gdb/dwarf2-frame.h

   1 /* Frame unwinder for frames with DWARF Call Frame Information.
   2
   3    Copyright (C) 2003, 2004, 2005, 2007, 2008 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 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 #ifndef DWARF2_FRAME_H
  23 #define DWARF2_FRAME_H 1
  24
  25 struct gdbarch;
  26 struct objfile;
  27 struct frame_info;
  28
  29 /* Register rule.  */
  30
  31 enum dwarf2_frame_reg_rule
  32 {
  33   /* Make certain that 0 maps onto the correct enum value; the
  34      corresponding structure is being initialized using memset zero.
  35      This indicates that CFI didn't provide any information at all
  36      about a register, leaving how to obtain its value totally
  37      unspecified.  */
  38   DWARF2_FRAME_REG_UNSPECIFIED = 0,
  39
  40   /* The term "undefined" comes from the DWARF2 CFI spec which this
  41      code is moddeling; it indicates that the register's value is
  42      "undefined".  GCC uses the less formal term "unsaved".  Its
  43      definition is a combination of REG_UNDEFINED and REG_UNSPECIFIED.
  44      The failure to differentiate the two helps explain a few problems
  45      with the CFI generated by GCC.  */
  46   DWARF2_FRAME_REG_UNDEFINED,
  47   DWARF2_FRAME_REG_SAVED_OFFSET,
  48   DWARF2_FRAME_REG_SAVED_REG,
  49   DWARF2_FRAME_REG_SAVED_EXP,
  50   DWARF2_FRAME_REG_SAME_VALUE,
  51
  52   /* These are defined in Dwarf3.  */
  53   DWARF2_FRAME_REG_SAVED_VAL_OFFSET,
  54   DWARF2_FRAME_REG_SAVED_VAL_EXP,
  55
  56   /* These aren't defined by the DWARF2 CFI specification, but are
  57      used internally by GDB.  */
  58   DWARF2_FRAME_REG_FN,          /* Call a registered function.  */
  59   DWARF2_FRAME_REG_RA,          /* Return Address.  */
  60   DWARF2_FRAME_REG_RA_OFFSET,   /* Return Address with offset.  */
  61   DWARF2_FRAME_REG_CFA,         /* Call Frame Address.  */
  62   DWARF2_FRAME_REG_CFA_OFFSET   /* Call Frame Address with offset.  */
  63 };
  64
  65 /* Register state.  */
  66
  67 struct dwarf2_frame_state_reg
  68 {
  69   /* Each register save state can be described in terms of a CFA slot,
  70      another register, or a location expression.  */
  71   union {
  72     LONGEST offset;
  73     ULONGEST reg;
  74     unsigned char *exp;
  75     struct value *(*fn) (struct frame_info *this_frame, void **this_cache,
  76                          int regnum);
  77   } loc;
  78   ULONGEST exp_len;
  79   enum dwarf2_frame_reg_rule how;
  80 };
  81
  82 /* Set the architecture-specific register state initialization
  83    function for GDBARCH to INIT_REG.  */
  84
  85 extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
  86                                        void (*init_reg) (struct gdbarch *, int,
  87                                              struct dwarf2_frame_state_reg *,
  88                                              struct frame_info *));
  89
  90 /* Set the architecture-specific signal trampoline recognition
  91    function for GDBARCH to SIGNAL_FRAME_P.  */
  92
  93 extern void
  94   dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
  95                                    int (*signal_frame_p) (struct gdbarch *,
  96                                                           struct frame_info *));
  97
  98 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
  99    register numbers.  */
 100
 101 extern void
 102   dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch,
 103                                   int (*adjust_regnum) (struct gdbarch *,
 104                                                         int, int));
 105
 106 /* Append the DWARF-2 frame unwinders to GDBARCH's list.  */
 107
 108 void dwarf2_append_unwinders (struct gdbarch *gdbarch);
 109
 110 /* Return the frame base methods for the function that contains PC, or
 111    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
 112
 113 extern const struct frame_base *
 114   dwarf2_frame_base_sniffer (struct frame_info *this_frame);
 115
 116 /* Register the DWARF CFI for OBJFILE.  */
 117
 118 void dwarf2_frame_build_info (struct objfile *objfile);
 119
 120 #endif /* dwarf2-frame.h */