gdb/dwarf2loc.h

   1 /* DWARF 2 location expression support for GDB.
   2
   3    Copyright (C) 2003-2014 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_loc_sect_off
  66   (sect_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 dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off
  71   (cu_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu,
  72    CORE_ADDR (*get_frame_pc) (void *baton),
  73    void *baton);
  74
  75 extern const gdb_byte *dwarf2_fetch_constant_bytes (sect_offset,
  76                                                     struct dwarf2_per_cu_data *,
  77                                                     struct obstack *,
  78                                                     LONGEST *);
  79
  80 struct type *dwarf2_get_die_type (cu_offset die_offset,
  81                                   struct dwarf2_per_cu_data *per_cu);
  82
  83 /* Evaluate a location description, starting at DATA and with length
  84    SIZE, to find the current location of variable of TYPE in the context
  85    of FRAME.  */
  86
  87 struct value *dwarf2_evaluate_loc_desc (struct type *type,
  88                                         struct frame_info *frame,
  89                                         const gdb_byte *data,
  90                                         size_t size,
  91                                         struct dwarf2_per_cu_data *per_cu);
  92
  93 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
  94                                   unsigned int addr_index);
  95
  96 /* The symbol location baton types used by the DWARF-2 reader (i.e.
  97    SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol).  "struct
  98    dwarf2_locexpr_baton" is for a symbol with a single location
  99    expression; "struct dwarf2_loclist_baton" is for a symbol with a
 100    location list.  */
 101
 102 struct dwarf2_locexpr_baton
 103 {
 104   /* Pointer to the start of the location expression.  Valid only if SIZE is
 105      not zero.  */
 106   const gdb_byte *data;
 107
 108   /* Length of the location expression.  For optimized out expressions it is
 109      zero.  */
 110   size_t size;
 111
 112   /* The compilation unit containing the symbol whose location
 113      we're computing.  */
 114   struct dwarf2_per_cu_data *per_cu;
 115 };
 116
 117 struct dwarf2_loclist_baton
 118 {
 119   /* The initial base address for the location list, based on the compilation
 120      unit.  */
 121   CORE_ADDR base_address;
 122
 123   /* Pointer to the start of the location list.  */
 124   const gdb_byte *data;
 125
 126   /* Length of the location list.  */
 127   size_t size;
 128
 129   /* The compilation unit containing the symbol whose location
 130      we're computing.  */
 131   struct dwarf2_per_cu_data *per_cu;
 132
 133   /* Non-zero if the location list lives in .debug_loc.dwo.
 134      The format of entries in this section are different.  */
 135   unsigned char from_dwo;
 136 };
 137
 138 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
 139 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
 140
 141 extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs;
 142 extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs;
 143
 144 /* Compile a DWARF location expression to an agent expression.
 145
 146    EXPR is the agent expression we are building.
 147    LOC is the agent value we modify.
 148    ARCH is the architecture.
 149    ADDR_SIZE is the size of addresses, in bytes.
 150    OP_PTR is the start of the location expression.
 151    OP_END is one past the last byte of the location expression.
 152
 153    This will throw an exception for various kinds of errors -- for
 154    example, if the expression cannot be compiled, or if the expression
 155    is invalid.  */
 156
 157 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
 158                                        struct axs_value *loc,
 159                                        struct gdbarch *arch,
 160                                        unsigned int addr_size,
 161                                        const gdb_byte *op_ptr,
 162                                        const gdb_byte *op_end,
 163                                        struct dwarf2_per_cu_data *per_cu);
 164
 165 /* Determined tail calls for constructing virtual tail call frames.  */
 166
 167 struct call_site_chain
 168   {
 169     /* Initially CALLERS == CALLEES == LENGTH.  For partially ambiguous result
 170        CALLERS + CALLEES < LENGTH.  */
 171     int callers, callees, length;
 172
 173     /* Variably sized array with LENGTH elements.  Later [0..CALLERS-1] contain
 174        top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
 175        (GDB "next") sites.  One is interested primarily in the PC field.  */
 176     struct call_site *call_site[1];
 177   };
 178
 179 struct call_site_stuff;
 180 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
 181                                                      CORE_ADDR caller_pc,
 182                                                      CORE_ADDR callee_pc);
 183
 184 #endif /* dwarf2loc.h */