diff options
Diffstat (limited to 'gdb/hppa-hpux-tdep.c')
| -rw-r--r-- | gdb/hppa-hpux-tdep.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/gdb/hppa-hpux-tdep.c b/gdb/hppa-hpux-tdep.c index 9623abe..08c2ece 100644 --- a/gdb/hppa-hpux-tdep.c +++ b/gdb/hppa-hpux-tdep.c @@ -505,6 +505,29 @@ hppa_hpux_skip_trampoline_code (CORE_ADDR pc) } } +void +hppa_skip_permanent_breakpoint (void) +{ + /* To step over a breakpoint instruction on the PA takes some + fiddling with the instruction address queue. + + When we stop at a breakpoint, the IA queue front (the instruction + we're executing now) points at the breakpoint instruction, and + the IA queue back (the next instruction to execute) points to + whatever instruction we would execute after the breakpoint, if it + were an ordinary instruction. This is the case even if the + breakpoint is in the delay slot of a branch instruction. + + Clearly, to step past the breakpoint, we need to set the queue + front to the back. But what do we put in the back? What + instruction comes after that one? Because of the branch delay + slot, the next insn is always at the back + 4. */ + write_register (HPPA_PCOQ_HEAD_REGNUM, read_register (HPPA_PCOQ_TAIL_REGNUM)); + write_register (HPPA_PCSQ_HEAD_REGNUM, read_register (HPPA_PCSQ_TAIL_REGNUM)); + + write_register (HPPA_PCOQ_TAIL_REGNUM, read_register (HPPA_PCOQ_TAIL_REGNUM) + 4); + /* We can leave the tail's space the same, since there's no jump. */ +} /* Exception handling support for the HP-UX ANSI C++ compiler. The compiler (aCC) provides a callback for exception events; |