1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger. 2 3 Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997, 4 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009, 2010 5 Free Software Foundation, Inc. 6 7 This file is part of GDB. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 21 22 #if !defined (FRAME_H) 23 #define FRAME_H 1 24 25 /* The following is the intended naming schema for frame functions. 26 It isn't 100% consistent, but it is aproaching that. Frame naming 27 schema: 28 29 Prefixes: 30 31 get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly 32 equivalent to THIS->next->unwind->what) 33 34 frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT 35 frame. 36 37 frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's 38 real caller. Any inlined functions in NEXT's stack frame are 39 skipped. Use these to ignore any potentially inlined functions, 40 e.g. inlined into the first instruction of a library trampoline. 41 42 get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is 43 inlined, skip to the containing stack frame. 44 45 put_frame_WHAT...(): Put a value into this frame (unsafe, need to 46 invalidate the frame / regcache afterwards) (better name more 47 strongly hinting at its unsafeness) 48 49 safe_....(): Safer version of various functions, doesn't throw an 50 error (leave this for later?). Returns non-zero / non-NULL if the 51 request succeeds, zero / NULL otherwize. 52 53 Suffixes: 54 55 void /frame/_WHAT(): Read WHAT's value into the buffer parameter. 56 57 ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the 58 alternative is *frame_unsigned_WHAT). 59 60 LONGEST /frame/_WHAT_signed(): Return WHAT signed value. 61 62 What: 63 64 /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return 65 *memory. 66 67 /frame/_register* (frame, regnum [, buf]): extract/return register. 68 69 CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most 70 stack *address, ... 71 72 */ 73 74 struct symtab_and_line; 75 struct frame_unwind; 76 struct frame_base; 77 struct block; 78 struct gdbarch; 79 struct ui_file; 80 81 /* The frame object. */ 82 83 struct frame_info; 84 85 /* The frame object's ID. This provides a per-frame unique identifier 86 that can be used to relocate a `struct frame_info' after a target 87 resume or a frame cache destruct. It of course assumes that the 88 inferior hasn't unwound the stack past that frame. */ 89 90 struct frame_id 91 { 92 /* The frame's stack address. This shall be constant through out 93 the lifetime of a frame. Note that this requirement applies to 94 not just the function body, but also the prologue and (in theory 95 at least) the epilogue. Since that value needs to fall either on 96 the boundary, or within the frame's address range, the frame's 97 outer-most address (the inner-most address of the previous frame) 98 is used. Watch out for all the legacy targets that still use the 99 function pointer register or stack pointer register. They are 100 wrong. 101 102 This field is valid only if stack_addr_p is true. Otherwise, this 103 frame represents the null frame. */ 104 CORE_ADDR stack_addr; 105 106 /* The frame's code address. This shall be constant through out the 107 lifetime of the frame. While the PC (a.k.a. resume address) 108 changes as the function is executed, this code address cannot. 109 Typically, it is set to the address of the entry point of the 110 frame's function (as returned by get_frame_func). 111 112 For inlined functions (INLINE_DEPTH != 0), this is the address of 113 the first executed instruction in the block corresponding to the 114 inlined function. 115 116 This field is valid only if code_addr_p is true. Otherwise, this 117 frame is considered to have a wildcard code address, i.e. one that 118 matches every address value in frame comparisons. */ 119 CORE_ADDR code_addr; 120 121 /* The frame's special address. This shall be constant through out the 122 lifetime of the frame. This is used for architectures that may have 123 frames that do not change the stack but are still distinct and have 124 some form of distinct identifier (e.g. the ia64 which uses a 2nd 125 stack for registers). This field is treated as unordered - i.e. will 126 not be used in frame ordering comparisons. 127 128 This field is valid only if special_addr_p is true. Otherwise, this 129 frame is considered to have a wildcard special address, i.e. one that 130 matches every address value in frame comparisons. */ 131 CORE_ADDR special_addr; 132 133 /* Flags to indicate the above fields have valid contents. */ 134 unsigned int stack_addr_p : 1; 135 unsigned int code_addr_p : 1; 136 unsigned int special_addr_p : 1; 137 138 /* The inline depth of this frame. A frame representing a "called" 139 inlined function will have this set to a nonzero value. */ 140 int inline_depth; 141 }; 142 143 /* Methods for constructing and comparing Frame IDs. */ 144 145 /* For convenience. All fields are zero. This means "there is no frame". */ 146 extern const struct frame_id null_frame_id; 147 148 /* This means "there is no frame ID, but there is a frame". It should be 149 replaced by best-effort frame IDs for the outermost frame, somehow. 150 The implementation is only special_addr_p set. */ 151 extern const struct frame_id outer_frame_id; 152 153 /* Flag to control debugging. */ 154 155 extern int frame_debug; 156 157 /* Construct a frame ID. The first parameter is the frame's constant 158 stack address (typically the outer-bound), and the second the 159 frame's constant code address (typically the entry point). 160 The special identifier address is set to indicate a wild card. */ 161 extern struct frame_id frame_id_build (CORE_ADDR stack_addr, 162 CORE_ADDR code_addr); 163 164 /* Construct a special frame ID. The first parameter is the frame's constant 165 stack address (typically the outer-bound), the second is the 166 frame's constant code address (typically the entry point), 167 and the third parameter is the frame's special identifier address. */ 168 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr, 169 CORE_ADDR code_addr, 170 CORE_ADDR special_addr); 171 172 /* Construct a wild card frame ID. The parameter is the frame's constant 173 stack address (typically the outer-bound). The code address as well 174 as the special identifier address are set to indicate wild cards. */ 175 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr); 176 177 /* Returns non-zero when L is a valid frame (a valid frame has a 178 non-zero .base). The outermost frame is valid even without an 179 ID. */ 180 extern int frame_id_p (struct frame_id l); 181 182 /* Returns non-zero when L is a valid frame representing an inlined 183 function. */ 184 extern int frame_id_inlined_p (struct frame_id l); 185 186 /* Returns non-zero when L and R identify the same frame, or, if 187 either L or R have a zero .func, then the same frame base. */ 188 extern int frame_id_eq (struct frame_id l, struct frame_id r); 189 190 /* Write the internal representation of a frame ID on the specified 191 stream. */ 192 extern void fprint_frame_id (struct ui_file *file, struct frame_id id); 193 194 195 /* Frame types. Some are real, some are signal trampolines, and some 196 are completely artificial (dummy). */ 197 198 enum frame_type 199 { 200 /* A true stack frame, created by the target program during normal 201 execution. */ 202 NORMAL_FRAME, 203 /* A fake frame, created by GDB when performing an inferior function 204 call. */ 205 DUMMY_FRAME, 206 /* A frame representing an inlined function, associated with an 207 upcoming (next, inner, younger) NORMAL_FRAME. */ 208 INLINE_FRAME, 209 /* In a signal handler, various OSs handle this in various ways. 210 The main thing is that the frame may be far from normal. */ 211 SIGTRAMP_FRAME, 212 /* Fake frame representing a cross-architecture call. */ 213 ARCH_FRAME, 214 /* Sentinel or registers frame. This frame obtains register values 215 direct from the inferior's registers. */ 216 SENTINEL_FRAME 217 }; 218 219 /* For every stopped thread, GDB tracks two frames: current and 220 selected. Current frame is the inner most frame of the selected 221 thread. Selected frame is the one being examined by the the GDB 222 CLI (selected using `up', `down', ...). The frames are created 223 on-demand (via get_prev_frame()) and then held in a frame cache. */ 224 /* FIXME: cagney/2002-11-28: Er, there is a lie here. If you do the 225 sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's 226 selected frame. At present GDB only tracks the selected frame of 227 the current thread. But be warned, that might change. */ 228 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected 229 and current frame can be active. Switching threads causes gdb to 230 discard all that cached frame information. Ulgh! Instead, current 231 and selected frame should be bound to a thread. */ 232 233 /* On demand, create the inner most frame using information found in 234 the inferior. If the inner most frame can't be created, throw an 235 error. */ 236 extern struct frame_info *get_current_frame (void); 237 238 /* Does the current target interface have enough state to be able to 239 query the current inferior for frame info, and is the inferior in a 240 state where that is possible? */ 241 extern int has_stack_frames (void); 242 243 /* Invalidates the frame cache (this function should have been called 244 invalidate_cached_frames). 245 246 FIXME: cagney/2002-11-28: There should be two methods: one that 247 reverts the thread's selected frame back to current frame (for when 248 the inferior resumes) and one that does not (for when the user 249 modifies the target invalidating the frame cache). */ 250 extern void reinit_frame_cache (void); 251 252 /* On demand, create the selected frame and then return it. If the 253 selected frame can not be created, this function prints then throws 254 an error. When MESSAGE is non-NULL, use it for the error message, 255 otherwize use a generic error message. */ 256 /* FIXME: cagney/2002-11-28: At present, when there is no selected 257 frame, this function always returns the current (inner most) frame. 258 It should instead, when a thread has previously had its frame 259 selected (but not resumed) and the frame cache invalidated, find 260 and then return that thread's previously selected frame. */ 261 extern struct frame_info *get_selected_frame (const char *message); 262 263 /* Select a specific frame. NULL, apparently implies re-select the 264 inner most frame. */ 265 extern void select_frame (struct frame_info *); 266 267 /* Given a FRAME, return the next (more inner, younger) or previous 268 (more outer, older) frame. */ 269 extern struct frame_info *get_prev_frame (struct frame_info *); 270 extern struct frame_info *get_next_frame (struct frame_info *); 271 272 /* Given a frame's ID, relocate the frame. Returns NULL if the frame 273 is not found. */ 274 extern struct frame_info *frame_find_by_id (struct frame_id id); 275 276 /* Base attributes of a frame: */ 277 278 /* The frame's `resume' address. Where the program will resume in 279 this frame. 280 281 This replaced: frame->pc; */ 282 extern CORE_ADDR get_frame_pc (struct frame_info *); 283 284 /* An address (not necessarily aligned to an instruction boundary) 285 that falls within THIS frame's code block. 286 287 When a function call is the last statement in a block, the return 288 address for the call may land at the start of the next block. 289 Similarly, if a no-return function call is the last statement in 290 the function, the return address may end up pointing beyond the 291 function, and possibly at the start of the next function. 292 293 These methods make an allowance for this. For call frames, this 294 function returns the frame's PC-1 which "should" be an address in 295 the frame's block. */ 296 297 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame); 298 299 /* The frame's inner-most bound. AKA the stack-pointer. Confusingly 300 known as top-of-stack. */ 301 302 extern CORE_ADDR get_frame_sp (struct frame_info *); 303 304 /* Following on from the `resume' address. Return the entry point 305 address of the function containing that resume address, or zero if 306 that function isn't known. */ 307 extern CORE_ADDR get_frame_func (struct frame_info *fi); 308 309 /* Closely related to the resume address, various symbol table 310 attributes that are determined by the PC. Note that for a normal 311 frame, the PC refers to the resume address after the return, and 312 not the call instruction. In such a case, the address is adjusted 313 so that it (approximately) identifies the call site (and not the 314 return site). 315 316 NOTE: cagney/2002-11-28: The frame cache could be used to cache the 317 computed value. Working on the assumption that the bottle-neck is 318 in the single step code, and that code causes the frame cache to be 319 constantly flushed, caching things in a frame is probably of little 320 benefit. As they say `show us the numbers'. 321 322 NOTE: cagney/2002-11-28: Plenty more where this one came from: 323 find_frame_block(), find_frame_partial_function(), 324 find_frame_symtab(), find_frame_function(). Each will need to be 325 carefully considered to determine if the real intent was for it to 326 apply to the PC or the adjusted PC. */ 327 extern void find_frame_sal (struct frame_info *frame, 328 struct symtab_and_line *sal); 329 330 /* Set the current source and line to the location given by frame 331 FRAME, if possible. When CENTER is true, adjust so the relevant 332 line is in the center of the next 'list'. */ 333 334 void set_current_sal_from_frame (struct frame_info *, int); 335 336 /* Return the frame base (what ever that is) (DEPRECATED). 337 338 Old code was trying to use this single method for two conflicting 339 purposes. Such code needs to be updated to use either of: 340 341 get_frame_id: A low level frame unique identifier, that consists of 342 both a stack and a function address, that can be used to uniquely 343 identify a frame. This value is determined by the frame's 344 low-level unwinder, the stack part [typically] being the 345 top-of-stack of the previous frame, and the function part being the 346 function's start address. Since the correct identification of a 347 frameless function requires both the a stack and function address, 348 the old get_frame_base method was not sufficient. 349 350 get_frame_base_address: get_frame_locals_address: 351 get_frame_args_address: A set of high-level debug-info dependant 352 addresses that fall within the frame. These addresses almost 353 certainly will not match the stack address part of a frame ID (as 354 returned by get_frame_base). 355 356 This replaced: frame->frame; */ 357 358 extern CORE_ADDR get_frame_base (struct frame_info *); 359 360 /* Return the per-frame unique identifer. Can be used to relocate a 361 frame after a frame cache flush (and other similar operations). If 362 FI is NULL, return the null_frame_id. 363 364 NOTE: kettenis/20040508: These functions return a structure. On 365 platforms where structures are returned in static storage (vax, 366 m68k), this may trigger compiler bugs in code like: 367 368 if (frame_id_eq (get_frame_id (l), get_frame_id (r))) 369 370 where the return value from the first get_frame_id (l) gets 371 overwritten by the second get_frame_id (r). Please avoid writing 372 code like this. Use code like: 373 374 struct frame_id id = get_frame_id (l); 375 if (frame_id_eq (id, get_frame_id (r))) 376 377 instead, since that avoids the bug. */ 378 extern struct frame_id get_frame_id (struct frame_info *fi); 379 extern struct frame_id get_stack_frame_id (struct frame_info *fi); 380 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame); 381 382 /* Assuming that a frame is `normal', return its base-address, or 0 if 383 the information isn't available. NOTE: This address is really only 384 meaningful to the frame's high-level debug info. */ 385 extern CORE_ADDR get_frame_base_address (struct frame_info *); 386 387 /* Assuming that a frame is `normal', return the base-address of the 388 local variables, or 0 if the information isn't available. NOTE: 389 This address is really only meaningful to the frame's high-level 390 debug info. Typically, the argument and locals share a single 391 base-address. */ 392 extern CORE_ADDR get_frame_locals_address (struct frame_info *); 393 394 /* Assuming that a frame is `normal', return the base-address of the 395 parameter list, or 0 if that information isn't available. NOTE: 396 This address is really only meaningful to the frame's high-level 397 debug info. Typically, the argument and locals share a single 398 base-address. */ 399 extern CORE_ADDR get_frame_args_address (struct frame_info *); 400 401 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1 402 for an invalid frame). */ 403 extern int frame_relative_level (struct frame_info *fi); 404 405 /* Return the frame's type. */ 406 407 extern enum frame_type get_frame_type (struct frame_info *); 408 409 /* Return the frame's program space. */ 410 extern struct program_space *get_frame_program_space (struct frame_info *); 411 412 /* Unwind THIS frame's program space from the NEXT frame. */ 413 extern struct program_space *frame_unwind_program_space (struct frame_info *); 414 415 /* Return the frame's address space. */ 416 extern struct address_space *get_frame_address_space (struct frame_info *); 417 418 /* For frames where we can not unwind further, describe why. */ 419 420 enum unwind_stop_reason 421 { 422 /* No particular reason; either we haven't tried unwinding yet, 423 or we didn't fail. */ 424 UNWIND_NO_REASON, 425 426 /* The previous frame's analyzer returns an invalid result 427 from this_id. 428 429 FIXME drow/2006-08-16: This is how GDB used to indicate end of 430 stack. We should migrate to a model where frames always have a 431 valid ID, and this becomes not just an error but an internal 432 error. But that's a project for another day. */ 433 UNWIND_NULL_ID, 434 435 /* All the conditions after this point are considered errors; 436 abnormal stack termination. If a backtrace stops for one 437 of these reasons, we'll let the user know. This marker 438 is not a valid stop reason. */ 439 UNWIND_FIRST_ERROR, 440 441 /* This frame ID looks like it ought to belong to a NEXT frame, 442 but we got it for a PREV frame. Normally, this is a sign of 443 unwinder failure. It could also indicate stack corruption. */ 444 UNWIND_INNER_ID, 445 446 /* This frame has the same ID as the previous one. That means 447 that unwinding further would almost certainly give us another 448 frame with exactly the same ID, so break the chain. Normally, 449 this is a sign of unwinder failure. It could also indicate 450 stack corruption. */ 451 UNWIND_SAME_ID, 452 453 /* The frame unwinder didn't find any saved PC, but we needed 454 one to unwind further. */ 455 UNWIND_NO_SAVED_PC, 456 }; 457 458 /* Return the reason why we can't unwind past this frame. */ 459 460 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *); 461 462 /* Translate a reason code to an informative string. */ 463 464 const char *frame_stop_reason_string (enum unwind_stop_reason); 465 466 /* Unwind the stack frame so that the value of REGNUM, in the previous 467 (up, older) frame is returned. If VALUEP is NULL, don't 468 fetch/compute the value. Instead just return the location of the 469 value. */ 470 extern void frame_register_unwind (struct frame_info *frame, int regnum, 471 int *optimizedp, enum lval_type *lvalp, 472 CORE_ADDR *addrp, int *realnump, 473 gdb_byte *valuep); 474 475 /* Fetch a register from this, or unwind a register from the next 476 frame. Note that the get_frame methods are wrappers to 477 frame->next->unwind. They all [potentially] throw an error if the 478 fetch fails. The value methods never return NULL, but usually 479 do return a lazy value. */ 480 481 extern void frame_unwind_register (struct frame_info *frame, 482 int regnum, gdb_byte *buf); 483 extern void get_frame_register (struct frame_info *frame, 484 int regnum, gdb_byte *buf); 485 486 struct value *frame_unwind_register_value (struct frame_info *frame, 487 int regnum); 488 struct value *get_frame_register_value (struct frame_info *frame, 489 int regnum); 490 491 extern LONGEST frame_unwind_register_signed (struct frame_info *frame, 492 int regnum); 493 extern LONGEST get_frame_register_signed (struct frame_info *frame, 494 int regnum); 495 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame, 496 int regnum); 497 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame, 498 int regnum); 499 500 501 /* Get the value of the register that belongs to this FRAME. This 502 function is a wrapper to the call sequence ``frame_register_unwind 503 (get_next_frame (FRAME))''. As per frame_register_unwind(), if 504 VALUEP is NULL, the registers value is not fetched/computed. */ 505 506 extern void frame_register (struct frame_info *frame, int regnum, 507 int *optimizedp, enum lval_type *lvalp, 508 CORE_ADDR *addrp, int *realnump, 509 gdb_byte *valuep); 510 511 /* The reverse. Store a register value relative to the specified 512 frame. Note: this call makes the frame's state undefined. The 513 register and frame caches must be flushed. */ 514 extern void put_frame_register (struct frame_info *frame, int regnum, 515 const gdb_byte *buf); 516 517 /* Read LEN bytes from one or multiple registers starting with REGNUM 518 in frame FRAME, starting at OFFSET, into BUF. */ 519 extern int get_frame_register_bytes (struct frame_info *frame, int regnum, 520 CORE_ADDR offset, int len, 521 gdb_byte *myaddr); 522 523 /* Write LEN bytes to one or multiple registers starting with REGNUM 524 in frame FRAME, starting at OFFSET, into BUF. */ 525 extern void put_frame_register_bytes (struct frame_info *frame, int regnum, 526 CORE_ADDR offset, int len, 527 const gdb_byte *myaddr); 528 529 /* Unwind the PC. Strictly speaking return the resume address of the 530 calling frame. For GDB, `pc' is the resume address and not a 531 specific register. */ 532 533 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame); 534 535 /* Discard the specified frame. Restoring the registers to the state 536 of the caller. */ 537 extern void frame_pop (struct frame_info *frame); 538 539 /* Return memory from the specified frame. A frame knows its thread / 540 LWP and hence can find its way down to a target. The assumption 541 here is that the current and previous frame share a common address 542 space. 543 544 If the memory read fails, these methods throw an error. 545 546 NOTE: cagney/2003-06-03: Should there be unwind versions of these 547 methods? That isn't clear. Can code, for instance, assume that 548 this and the previous frame's memory or architecture are identical? 549 If architecture / memory changes are always separated by special 550 adaptor frames this should be ok. */ 551 552 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, 553 gdb_byte *buf, int len); 554 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame, 555 CORE_ADDR memaddr, int len); 556 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame, 557 CORE_ADDR memaddr, int len); 558 559 /* Same as above, but return non-zero when the entire memory read 560 succeeds, zero otherwize. */ 561 extern int safe_frame_unwind_memory (struct frame_info *this_frame, 562 CORE_ADDR addr, gdb_byte *buf, int len); 563 564 /* Return this frame's architecture. */ 565 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame); 566 567 /* Return the previous frame's architecture. */ 568 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame); 569 570 /* Return the previous frame's architecture, skipping inline functions. */ 571 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame); 572 573 574 /* Values for the source flag to be used in print_frame_info_base(). */ 575 enum print_what 576 { 577 /* Print only the source line, like in stepi. */ 578 SRC_LINE = -1, 579 /* Print only the location, i.e. level, address (sometimes) 580 function, args, file, line, line num. */ 581 LOCATION, 582 /* Print both of the above. */ 583 SRC_AND_LOC, 584 /* Print location only, but always include the address. */ 585 LOC_AND_ADDRESS 586 }; 587 588 /* Allocate zero initialized memory from the frame cache obstack. 589 Appendices to the frame info (such as the unwind cache) should 590 allocate memory using this method. */ 591 592 extern void *frame_obstack_zalloc (unsigned long size); 593 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE))) 594 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE))) 595 596 /* Create a regcache, and copy the frame's registers into it. */ 597 struct regcache *frame_save_as_regcache (struct frame_info *this_frame); 598 599 extern struct block *get_frame_block (struct frame_info *, 600 CORE_ADDR *addr_in_block); 601 602 /* Return the `struct block' that belongs to the selected thread's 603 selected frame. If the inferior has no state, return NULL. 604 605 NOTE: cagney/2002-11-29: 606 607 No state? Does the inferior have any execution state (a core file 608 does, an executable does not). At present the code tests 609 `target_has_stack' but I'm left wondering if it should test 610 `target_has_registers' or, even, a merged target_has_state. 611 612 Should it look at the most recently specified SAL? If the target 613 has no state, should this function try to extract a block from the 614 most recently selected SAL? That way `list foo' would give it some 615 sort of reference point. Then again, perhaps that would confuse 616 things. 617 618 Calls to this function can be broken down into two categories: Code 619 that uses the selected block as an additional, but optional, data 620 point; Code that uses the selected block as a prop, when it should 621 have the relevant frame/block/pc explicitly passed in. 622 623 The latter can be eliminated by correctly parameterizing the code, 624 the former though is more interesting. Per the "address" command, 625 it occurs in the CLI code and makes it possible for commands to 626 work, even when the inferior has no state. */ 627 628 extern struct block *get_selected_block (CORE_ADDR *addr_in_block); 629 630 extern struct symbol *get_frame_function (struct frame_info *); 631 632 extern CORE_ADDR get_pc_function_start (CORE_ADDR); 633 634 extern struct frame_info *find_relative_frame (struct frame_info *, int *); 635 636 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level, 637 enum print_what print_what); 638 639 extern void print_stack_frame (struct frame_info *, int print_level, 640 enum print_what print_what); 641 642 extern void print_frame_info (struct frame_info *, int print_level, 643 enum print_what print_what, int args); 644 645 extern struct frame_info *block_innermost_frame (struct block *); 646 647 extern int deprecated_pc_in_call_dummy (struct gdbarch *gdbarch, CORE_ADDR pc); 648 649 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a 650 function called get_frame_register_p(). This slightly weird (and 651 older) variant of get_frame_register() returns zero (indicating the 652 register is unavailable) if either: the register isn't cached; or 653 the register has been optimized out. Problem is, neither check is 654 exactly correct. A register can't be optimized out (it may not 655 have been saved as part of a function call); The fact that a 656 register isn't in the register cache doesn't mean that the register 657 isn't available (it could have been fetched from memory). */ 658 659 extern int frame_register_read (struct frame_info *frame, int regnum, 660 gdb_byte *buf); 661 662 /* From stack.c. */ 663 extern void args_info (char *, int); 664 665 extern void locals_info (char *, int); 666 667 extern void (*deprecated_selected_frame_level_changed_hook) (int); 668 669 extern void return_command (char *, int); 670 671 /* Set FRAME's unwinder temporarily, so that we can call a sniffer. 672 Return a cleanup which should be called if unwinding fails, and 673 discarded if it succeeds. */ 674 675 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame, 676 const struct frame_unwind *unwind); 677 678 /* Notes (cagney/2002-11-27, drow/2003-09-06): 679 680 You might think that calls to this function can simply be replaced by a 681 call to get_selected_frame(). 682 683 Unfortunately, it isn't that easy. 684 685 The relevant code needs to be audited to determine if it is 686 possible (or practical) to instead pass the applicable frame in as a 687 parameter. For instance, DEPRECATED_DO_REGISTERS_INFO() relied on 688 the deprecated_selected_frame global, while its replacement, 689 PRINT_REGISTERS_INFO(), is parameterized with the selected frame. 690 The only real exceptions occur at the edge (in the CLI code) where 691 user commands need to pick up the selected frame before proceeding. 692 693 There are also some functions called with a NULL frame meaning either "the 694 program is not running" or "use the selected frame". 695 696 This is important. GDB is trying to stamp out the hack: 697 698 saved_frame = deprecated_safe_get_selected_frame (); 699 select_frame (...); 700 hack_using_global_selected_frame (); 701 select_frame (saved_frame); 702 703 Take care! 704 705 This function calls get_selected_frame if the inferior should have a 706 frame, or returns NULL otherwise. */ 707 708 extern struct frame_info *deprecated_safe_get_selected_frame (void); 709 710 /* Create a frame using the specified BASE and PC. */ 711 712 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc); 713 714 /* Return true if the frame unwinder for frame FI is UNWINDER; false 715 otherwise. */ 716 717 extern int frame_unwinder_is (struct frame_info *fi, 718 const struct frame_unwind *unwinder); 719 720 #endif /* !defined (FRAME_H) */ 721