Add a GYP flag to enable coverage gathering instrumentation in ASan builds.

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 339 matching lines @@
       # If this is set, the clang plugins used on the buildbot will be used.
       # Run tools/clang/scripts/update.sh to make sure they are compiled.
       # This causes 'clang_chrome_plugins_flags' to be set.
       # Has no effect if 'clang' is not set as well.
       'clang_use_chrome_plugins%': 1,
 
       # Enable building with ASAN (Clang's -fsanitize=address option).
       # -fsanitize=address only works with clang, but asan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/addresssanitizer
       'asan%': 0,
+      # Enable coverage gathering instrumentation in ASan.
+      'asan_coverage%': 0,
 
       # Enable building with LSan (Clang's -fsanitize=leak option).
       # -fsanitize=leak only works with clang, but lsan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/leaksanitizer
       'lsan%': 0,
 
       # Enable building with TSAN (Clang's -fsanitize=thread option).
       # -fsanitize=thread only works with clang, but tsan=1 implies clang=1
       # See http://clang.llvm.org/docs/ThreadSanitizer.html
       'tsan%': 0,
@@ skipping 556 matching lines @@
     'enable_one_click_signin%': '<(enable_one_click_signin)',
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'input_speech%': '<(input_speech)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
     'asan%': '<(asan)',
+    'asan_coverage%': '<(asan_coverage)',

[Alexander Potapenko, 2014/01/15 16:35:01]

Can we have asan_coverage=1 imply asan=1?

     'lsan%': '<(lsan)',
     'msan%': '<(msan)',
     'tsan%': '<(tsan)',
     'tsan_blacklist%': '<(tsan_blacklist)',
     'use_instrumented_libraries%': '<(use_instrumented_libraries)',
     'use_custom_libcxx%': '<(use_custom_libcxx)',
     'clang_type_profiler%': '<(clang_type_profiler)',
     'order_profiling%': '<(order_profiling)',
     'order_text_section%': '<(order_text_section)',
     'enable_extensions%': '<(enable_extensions)',
@@ skipping 2511 matching lines @@
                 ],
                 'ldflags': [
                   '-fsanitize=address',
                 ],
                 'defines': [
                   'ADDRESS_SANITIZER',
                 ],
               }],
             ],
           }],
+          ['asan_coverage==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-mllvm -asan-coverage=1',
+                ],
+              }],
+            ],
+          }],
           ['lsan==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=leak',
                 ],
                 'ldflags': [
                   '-fsanitize=leak',
                 ],
                 'defines': [
@@ skipping 634 matching lines @@
               'OTHER_CFLAGS': [
                 '-fsanitize=address',
                 '-w',  # http://crbug.com/162783
               ],
             },
             'defines': [
               'ADDRESS_SANITIZER',
               'MEMORY_TOOL_REPLACES_ALLOCATOR',
             ],
           }],
+          ['asan_coverage==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-mllvm -asan-coverage=1',

[Alexander Potapenko, 2014/01/15 16:35:01]

What about the xcode-specific flags?

+                ],
+              }],
+            ],
+          }],
         ],
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
             'conditions': [
               ['asan==1', {
                 'xcode_settings': {
                   'OTHER_LDFLAGS': [
                     '-fsanitize=address',
                   ],
@@ skipping 695 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',
   },
 }