| 1 | /* Code dealing with dummy stack frames, for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright 2002 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #if !defined (DUMMY_FRAME_H) |
| 23 | #define DUMMY_FRAME_H 1 |
| 24 | |
| 25 | struct frame_info; |
| 26 | struct regcache; |
| 27 | struct frame_unwind; |
| 28 | struct frame_id; |
| 29 | |
| 30 | /* GENERIC DUMMY FRAMES |
| 31 | |
| 32 | The following code serves to maintain the dummy stack frames for |
| 33 | inferior function calls (ie. when gdb calls into the inferior via |
| 34 | call_function_by_hand). This code saves the machine state before |
| 35 | the call in host memory, so we must maintain an independent stack |
| 36 | and keep it consistant etc. I am attempting to make this code |
| 37 | generic enough to be used by many targets. |
| 38 | |
| 39 | The cheapest and most generic way to do CALL_DUMMY on a new target |
| 40 | is probably to define CALL_DUMMY to be empty, |
| 41 | DEPRECATED_CALL_DUMMY_LENGTH to zero, and CALL_DUMMY_LOCATION to |
| 42 | AT_ENTRY. Then you must remember to define PUSH_RETURN_ADDRESS, |
| 43 | because no call instruction will be being executed by the target. |
| 44 | Also DEPRECATED_FRAME_CHAIN_VALID as |
| 45 | generic_{file,func}_frame_chain_valid and do not set |
| 46 | DEPRECATED_FIX_CALL_DUMMY. */ |
| 47 | |
| 48 | /* If the PC falls in a dummy frame, return a dummy frame |
| 49 | unwinder. */ |
| 50 | |
| 51 | extern const struct frame_unwind *dummy_frame_sniffer (struct frame_info *next_frame); |
| 52 | |
| 53 | /* Does the PC fall in a dummy frame? |
| 54 | |
| 55 | This function is used by "frame.c" when creating a new `struct |
| 56 | frame_info'. |
| 57 | |
| 58 | Note that there is also very similar code in breakpoint.c (where |
| 59 | the bpstat stop reason is computed). It is looking for a PC |
| 60 | falling on a dummy_frame breakpoint. Perhaphs this, and that code |
| 61 | should be combined? |
| 62 | |
| 63 | Architecture dependant code, that has access to a frame, should not |
| 64 | use this function. Instead (get_frame_type() == DUMMY_FRAME) |
| 65 | should be used. |
| 66 | |
| 67 | Hmm, but what about threads? When the dummy-frame code tries to |
| 68 | relocate a dummy frame's saved registers it definitly needs to |
| 69 | differentiate between threads (otherwize it will do things like |
| 70 | clean-up the wrong threads frames). However, when just trying to |
| 71 | identify a dummy-frame that shouldn't matter. The wost that can |
| 72 | happen is that a thread is marked as sitting in a dummy frame when, |
| 73 | in reality, its corrupted its stack, to the point that a PC is |
| 74 | pointing into a dummy frame. */ |
| 75 | |
| 76 | extern int pc_in_dummy_frame (CORE_ADDR pc); |
| 77 | |
| 78 | /* Return the regcache that belongs to the dummy-frame identifed by PC |
| 79 | and FP, or NULL if no such frame exists. */ |
| 80 | /* FIXME: cagney/2002-11-08: The function only exists because of |
| 81 | deprecated_generic_get_saved_register. Eliminate that function and |
| 82 | this, to, can go. */ |
| 83 | |
| 84 | extern struct regcache *deprecated_find_dummy_frame_regcache (CORE_ADDR pc, |
| 85 | CORE_ADDR fp); |
| 86 | #endif /* !defined (DUMMY_FRAME_H) */ |