[PATCH] dwarf: properly update all_comp_units_without_ranges in stash_comp_unit

[Jan Beulich]

On 18.09.2025 14:04, oltolm wrote:
>  	      each->next_unit_without_ranges = file->all_comp_units_without_ranges;
> -	      file->all_comp_units_without_ranges = each->next_unit_without_ranges;
> 
> The second line of this code is probably a bug because it does nothing. It
> was probably supposed to update "file->all_comp_units_without_ranges" to point
> to "each" - the new head of the list.

I agree, yet ...

> --- a/bfd/dwarf2.c
> +++ b/bfd/dwarf2.c
> @@ -5635,17 +5635,19 @@ stash_comp_unit (struct dwarf2_debug *stash, struct dwarf2_debug_file *file)
>  			     (splay_tree_value)each);
>  
>  	  if (file->all_comp_units)
> -	    file->all_comp_units->prev_unit = each;
> +	    {
> +	      file->all_comp_units->prev_unit = each;
> +	      each->next_unit = file->all_comp_units;
> +	    }
>  	  else
>  	    file->last_comp_unit = each;
>  
> -	  each->next_unit = file->all_comp_units;
>  	  file->all_comp_units = each;

... why this part of the change? The original code was correct afaics, while
the new code is correct only as long as what each points to starts out zero-
initialized (which right now it does, but which we may better not depend upon
here when it's easy to avoid such a dependency).

>  	  if (each->arange.high == 0)
>  	    {
>  	      each->next_unit_without_ranges = file->all_comp_units_without_ranges;
> -	      file->all_comp_units_without_ranges = each->next_unit_without_ranges;
> +	      file->all_comp_units_without_ranges = each;
>  	    }

As I assume the patch will need committing on your behalf, I could easily
reduce it to just this part while committing, provided you agree.

Jan