lto

build/common.gypi

 # 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1592 matching lines @@
             },
           }],
         ],
       },
       'Release_Base': {
         'abstract': 1,
         'defines': [
           'NDEBUG',
         ],
         'xcode_settings': {
-          'DEAD_CODE_STRIPPING': 'YES',  # -Wl,-dead_strip
+          #'DEAD_CODE_STRIPPING': 'YES',  # -Wl,-dead_strip  # lto + this = ld crash
           'GCC_OPTIMIZATION_LEVEL': '<(mac_release_optimization)',
-          'OTHER_CFLAGS': [ '<@(release_extra_cflags)', ],
+          'OTHER_CFLAGS': [ '<@(release_extra_cflags)',
+                '-Qunused-arguments',  # -flto for .S files for example.
+          ],
+          'LLVM_LTO': 'YES',  # -flto, XXX
+            # makes libtool complain like
+            # "descriptor.o is not an object file (not allowed in a library)"
+            # with xcodebuild? at least with xcode 3.2.6.
         },
         'msvs_settings': {
           'VCCLCompilerTool': {
             'RuntimeLibrary': '<(win_release_RuntimeLibrary)',
             'conditions': [
               # In official builds, each target will self-select
               # an optimization level.
               ['buildtype!="Official"', {
                   'Optimization': '<(win_release_Optimization)',
                 },
@@ skipping 1322 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }