+++ This bug was initially created as a clone of Bug #165025 +++

Description of problem:
GDB intermittently fails with gcj-generated (BC-ABI) .sos.

Version-Release number of selected component (if applicable):
gdb-6.3.0.0-1.24.ppc

How reproducible:
Always ... although no small test case unfortunately.

Steps to Reproduce:
1. start eclipse
2. gdb /usr/bin/java <pid>
3. thread apply all bt (or almost any command ... it happens quite frequently)
  
Actual results:
../../gdb-6.3/gdb/dwarf2-frame.c:454: internal-error: Unknown CFI 47 encountered.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) y
../../gdb-6.3/gdb/dwarf2-frame.c:454: internal-error: Unknown CFI 47 encountered.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Create a core file of GDB? (y or n) n

Expected results:
No gdb failures.

Additional info:
Andrew Cagney has looked into this and knows what the problem is.

-- Additional comment from cagney on 2005-08-03 15:32 EST --
GDB needs to handle DW_CFA_GNU_negative_offset_extended which has been in the
java sources since ~2001:

1.2          (aph      03-Jun-01):       .byte     0x2f     /* 
DW_CFA_GNU_negative_offset_extended */

It's actually 100% reproducable, and it occures on rhel4.

-- Additional comment from cagney on 2005-08-03 15:34 EST --
This needs to be added to dwarf2-frame.c:

            case DW_CFA_GNU_negative_offset_extended:
              insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
              insn_ptr = read_uleb128 (insn_ptr, insn_end, &offset);
              offset *= fs->data_align;
              dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
              fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
              fs->regs.reg[reg].loc.offset = -offset;
              break;



-- Additional comment from jkratoch on 2006-12-31 01:08 EST --
Patch committed as is to RawHide incl. an i386 testcase:
* Sat Dec 30 2006 Jan Kratochvil <jan.kratochvil> - 6.5-22
- Fix unwinding crash on older gcj(1) code (extended CFI support) (BZ 165025).