2017-06-22 4:53 GMT+02:00 <sisyph...@optusnet.com.au>: > -----Original Message----- From: Liu Hao > Sent: Thursday, June 22, 2017 11:46 AM > To: mingw-w64-public@lists.sourceforge.net > Subject: Re: [Mingw-w64-public] how to printf() 64-bit integer in 64-bit > compiler in strict ISO mode with all warnings enabled? > >>> So, I need to printf() uint64_t in my project, which is built in strict >>> ISO C11 mode and with all warnings enabled. >>> >>> If I try to use "%llu" I get warning that "unknown conversion type >>> character 'l' in format". If I use "%I64u" I get "ISO C does not support >>> the 'I64' ms_printf length modifier" warning. >>> And, yes, I have _POSIX_C_SOURCE defined on compiler's command line. >> >> >> In order to get C99 conforming `*printf()` functions you have to `#define >> __USE_MINGW_ANSI_STDIO 1` before inclusion of any standard headers. One >> preferable way to achieve that is adding `-D__USE_MINGW_ANSI_STDIO` into >> your CPPFLAGS. > > > This is what I invariably do, too. > > However, in a recent post to a gmp mailing list ( > https://gmplib.org/list-archives/gmp-bugs/2017-May/004162.html ), Keith > Marshall discouraged this, warning that it was *not* guaranteed to continue > to work into the future. > > Here's the relevant bit (from that post) of what he had to say: > > [--quote--] > > I would also point out that, as a "__USE_*" feature test, users should *not* > define "__USE_MINGW_ANSI_STDIO" themselves; the correct way to enable it is > to enable any of the "__STRICT_ANSI__" standards options, or to stipulate > "_GNU_SOURCE", "_POSIX_C_SOURCE", or "_XOPEN_SOURCE" feature dependencies, > (the latter two with an associated version stipulation), any of which will > cause the MinGW runtime headers to enable "__USE_MINGW_ANSI_STDIO" > implicitly. You may get away with an explicit definition today, but I will > offer no guarantee that a future MinGW Runtime release will not override any > such definition, just as GNU's glibc headers do for their "__USE_*" feature > tests. > > [--end quote--] > > AFAIK Keith's allegiance is with mpfr.org, and I don't know how/if those > remarks relate to mingw-w64.
Well, we don't intend to remove our gnu-ish printf/scanf implementation (C99) in near, or mid-term distance. I agree that this feature needs to be used carefully, as it modifies common Windows API expectations. I don't see why this gnu-style-formatter routines are should be bould to POSIX. But I admit, it is a work-a-round for a portability issue. As it is a C99 feature, STRICT_ANSI looks to me wrong too. For _GNU_SOURCE we could consider that too. > Any thoughts on that ? > > Cheers, > Rob Regards, Kai ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
