Add --enable-pgo option to build clang with PGO

tools/clang/scripts/package.py

 #!/usr/bin/env python
 # Copyright (c) 2015 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 will check out llvm and clang, and then package the results up
 to a tgz file."""
 
 import argparse
 import fnmatch
@@ skipping 145 matching lines @@
       exit_code = RunGsutil(gsutil_args)
       if exit_code != 0:
         print "gsutil failed, exit_code: %s" % exit_code
         sys.exit(exit_code)
 
 
 def main():
   parser = argparse.ArgumentParser(description='build and package clang')
   parser.add_argument('--upload', action='store_true',
                       help='Upload the target archive to Google Cloud Storage.')
+  parser.add_argument('--enable-pgo', action='store_true',
+                      help='Build clang with GO enabled.')

[Nico, 2017/04/07 15:58:53]

Typo GO.

Also, why have a flag for this? Shouldn't this just be the default?

[matthewtff.asm, 2017/04/11 12:14:43]

I believe it should be default. Made a flag just in case.

   args = parser.parse_args()
 
   # Check that the script is not going to upload a toolchain built from HEAD.
   use_head_revision = 'LLVM_FORCE_HEAD_REVISION' in os.environ
   if args.upload and use_head_revision:
     print ("--upload and LLVM_FORCE_HEAD_REVISION could not be used "
            "at the same time.")
     return 1
 
   expected_stamp = GetExpectedStamp()
   pdir = 'clang-' + expected_stamp
   golddir = 'llvmgold-' + expected_stamp
   print pdir
 
   if sys.platform == 'darwin':
     platform = 'Mac'
   elif sys.platform == 'win32':
     platform = 'Win'
   else:
     platform = 'Linux_x64'
 
   # Check if Google Cloud Storage already has the artifacts we want to build.
   if (args.upload and GsutilArchiveExists(pdir, platform) and
-      not sys.platform.startswith('linux') or
-      GsutilArchiveExists(golddir, platform)):
+      (not sys.platform.startswith('linux') or
+      GsutilArchiveExists(golddir, platform))):

[Nico, 2017/04/07 15:58:53]

This looks like a good change, but also unrelated.

     print ('Desired toolchain revision %s is already available '
            'in Google Cloud Storage:') % expected_stamp
     print 'gs://chromium-browser-clang-staging/%s/%s.tgz' % (platform, pdir)
     if sys.platform.startswith('linux'):
       print 'gs://chromium-browser-clang-staging/%s/%s.tgz' % (platform,
                                                                golddir)
     return 0
 
   with open('buildlog.txt', 'w') as log:
     Tee('Diff in llvm:\n', log)
@@ skipping 21 matching lines @@
     Tee('Starting build\n', log)
 
     # Do a clobber build.
     shutil.rmtree(LLVM_BOOTSTRAP_DIR, ignore_errors=True)
     shutil.rmtree(LLVM_BOOTSTRAP_INSTALL_DIR, ignore_errors=True)
     shutil.rmtree(LLVM_BUILD_DIR, ignore_errors=True)
 
     opt_flags = []
     if sys.platform.startswith('linux'):
       opt_flags += ['--lto-gold-plugin']
+
+    if sys.platform != 'win32' and args.enable_pgo:
+      opt_flags += ['--enable-pgo']
+    else:
+      opt_flags += ['--bootstrap']
+
     build_cmd = [sys.executable, os.path.join(THIS_DIR, 'update.py'),
-                 '--bootstrap', '--force-local-build',
-                 '--run-tests'] + opt_flags
+                 '--force-local-build', '--run-tests'] + opt_flags
     TeeCmd(build_cmd, log)
 
+  if args.enable_pgo:
+    global LLVM_RELEASE_DIR
+    LLVM_RELEASE_DIR = os.path.join(LLVM_RELEASE_DIR, 'tools', 'clang',
+        'stage2-instrumented-bins', 'tools', 'clang', 'stage2-bins')
+
   stamp = open(STAMP_FILE).read().rstrip()
   if stamp != expected_stamp:
     print 'Actual stamp (%s) != expected stamp (%s).' % (stamp, expected_stamp)
     return 1
 
   shutil.rmtree(pdir, ignore_errors=True)
 
   # Copy a whitelist of files to the directory we're going to tar up.
   # This supports the same patterns that the fnmatch module understands.
   exe_ext = '.exe' if sys.platform == 'win32' else ''
@@ skipping 65 matching lines @@
   # Set up symlinks.
   if sys.platform != 'win32':
     os.symlink('clang', os.path.join(pdir, 'bin', 'clang++'))
     os.symlink('clang', os.path.join(pdir, 'bin', 'clang-cl'))
 
   if sys.platform.startswith('linux'):
     os.symlink('lld', os.path.join(pdir, 'bin', 'ld.lld'))
 
   # Copy libc++ headers.
   if sys.platform == 'darwin':
-    shutil.copytree(os.path.join(LLVM_BOOTSTRAP_INSTALL_DIR, 'include', 'c++'),
+    install_dir = LLVM_RELEASE_DIR if args.enable_pgo else \
+        LLVM_BOOTSTRAP_INSTALL_DIR
+    shutil.copytree(os.path.join(install_dir, 'include', 'c++'),
                     os.path.join(pdir, 'include', 'c++'))
 
   # Copy buildlog over.
   shutil.copy('buildlog.txt', pdir)
 
   # Create archive.
   tar_entries = ['bin', 'lib', 'buildlog.txt']
   if sys.platform == 'darwin':
     tar_entries += ['include']
   with tarfile.open(pdir + '.tgz', 'w:gz') as tar:
@@ skipping 25 matching lines @@
   MaybeUpload(args, objdumpdir, platform)
 
   if sys.platform == 'win32' and args.upload:
     UploadPDBToSymbolServer()
 
   # FIXME: Warn if the file already exists on the server.
 
 
 if __name__ == '__main__':
   sys.exit(main())