Re: [RFA] PR python/18565 - make Frame.function work for inline frames

[Yao Qi <qiyaoltc at gmail dot com>]

On Tue, Jul 26, 2016 at 12:14 PM, Pedro Alves <palves@redhat.com> wrote:
> On 07/25/2016 04:01 PM, Tom Tromey wrote:
>
>>         *funname = xstrdup (SYMBOL_PRINT_NAME (func));
>> [...]
>>         if (*funlang == language_cplus)
>>           {
>>             /* It seems appropriate to use SYMBOL_PRINT_NAME() here,
>>                to display the demangled name that we already have
>>                stored in the symbol table, but we stored a version
>>                with DMGL_PARAMS turned on, and here we don't want to
>>                display parameters.  So remove the parameters.  */
>>             char *func_only = cp_remove_params (*funname);
>>
>> I'm not 100% sure that cp_remove_params cannot throw.
>> However, it's
>> simple to deal with this by adding a cleanup in find_frame_funname.  I'm
>> happy to do this if desired.
>>
>> Another approach might be to have a free_current_contents cleanup at the
>> start of find_frame_funname and discard it at the exit.  This would
>> maybe make it a bit safer in the face of future changes.
>
> Yet another approach would be to push the xstrdup call to after the
> cp_remove_params call, and remove the xfree call, something like:
>
>           if (*funlang == language_cplus)
>             {
>               char *func_only = cp_remove_params (SYMBOL_PRINT_NAME (func));
>
>               if (func_only)
>                 *funname = func_only;
>               else
>                 *funname = xstrdup (SYMBOL_PRINT_NAME (func));
>             }
>           else
>             *funname = xstrdup (SYMBOL_PRINT_NAME (func));
>         }
>
>
> In any case, IMO this would be the subject of a separate patch.

This is the prerequisite of Tom's patch, no?  It guarantees that *FUNNAME
is not allocated if exception is thrown, otherwise *FUNAME is allocated.
Tom's patch relies on this behaviour.

I am OK with Tom's original patch, but we need to fix find_frame_funname
first.

-- 
Yao (齐尧)