build: always disable strict aliasing

V8 relies on it.

PR-URL: #54339
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: targos

Diff for: common.gypi

@@ -489,7 +489,12 @@
       }],
       [ 'OS in "linux freebsd openbsd solaris android aix os400 cloudabi"', {
         'cflags': [ '-Wall', '-Wextra', '-Wno-unused-parameter', ],
-        'cflags_cc': [ '-fno-rtti', '-fno-exceptions', '-std=gnu++17' ],
+        'cflags_cc': [
+          '-fno-rtti',
+          '-fno-exceptions',
+          '-fno-strict-aliasing',
+          '-std=gnu++17',
+        ],
         'defines': [ '__STDC_FORMAT_MACROS' ],
         'ldflags': [ '-rdynamic' ],
         'target_conditions': [
@@ -620,12 +625,10 @@
           'GCC_ENABLE_CPP_EXCEPTIONS': 'NO',        # -fno-exceptions
           'GCC_ENABLE_CPP_RTTI': 'NO',              # -fno-rtti
           'GCC_ENABLE_PASCAL_STRINGS': 'NO',        # No -mpascal-strings
+          'GCC_STRICT_ALIASING': 'NO',              # -fno-strict-aliasing
           'PREBINDING': 'NO',                       # No -Wl,-prebind
           'MACOSX_DEPLOYMENT_TARGET': '11.0',       # -mmacosx-version-min=11.0
           'USE_HEADERMAP': 'NO',
-          'OTHER_CFLAGS': [
-            '-fno-strict-aliasing',
-          ],
           'WARNING_CFLAGS': [
             '-Wall',
             '-Wendif-labels',

Diff for: configure.py

@@ -1637,7 +1637,6 @@ def configure_v8(o, configs):
   o['variables']['v8_enable_javascript_promise_hooks'] = 1
   o['variables']['v8_enable_lite_mode'] = 1 if options.v8_lite_mode else 0
   o['variables']['v8_enable_gdbjit'] = 1 if options.gdb else 0
-  o['variables']['v8_no_strict_aliasing'] = 1  # Work around compiler bugs.
   o['variables']['v8_optimized_debug'] = 0 if options.v8_non_optimized_debug else 1
   o['variables']['dcheck_always_on'] = 1 if options.v8_with_dchecks else 0
   o['variables']['v8_enable_object_print'] = 0 if options.v8_disable_object_print else 1

Diff for: doc/api/process.md

@@ -1097,7 +1097,6 @@ An example of the possible output looks like:
      node_shared_zlib: 'false',
      node_use_openssl: 'true',
      node_shared_openssl: 'false',
-     strict_aliasing: 'true',
      target_arch: 'x64',
      v8_use_snapshot: 1
    }

Diff for: tools/v8_gypfiles/toolchain.gypi

@@ -69,9 +69,6 @@
     # Enable profiling support. Only required on Windows.
     'v8_enable_prof%': 0,
 
-    # Some versions of GCC 4.5 seem to need -fno-strict-aliasing.
-    'v8_no_strict_aliasing%': 0,
-
     # Chrome needs this definition unconditionally. For standalone V8 builds,
     # it's handled in gypfiles/standalone.gypi.
     'want_separate_host_toolset%': 1,
@@ -674,14 +671,6 @@
           'V8_ANDROID_LOG_STDOUT',
         ],
       }],
-      ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
-         or OS=="netbsd" or OS=="qnx" or OS=="aix" or OS=="os400"', {
-        'conditions': [
-          [ 'v8_no_strict_aliasing==1', {
-            'cflags': [ '-fno-strict-aliasing' ],
-          }],
-        ],  # conditions
-      }],
       ['OS=="solaris"', {
         'defines': [ '__C99FEATURES__=1' ],  # isinf() etc.
       }],
@@ -838,7 +827,6 @@
               ['OS=="mac"', {
                 'xcode_settings': {
                   'GCC_OPTIMIZATION_LEVEL': '3',  # -O3
-                  'GCC_STRICT_ALIASING': 'YES',
                 },
               }],
               ['v8_enable_slow_dchecks==1', {
@@ -897,12 +885,6 @@
           ['OS=="mac"', {
             'xcode_settings': {
               'GCC_OPTIMIZATION_LEVEL': '3',  # -O3
-
-              # -fstrict-aliasing.  Mainline gcc
-              # enables this at -O2 and above,
-              # but Apple gcc does not unless it
-              # is specified explicitly.
-              'GCC_STRICT_ALIASING': 'YES',
             },
           }],  # OS=="mac"
           ['OS=="win"', {