contrib/gdb-6.2.1/gdb/dwarf2-frame.h

   1 /* Frame unwinder for frames with DWARF Call Frame Information.
   2
   3    Copyright 2003, 2004 Free Software Foundation, Inc.
   4
   5    Contributed by Mark Kettenis.
   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 2 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, write to the Free Software
  21    Foundation, Inc., 59 Temple Place - Suite 330,
  22    Boston, MA 02111-1307, USA.  */
  23
  24 #ifndef DWARF2_FRAME_H
  25 #define DWARF2_FRAME_H 1
  26
  27 struct gdbarch;
  28 struct objfile;
  29 struct frame_info;
  30
  31 /* Register rule.  */
  32
  33 enum dwarf2_frame_reg_rule
  34 {
  35   /* Make certain that 0 maps onto the correct enum value; the
  36      corresponding structure is being initialized using memset zero.
  37      This indicates that CFI didn't provide any information at all
  38      about a register, leaving how to obtain its value totally
  39      unspecified.  */
  40   DWARF2_FRAME_REG_UNSPECIFIED = 0,
  41
  42   /* The term "undefined" comes from the DWARF2 CFI spec which this
  43      code is moddeling; it indicates that the register's value is
  44      "undefined".  GCC uses the less formal term "unsaved".  Its
  45      definition is a combination of REG_UNDEFINED and REG_UNSPECIFIED.
  46      The failure to differentiate the two helps explain a few problems
  47      with the CFI generated by GCC.  */
  48   DWARF2_FRAME_REG_UNDEFINED,
  49   DWARF2_FRAME_REG_SAVED_OFFSET,
  50   DWARF2_FRAME_REG_SAVED_REG,
  51   DWARF2_FRAME_REG_SAVED_EXP,
  52   DWARF2_FRAME_REG_SAME_VALUE,
  53
  54   /* These aren't defined by the DWARF2 CFI specification, but are
  55      used internally by GDB.  */
  56   DWARF2_FRAME_REG_RA,          /* Return Address.  */
  57   DWARF2_FRAME_REG_CFA          /* Call Frame Address.  */
  58 };
  59
  60 /* Register state.  */
  61
  62 struct dwarf2_frame_state_reg
  63 {
  64   /* Each register save state can be described in terms of a CFA slot,
  65      another register, or a location expression.  */
  66   union {
  67     LONGEST offset;
  68     ULONGEST reg;
  69     unsigned char *exp;
  70   } loc;
  71   ULONGEST exp_len;
  72   enum dwarf2_frame_reg_rule how;
  73 };
  74
  75 /* Set the architecture-specific register state initialization
  76    function for GDBARCH to INIT_REG.  */
  77
  78 extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
  79                                        void (*init_reg) (struct gdbarch *, int,
  80                                              struct dwarf2_frame_state_reg *));
  81
  82 /* Return the frame unwind methods for the function that contains PC,
  83    or NULL if it can't be handled by DWARF CFI frame unwinder.  */
  84
  85 extern const struct frame_unwind *
  86   dwarf2_frame_sniffer (struct frame_info *next_frame);
  87
  88 /* Return the frame base methods for the function that contains PC, or
  89    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
  90
  91 extern const struct frame_base *
  92   dwarf2_frame_base_sniffer (struct frame_info *next_frame);
  93
  94 /* Register the DWARF CFI for OBJFILE.  */
  95
  96 void dwarf2_frame_build_info (struct objfile *objfile);
  97
  98 #endif /* dwarf2-frame.h */