Re: [PATCH V2] Add warning options -W[no-]compare-distinct-pointer-types

[Joseph Myers <joseph@codesourcery.com>]

On Thu, 18 Aug 2022, Jose E. Marchesi via Gcc-patches wrote:

> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
> index de8780a1502..04af02add37 100644
> --- a/gcc/c/c-typeck.cc
> +++ b/gcc/c/c-typeck.cc
> @@ -12397,7 +12397,8 @@ build_binary_op (location_t location, enum tree_code code,
>  	    }
>  	  else
>  	    /* Avoid warning about the volatile ObjC EH puts on decls.  */
> -	    if (!objc_ok)
> +	    if (!objc_ok
> +                && warn_compare_distinct_pointer_types)
>  	      pedwarn (location, 0,
>  		       "comparison of distinct pointer types lacks a cast");
>  
> @@ -12517,8 +12518,9 @@ build_binary_op (location_t location, enum tree_code code,
>  	      int qual = ENCODE_QUAL_ADDR_SPACE (as_common);
>  	      result_type = build_pointer_type
>  			      (build_qualified_type (void_type_node, qual));
> -	      pedwarn (location, 0,
> -		       "comparison of distinct pointer types lacks a cast");
> +              if (warn_compare_distinct_pointer_types)
> +                pedwarn (location, 0,
> +                         "comparison of distinct pointer types lacks a cast");

I think this should use OPT_Wcompare_distinct_pointer_types in place of 0, 
and then you shouldn't need to check warn_compare_distinct_pointer_types 
(as well as the diagnostic then automatically telling the user what option 
controls it).

-- 
Joseph S. Myers
joseph@codesourcery.com