Commit | Line | Data |
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4f460812 | 1 | /* Cache and manage frames for GDB, the GNU debugger. |
96cb11df AC |
2 | |
3 | Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, | |
51603483 | 4 | 2001, 2002, 2003 Free Software Foundation, Inc. |
d65fe839 AC |
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" | |
39f77062 | 27 | #include "inferior.h" /* for inferior_ptid */ |
4e052eda | 28 | #include "regcache.h" |
4f460812 | 29 | #include "gdb_assert.h" |
e36180d7 AC |
30 | #include "gdb_string.h" |
31 | #include "builtin-regs.h" | |
4c1e7e9d AC |
32 | #include "gdb_obstack.h" |
33 | #include "dummy-frame.h" | |
a94dd1fd | 34 | #include "sentinel-frame.h" |
4c1e7e9d AC |
35 | #include "gdbcore.h" |
36 | #include "annotate.h" | |
6e7f8b9c | 37 | #include "language.h" |
494cca16 | 38 | #include "frame-unwind.h" |
eb4f72c5 AC |
39 | #include "command.h" |
40 | #include "gdbcmd.h" | |
41 | ||
ac2bd0a9 AC |
42 | /* Flag to control debugging. */ |
43 | ||
44 | static int frame_debug; | |
45 | ||
eb4f72c5 AC |
46 | /* Flag to indicate whether backtraces should stop at main. */ |
47 | ||
48 | static int backtrace_below_main; | |
d65fe839 | 49 | |
7a424e99 | 50 | /* Return a frame uniq ID that can be used to, later, re-find the |
101dcfbe AC |
51 | frame. */ |
52 | ||
7a424e99 AC |
53 | struct frame_id |
54 | get_frame_id (struct frame_info *fi) | |
101dcfbe AC |
55 | { |
56 | if (fi == NULL) | |
57 | { | |
7a424e99 | 58 | return null_frame_id; |
101dcfbe AC |
59 | } |
60 | else | |
61 | { | |
7a424e99 AC |
62 | struct frame_id id; |
63 | id.base = fi->frame; | |
64 | id.pc = fi->pc; | |
65 | return id; | |
101dcfbe AC |
66 | } |
67 | } | |
68 | ||
7a424e99 AC |
69 | const struct frame_id null_frame_id; /* All zeros. */ |
70 | ||
71 | struct frame_id | |
72 | frame_id_build (CORE_ADDR base, CORE_ADDR func_or_pc) | |
73 | { | |
74 | struct frame_id id; | |
75 | id.base = base; | |
76 | id.pc = func_or_pc; | |
77 | return id; | |
78 | } | |
79 | ||
80 | int | |
81 | frame_id_p (struct frame_id l) | |
82 | { | |
83 | /* The .func can be NULL but the .base cannot. */ | |
84 | return (l.base != 0); | |
85 | } | |
86 | ||
87 | int | |
88 | frame_id_eq (struct frame_id l, struct frame_id r) | |
89 | { | |
90 | /* If .base is different, the frames are different. */ | |
91 | if (l.base != r.base) | |
92 | return 0; | |
93 | /* Add a test to check that the frame ID's are for the same function | |
94 | here. */ | |
95 | return 1; | |
96 | } | |
97 | ||
98 | int | |
99 | frame_id_inner (struct frame_id l, struct frame_id r) | |
100 | { | |
101 | /* Only return non-zero when strictly inner than. Note that, per | |
102 | comment in "frame.h", there is some fuzz here. Frameless | |
103 | functions are not strictly inner than (same .base but different | |
104 | .func). */ | |
105 | return INNER_THAN (l.base, r.base); | |
106 | } | |
107 | ||
101dcfbe AC |
108 | struct frame_info * |
109 | frame_find_by_id (struct frame_id id) | |
110 | { | |
111 | struct frame_info *frame; | |
112 | ||
113 | /* ZERO denotes the null frame, let the caller decide what to do | |
114 | about it. Should it instead return get_current_frame()? */ | |
7a424e99 | 115 | if (!frame_id_p (id)) |
101dcfbe AC |
116 | return NULL; |
117 | ||
118 | for (frame = get_current_frame (); | |
119 | frame != NULL; | |
120 | frame = get_prev_frame (frame)) | |
121 | { | |
7a424e99 AC |
122 | struct frame_id this = get_frame_id (frame); |
123 | if (frame_id_eq (id, this)) | |
124 | /* An exact match. */ | |
125 | return frame; | |
126 | if (frame_id_inner (id, this)) | |
127 | /* Gone to far. */ | |
101dcfbe | 128 | return NULL; |
7a424e99 AC |
129 | /* Either, we're not yet gone far enough out along the frame |
130 | chain (inner(this,id), or we're comparing frameless functions | |
131 | (same .base, different .func, no test available). Struggle | |
132 | on until we've definitly gone to far. */ | |
101dcfbe AC |
133 | } |
134 | return NULL; | |
135 | } | |
136 | ||
f18c5a73 | 137 | CORE_ADDR |
12cc2063 | 138 | frame_pc_unwind (struct frame_info *this_frame) |
f18c5a73 | 139 | { |
12cc2063 | 140 | if (!this_frame->pc_unwind_cache_p) |
f18c5a73 | 141 | { |
12cc2063 AC |
142 | CORE_ADDR pc; |
143 | if (gdbarch_unwind_pc_p (current_gdbarch)) | |
144 | { | |
145 | /* The right way. The `pure' way. The one true way. This | |
146 | method depends solely on the register-unwind code to | |
147 | determine the value of registers in THIS frame, and hence | |
148 | the value of this frame's PC (resume address). A typical | |
149 | implementation is no more than: | |
150 | ||
151 | frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); | |
152 | return extract_address (buf, size of ISA_PC_REGNUM); | |
153 | ||
154 | Note: this method is very heavily dependent on a correct | |
155 | register-unwind implementation, it pays to fix that | |
156 | method first; this method is frame type agnostic, since | |
157 | it only deals with register values, it works with any | |
158 | frame. This is all in stark contrast to the old | |
159 | FRAME_SAVED_PC which would try to directly handle all the | |
160 | different ways that a PC could be unwound. */ | |
161 | pc = gdbarch_unwind_pc (current_gdbarch, this_frame); | |
162 | } | |
163 | else if (this_frame->level < 0) | |
164 | { | |
165 | /* FIXME: cagney/2003-03-06: Old code and and a sentinel | |
166 | frame. Do like was always done. Fetch the PC's value | |
167 | direct from the global registers array (via read_pc). | |
168 | This assumes that this frame belongs to the current | |
169 | global register cache. The assumption is dangerous. */ | |
170 | pc = read_pc (); | |
171 | } | |
8bedc050 | 172 | else if (DEPRECATED_FRAME_SAVED_PC_P ()) |
12cc2063 AC |
173 | { |
174 | /* FIXME: cagney/2003-03-06: Old code, but not a sentinel | |
175 | frame. Do like was always done. Note that this method, | |
176 | unlike unwind_pc(), tries to handle all the different | |
177 | frame cases directly. It fails. */ | |
8bedc050 | 178 | pc = DEPRECATED_FRAME_SAVED_PC (this_frame); |
12cc2063 AC |
179 | } |
180 | else | |
181 | internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method"); | |
182 | this_frame->pc_unwind_cache = pc; | |
183 | this_frame->pc_unwind_cache_p = 1; | |
f18c5a73 | 184 | } |
12cc2063 | 185 | return this_frame->pc_unwind_cache; |
f18c5a73 AC |
186 | } |
187 | ||
7a25a7c1 AC |
188 | static int |
189 | do_frame_unwind_register (void *src, int regnum, void *buf) | |
190 | { | |
191 | frame_unwind_register (src, regnum, buf); | |
192 | return 1; | |
193 | } | |
194 | ||
dbe9fe58 | 195 | void |
7a25a7c1 AC |
196 | frame_pop (struct frame_info *this_frame) |
197 | { | |
198 | struct regcache *scratch_regcache; | |
199 | struct cleanup *cleanups; | |
200 | ||
749b82f6 | 201 | if (DEPRECATED_POP_FRAME_P ()) |
7a25a7c1 AC |
202 | { |
203 | /* A legacy architecture that has implemented a custom pop | |
204 | function. All new architectures should instead be using the | |
205 | generic code below. */ | |
749b82f6 | 206 | DEPRECATED_POP_FRAME; |
7a25a7c1 AC |
207 | } |
208 | else | |
209 | { | |
210 | /* Make a copy of all the register values unwound from this | |
211 | frame. Save them in a scratch buffer so that there isn't a | |
212 | race betweening trying to extract the old values from the | |
213 | current_regcache while, at the same time writing new values | |
214 | into that same cache. */ | |
215 | struct regcache *scratch = regcache_xmalloc (current_gdbarch); | |
216 | struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch); | |
217 | regcache_save (scratch, do_frame_unwind_register, this_frame); | |
efd710d6 AC |
218 | /* FIXME: cagney/2003-03-16: It should be possible to tell the |
219 | target's register cache that it is about to be hit with a | |
220 | burst register transfer and that the sequence of register | |
221 | writes should be batched. The pair target_prepare_to_store() | |
222 | and target_store_registers() kind of suggest this | |
223 | functionality. Unfortunatly, they don't implement it. Their | |
224 | lack of a formal definition can lead to targets writing back | |
225 | bogus values (arguably a bug in the target code mind). */ | |
7a25a7c1 AC |
226 | /* Now copy those saved registers into the current regcache. |
227 | Here, regcache_cpy() calls regcache_restore(). */ | |
228 | regcache_cpy (current_regcache, scratch); | |
229 | do_cleanups (cleanups); | |
230 | } | |
231 | /* We've made right mess of GDB's local state, just discard | |
232 | everything. */ | |
dbe9fe58 AC |
233 | flush_cached_frames (); |
234 | } | |
c689142b | 235 | |
4f460812 AC |
236 | void |
237 | frame_register_unwind (struct frame_info *frame, int regnum, | |
238 | int *optimizedp, enum lval_type *lvalp, | |
239 | CORE_ADDR *addrp, int *realnump, void *bufferp) | |
240 | { | |
241 | struct frame_unwind_cache *cache; | |
242 | ||
243 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates | |
244 | that the value proper does not need to be fetched. */ | |
245 | gdb_assert (optimizedp != NULL); | |
246 | gdb_assert (lvalp != NULL); | |
247 | gdb_assert (addrp != NULL); | |
248 | gdb_assert (realnump != NULL); | |
249 | /* gdb_assert (bufferp != NULL); */ | |
250 | ||
a94dd1fd AC |
251 | /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame |
252 | is broken. There is always a frame. If there, for some reason, | |
253 | isn't, there is some pretty busted code as it should have | |
254 | detected the problem before calling here. */ | |
255 | gdb_assert (frame != NULL); | |
4f460812 AC |
256 | |
257 | /* Ask this frame to unwind its register. */ | |
494cca16 AC |
258 | frame->unwind->reg (frame, &frame->unwind_cache, regnum, |
259 | optimizedp, lvalp, addrp, realnump, bufferp); | |
4f460812 AC |
260 | } |
261 | ||
a216a322 AC |
262 | void |
263 | frame_register (struct frame_info *frame, int regnum, | |
264 | int *optimizedp, enum lval_type *lvalp, | |
265 | CORE_ADDR *addrp, int *realnump, void *bufferp) | |
266 | { | |
267 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates | |
268 | that the value proper does not need to be fetched. */ | |
269 | gdb_assert (optimizedp != NULL); | |
270 | gdb_assert (lvalp != NULL); | |
271 | gdb_assert (addrp != NULL); | |
272 | gdb_assert (realnump != NULL); | |
273 | /* gdb_assert (bufferp != NULL); */ | |
274 | ||
275 | /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset | |
276 | of the register in the register cache. It should instead return | |
277 | the REGNUM corresponding to that register. Translate the . */ | |
129c1cd6 | 278 | if (DEPRECATED_GET_SAVED_REGISTER_P ()) |
a216a322 | 279 | { |
129c1cd6 AC |
280 | DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, |
281 | regnum, lvalp); | |
a216a322 AC |
282 | /* Compute the REALNUM if the caller wants it. */ |
283 | if (*lvalp == lval_register) | |
284 | { | |
285 | int regnum; | |
286 | for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++) | |
287 | { | |
288 | if (*addrp == register_offset_hack (current_gdbarch, regnum)) | |
289 | { | |
290 | *realnump = regnum; | |
291 | return; | |
292 | } | |
293 | } | |
294 | internal_error (__FILE__, __LINE__, | |
295 | "Failed to compute the register number corresponding" | |
296 | " to 0x%s", paddr_d (*addrp)); | |
297 | } | |
298 | *realnump = -1; | |
299 | return; | |
300 | } | |
301 | ||
a94dd1fd AC |
302 | /* Obtain the register value by unwinding the register from the next |
303 | (more inner frame). */ | |
304 | gdb_assert (frame != NULL && frame->next != NULL); | |
305 | frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, | |
306 | realnump, bufferp); | |
a216a322 AC |
307 | } |
308 | ||
135c175f | 309 | void |
5b181d62 | 310 | frame_unwind_register (struct frame_info *frame, int regnum, void *buf) |
135c175f AC |
311 | { |
312 | int optimized; | |
313 | CORE_ADDR addr; | |
314 | int realnum; | |
315 | enum lval_type lval; | |
135c175f AC |
316 | frame_register_unwind (frame, regnum, &optimized, &lval, &addr, |
317 | &realnum, buf); | |
5b181d62 AC |
318 | } |
319 | ||
320 | void | |
321 | frame_unwind_signed_register (struct frame_info *frame, int regnum, | |
322 | LONGEST *val) | |
323 | { | |
324 | void *buf = alloca (MAX_REGISTER_RAW_SIZE); | |
325 | frame_unwind_register (frame, regnum, buf); | |
135c175f AC |
326 | (*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
327 | } | |
328 | ||
329 | void | |
330 | frame_unwind_unsigned_register (struct frame_info *frame, int regnum, | |
331 | ULONGEST *val) | |
332 | { | |
135c175f | 333 | void *buf = alloca (MAX_REGISTER_RAW_SIZE); |
5b181d62 | 334 | frame_unwind_register (frame, regnum, buf); |
135c175f AC |
335 | (*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
336 | } | |
4f460812 | 337 | |
5b181d62 AC |
338 | void |
339 | frame_read_register (struct frame_info *frame, int regnum, void *buf) | |
340 | { | |
341 | gdb_assert (frame != NULL && frame->next != NULL); | |
342 | frame_unwind_register (frame->next, regnum, buf); | |
343 | } | |
344 | ||
f908a0eb AC |
345 | void |
346 | frame_read_unsigned_register (struct frame_info *frame, int regnum, | |
347 | ULONGEST *val) | |
348 | { | |
349 | /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is | |
350 | always a frame. Both this, and the equivalent | |
351 | frame_read_signed_register() function, can only be called with a | |
352 | valid frame. If, for some reason, this function is called | |
353 | without a frame then the problem isn't here, but rather in the | |
354 | caller. It should of first created a frame and then passed that | |
355 | in. */ | |
356 | /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the | |
357 | ``current_frame'' should not be treated as a special case. While | |
358 | ``get_next_frame (current_frame) == NULL'' currently holds, it | |
359 | should, as far as possible, not be relied upon. In the future, | |
360 | ``get_next_frame (current_frame)'' may instead simply return a | |
361 | normal frame object that simply always gets register values from | |
362 | the register cache. Consequently, frame code should try to avoid | |
363 | tests like ``if get_next_frame() == NULL'' and instead just rely | |
364 | on recursive frame calls (like the below code) when manipulating | |
365 | a frame chain. */ | |
a94dd1fd AC |
366 | gdb_assert (frame != NULL && frame->next != NULL); |
367 | frame_unwind_unsigned_register (frame->next, regnum, val); | |
f908a0eb AC |
368 | } |
369 | ||
370 | void | |
371 | frame_read_signed_register (struct frame_info *frame, int regnum, | |
372 | LONGEST *val) | |
373 | { | |
a94dd1fd AC |
374 | /* See note above in frame_read_unsigned_register(). */ |
375 | gdb_assert (frame != NULL && frame->next != NULL); | |
376 | frame_unwind_signed_register (frame->next, regnum, val); | |
f908a0eb AC |
377 | } |
378 | ||
f796e4be | 379 | void |
4f460812 AC |
380 | generic_unwind_get_saved_register (char *raw_buffer, |
381 | int *optimizedp, | |
382 | CORE_ADDR *addrp, | |
383 | struct frame_info *frame, | |
384 | int regnum, | |
385 | enum lval_type *lvalp) | |
386 | { | |
387 | int optimizedx; | |
388 | CORE_ADDR addrx; | |
389 | int realnumx; | |
390 | enum lval_type lvalx; | |
391 | ||
392 | if (!target_has_registers) | |
393 | error ("No registers."); | |
394 | ||
395 | /* Keep things simple, ensure that all the pointers (except valuep) | |
396 | are non NULL. */ | |
397 | if (optimizedp == NULL) | |
398 | optimizedp = &optimizedx; | |
399 | if (lvalp == NULL) | |
400 | lvalp = &lvalx; | |
401 | if (addrp == NULL) | |
402 | addrp = &addrx; | |
403 | ||
a94dd1fd AC |
404 | gdb_assert (frame != NULL && frame->next != NULL); |
405 | frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, | |
406 | &realnumx, raw_buffer); | |
4f460812 AC |
407 | } |
408 | ||
cda5a58a | 409 | /* frame_register_read () |
d65fe839 | 410 | |
cda5a58a | 411 | Find and return the value of REGNUM for the specified stack frame. |
d65fe839 AC |
412 | The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). |
413 | ||
cda5a58a | 414 | Returns 0 if the register value could not be found. */ |
d65fe839 | 415 | |
cda5a58a AC |
416 | int |
417 | frame_register_read (struct frame_info *frame, int regnum, void *myaddr) | |
d65fe839 | 418 | { |
a216a322 AC |
419 | int optimized; |
420 | enum lval_type lval; | |
421 | CORE_ADDR addr; | |
422 | int realnum; | |
423 | frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr); | |
d65fe839 | 424 | |
c97dcfc7 AC |
425 | /* FIXME: cagney/2002-05-15: This test, is just bogus. |
426 | ||
427 | It indicates that the target failed to supply a value for a | |
428 | register because it was "not available" at this time. Problem | |
429 | is, the target still has the register and so get saved_register() | |
430 | may be returning a value saved on the stack. */ | |
431 | ||
d65fe839 | 432 | if (register_cached (regnum) < 0) |
cda5a58a | 433 | return 0; /* register value not available */ |
d65fe839 | 434 | |
a216a322 | 435 | return !optimized; |
d65fe839 | 436 | } |
e36180d7 AC |
437 | |
438 | ||
439 | /* Map between a frame register number and its name. A frame register | |
440 | space is a superset of the cooked register space --- it also | |
441 | includes builtin registers. */ | |
442 | ||
443 | int | |
444 | frame_map_name_to_regnum (const char *name, int len) | |
445 | { | |
446 | int i; | |
447 | ||
5f601589 AC |
448 | if (len < 0) |
449 | len = strlen (name); | |
450 | ||
e36180d7 AC |
451 | /* Search register name space. */ |
452 | for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++) | |
453 | if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i)) | |
454 | && strncmp (name, REGISTER_NAME (i), len) == 0) | |
455 | { | |
456 | return i; | |
457 | } | |
458 | ||
459 | /* Try builtin registers. */ | |
460 | i = builtin_reg_map_name_to_regnum (name, len); | |
461 | if (i >= 0) | |
462 | { | |
463 | /* A builtin register doesn't fall into the architecture's | |
464 | register range. */ | |
465 | gdb_assert (i >= NUM_REGS + NUM_PSEUDO_REGS); | |
466 | return i; | |
467 | } | |
468 | ||
469 | return -1; | |
470 | } | |
471 | ||
472 | const char * | |
473 | frame_map_regnum_to_name (int regnum) | |
474 | { | |
475 | if (regnum < 0) | |
476 | return NULL; | |
477 | if (regnum < NUM_REGS + NUM_PSEUDO_REGS) | |
478 | return REGISTER_NAME (regnum); | |
479 | return builtin_reg_map_regnum_to_name (regnum); | |
480 | } | |
4c1e7e9d | 481 | |
a94dd1fd AC |
482 | /* Create a sentinel frame. */ |
483 | ||
484 | struct frame_info * | |
485 | create_sentinel_frame (struct regcache *regcache) | |
486 | { | |
487 | struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
488 | frame->type = NORMAL_FRAME; | |
489 | frame->level = -1; | |
490 | /* Explicitly initialize the sentinel frame's cache. Provide it | |
491 | with the underlying regcache. In the future additional | |
492 | information, such as the frame's thread will be added. */ | |
493 | frame->unwind_cache = sentinel_frame_cache (regcache); | |
494 | /* For the moment there is only one sentinel frame implementation. */ | |
495 | frame->unwind = sentinel_frame_unwind; | |
496 | /* Link this frame back to itself. The frame is self referential | |
497 | (the unwound PC is the same as the pc), so make it so. */ | |
498 | frame->next = frame; | |
499 | /* Always unwind the PC as part of creating this frame. This | |
500 | ensures that the frame's PC points at something valid. */ | |
501 | /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel | |
502 | frame's PC may require information such as the frame's thread's | |
503 | stop reason. Is it possible to get to that? */ | |
504 | frame->pc = frame_pc_unwind (frame); | |
505 | return frame; | |
506 | } | |
507 | ||
4c1e7e9d AC |
508 | /* Info about the innermost stack frame (contents of FP register) */ |
509 | ||
510 | static struct frame_info *current_frame; | |
511 | ||
512 | /* Cache for frame addresses already read by gdb. Valid only while | |
513 | inferior is stopped. Control variables for the frame cache should | |
514 | be local to this module. */ | |
515 | ||
516 | static struct obstack frame_cache_obstack; | |
517 | ||
518 | void * | |
479ab5a0 | 519 | frame_obstack_zalloc (unsigned long size) |
4c1e7e9d | 520 | { |
479ab5a0 AC |
521 | void *data = obstack_alloc (&frame_cache_obstack, size); |
522 | memset (data, 0, size); | |
523 | return data; | |
4c1e7e9d AC |
524 | } |
525 | ||
6baff1d2 | 526 | CORE_ADDR * |
4c1e7e9d AC |
527 | frame_saved_regs_zalloc (struct frame_info *fi) |
528 | { | |
529 | fi->saved_regs = (CORE_ADDR *) | |
479ab5a0 | 530 | frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
6baff1d2 | 531 | return fi->saved_regs; |
4c1e7e9d AC |
532 | } |
533 | ||
6baff1d2 AC |
534 | CORE_ADDR * |
535 | get_frame_saved_regs (struct frame_info *fi) | |
536 | { | |
537 | return fi->saved_regs; | |
538 | } | |
4c1e7e9d | 539 | |
a94dd1fd AC |
540 | /* Return the innermost (currently executing) stack frame. This is |
541 | split into two functions. The function unwind_to_current_frame() | |
542 | is wrapped in catch exceptions so that, even when the unwind of the | |
543 | sentinel frame fails, the function still returns a stack frame. */ | |
544 | ||
545 | static int | |
546 | unwind_to_current_frame (struct ui_out *ui_out, void *args) | |
547 | { | |
548 | struct frame_info *frame = get_prev_frame (args); | |
549 | /* A sentinel frame can fail to unwind, eg, because it's PC value | |
550 | lands in somewhere like start. */ | |
551 | if (frame == NULL) | |
552 | return 1; | |
553 | current_frame = frame; | |
554 | return 0; | |
555 | } | |
4c1e7e9d AC |
556 | |
557 | struct frame_info * | |
558 | get_current_frame (void) | |
559 | { | |
0a1e1ca1 AC |
560 | /* First check, and report, the lack of registers. Having GDB |
561 | report "No stack!" or "No memory" when the target doesn't even | |
562 | have registers is very confusing. Besides, "printcmd.exp" | |
563 | explicitly checks that ``print $pc'' with no registers prints "No | |
564 | registers". */ | |
a94dd1fd AC |
565 | if (!target_has_registers) |
566 | error ("No registers."); | |
0a1e1ca1 AC |
567 | if (!target_has_stack) |
568 | error ("No stack."); | |
a94dd1fd AC |
569 | if (!target_has_memory) |
570 | error ("No memory."); | |
4c1e7e9d AC |
571 | if (current_frame == NULL) |
572 | { | |
a94dd1fd AC |
573 | struct frame_info *sentinel_frame = |
574 | create_sentinel_frame (current_regcache); | |
575 | if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame, | |
576 | NULL, RETURN_MASK_ERROR) != 0) | |
577 | { | |
578 | /* Oops! Fake a current frame? Is this useful? It has a PC | |
579 | of zero, for instance. */ | |
580 | current_frame = sentinel_frame; | |
581 | } | |
4c1e7e9d AC |
582 | } |
583 | return current_frame; | |
584 | } | |
585 | ||
6e7f8b9c AC |
586 | /* The "selected" stack frame is used by default for local and arg |
587 | access. May be zero, for no selected frame. */ | |
588 | ||
589 | struct frame_info *deprecated_selected_frame; | |
590 | ||
591 | /* Return the selected frame. Always non-null (unless there isn't an | |
592 | inferior sufficient for creating a frame) in which case an error is | |
593 | thrown. */ | |
594 | ||
595 | struct frame_info * | |
596 | get_selected_frame (void) | |
597 | { | |
598 | if (deprecated_selected_frame == NULL) | |
599 | /* Hey! Don't trust this. It should really be re-finding the | |
600 | last selected frame of the currently selected thread. This, | |
601 | though, is better than nothing. */ | |
602 | select_frame (get_current_frame ()); | |
603 | /* There is always a frame. */ | |
604 | gdb_assert (deprecated_selected_frame != NULL); | |
605 | return deprecated_selected_frame; | |
606 | } | |
607 | ||
608 | /* Select frame FI (or NULL - to invalidate the current frame). */ | |
609 | ||
610 | void | |
611 | select_frame (struct frame_info *fi) | |
612 | { | |
613 | register struct symtab *s; | |
614 | ||
615 | deprecated_selected_frame = fi; | |
616 | /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the | |
617 | frame is being invalidated. */ | |
618 | if (selected_frame_level_changed_hook) | |
619 | selected_frame_level_changed_hook (frame_relative_level (fi)); | |
620 | ||
621 | /* FIXME: kseitz/2002-08-28: It would be nice to call | |
622 | selected_frame_level_changed_event right here, but due to limitations | |
623 | in the current interfaces, we would end up flooding UIs with events | |
624 | because select_frame is used extensively internally. | |
625 | ||
626 | Once we have frame-parameterized frame (and frame-related) commands, | |
627 | the event notification can be moved here, since this function will only | |
628 | be called when the users selected frame is being changed. */ | |
629 | ||
630 | /* Ensure that symbols for this frame are read in. Also, determine the | |
631 | source language of this frame, and switch to it if desired. */ | |
632 | if (fi) | |
633 | { | |
634 | s = find_pc_symtab (fi->pc); | |
635 | if (s | |
636 | && s->language != current_language->la_language | |
637 | && s->language != language_unknown | |
638 | && language_mode == language_mode_auto) | |
639 | { | |
640 | set_language (s->language); | |
641 | } | |
642 | } | |
643 | } | |
644 | ||
4c1e7e9d AC |
645 | /* Return the register saved in the simplistic ``saved_regs'' cache. |
646 | If the value isn't here AND a value is needed, try the next inner | |
647 | most frame. */ | |
648 | ||
649 | static void | |
650 | frame_saved_regs_register_unwind (struct frame_info *frame, void **cache, | |
651 | int regnum, int *optimizedp, | |
652 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
653 | int *realnump, void *bufferp) | |
654 | { | |
655 | /* There is always a frame at this point. And THIS is the frame | |
656 | we're interested in. */ | |
657 | gdb_assert (frame != NULL); | |
658 | /* If we're using generic dummy frames, we'd better not be in a call | |
659 | dummy. (generic_call_dummy_register_unwind ought to have been called | |
660 | instead.) */ | |
07555a72 | 661 | gdb_assert (!(DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
5e0f933e | 662 | && (get_frame_type (frame) == DUMMY_FRAME))); |
4c1e7e9d | 663 | |
8f871025 | 664 | /* Only (older) architectures that implement the |
f30ee0bc AC |
665 | DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this |
666 | function. */ | |
667 | gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); | |
8f871025 | 668 | |
4c1e7e9d | 669 | /* Load the saved_regs register cache. */ |
a94dd1fd | 670 | if (get_frame_saved_regs (frame) == NULL) |
f30ee0bc | 671 | DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
4c1e7e9d | 672 | |
a94dd1fd AC |
673 | if (get_frame_saved_regs (frame) != NULL |
674 | && get_frame_saved_regs (frame)[regnum] != 0) | |
4c1e7e9d AC |
675 | { |
676 | if (regnum == SP_REGNUM) | |
677 | { | |
678 | /* SP register treated specially. */ | |
679 | *optimizedp = 0; | |
680 | *lvalp = not_lval; | |
681 | *addrp = 0; | |
682 | *realnump = -1; | |
683 | if (bufferp != NULL) | |
684 | store_address (bufferp, REGISTER_RAW_SIZE (regnum), | |
a94dd1fd | 685 | get_frame_saved_regs (frame)[regnum]); |
4c1e7e9d AC |
686 | } |
687 | else | |
688 | { | |
689 | /* Any other register is saved in memory, fetch it but cache | |
690 | a local copy of its value. */ | |
691 | *optimizedp = 0; | |
692 | *lvalp = lval_memory; | |
a94dd1fd | 693 | *addrp = get_frame_saved_regs (frame)[regnum]; |
4c1e7e9d AC |
694 | *realnump = -1; |
695 | if (bufferp != NULL) | |
696 | { | |
697 | #if 1 | |
698 | /* Save each register value, as it is read in, in a | |
699 | frame based cache. */ | |
700 | void **regs = (*cache); | |
701 | if (regs == NULL) | |
702 | { | |
703 | int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS) | |
704 | * sizeof (void *)); | |
479ab5a0 | 705 | regs = frame_obstack_zalloc (sizeof_cache); |
4c1e7e9d AC |
706 | (*cache) = regs; |
707 | } | |
708 | if (regs[regnum] == NULL) | |
709 | { | |
710 | regs[regnum] | |
479ab5a0 | 711 | = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum)); |
a94dd1fd | 712 | read_memory (get_frame_saved_regs (frame)[regnum], regs[regnum], |
4c1e7e9d AC |
713 | REGISTER_RAW_SIZE (regnum)); |
714 | } | |
715 | memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum)); | |
716 | #else | |
717 | /* Read the value in from memory. */ | |
a94dd1fd | 718 | read_memory (get_frame_saved_regs (frame)[regnum], bufferp, |
4c1e7e9d AC |
719 | REGISTER_RAW_SIZE (regnum)); |
720 | #endif | |
721 | } | |
722 | } | |
723 | return; | |
724 | } | |
725 | ||
726 | /* No luck, assume this and the next frame have the same register | |
a94dd1fd AC |
727 | value. Pass the request down the frame chain to the next frame. |
728 | Hopefully that will find the register's location, either in a | |
729 | register or in memory. */ | |
730 | frame_register (frame, regnum, optimizedp, lvalp, addrp, realnump, | |
731 | bufferp); | |
4c1e7e9d AC |
732 | } |
733 | ||
c170fb60 AC |
734 | static void |
735 | frame_saved_regs_id_unwind (struct frame_info *next_frame, void **cache, | |
736 | struct frame_id *id) | |
c689142b AC |
737 | { |
738 | int fromleaf; | |
c170fb60 AC |
739 | CORE_ADDR base; |
740 | CORE_ADDR pc; | |
741 | ||
742 | /* Start out by assuming it's NULL. */ | |
743 | (*id) = null_frame_id; | |
c689142b | 744 | |
a94dd1fd | 745 | if (frame_relative_level (next_frame) <= 0) |
c689142b AC |
746 | /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
747 | the frame chain, not just the inner most frame! The generic, | |
748 | per-architecture, frame code should handle this and the below | |
749 | should simply be removed. */ | |
750 | fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame); | |
751 | else | |
752 | fromleaf = 0; | |
753 | ||
754 | if (fromleaf) | |
755 | /* A frameless inner-most frame. The `FP' (which isn't an | |
756 | architecture frame-pointer register!) of the caller is the same | |
757 | as the callee. */ | |
758 | /* FIXME: 2002-11-09: There isn't any reason to special case this | |
759 | edge condition. Instead the per-architecture code should hande | |
760 | it locally. */ | |
c170fb60 | 761 | base = get_frame_base (next_frame); |
c689142b AC |
762 | else |
763 | { | |
764 | /* Two macros defined in tm.h specify the machine-dependent | |
765 | actions to be performed here. | |
766 | ||
767 | First, get the frame's chain-pointer. | |
768 | ||
769 | If that is zero, the frame is the outermost frame or a leaf | |
770 | called by the outermost frame. This means that if start | |
771 | calls main without a frame, we'll return 0 (which is fine | |
772 | anyway). | |
773 | ||
774 | Nope; there's a problem. This also returns when the current | |
775 | routine is a leaf of main. This is unacceptable. We move | |
776 | this to after the ffi test; I'd rather have backtraces from | |
777 | start go curfluy than have an abort called from main not show | |
778 | main. */ | |
d62d1979 | 779 | gdb_assert (FRAME_CHAIN_P ()); |
c170fb60 | 780 | base = FRAME_CHAIN (next_frame); |
c689142b | 781 | |
c170fb60 AC |
782 | if (!frame_chain_valid (base, next_frame)) |
783 | return; | |
c689142b | 784 | } |
c170fb60 AC |
785 | if (base == 0) |
786 | return; | |
c689142b AC |
787 | |
788 | /* FIXME: cagney/2002-06-08: This should probably return the frame's | |
789 | function and not the PC (a.k.a. resume address). */ | |
c170fb60 AC |
790 | pc = frame_pc_unwind (next_frame); |
791 | id->pc = pc; | |
792 | id->base = base; | |
c689142b AC |
793 | } |
794 | ||
494cca16 | 795 | const struct frame_unwind trad_frame_unwinder = { |
494cca16 AC |
796 | frame_saved_regs_id_unwind, |
797 | frame_saved_regs_register_unwind | |
798 | }; | |
799 | const struct frame_unwind *trad_frame_unwind = &trad_frame_unwinder; | |
800 | ||
801 | ||
ac2adee5 AC |
802 | /* Function: deprecated_generic_get_saved_register |
803 | ||
4c1e7e9d | 804 | Find register number REGNUM relative to FRAME and put its (raw, |
ac2adee5 | 805 | target format) contents in *RAW_BUFFER. |
4c1e7e9d AC |
806 | |
807 | Set *OPTIMIZED if the variable was optimized out (and thus can't be | |
808 | fetched). Note that this is never set to anything other than zero | |
809 | in this implementation. | |
810 | ||
811 | Set *LVAL to lval_memory, lval_register, or not_lval, depending on | |
812 | whether the value was fetched from memory, from a register, or in a | |
813 | strange and non-modifiable way (e.g. a frame pointer which was | |
814 | calculated rather than fetched). We will use not_lval for values | |
815 | fetched from generic dummy frames. | |
816 | ||
817 | Set *ADDRP to the address, either in memory or as a REGISTER_BYTE | |
818 | offset into the registers array. If the value is stored in a dummy | |
819 | frame, set *ADDRP to zero. | |
820 | ||
4c1e7e9d AC |
821 | The argument RAW_BUFFER must point to aligned memory. */ |
822 | ||
823 | void | |
824 | deprecated_generic_get_saved_register (char *raw_buffer, int *optimized, | |
825 | CORE_ADDR *addrp, | |
826 | struct frame_info *frame, int regnum, | |
827 | enum lval_type *lval) | |
828 | { | |
829 | if (!target_has_registers) | |
830 | error ("No registers."); | |
831 | ||
f30ee0bc | 832 | gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); |
8f871025 | 833 | |
4c1e7e9d AC |
834 | /* Normal systems don't optimize out things with register numbers. */ |
835 | if (optimized != NULL) | |
836 | *optimized = 0; | |
837 | ||
838 | if (addrp) /* default assumption: not found in memory */ | |
839 | *addrp = 0; | |
840 | ||
841 | /* Note: since the current frame's registers could only have been | |
842 | saved by frames INTERIOR TO the current frame, we skip examining | |
843 | the current frame itself: otherwise, we would be getting the | |
844 | previous frame's registers which were saved by the current frame. */ | |
845 | ||
a94dd1fd | 846 | if (frame != NULL) |
4c1e7e9d | 847 | { |
a94dd1fd AC |
848 | for (frame = get_next_frame (frame); |
849 | frame_relative_level (frame) >= 0; | |
850 | frame = get_next_frame (frame)) | |
4c1e7e9d | 851 | { |
a94dd1fd | 852 | if (get_frame_type (frame) == DUMMY_FRAME) |
4c1e7e9d | 853 | { |
a94dd1fd AC |
854 | if (lval) /* found it in a CALL_DUMMY frame */ |
855 | *lval = not_lval; | |
856 | if (raw_buffer) | |
857 | /* FIXME: cagney/2002-06-26: This should be via the | |
858 | gdbarch_register_read() method so that it, on the | |
859 | fly, constructs either a raw or pseudo register | |
860 | from the raw register cache. */ | |
861 | regcache_raw_read | |
862 | (generic_find_dummy_frame (get_frame_pc (frame), | |
863 | get_frame_base (frame)), | |
864 | regnum, raw_buffer); | |
865 | return; | |
4c1e7e9d | 866 | } |
a94dd1fd | 867 | |
f30ee0bc | 868 | DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
a94dd1fd AC |
869 | if (get_frame_saved_regs (frame) != NULL |
870 | && get_frame_saved_regs (frame)[regnum] != 0) | |
4c1e7e9d | 871 | { |
a94dd1fd AC |
872 | if (lval) /* found it saved on the stack */ |
873 | *lval = lval_memory; | |
874 | if (regnum == SP_REGNUM) | |
875 | { | |
876 | if (raw_buffer) /* SP register treated specially */ | |
877 | store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), | |
878 | get_frame_saved_regs (frame)[regnum]); | |
879 | } | |
880 | else | |
881 | { | |
882 | if (addrp) /* any other register */ | |
883 | *addrp = get_frame_saved_regs (frame)[regnum]; | |
884 | if (raw_buffer) | |
885 | read_memory (get_frame_saved_regs (frame)[regnum], raw_buffer, | |
886 | REGISTER_RAW_SIZE (regnum)); | |
887 | } | |
888 | return; | |
4c1e7e9d | 889 | } |
4c1e7e9d AC |
890 | } |
891 | } | |
892 | ||
893 | /* If we get thru the loop to this point, it means the register was | |
894 | not saved in any frame. Return the actual live-register value. */ | |
895 | ||
896 | if (lval) /* found it in a live register */ | |
897 | *lval = lval_register; | |
898 | if (addrp) | |
899 | *addrp = REGISTER_BYTE (regnum); | |
900 | if (raw_buffer) | |
901 | deprecated_read_register_gen (regnum, raw_buffer); | |
902 | } | |
903 | ||
eb4f72c5 AC |
904 | /* Determine the frame's type based on its PC. */ |
905 | ||
906 | static enum frame_type | |
907 | frame_type_from_pc (CORE_ADDR pc) | |
908 | { | |
909 | /* FIXME: cagney/2002-11-24: Can't yet directly call | |
910 | pc_in_dummy_frame() as some architectures don't set | |
911 | PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the | |
912 | latter is implemented by simply calling pc_in_dummy_frame). */ | |
913 | if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES | |
914 | && DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)) | |
915 | return DUMMY_FRAME; | |
916 | else | |
917 | { | |
918 | char *name; | |
919 | find_pc_partial_function (pc, &name, NULL, NULL); | |
920 | if (PC_IN_SIGTRAMP (pc, name)) | |
921 | return SIGTRAMP_FRAME; | |
922 | else | |
923 | return NORMAL_FRAME; | |
924 | } | |
925 | } | |
926 | ||
4c1e7e9d AC |
927 | /* Create an arbitrary (i.e. address specified by user) or innermost frame. |
928 | Always returns a non-NULL value. */ | |
929 | ||
930 | struct frame_info * | |
931 | create_new_frame (CORE_ADDR addr, CORE_ADDR pc) | |
932 | { | |
933 | struct frame_info *fi; | |
4c1e7e9d | 934 | |
479ab5a0 | 935 | fi = frame_obstack_zalloc (sizeof (struct frame_info)); |
4c1e7e9d AC |
936 | |
937 | fi->frame = addr; | |
938 | fi->pc = pc; | |
a94dd1fd | 939 | fi->next = create_sentinel_frame (current_regcache); |
eb4f72c5 | 940 | fi->type = frame_type_from_pc (pc); |
4c1e7e9d | 941 | |
e9582e71 AC |
942 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
943 | DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi); | |
4c1e7e9d AC |
944 | |
945 | /* Select/initialize an unwind function. */ | |
494cca16 | 946 | fi->unwind = frame_unwind_find_by_pc (current_gdbarch, fi->pc); |
4c1e7e9d AC |
947 | |
948 | return fi; | |
949 | } | |
950 | ||
03febf99 AC |
951 | /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the |
952 | innermost frame). Be careful to not fall off the bottom of the | |
953 | frame chain and onto the sentinel frame. */ | |
4c1e7e9d AC |
954 | |
955 | struct frame_info * | |
03febf99 | 956 | get_next_frame (struct frame_info *this_frame) |
4c1e7e9d | 957 | { |
03febf99 AC |
958 | if (this_frame->level > 0) |
959 | return this_frame->next; | |
a94dd1fd AC |
960 | else |
961 | return NULL; | |
4c1e7e9d AC |
962 | } |
963 | ||
964 | /* Flush the entire frame cache. */ | |
965 | ||
966 | void | |
967 | flush_cached_frames (void) | |
968 | { | |
969 | /* Since we can't really be sure what the first object allocated was */ | |
970 | obstack_free (&frame_cache_obstack, 0); | |
971 | obstack_init (&frame_cache_obstack); | |
972 | ||
973 | current_frame = NULL; /* Invalidate cache */ | |
974 | select_frame (NULL); | |
975 | annotate_frames_invalid (); | |
976 | } | |
977 | ||
978 | /* Flush the frame cache, and start a new one if necessary. */ | |
979 | ||
980 | void | |
981 | reinit_frame_cache (void) | |
982 | { | |
983 | flush_cached_frames (); | |
984 | ||
985 | /* FIXME: The inferior_ptid test is wrong if there is a corefile. */ | |
986 | if (PIDGET (inferior_ptid) != 0) | |
987 | { | |
988 | select_frame (get_current_frame ()); | |
989 | } | |
990 | } | |
991 | ||
eb4f72c5 AC |
992 | /* Create the previous frame using the deprecated methods |
993 | INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */ | |
4c1e7e9d | 994 | |
eb4f72c5 | 995 | static struct frame_info * |
03febf99 | 996 | legacy_get_prev_frame (struct frame_info *this_frame) |
4c1e7e9d AC |
997 | { |
998 | CORE_ADDR address = 0; | |
999 | struct frame_info *prev; | |
95adb866 | 1000 | int fromleaf; |
4c1e7e9d | 1001 | |
055bb976 AC |
1002 | /* Allocate the new frame but do not wire it in to the frame chain. |
1003 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along | |
1004 | frame->next to pull some fancy tricks (of course such code is, by | |
1005 | definition, recursive). Try to prevent it. | |
1006 | ||
1007 | There is no reason to worry about memory leaks, should the | |
1008 | remainder of the function fail. The allocated memory will be | |
1009 | quickly reclaimed when the frame cache is flushed, and the `we've | |
1010 | been here before' check, in get_prev_frame will stop repeated | |
1011 | memory allocation calls. */ | |
1012 | prev = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
1013 | prev->level = this_frame->level + 1; | |
1014 | ||
1015 | /* NOTE: cagney/2002-11-18: Should have been correctly setting the | |
1016 | frame's type here, before anything else, and not last, at the | |
1017 | bottom of this function. The various | |
1018 | DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC, | |
1019 | DEPRECATED_INIT_FRAME_PC_FIRST and | |
1020 | DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds | |
1021 | that handle the frame not being correctly set from the start. | |
1022 | Unfortunatly those same work-arounds rely on the type defaulting | |
1023 | to NORMAL_FRAME. Ulgh! The new frame code does not have this | |
1024 | problem. */ | |
1025 | prev->type = NORMAL_FRAME; | |
1026 | ||
1027 | /* Handle sentinel frame unwind as a special case. */ | |
1028 | if (this_frame->level < 0) | |
1029 | { | |
1030 | /* Try to unwind the PC. If that doesn't work, assume we've reached | |
1031 | the oldest frame and simply return. Is there a better sentinal | |
1032 | value? The unwound PC value is then used to initialize the new | |
1033 | previous frame's type. | |
1034 | ||
1035 | Note that the pc-unwind is intentionally performed before the | |
1036 | frame chain. This is ok since, for old targets, both | |
1037 | frame_pc_unwind (nee, FRAME_SAVED_PC) and FRAME_CHAIN()) assume | |
1038 | THIS_FRAME's data structures have already been initialized (using | |
1039 | DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order | |
1040 | doesn't matter. | |
1041 | ||
1042 | By unwinding the PC first, it becomes possible to, in the case of | |
1043 | a dummy frame, avoid also unwinding the frame ID. This is | |
1044 | because (well ignoring the PPC) a dummy frame can be located | |
1045 | using THIS_FRAME's frame ID. */ | |
1046 | ||
1047 | prev->pc = frame_pc_unwind (this_frame); | |
1048 | if (prev->pc == 0) | |
1049 | { | |
1050 | /* The allocated PREV_FRAME will be reclaimed when the frame | |
1051 | obstack is next purged. */ | |
1052 | if (frame_debug) | |
1053 | fprintf_unfiltered (gdb_stdlog, | |
1054 | "Outermost frame - unwound PC zero\n"); | |
1055 | return NULL; | |
1056 | } | |
1057 | prev->type = frame_type_from_pc (prev->pc); | |
1058 | ||
1059 | /* Set the unwind functions based on that identified PC. */ | |
1060 | prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc); | |
1061 | ||
1062 | /* Find the prev's frame's ID. */ | |
1063 | if (prev->type == DUMMY_FRAME | |
1064 | && gdbarch_unwind_dummy_id_p (current_gdbarch)) | |
1065 | { | |
1066 | /* When unwinding a normal frame, the stack structure is | |
1067 | determined by analyzing the frame's function's code (be | |
1068 | it using brute force prologue analysis, or the dwarf2 | |
1069 | CFI). In the case of a dummy frame, that simply isn't | |
1070 | possible. The The PC is either the program entry point, | |
1071 | or some random address on the stack. Trying to use that | |
1072 | PC to apply standard frame ID unwind techniques is just | |
1073 | asking for trouble. */ | |
1074 | /* Assume hand_function_call(), via SAVE_DUMMY_FRAME_TOS, | |
1075 | previously saved the dummy frame's ID. Things only work | |
1076 | if the two return the same value. */ | |
1077 | gdb_assert (SAVE_DUMMY_FRAME_TOS_P ()); | |
1078 | /* Use an architecture specific method to extract the prev's | |
1079 | dummy ID from the next frame. Note that this method uses | |
1080 | frame_register_unwind to obtain the register values | |
1081 | needed to determine the dummy frame's ID. */ | |
1082 | prev->id = gdbarch_unwind_dummy_id (current_gdbarch, this_frame); | |
1083 | } | |
1084 | else | |
1085 | { | |
1086 | /* We're unwinding a sentinel frame, the PC of which is | |
1087 | pointing at a stack dummy. Fake up the dummy frame's ID | |
1088 | using the same sequence as is found a traditional | |
1089 | unwinder. Once all architectures supply the | |
1090 | unwind_dummy_id method, this code can go away. */ | |
1091 | prev->id.base = read_fp (); | |
1092 | prev->id.pc = read_pc (); | |
1093 | } | |
1094 | ||
1095 | /* Check that the unwound ID is valid. */ | |
1096 | if (!frame_id_p (prev->id)) | |
1097 | { | |
1098 | if (frame_debug) | |
1099 | fprintf_unfiltered (gdb_stdlog, | |
1100 | "Outermost legacy sentinel frame - unwound frame ID invalid\n"); | |
1101 | return NULL; | |
1102 | } | |
1103 | ||
1104 | /* Check that the new frame isn't inner to (younger, below, | |
1105 | next) the old frame. If that happens the frame unwind is | |
1106 | going backwards. */ | |
1107 | /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since | |
1108 | that doesn't have a valid frame ID. Should instead set the | |
1109 | sentinel frame's frame ID to a `sentinel'. Leave it until | |
1110 | after the switch to storing the frame ID, instead of the | |
1111 | frame base, in the frame object. */ | |
1112 | ||
1113 | /* FIXME: cagney/2002-12-18: Instead of this hack, should only | |
1114 | store the frame ID in PREV_FRAME. Unfortunatly, some | |
1115 | architectures (HP/UX) still reply on EXTRA_FRAME_INFO and, | |
1116 | hence, still poke at the "struct frame_info" object directly. */ | |
1117 | prev->frame = prev->id.base; | |
1118 | ||
1119 | /* Link it in. */ | |
1120 | this_frame->prev = prev; | |
1121 | prev->next = this_frame; | |
1122 | ||
1123 | /* FIXME: cagney/2002-01-19: This call will go away. Instead of | |
1124 | initializing extra info, all frames will use the frame_cache | |
1125 | (passed to the unwind functions) to store additional frame | |
1126 | info. Unfortunatly legacy targets can't use | |
1127 | legacy_get_prev_frame() to unwind the sentinel frame and, | |
1128 | consequently, are forced to take this code path and rely on | |
1129 | the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to | |
1130 | initialize the inner-most frame. */ | |
1131 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) | |
1132 | { | |
1133 | DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev); | |
1134 | } | |
1135 | return prev; | |
1136 | } | |
1137 | ||
eb4f72c5 AC |
1138 | /* This code only works on normal frames. A sentinel frame, where |
1139 | the level is -1, should never reach this code. */ | |
03febf99 | 1140 | gdb_assert (this_frame->level >= 0); |
4c1e7e9d AC |
1141 | |
1142 | /* On some machines it is possible to call a function without | |
1143 | setting up a stack frame for it. On these machines, we | |
1144 | define this macro to take two args; a frameinfo pointer | |
1145 | identifying a frame and a variable to set or clear if it is | |
1146 | or isn't leafless. */ | |
1147 | ||
1148 | /* Still don't want to worry about this except on the innermost | |
03febf99 | 1149 | frame. This macro will set FROMLEAF if THIS_FRAME is a frameless |
95adb866 | 1150 | function invocation. */ |
03febf99 | 1151 | if (this_frame->level == 0) |
95adb866 AC |
1152 | /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
1153 | the frame chain, not just the inner most frame! The generic, | |
1154 | per-architecture, frame code should handle this and the below | |
1155 | should simply be removed. */ | |
03febf99 | 1156 | fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame); |
95adb866 AC |
1157 | else |
1158 | fromleaf = 0; | |
1159 | ||
1160 | if (fromleaf) | |
1161 | /* A frameless inner-most frame. The `FP' (which isn't an | |
1162 | architecture frame-pointer register!) of the caller is the same | |
1163 | as the callee. */ | |
1164 | /* FIXME: 2002-11-09: There isn't any reason to special case this | |
1165 | edge condition. Instead the per-architecture code should hande | |
1166 | it locally. */ | |
03febf99 | 1167 | address = get_frame_base (this_frame); |
95adb866 | 1168 | else |
4c1e7e9d AC |
1169 | { |
1170 | /* Two macros defined in tm.h specify the machine-dependent | |
1171 | actions to be performed here. | |
95adb866 | 1172 | |
4c1e7e9d | 1173 | First, get the frame's chain-pointer. |
95adb866 | 1174 | |
4c1e7e9d AC |
1175 | If that is zero, the frame is the outermost frame or a leaf |
1176 | called by the outermost frame. This means that if start | |
1177 | calls main without a frame, we'll return 0 (which is fine | |
1178 | anyway). | |
1179 | ||
1180 | Nope; there's a problem. This also returns when the current | |
1181 | routine is a leaf of main. This is unacceptable. We move | |
1182 | this to after the ffi test; I'd rather have backtraces from | |
1183 | start go curfluy than have an abort called from main not show | |
1184 | main. */ | |
d62d1979 | 1185 | gdb_assert (FRAME_CHAIN_P ()); |
03febf99 | 1186 | address = FRAME_CHAIN (this_frame); |
4c1e7e9d | 1187 | |
03febf99 | 1188 | if (!frame_chain_valid (address, this_frame)) |
4c1e7e9d AC |
1189 | return 0; |
1190 | } | |
1191 | if (address == 0) | |
1192 | return 0; | |
1193 | ||
055bb976 | 1194 | /* Link in the already allocated prev frame. */ |
03febf99 AC |
1195 | this_frame->prev = prev; |
1196 | prev->next = this_frame; | |
4c1e7e9d | 1197 | prev->frame = address; |
4c1e7e9d | 1198 | |
95adb866 | 1199 | /* This change should not be needed, FIXME! We should determine |
a5afb99f | 1200 | whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen |
e9582e71 AC |
1201 | after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple |
1202 | way to express what goes on here. | |
95adb866 | 1203 | |
e9582e71 AC |
1204 | DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places: |
1205 | create_new_frame (where the PC is already set up) and here (where | |
1206 | it isn't). DEPRECATED_INIT_FRAME_PC is only called from here, | |
1207 | always after DEPRECATED_INIT_EXTRA_FRAME_INFO. | |
95adb866 | 1208 | |
e9582e71 AC |
1209 | The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO |
1210 | requires the PC value (which hasn't been set yet). Some other | |
1211 | machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO | |
1212 | before they can do DEPRECATED_INIT_FRAME_PC. Phoo. | |
95adb866 | 1213 | |
2ca6c561 AC |
1214 | We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more |
1215 | complication to an already overcomplicated part of GDB. | |
1216 | gnu@cygnus.com, 15Sep92. | |
95adb866 | 1217 | |
a5afb99f | 1218 | Assuming that some machines need DEPRECATED_INIT_FRAME_PC after |
e9582e71 | 1219 | DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme: |
95adb866 AC |
1220 | |
1221 | SETUP_INNERMOST_FRAME(): Default version is just create_new_frame | |
1222 | (read_fp ()), read_pc ()). Machines with extra frame info would | |
1223 | do that (or the local equivalent) and then set the extra fields. | |
1224 | ||
1225 | SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that | |
1226 | create_new_frame would no longer init extra frame info; | |
1227 | SETUP_ARBITRARY_FRAME would have to do that. | |
1228 | ||
e9582e71 AC |
1229 | INIT_PREV_FRAME(fromleaf, prev) Replace |
1230 | DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC. | |
1231 | This should also return a flag saying whether to keep the new | |
1232 | frame, or whether to discard it, because on some machines (e.g. | |
1233 | mips) it is really awkward to have FRAME_CHAIN_VALID called | |
1234 | BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good way to | |
1235 | get information deduced in FRAME_CHAIN_VALID into the extra | |
1236 | fields of the new frame). std_frame_pc(fromleaf, prev) | |
95adb866 AC |
1237 | |
1238 | This is the default setting for INIT_PREV_FRAME. It just does | |
a5afb99f AC |
1239 | what the default DEPRECATED_INIT_FRAME_PC does. Some machines |
1240 | will call it from INIT_PREV_FRAME (either at the beginning, the | |
1241 | end, or in the middle). Some machines won't use it. | |
95adb866 AC |
1242 | |
1243 | kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */ | |
1244 | ||
1245 | /* NOTE: cagney/2002-11-09: Just ignore the above! There is no | |
1246 | reason for things to be this complicated. | |
1247 | ||
1248 | The trick is to assume that there is always a frame. Instead of | |
1249 | special casing the inner-most frame, create fake frame | |
1250 | (containing the hardware registers) that is inner to the | |
1251 | user-visible inner-most frame (...) and then unwind from that. | |
1252 | That way architecture code can use use the standard | |
1253 | frame_XX_unwind() functions and not differentiate between the | |
1254 | inner most and any other case. | |
1255 | ||
1256 | Since there is always a frame to unwind from, there is always | |
03febf99 | 1257 | somewhere (THIS_FRAME) to store all the info needed to construct |
95adb866 AC |
1258 | a new (previous) frame without having to first create it. This |
1259 | means that the convolution below - needing to carefully order a | |
1260 | frame's initialization - isn't needed. | |
1261 | ||
1262 | The irony here though, is that FRAME_CHAIN(), at least for a more | |
1263 | up-to-date architecture, always calls FRAME_SAVED_PC(), and | |
1264 | FRAME_SAVED_PC() computes the PC but without first needing the | |
1265 | frame! Instead of the convolution below, we could have simply | |
1266 | called FRAME_SAVED_PC() and been done with it! Note that | |
1267 | FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that | |
1268 | function does have somewhere to cache that PC value. */ | |
4c1e7e9d | 1269 | |
2ca6c561 | 1270 | if (DEPRECATED_INIT_FRAME_PC_FIRST_P ()) |
97f46953 | 1271 | prev->pc = (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf, prev)); |
4c1e7e9d | 1272 | |
e9582e71 AC |
1273 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
1274 | DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev); | |
4c1e7e9d AC |
1275 | |
1276 | /* This entry is in the frame queue now, which is good since | |
95adb866 AC |
1277 | FRAME_SAVED_PC may use that queue to figure out its value (see |
1278 | tm-sparc.h). We want the pc saved in the inferior frame. */ | |
a5afb99f AC |
1279 | if (DEPRECATED_INIT_FRAME_PC_P ()) |
1280 | prev->pc = DEPRECATED_INIT_FRAME_PC (fromleaf, prev); | |
4c1e7e9d | 1281 | |
95adb866 AC |
1282 | /* If ->frame and ->pc are unchanged, we are in the process of |
1283 | getting ourselves into an infinite backtrace. Some architectures | |
1284 | check this in FRAME_CHAIN or thereabouts, but it seems like there | |
1285 | is no reason this can't be an architecture-independent check. */ | |
03febf99 AC |
1286 | if (prev->frame == this_frame->frame |
1287 | && prev->pc == this_frame->pc) | |
4c1e7e9d | 1288 | { |
03febf99 | 1289 | this_frame->prev = NULL; |
95adb866 AC |
1290 | obstack_free (&frame_cache_obstack, prev); |
1291 | return NULL; | |
4c1e7e9d AC |
1292 | } |
1293 | ||
1294 | /* Initialize the code used to unwind the frame PREV based on the PC | |
1295 | (and probably other architectural information). The PC lets you | |
1296 | check things like the debug info at that point (dwarf2cfi?) and | |
1297 | use that to decide how the frame should be unwound. */ | |
494cca16 | 1298 | prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc); |
4c1e7e9d | 1299 | |
5a203e44 AC |
1300 | /* NOTE: cagney/2002-11-18: The code segments, found in |
1301 | create_new_frame and get_prev_frame(), that initializes the | |
1302 | frames type is subtly different. The latter only updates ->type | |
1303 | when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops | |
1304 | get_prev_frame() overriding the frame's type when the INIT code | |
1305 | has previously set it. This is really somewhat bogus. The | |
1306 | initialization, as seen in create_new_frame(), should occur | |
1307 | before the INIT function has been called. */ | |
07555a72 | 1308 | if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
ae45cd16 AC |
1309 | && (DEPRECATED_PC_IN_CALL_DUMMY_P () |
1310 | ? DEPRECATED_PC_IN_CALL_DUMMY (prev->pc, 0, 0) | |
1311 | : pc_in_dummy_frame (prev->pc))) | |
5a203e44 AC |
1312 | prev->type = DUMMY_FRAME; |
1313 | else | |
1314 | { | |
1315 | /* FIXME: cagney/2002-11-10: This should be moved to before the | |
1316 | INIT code above so that the INIT code knows what the frame's | |
1317 | type is (in fact, for a [generic] dummy-frame, the type can | |
1318 | be set and then the entire initialization can be skipped. | |
1319 | Unforunatly, its the INIT code that sets the PC (Hmm, catch | |
1320 | 22). */ | |
1321 | char *name; | |
1322 | find_pc_partial_function (prev->pc, &name, NULL, NULL); | |
1323 | if (PC_IN_SIGTRAMP (prev->pc, name)) | |
1324 | prev->type = SIGTRAMP_FRAME; | |
1325 | /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some | |
1326 | architectures are forcing the frame's type in INIT so we | |
1327 | don't want to override it here. Remember, NORMAL_FRAME == 0, | |
1328 | so it all works (just :-/). Once this initialization is | |
1329 | moved to the start of this function, all this nastness will | |
1330 | go away. */ | |
1331 | } | |
4c1e7e9d AC |
1332 | |
1333 | return prev; | |
1334 | } | |
1335 | ||
eb4f72c5 | 1336 | /* Return a structure containing various interesting information |
03febf99 | 1337 | about the frame that called THIS_FRAME. Returns NULL |
eb4f72c5 AC |
1338 | if there is no such frame. */ |
1339 | ||
1340 | struct frame_info * | |
03febf99 | 1341 | get_prev_frame (struct frame_info *this_frame) |
eb4f72c5 AC |
1342 | { |
1343 | struct frame_info *prev_frame; | |
1344 | ||
1345 | /* Return the inner-most frame, when the caller passes in NULL. */ | |
1346 | /* NOTE: cagney/2002-11-09: Not sure how this would happen. The | |
1347 | caller should have previously obtained a valid frame using | |
1348 | get_selected_frame() and then called this code - only possibility | |
1349 | I can think of is code behaving badly. | |
1350 | ||
1351 | NOTE: cagney/2003-01-10: Talk about code behaving badly. Check | |
1352 | block_innermost_frame(). It does the sequence: frame = NULL; | |
1353 | while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why | |
1354 | it couldn't be written better, I don't know. | |
1355 | ||
1356 | NOTE: cagney/2003-01-11: I suspect what is happening is | |
1357 | block_innermost_frame() is, when the target has no state | |
1358 | (registers, memory, ...), still calling this function. The | |
1359 | assumption being that this function will return NULL indicating | |
1360 | that a frame isn't possible, rather than checking that the target | |
1361 | has state and then calling get_current_frame() and | |
1362 | get_prev_frame(). This is a guess mind. */ | |
03febf99 | 1363 | if (this_frame == NULL) |
eb4f72c5 AC |
1364 | { |
1365 | /* NOTE: cagney/2002-11-09: There was a code segment here that | |
1366 | would error out when CURRENT_FRAME was NULL. The comment | |
1367 | that went with it made the claim ... | |
1368 | ||
1369 | ``This screws value_of_variable, which just wants a nice | |
1370 | clean NULL return from block_innermost_frame if there are no | |
1371 | frames. I don't think I've ever seen this message happen | |
1372 | otherwise. And returning NULL here is a perfectly legitimate | |
1373 | thing to do.'' | |
1374 | ||
1375 | Per the above, this code shouldn't even be called with a NULL | |
03febf99 | 1376 | THIS_FRAME. */ |
eb4f72c5 AC |
1377 | return current_frame; |
1378 | } | |
1379 | ||
1380 | /* There is always a frame. If this assertion fails, suspect that | |
1381 | something should be calling get_selected_frame() or | |
1382 | get_current_frame(). */ | |
03febf99 | 1383 | gdb_assert (this_frame != NULL); |
eb4f72c5 | 1384 | |
03febf99 | 1385 | if (this_frame->level >= 0 |
eb4f72c5 | 1386 | && !backtrace_below_main |
03febf99 | 1387 | && inside_main_func (get_frame_pc (this_frame))) |
eb4f72c5 AC |
1388 | /* Don't unwind past main(), bug always unwind the sentinel frame. |
1389 | Note, this is done _before_ the frame has been marked as | |
1390 | previously unwound. That way if the user later decides to | |
1391 | allow unwinds past main(), that just happens. */ | |
ac2bd0a9 AC |
1392 | { |
1393 | if (frame_debug) | |
1394 | fprintf_unfiltered (gdb_stdlog, | |
1395 | "Outermost frame - inside main func.\n"); | |
1396 | return NULL; | |
1397 | } | |
eb4f72c5 AC |
1398 | |
1399 | /* Only try to do the unwind once. */ | |
03febf99 AC |
1400 | if (this_frame->prev_p) |
1401 | return this_frame->prev; | |
1402 | this_frame->prev_p = 1; | |
eb4f72c5 | 1403 | |
b14185ce AC |
1404 | /* If we're inside the entry file, it isn't valid. Don't apply this |
1405 | test to a dummy frame - dummy frame PC's typically land in the | |
1406 | entry file. Don't apply this test to the sentinel frame. | |
1407 | Sentinel frames should always be allowed to unwind. */ | |
eb4f72c5 AC |
1408 | /* NOTE: drow/2002-12-25: should there be a way to disable this |
1409 | check? It assumes a single small entry file, and the way some | |
1410 | debug readers (e.g. dbxread) figure out which object is the | |
1411 | entry file is somewhat hokey. */ | |
1412 | /* NOTE: cagney/2003-01-10: If there is a way of disabling this test | |
1413 | then it should probably be moved to before the ->prev_p test, | |
1414 | above. */ | |
03febf99 AC |
1415 | if (this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
1416 | && inside_entry_file (get_frame_pc (this_frame))) | |
ac2bd0a9 AC |
1417 | { |
1418 | if (frame_debug) | |
1419 | fprintf_unfiltered (gdb_stdlog, | |
1420 | "Outermost frame - inside entry file\n"); | |
eb4f72c5 | 1421 | return NULL; |
ac2bd0a9 | 1422 | } |
eb4f72c5 | 1423 | |
b14185ce AC |
1424 | /* If we're already inside the entry function for the main objfile, |
1425 | then it isn't valid. Don't apply this test to a dummy frame - | |
1426 | dummy frame PC's typically land in the entry func. Don't apply | |
1427 | this test to the sentinel frame. Sentinel frames should always | |
1428 | be allowed to unwind. */ | |
1429 | /* NOTE: cagney/2003-02-25: Don't enable until someone has found | |
1430 | hard evidence that this is needed. */ | |
1431 | if (0 | |
03febf99 AC |
1432 | && this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
1433 | && inside_entry_func (get_frame_pc (this_frame))) | |
b14185ce AC |
1434 | { |
1435 | if (frame_debug) | |
1436 | fprintf_unfiltered (gdb_stdlog, | |
1437 | "Outermost frame - inside entry func\n"); | |
1438 | return NULL; | |
1439 | } | |
1440 | ||
eb4f72c5 | 1441 | /* If any of the old frame initialization methods are around, use |
055bb976 AC |
1442 | the legacy get_prev_frame method. */ |
1443 | if (legacy_frame_p (current_gdbarch)) | |
ac2bd0a9 | 1444 | { |
03febf99 | 1445 | prev_frame = legacy_get_prev_frame (this_frame); |
ac2bd0a9 AC |
1446 | if (frame_debug && prev_frame == NULL) |
1447 | fprintf_unfiltered (gdb_stdlog, | |
1448 | "Outermost frame - legacy_get_prev_frame NULL.\n"); | |
1449 | return prev_frame; | |
1450 | } | |
eb4f72c5 AC |
1451 | |
1452 | /* Allocate the new frame but do not wire it in to the frame chain. | |
1453 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along | |
1454 | frame->next to pull some fancy tricks (of course such code is, by | |
1455 | definition, recursive). Try to prevent it. | |
1456 | ||
1457 | There is no reason to worry about memory leaks, should the | |
1458 | remainder of the function fail. The allocated memory will be | |
1459 | quickly reclaimed when the frame cache is flushed, and the `we've | |
1460 | been here before' check above will stop repeated memory | |
1461 | allocation calls. */ | |
1462 | prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
03febf99 | 1463 | prev_frame->level = this_frame->level + 1; |
eb4f72c5 AC |
1464 | |
1465 | /* Try to unwind the PC. If that doesn't work, assume we've reached | |
1466 | the oldest frame and simply return. Is there a better sentinal | |
1467 | value? The unwound PC value is then used to initialize the new | |
1468 | previous frame's type. | |
1469 | ||
1470 | Note that the pc-unwind is intentionally performed before the | |
1471 | frame chain. This is ok since, for old targets, both | |
1472 | frame_pc_unwind (nee, FRAME_SAVED_PC) and FRAME_CHAIN()) assume | |
03febf99 | 1473 | THIS_FRAME's data structures have already been initialized (using |
e9582e71 AC |
1474 | DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
1475 | doesn't matter. | |
eb4f72c5 AC |
1476 | |
1477 | By unwinding the PC first, it becomes possible to, in the case of | |
1478 | a dummy frame, avoid also unwinding the frame ID. This is | |
1479 | because (well ignoring the PPC) a dummy frame can be located | |
03febf99 | 1480 | using THIS_FRAME's frame ID. */ |
eb4f72c5 | 1481 | |
03febf99 | 1482 | prev_frame->pc = frame_pc_unwind (this_frame); |
eb4f72c5 | 1483 | if (prev_frame->pc == 0) |
ac2bd0a9 AC |
1484 | { |
1485 | /* The allocated PREV_FRAME will be reclaimed when the frame | |
1486 | obstack is next purged. */ | |
1487 | if (frame_debug) | |
1488 | fprintf_unfiltered (gdb_stdlog, | |
1489 | "Outermost frame - unwound PC zero\n"); | |
1490 | return NULL; | |
1491 | } | |
eb4f72c5 AC |
1492 | prev_frame->type = frame_type_from_pc (prev_frame->pc); |
1493 | ||
1494 | /* Set the unwind functions based on that identified PC. */ | |
1495 | prev_frame->unwind = frame_unwind_find_by_pc (current_gdbarch, | |
1496 | prev_frame->pc); | |
1497 | ||
6314f104 AC |
1498 | /* Find the prev's frame's ID. */ |
1499 | switch (prev_frame->type) | |
218e5956 | 1500 | { |
6314f104 AC |
1501 | case DUMMY_FRAME: |
1502 | /* When unwinding a normal frame, the stack structure is | |
1503 | determined by analyzing the frame's function's code (be it | |
1504 | using brute force prologue analysis, or the dwarf2 CFI). In | |
1505 | the case of a dummy frame, that simply isn't possible. The | |
1506 | The PC is either the program entry point, or some random | |
1507 | address on the stack. Trying to use that PC to apply | |
1508 | standard frame ID unwind techniques is just asking for | |
1509 | trouble. */ | |
055bb976 AC |
1510 | gdb_assert (gdbarch_unwind_dummy_id_p (current_gdbarch)); |
1511 | /* Assume hand_function_call(), via SAVE_DUMMY_FRAME_TOS, | |
1512 | previously saved the dummy frame's ID. Things only work if | |
1513 | the two return the same value. */ | |
1514 | gdb_assert (SAVE_DUMMY_FRAME_TOS_P ()); | |
1515 | /* Use an architecture specific method to extract the prev's | |
1516 | dummy ID from the next frame. Note that this method uses | |
1517 | frame_register_unwind to obtain the register values needed to | |
1518 | determine the dummy frame's ID. */ | |
1519 | prev_frame->id = gdbarch_unwind_dummy_id (current_gdbarch, this_frame); | |
6314f104 AC |
1520 | break; |
1521 | case NORMAL_FRAME: | |
1522 | case SIGTRAMP_FRAME: | |
1523 | /* FIXME: cagney/2003-03-04: The below call isn't right. It | |
1524 | should instead be doing something like "prev_frame -> unwind | |
03febf99 | 1525 | -> id (this_frame, & prev_frame -> unwind_cache, & prev_frame |
6314f104 | 1526 | -> id)" but that requires more extensive (pending) changes. */ |
03febf99 | 1527 | this_frame->unwind->id (this_frame, &this_frame->unwind_cache, |
6314f104 AC |
1528 | &prev_frame->id); |
1529 | /* Check that the unwound ID is valid. */ | |
1530 | if (!frame_id_p (prev_frame->id)) | |
1531 | { | |
1532 | if (frame_debug) | |
1533 | fprintf_unfiltered (gdb_stdlog, | |
1534 | "Outermost frame - unwound frame ID invalid\n"); | |
1535 | return NULL; | |
1536 | } | |
1537 | /* Check that the new frame isn't inner to (younger, below, | |
1538 | next) the old frame. If that happens the frame unwind is | |
1539 | going backwards. */ | |
1540 | /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since | |
1541 | that doesn't have a valid frame ID. Should instead set the | |
1542 | sentinel frame's frame ID to a `sentinel'. Leave it until | |
1543 | after the switch to storing the frame ID, instead of the | |
1544 | frame base, in the frame object. */ | |
03febf99 AC |
1545 | if (this_frame->level >= 0 |
1546 | && frame_id_inner (prev_frame->id, get_frame_id (this_frame))) | |
6314f104 AC |
1547 | error ("Unwound frame inner-to selected frame (corrupt stack?)"); |
1548 | /* Note that, due to frameless functions, the stronger test of | |
1549 | the new frame being outer to the old frame can't be used - | |
1550 | frameless functions differ by only their PC value. */ | |
1551 | break; | |
1552 | default: | |
1553 | internal_error (__FILE__, __LINE__, "bad switch"); | |
218e5956 | 1554 | } |
218e5956 AC |
1555 | |
1556 | /* FIXME: cagney/2002-12-18: Instead of this hack, should only store | |
1557 | the frame ID in PREV_FRAME. Unfortunatly, some architectures | |
1558 | (HP/UX) still reply on EXTRA_FRAME_INFO and, hence, still poke at | |
1559 | the "struct frame_info" object directly. */ | |
1560 | prev_frame->frame = prev_frame->id.base; | |
eb4f72c5 AC |
1561 | |
1562 | /* Link it in. */ | |
03febf99 AC |
1563 | this_frame->prev = prev_frame; |
1564 | prev_frame->next = this_frame; | |
eb4f72c5 | 1565 | |
eb4f72c5 AC |
1566 | return prev_frame; |
1567 | } | |
1568 | ||
4c1e7e9d AC |
1569 | CORE_ADDR |
1570 | get_frame_pc (struct frame_info *frame) | |
1571 | { | |
1572 | return frame->pc; | |
1573 | } | |
1574 | ||
1058bca7 AC |
1575 | static int |
1576 | pc_notcurrent (struct frame_info *frame) | |
1577 | { | |
1578 | /* If FRAME is not the innermost frame, that normally means that | |
1579 | FRAME->pc points at the return instruction (which is *after* the | |
1580 | call instruction), and we want to get the line containing the | |
1581 | call (because the call is where the user thinks the program is). | |
1582 | However, if the next frame is either a SIGTRAMP_FRAME or a | |
1583 | DUMMY_FRAME, then the next frame will contain a saved interrupt | |
1584 | PC and such a PC indicates the current (rather than next) | |
1585 | instruction/line, consequently, for such cases, want to get the | |
1586 | line containing fi->pc. */ | |
1587 | struct frame_info *next = get_next_frame (frame); | |
1588 | int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME); | |
1589 | return notcurrent; | |
1590 | } | |
1591 | ||
1592 | void | |
1593 | find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal) | |
1594 | { | |
1595 | (*sal) = find_pc_line (frame->pc, pc_notcurrent (frame)); | |
1596 | } | |
1597 | ||
c193f6ac AC |
1598 | /* Per "frame.h", return the ``address'' of the frame. Code should |
1599 | really be using get_frame_id(). */ | |
1600 | CORE_ADDR | |
1601 | get_frame_base (struct frame_info *fi) | |
1602 | { | |
1603 | return fi->frame; | |
1604 | } | |
1605 | ||
85cf597a AC |
1606 | /* Level of the selected frame: 0 for innermost, 1 for its caller, ... |
1607 | or -1 for a NULL frame. */ | |
1608 | ||
1609 | int | |
1610 | frame_relative_level (struct frame_info *fi) | |
1611 | { | |
1612 | if (fi == NULL) | |
1613 | return -1; | |
1614 | else | |
1615 | return fi->level; | |
1616 | } | |
1617 | ||
5a203e44 AC |
1618 | enum frame_type |
1619 | get_frame_type (struct frame_info *frame) | |
1620 | { | |
1621 | /* Some targets still don't use [generic] dummy frames. Catch them | |
1622 | here. */ | |
07555a72 | 1623 | if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
5a203e44 AC |
1624 | && deprecated_frame_in_dummy (frame)) |
1625 | return DUMMY_FRAME; | |
1626 | return frame->type; | |
1627 | } | |
1628 | ||
1629 | void | |
1630 | deprecated_set_frame_type (struct frame_info *frame, enum frame_type type) | |
1631 | { | |
1632 | /* Arrrg! See comment in "frame.h". */ | |
1633 | frame->type = type; | |
1634 | } | |
1635 | ||
4c1e7e9d AC |
1636 | #ifdef FRAME_FIND_SAVED_REGS |
1637 | /* XXX - deprecated. This is a compatibility function for targets | |
f30ee0bc | 1638 | that do not yet implement DEPRECATED_FRAME_INIT_SAVED_REGS. */ |
4c1e7e9d AC |
1639 | /* Find the addresses in which registers are saved in FRAME. */ |
1640 | ||
1641 | void | |
95486978 AC |
1642 | deprecated_get_frame_saved_regs (struct frame_info *frame, |
1643 | struct frame_saved_regs *saved_regs_addr) | |
4c1e7e9d AC |
1644 | { |
1645 | if (frame->saved_regs == NULL) | |
1646 | { | |
1647 | frame->saved_regs = (CORE_ADDR *) | |
479ab5a0 | 1648 | frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
4c1e7e9d AC |
1649 | } |
1650 | if (saved_regs_addr == NULL) | |
1651 | { | |
1652 | struct frame_saved_regs saved_regs; | |
1653 | FRAME_FIND_SAVED_REGS (frame, saved_regs); | |
1654 | memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS); | |
1655 | } | |
1656 | else | |
1657 | { | |
1658 | FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr); | |
1659 | memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS); | |
1660 | } | |
1661 | } | |
1662 | #endif | |
1663 | ||
0394eb2a AC |
1664 | struct frame_extra_info * |
1665 | get_frame_extra_info (struct frame_info *fi) | |
1666 | { | |
1667 | return fi->extra_info; | |
1668 | } | |
1669 | ||
2c517d0e AC |
1670 | struct frame_extra_info * |
1671 | frame_extra_info_zalloc (struct frame_info *fi, long size) | |
1672 | { | |
479ab5a0 | 1673 | fi->extra_info = frame_obstack_zalloc (size); |
2c517d0e AC |
1674 | return fi->extra_info; |
1675 | } | |
1676 | ||
b87efeee | 1677 | void |
2f107107 | 1678 | deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc) |
b87efeee | 1679 | { |
2f107107 AC |
1680 | /* See comment in "frame.h". */ |
1681 | frame->pc = pc; | |
e0d2ae16 AC |
1682 | /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are |
1683 | maintaining a locally allocated frame object. Since such frame's | |
1684 | are not in the frame chain, it isn't possible to assume that the | |
1685 | frame has a next. Sigh. */ | |
1686 | if (frame->next != NULL) | |
1687 | { | |
1688 | /* While we're at it, update this frame's cached PC value, found | |
1689 | in the next frame. Oh for the day when "struct frame_info" | |
1690 | is opaque and this hack on hack can just go away. */ | |
1691 | frame->next->pc_unwind_cache = pc; | |
1692 | frame->next->pc_unwind_cache_p = 1; | |
1693 | } | |
2f107107 AC |
1694 | } |
1695 | ||
1696 | void | |
1697 | deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base) | |
1698 | { | |
1699 | /* See comment in "frame.h". */ | |
1700 | frame->frame = base; | |
b87efeee AC |
1701 | } |
1702 | ||
c8b8a898 AC |
1703 | void |
1704 | deprecated_set_frame_saved_regs_hack (struct frame_info *frame, | |
1705 | CORE_ADDR *saved_regs) | |
1706 | { | |
1707 | frame->saved_regs = saved_regs; | |
1708 | } | |
1709 | ||
1710 | void | |
1711 | deprecated_set_frame_extra_info_hack (struct frame_info *frame, | |
1712 | struct frame_extra_info *extra_info) | |
1713 | { | |
1714 | frame->extra_info = extra_info; | |
1715 | } | |
1716 | ||
483d36b2 AC |
1717 | void |
1718 | deprecated_set_frame_next_hack (struct frame_info *fi, | |
1719 | struct frame_info *next) | |
1720 | { | |
1721 | fi->next = next; | |
1722 | } | |
1723 | ||
1724 | void | |
1725 | deprecated_set_frame_prev_hack (struct frame_info *fi, | |
1726 | struct frame_info *prev) | |
1727 | { | |
1728 | fi->prev = prev; | |
1729 | } | |
1730 | ||
2d75187b AC |
1731 | struct context * |
1732 | deprecated_get_frame_context (struct frame_info *fi) | |
1733 | { | |
1734 | return fi->context; | |
1735 | } | |
1736 | ||
1737 | void | |
1738 | deprecated_set_frame_context (struct frame_info *fi, | |
1739 | struct context *context) | |
1740 | { | |
1741 | fi->context = context; | |
1742 | } | |
1743 | ||
c8b8a898 AC |
1744 | struct frame_info * |
1745 | deprecated_frame_xmalloc (void) | |
1746 | { | |
1747 | struct frame_info *frame = XMALLOC (struct frame_info); | |
1748 | memset (frame, 0, sizeof (struct frame_info)); | |
1749 | return frame; | |
1750 | } | |
1751 | ||
f6c609c4 AC |
1752 | struct frame_info * |
1753 | deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs, | |
1754 | long sizeof_extra_info) | |
1755 | { | |
1756 | struct frame_info *frame = deprecated_frame_xmalloc (); | |
1757 | make_cleanup (xfree, frame); | |
1758 | if (sizeof_saved_regs > 0) | |
1759 | { | |
1760 | frame->saved_regs = xcalloc (1, sizeof_saved_regs); | |
1761 | make_cleanup (xfree, frame->saved_regs); | |
1762 | } | |
1763 | if (sizeof_extra_info > 0) | |
1764 | { | |
1765 | frame->extra_info = xcalloc (1, sizeof_extra_info); | |
1766 | make_cleanup (xfree, frame->extra_info); | |
1767 | } | |
1768 | return frame; | |
1769 | } | |
c8b8a898 | 1770 | |
1594fa56 AC |
1771 | int |
1772 | legacy_frame_p (struct gdbarch *current_gdbarch) | |
1773 | { | |
1774 | return (DEPRECATED_INIT_FRAME_PC_P () | |
1775 | || DEPRECATED_INIT_FRAME_PC_FIRST_P () | |
1776 | || DEPRECATED_INIT_EXTRA_FRAME_INFO_P () | |
055bb976 AC |
1777 | || FRAME_CHAIN_P () |
1778 | || !gdbarch_unwind_dummy_id_p (current_gdbarch) | |
1779 | || !SAVE_DUMMY_FRAME_TOS_P ()); | |
1594fa56 AC |
1780 | } |
1781 | ||
4c1e7e9d AC |
1782 | void |
1783 | _initialize_frame (void) | |
1784 | { | |
1785 | obstack_init (&frame_cache_obstack); | |
eb4f72c5 AC |
1786 | |
1787 | /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest | |
1788 | `set backtrace {past,beyond,...}-main'. Also suggest adding `set | |
1789 | backtrace ...-start' to control backtraces past start. The | |
1790 | problem with `below' is that it stops the `up' command. */ | |
1791 | ||
1792 | add_setshow_boolean_cmd ("backtrace-below-main", class_obscure, | |
1793 | &backtrace_below_main, "\ | |
1794 | Set whether backtraces should continue past \"main\".\n\ | |
1795 | Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ | |
1796 | the backtrace at \"main\". Set this variable if you need to see the rest\n\ | |
1797 | of the stack trace.", "\ | |
1798 | Show whether backtraces should continue past \"main\".\n\ | |
1799 | Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ | |
1800 | the backtrace at \"main\". Set this variable if you need to see the rest\n\ | |
1801 | of the stack trace.", | |
1802 | NULL, NULL, &setlist, &showlist); | |
ac2bd0a9 AC |
1803 | |
1804 | ||
1805 | /* Debug this files internals. */ | |
1806 | add_show_from_set (add_set_cmd ("frame", class_maintenance, var_zinteger, | |
1807 | &frame_debug, "Set frame debugging.\n\ | |
1808 | When non-zero, frame specific internal debugging is enabled.", &setdebuglist), | |
1809 | &showdebuglist); | |
4c1e7e9d | 1810 | } |