Update merge_pgc_files.py in preparation for VS2017

build/vs_toolchain.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 import glob
 import json
 import os
 import pipes
 import platform
@@ skipping 200 matching lines @@
   ucrt_files = glob.glob(os.path.join(ucrt_dll_dirs, 'api-ms-win-*.dll'))
   assert len(ucrt_files) > 0
   for ucrt_src_file in ucrt_files:
     file_part = os.path.basename(ucrt_src_file)
     ucrt_dst_file = os.path.join(target_dir, file_part)
     _CopyRuntimeImpl(ucrt_dst_file, ucrt_src_file, False)
   _CopyRuntimeImpl(os.path.join(target_dir, 'ucrtbase' + suffix),
                     os.path.join(source_dir, 'ucrtbase' + suffix))
 
 
+def FindVCToolsRoot():
+  """In VS2017 the PGO runtime dependencies are located in
+  {toolchain_root}/VC/Tools/MSVC/{x.y.z}/bin/Host{target_cpu}/{target_cpu}/, the
+  {version_number} part is likely to change in case of a minor update of the
+  toolchain so we don't hardcode this value here (except for the major number).
+
+  This returns the '{toolchain_root}/VC/Tools/MSVC/{x.y.z}/bin/' path.
+
+  This function should only be called when using VS2017.
+  """
+  assert GetVisualStudioVersion() == '2017'
+  assert ('GYP_MSVS_OVERRIDE_PATH' in os.environ)
+  vc_tools_msvc_root = os.path.join(os.environ['GYP_MSVS_OVERRIDE_PATH'],
+      'VC', 'Tools', 'MSVC')
+  for directory in os.listdir(vc_tools_msvc_root):
+    if not os.path.isdir(os.path.join(vc_tools_msvc_root, directory)):
+      continue
+    if re.match('14\.\d+\.\d+', directory):
+      return os.path.join(vc_tools_msvc_root, directory, 'bin')
+  raise Exception('Unable to find the VC tools directory.')
+
+
 def _CopyPGORuntime(target_dir, target_cpu):
   """Copy the runtime dependencies required during a PGO build.
   """
   env_version = GetVisualStudioVersion()
   # These dependencies will be in a different location depending on the version
   # of the toolchain.
   if env_version == '2015':
     pgo_x86_runtime_dir = os.path.join(os.environ.get('GYP_MSVS_OVERRIDE_PATH'),
                                        'VC', 'bin')
     pgo_x64_runtime_dir = os.path.join(pgo_x86_runtime_dir, 'amd64')
   elif env_version == '2017':
-    # In VS2017 the PGO runtime dependencies are located in
-    # {toolchain_root}/VC/Tools/MSVC/{x.y.z}/bin/Host{target_cpu}/{target_cpu}/,
-    # the {version_number} part is likely to change in case of a minor update of
-    # the toolchain so we don't hardcode this value here (except for the major
-    # number).
-    vc_tools_msvc_root = os.path.join(os.environ.get('GYP_MSVS_OVERRIDE_PATH'),
-        'VC', 'Tools', 'MSVC')
-    pgo_runtime_root = None
-    for directory in os.listdir(vc_tools_msvc_root):
-      if not os.path.isdir(os.path.join(vc_tools_msvc_root, directory)):
-        continue
-      if re.match('14\.\d+\.\d+', directory):
-        pgo_runtime_root = os.path.join(vc_tools_msvc_root, directory, 'bin')
-        break
+    pgo_runtime_root = FindVCToolsRoot()
     assert pgo_runtime_root
     # There's no version of pgosweep.exe in HostX64/x86, so we use the copy
     # from HostX86/x86.
     pgo_x86_runtime_dir = os.path.join(pgo_runtime_root, 'HostX86', 'x86')
     pgo_x64_runtime_dir = os.path.join(pgo_runtime_root, 'HostX64', 'x64')
   else:
     raise Exception('Unexpected toolchain version: %s.' % env_version)
 
   # We need to copy 2 runtime dependencies used during the profiling step:
   #     - pgort140.dll: runtime library required to run the instrumented image.
@@ skipping 174 matching lines @@
       'copy_dlls': CopyDlls,
   }
   if len(sys.argv) < 2 or sys.argv[1] not in commands:
     print >>sys.stderr, 'Expected one of: %s' % ', '.join(commands)
     return 1
   return commands[sys.argv[1]](*sys.argv[2:])
 
 
 if __name__ == '__main__':
   sys.exit(main())