environment.py: Properly check platform on MSVC 2008
The 'Platform' envvar may not be set on Visual Studio 2008, at least
when using the SDK 7.0 compilers, so check the 'BUILD_PLAT' envvar so
that we do not mis-detect x64 build environments as x86.
@@ -171,8 +171,16 @@ def detect_windows_arch(compilers):
for compiler in compilers.values():
# Check if we're using and inside an MSVC toolchain environment
if compiler.id == 'msvc' and 'VCINSTALLDIR' in os.environ:
- # 'Platform' is only set when the target arch is not 'x86'.
- # It's 'x64' when targeting x86_64 and 'arm' when targeting ARM.
+ if float(compiler.get_toolset_version()) < 10.0:
+ # On MSVC 2008 and earlier, check 'BUILD_PLAT', where
+ # 'Win32' means 'x86'
+ platform = os.environ.get('BUILD_PLAT', 'x86')
+ if platform == 'Win32':
+ return 'x86'
+ else:
+ # On MSVC 2010 and later 'Platform' is only set when the
+ # target arch is not 'x86'. It's 'x64' when targeting
+ # x86_64 and 'arm' when targeting ARM.
platform = os.environ.get('Platform', 'x86').lower()
if platform == 'x86':
return platform
