Mac: set -obj_path_lto when building with LTO
This temporarily saves intermediate object files (other than cache hits
which are already persisted in the cache directory) so that `dsymutil`
can read the debug info out of them.
This change also adds an argument to linker_driver.py to clean this
directory up after `dsymutil` has run. I'm not sure this is the best
way to do it, so very open to other suggestions.
Bug: 1324104
Change-Id: I001e19b9824ff8bf969c5b713a3e0dbed52e5df5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3650843
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1004779}
NOKEYCHECK=True
GitOrigin-RevId: fb34ab468f55c8c383b31b341544627cb97efb25
diff --git a/compiler/BUILD.gn b/compiler/BUILD.gn
index c90821e..1817f17 100644
--- a/compiler/BUILD.gn
+++ b/compiler/BUILD.gn
@@ -680,9 +680,16 @@
# of "all" which means number of hardware threads) is faster.
ldflags += [ "-Wl,--thinlto-jobs=all" ]
if (is_apple) {
- ldflags +=
- [ "-Wl,-cache_path_lto," +
- rebase_path("$root_out_dir/thinlto-cache", root_build_dir) ]
+ # TODO(lgrey): Remove if/when we start running `dsymutil` through the
+ # clang driver. See https://crbug.com/1324104
+ object_path_lto =
+ rebase_path("$root_out_dir/lto-objects", root_build_dir)
+ ldflags += [
+ "-Wl,-cache_path_lto," +
+ rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
+ "-Wl,-object_path_lto,$object_path_lto",
+ "-Wcrl,clean_object_path_lto,$object_path_lto",
+ ]
} else {
ldflags +=
[ "-Wl,--thinlto-cache-dir=" +
