Switch rustup_wrapper to Rust implementation

For better Windows portability

tools/rustup_wrapper/src/main.rs

@@ -0,0 +1,43 @@
+use std::env;
+use std::process::{Command, Stdio};
+
+use home::cargo_home;
+
+/********************************
+ * Why do we need this wrapper?
+ ********************************
+ *
+ * The command `rustup component list` does not work with custom toolchains:
+ * > error: toolchain 'magisk' does not support components
+ *
+ * However, this command is used by several IDEs to determine available
+ * components that can be used, such as clippy, rustfmt etc.
+ * In this script, we simply redirect the output when using the nightly
+ * channel if any `component` command failed.
+*/
+
+fn main() -> std::io::Result<()> {
+    let rustup = cargo_home()?.join("bin").join("rustup");
+    let argv: Vec<String> = env::args().skip(1).collect();
+
+    if argv.iter().any(|s| s == "component") {
+        let status = Command::new(&rustup)
+            .args(&argv)
+            .stdout(Stdio::null())
+            .stderr(Stdio::null())
+            .status()?;
+        if !status.success() {
+            let mut cmd = Command::new(&rustup);
+            cmd.arg("+nightly");
+            if argv[0].starts_with('+') {
+                cmd.args(argv.iter().skip(1));
+            } else {
+                cmd.args(&argv);
+            }
+            return cmd.status().map(|_| ());
+        }
+    }
+
+    // Simply pass through
+    Command::new(&rustup).args(argv.iter()).status().map(|_| ())
+}