| 1 | /* DWARF 2 location expression support for GDB. |
| 2 | |
| 3 | Copyright (C) 2003-2016 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 | extern const gdb_byte *dwarf2_fetch_constant_bytes (sect_offset, |
| 76 | struct dwarf2_per_cu_data *, |
| 77 | struct obstack *, |
| 78 | LONGEST *); |
| 79 | |
| 80 | struct type *dwarf2_get_die_type (cu_offset die_offset, |
| 81 | struct dwarf2_per_cu_data *per_cu); |
| 82 | |
| 83 | /* Find the frame base information for FRAMEFUNC at PC. START is an |
| 84 | out parameter which is set to point to the DWARF expression to |
| 85 | compute. LENGTH is an out parameter which is set to the length of |
| 86 | the DWARF expression. This throws an exception on error or if an |
| 87 | expression is not found; the returned length will never be |
| 88 | zero. */ |
| 89 | |
| 90 | extern void func_get_frame_base_dwarf_block (struct symbol *framefunc, |
| 91 | CORE_ADDR pc, |
| 92 | const gdb_byte **start, |
| 93 | size_t *length); |
| 94 | |
| 95 | /* Evaluate a location description, starting at DATA and with length |
| 96 | SIZE, to find the current location of variable of TYPE in the context |
| 97 | of FRAME. */ |
| 98 | |
| 99 | struct value *dwarf2_evaluate_loc_desc (struct type *type, |
| 100 | struct frame_info *frame, |
| 101 | const gdb_byte *data, |
| 102 | size_t size, |
| 103 | struct dwarf2_per_cu_data *per_cu); |
| 104 | |
| 105 | /* A chain of addresses that might be needed to resolve a dynamic |
| 106 | property. */ |
| 107 | |
| 108 | struct property_addr_info |
| 109 | { |
| 110 | /* The type of the object whose dynamic properties, if any, are |
| 111 | being resolved. */ |
| 112 | struct type *type; |
| 113 | |
| 114 | /* If not NULL, a buffer containing the object's value. */ |
| 115 | const gdb_byte *valaddr; |
| 116 | |
| 117 | /* The address of that object. */ |
| 118 | CORE_ADDR addr; |
| 119 | |
| 120 | /* If not NULL, a pointer to the info for the object containing |
| 121 | the object described by this node. */ |
| 122 | struct property_addr_info *next; |
| 123 | }; |
| 124 | |
| 125 | /* Converts a dynamic property into a static one. FRAME is the frame in which |
| 126 | the property is evaluated; if NULL, the selected frame (if any) is used |
| 127 | instead. |
| 128 | |
| 129 | ADDR_STACK is the stack of addresses that might be needed to evaluate the |
| 130 | property. When evaluating a property that is not related to a type, it can |
| 131 | be NULL. |
| 132 | |
| 133 | Returns 1 if PROP could be converted and the static value is passed back |
| 134 | into VALUE, otherwise returns 0. */ |
| 135 | |
| 136 | int dwarf2_evaluate_property (const struct dynamic_prop *prop, |
| 137 | struct frame_info *frame, |
| 138 | struct property_addr_info *addr_stack, |
| 139 | CORE_ADDR *value); |
| 140 | |
| 141 | /* A helper for the compiler interface that compiles a single dynamic |
| 142 | property to C code. |
| 143 | |
| 144 | STREAM is where the C code is to be written. |
| 145 | RESULT_NAME is the name of the generated variable. |
| 146 | GDBARCH is the architecture to use. |
| 147 | REGISTERS_USED is a bit-vector that is filled to note which |
| 148 | registers are required by the generated expression. |
| 149 | PROP is the property for which code is generated. |
| 150 | ADDRESS is the address at which the property is considered to be |
| 151 | evaluated. |
| 152 | SYM the originating symbol, used for error reporting. */ |
| 153 | |
| 154 | void dwarf2_compile_property_to_c (struct ui_file *stream, |
| 155 | const char *result_name, |
| 156 | struct gdbarch *gdbarch, |
| 157 | unsigned char *registers_used, |
| 158 | const struct dynamic_prop *prop, |
| 159 | CORE_ADDR address, |
| 160 | struct symbol *sym); |
| 161 | |
| 162 | CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu, |
| 163 | unsigned int addr_index); |
| 164 | |
| 165 | /* The symbol location baton types used by the DWARF-2 reader (i.e. |
| 166 | SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct |
| 167 | dwarf2_locexpr_baton" is for a symbol with a single location |
| 168 | expression; "struct dwarf2_loclist_baton" is for a symbol with a |
| 169 | location list. */ |
| 170 | |
| 171 | struct dwarf2_locexpr_baton |
| 172 | { |
| 173 | /* Pointer to the start of the location expression. Valid only if SIZE is |
| 174 | not zero. */ |
| 175 | const gdb_byte *data; |
| 176 | |
| 177 | /* Length of the location expression. For optimized out expressions it is |
| 178 | zero. */ |
| 179 | size_t size; |
| 180 | |
| 181 | /* The compilation unit containing the symbol whose location |
| 182 | we're computing. */ |
| 183 | struct dwarf2_per_cu_data *per_cu; |
| 184 | }; |
| 185 | |
| 186 | struct dwarf2_loclist_baton |
| 187 | { |
| 188 | /* The initial base address for the location list, based on the compilation |
| 189 | unit. */ |
| 190 | CORE_ADDR base_address; |
| 191 | |
| 192 | /* Pointer to the start of the location list. */ |
| 193 | const gdb_byte *data; |
| 194 | |
| 195 | /* Length of the location list. */ |
| 196 | size_t size; |
| 197 | |
| 198 | /* The compilation unit containing the symbol whose location |
| 199 | we're computing. */ |
| 200 | struct dwarf2_per_cu_data *per_cu; |
| 201 | |
| 202 | /* Non-zero if the location list lives in .debug_loc.dwo. |
| 203 | The format of entries in this section are different. */ |
| 204 | unsigned char from_dwo; |
| 205 | }; |
| 206 | |
| 207 | /* The baton used when a dynamic property is an offset to a parent |
| 208 | type. This can be used, for instance, then the bound of an array |
| 209 | inside a record is determined by the value of another field inside |
| 210 | that record. */ |
| 211 | |
| 212 | struct dwarf2_offset_baton |
| 213 | { |
| 214 | /* The offset from the parent type where the value of the property |
| 215 | is stored. In the example provided above, this would be the offset |
| 216 | of the field being used as the array bound. */ |
| 217 | LONGEST offset; |
| 218 | |
| 219 | /* The type of the object whose property is dynamic. In the example |
| 220 | provided above, this would the the array's index type. */ |
| 221 | struct type *type; |
| 222 | }; |
| 223 | |
| 224 | /* A dynamic property is either expressed as a single location expression |
| 225 | or a location list. If the property is an indirection, pointing to |
| 226 | another die, keep track of the targeted type in REFERENCED_TYPE. */ |
| 227 | |
| 228 | struct dwarf2_property_baton |
| 229 | { |
| 230 | /* If the property is an indirection, we need to evaluate the location |
| 231 | in the context of the type REFERENCED_TYPE. |
| 232 | If NULL, the location is the actual value of the property. */ |
| 233 | struct type *referenced_type; |
| 234 | union |
| 235 | { |
| 236 | /* Location expression. */ |
| 237 | struct dwarf2_locexpr_baton locexpr; |
| 238 | |
| 239 | /* Location list to be evaluated in the context of REFERENCED_TYPE. */ |
| 240 | struct dwarf2_loclist_baton loclist; |
| 241 | |
| 242 | /* The location is an offset to REFERENCED_TYPE. */ |
| 243 | struct dwarf2_offset_baton offset_info; |
| 244 | }; |
| 245 | }; |
| 246 | |
| 247 | extern const struct symbol_computed_ops dwarf2_locexpr_funcs; |
| 248 | extern const struct symbol_computed_ops dwarf2_loclist_funcs; |
| 249 | |
| 250 | extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs; |
| 251 | extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs; |
| 252 | |
| 253 | /* Compile a DWARF location expression to an agent expression. |
| 254 | |
| 255 | EXPR is the agent expression we are building. |
| 256 | LOC is the agent value we modify. |
| 257 | ARCH is the architecture. |
| 258 | ADDR_SIZE is the size of addresses, in bytes. |
| 259 | OP_PTR is the start of the location expression. |
| 260 | OP_END is one past the last byte of the location expression. |
| 261 | |
| 262 | This will throw an exception for various kinds of errors -- for |
| 263 | example, if the expression cannot be compiled, or if the expression |
| 264 | is invalid. */ |
| 265 | |
| 266 | extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr, |
| 267 | struct axs_value *loc, |
| 268 | struct gdbarch *arch, |
| 269 | unsigned int addr_size, |
| 270 | const gdb_byte *op_ptr, |
| 271 | const gdb_byte *op_end, |
| 272 | struct dwarf2_per_cu_data *per_cu); |
| 273 | |
| 274 | /* Determined tail calls for constructing virtual tail call frames. */ |
| 275 | |
| 276 | struct call_site_chain |
| 277 | { |
| 278 | /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result |
| 279 | CALLERS + CALLEES < LENGTH. */ |
| 280 | int callers, callees, length; |
| 281 | |
| 282 | /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain |
| 283 | top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom |
| 284 | (GDB "next") sites. One is interested primarily in the PC field. */ |
| 285 | struct call_site *call_site[1]; |
| 286 | }; |
| 287 | |
| 288 | struct call_site_stuff; |
| 289 | extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch, |
| 290 | CORE_ADDR caller_pc, |
| 291 | CORE_ADDR callee_pc); |
| 292 | |
| 293 | /* A helper function to convert a DWARF register to an arch register. |
| 294 | ARCH is the architecture. |
| 295 | DWARF_REG is the register. |
| 296 | If DWARF_REG is bad then a complaint is issued and -1 is returned. |
| 297 | Note: Some targets get this wrong. */ |
| 298 | |
| 299 | extern int dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg); |
| 300 | |
| 301 | /* A wrapper on dwarf_reg_to_regnum to throw an exception if the |
| 302 | DWARF register cannot be translated to an architecture register. |
| 303 | This takes a ULONGEST instead of an int because some callers actually have |
| 304 | a ULONGEST. Negative values passed as ints will still be flagged as |
| 305 | invalid. */ |
| 306 | |
| 307 | extern int dwarf_reg_to_regnum_or_error (struct gdbarch *arch, |
| 308 | ULONGEST dwarf_reg); |
| 309 | |
| 310 | #endif /* dwarf2loc.h */ |