From 00a79dac63e869fbd81f082b39b7c6e226bef395 Mon Sep 17 00:00:00 2001
From: Alexander David Frick <Alex313031@gmail.com>
Date: Thu, 16 Dec 2021 06:20:03 -0600
Subject: [PATCH] Update BUILD.gn

---
 build/config/compiler/BUILD.gn | 44 ++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 7894edae..e8312419 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -129,8 +129,8 @@ declare_args() {
   # TODO(gbiv): We disable optimizations by default on most platforms because
   # the space overhead is too great. We should use some mixture of profiles and
   # optimization settings to better tune the size increase.
-  thin_lto_enable_optimizations =
-      (is_chromeos_ash || is_android || is_win || is_linux) && is_official_build
+  thin_lto_enable_optimizations = (is_chromeos_ash || is_android || is_win ||
+                                   is_linux || is_mac) && is_official_build
 
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
@@ -586,7 +586,6 @@ config("compiler") {
     }
 
     cflags_c += [ "-std=${standard_prefix}11" ]
-
     if (is_nacl && !is_nacl_saigo) {
       # This is for the pnacl_newlib toolchain. It's only used to build
       # a few independent ppapi test files that don't pull in any other
@@ -655,10 +654,11 @@ config("compiler") {
   if (!is_debug && use_thin_lto && is_a_target_toolchain) {
     assert(use_lld, "LTO is only supported with lld")
 
-    cflags += [
-      "-flto=thin",
-      "-fsplit-lto-unit",
-    ]
+    cflags += [ "-flto=thin" ]
+    if (!is_mac) {
+      # TODO(lgrey): Enable unit splitting for Mac when supported.
+      cflags += [ "-fsplit-lto-unit" ]
+    }
 
     # Limit the size of the ThinLTO cache to the lesser of 10% of
     # available disk space, 40GB and 100000 files.
@@ -673,7 +673,7 @@ config("compiler") {
         "/opt:lldltojobs=all",
         "-mllvm:-import-instr-limit=$import_instr_limit",
         # "/lldltocache:" +
-            # rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
+        #    rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
         # "/lldltocachepolicy:$cache_policy",
       ]
     } else {
@@ -692,6 +692,10 @@ config("compiler") {
         ldflags +=
             [ "-Wl,-cache_path_lto," +
               rebase_path("$root_out_dir/thinlto-cache", root_build_dir) ]
+      } else {
+        ldflags +=
+            # [ "-Wl,--thinlto-cache-dir=" +
+            #  rebase_path("$root_out_dir/thinlto-cache", root_build_dir) ]
       }
 
       # ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
@@ -1911,16 +1915,16 @@ if (is_win) {
   ]
 
   common_optimize_on_ldflags += [
-    "-mllvm:-extra-vectorizer-passes",
-    "-mllvm:-enable-cond-stores-vec",
-    "-mllvm:-slp-vectorize-hor-store",
-    "-mllvm:-enable-loopinterchange",
-    "-mllvm:-enable-loop-distribute",
-    "-mllvm:-enable-unroll-and-jam",
-    "-mllvm:-enable-loop-flatten",
-    "-mllvm:-interleave-small-loop-scalar-reduction",
-    "-mllvm:-unroll-runtime-multi-exit",
-    "-mllvm:-aggressive-ext-opt",
+    "-Wl,-mllvm,-extra-vectorizer-passes",
+    "-Wl,-mllvm,-enable-cond-stores-vec",
+    "-Wl,-mllvm,-slp-vectorize-hor-store",
+    "-Wl,-mllvm,-enable-loopinterchange",
+    "-Wl,-mllvm,-enable-loop-distribute",
+    "-Wl,-mllvm,-enable-unroll-and-jam",
+    "-Wl,-mllvm,-enable-loop-flatten",
+    "-Wl,-mllvm,-interleave-small-loop-scalar-reduction",
+    "-Wl,-mllvm,-unroll-runtime-multi-exit",
+    "-Wl,-mllvm,-aggressive-ext-opt",
   ]
 
   # /OPT:ICF is not desirable in Debug builds, since code-folding can result in
@@ -1936,7 +1940,7 @@ if (is_win) {
 } else {
   common_optimize_on_cflags = []
   common_optimize_on_ldflags = []
-
+  
   common_optimize_on_cflags += [
     "-mllvm", "-extra-vectorizer-passes",
     "-mllvm", "-enable-cond-stores-vec",
@@ -2175,7 +2179,7 @@ config("optimize_speed") {
 
 config("optimize_fuzzing") {
   cflags = [ "-O1" ] + common_optimize_on_cflags
-  rustflags = [ "-Copt-level=1" ]
+  rustflags = [ "-Copt-level=3" ]
   ldflags = common_optimize_on_ldflags
   visibility = [ ":default_optimization" ]
 }