Re: [PATCH] regex: fix a SIZE_MAX macro redefinition warning

On 05/06/16 08:15, Johannes Schindelin wrote:

The original version of this patch looked like this:

  diff --git a/compat/regex/regcomp.c b/compat/regex/regcomp.c
  index fba5986..d8bde06 100644
  --- a/compat/regex/regcomp.c
  +++ b/compat/regex/regcomp.c
  @@ -18,8 +18,6 @@
      Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
      02110-1301 USA.  */
   
  -#include <stdint.h>
  -
   static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
   					  size_t length, reg_syntax_t syntax);
   static void re_compile_fastmap_iter (regex_t *bufp,
  diff --git a/compat/regex/regex.c b/compat/regex/regex.c
  index 6aaae00..5cb23e5 100644
  --- a/compat/regex/regex.c
  +++ b/compat/regex/regex.c
  @@ -60,6 +60,7 @@
      GNU regex allows.  Include it before <regex.h>, which correctly
      #undefs RE_DUP_MAX and sets it to the right value.  */
   #include <limits.h>
  +#include <stdint.h>
   
   #ifdef GAWK
   #undef alloca

So, just move the unconditional inclusion to the start of the compilation unit root file, before the #include of the regex_internal.h header.

In some ways this is a better fix, because it makes it clear that, currently, the compat/regex code requires <stdint.h>. This would remove the need for such a comment.

This effectively makes the conditional inclusion of <stdint.h>, and the SIZE_MAX fallback, in regex_internal.h dead code. (The C99 standard _requires_ the definition of SIZE_MAX in <stdint.h>, thankfully! ;-). So, I was tempted to remove them as part of the patch. However, I also wanted to minimize the changes to the regex code, just in case we ever wanted to re-import a newer version from upstream. Setting HAVE_STDINT_H seemed like a good solution, but maybe the first patch would be more honest?

As I said earlier, I was a little concerned about the 'unconditional' aspect of the inclusion of <stdint.h>. At one time we wanted to support systems that didn't have <stdint.h> (or didn't have <inttypes.h> but did have <stdint.h>). However, it has been several months and we have not heard anyone scream, so ...

It is slightly amusing that the reason you #included <stdint.h> was to get the definition of 'intptr_t' and the C standard states that this type is optional. In practice, I suspect that the number of platforms which do not define 'intptr_t' and 'uintptr_t' in the <stdint.h> header is rather small.

Having said that ... If I'm reading the code/config correctly, HP-NONSTOP would be failing to compile at the moment. (Although it has <stdint.h>, it does not define 'intptr_t' - ie it defines 'NO_REGEX = YesPlease' and 'NO_INTPTR_T = \ UnfortunatelyYes').

Thanks. What do you think of replacing it with the original patch (above)?

ATB, Ramsay Jones