Refactors the scons script (by Vlad Losev).

scons/SConscript

@@ -95,9 +95,8 @@ import os
 ############################################################
 # Environments for building the targets, sorted by name.
 
-Import('env')
+Import('env', 'EnvCreator')
 
-EnvCreator = SConscript('SConstruct.common').EnvCreator
 env = EnvCreator.Create(env)
 
 # Note: The relative paths in SConscript files are relative to the location
@@ -114,11 +113,15 @@ env = EnvCreator.Create(env)
 env.Prepend(CPPPATH = ['..', '../include'])
 
 env_use_own_tuple = EnvCreator.Create(env, EnvCreator.UseOwnTuple)
-env_warning_ok = EnvCreator.Create(env, EnvCreator.WarningOk)
-env_with_exceptions = EnvCreator.Create(env, EnvCreator.WithExceptions)
 env_less_optimized = EnvCreator.Create(env, EnvCreator.LessOptimized)
 env_with_threads = EnvCreator.Create(env, EnvCreator.WithThreads)
-env_without_rtti = EnvCreator.Create(env, EnvCreator.NoRtti)
+# The following environments are used to compile gtest_unittest.cc, which
+# triggers a warning  in all but the most recent GCC versions when compiling
+# the EXPECT_EQ(NULL, ptr) statement.
+env_warning_ok = EnvCreator.Create(env, EnvCreator.WarningOk)
+env_with_exceptions = EnvCreator.Create(env_warning_ok,
+                                        EnvCreator.WithExceptions)
+env_without_rtti = EnvCreator.Create(env_warning_ok, EnvCreator.NoRtti)
 
 ############################################################
 # Helpers for creating build targets.

scons/SConstruct.common

@@ -82,6 +82,108 @@ class SConstructHelper:
     # Enable scons -h
     Help(vars.GenerateHelpText(self.env_base))
 
+  class EnvCreator:
+    """Creates new customized environments from a base one."""
+
+    def _Remove(cls, env, attribute, value):
+      """Removes the given attribute value from the environment."""
+
+      attribute_values = env[attribute]
+      if value in attribute_values:
+        attribute_values.remove(value)
+    _Remove = classmethod(_Remove)
+
+    def Create(cls, base_env, modifier=None):
+      # User should NOT create more than one environment with the same
+      # modifier (including None).
+      env = base_env.Clone()
+      if modifier:
+        modifier(env)
+      else:
+        env['OBJ_SUFFIX'] = ''  # Default suffix for unchanged environment.
+      return env;
+    Create = classmethod(Create)
+
+    # Each of the following methods modifies the environment for a particular
+    # purpose and can be used by clients for creating new environments.  Each
+    # one needs to set the OBJ_SUFFIX variable to a unique suffix to
+    # differentiate targets built with that environment.  Otherwise, SCons may
+    # complain about same target built with different settings.
+
+    def UseOwnTuple(cls, env):
+      """Instructs Google Test to use its internal implementation of tuple."""
+
+      env['OBJ_SUFFIX'] = '_use_own_tuple'
+      env.Append(CPPDEFINES = 'GTEST_USE_OWN_TR1_TUPLE=1')
+    UseOwnTuple = classmethod(UseOwnTuple)
+
+    def WarningOk(cls, env):
+      """Does not treat warnings as errors.
+
+      Necessary for compiling gtest_unittest.cc, which triggers a gcc
+      warning when testing EXPECT_EQ(NULL, ptr)."""
+
+      env['OBJ_SUFFIX'] = '_warning_ok'
+      if env['PLATFORM'] == 'win32':
+        cls._Remove(env, 'CCFLAGS', '-WX')
+      else:
+        cls._Remove(env, 'CCFLAGS', '-Werror')
+    WarningOk = classmethod(WarningOk)
+
+    def WithExceptions(cls, env):
+      """Re-enables exceptions."""
+
+      env['OBJ_SUFFIX'] = '_ex'
+      if env['PLATFORM'] == 'win32':
+        env.Append(CCFLAGS=['/EHsc'])
+        env.Append(CPPDEFINES='_HAS_EXCEPTIONS=1')
+        # Undoes the _TYPEINFO_ hack, which is unnecessary and only creates
+        # trouble when exceptions are enabled.
+        cls._Remove(env, 'CPPDEFINES', '_TYPEINFO_')
+        cls._Remove(env, 'CPPDEFINES', '_HAS_EXCEPTIONS=0')
+      else:
+        env.Append(CCFLAGS='-fexceptions')
+        cls._Remove(env, 'CCFLAGS', '-fno-exceptions')
+    WithExceptions = classmethod(WithExceptions)
+
+    def LessOptimized(cls, env):
+      """Disables certain optimizations on Windows.
+
+      We need to disable some optimization flags for some tests on
+      Windows; otherwise the redirection of stdout does not work
+      (apparently because of a compiler bug)."""
+
+      env['OBJ_SUFFIX'] = '_less_optimized'
+      if env['PLATFORM'] == 'win32':
+        for flag in ['/O1', '/Os', '/Og', '/Oy']:
+          cls._Remove(env, 'LINKFLAGS', flag)
+    LessOptimized = classmethod(LessOptimized)
+
+    def WithThreads(cls, env):
+      """Allows use of threads.
+
+      Currently only enables pthreads under GCC."""
+
+      env['OBJ_SUFFIX'] = '_with_threads'
+      if env['PLATFORM'] != 'win32':
+        # Assuming POSIX-like environment with GCC.
+        # TODO(vladl@google.com): sniff presence of pthread_atfork instead of
+        # selecting on a platform.
+        env.Append(CCFLAGS=['-pthread'])
+        env.Append(LINKFLAGS=['-pthread'])
+    WithThreads = classmethod(WithThreads)
+
+    def NoRtti(cls, env):
+      """Disables RTTI support."""
+
+      env['OBJ_SUFFIX'] = '_no_rtti'
+      if env['PLATFORM'] == 'win32':
+        env.Append(CCFLAGS=['/GR-'])
+      else:
+        env.Append(CCFLAGS=['-fno-rtti'])
+        env.Append(CPPDEFINES='GTEST_HAS_RTTI=0')
+    NoRtti = classmethod(NoRtti)
+
   def AllowVc71StlWithoutExceptions(self, env):
     env.Append(
         CPPDEFINES = [# needed for using some parts of STL with exception
@@ -219,6 +321,8 @@ class SConstructHelper:
     self.SetBuildNameAndDir(gcc_opt, 'opt')
 
   def BuildSelectedEnvironments(self):
+    EnvCreator = SConstructHelper.EnvCreator
+    Export('EnvCreator')
     # Build using whichever environments the 'BUILD' option selected
     for build_name in self.env_base['BUILD']:
       print 'BUILDING %s' % build_name
@@ -247,114 +351,6 @@ class SConstructHelper:
                  variant_dir=env['BUILD_DIR'],
                  duplicate=0)
 
-  class EnvCreator:
-    """Creates new customized environments from a base one."""
-
-    def _Remove(cls, env, attribute, value):
-      """Removes the given attribute value from the environment."""
-
-      attribute_values = env[attribute]
-      if value in attribute_values:
-        attribute_values.remove(value)
-    _Remove = classmethod(_Remove)
-
-    def Create(cls, base_env, modifier=None):
-      # User should NOT create more than one environment with the same
-      # modifier (including None).
-      env = base_env.Clone()
-      if modifier:
-        modifier(env)
-      else:
-        env['OBJ_SUFFIX'] = ''  # Default suffix for unchanged environment.
-      return env;
-    Create = classmethod(Create)
-
-    # Each of the following methods modifies the environment for a particular
-    # purpose and can be used by clients for creating new environments.  Each
-    # one needs to set the OBJ_SUFFIX variable to a unique suffix to
-    # differentiate targets built with that environment.  Otherwise, SCons may
-    # complain about same target built with different settings.
-
-    def UseOwnTuple(cls, env):
-      """Instructs Google Test to use its internal implementation of tuple."""
-
-      env['OBJ_SUFFIX'] = '_use_own_tuple'
-      env.Append(CPPDEFINES = 'GTEST_USE_OWN_TR1_TUPLE=1')
-    UseOwnTuple = classmethod(UseOwnTuple)
-
-    def WarningOk(cls, env):
-      """Does not treat warnings as errors.
-
-      Necessary for compiling gtest_unittest.cc, which triggers a gcc
-      warning when testing EXPECT_EQ(NULL, ptr)."""
-
-      env['OBJ_SUFFIX'] = '_warning_ok'
-      if env['PLATFORM'] == 'win32':
-        cls._Remove(env, 'CCFLAGS', '-WX')
-      else:
-        cls._Remove(env, 'CCFLAGS', '-Werror')
-    WarningOk = classmethod(WarningOk)
-
-    def WithExceptions(cls, env):
-      """Re-enables exceptions."""
-
-      # We compile gtest_unittest in this environment which means we need to
-      # allow warnings here as well.
-      cls.WarningOk(env)
-      env['OBJ_SUFFIX'] = '_ex'  # Overrides the suffix supplied by WarningOK.
-      if env['PLATFORM'] == 'win32':
-        env.Append(CCFLAGS=['/EHsc'])
-        env.Append(CPPDEFINES='_HAS_EXCEPTIONS=1')
-        # Undoes the _TYPEINFO_ hack, which is unnecessary and only creates
-        # trouble when exceptions are enabled.
-        cls._Remove(env, 'CPPDEFINES', '_TYPEINFO_')
-        cls._Remove(env, 'CPPDEFINES', '_HAS_EXCEPTIONS=0')
-      else:
-        env.Append(CCFLAGS='-fexceptions')
-        cls._Remove(env, 'CCFLAGS', '-fno-exceptions')
-    WithExceptions = classmethod(WithExceptions)
-
-    def LessOptimized(cls, env):
-      """Disables certain optimizations on Windows.
-
-      We need to disable some optimization flags for some tests on
-      Windows; otherwise the redirection of stdout does not work
-      (apparently because of a compiler bug)."""
-
-      env['OBJ_SUFFIX'] = '_less_optimized'
-      if env['PLATFORM'] == 'win32':
-        for flag in ['/O1', '/Os', '/Og', '/Oy']:
-          cls._Remove(env, 'LINKFLAGS', flag)
-    LessOptimized = classmethod(LessOptimized)
-
-    def WithThreads(cls, env):
-      """Allows use of threads.
-
-      Currently only enables pthreads under GCC."""
-
-      env['OBJ_SUFFIX'] = '_with_threads'
-      if env['PLATFORM'] != 'win32':
-        # Assuming POSIX-like environment with GCC.
-        # TODO(vladl@google.com): sniff presence of pthread_atfork instead of
-        # selecting on a platform.
-        env.Append(CCFLAGS=['-pthread'])
-        env.Append(LINKFLAGS=['-pthread'])
-    WithThreads = classmethod(WithThreads)
-
-    def NoRtti(cls, env):
-      """Disables RTTI support."""
-
-      # We compile gtest_unittest in this environment which means we need to
-      # allow warnings here as well.
-      cls.WarningOk(env)
-      env['OBJ_SUFFIX'] = '_no_rtti'  # Overrides suffix supplied by WarningOK.
-      if env['PLATFORM'] == 'win32':
-        env.Append(CCFLAGS=['/GR-'])
-      else:
-        env.Append(CCFLAGS=['-fno-rtti'])
-        env.Append(CPPDEFINES='GTEST_HAS_RTTI=0')
-    NoRtti = classmethod(NoRtti)
-
 
 sconstruct_helper = SConstructHelper()
 Return('sconstruct_helper')