Add leading underscore to asm symbols on Mach-O

[CathalMullan]

Fixes the linking error mentioned in ctz/graviola#127 (comment)

Tested manually on a M1 host.

[bjorn3]

Thanks!

View changes since this review

[bjorn3]

How long do a from-scratch cargo build and cargo test take for graviola? If it is fairly short (ideally <1min), maybe it could be added to CI?

[CathalMullan]

Yeah, should take less than a minute to run the lib tests.

[bjorn3]

If you want to work on adding it to CI, you can add it to https://github.com/rust-lang/rustc_codegen_cranelift/blob/main/build_system/tests.rs

The git repo and cargo project are defined like

rustc_codegen_cranelift/build_system/tests.rs

Lines 134 to 142 in e722ae6

	pub(crate) static REGEX_REPO: GitRepo = GitRepo::github(
	"rust-lang",
	"regex",
	"061ee815ef2c44101dba7b0b124600fcb03c1912",
	"dc26aefbeeac03ca",
	"regex",
	);
	static REGEX: CargoProject = CargoProject::new(REGEX_REPO.source_dir(), "regex_target");

and should be added after

rustc_codegen_cranelift/build_system/prepare.rs

Line 13 in e722ae6

crate::tests::REGEX_REPO.fetch(dirs);

The actual test instructions should be added to

rustc_codegen_cranelift/build_system/tests.rs

Lines 152 to 224 in e722ae6

	const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
	TestCase::custom("test.rust-random/rand", &|runner| {
	RAND_REPO.patch(&runner.dirs);
	RAND.clean(&runner.dirs);
	if runner.is_native {
	let mut test_cmd = RAND.test(&runner.target_compiler, &runner.dirs);
	test_cmd.arg("--workspace").arg("--").arg("-q");
	spawn_and_wait(test_cmd);
	} else {
	eprintln!("Cross-Compiling: Not running tests");
	let mut build_cmd = RAND.build(&runner.target_compiler, &runner.dirs);
	build_cmd.arg("--workspace").arg("--tests");
	spawn_and_wait(build_cmd);
	}
	}),
	TestCase::custom("test.regex", &|runner| {
	REGEX_REPO.patch(&runner.dirs);
	REGEX.clean(&runner.dirs);
	if runner.is_native {
	let mut run_cmd = REGEX.test(&runner.target_compiler, &runner.dirs);
	// regex-capi and regex-debug don't have any tests. Nor do they contain any code
	// that is useful to test with cg_clif. Skip building them to reduce test time.
	run_cmd.args([
	"-p",
	"regex",
	"-p",
	"regex-syntax",
	"--release",
	"--all-targets",
	"--",
	"-q",
	]);
	spawn_and_wait(run_cmd);
	let mut run_cmd = REGEX.test(&runner.target_compiler, &runner.dirs);
	// don't run integration tests for regex-autonata. they take like 2min each without
	// much extra coverage of simd usage.
	run_cmd.args(["-p", "regex-automata", "--release", "--lib", "--", "-q"]);
	spawn_and_wait(run_cmd);
	} else {
	eprintln!("Cross-Compiling: Not running tests");
	let mut build_cmd = REGEX.build(&runner.target_compiler, &runner.dirs);
	build_cmd.arg("--tests");
	spawn_and_wait(build_cmd);
	}
	}),
	TestCase::custom("test.portable-simd", &|runner| {
	apply_patches(
	&runner.dirs,
	"portable-simd",
	&runner.stdlib_source.join("library/portable-simd"),
	&PORTABLE_SIMD_SRC.to_path(&runner.dirs),
	);
	PORTABLE_SIMD.clean(&runner.dirs);
	let build_cmd = PORTABLE_SIMD.build(&runner.target_compiler, &runner.dirs);
	// FIXME uncomment once examples work: https://github.com/rust-lang/portable-simd/issues/470
	//build_cmd.arg("--all-targets");
	spawn_and_wait(build_cmd);
	if runner.is_native {
	let mut test_cmd = PORTABLE_SIMD.test(&runner.target_compiler, &runner.dirs);
	// FIXME remove --tests once examples work: https://github.com/rust-lang/portable-simd/issues/470
	test_cmd.arg("-q").arg("--tests");
	spawn_and_wait(test_cmd);
	}
	}),
	];

and finally it should be added to

rustc_codegen_cranelift/config.txt

Lines 36 to 39 in e722ae6

	testsuite.extended_sysroot
	test.rust-random/rand
	test.regex
	test.portable-simd

to enable the test.

Alternatively I may have time to add it somewhere in the coming days.