gdb/dwarf2-frame.h

   1 /* Frame unwinder for frames with DWARF Call Frame Information.
   2
   3    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    Contributed by Mark Kettenis.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #ifndef DWARF2_FRAME_H
  24 #define DWARF2_FRAME_H 1
  25
  26 struct gdbarch;
  27 struct objfile;
  28 struct frame_info;
  29
  30 /* Register rule.  */
  31
  32 enum dwarf2_frame_reg_rule
  33 {
  34   /* Make certain that 0 maps onto the correct enum value; the
  35      corresponding structure is being initialized using memset zero.
  36      This indicates that CFI didn't provide any information at all
  37      about a register, leaving how to obtain its value totally
  38      unspecified.  */
  39   DWARF2_FRAME_REG_UNSPECIFIED = 0,
  40
  41   /* The term "undefined" comes from the DWARF2 CFI spec which this
  42      code is moddeling; it indicates that the register's value is
  43      "undefined".  GCC uses the less formal term "unsaved".  Its
  44      definition is a combination of REG_UNDEFINED and REG_UNSPECIFIED.
  45      The failure to differentiate the two helps explain a few problems
  46      with the CFI generated by GCC.  */
  47   DWARF2_FRAME_REG_UNDEFINED,
  48   DWARF2_FRAME_REG_SAVED_OFFSET,
  49   DWARF2_FRAME_REG_SAVED_REG,
  50   DWARF2_FRAME_REG_SAVED_EXP,
  51   DWARF2_FRAME_REG_SAME_VALUE,
  52
  53   /* These are defined in Dwarf3.  */
  54   DWARF2_FRAME_REG_SAVED_VAL_OFFSET,
  55   DWARF2_FRAME_REG_SAVED_VAL_EXP,
  56
  57   /* These aren't defined by the DWARF2 CFI specification, but are
  58      used internally by GDB.  */
  59   DWARF2_FRAME_REG_FN,          /* Call a registered function.  */
  60   DWARF2_FRAME_REG_RA,          /* Return Address.  */
  61   DWARF2_FRAME_REG_RA_OFFSET,   /* Return Address with offset.  */
  62   DWARF2_FRAME_REG_CFA,         /* Call Frame Address.  */
  63   DWARF2_FRAME_REG_CFA_OFFSET   /* Call Frame Address with offset.  */
  64 };
  65
  66 /* Register state.  */
  67
  68 struct dwarf2_frame_state_reg
  69 {
  70   /* Each register save state can be described in terms of a CFA slot,
  71      another register, or a location expression.  */
  72   union {
  73     LONGEST offset;
  74     ULONGEST reg;
  75     const gdb_byte *exp;
  76     struct value *(*fn) (struct frame_info *this_frame, void **this_cache,
  77                          int regnum);
  78   } loc;
  79   ULONGEST exp_len;
  80   enum dwarf2_frame_reg_rule how;
  81 };
  82
  83 /* Set the architecture-specific register state initialization
  84    function for GDBARCH to INIT_REG.  */
  85
  86 extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
  87                                        void (*init_reg) (struct gdbarch *, int,
  88                                              struct dwarf2_frame_state_reg *,
  89                                              struct frame_info *));
  90
  91 /* Set the architecture-specific signal trampoline recognition
  92    function for GDBARCH to SIGNAL_FRAME_P.  */
  93
  94 extern void
  95   dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
  96                                    int (*signal_frame_p) (struct gdbarch *,
  97                                                           struct frame_info *));
  98
  99 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
 100    register numbers.  */
 101
 102 extern void
 103   dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch,
 104                                   int (*adjust_regnum) (struct gdbarch *,
 105                                                         int, int));
 106
 107 /* Append the DWARF-2 frame unwinders to GDBARCH's list.  */
 108
 109 void dwarf2_append_unwinders (struct gdbarch *gdbarch);
 110
 111 /* Return the frame base methods for the function that contains PC, or
 112    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
 113
 114 extern const struct frame_base *
 115   dwarf2_frame_base_sniffer (struct frame_info *this_frame);
 116
 117 /* Compute the DWARF CFA for a frame.  */
 118
 119 CORE_ADDR dwarf2_frame_cfa (struct frame_info *this_frame);
 120
 121 #endif /* dwarf2-frame.h */