bs->print_it = print_it_normal;
return bs;
}
+\f
+/* Return the frame which we can use to evaluate the expression
+ whose valid block is valid_block, or NULL if not in scope.
+
+ This whole concept is probably not the way to do things (it is incredibly
+ slow being the main reason, not to mention fragile (e.g. the sparc
+ frame pointer being fetched as 0 bug causes it to stop)). Instead,
+ introduce a version of "struct frame" which survives over calls to the
+ inferior, but which is better than FRAME_ADDR in the sense that it lets
+ us evaluate expressions relative to that frame (on some machines, it
+ can just be a FRAME_ADDR). Save one of those instead of (or in addition
+ to) the exp_valid_block, and then use it to evaluate the watchpoint
+ expression, with no need to do all this backtracing every time.
+
+ Or better yet, what if it just copied the struct frame and its next
+ frame? Off the top of my head, I would think that would work
+ because things like (a29k) rsize and msize, or (sparc) bottom just
+ depend on the frame, and aren't going to be different just because
+ the inferior has done something. Trying to recalculate them
+ strikes me as a lot of work, possibly even impossible. Saving the
+ next frame is needed at least on a29k, where get_saved_register
+ uses fi->next->saved_msp. For figuring out whether that frame is
+ still on the stack, I guess this needs to be machine-specific (e.g.
+ a29k) but I think
+
+ read_register (FP_REGNUM) INNER_THAN watchpoint_frame->frame
+
+ would generally work.
+
+ Of course the scope of the expression could be less than a whole
+ function; perhaps if the innermost frame is the one which the
+ watchpoint is relative to (another machine-specific thing, usually
+
+ FRAMELESS_FUNCTION_INVOCATION (get_current_frame(), fromleaf)
+ read_register (FP_REGNUM) == wp_frame->frame
+ && !fromleaf
+
+ ), *then* it could do a
+
+ contained_in (get_current_block (), wp->exp_valid_block).
+
+ */
+
+FRAME
+within_scope (valid_block)
+ struct block *valid_block;
+{
+ FRAME fr = get_current_frame ();
+ struct frame_info *fi = get_frame_info (fr);
+ CORE_ADDR func_start;
+
+ /* If caller_pc_valid is true, we are stepping through
+ a function prologue, which is bounded by callee_func_start
+ (inclusive) and callee_prologue_end (exclusive).
+ caller_pc is the pc of the caller.
+
+ Yes, this is hairy. */
+ static int caller_pc_valid = 0;
+ static CORE_ADDR caller_pc;
+ static CORE_ADDR callee_func_start;
+ static CORE_ADDR callee_prologue_end;
+
+ find_pc_partial_function (fi->pc, (PTR)NULL, &func_start);
+ func_start += FUNCTION_START_OFFSET;
+ if (fi->pc == func_start)
+ {
+ /* We just called a function. The only other case I
+ can think of where the pc would equal the pc of the
+ start of a function is a frameless function (i.e.
+ no prologue) where we branch back to the start
+ of the function. In that case, SKIP_PROLOGUE won't
+ find one, and we'll clear caller_pc_valid a few lines
+ down. */
+ caller_pc_valid = 1;
+ caller_pc = SAVED_PC_AFTER_CALL (fr);
+ callee_func_start = func_start;
+ SKIP_PROLOGUE (func_start);
+ callee_prologue_end = func_start;
+ }
+ if (caller_pc_valid)
+ {
+ if (fi->pc < callee_func_start
+ || fi->pc >= callee_prologue_end)
+ caller_pc_valid = 0;
+ }
+
+ if (contained_in (block_for_pc (caller_pc_valid
+ ? caller_pc
+ : fi->pc),
+ valid_block))
+ {
+ return fr;
+ }
+ fr = get_prev_frame (fr);
+
+ /* If any active frame is in the exp_valid_block, then it's
+ OK. Note that this might not be the same invocation of
+ the exp_valid_block that we were watching a little while
+ ago, or the same one as when the watchpoint was set (e.g.
+ we are watching a local variable in a recursive function.
+ When we return from a recursive invocation, then we are
+ suddenly watching a different instance of the variable).
+
+ At least for now I am going to consider this a feature. */
+ for (; fr != NULL; fr = get_prev_frame (fr))
+ {
+ fi = get_frame_info (fr);
+ if (contained_in (block_for_pc (fi->pc),
+ valid_block))
+ {
+ return fr;
+ }
+ }
+ return NULL;
+}
/* Possible return values for watchpoint_check (this can't be an enum
because of check_errors). */
PTR p;
{
bpstat bs = (bpstat) p;
+ FRAME fr;
int within_current_scope;
- if (bs->breakpoint_at->exp_valid_block != NULL)
- within_current_scope =
- contained_in (get_selected_block (), bs->breakpoint_at->exp_valid_block);
- else
+ if (bs->breakpoint_at->exp_valid_block == NULL)
within_current_scope = 1;
-
+ else
+ {
+ fr = within_scope (bs->breakpoint_at->exp_valid_block);
+ within_current_scope = fr != NULL;
+ if (within_current_scope)
+ /* If we end up stopping, the current frame will get selected
+ in normal_stop. So this call to select_frame won't affect
+ the user. */
+ select_frame (fr, -1);
+ }
+
if (within_current_scope)
{
/* We use value_{,free_to_}mark because it could be a
enable_breakpoint (bpt)
struct breakpoint *bpt;
{
+ FRAME save_selected_frame;
+ int save_selected_frame_level = -1;
+
bpt->enable = enabled;
if (xgdb_verbose && bpt->type == bp_breakpoint)
check_duplicates (bpt->address);
if (bpt->type == bp_watchpoint)
{
- if (bpt->exp_valid_block != NULL
- && !contained_in (get_selected_block (), bpt->exp_valid_block))
+ if (bpt->exp_valid_block != NULL)
{
- printf_filtered ("\
+ FRAME fr = within_scope (bpt->exp_valid_block);
+ if (fr == NULL)
+ {
+ printf_filtered ("\
Cannot enable watchpoint %d because the block in which its expression\n\
is valid is not currently in scope.\n", bpt->number);
- bpt->enable = disabled;
- return;
+ bpt->enable = disabled;
+ return;
+ }
+ save_selected_frame = selected_frame;
+ save_selected_frame_level = selected_frame_level;
+ select_frame (fr, -1);
}
value_free (bpt->val);
release_value (bpt->val);
if (VALUE_LAZY (bpt->val))
value_fetch_lazy (bpt->val);
+
+ if (save_selected_frame_level >= 0)
+ select_frame (save_selected_frame, save_selected_frame_level);
}
}
projects / binutils-gdb.git / commitdiff