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, 2010, 2011 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 40 cache->regcache = regcache; 41 return cache; 42 } 43 44 /* Here the register value is taken direct from the register cache. */ 45 46 static struct value * 47 sentinel_frame_prev_register (struct frame_info *this_frame, 48 void **this_prologue_cache, 49 int regnum) 50 { 51 struct gdbarch *gdbarch = get_frame_arch (this_frame); 52 struct frame_unwind_cache *cache = *this_prologue_cache; 53 struct value *value; 54 struct type *regtype = register_type (gdbarch, regnum); 55 56 /* Return the actual value. */ 57 value = allocate_value (regtype); 58 VALUE_LVAL (value) = lval_register; 59 VALUE_REGNUM (value) = regnum; 60 VALUE_FRAME_ID (value) = get_frame_id (this_frame); 61 62 /* Use the regcache_cooked_read() method so that it, on the fly, 63 constructs either a raw or pseudo register from the raw 64 register cache. */ 65 if (regcache_cooked_read (cache->regcache, 66 regnum, 67 value_contents_raw (value)) == REG_UNAVAILABLE) 68 mark_value_bytes_unavailable (value, 0, TYPE_LENGTH (regtype)); 69 70 return value; 71 } 72 73 static void 74 sentinel_frame_this_id (struct frame_info *this_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 static struct gdbarch * 85 sentinel_frame_prev_arch (struct frame_info *this_frame, 86 void **this_prologue_cache) 87 { 88 struct frame_unwind_cache *cache = *this_prologue_cache; 89 90 return get_regcache_arch (cache->regcache); 91 } 92 93 const struct frame_unwind sentinel_frame_unwind = 94 { 95 SENTINEL_FRAME, 96 default_frame_unwind_stop_reason, 97 sentinel_frame_this_id, 98 sentinel_frame_prev_register, 99 NULL, 100 NULL, 101 NULL, 102 sentinel_frame_prev_arch, 103 }; 104