[Bug c/65040] [5 Regression] gcc-5 -Wformat broken

["mark at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65040

Mark Wielaard <mark at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mark at gcc dot gnu.org

--- Comment #5 from Mark Wielaard <mark at gcc dot gnu.org> ---
Note that this also triggers for code that looks just fine to the user:

#include <stdio.h>
#include <inttypes.h>

int
main (int argc, char **argv)
{
  uint8_t u = 16;
  printf ("u = %02" PRIx8 "\n", u);
  return 0;
}

m.c: In function ‘main’:
m.c:8:11: warning: format ‘%x’ expects argument of type ‘unsigned int’, but
argument 2 has type ‘int’ [-Wformat=]
   printf ("u = %02" PRIx8 "\n", u);
           ^

Which is somewhat surprising since the user explicitly matched the type and
format specifier.

This is caused by the definition of the PRIx format specifiers all mapping back
to "x" in inttypes.h

/* lowercase hexadecimal notation.  */
# define PRIx8          "x"
# define PRIx16         "x"
# define PRIx32         "x"
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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug ipa/65039] [5 Regression] g++ 5 segmentation fault when compiling with -O2 optimization
Date: Thu, 12 Feb 2015 11:15:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?ide039

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I reproduced this with an out-of-date trunk build, but using today's trunk it
compiles OK, so seems to be fixed.