Re: [PATCH] stdint: port intptr_t to more-recent MinGW

[Paul Eggert]

Following up on this patch, here's a brief explanation. In 
<https://bugs.gnu.org/36597> we were battling with a problem building Emacs 
under 32-bit MinGW. The problem was that Gnulib stdint.in.h did this:

  # if !((defined __KLIBC__ && defined _INTPTR_T_DECLARED) \
	 || (defined __MINGW32__ && defined _INTPTR_T_DEFINED && defined 
_UINTPTR_T_DEFINED))
  #  undef intptr_t
  #  undef uintptr_t
  #  ifdef _WIN64
  typedef long long int gl_intptr_t;
  typedef unsigned long long int gl_uintptr_t;
  #  else
  typedef long int gl_intptr_t;
  typedef unsigned long int gl_uintptr_t;
  #  endif
  #  define intptr_t gl_intptr_t
  #  define uintptr_t gl_uintptr_t
  # endif

which makes intptr_t 'long', whereas Gnulib inttypes.in.h did this:

  #if !defined PRIdPTR
  # ifdef INTPTR_MAX
  #  define PRIdPTR @PRIPTR_PREFIX@ "d"
  # endif
  #endif

and since MinGW's PRIdPTR is already "d" this leaves it "d". Later when Emacs 
code did something like this:

  intptr_t ip; ...
  printf ("%PRIdPTR, ip);

GCC complained:

  warning: format '%d' expects argument of type 'int', but argument 2 has type 
'gl_intptr_t' {aka 'long int'} [-Wformat=]

The code ran OK since 'int' and 'long' are the same, but we wanted to squelch 
the warning.