gdb/dwarf2-frame.h

   1 /* Frame unwinder for frames with DWARF Call Frame Information.
   2
   3    Copyright (C) 2003, 2004, 2005 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., 51 Franklin Street, Fifth Floor,
  22    Boston, MA 02110-1301, 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_RA_OFFSET,   /* Return Address with offset.  */
  58   DWARF2_FRAME_REG_CFA,         /* Call Frame Address.  */
  59   DWARF2_FRAME_REG_CFA_OFFSET   /* Call Frame Address with offset.  */
  60 };
  61
  62 /* Register state.  */
  63
  64 struct dwarf2_frame_state_reg
  65 {
  66   /* Each register save state can be described in terms of a CFA slot,
  67      another register, or a location expression.  */
  68   union {
  69     LONGEST offset;
  70     ULONGEST reg;
  71     unsigned char *exp;
  72   } loc;
  73   ULONGEST exp_len;
  74   enum dwarf2_frame_reg_rule how;
  75 };
  76
  77 /* Set the architecture-specific register state initialization
  78    function for GDBARCH to INIT_REG.  */
  79
  80 extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
  81                                        void (*init_reg) (struct gdbarch *, int,
  82                                              struct dwarf2_frame_state_reg *));
  83
  84 /* Set the architecture-specific signal trampoline recognition
  85    function for GDBARCH to SIGNAL_FRAME_P.  */
  86
  87 extern void
  88   dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
  89                                    int (*signal_frame_p) (struct gdbarch *,
  90                                                           struct frame_info *));
  91
  92 /* Return the frame unwind methods for the function that contains PC,
  93    or NULL if it can't be handled by DWARF CFI frame unwinder.  */
  94
  95 extern const struct frame_unwind *
  96   dwarf2_frame_sniffer (struct frame_info *next_frame);
  97
  98 /* Return the frame base methods for the function that contains PC, or
  99    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
 100
 101 extern const struct frame_base *
 102   dwarf2_frame_base_sniffer (struct frame_info *next_frame);
 103
 104 /* Register the DWARF CFI for OBJFILE.  */
 105
 106 void dwarf2_frame_build_info (struct objfile *objfile);
 107
 108 #endif /* dwarf2-frame.h */