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

[Jim Meyering]

Bruno Haible wrote:
>> --- 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

Definitely.

> 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;

Good catch.

>>  /* 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
>        ;

Thanks for the speedy review!