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| author | Michael Snyder <msnyder@vmware.com> | 2008-10-23 23:24:45 +0000 |
|---|---|---|
| committer | Michael Snyder <msnyder@vmware.com> | 2008-10-23 23:24:45 +0000 |
| commit | 9e35d7264198bd63ab9151540d65273366543e96 (patch) | |
| tree | b8e8e7ad375250b4ce57f4b9f42f093f6821aaf1 | |
| parent | b0e6b885a8aa6bd592c86d03fbc8a7a2ecc56f3b (diff) | |
| download | binutils-gdb-9e35d7264198bd63ab9151540d65273366543e96.tar.gz | |
2008-10-18 Pedro Alves <pedro@codesourcery.com>
* infrun.c (adjust_pc_after_break): Do nothing if executing in
reverse.
| -rw-r--r-- | gdb/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/infrun.c | 29 |
2 files changed, 34 insertions, 0 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 0bc33667fff..12c46d0ef12 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -8,6 +8,11 @@ * infrun.c (handle_inferior_event): Set "stop_pc" when TARGET_WAITKIND_NO_HISTORY. +2008-10-18 Pedro Alves <pedro@codesourcery.com> + + * infrun.c (adjust_pc_after_break): Do nothing if executing in + reverse. + 2008-10-18 Hui Zhu <teawater@gmail.com> Remove "to_support_record_wait". diff --git a/gdb/infrun.c b/gdb/infrun.c index fc388a7ab5a..78fc8710b16 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1787,6 +1787,35 @@ 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); |