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

[Nitish Kumar Mishra <mishra dot nitish dot 88 at gmail dot com>]

Hi David !

>>GDB is linked with static libstdc++ and libgcc.
>>-static-libstdc++ -static-libgcc
>>Is your small test using those options?

Yes, I used those static options. I am using readline library in my
test program and compiling it with gcc-6.1
like this:
g++ -g test.c -o test -static-libstdc++ -static-libgcc
-I/opt/freeware/include -lreadline
and the binary is working fine means I am able to catch the exceptions.

>>Can you try linking GDB and testing GDB *without* those options?
----Today I will be working on this---

Thanks,
Nitish


On Wed, Feb 8, 2017 at 7:02 PM, David Edelsohn <dje.gcc@gmail.com> wrote:
> 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