Support Visual C++ PGO in Ninja generator

pylib/gyp/msvs_emulation.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 This module helps emulate Visual Studio 2008 behavior on top of other
 build systems, primarily ninja.
 """
 
 import os
@@ skipping 469 matching lines @@
     ld('TerminalServerAware', map={'1': ':NO', '2': ''}, prefix='/TSAWARE')
     ld('LinkIncremental', map={'1': ':NO', '2': ''}, prefix='/INCREMENTAL')
     ld('BaseAddress', prefix='/BASE:')
     ld('FixedBaseAddress', map={'1': ':NO', '2': ''}, prefix='/FIXED')
     ld('RandomizedBaseAddress',
         map={'1': ':NO', '2': ''}, prefix='/DYNAMICBASE')
     ld('DataExecutionPrevention',
         map={'1': ':NO', '2': ''}, prefix='/NXCOMPAT')
     ld('OptimizeReferences', map={'1': 'NOREF', '2': 'REF'}, prefix='/OPT:')
     ld('EnableCOMDATFolding', map={'1': 'NOICF', '2': 'ICF'}, prefix='/OPT:')
-    ld('LinkTimeCodeGeneration', map={'1': '/LTCG'})
+    ld('LinkTimeCodeGeneration',

[scottmg, 2013/11/23 17:15:13]

(Sorry, not at a Windows machine right now to check...) Does the Librarian
section also need to be modified to either 1) handle '1' instead of 'true', or
2) also handle the other LTCG options?

[yukawa, 2013/11/25 14:04:12]

Yeah, I believe that the Librarian should continue to use boolean since the
underlying MSVS object model uses bool as follows.
| bool LinkTimeCodeGeneration { get; set; } 
http://msdn.microsoft.com/en-us/library/microsoft.visualstudio.vcprojectengin...

Actually Skia is specifying both settings correctly.
https://code.google.com/p/skia/source/browse/trunk/gyp/common_conditions.gypi...

Does this make sense?

+        map={'1': '', '2': ':PGINSTRUMENT', '3': ':PGOPTIMIZE',
+             '4': ':PGUPDATE'},
+        prefix='/LTCG')
     ld('IgnoreDefaultLibraryNames', prefix='/NODEFAULTLIB:')
     ld('ResourceOnlyDLL', map={'true': '/NOENTRY'})
     ld('EntryPointSymbol', prefix='/ENTRY:')
     ld('Profile', map={'true': '/PROFILE'})
     ld('LargeAddressAware',
         map={'1': ':NO', '2': ''}, prefix='/LARGEADDRESSAWARE')
     # TODO(scottmg): This should sort of be somewhere else (not really a flag).
     ld('AdditionalDependencies', prefix='')
 
     # If the base address is not specifically controlled, DYNAMICBASE should
@@ skipping 371 matching lines @@
 
   # To determine processor word size on Windows, in addition to checking
   # PROCESSOR_ARCHITECTURE (which reflects the word size of the current
   # process), it is also necessary to check PROCESSOR_ARCHITEW6432 (which
   # contains the actual word size of the system when running thru WOW64).
   if ('64' in os.environ.get('PROCESSOR_ARCHITECTURE', '') or
       '64' in os.environ.get('PROCESSOR_ARCHITEW6432', '')):
     default_variables['MSVS_OS_BITS'] = 64
   else:
     default_variables['MSVS_OS_BITS'] = 32