--- a/accessible/atk/moz.build
+++ b/accessible/atk/moz.build
@@ -46,8 +46,10 @@ FINAL_LIBRARY = 'xul'
 if CONFIG['MOZ_ENABLE_GTK']:
     CFLAGS += CONFIG['TK_CFLAGS']
     CXXFLAGS += CONFIG['TK_CFLAGS']
 
 if CONFIG['MOZ_ENABLE_DBUS']:
     CXXFLAGS += CONFIG['MOZ_DBUS_CFLAGS']
 
 include('/ipc/chromium/chromium-config.mozbuild')
+
+FAIL_ON_WARNINGS = True

--- a/accessible/ipc/moz.build
+++ b/accessible/ipc/moz.build
@@ -24,8 +24,10 @@ if CONFIG['ACCESSIBILITY']:
     LOCAL_INCLUDES += [
         '../base',
         '../generic',
     ]
 
     FINAL_LIBRARY = 'xul'
 
 include('/ipc/chromium/chromium-config.mozbuild')
+
+FAIL_ON_WARNINGS = True

--- a/accessible/other/moz.build
+++ b/accessible/other/moz.build
@@ -17,8 +17,10 @@ SOURCES += [
 LOCAL_INCLUDES += [
     '/accessible/base',
     '/accessible/generic',
     '/accessible/html',
     '/accessible/xul',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/accessible/windows/ia2/moz.build
+++ b/accessible/windows/ia2/moz.build
@@ -45,8 +45,10 @@ LOCAL_INCLUDES += [
 ]
 
 FINAL_LIBRARY = 'xul'
 
 # The midl generated code include Windows headers which defines min and max
 # macros which conflicts with std::min/max.  Suppress the macros:
 if CONFIG['OS_ARCH'] == 'WINNT':
     DEFINES['NOMINMAX'] = True
+
+FAIL_ON_WARNINGS = True

--- a/accessible/windows/msaa/moz.build
+++ b/accessible/windows/msaa/moz.build
@@ -54,8 +54,10 @@ LOCAL_INCLUDES += [
     '/accessible/xpcom',
     '/accessible/xul',
     '/dom/base',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/accessible/windows/sdn/moz.build
+++ b/accessible/windows/sdn/moz.build
@@ -19,8 +19,10 @@ LOCAL_INCLUDES += [
     '/accessible/xul',
 ]
 
 # The midl generated code include Windows headers which defines min and max
 # macros which conflicts with std::min/max.  Suppress the macros:
 DEFINES['NOMINMAX'] = True
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/accessible/windows/uia/moz.build
+++ b/accessible/windows/uia/moz.build
@@ -18,8 +18,10 @@ LOCAL_INCLUDES += [
 ]
 
 FINAL_LIBRARY = 'xul'
 
 # The midl generated code include Windows headers which defines min and max
 # macros which conflicts with std::min/max.  Suppress the macros:
 if CONFIG['OS_ARCH'] == 'WINNT':
     DEFINES['NOMINMAX'] = True
+
+FAIL_ON_WARNINGS = True

--- a/b2g/app/moz.build
+++ b/b2g/app/moz.build
@@ -69,8 +69,10 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk
     ]
 
 DISABLE_STL_WRAPPING = True
 
 if CONFIG['OS_ARCH'] == 'WINNT':
     OS_LIBS += [
         'version',
     ]
+
+FAIL_ON_WARNINGS = True

--- a/b2g/gaia/moz.build
+++ b/b2g/gaia/moz.build
@@ -13,8 +13,10 @@ if CONFIG['OS_ARCH'] == 'WINNT':
     DEFINES['B2G_NAME'] = 'L"%s-bin%s"' % (PROGRAM, CONFIG['BIN_SUFFIX'])
     DEFINES['GAIA_PATH'] = 'L"gaia\\\\profile"'
 else:
     SOURCES += [
         'run-b2g.c',
     ]
     DEFINES['B2G_NAME'] = '"%s-bin%s"' % (PROGRAM, CONFIG['BIN_SUFFIX'])
     DEFINES['GAIA_PATH'] = '"gaia/profile"'
+
+FAIL_ON_WARNINGS = True

--- a/browser/app/moz.build
+++ b/browser/app/moz.build
@@ -67,8 +67,10 @@ DISABLE_STL_WRAPPING = True
 
 if CONFIG['MOZ_LINKER']:
     OS_LIBS += CONFIG['MOZ_ZLIB_LIBS']
 
 if CONFIG['HAVE_CLOCK_MONOTONIC']:
     OS_LIBS += CONFIG['REALTIME_LIBS']
 
 JAR_MANIFESTS += ['jar.mn']
+
+FAIL_ON_WARNINGS = True

--- a/browser/components/about/moz.build
+++ b/browser/components/about/moz.build
@@ -12,8 +12,10 @@ SOURCES += [
     'AboutRedirector.cpp',
 ]
 
 FINAL_LIBRARY = 'browsercomps'
 
 LOCAL_INCLUDES += [
     '../build',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/browser/components/build/moz.build
+++ b/browser/components/build/moz.build
@@ -29,8 +29,10 @@ if CONFIG['OS_ARCH'] == 'WINNT':
         'shlwapi',
         'version',
     ]
 
 # Mac: Need to link with CoreFoundation for Mac Migrators (PList reading code)
 # GTK2: Need to link with glib for GNOME shell service
 if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('cocoa', 'gtk2', 'gtk3'):
     OS_LIBS += CONFIG['TK_LIBS']
+
+FAIL_ON_WARNINGS = True

--- a/browser/components/dirprovider/moz.build
+++ b/browser/components/dirprovider/moz.build
@@ -16,8 +16,10 @@ XPCSHELL_TESTS_MANIFESTS += [
     'tests/unit/xpcshell.ini',
 ]
 
 FINAL_LIBRARY = 'browsercomps'
 
 LOCAL_INCLUDES += [
     '../build'
 ]
+
+FAIL_ON_WARNINGS = True

--- a/browser/components/feeds/moz.build
+++ b/browser/components/feeds/moz.build
@@ -34,8 +34,10 @@ EXTRA_PP_COMPONENTS += [
 FINAL_LIBRARY = 'browsercomps'
 
 for var in ('MOZ_APP_NAME', 'MOZ_MACBUNDLE_NAME'):
     DEFINES[var] = CONFIG[var]
 
 LOCAL_INCLUDES += [
     '../build',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/browser/components/migration/moz.build
+++ b/browser/components/migration/moz.build
@@ -47,8 +47,10 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'coco
     ]
     DEFINES['HAS_SAFARI_MIGRATOR'] = True
 
 EXTRA_PP_JS_MODULES += [
     'MigrationUtils.jsm',
 ]
 
 FINAL_LIBRARY = 'browsercomps'
+
+FAIL_ON_WARNINGS = True

--- a/browser/components/shell/moz.build
+++ b/browser/components/shell/moz.build
@@ -44,8 +44,10 @@ EXTRA_COMPONENTS += [
     'nsSetDefaultBrowser.js',
     'nsSetDefaultBrowser.manifest',
 ]
 
 for var in ('MOZ_APP_NAME', 'MOZ_APP_VERSION'):
     DEFINES[var] = '"%s"' % CONFIG[var]
 
 CXXFLAGS += CONFIG['TK_CFLAGS']
+
+FAIL_ON_WARNINGS = True

--- a/docshell/build/moz.build
+++ b/docshell/build/moz.build
@@ -19,8 +19,10 @@ LOCAL_INCLUDES += [
     '/uriloader/exthandler',
     '/uriloader/prefetch',
     ]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
     LOCAL_INCLUDES += ['/uriloader/exthandler/mac']
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/dom/media/bridge/moz.build
+++ b/dom/media/bridge/moz.build
@@ -21,8 +21,10 @@ LOCAL_INCLUDES += [
     '/media/webrtc/',
     '/media/webrtc/signaling/src/common/time_profiling',
     '/media/webrtc/signaling/src/media-conduit',
     '/media/webrtc/signaling/src/mediapipeline',
     '/media/webrtc/signaling/src/peerconnection',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/dom/media/omx/mediaresourcemanager/moz.build
+++ b/dom/media/omx/mediaresourcemanager/moz.build
@@ -31,8 +31,10 @@ CXXFLAGS += [
         'frameworks/base/include/utils',
         'frameworks/base/include/media/',
         'frameworks/base/include/media/stagefright/openmax',
         'frameworks/base/media/libstagefright/include',
     ]
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/dom/media/omx/moz.build
+++ b/dom/media/omx/moz.build
@@ -100,8 +100,10 @@ CXXFLAGS += [
         'frameworks/native/opengl/include',
         'frameworks/native/include',
         'hardware/libhardware/include/',
     ]
 ]
 
 if CONFIG['ANDROID_VERSION'] > '15':
     DEFINES['MOZ_OMX_WEBM_DECODER'] = True
+
+FAIL_ON_WARNINGS = True

--- a/mozglue/linker/moz.build
+++ b/mozglue/linker/moz.build
@@ -28,8 +28,10 @@ DEFINES['IMPL_MFBT'] = True
 
 DISABLE_STL_WRAPPING = True
 
 TEST_DIRS += ['tests']
 
 HOST_OS_LIBS += [
     'z',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/parser/xml/moz.build
+++ b/parser/xml/moz.build
@@ -31,8 +31,10 @@ SOURCES += [
     'nsSAXAttributes.cpp',
     'nsSAXLocator.cpp',
     'nsSAXXMLReader.cpp',
 ]
 
 MSVC_ENABLE_PGO = True
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/rdf/build/moz.build
+++ b/rdf/build/moz.build
@@ -13,8 +13,10 @@ SOURCES += [
 ]
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/rdf/base',
     '/rdf/datasource',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/rdf/tests/rdfcat/moz.build
+++ b/rdf/tests/rdfcat/moz.build
@@ -6,8 +6,10 @@
 
 GeckoProgram('rdfcat', linkage='dependent')
 
 SOURCES += [
     'rdfcat.cpp',
 ]
 
 CXXFLAGS += CONFIG['TK_CFLAGS']
+
+FAIL_ON_WARNINGS = True

--- a/rdf/tests/rdfpoll/moz.build
+++ b/rdf/tests/rdfpoll/moz.build
@@ -4,8 +4,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 GeckoProgram('rdfpoll', linkage='dependent')
 
 SOURCES += [
     'rdfpoll.cpp',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/rdf/tests/triplescat/moz.build
+++ b/rdf/tests/triplescat/moz.build
@@ -6,8 +6,10 @@
 
 GeckoProgram('triplescat', linkage='dependent')
 
 SOURCES += [
     'triplescat.cpp',
 ]
 
 CXXFLAGS += CONFIG['TK_CFLAGS']
+
+FAIL_ON_WARNINGS = True

--- a/rdf/util/internal/moz.build
+++ b/rdf/util/internal/moz.build
@@ -4,8 +4,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 include('../objs.mozbuild')
 
 SOURCES += rdf_util_src_cppsrcs
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/rdf/util/moz.build
+++ b/rdf/util/moz.build
@@ -13,8 +13,10 @@ EXPORTS += [
 include('objs.mozbuild')
 
 SOURCES += rdf_util_src_cppsrcs
 
 Library('rdfutil_external_s')
 
 # we don't want the shared lib, but we want to force the creation of a static lib.
 FORCE_STATIC_LIB = True
+
+FAIL_ON_WARNINGS = True

--- a/startupcache/moz.build
+++ b/startupcache/moz.build
@@ -21,8 +21,10 @@ EXPORTS.mozilla.scache += [
 # These files cannot be built in unified mode because they rely on plarena.h.
 SOURCES += [
     'StartupCache.cpp',
     'StartupCacheModule.cpp',
     'StartupCacheUtils.cpp',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/testing/tools/screenshot/moz.build
+++ b/testing/tools/screenshot/moz.build
@@ -18,8 +18,10 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'wi
         'win32-screenshot.cpp',
     ]
     USE_STATIC_LIBS = True
     if CONFIG['GNU_CC']:
         WIN32_EXE_LDFLAGS += ['-municode']
     OS_LIBS += [
         'gdiplus',
     ]
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/components/ctypes/tests/moz.build
+++ b/toolkit/components/ctypes/tests/moz.build
@@ -1,21 +1,24 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
 NO_DIST_INSTALL = True
 
 XPCSHELL_TESTS_MANIFESTS += ['unit/xpcshell.ini']
 MOCHITEST_CHROME_MANIFESTS += ['chrome/chrome.ini']
 
 UNIFIED_SOURCES += [
     'jsctypes-test-errno.cpp',
     'jsctypes-test-finalizer.cpp',
     'jsctypes-test.cpp',
 ]
 
 SharedLibrary('jsctypes-test')
 
 LOCAL_INCLUDES += [
     '/js/src/ctypes',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/devtools/server/moz.build
+++ b/toolkit/devtools/server/moz.build
@@ -69,8 +69,9 @@ EXTRA_JS_MODULES.devtools.server.actors 
     'actors/webgl.js',
 ]
 
 EXTRA_JS_MODULES.devtools.server.actors.utils += [
     'actors/utils/make-debugger.js',
     'actors/utils/map-uri-to-addon-id.js'
 ]
 
+FAIL_ON_WARNINGS = True

--- a/toolkit/library/StaticXULComponentsEnd/moz.build
+++ b/toolkit/library/StaticXULComponentsEnd/moz.build
@@ -8,8 +8,10 @@ SOURCES += [
 
 # Don't let LTO reorder StaticXULComponentsStart.o.
 if '-flto' in CONFIG['OS_CXXFLAGS']:
     SOURCES['StaticXULComponentsEnd.cpp'].flags += ['-fno-lto']
 
 Library('StaticXULComponentsEnd')
 
 DEFINES['MOZILLA_INTERNAL_API'] = True
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/system/androidproxy/moz.build
+++ b/toolkit/system/androidproxy/moz.build
@@ -4,8 +4,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 SOURCES += [
     'nsAndroidSystemProxySettings.cpp',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/system/dbus/moz.build
+++ b/toolkit/system/dbus/moz.build
@@ -11,8 +11,10 @@ SOURCES += [
 ]
 
 XPCOMBinaryComponent('dbusservice')
 
 CXXFLAGS += CONFIG['TK_CFLAGS']
 CXXFLAGS += CONFIG['MOZ_DBUS_GLIB_CFLAGS']
 
 OS_LIBS += CONFIG['MOZ_DBUS_GLIB_LIBS']
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/system/osxproxy/moz.build
+++ b/toolkit/system/osxproxy/moz.build
@@ -4,8 +4,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 SOURCES += [
     'nsOSXSystemProxySettings.mm',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/system/unixproxy/moz.build
+++ b/toolkit/system/unixproxy/moz.build
@@ -10,8 +10,10 @@ if CONFIG['MOZ_ENABLE_LIBPROXY']:
         'nsLibProxySettings.cpp',
     ]
 else:
     SOURCES += [
         'nsUnixSystemProxySettings.cpp',
     ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/toolkit/system/windowsproxy/moz.build
+++ b/toolkit/system/windowsproxy/moz.build
@@ -4,8 +4,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 SOURCES += [
     'nsWindowsSystemProxySettings.cpp',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/webapprt/mac/moz.build
+++ b/webapprt/mac/moz.build
@@ -22,8 +22,10 @@ LOCAL_INCLUDES += [
     '/xpcom/build',
 ]
 
 USE_LIBS += [
     'xpcomglue',
 ]
 
 DISABLE_STL_WRAPPING = True
+
+FAIL_ON_WARNINGS = True

--- a/webapprt/win/moz.build
+++ b/webapprt/win/moz.build
@@ -49,8 +49,10 @@ USE_LIBS += [
     'xpcomglue_staticruntime',
 ]
 
 DISABLE_STL_WRAPPING = True
 
 OS_LIBS += [
     'shell32',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/xpcom/reflect/xptcall/md/unix/moz.build
+++ b/xpcom/reflect/xptcall/md/unix/moz.build
@@ -324,8 +324,10 @@ if CONFIG['OS_ARCH'] == 'Linux':
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../..',
     '/xpcom/reflect/xptinfo',
 ]
 
 NO_PGO = True
+
+FAIL_ON_WARNINGS = True

--- a/xpcom/reflect/xptcall/md/win32/moz.build
+++ b/xpcom/reflect/xptcall/md/win32/moz.build
@@ -36,8 +36,10 @@ else:
         SOURCES['xptcinvoke.cpp'].no_pgo = True
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../..',
     '/xpcom/reflect/xptinfo',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/xpcom/reflect/xptcall/moz.build
+++ b/xpcom/reflect/xptcall/moz.build
@@ -18,8 +18,10 @@ EXPORTS += [
 
 MSVC_ENABLE_PGO = True
 
 LOCAL_INCLUDES += [
     '/xpcom/reflect/xptinfo',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/xpcom/tests/component/moz.build
+++ b/xpcom/tests/component/moz.build
@@ -16,8 +16,10 @@ DEFINES['LIBRARY_FILENAME'] = '%s%s%s' %
     CONFIG['DLL_PREFIX'],
     LIBRARY_NAME,
     CONFIG['DLL_SUFFIX']
 )
 
 # Need to link with CoreFoundation on Mac
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     OS_LIBS += CONFIG['TK_LIBS']
+
+FAIL_ON_WARNINGS = True

--- a/xpcom/tests/component_no_aslr/moz.build
+++ b/xpcom/tests/component_no_aslr/moz.build
@@ -16,8 +16,10 @@ DEFINES['LIBRARY_FILENAME'] = '%s%s%s' %
     CONFIG['DLL_PREFIX'],
     LIBRARY_NAME,
     CONFIG['DLL_SUFFIX']
 )
 
 # Need to link with CoreFoundation on Mac
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     OS_LIBS += CONFIG['TK_LIBS']
+
+FAIL_ON_WARNINGS = True

--- a/xpfe/components/build/moz.build
+++ b/xpfe/components/build/moz.build
@@ -8,8 +8,10 @@ SOURCES += [
     'nsModule.cpp',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../directory',
 ]
+
+FAIL_ON_WARNINGS = True

--- a/xpfe/components/windowds/moz.build
+++ b/xpfe/components/windowds/moz.build
@@ -10,8 +10,10 @@ XPIDL_SOURCES += [
 
 XPIDL_MODULE = 'windowds'
 
 SOURCES += [
     'nsWindowDataSource.cpp',
 ]
 
 FINAL_LIBRARY = 'xul'
+
+FAIL_ON_WARNINGS = True

--- a/xulrunner/app/moz.build
+++ b/xulrunner/app/moz.build
@@ -48,8 +48,10 @@ if CONFIG['OS_ARCH'] == 'WINNT':
         'shell32',
         'ole32',
         'oleaut32',
         'version',
         'winspool',
     ]
 
 DISABLE_STL_WRAPPING = True
+
+FAIL_ON_WARNINGS = True

--- a/xulrunner/examples/simple/components/src/moz.build
+++ b/xulrunner/examples/simple/components/src/moz.build
@@ -11,8 +11,10 @@ SOURCES += [
 XPCOMBinaryComponent('simpletest')
 
 EXTRA_COMPONENTS += [
     'SimpleTest.js',
     'SimpleTest.manifest',
 ]
 
 XPI_NAME = 'simple'
+
+FAIL_ON_WARNINGS = True

--- a/xulrunner/stub/moz.build
+++ b/xulrunner/stub/moz.build
@@ -42,8 +42,10 @@ if CONFIG['OS_ARCH'] == 'WINNT':
         'shell32',
     ]
 
 DISABLE_STL_WRAPPING = True
 
 # Need to link with CoreFoundation on Mac
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     OS_LIBS += CONFIG['TK_LIBS']
+
+FAIL_ON_WARNINGS = True

--- a/xulrunner/tools/redit/moz.build
+++ b/xulrunner/tools/redit/moz.build
@@ -8,8 +8,10 @@ if CONFIG['OS_ARCH'] == 'WINNT':
     GeckoProgram('redit')
     SOURCES += [
         'redit.cpp',
     ]
     for var in ('WIN32_LEAN_AND_MEAN', 'UNICODE', '_UNICODE'):
         DEFINES[var] = True
     if CONFIG['GNU_CC']:
         WIN32_EXE_LDFLAGS += ['-municode']
+
+FAIL_ON_WARNINGS = True