1 /* Builtin frame register, for GDB, the GNU debugger. 2 3 Copyright (C) 2002, 2005, 2007, 2008, 2009 Free Software Foundation, Inc. 4 5 Contributed by Red Hat. 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 #include "defs.h" 23 #include "user-regs.h" 24 #include "frame.h" 25 #include "gdbtypes.h" 26 #include "value.h" 27 #include "gdb_string.h" 28 29 30 static struct value * 31 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton) 32 { 33 struct gdbarch *gdbarch = get_frame_arch (frame); 34 if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0) 35 /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the 36 register name table overrides this built-in $fp register, there 37 is no real reason for this gdbarch_deprecated_fp_regnum trickery here. 38 An architecture wanting to implement "$fp" as alias for a raw 39 register can do so by adding "fp" to register name table (mind 40 you, doing this is probably a dangerous thing). */ 41 return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch), 42 frame); 43 else 44 { 45 struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr; 46 struct value *val = allocate_value (data_ptr_type); 47 gdb_byte *buf = value_contents_raw (val); 48 if (frame == NULL) 49 memset (buf, 0, TYPE_LENGTH (value_type (val))); 50 else 51 gdbarch_address_to_pointer (gdbarch, data_ptr_type, 52 buf, get_frame_base_address (frame)); 53 return val; 54 } 55 } 56 57 static struct value * 58 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton) 59 { 60 struct gdbarch *gdbarch = get_frame_arch (frame); 61 if (gdbarch_pc_regnum (gdbarch) >= 0) 62 return value_of_register (gdbarch_pc_regnum (gdbarch), frame); 63 else 64 { 65 struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr; 66 struct value *val = allocate_value (func_ptr_type); 67 gdb_byte *buf = value_contents_raw (val); 68 if (frame == NULL) 69 memset (buf, 0, TYPE_LENGTH (value_type (val))); 70 else 71 gdbarch_address_to_pointer (gdbarch, func_ptr_type, 72 buf, get_frame_pc (frame)); 73 return val; 74 } 75 } 76 77 static struct value * 78 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton) 79 { 80 struct gdbarch *gdbarch = get_frame_arch (frame); 81 if (gdbarch_sp_regnum (gdbarch) >= 0) 82 return value_of_register (gdbarch_sp_regnum (gdbarch), frame); 83 error (_("Standard register ``$sp'' is not available for this target")); 84 } 85 86 static struct value * 87 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton) 88 { 89 struct gdbarch *gdbarch = get_frame_arch (frame); 90 if (gdbarch_ps_regnum (gdbarch) >= 0) 91 return value_of_register (gdbarch_ps_regnum (gdbarch), frame); 92 error (_("Standard register ``$ps'' is not available for this target")); 93 } 94 95 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */ 96 97 void 98 _initialize_frame_reg (void) 99 { 100 /* Frame based $fp, $pc, $sp and $ps. These only come into play 101 when the target does not define its own version of these 102 registers. */ 103 user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL); 104 user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL); 105 user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL); 106 user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL); 107 } 108