| 1 | /* Traditional frame unwind support, for GDB the GNU Debugger. |
| 2 | |
| 3 | Copyright 2003 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "frame.h" |
| 24 | #include "trad-frame.h" |
| 25 | #include "regcache.h" |
| 26 | |
| 27 | /* A traditional frame is unwound by analysing the function prologue |
| 28 | and using the information gathered to track registers. For |
| 29 | non-optimized frames, the technique is reliable (just need to check |
| 30 | for all potential instruction sequences). */ |
| 31 | |
| 32 | struct trad_frame_saved_reg * |
| 33 | trad_frame_alloc_saved_regs (struct frame_info *next_frame) |
| 34 | { |
| 35 | int regnum; |
| 36 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 37 | int numregs = NUM_REGS + NUM_PSEUDO_REGS; |
| 38 | struct trad_frame_saved_reg *this_saved_regs |
| 39 | = FRAME_OBSTACK_CALLOC (numregs, struct trad_frame_saved_reg); |
| 40 | for (regnum = 0; regnum < numregs; regnum++) |
| 41 | { |
| 42 | this_saved_regs[regnum].realreg = regnum; |
| 43 | this_saved_regs[regnum].addr = -1; |
| 44 | } |
| 45 | return this_saved_regs; |
| 46 | } |
| 47 | |
| 48 | enum { REG_VALUE = -1, REG_UNKNOWN = -2 }; |
| 49 | |
| 50 | int |
| 51 | trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) |
| 52 | { |
| 53 | return (this_saved_regs[regnum].realreg == REG_VALUE); |
| 54 | } |
| 55 | |
| 56 | int |
| 57 | trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) |
| 58 | { |
| 59 | return (this_saved_regs[regnum].realreg >= 0 |
| 60 | && this_saved_regs[regnum].addr != -1); |
| 61 | } |
| 62 | |
| 63 | int |
| 64 | trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[], |
| 65 | int regnum) |
| 66 | { |
| 67 | return (this_saved_regs[regnum].realreg >= 0 |
| 68 | && this_saved_regs[regnum].addr == -1); |
| 69 | } |
| 70 | |
| 71 | void |
| 72 | trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[], |
| 73 | int regnum, LONGEST val) |
| 74 | { |
| 75 | /* Make the REALREG invalid, indicating that the ADDR contains the |
| 76 | register's value. */ |
| 77 | this_saved_regs[regnum].realreg = REG_VALUE; |
| 78 | this_saved_regs[regnum].addr = val; |
| 79 | } |
| 80 | |
| 81 | void |
| 82 | trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[], |
| 83 | int regnum) |
| 84 | { |
| 85 | /* Make the REALREG invalid, indicating that the value is not known. */ |
| 86 | this_saved_regs[regnum].realreg = REG_UNKNOWN; |
| 87 | this_saved_regs[regnum].addr = -1; |
| 88 | } |
| 89 | |
| 90 | void |
| 91 | trad_frame_prev_register (struct frame_info *next_frame, |
| 92 | struct trad_frame_saved_reg this_saved_regs[], |
| 93 | int regnum, int *optimizedp, |
| 94 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 95 | int *realregp, void *bufferp) |
| 96 | { |
| 97 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 98 | if (trad_frame_addr_p (this_saved_regs, regnum)) |
| 99 | { |
| 100 | /* The register was saved in memory. */ |
| 101 | *optimizedp = 0; |
| 102 | *lvalp = lval_memory; |
| 103 | *addrp = this_saved_regs[regnum].addr; |
| 104 | *realregp = -1; |
| 105 | if (bufferp != NULL) |
| 106 | { |
| 107 | /* Read the value in from memory. */ |
| 108 | get_frame_memory (next_frame, this_saved_regs[regnum].addr, bufferp, |
| 109 | register_size (gdbarch, regnum)); |
| 110 | } |
| 111 | } |
| 112 | else if (trad_frame_realreg_p (this_saved_regs, regnum)) |
| 113 | { |
| 114 | /* Ask the next frame to return the value of the register. */ |
| 115 | frame_register_unwind (next_frame, this_saved_regs[regnum].realreg, |
| 116 | optimizedp, lvalp, addrp, realregp, bufferp); |
| 117 | } |
| 118 | else if (trad_frame_value_p (this_saved_regs, regnum)) |
| 119 | { |
| 120 | /* The register's value is available. */ |
| 121 | *optimizedp = 0; |
| 122 | *lvalp = not_lval; |
| 123 | *addrp = 0; |
| 124 | *realregp = -1; |
| 125 | if (bufferp != NULL) |
| 126 | store_unsigned_integer (bufferp, register_size (gdbarch, regnum), |
| 127 | this_saved_regs[regnum].addr); |
| 128 | } |
| 129 | else |
| 130 | { |
| 131 | error ("Register %s not available", |
| 132 | gdbarch_register_name (gdbarch, regnum)); |
| 133 | } |
| 134 | } |