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 501bc9f127241f04ce1d505ceecb8a902a7482e1..64c520700d6fb4ba016fe52a1ceff21bec9b49c2 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 +564,13 @@ 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%.
+    # In package.py we copy the .so into our package.
+    tcmalloc_ldflags = ['-L' + BINUTILS_LIB_DIR, '-ltcmalloc_minimal']
+    # Make sure that tblgen and the test suite can find tcmalloc.
+    os.environ['LD_LIBRARY_PATH'] = \
+        BINUTILS_LIB_DIR + os.pathsep + os.environ.get('LD_LIBRARY_PATH', '')
+
     lto_cflags = ['-flto=thin']
     lto_ldflags = ['-fuse-ld=lld']
     if args.gcc_toolchain:
@@ -577,7 +583,7 @@ 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)]