gdb/dwarf2-frame.h

   1 /* Frame unwinder for frames with DWARF Call Frame Information.
   2
   3    Copyright (C) 2003, 2004, 2005, 2007 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 are defined in Dwarf3.  */
  55   DWARF2_FRAME_REG_SAVED_VAL_OFFSET,
  56   DWARF2_FRAME_REG_SAVED_VAL_EXP,
  57
  58   /* These aren't defined by the DWARF2 CFI specification, but are
  59      used internally by GDB.  */
  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     unsigned char *exp;
  76   } loc;
  77   ULONGEST exp_len;
  78   enum dwarf2_frame_reg_rule how;
  79 };
  80
  81 /* Set the architecture-specific register state initialization
  82    function for GDBARCH to INIT_REG.  */
  83
  84 extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
  85                                        void (*init_reg) (struct gdbarch *, int,
  86                                              struct dwarf2_frame_state_reg *,
  87                                              struct frame_info *));
  88
  89 /* Set the architecture-specific signal trampoline recognition
  90    function for GDBARCH to SIGNAL_FRAME_P.  */
  91
  92 extern void
  93   dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
  94                                    int (*signal_frame_p) (struct gdbarch *,
  95                                                           struct frame_info *));
  96
  97 /* Set the architecture-specific mapping of .eh_frame register numbers to
  98    DWARF register numbers.  */
  99
 100 extern void
 101   dwarf2_frame_set_eh_frame_regnum (struct gdbarch *gdbarch,
 102                                     int (*eh_frame_regnum) (struct gdbarch *,
 103                                                             int));
 104
 105 /* Translate a .eh_frame register to DWARF register.  */
 106
 107 extern int
 108   dwarf2_frame_eh_frame_regnum (struct gdbarch *gdbarch, int regnum);
 109
 110 /* Return the frame unwind methods for the function that contains PC,
 111    or NULL if it can't be handled by DWARF CFI frame unwinder.  */
 112
 113 extern const struct frame_unwind *
 114   dwarf2_frame_sniffer (struct frame_info *next_frame);
 115
 116 /* Return the frame base methods for the function that contains PC, or
 117    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
 118
 119 extern const struct frame_base *
 120   dwarf2_frame_base_sniffer (struct frame_info *next_frame);
 121
 122 /* Register the DWARF CFI for OBJFILE.  */
 123
 124 void dwarf2_frame_build_info (struct objfile *objfile);
 125
 126 #endif /* dwarf2-frame.h */