| 1 | /* Cache and manage frames for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, |
| 4 | 2001, 2002, 2003 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "frame.h" |
| 25 | #include "target.h" |
| 26 | #include "value.h" |
| 27 | #include "inferior.h" /* for inferior_ptid */ |
| 28 | #include "regcache.h" |
| 29 | #include "gdb_assert.h" |
| 30 | #include "gdb_string.h" |
| 31 | #include "user-regs.h" |
| 32 | #include "gdb_obstack.h" |
| 33 | #include "dummy-frame.h" |
| 34 | #include "sentinel-frame.h" |
| 35 | #include "gdbcore.h" |
| 36 | #include "annotate.h" |
| 37 | #include "language.h" |
| 38 | #include "frame-unwind.h" |
| 39 | #include "frame-base.h" |
| 40 | #include "command.h" |
| 41 | #include "gdbcmd.h" |
| 42 | |
| 43 | /* We keep a cache of stack frames, each of which is a "struct |
| 44 | frame_info". The innermost one gets allocated (in |
| 45 | wait_for_inferior) each time the inferior stops; current_frame |
| 46 | points to it. Additional frames get allocated (in get_prev_frame) |
| 47 | as needed, and are chained through the next and prev fields. Any |
| 48 | time that the frame cache becomes invalid (most notably when we |
| 49 | execute something, but also if we change how we interpret the |
| 50 | frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything |
| 51 | which reads new symbols)), we should call reinit_frame_cache. */ |
| 52 | |
| 53 | struct frame_info |
| 54 | { |
| 55 | /* Level of this frame. The inner-most (youngest) frame is at level |
| 56 | 0. As you move towards the outer-most (oldest) frame, the level |
| 57 | increases. This is a cached value. It could just as easily be |
| 58 | computed by counting back from the selected frame to the inner |
| 59 | most frame. */ |
| 60 | /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be |
| 61 | reserved to indicate a bogus frame - one that has been created |
| 62 | just to keep GDB happy (GDB always needs a frame). For the |
| 63 | moment leave this as speculation. */ |
| 64 | int level; |
| 65 | |
| 66 | /* The frame's type. */ |
| 67 | /* FIXME: cagney/2003-04-02: Should instead be returning |
| 68 | ->unwind->type. Unfortunatly, legacy code is still explicitly |
| 69 | setting the type using the method deprecated_set_frame_type. |
| 70 | Eliminate that method and this field can be eliminated. */ |
| 71 | enum frame_type type; |
| 72 | |
| 73 | /* For each register, address of where it was saved on entry to the |
| 74 | frame, or zero if it was not saved on entry to this frame. This |
| 75 | includes special registers such as pc and fp saved in special |
| 76 | ways in the stack frame. The SP_REGNUM is even more special, the |
| 77 | address here is the sp for the previous frame, not the address |
| 78 | where the sp was saved. */ |
| 79 | /* Allocated by frame_saved_regs_zalloc () which is called / |
| 80 | initialized by DEPRECATED_FRAME_INIT_SAVED_REGS(). */ |
| 81 | CORE_ADDR *saved_regs; /*NUM_REGS + NUM_PSEUDO_REGS*/ |
| 82 | |
| 83 | /* Anything extra for this structure that may have been defined in |
| 84 | the machine dependent files. */ |
| 85 | /* Allocated by frame_extra_info_zalloc () which is called / |
| 86 | initialized by DEPRECATED_INIT_EXTRA_FRAME_INFO */ |
| 87 | struct frame_extra_info *extra_info; |
| 88 | |
| 89 | /* If dwarf2 unwind frame informations is used, this structure holds |
| 90 | all related unwind data. */ |
| 91 | struct context *context; |
| 92 | |
| 93 | /* The frame's low-level unwinder and corresponding cache. The |
| 94 | low-level unwinder is responsible for unwinding register values |
| 95 | for the previous frame. The low-level unwind methods are |
| 96 | selected based on the presence, or otherwize, of register unwind |
| 97 | information such as CFI. */ |
| 98 | void *prologue_cache; |
| 99 | const struct frame_unwind *unwind; |
| 100 | |
| 101 | /* Cached copy of the previous frame's resume address. */ |
| 102 | struct { |
| 103 | int p; |
| 104 | CORE_ADDR value; |
| 105 | } prev_pc; |
| 106 | |
| 107 | /* Cached copy of the previous frame's function address. */ |
| 108 | struct |
| 109 | { |
| 110 | CORE_ADDR addr; |
| 111 | int p; |
| 112 | } prev_func; |
| 113 | |
| 114 | /* This frame's ID. */ |
| 115 | struct |
| 116 | { |
| 117 | int p; |
| 118 | struct frame_id value; |
| 119 | } this_id; |
| 120 | |
| 121 | /* The frame's high-level base methods, and corresponding cache. |
| 122 | The high level base methods are selected based on the frame's |
| 123 | debug info. */ |
| 124 | const struct frame_base *base; |
| 125 | void *base_cache; |
| 126 | |
| 127 | /* Pointers to the next (down, inner, younger) and previous (up, |
| 128 | outer, older) frame_info's in the frame cache. */ |
| 129 | struct frame_info *next; /* down, inner, younger */ |
| 130 | int prev_p; |
| 131 | struct frame_info *prev; /* up, outer, older */ |
| 132 | }; |
| 133 | |
| 134 | /* Flag to control debugging. */ |
| 135 | |
| 136 | static int frame_debug; |
| 137 | |
| 138 | /* Flag to indicate whether backtraces should stop at main et.al. */ |
| 139 | |
| 140 | static int backtrace_past_main; |
| 141 | static unsigned int backtrace_limit = UINT_MAX; |
| 142 | |
| 143 | |
| 144 | void |
| 145 | fprint_frame_id (struct ui_file *file, struct frame_id id) |
| 146 | { |
| 147 | fprintf_unfiltered (file, "{stack=0x%s,code=0x%s}", |
| 148 | paddr_nz (id.stack_addr), |
| 149 | paddr_nz (id.code_addr)); |
| 150 | } |
| 151 | |
| 152 | static void |
| 153 | fprint_frame_type (struct ui_file *file, enum frame_type type) |
| 154 | { |
| 155 | switch (type) |
| 156 | { |
| 157 | case UNKNOWN_FRAME: |
| 158 | fprintf_unfiltered (file, "UNKNOWN_FRAME"); |
| 159 | return; |
| 160 | case NORMAL_FRAME: |
| 161 | fprintf_unfiltered (file, "NORMAL_FRAME"); |
| 162 | return; |
| 163 | case DUMMY_FRAME: |
| 164 | fprintf_unfiltered (file, "DUMMY_FRAME"); |
| 165 | return; |
| 166 | case SIGTRAMP_FRAME: |
| 167 | fprintf_unfiltered (file, "SIGTRAMP_FRAME"); |
| 168 | return; |
| 169 | default: |
| 170 | fprintf_unfiltered (file, "<unknown type>"); |
| 171 | return; |
| 172 | }; |
| 173 | } |
| 174 | |
| 175 | static void |
| 176 | fprint_frame (struct ui_file *file, struct frame_info *fi) |
| 177 | { |
| 178 | if (fi == NULL) |
| 179 | { |
| 180 | fprintf_unfiltered (file, "<NULL frame>"); |
| 181 | return; |
| 182 | } |
| 183 | fprintf_unfiltered (file, "{"); |
| 184 | fprintf_unfiltered (file, "level=%d", fi->level); |
| 185 | fprintf_unfiltered (file, ","); |
| 186 | fprintf_unfiltered (file, "type="); |
| 187 | fprint_frame_type (file, fi->type); |
| 188 | fprintf_unfiltered (file, ","); |
| 189 | fprintf_unfiltered (file, "unwind="); |
| 190 | if (fi->unwind != NULL) |
| 191 | gdb_print_host_address (fi->unwind, file); |
| 192 | else |
| 193 | fprintf_unfiltered (file, "<unknown>"); |
| 194 | fprintf_unfiltered (file, ","); |
| 195 | fprintf_unfiltered (file, "pc="); |
| 196 | if (fi->next != NULL && fi->next->prev_pc.p) |
| 197 | fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_pc.value)); |
| 198 | else |
| 199 | fprintf_unfiltered (file, "<unknown>"); |
| 200 | fprintf_unfiltered (file, ","); |
| 201 | fprintf_unfiltered (file, "id="); |
| 202 | if (fi->this_id.p) |
| 203 | fprint_frame_id (file, fi->this_id.value); |
| 204 | else |
| 205 | fprintf_unfiltered (file, "<unknown>"); |
| 206 | fprintf_unfiltered (file, ","); |
| 207 | fprintf_unfiltered (file, "func="); |
| 208 | if (fi->next != NULL && fi->next->prev_func.p) |
| 209 | fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_func.addr)); |
| 210 | else |
| 211 | fprintf_unfiltered (file, "<unknown>"); |
| 212 | fprintf_unfiltered (file, "}"); |
| 213 | } |
| 214 | |
| 215 | /* Return a frame uniq ID that can be used to, later, re-find the |
| 216 | frame. */ |
| 217 | |
| 218 | struct frame_id |
| 219 | get_frame_id (struct frame_info *fi) |
| 220 | { |
| 221 | if (fi == NULL) |
| 222 | { |
| 223 | return null_frame_id; |
| 224 | } |
| 225 | if (!fi->this_id.p) |
| 226 | { |
| 227 | gdb_assert (!legacy_frame_p (current_gdbarch)); |
| 228 | if (frame_debug) |
| 229 | fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ", |
| 230 | fi->level); |
| 231 | /* Find the unwinder. */ |
| 232 | if (fi->unwind == NULL) |
| 233 | { |
| 234 | fi->unwind = frame_unwind_find_by_frame (fi->next); |
| 235 | /* FIXME: cagney/2003-04-02: Rather than storing the frame's |
| 236 | type in the frame, the unwinder's type should be returned |
| 237 | directly. Unfortunatly, legacy code, called by |
| 238 | legacy_get_prev_frame, explicitly set the frames type |
| 239 | using the method deprecated_set_frame_type(). */ |
| 240 | gdb_assert (fi->unwind->type != UNKNOWN_FRAME); |
| 241 | fi->type = fi->unwind->type; |
| 242 | } |
| 243 | /* Find THIS frame's ID. */ |
| 244 | fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value); |
| 245 | fi->this_id.p = 1; |
| 246 | if (frame_debug) |
| 247 | { |
| 248 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 249 | fprint_frame_id (gdb_stdlog, fi->this_id.value); |
| 250 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 251 | } |
| 252 | } |
| 253 | return fi->this_id.value; |
| 254 | } |
| 255 | |
| 256 | const struct frame_id null_frame_id; /* All zeros. */ |
| 257 | |
| 258 | struct frame_id |
| 259 | frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr) |
| 260 | { |
| 261 | struct frame_id id; |
| 262 | id.stack_addr = stack_addr; |
| 263 | id.code_addr = code_addr; |
| 264 | return id; |
| 265 | } |
| 266 | |
| 267 | int |
| 268 | frame_id_p (struct frame_id l) |
| 269 | { |
| 270 | int p; |
| 271 | /* The .code can be NULL but the .stack cannot. */ |
| 272 | p = (l.stack_addr != 0); |
| 273 | if (frame_debug) |
| 274 | { |
| 275 | fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l="); |
| 276 | fprint_frame_id (gdb_stdlog, l); |
| 277 | fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", p); |
| 278 | } |
| 279 | return p; |
| 280 | } |
| 281 | |
| 282 | int |
| 283 | frame_id_eq (struct frame_id l, struct frame_id r) |
| 284 | { |
| 285 | int eq; |
| 286 | if (l.stack_addr == 0 || r.stack_addr == 0) |
| 287 | /* Like a NaN, if either ID is invalid, the result is false. */ |
| 288 | eq = 0; |
| 289 | else if (l.stack_addr != r.stack_addr) |
| 290 | /* If .stack addresses are different, the frames are different. */ |
| 291 | eq = 0; |
| 292 | else if (l.code_addr == 0 || r.code_addr == 0) |
| 293 | /* A zero code addr is a wild card, always succeed. */ |
| 294 | eq = 1; |
| 295 | else if (l.code_addr == r.code_addr) |
| 296 | /* The .stack and .code are identical, the ID's are identical. */ |
| 297 | eq = 1; |
| 298 | else |
| 299 | /* No luck. */ |
| 300 | eq = 0; |
| 301 | if (frame_debug) |
| 302 | { |
| 303 | fprintf_unfiltered (gdb_stdlog, "{ frame_id_eq (l="); |
| 304 | fprint_frame_id (gdb_stdlog, l); |
| 305 | fprintf_unfiltered (gdb_stdlog, ",r="); |
| 306 | fprint_frame_id (gdb_stdlog, r); |
| 307 | fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", eq); |
| 308 | } |
| 309 | return eq; |
| 310 | } |
| 311 | |
| 312 | int |
| 313 | frame_id_inner (struct frame_id l, struct frame_id r) |
| 314 | { |
| 315 | int inner; |
| 316 | if (l.stack_addr == 0 || r.stack_addr == 0) |
| 317 | /* Like NaN, any operation involving an invalid ID always fails. */ |
| 318 | inner = 0; |
| 319 | else |
| 320 | /* Only return non-zero when strictly inner than. Note that, per |
| 321 | comment in "frame.h", there is some fuzz here. Frameless |
| 322 | functions are not strictly inner than (same .stack but |
| 323 | different .code). */ |
| 324 | inner = INNER_THAN (l.stack_addr, r.stack_addr); |
| 325 | if (frame_debug) |
| 326 | { |
| 327 | fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l="); |
| 328 | fprint_frame_id (gdb_stdlog, l); |
| 329 | fprintf_unfiltered (gdb_stdlog, ",r="); |
| 330 | fprint_frame_id (gdb_stdlog, r); |
| 331 | fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner); |
| 332 | } |
| 333 | return inner; |
| 334 | } |
| 335 | |
| 336 | struct frame_info * |
| 337 | frame_find_by_id (struct frame_id id) |
| 338 | { |
| 339 | struct frame_info *frame; |
| 340 | |
| 341 | /* ZERO denotes the null frame, let the caller decide what to do |
| 342 | about it. Should it instead return get_current_frame()? */ |
| 343 | if (!frame_id_p (id)) |
| 344 | return NULL; |
| 345 | |
| 346 | for (frame = get_current_frame (); |
| 347 | frame != NULL; |
| 348 | frame = get_prev_frame (frame)) |
| 349 | { |
| 350 | struct frame_id this = get_frame_id (frame); |
| 351 | if (frame_id_eq (id, this)) |
| 352 | /* An exact match. */ |
| 353 | return frame; |
| 354 | if (frame_id_inner (id, this)) |
| 355 | /* Gone to far. */ |
| 356 | return NULL; |
| 357 | /* Either, we're not yet gone far enough out along the frame |
| 358 | chain (inner(this,id), or we're comparing frameless functions |
| 359 | (same .base, different .func, no test available). Struggle |
| 360 | on until we've definitly gone to far. */ |
| 361 | } |
| 362 | return NULL; |
| 363 | } |
| 364 | |
| 365 | CORE_ADDR |
| 366 | frame_pc_unwind (struct frame_info *this_frame) |
| 367 | { |
| 368 | if (!this_frame->prev_pc.p) |
| 369 | { |
| 370 | CORE_ADDR pc; |
| 371 | if (gdbarch_unwind_pc_p (current_gdbarch)) |
| 372 | { |
| 373 | /* The right way. The `pure' way. The one true way. This |
| 374 | method depends solely on the register-unwind code to |
| 375 | determine the value of registers in THIS frame, and hence |
| 376 | the value of this frame's PC (resume address). A typical |
| 377 | implementation is no more than: |
| 378 | |
| 379 | frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); |
| 380 | return extract_unsigned_integer (buf, size of ISA_PC_REGNUM); |
| 381 | |
| 382 | Note: this method is very heavily dependent on a correct |
| 383 | register-unwind implementation, it pays to fix that |
| 384 | method first; this method is frame type agnostic, since |
| 385 | it only deals with register values, it works with any |
| 386 | frame. This is all in stark contrast to the old |
| 387 | FRAME_SAVED_PC which would try to directly handle all the |
| 388 | different ways that a PC could be unwound. */ |
| 389 | pc = gdbarch_unwind_pc (current_gdbarch, this_frame); |
| 390 | } |
| 391 | else if (this_frame->level < 0) |
| 392 | { |
| 393 | /* FIXME: cagney/2003-03-06: Old code and and a sentinel |
| 394 | frame. Do like was always done. Fetch the PC's value |
| 395 | direct from the global registers array (via read_pc). |
| 396 | This assumes that this frame belongs to the current |
| 397 | global register cache. The assumption is dangerous. */ |
| 398 | pc = read_pc (); |
| 399 | } |
| 400 | else if (DEPRECATED_FRAME_SAVED_PC_P ()) |
| 401 | { |
| 402 | /* FIXME: cagney/2003-03-06: Old code, but not a sentinel |
| 403 | frame. Do like was always done. Note that this method, |
| 404 | unlike unwind_pc(), tries to handle all the different |
| 405 | frame cases directly. It fails. */ |
| 406 | pc = DEPRECATED_FRAME_SAVED_PC (this_frame); |
| 407 | } |
| 408 | else |
| 409 | internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method"); |
| 410 | this_frame->prev_pc.value = pc; |
| 411 | this_frame->prev_pc.p = 1; |
| 412 | if (frame_debug) |
| 413 | fprintf_unfiltered (gdb_stdlog, |
| 414 | "{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n", |
| 415 | this_frame->level, |
| 416 | paddr_nz (this_frame->prev_pc.value)); |
| 417 | } |
| 418 | return this_frame->prev_pc.value; |
| 419 | } |
| 420 | |
| 421 | CORE_ADDR |
| 422 | frame_func_unwind (struct frame_info *fi) |
| 423 | { |
| 424 | if (!fi->prev_func.p) |
| 425 | { |
| 426 | /* Make certain that this, and not the adjacent, function is |
| 427 | found. */ |
| 428 | CORE_ADDR addr_in_block = frame_unwind_address_in_block (fi); |
| 429 | fi->prev_func.p = 1; |
| 430 | fi->prev_func.addr = get_pc_function_start (addr_in_block); |
| 431 | if (frame_debug) |
| 432 | fprintf_unfiltered (gdb_stdlog, |
| 433 | "{ frame_func_unwind (fi=%d) -> 0x%s }\n", |
| 434 | fi->level, paddr_nz (fi->prev_func.addr)); |
| 435 | } |
| 436 | return fi->prev_func.addr; |
| 437 | } |
| 438 | |
| 439 | CORE_ADDR |
| 440 | get_frame_func (struct frame_info *fi) |
| 441 | { |
| 442 | return frame_func_unwind (fi->next); |
| 443 | } |
| 444 | |
| 445 | static int |
| 446 | do_frame_unwind_register (void *src, int regnum, void *buf) |
| 447 | { |
| 448 | frame_unwind_register (src, regnum, buf); |
| 449 | return 1; |
| 450 | } |
| 451 | |
| 452 | void |
| 453 | frame_pop (struct frame_info *this_frame) |
| 454 | { |
| 455 | struct regcache *scratch_regcache; |
| 456 | struct cleanup *cleanups; |
| 457 | |
| 458 | if (DEPRECATED_POP_FRAME_P ()) |
| 459 | { |
| 460 | /* A legacy architecture that has implemented a custom pop |
| 461 | function. All new architectures should instead be using the |
| 462 | generic code below. */ |
| 463 | DEPRECATED_POP_FRAME; |
| 464 | } |
| 465 | else |
| 466 | { |
| 467 | /* Make a copy of all the register values unwound from this |
| 468 | frame. Save them in a scratch buffer so that there isn't a |
| 469 | race betweening trying to extract the old values from the |
| 470 | current_regcache while, at the same time writing new values |
| 471 | into that same cache. */ |
| 472 | struct regcache *scratch = regcache_xmalloc (current_gdbarch); |
| 473 | struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch); |
| 474 | regcache_save (scratch, do_frame_unwind_register, this_frame); |
| 475 | /* FIXME: cagney/2003-03-16: It should be possible to tell the |
| 476 | target's register cache that it is about to be hit with a |
| 477 | burst register transfer and that the sequence of register |
| 478 | writes should be batched. The pair target_prepare_to_store() |
| 479 | and target_store_registers() kind of suggest this |
| 480 | functionality. Unfortunatly, they don't implement it. Their |
| 481 | lack of a formal definition can lead to targets writing back |
| 482 | bogus values (arguably a bug in the target code mind). */ |
| 483 | /* Now copy those saved registers into the current regcache. |
| 484 | Here, regcache_cpy() calls regcache_restore(). */ |
| 485 | regcache_cpy (current_regcache, scratch); |
| 486 | do_cleanups (cleanups); |
| 487 | } |
| 488 | /* We've made right mess of GDB's local state, just discard |
| 489 | everything. */ |
| 490 | flush_cached_frames (); |
| 491 | } |
| 492 | |
| 493 | void |
| 494 | frame_register_unwind (struct frame_info *frame, int regnum, |
| 495 | int *optimizedp, enum lval_type *lvalp, |
| 496 | CORE_ADDR *addrp, int *realnump, void *bufferp) |
| 497 | { |
| 498 | struct frame_unwind_cache *cache; |
| 499 | |
| 500 | if (frame_debug) |
| 501 | { |
| 502 | fprintf_unfiltered (gdb_stdlog, |
| 503 | "{ frame_register_unwind (frame=%d,regnum=\"%s\",...) ", |
| 504 | frame->level, frame_map_regnum_to_name (frame, regnum)); |
| 505 | } |
| 506 | |
| 507 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates |
| 508 | that the value proper does not need to be fetched. */ |
| 509 | gdb_assert (optimizedp != NULL); |
| 510 | gdb_assert (lvalp != NULL); |
| 511 | gdb_assert (addrp != NULL); |
| 512 | gdb_assert (realnump != NULL); |
| 513 | /* gdb_assert (bufferp != NULL); */ |
| 514 | |
| 515 | /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame |
| 516 | is broken. There is always a frame. If there, for some reason, |
| 517 | isn't, there is some pretty busted code as it should have |
| 518 | detected the problem before calling here. */ |
| 519 | gdb_assert (frame != NULL); |
| 520 | |
| 521 | /* Find the unwinder. */ |
| 522 | if (frame->unwind == NULL) |
| 523 | { |
| 524 | frame->unwind = frame_unwind_find_by_frame (frame->next); |
| 525 | /* FIXME: cagney/2003-04-02: Rather than storing the frame's |
| 526 | type in the frame, the unwinder's type should be returned |
| 527 | directly. Unfortunatly, legacy code, called by |
| 528 | legacy_get_prev_frame, explicitly set the frames type using |
| 529 | the method deprecated_set_frame_type(). */ |
| 530 | gdb_assert (frame->unwind->type != UNKNOWN_FRAME); |
| 531 | frame->type = frame->unwind->type; |
| 532 | } |
| 533 | |
| 534 | /* Ask this frame to unwind its register. See comment in |
| 535 | "frame-unwind.h" for why NEXT frame and this unwind cace are |
| 536 | passed in. */ |
| 537 | frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum, |
| 538 | optimizedp, lvalp, addrp, realnump, bufferp); |
| 539 | |
| 540 | if (frame_debug) |
| 541 | { |
| 542 | fprintf_unfiltered (gdb_stdlog, "->"); |
| 543 | fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp)); |
| 544 | fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp)); |
| 545 | fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp))); |
| 546 | fprintf_unfiltered (gdb_stdlog, " *bufferp="); |
| 547 | if (bufferp == NULL) |
| 548 | fprintf_unfiltered (gdb_stdlog, "<NULL>"); |
| 549 | else |
| 550 | { |
| 551 | int i; |
| 552 | const unsigned char *buf = bufferp; |
| 553 | fprintf_unfiltered (gdb_stdlog, "["); |
| 554 | for (i = 0; i < register_size (current_gdbarch, regnum); i++) |
| 555 | fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]); |
| 556 | fprintf_unfiltered (gdb_stdlog, "]"); |
| 557 | } |
| 558 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 559 | } |
| 560 | } |
| 561 | |
| 562 | void |
| 563 | frame_register (struct frame_info *frame, int regnum, |
| 564 | int *optimizedp, enum lval_type *lvalp, |
| 565 | CORE_ADDR *addrp, int *realnump, void *bufferp) |
| 566 | { |
| 567 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates |
| 568 | that the value proper does not need to be fetched. */ |
| 569 | gdb_assert (optimizedp != NULL); |
| 570 | gdb_assert (lvalp != NULL); |
| 571 | gdb_assert (addrp != NULL); |
| 572 | gdb_assert (realnump != NULL); |
| 573 | /* gdb_assert (bufferp != NULL); */ |
| 574 | |
| 575 | /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset |
| 576 | of the register in the register cache. It should instead return |
| 577 | the REGNUM corresponding to that register. Translate the . */ |
| 578 | if (DEPRECATED_GET_SAVED_REGISTER_P ()) |
| 579 | { |
| 580 | DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, |
| 581 | regnum, lvalp); |
| 582 | /* Compute the REALNUM if the caller wants it. */ |
| 583 | if (*lvalp == lval_register) |
| 584 | { |
| 585 | int regnum; |
| 586 | for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++) |
| 587 | { |
| 588 | if (*addrp == register_offset_hack (current_gdbarch, regnum)) |
| 589 | { |
| 590 | *realnump = regnum; |
| 591 | return; |
| 592 | } |
| 593 | } |
| 594 | internal_error (__FILE__, __LINE__, |
| 595 | "Failed to compute the register number corresponding" |
| 596 | " to 0x%s", paddr_d (*addrp)); |
| 597 | } |
| 598 | *realnump = -1; |
| 599 | return; |
| 600 | } |
| 601 | |
| 602 | /* Obtain the register value by unwinding the register from the next |
| 603 | (more inner frame). */ |
| 604 | gdb_assert (frame != NULL && frame->next != NULL); |
| 605 | frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, |
| 606 | realnump, bufferp); |
| 607 | } |
| 608 | |
| 609 | void |
| 610 | frame_unwind_register (struct frame_info *frame, int regnum, void *buf) |
| 611 | { |
| 612 | int optimized; |
| 613 | CORE_ADDR addr; |
| 614 | int realnum; |
| 615 | enum lval_type lval; |
| 616 | frame_register_unwind (frame, regnum, &optimized, &lval, &addr, |
| 617 | &realnum, buf); |
| 618 | } |
| 619 | |
| 620 | void |
| 621 | get_frame_register (struct frame_info *frame, |
| 622 | int regnum, void *buf) |
| 623 | { |
| 624 | frame_unwind_register (frame->next, regnum, buf); |
| 625 | } |
| 626 | |
| 627 | LONGEST |
| 628 | frame_unwind_register_signed (struct frame_info *frame, int regnum) |
| 629 | { |
| 630 | char buf[MAX_REGISTER_SIZE]; |
| 631 | frame_unwind_register (frame, regnum, buf); |
| 632 | return extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| 633 | } |
| 634 | |
| 635 | LONGEST |
| 636 | get_frame_register_signed (struct frame_info *frame, int regnum) |
| 637 | { |
| 638 | return frame_unwind_register_signed (frame->next, regnum); |
| 639 | } |
| 640 | |
| 641 | ULONGEST |
| 642 | frame_unwind_register_unsigned (struct frame_info *frame, int regnum) |
| 643 | { |
| 644 | char buf[MAX_REGISTER_SIZE]; |
| 645 | frame_unwind_register (frame, regnum, buf); |
| 646 | return extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| 647 | } |
| 648 | |
| 649 | ULONGEST |
| 650 | get_frame_register_unsigned (struct frame_info *frame, int regnum) |
| 651 | { |
| 652 | return frame_unwind_register_unsigned (frame->next, regnum); |
| 653 | } |
| 654 | |
| 655 | void |
| 656 | frame_unwind_signed_register (struct frame_info *frame, int regnum, |
| 657 | LONGEST *val) |
| 658 | { |
| 659 | char buf[MAX_REGISTER_SIZE]; |
| 660 | frame_unwind_register (frame, regnum, buf); |
| 661 | (*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| 662 | } |
| 663 | |
| 664 | void |
| 665 | frame_unwind_unsigned_register (struct frame_info *frame, int regnum, |
| 666 | ULONGEST *val) |
| 667 | { |
| 668 | char buf[MAX_REGISTER_SIZE]; |
| 669 | frame_unwind_register (frame, regnum, buf); |
| 670 | (*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| 671 | } |
| 672 | |
| 673 | void |
| 674 | frame_read_register (struct frame_info *frame, int regnum, void *buf) |
| 675 | { |
| 676 | gdb_assert (frame != NULL && frame->next != NULL); |
| 677 | frame_unwind_register (frame->next, regnum, buf); |
| 678 | } |
| 679 | |
| 680 | void |
| 681 | frame_read_unsigned_register (struct frame_info *frame, int regnum, |
| 682 | ULONGEST *val) |
| 683 | { |
| 684 | /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is |
| 685 | always a frame. Both this, and the equivalent |
| 686 | frame_read_signed_register() function, can only be called with a |
| 687 | valid frame. If, for some reason, this function is called |
| 688 | without a frame then the problem isn't here, but rather in the |
| 689 | caller. It should of first created a frame and then passed that |
| 690 | in. */ |
| 691 | /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the |
| 692 | ``current_frame'' should not be treated as a special case. While |
| 693 | ``get_next_frame (current_frame) == NULL'' currently holds, it |
| 694 | should, as far as possible, not be relied upon. In the future, |
| 695 | ``get_next_frame (current_frame)'' may instead simply return a |
| 696 | normal frame object that simply always gets register values from |
| 697 | the register cache. Consequently, frame code should try to avoid |
| 698 | tests like ``if get_next_frame() == NULL'' and instead just rely |
| 699 | on recursive frame calls (like the below code) when manipulating |
| 700 | a frame chain. */ |
| 701 | gdb_assert (frame != NULL && frame->next != NULL); |
| 702 | frame_unwind_unsigned_register (frame->next, regnum, val); |
| 703 | } |
| 704 | |
| 705 | void |
| 706 | frame_read_signed_register (struct frame_info *frame, int regnum, |
| 707 | LONGEST *val) |
| 708 | { |
| 709 | /* See note above in frame_read_unsigned_register(). */ |
| 710 | gdb_assert (frame != NULL && frame->next != NULL); |
| 711 | frame_unwind_signed_register (frame->next, regnum, val); |
| 712 | } |
| 713 | |
| 714 | void |
| 715 | put_frame_register (struct frame_info *frame, int regnum, const void *buf) |
| 716 | { |
| 717 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 718 | int realnum; |
| 719 | int optim; |
| 720 | enum lval_type lval; |
| 721 | CORE_ADDR addr; |
| 722 | frame_register (frame, regnum, &optim, &lval, &addr, &realnum, NULL); |
| 723 | if (optim) |
| 724 | error ("Attempt to assign to a value that was optimized out."); |
| 725 | switch (lval) |
| 726 | { |
| 727 | case lval_memory: |
| 728 | { |
| 729 | /* FIXME: write_memory doesn't yet take constant buffers. |
| 730 | Arrrg! */ |
| 731 | char tmp[MAX_REGISTER_SIZE]; |
| 732 | memcpy (tmp, buf, register_size (gdbarch, regnum)); |
| 733 | write_memory (addr, tmp, register_size (gdbarch, regnum)); |
| 734 | break; |
| 735 | } |
| 736 | case lval_register: |
| 737 | regcache_cooked_write (current_regcache, realnum, buf); |
| 738 | break; |
| 739 | default: |
| 740 | error ("Attempt to assign to an unmodifiable value."); |
| 741 | } |
| 742 | } |
| 743 | |
| 744 | /* frame_register_read () |
| 745 | |
| 746 | Find and return the value of REGNUM for the specified stack frame. |
| 747 | The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). |
| 748 | |
| 749 | Returns 0 if the register value could not be found. */ |
| 750 | |
| 751 | int |
| 752 | frame_register_read (struct frame_info *frame, int regnum, void *myaddr) |
| 753 | { |
| 754 | int optimized; |
| 755 | enum lval_type lval; |
| 756 | CORE_ADDR addr; |
| 757 | int realnum; |
| 758 | frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr); |
| 759 | |
| 760 | /* FIXME: cagney/2002-05-15: This test, is just bogus. |
| 761 | |
| 762 | It indicates that the target failed to supply a value for a |
| 763 | register because it was "not available" at this time. Problem |
| 764 | is, the target still has the register and so get saved_register() |
| 765 | may be returning a value saved on the stack. */ |
| 766 | |
| 767 | if (register_cached (regnum) < 0) |
| 768 | return 0; /* register value not available */ |
| 769 | |
| 770 | return !optimized; |
| 771 | } |
| 772 | |
| 773 | |
| 774 | /* Map between a frame register number and its name. A frame register |
| 775 | space is a superset of the cooked register space --- it also |
| 776 | includes builtin registers. */ |
| 777 | |
| 778 | int |
| 779 | frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len) |
| 780 | { |
| 781 | return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len); |
| 782 | } |
| 783 | |
| 784 | const char * |
| 785 | frame_map_regnum_to_name (struct frame_info *frame, int regnum) |
| 786 | { |
| 787 | return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum); |
| 788 | } |
| 789 | |
| 790 | /* Create a sentinel frame. */ |
| 791 | |
| 792 | static struct frame_info * |
| 793 | create_sentinel_frame (struct regcache *regcache) |
| 794 | { |
| 795 | struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| 796 | frame->type = NORMAL_FRAME; |
| 797 | frame->level = -1; |
| 798 | /* Explicitly initialize the sentinel frame's cache. Provide it |
| 799 | with the underlying regcache. In the future additional |
| 800 | information, such as the frame's thread will be added. */ |
| 801 | frame->prologue_cache = sentinel_frame_cache (regcache); |
| 802 | /* For the moment there is only one sentinel frame implementation. */ |
| 803 | frame->unwind = sentinel_frame_unwind; |
| 804 | /* Link this frame back to itself. The frame is self referential |
| 805 | (the unwound PC is the same as the pc), so make it so. */ |
| 806 | frame->next = frame; |
| 807 | /* Make the sentinel frame's ID valid, but invalid. That way all |
| 808 | comparisons with it should fail. */ |
| 809 | frame->this_id.p = 1; |
| 810 | frame->this_id.value = null_frame_id; |
| 811 | if (frame_debug) |
| 812 | { |
| 813 | fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> "); |
| 814 | fprint_frame (gdb_stdlog, frame); |
| 815 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 816 | } |
| 817 | return frame; |
| 818 | } |
| 819 | |
| 820 | /* Info about the innermost stack frame (contents of FP register) */ |
| 821 | |
| 822 | static struct frame_info *current_frame; |
| 823 | |
| 824 | /* Cache for frame addresses already read by gdb. Valid only while |
| 825 | inferior is stopped. Control variables for the frame cache should |
| 826 | be local to this module. */ |
| 827 | |
| 828 | static struct obstack frame_cache_obstack; |
| 829 | |
| 830 | void * |
| 831 | frame_obstack_zalloc (unsigned long size) |
| 832 | { |
| 833 | void *data = obstack_alloc (&frame_cache_obstack, size); |
| 834 | memset (data, 0, size); |
| 835 | return data; |
| 836 | } |
| 837 | |
| 838 | CORE_ADDR * |
| 839 | frame_saved_regs_zalloc (struct frame_info *fi) |
| 840 | { |
| 841 | fi->saved_regs = (CORE_ADDR *) |
| 842 | frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
| 843 | return fi->saved_regs; |
| 844 | } |
| 845 | |
| 846 | CORE_ADDR * |
| 847 | get_frame_saved_regs (struct frame_info *fi) |
| 848 | { |
| 849 | return fi->saved_regs; |
| 850 | } |
| 851 | |
| 852 | /* Return the innermost (currently executing) stack frame. This is |
| 853 | split into two functions. The function unwind_to_current_frame() |
| 854 | is wrapped in catch exceptions so that, even when the unwind of the |
| 855 | sentinel frame fails, the function still returns a stack frame. */ |
| 856 | |
| 857 | static int |
| 858 | unwind_to_current_frame (struct ui_out *ui_out, void *args) |
| 859 | { |
| 860 | struct frame_info *frame = get_prev_frame (args); |
| 861 | /* A sentinel frame can fail to unwind, eg, because it's PC value |
| 862 | lands in somewhere like start. */ |
| 863 | if (frame == NULL) |
| 864 | return 1; |
| 865 | current_frame = frame; |
| 866 | return 0; |
| 867 | } |
| 868 | |
| 869 | struct frame_info * |
| 870 | get_current_frame (void) |
| 871 | { |
| 872 | /* First check, and report, the lack of registers. Having GDB |
| 873 | report "No stack!" or "No memory" when the target doesn't even |
| 874 | have registers is very confusing. Besides, "printcmd.exp" |
| 875 | explicitly checks that ``print $pc'' with no registers prints "No |
| 876 | registers". */ |
| 877 | if (!target_has_registers) |
| 878 | error ("No registers."); |
| 879 | if (!target_has_stack) |
| 880 | error ("No stack."); |
| 881 | if (!target_has_memory) |
| 882 | error ("No memory."); |
| 883 | if (current_frame == NULL) |
| 884 | { |
| 885 | struct frame_info *sentinel_frame = |
| 886 | create_sentinel_frame (current_regcache); |
| 887 | if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame, |
| 888 | NULL, RETURN_MASK_ERROR) != 0) |
| 889 | { |
| 890 | /* Oops! Fake a current frame? Is this useful? It has a PC |
| 891 | of zero, for instance. */ |
| 892 | current_frame = sentinel_frame; |
| 893 | } |
| 894 | } |
| 895 | return current_frame; |
| 896 | } |
| 897 | |
| 898 | /* The "selected" stack frame is used by default for local and arg |
| 899 | access. May be zero, for no selected frame. */ |
| 900 | |
| 901 | struct frame_info *deprecated_selected_frame; |
| 902 | |
| 903 | /* Return the selected frame. Always non-null (unless there isn't an |
| 904 | inferior sufficient for creating a frame) in which case an error is |
| 905 | thrown. */ |
| 906 | |
| 907 | struct frame_info * |
| 908 | get_selected_frame (void) |
| 909 | { |
| 910 | if (deprecated_selected_frame == NULL) |
| 911 | /* Hey! Don't trust this. It should really be re-finding the |
| 912 | last selected frame of the currently selected thread. This, |
| 913 | though, is better than nothing. */ |
| 914 | select_frame (get_current_frame ()); |
| 915 | /* There is always a frame. */ |
| 916 | gdb_assert (deprecated_selected_frame != NULL); |
| 917 | return deprecated_selected_frame; |
| 918 | } |
| 919 | |
| 920 | /* This is a variant of get_selected_frame which can be called when |
| 921 | the inferior does not have a frame; in that case it will return |
| 922 | NULL instead of calling error (). */ |
| 923 | |
| 924 | struct frame_info * |
| 925 | deprecated_safe_get_selected_frame (void) |
| 926 | { |
| 927 | if (!target_has_registers || !target_has_stack || !target_has_memory) |
| 928 | return NULL; |
| 929 | return get_selected_frame (); |
| 930 | } |
| 931 | |
| 932 | /* Select frame FI (or NULL - to invalidate the current frame). */ |
| 933 | |
| 934 | void |
| 935 | select_frame (struct frame_info *fi) |
| 936 | { |
| 937 | register struct symtab *s; |
| 938 | |
| 939 | deprecated_selected_frame = fi; |
| 940 | /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the |
| 941 | frame is being invalidated. */ |
| 942 | if (selected_frame_level_changed_hook) |
| 943 | selected_frame_level_changed_hook (frame_relative_level (fi)); |
| 944 | |
| 945 | /* FIXME: kseitz/2002-08-28: It would be nice to call |
| 946 | selected_frame_level_changed_event right here, but due to limitations |
| 947 | in the current interfaces, we would end up flooding UIs with events |
| 948 | because select_frame is used extensively internally. |
| 949 | |
| 950 | Once we have frame-parameterized frame (and frame-related) commands, |
| 951 | the event notification can be moved here, since this function will only |
| 952 | be called when the users selected frame is being changed. */ |
| 953 | |
| 954 | /* Ensure that symbols for this frame are read in. Also, determine the |
| 955 | source language of this frame, and switch to it if desired. */ |
| 956 | if (fi) |
| 957 | { |
| 958 | s = find_pc_symtab (get_frame_pc (fi)); |
| 959 | if (s |
| 960 | && s->language != current_language->la_language |
| 961 | && s->language != language_unknown |
| 962 | && language_mode == language_mode_auto) |
| 963 | { |
| 964 | set_language (s->language); |
| 965 | } |
| 966 | } |
| 967 | } |
| 968 | |
| 969 | /* Return the register saved in the simplistic ``saved_regs'' cache. |
| 970 | If the value isn't here AND a value is needed, try the next inner |
| 971 | most frame. */ |
| 972 | |
| 973 | static void |
| 974 | legacy_saved_regs_prev_register (struct frame_info *next_frame, |
| 975 | void **this_prologue_cache, |
| 976 | int regnum, int *optimizedp, |
| 977 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 978 | int *realnump, void *bufferp) |
| 979 | { |
| 980 | /* HACK: New code is passed the next frame and this cache. |
| 981 | Unfortunatly, old code expects this frame. Since this is a |
| 982 | backward compatibility hack, cheat by walking one level along the |
| 983 | prologue chain to the frame the old code expects. |
| 984 | |
| 985 | Do not try this at home. Professional driver, closed course. */ |
| 986 | struct frame_info *frame = next_frame->prev; |
| 987 | gdb_assert (frame != NULL); |
| 988 | |
| 989 | if (get_frame_saved_regs (frame) == NULL) |
| 990 | { |
| 991 | /* If nothing's initialized the saved regs, do it now. */ |
| 992 | gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); |
| 993 | DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
| 994 | gdb_assert (get_frame_saved_regs (frame) != NULL); |
| 995 | } |
| 996 | |
| 997 | if (get_frame_saved_regs (frame) != NULL |
| 998 | && get_frame_saved_regs (frame)[regnum] != 0) |
| 999 | { |
| 1000 | if (regnum == SP_REGNUM) |
| 1001 | { |
| 1002 | /* SP register treated specially. */ |
| 1003 | *optimizedp = 0; |
| 1004 | *lvalp = not_lval; |
| 1005 | *addrp = 0; |
| 1006 | *realnump = -1; |
| 1007 | if (bufferp != NULL) |
| 1008 | /* NOTE: cagney/2003-05-09: In-lined store_address with |
| 1009 | it's body - store_unsigned_integer. */ |
| 1010 | store_unsigned_integer (bufferp, REGISTER_RAW_SIZE (regnum), |
| 1011 | get_frame_saved_regs (frame)[regnum]); |
| 1012 | } |
| 1013 | else |
| 1014 | { |
| 1015 | /* Any other register is saved in memory, fetch it but cache |
| 1016 | a local copy of its value. */ |
| 1017 | *optimizedp = 0; |
| 1018 | *lvalp = lval_memory; |
| 1019 | *addrp = get_frame_saved_regs (frame)[regnum]; |
| 1020 | *realnump = -1; |
| 1021 | if (bufferp != NULL) |
| 1022 | { |
| 1023 | #if 1 |
| 1024 | /* Save each register value, as it is read in, in a |
| 1025 | frame based cache. */ |
| 1026 | void **regs = (*this_prologue_cache); |
| 1027 | if (regs == NULL) |
| 1028 | { |
| 1029 | int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS) |
| 1030 | * sizeof (void *)); |
| 1031 | regs = frame_obstack_zalloc (sizeof_cache); |
| 1032 | (*this_prologue_cache) = regs; |
| 1033 | } |
| 1034 | if (regs[regnum] == NULL) |
| 1035 | { |
| 1036 | regs[regnum] |
| 1037 | = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum)); |
| 1038 | read_memory (get_frame_saved_regs (frame)[regnum], regs[regnum], |
| 1039 | REGISTER_RAW_SIZE (regnum)); |
| 1040 | } |
| 1041 | memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum)); |
| 1042 | #else |
| 1043 | /* Read the value in from memory. */ |
| 1044 | read_memory (get_frame_saved_regs (frame)[regnum], bufferp, |
| 1045 | REGISTER_RAW_SIZE (regnum)); |
| 1046 | #endif |
| 1047 | } |
| 1048 | } |
| 1049 | return; |
| 1050 | } |
| 1051 | |
| 1052 | /* No luck. Assume this and the next frame have the same register |
| 1053 | value. Pass the unwind request down the frame chain to the next |
| 1054 | frame. Hopefully that frame will find the register's location. */ |
| 1055 | frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp, |
| 1056 | realnump, bufferp); |
| 1057 | } |
| 1058 | |
| 1059 | static void |
| 1060 | legacy_saved_regs_this_id (struct frame_info *next_frame, |
| 1061 | void **this_prologue_cache, |
| 1062 | struct frame_id *id) |
| 1063 | { |
| 1064 | /* legacy_get_prev_frame() always sets ->this_id.p, hence this is |
| 1065 | never needed. */ |
| 1066 | internal_error (__FILE__, __LINE__, "legacy_saved_regs_this_id() called"); |
| 1067 | } |
| 1068 | |
| 1069 | const struct frame_unwind legacy_saved_regs_unwinder = { |
| 1070 | /* Not really. It gets overridden by legacy_get_prev_frame. */ |
| 1071 | UNKNOWN_FRAME, |
| 1072 | legacy_saved_regs_this_id, |
| 1073 | legacy_saved_regs_prev_register |
| 1074 | }; |
| 1075 | const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder; |
| 1076 | |
| 1077 | |
| 1078 | /* Function: deprecated_generic_get_saved_register |
| 1079 | Find register number REGNUM relative to FRAME and put its (raw, |
| 1080 | target format) contents in *RAW_BUFFER. |
| 1081 | |
| 1082 | Set *OPTIMIZED if the variable was optimized out (and thus can't be |
| 1083 | fetched). Note that this is never set to anything other than zero |
| 1084 | in this implementation. |
| 1085 | |
| 1086 | Set *LVAL to lval_memory, lval_register, or not_lval, depending on |
| 1087 | whether the value was fetched from memory, from a register, or in a |
| 1088 | strange and non-modifiable way (e.g. a frame pointer which was |
| 1089 | calculated rather than fetched). We will use not_lval for values |
| 1090 | fetched from generic dummy frames. |
| 1091 | |
| 1092 | Set *ADDRP to the address, either in memory or as a REGISTER_BYTE |
| 1093 | offset into the registers array. If the value is stored in a dummy |
| 1094 | frame, set *ADDRP to zero. |
| 1095 | |
| 1096 | The argument RAW_BUFFER must point to aligned memory. */ |
| 1097 | |
| 1098 | void |
| 1099 | deprecated_generic_get_saved_register (char *raw_buffer, int *optimized, |
| 1100 | CORE_ADDR *addrp, |
| 1101 | struct frame_info *frame, int regnum, |
| 1102 | enum lval_type *lval) |
| 1103 | { |
| 1104 | if (!target_has_registers) |
| 1105 | error ("No registers."); |
| 1106 | |
| 1107 | /* Normal systems don't optimize out things with register numbers. */ |
| 1108 | if (optimized != NULL) |
| 1109 | *optimized = 0; |
| 1110 | |
| 1111 | if (addrp) /* default assumption: not found in memory */ |
| 1112 | *addrp = 0; |
| 1113 | |
| 1114 | /* Note: since the current frame's registers could only have been |
| 1115 | saved by frames INTERIOR TO the current frame, we skip examining |
| 1116 | the current frame itself: otherwise, we would be getting the |
| 1117 | previous frame's registers which were saved by the current frame. */ |
| 1118 | |
| 1119 | if (frame != NULL) |
| 1120 | { |
| 1121 | for (frame = get_next_frame (frame); |
| 1122 | frame_relative_level (frame) >= 0; |
| 1123 | frame = get_next_frame (frame)) |
| 1124 | { |
| 1125 | if (get_frame_type (frame) == DUMMY_FRAME) |
| 1126 | { |
| 1127 | if (lval) /* found it in a CALL_DUMMY frame */ |
| 1128 | *lval = not_lval; |
| 1129 | if (raw_buffer) |
| 1130 | /* FIXME: cagney/2002-06-26: This should be via the |
| 1131 | gdbarch_register_read() method so that it, on the |
| 1132 | fly, constructs either a raw or pseudo register |
| 1133 | from the raw register cache. */ |
| 1134 | regcache_raw_read |
| 1135 | (deprecated_find_dummy_frame_regcache (get_frame_pc (frame), |
| 1136 | get_frame_base (frame)), |
| 1137 | regnum, raw_buffer); |
| 1138 | return; |
| 1139 | } |
| 1140 | |
| 1141 | DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
| 1142 | if (get_frame_saved_regs (frame) != NULL |
| 1143 | && get_frame_saved_regs (frame)[regnum] != 0) |
| 1144 | { |
| 1145 | if (lval) /* found it saved on the stack */ |
| 1146 | *lval = lval_memory; |
| 1147 | if (regnum == SP_REGNUM) |
| 1148 | { |
| 1149 | if (raw_buffer) /* SP register treated specially */ |
| 1150 | /* NOTE: cagney/2003-05-09: In-line store_address |
| 1151 | with it's body - store_unsigned_integer. */ |
| 1152 | store_unsigned_integer (raw_buffer, |
| 1153 | REGISTER_RAW_SIZE (regnum), |
| 1154 | get_frame_saved_regs (frame)[regnum]); |
| 1155 | } |
| 1156 | else |
| 1157 | { |
| 1158 | if (addrp) /* any other register */ |
| 1159 | *addrp = get_frame_saved_regs (frame)[regnum]; |
| 1160 | if (raw_buffer) |
| 1161 | read_memory (get_frame_saved_regs (frame)[regnum], raw_buffer, |
| 1162 | REGISTER_RAW_SIZE (regnum)); |
| 1163 | } |
| 1164 | return; |
| 1165 | } |
| 1166 | } |
| 1167 | } |
| 1168 | |
| 1169 | /* If we get thru the loop to this point, it means the register was |
| 1170 | not saved in any frame. Return the actual live-register value. */ |
| 1171 | |
| 1172 | if (lval) /* found it in a live register */ |
| 1173 | *lval = lval_register; |
| 1174 | if (addrp) |
| 1175 | *addrp = REGISTER_BYTE (regnum); |
| 1176 | if (raw_buffer) |
| 1177 | deprecated_read_register_gen (regnum, raw_buffer); |
| 1178 | } |
| 1179 | |
| 1180 | /* Determine the frame's type based on its PC. */ |
| 1181 | |
| 1182 | static enum frame_type |
| 1183 | frame_type_from_pc (CORE_ADDR pc) |
| 1184 | { |
| 1185 | /* FIXME: cagney/2002-11-24: Can't yet directly call |
| 1186 | pc_in_dummy_frame() as some architectures don't set |
| 1187 | PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the |
| 1188 | latter is implemented by simply calling pc_in_dummy_frame). */ |
| 1189 | if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
| 1190 | && DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)) |
| 1191 | return DUMMY_FRAME; |
| 1192 | else |
| 1193 | { |
| 1194 | char *name; |
| 1195 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 1196 | if (PC_IN_SIGTRAMP (pc, name)) |
| 1197 | return SIGTRAMP_FRAME; |
| 1198 | else |
| 1199 | return NORMAL_FRAME; |
| 1200 | } |
| 1201 | } |
| 1202 | |
| 1203 | /* Create an arbitrary (i.e. address specified by user) or innermost frame. |
| 1204 | Always returns a non-NULL value. */ |
| 1205 | |
| 1206 | struct frame_info * |
| 1207 | create_new_frame (CORE_ADDR addr, CORE_ADDR pc) |
| 1208 | { |
| 1209 | struct frame_info *fi; |
| 1210 | |
| 1211 | if (frame_debug) |
| 1212 | { |
| 1213 | fprintf_unfiltered (gdb_stdlog, |
| 1214 | "{ create_new_frame (addr=0x%s, pc=0x%s) ", |
| 1215 | paddr_nz (addr), paddr_nz (pc)); |
| 1216 | } |
| 1217 | |
| 1218 | fi = frame_obstack_zalloc (sizeof (struct frame_info)); |
| 1219 | |
| 1220 | fi->next = create_sentinel_frame (current_regcache); |
| 1221 | |
| 1222 | /* Select/initialize both the unwind function and the frame's type |
| 1223 | based on the PC. */ |
| 1224 | fi->unwind = frame_unwind_find_by_frame (fi->next); |
| 1225 | if (fi->unwind->type != UNKNOWN_FRAME) |
| 1226 | fi->type = fi->unwind->type; |
| 1227 | else |
| 1228 | fi->type = frame_type_from_pc (pc); |
| 1229 | |
| 1230 | fi->this_id.p = 1; |
| 1231 | deprecated_update_frame_base_hack (fi, addr); |
| 1232 | deprecated_update_frame_pc_hack (fi, pc); |
| 1233 | |
| 1234 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
| 1235 | DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi); |
| 1236 | |
| 1237 | if (frame_debug) |
| 1238 | { |
| 1239 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1240 | fprint_frame (gdb_stdlog, fi); |
| 1241 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 1242 | } |
| 1243 | |
| 1244 | return fi; |
| 1245 | } |
| 1246 | |
| 1247 | /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the |
| 1248 | innermost frame). Be careful to not fall off the bottom of the |
| 1249 | frame chain and onto the sentinel frame. */ |
| 1250 | |
| 1251 | struct frame_info * |
| 1252 | get_next_frame (struct frame_info *this_frame) |
| 1253 | { |
| 1254 | if (this_frame->level > 0) |
| 1255 | return this_frame->next; |
| 1256 | else |
| 1257 | return NULL; |
| 1258 | } |
| 1259 | |
| 1260 | struct frame_info * |
| 1261 | deprecated_get_next_frame_hack (struct frame_info *this_frame) |
| 1262 | { |
| 1263 | return this_frame->next; |
| 1264 | } |
| 1265 | |
| 1266 | /* Flush the entire frame cache. */ |
| 1267 | |
| 1268 | void |
| 1269 | flush_cached_frames (void) |
| 1270 | { |
| 1271 | /* Since we can't really be sure what the first object allocated was */ |
| 1272 | obstack_free (&frame_cache_obstack, 0); |
| 1273 | obstack_init (&frame_cache_obstack); |
| 1274 | |
| 1275 | current_frame = NULL; /* Invalidate cache */ |
| 1276 | select_frame (NULL); |
| 1277 | annotate_frames_invalid (); |
| 1278 | if (frame_debug) |
| 1279 | fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n"); |
| 1280 | } |
| 1281 | |
| 1282 | /* Flush the frame cache, and start a new one if necessary. */ |
| 1283 | |
| 1284 | void |
| 1285 | reinit_frame_cache (void) |
| 1286 | { |
| 1287 | flush_cached_frames (); |
| 1288 | |
| 1289 | /* FIXME: The inferior_ptid test is wrong if there is a corefile. */ |
| 1290 | if (PIDGET (inferior_ptid) != 0) |
| 1291 | { |
| 1292 | select_frame (get_current_frame ()); |
| 1293 | } |
| 1294 | } |
| 1295 | |
| 1296 | /* Create the previous frame using the deprecated methods |
| 1297 | INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */ |
| 1298 | |
| 1299 | static struct frame_info * |
| 1300 | legacy_get_prev_frame (struct frame_info *this_frame) |
| 1301 | { |
| 1302 | CORE_ADDR address = 0; |
| 1303 | struct frame_info *prev; |
| 1304 | int fromleaf; |
| 1305 | |
| 1306 | /* Don't frame_debug print legacy_get_prev_frame() here, just |
| 1307 | confuses the output. */ |
| 1308 | |
| 1309 | /* Allocate the new frame. |
| 1310 | |
| 1311 | There is no reason to worry about memory leaks, should the |
| 1312 | remainder of the function fail. The allocated memory will be |
| 1313 | quickly reclaimed when the frame cache is flushed, and the `we've |
| 1314 | been here before' check, in get_prev_frame will stop repeated |
| 1315 | memory allocation calls. */ |
| 1316 | prev = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| 1317 | prev->level = this_frame->level + 1; |
| 1318 | |
| 1319 | /* Do not completly wire it in to the frame chain. Some (bad) code |
| 1320 | in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull |
| 1321 | some fancy tricks (of course such code is, by definition, |
| 1322 | recursive). |
| 1323 | |
| 1324 | On the other hand, methods, such as get_frame_pc() and |
| 1325 | get_frame_base() rely on being able to walk along the frame |
| 1326 | chain. Make certain that at least they work by providing that |
| 1327 | link. Of course things manipulating prev can't go back. */ |
| 1328 | prev->next = this_frame; |
| 1329 | |
| 1330 | /* NOTE: cagney/2002-11-18: Should have been correctly setting the |
| 1331 | frame's type here, before anything else, and not last, at the |
| 1332 | bottom of this function. The various |
| 1333 | DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC, |
| 1334 | DEPRECATED_INIT_FRAME_PC_FIRST and |
| 1335 | DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds |
| 1336 | that handle the frame not being correctly set from the start. |
| 1337 | Unfortunatly those same work-arounds rely on the type defaulting |
| 1338 | to NORMAL_FRAME. Ulgh! The new frame code does not have this |
| 1339 | problem. */ |
| 1340 | prev->type = UNKNOWN_FRAME; |
| 1341 | |
| 1342 | /* A legacy frame's ID is always computed here. Mark it as valid. */ |
| 1343 | prev->this_id.p = 1; |
| 1344 | |
| 1345 | /* Handle sentinel frame unwind as a special case. */ |
| 1346 | if (this_frame->level < 0) |
| 1347 | { |
| 1348 | /* Try to unwind the PC. If that doesn't work, assume we've reached |
| 1349 | the oldest frame and simply return. Is there a better sentinal |
| 1350 | value? The unwound PC value is then used to initialize the new |
| 1351 | previous frame's type. |
| 1352 | |
| 1353 | Note that the pc-unwind is intentionally performed before the |
| 1354 | frame chain. This is ok since, for old targets, both |
| 1355 | frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and |
| 1356 | DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures |
| 1357 | have already been initialized (using |
| 1358 | DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
| 1359 | doesn't matter. |
| 1360 | |
| 1361 | By unwinding the PC first, it becomes possible to, in the case of |
| 1362 | a dummy frame, avoid also unwinding the frame ID. This is |
| 1363 | because (well ignoring the PPC) a dummy frame can be located |
| 1364 | using THIS_FRAME's frame ID. */ |
| 1365 | |
| 1366 | deprecated_update_frame_pc_hack (prev, frame_pc_unwind (this_frame)); |
| 1367 | if (get_frame_pc (prev) == 0) |
| 1368 | { |
| 1369 | /* The allocated PREV_FRAME will be reclaimed when the frame |
| 1370 | obstack is next purged. */ |
| 1371 | if (frame_debug) |
| 1372 | { |
| 1373 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1374 | fprint_frame (gdb_stdlog, NULL); |
| 1375 | fprintf_unfiltered (gdb_stdlog, |
| 1376 | " // unwound legacy PC zero }\n"); |
| 1377 | } |
| 1378 | return NULL; |
| 1379 | } |
| 1380 | |
| 1381 | /* Set the unwind functions based on that identified PC. Ditto |
| 1382 | for the "type" but strongly prefer the unwinder's frame type. */ |
| 1383 | prev->unwind = frame_unwind_find_by_frame (prev->next); |
| 1384 | if (prev->unwind->type == UNKNOWN_FRAME) |
| 1385 | prev->type = frame_type_from_pc (get_frame_pc (prev)); |
| 1386 | else |
| 1387 | prev->type = prev->unwind->type; |
| 1388 | |
| 1389 | /* Find the prev's frame's ID. */ |
| 1390 | if (prev->type == DUMMY_FRAME |
| 1391 | && gdbarch_unwind_dummy_id_p (current_gdbarch)) |
| 1392 | { |
| 1393 | /* When unwinding a normal frame, the stack structure is |
| 1394 | determined by analyzing the frame's function's code (be |
| 1395 | it using brute force prologue analysis, or the dwarf2 |
| 1396 | CFI). In the case of a dummy frame, that simply isn't |
| 1397 | possible. The The PC is either the program entry point, |
| 1398 | or some random address on the stack. Trying to use that |
| 1399 | PC to apply standard frame ID unwind techniques is just |
| 1400 | asking for trouble. */ |
| 1401 | /* Use an architecture specific method to extract the prev's |
| 1402 | dummy ID from the next frame. Note that this method uses |
| 1403 | frame_register_unwind to obtain the register values |
| 1404 | needed to determine the dummy frame's ID. */ |
| 1405 | prev->this_id.value = gdbarch_unwind_dummy_id (current_gdbarch, |
| 1406 | this_frame); |
| 1407 | } |
| 1408 | else |
| 1409 | { |
| 1410 | /* We're unwinding a sentinel frame, the PC of which is |
| 1411 | pointing at a stack dummy. Fake up the dummy frame's ID |
| 1412 | using the same sequence as is found a traditional |
| 1413 | unwinder. Once all architectures supply the |
| 1414 | unwind_dummy_id method, this code can go away. */ |
| 1415 | prev->this_id.value = frame_id_build (deprecated_read_fp (), |
| 1416 | read_pc ()); |
| 1417 | } |
| 1418 | |
| 1419 | /* Check that the unwound ID is valid. */ |
| 1420 | if (!frame_id_p (prev->this_id.value)) |
| 1421 | { |
| 1422 | if (frame_debug) |
| 1423 | { |
| 1424 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1425 | fprint_frame (gdb_stdlog, NULL); |
| 1426 | fprintf_unfiltered (gdb_stdlog, |
| 1427 | " // unwound legacy ID invalid }\n"); |
| 1428 | } |
| 1429 | return NULL; |
| 1430 | } |
| 1431 | |
| 1432 | /* Check that the new frame isn't inner to (younger, below, |
| 1433 | next) the old frame. If that happens the frame unwind is |
| 1434 | going backwards. */ |
| 1435 | /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since |
| 1436 | that doesn't have a valid frame ID. Should instead set the |
| 1437 | sentinel frame's frame ID to a `sentinel'. Leave it until |
| 1438 | after the switch to storing the frame ID, instead of the |
| 1439 | frame base, in the frame object. */ |
| 1440 | |
| 1441 | /* Link it in. */ |
| 1442 | this_frame->prev = prev; |
| 1443 | |
| 1444 | /* FIXME: cagney/2002-01-19: This call will go away. Instead of |
| 1445 | initializing extra info, all frames will use the frame_cache |
| 1446 | (passed to the unwind functions) to store additional frame |
| 1447 | info. Unfortunatly legacy targets can't use |
| 1448 | legacy_get_prev_frame() to unwind the sentinel frame and, |
| 1449 | consequently, are forced to take this code path and rely on |
| 1450 | the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to |
| 1451 | initialize the inner-most frame. */ |
| 1452 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
| 1453 | { |
| 1454 | DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev); |
| 1455 | } |
| 1456 | |
| 1457 | if (prev->type == NORMAL_FRAME) |
| 1458 | prev->this_id.value.code_addr |
| 1459 | = get_pc_function_start (prev->this_id.value.code_addr); |
| 1460 | |
| 1461 | if (frame_debug) |
| 1462 | { |
| 1463 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1464 | fprint_frame (gdb_stdlog, prev); |
| 1465 | fprintf_unfiltered (gdb_stdlog, " } // legacy innermost frame\n"); |
| 1466 | } |
| 1467 | return prev; |
| 1468 | } |
| 1469 | |
| 1470 | /* This code only works on normal frames. A sentinel frame, where |
| 1471 | the level is -1, should never reach this code. */ |
| 1472 | gdb_assert (this_frame->level >= 0); |
| 1473 | |
| 1474 | /* On some machines it is possible to call a function without |
| 1475 | setting up a stack frame for it. On these machines, we |
| 1476 | define this macro to take two args; a frameinfo pointer |
| 1477 | identifying a frame and a variable to set or clear if it is |
| 1478 | or isn't leafless. */ |
| 1479 | |
| 1480 | /* Still don't want to worry about this except on the innermost |
| 1481 | frame. This macro will set FROMLEAF if THIS_FRAME is a frameless |
| 1482 | function invocation. */ |
| 1483 | if (this_frame->level == 0) |
| 1484 | /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
| 1485 | the frame chain, not just the inner most frame! The generic, |
| 1486 | per-architecture, frame code should handle this and the below |
| 1487 | should simply be removed. */ |
| 1488 | fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame); |
| 1489 | else |
| 1490 | fromleaf = 0; |
| 1491 | |
| 1492 | if (fromleaf) |
| 1493 | /* A frameless inner-most frame. The `FP' (which isn't an |
| 1494 | architecture frame-pointer register!) of the caller is the same |
| 1495 | as the callee. */ |
| 1496 | /* FIXME: 2002-11-09: There isn't any reason to special case this |
| 1497 | edge condition. Instead the per-architecture code should hande |
| 1498 | it locally. */ |
| 1499 | /* FIXME: cagney/2003-06-16: This returns the inner most stack |
| 1500 | address for the previous frame, that, however, is wrong. It |
| 1501 | should be the inner most stack address for the previous to |
| 1502 | previous frame. This is because it is the previous to previous |
| 1503 | frame's innermost stack address that is constant through out |
| 1504 | the lifetime of the previous frame (trust me :-). */ |
| 1505 | address = get_frame_base (this_frame); |
| 1506 | else |
| 1507 | { |
| 1508 | /* Two macros defined in tm.h specify the machine-dependent |
| 1509 | actions to be performed here. |
| 1510 | |
| 1511 | First, get the frame's chain-pointer. |
| 1512 | |
| 1513 | If that is zero, the frame is the outermost frame or a leaf |
| 1514 | called by the outermost frame. This means that if start |
| 1515 | calls main without a frame, we'll return 0 (which is fine |
| 1516 | anyway). |
| 1517 | |
| 1518 | Nope; there's a problem. This also returns when the current |
| 1519 | routine is a leaf of main. This is unacceptable. We move |
| 1520 | this to after the ffi test; I'd rather have backtraces from |
| 1521 | start go curfluy than have an abort called from main not show |
| 1522 | main. */ |
| 1523 | if (DEPRECATED_FRAME_CHAIN_P ()) |
| 1524 | address = DEPRECATED_FRAME_CHAIN (this_frame); |
| 1525 | else |
| 1526 | { |
| 1527 | /* Someone is part way through coverting an old architecture |
| 1528 | to the new frame code. Implement FRAME_CHAIN the way the |
| 1529 | new frame will. */ |
| 1530 | /* Find PREV frame's unwinder. */ |
| 1531 | prev->unwind = frame_unwind_find_by_frame (this_frame->next); |
| 1532 | /* FIXME: cagney/2003-04-02: Rather than storing the frame's |
| 1533 | type in the frame, the unwinder's type should be returned |
| 1534 | directly. Unfortunatly, legacy code, called by |
| 1535 | legacy_get_prev_frame, explicitly set the frames type |
| 1536 | using the method deprecated_set_frame_type(). */ |
| 1537 | prev->type = prev->unwind->type; |
| 1538 | /* Find PREV frame's ID. */ |
| 1539 | prev->unwind->this_id (this_frame, |
| 1540 | &prev->prologue_cache, |
| 1541 | &prev->this_id.value); |
| 1542 | prev->this_id.p = 1; |
| 1543 | address = prev->this_id.value.stack_addr; |
| 1544 | } |
| 1545 | |
| 1546 | if (!legacy_frame_chain_valid (address, this_frame)) |
| 1547 | { |
| 1548 | if (frame_debug) |
| 1549 | { |
| 1550 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1551 | fprint_frame (gdb_stdlog, NULL); |
| 1552 | fprintf_unfiltered (gdb_stdlog, |
| 1553 | " // legacy frame chain invalid }\n"); |
| 1554 | } |
| 1555 | return NULL; |
| 1556 | } |
| 1557 | } |
| 1558 | if (address == 0) |
| 1559 | { |
| 1560 | if (frame_debug) |
| 1561 | { |
| 1562 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1563 | fprint_frame (gdb_stdlog, NULL); |
| 1564 | fprintf_unfiltered (gdb_stdlog, |
| 1565 | " // legacy frame chain NULL }\n"); |
| 1566 | } |
| 1567 | return NULL; |
| 1568 | } |
| 1569 | |
| 1570 | /* Link in the already allocated prev frame. */ |
| 1571 | this_frame->prev = prev; |
| 1572 | deprecated_update_frame_base_hack (prev, address); |
| 1573 | |
| 1574 | /* This change should not be needed, FIXME! We should determine |
| 1575 | whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen |
| 1576 | after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple |
| 1577 | way to express what goes on here. |
| 1578 | |
| 1579 | DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places: |
| 1580 | create_new_frame (where the PC is already set up) and here (where |
| 1581 | it isn't). DEPRECATED_INIT_FRAME_PC is only called from here, |
| 1582 | always after DEPRECATED_INIT_EXTRA_FRAME_INFO. |
| 1583 | |
| 1584 | The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO |
| 1585 | requires the PC value (which hasn't been set yet). Some other |
| 1586 | machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO |
| 1587 | before they can do DEPRECATED_INIT_FRAME_PC. Phoo. |
| 1588 | |
| 1589 | We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more |
| 1590 | complication to an already overcomplicated part of GDB. |
| 1591 | gnu@cygnus.com, 15Sep92. |
| 1592 | |
| 1593 | Assuming that some machines need DEPRECATED_INIT_FRAME_PC after |
| 1594 | DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme: |
| 1595 | |
| 1596 | SETUP_INNERMOST_FRAME(): Default version is just create_new_frame |
| 1597 | (deprecated_read_fp ()), read_pc ()). Machines with extra frame |
| 1598 | info would do that (or the local equivalent) and then set the |
| 1599 | extra fields. |
| 1600 | |
| 1601 | SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that |
| 1602 | create_new_frame would no longer init extra frame info; |
| 1603 | SETUP_ARBITRARY_FRAME would have to do that. |
| 1604 | |
| 1605 | INIT_PREV_FRAME(fromleaf, prev) Replace |
| 1606 | DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC. |
| 1607 | This should also return a flag saying whether to keep the new |
| 1608 | frame, or whether to discard it, because on some machines (e.g. |
| 1609 | mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID |
| 1610 | called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good |
| 1611 | way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID |
| 1612 | into the extra fields of the new frame). std_frame_pc(fromleaf, |
| 1613 | prev) |
| 1614 | |
| 1615 | This is the default setting for INIT_PREV_FRAME. It just does |
| 1616 | what the default DEPRECATED_INIT_FRAME_PC does. Some machines |
| 1617 | will call it from INIT_PREV_FRAME (either at the beginning, the |
| 1618 | end, or in the middle). Some machines won't use it. |
| 1619 | |
| 1620 | kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */ |
| 1621 | |
| 1622 | /* NOTE: cagney/2002-11-09: Just ignore the above! There is no |
| 1623 | reason for things to be this complicated. |
| 1624 | |
| 1625 | The trick is to assume that there is always a frame. Instead of |
| 1626 | special casing the inner-most frame, create fake frame |
| 1627 | (containing the hardware registers) that is inner to the |
| 1628 | user-visible inner-most frame (...) and then unwind from that. |
| 1629 | That way architecture code can use use the standard |
| 1630 | frame_XX_unwind() functions and not differentiate between the |
| 1631 | inner most and any other case. |
| 1632 | |
| 1633 | Since there is always a frame to unwind from, there is always |
| 1634 | somewhere (THIS_FRAME) to store all the info needed to construct |
| 1635 | a new (previous) frame without having to first create it. This |
| 1636 | means that the convolution below - needing to carefully order a |
| 1637 | frame's initialization - isn't needed. |
| 1638 | |
| 1639 | The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least |
| 1640 | for a more up-to-date architecture, always calls |
| 1641 | FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but |
| 1642 | without first needing the frame! Instead of the convolution |
| 1643 | below, we could have simply called FRAME_SAVED_PC() and been done |
| 1644 | with it! Note that FRAME_SAVED_PC() is being superseed by |
| 1645 | frame_pc_unwind() and that function does have somewhere to cache |
| 1646 | that PC value. */ |
| 1647 | |
| 1648 | if (DEPRECATED_INIT_FRAME_PC_FIRST_P ()) |
| 1649 | deprecated_update_frame_pc_hack (prev, |
| 1650 | DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf, |
| 1651 | prev)); |
| 1652 | |
| 1653 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
| 1654 | DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev); |
| 1655 | |
| 1656 | /* This entry is in the frame queue now, which is good since |
| 1657 | FRAME_SAVED_PC may use that queue to figure out its value (see |
| 1658 | tm-sparc.h). We want the pc saved in the inferior frame. */ |
| 1659 | if (DEPRECATED_INIT_FRAME_PC_P ()) |
| 1660 | deprecated_update_frame_pc_hack (prev, |
| 1661 | DEPRECATED_INIT_FRAME_PC (fromleaf, |
| 1662 | prev)); |
| 1663 | |
| 1664 | /* If ->frame and ->pc are unchanged, we are in the process of |
| 1665 | getting ourselves into an infinite backtrace. Some architectures |
| 1666 | check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems |
| 1667 | like there is no reason this can't be an architecture-independent |
| 1668 | check. */ |
| 1669 | if (get_frame_base (prev) == get_frame_base (this_frame) |
| 1670 | && get_frame_pc (prev) == get_frame_pc (this_frame)) |
| 1671 | { |
| 1672 | this_frame->prev = NULL; |
| 1673 | obstack_free (&frame_cache_obstack, prev); |
| 1674 | if (frame_debug) |
| 1675 | { |
| 1676 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1677 | fprint_frame (gdb_stdlog, NULL); |
| 1678 | fprintf_unfiltered (gdb_stdlog, |
| 1679 | " // legacy this.id == prev.id }\n"); |
| 1680 | } |
| 1681 | return NULL; |
| 1682 | } |
| 1683 | |
| 1684 | /* Initialize the code used to unwind the frame PREV based on the PC |
| 1685 | (and probably other architectural information). The PC lets you |
| 1686 | check things like the debug info at that point (dwarf2cfi?) and |
| 1687 | use that to decide how the frame should be unwound. |
| 1688 | |
| 1689 | If there isn't a FRAME_CHAIN, the code above will have already |
| 1690 | done this. */ |
| 1691 | if (prev->unwind == NULL) |
| 1692 | prev->unwind = frame_unwind_find_by_frame (prev->next); |
| 1693 | |
| 1694 | /* If the unwinder provides a frame type, use it. Otherwize |
| 1695 | continue on to that heuristic mess. */ |
| 1696 | if (prev->unwind->type != UNKNOWN_FRAME) |
| 1697 | { |
| 1698 | prev->type = prev->unwind->type; |
| 1699 | if (prev->type == NORMAL_FRAME) |
| 1700 | /* FIXME: cagney/2003-06-16: would get_frame_pc() be better? */ |
| 1701 | prev->this_id.value.code_addr |
| 1702 | = get_pc_function_start (prev->this_id.value.code_addr); |
| 1703 | if (frame_debug) |
| 1704 | { |
| 1705 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1706 | fprint_frame (gdb_stdlog, prev); |
| 1707 | fprintf_unfiltered (gdb_stdlog, " } // legacy with unwound type\n"); |
| 1708 | } |
| 1709 | return prev; |
| 1710 | } |
| 1711 | |
| 1712 | /* NOTE: cagney/2002-11-18: The code segments, found in |
| 1713 | create_new_frame and get_prev_frame(), that initializes the |
| 1714 | frames type is subtly different. The latter only updates ->type |
| 1715 | when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops |
| 1716 | get_prev_frame() overriding the frame's type when the INIT code |
| 1717 | has previously set it. This is really somewhat bogus. The |
| 1718 | initialization, as seen in create_new_frame(), should occur |
| 1719 | before the INIT function has been called. */ |
| 1720 | if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
| 1721 | && (DEPRECATED_PC_IN_CALL_DUMMY_P () |
| 1722 | ? DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (prev), 0, 0) |
| 1723 | : pc_in_dummy_frame (get_frame_pc (prev)))) |
| 1724 | prev->type = DUMMY_FRAME; |
| 1725 | else |
| 1726 | { |
| 1727 | /* FIXME: cagney/2002-11-10: This should be moved to before the |
| 1728 | INIT code above so that the INIT code knows what the frame's |
| 1729 | type is (in fact, for a [generic] dummy-frame, the type can |
| 1730 | be set and then the entire initialization can be skipped. |
| 1731 | Unforunatly, its the INIT code that sets the PC (Hmm, catch |
| 1732 | 22). */ |
| 1733 | char *name; |
| 1734 | find_pc_partial_function (get_frame_pc (prev), &name, NULL, NULL); |
| 1735 | if (PC_IN_SIGTRAMP (get_frame_pc (prev), name)) |
| 1736 | prev->type = SIGTRAMP_FRAME; |
| 1737 | /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some |
| 1738 | architectures are forcing the frame's type in INIT so we |
| 1739 | don't want to override it here. Remember, NORMAL_FRAME == 0, |
| 1740 | so it all works (just :-/). Once this initialization is |
| 1741 | moved to the start of this function, all this nastness will |
| 1742 | go away. */ |
| 1743 | } |
| 1744 | |
| 1745 | if (prev->type == NORMAL_FRAME) |
| 1746 | prev->this_id.value.code_addr |
| 1747 | = get_pc_function_start (prev->this_id.value.code_addr); |
| 1748 | |
| 1749 | if (frame_debug) |
| 1750 | { |
| 1751 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1752 | fprint_frame (gdb_stdlog, prev); |
| 1753 | fprintf_unfiltered (gdb_stdlog, " } // legacy with confused type\n"); |
| 1754 | } |
| 1755 | |
| 1756 | return prev; |
| 1757 | } |
| 1758 | |
| 1759 | /* Return a structure containing various interesting information |
| 1760 | about the frame that called THIS_FRAME. Returns NULL |
| 1761 | if there is no such frame. */ |
| 1762 | |
| 1763 | struct frame_info * |
| 1764 | get_prev_frame (struct frame_info *this_frame) |
| 1765 | { |
| 1766 | struct frame_info *prev_frame; |
| 1767 | |
| 1768 | if (frame_debug) |
| 1769 | { |
| 1770 | fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame="); |
| 1771 | if (this_frame != NULL) |
| 1772 | fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level); |
| 1773 | else |
| 1774 | fprintf_unfiltered (gdb_stdlog, "<NULL>"); |
| 1775 | fprintf_unfiltered (gdb_stdlog, ") "); |
| 1776 | } |
| 1777 | |
| 1778 | /* Return the inner-most frame, when the caller passes in NULL. */ |
| 1779 | /* NOTE: cagney/2002-11-09: Not sure how this would happen. The |
| 1780 | caller should have previously obtained a valid frame using |
| 1781 | get_selected_frame() and then called this code - only possibility |
| 1782 | I can think of is code behaving badly. |
| 1783 | |
| 1784 | NOTE: cagney/2003-01-10: Talk about code behaving badly. Check |
| 1785 | block_innermost_frame(). It does the sequence: frame = NULL; |
| 1786 | while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why |
| 1787 | it couldn't be written better, I don't know. |
| 1788 | |
| 1789 | NOTE: cagney/2003-01-11: I suspect what is happening is |
| 1790 | block_innermost_frame() is, when the target has no state |
| 1791 | (registers, memory, ...), still calling this function. The |
| 1792 | assumption being that this function will return NULL indicating |
| 1793 | that a frame isn't possible, rather than checking that the target |
| 1794 | has state and then calling get_current_frame() and |
| 1795 | get_prev_frame(). This is a guess mind. */ |
| 1796 | if (this_frame == NULL) |
| 1797 | { |
| 1798 | /* NOTE: cagney/2002-11-09: There was a code segment here that |
| 1799 | would error out when CURRENT_FRAME was NULL. The comment |
| 1800 | that went with it made the claim ... |
| 1801 | |
| 1802 | ``This screws value_of_variable, which just wants a nice |
| 1803 | clean NULL return from block_innermost_frame if there are no |
| 1804 | frames. I don't think I've ever seen this message happen |
| 1805 | otherwise. And returning NULL here is a perfectly legitimate |
| 1806 | thing to do.'' |
| 1807 | |
| 1808 | Per the above, this code shouldn't even be called with a NULL |
| 1809 | THIS_FRAME. */ |
| 1810 | return current_frame; |
| 1811 | } |
| 1812 | |
| 1813 | /* There is always a frame. If this assertion fails, suspect that |
| 1814 | something should be calling get_selected_frame() or |
| 1815 | get_current_frame(). */ |
| 1816 | gdb_assert (this_frame != NULL); |
| 1817 | |
| 1818 | if (this_frame->level >= 0 |
| 1819 | && !backtrace_past_main |
| 1820 | && inside_main_func (get_frame_pc (this_frame))) |
| 1821 | /* Don't unwind past main(), bug always unwind the sentinel frame. |
| 1822 | Note, this is done _before_ the frame has been marked as |
| 1823 | previously unwound. That way if the user later decides to |
| 1824 | allow unwinds past main(), that just happens. */ |
| 1825 | { |
| 1826 | if (frame_debug) |
| 1827 | fprintf_unfiltered (gdb_stdlog, "-> NULL // inside main func }\n"); |
| 1828 | return NULL; |
| 1829 | } |
| 1830 | |
| 1831 | if (this_frame->level > backtrace_limit) |
| 1832 | { |
| 1833 | error ("Backtrace limit of %d exceeded", backtrace_limit); |
| 1834 | } |
| 1835 | |
| 1836 | /* If we're already inside the entry function for the main objfile, |
| 1837 | then it isn't valid. Don't apply this test to a dummy frame - |
| 1838 | dummy frame PC's typically land in the entry func. Don't apply |
| 1839 | this test to the sentinel frame. Sentinel frames should always |
| 1840 | be allowed to unwind. */ |
| 1841 | /* NOTE: cagney/2003-02-25: Don't enable until someone has found |
| 1842 | hard evidence that this is needed. */ |
| 1843 | /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func - wasn't |
| 1844 | checking for "main" in the minimal symbols. With that fixed |
| 1845 | asm-source tests now stop in "main" instead of halting the |
| 1846 | backtrace in wierd and wonderful ways somewhere inside the entry |
| 1847 | file. Suspect that inside_entry_file and inside_entry_func tests |
| 1848 | were added to work around that (now fixed) case. */ |
| 1849 | /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right) |
| 1850 | suggested having the inside_entry_func test use the |
| 1851 | inside_main_func msymbol trick (along with entry_point_address I |
| 1852 | guess) to determine the address range of the start function. |
| 1853 | That should provide a far better stopper than the current |
| 1854 | heuristics. */ |
| 1855 | /* NOTE: cagney/2003-07-15: Need to add a "set backtrace |
| 1856 | beyond-entry-func" command so that this can be selectively |
| 1857 | disabled. */ |
| 1858 | if (0 |
| 1859 | #if 0 |
| 1860 | && backtrace_beyond_entry_func |
| 1861 | #endif |
| 1862 | && this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
| 1863 | && inside_entry_func (get_frame_pc (this_frame))) |
| 1864 | { |
| 1865 | if (frame_debug) |
| 1866 | { |
| 1867 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1868 | fprint_frame (gdb_stdlog, NULL); |
| 1869 | fprintf_unfiltered (gdb_stdlog, "// inside entry func }\n"); |
| 1870 | } |
| 1871 | return NULL; |
| 1872 | } |
| 1873 | |
| 1874 | /* Only try to do the unwind once. */ |
| 1875 | if (this_frame->prev_p) |
| 1876 | { |
| 1877 | if (frame_debug) |
| 1878 | { |
| 1879 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1880 | fprint_frame (gdb_stdlog, this_frame->prev); |
| 1881 | fprintf_unfiltered (gdb_stdlog, " // cached \n"); |
| 1882 | } |
| 1883 | return this_frame->prev; |
| 1884 | } |
| 1885 | this_frame->prev_p = 1; |
| 1886 | |
| 1887 | #if 0 |
| 1888 | /* If we're inside the entry file, it isn't valid. Don't apply this |
| 1889 | test to a dummy frame - dummy frame PC's typically land in the |
| 1890 | entry file. Don't apply this test to the sentinel frame. |
| 1891 | Sentinel frames should always be allowed to unwind. */ |
| 1892 | /* NOTE: drow/2002-12-25: should there be a way to disable this |
| 1893 | check? It assumes a single small entry file, and the way some |
| 1894 | debug readers (e.g. dbxread) figure out which object is the |
| 1895 | entry file is somewhat hokey. */ |
| 1896 | /* NOTE: cagney/2003-01-10: If there is a way of disabling this test |
| 1897 | then it should probably be moved to before the ->prev_p test, |
| 1898 | above. */ |
| 1899 | /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call to |
| 1900 | inside_entry_file destroys a meaningful backtrace under some |
| 1901 | conditions. E. g. the backtrace tests in the asm-source testcase |
| 1902 | are broken for some targets. In this test the functions are all |
| 1903 | implemented as part of one file and the testcase is not necessarily |
| 1904 | linked with a start file (depending on the target). What happens is, |
| 1905 | that the first frame is printed normaly and following frames are |
| 1906 | treated as being inside the enttry file then. This way, only the |
| 1907 | #0 frame is printed in the backtrace output. */ |
| 1908 | if (this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
| 1909 | && inside_entry_file (get_frame_pc (this_frame))) |
| 1910 | { |
| 1911 | if (frame_debug) |
| 1912 | { |
| 1913 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1914 | fprint_frame (gdb_stdlog, NULL); |
| 1915 | fprintf_unfiltered (gdb_stdlog, " // inside entry file }\n"); |
| 1916 | } |
| 1917 | return NULL; |
| 1918 | } |
| 1919 | #endif |
| 1920 | |
| 1921 | /* If any of the old frame initialization methods are around, use |
| 1922 | the legacy get_prev_frame method. */ |
| 1923 | if (legacy_frame_p (current_gdbarch)) |
| 1924 | { |
| 1925 | prev_frame = legacy_get_prev_frame (this_frame); |
| 1926 | return prev_frame; |
| 1927 | } |
| 1928 | |
| 1929 | /* Check that this frame's ID was valid. If it wasn't, don't try to |
| 1930 | unwind to the prev frame. Be careful to not apply this test to |
| 1931 | the sentinel frame. */ |
| 1932 | if (this_frame->level >= 0 && !frame_id_p (get_frame_id (this_frame))) |
| 1933 | { |
| 1934 | if (frame_debug) |
| 1935 | { |
| 1936 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1937 | fprint_frame (gdb_stdlog, NULL); |
| 1938 | fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n"); |
| 1939 | } |
| 1940 | return NULL; |
| 1941 | } |
| 1942 | |
| 1943 | /* Check that this frame's ID isn't inner to (younger, below, next) |
| 1944 | the next frame. This happens when a frame unwind goes backwards. |
| 1945 | Since the sentinel frame doesn't really exist, don't compare the |
| 1946 | inner-most against that sentinel. */ |
| 1947 | if (this_frame->level > 0 |
| 1948 | && frame_id_inner (get_frame_id (this_frame), |
| 1949 | get_frame_id (this_frame->next))) |
| 1950 | error ("Previous frame inner to this frame (corrupt stack?)"); |
| 1951 | |
| 1952 | /* Check that this and the next frame are not identical. If they |
| 1953 | are, there is most likely a stack cycle. As with the inner-than |
| 1954 | test above, avoid comparing the inner-most and sentinel frames. */ |
| 1955 | if (this_frame->level > 0 |
| 1956 | && frame_id_eq (get_frame_id (this_frame), |
| 1957 | get_frame_id (this_frame->next))) |
| 1958 | error ("Previous frame identical to this frame (corrupt stack?)"); |
| 1959 | |
| 1960 | /* Allocate the new frame but do not wire it in to the frame chain. |
| 1961 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along |
| 1962 | frame->next to pull some fancy tricks (of course such code is, by |
| 1963 | definition, recursive). Try to prevent it. |
| 1964 | |
| 1965 | There is no reason to worry about memory leaks, should the |
| 1966 | remainder of the function fail. The allocated memory will be |
| 1967 | quickly reclaimed when the frame cache is flushed, and the `we've |
| 1968 | been here before' check above will stop repeated memory |
| 1969 | allocation calls. */ |
| 1970 | prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| 1971 | prev_frame->level = this_frame->level + 1; |
| 1972 | |
| 1973 | /* Try to unwind the PC. If that doesn't work, assume we've reached |
| 1974 | the oldest frame and simply return. Is there a better sentinal |
| 1975 | value? The unwound PC value is then used to initialize the new |
| 1976 | previous frame's type. |
| 1977 | |
| 1978 | Note that the pc-unwind is intentionally performed before the |
| 1979 | frame chain. This is ok since, for old targets, both |
| 1980 | frame_pc_unwind (nee, FRAME_SAVED_PC) and |
| 1981 | DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures |
| 1982 | have already been initialized (using |
| 1983 | DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
| 1984 | doesn't matter. |
| 1985 | |
| 1986 | By unwinding the PC first, it becomes possible to, in the case of |
| 1987 | a dummy frame, avoid also unwinding the frame ID. This is |
| 1988 | because (well ignoring the PPC) a dummy frame can be located |
| 1989 | using THIS_FRAME's frame ID. */ |
| 1990 | |
| 1991 | if (frame_pc_unwind (this_frame) == 0) |
| 1992 | { |
| 1993 | /* The allocated PREV_FRAME will be reclaimed when the frame |
| 1994 | obstack is next purged. */ |
| 1995 | if (frame_debug) |
| 1996 | { |
| 1997 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1998 | fprint_frame (gdb_stdlog, NULL); |
| 1999 | fprintf_unfiltered (gdb_stdlog, " // unwound PC zero }\n"); |
| 2000 | } |
| 2001 | return NULL; |
| 2002 | } |
| 2003 | |
| 2004 | /* Don't yet compute ->unwind (and hence ->type). It is computed |
| 2005 | on-demand in get_frame_type, frame_register_unwind, and |
| 2006 | get_frame_id. */ |
| 2007 | |
| 2008 | /* Don't yet compute the frame's ID. It is computed on-demand by |
| 2009 | get_frame_id(). */ |
| 2010 | |
| 2011 | /* The unwound frame ID is validate at the start of this function, |
| 2012 | as part of the logic to decide if that frame should be further |
| 2013 | unwound, and not here while the prev frame is being created. |
| 2014 | Doing this makes it possible for the user to examine a frame that |
| 2015 | has an invalid frame ID. |
| 2016 | |
| 2017 | Some very old VAX code noted: [...] For the sake of argument, |
| 2018 | suppose that the stack is somewhat trashed (which is one reason |
| 2019 | that "info frame" exists). So, return 0 (indicating we don't |
| 2020 | know the address of the arglist) if we don't know what frame this |
| 2021 | frame calls. */ |
| 2022 | |
| 2023 | /* Link it in. */ |
| 2024 | this_frame->prev = prev_frame; |
| 2025 | prev_frame->next = this_frame; |
| 2026 | |
| 2027 | if (frame_debug) |
| 2028 | { |
| 2029 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 2030 | fprint_frame (gdb_stdlog, prev_frame); |
| 2031 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 2032 | } |
| 2033 | |
| 2034 | return prev_frame; |
| 2035 | } |
| 2036 | |
| 2037 | CORE_ADDR |
| 2038 | get_frame_pc (struct frame_info *frame) |
| 2039 | { |
| 2040 | gdb_assert (frame->next != NULL); |
| 2041 | return frame_pc_unwind (frame->next); |
| 2042 | } |
| 2043 | |
| 2044 | /* Return an address of that falls within the frame's code block. */ |
| 2045 | |
| 2046 | CORE_ADDR |
| 2047 | frame_unwind_address_in_block (struct frame_info *next_frame) |
| 2048 | { |
| 2049 | /* A draft address. */ |
| 2050 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 2051 | |
| 2052 | /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel), |
| 2053 | and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS |
| 2054 | frame's PC ends up pointing at the instruction fallowing the |
| 2055 | "call". Adjust that PC value so that it falls on the call |
| 2056 | instruction (which, hopefully, falls within THIS frame's code |
| 2057 | block. So far it's proved to be a very good approximation. See |
| 2058 | get_frame_type for why ->type can't be used. */ |
| 2059 | if (next_frame->level >= 0 |
| 2060 | && get_frame_type (next_frame) == NORMAL_FRAME) |
| 2061 | --pc; |
| 2062 | return pc; |
| 2063 | } |
| 2064 | |
| 2065 | CORE_ADDR |
| 2066 | get_frame_address_in_block (struct frame_info *this_frame) |
| 2067 | { |
| 2068 | return frame_unwind_address_in_block (this_frame->next); |
| 2069 | } |
| 2070 | |
| 2071 | static int |
| 2072 | pc_notcurrent (struct frame_info *frame) |
| 2073 | { |
| 2074 | /* If FRAME is not the innermost frame, that normally means that |
| 2075 | FRAME->pc points at the return instruction (which is *after* the |
| 2076 | call instruction), and we want to get the line containing the |
| 2077 | call (because the call is where the user thinks the program is). |
| 2078 | However, if the next frame is either a SIGTRAMP_FRAME or a |
| 2079 | DUMMY_FRAME, then the next frame will contain a saved interrupt |
| 2080 | PC and such a PC indicates the current (rather than next) |
| 2081 | instruction/line, consequently, for such cases, want to get the |
| 2082 | line containing fi->pc. */ |
| 2083 | struct frame_info *next = get_next_frame (frame); |
| 2084 | int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME); |
| 2085 | return notcurrent; |
| 2086 | } |
| 2087 | |
| 2088 | void |
| 2089 | find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal) |
| 2090 | { |
| 2091 | (*sal) = find_pc_line (get_frame_pc (frame), pc_notcurrent (frame)); |
| 2092 | } |
| 2093 | |
| 2094 | /* Per "frame.h", return the ``address'' of the frame. Code should |
| 2095 | really be using get_frame_id(). */ |
| 2096 | CORE_ADDR |
| 2097 | get_frame_base (struct frame_info *fi) |
| 2098 | { |
| 2099 | return get_frame_id (fi).stack_addr; |
| 2100 | } |
| 2101 | |
| 2102 | /* High-level offsets into the frame. Used by the debug info. */ |
| 2103 | |
| 2104 | CORE_ADDR |
| 2105 | get_frame_base_address (struct frame_info *fi) |
| 2106 | { |
| 2107 | if (get_frame_type (fi) != NORMAL_FRAME) |
| 2108 | return 0; |
| 2109 | if (fi->base == NULL) |
| 2110 | fi->base = frame_base_find_by_frame (fi->next); |
| 2111 | /* Sneaky: If the low-level unwind and high-level base code share a |
| 2112 | common unwinder, let them share the prologue cache. */ |
| 2113 | if (fi->base->unwind == fi->unwind) |
| 2114 | return fi->base->this_base (fi->next, &fi->prologue_cache); |
| 2115 | return fi->base->this_base (fi->next, &fi->base_cache); |
| 2116 | } |
| 2117 | |
| 2118 | CORE_ADDR |
| 2119 | get_frame_locals_address (struct frame_info *fi) |
| 2120 | { |
| 2121 | void **cache; |
| 2122 | if (get_frame_type (fi) != NORMAL_FRAME) |
| 2123 | return 0; |
| 2124 | /* If there isn't a frame address method, find it. */ |
| 2125 | if (fi->base == NULL) |
| 2126 | fi->base = frame_base_find_by_frame (fi->next); |
| 2127 | /* Sneaky: If the low-level unwind and high-level base code share a |
| 2128 | common unwinder, let them share the prologue cache. */ |
| 2129 | if (fi->base->unwind == fi->unwind) |
| 2130 | cache = &fi->prologue_cache; |
| 2131 | else |
| 2132 | cache = &fi->base_cache; |
| 2133 | return fi->base->this_locals (fi->next, cache); |
| 2134 | } |
| 2135 | |
| 2136 | CORE_ADDR |
| 2137 | get_frame_args_address (struct frame_info *fi) |
| 2138 | { |
| 2139 | void **cache; |
| 2140 | if (get_frame_type (fi) != NORMAL_FRAME) |
| 2141 | return 0; |
| 2142 | /* If there isn't a frame address method, find it. */ |
| 2143 | if (fi->base == NULL) |
| 2144 | fi->base = frame_base_find_by_frame (fi->next); |
| 2145 | /* Sneaky: If the low-level unwind and high-level base code share a |
| 2146 | common unwinder, let them share the prologue cache. */ |
| 2147 | if (fi->base->unwind == fi->unwind) |
| 2148 | cache = &fi->prologue_cache; |
| 2149 | else |
| 2150 | cache = &fi->base_cache; |
| 2151 | return fi->base->this_args (fi->next, cache); |
| 2152 | } |
| 2153 | |
| 2154 | /* Level of the selected frame: 0 for innermost, 1 for its caller, ... |
| 2155 | or -1 for a NULL frame. */ |
| 2156 | |
| 2157 | int |
| 2158 | frame_relative_level (struct frame_info *fi) |
| 2159 | { |
| 2160 | if (fi == NULL) |
| 2161 | return -1; |
| 2162 | else |
| 2163 | return fi->level; |
| 2164 | } |
| 2165 | |
| 2166 | enum frame_type |
| 2167 | get_frame_type (struct frame_info *frame) |
| 2168 | { |
| 2169 | /* Some targets still don't use [generic] dummy frames. Catch them |
| 2170 | here. */ |
| 2171 | if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
| 2172 | && deprecated_frame_in_dummy (frame)) |
| 2173 | return DUMMY_FRAME; |
| 2174 | |
| 2175 | /* Some legacy code, e.g, mips_init_extra_frame_info() wants |
| 2176 | to determine the frame's type prior to it being completely |
| 2177 | initialized. Don't attempt to lazily initialize ->unwind for |
| 2178 | legacy code. It will be initialized in legacy_get_prev_frame(). */ |
| 2179 | if (frame->unwind == NULL && !legacy_frame_p (current_gdbarch)) |
| 2180 | { |
| 2181 | /* Initialize the frame's unwinder because it is that which |
| 2182 | provides the frame's type. */ |
| 2183 | frame->unwind = frame_unwind_find_by_frame (frame->next); |
| 2184 | /* FIXME: cagney/2003-04-02: Rather than storing the frame's |
| 2185 | type in the frame, the unwinder's type should be returned |
| 2186 | directly. Unfortunatly, legacy code, called by |
| 2187 | legacy_get_prev_frame, explicitly set the frames type using |
| 2188 | the method deprecated_set_frame_type(). */ |
| 2189 | gdb_assert (frame->unwind->type != UNKNOWN_FRAME); |
| 2190 | frame->type = frame->unwind->type; |
| 2191 | } |
| 2192 | if (frame->type == UNKNOWN_FRAME) |
| 2193 | return NORMAL_FRAME; |
| 2194 | else |
| 2195 | return frame->type; |
| 2196 | } |
| 2197 | |
| 2198 | void |
| 2199 | deprecated_set_frame_type (struct frame_info *frame, enum frame_type type) |
| 2200 | { |
| 2201 | /* Arrrg! See comment in "frame.h". */ |
| 2202 | frame->type = type; |
| 2203 | } |
| 2204 | |
| 2205 | struct frame_extra_info * |
| 2206 | get_frame_extra_info (struct frame_info *fi) |
| 2207 | { |
| 2208 | return fi->extra_info; |
| 2209 | } |
| 2210 | |
| 2211 | struct frame_extra_info * |
| 2212 | frame_extra_info_zalloc (struct frame_info *fi, long size) |
| 2213 | { |
| 2214 | fi->extra_info = frame_obstack_zalloc (size); |
| 2215 | return fi->extra_info; |
| 2216 | } |
| 2217 | |
| 2218 | void |
| 2219 | deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc) |
| 2220 | { |
| 2221 | if (frame_debug) |
| 2222 | fprintf_unfiltered (gdb_stdlog, |
| 2223 | "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n", |
| 2224 | frame->level, paddr_nz (pc)); |
| 2225 | /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are |
| 2226 | maintaining a locally allocated frame object. Since such frame's |
| 2227 | are not in the frame chain, it isn't possible to assume that the |
| 2228 | frame has a next. Sigh. */ |
| 2229 | if (frame->next != NULL) |
| 2230 | { |
| 2231 | /* While we're at it, update this frame's cached PC value, found |
| 2232 | in the next frame. Oh for the day when "struct frame_info" |
| 2233 | is opaque and this hack on hack can just go away. */ |
| 2234 | frame->next->prev_pc.value = pc; |
| 2235 | frame->next->prev_pc.p = 1; |
| 2236 | } |
| 2237 | } |
| 2238 | |
| 2239 | void |
| 2240 | deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base) |
| 2241 | { |
| 2242 | if (frame_debug) |
| 2243 | fprintf_unfiltered (gdb_stdlog, |
| 2244 | "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n", |
| 2245 | frame->level, paddr_nz (base)); |
| 2246 | /* See comment in "frame.h". */ |
| 2247 | frame->this_id.value.stack_addr = base; |
| 2248 | } |
| 2249 | |
| 2250 | void |
| 2251 | deprecated_set_frame_saved_regs_hack (struct frame_info *frame, |
| 2252 | CORE_ADDR *saved_regs) |
| 2253 | { |
| 2254 | frame->saved_regs = saved_regs; |
| 2255 | } |
| 2256 | |
| 2257 | void |
| 2258 | deprecated_set_frame_extra_info_hack (struct frame_info *frame, |
| 2259 | struct frame_extra_info *extra_info) |
| 2260 | { |
| 2261 | frame->extra_info = extra_info; |
| 2262 | } |
| 2263 | |
| 2264 | void |
| 2265 | deprecated_set_frame_next_hack (struct frame_info *fi, |
| 2266 | struct frame_info *next) |
| 2267 | { |
| 2268 | fi->next = next; |
| 2269 | } |
| 2270 | |
| 2271 | void |
| 2272 | deprecated_set_frame_prev_hack (struct frame_info *fi, |
| 2273 | struct frame_info *prev) |
| 2274 | { |
| 2275 | fi->prev = prev; |
| 2276 | } |
| 2277 | |
| 2278 | struct context * |
| 2279 | deprecated_get_frame_context (struct frame_info *fi) |
| 2280 | { |
| 2281 | return fi->context; |
| 2282 | } |
| 2283 | |
| 2284 | void |
| 2285 | deprecated_set_frame_context (struct frame_info *fi, |
| 2286 | struct context *context) |
| 2287 | { |
| 2288 | fi->context = context; |
| 2289 | } |
| 2290 | |
| 2291 | struct frame_info * |
| 2292 | deprecated_frame_xmalloc (void) |
| 2293 | { |
| 2294 | struct frame_info *frame = XMALLOC (struct frame_info); |
| 2295 | memset (frame, 0, sizeof (*frame)); |
| 2296 | frame->this_id.p = 1; |
| 2297 | return frame; |
| 2298 | } |
| 2299 | |
| 2300 | struct frame_info * |
| 2301 | deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs, |
| 2302 | long sizeof_extra_info) |
| 2303 | { |
| 2304 | struct frame_info *frame = deprecated_frame_xmalloc (); |
| 2305 | make_cleanup (xfree, frame); |
| 2306 | if (sizeof_saved_regs > 0) |
| 2307 | { |
| 2308 | frame->saved_regs = xcalloc (1, sizeof_saved_regs); |
| 2309 | make_cleanup (xfree, frame->saved_regs); |
| 2310 | } |
| 2311 | if (sizeof_extra_info > 0) |
| 2312 | { |
| 2313 | frame->extra_info = xcalloc (1, sizeof_extra_info); |
| 2314 | make_cleanup (xfree, frame->extra_info); |
| 2315 | } |
| 2316 | return frame; |
| 2317 | } |
| 2318 | |
| 2319 | /* Memory access methods. */ |
| 2320 | |
| 2321 | void |
| 2322 | get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, void *buf, |
| 2323 | int len) |
| 2324 | { |
| 2325 | read_memory (addr, buf, len); |
| 2326 | } |
| 2327 | |
| 2328 | LONGEST |
| 2329 | get_frame_memory_signed (struct frame_info *this_frame, CORE_ADDR addr, |
| 2330 | int len) |
| 2331 | { |
| 2332 | return read_memory_integer (addr, len); |
| 2333 | } |
| 2334 | |
| 2335 | ULONGEST |
| 2336 | get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr, |
| 2337 | int len) |
| 2338 | { |
| 2339 | return read_memory_unsigned_integer (addr, len); |
| 2340 | } |
| 2341 | |
| 2342 | /* Architecture method. */ |
| 2343 | |
| 2344 | struct gdbarch * |
| 2345 | get_frame_arch (struct frame_info *this_frame) |
| 2346 | { |
| 2347 | return current_gdbarch; |
| 2348 | } |
| 2349 | |
| 2350 | /* Stack pointer methods. */ |
| 2351 | |
| 2352 | CORE_ADDR |
| 2353 | get_frame_sp (struct frame_info *this_frame) |
| 2354 | { |
| 2355 | return frame_sp_unwind (this_frame->next); |
| 2356 | } |
| 2357 | |
| 2358 | CORE_ADDR |
| 2359 | frame_sp_unwind (struct frame_info *next_frame) |
| 2360 | { |
| 2361 | /* Normality, an architecture that provides a way of obtaining any |
| 2362 | frame inner-most address. */ |
| 2363 | if (gdbarch_unwind_sp_p (current_gdbarch)) |
| 2364 | return gdbarch_unwind_sp (current_gdbarch, next_frame); |
| 2365 | /* Things are looking grim. If it's the inner-most frame and there |
| 2366 | is a TARGET_READ_SP then that can be used. */ |
| 2367 | if (next_frame->level < 0 && TARGET_READ_SP_P ()) |
| 2368 | return TARGET_READ_SP (); |
| 2369 | /* Now things are really are grim. Hope that the value returned by |
| 2370 | the SP_REGNUM register is meaningful. */ |
| 2371 | if (SP_REGNUM >= 0) |
| 2372 | { |
| 2373 | ULONGEST sp; |
| 2374 | frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp); |
| 2375 | return sp; |
| 2376 | } |
| 2377 | internal_error (__FILE__, __LINE__, "Missing unwind SP method"); |
| 2378 | } |
| 2379 | |
| 2380 | |
| 2381 | int |
| 2382 | legacy_frame_p (struct gdbarch *current_gdbarch) |
| 2383 | { |
| 2384 | return (DEPRECATED_INIT_FRAME_PC_P () |
| 2385 | || DEPRECATED_INIT_FRAME_PC_FIRST_P () |
| 2386 | || DEPRECATED_INIT_EXTRA_FRAME_INFO_P () |
| 2387 | || DEPRECATED_FRAME_CHAIN_P () |
| 2388 | || !gdbarch_unwind_dummy_id_p (current_gdbarch)); |
| 2389 | } |
| 2390 | |
| 2391 | extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */ |
| 2392 | |
| 2393 | static struct cmd_list_element *set_backtrace_cmdlist; |
| 2394 | static struct cmd_list_element *show_backtrace_cmdlist; |
| 2395 | |
| 2396 | static void |
| 2397 | set_backtrace_cmd (char *args, int from_tty) |
| 2398 | { |
| 2399 | help_list (set_backtrace_cmdlist, "set backtrace ", -1, gdb_stdout); |
| 2400 | } |
| 2401 | |
| 2402 | static void |
| 2403 | show_backtrace_cmd (char *args, int from_tty) |
| 2404 | { |
| 2405 | cmd_show_list (show_backtrace_cmdlist, from_tty, ""); |
| 2406 | } |
| 2407 | |
| 2408 | void |
| 2409 | _initialize_frame (void) |
| 2410 | { |
| 2411 | obstack_init (&frame_cache_obstack); |
| 2412 | |
| 2413 | add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, "\ |
| 2414 | Set backtrace specific variables.\n\ |
| 2415 | Configure backtrace variables such as the backtrace limit", |
| 2416 | &set_backtrace_cmdlist, "set backtrace ", |
| 2417 | 0/*allow-unknown*/, &setlist); |
| 2418 | add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, "\ |
| 2419 | Show backtrace specific variables\n\ |
| 2420 | Show backtrace variables such as the backtrace limit", |
| 2421 | &show_backtrace_cmdlist, "show backtrace ", |
| 2422 | 0/*allow-unknown*/, &showlist); |
| 2423 | |
| 2424 | add_setshow_boolean_cmd ("past-main", class_obscure, |
| 2425 | &backtrace_past_main, "\ |
| 2426 | Set whether backtraces should continue past \"main\".\n\ |
| 2427 | Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ |
| 2428 | the backtrace at \"main\". Set this variable if you need to see the rest\n\ |
| 2429 | of the stack trace.", "\ |
| 2430 | Show whether backtraces should continue past \"main\".\n\ |
| 2431 | Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ |
| 2432 | the backtrace at \"main\". Set this variable if you need to see the rest\n\ |
| 2433 | of the stack trace.", |
| 2434 | NULL, NULL, &set_backtrace_cmdlist, |
| 2435 | &show_backtrace_cmdlist); |
| 2436 | |
| 2437 | add_setshow_uinteger_cmd ("limit", class_obscure, |
| 2438 | &backtrace_limit, "\ |
| 2439 | Set an upper bound on the number of backtrace levels.\n\ |
| 2440 | No more than the specified number of frames can be displayed or examined.\n\ |
| 2441 | Zero is unlimited.", "\ |
| 2442 | Show the upper bound on the number of backtrace levels.", |
| 2443 | NULL, NULL, &set_backtrace_cmdlist, |
| 2444 | &show_backtrace_cmdlist); |
| 2445 | |
| 2446 | /* Debug this files internals. */ |
| 2447 | add_show_from_set (add_set_cmd ("frame", class_maintenance, var_zinteger, |
| 2448 | &frame_debug, "Set frame debugging.\n\ |
| 2449 | When non-zero, frame specific internal debugging is enabled.", &setdebuglist), |
| 2450 | &showdebuglist); |
| 2451 | } |