gdb/trad-frame.c

   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     this_saved_regs[regnum].realnum = regnum;
  42   return this_saved_regs;
  43 }
  44
  45 void
  46 trad_frame_register_value (struct trad_frame_saved_reg this_saved_regs[],
  47                            int regnum, LONGEST val)
  48 {
  49   /* Make the REALNUM invalid, indicating that the ADDR contains the
  50      register's value.  */
  51   this_saved_regs[regnum].realnum = -1;
  52   this_saved_regs[regnum].addr = val;
  53 }
  54
  55 void
  56 trad_frame_prev_register (struct frame_info *next_frame,
  57                           struct trad_frame_saved_reg this_saved_regs[],
  58                           int regnum, int *optimizedp,
  59                           enum lval_type *lvalp, CORE_ADDR *addrp,
  60                           int *realnump, void *bufferp)
  61 {
  62   struct gdbarch *gdbarch = get_frame_arch (next_frame);
  63   if (this_saved_regs[regnum].realnum >= 0
  64       && this_saved_regs[regnum].addr != 0)
  65     {
  66       /* The register was saved in memory.  */
  67       *optimizedp = 0;
  68       *lvalp = lval_memory;
  69       *addrp = this_saved_regs[regnum].addr;
  70       *realnump = -1;
  71       if (bufferp != NULL)
  72         {
  73           /* Read the value in from memory.  */
  74           get_frame_memory (next_frame, this_saved_regs[regnum].addr, bufferp,
  75                             register_size (gdbarch, regnum));
  76         }
  77     }
  78   else if (this_saved_regs[regnum].realnum >= 0
  79            && this_saved_regs[regnum].addr == 0)
  80     {
  81       /* As the next frame to return the value of the register.  */
  82       frame_register_unwind (next_frame, this_saved_regs[regnum].realnum,
  83                              optimizedp, lvalp, addrp, realnump, bufferp);
  84     }
  85   else
  86     {
  87       /* The register's value is available.  */
  88       *optimizedp = 0;
  89       *lvalp = not_lval;
  90       *addrp = 0;
  91       *realnump = -1;
  92       if (bufferp != NULL)
  93         store_unsigned_integer (bufferp, register_size (gdbarch, regnum),
  94                                 this_saved_regs[regnum].addr);
  95     }
  96 }