STINNER Victor added the comment: 2013/5/6 Mark Dickinson <rep...@bugs.python.org>: > Concentrating on uint32_t for specificity, there are essentially three cases: > > (1) The platform (either in stdint.h or inttypes.h) #defines uint32_t. > > (2) The platform (either in stdint.h or inttypes.h) makes a typedef for > uint32_t. > > (3) The platform doesn't do (1) *or* (2), but nevertheless, there's an > unsigned integer type that has exact 32-bit width (and it's probably called > "unsigned int").
So in all these 3 cases, it is possible to use "uint32_t" in the code. > [Oh, and (4) Windows. Let's leave that out of this discussion, since there > don't seem to be any Windows-specific problems in practice here, and we don't > use autoconf.] Windows issues can be fixed in PC/pyconfig.h. > So cases (1) and (3) lead to uint32_t being #defined, while cases (1) and (2) > lead to HAVE_UINT32_T being defined. We want to catch all 3 cases, so we > have to check for *both* uint32_t and HAVE_UINT32_T in pyport.h. Sorry I still don't understand why do you need HAVE_UINT32_T define. According to what you wrote above, uint32_t can always be used on any platform. > Note that using AC_TYPE_UINT32_T and checking whether uint32_t is defined is > not enough on platforms that do (2): because uint32_t is a typedef rather > than a #define, there's no easy way for pyport.h to find it. Prior to the > issue #10052 fix, we assumed that any platform doing (2) would, following > C99, also define UINT32_MAX, but that turned out not to be true on some > badly-behaved platforms. Why should Python do extra checks in pyport.h (ex: check if UINT32_MAX is available)? Can't we rely on stdint.h? If stdint.h is not available, we can ask configure to build it for us using AX_CREATE_STDINT_H. Oh, it looks like this macro is not part of autotools directly. It's a third party module released under the GNU GPLv3+ license. Can we include a GPL script in our tool chain? I contacted the author by email to ask him if we can distribute it under a different license (compatible with the Python license). http://www.gnu.org/software/autoconf-archive/ax_create_stdint_h.html http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_create_stdint_h.m4 ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue17884> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
