Add the ability to compile with profiler guided optimizations on Windows...

SConstruct

 # Copyright 2008 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 237 matching lines @@
       'CCFLAGS':      ['/O2'],
       'LINKFLAGS':    ['/OPT:REF', '/OPT:ICF'],
       'msvcrt:static': {
         'CCFLAGS': ['/MT']
       },
       'msvcrt:shared': {
         'CCFLAGS': ['/MD']
       },
       'msvcltcg:on': {
         'CCFLAGS':      ['/GL'],
-        'LINKFLAGS':    ['/LTCG'],
         'ARFLAGS':      ['/LTCG'],
+        'pgo:off': {
+          'LINKFLAGS':    ['/LTCG'],
+        },
+        'pgo:instrument': {
+          'LINKFLAGS':    ['/LTCG:PGI']
+        },
+        'pgo:optimize': {
+          'LINKFLAGS':    ['/LTCG:PGO']
+        }
       }
     }
   }
 }
 
 
 V8_EXTRA_FLAGS = {
   'gcc': {
     'all': {
       'WARNINGFLAGS': ['-Wall',
@@ skipping 250 matching lines @@
       'CCFLAGS':   ['/O2'],
       'LINKFLAGS': ['/OPT:REF', '/OPT:ICF'],
       'msvcrt:static': {
         'CCFLAGS': ['/MT']
       },
       'msvcrt:shared': {
         'CCFLAGS': ['/MD']
       },
       'msvcltcg:on': {
         'CCFLAGS':      ['/GL'],
-        'LINKFLAGS':    ['/LTCG'],
+        'pgo:off': {
+          'LINKFLAGS':    ['/LTCG'],
+        },
+      },
+      'pgo:instrument': {
+        'LINKFLAGS':    ['/LTCG:PGI']
+      },
+      'pgo:optimize': {
+        'LINKFLAGS':    ['/LTCG:PGO']
       }
     },
     'arch:ia32': {
       'CPPDEFINES': ['V8_TARGET_ARCH_IA32'],
       'LINKFLAGS': ['/MACHINE:X86']
     },
     'arch:x64': {
       'CPPDEFINES': ['V8_TARGET_ARCH_X64'],
       'LINKFLAGS': ['/MACHINE:X64', '/STACK:2091752']
     },
@@ skipping 163 matching lines @@
   },
   'visibility': {
     'values': ['default', 'hidden'],
     'default': 'hidden',
     'help': 'shared library symbol visibility'
   },
   'armvariant': {
     'values': ['arm', 'thumb2', 'none'],
     'default': 'none',
     'help': 'generate thumb2 instructions instead of arm instructions (default)'
+  },
+  'pgo': {
+    'values': ['off', 'instrument', 'optimize'],
+    'default': 'off',
+    'help': 'select profile guided optimization variant',
   }
 }
 
 
 def GetOptions():
   result = Options()
   result.Add('mode', 'compilation mode (debug, release)', 'release')
   result.Add('sample', 'build sample (shell, process, lineprocessor)', '')
   result.Add('env', 'override environment settings (NAME0:value0,NAME1:value1,...)', '')
   result.Add('importenv', 'import environment settings (NAME0,NAME1,...)', '')
@@ skipping 67 matching lines @@
   if not IsLegal(env, 'regexp', ["native", "interpreted"]):
     return False
   if env['os'] == 'win32' and env['library'] == 'shared' and env['prof'] == 'on':
     Abort("Profiling on windows only supported for static library.")
   if env['prof'] == 'oprofile' and env['os'] != 'linux':
     Abort("OProfile is only supported on Linux.")
   if env['os'] == 'win32' and env['soname'] == 'on':
     Abort("Shared Object soname not applicable for Windows.")
   if env['soname'] == 'on' and env['library'] == 'static':
     Abort("Shared Object soname not applicable for static library.")
+  if env['os'] != 'win32' and env['pgo'] != 'off':
+    Abort("Profile guided optimization only supported on Windows.")
   for (name, option) in SIMPLE_OPTIONS.iteritems():
     if (not option.get('default')) and (name not in ARGUMENTS):
       message = ("A value for option %s must be specified (%s)." %
           (name, ", ".join(option['values'])))
       Abort(message)
     if not env[name] in option['values']:
       message = ("Unknown %s value '%s'.  Possible values are (%s)." %
           (name, env[name], ", ".join(option['values'])))
       Abort(message)
 
@@ skipping 65 matching lines @@
 
   def ApplyEnvOverrides(self, env):
     if not self.env_overrides:
       return
     if type(env['ENV']) == DictType:
       env['ENV'].update(**self.env_overrides)
     else:
       env['ENV'] = self.env_overrides
 
 
-def PostprocessOptions(options):
+def PostprocessOptions(options, os):
   # Adjust architecture if the simulator option has been set
   if (options['simulator'] != 'none') and (options['arch'] != options['simulator']):
     if 'arch' in ARGUMENTS:
       # Print a warning if arch has explicitly been set
       print "Warning: forcing architecture to match simulator (%s)" % options['simulator']
     options['arch'] = options['simulator']
   if (options['prof'] != 'off') and (options['profilingsupport'] == 'off'):
     # Print a warning if profiling is enabled without profiling support
     print "Warning: forcing profilingsupport on when prof is on"
     options['profilingsupport'] = 'on'
+  if os == 'win32' and options['pgo'] != 'off' and options['msvcltcg'] == 'off':
+    if 'msvcltcg' in ARGUMENTS:
+      print "Warning: forcing msvcltcg on as it is required for pgo (%s)" % options['pgo']
+    options['msvcltcg'] = 'on'
   if (options['armvariant'] == 'none' and options['arch'] == 'arm'):
     options['armvariant'] = 'arm'
   if (options['armvariant'] != 'none' and options['arch'] != 'arm'):
     options['armvariant'] = 'none'
   if options['arch'] == 'mips':
     if ('regexp' in ARGUMENTS) and options['regexp'] == 'native':
       # Print a warning if native regexp is specified for mips
       print "Warning: forcing regexp to interpreted for mips"
     options['regexp'] = 'interpreted'
 
@@ skipping 10 matching lines @@
     if pos == -1:
       continue
     overrides[override[:pos].strip()] = override[pos+1:].strip()
   return overrides
 
 
 def BuildSpecific(env, mode, env_overrides):
   options = {'mode': mode}
   for option in SIMPLE_OPTIONS:
     options[option] = env[option]
-  PostprocessOptions(options)
+  PostprocessOptions(options, env['os'])
 
   context = BuildContext(options, env_overrides, samples=SplitList(env['sample']))
 
   # Remove variables which can't be imported from the user's external
   # environment into a construction environment.
   user_environ = os.environ.copy()
   try:
     del user_environ['ENV']
   except KeyError:
     pass
@@ skipping 128 matching lines @@
 # version of scons.  Also, there's a bug in some revisions that
 # doesn't allow this flag to be set, so we swallow any exceptions.
 # Lovely.
 try:
   SetOption('warn', 'no-deprecated')
 except:
   pass
 
 
 Build()