Re: inttypes.h error for Bison

[Bruno Haible]

Paul Eggert wrote:
> 2007-07-02  Paul Eggert  <address@hidden>
> 
>       * lib/inttypes_.h [defined __cplusplus&&!defined __STDC_LIMIT_MACROS]:
>       #define __STDC_LIMIT_MACROS temporarily while including
>       <stdint.h>, so that __STDC_LIMIT_MACROS is defined.
>       Problem reported by Joel E. Denny in
>       <http://lists.gnu.org/archive/html/bug-gnulib/2007-07/msg00008.html>.

Thanks Paul. But I think __STDC_LIMIT_MACROS needs to be defined before
the _first_ inclusion of <stdint.h>: When you look at glibc's <stdint.h>
and gnulib's <stdint.h>, they expand to nothing if the file has already
been included - even with a different setting of __STDC_LIMIT_MACROS.
In other words,
  #include <stdint.h>
  #include <inttypes.h>
still fails in C++ mode with your patch. Therefore I would say that
gl_INTTYPES_H should do the following:

AH_VERBATIM([__STDC_LIMIT_MACROS],
[/* Ensure that <stdint.h> defines the limit macros, since gnulib's
   <inttypes.h> relies on them.  */
#if defined __cplusplus && !defined __STDC_LIMIT_MACROS
# define __STDC_LIMIT_MACROS 1
#endif
])

This will end up in <config.h>.

But even with your patch, and even with the addition of this code to
config.h, Joel's test case still fails.

Here we see that there is also a problem in bison:
examples/calc++/calc++-scanner.cc is compiled through the command line
    g++  -I. -I../../lib -g -O2 ... -c -o calc++-scanner.o calc++-scanner.cc
which makes ../../lib/inttypes.h visible, but ../../lib/config.h has never
been included.

So apparently there are two kinds of bison sources: Those which use
<config.h> and which link against libbison.a, and those which don't.
The examples/calc++ is in the second category.

This -I../../lib originates from this line in examples/calc++/Makefile.in:
DEFAULT_INCLUDES = -I. -I$(top_builddir)/address@hidden@
which automake has put there, to ensure that <config.h> is found.

There are two ways to fix this:
  - Define DEFAULT_INCLUDES yourself in examples/calc++/Makefile.am, or
  - Move config.h to a different directory, such as $(top_builddir).

Bruno