From 6ed1173d9a3090387e51a6db712091b9f08afc33 Mon Sep 17 00:00:00 2001
From: Richard Howell <rhow@meta.com>
Date: Thu, 10 Oct 2024 10:37:20 -0700
Subject: [PATCH] add dsym_uses_parallel_linker

Summary: Add the `dsym_uses_parallel_linker` attribute to be able to enable parallel dSYM generation for improved performance and reduced output size.

Reviewed By: maxovtsin

Differential Revision: D64131359

fbshipit-source-id: 5dd85aa3435cbecc544e9947a086518dfa9bb433
---
 prelude/apple/apple_dsym.bzl               | 17 ++++++++++-------
 prelude/apple/apple_rules_impl_utility.bzl |  1 +
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/prelude/apple/apple_dsym.bzl b/prelude/apple/apple_dsym.bzl
index 3bbf5180b914..f0726af1bea3 100644
--- a/prelude/apple/apple_dsym.bzl
+++ b/prelude/apple/apple_dsym.bzl
@@ -21,27 +21,30 @@ def get_apple_dsym(ctx: AnalysisContext, executable: Artifact, debug_info: list[
 def get_apple_dsym_ext(ctx: AnalysisContext, executable: [ArgLike, Artifact], debug_info: list[ArgLike], action_identifier: str, output_path: str) -> Artifact:
     dsymutil = ctx.attrs._apple_toolchain[AppleToolchainInfo].dsymutil
     output = ctx.actions.declare_output(output_path, dir = True)
-
     cmd = cmd_args(
         [
             dsymutil,
             "--verify-dwarf={}".format(ctx.attrs._dsymutil_verify_dwarf),
             # Reproducers are not useful, we can reproduce from the action digest.
             "--reproducer=Off",
-        ] + ctx.attrs._dsymutil_extra_flags + [
-            "-o",
-            output.as_output(),
         ],
-        executable,
         # Mach-O executables don't contain DWARF data.
         # Instead, they contain paths to the object files which themselves contain DWARF data.
-        #
         # So, those object files are needed for dsymutil to be to create the dSYM bundle.
         hidden = debug_info,
     )
+    if ctx.attrs.dsym_uses_parallel_linker:
+        cmd.add("--linker=parallel")
 
+    cmd.add(ctx.attrs._dsymutil_extra_flags)
+    cmd.add(
+        [
+            "-o",
+            output.as_output(),
+            executable,
+        ],
+    )
     ctx.actions.run(cmd, category = "apple_dsym", identifier = action_identifier)
-
     return output
 
 def get_apple_dsym_info_json(binary_dsyms: list[Artifact], dep_dsyms: list[Artifact]) -> dict[str, typing.Any]:
diff --git a/prelude/apple/apple_rules_impl_utility.bzl b/prelude/apple/apple_rules_impl_utility.bzl
index 48de586122b8..b1f14f0ec845 100644
--- a/prelude/apple/apple_rules_impl_utility.bzl
+++ b/prelude/apple/apple_rules_impl_utility.bzl
@@ -66,6 +66,7 @@ APPLE_VALIDATION_DEPS_ATTR_TYPE = attrs.set(attrs.dep(), sorted = True, default
 
 def apple_dsymutil_attrs():
     return {
+        "dsym_uses_parallel_linker": attrs.bool(default = False),
         "_dsymutil_extra_flags": attrs.list(attrs.string()),
         "_dsymutil_verify_dwarf": attrs.string(),
     }