Re: [Qemu-devel] Re: [PATCH] win32: use PRId64 instead of %lld

[Daniel P. Berrange]

On Mon, Jan 25, 2010 at 07:47:56PM +0200, Michael S. Tsirkin wrote:
> On Mon, Jan 25, 2010 at 06:32:06PM +0100, Stefan Weil wrote:
> > Michael S. Tsirkin schrieb:
> > > On Sun, Jan 24, 2010 at 09:23:41PM +0000, Herve Poussineau wrote:
> > >> Replace %lld occurrences by PRId64.
> > >
> > > This is wrong.
> > > long long values should be printed with %lld.
> > > size_t - with %zd. PRId64 is for int64_t.
> > >
> > 
> > size_t => %zu, ssize_t => %zd might be better.
> > 
> > And none of them works on win32, so using them
> > there can result in a crash:
> > 
> >     size_t st = 4711;
> >     fprintf(stderr, "st=%zu, %s\n", st, "test");
> > 
> > printf functions on win32 don't know %z.
> > They run
> > 
> >     fprintf(stderr, "st=zu, %s\n", st, "test");
> > 
> > which results in an memory access fault when printf
> > wants to read the memory at address 0x4711.
> > 
> > Regards,
> > Stefan Weil
> 
> Let's just implement a compliant printf?

It is a shame that QEMU isn't using GNULIB, since that comes with a nice
portable replacement printf() implementation that is transparently used
on any broken platform. Beyond just Win32, a great many UNIX have broken
printf() in one form or another too:

  http://www.gnu.org/software/hello/manual/gnulib/printf.html

I don't know how easy it would be to extract the gnulib printf() impl on
its own and use that in QEMU without the entire gnulib infrastructure

Daniel
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