From 45083c49346259d44b607b5a0162d495df8d39ab Mon Sep 17 00:00:00 2001
From: David Major <dmajor@mozilla.com>
Date: Wed, 1 Aug 2018 17:59:23 -0400
Subject: [PATCH] Bug 1341525: Enable PGO in 64-bit clang-cl builds. r=froydnj

---
 Makefile.in                             |  4 ++++
 build/moz.configure/toolchain.configure | 25 +++++++++++++++++++++++--
 build/mozconfig.clang-cl                |  7 ++++++-
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index 21d5ad3e97215..ad3e84cd8e282 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -314,6 +314,10 @@ endif
 else
 ifdef CLANG_CL
 maybe_clobber_profiledbuild: clean
+# 32-bit PGO is currently blocked by bug 1479800
+ifeq ($(CPU_ARCH),x86_64)
+	$(LLVM_PROFDATA) merge -o $(DEPTH)/merged.profdata $(DEPTH)/*.profraw
+endif
 else
 maybe_clobber_profiledbuild:
 	$(RM) $(DIST)/bin/*.pgc
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 272547fe535f8..5d74de7d20bdf 100755
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -1240,10 +1240,14 @@ set_config('WRAP_SYSTEM_INCLUDES', wrap_system_includes)
 set_config('VISIBILITY_FLAGS', visibility_flags)
 
 
-@depends(c_compiler)
+@depends(c_compiler, check_build_environment, target)
 @imports('multiprocessing')
 @imports(_from='__builtin__', _import='min')
-def pgo_flags(compiler):
+def pgo_flags(compiler, build_env, target):
+    topobjdir = build_env.topobjdir
+    if topobjdir.endswith('/js/src'):
+        topobjdir = topobjdir[:-7]
+
     if compiler.type in ('gcc', 'clang'):
         return namespace(
             gen_cflags=['-fprofile-generate'],
@@ -1253,6 +1257,18 @@ def pgo_flags(compiler):
             use_ldflags=['-fprofile-use'],
         )
 
+    if compiler.type == 'clang-cl':
+        profdata = os.path.join(topobjdir, 'merged.profdata')
+        # 32-bit PGO is currently blocked by bug 1479800
+        if target.cpu == 'x86_64':
+          return namespace(
+              gen_cflags=['-fprofile-instr-generate'],
+              gen_ldflags=['clang_rt.profile-x86_64.lib'],
+              use_cflags=['-fprofile-instr-use=%s' % profdata,
+                          '-Wno-error=profile-instr-unprofiled'],
+              use_ldflags=[],
+          )
+
     if compiler.type == 'msvc':
         num_cores = min(8, multiprocessing.cpu_count())
         cgthreads = '-CGTHREADS:%s' % num_cores
@@ -1282,6 +1298,11 @@ set_config('PROFILE_GEN_LDFLAGS', pgo_flags.gen_ldflags)
 set_config('PROFILE_USE_CFLAGS', pgo_flags.use_cflags)
 set_config('PROFILE_USE_LDFLAGS', pgo_flags.use_ldflags)
 
+llvm_profdata = check_prog('LLVM_PROFDATA', ['llvm-profdata'],
+                           allow_missing=True)
+
+add_old_configure_assignment('LLVM_PROFDATA', llvm_profdata)
+
 
 @depends(c_compiler)
 def preprocess_option(compiler):
diff --git a/build/mozconfig.clang-cl b/build/mozconfig.clang-cl
index 3ab9401d2f930..4591b407ed1b3 100644
--- a/build/mozconfig.clang-cl
+++ b/build/mozconfig.clang-cl
@@ -1,8 +1,13 @@
 if test -d "$topsrcdir/clang/bin"; then
     CLANG_DIR=`cd "$topsrcdir/clang/bin" ; pwd`
     export PATH="${CLANG_DIR}:${PATH}"
-
     mk_export_correct_style PATH
+
+    if $(cd $topsrcdir/clang/lib/clang/* && test -d lib/windows); then
+        CLANG_LIB_DIR="$(cd $topsrcdir/clang/lib/clang/* && cd lib/windows && pwd)"
+        export LIB=$LIB:$CLANG_LIB_DIR
+        mk_export_correct_style LIB
+    fi
 fi
 
 export CC=clang-cl