| 1 | /* Cache and manage the values of registers for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986-2020 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 | #ifndef REGCACHE_H |
| 21 | #define REGCACHE_H |
| 22 | |
| 23 | #include "gdbsupport/common-regcache.h" |
| 24 | #include "gdbsupport/function-view.h" |
| 25 | #include <forward_list> |
| 26 | |
| 27 | struct regcache; |
| 28 | struct regset; |
| 29 | struct gdbarch; |
| 30 | struct address_space; |
| 31 | class thread_info; |
| 32 | |
| 33 | extern struct regcache *get_current_regcache (void); |
| 34 | extern struct regcache *get_thread_regcache (ptid_t ptid); |
| 35 | |
| 36 | /* Get the regcache of THREAD. */ |
| 37 | extern struct regcache *get_thread_regcache (thread_info *thread); |
| 38 | |
| 39 | extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *); |
| 40 | extern struct regcache *get_thread_arch_aspace_regcache (ptid_t, |
| 41 | struct gdbarch *, |
| 42 | struct address_space *); |
| 43 | |
| 44 | extern enum register_status |
| 45 | regcache_raw_read_signed (struct regcache *regcache, |
| 46 | int regnum, LONGEST *val); |
| 47 | |
| 48 | extern void regcache_raw_write_signed (struct regcache *regcache, |
| 49 | int regnum, LONGEST val); |
| 50 | extern void regcache_raw_write_unsigned (struct regcache *regcache, |
| 51 | int regnum, ULONGEST val); |
| 52 | |
| 53 | /* Return the register's value in signed or throw if it's not |
| 54 | available. */ |
| 55 | |
| 56 | extern LONGEST regcache_raw_get_signed (struct regcache *regcache, |
| 57 | int regnum); |
| 58 | |
| 59 | /* Read a register as a signed/unsigned quantity. */ |
| 60 | extern enum register_status |
| 61 | regcache_cooked_read_signed (struct regcache *regcache, |
| 62 | int regnum, LONGEST *val); |
| 63 | extern enum register_status |
| 64 | regcache_cooked_read_unsigned (struct regcache *regcache, |
| 65 | int regnum, ULONGEST *val); |
| 66 | extern void regcache_cooked_write_signed (struct regcache *regcache, |
| 67 | int regnum, LONGEST val); |
| 68 | extern void regcache_cooked_write_unsigned (struct regcache *regcache, |
| 69 | int regnum, ULONGEST val); |
| 70 | |
| 71 | /* Special routines to read/write the PC. */ |
| 72 | |
| 73 | /* For regcache_read_pc see gdbsupport/common-regcache.h. */ |
| 74 | extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc); |
| 75 | |
| 76 | /* Mapping between register numbers and offsets in a buffer, for use |
| 77 | in the '*regset' functions below and with traditional frame caches. |
| 78 | In an array of 'regcache_map_entry' each element is interpreted |
| 79 | like follows: |
| 80 | |
| 81 | - If 'regno' is a register number: Map register 'regno' to the |
| 82 | current offset (starting with 0) and increase the current offset |
| 83 | by 'size' (or the register's size, if 'size' is zero). Repeat |
| 84 | this with consecutive register numbers up to 'regno+count-1'. |
| 85 | |
| 86 | For each described register, if 'size' is larger than the |
| 87 | register's size, the register's value is assumed to be stored in |
| 88 | the first N (where N is the register size) bytes at the current |
| 89 | offset. The remaining 'size' - N bytes are filled with zeroes by |
| 90 | 'regcache_collect_regset' and ignored by other consumers. |
| 91 | |
| 92 | If 'size' is smaller than the register's size, only the first |
| 93 | 'size' bytes of a register's value are assumed to be stored at |
| 94 | the current offset. 'regcache_collect_regset' copies the first |
| 95 | 'size' bytes of a register's value to the output buffer. |
| 96 | 'regcache_supply_regset' copies the bytes from the input buffer |
| 97 | into the first 'size' bytes of the register's value leaving the |
| 98 | remaining bytes of the register's value unchanged. Frame caches |
| 99 | read the 'size' bytes from the stack frame and zero extend them |
| 100 | to generate the register's value. |
| 101 | |
| 102 | - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current |
| 103 | offset. |
| 104 | |
| 105 | - If count=0: End of the map. */ |
| 106 | |
| 107 | struct regcache_map_entry |
| 108 | { |
| 109 | int count; |
| 110 | int regno; |
| 111 | int size; |
| 112 | }; |
| 113 | |
| 114 | /* Special value for the 'regno' field in the struct above. */ |
| 115 | |
| 116 | enum |
| 117 | { |
| 118 | REGCACHE_MAP_SKIP = -1, |
| 119 | }; |
| 120 | |
| 121 | /* Calculate and return the total size of all the registers in a |
| 122 | regcache_map_entry. */ |
| 123 | |
| 124 | static inline int |
| 125 | regcache_map_entry_size (const struct regcache_map_entry *map) |
| 126 | { |
| 127 | int size = 0; |
| 128 | for (int i = 0; map[i].count != 0; i++) |
| 129 | size += (map[i].count * map[i].size); |
| 130 | return size; |
| 131 | } |
| 132 | |
| 133 | /* Transfer a set of registers (as described by REGSET) between |
| 134 | REGCACHE and BUF. If REGNUM == -1, transfer all registers |
| 135 | belonging to the regset, otherwise just the register numbered |
| 136 | REGNUM. The REGSET's 'regmap' field must point to an array of |
| 137 | 'struct regcache_map_entry'. |
| 138 | |
| 139 | These functions are suitable for the 'regset_supply' and |
| 140 | 'regset_collect' fields in a regset structure. */ |
| 141 | |
| 142 | extern void regcache_supply_regset (const struct regset *regset, |
| 143 | struct regcache *regcache, |
| 144 | int regnum, const void *buf, |
| 145 | size_t size); |
| 146 | extern void regcache_collect_regset (const struct regset *regset, |
| 147 | const struct regcache *regcache, |
| 148 | int regnum, void *buf, size_t size); |
| 149 | |
| 150 | |
| 151 | /* The type of a register. This function is slightly more efficient |
| 152 | then its gdbarch vector counterpart since it returns a precomputed |
| 153 | value stored in a table. */ |
| 154 | |
| 155 | extern struct type *register_type (struct gdbarch *gdbarch, int regnum); |
| 156 | |
| 157 | |
| 158 | /* Return the size of register REGNUM. All registers should have only |
| 159 | one size. */ |
| 160 | |
| 161 | extern int register_size (struct gdbarch *gdbarch, int regnum); |
| 162 | |
| 163 | typedef gdb::function_view<register_status (int regnum, gdb_byte *buf)> |
| 164 | register_read_ftype; |
| 165 | |
| 166 | /* A (register_number, register_value) pair. */ |
| 167 | |
| 168 | typedef struct cached_reg |
| 169 | { |
| 170 | int num; |
| 171 | gdb_byte *data; |
| 172 | } cached_reg_t; |
| 173 | |
| 174 | /* Buffer of registers. */ |
| 175 | |
| 176 | class reg_buffer : public reg_buffer_common |
| 177 | { |
| 178 | public: |
| 179 | reg_buffer (gdbarch *gdbarch, bool has_pseudo); |
| 180 | |
| 181 | DISABLE_COPY_AND_ASSIGN (reg_buffer); |
| 182 | |
| 183 | /* Return regcache's architecture. */ |
| 184 | gdbarch *arch () const; |
| 185 | |
| 186 | /* See gdbsupport/common-regcache.h. */ |
| 187 | enum register_status get_register_status (int regnum) const override; |
| 188 | |
| 189 | /* See gdbsupport/common-regcache.h. */ |
| 190 | void raw_collect (int regnum, void *buf) const override; |
| 191 | |
| 192 | /* Collect register REGNUM from REGCACHE. Store collected value as an integer |
| 193 | at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED. |
| 194 | If ADDR_LEN is greater than the register size, then the integer will be |
| 195 | sign or zero extended. If ADDR_LEN is smaller than the register size, then |
| 196 | the most significant bytes of the integer will be truncated. */ |
| 197 | void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len, |
| 198 | bool is_signed) const; |
| 199 | |
| 200 | /* Collect register REGNUM from REGCACHE, starting at OFFSET in register, |
| 201 | reading only LEN. */ |
| 202 | void raw_collect_part (int regnum, int offset, int len, gdb_byte *out) const; |
| 203 | |
| 204 | /* See gdbsupport/common-regcache.h. */ |
| 205 | void raw_supply (int regnum, const void *buf) override; |
| 206 | |
| 207 | void raw_supply (int regnum, const reg_buffer &src) |
| 208 | { |
| 209 | raw_supply (regnum, src.register_buffer (regnum)); |
| 210 | } |
| 211 | |
| 212 | /* Supply register REGNUM to REGCACHE. Value to supply is an integer stored |
| 213 | at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED. |
| 214 | If the register size is greater than ADDR_LEN, then the integer will be |
| 215 | sign or zero extended. If the register size is smaller than the integer, |
| 216 | then the most significant bytes of the integer will be truncated. */ |
| 217 | void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len, |
| 218 | bool is_signed); |
| 219 | |
| 220 | /* Supply register REGNUM with zeroed value to REGCACHE. This is not the same |
| 221 | as calling raw_supply with NULL (which will set the state to |
| 222 | unavailable). */ |
| 223 | void raw_supply_zeroed (int regnum); |
| 224 | |
| 225 | /* Supply register REGNUM to REGCACHE, starting at OFFSET in register, writing |
| 226 | only LEN, without editing the rest of the register. */ |
| 227 | void raw_supply_part (int regnum, int offset, int len, const gdb_byte *in); |
| 228 | |
| 229 | void invalidate (int regnum); |
| 230 | |
| 231 | virtual ~reg_buffer () = default; |
| 232 | |
| 233 | /* See gdbsupport/common-regcache.h. */ |
| 234 | bool raw_compare (int regnum, const void *buf, int offset) const override; |
| 235 | |
| 236 | protected: |
| 237 | /* Assert on the range of REGNUM. */ |
| 238 | void assert_regnum (int regnum) const; |
| 239 | |
| 240 | int num_raw_registers () const; |
| 241 | |
| 242 | gdb_byte *register_buffer (int regnum) const; |
| 243 | |
| 244 | /* Save a register cache. The set of registers saved into the |
| 245 | regcache determined by the save_reggroup. COOKED_READ returns |
| 246 | zero iff the register's value can't be returned. */ |
| 247 | void save (register_read_ftype cooked_read); |
| 248 | |
| 249 | struct regcache_descr *m_descr; |
| 250 | |
| 251 | bool m_has_pseudo; |
| 252 | /* The register buffers. */ |
| 253 | std::unique_ptr<gdb_byte[]> m_registers; |
| 254 | /* Register cache status. */ |
| 255 | std::unique_ptr<register_status[]> m_register_status; |
| 256 | |
| 257 | friend class regcache; |
| 258 | friend class detached_regcache; |
| 259 | }; |
| 260 | |
| 261 | /* An abstract class which only has methods doing read. */ |
| 262 | |
| 263 | class readable_regcache : public reg_buffer |
| 264 | { |
| 265 | public: |
| 266 | readable_regcache (gdbarch *gdbarch, bool has_pseudo) |
| 267 | : reg_buffer (gdbarch, has_pseudo) |
| 268 | {} |
| 269 | |
| 270 | /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache, |
| 271 | return its value in *BUF and return its availability status. */ |
| 272 | |
| 273 | enum register_status raw_read (int regnum, gdb_byte *buf); |
| 274 | template<typename T, typename = RequireLongest<T>> |
| 275 | enum register_status raw_read (int regnum, T *val); |
| 276 | |
| 277 | /* Partial transfer of raw registers. Return the status of the register. */ |
| 278 | enum register_status raw_read_part (int regnum, int offset, int len, |
| 279 | gdb_byte *buf); |
| 280 | |
| 281 | /* Make certain that the register REGNUM is up-to-date. */ |
| 282 | virtual void raw_update (int regnum) = 0; |
| 283 | |
| 284 | /* Transfer a raw register [0..NUM_REGS+NUM_PSEUDO_REGS) from core-gdb to |
| 285 | this regcache, return its value in *BUF and return its availability status. */ |
| 286 | enum register_status cooked_read (int regnum, gdb_byte *buf); |
| 287 | template<typename T, typename = RequireLongest<T>> |
| 288 | enum register_status cooked_read (int regnum, T *val); |
| 289 | |
| 290 | /* Partial transfer of a cooked register. */ |
| 291 | enum register_status cooked_read_part (int regnum, int offset, int len, |
| 292 | gdb_byte *buf); |
| 293 | |
| 294 | /* Read register REGNUM from the regcache and return a new value. This |
| 295 | will call mark_value_bytes_unavailable as appropriate. */ |
| 296 | struct value *cooked_read_value (int regnum); |
| 297 | |
| 298 | protected: |
| 299 | |
| 300 | /* Perform a partial register transfer using a read, modify, write |
| 301 | operation. Will fail if register is currently invalid. */ |
| 302 | enum register_status read_part (int regnum, int offset, int len, |
| 303 | gdb_byte *out, bool is_raw); |
| 304 | }; |
| 305 | |
| 306 | /* Buffer of registers, can be read and written. */ |
| 307 | |
| 308 | class detached_regcache : public readable_regcache |
| 309 | { |
| 310 | public: |
| 311 | detached_regcache (gdbarch *gdbarch, bool has_pseudo) |
| 312 | : readable_regcache (gdbarch, has_pseudo) |
| 313 | {} |
| 314 | |
| 315 | void raw_update (int regnum) override |
| 316 | {} |
| 317 | |
| 318 | DISABLE_COPY_AND_ASSIGN (detached_regcache); |
| 319 | }; |
| 320 | |
| 321 | class readonly_detached_regcache; |
| 322 | |
| 323 | /* The register cache for storing raw register values. */ |
| 324 | |
| 325 | class regcache : public detached_regcache |
| 326 | { |
| 327 | public: |
| 328 | DISABLE_COPY_AND_ASSIGN (regcache); |
| 329 | |
| 330 | /* Return REGCACHE's address space. */ |
| 331 | const address_space *aspace () const |
| 332 | { |
| 333 | return m_aspace; |
| 334 | } |
| 335 | |
| 336 | /* Restore 'this' regcache. The set of registers restored into |
| 337 | the regcache determined by the restore_reggroup. |
| 338 | Writes to regcache will go through to the target. SRC is a |
| 339 | read-only register cache. */ |
| 340 | void restore (readonly_detached_regcache *src); |
| 341 | |
| 342 | /* Update the value of raw register REGNUM (in the range [0..NUM_REGS)) and |
| 343 | transfer its value to core-gdb. */ |
| 344 | |
| 345 | void raw_write (int regnum, const gdb_byte *buf); |
| 346 | |
| 347 | template<typename T, typename = RequireLongest<T>> |
| 348 | void raw_write (int regnum, T val); |
| 349 | |
| 350 | /* Transfer of pseudo-registers. */ |
| 351 | void cooked_write (int regnum, const gdb_byte *buf); |
| 352 | |
| 353 | template<typename T, typename = RequireLongest<T>> |
| 354 | void cooked_write (int regnum, T val); |
| 355 | |
| 356 | void raw_update (int regnum) override; |
| 357 | |
| 358 | /* Partial transfer of raw registers. Perform read, modify, write style |
| 359 | operations. */ |
| 360 | void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf); |
| 361 | |
| 362 | /* Partial transfer of a cooked register. Perform read, modify, write style |
| 363 | operations. */ |
| 364 | void cooked_write_part (int regnum, int offset, int len, |
| 365 | const gdb_byte *buf); |
| 366 | |
| 367 | void supply_regset (const struct regset *regset, |
| 368 | int regnum, const void *buf, size_t size); |
| 369 | |
| 370 | |
| 371 | void collect_regset (const struct regset *regset, int regnum, |
| 372 | void *buf, size_t size) const; |
| 373 | |
| 374 | /* Return REGCACHE's ptid. */ |
| 375 | |
| 376 | ptid_t ptid () const |
| 377 | { |
| 378 | gdb_assert (m_ptid != minus_one_ptid); |
| 379 | |
| 380 | return m_ptid; |
| 381 | } |
| 382 | |
| 383 | void set_ptid (const ptid_t ptid) |
| 384 | { |
| 385 | this->m_ptid = ptid; |
| 386 | } |
| 387 | |
| 388 | /* Dump the contents of a register from the register cache to the target |
| 389 | debug. */ |
| 390 | void debug_print_register (const char *func, int regno); |
| 391 | |
| 392 | static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid); |
| 393 | protected: |
| 394 | regcache (gdbarch *gdbarch, const address_space *aspace_); |
| 395 | |
| 396 | static std::forward_list<regcache *> current_regcache; |
| 397 | |
| 398 | private: |
| 399 | |
| 400 | /* Helper function for transfer_regset. Copies across a single register. */ |
| 401 | void transfer_regset_register (struct regcache *out_regcache, int regnum, |
| 402 | const gdb_byte *in_buf, gdb_byte *out_buf, |
| 403 | int slot_size, int offs) const; |
| 404 | |
| 405 | /* Transfer a single or all registers belonging to a certain register |
| 406 | set to or from a buffer. This is the main worker function for |
| 407 | regcache_supply_regset and regcache_collect_regset. */ |
| 408 | void transfer_regset (const struct regset *regset, |
| 409 | struct regcache *out_regcache, |
| 410 | int regnum, const gdb_byte *in_buf, |
| 411 | gdb_byte *out_buf, size_t size) const; |
| 412 | |
| 413 | /* Perform a partial register transfer using a read, modify, write |
| 414 | operation. */ |
| 415 | enum register_status write_part (int regnum, int offset, int len, |
| 416 | const gdb_byte *in, bool is_raw); |
| 417 | |
| 418 | /* The address space of this register cache (for registers where it |
| 419 | makes sense, like PC or SP). */ |
| 420 | const address_space * const m_aspace; |
| 421 | |
| 422 | /* If this is a read-write cache, which thread's registers is |
| 423 | it connected to? */ |
| 424 | ptid_t m_ptid; |
| 425 | |
| 426 | friend struct regcache * |
| 427 | get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch, |
| 428 | struct address_space *aspace); |
| 429 | |
| 430 | friend void |
| 431 | registers_changed_ptid (ptid_t ptid); |
| 432 | }; |
| 433 | |
| 434 | class readonly_detached_regcache : public readable_regcache |
| 435 | { |
| 436 | public: |
| 437 | readonly_detached_regcache (regcache &src); |
| 438 | |
| 439 | /* Create a readonly regcache by getting contents from COOKED_READ. */ |
| 440 | |
| 441 | readonly_detached_regcache (gdbarch *gdbarch, register_read_ftype cooked_read) |
| 442 | : readable_regcache (gdbarch, true) |
| 443 | { |
| 444 | save (cooked_read); |
| 445 | } |
| 446 | |
| 447 | DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache); |
| 448 | |
| 449 | void raw_update (int regnum) override |
| 450 | {} |
| 451 | }; |
| 452 | |
| 453 | extern void registers_changed (void); |
| 454 | extern void registers_changed_ptid (ptid_t); |
| 455 | |
| 456 | /* Indicate that registers of THREAD may have changed, so invalidate |
| 457 | the cache. */ |
| 458 | extern void registers_changed_thread (thread_info *thread); |
| 459 | |
| 460 | /* An abstract base class for register dump. */ |
| 461 | |
| 462 | class register_dump |
| 463 | { |
| 464 | public: |
| 465 | void dump (ui_file *file); |
| 466 | virtual ~register_dump () = default; |
| 467 | |
| 468 | protected: |
| 469 | register_dump (gdbarch *arch) |
| 470 | : m_gdbarch (arch) |
| 471 | {} |
| 472 | |
| 473 | /* Dump the register REGNUM contents. If REGNUM is -1, print the |
| 474 | header. */ |
| 475 | virtual void dump_reg (ui_file *file, int regnum) = 0; |
| 476 | |
| 477 | gdbarch *m_gdbarch; |
| 478 | }; |
| 479 | |
| 480 | #endif /* REGCACHE_H */ |