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 /* Return the OBJFILE associated with the compilation unit CU.  If CU
  35    came from a separate debuginfo file, then the master objfile is
  36    returned.  */
  37 struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu);
  38
  39 /* Return the address size given in the compilation unit header for CU.  */
  40 CORE_ADDR dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu);
  41
  42 /* Return the offset size given in the compilation unit header for CU.  */
  43 int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu);
  44
  45 /* Return the text offset of the CU.  The returned offset comes from
  46    this CU's objfile.  If this objfile came from a separate debuginfo
  47    file, then the offset may be different from the corresponding
  48    offset in the parent objfile.  */
  49 CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu);
  50
  51 /* Find a particular location expression from a location list.  */
  52 const gdb_byte *dwarf2_find_location_expression
  53   (struct dwarf2_loclist_baton *baton,
  54    size_t *locexpr_length,
  55    CORE_ADDR pc);
  56
  57 struct dwarf2_locexpr_baton dwarf2_fetch_die_location_block
  58   (unsigned int offset, struct dwarf2_per_cu_data *per_cu,
  59    CORE_ADDR (*get_frame_pc) (void *baton),
  60    void *baton);
  61
  62 /* Evaluate a location description, starting at DATA and with length
  63    SIZE, to find the current location of variable of TYPE in the context
  64    of FRAME.  */
  65
  66 struct value *dwarf2_evaluate_loc_desc (struct type *type,
  67                                         struct frame_info *frame,
  68                                         const gdb_byte *data,
  69                                         unsigned short size,
  70                                         struct dwarf2_per_cu_data *per_cu);
  71
  72 /* The symbol location baton types used by the DWARF-2 reader (i.e.
  73    SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol).  "struct
  74    dwarf2_locexpr_baton" is for a symbol with a single location
  75    expression; "struct dwarf2_loclist_baton" is for a symbol with a
  76    location list.  */
  77
  78 struct dwarf2_locexpr_baton
  79 {
  80   /* Pointer to the start of the location expression.  */
  81   const gdb_byte *data;
  82
  83   /* Length of the location expression.  */
  84   unsigned long size;
  85
  86   /* The compilation unit containing the symbol whose location
  87      we're computing.  */
  88   struct dwarf2_per_cu_data *per_cu;
  89 };
  90
  91 struct dwarf2_loclist_baton
  92 {
  93   /* The initial base address for the location list, based on the compilation
  94      unit.  */
  95   CORE_ADDR base_address;
  96
  97   /* Pointer to the start of the location list.  */
  98   const gdb_byte *data;
  99
 100   /* Length of the location list.  */
 101   unsigned long size;
 102
 103   /* The compilation unit containing the symbol whose location
 104      we're computing.  */
 105   struct dwarf2_per_cu_data *per_cu;
 106 };
 107
 108 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
 109 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
 110
 111 /* Compile a DWARF location expression to an agent expression.
 112
 113    EXPR is the agent expression we are building.
 114    LOC is the agent value we modify.
 115    ARCH is the architecture.
 116    ADDR_SIZE is the size of addresses, in bytes.
 117    OP_PTR is the start of the location expression.
 118    OP_END is one past the last byte of the location expression.
 119
 120    This will throw an exception for various kinds of errors -- for
 121    example, if the expression cannot be compiled, or if the expression
 122    is invalid.  */
 123
 124 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
 125                                        struct axs_value *loc,
 126                                        struct gdbarch *arch,
 127                                        unsigned int addr_size,
 128                                        const gdb_byte *op_ptr,
 129                                        const gdb_byte *op_end,
 130                                        struct dwarf2_per_cu_data *per_cu);
 131
 132 #endif /* dwarf2loc.h */