chromium-dev/gcc-enable-lto.patch

Index: chromium-85.0.4183.69/build/config/BUILDCONFIG.gn
===================================================================
--- chromium-85.0.4183.69.orig/build/config/BUILDCONFIG.gn
+++ chromium-85.0.4183.69/build/config/BUILDCONFIG.gn
@@ -130,6 +130,8 @@ declare_args() {
   # separate flags.
   is_official_build = false
 
+  gcc_lto = false
+
   # Set to true when compiling with the Clang compiler.
   is_clang = current_os != "linux" ||
              (current_cpu != "s390x" && current_cpu != "s390" &&
@@ -441,6 +443,12 @@ default_compiler_configs = [
   "//build/config/sanitizers:default_sanitizer_flags",
 ]
 
+if (gcc_lto) {
+  default_compiler_configs += [
+    "//build/config/compiler:gcc_lto",
+  ]
+}
+
 if (is_win) {
   default_compiler_configs += [
     "//build/config/win:default_cfg_compiler",
Index: chromium-85.0.4183.69/build/config/compiler/BUILD.gn
===================================================================
--- chromium-85.0.4183.69.orig/build/config/compiler/BUILD.gn
+++ chromium-85.0.4183.69/build/config/compiler/BUILD.gn
@@ -1947,6 +1947,10 @@ if (is_win) {
   }
 }
 
+config("gcc_lto") {
+  cflags = [ "-flto" ]
+}
+
 config("default_stack_frames") {
   if (is_posix || is_fuchsia) {
     if (enable_frame_pointers) {
Index: chromium-85.0.4183.69/sandbox/linux/BUILD.gn
===================================================================
--- chromium-85.0.4183.69.orig/sandbox/linux/BUILD.gn
+++ chromium-85.0.4183.69/sandbox/linux/BUILD.gn
@@ -250,6 +250,9 @@ component("seccomp_bpf") {
     "//build:chromeos_buildflags",
     "//sandbox:sandbox_buildflags",
   ]
+  if (gcc_lto) {
+    configs -= [ "//build/config/compiler:gcc_lto" ]
+  }
 
   if (is_android) {
     sources += [
Index: chromium-96.0.4664.93/base/BUILD.gn
===================================================================     
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1986,6 +1986,10 @@
         ]
       }

+      if (gcc_lto) {
+        configs -= [ "//build/config/compiler:gcc_lto" ]
+      }
+
       if (current_cpu == "x64") {
         defines += [ "PA_PCSCAN_STACK_SUPPORTED" ]
         sources += [ "allocator/partition_allocator/starscan/stack/asm/x64/push_registers_asm.cc" ]