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 struct dwarf2_per_cu_data;
  30 struct agent_expr;
  31 struct axs_value;
  32
  33 /* Register rule.  */
  34
  35 enum dwarf2_frame_reg_rule
  36 {
  37   /* Make certain that 0 maps onto the correct enum value; the
  38      corresponding structure is being initialized using memset zero.
  39      This indicates that CFI didn't provide any information at all
  40      about a register, leaving how to obtain its value totally
  41      unspecified.  */
  42   DWARF2_FRAME_REG_UNSPECIFIED = 0,
  43
  44   /* The term "undefined" comes from the DWARF2 CFI spec which this
  45      code is moddeling; it indicates that the register's value is
  46      "undefined".  GCC uses the less formal term "unsaved".  Its
  47      definition is a combination of REG_UNDEFINED and REG_UNSPECIFIED.
  48      The failure to differentiate the two helps explain a few problems
  49      with the CFI generated by GCC.  */
  50   DWARF2_FRAME_REG_UNDEFINED,
  51   DWARF2_FRAME_REG_SAVED_OFFSET,
  52   DWARF2_FRAME_REG_SAVED_REG,
  53   DWARF2_FRAME_REG_SAVED_EXP,
  54   DWARF2_FRAME_REG_SAME_VALUE,
  55
  56   /* These are defined in Dwarf3.  */
  57   DWARF2_FRAME_REG_SAVED_VAL_OFFSET,
  58   DWARF2_FRAME_REG_SAVED_VAL_EXP,
  59
  60   /* These aren't defined by the DWARF2 CFI specification, but are
  61      used internally by GDB.  */
  62   DWARF2_FRAME_REG_FN,          /* Call a registered function.  */
  63   DWARF2_FRAME_REG_RA,          /* Return Address.  */
  64   DWARF2_FRAME_REG_RA_OFFSET,   /* Return Address with offset.  */
  65   DWARF2_FRAME_REG_CFA,         /* Call Frame Address.  */
  66   DWARF2_FRAME_REG_CFA_OFFSET   /* Call Frame Address with offset.  */
  67 };
  68
  69 /* Register state.  */
  70
  71 struct dwarf2_frame_state_reg
  72 {
  73   /* Each register save state can be described in terms of a CFA slot,
  74      another register, or a location expression.  */
  75   union {
  76     LONGEST offset;
  77     ULONGEST reg;
  78     const gdb_byte *exp;
  79     struct value *(*fn) (struct frame_info *this_frame, void **this_cache,
  80                          int regnum);
  81   } loc;
  82   ULONGEST exp_len;
  83   enum dwarf2_frame_reg_rule how;
  84 };
  85
  86 /* Set the architecture-specific register state initialization
  87    function for GDBARCH to INIT_REG.  */
  88
  89 extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
  90                                        void (*init_reg) (struct gdbarch *, int,
  91                                              struct dwarf2_frame_state_reg *,
  92                                              struct frame_info *));
  93
  94 /* Set the architecture-specific signal trampoline recognition
  95    function for GDBARCH to SIGNAL_FRAME_P.  */
  96
  97 extern void
  98   dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
  99                                    int (*signal_frame_p) (struct gdbarch *,
 100                                                           struct frame_info *));
 101
 102 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
 103    register numbers.  */
 104
 105 extern void
 106   dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch,
 107                                   int (*adjust_regnum) (struct gdbarch *,
 108                                                         int, int));
 109
 110 /* Append the DWARF-2 frame unwinders to GDBARCH's list.  */
 111
 112 void dwarf2_append_unwinders (struct gdbarch *gdbarch);
 113
 114 /* Return the frame base methods for the function that contains PC, or
 115    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
 116
 117 extern const struct frame_base *
 118   dwarf2_frame_base_sniffer (struct frame_info *this_frame);
 119
 120 /* Compute the DWARF CFA for a frame.  */
 121
 122 CORE_ADDR dwarf2_frame_cfa (struct frame_info *this_frame);
 123
 124 /* Update the agent expression EXPR with code to compute the CFA for a
 125    frame at PC.  GDBARCH is the architecture of the function at PC.
 126    This function may call dwarf2_compile_expr_to_ax; DATA is passed
 127    through to that function if needed.  */
 128
 129 extern void dwarf2_compile_cfa_to_ax (struct agent_expr *expr,
 130                                       struct axs_value *loc,
 131                                       struct gdbarch *gdbarch,
 132                                       CORE_ADDR pc,
 133                                       struct dwarf2_per_cu_data *data);
 134
 135 #endif /* dwarf2-frame.h */