Enable warning on ASan-enabled build

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 3956 matching lines @@
                   '<(DEPTH)/base/base.gyp:sanitizer_options',
                 ],
               }],
             ],
           }],
           ['asan==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=address',
-                  '-w',  # http://crbug.com/162783
+                  '-Wno-error=macro-redefined',  # http://crbug.com/162783
                 ],
                 'ldflags': [
                   '-fsanitize=address',
                 ],
               }],
             ],
             'conditions': [
               ['OS=="mac"', {
                 'cflags': [
                   '-mllvm -asan-globals=0',  # http://crbug.com/352073
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
                 ],
               }],
             ],
           }],
           ['ubsan==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=undefined',
                   # -fsanitize=vptr is incompatible with -fno-rtti.
                   '-fno-sanitize=vptr',
-                  '-w',  # http://crbug.com/162783
+                  '-Wno-error=macro-redefined',  # http://crbug.com/162783
                 ],
                 'ldflags': [
                   '-fsanitize=undefined',
                   # -fsanitize=vptr is incompatible with -fno-rtti.
                   '-fno-sanitize=vptr',
                 ],
               }],
             ],
+            'conditions': [
+              ['OS=="mac"', {
+                'cflags': [
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
+                ],
+              }],
+            ],
           }],
           ['ubsan_vptr==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=vptr',
                   '-fsanitize=null',  # Avoid dereferences on null pointer objects.
                   '-fsanitize-blacklist=<(ubsan_vptr_blacklist)',
-                  '-w',  # http://crbug.com/162783
+                  '-Wno-error=macro-redefined',  # http://crbug.com/162783
                 ],
                 'cflags_cc!': [
                   '-fno-rtti',
                 ],
                 'cflags!': [
                   '-fno-rtti',
                 ],
                 'ldflags': [
                   '-fsanitize=vptr',  # -fsanitize=null is not necessary.
                 ],
                 'defines': [
                   'UNDEFINED_SANITIZER',
                 ],
               }],
             ],
+            'conditions': [
+              ['OS=="mac"', {
+                'cflags': [
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
+                ],
+              }],
+            ],
           }],
           ['asan_coverage!=0', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-mllvm -asan-coverage=<(asan_coverage)',
                 ],
               }],
             ],
           }],
@@ skipping 553 matching lines @@
               }],
             ],
           }],
           # Settings for building host targets using the system toolchain.
           ['_toolset=="host"', {
             'cflags!': [
               # Due to issues in Clang build system, using ASan on 32-bit
               # binaries on x86_64 host is problematic.
               # TODO(eugenis): re-enable.
               '-fsanitize=address',
-              '-w',  # http://crbug.com/162783
+              '-Wno-error=macro-redefined',  # http://crbug.com/162783
+
             ],
             'ldflags!': [
               '-fsanitize=address',
               '-Wl,-z,noexecstack',
               '-Wl,--gc-sections',
               '-Wl,-O1',
               '-Wl,--as-needed',
               '-Wl,--warn-shared-textrel',
               '-Wl,--fatal-warnings',
             ],
+            'conditions': [
+              ['OS=="mac"', {
+                'cflags!': [
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
+                ],
+              }],
+            ],
           }],
           # Settings for building host targets on mac.
           ['_toolset=="host" and host_os=="mac"', {
             'ldflags!': [
               '-Wl,-z,now',
               '-Wl,-z,relro',
             ],
           }],
         ],
       },
@@ skipping 132 matching lines @@
           ['clang==1', {
             'variables': {
               'clang_dir': '../third_party/llvm-build/Release+Asserts/bin',
             },
           }],
           ['asan==1', {
             'xcode_settings': {
               'OTHER_CFLAGS': [
                 '-fsanitize=address',
                 '-mllvm -asan-globals=0',  # http://crbug.com/352073
-                '-w',  # http://crbug.com/162783
+                '-Wno-error=macro-redefined',  # http://crbug.com/162783
+                '-Wno-error=unused-function',  # http://crbug.com/162783
                 '-gline-tables-only',
               ],
             },
           }],
           ['asan_coverage!=0', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-mllvm -asan-coverage=<(asan_coverage)',
                 ],
@@ skipping 837 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',
   },
 }