void
sparc_software_single_step (enum target_signal sig, int insert_breakpoints_p)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
static CORE_ADDR npc, nnpc;
static char npc_save[4], nnpc_save[4];
if (insert_breakpoints_p)
{
CORE_ADDR pc;
pc = sparc_address_from_register (tdep->pc_regnum);
npc = sparc_address_from_register (tdep->npc_regnum);
/* Analyze the instruction at PC. */
nnpc = sparc_analyze_control_transfer (pc, &npc);
if (npc != 0)
target_insert_breakpoint (npc, npc_save);
if (nnpc != 0)
target_insert_breakpoint (nnpc, nnpc_save);
/* Assert that we have set at least one breakpoint, and that
they're not set at the same spot. */
gdb_assert (npc != 0 || nnpc != 0);
gdb_assert (nnpc != npc);
}
else
{
if (npc != 0)
target_remove_breakpoint (npc, npc_save);
if (nnpc != 0)
target_remove_breakpoint (nnpc, nnpc_save);
}
}
void
single_step ()
{
branch_type br, isannulled();
CORE_ADDR pc;
long pc_instruction;
if (!one_stepped)
{
/* Always set breakpoint for NPC. */
next_pc = read_register (NPC_REGNUM);
npc4 = next_pc + 4; /* branch not taken */
target_insert_breakpoint (next_pc, break_mem[0]);
/* printf ("set break at %x\n",next_pc); */
pc = read_register (PC_REGNUM);
pc_instruction = read_memory_integer (pc, sizeof(pc_instruction));
br = isannulled (pc_instruction, pc, &target);
brknpc4 = brktrg = 0;
if (br == bicca)
{
/* Conditional annulled branch will either end up at
npc (if taken) or at npc+4 (if not taken).
Trap npc+4. */
brknpc4 = 1;
target_insert_breakpoint (npc4, break_mem[1]);
}
else if (br == baa && target != next_pc)
{
/* Unconditional annulled branch will always end up at
the target. */
brktrg = 1;
target_insert_breakpoint (target, break_mem[2]);
}
/* We are ready to let it go */
one_stepped = 1;
return;
}
else
{
/* Remove breakpoints */
target_remove_breakpoint (next_pc, break_mem[0]);
if (brknpc4)
target_remove_breakpoint (npc4, break_mem[1]);
if (brktrg)
target_remove_breakpoint (target, break_mem[2]);
one_stepped = 0;
}
}
static void
exec_one_dummy_insn (void)
{
#define DUMMY_INSN_ADDR (TEXT_SEGMENT_BASE)+0x200
char shadow_contents[BREAKPOINT_MAX]; /* Stash old bkpt addr contents */
int ret, status, pid;
CORE_ADDR prev_pc;
/* We plant one dummy breakpoint into DUMMY_INSN_ADDR address. We
assume that this address will never be executed again by the real
code. */
target_insert_breakpoint (DUMMY_INSN_ADDR, shadow_contents);
/* You might think this could be done with a single ptrace call, and
you'd be correct for just about every platform I've ever worked
on. However, rs6000-ibm-aix4.1.3 seems to have screwed this up --
the inferior never hits the breakpoint (it's also worth noting
powerpc-ibm-aix4.1.3 works correctly). */
prev_pc = read_pc ();
write_pc (DUMMY_INSN_ADDR);
if (ARCH64 ())
ret = rs6000_ptrace64 (PT_CONTINUE, PIDGET (inferior_ptid), 1, 0, NULL);
else
ret = rs6000_ptrace32 (PT_CONTINUE, PIDGET (inferior_ptid), (int *)1, 0, NULL);
if (ret != 0)
perror ("pt_continue");
do
{
pid = wait (&status);
}
while (pid != PIDGET (inferior_ptid));
write_pc (prev_pc);
target_remove_breakpoint (DUMMY_INSN_ADDR, shadow_contents);
}
