| 1 | /* Get info from stack frames; |
| 2 | convert between frames, blocks, functions and pc values. |
| 3 | Copyright (C) 1986, 1987, 1988, 1989 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 <stdio.h> |
| 22 | #include "defs.h" |
| 23 | #include "param.h" |
| 24 | #include "symtab.h" |
| 25 | #include "frame.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "value.h" /* for read_register */ |
| 28 | #include "target.h" /* for target_has_stack */ |
| 29 | |
| 30 | CORE_ADDR read_pc (); /* In infcmd.c */ |
| 31 | |
| 32 | /* Start and end of object file containing the entry point. |
| 33 | STARTUP_FILE_END is the first address of the next file. |
| 34 | This file is assumed to be a startup file |
| 35 | and frames with pc's inside it |
| 36 | are treated as nonexistent. |
| 37 | |
| 38 | Setting these variables is necessary so that backtraces do not fly off |
| 39 | the bottom of the stack. */ |
| 40 | CORE_ADDR startup_file_start; |
| 41 | CORE_ADDR startup_file_end; |
| 42 | |
| 43 | /* Is ADDR outside the startup file? Note that if your machine |
| 44 | has a way to detect the bottom of the stack, there is no need |
| 45 | to call this function from FRAME_CHAIN_VALID; the reason for |
| 46 | doing so is that some machines have no way of detecting bottom |
| 47 | of stack. */ |
| 48 | int |
| 49 | outside_startup_file (addr) |
| 50 | CORE_ADDR addr; |
| 51 | { |
| 52 | return !(addr >= startup_file_start && addr < startup_file_end); |
| 53 | } |
| 54 | |
| 55 | /* Support an alternate method to avoid running off the bottom of |
| 56 | the stack (or top, depending upon your stack orientation). |
| 57 | |
| 58 | There are two frames that are "special", the frame for the function |
| 59 | containing the process entry point, since it has no predecessor frame, |
| 60 | and the frame for the function containing the user code entry point |
| 61 | (the main() function), since all the predecessor frames are for the |
| 62 | process startup code. Since we have no guarantee that the linked |
| 63 | in startup modules have any debugging information that gdb can use, |
| 64 | we need to avoid following frame pointers back into frames that might |
| 65 | have been built in the startup code, as we might get hopelessly |
| 66 | confused. However, we almost always have debugging information |
| 67 | available for main(). |
| 68 | |
| 69 | These variables are used to save the range of PC values which are valid |
| 70 | within the main() function and within the function containing the process |
| 71 | entry point. If we always consider the frame for main() as the outermost |
| 72 | frame when debugging user code, and the frame for the process entry |
| 73 | point function as the outermost frame when debugging startup code, then |
| 74 | all we have to do is have FRAME_CHAIN_VALID return false whenever a |
| 75 | frame's current PC is within the range specified by these variables. |
| 76 | In essence, we set "blocks" in the frame chain beyond which we will |
| 77 | not proceed when following the frame chain. |
| 78 | |
| 79 | A nice side effect is that we can still debug startup code without |
| 80 | running off the end of the frame chain, assuming that we have usable |
| 81 | debugging information in the startup modules, and if we choose to not |
| 82 | use the block at main, or can't find it for some reason, everything |
| 83 | still works as before. And if we have no startup code debugging |
| 84 | information but we do have usable information for main(), backtraces |
| 85 | from user code don't go wandering off into the startup code. |
| 86 | |
| 87 | To use this method, define your FRAME_CHAIN_VALID macro like: |
| 88 | |
| 89 | #define FRAME_CHAIN_VALID(chain, thisframe) \ |
| 90 | (chain != 0 \ |
| 91 | && !(inside_main_scope ((thisframe)->pc)) \ |
| 92 | && !(inside_entry_scope ((thisframe)->pc))) |
| 93 | |
| 94 | and add initializations of the four scope controlling variables inside |
| 95 | the object file / debugging information processing modules. */ |
| 96 | |
| 97 | CORE_ADDR entry_scope_lowpc; |
| 98 | CORE_ADDR entry_scope_highpc; |
| 99 | CORE_ADDR main_scope_lowpc; |
| 100 | CORE_ADDR main_scope_highpc; |
| 101 | |
| 102 | /* Test a specified PC value to see if it is in the range of addresses |
| 103 | that correspond to the main() function. See comments above for why |
| 104 | we might want to do this. |
| 105 | |
| 106 | Typically called from FRAME_CHAIN_VALID. */ |
| 107 | |
| 108 | int |
| 109 | inside_main_scope (pc) |
| 110 | CORE_ADDR pc; |
| 111 | { |
| 112 | return (main_scope_lowpc <= pc && pc < main_scope_highpc); |
| 113 | } |
| 114 | |
| 115 | /* Test a specified PC value to see if it is in the range of addresses |
| 116 | that correspond to the process entry point function. See comments above |
| 117 | for why we might want to do this. |
| 118 | |
| 119 | Typically called from FRAME_CHAIN_VALID. */ |
| 120 | |
| 121 | int |
| 122 | inside_entry_scope (pc) |
| 123 | CORE_ADDR pc; |
| 124 | { |
| 125 | return (entry_scope_lowpc <= pc && pc < entry_scope_highpc); |
| 126 | } |
| 127 | |
| 128 | /* Address of innermost stack frame (contents of FP register) */ |
| 129 | |
| 130 | static FRAME current_frame; |
| 131 | |
| 132 | /* |
| 133 | * Cache for frame addresses already read by gdb. Valid only while |
| 134 | * inferior is stopped. Control variables for the frame cache should |
| 135 | * be local to this module. |
| 136 | */ |
| 137 | struct obstack frame_cache_obstack; |
| 138 | |
| 139 | /* Return the innermost (currently executing) stack frame. */ |
| 140 | |
| 141 | FRAME |
| 142 | get_current_frame () |
| 143 | { |
| 144 | /* We assume its address is kept in a general register; |
| 145 | param.h says which register. */ |
| 146 | |
| 147 | return current_frame; |
| 148 | } |
| 149 | |
| 150 | void |
| 151 | set_current_frame (frame) |
| 152 | FRAME frame; |
| 153 | { |
| 154 | current_frame = frame; |
| 155 | } |
| 156 | |
| 157 | FRAME |
| 158 | create_new_frame (addr, pc) |
| 159 | FRAME_ADDR addr; |
| 160 | CORE_ADDR pc; |
| 161 | { |
| 162 | struct frame_info *fci; /* Same type as FRAME */ |
| 163 | |
| 164 | fci = (struct frame_info *) |
| 165 | obstack_alloc (&frame_cache_obstack, |
| 166 | sizeof (struct frame_info)); |
| 167 | |
| 168 | /* Arbitrary frame */ |
| 169 | fci->next = (struct frame_info *) 0; |
| 170 | fci->prev = (struct frame_info *) 0; |
| 171 | fci->frame = addr; |
| 172 | fci->next_frame = 0; /* Since arbitrary */ |
| 173 | fci->pc = pc; |
| 174 | |
| 175 | #ifdef INIT_EXTRA_FRAME_INFO |
| 176 | INIT_EXTRA_FRAME_INFO (0, fci); |
| 177 | #endif |
| 178 | |
| 179 | return fci; |
| 180 | } |
| 181 | |
| 182 | /* Return the frame that called FRAME. |
| 183 | If FRAME is the original frame (it has no caller), return 0. */ |
| 184 | |
| 185 | FRAME |
| 186 | get_prev_frame (frame) |
| 187 | FRAME frame; |
| 188 | { |
| 189 | /* We're allowed to know that FRAME and "struct frame_info *" are |
| 190 | the same */ |
| 191 | return get_prev_frame_info (frame); |
| 192 | } |
| 193 | |
| 194 | /* Return the frame that FRAME calls (0 if FRAME is the innermost |
| 195 | frame). */ |
| 196 | |
| 197 | FRAME |
| 198 | get_next_frame (frame) |
| 199 | FRAME frame; |
| 200 | { |
| 201 | /* We're allowed to know that FRAME and "struct frame_info *" are |
| 202 | the same */ |
| 203 | return frame->next; |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * Flush the entire frame cache. |
| 208 | */ |
| 209 | void |
| 210 | flush_cached_frames () |
| 211 | { |
| 212 | /* Since we can't really be sure what the first object allocated was */ |
| 213 | obstack_free (&frame_cache_obstack, 0); |
| 214 | obstack_init (&frame_cache_obstack); |
| 215 | |
| 216 | current_frame = (struct frame_info *) 0; /* Invalidate cache */ |
| 217 | } |
| 218 | |
| 219 | /* Flush the frame cache, and start a new one if necessary. */ |
| 220 | void |
| 221 | reinit_frame_cache () |
| 222 | { |
| 223 | FRAME fr = current_frame; |
| 224 | flush_cached_frames (); |
| 225 | if (fr) |
| 226 | set_current_frame ( create_new_frame (read_register (FP_REGNUM), |
| 227 | read_pc ())); |
| 228 | } |
| 229 | |
| 230 | /* Return a structure containing various interesting information |
| 231 | about a specified stack frame. */ |
| 232 | /* How do I justify including this function? Well, the FRAME |
| 233 | identifier format has gone through several changes recently, and |
| 234 | it's not completely inconceivable that it could happen again. If |
| 235 | it does, have this routine around will help */ |
| 236 | |
| 237 | struct frame_info * |
| 238 | get_frame_info (frame) |
| 239 | FRAME frame; |
| 240 | { |
| 241 | return frame; |
| 242 | } |
| 243 | |
| 244 | /* If a machine allows frameless functions, it should define a macro |
| 245 | FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct |
| 246 | frame_info for the frame, and FRAMELESS should be set to nonzero |
| 247 | if it represents a frameless function invocation. */ |
| 248 | |
| 249 | /* Return nonzero if the function for this frame has a prologue. Many |
| 250 | machines can define FRAMELESS_FUNCTION_INVOCATION to just call this |
| 251 | function. */ |
| 252 | |
| 253 | int |
| 254 | frameless_look_for_prologue (frame) |
| 255 | FRAME frame; |
| 256 | { |
| 257 | CORE_ADDR func_start, after_prologue; |
| 258 | func_start = (get_pc_function_start (frame->pc) + |
| 259 | FUNCTION_START_OFFSET); |
| 260 | if (func_start) |
| 261 | { |
| 262 | after_prologue = func_start; |
| 263 | #ifdef SKIP_PROLOGUE_FRAMELESS_P |
| 264 | /* This is faster, since only care whether there *is* a prologue, |
| 265 | not how long it is. */ |
| 266 | SKIP_PROLOGUE_FRAMELESS_P (after_prologue); |
| 267 | #else |
| 268 | SKIP_PROLOGUE (after_prologue); |
| 269 | #endif |
| 270 | return after_prologue == func_start; |
| 271 | } |
| 272 | else |
| 273 | /* If we can't find the start of the function, we don't really |
| 274 | know whether the function is frameless, but we should be able |
| 275 | to get a reasonable (i.e. best we can do under the |
| 276 | circumstances) backtrace by saying that it isn't. */ |
| 277 | return 0; |
| 278 | } |
| 279 | |
| 280 | /* Default a few macros that people seldom redefine. */ |
| 281 | |
| 282 | #if !defined (INIT_FRAME_PC) |
| 283 | #define INIT_FRAME_PC(fromleaf, prev) \ |
| 284 | prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \ |
| 285 | prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ()); |
| 286 | #endif |
| 287 | |
| 288 | #ifndef FRAME_CHAIN_COMBINE |
| 289 | #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain) |
| 290 | #endif |
| 291 | |
| 292 | /* Return a structure containing various interesting information |
| 293 | about the frame that called NEXT_FRAME. Returns NULL |
| 294 | if there is no such frame. */ |
| 295 | |
| 296 | struct frame_info * |
| 297 | get_prev_frame_info (next_frame) |
| 298 | FRAME next_frame; |
| 299 | { |
| 300 | FRAME_ADDR address; |
| 301 | struct frame_info *prev; |
| 302 | int fromleaf = 0; |
| 303 | |
| 304 | /* If the requested entry is in the cache, return it. |
| 305 | Otherwise, figure out what the address should be for the entry |
| 306 | we're about to add to the cache. */ |
| 307 | |
| 308 | if (!next_frame) |
| 309 | { |
| 310 | if (!current_frame) |
| 311 | { |
| 312 | error ("You haven't set up a process's stack to examine."); |
| 313 | } |
| 314 | |
| 315 | return current_frame; |
| 316 | } |
| 317 | |
| 318 | /* If we have the prev one, return it */ |
| 319 | if (next_frame->prev) |
| 320 | return next_frame->prev; |
| 321 | |
| 322 | /* On some machines it is possible to call a function without |
| 323 | setting up a stack frame for it. On these machines, we |
| 324 | define this macro to take two args; a frameinfo pointer |
| 325 | identifying a frame and a variable to set or clear if it is |
| 326 | or isn't leafless. */ |
| 327 | #ifdef FRAMELESS_FUNCTION_INVOCATION |
| 328 | /* Still don't want to worry about this except on the innermost |
| 329 | frame. This macro will set FROMLEAF if NEXT_FRAME is a |
| 330 | frameless function invocation. */ |
| 331 | if (!(next_frame->next)) |
| 332 | { |
| 333 | FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf); |
| 334 | if (fromleaf) |
| 335 | address = next_frame->frame; |
| 336 | } |
| 337 | #endif |
| 338 | |
| 339 | if (!fromleaf) |
| 340 | { |
| 341 | /* Two macros defined in tm.h specify the machine-dependent |
| 342 | actions to be performed here. |
| 343 | First, get the frame's chain-pointer. |
| 344 | If that is zero, the frame is the outermost frame or a leaf |
| 345 | called by the outermost frame. This means that if start |
| 346 | calls main without a frame, we'll return 0 (which is fine |
| 347 | anyway). |
| 348 | |
| 349 | Nope; there's a problem. This also returns when the current |
| 350 | routine is a leaf of main. This is unacceptable. We move |
| 351 | this to after the ffi test; I'd rather have backtraces from |
| 352 | start go curfluy than have an abort called from main not show |
| 353 | main. */ |
| 354 | address = FRAME_CHAIN (next_frame); |
| 355 | if (!FRAME_CHAIN_VALID (address, next_frame)) |
| 356 | return 0; |
| 357 | address = FRAME_CHAIN_COMBINE (address, next_frame); |
| 358 | } |
| 359 | if (address == 0) |
| 360 | return 0; |
| 361 | |
| 362 | prev = (struct frame_info *) |
| 363 | obstack_alloc (&frame_cache_obstack, |
| 364 | sizeof (struct frame_info)); |
| 365 | |
| 366 | if (next_frame) |
| 367 | next_frame->prev = prev; |
| 368 | prev->next = next_frame; |
| 369 | prev->prev = (struct frame_info *) 0; |
| 370 | prev->frame = address; |
| 371 | prev->next_frame = prev->next ? prev->next->frame : 0; |
| 372 | |
| 373 | #ifdef INIT_EXTRA_FRAME_INFO |
| 374 | INIT_EXTRA_FRAME_INFO(fromleaf, prev); |
| 375 | #endif |
| 376 | |
| 377 | /* This entry is in the frame queue now, which is good since |
| 378 | FRAME_SAVED_PC may use that queue to figure out it's value |
| 379 | (see tm-sparc.h). We want the pc saved in the inferior frame. */ |
| 380 | INIT_FRAME_PC(fromleaf, prev); |
| 381 | |
| 382 | return prev; |
| 383 | } |
| 384 | |
| 385 | CORE_ADDR |
| 386 | get_frame_pc (frame) |
| 387 | FRAME frame; |
| 388 | { |
| 389 | struct frame_info *fi; |
| 390 | fi = get_frame_info (frame); |
| 391 | return fi->pc; |
| 392 | } |
| 393 | |
| 394 | #if defined (FRAME_FIND_SAVED_REGS) |
| 395 | /* Find the addresses in which registers are saved in FRAME. */ |
| 396 | |
| 397 | void |
| 398 | get_frame_saved_regs (frame_info_addr, saved_regs_addr) |
| 399 | struct frame_info *frame_info_addr; |
| 400 | struct frame_saved_regs *saved_regs_addr; |
| 401 | { |
| 402 | FRAME_FIND_SAVED_REGS (frame_info_addr, *saved_regs_addr); |
| 403 | } |
| 404 | #endif |
| 405 | |
| 406 | /* Return the innermost lexical block in execution |
| 407 | in a specified stack frame. The frame address is assumed valid. */ |
| 408 | |
| 409 | struct block * |
| 410 | get_frame_block (frame) |
| 411 | FRAME frame; |
| 412 | { |
| 413 | struct frame_info *fi; |
| 414 | CORE_ADDR pc; |
| 415 | |
| 416 | fi = get_frame_info (frame); |
| 417 | |
| 418 | pc = fi->pc; |
| 419 | if (fi->next_frame != 0) |
| 420 | /* We are not in the innermost frame. We need to subtract one to |
| 421 | get the correct block, in case the call instruction was the |
| 422 | last instruction of the block. If there are any machines on |
| 423 | which the saved pc does not point to after the call insn, we |
| 424 | probably want to make fi->pc point after the call insn anyway. */ |
| 425 | --pc; |
| 426 | return block_for_pc (pc); |
| 427 | } |
| 428 | |
| 429 | struct block * |
| 430 | get_current_block () |
| 431 | { |
| 432 | return block_for_pc (read_pc ()); |
| 433 | } |
| 434 | |
| 435 | CORE_ADDR |
| 436 | get_pc_function_start (pc) |
| 437 | CORE_ADDR pc; |
| 438 | { |
| 439 | register struct block *bl = block_for_pc (pc); |
| 440 | register struct symbol *symbol; |
| 441 | if (bl == 0 || (symbol = block_function (bl)) == 0) |
| 442 | { |
| 443 | register int misc_index = find_pc_misc_function (pc); |
| 444 | if (misc_index >= 0) |
| 445 | return misc_function_vector[misc_index].address; |
| 446 | return 0; |
| 447 | } |
| 448 | bl = SYMBOL_BLOCK_VALUE (symbol); |
| 449 | return BLOCK_START (bl); |
| 450 | } |
| 451 | |
| 452 | /* Return the symbol for the function executing in frame FRAME. */ |
| 453 | |
| 454 | struct symbol * |
| 455 | get_frame_function (frame) |
| 456 | FRAME frame; |
| 457 | { |
| 458 | register struct block *bl = get_frame_block (frame); |
| 459 | if (bl == 0) |
| 460 | return 0; |
| 461 | return block_function (bl); |
| 462 | } |
| 463 | \f |
| 464 | /* Return the blockvector immediately containing the innermost lexical block |
| 465 | containing the specified pc value, or 0 if there is none. |
| 466 | PINDEX is a pointer to the index value of the block. If PINDEX |
| 467 | is NULL, we don't pass this information back to the caller. */ |
| 468 | |
| 469 | struct blockvector * |
| 470 | blockvector_for_pc (pc, pindex) |
| 471 | register CORE_ADDR pc; |
| 472 | int *pindex; |
| 473 | { |
| 474 | register struct block *b; |
| 475 | register int bot, top, half; |
| 476 | register struct symtab *s; |
| 477 | struct blockvector *bl; |
| 478 | |
| 479 | /* First search all symtabs for one whose file contains our pc */ |
| 480 | s = find_pc_symtab (pc); |
| 481 | if (s == 0) |
| 482 | return 0; |
| 483 | |
| 484 | bl = BLOCKVECTOR (s); |
| 485 | b = BLOCKVECTOR_BLOCK (bl, 0); |
| 486 | |
| 487 | /* Then search that symtab for the smallest block that wins. */ |
| 488 | /* Use binary search to find the last block that starts before PC. */ |
| 489 | |
| 490 | bot = 0; |
| 491 | top = BLOCKVECTOR_NBLOCKS (bl); |
| 492 | |
| 493 | while (top - bot > 1) |
| 494 | { |
| 495 | half = (top - bot + 1) >> 1; |
| 496 | b = BLOCKVECTOR_BLOCK (bl, bot + half); |
| 497 | if (BLOCK_START (b) <= pc) |
| 498 | bot += half; |
| 499 | else |
| 500 | top = bot + half; |
| 501 | } |
| 502 | |
| 503 | /* Now search backward for a block that ends after PC. */ |
| 504 | |
| 505 | while (bot >= 0) |
| 506 | { |
| 507 | b = BLOCKVECTOR_BLOCK (bl, bot); |
| 508 | if (BLOCK_END (b) > pc) |
| 509 | { |
| 510 | if (pindex) |
| 511 | *pindex = bot; |
| 512 | return bl; |
| 513 | } |
| 514 | bot--; |
| 515 | } |
| 516 | |
| 517 | return 0; |
| 518 | } |
| 519 | |
| 520 | /* Return the innermost lexical block containing the specified pc value, |
| 521 | or 0 if there is none. */ |
| 522 | |
| 523 | struct block * |
| 524 | block_for_pc (pc) |
| 525 | register CORE_ADDR pc; |
| 526 | { |
| 527 | register struct blockvector *bl; |
| 528 | int index; |
| 529 | |
| 530 | bl = blockvector_for_pc (pc, &index); |
| 531 | if (bl) |
| 532 | return BLOCKVECTOR_BLOCK (bl, index); |
| 533 | return 0; |
| 534 | } |
| 535 | |
| 536 | /* Return the function containing pc value PC. |
| 537 | Returns 0 if function is not known. */ |
| 538 | |
| 539 | struct symbol * |
| 540 | find_pc_function (pc) |
| 541 | CORE_ADDR pc; |
| 542 | { |
| 543 | register struct block *b = block_for_pc (pc); |
| 544 | if (b == 0) |
| 545 | return 0; |
| 546 | return block_function (b); |
| 547 | } |
| 548 | |
| 549 | /* These variables are used to cache the most recent result |
| 550 | * of find_pc_partial_function. */ |
| 551 | |
| 552 | static CORE_ADDR cache_pc_function_low = 0; |
| 553 | static CORE_ADDR cache_pc_function_high = 0; |
| 554 | static char *cache_pc_function_name = 0; |
| 555 | |
| 556 | /* Clear cache, e.g. when symbol table is discarded. */ |
| 557 | |
| 558 | void |
| 559 | clear_pc_function_cache() |
| 560 | { |
| 561 | cache_pc_function_low = 0; |
| 562 | cache_pc_function_high = 0; |
| 563 | cache_pc_function_name = (char *)0; |
| 564 | } |
| 565 | |
| 566 | /* Finds the "function" (text symbol) that is smaller than PC |
| 567 | but greatest of all of the potential text symbols. Sets |
| 568 | *NAME and/or *ADDRESS conditionally if that pointer is non-zero. |
| 569 | Returns 0 if it couldn't find anything, 1 if it did. On a zero |
| 570 | return, *NAME and *ADDRESS are always set to zero. On a 1 return, |
| 571 | *NAME and *ADDRESS contain real information. */ |
| 572 | |
| 573 | int |
| 574 | find_pc_partial_function (pc, name, address) |
| 575 | CORE_ADDR pc; |
| 576 | char **name; |
| 577 | CORE_ADDR *address; |
| 578 | { |
| 579 | struct partial_symtab *pst; |
| 580 | struct symbol *f; |
| 581 | int miscfunc; |
| 582 | struct partial_symbol *psb; |
| 583 | |
| 584 | if (pc >= cache_pc_function_low && pc < cache_pc_function_high) |
| 585 | { |
| 586 | if (address) |
| 587 | *address = cache_pc_function_low; |
| 588 | if (name) |
| 589 | *name = cache_pc_function_name; |
| 590 | return 1; |
| 591 | } |
| 592 | |
| 593 | pst = find_pc_psymtab (pc); |
| 594 | if (pst) |
| 595 | { |
| 596 | if (pst->readin) |
| 597 | { |
| 598 | /* The information we want has already been read in. |
| 599 | We can go to the already readin symbols and we'll get |
| 600 | the best possible answer. */ |
| 601 | f = find_pc_function (pc); |
| 602 | if (!f) |
| 603 | { |
| 604 | return_error: |
| 605 | /* No available symbol. */ |
| 606 | if (name != 0) |
| 607 | *name = 0; |
| 608 | if (address != 0) |
| 609 | *address = 0; |
| 610 | return 0; |
| 611 | } |
| 612 | |
| 613 | cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f)); |
| 614 | cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f)); |
| 615 | cache_pc_function_name = SYMBOL_NAME (f); |
| 616 | if (name) |
| 617 | *name = cache_pc_function_name; |
| 618 | if (address) |
| 619 | *address = cache_pc_function_low; |
| 620 | return 1; |
| 621 | } |
| 622 | |
| 623 | /* Get the information from a combination of the pst |
| 624 | (static symbols), and the misc function vector (extern |
| 625 | symbols). */ |
| 626 | miscfunc = find_pc_misc_function (pc); |
| 627 | psb = find_pc_psymbol (pst, pc); |
| 628 | |
| 629 | if (!psb && miscfunc == -1) |
| 630 | { |
| 631 | goto return_error; |
| 632 | } |
| 633 | if (psb |
| 634 | && (miscfunc == -1 |
| 635 | || (SYMBOL_VALUE_ADDRESS (psb) |
| 636 | >= misc_function_vector[miscfunc].address))) |
| 637 | { |
| 638 | /* This case isn't being cached currently. */ |
| 639 | if (address) |
| 640 | *address = SYMBOL_VALUE_ADDRESS (psb); |
| 641 | if (name) |
| 642 | *name = SYMBOL_NAME (psb); |
| 643 | return 1; |
| 644 | } |
| 645 | } |
| 646 | else |
| 647 | /* Must be in the misc function stuff. */ |
| 648 | { |
| 649 | miscfunc = find_pc_misc_function (pc); |
| 650 | if (miscfunc == -1) |
| 651 | goto return_error; |
| 652 | } |
| 653 | |
| 654 | { |
| 655 | if (misc_function_vector[miscfunc].type == mf_text) |
| 656 | cache_pc_function_low = misc_function_vector[miscfunc].address; |
| 657 | else |
| 658 | /* It is a transfer table for Sun shared libraries. */ |
| 659 | cache_pc_function_low = pc - FUNCTION_START_OFFSET; |
| 660 | } |
| 661 | cache_pc_function_name = misc_function_vector[miscfunc].name; |
| 662 | if (miscfunc < misc_function_count /* && FIXME mf_text again? */ ) |
| 663 | cache_pc_function_high = misc_function_vector[miscfunc+1].address; |
| 664 | else |
| 665 | cache_pc_function_high = cache_pc_function_low + 1; |
| 666 | if (address) |
| 667 | *address = cache_pc_function_low; |
| 668 | if (name) |
| 669 | *name = cache_pc_function_name; |
| 670 | return 1; |
| 671 | } |
| 672 | |
| 673 | /* Find the misc function whose address is the largest |
| 674 | while being less than PC. Return its index in misc_function_vector. |
| 675 | Returns -1 if PC is not in suitable range. */ |
| 676 | |
| 677 | int |
| 678 | find_pc_misc_function (pc) |
| 679 | register CORE_ADDR pc; |
| 680 | { |
| 681 | register int lo = 0; |
| 682 | register int hi = misc_function_count-1; |
| 683 | register int new; |
| 684 | |
| 685 | /* Note that the last thing in the vector is always _etext. */ |
| 686 | /* Actually, "end", now that non-functions |
| 687 | go on the misc_function_vector. */ |
| 688 | |
| 689 | /* Above statement is not *always* true - fix for case where there are */ |
| 690 | /* no misc functions at all (ie no symbol table has been read). */ |
| 691 | if (hi < 0) return -1; /* no misc functions recorded */ |
| 692 | |
| 693 | /* trivial reject range test */ |
| 694 | if (pc < misc_function_vector[0].address || |
| 695 | pc > misc_function_vector[hi].address) |
| 696 | return -1; |
| 697 | |
| 698 | /* Note that the following search will not return hi if |
| 699 | pc == misc_function_vector[hi].address. If "end" points to the |
| 700 | first unused location, this is correct and the above test |
| 701 | simply needs to be changed to |
| 702 | "pc >= misc_function_vector[hi].address". */ |
| 703 | do { |
| 704 | new = (lo + hi) >> 1; |
| 705 | if (misc_function_vector[new].address == pc) |
| 706 | return new; /* an exact match */ |
| 707 | else if (misc_function_vector[new].address > pc) |
| 708 | hi = new; |
| 709 | else |
| 710 | lo = new; |
| 711 | } while (hi-lo != 1); |
| 712 | |
| 713 | /* if here, we had no exact match, so return the lower choice */ |
| 714 | return lo; |
| 715 | } |
| 716 | |
| 717 | /* Return the innermost stack frame executing inside of the specified block, |
| 718 | or zero if there is no such frame. */ |
| 719 | |
| 720 | FRAME |
| 721 | block_innermost_frame (block) |
| 722 | struct block *block; |
| 723 | { |
| 724 | struct frame_info *fi; |
| 725 | register FRAME frame; |
| 726 | register CORE_ADDR start = BLOCK_START (block); |
| 727 | register CORE_ADDR end = BLOCK_END (block); |
| 728 | |
| 729 | frame = 0; |
| 730 | while (1) |
| 731 | { |
| 732 | frame = get_prev_frame (frame); |
| 733 | if (frame == 0) |
| 734 | return 0; |
| 735 | fi = get_frame_info (frame); |
| 736 | if (fi->pc >= start && fi->pc < end) |
| 737 | return frame; |
| 738 | } |
| 739 | } |
| 740 | |
| 741 | void |
| 742 | _initialize_blockframe () |
| 743 | { |
| 744 | obstack_init (&frame_cache_obstack); |
| 745 | } |