clang: Link lld against tcmalloc.

tools/clang/scripts/update.py

Index: tools/clang/scripts/update.py
diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
index e7abcb704bca7bf7335005c6bfce08b61ee05717..75a5c0e376f26e36cf4d229735227676501a7c52 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -34,7 +34,7 @@ if use_head_revision:
   CLANG_REVISION = 'HEAD'
 
 # This is incremented when pushing a new build of Clang at the same revision.
-CLANG_SUB_REVISION=1
+CLANG_SUB_REVISION=2
 
 PACKAGE_VERSION = "%s-%s" % (CLANG_REVISION, CLANG_SUB_REVISION)
 
@@ -66,11 +66,10 @@ LLVM_BUILD_TOOLS_DIR = os.path.abspath(
     os.path.join(LLVM_DIR, '..', 'llvm-build-tools'))
 STAMP_FILE = os.path.normpath(
     os.path.join(LLVM_DIR, '..', 'llvm-build', 'cr_build_revision'))
-BINUTILS_DIR = os.path.join(THIRD_PARTY_DIR, 'binutils')
-BINUTILS_BIN_DIR = os.path.join(BINUTILS_DIR, BINUTILS_DIR,
-                                'Linux_x64', 'Release', 'bin')
-BFD_PLUGINS_DIR = os.path.join(BINUTILS_DIR, 'Linux_x64', 'Release',
-                               'lib', 'bfd-plugins')
+BINUTILS_DIR = os.path.join(THIRD_PARTY_DIR, 'binutils', 'Linux_x64', 'Release')
+BINUTILS_BIN_DIR = os.path.join(BINUTILS_DIR, 'bin')
+BINUTILS_LIB_DIR = os.path.join(BINUTILS_DIR, 'lib')
+BFD_PLUGINS_DIR = os.path.join(BINUTILS_LIB_DIR, 'bfd-plugins')
 VERSION = '5.0.0'
 ANDROID_NDK_DIR = os.path.join(
     CHROMIUM_DIR, 'third_party', 'android_tools', 'ndk')
@@ -503,7 +502,7 @@ def UpdateClang(args):
 
   binutils_incdir = ''
   if sys.platform.startswith('linux'):
-    binutils_incdir = os.path.join(BINUTILS_DIR, 'Linux_x64/Release/include')
+    binutils_incdir = os.path.join(BINUTILS_DIR, 'include')
 
   if args.bootstrap:
     print 'Building bootstrap compiler'
@@ -565,6 +564,11 @@ def UpdateClang(args):
                 os.path.join(LLVM_BOOTSTRAP_INSTALL_DIR, 'lib', 'LLVMgold.so'),
                 os.path.join(BFD_PLUGINS_DIR, 'LLVMgold.so')])
 
+    # Link against binutils's copy of tcmalloc to speed up the linker by ~10%.
+    tcmalloc_ldflags = [
+        '-L' + BINUTILS_LIB_DIR, '-ltcmalloc_minimal',
+        '-Wl,-rpath,\\$ORIGIN/../../../binutils/Linux_x64/Release/lib']

[hans, 2017/04/28 23:23:26]

Does package.py need an update to include the .so?

[pcc1, 2017/04/28 23:27:16]

The .so is part of binutils, so wouldn't it come with the binutils package?

+
     lto_cflags = ['-flto=thin']
     lto_ldflags = ['-fuse-ld=lld']
     if args.gcc_toolchain:
@@ -577,7 +581,7 @@ def UpdateClang(args):
         '-DCMAKE_CXX_COMPILER=' + cxx,
         '-DCMAKE_C_FLAGS=' + ' '.join(lto_cflags),
         '-DCMAKE_CXX_FLAGS=' + ' '.join(lto_cflags),
-        '-DCMAKE_EXE_LINKER_FLAGS=' + ' '.join(lto_ldflags),
+        '-DCMAKE_EXE_LINKER_FLAGS=' + ' '.join(lto_ldflags + tcmalloc_ldflags),
         '-DCMAKE_SHARED_LINKER_FLAGS=' + ' '.join(lto_ldflags),
         '-DCMAKE_MODULE_LINKER_FLAGS=' + ' '.join(lto_ldflags)]
 
@@ -585,6 +589,10 @@ def UpdateClang(args):
     lto_env = os.environ.copy()
     lto_env['PATH'] = BINUTILS_BIN_DIR + os.pathsep + lto_env.get('PATH', '')
 
+    # Also need to make sure that tblgen can find the tcmalloc DSO.
+    lto_env['LD_LIBRARY_PATH'] = \
+        BINUTILS_LIB_DIR + os.pathsep + lto_env.get('LD_LIBRARY_PATH', '')
+
     RmCmakeCache('.')
     RunCommand(['cmake'] + lto_cmake_args + [LLVM_DIR], env=lto_env)
     RunCommand(['ninja', 'LLVMgold', 'lld'], env=lto_env)