Re: [PATCH] S390: Add use of unavailable-stack frame ID

[Andreas Arnez <arnez@linux.vnet.ibm.com>]

On Thu, Mar 10 2016, Pedro Alves wrote:

> On 03/07/2016 10:19 AM, Andreas Arnez wrote:
>> When determining the frame ID of an inline frame, GDB currently asserts
>> that a valid ID of the underlying real frame is found, and that it does
>> not match outer_frame_id.  From inline_frame_this_id():
>>
>>    /* For now, require we don't match outer_frame_id either (see
>>       comment above).  */
>>    gdb_assert (!frame_id_eq (*this_id, outer_frame_id));
>>
>> However, this assertion may fail when the real frame's unwinder can not
>> determine the frame ID.  This happened on an s390x target with a binary
>> that lacked call frame information and also confused the prologue
>> analyzer, because then s390_frame_this_id() left the frame ID at its
>> default.
>>
>> To fix this, this change enhances s390_frame_this_id such that an
>> unavailable-stack frame ID is built if no frame base can be determined
>> but the function address is available.
>>
>
> Seeing all these makes me want this:
>
>  https://sourceware.org/ml/gdb-patches/2016-02/msg00778.html
>
> even more.  :-)

Agreed.  It's on Yao's todo list, right?  ;-) --

  https://sourceware.org/ml/gdb-patches/2016-02/msg00858.html

--
Andreas