GDB 7.0 regressions: s390(x)-linux, ppc(64)-linux, spu-elf

["Ulrich Weigand" <uweigand@de.ibm.com>]

Hello Joel,

I've now analyzed the GDB test suite for regressions on the platforms I'm
most interested in: s390(x)-linux, ppc(64)-linux, and spu-elf.  Unfortunately,
this did show up a number of real regressions as compared to the last release.
I'm sorry I didn't get to do this earlier; I hope it's not too late to get
(some of) these problems fixed in the GDB 7.0 release ...


1. Write access to bit fields broken
   This is a real regression caused by Dan's bitfield changes.  It shows up
   as multiple store.exp failures on 64-bit big-endian platforms.
   Proposed fix is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00856.html

2. Displaced stepping broken on PowerPC
   This is a real regression caused by the ARM displaced stepping changes.
   The effect is that non-stop mode no longer works at all on PowerPC.
   Proposed fix is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00855.html

3. Displaced stepping missing on S/390
   Displaced stepping was in fact never supported on S/390, but this fact
   now shows up as non-stop test case regressions.  I'd suggest to simply
   add support for displaced stepping on this platform.
   Fix (committed to mainline) is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00853.html

4. Obj-C method calls broken on 64-bit PowerPC
   It looks like this never worked on ppc64 due to lack of support for
   platforms using function descriptors throughout the Obj-C code.
   However, it now shows up as about 20 test cases running into timeout,
   causing a significant increase in run time for the test suite, so it
   would be good to get it fixed simply for that reason.
   Proposed fix is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00857.html

5. PIE detection not enabled on PowerPC and S/390
   The new code to detect PIE executables was not actually enabled on
   these platforms, causing the new test case to fail.
   Obvious fix (committed to mainline) is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00852.html
  
6. SPU gdbserver regressions when killing inferior
   This is a real regression caused by gdbserver changes to enable multi-
   executable support in gdbserver, which were not fully implemented for SPU.
   Fix (committed to mainline) is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00851.html

7. Many-thread test cases crash (stack overflow) on 64-bit S/390
   These are new tests, so not strictly a regression, but easy to fix.
   Test-case only fix (committed to mainline) is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00850.html

8. dump.exp test case regression on 64-bit S/390
   A test case bug was exposed by fixes to type handling in GDB.
   Test-case only fix (committed to mainline) is here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00849.html

9. Silence noisy test case compiler failures on SPU
   A new C++ test fails during compilation due to the resulting executable
   exceeding local storage size.  The new PIE test fails noisily due to PIE
   not being supported by the compiler.  Not regressions in the strict sense,
   but cause confusing output during the regression run.
   Test-case only fixes (committed to mainline) are here:
   http://sourceware.org/ml/gdb-patches/2009-09/msg00848.html
   http://sourceware.org/ml/gdb-patches/2009-09/msg00847.html


In addition, I'm still seeing new failures in some of the gdb.opt tests
(which appear at first glance to be causes by problems in the debug info
created by the compiler) and some of the gdb.python tests (which I haven't
yet analyzed due to lack of Python skills) ...

How should we proceed with these issues?  Should I commit the fixes
to the branch?  What's the deadline?

Thanks,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com