Re: GDB unusable on AIX and lucky to work on HP-UX (PR1170)

[Michael Veksler <VEKSLER at il dot ibm dot com>]

Joel Brobecker <brobecker@gnat.com> wrote on 2004-09-23 18:45:27:

> Michael,
>
> would have some code that would demonstrate the problem without
> the fiddling? I just looked at the testsuite results on AIX, where
> I use GCC 3.2.3 configured with C,C++ and Ada, and I didn't see any
> such internal-error.
>

There is a real test case in the PR. It generates inputs too big to
understand. If you look at the PR, you can see my analysis that start
with this huge test case, and reduced to simple several lines
that do require fiddling. Unfortunately, /bin/as does not guarantee
order preservation, which makes my fiddling valid:
1. Since future versions of /bin/as may reorder things this way.
2. Any technology that does post link optimization will cause
   such problems. I would suspect that FDPR will make the simplest
   C code impossible to debug in GDB.
      http://www.haifa.il.ibm.com/projects/systems/cot/fdpr/

The test case is as simple as:
      $ cat bug.cpp
      #include <string>
      #include <iostream>
      int main() {}
      $ g++ -g -fno-inline -fno-default-inline bug.cpp

Note that these flags are critical if you don't want an even bigger
tests case.