Re: RFA: Wrong frontend options are a warning, not error

[Geoff Keating <geoffk at geoffk dot org>]

Neil Booth <neil@daikokuya.co.uk> writes:

> When I created c-opts.c, I originally made it an error to specify
> a switch to e.g. C++ that was C-only.  Someone (Fergus?) requested
> it be made a warning to be better backwards compatible.
> 
> I did that, but toplev.c was still raising an "unrecognised option"
> error as c-opts.c was claiming zero switches were being processed.
> 
> This fixes that.  OK to commit (being a bug fix)?

This is OK.

> 	* c-opts.c (find_opt): Don't complain about wrong languages
> 	here.  Return exact matches even for wrong language.
> 	(c_common_decode_option): Complain about wrong languages
> 	here.
> 
> Index: c-opts.c
> ===================================================================
> RCS file: /cvs/gcc/gcc/gcc/c-opts.c,v
> retrieving revision 1.14
> diff -u -p -r1.14 c-opts.c
> --- c-opts.c	14 Aug 2002 22:34:47 -0000	1.14
> +++ c-opts.c	26 Aug 2002 04:04:28 -0000
> @@ -374,7 +374,10 @@ missing_arg (opt_index)
>     Complications arise since some options can be suffixed with an
>     argument, and multiple complete matches can occur, e.g. -pedantic
>     and -pedantic-errors.  Also, some options are only accepted by some
> -   languages.  */
> +   languages.  If a switch matches for a different language and
> +   doesn't match any alternatives for the true front end, the index of
> +   the matched switch is returned anyway.  The caller should check for
> +   this case.  */
>  static size_t
>  find_opt (input, lang_flag)
>       const char *input;
> @@ -382,7 +385,7 @@ find_opt (input, lang_flag)
>  {
>    size_t md, mn, mx;
>    size_t opt_len;
> -  size_t wrong_lang = N_OPTS;
> +  size_t result = N_OPTS;
>    int comp;
>  
>    mn = 0;
> @@ -403,13 +406,7 @@ find_opt (input, lang_flag)
>  	{
>  	  /* The switch matches.  It it an exact match?  */
>  	  if (input[opt_len] == '\0')
> -	    {
> -	    exact_match:
> -	      if (cl_options[md].flags & lang_flag)
> -		return md;
> -	      wrong_lang = md;
> -	      break;
> -	    }
> +	    return md;
>  	  else
>  	    {
>  	      mn = md + 1;
> @@ -423,9 +420,10 @@ find_opt (input, lang_flag)
>  	      /* Is this switch valid for this front end?  */
>  	      if (!(cl_options[md].flags & lang_flag))
>  		{
> -		  /* If subsequently we don't find a good match,
> -		     report this as a bad match.  */
> -		  wrong_lang = md;
> +		  /* If subsequently we don't find a better match,
> +		     return this and let the caller report it as a bad
> +		     match.  */
> +		  result = md;
>  		  continue;
>  		}
>  
> @@ -444,7 +442,7 @@ find_opt (input, lang_flag)
>  		  if (memcmp (input, cl_options[md].opt_text, opt_len))
>  		    break;
>  		  if (input[opt_len] == '\0')
> -		    goto exact_match;
> +		    return md;
>  		  if (cl_options[md].flags & lang_flag
>  		      && cl_options[md].flags & CL_JOINED)
>  		    mx = md;
> @@ -455,10 +453,7 @@ find_opt (input, lang_flag)
>  	}
>      }
>  
> -  if (wrong_lang != N_OPTS)
> -    complain_wrong_lang (wrong_lang);
> -
> -  return N_OPTS;
> +  return result;
>  }
>  
>  /* Defer option CODE with argument ARG.  */
> @@ -534,7 +529,7 @@ c_common_decode_option (argc, argv)
>    const char *opt, *arg = 0;
>    char *dup = 0;
>    bool on = true;
> -  int result;
> +  int result, lang_flag;
>    const struct cl_option *option;
>    enum opt_code code;
>  
> @@ -574,7 +569,8 @@ c_common_decode_option (argc, argv)
>    result = cpp_handle_option (parse_in, argc, argv);
>  
>    /* Skip over '-'.  */
> -  opt_index = find_opt (opt + 1, lang_flags[(c_language << 1) + flag_objc]);
> +  lang_flag = lang_flags[(c_language << 1) + flag_objc];
> +  opt_index = find_opt (opt + 1, lang_flag);
>    if (opt_index == N_OPTS)
>      goto done;
>  
> @@ -608,6 +604,15 @@ c_common_decode_option (argc, argv)
>  	  result = argc;
>  	  goto done;
>  	}
> +    }
> +
> +  /* Complain about the wrong language after we've swallowed any
> +     necessary extra argument.  Eventually make this a hard error
> +     after the call to find_opt, and return argc.  */
> +  if (!(cl_options[opt_index].flags & lang_flag))
> +    {
> +      complain_wrong_lang (opt_index);
> +      goto done;
>      }
>  
>    switch (code = option->opt_code)

-- 
- Geoffrey Keating <geoffk@geoffk.org> <geoffk@redhat.com>