Support the 'use_system_yasm' variable (libjpeg_turbo)....

libjpeg.gyp

 # Copyright (c) 2011 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.
 
 {
   'variables': {
     'shared_generated_dir': '<(SHARED_INTERMEDIATE_DIR)/third_party/libjpeg_turbo',
     'conditions': [
       [ 'chromeos==1 or OS=="freebsd" or OS=="openbsd"', {
         # Link to system .so since we already use it due to GTK.
         # See crbug.com/30288 and 31427 for why we skip OS=="linux" above.
         'use_system_libjpeg%': 1,
       }, {  # chromeos!=1 and OS!="freebsd" and OS!="openbsd"
         'use_system_libjpeg%': 0,
       }],
       [ 'OS=="win"', {
         'object_suffix': 'obj',
       }, {
         'object_suffix': 'o',
       }],
     ],
+
+    'use_system_yasm%': 0,
   },
   'conditions': [
     [ 'use_system_libjpeg==0', {
       'targets': [
         {
           'target_name': 'libjpeg',
           'type': '<(library)',
           'include_dirs': [
             '.',
           ],
@@ skipping 116 matching lines @@
                 'simd/jfss2int-64.asm',
                 'simd/jiss2red-64.asm',
                 'simd/jiss2int-64.asm',
                 'simd/jiss2fst-64.asm',
                 'simd/jcqnts2f-64.asm',
                 'simd/jiss2flt-64.asm',
               ],
             }],
 
             # Build rules for an asm file.
-            # On Windows, we use the precompiled yasm binary. On Linux and Mac,
-            # we build yasm and use it as ffmpeg does.
+            # On Windows, we use the precompiled yasm binary. On Linux, we build
+            # our patched yasm and use it except when use_system_yasm is 1. On
+            # Mac, we always build our patched yasm and use it because of
+            # <http://www.tortall.net/projects/yasm/ticket/236>.
             [ 'OS=="win"', {
               'variables': {
                 'yasm_path': '../yasm/binaries/win/yasm<(EXECUTABLE_SUFFIX)',
+                'yasm_format': '-fwin32',
+                'yasm_flags': [
+                  '-DWIN32',
+                  '-DMSVC',
+                  '-Iwin/'
+                ],
               },
-              'rules': [
-                {
-                  'rule_name': 'assemble',
-                  'extension': 'asm',
-                  'inputs': [ '<(RULE_INPUT_PATH)', ],
-                  'outputs': [
-                    '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
-                  ],
-                  'action': [
-                    '<(yasm_path)',
-                    '-fwin32',
-                    '-DWIN32',
-                    '-DMSVC',
-                    '-DRGBX_FILLER_0XFF',
-                    '-DSTRICT_MEMORY_ACCESS',
-                    '-Iwin/',
-                    '-Isimd/',
-                    '-o', '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
-                    '<(RULE_INPUT_PATH)',
-                  ],
-                  'process_outputs_as_sources': 1,
-                  'message': 'Building <(RULE_INPUT_ROOT).<(object_suffix)',
-                },
-              ],
             }],
             [ 'OS=="mac"', {
               'dependencies': [
                 '../yasm/yasm.gyp:yasm#host',
               ],
               'variables': {
                 'yasm_path': '<(PRODUCT_DIR)/yasm',
+                'yasm_format': '-fmacho',
+                'yasm_flags': [
+                  '-DMACHO',
+                  '-Imac/'
+                ],
               },
-              'rules': [
-                {
-                  'rule_name': 'assemble',
-                  'extension': 'asm',
-                  'inputs': [ '<(yasm_path)', ],
-                  'outputs': [
-                    '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
-                  ],
-                  'action': [
-                    '<(yasm_path)',
-                    '-fmacho',
-                    '-DMACHO',
-                    '-DRGBX_FILLER_0XFF',
-                    '-DSTRICT_MEMORY_ACCESS',
-                    '-Imac/',
-                    '-Isimd/',
-                    '-o', '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
-                    '<(RULE_INPUT_PATH)',
-                  ],
-                  'process_outputs_as_sources': 1,
-                  'message': 'Building <(RULE_INPUT_ROOT).<(object_suffix)',
-                },
-              ],
             }],
             [ 'OS=="linux"', {
-              'dependencies': [
-                '../yasm/yasm.gyp:yasm#host',
+              'conditions': [
+                [ 'use_system_yasm==0', {
+                  'dependencies': [
+                    '../yasm/yasm.gyp:yasm#host',
+                  ],
+                }],
               ],
               'variables': {
-                'yasm_path': '<(PRODUCT_DIR)/yasm',
                 'conditions': [
+                  [ 'use_system_yasm==1', {
+                    'yasm_path': '<!(which yasm)',
+                  }, {
+                    'yasm_path': '<(PRODUCT_DIR)/yasm',
+                  }],
                   [ 'target_arch=="ia32"', {
                     'yasm_format': '-felf',
                     'yasm_flag': '-D__X86__',
+                    'yasm_flags': [
+                      '-D__x86__',
+                      '-DELF',
+                      '-Ilinux/'
+                    ],
                   }, {
                     'yasm_format': '-felf64',
                     'yasm_flag': '-D__x86_64__',
+                    'yasm_flags': [
+                      '-D__x86_64__',
+                      '-DELF',
+                      '-Ilinux/'
+                    ],
                   }],
                 ],
               },
-              'rules': [
-                {
-                  'rule_name': 'assemble',
-                  'extension': 'asm',
-                  'inputs': [ '<(RULE_INPUT_PATH)', ],
-                  'outputs': [
-                    '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
-                  ],
-                  'action': [
-                    '<(yasm_path)',
-                    '<(yasm_format)',
-                    '-DELF',
-                    '<(yasm_flag)',
-                    '-DRGBX_FILLER_0XFF',
-                    '-DSTRICT_MEMORY_ACCESS',
-                    '-Ilinux/',
-                    '-Isimd/',
-                    '-o', '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
-                    '<(RULE_INPUT_PATH)',
-                  ],
-                  'process_outputs_as_sources': 1,
-                  'message': 'Building <(RULE_INPUT_ROOT).<(object_suffix)',
-                },
+            }],
+          ],
+          'rules': [
+            {
+              'rule_name': 'assemble',
+              'extension': 'asm',
+              'inputs': [ '<(yasm_path)', ],
+              'outputs': [
+                '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
               ],
-            }],
+              'action': [
+                '<(yasm_path)',
+                '<(yasm_format)',
+                '<@(yasm_flags)',
+                '-DRGBX_FILLER_0XFF',
+                '-DSTRICT_MEMORY_ACCESS',
+                '-Isimd/',
+                '-o', '<(shared_generated_dir)/<(RULE_INPUT_ROOT).<(object_suffix)',
+                '<(RULE_INPUT_PATH)',
+              ],
+              'process_outputs_as_sources': 1,
+              'message': 'Building <(RULE_INPUT_ROOT).<(object_suffix)',
+            },
           ],
         },
       ],
     }, { # else: use_system_libjpeg != 0
       'targets': [
         {
           'target_name': 'libjpeg',
           'type': 'settings',
           'direct_dependent_settings': {
             'defines': [
               'USE_SYSTEM_LIBJPEG',
             ],
           },
           'link_settings': {
             'libraries': [
               '-ljpeg',
             ],
           },
         },
       ],
     }],
   ],
 }
 
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