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 struct symbol_computed_ops;
  24 struct objfile;
  25 struct dwarf2_per_cu_data;
  26 struct dwarf2_loclist_baton;
  27 struct agent_expr;
  28 struct axs_value;
  29
  30 /* This header is private to the DWARF-2 reader.  It is shared between
  31    dwarf2read.c and dwarf2loc.c.  */
  32
  33 /* `set debug entry-values' setting.  */
  34 extern int entry_values_debug;
  35
  36 /* Return the OBJFILE associated with the compilation unit CU.  If CU
  37    came from a separate debuginfo file, then the master objfile is
  38    returned.  */
  39 struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu);
  40
  41 /* Return the address size given in the compilation unit header for CU.  */
  42 CORE_ADDR dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu);
  43
  44 /* Return the DW_FORM_ref_addr size given in the compilation unit header for
  45    CU.  */
  46 int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data *cu);
  47
  48 /* Return the offset size given in the compilation unit header for CU.  */
  49 int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu);
  50
  51 /* Return the text offset of the CU.  The returned offset comes from
  52    this CU's objfile.  If this objfile came from a separate debuginfo
  53    file, then the offset may be different from the corresponding
  54    offset in the parent objfile.  */
  55 CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu);
  56
  57 /* Find a particular location expression from a location list.  */
  58 const gdb_byte *dwarf2_find_location_expression
  59   (struct dwarf2_loclist_baton *baton,
  60    size_t *locexpr_length,
  61    CORE_ADDR pc);
  62
  63 struct dwarf2_locexpr_baton dwarf2_fetch_die_location_block
  64   (unsigned int offset, struct dwarf2_per_cu_data *per_cu,
  65    CORE_ADDR (*get_frame_pc) (void *baton),
  66    void *baton);
  67
  68 struct type *dwarf2_get_die_type (unsigned int die_offset,
  69                                   struct dwarf2_per_cu_data *per_cu);
  70
  71 /* Evaluate a location description, starting at DATA and with length
  72    SIZE, to find the current location of variable of TYPE in the context
  73    of FRAME.  */
  74
  75 struct value *dwarf2_evaluate_loc_desc (struct type *type,
  76                                         struct frame_info *frame,
  77                                         const gdb_byte *data,
  78                                         unsigned short size,
  79                                         struct dwarf2_per_cu_data *per_cu);
  80
  81 /* The symbol location baton types used by the DWARF-2 reader (i.e.
  82    SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol).  "struct
  83    dwarf2_locexpr_baton" is for a symbol with a single location
  84    expression; "struct dwarf2_loclist_baton" is for a symbol with a
  85    location list.  */
  86
  87 struct dwarf2_locexpr_baton
  88 {
  89   /* Pointer to the start of the location expression.  Valid only if SIZE is
  90      not zero.  */
  91   const gdb_byte *data;
  92
  93   /* Length of the location expression.  For optimized out expressions it is
  94      zero.  */
  95   unsigned long size;
  96
  97   /* The compilation unit containing the symbol whose location
  98      we're computing.  */
  99   struct dwarf2_per_cu_data *per_cu;
 100 };
 101
 102 struct dwarf2_loclist_baton
 103 {
 104   /* The initial base address for the location list, based on the compilation
 105      unit.  */
 106   CORE_ADDR base_address;
 107
 108   /* Pointer to the start of the location list.  */
 109   const gdb_byte *data;
 110
 111   /* Length of the location list.  */
 112   unsigned long size;
 113
 114   /* The compilation unit containing the symbol whose location
 115      we're computing.  */
 116   struct dwarf2_per_cu_data *per_cu;
 117 };
 118
 119 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
 120 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
 121
 122 /* Compile a DWARF location expression to an agent expression.
 123
 124    EXPR is the agent expression we are building.
 125    LOC is the agent value we modify.
 126    ARCH is the architecture.
 127    ADDR_SIZE is the size of addresses, in bytes.
 128    OP_PTR is the start of the location expression.
 129    OP_END is one past the last byte of the location expression.
 130
 131    This will throw an exception for various kinds of errors -- for
 132    example, if the expression cannot be compiled, or if the expression
 133    is invalid.  */
 134
 135 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
 136                                        struct axs_value *loc,
 137                                        struct gdbarch *arch,
 138                                        unsigned int addr_size,
 139                                        const gdb_byte *op_ptr,
 140                                        const gdb_byte *op_end,
 141                                        struct dwarf2_per_cu_data *per_cu);
 142
 143 /* Determined tail calls for constructing virtual tail call frames.  */
 144
 145 struct call_site_chain
 146   {
 147     /* Initially CALLERS == CALLEES == LENGTH.  For partially ambiguous result
 148        CALLERS + CALLEES < LENGTH.  */
 149     int callers, callees, length;
 150
 151     /* Variably sized array with LENGTH elements.  Later [0..CALLERS-1] contain
 152        top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
 153        (GDB "next") sites.  One is interested primarily in the PC field.  */
 154     struct call_site *call_site[1];
 155   };
 156
 157 struct call_site_stuff;
 158 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
 159                                                      CORE_ADDR caller_pc,
 160                                                      CORE_ADDR callee_pc);
 161
 162 #endif /* dwarf2loc.h */