Re: [PATCH] Add cast to VEC_iterate

[Simon Marchi <simon.marchi@polymtl.ca>]

On 28 October 2015 at 15:59, Pedro Alves <palves@redhat.com> wrote:
> Fixes this in C++:
>
>  ../../src/gdb/break-catch-sig.c: In function ‘int VEC_gdb_signal_type_iterate(const VEC_gdb_signal_type*, unsigned int, gdb_signal_type*)’:
>  ../../src/gdb/common/vec.h:576:12: error: invalid conversion from ‘int’ to ‘gdb_signal_type {aka gdb_signal}’ [-fpermissive]
>         *ptr = 0;          \
>              ^
>  ../../src/gdb/common/vec.h:417:1: note: in expansion of macro ‘DEF_VEC_FUNC_P’
>   DEF_VEC_FUNC_P(T)         \
>   ^
>  ../../src/gdb/break-catch-sig.c:37:1: note: in expansion of macro ‘DEF_VEC_I’
>   DEF_VEC_I (gdb_signal_type);
>   ^
>
> I actually carried a different fix in the C++ branch that removed this
> assignment and then adjusted all callers that depended on it.  The
> thinking was that this is for the case where we're returning false,
> indicating end of iteration.  But that results in a much larger and
> tricker patch; looking back it seems quite pointless.  I looked at the
> history of GCC's C++ conversion and saw that they added this same cast
> to their version of vec.h, FWIW.  (GCC's vec.h is completely different
> nowadays, having been converted to templates meanwhile.)
>
> gdb/ChangeLog:
> 2015-10-28  Pedro Alves  <palves@redhat.com>
>
>         * common/vec.h (DEF_VEC_FUNC_P) [iterate]: Cast 0 to type T.
> ---
>  gdb/common/vec.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gdb/common/vec.h b/gdb/common/vec.h
> index 2564485..6189283 100644
> --- a/gdb/common/vec.h
> +++ b/gdb/common/vec.h
> @@ -573,7 +573,7 @@ static inline int VEC_OP (T,iterate)                                          \
>      }                                                                    \
>    else                                                                   \
>      {                                                                    \
> -      *ptr = 0;                                                                  \
> +      *ptr = (T) 0;                                                      \
>        return 0;                                                                  \
>      }                                                                    \
>  }                                                                        \
> --
> 1.9.3
>

LGTM.