[committed][gdb/symtab] Handle invalid partial DIE reference

[Tom de Vries <tdevries@suse.de>]

On 7/24/20 12:52 PM, Tom de Vries wrote:
> Hi,
> 
> When reverting commit 9cfd2b89bd "[gdb/testsuite] Fix
> gdb.arch/amd64-entry-value-paramref.S", we run into an internal-error:
> ...
> (gdb) file amd64-entry-value-paramref^M
> Reading symbols from amd64-entry-value-paramref...^M
> src/gdb/dwarf2/read.c:18903: internal-error: could not find partial DIE
>   0x1b7 in cache [from module amd64-entry-value-paramref]^M
> 
> A problem internal to GDB has been detected,^M
> further debugging may prove unreliable.^M
> ...
> because of invalid dwarf.
> 
> In contrast, when using -readnow, we have:
> ...
> (gdb) file -readnow amd64-entry-value-paramref
> Reading symbols from amd64-entry-value-paramref...
> Expanding full symbols from amd64-entry-value-paramref...
> Dwarf Error: Cannot find DIE at 0x1b7 referenced from DIE at 0x11a \
>   [in module amd64-entry-value-paramref]
> (gdb)
> ...
> 
> Change the internal error into a Dwarf Error, such that we have:
> ...
> (gdb) file amd64-entry-value-paramref^M
> Reading symbols from amd64-entry-value-paramref...^M
> Dwarf Error: Cannot not find DIE at 0x1b7 \
>   [from module amd64-entry-value-paramref]^M
> ^M
> (No debugging symbols found in amd64-entry-value-paramref)^M
> (gdb)
> ...
> 
> Build and tested on x86_64-linux.
> 
> Any comments?
> 

Pushed.

Thanks,
- Tom

> [gdb/symtab] Handle invalid partial DIE reference
> 
> gdb/ChangeLog:
> 
> 2020-07-24  Tom de Vries  <tdevries@suse.de>
> 
> 	PR symtab/23270
> 	* dwarf2/read.c (find_partial_die): Change internal error into Dwarf
> 	Error.
> 
> ---
>  gdb/dwarf2/read.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
> index 39ed455def..7726f193da 100644
> --- a/gdb/dwarf2/read.c
> +++ b/gdb/dwarf2/read.c
> @@ -18900,9 +18900,7 @@ find_partial_die (sect_offset sect_off, int offset_in_dwz, struct dwarf2_cu *cu)
>      }
>  
>    if (pd == NULL)
> -    internal_error (__FILE__, __LINE__,
> -		    _("could not find partial DIE %s "
> -		      "in cache [from module %s]\n"),
> +    error (_("Dwarf Error: Cannot not find DIE at %s [from module %s]\n"),
>  		    sect_offset_str (sect_off), bfd_get_filename (objfile->obfd));
>    return { cu, pd };
>  }
>