[DynInst_API:] the PRIx64 commit breaks the build with some <inttypes.h>

["Mark W. Krentel" <krentel@xxxxxxxx>]

One of my cron jobs tripped an alarm for Dyninst master on powerpc
this morning.

This one is bizarre, but the last commit about the PRIx64 macros
breaks the build on some systems, depending on the exact version of
the <inttypes.h> header file.

Here is a unit test that reproduces the problem.  This is a snippet
from instructionAPI/h/Result.h, near line 453.

print.cpp:

#include <sstream>
#include <string.h>
#include <inttypes.h>

int
main(int argc, char **argv)
{
    char hex[20];
    int64_t val = 123;

    snprintf(hex, 20, "%" PRIx64, val);

    printf("ans = %s\n", hex);
    return 0;
}

On one power8 system with glibc-headers-2.17-157.el7.ppc64le,

$ g++ -g -O -std=c++11 print.cpp

print.cpp: In function 'int main(int, char**)':
print.cpp:11:27: error: expected ')' before 'PRIx64'
     snprintf(hex, 20, "%" PRIx64, val);
                           ^~~~~~

Building Dyninst, I get the same error in Result.h near line 453.

I had to diff <inttypes.h> across systems to figure out what's going
on.  The powerpc version has the following.  The x86_64 version does
not have the #if on lines 44-46.

  44  /* The ISO C99 standard specifies that these macros must only be
  45     defined if explicitly requested.  */
  46  #if !defined __cplusplus || defined __STDC_FORMAT_MACROS
  47
  48  # if __WORDSIZE == 64
  49  #  define __PRI64_PREFIX        "l"
  50  #  define __PRIPTR_PREFIX       "l"
  51  # else
  52  #  define __PRI64_PREFIX        "ll"
  53  #  define __PRIPTR_PREFIX
  54  # endif

So, on powerpc, things like PRIx64 are either not defined or else not
defined the way you want them.

I'm not sure if this is a glibc-headers version issue, or an x86 vs
ppc issue.  It seems to be more common on powerpc, but older RH 6.x
x86_64 systems also have the same problem.

Anyway, I'll let you decide the best and most portable way of handling
this.  Maybe you just want to define __STDC_FORMAT_MACROS and test
that it doesn't break anything else.

Blech.  My kingdom for portability!

--Mark