SCons: msvc does not need this /TP option any more after we rename .C => .cpp. Also fix a CXX_GLOBAL_CSTD bug (not quite sure)

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@19693 a592a061-630c-0410-9148-cb99ea01b6c8

development/scons/SConstruct

@@ -448,11 +448,10 @@ C_COMPILER = env.subst('$CC')
 C_CCFLAGS = env.subst('$CCFLAGS').split()
 # if we use ms vc, the commands are fine (cl.exe and link.exe)
 if use_vc:
-    # /TP treat all source code as C++
     # C4819: The file contains a character that cannot be represented
     #   in the current code page (number)
     # C4996: foo was decleared deprecated
-    CCFLAGS_required.extend(['/TP', '/EHsc'])
+    CCFLAGS_required.append('/EHsc')
     if mode == 'debug':
         CCFLAGS_default.extend(['/wd4819', '/wd4996', '/nologo', '/MDd'])
         # the flags are also needed in C mode (for intl lib)

development/scons/scons_utils.py

@@ -236,7 +236,8 @@ int main()
 }
 '''
     conf.Message('Checking for the use of global cstd... ')
-    ret = conf.TryLink(check_global_cstd_source, '.c')
+    # if can not compile, define CXX_GLOBAL_CSTD
+    ret = not conf.TryLink(check_global_cstd_source, '.c')
     conf.Result(ret)
     return ret