Fix review comments and other improvements

compiler/rustc_codegen_llvm/src/back/archive.rs

@@ -108,8 +108,8 @@ impl ArchiveBuilderBuilder for LlvmArchiveBuilderBuilder {
  fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a> {
  // Keeping LlvmArchiveBuilder around in case of a regression caused by using
  // ArArchiveBuilder.
- // FIXME remove a couple of months after #128936 gets merged in case no
- // regression is found.
+ // FIXME(#128955) remove a couple of months after #128936 gets merged in case
+ // no regression is found.
  if false {
  Box::new(LlvmArchiveBuilder { sess, additions: Vec::new() })
  } else {

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -308,10 +308,8 @@ impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
  .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
  if !skip(&file_name) {
  if entry.is_thin() {
- self.entries.push((
- file_name.clone().into_bytes(),
- ArchiveEntry::File(PathBuf::from(file_name)),
- ));
+ let member_path = archive_path.parent().unwrap().join(Path::new(&file_name));
+ self.entries.push((file_name.into_bytes(), ArchiveEntry::File(member_path)));
  } else {
  self.entries.push((
  file_name.into_bytes(),

tests/run-make/staticlib-thin-archive/bin.rs

@@ -1,10 +1,5 @@
-#[link(name = "rust_archive", kind = "static")]
-extern "C" {
- fn simple_fn();
-}
-
 fn main() {
  unsafe {
- simple_fn();
+ rust_lib::simple_fn();
  }
 }

tests/run-make/staticlib-thin-archive/rmake.rs

@@ -1,13 +1,28 @@
-// Regression test for https:/rust-lang/rust/issues/107407
+// Regression test for https:/rust-lang/rust/issues/107407 which
+// checks that rustc can read thin archive. Before the object crate added thin
+// archive support rustc would add emit object files to the staticlib and after
+// the object crate added thin archive support it would previously crash the
+// compiler due to a missing special case for thin archive members.
+use std::path::Path;
 
-use run_make_support::{llvm_ar, rustc, static_lib_name};
+use run_make_support::{llvm_ar, rust_lib_name, rustc, static_lib_name};
 
 fn main() {
- rustc().input("simple_obj.rs").emit("obj").run();
- llvm_ar().obj_to_thin_ar().output_input(static_lib_name("thin_archive"), "simple_obj.o").run();
- rustc().input("rust_archive.rs").run();
- // Disable lld as it ignores the symbol table in the archive file.
- rustc()
- .input("bin.rs") /*.arg("-Zlinker-features=-lld")*/
+ std::fs::create_dir("archive").unwrap();
+
+ // Build a thin archive
+ rustc().input("simple_obj.rs").emit("obj").output("archive/simple_obj.o").run();
+ llvm_ar()
+ .obj_to_thin_ar()
+ .output_input(
+ Path::new("archive").join(static_lib_name("thin_archive")),
+ "archive/simple_obj.o",
+ )
  .run();
+
+ // Build an rlib which includes the members of this thin archive
+ rustc().input("rust_lib.rs").library_search_path("archive").run();
+
+ // Build a binary which requires a symbol from the thin archive
+ rustc().input("bin.rs").extern_("rust_lib", rust_lib_name("rust_lib")).run();
 }

tests/run-make/staticlib-thin-archive/rust_lib.rs

@@ -0,0 +1,6 @@
+#![crate_type = "rlib"]
+
+#[link(name = "thin_archive", kind = "static")]
+extern "C" {
+ pub fn simple_fn();
+}