Refactor Cortex-A8 erratum workaround in preparation

[binutils-gdb.git] / gdb / breakpoint.c

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index c059861138220639e88013fc45cfce2f36fdc1a7..d2dafef0b03b2be5219417a65e28fd973036e6de 100644 (file)
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1604,7 +1604,6 @@ breakpoint_xfer_memory (gdb_byte *readbuf, gdb_byte *writebuf,
   /* Left boundary, right boundary and median element of our binary
      search.  */
   unsigned bc_l, bc_r, bc;
-  size_t i;
 
   /* Find BC_L which is a leftmost element which may affect BUF
      content.  It is safe to report lower value but a failure to
@@ -1659,9 +1658,6 @@ breakpoint_xfer_memory (gdb_byte *readbuf, gdb_byte *writebuf,
   for (bc = bc_l; bc < bp_location_count; bc++)
   {
     struct bp_location *bl = bp_location[bc];
-    CORE_ADDR bp_addr = 0;
-    int bp_size = 0;
-    int bptoffset = 0;
 
     /* bp_location array has BL->OWNER always non-NULL.  */
     if (bl->owner->type == bp_none)
@@ -2219,11 +2215,22 @@ should_be_inserted (struct bp_location *bl)
     return 0;
 
   /* Don't insert a breakpoint if we're trying to step past its
-     location.  */
+     location, except if the breakpoint is a single-step breakpoint,
+     and the breakpoint's thread is the thread which is stepping past
+     a breakpoint.  */
   if ((bl->loc_type == bp_loc_software_breakpoint
        || bl->loc_type == bp_loc_hardware_breakpoint)
       && stepping_past_instruction_at (bl->pspace->aspace,
-                                      bl->address))
+                                      bl->address)
+      /* The single-step breakpoint may be inserted at the location
+        we're trying to step if the instruction branches to itself.
+        However, the instruction won't be executed at all and it may
+        break the semantics of the instruction, for example, the
+        instruction is a conditional branch or updates some flags.
+        We can't fix it unless GDB is able to emulate the instruction
+        or switch to displaced stepping.  */
+      && !(bl->owner->type == bp_single_step
+          && thread_is_stepping_over_breakpoint (bl->owner->thread)))
     {
       if (debug_infrun)
        {
@@ -3764,6 +3771,14 @@ create_exception_master_breakpoint (void)
     }
 }
 
+/* Does B have a location spec?  */
+
+static int
+breakpoint_event_location_empty_p (const struct breakpoint *b)
+{
+  return b->location != NULL && event_location_empty_p (b->location);
+}
+
 void
 update_breakpoints_after_exec (void)
 {
@@ -3878,7 +3893,7 @@ update_breakpoints_after_exec (void)
     /* Without a symbolic address, we have little hope of the
        pre-exec() address meaning the same thing in the post-exec()
        a.out.  */
-    if (event_location_empty_p (b->location))
+    if (breakpoint_event_location_empty_p (b))
       {
        delete_breakpoint (b);
        continue;
@@ -4123,7 +4138,7 @@ void
 breakpoint_init_inferior (enum inf_context context)
 {
   struct breakpoint *b, *b_tmp;
-  struct bp_location *bl, **blp_tmp;
+  struct bp_location *bl;
   int ix;
   struct program_space *pspace = current_program_space;
 
@@ -4333,7 +4348,6 @@ int
 breakpoint_inserted_here_p (struct address_space *aspace, CORE_ADDR pc)
 {
   struct bp_location **blp, **blp_tmp = NULL;
-  struct bp_location *bl;
 
   ALL_BP_LOCATIONS_AT_ADDR (blp, blp_tmp, pc)
     {
@@ -4357,7 +4371,6 @@ software_breakpoint_inserted_here_p (struct address_space *aspace,
                                     CORE_ADDR pc)
 {
   struct bp_location **blp, **blp_tmp = NULL;
-  struct bp_location *bl;
 
   ALL_BP_LOCATIONS_AT_ADDR (blp, blp_tmp, pc)
     {
@@ -4380,7 +4393,6 @@ hardware_breakpoint_inserted_here_p (struct address_space *aspace,
                                     CORE_ADDR pc)
 {
   struct bp_location **blp, **blp_tmp = NULL;
-  struct bp_location *bl;
 
   ALL_BP_LOCATIONS_AT_ADDR (blp, blp_tmp, pc)
     {
@@ -5800,7 +5812,6 @@ struct bpstat_what
 bpstat_what (bpstat bs_head)
 {
   struct bpstat_what retval;
-  int jit_event = 0;
   bpstat bs;
 
   retval.main_action = BPSTAT_WHAT_KEEP_CHECKING;
@@ -5922,7 +5933,6 @@ bpstat_what (bpstat bs_head)
            }
          break;
        case bp_jit_event:
-         jit_event = 1;
          this_action = BPSTAT_WHAT_SINGLE;
          break;
        case bp_call_dummy:
@@ -10378,7 +10388,7 @@ find_breakpoint_range_end (struct symtab_and_line sal)
 static void
 break_range_command (char *arg, int from_tty)
 {
-  char *arg_start, *addr_string_start, *addr_string_end;
+  char *arg_start, *addr_string_start;
   struct linespec_result canonical_start, canonical_end;
   int bp_count, can_use_bp, length;
   CORE_ADDR end;
@@ -13063,7 +13073,7 @@ static void
 bkpt_re_set (struct breakpoint *b)
 {
   /* FIXME: is this still reachable?  */
-  if (event_location_empty_p (b->location))
+  if (breakpoint_event_location_empty_p (b))
     {
       /* Anything without a location can't be re-set.  */
       delete_breakpoint (b);
@@ -15722,8 +15732,6 @@ save_breakpoints (char *filename, int from_tty,
 
     if (tp->type != bp_dprintf && tp->commands)
       {
-       struct gdb_exception exception;
-
        fprintf_unfiltered (fp, "  commands\n");
        
        ui_out_redirect (current_uiout, fp);