Re: [PATCH] mark functions with const and pure attributes

[Bruno Haible]

Hi Jim,

> --- a/lib/quotearg.c
> +++ b/lib/quotearg.c
> @@ -17,6 +17,11 @@
> 
>  /* Written by Paul Eggert <address@hidden> */
> 
> +/* Without this pragma, gcc 4.7.0 20111124 mistakenly suggests that
> +   the quoting_options_from_style function might be candidate for
> +   attribute 'pure'  */
> +# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
> +
>  #include <config.h>
> 
>  #include "quotearg.h"

This pragma line should be enclosed in

#if (__GNUC__ == 4 && 3 <= __GNUC_MINOR__) || 4 < __GNUC__
#endif

like it is done in
  lib/anytostr.c
  lib/poll.c
  tests/test-intprops.c
  tests/test-nl_langinfo.c

Otherwise (most likely) earlier versions of GCC will warn about an unsupported
pragma.

> --- a/lib/uniwidth.in.h
> +++ b/lib/uniwidth.in.h
> @@ -38,7 +38,7 @@ extern "C" {
> 
>  /* Determine number of column positions required for UC.  */
>  extern int
> -       uc_width (ucs4_t uc, const char *encoding);
> +       uc_width (ucs4_t uc, const char *encoding) _GL_ATTRIBUTE_PURE;
> 
>  /* Determine number of column positions required for first N units
>     (or fewer if S ends before this) in S.  */

This header file is installed as a public header file by libunistring.
It cannot presuppose the macro definitions of gnulib-common.m4. Therefore
here one needs to write

extern int
       uc_width (ucs4_t uc, const char *encoding)
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
       __attribute__ ((__pure__))
#endif
       ;

Bruno
-- 
In memoriam George Moscone <http://en.wikipedia.org/wiki/George_Moscone>