Add missing functions in bionic

2025-09-06 06:36:58 +00:00 · 2019-06-23 14:54:48 -07:00
parent 4cc7aced15
commit 28cd6a75e7
7 changed files with 221 additions and 100 deletions
--- a/native/jni/utils/missing.cpp
+++ b/native/jni/utils/missing.cpp
@@ -0,0 +1,139 @@
+/*
+ * Host all missing/incomplete implementation in bionic
+ * Copied from various sources
+ * */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <mntent.h>
+
+#include "missing.h"
+
+/* Original source: https://opensource.apple.com/source/cvs/cvs-19/cvs/lib/getline.c
+ * License: GPL 2 or later
+ * Adjusted to match POSIX */
+#define MIN_CHUNK 64
+ssize_t __getdelim(char **lineptr, size_t *n, int delim, FILE *stream) {
+	size_t nchars_avail;
+	char *read_pos;
+
+	if (!lineptr || !n || !stream) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (!*lineptr) {
+		*n = MIN_CHUNK;
+		*lineptr = (char *) malloc(*n);
+		if (!*lineptr) {
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+
+	nchars_avail = *n;
+	read_pos = *lineptr;
+
+	for (;;) {
+		int save_errno;
+		int c = getc(stream);
+
+		save_errno = errno;
+
+		if (nchars_avail < 2) {
+			if (*n > MIN_CHUNK)
+				*n *= 2;
+			else
+				*n += MIN_CHUNK;
+
+			nchars_avail = *n + *lineptr - read_pos;
+			*lineptr = (char *) realloc(*lineptr, *n);
+			if (!*lineptr) {
+				errno = ENOMEM;
+				return -1;
+			}
+			read_pos = *n - nchars_avail + *lineptr;
+		}
+
+		if (ferror(stream)) {
+			errno = save_errno;
+			return -1;
+		}
+
+		if (c == EOF) {
+			if (read_pos == *lineptr)
+				return -1;
+			else
+				break;
+		}
+
+		*read_pos++ = c;
+		nchars_avail--;
+
+		if (c == delim)
+			break;
+	}
+
+	*read_pos = '\0';
+
+	return read_pos - *lineptr;
+}
+
+ssize_t __getline(char **lineptr, size_t *n, FILE *stream) {
+	return getdelim(lineptr, n, '\n', stream);
+}
+
+/* mntent functions are copied from AOSP libc/bionic/mntent.cpp */
+
+struct mntent *__getmntent_r(FILE* fp, struct mntent* e, char* buf, int buf_len) {
+	memset(e, 0, sizeof(*e));
+	while (fgets(buf, buf_len, fp) != nullptr) {
+		// Entries look like "proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0".
+		// That is: mnt_fsname mnt_dir mnt_type mnt_opts 0 0.
+		int fsname0, fsname1, dir0, dir1, type0, type1, opts0, opts1;
+		if (sscanf(buf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
+				   &fsname0, &fsname1, &dir0, &dir1, &type0, &type1, &opts0, &opts1,
+				   &e->mnt_freq, &e->mnt_passno) == 2) {
+			e->mnt_fsname = &buf[fsname0];
+			buf[fsname1] = '\0';
+			e->mnt_dir = &buf[dir0];
+			buf[dir1] = '\0';
+			e->mnt_type = &buf[type0];
+			buf[type1] = '\0';
+			e->mnt_opts = &buf[opts0];
+			buf[opts1] = '\0';
+			return e;
+		}
+	}
+	return nullptr;
+}
+
+FILE *__setmntent(const char* path, const char* mode) {
+	return fopen(path, mode);
+}
+
+int __endmntent(FILE* fp) {
+	if (fp != nullptr) {
+		fclose(fp);
+	}
+	return 1;
+}
+
+char *__hasmntopt(const struct mntent* mnt, const char* opt) {
+	char* token = mnt->mnt_opts;
+	char* const end = mnt->mnt_opts + strlen(mnt->mnt_opts);
+	const size_t optLen = strlen(opt);
+	while (token) {
+		char* const tokenEnd = token + optLen;
+		if (tokenEnd > end) break;
+		if (memcmp(token, opt, optLen) == 0 &&
+			(*tokenEnd == '\0' || *tokenEnd == ',' || *tokenEnd == '=')) {
+			return token;
+		}
+		token = strchr(token, ',');
+		if (token) token++;
+	}
+	return nullptr;
+}
+