Re: [PATCH v2 2/2] gas: re-work line number tracking for macros and their expansions

[Andrew Burgess <aburgess@redhat.com>]

Jan Beulich <jbeulich@suse.com> writes:

> On 14.12.2022 17:58, Andrew Burgess wrote:
>> Anyway, hopefully the reproducer helps track down the problem.
>
> It did indeed. Below the patch that addresses the issue for me,
> but before committing I will want to run this through the full set
> of tests (after extending the testcase which didn't catch the issue).
>
> Jan

Can confirm that the patch below fixes the gdb.asm/asm-source.exp test
failure that I was seeing.

Thanks,
Andrew

>
> gas: restore Dwarf info generation after macro diagnostic adjustments
>
> While 6fdb723799e2 ("gas: re-work line number tracking for macros and
> their expansions") was meant to leave generated Dwarf as is, it really
> didn't (and the testcase intended to catch that wasn't covering the case
> which broke). Its adjustment to buffer_and_nest() didn't go far enough,
> leading to the "linefile" directive inserted at the top to also be
> processed later in the PR gas/16908 workaround (which clearly isn't
> intended - it's being put there for processing during macro expansion
> only). That unnoticed flaw in turn led me to worked around it by a
> (suspicious to me already at the time) conditional in as_where().
>
> --- a/gas/input-scrub.c
> +++ b/gas/input-scrub.c
> @@ -564,9 +564,6 @@ as_where (unsigned int *linep)
>  
>        do
>  	{
> -	  if (!saved->is_linefile)
> -	    break;
> -
>  	  if (expansion != expanding_macro)
>  	    /* Nothing.  */;
>  	  else if (saved->logical_input_file != NULL
> --- a/gas/macro.c
> +++ b/gas/macro.c
> @@ -120,8 +120,7 @@ buffer_and_nest (const char *from, const
>    size_t from_len;
>    size_t to_len = strlen (to);
>    int depth = 1;
> -  size_t line_start = ptr->len;
> -  size_t more = get_line (ptr);
> +  size_t line_start, more;
>  
>    if (to_len == 4 && strcasecmp (to, "ENDR") == 0)
>      {
> @@ -147,6 +146,8 @@ buffer_and_nest (const char *from, const
>      xfree (linefile);
>    }
>  
> +  line_start = ptr->len;
> +  more = get_line (ptr);
>    while (more)
>      {
>        /* Try to find the first pseudo op on the line.  */