Re: [RFA]dwarf reader: Avoid complaint on const type

[Doug Evans <dje@google.com>]

On Sun, Jun 20, 2010 at 3:39 PM, Pierre Muller
<pierre.muller@ics-cnrs.unistra.fr> wrote:
> 2010-06-21  Pierre Muller  <muller@ics.u-strasbg.fr>
>
>        * dwarf2read.c (process_die): Do not call new_symbol
>        for DW_TAG_volatile_type and DW_TAG_const_type.
>        (new_symbol): Do not add the name of DW_TAG_volatile_type
>        and DW_TAG_const_type to the symbol list.
>
>
>
> Index: dwarf2read.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2read.c,v
> retrieving revision 1.400
> diff -u -p -r1.400 dwarf2read.c
> --- dwarf2read.c        17 Jun 2010 22:36:41 -0000      1.400
> +++ dwarf2read.c        20 Jun 2010 21:57:23 -0000
> @@ -3210,12 +3210,14 @@ process_die (struct die_info *die, struc
>     case DW_TAG_base_type:
>     case DW_TAG_subrange_type:
>     case DW_TAG_typedef:
> -    case DW_TAG_const_type:
> -    case DW_TAG_volatile_type:
>       /* Add a typedef symbol for the type definition, if it has a
>          DW_AT_name.  */
>       new_symbol (die, read_type_die (die, cu), cu);
>       break;
> +    case DW_TAG_const_type:
> +    case DW_TAG_volatile_type:
> +      read_type_die (die, cu);
> +      break;
>     case DW_TAG_common_block:
>       read_common_block (die, cu);
>       break;
> @@ -8912,12 +8914,16 @@ new_symbol (struct die_info *die, struct
>          break;
>        case DW_TAG_base_type:
>         case DW_TAG_subrange_type:
> -        case DW_TAG_const_type:
> -        case DW_TAG_volatile_type:
>          SYMBOL_CLASS (sym) = LOC_TYPEDEF;
>          SYMBOL_DOMAIN (sym) = VAR_DOMAIN;
>          add_symbol_to_list (sym, cu->list_in_scope);
>          break;
> +        case DW_TAG_const_type:
> +        case DW_TAG_volatile_type:
> +         /* The name of the type given in the dwarf name atribute is the
> +            name of the `normal' type and not a new type name, so
> +            do not register this as a new type name.  */
> +         break;
>        case DW_TAG_enumerator:
>          attr = dwarf2_attr (die, DW_AT_const_value, cu);
>          if (attr)
>
>

Hi.  I'd like to reach closure on this and get rid of this testsuite failure.

I *think* the patch to process_die is ok.

I'm not sure about the patch to new_symbol though.
AFAICT, new_symbol will never be called for
DW_TAG_volatile_type/const_type (*including* via bad debug info - IOW
the code itself would never call new_symbol for these tags).
*If* that is true, I wouldn't mind calling gdb_assert (0) for those
tags - make it clearer to the caller what the API is.
One may want to just leave it alone and let the default case flag a complaint.