diff -r a7db9f505e88 Lib/distutils/cygwinccompiler.py --- a/Lib/distutils/cygwinccompiler.py Sun Jun 23 16:12:32 2013 -0400 +++ b/Lib/distutils/cygwinccompiler.py Thu Jul 11 17:15:05 2013 +0100 @@ -319,13 +319,18 @@ else: entry_point = '' - self.set_executables(compiler='gcc -mno-cygwin -O -Wall', - compiler_so='gcc -mno-cygwin -mdll -O -Wall', - compiler_cxx='g++ -mno-cygwin -O -Wall', - linker_exe='gcc -mno-cygwin', - linker_so='%s -mno-cygwin %s %s' - % (self.linker_dll, shared_option, - entry_point)) + if self.gcc_version < '4' or is_cygwingcc(): + no_cygwin = ' -mno-cygwin' + else: + no_cygwin = '' + + self.set_executables(compiler='gcc%s -O -Wall' % no_cygwin, + compiler_so='gcc%s -mdll -O -Wall' % no_cygwin, + compiler_cxx='g++%s -O -Wall' % no_cygwin, + linker_exe='gcc%s' % no_cygwin, + linker_so='%s%s %s %s' + % (self.linker_dll, no_cygwin, + shared_option, entry_point)) # Maybe we should also append -mthreads, but then the finished # dlls need another dll (mingwm10.dll see Mingw32 docs) # (-mthreads: Support thread-safe exception handling on `Mingw32') @@ -447,3 +452,10 @@ else: dllwrap_version = None return (gcc_version, ld_version, dllwrap_version) + +def is_cygwingcc(): + '''Try to determine if the gcc that would be used is from cygwin.''' + out_string = os.popen('gcc -dumpmachine').read() + # out_string is the target triplet cpu-vendor-os + # Cygwin's gcc sets the os to 'cygwin' + return out_string.strip().endswith('cygwin')