Re: [patch] dwarf2read.c: Rewrite signatured type handling

[Doug Evans <dje at google dot com>]

On Tue, Apr 16, 2013 at 8:34 AM, Tom Tromey <tromey@redhat.com> wrote:
>>>>>> "Doug" == Doug Evans <dje@google.com> writes:
>
> Doug> This patch simplifies and improves signature type handling a bit.
> Doug> For one, it no longer calls error on certain kinds of bad debug info,
> Doug> instead it just creates a TYPE_CODE_ERROR type.
> Doug> I like calling error() early on - errors are detected sooner.
> Doug> But this code has been in use for a fair while,
> Doug> and in general we want gdb to at least limp along in the presence
> Doug> of bad debug info.
>
> Doug> Plus it paves the way for a subsequent optimization for Fission.
>
> Doug> Regression tested on amd64-linux with/without Fission.
>
> Doug> I will check this in in a few days if there are no objections.
>
> No objections -- one nit, one question.
>
> Doug> +
> Doug> +static struct die_info *
> Doug> +follow_die_sig (struct die_info *src_die, struct attribute *attr,
> Doug> +         struct dwarf2_cu **ref_cu)
> Doug> +{
>
> This function needs a comment.

Righto.

> Doug> +  sig_type = lookup_signatured_type (signature);
> Doug> +  /* sig_type will be NULL if the signatured type is missing from
> Doug> +     the debug info.  */
> Doug> +  if (sig_type == NULL)
> Doug> +    {
> Doug> +      error (_("Dwarf Error: Cannot find signatured DIE %s referenced"
> Doug> +               " from DIE at 0x%x [in module %s]"),
> Doug> +             hex_string (signature), src_die->offset.sect_off,
> Doug> +      (*ref_cu)->objfile->name);
>
> I'm curious why there are errors calls in this function still.

Fixing this requires changes beyond the scope of this patch.
This function returns a struct die_info *, not a struct type *.
See this function's cousin: follow_die_ref.