits>
+
+static_assert(!std::is_convertible_v<decltype(nullptr), std::string>);
+static_assert(!std::is_constructible_v<std::string, decltype(nullptr)>);
+static_assert(!std::is_assignable_v<std::string, decltype(nullptr)>);

module/jni/libcxx/test/std/strings/basic.string/string.cons/pointer_alloc.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string(const charT* s, const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class charT>
+TEST_CONSTEXPR_CXX20 void
+test(const charT* s)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+    typedef typename S::traits_type T;
+    typedef typename S::allocator_type A;
+    std::size_t n = T::length(s);
+    S s2(s);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == n);
+    assert(T::compare(s2.data(), s, n) == 0);
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+}
+
+template <class charT, class A>
+TEST_CONSTEXPR_CXX20 void
+test(const charT* s, const A& a)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+    typedef typename S::traits_type T;
+    std::size_t n = T::length(s);
+    S s2(s, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == n);
+    assert(T::compare(s2.data(), s, n) == 0);
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+    {
+    typedef test_allocator<char> A;
+
+    test("");
+    test("", A(2));
+
+    test("1");
+    test("1", A(2));
+
+    test("1234567980");
+    test("1234567980", A(2));
+
+    test("123456798012345679801234567980123456798012345679801234567980");
+    test("123456798012345679801234567980123456798012345679801234567980", A(2));
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef min_allocator<char> A;
+
+    test("");
+    test("", A());
+
+    test("1");
+    test("1", A());
+
+    test("1234567980");
+    test("1234567980", A());
+
+    test("123456798012345679801234567980123456798012345679801234567980");
+    test("123456798012345679801234567980123456798012345679801234567980", A());
+    }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/pointer_assignment.pass.cpp

@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   operator=(const charT* s); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s1, const typename S::value_type* s2)
+{
+    typedef typename S::traits_type T;
+    s1 = s2;
+    LIBCPP_ASSERT(s1.__invariants());
+    assert(s1.size() == T::length(s2));
+    assert(T::compare(s1.data(), s2, s1.size()) == 0);
+    assert(s1.capacity() >= s1.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), "");
+    test(S("1"), "");
+    test(S(), "1");
+    test(S("1"), "2");
+    test(S("1"), "2");
+
+    test(S(),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+    test(S("123456789"),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), "");
+    test(S("1"), "");
+    test(S(), "1");
+    test(S("1"), "2");
+    test(S("1"), "2");
+
+    test(S(),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+    test(S("123456789"),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/pointer_size_alloc.pass.cpp

@@ -0,0 +1,104 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string(const charT* s, size_type n, const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class charT>
+TEST_CONSTEXPR_CXX20 void
+test(const charT* s, unsigned n)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+    typedef typename S::traits_type T;
+    typedef typename S::allocator_type A;
+    S s2(s, n);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == n);
+    assert(T::compare(s2.data(), s, n) == 0);
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+}
+
+template <class charT, class A>
+TEST_CONSTEXPR_CXX20 void
+test(const charT* s, unsigned n, const A& a)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+    typedef typename S::traits_type T;
+    S s2(s, n, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == n);
+    assert(T::compare(s2.data(), s, n) == 0);
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+
+    test("", 0);
+    test("", 0, A(2));
+
+    test("1", 1);
+    test("1", 1, A(2));
+
+    test("1234567980", 10);
+    test("1234567980", 10, A(2));
+
+    test("123456798012345679801234567980123456798012345679801234567980", 60);
+    test("123456798012345679801234567980123456798012345679801234567980", 60, A(2));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+
+    test("", 0);
+    test("", 0, A());
+
+    test("1", 1);
+    test("1", 1, A());
+
+    test("1234567980", 10);
+    test("1234567980", 10, A());
+
+    test("123456798012345679801234567980123456798012345679801234567980", 60);
+    test("123456798012345679801234567980123456798012345679801234567980", 60, A());
+  }
+#endif
+
+#if TEST_STD_VER > 3
+  {   // LWG 2946
+    std::string s({"abc", 1});
+    assert(s.size() == 1);
+    assert(s == "a");
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/size_char_alloc.pass.cpp

@@ -0,0 +1,134 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string(size_type n, charT c, const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class charT>
+TEST_CONSTEXPR_CXX20 void
+test(unsigned n, charT c)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+    typedef typename S::allocator_type A;
+    S s2(n, c);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == n);
+    for (unsigned i = 0; i < n; ++i)
+        assert(s2[i] == c);
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+}
+
+template <class charT, class A>
+TEST_CONSTEXPR_CXX20 void
+test(unsigned n, charT c, const A& a)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+    S s2(n, c, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == n);
+    for (unsigned i = 0; i < n; ++i)
+        assert(s2[i] == c);
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+}
+
+template <class Tp>
+TEST_CONSTEXPR_CXX20 void
+test(Tp n, Tp c)
+{
+    typedef char charT;
+    typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+    typedef typename S::allocator_type A;
+    S s2(n, c);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == static_cast<std::size_t>(n));
+    for (int i = 0; i < n; ++i)
+        assert(s2[i] == c);
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+}
+
+template <class Tp, class A>
+TEST_CONSTEXPR_CXX20 void
+test(Tp n, Tp c, const A& a)
+{
+    typedef char charT;
+    typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+    S s2(n, c, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == static_cast<std::size_t>(n));
+    for (int i = 0; i < n; ++i)
+        assert(s2[i] == c);
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+
+    test(0, 'a');
+    test(0, 'a', A(2));
+
+    test(1, 'a');
+    test(1, 'a', A(2));
+
+    test(10, 'a');
+    test(10, 'a', A(2));
+
+    test(100, 'a');
+    test(100, 'a', A(2));
+
+    test(static_cast<char>(100), static_cast<char>(65));
+    test(static_cast<char>(100), static_cast<char>(65), A(3));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+
+    test(0, 'a');
+    test(0, 'a', A());
+
+    test(1, 'a');
+    test(1, 'a', A());
+
+    test(10, 'a');
+    test(10, 'a', A());
+
+    test(100, 'a');
+    test(100, 'a', A());
+
+    test(static_cast<char>(100), static_cast<char>(65));
+    test(static_cast<char>(100), static_cast<char>(65), A());
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/string_view.pass.cpp

@@ -0,0 +1,125 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// explicit basic_string(basic_string_view<CharT, traits> sv, const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <algorithm>
+#include <cassert>
+#include <stdexcept>
+#include <string_view>
+#include <string>
+#include <type_traits>
+
+#include "min_allocator.h"
+#include "test_allocator.h"
+#include "test_macros.h"
+
+static_assert(!std::is_convertible<std::string_view, std::string const&>::value, "");
+static_assert(!std::is_convertible<std::string_view, std::string>::value, "");
+
+template <class charT>
+TEST_CONSTEXPR_CXX20 void
+test(std::basic_string_view<charT> sv)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+    typedef typename S::traits_type T;
+    typedef typename S::allocator_type A;
+  {
+    S s2(sv);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == sv.size());
+    assert(T::compare(s2.data(), sv.data(), sv.size()) == 0);
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+  }
+  {
+    S s2;
+    s2 = sv;
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == sv.size());
+    assert(T::compare(s2.data(), sv.data(), sv.size()) == 0);
+    assert(s2.get_allocator() == A());
+    assert(s2.capacity() >= s2.size());
+  }
+}
+
+template <class charT, class A>
+TEST_CONSTEXPR_CXX20 void
+test(std::basic_string_view<charT> sv, const A& a)
+{
+    typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+    typedef typename S::traits_type T;
+  {
+    S s2(sv, a);
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == sv.size());
+    assert(T::compare(s2.data(), sv.data(), sv.size()) == 0);
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+  }
+  {
+    S s2(a);
+    s2 = sv;
+    LIBCPP_ASSERT(s2.__invariants());
+    assert(s2.size() == sv.size());
+    assert(T::compare(s2.data(), sv.data(), sv.size()) == 0);
+    assert(s2.get_allocator() == a);
+    assert(s2.capacity() >= s2.size());
+  }
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+
+    test(SV(""));
+    test(SV(""), A(2));
+
+    test(SV("1"));
+    test(SV("1") ,A(2));
+
+    test(SV("1234567980"));
+    test(SV("1234567980"), A(2));
+
+    test(SV("123456798012345679801234567980123456798012345679801234567980"));
+    test(SV("123456798012345679801234567980123456798012345679801234567980"), A(2));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+
+    test(SV(""));
+    test(SV(""), A());
+
+    test(SV("1"));
+    test(SV("1") ,A());
+
+    test(SV("1234567980"));
+    test(SV("1234567980"), A());
+
+    test(SV("123456798012345679801234567980123456798012345679801234567980"));
+    test(SV("123456798012345679801234567980123456798012345679801234567980"), A());
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/string_view_assignment.pass.cpp

@@ -0,0 +1,84 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& operator=(basic_string_view<charT, traits> sv); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(S s1, SV sv)
+{
+    typedef typename S::traits_type T;
+    s1 = sv;
+    LIBCPP_ASSERT(s1.__invariants());
+    assert(s1.size() == sv.size());
+    assert(T::compare(s1.data(), sv.data(), s1.size()) == 0);
+    assert(s1.capacity() >= s1.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(""));
+    test(S("1"), SV(""));
+    test(S(), SV("1"));
+    test(S("1"), SV("2"));
+    test(S("1"), SV("2"));
+
+    test(S(),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("123456789"),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::string_view SV;
+    test(S(), SV(""));
+    test(S("1"), SV(""));
+    test(S(), SV("1"));
+    test(S("1"), SV("2"));
+    test(S("1"), SV("2"));
+
+    test(S(),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("123456789"),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890"
+           "1234567890123456789012345678901234567890123456789012345678901234567890"),
+         SV("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/string_view_deduction.pass.cpp

@@ -0,0 +1,124 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++03, c++11, c++14
+
+// template<class charT,
+//          class traits,
+//          class Allocator = allocator<charT>
+//          >
+// basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
+//   -> basic_string<charT, traits, Allocator>;
+//
+//  The deduction guide shall not participate in overload resolution if Allocator
+//  is a type that does not qualify as an allocator.
+
+#include <string>
+#include <string_view>
+#include <iterator>
+#include <memory>
+#include <type_traits>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class StringView, class Allocator, class = void>
+struct CanDeduce : std::false_type { };
+
+template <class StringView, class Allocator>
+struct CanDeduce<StringView, Allocator, decltype((void)
+  std::basic_string{std::declval<StringView>(), std::declval<Allocator>()}
+)> : std::true_type { };
+
+struct NotAnAllocator { };
+static_assert( CanDeduce<std::string_view, std::allocator<char>>::value);
+static_assert(!CanDeduce<std::string_view, NotAnAllocator>::value);
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1(sv);
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+
+  {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, std::allocator<char>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+  {
+    std::wstring_view sv = L"12345678901234";
+    std::basic_string s1{sv, test_allocator<wchar_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      wchar_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<wchar_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   test_allocator<wchar_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+#endif
+#ifndef TEST_HAS_NO_CHAR8_T
+  {
+    std::u8string_view sv = u8"12345678901234";
+    std::basic_string s1{sv, min_allocator<char8_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char8_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char8_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char8_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+#endif
+  {
+    std::u16string_view sv = u"12345678901234";
+    std::basic_string s1{sv, min_allocator<char16_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char16_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char16_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char16_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+  {
+    std::u32string_view sv = U"12345678901234";
+    std::basic_string s1{sv, explicit_allocator<char32_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                        char32_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,      std::char_traits<char32_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type, explicit_allocator<char32_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/string_view_size_size_deduction.pass.cpp

@@ -0,0 +1,128 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++03, c++11, c++14
+
+// template<class charT,
+//          class traits,
+//          class Allocator = allocator<charT>
+//          >
+// basic_string(basic_string_view<charT, traits>,
+//                typename see below::size_type,
+//                typename see below::size_type,
+//                const Allocator& = Allocator())
+//   -> basic_string<charT, traits, Allocator>;
+//
+//  A size_type parameter type in a basic_string deduction guide refers to the size_type
+//  member type of the type deduced by the deduction guide.
+//
+//  The deduction guide shall not participate in overload resolution if Allocator
+//  is a type that does not qualify as an allocator.
+
+#include <string>
+#include <string_view>
+#include <iterator>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class StringView, class Size, class Allocator, class = void>
+struct CanDeduce : std::false_type { };
+
+template <class StringView, class Size, class Allocator>
+struct CanDeduce<StringView, Size, Allocator, decltype((void)
+  std::basic_string{std::declval<StringView>(), std::declval<Size>(), std::declval<Size>(), std::declval<Allocator>()}
+)> : std::true_type { };
+
+struct NotAnAllocator { };
+static_assert( CanDeduce<std::string_view, std::size_t, std::allocator<char>>::value);
+static_assert(!CanDeduce<std::string_view, std::size_t, NotAnAllocator>::value);
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, 0, 4};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+
+  {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, 0, 4, std::allocator<char>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+  {
+    std::wstring_view sv = L"12345678901234";
+    std::basic_string s1{sv, 0, 4, test_allocator<wchar_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      wchar_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<wchar_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   test_allocator<wchar_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+#endif
+#ifndef TEST_HAS_NO_CHAR8_T
+  {
+    std::u8string_view sv = u8"12345678901234";
+    std::basic_string s1{sv, 0, 4, min_allocator<char8_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char8_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char8_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char8_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+#endif
+  {
+    std::u16string_view sv = u"12345678901234";
+    std::basic_string s1{sv, 0, 4, min_allocator<char16_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char16_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char16_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char16_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+  {
+    std::u32string_view sv = U"12345678901234";
+    std::basic_string s1{sv, 0, 4, explicit_allocator<char32_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                        char32_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,      std::char_traits<char32_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type, explicit_allocator<char32_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.cons/substr.pass.cpp

@@ -0,0 +1,233 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string(const basic_string<charT,traits,Allocator>& str,
+//              size_type pos, size_type n,
+//              const Allocator& a = Allocator()); // constexpr since C++20
+//
+// basic_string(const basic_string<charT,traits,Allocator>& str,
+//              size_type pos,
+//              const Allocator& a = Allocator()); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <vector>
+#include <scoped_allocator>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S str, unsigned pos)
+{
+    typedef typename S::traits_type T;
+    typedef typename S::allocator_type A;
+
+    if (pos <= str.size())
+    {
+        S s2(str, pos);
+        LIBCPP_ASSERT(s2.__invariants());
+        typename S::size_type rlen = str.size() - pos;
+        assert(s2.size() == rlen);
+        assert(T::compare(s2.data(), str.data() + pos, rlen) == 0);
+        assert(s2.get_allocator() == A());
+        assert(s2.capacity() >= s2.size());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            S s2(str, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S str, unsigned pos, unsigned n)
+{
+    typedef typename S::traits_type T;
+    typedef typename S::allocator_type A;
+    if (pos <= str.size())
+    {
+        S s2(str, pos, n);
+        LIBCPP_ASSERT(s2.__invariants());
+        typename S::size_type rlen = std::min<typename S::size_type>(str.size() - pos, n);
+        assert(s2.size() == rlen);
+        assert(T::compare(s2.data(), str.data() + pos, rlen) == 0);
+        assert(s2.get_allocator() == A());
+        assert(s2.capacity() >= s2.size());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            S s2(str, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S str, unsigned pos, unsigned n, const typename S::allocator_type& a)
+{
+    typedef typename S::traits_type T;
+
+    if (pos <= str.size())
+    {
+        S s2(str, pos, n, a);
+        LIBCPP_ASSERT(s2.__invariants());
+        typename S::size_type rlen = std::min<typename S::size_type>(str.size() - pos, n);
+        assert(s2.size() == rlen);
+        assert(T::compare(s2.data(), str.data() + pos, rlen) == 0);
+        assert(s2.get_allocator() == a);
+        assert(s2.capacity() >= s2.size());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            S s2(str, pos, n, a);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+void test_lwg2583()
+{
+#if TEST_STD_VER >= 11 && !defined(TEST_HAS_NO_EXCEPTIONS)
+    typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> StringA;
+    std::vector<StringA, std::scoped_allocator_adaptor<test_allocator<StringA>>> vs;
+    StringA s{"1234"};
+    vs.emplace_back(s, 2);
+
+    try { vs.emplace_back(s, 5); }
+    catch (const std::out_of_range&) { return; }
+    assert(false);
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef test_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+
+    test(S(A(3)), 0);
+    test(S(A(3)), 1);
+    test(S("1", A(5)), 0);
+    test(S("1", A(5)), 1);
+    test(S("1", A(5)), 2);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 0);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 5);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 500);
+
+    test(S(A(3)), 0, 0);
+    test(S(A(3)), 0, 1);
+    test(S(A(3)), 1, 0);
+    test(S(A(3)), 1, 1);
+    test(S(A(3)), 1, 2);
+    test(S("1", A(5)), 0, 0);
+    test(S("1", A(5)), 0, 1);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 0);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 1);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 10);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 100);
+
+    test(S(A(3)), 0, 0, A(4));
+    test(S(A(3)), 0, 1, A(4));
+    test(S(A(3)), 1, 0, A(4));
+    test(S(A(3)), 1, 1, A(4));
+    test(S(A(3)), 1, 2, A(4));
+    test(S("1", A(5)), 0, 0, A(6));
+    test(S("1", A(5)), 0, 1, A(6));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 0, A(8));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 1, A(8));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 10, A(8));
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), 50, 100, A(8));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef min_allocator<char> A;
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+
+    test(S(A()), 0);
+    test(S(A()), 1);
+    test(S("1", A()), 0);
+    test(S("1", A()), 1);
+    test(S("1", A()), 2);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 0);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 5);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 500);
+
+    test(S(A()), 0, 0);
+    test(S(A()), 0, 1);
+    test(S(A()), 1, 0);
+    test(S(A()), 1, 1);
+    test(S(A()), 1, 2);
+    test(S("1", A()), 0, 0);
+    test(S("1", A()), 0, 1);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 0);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 1);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 10);
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 100);
+
+    test(S(A()), 0, 0, A());
+    test(S(A()), 0, 1, A());
+    test(S(A()), 1, 0, A());
+    test(S(A()), 1, 1, A());
+    test(S(A()), 1, 2, A());
+    test(S("1", A()), 0, 0, A());
+    test(S("1", A()), 0, 1, A());
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 0, A());
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 1, A());
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 10, A());
+    test(S("1234567890123456789012345678901234567890123456789012345678901234567890", A()), 50, 100, A());
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+  test_lwg2583();
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.contains/contains.char.pass.cpp

@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <string>
+
+// constexpr bool contains(charT x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test()
+{
+    using S = std::string;
+
+    S s1 {};
+    S s2 {"abcde", 5};
+
+    ASSERT_NOEXCEPT(s1.contains('e'));
+
+    assert(!s1.contains('c'));
+    assert(!s1.contains('e'));
+    assert(!s1.contains('x'));
+    assert( s2.contains('c'));
+    assert( s2.contains('e'));
+    assert(!s2.contains('x'));
+
+    return true;
+}
+
+int main(int, char**)
+{
+  test();
+  static_assert(test());
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.contains/contains.ptr.pass.cpp

@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <string>
+
+// constexpr bool contains(const CharT *x) const;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test()
+{
+    using S = std::string;
+
+    const char* s = "abcde";
+    S s0;
+    S s1 {s + 4, 1};
+    S s3 {s + 2, 3};
+    S sNot {"xyz", 3};
+
+    assert(s0.contains(""));
+    assert(!s0.contains("e"));
+
+    assert( s1.contains(""));
+    assert(!s1.contains("d"));
+    assert( s1.contains("e"));
+    assert(!s1.contains("de"));
+    assert(!s1.contains("cd"));
+    assert(!s1.contains("cde"));
+    assert(!s1.contains("bcde"));
+    assert(!s1.contains("abcde"));
+    assert(!s1.contains("xyz"));
+
+    assert( s3.contains(""));
+    assert( s3.contains("d"));
+    assert( s3.contains("e"));
+    assert( s3.contains("de"));
+    assert( s3.contains("cd"));
+    assert(!s3.contains("ce"));
+    assert( s3.contains("cde"));
+    assert(!s3.contains("edc"));
+    assert(!s3.contains("bcde"));
+    assert(!s3.contains("abcde"));
+    assert(!s3.contains("xyz"));
+
+    assert( sNot.contains(""));
+    assert(!sNot.contains("d"));
+    assert(!sNot.contains("e"));
+    assert(!sNot.contains("de"));
+    assert(!sNot.contains("cd"));
+    assert(!sNot.contains("cde"));
+    assert(!sNot.contains("bcde"));
+    assert(!sNot.contains("abcde"));
+    assert( sNot.contains("xyz"));
+    assert(!sNot.contains("zyx"));
+
+    return true;
+}
+
+int main(int, char**)
+{
+  test();
+  static_assert(test());
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.contains/contains.string_view.pass.cpp

@@ -0,0 +1,95 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <string>
+
+// constexpr bool contains(basic_string_view x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test()
+{
+    using S = std::string;
+    using SV = std::string_view;
+
+    const char* s = "abcde";
+    S s0;
+    S s1 {s + 1, 1};
+    S s3 {s + 1, 3};
+    S s5 {s    , 5};
+    S sNot {"xyz", 3};
+
+    SV sv0;
+    SV sv1 {s + 1, 1};
+    SV sv2 {s + 1, 2};
+    SV sv3 {s + 1, 3};
+    SV sv4 {s + 1, 4};
+    SV sv5 {s    , 5};
+    SV svNot  {"xyz", 3};
+    SV svNot2 {"bd" , 2};
+    SV svNot3 {"dcb", 3};
+
+    ASSERT_NOEXCEPT(s0.contains(sv0));
+
+    assert( s0.contains(sv0));
+    assert(!s0.contains(sv1));
+
+    assert( s1.contains(sv0));
+    assert( s1.contains(sv1));
+    assert(!s1.contains(sv2));
+    assert(!s1.contains(sv3));
+    assert(!s1.contains(sv4));
+    assert(!s1.contains(sv5));
+    assert(!s1.contains(svNot));
+    assert(!s1.contains(svNot2));
+    assert(!s1.contains(svNot3));
+
+    assert( s3.contains(sv0));
+    assert( s3.contains(sv1));
+    assert( s3.contains(sv2));
+    assert( s3.contains(sv3));
+    assert(!s3.contains(sv4));
+    assert(!s3.contains(sv5));
+    assert(!s3.contains(svNot));
+    assert(!s3.contains(svNot2));
+    assert(!s3.contains(svNot3));
+
+    assert( s5.contains(sv0));
+    assert( s5.contains(sv1));
+    assert( s5.contains(sv2));
+    assert( s5.contains(sv3));
+    assert( s5.contains(sv4));
+    assert( s5.contains(sv5));
+    assert(!s5.contains(svNot));
+    assert(!s5.contains(svNot2));
+    assert(!s5.contains(svNot3));
+
+    assert( sNot.contains(sv0));
+    assert(!sNot.contains(sv1));
+    assert(!sNot.contains(sv2));
+    assert(!sNot.contains(sv3));
+    assert(!sNot.contains(sv4));
+    assert(!sNot.contains(sv5));
+    assert( sNot.contains(svNot));
+    assert(!sNot.contains(svNot2));
+    assert(!sNot.contains(svNot3));
+
+    return true;
+}
+
+int main(int, char**)
+{
+  test();
+  static_assert(test());
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.ends_with/ends_with.char.pass.cpp

@@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <string>
+
+// constexpr bool ends_with(charT x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test() {
+  {
+    typedef std::string S;
+    S  s1 {};
+    S  s2 { "abcde", 5 };
+
+    ASSERT_NOEXCEPT(s1.ends_with('e'));
+
+    assert (!s1.ends_with('e'));
+    assert (!s1.ends_with('x'));
+    assert ( s2.ends_with('e'));
+    assert (!s2.ends_with('x'));
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+  static_assert(test());
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.ends_with/ends_with.ptr.pass.cpp

@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <string>
+
+// constexpr bool ends_with(const CharT *x) const;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test() {
+  {
+    typedef std::string S;
+    const char *s = "abcde";
+
+    S   s0;
+    S   s1  { s + 4, 1 };
+    S   s2  { s + 3, 2 };
+//  S   s3  { s + 2, 3 };
+//  S   s4  { s + 1, 4 };
+//  S   s5  { s,     5 };
+    S  sNot { "def", 3 };
+
+    LIBCPP_ASSERT_NOEXCEPT(s0.ends_with(""));
+
+    assert ( s0.ends_with(""));
+    assert (!s0.ends_with("e"));
+
+    assert ( s1.ends_with(""));
+    assert ( s1.ends_with("e"));
+    assert (!s1.ends_with("de"));
+    assert (!s1.ends_with("cde"));
+    assert (!s1.ends_with("bcde"));
+    assert (!s1.ends_with("abcde"));
+    assert (!s1.ends_with("def"));
+
+    assert ( s2.ends_with(""));
+    assert ( s2.ends_with("e"));
+    assert ( s2.ends_with("de"));
+    assert (!s2.ends_with("cde"));
+    assert (!s2.ends_with("bcde"));
+    assert (!s2.ends_with("abcde"));
+    assert (!s2.ends_with("def"));
+
+    assert ( sNot.ends_with(""));
+    assert (!sNot.ends_with("e"));
+    assert (!sNot.ends_with("de"));
+    assert (!sNot.ends_with("cde"));
+    assert (!sNot.ends_with("bcde"));
+    assert (!sNot.ends_with("abcde"));
+    assert ( sNot.ends_with("def"));
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.ends_with/ends_with.string_view.pass.cpp

@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <string>
+
+// constexpr bool ends_with(basic_string_view x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test() {
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    const char *s = "abcde";
+
+    S   s0;
+    S   s1  { s + 4, 1 };
+    S   s2  { s + 3, 2 };
+//  S   s3  { s + 2, 3 };
+//  S   s4  { s + 1, 4 };
+//  S   s5  { s,     5 };
+    S  sNot { "def", 3 };
+
+    SV  sv0;
+    SV  sv1 { s + 4, 1 };
+    SV  sv2 { s + 3, 2 };
+    SV  sv3 { s + 2, 3 };
+    SV  sv4 { s + 1, 4 };
+    SV  sv5 { s    , 5 };
+    SV svNot {"def", 3 };
+
+    ASSERT_NOEXCEPT(s0.ends_with(sv0));
+
+    assert ( s0.ends_with(sv0));
+    assert (!s0.ends_with(sv1));
+
+    assert ( s1.ends_with(sv0));
+    assert ( s1.ends_with(sv1));
+    assert (!s1.ends_with(sv2));
+    assert (!s1.ends_with(sv3));
+    assert (!s1.ends_with(sv4));
+    assert (!s1.ends_with(sv5));
+    assert (!s1.ends_with(svNot));
+
+    assert ( s2.ends_with(sv0));
+    assert ( s2.ends_with(sv1));
+    assert ( s2.ends_with(sv2));
+    assert (!s2.ends_with(sv3));
+    assert (!s2.ends_with(sv4));
+    assert (!s2.ends_with(sv5));
+    assert (!s2.ends_with(svNot));
+
+    assert ( sNot.ends_with(sv0));
+    assert (!sNot.ends_with(sv1));
+    assert (!sNot.ends_with(sv2));
+    assert (!sNot.ends_with(sv3));
+    assert (!sNot.ends_with(sv4));
+    assert (!sNot.ends_with(sv5));
+    assert ( sNot.ends_with(svNot));
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/begin.pass.cpp

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+//       iterator begin(); // constexpr since C++20
+// const_iterator begin() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    const S& cs = s;
+    typename S::iterator b = s.begin();
+    typename S::const_iterator cb = cs.begin();
+    if (!s.empty())
+    {
+        assert(*b == s[0]);
+    }
+    assert(b == cb);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/cbegin.pass.cpp

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_iterator cbegin() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    typename S::const_iterator cb = s.cbegin();
+    if (!s.empty())
+    {
+        assert(*cb == s[0]);
+    }
+    assert(cb == s.begin());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/cend.pass.cpp

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_iterator cend() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    typename S::const_iterator ce = s.cend();
+    assert(ce == s.end());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/crbegin.pass.cpp

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_reverse_iterator crbegin() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    typename S::const_reverse_iterator cb = s.crbegin();
+    if (!s.empty())
+    {
+        assert(*cb == s.back());
+    }
+    assert(cb == s.rbegin());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/crend.pass.cpp

@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_reverse_iterator crend() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(const S& s)
+{
+    typename S::const_reverse_iterator ce = s.crend();
+    assert(ce == s.rend());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/end.pass.cpp

@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+//       iterator end(); // constexpr since C++20
+// const_iterator end() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    const S& cs = s;
+    typename S::iterator e = s.end();
+    typename S::const_iterator ce = cs.end();
+    if (s.empty())
+    {
+        assert(e == s.begin());
+        assert(ce == cs.begin());
+    }
+    assert(static_cast<std::size_t>(e - s.begin()) == s.size());
+    assert(static_cast<std::size_t>(ce - cs.begin()) == cs.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/iterator_concept_conformance.compile.pass.cpp

@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// iterator, const_iterator, reverse_iterator, const_reverse_iterator
+
+#include <string>
+
+#include <iterator>
+
+using iterator = std::string::iterator;
+using const_iterator = std::string::const_iterator;
+using reverse_iterator = std::string::reverse_iterator;
+using const_reverse_iterator = std::string::const_reverse_iterator;
+using value_type = char;
+
+static_assert(std::contiguous_iterator<iterator>);
+static_assert(std::indirectly_writable<iterator, value_type>);
+static_assert(std::sentinel_for<iterator, iterator>);
+static_assert(std::sentinel_for<iterator, const_iterator>);
+static_assert(!std::sentinel_for<iterator, reverse_iterator>);
+static_assert(!std::sentinel_for<iterator, const_reverse_iterator>);
+static_assert(std::sized_sentinel_for<iterator, iterator>);
+static_assert(std::sized_sentinel_for<iterator, const_iterator>);
+static_assert(!std::sized_sentinel_for<iterator, reverse_iterator>);
+static_assert(!std::sized_sentinel_for<iterator, const_reverse_iterator>);
+static_assert( std::indirectly_movable<iterator, iterator>);
+static_assert( std::indirectly_movable_storable<iterator, iterator>);
+static_assert(!std::indirectly_movable<iterator, const_iterator>);
+static_assert(!std::indirectly_movable_storable<iterator, const_iterator>);
+static_assert( std::indirectly_movable<iterator, reverse_iterator>);
+static_assert( std::indirectly_movable_storable<iterator, reverse_iterator>);
+static_assert(!std::indirectly_movable<iterator, const_reverse_iterator>);
+static_assert(!std::indirectly_movable_storable<iterator, const_reverse_iterator>);
+static_assert( std::indirectly_copyable<iterator, iterator>);
+static_assert( std::indirectly_copyable_storable<iterator, iterator>);
+static_assert(!std::indirectly_copyable<iterator, const_iterator>);
+static_assert(!std::indirectly_copyable_storable<iterator, const_iterator>);
+static_assert( std::indirectly_copyable<iterator, reverse_iterator>);
+static_assert( std::indirectly_copyable_storable<iterator, reverse_iterator>);
+static_assert(!std::indirectly_copyable<iterator, const_reverse_iterator>);
+static_assert(!std::indirectly_copyable_storable<iterator, const_reverse_iterator>);
+static_assert( std::indirectly_swappable<iterator, iterator>);
+
+static_assert(std::contiguous_iterator<const_iterator>);
+static_assert(!std::indirectly_writable<const_iterator, value_type>);
+static_assert(std::sentinel_for<const_iterator, iterator>);
+static_assert(std::sentinel_for<const_iterator, const_iterator>);
+static_assert(!std::sentinel_for<const_iterator, reverse_iterator>);
+static_assert(!std::sentinel_for<const_iterator, const_reverse_iterator>);
+static_assert(std::sized_sentinel_for<const_iterator, iterator>);
+static_assert(std::sized_sentinel_for<const_iterator, const_iterator>);
+static_assert(!std::sized_sentinel_for<const_iterator, reverse_iterator>);
+static_assert(!std::sized_sentinel_for<const_iterator, const_reverse_iterator>);
+static_assert( std::indirectly_movable<const_iterator, iterator>);
+static_assert( std::indirectly_movable_storable<const_iterator, iterator>);
+static_assert(!std::indirectly_movable<const_iterator, const_iterator>);
+static_assert(!std::indirectly_movable_storable<const_iterator, const_iterator>);
+static_assert( std::indirectly_movable<const_iterator, reverse_iterator>);
+static_assert( std::indirectly_movable_storable<const_iterator, reverse_iterator>);
+static_assert(!std::indirectly_movable<const_iterator, const_reverse_iterator>);
+static_assert(!std::indirectly_movable_storable<const_iterator, const_reverse_iterator>);
+static_assert( std::indirectly_copyable<const_iterator, iterator>);
+static_assert( std::indirectly_copyable_storable<const_iterator, iterator>);
+static_assert(!std::indirectly_copyable<const_iterator, const_iterator>);
+static_assert(!std::indirectly_copyable_storable<const_iterator, const_iterator>);
+static_assert( std::indirectly_copyable<const_iterator, reverse_iterator>);
+static_assert( std::indirectly_copyable_storable<const_iterator, reverse_iterator>);
+static_assert(!std::indirectly_copyable<const_iterator, const_reverse_iterator>);
+static_assert(!std::indirectly_copyable_storable<const_iterator, const_reverse_iterator>);
+static_assert(!std::indirectly_swappable<const_iterator, const_iterator>);

module/jni/libcxx/test/std/strings/basic.string/string.iterators/iterators.pass.cpp

@@ -0,0 +1,85 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11
+
+// <string>
+
+// iterator       begin(); // constexpr since C++20
+// iterator       end(); // constexpr since C++20
+// const_iterator begin()  const; // constexpr since C++20
+// const_iterator end()    const; // constexpr since C++20
+// const_iterator cbegin() const; // constexpr since C++20
+// const_iterator cend()   const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+template<class C>
+TEST_CONSTEXPR_CXX20 void test()
+{
+    { // N3644 testing
+        typename C::iterator ii1{}, ii2{};
+        typename C::iterator ii4 = ii1;
+        typename C::const_iterator cii{};
+
+        assert ( ii1 == ii2 );
+        assert ( ii1 == ii4 );
+
+        assert (!(ii1 != ii2 ));
+
+        assert ( (ii1 == cii ));
+        assert ( (cii == ii1 ));
+        assert (!(ii1 != cii ));
+        assert (!(cii != ii1 ));
+        assert (!(ii1 <  cii ));
+        assert (!(cii <  ii1 ));
+        assert ( (ii1 <= cii ));
+        assert ( (cii <= ii1 ));
+        assert (!(ii1 >  cii ));
+        assert (!(cii >  ii1 ));
+        assert ( (ii1 >= cii ));
+        assert ( (cii >= ii1 ));
+        assert (cii - ii1 == 0);
+        assert (ii1 - cii == 0);
+    }
+    {
+        C a;
+        typename C::iterator i1 = a.begin();
+        typename C::iterator i2;
+        i2 = i1;
+        assert ( i1 == i2 );
+    }
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+    test<std::string>();
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+    test<std::wstring>();
+#endif
+
+#ifndef TEST_HAS_NO_CHAR8_T
+    test<std::u8string>();
+#endif
+
+    test<std::u16string>();
+    test<std::u32string>();
+
+    return true;
+}
+
+int main(int, char**)
+{
+    test();
+#if TEST_STD_VER > 17
+    static_assert(test());
+#endif
+    return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/rbegin.pass.cpp

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+//       reverse_iterator rbegin(); // constexpr since C++20
+// const_reverse_iterator rbegin() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    const S& cs = s;
+    typename S::reverse_iterator b = s.rbegin();
+    typename S::const_reverse_iterator cb = cs.rbegin();
+    if (!s.empty())
+    {
+        assert(*b == s.back());
+    }
+    assert(b == cb);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.iterators/rend.pass.cpp

@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+//       reverse_iterator rend(); // constexpr since C++20
+// const_reverse_iterator rend() const; // constexpr since C++20
+
+#include <string>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s)
+{
+    const S& cs = s;
+    typename S::reverse_iterator e = s.rend();
+    typename S::const_reverse_iterator ce = cs.rend();
+    if (s.empty())
+    {
+        assert(e == s.rbegin());
+        assert(ce == cs.rbegin());
+    }
+    assert(static_cast<std::size_t>(e - s.rbegin()) == s.size());
+    assert(static_cast<std::size_t>(ce - cs.rbegin()) == cs.size());
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S());
+    test(S("123"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S());
+    test(S("123"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/robust_against_adl.pass.cpp

@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+#include <cassert>
+#include <string>
+
+#include "test_macros.h"
+
+struct Incomplete;
+template<class T> struct Holder { T t; };
+
+template<class T>
+struct Charlike {
+    char ch_;
+    TEST_CONSTEXPR Charlike(char ch) : ch_(ch) {}
+    TEST_CONSTEXPR operator char() const { return ch_; }
+};
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  std::string s;
+  Charlike<Holder<Incomplete> > a[] = {'m', 'a', 'h', 'i'};
+  s.append(a, a+4);
+  s.assign(a, a+4);
+  s.insert(s.begin(), a, a+4);
+  s.replace(s.begin(), s.begin()+4, a, a+4);
+  assert(s == "mahimahi");
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/T_size_size.pass.cpp

@@ -0,0 +1,210 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template <class T>
+//    basic_string& append(const T& t, size_type pos, size_type n=npos); // C++17, constexpr since C++20
+
+#include <string>
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(S s, SV sv, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.append(sv, pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.append(sv, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test_npos(S s, SV sv, typename S::size_type pos, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.append(sv, pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.append(sv, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S("12345"));
+    test(S("12345"), SV("12345"), 2, 2, S("1234534"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("123451234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("12345678901234567890234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("123456789012345678906789012345"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S("12345"));
+    test(S("12345"), SV("12345"), 2, 2, S("1234534"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("123451234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("12345678901234567890234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("123456789012345678906789012345"));
+  }
+#endif
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test_npos(S(), SV(), 0, S());
+    test_npos(S(), SV(), 1, S());
+    test_npos(S(), SV("12345"), 0, S("12345"));
+    test_npos(S(), SV("12345"), 1, S("2345"));
+    test_npos(S(), SV("12345"), 3, S("45"));
+    test_npos(S(), SV("12345"), 5, S(""));
+    test_npos(S(), SV("12345"), 6, S("not happening"));
+  }
+
+  {
+    std::string s;
+    std::string_view sv = "EFGH";
+    char arr[] = "IJKL";
+
+    s.append("CDEF", 0);    // calls append(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.append("QRST", 0, std::string::npos); // calls append(string("QRST"), pos, npos)
+    assert(s == "QRST");
+    s.clear();
+
+    s.append(sv, 0);  // calls append(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.append(sv, 0, std::string::npos);   // calls append(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.append(arr, 0);     // calls append(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.append(arr, 0, std::string::npos);    // calls append(string("IJKL"), pos, npos)
+    assert(s == "IJKL");
+    s.clear();
+
+    s.append(arr, 0);     // calls append(const char *, len)
+    assert(s == "");
+    s.clear();
+  }
+
+  {
+    std::string s = "ABCD";
+    std::string_view sv = s;
+    s.append(sv);
+    assert(s == "ABCDABCD");
+
+    sv = s;
+    s.append(sv, 0, std::string::npos);
+    assert(s == "ABCDABCDABCDABCD");
+
+    sv = s;
+    s.append(sv, sv.size());
+    assert(s == "ABCDABCDABCDABCD");
+  }
+
+  {
+    std::string s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    std::string_view sv = s;
+    s.append(sv);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ");
+
+    sv = s;
+    s.append(sv, 0, std::string::npos);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/initializer_list.pass.cpp

@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string& append(initializer_list<charT> il); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string s("123");
+    s.append({'a', 'b', 'c'});
+    assert(s == "123abc");
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s("123");
+    s.append({'a', 'b', 'c'});
+    assert(s == "123abc");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/iterator.pass.cpp

@@ -0,0 +1,266 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class InputIterator>
+//   basic_string& append(InputIterator first, InputIterator last); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+#include "min_allocator.h"
+
+template <class S, class It>
+TEST_CONSTEXPR_CXX20 void
+test(S s, It first, It last, S expected)
+{
+    s.append(first, last);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+#ifndef TEST_HAS_NO_EXCEPTIONS
+struct Widget { operator char() const { throw 42; } };
+
+template <class S, class It>
+TEST_CONSTEXPR_CXX20 void
+test_exceptions(S s, It first, It last)
+{
+    S original = s;
+    typename S::iterator begin = s.begin();
+    typename S::iterator end = s.end();
+
+    try {
+        s.append(first, last);
+        assert(false);
+    } catch (...) {}
+
+    // Part of "no effects" is that iterators and pointers
+    // into the string must not have been invalidated.
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == original);
+    assert(s.begin() == begin);
+    assert(s.end() == end);
+}
+#endif
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), s, s, S());
+    test(S(), s, s+1, S("A"));
+    test(S(), s, s+10, S("ABCDEFGHIJ"));
+    test(S(), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), s, s, S("12345"));
+    test(S("12345"), s, s+1, S("12345A"));
+    test(S("12345"), s, s+10, S("12345ABCDEFGHIJ"));
+    test(S("12345"), s, s+52, S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), s, s, S("1234567890"));
+    test(S("1234567890"), s, s+1, S("1234567890A"));
+    test(S("1234567890"), s, s+10, S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), s, s+52, S("1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), s, s, S("12345678901234567890"));
+    test(S("12345678901234567890"), s, s+1, S("12345678901234567890""A"));
+    test(S("12345678901234567890"), s, s+10, S("12345678901234567890""ABCDEFGHIJ"));
+    test(S("12345678901234567890"), s, s+52,
+         S("12345678901234567890""ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S("12345"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("12345A"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("12345ABCDEFGHIJ"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S("1234567890"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("1234567890A"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S("12345678901234567890"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("12345678901234567890""A"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("12345678901234567890""ABCDEFGHIJ"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("12345678901234567890""ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), s, s, S());
+    test(S(), s, s+1, S("A"));
+    test(S(), s, s+10, S("ABCDEFGHIJ"));
+    test(S(), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), s, s, S("12345"));
+    test(S("12345"), s, s+1, S("12345A"));
+    test(S("12345"), s, s+10, S("12345ABCDEFGHIJ"));
+    test(S("12345"), s, s+52, S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), s, s, S("1234567890"));
+    test(S("1234567890"), s, s+1, S("1234567890A"));
+    test(S("1234567890"), s, s+10, S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), s, s+52, S("1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), s, s, S("12345678901234567890"));
+    test(S("12345678901234567890"), s, s+1, S("12345678901234567890""A"));
+    test(S("12345678901234567890"), s, s+10, S("12345678901234567890""ABCDEFGHIJ"));
+    test(S("12345678901234567890"), s, s+52,
+         S("12345678901234567890""ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S("12345"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("12345A"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("12345ABCDEFGHIJ"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S("1234567890"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("1234567890A"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S("12345678901234567890"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("12345678901234567890""A"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("12345678901234567890""ABCDEFGHIJ"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("12345678901234567890""ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+  }
+#endif
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  if (!TEST_IS_CONSTANT_EVALUATED) { // test iterator operations that throw
+    typedef std::string S;
+    typedef ThrowingIterator<char> TIter;
+    typedef cpp17_input_iterator<TIter> IIter;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test_exceptions(S(), IIter(TIter(s, s+10, 4, TIter::TAIncrement)), IIter(TIter()));
+    test_exceptions(S(), IIter(TIter(s, s+10, 5, TIter::TADereference)), IIter(TIter()));
+    test_exceptions(S(), IIter(TIter(s, s+10, 6, TIter::TAComparison)), IIter(TIter()));
+
+    test_exceptions(S(), TIter(s, s+10, 4, TIter::TAIncrement), TIter());
+    test_exceptions(S(), TIter(s, s+10, 5, TIter::TADereference), TIter());
+    test_exceptions(S(), TIter(s, s+10, 6, TIter::TAComparison), TIter());
+
+    Widget w[100];
+    test_exceptions(S(), w, w+100);
+  }
+#endif
+
+  { // test appending to self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.append(s_short.begin(), s_short.end());
+    assert(s_short == "123/123/");
+    s_short.append(s_short.begin(), s_short.end());
+    assert(s_short == "123/123/123/123/");
+    s_short.append(s_short.begin(), s_short.end());
+    assert(s_short == "123/123/123/123/123/123/123/123/");
+
+    s_long.append(s_long.begin(), s_long.end());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+  }
+
+  { // test appending a different type
+    typedef std::string S;
+    const uint8_t p[] = "ABCD";
+
+    S s;
+    s.append(p, p + 4);
+    assert(s == "ABCD");
+  }
+
+  { // regression-test appending to self in sneaky ways
+    std::string s_short = "hello";
+    std::string s_long = "Lorem ipsum dolor sit amet, consectetur/";
+    std::string s_othertype = "hello";
+    std::string s_sneaky = "hello";
+
+    test(s_short, s_short.data() + s_short.size(), s_short.data() + s_short.size() + 1,
+         std::string("hello\0", 6));
+    test(s_long, s_long.data() + s_long.size(), s_long.data() + s_long.size() + 1,
+         std::string("Lorem ipsum dolor sit amet, consectetur/\0", 41));
+
+    s_sneaky.reserve(12);
+    test(s_sneaky, s_sneaky.data(), s_sneaky.data() + 6, std::string("hellohello\0", 11));
+
+     if (!TEST_IS_CONSTANT_EVALUATED) {
+       const unsigned char *first = reinterpret_cast<const unsigned char*>(s_othertype.data());
+       test(s_othertype, first + 2, first + 5, std::string("hellollo"));
+     }
+  }
+
+  { // test with a move iterator that returns char&&
+    typedef forward_iterator<const char*> It;
+    typedef std::move_iterator<It> MoveIt;
+    const char p[] = "ABCD";
+    std::string s;
+    s.append(MoveIt(It(std::begin(p))), MoveIt(It(std::end(p) - 1)));
+    assert(s == "ABCD");
+  }
+  { // test with a move iterator that returns char&&
+    typedef const char* It;
+    typedef std::move_iterator<It> MoveIt;
+    const char p[] = "ABCD";
+    std::string s;
+    s.append(MoveIt(It(std::begin(p))), MoveIt(It(std::end(p) - 1)));
+    assert(s == "ABCD");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/pointer.pass.cpp

@@ -0,0 +1,90 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& append(const charT* s); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, const typename S::value_type* str, S expected)
+{
+    s.append(str);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), "", S());
+    test(S(), "12345", S("12345"));
+    test(S(), "12345678901234567890", S("12345678901234567890"));
+
+    test(S("12345"), "", S("12345"));
+    test(S("12345"), "12345", S("1234512345"));
+    test(S("12345"), "1234567890", S("123451234567890"));
+
+    test(S("12345678901234567890"), "", S("12345678901234567890"));
+    test(S("12345678901234567890"), "12345", S("1234567890123456789012345"));
+    test(S("12345678901234567890"), "12345678901234567890",
+         S("1234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), "", S());
+    test(S(), "12345", S("12345"));
+    test(S(), "12345678901234567890", S("12345678901234567890"));
+
+    test(S("12345"), "", S("12345"));
+    test(S("12345"), "12345", S("1234512345"));
+    test(S("12345"), "1234567890", S("123451234567890"));
+
+    test(S("12345678901234567890"), "", S("12345678901234567890"));
+    test(S("12345678901234567890"), "12345", S("1234567890123456789012345"));
+    test(S("12345678901234567890"), "12345678901234567890",
+         S("1234567890123456789012345678901234567890"));
+  }
+#endif
+
+  { // test appending to self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.append(s_short.c_str());
+    assert(s_short == "123/123/");
+    s_short.append(s_short.c_str());
+    assert(s_short == "123/123/123/123/");
+    s_short.append(s_short.c_str());
+    assert(s_short == "123/123/123/123/123/123/123/123/");
+
+    s_long.append(s_long.c_str());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/pointer_size.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   append(const charT* s, size_type n); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, const typename S::value_type* str, typename S::size_type n, S expected)
+{
+    s.append(str, n);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), "", 0, S());
+    test(S(), "12345", 3, S("123"));
+    test(S(), "12345", 4, S("1234"));
+    test(S(), "12345678901234567890", 0, S());
+    test(S(), "12345678901234567890", 1, S("1"));
+    test(S(), "12345678901234567890", 3, S("123"));
+    test(S(), "12345678901234567890", 20, S("12345678901234567890"));
+
+    test(S("12345"), "", 0, S("12345"));
+    test(S("12345"), "12345", 5, S("1234512345"));
+    test(S("12345"), "1234567890", 10, S("123451234567890"));
+
+    test(S("12345678901234567890"), "", 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), "12345", 5, S("1234567890123456789012345"));
+    test(S("12345678901234567890"), "12345678901234567890", 20,
+         S("1234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), "", 0, S());
+    test(S(), "12345", 3, S("123"));
+    test(S(), "12345", 4, S("1234"));
+    test(S(), "12345678901234567890", 0, S());
+    test(S(), "12345678901234567890", 1, S("1"));
+    test(S(), "12345678901234567890", 3, S("123"));
+    test(S(), "12345678901234567890", 20, S("12345678901234567890"));
+
+    test(S("12345"), "", 0, S("12345"));
+    test(S("12345"), "12345", 5, S("1234512345"));
+    test(S("12345"), "1234567890", 10, S("123451234567890"));
+
+    test(S("12345678901234567890"), "", 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), "12345", 5, S("1234567890123456789012345"));
+    test(S("12345678901234567890"), "12345678901234567890", 20,
+         S("1234567890123456789012345678901234567890"));
+  }
+#endif
+
+  { // test appending to self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.append(s_short.data(), s_short.size());
+    assert(s_short == "123/123/");
+    s_short.append(s_short.data(), s_short.size());
+    assert(s_short == "123/123/123/123/");
+    s_short.append(s_short.data(), s_short.size());
+    assert(s_short == "123/123/123/123/123/123/123/123/");
+
+    s_long.append(s_long.data(), s_long.size());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/push_back.pass.cpp

@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void push_back(charT c) // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+struct veryLarge
+{
+  long long a;
+  char b;
+};
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::value_type c, S expected)
+{
+    s.push_back(c);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 'a', S(1, 'a'));
+    test(S("12345"), 'a', S("12345a"));
+    test(S("12345678901234567890"), 'a', S("12345678901234567890a"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 'a', S(1, 'a'));
+    test(S("12345"), 'a', S("12345a"));
+    test(S("12345678901234567890"), 'a', S("12345678901234567890a"));
+  }
+#endif
+
+  {
+// https://llvm.org/PR31454
+    std::basic_string<veryLarge> s;
+    veryLarge vl = {};
+    s.push_back(vl);
+    s.push_back(vl);
+    s.push_back(vl);
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/size_char.pass.cpp

@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   append(size_type n, charT c); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type n, typename S::value_type c, S expected)
+{
+    s.append(n, c);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 0, 'a', S());
+    test(S(), 1, 'a', S(1, 'a'));
+    test(S(), 10, 'a', S(10, 'a'));
+    test(S(), 100, 'a', S(100, 'a'));
+
+    test(S("12345"), 0, 'a', S("12345"));
+    test(S("12345"), 1, 'a', S("12345a"));
+    test(S("12345"), 10, 'a', S("12345aaaaaaaaaa"));
+
+    test(S("12345678901234567890"), 0, 'a', S("12345678901234567890"));
+    test(S("12345678901234567890"), 1, 'a', S("12345678901234567890a"));
+    test(S("12345678901234567890"), 10, 'a', S("12345678901234567890aaaaaaaaaa"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 0, 'a', S());
+    test(S(), 1, 'a', S(1, 'a'));
+    test(S(), 10, 'a', S(10, 'a'));
+    test(S(), 100, 'a', S(100, 'a'));
+
+    test(S("12345"), 0, 'a', S("12345"));
+    test(S("12345"), 1, 'a', S("12345a"));
+    test(S("12345"), 10, 'a', S("12345aaaaaaaaaa"));
+
+    test(S("12345678901234567890"), 0, 'a', S("12345678901234567890"));
+    test(S("12345678901234567890"), 1, 'a', S("12345678901234567890a"));
+    test(S("12345678901234567890"), 10, 'a', S("12345678901234567890aaaaaaaaaa"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/string.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   append(const basic_string<charT,traits>& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S str, S expected)
+{
+    s.append(str);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S(), S());
+    test(S(), S("12345"), S("12345"));
+    test(S(), S("1234567890"), S("1234567890"));
+    test(S(), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), S(), S("12345"));
+    test(S("12345"), S("12345"), S("1234512345"));
+    test(S("12345"), S("1234567890"), S("123451234567890"));
+    test(S("12345"), S("12345678901234567890"), S("1234512345678901234567890"));
+
+    test(S("1234567890"), S(), S("1234567890"));
+    test(S("1234567890"), S("12345"), S("123456789012345"));
+    test(S("1234567890"), S("1234567890"), S("12345678901234567890"));
+    test(S("1234567890"), S("12345678901234567890"), S("123456789012345678901234567890"));
+
+    test(S("12345678901234567890"), S(), S("12345678901234567890"));
+    test(S("12345678901234567890"), S("12345"), S("1234567890123456789012345"));
+    test(S("12345678901234567890"), S("1234567890"), S("123456789012345678901234567890"));
+    test(S("12345678901234567890"), S("12345678901234567890"),
+         S("1234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S(), S());
+    test(S(), S("12345"), S("12345"));
+    test(S(), S("1234567890"), S("1234567890"));
+    test(S(), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), S(), S("12345"));
+    test(S("12345"), S("12345"), S("1234512345"));
+    test(S("12345"), S("1234567890"), S("123451234567890"));
+    test(S("12345"), S("12345678901234567890"), S("1234512345678901234567890"));
+
+    test(S("1234567890"), S(), S("1234567890"));
+    test(S("1234567890"), S("12345"), S("123456789012345"));
+    test(S("1234567890"), S("1234567890"), S("12345678901234567890"));
+    test(S("1234567890"), S("12345678901234567890"), S("123456789012345678901234567890"));
+
+    test(S("12345678901234567890"), S(), S("12345678901234567890"));
+    test(S("12345678901234567890"), S("12345"), S("1234567890123456789012345"));
+    test(S("12345678901234567890"), S("1234567890"), S("123456789012345678901234567890"));
+    test(S("12345678901234567890"), S("12345678901234567890"),
+         S("1234567890123456789012345678901234567890"));
+  }
+#endif
+
+#if TEST_STD_VER > 3
+  {   // LWG 2946
+    std::string s;
+    s.append({"abc", 1});
+    assert(s.size() == 1);
+    assert(s == "a");
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/string_size_size.pass.cpp

@@ -0,0 +1,147 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   append(const basic_string<charT,traits>& str, size_type pos, size_type n = npos); // constexpr since C++20
+//  the "= npos" was added for C++14
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S str, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    if (pos <= str.size())
+    {
+        s.append(str, pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.append(str, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test_npos(S s, S str, typename S::size_type pos, S expected)
+{
+    if (pos <= str.size())
+    {
+        s.append(str, pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.append(str, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S(), 0, 0, S());
+    test(S(), S(), 1, 0, S());
+    test(S(), S("12345"), 0, 3, S("123"));
+    test(S(), S("12345"), 1, 4, S("2345"));
+    test(S(), S("12345"), 3, 15, S("45"));
+    test(S(), S("12345"), 5, 15, S(""));
+    test(S(), S("12345"), 6, 15, S("not happening"));
+    test(S(), S("12345678901234567890"), 0, 0, S());
+    test(S(), S("12345678901234567890"), 1, 1, S("2"));
+    test(S(), S("12345678901234567890"), 2, 3, S("345"));
+    test(S(), S("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), S("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), S(), 0, 0, S("12345"));
+    test(S("12345"), S("12345"), 2, 2, S("1234534"));
+    test(S("12345"), S("1234567890"), 0, 100, S("123451234567890"));
+
+    test(S("12345678901234567890"), S(), 0, 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), S("12345"), 1, 3, S("12345678901234567890234"));
+    test(S("12345678901234567890"), S("12345678901234567890"), 5, 10,
+         S("123456789012345678906789012345"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S(), 0, 0, S());
+    test(S(), S(), 1, 0, S());
+    test(S(), S("12345"), 0, 3, S("123"));
+    test(S(), S("12345"), 1, 4, S("2345"));
+    test(S(), S("12345"), 3, 15, S("45"));
+    test(S(), S("12345"), 5, 15, S(""));
+    test(S(), S("12345"), 6, 15, S("not happening"));
+    test(S(), S("12345678901234567890"), 0, 0, S());
+    test(S(), S("12345678901234567890"), 1, 1, S("2"));
+    test(S(), S("12345678901234567890"), 2, 3, S("345"));
+    test(S(), S("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), S("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), S(), 0, 0, S("12345"));
+    test(S("12345"), S("12345"), 2, 2, S("1234534"));
+    test(S("12345"), S("1234567890"), 0, 100, S("123451234567890"));
+
+    test(S("12345678901234567890"), S(), 0, 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), S("12345"), 1, 3, S("12345678901234567890234"));
+    test(S("12345678901234567890"), S("12345678901234567890"), 5, 10,
+         S("123456789012345678906789012345"));
+  }
+#endif
+  {
+    typedef std::string S;
+    test_npos(S(), S(), 0, S());
+    test_npos(S(), S(), 1, S());
+    test_npos(S(), S("12345"), 0, S("12345"));
+    test_npos(S(), S("12345"), 1, S("2345"));
+    test_npos(S(), S("12345"), 3, S("45"));
+    test_npos(S(), S("12345"), 5, S(""));
+    test_npos(S(), S("12345"), 6, S("not happening"));
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_append/string_view.pass.cpp

@@ -0,0 +1,93 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   append(basic_string_view<charT,traits> sv); // constexpr since C++20
+
+#include <string>
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(S s, SV sv, S expected)
+{
+    s.append(sv);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S("12345"));
+    test(S("12345"), SV("12345"), S("1234512345"));
+    test(S("12345"), SV("1234567890"), S("123451234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("1234512345678901234567890"));
+
+    test(S("1234567890"), SV(), S("1234567890"));
+    test(S("1234567890"), SV("12345"), S("123456789012345"));
+    test(S("1234567890"), SV("1234567890"), S("12345678901234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("123456789012345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), S("1234567890123456789012345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("123456789012345678901234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("1234567890123456789012345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S("12345"));
+    test(S("12345"), SV("12345"), S("1234512345"));
+    test(S("12345"), SV("1234567890"), S("123451234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("1234512345678901234567890"));
+
+    test(S("1234567890"), SV(), S("1234567890"));
+    test(S("1234567890"), SV("12345"), S("123456789012345"));
+    test(S("1234567890"), SV("1234567890"), S("12345678901234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("123456789012345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), S("1234567890123456789012345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("123456789012345678901234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("1234567890123456789012345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/T_size_size.pass.cpp

@@ -0,0 +1,205 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template <class T>
+//    basic_string& assign(const T& t, size_type pos, size_type n=npos); // C++17, constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(S s, SV sv, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.assign(sv, pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.assign(sv, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test_npos(S s, SV sv, typename S::size_type pos, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.assign(sv, pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.assign(sv, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S());
+    test(S("12345"), SV("12345"), 2, 2, S("34"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("1234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S());
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("6789012345"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S());
+    test(S("12345"), SV("12345"), 2, 2, S("34"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("1234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S());
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("6789012345"));
+  }
+#endif
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test_npos(S(), SV(), 0, S());
+    test_npos(S(), SV(), 1, S());
+    test_npos(S(), SV("12345"), 0, S("12345"));
+    test_npos(S(), SV("12345"), 1, S("2345"));
+    test_npos(S(), SV("12345"), 3, S("45"));
+    test_npos(S(), SV("12345"), 5, S(""));
+    test_npos(S(), SV("12345"), 6, S("not happening"));
+  }
+
+  {
+    std::string s = "ABCD";
+    std::string_view sv = "EFGH";
+    char arr[] = "IJKL";
+
+    s.assign("CDEF", 0);    // calls assign(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.assign("QRST", 0, std::string::npos); // calls assign(string("QRST", pos, len)
+    assert(s == "QRST");
+    s.clear();
+
+    s.assign(sv, 0);  // calls assign(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.assign(sv, 0, std::string::npos);   // calls assign(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.assign(arr, 0);     // calls assign(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.assign(arr, 0, std::string::npos);    // calls assign(string("IJKL"), pos, npos)
+    assert(s == "IJKL");
+    s.clear();
+
+    s.assign(arr, 0);     // calls assign(const char *, len)
+    assert(s == "");
+    s.clear();
+  }
+
+  {
+    std::string s = "ABCD";
+    std::string_view sv = s;
+    s.assign(sv);
+    assert(s == "ABCD");
+
+    sv = s;
+    s.assign(sv, 0, std::string::npos);
+    assert(s == "ABCD");
+  }
+
+  {
+    std::string s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    std::string_view sv = s;
+    s.assign(sv);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+
+    sv = s;
+    s.assign(sv, 0, std::string::npos);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/initializer_list.pass.cpp

@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// basic_string& assign(initializer_list<charT> il); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string s("123");
+    s.assign({'a', 'b', 'c'});
+    assert(s == "abc");
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s("123");
+    s.assign({'a', 'b', 'c'});
+    assert(s == "abc");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/iterator.pass.cpp

@@ -0,0 +1,237 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class InputIterator>
+//   basic_string& assign(InputIterator first, InputIterator last); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+#include "min_allocator.h"
+
+template <class S, class It>
+TEST_CONSTEXPR_CXX20 void
+test(S s, It first, It last, S expected)
+{
+    s.assign(first, last);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+#ifndef TEST_HAS_NO_EXCEPTIONS
+struct Widget { operator char() const { throw 42; } };
+
+template <class S, class It>
+void
+test_exceptions(S s, It first, It last)
+{
+    S original = s;
+    typename S::iterator begin = s.begin();
+    typename S::iterator end = s.end();
+
+    try {
+        s.assign(first, last);
+        assert(false);
+    } catch (...) {}
+
+    // Part of "no effects" is that iterators and pointers
+    // into the string must not have been invalidated.
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == original);
+    assert(s.begin() == begin);
+    assert(s.end() == end);
+}
+#endif
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), s, s, S());
+    test(S(), s, s+1, S("A"));
+    test(S(), s, s+10, S("ABCDEFGHIJ"));
+    test(S(), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), s, s, S());
+    test(S("12345"), s, s+1, S("A"));
+    test(S("12345"), s, s+10, S("ABCDEFGHIJ"));
+    test(S("12345"), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), s, s, S());
+    test(S("1234567890"), s, s+1, S("A"));
+    test(S("1234567890"), s, s+10, S("ABCDEFGHIJ"));
+    test(S("1234567890"), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), s, s, S());
+    test(S("12345678901234567890"), s, s+1, S("A"));
+    test(S("12345678901234567890"), s, s+10, S("ABCDEFGHIJ"));
+    test(S("12345678901234567890"), s, s+52,
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S());
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("A"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S());
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("A"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S());
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("A"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), s, s, S());
+    test(S(), s, s+1, S("A"));
+    test(S(), s, s+10, S("ABCDEFGHIJ"));
+    test(S(), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), s, s, S());
+    test(S("12345"), s, s+1, S("A"));
+    test(S("12345"), s, s+10, S("ABCDEFGHIJ"));
+    test(S("12345"), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), s, s, S());
+    test(S("1234567890"), s, s+1, S("A"));
+    test(S("1234567890"), s, s+10, S("ABCDEFGHIJ"));
+    test(S("1234567890"), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), s, s, S());
+    test(S("12345678901234567890"), s, s+1, S("A"));
+    test(S("12345678901234567890"), s, s+10, S("ABCDEFGHIJ"));
+    test(S("12345678901234567890"), s, s+52,
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S());
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("A"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S());
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("A"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
+         S());
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
+         S("A"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
+         S("ABCDEFGHIJ"));
+    test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+  }
+#endif
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  if (!TEST_IS_CONSTANT_EVALUATED) { // test iterator operations that throw
+    typedef std::string S;
+    typedef ThrowingIterator<char> TIter;
+    typedef cpp17_input_iterator<TIter> IIter;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test_exceptions(S(), IIter(TIter(s, s+10, 4, TIter::TAIncrement)), IIter(TIter()));
+    test_exceptions(S(), IIter(TIter(s, s+10, 5, TIter::TADereference)), IIter(TIter()));
+    test_exceptions(S(), IIter(TIter(s, s+10, 6, TIter::TAComparison)), IIter(TIter()));
+
+    test_exceptions(S(), TIter(s, s+10, 4, TIter::TAIncrement), TIter());
+    test_exceptions(S(), TIter(s, s+10, 5, TIter::TADereference), TIter());
+    test_exceptions(S(), TIter(s, s+10, 6, TIter::TAComparison), TIter());
+
+    Widget w[100];
+    test_exceptions(S(), w, w+100);
+  }
+#endif
+
+  { // test assigning to self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.assign(s_short.begin(), s_short.end());
+    assert(s_short == "123/");
+    s_short.assign(s_short.begin() + 2, s_short.end());
+    assert(s_short == "3/");
+
+    s_long.assign(s_long.begin(), s_long.end());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/");
+
+    s_long.assign(s_long.begin() + 30, s_long.end());
+    assert(s_long == "nsectetur/");
+  }
+
+  { // test assigning a different type
+    typedef std::string S;
+    const uint8_t p[] = "ABCD";
+
+    S s;
+    s.assign(p, p + 4);
+    assert(s == "ABCD");
+  }
+
+  { // regression-test assigning to self in sneaky ways
+    std::string sneaky = "hello";
+    sneaky.resize(sneaky.capacity(), 'x');
+    std::string expected = sneaky + std::string(1, '\0');
+    test(sneaky, sneaky.data(), sneaky.data() + sneaky.size() + 1, expected);
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+    return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/pointer.pass.cpp

@@ -0,0 +1,88 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& assign(const charT* s); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, const typename S::value_type* str, S expected)
+{
+    s.assign(str);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), "", S());
+    test(S(), "12345", S("12345"));
+    test(S(), "12345678901234567890", S("12345678901234567890"));
+
+    test(S("12345"), "", S());
+    test(S("12345"), "12345", S("12345"));
+    test(S("12345"), "1234567890", S("1234567890"));
+
+    test(S("12345678901234567890"), "", S());
+    test(S("12345678901234567890"), "12345", S("12345"));
+    test(S("12345678901234567890"), "12345678901234567890",
+         S("12345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), "", S());
+    test(S(), "12345", S("12345"));
+    test(S(), "12345678901234567890", S("12345678901234567890"));
+
+    test(S("12345"), "", S());
+    test(S("12345"), "12345", S("12345"));
+    test(S("12345"), "1234567890", S("1234567890"));
+
+    test(S("12345678901234567890"), "", S());
+    test(S("12345678901234567890"), "12345", S("12345"));
+    test(S("12345678901234567890"), "12345678901234567890",
+         S("12345678901234567890"));
+  }
+#endif
+
+  { // test assignment to self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.assign(s_short.c_str());
+    assert(s_short == "123/");
+    s_short.assign(s_short.c_str() + 2);
+    assert(s_short == "3/");
+
+    s_long.assign(s_long.c_str() + 30);
+    assert(s_long == "nsectetur/");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/pointer_size.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(const charT* s, size_type n); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, const typename S::value_type* str, typename S::size_type n, S expected)
+{
+    s.assign(str, n);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), "", 0, S());
+    test(S(), "12345", 3, S("123"));
+    test(S(), "12345", 4, S("1234"));
+    test(S(), "12345678901234567890", 0, S());
+    test(S(), "12345678901234567890", 1, S("1"));
+    test(S(), "12345678901234567890", 3, S("123"));
+    test(S(), "12345678901234567890", 20, S("12345678901234567890"));
+
+    test(S("12345"), "", 0, S());
+    test(S("12345"), "12345", 5, S("12345"));
+    test(S("12345"), "1234567890", 10, S("1234567890"));
+
+    test(S("12345678901234567890"), "", 0, S());
+    test(S("12345678901234567890"), "12345", 5, S("12345"));
+    test(S("12345678901234567890"), "12345678901234567890", 20,
+         S("12345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), "", 0, S());
+    test(S(), "12345", 3, S("123"));
+    test(S(), "12345", 4, S("1234"));
+    test(S(), "12345678901234567890", 0, S());
+    test(S(), "12345678901234567890", 1, S("1"));
+    test(S(), "12345678901234567890", 3, S("123"));
+    test(S(), "12345678901234567890", 20, S("12345678901234567890"));
+
+    test(S("12345"), "", 0, S());
+    test(S("12345"), "12345", 5, S("12345"));
+    test(S("12345"), "1234567890", 10, S("1234567890"));
+
+    test(S("12345678901234567890"), "", 0, S());
+    test(S("12345678901234567890"), "12345", 5, S("12345"));
+    test(S("12345678901234567890"), "12345678901234567890", 20,
+         S("12345678901234567890"));
+  }
+#endif
+  { // test assign to self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.assign(s_short.data(), s_short.size());
+    assert(s_short == "123/");
+    s_short.assign(s_short.data() + 2, s_short.size() - 2);
+    assert(s_short == "3/");
+
+    s_long.assign(s_long.data(), s_long.size());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/");
+
+    s_long.assign(s_long.data() + 2, 8 );
+    assert(s_long == "rem ipsu");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/rv_string.pass.cpp

@@ -0,0 +1,91 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(basic_string<charT,traits>&& str); // constexpr since C++20
+
+#include <string>
+#include <utility>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S str, S expected)
+{
+    s.assign(std::move(str));
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S(), S());
+    test(S(), S("12345"), S("12345"));
+    test(S(), S("1234567890"), S("1234567890"));
+    test(S(), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), S(), S());
+    test(S("12345"), S("12345"), S("12345"));
+    test(S("12345"), S("1234567890"), S("1234567890"));
+    test(S("12345"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), S(), S());
+    test(S("1234567890"), S("12345"), S("12345"));
+    test(S("1234567890"), S("1234567890"), S("1234567890"));
+    test(S("1234567890"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), S(), S());
+    test(S("12345678901234567890"), S("12345"), S("12345"));
+    test(S("12345678901234567890"), S("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), S("12345678901234567890"),
+         S("12345678901234567890"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S(), S());
+    test(S(), S("12345"), S("12345"));
+    test(S(), S("1234567890"), S("1234567890"));
+    test(S(), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), S(), S());
+    test(S("12345"), S("12345"), S("12345"));
+    test(S("12345"), S("1234567890"), S("1234567890"));
+    test(S("12345"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), S(), S());
+    test(S("1234567890"), S("12345"), S("12345"));
+    test(S("1234567890"), S("1234567890"), S("1234567890"));
+    test(S("1234567890"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), S(), S());
+    test(S("12345678901234567890"), S("12345"), S("12345"));
+    test(S("12345678901234567890"), S("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), S("12345678901234567890"),
+         S("12345678901234567890"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/size_char.pass.cpp

@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(size_type n, charT c); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type n, typename S::value_type c, S expected)
+{
+    s.assign(n, c);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), 0, 'a', S());
+    test(S(), 1, 'a', S(1, 'a'));
+    test(S(), 10, 'a', S(10, 'a'));
+    test(S(), 100, 'a', S(100, 'a'));
+
+    test(S("12345"), 0, 'a', S());
+    test(S("12345"), 1, 'a', S(1, 'a'));
+    test(S("12345"), 10, 'a', S(10, 'a'));
+
+    test(S("12345678901234567890"), 0, 'a', S());
+    test(S("12345678901234567890"), 1, 'a', S(1, 'a'));
+    test(S("12345678901234567890"), 10, 'a', S(10, 'a'));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), 0, 'a', S());
+    test(S(), 1, 'a', S(1, 'a'));
+    test(S(), 10, 'a', S(10, 'a'));
+    test(S(), 100, 'a', S(100, 'a'));
+
+    test(S("12345"), 0, 'a', S());
+    test(S("12345"), 1, 'a', S(1, 'a'));
+    test(S("12345"), 10, 'a', S(10, 'a'));
+
+    test(S("12345678901234567890"), 0, 'a', S());
+    test(S("12345678901234567890"), 1, 'a', S(1, 'a'));
+    test(S("12345678901234567890"), 10, 'a', S(10, 'a'));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/string.pass.cpp

@@ -0,0 +1,127 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(const basic_string<charT,traits>& str); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+#include "test_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S str, S expected)
+{
+    s.assign(str);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+testAlloc(S s, S str, const typename S::allocator_type& a)
+{
+    s.assign(str);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == str);
+    assert(s.get_allocator() == a);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S(), S());
+    test(S(), S("12345"), S("12345"));
+    test(S(), S("1234567890"), S("1234567890"));
+    test(S(), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), S(), S());
+    test(S("12345"), S("12345"), S("12345"));
+    test(S("12345"), S("1234567890"), S("1234567890"));
+    test(S("12345"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), S(), S());
+    test(S("1234567890"), S("12345"), S("12345"));
+    test(S("1234567890"), S("1234567890"), S("1234567890"));
+    test(S("1234567890"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), S(), S());
+    test(S("12345678901234567890"), S("12345"), S("12345"));
+    test(S("12345678901234567890"), S("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), S("12345678901234567890"),
+         S("12345678901234567890"));
+
+    testAlloc(S(), S(), std::allocator<char>());
+    testAlloc(S(), S("12345"), std::allocator<char>());
+    testAlloc(S(), S("1234567890"), std::allocator<char>());
+    testAlloc(S(), S("12345678901234567890"), std::allocator<char>());
+  }
+
+  { //  LWG#5579 make sure assign takes the allocators where appropriate
+    typedef other_allocator<char> A;  // has POCCA --> true
+    typedef std::basic_string<char, std::char_traits<char>, A> S;
+    testAlloc(S(A(5)), S(A(3)), A(3));
+    testAlloc(S(A(5)), S("1"), A());
+    testAlloc(S(A(5)), S("1", A(7)), A(7));
+    testAlloc(S(A(5)), S("1234567890123456789012345678901234567890123456789012345678901234567890", A(7)), A(7));
+  }
+
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S(), S());
+    test(S(), S("12345"), S("12345"));
+    test(S(), S("1234567890"), S("1234567890"));
+    test(S(), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), S(), S());
+    test(S("12345"), S("12345"), S("12345"));
+    test(S("12345"), S("1234567890"), S("1234567890"));
+    test(S("12345"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), S(), S());
+    test(S("1234567890"), S("12345"), S("12345"));
+    test(S("1234567890"), S("1234567890"), S("1234567890"));
+    test(S("1234567890"), S("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), S(), S());
+    test(S("12345678901234567890"), S("12345"), S("12345"));
+    test(S("12345678901234567890"), S("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), S("12345678901234567890"),
+         S("12345678901234567890"));
+
+    testAlloc(S(), S(), min_allocator<char>());
+    testAlloc(S(), S("12345"), min_allocator<char>());
+    testAlloc(S(), S("1234567890"), min_allocator<char>());
+    testAlloc(S(), S("12345678901234567890"), min_allocator<char>());
+  }
+#endif
+#if TEST_STD_VER > 14
+  {
+    typedef std::string S;
+    static_assert(noexcept(S().assign(S())), "");  // LWG#2063
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/string_size_size.pass.cpp

@@ -0,0 +1,147 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(const basic_string<charT,traits>& str, size_type pos, size_type n=npos); // constexpr since C++20
+// the =npos was added for C++14
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S str, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    if (pos <= str.size())
+    {
+        s.assign(str, pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.assign(str, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test_npos(S s, S str, typename S::size_type pos, S expected)
+{
+    if (pos <= str.size())
+    {
+        s.assign(str, pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.assign(str, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(), S(), 0, 0, S());
+    test(S(), S(), 1, 0, S());
+    test(S(), S("12345"), 0, 3, S("123"));
+    test(S(), S("12345"), 1, 4, S("2345"));
+    test(S(), S("12345"), 3, 15, S("45"));
+    test(S(), S("12345"), 5, 15, S(""));
+    test(S(), S("12345"), 6, 15, S("not happening"));
+    test(S(), S("12345678901234567890"), 0, 0, S());
+    test(S(), S("12345678901234567890"), 1, 1, S("2"));
+    test(S(), S("12345678901234567890"), 2, 3, S("345"));
+    test(S(), S("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), S("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), S(), 0, 0, S());
+    test(S("12345"), S("12345"), 2, 2, S("34"));
+    test(S("12345"), S("1234567890"), 0, 100, S("1234567890"));
+
+    test(S("12345678901234567890"), S(), 0, 0, S());
+    test(S("12345678901234567890"), S("12345"), 1, 3, S("234"));
+    test(S("12345678901234567890"), S("12345678901234567890"), 5, 10,
+         S("6789012345"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(), S(), 0, 0, S());
+    test(S(), S(), 1, 0, S());
+    test(S(), S("12345"), 0, 3, S("123"));
+    test(S(), S("12345"), 1, 4, S("2345"));
+    test(S(), S("12345"), 3, 15, S("45"));
+    test(S(), S("12345"), 5, 15, S(""));
+    test(S(), S("12345"), 6, 15, S("not happening"));
+    test(S(), S("12345678901234567890"), 0, 0, S());
+    test(S(), S("12345678901234567890"), 1, 1, S("2"));
+    test(S(), S("12345678901234567890"), 2, 3, S("345"));
+    test(S(), S("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), S("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), S(), 0, 0, S());
+    test(S("12345"), S("12345"), 2, 2, S("34"));
+    test(S("12345"), S("1234567890"), 0, 100, S("1234567890"));
+
+    test(S("12345678901234567890"), S(), 0, 0, S());
+    test(S("12345678901234567890"), S("12345"), 1, 3, S("234"));
+    test(S("12345678901234567890"), S("12345678901234567890"), 5, 10,
+         S("6789012345"));
+  }
+#endif
+  {
+    typedef std::string S;
+    test_npos(S(), S(), 0, S());
+    test_npos(S(), S(), 1, S());
+    test_npos(S(), S("12345"), 0, S("12345"));
+    test_npos(S(), S("12345"), 1, S("2345"));
+    test_npos(S(), S("12345"), 3, S("45"));
+    test_npos(S(), S("12345"), 5, S(""));
+    test_npos(S(), S("12345"), 6, S("not happening"));
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/string_view.pass.cpp

@@ -0,0 +1,115 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(basic_string_view<charT,traits> sv); // constexpr since C++20
+
+#include <string>
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+#include "test_allocator.h"
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+test(S s, SV sv, S expected)
+{
+    s.assign(sv);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+template <class S, class SV>
+TEST_CONSTEXPR_CXX20 void
+testAlloc(S s, SV sv, const typename S::allocator_type& a)
+{
+    s.assign(sv);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == sv);
+    assert(s.get_allocator() == a);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S());
+    test(S("12345"), SV("12345"), S("12345"));
+    test(S("12345"), SV("1234567890"), S("1234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), SV(), S());
+    test(S("1234567890"), SV("12345"), S("12345"));
+    test(S("1234567890"), SV("1234567890"), S("1234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S());
+    test(S("12345678901234567890"), SV("12345"), S("12345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("12345678901234567890"));
+
+    testAlloc(S(), SV(), std::allocator<char>());
+    testAlloc(S(), SV("12345"), std::allocator<char>());
+    testAlloc(S(), SV("1234567890"), std::allocator<char>());
+    testAlloc(S(), SV("12345678901234567890"), std::allocator<char>());
+  }
+
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S());
+    test(S("12345"), SV("12345"), S("12345"));
+    test(S("12345"), SV("1234567890"), S("1234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), SV(), S());
+    test(S("1234567890"), SV("12345"), S("12345"));
+    test(S("1234567890"), SV("1234567890"), S("1234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S());
+    test(S("12345678901234567890"), SV("12345"), S("12345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("12345678901234567890"));
+
+    testAlloc(S(), SV(), min_allocator<char>());
+    testAlloc(S(), SV("12345"), min_allocator<char>());
+    testAlloc(S(), SV("1234567890"), min_allocator<char>());
+    testAlloc(S(), SV("12345678901234567890"), min_allocator<char>());
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_copy/copy.pass.cpp

@@ -0,0 +1,191 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// size_type copy(charT* s, size_type n, size_type pos = 0) const; // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S str, typename S::value_type* s, typename S::size_type n,
+     typename S::size_type pos)
+{
+    const S& cs = str;
+    if (pos <= cs.size())
+    {
+        typename S::size_type r = cs.copy(s, n, pos);
+        typename S::size_type rlen = std::min(n, cs.size() - pos);
+        assert(r == rlen);
+        for (r = 0; r < rlen; ++r)
+            assert(S::traits_type::eq(cs[pos+r], s[r]));
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            typename S::size_type r = cs.copy(s, n, pos);
+            ((void)r); // Prevent unused warning
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    char s[50];
+    test(S(""), s, 0, 0);
+    test(S(""), s, 0, 1);
+    test(S(""), s, 1, 0);
+    test(S("abcde"), s, 0, 0);
+    test(S("abcde"), s, 0, 1);
+    test(S("abcde"), s, 0, 2);
+    test(S("abcde"), s, 0, 4);
+    test(S("abcde"), s, 0, 5);
+    test(S("abcde"), s, 0, 6);
+    test(S("abcde"), s, 1, 0);
+    test(S("abcde"), s, 1, 1);
+    test(S("abcde"), s, 1, 2);
+    test(S("abcde"), s, 1, 4);
+    test(S("abcde"), s, 1, 5);
+    test(S("abcde"), s, 2, 0);
+    test(S("abcde"), s, 2, 1);
+    test(S("abcde"), s, 2, 2);
+    test(S("abcde"), s, 2, 4);
+    test(S("abcde"), s, 4, 0);
+    test(S("abcde"), s, 4, 1);
+    test(S("abcde"), s, 4, 2);
+    test(S("abcde"), s, 5, 0);
+    test(S("abcde"), s, 5, 1);
+    test(S("abcde"), s, 6, 0);
+    test(S("abcdefghijklmnopqrst"), s, 0, 0);
+    test(S("abcdefghijklmnopqrst"), s, 0, 1);
+    test(S("abcdefghijklmnopqrst"), s, 0, 2);
+    test(S("abcdefghijklmnopqrst"), s, 0, 10);
+    test(S("abcdefghijklmnopqrst"), s, 0, 19);
+    test(S("abcdefghijklmnopqrst"), s, 0, 20);
+    test(S("abcdefghijklmnopqrst"), s, 0, 21);
+    test(S("abcdefghijklmnopqrst"), s, 1, 0);
+    test(S("abcdefghijklmnopqrst"), s, 1, 1);
+    test(S("abcdefghijklmnopqrst"), s, 1, 2);
+    test(S("abcdefghijklmnopqrst"), s, 1, 9);
+    test(S("abcdefghijklmnopqrst"), s, 1, 18);
+    test(S("abcdefghijklmnopqrst"), s, 1, 19);
+    test(S("abcdefghijklmnopqrst"), s, 1, 20);
+    test(S("abcdefghijklmnopqrst"), s, 2, 0);
+    test(S("abcdefghijklmnopqrst"), s, 2, 1);
+    test(S("abcdefghijklmnopqrst"), s, 2, 2);
+    test(S("abcdefghijklmnopqrst"), s, 2, 9);
+    test(S("abcdefghijklmnopqrst"), s, 2, 17);
+    test(S("abcdefghijklmnopqrst"), s, 2, 18);
+    test(S("abcdefghijklmnopqrst"), s, 2, 19);
+    test(S("abcdefghijklmnopqrst"), s, 10, 0);
+    test(S("abcdefghijklmnopqrst"), s, 10, 1);
+    test(S("abcdefghijklmnopqrst"), s, 10, 2);
+    test(S("abcdefghijklmnopqrst"), s, 10, 5);
+    test(S("abcdefghijklmnopqrst"), s, 10, 9);
+    test(S("abcdefghijklmnopqrst"), s, 10, 10);
+    test(S("abcdefghijklmnopqrst"), s, 10, 11);
+    test(S("abcdefghijklmnopqrst"), s, 19, 0);
+    test(S("abcdefghijklmnopqrst"), s, 19, 1);
+    test(S("abcdefghijklmnopqrst"), s, 19, 2);
+    test(S("abcdefghijklmnopqrst"), s, 20, 0);
+    test(S("abcdefghijklmnopqrst"), s, 20, 1);
+    test(S("abcdefghijklmnopqrst"), s, 21, 0);
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    char s[50];
+    test(S(""), s, 0, 0);
+    test(S(""), s, 0, 1);
+    test(S(""), s, 1, 0);
+    test(S("abcde"), s, 0, 0);
+    test(S("abcde"), s, 0, 1);
+    test(S("abcde"), s, 0, 2);
+    test(S("abcde"), s, 0, 4);
+    test(S("abcde"), s, 0, 5);
+    test(S("abcde"), s, 0, 6);
+    test(S("abcde"), s, 1, 0);
+    test(S("abcde"), s, 1, 1);
+    test(S("abcde"), s, 1, 2);
+    test(S("abcde"), s, 1, 4);
+    test(S("abcde"), s, 1, 5);
+    test(S("abcde"), s, 2, 0);
+    test(S("abcde"), s, 2, 1);
+    test(S("abcde"), s, 2, 2);
+    test(S("abcde"), s, 2, 4);
+    test(S("abcde"), s, 4, 0);
+    test(S("abcde"), s, 4, 1);
+    test(S("abcde"), s, 4, 2);
+    test(S("abcde"), s, 5, 0);
+    test(S("abcde"), s, 5, 1);
+    test(S("abcde"), s, 6, 0);
+    test(S("abcdefghijklmnopqrst"), s, 0, 0);
+    test(S("abcdefghijklmnopqrst"), s, 0, 1);
+    test(S("abcdefghijklmnopqrst"), s, 0, 2);
+    test(S("abcdefghijklmnopqrst"), s, 0, 10);
+    test(S("abcdefghijklmnopqrst"), s, 0, 19);
+    test(S("abcdefghijklmnopqrst"), s, 0, 20);
+    test(S("abcdefghijklmnopqrst"), s, 0, 21);
+    test(S("abcdefghijklmnopqrst"), s, 1, 0);
+    test(S("abcdefghijklmnopqrst"), s, 1, 1);
+    test(S("abcdefghijklmnopqrst"), s, 1, 2);
+    test(S("abcdefghijklmnopqrst"), s, 1, 9);
+    test(S("abcdefghijklmnopqrst"), s, 1, 18);
+    test(S("abcdefghijklmnopqrst"), s, 1, 19);
+    test(S("abcdefghijklmnopqrst"), s, 1, 20);
+    test(S("abcdefghijklmnopqrst"), s, 2, 0);
+    test(S("abcdefghijklmnopqrst"), s, 2, 1);
+    test(S("abcdefghijklmnopqrst"), s, 2, 2);
+    test(S("abcdefghijklmnopqrst"), s, 2, 9);
+    test(S("abcdefghijklmnopqrst"), s, 2, 17);
+    test(S("abcdefghijklmnopqrst"), s, 2, 18);
+    test(S("abcdefghijklmnopqrst"), s, 2, 19);
+    test(S("abcdefghijklmnopqrst"), s, 10, 0);
+    test(S("abcdefghijklmnopqrst"), s, 10, 1);
+    test(S("abcdefghijklmnopqrst"), s, 10, 2);
+    test(S("abcdefghijklmnopqrst"), s, 10, 5);
+    test(S("abcdefghijklmnopqrst"), s, 10, 9);
+    test(S("abcdefghijklmnopqrst"), s, 10, 10);
+    test(S("abcdefghijklmnopqrst"), s, 10, 11);
+    test(S("abcdefghijklmnopqrst"), s, 19, 0);
+    test(S("abcdefghijklmnopqrst"), s, 19, 1);
+    test(S("abcdefghijklmnopqrst"), s, 19, 2);
+    test(S("abcdefghijklmnopqrst"), s, 20, 0);
+    test(S("abcdefghijklmnopqrst"), s, 20, 1);
+    test(S("abcdefghijklmnopqrst"), s, 21, 0);
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_erase/iter.pass.cpp

@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator erase(const_iterator p); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::difference_type pos, S expected)
+{
+    typename S::const_iterator p = s.begin() + pos;
+    typename S::iterator i = s.erase(p);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s[s.size()] == typename S::value_type());
+    assert(s == expected);
+    assert(i - s.begin() == pos);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S("abcde"), 0, S("bcde"));
+    test(S("abcde"), 1, S("acde"));
+    test(S("abcde"), 2, S("abde"));
+    test(S("abcde"), 4, S("abcd"));
+    test(S("abcdefghij"), 0, S("bcdefghij"));
+    test(S("abcdefghij"), 1, S("acdefghij"));
+    test(S("abcdefghij"), 5, S("abcdeghij"));
+    test(S("abcdefghij"), 9, S("abcdefghi"));
+    test(S("abcdefghijklmnopqrst"), 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("abcdefghijklmnopqrs"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S("abcde"), 0, S("bcde"));
+    test(S("abcde"), 1, S("acde"));
+    test(S("abcde"), 2, S("abde"));
+    test(S("abcde"), 4, S("abcd"));
+    test(S("abcdefghij"), 0, S("bcdefghij"));
+    test(S("abcdefghij"), 1, S("acdefghij"));
+    test(S("abcdefghij"), 5, S("abcdeghij"));
+    test(S("abcdefghij"), 9, S("abcdefghi"));
+    test(S("abcdefghijklmnopqrst"), 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("abcdefghijklmnopqrs"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_erase/iter_iter.pass.cpp

@@ -0,0 +1,161 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator erase(const_iterator first, const_iterator last); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::difference_type pos, typename S::difference_type n, S expected)
+{
+    typename S::const_iterator first = s.cbegin() + pos;
+    typename S::const_iterator last = s.cbegin() + pos + n;
+    typename S::iterator i = s.erase(first, last);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s[s.size()] == typename S::value_type());
+    assert(s == expected);
+    assert(i - s.begin() == pos);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(""), 0, 0, S(""));
+    test(S("abcde"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 1, S("bcde"));
+    test(S("abcde"), 0, 2, S("cde"));
+    test(S("abcde"), 0, 4, S("e"));
+    test(S("abcde"), 0, 5, S(""));
+    test(S("abcde"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 1, S("acde"));
+    test(S("abcde"), 1, 2, S("ade"));
+    test(S("abcde"), 1, 3, S("ae"));
+    test(S("abcde"), 1, 4, S("a"));
+    test(S("abcde"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, 1, S("abde"));
+    test(S("abcde"), 2, 2, S("abe"));
+    test(S("abcde"), 2, 3, S("ab"));
+    test(S("abcde"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, 1, S("abcd"));
+    test(S("abcde"), 5, 0, S("abcde"));
+    test(S("abcdefghij"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 5, S("fghij"));
+    test(S("abcdefghij"), 0, 9, S("j"));
+    test(S("abcdefghij"), 0, 10, S(""));
+    test(S("abcdefghij"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 4, S("afghij"));
+    test(S("abcdefghij"), 1, 8, S("aj"));
+    test(S("abcdefghij"), 1, 9, S("a"));
+    test(S("abcdefghij"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 2, S("abcdehij"));
+    test(S("abcdefghij"), 5, 4, S("abcdej"));
+    test(S("abcdefghij"), 5, 5, S("abcde"));
+    test(S("abcdefghij"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, S(""));
+    test(S("abcdefghijklmnopqrst"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, S("a"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, S("abcdefghijklmnopqrst"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(""), 0, 0, S(""));
+    test(S("abcde"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 1, S("bcde"));
+    test(S("abcde"), 0, 2, S("cde"));
+    test(S("abcde"), 0, 4, S("e"));
+    test(S("abcde"), 0, 5, S(""));
+    test(S("abcde"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 1, S("acde"));
+    test(S("abcde"), 1, 2, S("ade"));
+    test(S("abcde"), 1, 3, S("ae"));
+    test(S("abcde"), 1, 4, S("a"));
+    test(S("abcde"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, 1, S("abde"));
+    test(S("abcde"), 2, 2, S("abe"));
+    test(S("abcde"), 2, 3, S("ab"));
+    test(S("abcde"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, 1, S("abcd"));
+    test(S("abcde"), 5, 0, S("abcde"));
+    test(S("abcdefghij"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 5, S("fghij"));
+    test(S("abcdefghij"), 0, 9, S("j"));
+    test(S("abcdefghij"), 0, 10, S(""));
+    test(S("abcdefghij"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 4, S("afghij"));
+    test(S("abcdefghij"), 1, 8, S("aj"));
+    test(S("abcdefghij"), 1, 9, S("a"));
+    test(S("abcdefghij"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 2, S("abcdehij"));
+    test(S("abcdefghij"), 5, 4, S("abcdej"));
+    test(S("abcdefghij"), 5, 5, S("abcde"));
+    test(S("abcdefghij"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, S(""));
+    test(S("abcdefghijklmnopqrst"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, S("a"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, S("abcdefghijklmnopqrst"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_erase/pop_back.pass.cpp

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void pop_back(); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S expected)
+{
+    s.pop_back();
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s[s.size()] == typename S::value_type());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S("abcde"), S("abcd"));
+    test(S("abcdefghij"), S("abcdefghi"));
+    test(S("abcdefghijklmnopqrst"), S("abcdefghijklmnopqrs"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S("abcde"), S("abcd"));
+    test(S("abcdefghij"), S("abcdefghi"));
+    test(S("abcdefghijklmnopqrst"), S("abcdefghijklmnopqrs"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_erase/size_size.pass.cpp

@@ -0,0 +1,312 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   erase(size_type pos = 0, size_type n = npos); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos <= old_size)
+    {
+        s.erase(pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s[s.size()] == typename S::value_type());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.erase(pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type pos, S expected)
+{
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos <= old_size)
+    {
+        s.erase(pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s[s.size()] == typename S::value_type());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.erase(pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, S expected)
+{
+    s.erase();
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s[s.size()] == typename S::value_type());
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(""), 0, 0, S(""));
+    test(S(""), 0, 1, S(""));
+    test(S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 1, S("bcde"));
+    test(S("abcde"), 0, 2, S("cde"));
+    test(S("abcde"), 0, 4, S("e"));
+    test(S("abcde"), 0, 5, S(""));
+    test(S("abcde"), 0, 6, S(""));
+    test(S("abcde"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 1, S("acde"));
+    test(S("abcde"), 1, 2, S("ade"));
+    test(S("abcde"), 1, 3, S("ae"));
+    test(S("abcde"), 1, 4, S("a"));
+    test(S("abcde"), 1, 5, S("a"));
+    test(S("abcde"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, 1, S("abde"));
+    test(S("abcde"), 2, 2, S("abe"));
+    test(S("abcde"), 2, 3, S("ab"));
+    test(S("abcde"), 2, 4, S("ab"));
+    test(S("abcde"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, 1, S("abcd"));
+    test(S("abcde"), 4, 2, S("abcd"));
+    test(S("abcde"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, 1, S("abcde"));
+    test(S("abcde"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 5, S("fghij"));
+    test(S("abcdefghij"), 0, 9, S("j"));
+    test(S("abcdefghij"), 0, 10, S(""));
+    test(S("abcdefghij"), 0, 11, S(""));
+    test(S("abcdefghij"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 4, S("afghij"));
+    test(S("abcdefghij"), 1, 8, S("aj"));
+    test(S("abcdefghij"), 1, 9, S("a"));
+    test(S("abcdefghij"), 1, 10, S("a"));
+    test(S("abcdefghij"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 2, S("abcdehij"));
+    test(S("abcdefghij"), 5, 4, S("abcdej"));
+    test(S("abcdefghij"), 5, 5, S("abcde"));
+    test(S("abcdefghij"), 5, 6, S("abcde"));
+    test(S("abcdefghij"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, S("abcdefghi"));
+    test(S("abcdefghij"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, S(""));
+    test(S("abcdefghijklmnopqrst"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, S("a"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, S("can't happen"));
+
+    test(S(""), 0, S(""));
+    test(S(""), 1, S("can't happen"));
+    test(S("abcde"), 0, S(""));
+    test(S("abcde"), 1, S("a"));
+    test(S("abcde"), 2, S("ab"));
+    test(S("abcde"), 4, S("abcd"));
+    test(S("abcde"), 5, S("abcde"));
+    test(S("abcde"), 6, S("can't happen"));
+    test(S("abcdefghij"), 0, S(""));
+    test(S("abcdefghij"), 1, S("a"));
+    test(S("abcdefghij"), 5, S("abcde"));
+    test(S("abcdefghij"), 9, S("abcdefghi"));
+    test(S("abcdefghij"), 10, S("abcdefghij"));
+    test(S("abcdefghij"), 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 10, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 19, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 20, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 21, S("can't happen"));
+
+    test(S(""), S(""));
+    test(S("abcde"), S(""));
+    test(S("abcdefghij"), S(""));
+    test(S("abcdefghijklmnopqrst"), S(""));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(""), 0, 0, S(""));
+    test(S(""), 0, 1, S(""));
+    test(S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 1, S("bcde"));
+    test(S("abcde"), 0, 2, S("cde"));
+    test(S("abcde"), 0, 4, S("e"));
+    test(S("abcde"), 0, 5, S(""));
+    test(S("abcde"), 0, 6, S(""));
+    test(S("abcde"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 1, S("acde"));
+    test(S("abcde"), 1, 2, S("ade"));
+    test(S("abcde"), 1, 3, S("ae"));
+    test(S("abcde"), 1, 4, S("a"));
+    test(S("abcde"), 1, 5, S("a"));
+    test(S("abcde"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, 1, S("abde"));
+    test(S("abcde"), 2, 2, S("abe"));
+    test(S("abcde"), 2, 3, S("ab"));
+    test(S("abcde"), 2, 4, S("ab"));
+    test(S("abcde"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, 1, S("abcd"));
+    test(S("abcde"), 4, 2, S("abcd"));
+    test(S("abcde"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, 1, S("abcde"));
+    test(S("abcde"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 5, S("fghij"));
+    test(S("abcdefghij"), 0, 9, S("j"));
+    test(S("abcdefghij"), 0, 10, S(""));
+    test(S("abcdefghij"), 0, 11, S(""));
+    test(S("abcdefghij"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 4, S("afghij"));
+    test(S("abcdefghij"), 1, 8, S("aj"));
+    test(S("abcdefghij"), 1, 9, S("a"));
+    test(S("abcdefghij"), 1, 10, S("a"));
+    test(S("abcdefghij"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 2, S("abcdehij"));
+    test(S("abcdefghij"), 5, 4, S("abcdej"));
+    test(S("abcdefghij"), 5, 5, S("abcde"));
+    test(S("abcdefghij"), 5, 6, S("abcde"));
+    test(S("abcdefghij"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, S("abcdefghi"));
+    test(S("abcdefghij"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, S(""));
+    test(S("abcdefghijklmnopqrst"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, S("a"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, S("can't happen"));
+
+    test(S(""), 0, S(""));
+    test(S(""), 1, S("can't happen"));
+    test(S("abcde"), 0, S(""));
+    test(S("abcde"), 1, S("a"));
+    test(S("abcde"), 2, S("ab"));
+    test(S("abcde"), 4, S("abcd"));
+    test(S("abcde"), 5, S("abcde"));
+    test(S("abcde"), 6, S("can't happen"));
+    test(S("abcdefghij"), 0, S(""));
+    test(S("abcdefghij"), 1, S("a"));
+    test(S("abcdefghij"), 5, S("abcde"));
+    test(S("abcdefghij"), 9, S("abcdefghi"));
+    test(S("abcdefghij"), 10, S("abcdefghij"));
+    test(S("abcdefghij"), 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 10, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 19, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 20, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 21, S("can't happen"));
+
+    test(S(""), S(""));
+    test(S("abcde"), S(""));
+    test(S("abcdefghij"), S(""));
+    test(S("abcdefghijklmnopqrst"), S(""));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_char.pass.cpp

@@ -0,0 +1,86 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator insert(const_iterator p, charT c); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S& s, typename S::const_iterator p, typename S::value_type c, S expected)
+{
+    bool sufficient_cap = s.size() < s.capacity();
+    typename S::difference_type pos = p - s.begin();
+    typename S::iterator i = s.insert(p, c);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+    assert(i - s.begin() == pos);
+    assert(*i == c);
+    if (sufficient_cap)
+        assert(i == p);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    S s;
+    test(s, s.begin(), '1', S("1"));
+    test(s, s.begin(), 'a', S("a1"));
+    test(s, s.end(), 'b', S("a1b"));
+    test(s, s.end()-1, 'c', S("a1cb"));
+    test(s, s.end()-2, 'd', S("a1dcb"));
+    test(s, s.end()-3, '2', S("a12dcb"));
+    test(s, s.end()-4, '3', S("a132dcb"));
+    test(s, s.end()-5, '4', S("a1432dcb"));
+    test(s, s.begin()+1, '5', S("a51432dcb"));
+    test(s, s.begin()+2, '6', S("a561432dcb"));
+    test(s, s.begin()+3, '7', S("a5671432dcb"));
+    test(s, s.begin()+4, 'A', S("a567A1432dcb"));
+    test(s, s.begin()+5, 'B', S("a567AB1432dcb"));
+    test(s, s.begin()+6, 'C', S("a567ABC1432dcb"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s;
+    test(s, s.begin(), '1', S("1"));
+    test(s, s.begin(), 'a', S("a1"));
+    test(s, s.end(), 'b', S("a1b"));
+    test(s, s.end()-1, 'c', S("a1cb"));
+    test(s, s.end()-2, 'd', S("a1dcb"));
+    test(s, s.end()-3, '2', S("a12dcb"));
+    test(s, s.end()-4, '3', S("a132dcb"));
+    test(s, s.end()-5, '4', S("a1432dcb"));
+    test(s, s.begin()+1, '5', S("a51432dcb"));
+    test(s, s.begin()+2, '6', S("a561432dcb"));
+    test(s, s.begin()+3, '7', S("a5671432dcb"));
+    test(s, s.begin()+4, 'A', S("a567A1432dcb"));
+    test(s, s.begin()+5, 'B', S("a567AB1432dcb"));
+    test(s, s.begin()+6, 'C', S("a567ABC1432dcb"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_initializer_list.pass.cpp

@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <string>
+
+// iterator insert(const_iterator p, initializer_list<charT> il); // constexpr since C++20
+
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    std::string s("123456");
+    std::string::iterator i = s.insert(s.begin() + 3, {'a', 'b', 'c'});
+    assert(i - s.begin() == 3);
+    assert(s == "123abc456");
+  }
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    S s("123456");
+    S::iterator i = s.insert(s.begin() + 3, {'a', 'b', 'c'});
+    assert(i - s.begin() == 3);
+    assert(s == "123abc456");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_iter_iter.pass.cpp

@@ -0,0 +1,245 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class InputIterator>
+//   iterator insert(const_iterator p, InputIterator first, InputIterator last); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+#include "min_allocator.h"
+
+template <class S, class It>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::difference_type pos, It first, It last, S expected)
+{
+    typename S::const_iterator p = s.cbegin() + pos;
+    typename S::iterator i = s.insert(p, first, last);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(i - s.begin() == pos);
+    assert(s == expected);
+}
+
+#ifndef TEST_HAS_NO_EXCEPTIONS
+struct Widget { operator char() const { throw 42; } };
+
+template <class S, class It>
+TEST_CONSTEXPR_CXX20 void
+test_exceptions(S s, typename S::difference_type pos, It first, It last)
+{
+    typename S::const_iterator p = s.cbegin() + pos;
+
+    S original = s;
+    typename S::iterator begin = s.begin();
+    typename S::iterator end = s.end();
+
+    try {
+        s.insert(p, first, last);
+        assert(false);
+    } catch (...) {}
+
+    // Part of "no effects" is that iterators and pointers
+    // into the string must not have been invalidated.
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == original);
+    assert(s.begin() == begin);
+    assert(s.end() == end);
+}
+#endif
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), 0, s, s, S());
+    test(S(), 0, s, s+1, S("A"));
+    test(S(), 0, s, s+10, S("ABCDEFGHIJ"));
+    test(S(), 0, s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), 0, s, s, S("12345"));
+    test(S("12345"), 1, s, s+1, S("1A2345"));
+    test(S("12345"), 4, s, s+10, S("1234ABCDEFGHIJ5"));
+    test(S("12345"), 5, s, s+52, S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), 0, s, s, S("1234567890"));
+    test(S("1234567890"), 1, s, s+1, S("1A234567890"));
+    test(S("1234567890"), 10, s, s+10, S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), 8, s, s+52, S("12345678ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz90"));
+
+    test(S("12345678901234567890"), 3, s, s, S("12345678901234567890"));
+    test(S("12345678901234567890"), 3, s, s+1, S("123A45678901234567890"));
+    test(S("12345678901234567890"), 15, s, s+10, S("123456789012345ABCDEFGHIJ67890"));
+    test(S("12345678901234567890"), 20, s, s+52,
+         S("12345678901234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("ABCDEFGHIJ"));
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52), S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S("12345"));
+    test(S("12345"), 1, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("1A2345"));
+    test(S("12345"), 4, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("1234ABCDEFGHIJ5"));
+    test(S("12345"), 5, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52), S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S("1234567890"));
+    test(S("1234567890"), 1, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("1A234567890"));
+    test(S("1234567890"), 10, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), 8, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52), S("12345678ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz90"));
+
+    test(S("12345678901234567890"), 3, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S("12345678901234567890"));
+    test(S("12345678901234567890"), 3, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("123A45678901234567890"));
+    test(S("12345678901234567890"), 15, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("123456789012345ABCDEFGHIJ67890"));
+    test(S("12345678901234567890"), 20, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("12345678901234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), 0, s, s, S());
+    test(S(), 0, s, s+1, S("A"));
+    test(S(), 0, s, s+10, S("ABCDEFGHIJ"));
+    test(S(), 0, s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), 0, s, s, S("12345"));
+    test(S("12345"), 1, s, s+1, S("1A2345"));
+    test(S("12345"), 4, s, s+10, S("1234ABCDEFGHIJ5"));
+    test(S("12345"), 5, s, s+52, S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), 0, s, s, S("1234567890"));
+    test(S("1234567890"), 1, s, s+1, S("1A234567890"));
+    test(S("1234567890"), 10, s, s+10, S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), 8, s, s+52, S("12345678ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz90"));
+
+    test(S("12345678901234567890"), 3, s, s, S("12345678901234567890"));
+    test(S("12345678901234567890"), 3, s, s+1, S("123A45678901234567890"));
+    test(S("12345678901234567890"), 15, s, s+10, S("123456789012345ABCDEFGHIJ67890"));
+    test(S("12345678901234567890"), 20, s, s+52,
+         S("12345678901234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("ABCDEFGHIJ"));
+    test(S(), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52), S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S("12345"));
+    test(S("12345"), 1, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("1A2345"));
+    test(S("12345"), 4, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("1234ABCDEFGHIJ5"));
+    test(S("12345"), 5, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52), S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), 0, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S("1234567890"));
+    test(S("1234567890"), 1, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("1A234567890"));
+    test(S("1234567890"), 10, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), 8, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52), S("12345678ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz90"));
+
+    test(S("12345678901234567890"), 3, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S("12345678901234567890"));
+    test(S("12345678901234567890"), 3, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("123A45678901234567890"));
+    test(S("12345678901234567890"), 15, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), S("123456789012345ABCDEFGHIJ67890"));
+    test(S("12345678901234567890"), 20, cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
+         S("12345678901234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+  }
+#endif
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  if (!TEST_IS_CONSTANT_EVALUATED) { // test iterator operations that throw
+    typedef std::string S;
+    typedef ThrowingIterator<char> TIter;
+    typedef cpp17_input_iterator<TIter> IIter;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test_exceptions(S(), 0, IIter(TIter(s, s+10, 4, TIter::TAIncrement)), IIter(TIter()));
+    test_exceptions(S(), 0, IIter(TIter(s, s+10, 5, TIter::TADereference)), IIter(TIter()));
+    test_exceptions(S(), 0, IIter(TIter(s, s+10, 6, TIter::TAComparison)), IIter(TIter()));
+
+    test_exceptions(S(), 0, TIter(s, s+10, 4, TIter::TAIncrement), TIter());
+    test_exceptions(S(), 0, TIter(s, s+10, 5, TIter::TADereference), TIter());
+    test_exceptions(S(), 0, TIter(s, s+10, 6, TIter::TAComparison), TIter());
+
+    Widget w[100];
+    test_exceptions(S(), 0, w, w+100);
+  }
+#endif
+
+  { // test inserting into self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.insert(s_short.begin(), s_short.begin(), s_short.end());
+    assert(s_short == "123/123/");
+    s_short.insert(s_short.begin(), s_short.begin(), s_short.end());
+    assert(s_short == "123/123/123/123/");
+    s_short.insert(s_short.begin(), s_short.begin(), s_short.end());
+    assert(s_short == "123/123/123/123/123/123/123/123/");
+
+    s_long.insert(s_long.begin(), s_long.begin(), s_long.end());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+  }
+
+  { // test assigning a different type
+    typedef std::string S;
+    const uint8_t p[] = "ABCD";
+
+    S s;
+    s.insert(s.begin(), p, p + 4);
+    assert(s == "ABCD");
+  }
+
+  if (!TEST_IS_CONSTANT_EVALUATED) { // regression-test inserting into self in sneaky ways
+    std::string s_short = "hello";
+    std::string s_long = "Lorem ipsum dolor sit amet, consectetur/";
+    std::string s_othertype = "hello";
+    const unsigned char *first = reinterpret_cast<const unsigned char*>(s_othertype.data());
+
+    test(s_short, 0, s_short.data() + s_short.size(), s_short.data() + s_short.size() + 1,
+         std::string("\0hello", 6));
+    test(s_long, 0, s_long.data() + s_long.size(), s_long.data() + s_long.size() + 1,
+         std::string("\0Lorem ipsum dolor sit amet, consectetur/", 41));
+    test(s_othertype, 1, first + 2, first + 5, std::string("hlloello"));
+  }
+
+  { // test with a move iterator that returns char&&
+    typedef cpp17_input_iterator<const char*> It;
+    typedef std::move_iterator<It> MoveIt;
+    const char p[] = "ABCD";
+    std::string s;
+    s.insert(s.begin(), MoveIt(It(std::begin(p))), MoveIt(It(std::end(p) - 1)));
+    assert(s == "ABCD");
+  }
+  { // test with a move iterator that returns char&&
+    typedef forward_iterator<const char*> It;
+    typedef std::move_iterator<It> MoveIt;
+    const char p[] = "ABCD";
+    std::string s;
+    s.insert(s.begin(), MoveIt(It(std::begin(p))), MoveIt(It(std::end(p) - 1)));
+    assert(s == "ABCD");
+  }
+  { // test with a move iterator that returns char&&
+    typedef const char* It;
+    typedef std::move_iterator<It> MoveIt;
+    const char p[] = "ABCD";
+    std::string s;
+    s.insert(s.begin(), MoveIt(It(std::begin(p))), MoveIt(It(std::end(p) - 1)));
+    assert(s == "ABCD");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_size_char.pass.cpp

@@ -0,0 +1,180 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator insert(const_iterator p, size_type n, charT c); // constexpr since C++20
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::difference_type pos, typename S::size_type n,
+     typename S::value_type c, S expected)
+{
+    typename S::const_iterator p = s.cbegin() + pos;
+    typename S::iterator i = s.insert(p, n, c);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(i - s.begin() == pos);
+    assert(s == expected);
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(""), 0, 0, '1', S(""));
+    test(S(""), 0, 5, '1', S("11111"));
+    test(S(""), 0, 10, '1', S("1111111111"));
+    test(S(""), 0, 20, '1', S("11111111111111111111"));
+    test(S("abcde"), 0, 0, '1', S("abcde"));
+    test(S("abcde"), 0, 5, '1', S("11111abcde"));
+    test(S("abcde"), 0, 10, '1', S("1111111111abcde"));
+    test(S("abcde"), 0, 20, '1', S("11111111111111111111abcde"));
+    test(S("abcde"), 1, 0, '1', S("abcde"));
+    test(S("abcde"), 1, 5, '1', S("a11111bcde"));
+    test(S("abcde"), 1, 10, '1', S("a1111111111bcde"));
+    test(S("abcde"), 1, 20, '1', S("a11111111111111111111bcde"));
+    test(S("abcde"), 2, 0, '1', S("abcde"));
+    test(S("abcde"), 2, 5, '1', S("ab11111cde"));
+    test(S("abcde"), 2, 10, '1', S("ab1111111111cde"));
+    test(S("abcde"), 2, 20, '1', S("ab11111111111111111111cde"));
+    test(S("abcde"), 4, 0, '1', S("abcde"));
+    test(S("abcde"), 4, 5, '1', S("abcd11111e"));
+    test(S("abcde"), 4, 10, '1', S("abcd1111111111e"));
+    test(S("abcde"), 4, 20, '1', S("abcd11111111111111111111e"));
+    test(S("abcde"), 5, 0, '1', S("abcde"));
+    test(S("abcde"), 5, 5, '1', S("abcde11111"));
+    test(S("abcde"), 5, 10, '1', S("abcde1111111111"));
+    test(S("abcde"), 5, 20, '1', S("abcde11111111111111111111"));
+    test(S("abcdefghij"), 0, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 0, 5, '1', S("11111abcdefghij"));
+    test(S("abcdefghij"), 0, 10, '1', S("1111111111abcdefghij"));
+    test(S("abcdefghij"), 0, 20, '1', S("11111111111111111111abcdefghij"));
+    test(S("abcdefghij"), 1, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 1, 5, '1', S("a11111bcdefghij"));
+    test(S("abcdefghij"), 1, 10, '1', S("a1111111111bcdefghij"));
+    test(S("abcdefghij"), 1, 20, '1', S("a11111111111111111111bcdefghij"));
+    test(S("abcdefghij"), 5, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 5, 5, '1', S("abcde11111fghij"));
+    test(S("abcdefghij"), 5, 10, '1', S("abcde1111111111fghij"));
+    test(S("abcdefghij"), 5, 20, '1', S("abcde11111111111111111111fghij"));
+    test(S("abcdefghij"), 9, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 9, 5, '1', S("abcdefghi11111j"));
+    test(S("abcdefghij"), 9, 10, '1', S("abcdefghi1111111111j"));
+    test(S("abcdefghij"), 9, 20, '1', S("abcdefghi11111111111111111111j"));
+    test(S("abcdefghij"), 10, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 10, 5, '1', S("abcdefghij11111"));
+    test(S("abcdefghij"), 10, 10, '1', S("abcdefghij1111111111"));
+    test(S("abcdefghij"), 10, 20, '1', S("abcdefghij11111111111111111111"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 5, '1', S("11111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, '1', S("1111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, '1', S("11111111111111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 5, '1', S("a11111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 10, '1', S("a1111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, '1', S("a11111111111111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, '1', S("abcdefghij11111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, '1', S("abcdefghij1111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 20, '1', S("abcdefghij11111111111111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 5, '1', S("abcdefghijklmnopqrs11111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 10, '1', S("abcdefghijklmnopqrs1111111111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 20, '1', S("abcdefghijklmnopqrs11111111111111111111t"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 5, '1', S("abcdefghijklmnopqrst11111"));
+    test(S("abcdefghijklmnopqrst"), 20, 10, '1', S("abcdefghijklmnopqrst1111111111"));
+    test(S("abcdefghijklmnopqrst"), 20, 20, '1', S("abcdefghijklmnopqrst11111111111111111111"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(""), 0, 0, '1', S(""));
+    test(S(""), 0, 5, '1', S("11111"));
+    test(S(""), 0, 10, '1', S("1111111111"));
+    test(S(""), 0, 20, '1', S("11111111111111111111"));
+    test(S("abcde"), 0, 0, '1', S("abcde"));
+    test(S("abcde"), 0, 5, '1', S("11111abcde"));
+    test(S("abcde"), 0, 10, '1', S("1111111111abcde"));
+    test(S("abcde"), 0, 20, '1', S("11111111111111111111abcde"));
+    test(S("abcde"), 1, 0, '1', S("abcde"));
+    test(S("abcde"), 1, 5, '1', S("a11111bcde"));
+    test(S("abcde"), 1, 10, '1', S("a1111111111bcde"));
+    test(S("abcde"), 1, 20, '1', S("a11111111111111111111bcde"));
+    test(S("abcde"), 2, 0, '1', S("abcde"));
+    test(S("abcde"), 2, 5, '1', S("ab11111cde"));
+    test(S("abcde"), 2, 10, '1', S("ab1111111111cde"));
+    test(S("abcde"), 2, 20, '1', S("ab11111111111111111111cde"));
+    test(S("abcde"), 4, 0, '1', S("abcde"));
+    test(S("abcde"), 4, 5, '1', S("abcd11111e"));
+    test(S("abcde"), 4, 10, '1', S("abcd1111111111e"));
+    test(S("abcde"), 4, 20, '1', S("abcd11111111111111111111e"));
+    test(S("abcde"), 5, 0, '1', S("abcde"));
+    test(S("abcde"), 5, 5, '1', S("abcde11111"));
+    test(S("abcde"), 5, 10, '1', S("abcde1111111111"));
+    test(S("abcde"), 5, 20, '1', S("abcde11111111111111111111"));
+    test(S("abcdefghij"), 0, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 0, 5, '1', S("11111abcdefghij"));
+    test(S("abcdefghij"), 0, 10, '1', S("1111111111abcdefghij"));
+    test(S("abcdefghij"), 0, 20, '1', S("11111111111111111111abcdefghij"));
+    test(S("abcdefghij"), 1, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 1, 5, '1', S("a11111bcdefghij"));
+    test(S("abcdefghij"), 1, 10, '1', S("a1111111111bcdefghij"));
+    test(S("abcdefghij"), 1, 20, '1', S("a11111111111111111111bcdefghij"));
+    test(S("abcdefghij"), 5, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 5, 5, '1', S("abcde11111fghij"));
+    test(S("abcdefghij"), 5, 10, '1', S("abcde1111111111fghij"));
+    test(S("abcdefghij"), 5, 20, '1', S("abcde11111111111111111111fghij"));
+    test(S("abcdefghij"), 9, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 9, 5, '1', S("abcdefghi11111j"));
+    test(S("abcdefghij"), 9, 10, '1', S("abcdefghi1111111111j"));
+    test(S("abcdefghij"), 9, 20, '1', S("abcdefghi11111111111111111111j"));
+    test(S("abcdefghij"), 10, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 10, 5, '1', S("abcdefghij11111"));
+    test(S("abcdefghij"), 10, 10, '1', S("abcdefghij1111111111"));
+    test(S("abcdefghij"), 10, 20, '1', S("abcdefghij11111111111111111111"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 5, '1', S("11111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, '1', S("1111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, '1', S("11111111111111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 5, '1', S("a11111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 10, '1', S("a1111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, '1', S("a11111111111111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, '1', S("abcdefghij11111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, '1', S("abcdefghij1111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 20, '1', S("abcdefghij11111111111111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 5, '1', S("abcdefghijklmnopqrs11111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 10, '1', S("abcdefghijklmnopqrs1111111111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 20, '1', S("abcdefghijklmnopqrs11111111111111111111t"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 5, '1', S("abcdefghijklmnopqrst11111"));
+    test(S("abcdefghijklmnopqrst"), 20, 10, '1', S("abcdefghijklmnopqrst1111111111"));
+    test(S("abcdefghijklmnopqrst"), 20, 20, '1', S("abcdefghijklmnopqrst11111111111111111111"));
+  }
+#endif
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}

module/jni/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer.pass.cpp

@@ -0,0 +1,247 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   insert(size_type pos, const charT* s); // constexpr since C++20
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+TEST_CONSTEXPR_CXX20 void
+test(S s, typename S::size_type pos, const typename S::value_type* str, S expected)
+{
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos <= old_size)
+    {
+        s.insert(pos, str);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else if (!TEST_IS_CONSTANT_EVALUATED)
+    {
+        try
+        {
+            s.insert(pos, str);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+TEST_CONSTEXPR_CXX20 bool test() {
+  {
+    typedef std::string S;
+    test(S(""), 0, "", S(""));
+    test(S(""), 0, "12345", S("12345"));
+    test(S(""), 0, "1234567890", S("1234567890"));
+    test(S(""), 0, "12345678901234567890", S("12345678901234567890"));
+    test(S(""), 1, "", S("can't happen"));
+    test(S(""), 1, "12345", S("can't happen"));
+    test(S(""), 1, "1234567890", S("can't happen"));
+    test(S(""), 1, "12345678901234567890", S("can't happen"));
+    test(S("abcde"), 0, "", S("abcde"));
+    test(S("abcde"), 0, "12345", S("12345abcde"));
+    test(S("abcde"), 0, "1234567890", S("1234567890abcde"));
+    test(S("abcde"), 0, "12345678901234567890", S("12345678901234567890abcde"));
+    test(S("abcde"), 1, "", S("abcde"));
+    test(S("abcde"), 1, "12345", S("a12345bcde"));
+    test(S("abcde"), 1, "1234567890", S("a1234567890bcde"));
+    test(S("abcde"), 1, "12345678901234567890", S("a12345678901234567890bcde"));
+    test(S("abcde"), 2, "", S("abcde"));
+    test(S("abcde"), 2, "12345", S("ab12345cde"));
+    test(S("abcde"), 2, "1234567890", S("ab1234567890cde"));
+    test(S("abcde"), 2, "12345678901234567890", S("ab12345678901234567890cde"));
+    test(S("abcde"), 4, "", S("abcde"));
+    test(S("abcde"), 4, "12345", S("abcd12345e"));
+    test(S("abcde"), 4, "1234567890", S("abcd1234567890e"));
+    test(S("abcde"), 4, "12345678901234567890", S("abcd12345678901234567890e"));
+    test(S("abcde"), 5, "", S("abcde"));
+    test(S("abcde"), 5, "12345", S("abcde12345"));
+    test(S("abcde"), 5, "1234567890", S("abcde1234567890"));
+    test(S("abcde"), 5, "12345678901234567890", S("abcde12345678901234567890"));
+    test(S("abcde"), 6, "", S("can't happen"));
+    test(S("abcde"), 6, "12345", S("can't happen"));
+    test(S("abcde"), 6, "1234567890", S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", S("can't happen"));
+    test(S("abcdefghij"), 0, "", S("abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 1, "", S("abcdefghij"));
+    test(S("abcdefghij"), 1, "12345", S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 5, "", S("abcdefghij"));
+    test(S("abcdefghij"), 5, "12345", S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, "1234567890", S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 9, "", S("abcdefghij"));
+    test(S("abcdefghij"), 9, "12345", S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, "1234567890", S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 10, "", S("abcdefghij"));
+    test(S("abcdefghij"), 10, "12345", S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, "1234567890", S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, "12345678901234567890", S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 11, "", S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 20, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 21, "", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", S("can't happen"));
+  }
+#if TEST_STD_VER >= 11
+  {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S(""), 0, "", S(""));
+    test(S(""), 0, "12345", S("12345"));
+    test(S(""), 0, "1234567890", S("1234567890"));
+    test(S(""), 0, "12345678901234567890", S("12345678901234567890"));
+    test(S(""), 1, "", S("can't happen"));
+    test(S(""), 1, "12345", S("can't happen"));
+    test(S(""), 1, "1234567890", S("can't happen"));
+    test(S(""), 1, "12345678901234567890", S("can't happen"));
+    test(S("abcde"), 0, "", S("abcde"));
+    test(S("abcde"), 0, "12345", S("12345abcde"));
+    test(S("abcde"), 0, "1234567890", S("1234567890abcde"));
+    test(S("abcde"), 0, "12345678901234567890", S("12345678901234567890abcde"));
+    test(S("abcde"), 1, "", S("abcde"));
+    test(S("abcde"), 1, "12345", S("a12345bcde"));
+    test(S("abcde"), 1, "1234567890", S("a1234567890bcde"));
+    test(S("abcde"), 1, "12345678901234567890", S("a12345678901234567890bcde"));
+    test(S("abcde"), 2, "", S("abcde"));
+    test(S("abcde"), 2, "12345", S("ab12345cde"));
+    test(S("abcde"), 2, "1234567890", S("ab1234567890cde"));
+    test(S("abcde"), 2, "12345678901234567890", S("ab12345678901234567890cde"));
+    test(S("abcde"), 4, "", S("abcde"));
+    test(S("abcde"), 4, "12345", S("abcd12345e"));
+    test(S("abcde"), 4, "1234567890", S("abcd1234567890e"));
+    test(S("abcde"), 4, "12345678901234567890", S("abcd12345678901234567890e"));
+    test(S("abcde"), 5, "", S("abcde"));
+    test(S("abcde"), 5, "12345", S("abcde12345"));
+    test(S("abcde"), 5, "1234567890", S("abcde1234567890"));
+    test(S("abcde"), 5, "12345678901234567890", S("abcde12345678901234567890"));
+    test(S("abcde"), 6, "", S("can't happen"));
+    test(S("abcde"), 6, "12345", S("can't happen"));
+    test(S("abcde"), 6, "1234567890", S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", S("can't happen"));
+    test(S("abcdefghij"), 0, "", S("abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 1, "", S("abcdefghij"));
+    test(S("abcdefghij"), 1, "12345", S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 5, "", S("abcdefghij"));
+    test(S("abcdefghij"), 5, "12345", S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, "1234567890", S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 9, "", S("abcdefghij"));
+    test(S("abcdefghij"), 9, "12345", S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, "1234567890", S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 10, "", S("abcdefghij"));
+    test(S("abcdefghij"), 10, "12345", S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, "1234567890", S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, "12345678901234567890", S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 11, "", S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 20, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 21, "", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", S("can't happen"));
+  }
+#endif
+
+  { // test inserting into self
+    typedef std::string S;
+    S s_short = "123/";
+    S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+    s_short.insert(0, s_short.c_str());
+    assert(s_short == "123/123/");
+    s_short.insert(0, s_short.c_str());
+    assert(s_short == "123/123/123/123/");
+    s_short.insert(0, s_short.c_str());
+    assert(s_short == "123/123/123/123/123/123/123/123/");
+
+    s_long.insert(0, s_long.c_str());
+    assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  static_assert(test());
+#endif
+
+  return 0;
+}