1 /* Builtin frame register, for GDB, the GNU debugger. 2 3 Copyright (C) 2002, 2005, 2007, 2008, 2009, 2010 4 Free Software Foundation, Inc. 5 6 Contributed by Red Hat. 7 8 This file is part of GDB. 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 3 of the License, or 13 (at your option) any later version. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 22 23 #include "defs.h" 24 #include "user-regs.h" 25 #include "frame.h" 26 #include "gdbtypes.h" 27 #include "value.h" 28 #include "gdb_string.h" 29 30 31 static struct value * 32 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton) 33 { 34 struct gdbarch *gdbarch = get_frame_arch (frame); 35 36 if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0) 37 /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the 38 register name table overrides this built-in $fp register, there 39 is no real reason for this gdbarch_deprecated_fp_regnum trickery here. 40 An architecture wanting to implement "$fp" as alias for a raw 41 register can do so by adding "fp" to register name table (mind 42 you, doing this is probably a dangerous thing). */ 43 return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch), 44 frame); 45 else 46 { 47 struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr; 48 struct value *val = allocate_value (data_ptr_type); 49 gdb_byte *buf = value_contents_raw (val); 50 51 if (frame == NULL) 52 memset (buf, 0, TYPE_LENGTH (value_type (val))); 53 else 54 gdbarch_address_to_pointer (gdbarch, data_ptr_type, 55 buf, get_frame_base_address (frame)); 56 return val; 57 } 58 } 59 60 static struct value * 61 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton) 62 { 63 struct gdbarch *gdbarch = get_frame_arch (frame); 64 65 if (gdbarch_pc_regnum (gdbarch) >= 0) 66 return value_of_register (gdbarch_pc_regnum (gdbarch), frame); 67 else 68 { 69 struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr; 70 struct value *val = allocate_value (func_ptr_type); 71 gdb_byte *buf = value_contents_raw (val); 72 73 if (frame == NULL) 74 memset (buf, 0, TYPE_LENGTH (value_type (val))); 75 else 76 gdbarch_address_to_pointer (gdbarch, func_ptr_type, 77 buf, get_frame_pc (frame)); 78 return val; 79 } 80 } 81 82 static struct value * 83 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton) 84 { 85 struct gdbarch *gdbarch = get_frame_arch (frame); 86 87 if (gdbarch_sp_regnum (gdbarch) >= 0) 88 return value_of_register (gdbarch_sp_regnum (gdbarch), frame); 89 error (_("Standard register ``$sp'' is not available for this target")); 90 } 91 92 static struct value * 93 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton) 94 { 95 struct gdbarch *gdbarch = get_frame_arch (frame); 96 97 if (gdbarch_ps_regnum (gdbarch) >= 0) 98 return value_of_register (gdbarch_ps_regnum (gdbarch), frame); 99 error (_("Standard register ``$ps'' is not available for this target")); 100 } 101 102 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */ 103 104 void 105 _initialize_frame_reg (void) 106 { 107 /* Frame based $fp, $pc, $sp and $ps. These only come into play 108 when the target does not define its own version of these 109 registers. */ 110 user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL); 111 user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL); 112 user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL); 113 user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL); 114 } 115