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 */ 163