Re: PR28977 tc-i386.c internal error in parse_register

[Jan Beulich <jbeulich@suse.com>]

On 18.03.2022 07:56, Alan Modra via Binutils wrote:
> 	PR 28977
> 	* config/tc-i386.c (parse_register): Handle X_op not O_register
> 	as for a non-reg_section symbol.  Simplify array bounds check.

Hmm, isn't it that ...

> --- a/gas/config/tc-i386.c
> +++ b/gas/config/tc-i386.c
> @@ -12952,17 +12952,18 @@ parse_register (char *reg_string, char **end_op)
>  	{

... the if() right outside of context here is pointing at the actual
problem? Why would "s=%rdx % %rcx" result in a reg_section expression?
Imo this clearly ought to be expr_section.

Jan

>  	  const expressionS *e = symbol_get_value_expression (symbolP);
>  
> -	  know (e->X_op == O_register);
> -	  know (e->X_add_number >= 0
> -		&& (valueT) e->X_add_number < i386_regtab_size);
> -	  r = i386_regtab + e->X_add_number;
> -	  if (!check_register (r))
> +	  if (e->X_op == O_register
> +	      && (valueT) e->X_add_number < i386_regtab_size)
>  	    {
> -	      as_bad (_("register '%s%s' cannot be used here"),
> -		      register_prefix, r->reg_name);
> -	      r = &bad_reg;
> +	      r = i386_regtab + e->X_add_number;
> +	      if (!check_register (r))
> +		{
> +		  as_bad (_("register '%s%s' cannot be used here"),
> +			  register_prefix, r->reg_name);
> +		  r = &bad_reg;
> +		}
> +	      *end_op = input_line_pointer;
>  	    }
> -	  *end_op = input_line_pointer;
>  	}
>        *input_line_pointer = c;
>        input_line_pointer = save;
>