-static struct frame_info *
-legacy_get_prev_frame (struct frame_info *this_frame)
-{
- CORE_ADDR address = 0;
- struct frame_info *prev;
- int fromleaf;
-
- /* Don't frame_debug print legacy_get_prev_frame() here, just
- confuses the output. */
-
- /* Allocate the new frame.
-
- There is no reason to worry about memory leaks, should the
- remainder of the function fail. The allocated memory will be
- quickly reclaimed when the frame cache is flushed, and the `we've
- been here before' check, in get_prev_frame will stop repeated
- memory allocation calls. */
- prev = FRAME_OBSTACK_ZALLOC (struct frame_info);
- prev->level = this_frame->level + 1;
-
- /* Do not completly wire it in to the frame chain. Some (bad) code
- in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull
- some fancy tricks (of course such code is, by definition,
- recursive).
-
- On the other hand, methods, such as get_frame_pc() and
- get_frame_base() rely on being able to walk along the frame
- chain. Make certain that at least they work by providing that
- link. Of course things manipulating prev can't go back. */
- prev->next = this_frame;
-
- /* NOTE: cagney/2002-11-18: Should have been correctly setting the
- frame's type here, before anything else, and not last, at the
- bottom of this function. The various
- DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
- DEPRECATED_INIT_FRAME_PC_FIRST and
- DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
- that handle the frame not being correctly set from the start.
- Unfortunatly those same work-arounds rely on the type defaulting
- to NORMAL_FRAME. Ulgh! The new frame code does not have this
- problem. */
- prev->type = UNKNOWN_FRAME;
-
- /* A legacy frame's ID is always computed here. Mark it as valid. */
- prev->this_id.p = 1;
-
- /* Handle sentinel frame unwind as a special case. */
- if (this_frame->level < 0)
- {
- /* Try to unwind the PC. If that doesn't work, assume we've reached
- the oldest frame and simply return. Is there a better sentinal
- value? The unwound PC value is then used to initialize the new
- previous frame's type.
-
- Note that the pc-unwind is intentionally performed before the
- frame chain. This is ok since, for old targets, both
- frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and
- DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
- have already been initialized (using
- DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
- doesn't matter.
-
- By unwinding the PC first, it becomes possible to, in the case of
- a dummy frame, avoid also unwinding the frame ID. This is
- because (well ignoring the PPC) a dummy frame can be located
- using THIS_FRAME's frame ID. */
-
- deprecated_update_frame_pc_hack (prev, frame_pc_unwind (this_frame));
- if (get_frame_pc (prev) == 0)
- {
- /* The allocated PREV_FRAME will be reclaimed when the frame
- obstack is next purged. */
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog,
- " // unwound legacy PC zero }\n");
- }
- return NULL;
- }
-
- /* Set the unwind functions based on that identified PC. Ditto
- for the "type" but strongly prefer the unwinder's frame type. */
- prev->unwind = frame_unwind_find_by_pc (current_gdbarch,
- get_frame_pc (prev));
- if (prev->unwind->type == UNKNOWN_FRAME)
- prev->type = frame_type_from_pc (get_frame_pc (prev));
- else
- prev->type = prev->unwind->type;
-
- /* Find the prev's frame's ID. */
- if (prev->type == DUMMY_FRAME
- && gdbarch_unwind_dummy_id_p (current_gdbarch))
- {
- /* When unwinding a normal frame, the stack structure is
- determined by analyzing the frame's function's code (be
- it using brute force prologue analysis, or the dwarf2
- CFI). In the case of a dummy frame, that simply isn't
- possible. The The PC is either the program entry point,
- or some random address on the stack. Trying to use that
- PC to apply standard frame ID unwind techniques is just
- asking for trouble. */
- /* Assume call_function_by_hand(), via SAVE_DUMMY_FRAME_TOS,
- previously saved the dummy frame's ID. Things only work
- if the two return the same value. */
- gdb_assert (SAVE_DUMMY_FRAME_TOS_P ());
- /* Use an architecture specific method to extract the prev's
- dummy ID from the next frame. Note that this method uses
- frame_register_unwind to obtain the register values
- needed to determine the dummy frame's ID. */
- prev->this_id.value = gdbarch_unwind_dummy_id (current_gdbarch,
- this_frame);
- }
- else
- {
- /* We're unwinding a sentinel frame, the PC of which is
- pointing at a stack dummy. Fake up the dummy frame's ID
- using the same sequence as is found a traditional
- unwinder. Once all architectures supply the
- unwind_dummy_id method, this code can go away. */
- prev->this_id.value = frame_id_build (deprecated_read_fp (),
- read_pc ());
- }
-
- /* Check that the unwound ID is valid. */
- if (!frame_id_p (prev->this_id.value))
- {
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog,
- " // unwound legacy ID invalid }\n");
- }
- return NULL;
- }
-
- /* Check that the new frame isn't inner to (younger, below,
- next) the old frame. If that happens the frame unwind is
- going backwards. */
- /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
- that doesn't have a valid frame ID. Should instead set the
- sentinel frame's frame ID to a `sentinel'. Leave it until
- after the switch to storing the frame ID, instead of the
- frame base, in the frame object. */
-
- /* Link it in. */
- this_frame->prev = prev;
-
- /* FIXME: cagney/2002-01-19: This call will go away. Instead of
- initializing extra info, all frames will use the frame_cache
- (passed to the unwind functions) to store additional frame
- info. Unfortunatly legacy targets can't use
- legacy_get_prev_frame() to unwind the sentinel frame and,
- consequently, are forced to take this code path and rely on
- the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
- initialize the inner-most frame. */
- if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
- {
- DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev);
- }
-
- if (prev->type == NORMAL_FRAME)
- prev->this_id.value.code_addr
- = get_pc_function_start (prev->this_id.value.code_addr);
-
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, prev);
- fprintf_unfiltered (gdb_stdlog, " } // legacy innermost frame\n");
- }
- return prev;
- }
-
- /* This code only works on normal frames. A sentinel frame, where
- the level is -1, should never reach this code. */
- gdb_assert (this_frame->level >= 0);
-
- /* On some machines it is possible to call a function without
- setting up a stack frame for it. On these machines, we
- define this macro to take two args; a frameinfo pointer
- identifying a frame and a variable to set or clear if it is
- or isn't leafless. */
-
- /* Still don't want to worry about this except on the innermost
- frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
- function invocation. */
- if (this_frame->level == 0)
- /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
- the frame chain, not just the inner most frame! The generic,
- per-architecture, frame code should handle this and the below
- should simply be removed. */
- fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame);
- else
- fromleaf = 0;
-
- if (fromleaf)
- /* A frameless inner-most frame. The `FP' (which isn't an
- architecture frame-pointer register!) of the caller is the same
- as the callee. */
- /* FIXME: 2002-11-09: There isn't any reason to special case this
- edge condition. Instead the per-architecture code should hande
- it locally. */
- address = get_frame_base (this_frame);
- else
- {
- /* Two macros defined in tm.h specify the machine-dependent
- actions to be performed here.
-
- First, get the frame's chain-pointer.