Set '-m32' option for host and target platforms

build/common.gypi

 # Copyright 2012 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 134 matching lines @@
                 'target_conditions': [
                   ['_toolset=="target"', {
                     'cflags': ['-mfloat-abi=hard',],
                   }],
                 ],
               }, {
                 'defines': [
                   'USE_EABI_HARDFLOAT=0',
                 ],
               }],
-              # The ARM assembler assumes the host is 32 bits,
-              # so force building 32-bit host tools.
-              ['host_arch=="x64" or OS=="android"', {
-                'target_conditions': [
-                  ['_toolset=="host"', {
-                    'cflags': ['-m32'],
-                    'ldflags': ['-m32'],
-                  }],
-                ],
-              }],
             ],
           }],
           ['v8_target_arch=="ia32"', {
             'defines': [
               'V8_TARGET_ARCH_IA32',
             ],
           }],
           ['v8_target_arch=="mips"', {
             'defines': [
               'V8_TARGET_ARCH_MIPS',
@@ skipping 41 matching lines @@
                 'defines': [
                   '__mips_soft_float=1'
                 ],
               }],
               ['mips_arch_variant=="mips32r2"', {
                 'defines': ['_MIPS_ARCH_MIPS32R2',],
               }],
               ['mips_arch_variant=="loongson"', {
                 'defines': ['_MIPS_ARCH_LOONGSON',],
               }],
-              # The MIPS assembler assumes the host is 32 bits,
-              # so force building 32-bit host tools.
-              ['host_arch=="x64"', {
-                'target_conditions': [
-                  ['_toolset=="host"', {
-                    'cflags': ['-m32'],
-                    'ldflags': ['-m32'],
-                  }],
-                ],
-              }],
             ],
           }],
           ['v8_target_arch=="x64"', {
             'defines': [
               'V8_TARGET_ARCH_X64',
             ],
           }],
         ],
       }, {  # Section for OS=="mac".
         'conditions': [
@@ skipping 37 matching lines @@
       ['OS=="win" and v8_target_arch=="x64"', {
         'msvs_settings': {
           'VCLinkerTool': {
             'StackReserveSize': '2097152',
           },
         },
       }],
       ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
          or OS=="netbsd"', {
         'conditions': [
-          [ 'v8_target_arch!="x64"', {
-            # Pass -m32 to the compiler iff it understands the flag.
-            'variables': {
-              'm32flag': '<!((echo | $(echo ${CXX:-$(which g++)}) -m32 -E - > /dev/null 2>&1) && echo -n "-m32" || true)',
-            },
-            'cflags': [ '<(m32flag)' ],
-            'ldflags': [ '<(m32flag)' ],
-          }],
           [ 'v8_no_strict_aliasing==1', {
             'cflags': [ '-fno-strict-aliasing' ],
           }],
         ],  # conditions
       }],
       ['OS=="solaris"', {
         'defines': [ '__C99FEATURES__=1' ],  # isinf() etc.
       }],
+      ['v8_target_arch!="x64"', {

[Jakob Kummerow, 2012/05/15 14:05:34]

The condition must check for OS as well, as the shell commands are not available
e.g. on Windows.
Also, I have a weak preference to explicitly list the affected architectures,
but I don't feel strongly about that.
The following should work:

['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or \
   OS=="solaris" or OS=="netbsd" or OS=="mac") and \
  (v8_target_arch=="arm" or v8_target_arch=="ia32" or \
   v8_target_arch=="mips")', {

(Mac is tricky since you can use GYP to generate either Xcode project files or
Makefiles there. In order not to break the latter, I think we have to include
OS=="mac" here, but I might be wrong. Do you have a Mac around where you can
test this?)

[yongsheng, 2012/05/15 14:20:49]

I'll change it. 
Sorry, I don't have Mac. Buildbot will test this? right?

[yongsheng, 2012/05/15 14:36:03]

Sorry, I forget "Android". will add it.

+        # Check whether the host compiler and target compiler support '-m32' option and set it if yes

[Jakob Kummerow, 2012/05/15 14:05:34]

nit: for comments, please keep the 80-col limit per line, and end sentences with
a full stop.

[yongsheng, 2012/05/15 14:20:49]

okay,thanks a lot for your review.

+        # except that 'v8_target_arch'is x64
+        'target_conditions': [
+          ['_toolset=="host"', {
+            'variables': {
+              'm32flag': '<!((echo | $(echo ${CXX_host:-${CXX:-$(which g++)}}) -m32 -E - > /dev/null 2>&1) && echo -n "-m32" || true)',
+            },
+            'cflags': [ '<(m32flag)' ],
+            'ldflags': [ '<(m32flag)' ],
+          }],
+          ['_toolset=="target"', {
+            'variables': {
+              'm32flag': '<!((echo | $(echo ${CXX_target:-${CXX:-$(which g++)}}) -m32 -E - > /dev/null 2>&1) && echo -n "-m32" || true)',
+            },
+            'cflags': [ '<(m32flag)' ],
+            'ldflags': [ '<(m32flag)' ],
+          }],
+        ],
+      }],
     ],  # conditions
     'configurations': {
       'Debug': {
         'defines': [
           'DEBUG',
           'ENABLE_DISASSEMBLER',
           'V8_ENABLE_CHECKS',
           'OBJECT_PRINT',
         ],
         'msvs_settings': {
@@ skipping 93 matching lines @@
                 'OptimizeReferences': '2',
                 'EnableCOMDATFolding': '2',
               },
             },
           }],  # OS=="win"
         ],  # conditions
       },  # Release
     },  # configurations
   },  # target_defaults
 }