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Re: [PATCH] issue a correct fix-it hint for bad argument in GCC diagnostics (PR 80619)
- From: Jeff Law <law at redhat dot com>
- To: Martin Sebor <msebor at gmail dot com>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 8 Aug 2019 10:45:35 -0600
- Subject: Re: [PATCH] issue a correct fix-it hint for bad argument in GCC diagnostics (PR 80619)
- References: <89c63048-ce6a-ad21-b671-5a79f380a26b@gmail.com>
On 8/5/19 11:51 AM, Martin Sebor wrote:
> When the argument to a directive with a length modifier like %lu
> in a call to a GCC diagnostic function such as warning()) is not
> of the right integer type, GCC suggests to replace the length
> modifier in the directive with 'w'. For instance:
>
> warning: format ‘%lu’ expects argument of type ‘long unsigned int’,
> but argument 2 has type ‘int’ [-Wformat=]
> f ("%lu", 0);
> ~~^
> %wu
>
> To issue the right hint (i.e., %u in the message above) the attached
> patch introduces a new format_lengths enumerator to represent the 'w'
> modifier.
>
> Tested on x86_64-linux.
>
> Martin
>
> gcc-80619.diff
>
> PR c/80619 - bad fix-it hint for GCC %lu directive with int argument: %wu
>
> gcc/c-family/ChangeLog:
>
> PR c/80619
> * c-format.c (printf_length_specs): Set FMT_LEN_w for "w".
> (asm_fprintf_length_spec): Same.
> * c-format.h (format_lengths): Add FMT_LEN_w.
>
> gcc/testsuite/ChangeLog:
>
> PR c/80619
> * gcc.dg/format/pr80619.c: New test.
OK
jeff