--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mozilla-pgo.patch Sun Dec 27 10:49:49 2020 +0100
@@ -0,0 +1,225 @@
+# HG changeset patch
+# User Wolfgang Rosenauer <wr@rosenauer.org>
+# Parent 431962e810598b34327620fb99e06768e9a29c38
+
+diff --git a/build/moz.configure/lto-pgo.configure b/build/moz.configure/lto-pgo.configure
+--- a/build/moz.configure/lto-pgo.configure
++++ b/build/moz.configure/lto-pgo.configure
+@@ -223,23 +223,23 @@ def lto(value, c_compiler, ld64_known_go
+ "configure."
+ )
+
+ if c_compiler.type == "clang":
+ if len(value) and value[0].lower() == "full":
+ cflags.append("-flto")
+ ldflags.append("-flto")
+ else:
+- cflags.append("-flto=thin")
+- ldflags.append("-flto=thin")
++ cflags.append("-flto")
++ ldflags.append("-flto")
+ elif c_compiler.type == "clang-cl":
+ if len(value) and value[0].lower() == "full":
+ cflags.append("-flto")
+ else:
+- cflags.append("-flto=thin")
++ cflags.append("-flto")
+ # With clang-cl, -flto can only be used with -c or -fuse-ld=lld.
+ # AC_TRY_LINKs during configure don't have -c, so pass -fuse-ld=lld.
+ cflags.append("-fuse-ld=lld")
+
+ # Explicitly set the CPU to optimize for so the linker doesn't
+ # choose a poor default. Rust compilation by default uses the
+ # pentium4 CPU on x86:
+ #
+@@ -263,17 +263,17 @@ def lto(value, c_compiler, ld64_known_go
+ ldflags.append("-mllvm:-mcpu=x86-64")
+ # We do not need special flags for arm64. Hooray for fixed-length
+ # instruction sets.
+ else:
+ num_cores = multiprocessing.cpu_count()
+ if len(value) and value[0].lower() == "full":
+ cflags.append("-flto")
+ else:
+- cflags.append("-flto=thin")
++ cflags.append("-flto")
+ cflags.append("-flifetime-dse=1")
+
+ ldflags.append("-flto=%s" % num_cores)
+ ldflags.append("-flifetime-dse=1")
+
+ # Tell LTO not to inline functions above a certain size, to mitigate
+ # binary size growth while still getting good performance.
+ # (For hot functions, PGO will put a multiplier on this limit.)
+diff --git a/build/pgo/profileserver.py b/build/pgo/profileserver.py
+--- a/build/pgo/profileserver.py
++++ b/build/pgo/profileserver.py
+@@ -6,17 +6,17 @@
+
+ import json
+ import os
+ import sys
+ import glob
+ import subprocess
+
+ import mozcrash
+-from mozbuild.base import MozbuildObject, BinaryNotFoundException
++from mozbuild.base import MozbuildObject, BinaryNotFoundException, BuildEnvironmentNotFoundException
+ from mozfile import TemporaryDirectory
+ from mozhttpd import MozHttpd
+ from mozprofile import FirefoxProfile, Preferences
+ from mozprofile.permissions import ServerLocations
+ from mozrunner import FirefoxRunner, CLI
+ from six import string_types
+
+ PORT = 8888
+@@ -82,19 +82,32 @@ if __name__ == "__main__":
+ docroot=os.path.join(build.topsrcdir, "build", "pgo"),
+ path_mappings=path_mappings,
+ )
+ httpd.start(block=False)
+
+ locations = ServerLocations()
+ locations.add_host(host="127.0.0.1", port=PORT, options="primary,privileged")
+
+- old_profraw_files = glob.glob("*.profraw")
+- for f in old_profraw_files:
+- os.remove(f)
++ using_gcc = False
++ try:
++ if build.config_environment.substs.get('CC_TYPE') == 'gcc':
++ using_gcc = True
++ except BuildEnvironmentNotFoundException:
++ pass
++
++ if using_gcc:
++ for dirpath, _, filenames in os.walk('.'):
++ for f in filenames:
++ if f.endswith('.gcda'):
++ os.remove(os.path.join(dirpath, f))
++ else:
++ old_profraw_files = glob.glob('*.profraw')
++ for f in old_profraw_files:
++ os.remove(f)
+
+ with TemporaryDirectory() as profilePath:
+ # TODO: refactor this into mozprofile
+ profile_data_dir = os.path.join(build.topsrcdir, "testing", "profiles")
+ with open(os.path.join(profile_data_dir, "profiles.json"), "r") as fh:
+ base_profiles = json.load(fh)["profileserver"]
+
+ prefpaths = [
+@@ -207,16 +220,20 @@ if __name__ == "__main__":
+
+ # Try to move the crash reports to the artifacts even if Firefox appears
+ # to exit successfully, in case there's a crash that doesn't set the
+ # return code to non-zero for some reason.
+ if get_crashreports(profilePath, name="Firefox exited successfully?") != 0:
+ print("Firefox exited successfully, but produced a crashreport")
+ sys.exit(1)
+
++ print('Copying profile data....')
++ os.system('pwd');
++ os.system('tar cf profdata.tar.gz `find . -name "*.gcda"`; cd ..; tar xf instrumented/profdata.tar.gz;');
++
+ llvm_profdata = env.get("LLVM_PROFDATA")
+ if llvm_profdata:
+ profraw_files = glob.glob("*.profraw")
+ if not profraw_files:
+ print(
+ "Could not find profraw files in the current directory: %s"
+ % os.getcwd()
+ )
+diff --git a/build/unix/mozconfig.unix b/build/unix/mozconfig.unix
+--- a/build/unix/mozconfig.unix
++++ b/build/unix/mozconfig.unix
+@@ -1,16 +1,25 @@
+ . "$topsrcdir/build/mozconfig.common"
+
+ TOOLTOOL_DIR=${TOOLTOOL_DIR:-$topsrcdir}
+
+ if [ -n "$FORCE_GCC" ]; then
+ CC="$MOZ_FETCHES_DIR/gcc/bin/gcc"
+ CXX="$MOZ_FETCHES_DIR/gcc/bin/g++"
+
++ if [ -n "$MOZ_PGO" ]; then
++ if [ -z "$USE_ARTIFACT" ]; then
++ ac_add_options --enable-lto
++ fi
++ export AR="$topsrcdir/gcc/bin/gcc-ar"
++ export NM="$topsrcdir/gcc/bin/gcc-nm"
++ export RANLIB="$topsrcdir/gcc/bin/gcc-ranlib"
++ fi
++
+ # We want to make sure we use binutils and other binaries in the tooltool
+ # package.
+ mk_add_options "export PATH=$MOZ_FETCHES_DIR/gcc/bin:$PATH"
+ ac_add_options --with-clang-path=$MOZ_FETCHES_DIR/clang/bin/clang
+ else
+ CC="$MOZ_FETCHES_DIR/clang/bin/clang"
+ CXX="$MOZ_FETCHES_DIR/clang/bin/clang++"
+
+diff --git a/extensions/spellcheck/src/moz.build b/extensions/spellcheck/src/moz.build
+--- a/extensions/spellcheck/src/moz.build
++++ b/extensions/spellcheck/src/moz.build
+@@ -26,8 +26,10 @@ LOCAL_INCLUDES += [
+ ]
+ EXPORTS.mozilla += [
+ "mozInlineSpellChecker.h",
+ "mozSpellChecker.h",
+ ]
+
+ if CONFIG["CC_TYPE"] in ("clang", "gcc"):
+ CXXFLAGS += ["-Wno-error=shadow"]
++
++CXXFLAGS += ['-fno-devirtualize']
+diff --git a/python/mozbuild/mozbuild/build_commands.py b/python/mozbuild/mozbuild/build_commands.py
+--- a/python/mozbuild/mozbuild/build_commands.py
++++ b/python/mozbuild/mozbuild/build_commands.py
+@@ -121,19 +121,18 @@ class Build(MachCommandBase):
+ silent=not verbose,
+ ensure_exit_code=False,
+ append_env=append_env,
+ )
+ if status != 0:
+ return status
+
+ pgo_env = os.environ.copy()
+- pgo_env["LLVM_PROFDATA"] = instr.config_environment.substs.get(
+- "LLVM_PROFDATA"
+- )
++ if instr.config_environment.substs.get('CC_TYPE') != 'gcc':
++ pgo_env["LLVM_PROFDATA"] = instr.config_environment.substs.get("LLVM_PROFDATA")
+ pgo_env["JARLOG_FILE"] = mozpath.join(orig_topobjdir, "jarlog/en-US.log")
+ pgo_cmd = [
+ instr.virtualenv_manager.python_path,
+ mozpath.join(self.topsrcdir, "build/pgo/profileserver.py"),
+ ]
+ subprocess.check_call(
+ pgo_cmd, cwd=instr.topobjdir, env=ensure_subprocess_env(pgo_env)
+ )
+diff --git a/toolkit/components/terminator/nsTerminator.cpp b/toolkit/components/terminator/nsTerminator.cpp
+--- a/toolkit/components/terminator/nsTerminator.cpp
++++ b/toolkit/components/terminator/nsTerminator.cpp
+@@ -413,16 +413,21 @@ void nsTerminator::StartWatchdog() {
+ // Defend against overflow
+ crashAfterMS = INT32_MAX;
+ } else {
+ crashAfterMS *= scaleUp;
+ }
+ }
+ #endif
+
++ // Disable watchdog for PGO train builds - writting profile information at
++ // exit may take time and it is better to make build hang rather than
++ // silently produce poorly performing binary.
++ crashAfterMS = INT32_MAX;
++
+ UniquePtr<Options> options(new Options());
+ const PRIntervalTime ticksDuration = PR_MillisecondsToInterval(1000);
+ options->crashAfterTicks = crashAfterMS / ticksDuration;
+ // Handle systems where ticksDuration is greater than crashAfterMS.
+ if (options->crashAfterTicks == 0) {
+ options->crashAfterTicks = crashAfterMS / 1000;
+ }
+