ARM: Support hardfloat in SCons build and make it a build time setting

SConstruct

 # Copyright 2010 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 136 matching lines @@
       'CCFLAGS':      ['-m32'],
       'LINKFLAGS':    ['-m32']
     },
     'arch:arm': {
       'CPPDEFINES':   ['V8_TARGET_ARCH_ARM'],
       'unalignedaccesses:on' : {
         'CPPDEFINES' : ['CAN_USE_UNALIGNED_ACCESSES=1']
       },
       'unalignedaccesses:off' : {
         'CPPDEFINES' : ['CAN_USE_UNALIGNED_ACCESSES=0']
+      },
+      'armeabi:softfloat' : {
+        'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
+        'simulator:none': {
+          'CCFLAGS':     ['-mfloat-abi=softfp'],
+        }
+      },
+      'armeabi:hardfloat' : {
+        'CPPDEFINES' : ['USE_EABI_HARDFLOAT=1', 'CAN_USE_VFP_INSTRUCTIONS'],
+        'simulator:none': {
+          'CCFLAGS':     ['-mfloat-abi=hard'],
+        }
       }
     },
     'simulator:arm': {
       'CCFLAGS':      ['-m32'],
       'LINKFLAGS':    ['-m32'],
     },
     'arch:mips': {
       'CPPDEFINES':   ['V8_TARGET_ARCH_MIPS'],
       'mips_arch_variant:mips32r2': {
         'CPPDEFINES':    ['_MIPS_ARCH_MIPS32R2']
@@ skipping 112 matching lines @@
       'WARNINGFLAGS': ['-pedantic'],
       'library:shared': {
         'soname:on': {
           'LINKFLAGS': ['-Wl,-soname,${SONAME}']
         }
       }
     },
     'os:macos': {
       'WARNINGFLAGS': ['-pedantic']
     },
+    'arch:arm': {
+      # This is to silence warnings about ABI changes that some versions of the
+      # CodeSourcery G++ tool chain produce for each occurrence of varargs.
+      'WARNINGFLAGS': ['-Wno-abi']
+    },
     'disassembler:on': {
       'CPPDEFINES':   ['ENABLE_DISASSEMBLER']
     }
   },
   'msvc': {
     'all': {
       'WARNINGFLAGS': ['/W3', '/WX', '/wd4351', '/wd4355', '/wd4800']
     },
     'library:shared': {
       'CPPDEFINES': ['BUILDING_V8_SHARED'],
@@ skipping 63 matching lines @@
   }
 }
 
 
 CCTEST_EXTRA_FLAGS = {
   'all': {
     'CPPPATH': [join(root_dir, 'src')],
   },
   'gcc': {
     'all': {
-      'LIBPATH': [abspath('.')]
+      'LIBPATH':      [abspath('.')],
+      'CCFLAGS':      ['$DIALECTFLAGS', '$WARNINGFLAGS'],
+      'CXXFLAGS':     ['$CCFLAGS', '-fno-rtti', '-fno-exceptions'],
+      'LINKFLAGS':    ['$CCFLAGS'],
     },
     'os:linux': {
       'LIBS':         ['pthread'],
     },
     'os:macos': {
       'LIBS':         ['pthread'],
     },
     'os:freebsd': {
       'LIBS':         ['execinfo', 'pthread']
     },
@@ skipping 29 matching lines @@
   }
 }
 
 
 SAMPLE_FLAGS = {
   'all': {
     'CPPPATH': [join(abspath('.'), 'include')],
   },
   'gcc': {
     'all': {
-      'LIBPATH': ['.'],
-      'CCFLAGS': ['-fno-rtti', '-fno-exceptions']
+      'LIBPATH':      ['.'],
+      'CCFLAGS':      ['$DIALECTFLAGS', '$WARNINGFLAGS'],
+      'CXXFLAGS':     ['$CCFLAGS', '-fno-rtti', '-fno-exceptions'],
+      'LINKFLAGS':    ['$CCFLAGS'],
     },
     'os:linux': {
       'LIBS':         ['pthread'],
     },
     'os:macos': {
       'LIBS':         ['pthread'],
     },
     'os:freebsd': {
       'LIBPATH' :     ['/usr/local/lib'],
       'LIBS':         ['execinfo', 'pthread']
     },
     'os:solaris': {
       'LIBPATH' :     ['/usr/local/lib'],
       'LIBS':         ['m', 'pthread', 'socket', 'nsl', 'rt'],
       'LINKFLAGS':    ['-mt']
     },
     'os:openbsd': {
       'LIBPATH' :     ['/usr/local/lib'],
       'LIBS':         ['execinfo', 'pthread']
     },
     'os:win32': {
       'LIBS':         ['winmm', 'ws2_32']
     },
     'arch:arm': {
-      'LINKFLAGS':   ARM_LINK_FLAGS
+      'LINKFLAGS':   ARM_LINK_FLAGS,
+      'armeabi:softfloat' : {
+        'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
+        'simulator:none': {
+          'CCFLAGS':     ['-mfloat-abi=softfp'],
+        }
+      },
+      'armeabi:hardfloat' : {
+        'CPPDEFINES' : ['USE_EABI_HARDFLOAT=1', 'CAN_USE_VFP_INSTRUCTIONS'],
+        'simulator:none': {
+          'CCFLAGS':     ['-mfloat-abi=hard'],
+        }
+      }
     },
     'arch:ia32': {
       'CCFLAGS':      ['-m32'],
       'LINKFLAGS':    ['-m32']
     },
     'arch:x64': {
       'CCFLAGS':      ['-m64'],
       'LINKFLAGS':    ['-m64']
     },
     'arch:mips': {
@@ skipping 81 matching lines @@
   }
 }
 
 
 PREPARSER_FLAGS = {
   'all': {
     'CPPPATH': [join(abspath('.'), 'include'), join(abspath('.'), 'src')]
   },
   'gcc': {
     'all': {
-      'LIBPATH': ['.'],
-      'CCFLAGS': ['-fno-rtti', '-fno-exceptions']
+      'LIBPATH':      ['.'],
+      'CCFLAGS':      ['$DIALECTFLAGS', '$WARNINGFLAGS'],
+      'CXXFLAGS':     ['$CCFLAGS', '-fno-rtti', '-fno-exceptions'],
+      'LINKFLAGS':    ['$CCFLAGS'],
     },
     'os:win32': {
       'LIBS':         ['winmm', 'ws2_32']
     },
     'arch:arm': {
-      'LINKFLAGS':   ARM_LINK_FLAGS
+      'LINKFLAGS':   ARM_LINK_FLAGS,
+      'armeabi:softfloat' : {
+        'simulator:none': {
+          'CCFLAGS':     ['-mfloat-abi=softfp'],
+        }
+      },
+      'armeabi:hardfloat' : {
+        'simulator:none': {
+          'CCFLAGS':     ['-mfloat-abi=hard'],
+        }
+      }
     },
     'arch:ia32': {
       'CCFLAGS':      ['-m32'],
       'LINKFLAGS':    ['-m32']
     },
     'arch:x64': {
       'CCFLAGS':      ['-m64'],
       'LINKFLAGS':    ['-m64']
     },
     'arch:mips': {
@@ skipping 99 matching lines @@
       'msvcrt:shared': {
         'CCFLAGS':  ['/MDd']
       }
     }
   }
 }
 
 
 D8_FLAGS = {
   'gcc': {
+    'all': {
+      'CCFLAGS': ['$DIALECTFLAGS', '$WARNINGFLAGS'],
+      'CXXFLAGS': ['$CCFLAGS', '-fno-rtti', '-fno-exceptions'],
+      'LINKFLAGS': ['$CCFLAGS'],
+    },
     'console:readline': {
       'LIBS': ['readline']
     },
     'os:linux': {
       'LIBS': ['pthread'],
     },
     'os:macos': {
       'LIBS': ['pthread'],
     },
     'os:freebsd': {
@@ skipping 216 matching lines @@
   'strictaliasing': {
     'values': ['default', 'off'],
     'guess': GuessStrictAliasing,
     'help': 'assume strict aliasing while optimizing'
   },
   'pgo': {
     'values': ['off', 'instrument', 'optimize'],
     'default': 'off',
     'help': 'select profile guided optimization variant',
   },
+  'armeabi': {
+    'values': ['hardfloat', 'softfloat'],
+    'default': 'softfloat',
+    'help': 'generate calling conventiont according to selected ARM EABI variant'
+  },
   'mipsabi': {
     'values': ['hardfloat', 'softfloat', 'none'],
     'default': 'hardfloat',
     'help': 'generate calling conventiont according to selected mips ABI'
   },
   'mips_arch_variant': {
     'values': ['mips32r2', 'mips32r1'],
     'default': 'mips32r2',
     'help': 'mips variant'
   }
@@ skipping 430 matching lines @@
 # version of scons.  Also, there's a bug in some revisions that
 # doesn't allow this flag to be set, so we swallow any exceptions.
 # Lovely.
 try:
   SetOption('warn', 'no-deprecated')
 except:
   pass
 
 
 Build()