Don't use -O3 with sanitizers.

build/toolchain.gypi

 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 13 matching lines @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 # Shared definitions for all V8-related targets.
 
 {
   'variables': {
     'msvs_use_common_release': 0,
     'clang%': 0,
+    'asan%': 0,
+    'lsan%': 0,
+    'msan%': 0,
+    'tsan%': 0,
+    'ubsan%': 0,
+    'ubsan_vptr%': 0,
     'v8_target_arch%': '<(target_arch)',
     'v8_host_byteorder%': '<!(python -c "import sys; print sys.byteorder")',
     # Native Client builds currently use the V8 ARM JIT and
     # arm/simulator-arm.cc to defer the significant effort required
     # for NaCl JIT support. The nacl_target_arch variable provides
     # the 'true' target arch for places in this file that need it.
     # TODO(bradchen): get rid of nacl_target_arch when someday
     # NaCl V8 builds stop using the ARM simulator
     'nacl_target_arch%': 'none',     # must be set externally
 
@@ skipping 969 matching lines @@
               '-O0',
               '-O1',
               '-Os',
             ],
             'cflags': [
               '-fdata-sections',
               '-ffunction-sections',
             ],
             'conditions': [
               # TODO(crbug.com/272548): Avoid -O3 in NaCl
-              ['nacl_target_arch=="none"', {
+              # Don't use -O3 with sanitizers.
+              ['nacl_target_arch=="none" and asan==0 and msan==0 and lsan==0 \
+                and tsan==0 and ubsan==0 and ubsan_vptr==0', {
                 'cflags': ['-O3'],
                 'cflags!': ['-O2'],
                 }, {
                 'cflags': ['-O2'],
                 'cflags!': ['-O3'],
               }],
             ],
           }],
           ['OS=="mac"', {
             'xcode_settings': {
@@ skipping 64 matching lines @@
             'cflags!': [
               '-Os',
             ],
             'cflags': [
               '-fdata-sections',
               '-ffunction-sections',
               '<(wno_array_bounds)',
             ],
             'conditions': [
               # TODO(crbug.com/272548): Avoid -O3 in NaCl
-              ['nacl_target_arch=="none"', {
+              # Don't use -O3 with sanitizers.
+              ['nacl_target_arch=="none" and asan==0 and msan==0 and lsan==0 \
+                and tsan==0 and ubsan==0 and ubsan_vptr==0', {
                 'cflags': ['-O3'],
                 'cflags!': ['-O2'],
               }, {
                 'cflags': ['-O2'],
                 'cflags!': ['-O3'],
               }],
             ],
           }],
           ['OS=="android"', {
             'cflags!': [
@@ skipping 43 matching lines @@
           ['v8_enable_slow_dchecks==1', {
             'defines': [
               'ENABLE_SLOW_DCHECKS',
             ],
           }],
         ],  # conditions
       },  # Release
     },  # configurations
   },  # target_defaults
 }