- /* Link in the already allocated prev frame. */
- this_frame->prev = prev;
- deprecated_update_frame_base_hack (prev, address);
-
- /* This change should not be needed, FIXME! We should determine
- whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
- after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
- way to express what goes on here.
-
- DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
- create_new_frame (where the PC is already set up) and here (where
- it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
- always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
-
- The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
- requires the PC value (which hasn't been set yet). Some other
- machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
- before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
-
- We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
- complication to an already overcomplicated part of GDB.
- gnu@cygnus.com, 15Sep92.
-
- Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
- DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
-
- SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
- (deprecated_read_fp ()), read_pc ()). Machines with extra frame
- info would do that (or the local equivalent) and then set the
- extra fields.
-
- SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
- create_new_frame would no longer init extra frame info;
- SETUP_ARBITRARY_FRAME would have to do that.
-
- INIT_PREV_FRAME(fromleaf, prev) Replace
- DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
- This should also return a flag saying whether to keep the new
- frame, or whether to discard it, because on some machines (e.g.
- mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
- called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
- way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
- into the extra fields of the new frame). std_frame_pc(fromleaf,
- prev)
-
- This is the default setting for INIT_PREV_FRAME. It just does
- what the default DEPRECATED_INIT_FRAME_PC does. Some machines
- will call it from INIT_PREV_FRAME (either at the beginning, the
- end, or in the middle). Some machines won't use it.
-
- kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
-
- /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
- reason for things to be this complicated.
-
- The trick is to assume that there is always a frame. Instead of
- special casing the inner-most frame, create fake frame
- (containing the hardware registers) that is inner to the
- user-visible inner-most frame (...) and then unwind from that.
- That way architecture code can use use the standard
- frame_XX_unwind() functions and not differentiate between the
- inner most and any other case.
-
- Since there is always a frame to unwind from, there is always
- somewhere (THIS_FRAME) to store all the info needed to construct
- a new (previous) frame without having to first create it. This
- means that the convolution below - needing to carefully order a
- frame's initialization - isn't needed.
-
- The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
- for a more up-to-date architecture, always calls
- FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
- without first needing the frame! Instead of the convolution
- below, we could have simply called FRAME_SAVED_PC() and been done
- with it! Note that FRAME_SAVED_PC() is being superseed by
- frame_pc_unwind() and that function does have somewhere to cache
- that PC value. */
-
- if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
- deprecated_update_frame_pc_hack (prev,
- DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf,
- prev));
-
- if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
- DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev);
-
- /* This entry is in the frame queue now, which is good since
- FRAME_SAVED_PC may use that queue to figure out its value (see
- tm-sparc.h). We want the pc saved in the inferior frame. */
- if (DEPRECATED_INIT_FRAME_PC_P ())
- deprecated_update_frame_pc_hack (prev,
- DEPRECATED_INIT_FRAME_PC (fromleaf,
- prev));
-
- /* If ->frame and ->pc are unchanged, we are in the process of
- getting ourselves into an infinite backtrace. Some architectures
- check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
- like there is no reason this can't be an architecture-independent
- check. */
- if (get_frame_base (prev) == get_frame_base (this_frame)
- && get_frame_pc (prev) == get_frame_pc (this_frame))
- {
- this_frame->prev = NULL;
- obstack_free (&frame_cache_obstack, prev);
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog,
- " // legacy this.id == prev.id }\n");
- }
- return NULL;
- }
-
- /* Initialize the code used to unwind the frame PREV based on the PC
- (and probably other architectural information). The PC lets you
- check things like the debug info at that point (dwarf2cfi?) and
- use that to decide how the frame should be unwound.
-
- If there isn't a FRAME_CHAIN, the code above will have already
- done this. */
- if (prev->unwind == NULL)
- prev->unwind = frame_unwind_find_by_frame (prev->next);
-
- /* If the unwinder provides a frame type, use it. Otherwize
- continue on to that heuristic mess. */
- if (prev->unwind->type != UNKNOWN_FRAME)
- {
- prev->type = prev->unwind->type;
- if (prev->type == NORMAL_FRAME)
- /* FIXME: cagney/2003-06-16: would get_frame_pc() be better? */
- 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 with unwound type\n");
- }
- return prev;
- }
-
- /* NOTE: cagney/2002-11-18: The code segments, found in
- create_new_frame and get_prev_frame(), that initializes the
- frames type is subtly different. The latter only updates ->type
- when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
- get_prev_frame() overriding the frame's type when the INIT code
- has previously set it. This is really somewhat bogus. The
- initialization, as seen in create_new_frame(), should occur
- before the INIT function has been called. */
- if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
- && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
- ? DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (prev), 0, 0)
- : pc_in_dummy_frame (get_frame_pc (prev))))
- prev->type = DUMMY_FRAME;
- else
- {
- /* FIXME: cagney/2002-11-10: This should be moved to before the
- INIT code above so that the INIT code knows what the frame's
- type is (in fact, for a [generic] dummy-frame, the type can
- be set and then the entire initialization can be skipped.
- Unforunatly, its the INIT code that sets the PC (Hmm, catch
- 22). */
- char *name;
- find_pc_partial_function (get_frame_pc (prev), &name, NULL, NULL);
- if (PC_IN_SIGTRAMP (get_frame_pc (prev), name))
- prev->type = SIGTRAMP_FRAME;
- /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
- architectures are forcing the frame's type in INIT so we
- don't want to override it here. Remember, NORMAL_FRAME == 0,
- so it all works (just :-/). Once this initialization is
- moved to the start of this function, all this nastness will
- go away. */
- }