| 1 | /* Branch trace support for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2013-2015 Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by Intel Corp. <markus.t.metzger@intel.com>. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #ifndef BTRACE_H |
| 23 | #define BTRACE_H |
| 24 | |
| 25 | /* Branch tracing (btrace) is a per-thread control-flow execution trace of the |
| 26 | inferior. For presentation purposes, the branch trace is represented as a |
| 27 | list of sequential control-flow blocks, one such list per thread. */ |
| 28 | |
| 29 | #include "btrace-common.h" |
| 30 | |
| 31 | struct thread_info; |
| 32 | struct btrace_function; |
| 33 | |
| 34 | /* A branch trace instruction. |
| 35 | |
| 36 | This represents a single instruction in a branch trace. */ |
| 37 | struct btrace_insn |
| 38 | { |
| 39 | /* The address of this instruction. */ |
| 40 | CORE_ADDR pc; |
| 41 | }; |
| 42 | |
| 43 | /* A vector of branch trace instructions. */ |
| 44 | typedef struct btrace_insn btrace_insn_s; |
| 45 | DEF_VEC_O (btrace_insn_s); |
| 46 | |
| 47 | /* A doubly-linked list of branch trace function segments. */ |
| 48 | struct btrace_func_link |
| 49 | { |
| 50 | struct btrace_function *prev; |
| 51 | struct btrace_function *next; |
| 52 | }; |
| 53 | |
| 54 | /* Flags for btrace function segments. */ |
| 55 | enum btrace_function_flag |
| 56 | { |
| 57 | /* The 'up' link interpretation. |
| 58 | If set, it points to the function segment we returned to. |
| 59 | If clear, it points to the function segment we called from. */ |
| 60 | BFUN_UP_LINKS_TO_RET = (1 << 0), |
| 61 | |
| 62 | /* The 'up' link points to a tail call. This obviously only makes sense |
| 63 | if bfun_up_links_to_ret is clear. */ |
| 64 | BFUN_UP_LINKS_TO_TAILCALL = (1 << 1) |
| 65 | }; |
| 66 | |
| 67 | /* A branch trace function segment. |
| 68 | |
| 69 | This represents a function segment in a branch trace, i.e. a consecutive |
| 70 | number of instructions belonging to the same function. |
| 71 | |
| 72 | We do not allow function segments without any instructions. */ |
| 73 | struct btrace_function |
| 74 | { |
| 75 | /* The full and minimal symbol for the function. Both may be NULL. */ |
| 76 | struct minimal_symbol *msym; |
| 77 | struct symbol *sym; |
| 78 | |
| 79 | /* The previous and next segment belonging to the same function. |
| 80 | If a function calls another function, the former will have at least |
| 81 | two segments: one before the call and another after the return. */ |
| 82 | struct btrace_func_link segment; |
| 83 | |
| 84 | /* The previous and next function in control flow order. */ |
| 85 | struct btrace_func_link flow; |
| 86 | |
| 87 | /* The directly preceding function segment in a (fake) call stack. */ |
| 88 | struct btrace_function *up; |
| 89 | |
| 90 | /* The instructions in this function segment. |
| 91 | The instruction vector will never be empty. */ |
| 92 | VEC (btrace_insn_s) *insn; |
| 93 | |
| 94 | /* The instruction number offset for the first instruction in this |
| 95 | function segment. */ |
| 96 | unsigned int insn_offset; |
| 97 | |
| 98 | /* The function number in control-flow order. */ |
| 99 | unsigned int number; |
| 100 | |
| 101 | /* The function level in a back trace across the entire branch trace. |
| 102 | A caller's level is one lower than the level of its callee. |
| 103 | |
| 104 | Levels can be negative if we see returns for which we have not seen |
| 105 | the corresponding calls. The branch trace thread information provides |
| 106 | a fixup to normalize function levels so the smallest level is zero. */ |
| 107 | int level; |
| 108 | |
| 109 | /* The source line range of this function segment (both inclusive). */ |
| 110 | int lbegin, lend; |
| 111 | |
| 112 | /* A bit-vector of btrace_function_flag. */ |
| 113 | enum btrace_function_flag flags; |
| 114 | }; |
| 115 | |
| 116 | /* A branch trace instruction iterator. */ |
| 117 | struct btrace_insn_iterator |
| 118 | { |
| 119 | /* The branch trace function segment containing the instruction. |
| 120 | Will never be NULL. */ |
| 121 | const struct btrace_function *function; |
| 122 | |
| 123 | /* The index into the function segment's instruction vector. */ |
| 124 | unsigned int index; |
| 125 | }; |
| 126 | |
| 127 | /* A branch trace function call iterator. */ |
| 128 | struct btrace_call_iterator |
| 129 | { |
| 130 | /* The branch trace information for this thread. Will never be NULL. */ |
| 131 | const struct btrace_thread_info *btinfo; |
| 132 | |
| 133 | /* The branch trace function segment. |
| 134 | This will be NULL for the iterator pointing to the end of the trace. */ |
| 135 | const struct btrace_function *function; |
| 136 | }; |
| 137 | |
| 138 | /* Branch trace iteration state for "record instruction-history". */ |
| 139 | struct btrace_insn_history |
| 140 | { |
| 141 | /* The branch trace instruction range from BEGIN (inclusive) to |
| 142 | END (exclusive) that has been covered last time. */ |
| 143 | struct btrace_insn_iterator begin; |
| 144 | struct btrace_insn_iterator end; |
| 145 | }; |
| 146 | |
| 147 | /* Branch trace iteration state for "record function-call-history". */ |
| 148 | struct btrace_call_history |
| 149 | { |
| 150 | /* The branch trace function range from BEGIN (inclusive) to END (exclusive) |
| 151 | that has been covered last time. */ |
| 152 | struct btrace_call_iterator begin; |
| 153 | struct btrace_call_iterator end; |
| 154 | }; |
| 155 | |
| 156 | /* Branch trace thread flags. */ |
| 157 | enum btrace_thread_flag |
| 158 | { |
| 159 | /* The thread is to be stepped forwards. */ |
| 160 | BTHR_STEP = (1 << 0), |
| 161 | |
| 162 | /* The thread is to be stepped backwards. */ |
| 163 | BTHR_RSTEP = (1 << 1), |
| 164 | |
| 165 | /* The thread is to be continued forwards. */ |
| 166 | BTHR_CONT = (1 << 2), |
| 167 | |
| 168 | /* The thread is to be continued backwards. */ |
| 169 | BTHR_RCONT = (1 << 3), |
| 170 | |
| 171 | /* The thread is to be moved. */ |
| 172 | BTHR_MOVE = (BTHR_STEP | BTHR_RSTEP | BTHR_CONT | BTHR_RCONT) |
| 173 | }; |
| 174 | |
| 175 | /* Branch trace information per thread. |
| 176 | |
| 177 | This represents the branch trace configuration as well as the entry point |
| 178 | into the branch trace data. For the latter, it also contains the index into |
| 179 | an array of branch trace blocks used for iterating though the branch trace |
| 180 | blocks of a thread. */ |
| 181 | struct btrace_thread_info |
| 182 | { |
| 183 | /* The target branch trace information for this thread. |
| 184 | |
| 185 | This contains the branch trace configuration as well as any |
| 186 | target-specific information necessary for implementing branch tracing on |
| 187 | the underlying architecture. */ |
| 188 | struct btrace_target_info *target; |
| 189 | |
| 190 | /* The current branch trace for this thread (both inclusive). |
| 191 | |
| 192 | The last instruction of END is the current instruction, which is not |
| 193 | part of the execution history. |
| 194 | Both will be NULL if there is no branch trace available. If there is |
| 195 | branch trace available, both will be non-NULL. */ |
| 196 | struct btrace_function *begin; |
| 197 | struct btrace_function *end; |
| 198 | |
| 199 | /* The function level offset. When added to each function's LEVEL, |
| 200 | this normalizes the function levels such that the smallest level |
| 201 | becomes zero. */ |
| 202 | int level; |
| 203 | |
| 204 | /* A bit-vector of btrace_thread_flag. */ |
| 205 | enum btrace_thread_flag flags; |
| 206 | |
| 207 | /* The instruction history iterator. */ |
| 208 | struct btrace_insn_history *insn_history; |
| 209 | |
| 210 | /* The function call history iterator. */ |
| 211 | struct btrace_call_history *call_history; |
| 212 | |
| 213 | /* The current replay position. NULL if not replaying. */ |
| 214 | struct btrace_insn_iterator *replay; |
| 215 | }; |
| 216 | |
| 217 | /* Enable branch tracing for a thread. */ |
| 218 | extern void btrace_enable (struct thread_info *tp); |
| 219 | |
| 220 | /* Disable branch tracing for a thread. |
| 221 | This will also delete the current branch trace data. */ |
| 222 | extern void btrace_disable (struct thread_info *); |
| 223 | |
| 224 | /* Disable branch tracing for a thread during teardown. |
| 225 | This is similar to btrace_disable, except that it will use |
| 226 | target_teardown_btrace instead of target_disable_btrace. */ |
| 227 | extern void btrace_teardown (struct thread_info *); |
| 228 | |
| 229 | /* Fetch the branch trace for a single thread. */ |
| 230 | extern void btrace_fetch (struct thread_info *); |
| 231 | |
| 232 | /* Clear the branch trace for a single thread. */ |
| 233 | extern void btrace_clear (struct thread_info *); |
| 234 | |
| 235 | /* Clear the branch trace for all threads when an object file goes away. */ |
| 236 | extern void btrace_free_objfile (struct objfile *); |
| 237 | |
| 238 | /* Parse a branch trace xml document into a block vector. */ |
| 239 | extern VEC (btrace_block_s) *parse_xml_btrace (const char*); |
| 240 | |
| 241 | /* Dereference a branch trace instruction iterator. Return a pointer to the |
| 242 | instruction the iterator points to. */ |
| 243 | extern const struct btrace_insn * |
| 244 | btrace_insn_get (const struct btrace_insn_iterator *); |
| 245 | |
| 246 | /* Return the instruction number for a branch trace iterator. |
| 247 | Returns one past the maximum instruction number for the end iterator. |
| 248 | Returns zero if the iterator does not point to a valid instruction. */ |
| 249 | extern unsigned int btrace_insn_number (const struct btrace_insn_iterator *); |
| 250 | |
| 251 | /* Initialize a branch trace instruction iterator to point to the begin/end of |
| 252 | the branch trace. Throws an error if there is no branch trace. */ |
| 253 | extern void btrace_insn_begin (struct btrace_insn_iterator *, |
| 254 | const struct btrace_thread_info *); |
| 255 | extern void btrace_insn_end (struct btrace_insn_iterator *, |
| 256 | const struct btrace_thread_info *); |
| 257 | |
| 258 | /* Increment/decrement a branch trace instruction iterator by at most STRIDE |
| 259 | instructions. Return the number of instructions by which the instruction |
| 260 | iterator has been advanced. |
| 261 | Returns zero, if the operation failed or STRIDE had been zero. */ |
| 262 | extern unsigned int btrace_insn_next (struct btrace_insn_iterator *, |
| 263 | unsigned int stride); |
| 264 | extern unsigned int btrace_insn_prev (struct btrace_insn_iterator *, |
| 265 | unsigned int stride); |
| 266 | |
| 267 | /* Compare two branch trace instruction iterators. |
| 268 | Return a negative number if LHS < RHS. |
| 269 | Return zero if LHS == RHS. |
| 270 | Return a positive number if LHS > RHS. */ |
| 271 | extern int btrace_insn_cmp (const struct btrace_insn_iterator *lhs, |
| 272 | const struct btrace_insn_iterator *rhs); |
| 273 | |
| 274 | /* Find an instruction in the function branch trace by its number. |
| 275 | If the instruction is found, initialize the branch trace instruction |
| 276 | iterator to point to this instruction and return non-zero. |
| 277 | Return zero otherwise. */ |
| 278 | extern int btrace_find_insn_by_number (struct btrace_insn_iterator *, |
| 279 | const struct btrace_thread_info *, |
| 280 | unsigned int number); |
| 281 | |
| 282 | /* Dereference a branch trace call iterator. Return a pointer to the |
| 283 | function the iterator points to or NULL if the interator points past |
| 284 | the end of the branch trace. */ |
| 285 | extern const struct btrace_function * |
| 286 | btrace_call_get (const struct btrace_call_iterator *); |
| 287 | |
| 288 | /* Return the function number for a branch trace call iterator. |
| 289 | Returns one past the maximum function number for the end iterator. |
| 290 | Returns zero if the iterator does not point to a valid function. */ |
| 291 | extern unsigned int btrace_call_number (const struct btrace_call_iterator *); |
| 292 | |
| 293 | /* Initialize a branch trace call iterator to point to the begin/end of |
| 294 | the branch trace. Throws an error if there is no branch trace. */ |
| 295 | extern void btrace_call_begin (struct btrace_call_iterator *, |
| 296 | const struct btrace_thread_info *); |
| 297 | extern void btrace_call_end (struct btrace_call_iterator *, |
| 298 | const struct btrace_thread_info *); |
| 299 | |
| 300 | /* Increment/decrement a branch trace call iterator by at most STRIDE function |
| 301 | segments. Return the number of function segments by which the call |
| 302 | iterator has been advanced. |
| 303 | Returns zero, if the operation failed or STRIDE had been zero. */ |
| 304 | extern unsigned int btrace_call_next (struct btrace_call_iterator *, |
| 305 | unsigned int stride); |
| 306 | extern unsigned int btrace_call_prev (struct btrace_call_iterator *, |
| 307 | unsigned int stride); |
| 308 | |
| 309 | /* Compare two branch trace call iterators. |
| 310 | Return a negative number if LHS < RHS. |
| 311 | Return zero if LHS == RHS. |
| 312 | Return a positive number if LHS > RHS. */ |
| 313 | extern int btrace_call_cmp (const struct btrace_call_iterator *lhs, |
| 314 | const struct btrace_call_iterator *rhs); |
| 315 | |
| 316 | /* Find a function in the function branch trace by its NUMBER. |
| 317 | If the function is found, initialize the branch trace call |
| 318 | iterator to point to this function and return non-zero. |
| 319 | Return zero otherwise. */ |
| 320 | extern int btrace_find_call_by_number (struct btrace_call_iterator *, |
| 321 | const struct btrace_thread_info *, |
| 322 | unsigned int number); |
| 323 | |
| 324 | /* Set the branch trace instruction history from BEGIN (inclusive) to |
| 325 | END (exclusive). */ |
| 326 | extern void btrace_set_insn_history (struct btrace_thread_info *, |
| 327 | const struct btrace_insn_iterator *begin, |
| 328 | const struct btrace_insn_iterator *end); |
| 329 | |
| 330 | /* Set the branch trace function call history from BEGIN (inclusive) to |
| 331 | END (exclusive). */ |
| 332 | extern void btrace_set_call_history (struct btrace_thread_info *, |
| 333 | const struct btrace_call_iterator *begin, |
| 334 | const struct btrace_call_iterator *end); |
| 335 | |
| 336 | /* Determine if branch tracing is currently replaying TP. */ |
| 337 | extern int btrace_is_replaying (struct thread_info *tp); |
| 338 | |
| 339 | /* Return non-zero if the branch trace for TP is empty; zero otherwise. */ |
| 340 | extern int btrace_is_empty (struct thread_info *tp); |
| 341 | |
| 342 | |
| 343 | #endif /* BTRACE_H */ |