gdb/dwarf2loc.h

   1 /* DWARF 2 location expression support for GDB.
   2
   3    Copyright (C) 2003, 2005, 2007-2012 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #if !defined (DWARF2LOC_H)
  21 #define DWARF2LOC_H
  22
  23 #include "dwarf2expr.h"
  24
  25 struct symbol_computed_ops;
  26 struct objfile;
  27 struct dwarf2_per_cu_data;
  28 struct dwarf2_loclist_baton;
  29 struct agent_expr;
  30 struct axs_value;
  31
  32 /* This header is private to the DWARF-2 reader.  It is shared between
  33    dwarf2read.c and dwarf2loc.c.  */
  34
  35 /* `set debug entry-values' setting.  */
  36 extern unsigned int entry_values_debug;
  37
  38 /* Return the OBJFILE associated with the compilation unit CU.  If CU
  39    came from a separate debuginfo file, then the master objfile is
  40    returned.  */
  41 struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu);
  42
  43 /* Return the address size given in the compilation unit header for CU.  */
  44 int dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu);
  45
  46 /* Return the DW_FORM_ref_addr size given in the compilation unit header for
  47    CU.  */
  48 int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data *cu);
  49
  50 /* Return the offset size given in the compilation unit header for CU.  */
  51 int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu);
  52
  53 /* Return the text offset of the CU.  The returned offset comes from
  54    this CU's objfile.  If this objfile came from a separate debuginfo
  55    file, then the offset may be different from the corresponding
  56    offset in the parent objfile.  */
  57 CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu);
  58
  59 /* Find a particular location expression from a location list.  */
  60 const gdb_byte *dwarf2_find_location_expression
  61   (struct dwarf2_loclist_baton *baton,
  62    size_t *locexpr_length,
  63    CORE_ADDR pc);
  64
  65 struct dwarf2_locexpr_baton dwarf2_fetch_die_location_block
  66   (cu_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu,
  67    CORE_ADDR (*get_frame_pc) (void *baton),
  68    void *baton);
  69
  70 struct type *dwarf2_get_die_type (cu_offset die_offset,
  71                                   struct dwarf2_per_cu_data *per_cu);
  72
  73 /* Evaluate a location description, starting at DATA and with length
  74    SIZE, to find the current location of variable of TYPE in the context
  75    of FRAME.  */
  76
  77 struct value *dwarf2_evaluate_loc_desc (struct type *type,
  78                                         struct frame_info *frame,
  79                                         const gdb_byte *data,
  80                                         size_t size,
  81                                         struct dwarf2_per_cu_data *per_cu);
  82
  83 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
  84                                   unsigned int addr_index);
  85
  86 /* The symbol location baton types used by the DWARF-2 reader (i.e.
  87    SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol).  "struct
  88    dwarf2_locexpr_baton" is for a symbol with a single location
  89    expression; "struct dwarf2_loclist_baton" is for a symbol with a
  90    location list.  */
  91
  92 struct dwarf2_locexpr_baton
  93 {
  94   /* Pointer to the start of the location expression.  Valid only if SIZE is
  95      not zero.  */
  96   const gdb_byte *data;
  97
  98   /* Length of the location expression.  For optimized out expressions it is
  99      zero.  */
 100   size_t size;
 101
 102   /* The compilation unit containing the symbol whose location
 103      we're computing.  */
 104   struct dwarf2_per_cu_data *per_cu;
 105 };
 106
 107 struct dwarf2_loclist_baton
 108 {
 109   /* The initial base address for the location list, based on the compilation
 110      unit.  */
 111   CORE_ADDR base_address;
 112
 113   /* Pointer to the start of the location list.  */
 114   const gdb_byte *data;
 115
 116   /* Length of the location list.  */
 117   size_t size;
 118
 119   /* The compilation unit containing the symbol whose location
 120      we're computing.  */
 121   struct dwarf2_per_cu_data *per_cu;
 122
 123   /* Non-zero if the location list lives in .debug_loc.dwo.
 124      The format of entries in this section are different.  */
 125   unsigned char from_dwo;
 126 };
 127
 128 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
 129 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
 130
 131 /* Compile a DWARF location expression to an agent expression.
 132
 133    EXPR is the agent expression we are building.
 134    LOC is the agent value we modify.
 135    ARCH is the architecture.
 136    ADDR_SIZE is the size of addresses, in bytes.
 137    OP_PTR is the start of the location expression.
 138    OP_END is one past the last byte of the location expression.
 139
 140    This will throw an exception for various kinds of errors -- for
 141    example, if the expression cannot be compiled, or if the expression
 142    is invalid.  */
 143
 144 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
 145                                        struct axs_value *loc,
 146                                        struct gdbarch *arch,
 147                                        unsigned int addr_size,
 148                                        const gdb_byte *op_ptr,
 149                                        const gdb_byte *op_end,
 150                                        struct dwarf2_per_cu_data *per_cu);
 151
 152 /* Determined tail calls for constructing virtual tail call frames.  */
 153
 154 struct call_site_chain
 155   {
 156     /* Initially CALLERS == CALLEES == LENGTH.  For partially ambiguous result
 157        CALLERS + CALLEES < LENGTH.  */
 158     int callers, callees, length;
 159
 160     /* Variably sized array with LENGTH elements.  Later [0..CALLERS-1] contain
 161        top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
 162        (GDB "next") sites.  One is interested primarily in the PC field.  */
 163     struct call_site *call_site[1];
 164   };
 165
 166 struct call_site_stuff;
 167 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
 168                                                      CORE_ADDR caller_pc,
 169                                                      CORE_ADDR callee_pc);
 170
 171 #endif /* dwarf2loc.h */