1 /* Code dealing with register stack frames, for GDB, the GNU debugger. 2 3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2007, 2008, 2009 5 Free Software 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 3 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, see <http://www.gnu.org/licenses/>. */ 21 22 23 #include "defs.h" 24 #include "regcache.h" 25 #include "sentinel-frame.h" 26 #include "inferior.h" 27 #include "frame-unwind.h" 28 29 struct frame_unwind_cache 30 { 31 struct regcache *regcache; 32 }; 33 34 void * 35 sentinel_frame_cache (struct regcache *regcache) 36 { 37 struct frame_unwind_cache *cache = 38 FRAME_OBSTACK_ZALLOC (struct frame_unwind_cache); 39 cache->regcache = regcache; 40 return cache; 41 } 42 43 /* Here the register value is taken direct from the register cache. */ 44 45 static struct value * 46 sentinel_frame_prev_register (struct frame_info *this_frame, 47 void **this_prologue_cache, 48 int regnum) 49 { 50 struct gdbarch *gdbarch = get_frame_arch (this_frame); 51 struct frame_unwind_cache *cache = *this_prologue_cache; 52 struct value *value; 53 54 /* Return the actual value. */ 55 value = allocate_value (register_type (gdbarch, regnum)); 56 VALUE_LVAL (value) = lval_register; 57 VALUE_REGNUM (value) = regnum; 58 VALUE_FRAME_ID (value) = get_frame_id (this_frame); 59 60 /* Use the regcache_cooked_read() method so that it, on the fly, 61 constructs either a raw or pseudo register from the raw 62 register cache. */ 63 regcache_cooked_read (cache->regcache, regnum, value_contents_raw (value)); 64 65 return value; 66 } 67 68 static void 69 sentinel_frame_this_id (struct frame_info *this_frame, 70 void **this_prologue_cache, 71 struct frame_id *this_id) 72 { 73 /* The sentinel frame is used as a starting point for creating the 74 previous (inner most) frame. That frame's THIS_ID method will be 75 called to determine the inner most frame's ID. Not this one. */ 76 internal_error (__FILE__, __LINE__, _("sentinel_frame_this_id called")); 77 } 78 79 static struct gdbarch * 80 sentinel_frame_prev_arch (struct frame_info *this_frame, 81 void **this_prologue_cache) 82 { 83 struct frame_unwind_cache *cache = *this_prologue_cache; 84 return get_regcache_arch (cache->regcache); 85 } 86 87 const struct frame_unwind sentinel_frame_unwinder = 88 { 89 SENTINEL_FRAME, 90 sentinel_frame_this_id, 91 sentinel_frame_prev_register, 92 NULL, 93 NULL, 94 NULL, 95 sentinel_frame_prev_arch, 96 }; 97 98 const struct frame_unwind *const sentinel_frame_unwind = &sentinel_frame_unwinder; 99