1 /* DWARF 2 location expression support for GDB. 2 3 Copyright (C) 2003-2013 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 struct type *dwarf2_get_die_type (cu_offset die_offset, 76 struct dwarf2_per_cu_data *per_cu); 77 78 /* Evaluate a location description, starting at DATA and with length 79 SIZE, to find the current location of variable of TYPE in the context 80 of FRAME. */ 81 82 struct value *dwarf2_evaluate_loc_desc (struct type *type, 83 struct frame_info *frame, 84 const gdb_byte *data, 85 size_t size, 86 struct dwarf2_per_cu_data *per_cu); 87 88 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu, 89 unsigned int addr_index); 90 91 /* The symbol location baton types used by the DWARF-2 reader (i.e. 92 SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct 93 dwarf2_locexpr_baton" is for a symbol with a single location 94 expression; "struct dwarf2_loclist_baton" is for a symbol with a 95 location list. */ 96 97 struct dwarf2_locexpr_baton 98 { 99 /* Pointer to the start of the location expression. Valid only if SIZE is 100 not zero. */ 101 const gdb_byte *data; 102 103 /* Length of the location expression. For optimized out expressions it is 104 zero. */ 105 size_t size; 106 107 /* The compilation unit containing the symbol whose location 108 we're computing. */ 109 struct dwarf2_per_cu_data *per_cu; 110 }; 111 112 struct dwarf2_loclist_baton 113 { 114 /* The initial base address for the location list, based on the compilation 115 unit. */ 116 CORE_ADDR base_address; 117 118 /* Pointer to the start of the location list. */ 119 const gdb_byte *data; 120 121 /* Length of the location list. */ 122 size_t size; 123 124 /* The compilation unit containing the symbol whose location 125 we're computing. */ 126 struct dwarf2_per_cu_data *per_cu; 127 128 /* Non-zero if the location list lives in .debug_loc.dwo. 129 The format of entries in this section are different. */ 130 unsigned char from_dwo; 131 }; 132 133 extern const struct symbol_computed_ops dwarf2_locexpr_funcs; 134 extern const struct symbol_computed_ops dwarf2_loclist_funcs; 135 136 /* Compile a DWARF location expression to an agent expression. 137 138 EXPR is the agent expression we are building. 139 LOC is the agent value we modify. 140 ARCH is the architecture. 141 ADDR_SIZE is the size of addresses, in bytes. 142 OP_PTR is the start of the location expression. 143 OP_END is one past the last byte of the location expression. 144 145 This will throw an exception for various kinds of errors -- for 146 example, if the expression cannot be compiled, or if the expression 147 is invalid. */ 148 149 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr, 150 struct axs_value *loc, 151 struct gdbarch *arch, 152 unsigned int addr_size, 153 const gdb_byte *op_ptr, 154 const gdb_byte *op_end, 155 struct dwarf2_per_cu_data *per_cu); 156 157 /* Determined tail calls for constructing virtual tail call frames. */ 158 159 struct call_site_chain 160 { 161 /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result 162 CALLERS + CALLEES < LENGTH. */ 163 int callers, callees, length; 164 165 /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain 166 top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom 167 (GDB "next") sites. One is interested primarily in the PC field. */ 168 struct call_site *call_site[1]; 169 }; 170 171 struct call_site_stuff; 172 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch, 173 CORE_ADDR caller_pc, 174 CORE_ADDR callee_pc); 175 176 #endif /* dwarf2loc.h */ 177