| 1 | /* Get info from stack frames; |
| 2 | convert between frames, blocks, functions and pc values. |
| 3 | Copyright 1986, 1987, 1988, 1989, 1991 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "symtab.h" |
| 23 | #include "bfd.h" |
| 24 | #include "symfile.h" |
| 25 | #include "objfiles.h" |
| 26 | #include "frame.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "value.h" /* for read_register */ |
| 29 | #include "target.h" /* for target_has_stack */ |
| 30 | #include "inferior.h" /* for read_pc */ |
| 31 | |
| 32 | /* Is ADDR inside the startup file? Note that if your machine |
| 33 | has a way to detect the bottom of the stack, there is no need |
| 34 | to call this function from FRAME_CHAIN_VALID; the reason for |
| 35 | doing so is that some machines have no way of detecting bottom |
| 36 | of stack. |
| 37 | |
| 38 | A PC of zero is always considered to be the bottom of the stack. */ |
| 39 | |
| 40 | int |
| 41 | inside_entry_file (addr) |
| 42 | CORE_ADDR addr; |
| 43 | { |
| 44 | if (addr == 0) |
| 45 | return 1; |
| 46 | if (symfile_objfile == 0) |
| 47 | return 0; |
| 48 | #if CALL_DUMMY_LOCATION == AT_ENTRY_POINT |
| 49 | /* Do not stop backtracing if the pc is in the call dummy |
| 50 | at the entry point. */ |
| 51 | if (PC_IN_CALL_DUMMY (addr, 0, 0)) |
| 52 | return 0; |
| 53 | #endif |
| 54 | return (addr >= symfile_objfile -> ei.entry_file_lowpc && |
| 55 | addr < symfile_objfile -> ei.entry_file_highpc); |
| 56 | } |
| 57 | |
| 58 | /* Test a specified PC value to see if it is in the range of addresses |
| 59 | that correspond to the main() function. See comments above for why |
| 60 | we might want to do this. |
| 61 | |
| 62 | Typically called from FRAME_CHAIN_VALID. |
| 63 | |
| 64 | A PC of zero is always considered to be the bottom of the stack. */ |
| 65 | |
| 66 | int |
| 67 | inside_main_func (pc) |
| 68 | CORE_ADDR pc; |
| 69 | { |
| 70 | if (pc == 0) |
| 71 | return 1; |
| 72 | if (symfile_objfile == 0) |
| 73 | return 0; |
| 74 | return (symfile_objfile -> ei.main_func_lowpc <= pc && |
| 75 | symfile_objfile -> ei.main_func_highpc > pc); |
| 76 | } |
| 77 | |
| 78 | /* Test a specified PC value to see if it is in the range of addresses |
| 79 | that correspond to the process entry point function. See comments |
| 80 | in objfiles.h for why we might want to do this. |
| 81 | |
| 82 | Typically called from FRAME_CHAIN_VALID. |
| 83 | |
| 84 | A PC of zero is always considered to be the bottom of the stack. */ |
| 85 | |
| 86 | int |
| 87 | inside_entry_func (pc) |
| 88 | CORE_ADDR pc; |
| 89 | { |
| 90 | if (pc == 0) |
| 91 | return 1; |
| 92 | if (symfile_objfile == 0) |
| 93 | return 0; |
| 94 | #if CALL_DUMMY_LOCATION == AT_ENTRY_POINT |
| 95 | /* Do not stop backtracing if the pc is in the call dummy |
| 96 | at the entry point. */ |
| 97 | if (PC_IN_CALL_DUMMY (pc, 0, 0)) |
| 98 | return 0; |
| 99 | #endif |
| 100 | return (symfile_objfile -> ei.entry_func_lowpc <= pc && |
| 101 | symfile_objfile -> ei.entry_func_highpc > pc); |
| 102 | } |
| 103 | |
| 104 | /* Address of innermost stack frame (contents of FP register) */ |
| 105 | |
| 106 | static FRAME current_frame; |
| 107 | |
| 108 | /* |
| 109 | * Cache for frame addresses already read by gdb. Valid only while |
| 110 | * inferior is stopped. Control variables for the frame cache should |
| 111 | * be local to this module. |
| 112 | */ |
| 113 | struct obstack frame_cache_obstack; |
| 114 | |
| 115 | /* Return the innermost (currently executing) stack frame. */ |
| 116 | |
| 117 | FRAME |
| 118 | get_current_frame () |
| 119 | { |
| 120 | /* We assume its address is kept in a general register; |
| 121 | param.h says which register. */ |
| 122 | |
| 123 | return current_frame; |
| 124 | } |
| 125 | |
| 126 | void |
| 127 | set_current_frame (frame) |
| 128 | FRAME frame; |
| 129 | { |
| 130 | current_frame = frame; |
| 131 | } |
| 132 | |
| 133 | FRAME |
| 134 | create_new_frame (addr, pc) |
| 135 | FRAME_ADDR addr; |
| 136 | CORE_ADDR pc; |
| 137 | { |
| 138 | struct frame_info *fci; /* Same type as FRAME */ |
| 139 | char *name; |
| 140 | |
| 141 | fci = (struct frame_info *) |
| 142 | obstack_alloc (&frame_cache_obstack, |
| 143 | sizeof (struct frame_info)); |
| 144 | |
| 145 | /* Arbitrary frame */ |
| 146 | fci->next = (struct frame_info *) 0; |
| 147 | fci->prev = (struct frame_info *) 0; |
| 148 | fci->frame = addr; |
| 149 | fci->pc = pc; |
| 150 | find_pc_partial_function (pc, &name, (CORE_ADDR *)NULL,(CORE_ADDR *)NULL); |
| 151 | fci->signal_handler_caller = IN_SIGTRAMP (fci->pc, name); |
| 152 | |
| 153 | #ifdef INIT_EXTRA_FRAME_INFO |
| 154 | INIT_EXTRA_FRAME_INFO (0, fci); |
| 155 | #endif |
| 156 | |
| 157 | return fci; |
| 158 | } |
| 159 | |
| 160 | /* Return the frame that called FRAME. |
| 161 | If FRAME is the original frame (it has no caller), return 0. */ |
| 162 | |
| 163 | FRAME |
| 164 | get_prev_frame (frame) |
| 165 | FRAME frame; |
| 166 | { |
| 167 | /* We're allowed to know that FRAME and "struct frame_info *" are |
| 168 | the same */ |
| 169 | return get_prev_frame_info (frame); |
| 170 | } |
| 171 | |
| 172 | /* Return the frame that FRAME calls (0 if FRAME is the innermost |
| 173 | frame). */ |
| 174 | |
| 175 | FRAME |
| 176 | get_next_frame (frame) |
| 177 | FRAME frame; |
| 178 | { |
| 179 | /* We're allowed to know that FRAME and "struct frame_info *" are |
| 180 | the same */ |
| 181 | return frame->next; |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * Flush the entire frame cache. |
| 186 | */ |
| 187 | void |
| 188 | flush_cached_frames () |
| 189 | { |
| 190 | /* Since we can't really be sure what the first object allocated was */ |
| 191 | obstack_free (&frame_cache_obstack, 0); |
| 192 | obstack_init (&frame_cache_obstack); |
| 193 | |
| 194 | current_frame = (struct frame_info *) 0; /* Invalidate cache */ |
| 195 | } |
| 196 | |
| 197 | /* Flush the frame cache, and start a new one if necessary. */ |
| 198 | void |
| 199 | reinit_frame_cache () |
| 200 | { |
| 201 | flush_cached_frames (); |
| 202 | if (target_has_stack) |
| 203 | { |
| 204 | set_current_frame (create_new_frame (read_fp (), read_pc ())); |
| 205 | select_frame (get_current_frame (), 0); |
| 206 | } |
| 207 | else |
| 208 | { |
| 209 | set_current_frame (0); |
| 210 | select_frame ((FRAME) 0, -1); |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | /* Return a structure containing various interesting information |
| 215 | about a specified stack frame. */ |
| 216 | /* How do I justify including this function? Well, the FRAME |
| 217 | identifier format has gone through several changes recently, and |
| 218 | it's not completely inconceivable that it could happen again. If |
| 219 | it does, have this routine around will help */ |
| 220 | |
| 221 | struct frame_info * |
| 222 | get_frame_info (frame) |
| 223 | FRAME frame; |
| 224 | { |
| 225 | return frame; |
| 226 | } |
| 227 | |
| 228 | /* If a machine allows frameless functions, it should define a macro |
| 229 | FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct |
| 230 | frame_info for the frame, and FRAMELESS should be set to nonzero |
| 231 | if it represents a frameless function invocation. */ |
| 232 | |
| 233 | /* Return nonzero if the function for this frame lacks a prologue. Many |
| 234 | machines can define FRAMELESS_FUNCTION_INVOCATION to just call this |
| 235 | function. */ |
| 236 | |
| 237 | int |
| 238 | frameless_look_for_prologue (frame) |
| 239 | FRAME frame; |
| 240 | { |
| 241 | CORE_ADDR func_start, after_prologue; |
| 242 | func_start = (get_pc_function_start (frame->pc) + |
| 243 | FUNCTION_START_OFFSET); |
| 244 | if (func_start) |
| 245 | { |
| 246 | after_prologue = func_start; |
| 247 | #ifdef SKIP_PROLOGUE_FRAMELESS_P |
| 248 | /* This is faster, since only care whether there *is* a prologue, |
| 249 | not how long it is. */ |
| 250 | SKIP_PROLOGUE_FRAMELESS_P (after_prologue); |
| 251 | #else |
| 252 | SKIP_PROLOGUE (after_prologue); |
| 253 | #endif |
| 254 | return after_prologue == func_start; |
| 255 | } |
| 256 | else |
| 257 | /* If we can't find the start of the function, we don't really |
| 258 | know whether the function is frameless, but we should be able |
| 259 | to get a reasonable (i.e. best we can do under the |
| 260 | circumstances) backtrace by saying that it isn't. */ |
| 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | /* Default a few macros that people seldom redefine. */ |
| 265 | |
| 266 | #if !defined (INIT_FRAME_PC) |
| 267 | #define INIT_FRAME_PC(fromleaf, prev) \ |
| 268 | prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \ |
| 269 | prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ()); |
| 270 | #endif |
| 271 | |
| 272 | #ifndef FRAME_CHAIN_COMBINE |
| 273 | #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain) |
| 274 | #endif |
| 275 | |
| 276 | /* Return a structure containing various interesting information |
| 277 | about the frame that called NEXT_FRAME. Returns NULL |
| 278 | if there is no such frame. */ |
| 279 | |
| 280 | struct frame_info * |
| 281 | get_prev_frame_info (next_frame) |
| 282 | FRAME next_frame; |
| 283 | { |
| 284 | FRAME_ADDR address = 0; |
| 285 | struct frame_info *prev; |
| 286 | int fromleaf = 0; |
| 287 | char *name; |
| 288 | |
| 289 | /* If the requested entry is in the cache, return it. |
| 290 | Otherwise, figure out what the address should be for the entry |
| 291 | we're about to add to the cache. */ |
| 292 | |
| 293 | if (!next_frame) |
| 294 | { |
| 295 | if (!current_frame) |
| 296 | { |
| 297 | error ("You haven't set up a process's stack to examine."); |
| 298 | } |
| 299 | |
| 300 | return current_frame; |
| 301 | } |
| 302 | |
| 303 | /* If we have the prev one, return it */ |
| 304 | if (next_frame->prev) |
| 305 | return next_frame->prev; |
| 306 | |
| 307 | /* On some machines it is possible to call a function without |
| 308 | setting up a stack frame for it. On these machines, we |
| 309 | define this macro to take two args; a frameinfo pointer |
| 310 | identifying a frame and a variable to set or clear if it is |
| 311 | or isn't leafless. */ |
| 312 | #ifdef FRAMELESS_FUNCTION_INVOCATION |
| 313 | /* Still don't want to worry about this except on the innermost |
| 314 | frame. This macro will set FROMLEAF if NEXT_FRAME is a |
| 315 | frameless function invocation. */ |
| 316 | if (!(next_frame->next)) |
| 317 | { |
| 318 | FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf); |
| 319 | if (fromleaf) |
| 320 | address = next_frame->frame; |
| 321 | } |
| 322 | #endif |
| 323 | |
| 324 | if (!fromleaf) |
| 325 | { |
| 326 | /* Two macros defined in tm.h specify the machine-dependent |
| 327 | actions to be performed here. |
| 328 | First, get the frame's chain-pointer. |
| 329 | If that is zero, the frame is the outermost frame or a leaf |
| 330 | called by the outermost frame. This means that if start |
| 331 | calls main without a frame, we'll return 0 (which is fine |
| 332 | anyway). |
| 333 | |
| 334 | Nope; there's a problem. This also returns when the current |
| 335 | routine is a leaf of main. This is unacceptable. We move |
| 336 | this to after the ffi test; I'd rather have backtraces from |
| 337 | start go curfluy than have an abort called from main not show |
| 338 | main. */ |
| 339 | address = FRAME_CHAIN (next_frame); |
| 340 | if (!FRAME_CHAIN_VALID (address, next_frame)) |
| 341 | return 0; |
| 342 | address = FRAME_CHAIN_COMBINE (address, next_frame); |
| 343 | } |
| 344 | if (address == 0) |
| 345 | return 0; |
| 346 | |
| 347 | prev = (struct frame_info *) |
| 348 | obstack_alloc (&frame_cache_obstack, |
| 349 | sizeof (struct frame_info)); |
| 350 | |
| 351 | if (next_frame) |
| 352 | next_frame->prev = prev; |
| 353 | prev->next = next_frame; |
| 354 | prev->prev = (struct frame_info *) 0; |
| 355 | prev->frame = address; |
| 356 | prev->signal_handler_caller = 0; |
| 357 | |
| 358 | /* This change should not be needed, FIXME! We should |
| 359 | determine whether any targets *need* INIT_FRAME_PC to happen |
| 360 | after INIT_EXTRA_FRAME_INFO and come up with a simple way to |
| 361 | express what goes on here. |
| 362 | |
| 363 | INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame |
| 364 | (where the PC is already set up) and here (where it isn't). |
| 365 | INIT_FRAME_PC is only called from here, always after |
| 366 | INIT_EXTRA_FRAME_INFO. |
| 367 | |
| 368 | The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC |
| 369 | value (which hasn't been set yet). Some other machines appear to |
| 370 | require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo. |
| 371 | |
| 372 | We shouldn't need INIT_FRAME_PC_FIRST to add more complication to |
| 373 | an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92. |
| 374 | |
| 375 | To answer the question, yes the sparc needs INIT_FRAME_PC after |
| 376 | INIT_EXTRA_FRAME_INFO. Suggested scheme: |
| 377 | |
| 378 | SETUP_INNERMOST_FRAME() |
| 379 | Default version is just create_new_frame (read_fp ()), |
| 380 | read_pc ()). Machines with extra frame info would do that (or the |
| 381 | local equivalent) and then set the extra fields. |
| 382 | SETUP_ARBITRARY_FRAME(argc, argv) |
| 383 | Only change here is that create_new_frame would no longer init extra |
| 384 | frame info; SETUP_ARBITRARY_FRAME would have to do that. |
| 385 | INIT_PREV_FRAME(fromleaf, prev) |
| 386 | Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. |
| 387 | std_frame_pc(fromleaf, prev) |
| 388 | This is the default setting for INIT_PREV_FRAME. It just does what |
| 389 | the default INIT_FRAME_PC does. Some machines will call it from |
| 390 | INIT_PREV_FRAME (either at the beginning, the end, or in the middle). |
| 391 | Some machines won't use it. |
| 392 | kingdon@cygnus.com, 13Apr93. */ |
| 393 | |
| 394 | #ifdef INIT_FRAME_PC_FIRST |
| 395 | INIT_FRAME_PC_FIRST (fromleaf, prev); |
| 396 | #endif |
| 397 | |
| 398 | #ifdef INIT_EXTRA_FRAME_INFO |
| 399 | INIT_EXTRA_FRAME_INFO(fromleaf, prev); |
| 400 | #endif |
| 401 | |
| 402 | /* This entry is in the frame queue now, which is good since |
| 403 | FRAME_SAVED_PC may use that queue to figure out it's value |
| 404 | (see tm-sparc.h). We want the pc saved in the inferior frame. */ |
| 405 | INIT_FRAME_PC(fromleaf, prev); |
| 406 | |
| 407 | find_pc_partial_function (prev->pc, &name, |
| 408 | (CORE_ADDR *)NULL,(CORE_ADDR *)NULL); |
| 409 | if (IN_SIGTRAMP (prev->pc, name)) |
| 410 | prev->signal_handler_caller = 1; |
| 411 | |
| 412 | return prev; |
| 413 | } |
| 414 | |
| 415 | CORE_ADDR |
| 416 | get_frame_pc (frame) |
| 417 | FRAME frame; |
| 418 | { |
| 419 | struct frame_info *fi; |
| 420 | fi = get_frame_info (frame); |
| 421 | return fi->pc; |
| 422 | } |
| 423 | |
| 424 | #if defined (FRAME_FIND_SAVED_REGS) |
| 425 | /* Find the addresses in which registers are saved in FRAME. */ |
| 426 | |
| 427 | void |
| 428 | get_frame_saved_regs (frame_info_addr, saved_regs_addr) |
| 429 | struct frame_info *frame_info_addr; |
| 430 | struct frame_saved_regs *saved_regs_addr; |
| 431 | { |
| 432 | FRAME_FIND_SAVED_REGS (frame_info_addr, *saved_regs_addr); |
| 433 | } |
| 434 | #endif |
| 435 | |
| 436 | /* Return the innermost lexical block in execution |
| 437 | in a specified stack frame. The frame address is assumed valid. */ |
| 438 | |
| 439 | struct block * |
| 440 | get_frame_block (frame) |
| 441 | FRAME frame; |
| 442 | { |
| 443 | struct frame_info *fi; |
| 444 | CORE_ADDR pc; |
| 445 | |
| 446 | fi = get_frame_info (frame); |
| 447 | |
| 448 | pc = fi->pc; |
| 449 | if (fi->next != 0 && fi->next->signal_handler_caller == 0) |
| 450 | /* We are not in the innermost frame and we were not interrupted |
| 451 | by a signal. We need to subtract one to get the correct block, |
| 452 | in case the call instruction was the last instruction of the block. |
| 453 | If there are any machines on which the saved pc does not point to |
| 454 | after the call insn, we probably want to make fi->pc point after |
| 455 | the call insn anyway. */ |
| 456 | --pc; |
| 457 | return block_for_pc (pc); |
| 458 | } |
| 459 | |
| 460 | struct block * |
| 461 | get_current_block () |
| 462 | { |
| 463 | return block_for_pc (read_pc ()); |
| 464 | } |
| 465 | |
| 466 | CORE_ADDR |
| 467 | get_pc_function_start (pc) |
| 468 | CORE_ADDR pc; |
| 469 | { |
| 470 | register struct block *bl; |
| 471 | register struct symbol *symbol; |
| 472 | register struct minimal_symbol *msymbol; |
| 473 | CORE_ADDR fstart; |
| 474 | |
| 475 | if ((bl = block_for_pc (pc)) != NULL && |
| 476 | (symbol = block_function (bl)) != NULL) |
| 477 | { |
| 478 | bl = SYMBOL_BLOCK_VALUE (symbol); |
| 479 | fstart = BLOCK_START (bl); |
| 480 | } |
| 481 | else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL) |
| 482 | { |
| 483 | fstart = SYMBOL_VALUE_ADDRESS (msymbol); |
| 484 | } |
| 485 | else |
| 486 | { |
| 487 | fstart = 0; |
| 488 | } |
| 489 | return (fstart); |
| 490 | } |
| 491 | |
| 492 | /* Return the symbol for the function executing in frame FRAME. */ |
| 493 | |
| 494 | struct symbol * |
| 495 | get_frame_function (frame) |
| 496 | FRAME frame; |
| 497 | { |
| 498 | register struct block *bl = get_frame_block (frame); |
| 499 | if (bl == 0) |
| 500 | return 0; |
| 501 | return block_function (bl); |
| 502 | } |
| 503 | \f |
| 504 | /* Return the blockvector immediately containing the innermost lexical block |
| 505 | containing the specified pc value, or 0 if there is none. |
| 506 | PINDEX is a pointer to the index value of the block. If PINDEX |
| 507 | is NULL, we don't pass this information back to the caller. */ |
| 508 | |
| 509 | struct blockvector * |
| 510 | blockvector_for_pc (pc, pindex) |
| 511 | register CORE_ADDR pc; |
| 512 | int *pindex; |
| 513 | { |
| 514 | register struct block *b; |
| 515 | register int bot, top, half; |
| 516 | register struct symtab *s; |
| 517 | struct blockvector *bl; |
| 518 | |
| 519 | /* First search all symtabs for one whose file contains our pc */ |
| 520 | s = find_pc_symtab (pc); |
| 521 | if (s == 0) |
| 522 | return 0; |
| 523 | |
| 524 | bl = BLOCKVECTOR (s); |
| 525 | b = BLOCKVECTOR_BLOCK (bl, 0); |
| 526 | |
| 527 | /* Then search that symtab for the smallest block that wins. */ |
| 528 | /* Use binary search to find the last block that starts before PC. */ |
| 529 | |
| 530 | bot = 0; |
| 531 | top = BLOCKVECTOR_NBLOCKS (bl); |
| 532 | |
| 533 | while (top - bot > 1) |
| 534 | { |
| 535 | half = (top - bot + 1) >> 1; |
| 536 | b = BLOCKVECTOR_BLOCK (bl, bot + half); |
| 537 | if (BLOCK_START (b) <= pc) |
| 538 | bot += half; |
| 539 | else |
| 540 | top = bot + half; |
| 541 | } |
| 542 | |
| 543 | /* Now search backward for a block that ends after PC. */ |
| 544 | |
| 545 | while (bot >= 0) |
| 546 | { |
| 547 | b = BLOCKVECTOR_BLOCK (bl, bot); |
| 548 | if (BLOCK_END (b) > pc) |
| 549 | { |
| 550 | if (pindex) |
| 551 | *pindex = bot; |
| 552 | return bl; |
| 553 | } |
| 554 | bot--; |
| 555 | } |
| 556 | |
| 557 | return 0; |
| 558 | } |
| 559 | |
| 560 | /* Return the innermost lexical block containing the specified pc value, |
| 561 | or 0 if there is none. */ |
| 562 | |
| 563 | struct block * |
| 564 | block_for_pc (pc) |
| 565 | register CORE_ADDR pc; |
| 566 | { |
| 567 | register struct blockvector *bl; |
| 568 | int index; |
| 569 | |
| 570 | bl = blockvector_for_pc (pc, &index); |
| 571 | if (bl) |
| 572 | return BLOCKVECTOR_BLOCK (bl, index); |
| 573 | return 0; |
| 574 | } |
| 575 | |
| 576 | /* Return the function containing pc value PC. |
| 577 | Returns 0 if function is not known. */ |
| 578 | |
| 579 | struct symbol * |
| 580 | find_pc_function (pc) |
| 581 | CORE_ADDR pc; |
| 582 | { |
| 583 | register struct block *b = block_for_pc (pc); |
| 584 | if (b == 0) |
| 585 | return 0; |
| 586 | return block_function (b); |
| 587 | } |
| 588 | |
| 589 | /* These variables are used to cache the most recent result |
| 590 | * of find_pc_partial_function. */ |
| 591 | |
| 592 | static CORE_ADDR cache_pc_function_low = 0; |
| 593 | static CORE_ADDR cache_pc_function_high = 0; |
| 594 | static char *cache_pc_function_name = 0; |
| 595 | |
| 596 | /* Clear cache, e.g. when symbol table is discarded. */ |
| 597 | |
| 598 | void |
| 599 | clear_pc_function_cache() |
| 600 | { |
| 601 | cache_pc_function_low = 0; |
| 602 | cache_pc_function_high = 0; |
| 603 | cache_pc_function_name = (char *)0; |
| 604 | } |
| 605 | |
| 606 | /* Finds the "function" (text symbol) that is smaller than PC but |
| 607 | greatest of all of the potential text symbols. Sets *NAME and/or |
| 608 | *ADDRESS conditionally if that pointer is non-null. If ENDADDR is |
| 609 | non-null, then set *ENDADDR to be the end of the function |
| 610 | (exclusive), but passing ENDADDR as non-null means that the |
| 611 | function might cause symbols to be read. This function either |
| 612 | succeeds or fails (not halfway succeeds). If it succeeds, it sets |
| 613 | *NAME, *ADDRESS, and *ENDADDR to real information and returns 1. |
| 614 | If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero |
| 615 | and returns 0. */ |
| 616 | |
| 617 | int |
| 618 | find_pc_partial_function (pc, name, address, endaddr) |
| 619 | CORE_ADDR pc; |
| 620 | char **name; |
| 621 | CORE_ADDR *address; |
| 622 | CORE_ADDR *endaddr; |
| 623 | { |
| 624 | struct partial_symtab *pst; |
| 625 | struct symbol *f; |
| 626 | struct minimal_symbol *msymbol; |
| 627 | struct partial_symbol *psb; |
| 628 | struct obj_section *sec; |
| 629 | |
| 630 | if (pc >= cache_pc_function_low && pc < cache_pc_function_high) |
| 631 | goto return_cached_value; |
| 632 | |
| 633 | /* If sigtramp is in the u area, it counts as a function (especially |
| 634 | important for step_1). */ |
| 635 | #if defined SIGTRAMP_START |
| 636 | if (IN_SIGTRAMP (pc, (char *)NULL)) |
| 637 | { |
| 638 | cache_pc_function_low = SIGTRAMP_START; |
| 639 | cache_pc_function_high = SIGTRAMP_END; |
| 640 | cache_pc_function_name = "<sigtramp>"; |
| 641 | |
| 642 | goto return_cached_value; |
| 643 | } |
| 644 | #endif |
| 645 | |
| 646 | msymbol = lookup_minimal_symbol_by_pc (pc); |
| 647 | pst = find_pc_psymtab (pc); |
| 648 | if (pst) |
| 649 | { |
| 650 | /* Need to read the symbols to get a good value for the end address. */ |
| 651 | if (endaddr != NULL && !pst->readin) |
| 652 | { |
| 653 | /* Need to get the terminal in case symbol-reading produces |
| 654 | output. */ |
| 655 | target_terminal_ours_for_output (); |
| 656 | PSYMTAB_TO_SYMTAB (pst); |
| 657 | } |
| 658 | |
| 659 | if (pst->readin) |
| 660 | { |
| 661 | /* Checking whether the msymbol has a larger value is for the |
| 662 | "pathological" case mentioned in print_frame_info. */ |
| 663 | f = find_pc_function (pc); |
| 664 | if (f != NULL |
| 665 | && (msymbol == NULL |
| 666 | || (BLOCK_START (SYMBOL_BLOCK_VALUE (f)) |
| 667 | >= SYMBOL_VALUE_ADDRESS (msymbol)))) |
| 668 | { |
| 669 | cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f)); |
| 670 | cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f)); |
| 671 | cache_pc_function_name = SYMBOL_NAME (f); |
| 672 | goto return_cached_value; |
| 673 | } |
| 674 | } |
| 675 | else |
| 676 | { |
| 677 | /* Now that static symbols go in the minimal symbol table, perhaps |
| 678 | we could just ignore the partial symbols. But at least for now |
| 679 | we use the partial or minimal symbol, whichever is larger. */ |
| 680 | psb = find_pc_psymbol (pst, pc); |
| 681 | |
| 682 | if (psb |
| 683 | && (msymbol == NULL || |
| 684 | (SYMBOL_VALUE_ADDRESS (psb) |
| 685 | >= SYMBOL_VALUE_ADDRESS (msymbol)))) |
| 686 | { |
| 687 | /* This case isn't being cached currently. */ |
| 688 | if (address) |
| 689 | *address = SYMBOL_VALUE_ADDRESS (psb); |
| 690 | if (name) |
| 691 | *name = SYMBOL_NAME (psb); |
| 692 | /* endaddr non-NULL can't happen here. */ |
| 693 | return 1; |
| 694 | } |
| 695 | } |
| 696 | } |
| 697 | |
| 698 | /* Not in the normal symbol tables, see if the pc is in a known section. |
| 699 | If it's not, then give up. This ensures that anything beyond the end |
| 700 | of the text seg doesn't appear to be part of the last function in the |
| 701 | text segment. */ |
| 702 | |
| 703 | sec = find_pc_section (pc); |
| 704 | |
| 705 | if (!sec) |
| 706 | msymbol = NULL; |
| 707 | |
| 708 | /* Must be in the minimal symbol table. */ |
| 709 | if (msymbol == NULL) |
| 710 | { |
| 711 | /* No available symbol. */ |
| 712 | if (name != NULL) |
| 713 | *name = 0; |
| 714 | if (address != NULL) |
| 715 | *address = 0; |
| 716 | if (endaddr != NULL) |
| 717 | *endaddr = 0; |
| 718 | return 0; |
| 719 | } |
| 720 | |
| 721 | /* See if we're in a transfer table for Sun shared libs. */ |
| 722 | |
| 723 | if (msymbol -> type == mst_text) |
| 724 | cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol); |
| 725 | else |
| 726 | /* It is a transfer table for Sun shared libraries. */ |
| 727 | cache_pc_function_low = pc - FUNCTION_START_OFFSET; |
| 728 | |
| 729 | cache_pc_function_name = SYMBOL_NAME (msymbol); |
| 730 | |
| 731 | /* Use the lesser of the next minimal symbol, or the end of the section, as |
| 732 | the end of the function. */ |
| 733 | |
| 734 | if (SYMBOL_NAME (msymbol + 1) != NULL |
| 735 | && SYMBOL_VALUE_ADDRESS (msymbol + 1) < sec->endaddr) |
| 736 | cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + 1); |
| 737 | else |
| 738 | /* We got the start address from the last msymbol in the objfile. |
| 739 | So the end address is the end of the section. */ |
| 740 | cache_pc_function_high = sec->endaddr; |
| 741 | |
| 742 | return_cached_value: |
| 743 | if (address) |
| 744 | *address = cache_pc_function_low; |
| 745 | if (name) |
| 746 | *name = cache_pc_function_name; |
| 747 | if (endaddr) |
| 748 | *endaddr = cache_pc_function_high; |
| 749 | return 1; |
| 750 | } |
| 751 | |
| 752 | /* Return the innermost stack frame executing inside of BLOCK, |
| 753 | or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */ |
| 754 | |
| 755 | FRAME |
| 756 | block_innermost_frame (block) |
| 757 | struct block *block; |
| 758 | { |
| 759 | struct frame_info *fi; |
| 760 | register FRAME frame; |
| 761 | register CORE_ADDR start; |
| 762 | register CORE_ADDR end; |
| 763 | |
| 764 | if (block == NULL) |
| 765 | return NULL; |
| 766 | |
| 767 | start = BLOCK_START (block); |
| 768 | end = BLOCK_END (block); |
| 769 | |
| 770 | frame = 0; |
| 771 | while (1) |
| 772 | { |
| 773 | frame = get_prev_frame (frame); |
| 774 | if (frame == 0) |
| 775 | return 0; |
| 776 | fi = get_frame_info (frame); |
| 777 | if (fi->pc >= start && fi->pc < end) |
| 778 | return frame; |
| 779 | } |
| 780 | } |
| 781 | |
| 782 | #ifdef SIGCONTEXT_PC_OFFSET |
| 783 | /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */ |
| 784 | |
| 785 | CORE_ADDR |
| 786 | sigtramp_saved_pc (frame) |
| 787 | FRAME frame; |
| 788 | { |
| 789 | CORE_ADDR sigcontext_addr; |
| 790 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; |
| 791 | int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT; |
| 792 | int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT; |
| 793 | |
| 794 | /* Get sigcontext address, it is the third parameter on the stack. */ |
| 795 | if (frame->next) |
| 796 | sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next) |
| 797 | + FRAME_ARGS_SKIP + sigcontext_offs, |
| 798 | ptrbytes); |
| 799 | else |
| 800 | sigcontext_addr = read_memory_integer (read_register (SP_REGNUM) |
| 801 | + sigcontext_offs, |
| 802 | ptrbytes); |
| 803 | |
| 804 | /* Don't cause a memory_error when accessing sigcontext in case the stack |
| 805 | layout has changed or the stack is corrupt. */ |
| 806 | target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes); |
| 807 | return extract_unsigned_integer (buf, ptrbytes); |
| 808 | } |
| 809 | #endif /* SIGCONTEXT_PC_OFFSET */ |
| 810 | |
| 811 | void |
| 812 | _initialize_blockframe () |
| 813 | { |
| 814 | obstack_init (&frame_cache_obstack); |
| 815 | } |