- /* Link it in. */
- next_frame->prev = prev;
- prev->next = next_frame;
- prev->frame = address;
- prev->level = next_frame->level + 1;
- /* FIXME: cagney/2002-11-18: Should be setting the frame's type
- here, before anything else, and not last. Various INIT functions
- are full of work-arounds for the frames type not being set
- correctly from the word go. Ulgh! */
- prev->type = NORMAL_FRAME;
-
- /* This change should not be needed, FIXME! We should determine
- whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
- after INIT_EXTRA_FRAME_INFO and come up with a simple way to
- express what goes on here.
-
- 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
- INIT_EXTRA_FRAME_INFO.
-
- The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
- PC value (which hasn't been set yet). Some other machines appear
- to require 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
- INIT_EXTRA_FRAME_INFO, one possible scheme:
-
- SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
- (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 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
- FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
- no good way to get information deduced in 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 (NEXT_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 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 ())
- prev->pc = (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf, prev));
-
- if (INIT_EXTRA_FRAME_INFO_P ())
- 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 ())
- prev->pc = 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 FRAME_CHAIN or thereabouts, but it seems like there
- is no reason this can't be an architecture-independent check. */
- if (prev->frame == next_frame->frame
- && prev->pc == next_frame->pc)
projects / deliverable / binutils-gdb.git / blobdiff