Re: GC_descr_obj_sz miscompilation (was RE: GC_enable_incremental())

[Ranjit Mathew <rmathew at gmail dot com>]

Boehm, Hans wrote:
> 
> 1) The multithreaded GC doesn't run under gdb 6.1.  I suspect
> some signals are being misdirected, or the like.  (I mention
> this here only because it might frustrate others, too.)

You might have better luck with GDB 6.2/6.2.1. From
the NEWS file for 6.2:
--------------------------- 8< ---------------------------
* Fix for ``many threads''

On GNU/Linux systems that use the NPTL threads library, a program
rapidly creating and deleting threads would confuse GDB leading to the
error message:

        ptrace: No such process.
        thread_db_get_info: cannot get thread info: generic error

This problem has been fixed.

[...]

* Signal trampoline code overhauled

Many generic problems with GDB's signal handling code have been fixed.
These include: backtraces through non-contiguous stacks; recognition
of sa_sigaction signal trampolines; backtrace from a NULL pointer
call; backtrace through a signal trampoline; step into and out of
signal handlers; and single-stepping in the signal trampoline.

Please note that kernel bugs are a limiting factor here.  These
features have been shown to work on an s390 GNU/Linux system that
include a 2.6.8-rc1 kernel.  Ref PR breakpoints/1702.
--------------------------- 8< ---------------------------

HTH,
Ranjit.

-- 
Ranjit Mathew          Email: rmathew AT gmail DOT com

Bangalore, INDIA.      Web: http://ranjitmathew.tripod.com/