darkkirb/old-cross-binutils
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

* infrun.c (adjust_pc_after_break): Do nothing if executing in

Browse source 
reverse.
This commit is contained in:
Pedro Alves 2008-10-18 03:24:34 +00:00
parent b4f899bb85
commit 4058b83970
2 changed files with 34 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
gdb/ChangeLog
View file

@ -1,3 +1,8 @@
2008-10-18 Pedro Alves <pedro@codesourcery.com>
* infrun.c (adjust_pc_after_break): Do nothing if executing in
reverse.
2008-10-17 Pedro Alves <pedro@codesourcery.com>
* infcmd.c (GO_USAGE): Delete.

29
gdb/infrun.c
View file

@ -1826,6 +1826,35 @@ adjust_pc_after_break (struct execution_control_state *ecs)
if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP)
return;
/* In reverse execution, when a breakpoint is hit, the instruction
under it has already been de-executed. The reported PC always
points at the breakpoint address, so adjusting it further would
be wrong. E.g., consider this case on a decr_pc_after_break == 1
architecture:
B1 0x08000000 : INSN1
B2 0x08000001 : INSN2
0x08000002 : INSN3
PC -> 0x08000003 : INSN4
Say you're stopped at 0x08000003 as above. Reverse continuing
from that point should hit B2 as below. Reading the PC when the
SIGTRAP is reported should read 0x08000001 and INSN2 should have
been de-executed already.
B1 0x08000000 : INSN1
B2 PC -> 0x08000001 : INSN2
0x08000002 : INSN3
0x08000003 : INSN4
We can't apply the same logic as for forward execution, because
we would wrongly adjust the PC to 0x08000000, since there's a
breakpoint at PC - 1. We'd then report a hit on B1, although
INSN1 hadn't been de-executed yet. Doing nothing is the correct
behaviour. */
if (execution_direction == EXEC_REVERSE)
return;
/* If this target does not decrement the PC after breakpoints, then
we have nothing to do. */
regcache = get_thread_regcache (ecs->ptid);