Add ar command in run-make-support

Cargo.lock

@@ -228,6 +228,12 @@ dependencies = [
  "backtrace",
 ]
 
+[[package]]
+name = "ar"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d67af77d68a931ecd5cbd8a3b5987d63a1d1d1278f7f6a60ae33db485cdebb69"
+
 [[package]]
 name = "ar_archive_writer"
 version = "0.2.0"
@@ -3394,6 +3400,7 @@ dependencies = [
 name = "run_make_support"
 version = "0.2.0"
 dependencies = [
+ "ar",
  "gimli 0.28.1",
  "object 0.34.0",
  "regex",

src/tools/run-make-support/Cargo.toml

@@ -9,3 +9,4 @@ similar = "2.5.0"
 wasmparser = "0.118.2"
 regex = "1.8" # 1.8 to avoid memchr 2.6.0, as 2.5.0 is pinned in the workspace
 gimli = "0.28.1"
+ar = "0.9.0"

src/tools/run-make-support/src/lib.rs

@@ -63,10 +63,15 @@ pub fn target() -> String {
 
 /// `AR`
 #[track_caller]
-#[must_use]
-pub fn ar_command() -> Command {
-    let ar_path = env_var("AR");
-    Command::new(ar_path)
+pub fn ar(inputs: &[impl AsRef<Path>], output_path: impl AsRef<Path>) {
+    let output = fs::File::create(&output_path).expect(&format!(
+        "the file in path \"{}\" could not be created",
+        output_path.as_ref().display()
+    ));
+    let mut builder = ar::Builder::new(output);
+    for input in inputs {
+        builder.append_path(input).unwrap();
+    }
 }
 
 /// Check if target is windows-like.

tests/run-make/invalid-library/rmake.rs

@@ -1,8 +1,8 @@
 use run_make_support::fs_wrapper::create_file;
-use run_make_support::{ar_command, rustc};
+use run_make_support::{ar, rustc};
 
 fn main() {
     create_file("lib.rmeta");
-    ar_command().arg("crus").arg("libfoo-ffffffff-1.0.rlib").arg("lib.rmeta").run();
+    ar(&["lib.rmeta"], "libfoo-ffffffff-1.0.rlib");
     rustc().input("foo.rs").run_fail().assert_stderr_contains("found invalid metadata");
 }