Re: Issue with Latest GDB on AIX with GCC-6.12

[David Edelsohn <dje dot gcc at gmail dot com>]

On Wed, Feb 8, 2017 at 7:06 AM, Pedro Alves <palves@redhat.com> wrote:
> On 02/08/2017 06:16 AM, Nitish Kumar Mishra wrote:
>
>> I tried adding try/catch block earlier in throw_it and
>> throw_exception_cxx functions
>> but got no significant results.
>> I had tried adding try catch block in these functions:
>> kill_command
>> command_handler
>> command_line_handler
>> execute_command
>> throw_it
>> throw_exception_cxx,
>> but no progress. Output is exactly same as we got earlier (Other than
>> extra frames for new
>> try catch functions). None of the print statements in catch blocks for
>> above functions worked.
>
> Eh, it sounds like _no_ exception catching works then?  I just
> confirmed now that at least on GNU/Linux, GDB does not throw any
> exception internally during startup.  This backtrace in question may
> well not be special at all, and may be that _all_ exception catching
> is broken.  I'd try experimenting with simple things like:
>
> try
> {
>   throw 1;
> }
> catch (...)
> {
>    printf (....);
> }
>
> right at the start of gdb's main().  Not in a separately
> compiled test program, but really inside gdb, to avoid
> differences in how gdb vs the test program is built.
>
> It could also be that this is only triggered due to
> GDB's binary size, hence not triggered in a small program -- I
> recall that there was some trouble with the size of some sessions
> and the linker in the AIX 7.1 box couldn't link gdb, or something
> like that?  Maybe that's not fully/correctly sorted out.

Nitish,

GDB is linked with static libstdc++ and libgcc.

-static-libstdc++ -static-libgcc

Is your small test using those options?

Can you try linking GDB and testing GDB *without* those options?

Thanks, David