Clang toolchain: checkout LLD on all platforms but Darwin.

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 440 matching lines @@
 
   DownloadHostGcc(args)
   AddSvnToPathOnWin()
   AddCMakeToPath()
   AddGnuWinToPath()
 
   DeleteChromeToolsShim()
 
   Checkout('LLVM', LLVM_REPO_URL + '/llvm/trunk', LLVM_DIR)
   Checkout('Clang', LLVM_REPO_URL + '/cfe/trunk', CLANG_DIR)
-  if sys.platform == 'win32' or use_head_revision:
+  if sys.platform != 'darwin':
     Checkout('LLD', LLVM_REPO_URL + '/lld/trunk', LLD_DIR)
   elif os.path.exists(LLD_DIR):
     # In case someone sends a tryjob that temporary adds lld to the checkout,
     # make sure it's not around on future builds.
     RmTree(LLD_DIR)
   Checkout('compiler-rt', LLVM_REPO_URL + '/compiler-rt/trunk', COMPILER_RT_DIR)
   if sys.platform == 'darwin':
     # clang needs a libc++ checkout, else -stdlib=libc++ won't find includes
     # (i.e. this is needed for bootstrap builds).
     Checkout('libcxx', LLVM_REPO_URL + '/libcxx/trunk', LIBCXX_DIR)
@@ skipping 19 matching lines @@
         [cxx, '-print-file-name=libstdc++.so.6']).rstrip()
     os.environ['LD_LIBRARY_PATH'] = os.path.dirname(libstdcpp)
 
   cflags = []
   cxxflags = []
   ldflags = []
 
   base_cmake_args = ['-GNinja',
                      '-DCMAKE_BUILD_TYPE=Release',
                      '-DLLVM_ENABLE_ASSERTIONS=ON',
-                     '-DLLVM_ENABLE_THREADS=OFF',
                      # 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')
 
   if args.bootstrap:
     print 'Building bootstrap compiler'
@@ skipping 48 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')])
 
-    lto_cflags = ['-flto']
-    lto_ldflags = ['-fuse-ld=gold']
+    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_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', '')
 
     RmCmakeCache('.')
     RunCommand(['cmake'] + lto_cmake_args + [LLVM_DIR], env=lto_env)
-    RunCommand(['ninja', 'LLVMgold'], 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 = ''
 
   if sys.platform == 'darwin' and args.bootstrap:
     # When building on 10.9, /usr/include usually doesn't exist, and while
@@ skipping 24 matching lines @@
     deployment_env['MACOSX_DEPLOYMENT_TARGET'] = deployment_target
 
   cmake_args = []
   # TODO(thakis): Unconditionally append this to base_cmake_args instead once
   # compiler-rt can build with clang-cl on Windows (http://llvm.org/PR23698)
   cc_args = base_cmake_args if sys.platform != 'win32' else cmake_args
   if cc is not None:  cc_args.append('-DCMAKE_C_COMPILER=' + cc)
   if cxx is not None: cc_args.append('-DCMAKE_CXX_COMPILER=' + cxx)
   chrome_tools = list(set(['plugins', 'blink_gc_plugin'] + args.extra_tools))
   cmake_args += base_cmake_args + [
+      '-DLLVM_ENABLE_THREADS=OFF',
       '-DLLVM_BINUTILS_INCDIR=' + binutils_incdir,
       '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
       '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags),
       '-DCMAKE_EXE_LINKER_FLAGS=' + ' '.join(ldflags),
       '-DCMAKE_SHARED_LINKER_FLAGS=' + ' '.join(ldflags),
       '-DCMAKE_MODULE_LINKER_FLAGS=' + ' '.join(ldflags),
       '-DCMAKE_INSTALL_PREFIX=' + LLVM_BUILD_DIR,
       # TODO(thakis): Remove this once official builds pass -Wl,--build-id
       # explicitly, https://crbug.com/622775
       '-DENABLE_LINKER_BUILD_ID=ON',
       '-DCHROMIUM_TOOLS_SRC=%s' % os.path.join(CHROMIUM_DIR, 'tools', 'clang'),
       '-DCHROMIUM_TOOLS=%s' % ';'.join(chrome_tools)]
 
   EnsureDirExists(LLVM_BUILD_DIR)
   os.chdir(LLVM_BUILD_DIR)
   RmCmakeCache('.')
   RunCommand(['cmake'] + cmake_args + [LLVM_DIR],
              msvc_arch='x64', env=deployment_env)
 
   if args.gcc_toolchain:
     # Copy in the right stdlibc++.so.6 so clang can start.
     if not os.path.exists(os.path.join(LLVM_BUILD_DIR, 'lib')):
       os.mkdir(os.path.join(LLVM_BUILD_DIR, 'lib'))
     libstdcpp = subprocess.check_output(
         [cxx] + cxxflags + ['-print-file-name=libstdc++.so.6']).rstrip()
     CopyFile(libstdcpp, os.path.join(LLVM_BUILD_DIR, 'lib'))
 
   RunCommand(['ninja'], msvc_arch='x64')
 
+  # Copy LTO-optimized lld, if any.
+  if args.bootstrap and args.lto_gold_plugin:
+    CopyFile(os.path.join(LLVM_LTO_GOLD_PLUGIN_DIR, 'bin', 'lld'),
+             os.path.join(LLVM_BUILD_DIR, 'bin'))
+
   if chrome_tools:
     # If any Chromium tools were built, install those now.
     RunCommand(['ninja', 'cr-install'], msvc_arch='x64')
 
   if sys.platform == 'darwin':
     # See http://crbug.com/256342
     RunCommand(['strip', '-x', os.path.join(LLVM_BUILD_DIR, 'bin', 'clang')])
   elif sys.platform.startswith('linux'):
     RunCommand(['strip', os.path.join(LLVM_BUILD_DIR, 'bin', 'clang')])
 
   VeryifyVersionOfBuiltClangMatchesVERSION()
 
   # Do an out-of-tree build of compiler-rt.
   # On Windows, this is used to get the 32-bit ASan run-time.
   # TODO(hans): Remove once the regular build above produces this.
   # On Mac and Linux, this is used to get the regular 64-bit run-time.
   # Do a clobbered build due to cmake changes.
   if os.path.isdir(COMPILER_RT_BUILD_DIR):
     RmTree(COMPILER_RT_BUILD_DIR)
   os.makedirs(COMPILER_RT_BUILD_DIR)
   os.chdir(COMPILER_RT_BUILD_DIR)
   # TODO(thakis): Add this once compiler-rt can build with clang-cl (see
   # above).
   #if args.bootstrap and sys.platform == 'win32':
     # The bootstrap compiler produces 64-bit binaries by default.
     #cflags += ['-m32']
     #cxxflags += ['-m32']
   compiler_rt_args = base_cmake_args + [
+      '-DLLVM_ENABLE_THREADS=OFF',
       '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
       '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags)]
   if sys.platform == 'darwin':
     compiler_rt_args += ['-DCOMPILER_RT_ENABLE_IOS=ON']
   if sys.platform != 'win32':
     compiler_rt_args += ['-DLLVM_CONFIG_PATH=' +
                          os.path.join(LLVM_BUILD_DIR, 'bin', 'llvm-config'),
                         '-DSANITIZER_MIN_OSX_VERSION="10.7"']
   # compiler-rt is part of the llvm checkout on Windows but a stand-alone
   # directory elsewhere, see the TODO above COMPILER_RT_DIR.
@@ skipping 82 matching lines @@
 
       # Build ASan runtime for Android in a separate build tree.
       build_dir = os.path.join(LLVM_BUILD_DIR, 'android-' + target_arch)
       if not os.path.exists(build_dir):
         os.mkdir(os.path.join(build_dir))
       os.chdir(build_dir)
       cflags = ['--target=%s-linux-androideabi' % target_arch,
                 '--sysroot=%s/sysroot' % toolchain_dir,
                 '-B%s' % toolchain_dir]
       android_args = base_cmake_args + [
+        '-DLLVM_ENABLE_THREADS=OFF',
         '-DCMAKE_C_COMPILER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang'),
         '-DCMAKE_CXX_COMPILER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang++'),
         '-DLLVM_CONFIG_PATH=' + os.path.join(LLVM_BUILD_DIR, 'bin/llvm-config'),
         '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
         '-DCMAKE_CXX_FLAGS=' + ' '.join(cflags),
         '-DANDROID=1']
       RmCmakeCache('.')
       RunCommand(['cmake'] + android_args + [COMPILER_RT_DIR])
       RunCommand(['ninja', 'libclang_rt.asan-%s-android.so' % target_arch])
 
@@ skipping 105 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())