gdb/dwarf2loc.h

   1 /* DWARF 2 location expression support for GDB.
   2
   3    Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #if !defined (DWARF2LOC_H)
  22 #define DWARF2LOC_H
  23
  24 struct symbol_computed_ops;
  25 struct objfile;
  26 struct dwarf2_per_cu_data;
  27 struct dwarf2_loclist_baton;
  28 struct agent_expr;
  29 struct axs_value;
  30
  31 /* This header is private to the DWARF-2 reader.  It is shared between
  32    dwarf2read.c and dwarf2loc.c.  */
  33
  34 /* `set debug entry-values' setting.  */
  35 extern int entry_values_debug;
  36
  37 /* Return the OBJFILE associated with the compilation unit CU.  If CU
  38    came from a separate debuginfo file, then the master objfile is
  39    returned.  */
  40 struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu);
  41
  42 /* Return the address size given in the compilation unit header for CU.  */
  43 CORE_ADDR dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu);
  44
  45 /* Return the DW_FORM_ref_addr size given in the compilation unit header for
  46    CU.  */
  47 int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data *cu);
  48
  49 /* Return the offset size given in the compilation unit header for CU.  */
  50 int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu);
  51
  52 /* Return the text offset of the CU.  The returned offset comes from
  53    this CU's objfile.  If this objfile came from a separate debuginfo
  54    file, then the offset may be different from the corresponding
  55    offset in the parent objfile.  */
  56 CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu);
  57
  58 /* Find a particular location expression from a location list.  */
  59 const gdb_byte *dwarf2_find_location_expression
  60   (struct dwarf2_loclist_baton *baton,
  61    size_t *locexpr_length,
  62    CORE_ADDR pc);
  63
  64 struct dwarf2_locexpr_baton dwarf2_fetch_die_location_block
  65   (unsigned int offset, struct dwarf2_per_cu_data *per_cu,
  66    CORE_ADDR (*get_frame_pc) (void *baton),
  67    void *baton);
  68
  69 struct type *dwarf2_get_die_type (unsigned int die_offset,
  70                                   struct dwarf2_per_cu_data *per_cu);
  71
  72 /* Evaluate a location description, starting at DATA and with length
  73    SIZE, to find the current location of variable of TYPE in the context
  74    of FRAME.  */
  75
  76 struct value *dwarf2_evaluate_loc_desc (struct type *type,
  77                                         struct frame_info *frame,
  78                                         const gdb_byte *data,
  79                                         unsigned short size,
  80                                         struct dwarf2_per_cu_data *per_cu);
  81
  82 /* The symbol location baton types used by the DWARF-2 reader (i.e.
  83    SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol).  "struct
  84    dwarf2_locexpr_baton" is for a symbol with a single location
  85    expression; "struct dwarf2_loclist_baton" is for a symbol with a
  86    location list.  */
  87
  88 struct dwarf2_locexpr_baton
  89 {
  90   /* Pointer to the start of the location expression.  */
  91   const gdb_byte *data;
  92
  93   /* Length of the location expression.  */
  94   unsigned long size;
  95
  96   /* The compilation unit containing the symbol whose location
  97      we're computing.  */
  98   struct dwarf2_per_cu_data *per_cu;
  99 };
 100
 101 struct dwarf2_loclist_baton
 102 {
 103   /* The initial base address for the location list, based on the compilation
 104      unit.  */
 105   CORE_ADDR base_address;
 106
 107   /* Pointer to the start of the location list.  */
 108   const gdb_byte *data;
 109
 110   /* Length of the location list.  */
 111   unsigned long size;
 112
 113   /* The compilation unit containing the symbol whose location
 114      we're computing.  */
 115   struct dwarf2_per_cu_data *per_cu;
 116 };
 117
 118 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
 119 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
 120
 121 /* Compile a DWARF location expression to an agent expression.
 122
 123    EXPR is the agent expression we are building.
 124    LOC is the agent value we modify.
 125    ARCH is the architecture.
 126    ADDR_SIZE is the size of addresses, in bytes.
 127    OP_PTR is the start of the location expression.
 128    OP_END is one past the last byte of the location expression.
 129
 130    This will throw an exception for various kinds of errors -- for
 131    example, if the expression cannot be compiled, or if the expression
 132    is invalid.  */
 133
 134 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
 135                                        struct axs_value *loc,
 136                                        struct gdbarch *arch,
 137                                        unsigned int addr_size,
 138                                        const gdb_byte *op_ptr,
 139                                        const gdb_byte *op_end,
 140                                        struct dwarf2_per_cu_data *per_cu);
 141
 142 #endif /* dwarf2loc.h */