1 /* Code dealing with register stack frames, for GDB, the GNU debugger. 2 3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software 5 Foundation, Inc. 6 7 This file is part of GDB. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 2 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 59 Temple Place - Suite 330, 22 Boston, MA 02111-1307, USA. */ 23 24 25 #include "defs.h" 26 #include "regcache.h" 27 #include "sentinel-frame.h" 28 #include "inferior.h" 29 #include "frame-unwind.h" 30 31 struct frame_unwind_cache 32 { 33 struct regcache *regcache; 34 }; 35 36 void * 37 sentinel_frame_cache (struct regcache *regcache) 38 { 39 struct frame_unwind_cache *cache = 40 FRAME_OBSTACK_ZALLOC (struct frame_unwind_cache); 41 cache->regcache = regcache; 42 return cache; 43 } 44 45 /* Here the register value is taken direct from the register cache. */ 46 47 static void 48 sentinel_frame_prev_register (struct frame_info *next_frame, 49 void **this_prologue_cache, 50 int regnum, int *optimized, 51 enum lval_type *lvalp, CORE_ADDR *addrp, 52 int *realnum, void *bufferp) 53 { 54 struct frame_unwind_cache *cache = *this_prologue_cache; 55 /* Describe the register's location. A reg-frame maps all registers 56 onto the corresponding hardware register. */ 57 *optimized = 0; 58 *lvalp = lval_register; 59 *addrp = register_offset_hack (current_gdbarch, regnum); 60 *realnum = regnum; 61 62 /* If needed, find and return the value of the register. */ 63 if (bufferp != NULL) 64 { 65 /* Return the actual value. */ 66 /* Use the regcache_cooked_read() method so that it, on the fly, 67 constructs either a raw or pseudo register from the raw 68 register cache. */ 69 regcache_cooked_read (cache->regcache, regnum, bufferp); 70 } 71 } 72 73 static void 74 sentinel_frame_this_id (struct frame_info *next_frame, 75 void **this_prologue_cache, 76 struct frame_id *this_id) 77 { 78 /* The sentinel frame is used as a starting point for creating the 79 previous (inner most) frame. That frame's THIS_ID method will be 80 called to determine the inner most frame's ID. Not this one. */ 81 internal_error (__FILE__, __LINE__, "sentinel_frame_this_id called"); 82 } 83 84 const struct frame_unwind sentinel_frame_unwinder = 85 { 86 SENTINEL_FRAME, 87 sentinel_frame_this_id, 88 sentinel_frame_prev_register 89 }; 90 91 const struct frame_unwind *const sentinel_frame_unwind = &sentinel_frame_unwinder; 92