clang: Link lld against tcmalloc.

tools/clang/scripts/update.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """This script is used to download prebuilt clang binaries.
 
 It is also used by package.py to build the prebuilt clang binaries."""
 
 import argparse
@@ skipping 16 matching lines @@
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://chromium.googlesource.com/chromium/src/+/master/docs/updating_clang.md
 # Reverting problematic clang rolls is safe, though.
 CLANG_REVISION = '300839'
 
 use_head_revision = 'LLVM_FORCE_HEAD_REVISION' in os.environ
 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)
 
 # Path constants. (All of these should be absolute paths.)
 THIS_DIR = os.path.abspath(os.path.dirname(__file__))
 CHROMIUM_DIR = os.path.abspath(os.path.join(THIS_DIR, '..', '..', '..'))
 THIRD_PARTY_DIR = os.path.join(CHROMIUM_DIR, 'third_party')
 LLVM_DIR = os.path.join(THIRD_PARTY_DIR, 'llvm')
 LLVM_BOOTSTRAP_DIR = os.path.join(THIRD_PARTY_DIR, 'llvm-bootstrap')
 LLVM_BOOTSTRAP_INSTALL_DIR = os.path.join(THIRD_PARTY_DIR,
@@ skipping 11 matching lines @@
 if sys.platform == 'win32':
   COMPILER_RT_DIR = os.path.join(LLVM_DIR, 'projects', 'compiler-rt')
 else:
   COMPILER_RT_DIR = os.path.join(LLVM_DIR, 'compiler-rt')
 LIBCXX_DIR = os.path.join(LLVM_DIR, 'projects', 'libcxx')
 LIBCXXABI_DIR = os.path.join(LLVM_DIR, 'projects', 'libcxxabi')
 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')
 
 # URL for pre-built binaries.
 CDS_URL = os.environ.get('CDS_CLANG_BUCKET_OVERRIDE',
     'https://commondatastorage.googleapis.com/chromium-browser-clang')
 
 LLVM_REPO_URL='https://llvm.org/svn/llvm-project'
 if 'LLVM_REPO_URL' in os.environ:
@@ skipping 412 matching lines @@
 
   base_cmake_args = ['-GNinja',
                      '-DCMAKE_BUILD_TYPE=Release',
                      '-DLLVM_ENABLE_ASSERTIONS=ON',
                      # Statically link MSVCRT to avoid DLL dependencies.
                      '-DLLVM_USE_CRT_RELEASE=MT',
                      ]
 
   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'
     EnsureDirExists(LLVM_BOOTSTRAP_DIR)
     os.chdir(LLVM_BOOTSTRAP_DIR)
     bootstrap_args = base_cmake_args + [
         '-DLLVM_BINUTILS_INCDIR=' + binutils_incdir,
         '-DLLVM_TARGETS_TO_BUILD=host',
         '-DCMAKE_INSTALL_PREFIX=' + LLVM_BOOTSTRAP_INSTALL_DIR,
         '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
@@ skipping 41 matching lines @@
     EnsureDirExists(LLVM_LTO_GOLD_PLUGIN_DIR)
     os.chdir(LLVM_LTO_GOLD_PLUGIN_DIR)
 
     # Create a symlink to LLVMgold.so build in the previous step so that ar
     # and ranlib could find it while linking LLVMgold.so with LTO.
     EnsureDirExists(BFD_PLUGINS_DIR)
     RunCommand(['ln', '-sf',
                 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:
       # Tell the bootstrap compiler to use a specific gcc prefix to search
       # for standard library headers and shared object files.
       lto_cflags += ['--gcc-toolchain=' + args.gcc_toolchain]
     lto_cmake_args = base_cmake_args + [
         '-DLLVM_BINUTILS_INCDIR=' + binutils_incdir,
         '-DCMAKE_C_COMPILER=' + cc,
         '-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)]
 
     # We need to use the proper binutils which support LLVM Gold plugin.
     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)
 
 
   # LLVM uses C++11 starting in llvm 3.5. On Linux, this means libstdc++4.7+ is
   # needed, on OS X it requires libc++. clang only automatically links to libc++
   # when targeting OS X 10.9+, so add stdlib=libc++ explicitly so clang can run
   # on OS X versions as old as 10.7.
   deployment_target = ''
@@ skipping 310 matching lines @@
     args.force_local_build = True
     if 'OS=android' not in os.environ.get('GYP_DEFINES', ''):
       # Only build the Android ASan rt on ToT bots when targetting Android.
       args.with_android = False
 
   return UpdateClang(args)
 
 
 if __name__ == '__main__':
   sys.exit(main())