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" |
da62e633 | 39 | #include "frame-base.h" |
eb4f72c5 AC |
40 | #include "command.h" |
41 | #include "gdbcmd.h" | |
42 | ||
ac2bd0a9 AC |
43 | /* Flag to control debugging. */ |
44 | ||
45 | static int frame_debug; | |
46 | ||
eb4f72c5 AC |
47 | /* Flag to indicate whether backtraces should stop at main. */ |
48 | ||
49 | static int backtrace_below_main; | |
d65fe839 | 50 | |
7a424e99 | 51 | /* Return a frame uniq ID that can be used to, later, re-find the |
101dcfbe AC |
52 | frame. */ |
53 | ||
7a424e99 AC |
54 | struct frame_id |
55 | get_frame_id (struct frame_info *fi) | |
101dcfbe AC |
56 | { |
57 | if (fi == NULL) | |
58 | { | |
7a424e99 | 59 | return null_frame_id; |
101dcfbe | 60 | } |
06c77151 | 61 | if (!fi->id_p) |
101dcfbe | 62 | { |
06c77151 AC |
63 | gdb_assert (!legacy_frame_p (current_gdbarch)); |
64 | /* Find THIS frame's ID. */ | |
65 | fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->id); | |
66 | fi->id_p = 1; | |
67 | /* FIXME: cagney/2002-12-18: Instead of this hack, should only | |
68 | store the frame ID in PREV_FRAME. Unfortunatly, some | |
69 | architectures (HP/UX) still reply on EXTRA_FRAME_INFO and, | |
70 | hence, still poke at the "struct frame_info" object directly. */ | |
71 | fi->frame = fi->id.base; | |
101dcfbe | 72 | } |
06c77151 | 73 | return frame_id_build (fi->frame, fi->pc); |
101dcfbe AC |
74 | } |
75 | ||
7a424e99 AC |
76 | const struct frame_id null_frame_id; /* All zeros. */ |
77 | ||
78 | struct frame_id | |
79 | frame_id_build (CORE_ADDR base, CORE_ADDR func_or_pc) | |
80 | { | |
81 | struct frame_id id; | |
82 | id.base = base; | |
83 | id.pc = func_or_pc; | |
84 | return id; | |
85 | } | |
86 | ||
87 | int | |
88 | frame_id_p (struct frame_id l) | |
89 | { | |
90 | /* The .func can be NULL but the .base cannot. */ | |
91 | return (l.base != 0); | |
92 | } | |
93 | ||
94 | int | |
95 | frame_id_eq (struct frame_id l, struct frame_id r) | |
96 | { | |
97 | /* If .base is different, the frames are different. */ | |
98 | if (l.base != r.base) | |
99 | return 0; | |
100 | /* Add a test to check that the frame ID's are for the same function | |
101 | here. */ | |
102 | return 1; | |
103 | } | |
104 | ||
105 | int | |
106 | frame_id_inner (struct frame_id l, struct frame_id r) | |
107 | { | |
108 | /* Only return non-zero when strictly inner than. Note that, per | |
109 | comment in "frame.h", there is some fuzz here. Frameless | |
110 | functions are not strictly inner than (same .base but different | |
111 | .func). */ | |
112 | return INNER_THAN (l.base, r.base); | |
113 | } | |
114 | ||
101dcfbe AC |
115 | struct frame_info * |
116 | frame_find_by_id (struct frame_id id) | |
117 | { | |
118 | struct frame_info *frame; | |
119 | ||
120 | /* ZERO denotes the null frame, let the caller decide what to do | |
121 | about it. Should it instead return get_current_frame()? */ | |
7a424e99 | 122 | if (!frame_id_p (id)) |
101dcfbe AC |
123 | return NULL; |
124 | ||
125 | for (frame = get_current_frame (); | |
126 | frame != NULL; | |
127 | frame = get_prev_frame (frame)) | |
128 | { | |
7a424e99 AC |
129 | struct frame_id this = get_frame_id (frame); |
130 | if (frame_id_eq (id, this)) | |
131 | /* An exact match. */ | |
132 | return frame; | |
133 | if (frame_id_inner (id, this)) | |
134 | /* Gone to far. */ | |
101dcfbe | 135 | return NULL; |
7a424e99 AC |
136 | /* Either, we're not yet gone far enough out along the frame |
137 | chain (inner(this,id), or we're comparing frameless functions | |
138 | (same .base, different .func, no test available). Struggle | |
139 | on until we've definitly gone to far. */ | |
101dcfbe AC |
140 | } |
141 | return NULL; | |
142 | } | |
143 | ||
f18c5a73 | 144 | CORE_ADDR |
12cc2063 | 145 | frame_pc_unwind (struct frame_info *this_frame) |
f18c5a73 | 146 | { |
12cc2063 | 147 | if (!this_frame->pc_unwind_cache_p) |
f18c5a73 | 148 | { |
12cc2063 AC |
149 | CORE_ADDR pc; |
150 | if (gdbarch_unwind_pc_p (current_gdbarch)) | |
151 | { | |
152 | /* The right way. The `pure' way. The one true way. This | |
153 | method depends solely on the register-unwind code to | |
154 | determine the value of registers in THIS frame, and hence | |
155 | the value of this frame's PC (resume address). A typical | |
156 | implementation is no more than: | |
157 | ||
158 | frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); | |
159 | return extract_address (buf, size of ISA_PC_REGNUM); | |
160 | ||
161 | Note: this method is very heavily dependent on a correct | |
162 | register-unwind implementation, it pays to fix that | |
163 | method first; this method is frame type agnostic, since | |
164 | it only deals with register values, it works with any | |
165 | frame. This is all in stark contrast to the old | |
166 | FRAME_SAVED_PC which would try to directly handle all the | |
167 | different ways that a PC could be unwound. */ | |
168 | pc = gdbarch_unwind_pc (current_gdbarch, this_frame); | |
169 | } | |
170 | else if (this_frame->level < 0) | |
171 | { | |
172 | /* FIXME: cagney/2003-03-06: Old code and and a sentinel | |
173 | frame. Do like was always done. Fetch the PC's value | |
174 | direct from the global registers array (via read_pc). | |
175 | This assumes that this frame belongs to the current | |
176 | global register cache. The assumption is dangerous. */ | |
177 | pc = read_pc (); | |
178 | } | |
8bedc050 | 179 | else if (DEPRECATED_FRAME_SAVED_PC_P ()) |
12cc2063 AC |
180 | { |
181 | /* FIXME: cagney/2003-03-06: Old code, but not a sentinel | |
182 | frame. Do like was always done. Note that this method, | |
183 | unlike unwind_pc(), tries to handle all the different | |
184 | frame cases directly. It fails. */ | |
8bedc050 | 185 | pc = DEPRECATED_FRAME_SAVED_PC (this_frame); |
12cc2063 AC |
186 | } |
187 | else | |
188 | internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method"); | |
189 | this_frame->pc_unwind_cache = pc; | |
190 | this_frame->pc_unwind_cache_p = 1; | |
f18c5a73 | 191 | } |
12cc2063 | 192 | return this_frame->pc_unwind_cache; |
f18c5a73 AC |
193 | } |
194 | ||
7a25a7c1 AC |
195 | static int |
196 | do_frame_unwind_register (void *src, int regnum, void *buf) | |
197 | { | |
198 | frame_unwind_register (src, regnum, buf); | |
199 | return 1; | |
200 | } | |
201 | ||
dbe9fe58 | 202 | void |
7a25a7c1 AC |
203 | frame_pop (struct frame_info *this_frame) |
204 | { | |
205 | struct regcache *scratch_regcache; | |
206 | struct cleanup *cleanups; | |
207 | ||
749b82f6 | 208 | if (DEPRECATED_POP_FRAME_P ()) |
7a25a7c1 AC |
209 | { |
210 | /* A legacy architecture that has implemented a custom pop | |
211 | function. All new architectures should instead be using the | |
212 | generic code below. */ | |
749b82f6 | 213 | DEPRECATED_POP_FRAME; |
7a25a7c1 AC |
214 | } |
215 | else | |
216 | { | |
217 | /* Make a copy of all the register values unwound from this | |
218 | frame. Save them in a scratch buffer so that there isn't a | |
219 | race betweening trying to extract the old values from the | |
220 | current_regcache while, at the same time writing new values | |
221 | into that same cache. */ | |
222 | struct regcache *scratch = regcache_xmalloc (current_gdbarch); | |
223 | struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch); | |
224 | regcache_save (scratch, do_frame_unwind_register, this_frame); | |
efd710d6 AC |
225 | /* FIXME: cagney/2003-03-16: It should be possible to tell the |
226 | target's register cache that it is about to be hit with a | |
227 | burst register transfer and that the sequence of register | |
228 | writes should be batched. The pair target_prepare_to_store() | |
229 | and target_store_registers() kind of suggest this | |
230 | functionality. Unfortunatly, they don't implement it. Their | |
231 | lack of a formal definition can lead to targets writing back | |
232 | bogus values (arguably a bug in the target code mind). */ | |
7a25a7c1 AC |
233 | /* Now copy those saved registers into the current regcache. |
234 | Here, regcache_cpy() calls regcache_restore(). */ | |
235 | regcache_cpy (current_regcache, scratch); | |
236 | do_cleanups (cleanups); | |
237 | } | |
238 | /* We've made right mess of GDB's local state, just discard | |
239 | everything. */ | |
dbe9fe58 AC |
240 | flush_cached_frames (); |
241 | } | |
c689142b | 242 | |
4f460812 AC |
243 | void |
244 | frame_register_unwind (struct frame_info *frame, int regnum, | |
245 | int *optimizedp, enum lval_type *lvalp, | |
246 | CORE_ADDR *addrp, int *realnump, void *bufferp) | |
247 | { | |
248 | struct frame_unwind_cache *cache; | |
249 | ||
250 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates | |
251 | that the value proper does not need to be fetched. */ | |
252 | gdb_assert (optimizedp != NULL); | |
253 | gdb_assert (lvalp != NULL); | |
254 | gdb_assert (addrp != NULL); | |
255 | gdb_assert (realnump != NULL); | |
256 | /* gdb_assert (bufferp != NULL); */ | |
257 | ||
a94dd1fd AC |
258 | /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame |
259 | is broken. There is always a frame. If there, for some reason, | |
260 | isn't, there is some pretty busted code as it should have | |
261 | detected the problem before calling here. */ | |
262 | gdb_assert (frame != NULL); | |
4f460812 | 263 | |
6dc42492 AC |
264 | /* Ask this frame to unwind its register. See comment in |
265 | "frame-unwind.h" for why NEXT frame and this unwind cace are | |
266 | passed in. */ | |
267 | frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum, | |
268 | optimizedp, lvalp, addrp, realnump, bufferp); | |
269 | ||
4f460812 AC |
270 | } |
271 | ||
a216a322 AC |
272 | void |
273 | frame_register (struct frame_info *frame, int regnum, | |
274 | int *optimizedp, enum lval_type *lvalp, | |
275 | CORE_ADDR *addrp, int *realnump, void *bufferp) | |
276 | { | |
277 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates | |
278 | that the value proper does not need to be fetched. */ | |
279 | gdb_assert (optimizedp != NULL); | |
280 | gdb_assert (lvalp != NULL); | |
281 | gdb_assert (addrp != NULL); | |
282 | gdb_assert (realnump != NULL); | |
283 | /* gdb_assert (bufferp != NULL); */ | |
284 | ||
285 | /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset | |
286 | of the register in the register cache. It should instead return | |
287 | the REGNUM corresponding to that register. Translate the . */ | |
129c1cd6 | 288 | if (DEPRECATED_GET_SAVED_REGISTER_P ()) |
a216a322 | 289 | { |
129c1cd6 AC |
290 | DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, |
291 | regnum, lvalp); | |
a216a322 AC |
292 | /* Compute the REALNUM if the caller wants it. */ |
293 | if (*lvalp == lval_register) | |
294 | { | |
295 | int regnum; | |
296 | for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++) | |
297 | { | |
298 | if (*addrp == register_offset_hack (current_gdbarch, regnum)) | |
299 | { | |
300 | *realnump = regnum; | |
301 | return; | |
302 | } | |
303 | } | |
304 | internal_error (__FILE__, __LINE__, | |
305 | "Failed to compute the register number corresponding" | |
306 | " to 0x%s", paddr_d (*addrp)); | |
307 | } | |
308 | *realnump = -1; | |
309 | return; | |
310 | } | |
311 | ||
a94dd1fd AC |
312 | /* Obtain the register value by unwinding the register from the next |
313 | (more inner frame). */ | |
314 | gdb_assert (frame != NULL && frame->next != NULL); | |
315 | frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, | |
316 | realnump, bufferp); | |
a216a322 AC |
317 | } |
318 | ||
135c175f | 319 | void |
5b181d62 | 320 | frame_unwind_register (struct frame_info *frame, int regnum, void *buf) |
135c175f AC |
321 | { |
322 | int optimized; | |
323 | CORE_ADDR addr; | |
324 | int realnum; | |
325 | enum lval_type lval; | |
135c175f AC |
326 | frame_register_unwind (frame, regnum, &optimized, &lval, &addr, |
327 | &realnum, buf); | |
5b181d62 AC |
328 | } |
329 | ||
330 | void | |
331 | frame_unwind_signed_register (struct frame_info *frame, int regnum, | |
332 | LONGEST *val) | |
333 | { | |
334 | void *buf = alloca (MAX_REGISTER_RAW_SIZE); | |
335 | frame_unwind_register (frame, regnum, buf); | |
135c175f AC |
336 | (*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
337 | } | |
338 | ||
339 | void | |
340 | frame_unwind_unsigned_register (struct frame_info *frame, int regnum, | |
341 | ULONGEST *val) | |
342 | { | |
135c175f | 343 | void *buf = alloca (MAX_REGISTER_RAW_SIZE); |
5b181d62 | 344 | frame_unwind_register (frame, regnum, buf); |
135c175f AC |
345 | (*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
346 | } | |
4f460812 | 347 | |
5b181d62 AC |
348 | void |
349 | frame_read_register (struct frame_info *frame, int regnum, void *buf) | |
350 | { | |
351 | gdb_assert (frame != NULL && frame->next != NULL); | |
352 | frame_unwind_register (frame->next, regnum, buf); | |
353 | } | |
354 | ||
f908a0eb AC |
355 | void |
356 | frame_read_unsigned_register (struct frame_info *frame, int regnum, | |
357 | ULONGEST *val) | |
358 | { | |
359 | /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is | |
360 | always a frame. Both this, and the equivalent | |
361 | frame_read_signed_register() function, can only be called with a | |
362 | valid frame. If, for some reason, this function is called | |
363 | without a frame then the problem isn't here, but rather in the | |
364 | caller. It should of first created a frame and then passed that | |
365 | in. */ | |
366 | /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the | |
367 | ``current_frame'' should not be treated as a special case. While | |
368 | ``get_next_frame (current_frame) == NULL'' currently holds, it | |
369 | should, as far as possible, not be relied upon. In the future, | |
370 | ``get_next_frame (current_frame)'' may instead simply return a | |
371 | normal frame object that simply always gets register values from | |
372 | the register cache. Consequently, frame code should try to avoid | |
373 | tests like ``if get_next_frame() == NULL'' and instead just rely | |
374 | on recursive frame calls (like the below code) when manipulating | |
375 | a frame chain. */ | |
a94dd1fd AC |
376 | gdb_assert (frame != NULL && frame->next != NULL); |
377 | frame_unwind_unsigned_register (frame->next, regnum, val); | |
f908a0eb AC |
378 | } |
379 | ||
380 | void | |
381 | frame_read_signed_register (struct frame_info *frame, int regnum, | |
382 | LONGEST *val) | |
383 | { | |
a94dd1fd AC |
384 | /* See note above in frame_read_unsigned_register(). */ |
385 | gdb_assert (frame != NULL && frame->next != NULL); | |
386 | frame_unwind_signed_register (frame->next, regnum, val); | |
f908a0eb AC |
387 | } |
388 | ||
f796e4be | 389 | void |
4f460812 AC |
390 | generic_unwind_get_saved_register (char *raw_buffer, |
391 | int *optimizedp, | |
392 | CORE_ADDR *addrp, | |
393 | struct frame_info *frame, | |
394 | int regnum, | |
395 | enum lval_type *lvalp) | |
396 | { | |
397 | int optimizedx; | |
398 | CORE_ADDR addrx; | |
399 | int realnumx; | |
400 | enum lval_type lvalx; | |
401 | ||
402 | if (!target_has_registers) | |
403 | error ("No registers."); | |
404 | ||
405 | /* Keep things simple, ensure that all the pointers (except valuep) | |
406 | are non NULL. */ | |
407 | if (optimizedp == NULL) | |
408 | optimizedp = &optimizedx; | |
409 | if (lvalp == NULL) | |
410 | lvalp = &lvalx; | |
411 | if (addrp == NULL) | |
412 | addrp = &addrx; | |
413 | ||
a94dd1fd AC |
414 | gdb_assert (frame != NULL && frame->next != NULL); |
415 | frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, | |
416 | &realnumx, raw_buffer); | |
4f460812 AC |
417 | } |
418 | ||
cda5a58a | 419 | /* frame_register_read () |
d65fe839 | 420 | |
cda5a58a | 421 | Find and return the value of REGNUM for the specified stack frame. |
d65fe839 AC |
422 | The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). |
423 | ||
cda5a58a | 424 | Returns 0 if the register value could not be found. */ |
d65fe839 | 425 | |
cda5a58a AC |
426 | int |
427 | frame_register_read (struct frame_info *frame, int regnum, void *myaddr) | |
d65fe839 | 428 | { |
a216a322 AC |
429 | int optimized; |
430 | enum lval_type lval; | |
431 | CORE_ADDR addr; | |
432 | int realnum; | |
433 | frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr); | |
d65fe839 | 434 | |
c97dcfc7 AC |
435 | /* FIXME: cagney/2002-05-15: This test, is just bogus. |
436 | ||
437 | It indicates that the target failed to supply a value for a | |
438 | register because it was "not available" at this time. Problem | |
439 | is, the target still has the register and so get saved_register() | |
440 | may be returning a value saved on the stack. */ | |
441 | ||
d65fe839 | 442 | if (register_cached (regnum) < 0) |
cda5a58a | 443 | return 0; /* register value not available */ |
d65fe839 | 444 | |
a216a322 | 445 | return !optimized; |
d65fe839 | 446 | } |
e36180d7 AC |
447 | |
448 | ||
449 | /* Map between a frame register number and its name. A frame register | |
450 | space is a superset of the cooked register space --- it also | |
451 | includes builtin registers. */ | |
452 | ||
453 | int | |
454 | frame_map_name_to_regnum (const char *name, int len) | |
455 | { | |
456 | int i; | |
457 | ||
5f601589 AC |
458 | if (len < 0) |
459 | len = strlen (name); | |
460 | ||
e36180d7 AC |
461 | /* Search register name space. */ |
462 | for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++) | |
463 | if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i)) | |
464 | && strncmp (name, REGISTER_NAME (i), len) == 0) | |
465 | { | |
466 | return i; | |
467 | } | |
468 | ||
469 | /* Try builtin registers. */ | |
470 | i = builtin_reg_map_name_to_regnum (name, len); | |
471 | if (i >= 0) | |
472 | { | |
473 | /* A builtin register doesn't fall into the architecture's | |
474 | register range. */ | |
475 | gdb_assert (i >= NUM_REGS + NUM_PSEUDO_REGS); | |
476 | return i; | |
477 | } | |
478 | ||
479 | return -1; | |
480 | } | |
481 | ||
482 | const char * | |
483 | frame_map_regnum_to_name (int regnum) | |
484 | { | |
485 | if (regnum < 0) | |
486 | return NULL; | |
487 | if (regnum < NUM_REGS + NUM_PSEUDO_REGS) | |
488 | return REGISTER_NAME (regnum); | |
489 | return builtin_reg_map_regnum_to_name (regnum); | |
490 | } | |
4c1e7e9d | 491 | |
a94dd1fd AC |
492 | /* Create a sentinel frame. */ |
493 | ||
494 | struct frame_info * | |
495 | create_sentinel_frame (struct regcache *regcache) | |
496 | { | |
497 | struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
498 | frame->type = NORMAL_FRAME; | |
499 | frame->level = -1; | |
500 | /* Explicitly initialize the sentinel frame's cache. Provide it | |
501 | with the underlying regcache. In the future additional | |
502 | information, such as the frame's thread will be added. */ | |
6dc42492 | 503 | frame->prologue_cache = sentinel_frame_cache (regcache); |
a94dd1fd AC |
504 | /* For the moment there is only one sentinel frame implementation. */ |
505 | frame->unwind = sentinel_frame_unwind; | |
506 | /* Link this frame back to itself. The frame is self referential | |
507 | (the unwound PC is the same as the pc), so make it so. */ | |
508 | frame->next = frame; | |
509 | /* Always unwind the PC as part of creating this frame. This | |
510 | ensures that the frame's PC points at something valid. */ | |
511 | /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel | |
512 | frame's PC may require information such as the frame's thread's | |
513 | stop reason. Is it possible to get to that? */ | |
514 | frame->pc = frame_pc_unwind (frame); | |
515 | return frame; | |
516 | } | |
517 | ||
4c1e7e9d AC |
518 | /* Info about the innermost stack frame (contents of FP register) */ |
519 | ||
520 | static struct frame_info *current_frame; | |
521 | ||
522 | /* Cache for frame addresses already read by gdb. Valid only while | |
523 | inferior is stopped. Control variables for the frame cache should | |
524 | be local to this module. */ | |
525 | ||
526 | static struct obstack frame_cache_obstack; | |
527 | ||
528 | void * | |
479ab5a0 | 529 | frame_obstack_zalloc (unsigned long size) |
4c1e7e9d | 530 | { |
479ab5a0 AC |
531 | void *data = obstack_alloc (&frame_cache_obstack, size); |
532 | memset (data, 0, size); | |
533 | return data; | |
4c1e7e9d AC |
534 | } |
535 | ||
6baff1d2 | 536 | CORE_ADDR * |
4c1e7e9d AC |
537 | frame_saved_regs_zalloc (struct frame_info *fi) |
538 | { | |
539 | fi->saved_regs = (CORE_ADDR *) | |
479ab5a0 | 540 | frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
6baff1d2 | 541 | return fi->saved_regs; |
4c1e7e9d AC |
542 | } |
543 | ||
6baff1d2 AC |
544 | CORE_ADDR * |
545 | get_frame_saved_regs (struct frame_info *fi) | |
546 | { | |
547 | return fi->saved_regs; | |
548 | } | |
4c1e7e9d | 549 | |
a94dd1fd AC |
550 | /* Return the innermost (currently executing) stack frame. This is |
551 | split into two functions. The function unwind_to_current_frame() | |
552 | is wrapped in catch exceptions so that, even when the unwind of the | |
553 | sentinel frame fails, the function still returns a stack frame. */ | |
554 | ||
555 | static int | |
556 | unwind_to_current_frame (struct ui_out *ui_out, void *args) | |
557 | { | |
558 | struct frame_info *frame = get_prev_frame (args); | |
559 | /* A sentinel frame can fail to unwind, eg, because it's PC value | |
560 | lands in somewhere like start. */ | |
561 | if (frame == NULL) | |
562 | return 1; | |
563 | current_frame = frame; | |
564 | return 0; | |
565 | } | |
4c1e7e9d AC |
566 | |
567 | struct frame_info * | |
568 | get_current_frame (void) | |
569 | { | |
0a1e1ca1 AC |
570 | /* First check, and report, the lack of registers. Having GDB |
571 | report "No stack!" or "No memory" when the target doesn't even | |
572 | have registers is very confusing. Besides, "printcmd.exp" | |
573 | explicitly checks that ``print $pc'' with no registers prints "No | |
574 | registers". */ | |
a94dd1fd AC |
575 | if (!target_has_registers) |
576 | error ("No registers."); | |
0a1e1ca1 AC |
577 | if (!target_has_stack) |
578 | error ("No stack."); | |
a94dd1fd AC |
579 | if (!target_has_memory) |
580 | error ("No memory."); | |
4c1e7e9d AC |
581 | if (current_frame == NULL) |
582 | { | |
a94dd1fd AC |
583 | struct frame_info *sentinel_frame = |
584 | create_sentinel_frame (current_regcache); | |
585 | if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame, | |
586 | NULL, RETURN_MASK_ERROR) != 0) | |
587 | { | |
588 | /* Oops! Fake a current frame? Is this useful? It has a PC | |
589 | of zero, for instance. */ | |
590 | current_frame = sentinel_frame; | |
591 | } | |
4c1e7e9d AC |
592 | } |
593 | return current_frame; | |
594 | } | |
595 | ||
6e7f8b9c AC |
596 | /* The "selected" stack frame is used by default for local and arg |
597 | access. May be zero, for no selected frame. */ | |
598 | ||
599 | struct frame_info *deprecated_selected_frame; | |
600 | ||
601 | /* Return the selected frame. Always non-null (unless there isn't an | |
602 | inferior sufficient for creating a frame) in which case an error is | |
603 | thrown. */ | |
604 | ||
605 | struct frame_info * | |
606 | get_selected_frame (void) | |
607 | { | |
608 | if (deprecated_selected_frame == NULL) | |
609 | /* Hey! Don't trust this. It should really be re-finding the | |
610 | last selected frame of the currently selected thread. This, | |
611 | though, is better than nothing. */ | |
612 | select_frame (get_current_frame ()); | |
613 | /* There is always a frame. */ | |
614 | gdb_assert (deprecated_selected_frame != NULL); | |
615 | return deprecated_selected_frame; | |
616 | } | |
617 | ||
618 | /* Select frame FI (or NULL - to invalidate the current frame). */ | |
619 | ||
620 | void | |
621 | select_frame (struct frame_info *fi) | |
622 | { | |
623 | register struct symtab *s; | |
624 | ||
625 | deprecated_selected_frame = fi; | |
626 | /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the | |
627 | frame is being invalidated. */ | |
628 | if (selected_frame_level_changed_hook) | |
629 | selected_frame_level_changed_hook (frame_relative_level (fi)); | |
630 | ||
631 | /* FIXME: kseitz/2002-08-28: It would be nice to call | |
632 | selected_frame_level_changed_event right here, but due to limitations | |
633 | in the current interfaces, we would end up flooding UIs with events | |
634 | because select_frame is used extensively internally. | |
635 | ||
636 | Once we have frame-parameterized frame (and frame-related) commands, | |
637 | the event notification can be moved here, since this function will only | |
638 | be called when the users selected frame is being changed. */ | |
639 | ||
640 | /* Ensure that symbols for this frame are read in. Also, determine the | |
641 | source language of this frame, and switch to it if desired. */ | |
642 | if (fi) | |
643 | { | |
644 | s = find_pc_symtab (fi->pc); | |
645 | if (s | |
646 | && s->language != current_language->la_language | |
647 | && s->language != language_unknown | |
648 | && language_mode == language_mode_auto) | |
649 | { | |
650 | set_language (s->language); | |
651 | } | |
652 | } | |
653 | } | |
654 | ||
4c1e7e9d AC |
655 | /* Return the register saved in the simplistic ``saved_regs'' cache. |
656 | If the value isn't here AND a value is needed, try the next inner | |
657 | most frame. */ | |
658 | ||
659 | static void | |
6dc42492 AC |
660 | legacy_saved_regs_prev_register (struct frame_info *next_frame, |
661 | void **this_prologue_cache, | |
662 | int regnum, int *optimizedp, | |
663 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
664 | int *realnump, void *bufferp) | |
4c1e7e9d | 665 | { |
6dc42492 AC |
666 | /* HACK: New code is passed the next frame and this cache. |
667 | Unfortunatly, old code expects this frame. Since this is a | |
668 | backward compatibility hack, cheat by walking one level along the | |
669 | prologue chain to the frame the old code expects. | |
670 | ||
671 | Do not try this at home. Professional driver, closed course. */ | |
672 | struct frame_info *frame = next_frame->prev; | |
4c1e7e9d | 673 | gdb_assert (frame != NULL); |
4c1e7e9d | 674 | |
8f871025 | 675 | /* Only (older) architectures that implement the |
f30ee0bc AC |
676 | DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this |
677 | function. */ | |
678 | gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); | |
8f871025 | 679 | |
4c1e7e9d | 680 | /* Load the saved_regs register cache. */ |
a94dd1fd | 681 | if (get_frame_saved_regs (frame) == NULL) |
f30ee0bc | 682 | DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
4c1e7e9d | 683 | |
a94dd1fd AC |
684 | if (get_frame_saved_regs (frame) != NULL |
685 | && get_frame_saved_regs (frame)[regnum] != 0) | |
4c1e7e9d AC |
686 | { |
687 | if (regnum == SP_REGNUM) | |
688 | { | |
689 | /* SP register treated specially. */ | |
690 | *optimizedp = 0; | |
691 | *lvalp = not_lval; | |
692 | *addrp = 0; | |
693 | *realnump = -1; | |
694 | if (bufferp != NULL) | |
695 | store_address (bufferp, REGISTER_RAW_SIZE (regnum), | |
a94dd1fd | 696 | get_frame_saved_regs (frame)[regnum]); |
4c1e7e9d AC |
697 | } |
698 | else | |
699 | { | |
700 | /* Any other register is saved in memory, fetch it but cache | |
701 | a local copy of its value. */ | |
702 | *optimizedp = 0; | |
703 | *lvalp = lval_memory; | |
a94dd1fd | 704 | *addrp = get_frame_saved_regs (frame)[regnum]; |
4c1e7e9d AC |
705 | *realnump = -1; |
706 | if (bufferp != NULL) | |
707 | { | |
708 | #if 1 | |
709 | /* Save each register value, as it is read in, in a | |
710 | frame based cache. */ | |
6dc42492 | 711 | void **regs = (*this_prologue_cache); |
4c1e7e9d AC |
712 | if (regs == NULL) |
713 | { | |
714 | int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS) | |
715 | * sizeof (void *)); | |
479ab5a0 | 716 | regs = frame_obstack_zalloc (sizeof_cache); |
6dc42492 | 717 | (*this_prologue_cache) = regs; |
4c1e7e9d AC |
718 | } |
719 | if (regs[regnum] == NULL) | |
720 | { | |
721 | regs[regnum] | |
479ab5a0 | 722 | = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum)); |
a94dd1fd | 723 | read_memory (get_frame_saved_regs (frame)[regnum], regs[regnum], |
4c1e7e9d AC |
724 | REGISTER_RAW_SIZE (regnum)); |
725 | } | |
726 | memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum)); | |
727 | #else | |
728 | /* Read the value in from memory. */ | |
a94dd1fd | 729 | read_memory (get_frame_saved_regs (frame)[regnum], bufferp, |
4c1e7e9d AC |
730 | REGISTER_RAW_SIZE (regnum)); |
731 | #endif | |
732 | } | |
733 | } | |
734 | return; | |
735 | } | |
736 | ||
6dc42492 AC |
737 | /* No luck. Assume this and the next frame have the same register |
738 | value. Pass the unwind request down the frame chain to the next | |
739 | frame. Hopefully that frame will find the register's location. */ | |
740 | frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp, | |
741 | realnump, bufferp); | |
4c1e7e9d AC |
742 | } |
743 | ||
c170fb60 | 744 | static void |
6dc42492 AC |
745 | legacy_saved_regs_this_id (struct frame_info *next_frame, |
746 | void **this_prologue_cache, | |
747 | struct frame_id *id) | |
c689142b AC |
748 | { |
749 | int fromleaf; | |
c170fb60 AC |
750 | CORE_ADDR base; |
751 | CORE_ADDR pc; | |
752 | ||
6dc42492 AC |
753 | if (frame_relative_level (next_frame) < 0) |
754 | { | |
755 | /* FIXME: cagney/2003-03-14: We've got the extra special case of | |
756 | unwinding a sentinel frame, the PC of which is pointing at a | |
757 | stack dummy. Fake up the dummy frame's ID using the same | |
758 | sequence as is found a traditional unwinder. */ | |
759 | (*id).base = read_fp (); | |
760 | (*id).pc = read_pc (); | |
761 | return; | |
762 | } | |
763 | ||
c170fb60 AC |
764 | /* Start out by assuming it's NULL. */ |
765 | (*id) = null_frame_id; | |
c689142b | 766 | |
a94dd1fd | 767 | if (frame_relative_level (next_frame) <= 0) |
c689142b AC |
768 | /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
769 | the frame chain, not just the inner most frame! The generic, | |
770 | per-architecture, frame code should handle this and the below | |
771 | should simply be removed. */ | |
772 | fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame); | |
773 | else | |
774 | fromleaf = 0; | |
775 | ||
776 | if (fromleaf) | |
777 | /* A frameless inner-most frame. The `FP' (which isn't an | |
778 | architecture frame-pointer register!) of the caller is the same | |
779 | as the callee. */ | |
780 | /* FIXME: 2002-11-09: There isn't any reason to special case this | |
781 | edge condition. Instead the per-architecture code should hande | |
782 | it locally. */ | |
c170fb60 | 783 | base = get_frame_base (next_frame); |
c689142b AC |
784 | else |
785 | { | |
786 | /* Two macros defined in tm.h specify the machine-dependent | |
787 | actions to be performed here. | |
788 | ||
789 | First, get the frame's chain-pointer. | |
790 | ||
791 | If that is zero, the frame is the outermost frame or a leaf | |
792 | called by the outermost frame. This means that if start | |
793 | calls main without a frame, we'll return 0 (which is fine | |
794 | anyway). | |
795 | ||
796 | Nope; there's a problem. This also returns when the current | |
797 | routine is a leaf of main. This is unacceptable. We move | |
798 | this to after the ffi test; I'd rather have backtraces from | |
799 | start go curfluy than have an abort called from main not show | |
800 | main. */ | |
618ce49f AC |
801 | gdb_assert (DEPRECATED_FRAME_CHAIN_P ()); |
802 | base = DEPRECATED_FRAME_CHAIN (next_frame); | |
c689142b | 803 | |
c170fb60 AC |
804 | if (!frame_chain_valid (base, next_frame)) |
805 | return; | |
c689142b | 806 | } |
c170fb60 AC |
807 | if (base == 0) |
808 | return; | |
c689142b AC |
809 | |
810 | /* FIXME: cagney/2002-06-08: This should probably return the frame's | |
811 | function and not the PC (a.k.a. resume address). */ | |
c170fb60 AC |
812 | pc = frame_pc_unwind (next_frame); |
813 | id->pc = pc; | |
814 | id->base = base; | |
c689142b AC |
815 | } |
816 | ||
6dc42492 AC |
817 | const struct frame_unwind legacy_saved_regs_unwinder = { |
818 | legacy_saved_regs_this_id, | |
819 | legacy_saved_regs_prev_register | |
494cca16 | 820 | }; |
6dc42492 | 821 | const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder; |
494cca16 AC |
822 | |
823 | ||
ac2adee5 | 824 | /* Function: deprecated_generic_get_saved_register |
4c1e7e9d | 825 | Find register number REGNUM relative to FRAME and put its (raw, |
ac2adee5 | 826 | target format) contents in *RAW_BUFFER. |
4c1e7e9d AC |
827 | |
828 | Set *OPTIMIZED if the variable was optimized out (and thus can't be | |
829 | fetched). Note that this is never set to anything other than zero | |
830 | in this implementation. | |
831 | ||
832 | Set *LVAL to lval_memory, lval_register, or not_lval, depending on | |
833 | whether the value was fetched from memory, from a register, or in a | |
834 | strange and non-modifiable way (e.g. a frame pointer which was | |
835 | calculated rather than fetched). We will use not_lval for values | |
836 | fetched from generic dummy frames. | |
837 | ||
838 | Set *ADDRP to the address, either in memory or as a REGISTER_BYTE | |
839 | offset into the registers array. If the value is stored in a dummy | |
840 | frame, set *ADDRP to zero. | |
841 | ||
4c1e7e9d AC |
842 | The argument RAW_BUFFER must point to aligned memory. */ |
843 | ||
844 | void | |
845 | deprecated_generic_get_saved_register (char *raw_buffer, int *optimized, | |
846 | CORE_ADDR *addrp, | |
847 | struct frame_info *frame, int regnum, | |
848 | enum lval_type *lval) | |
849 | { | |
850 | if (!target_has_registers) | |
851 | error ("No registers."); | |
852 | ||
f30ee0bc | 853 | gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); |
8f871025 | 854 | |
4c1e7e9d AC |
855 | /* Normal systems don't optimize out things with register numbers. */ |
856 | if (optimized != NULL) | |
857 | *optimized = 0; | |
858 | ||
859 | if (addrp) /* default assumption: not found in memory */ | |
860 | *addrp = 0; | |
861 | ||
862 | /* Note: since the current frame's registers could only have been | |
863 | saved by frames INTERIOR TO the current frame, we skip examining | |
864 | the current frame itself: otherwise, we would be getting the | |
865 | previous frame's registers which were saved by the current frame. */ | |
866 | ||
a94dd1fd | 867 | if (frame != NULL) |
4c1e7e9d | 868 | { |
a94dd1fd AC |
869 | for (frame = get_next_frame (frame); |
870 | frame_relative_level (frame) >= 0; | |
871 | frame = get_next_frame (frame)) | |
4c1e7e9d | 872 | { |
a94dd1fd | 873 | if (get_frame_type (frame) == DUMMY_FRAME) |
4c1e7e9d | 874 | { |
a94dd1fd AC |
875 | if (lval) /* found it in a CALL_DUMMY frame */ |
876 | *lval = not_lval; | |
877 | if (raw_buffer) | |
878 | /* FIXME: cagney/2002-06-26: This should be via the | |
879 | gdbarch_register_read() method so that it, on the | |
880 | fly, constructs either a raw or pseudo register | |
881 | from the raw register cache. */ | |
882 | regcache_raw_read | |
883 | (generic_find_dummy_frame (get_frame_pc (frame), | |
884 | get_frame_base (frame)), | |
885 | regnum, raw_buffer); | |
886 | return; | |
4c1e7e9d | 887 | } |
a94dd1fd | 888 | |
f30ee0bc | 889 | DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
a94dd1fd AC |
890 | if (get_frame_saved_regs (frame) != NULL |
891 | && get_frame_saved_regs (frame)[regnum] != 0) | |
4c1e7e9d | 892 | { |
a94dd1fd AC |
893 | if (lval) /* found it saved on the stack */ |
894 | *lval = lval_memory; | |
895 | if (regnum == SP_REGNUM) | |
896 | { | |
897 | if (raw_buffer) /* SP register treated specially */ | |
898 | store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), | |
899 | get_frame_saved_regs (frame)[regnum]); | |
900 | } | |
901 | else | |
902 | { | |
903 | if (addrp) /* any other register */ | |
904 | *addrp = get_frame_saved_regs (frame)[regnum]; | |
905 | if (raw_buffer) | |
906 | read_memory (get_frame_saved_regs (frame)[regnum], raw_buffer, | |
907 | REGISTER_RAW_SIZE (regnum)); | |
908 | } | |
909 | return; | |
4c1e7e9d | 910 | } |
4c1e7e9d AC |
911 | } |
912 | } | |
913 | ||
914 | /* If we get thru the loop to this point, it means the register was | |
915 | not saved in any frame. Return the actual live-register value. */ | |
916 | ||
917 | if (lval) /* found it in a live register */ | |
918 | *lval = lval_register; | |
919 | if (addrp) | |
920 | *addrp = REGISTER_BYTE (regnum); | |
921 | if (raw_buffer) | |
922 | deprecated_read_register_gen (regnum, raw_buffer); | |
923 | } | |
924 | ||
eb4f72c5 AC |
925 | /* Determine the frame's type based on its PC. */ |
926 | ||
927 | static enum frame_type | |
928 | frame_type_from_pc (CORE_ADDR pc) | |
929 | { | |
930 | /* FIXME: cagney/2002-11-24: Can't yet directly call | |
931 | pc_in_dummy_frame() as some architectures don't set | |
932 | PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the | |
933 | latter is implemented by simply calling pc_in_dummy_frame). */ | |
934 | if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES | |
935 | && DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)) | |
936 | return DUMMY_FRAME; | |
937 | else | |
938 | { | |
939 | char *name; | |
940 | find_pc_partial_function (pc, &name, NULL, NULL); | |
941 | if (PC_IN_SIGTRAMP (pc, name)) | |
942 | return SIGTRAMP_FRAME; | |
943 | else | |
944 | return NORMAL_FRAME; | |
945 | } | |
946 | } | |
947 | ||
4c1e7e9d AC |
948 | /* Create an arbitrary (i.e. address specified by user) or innermost frame. |
949 | Always returns a non-NULL value. */ | |
950 | ||
951 | struct frame_info * | |
952 | create_new_frame (CORE_ADDR addr, CORE_ADDR pc) | |
953 | { | |
954 | struct frame_info *fi; | |
4c1e7e9d | 955 | |
479ab5a0 | 956 | fi = frame_obstack_zalloc (sizeof (struct frame_info)); |
4c1e7e9d AC |
957 | |
958 | fi->frame = addr; | |
959 | fi->pc = pc; | |
a94dd1fd | 960 | fi->next = create_sentinel_frame (current_regcache); |
eb4f72c5 | 961 | fi->type = frame_type_from_pc (pc); |
4c1e7e9d | 962 | |
e9582e71 AC |
963 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
964 | DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi); | |
4c1e7e9d AC |
965 | |
966 | /* Select/initialize an unwind function. */ | |
494cca16 | 967 | fi->unwind = frame_unwind_find_by_pc (current_gdbarch, fi->pc); |
4c1e7e9d AC |
968 | |
969 | return fi; | |
970 | } | |
971 | ||
03febf99 AC |
972 | /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the |
973 | innermost frame). Be careful to not fall off the bottom of the | |
974 | frame chain and onto the sentinel frame. */ | |
4c1e7e9d AC |
975 | |
976 | struct frame_info * | |
03febf99 | 977 | get_next_frame (struct frame_info *this_frame) |
4c1e7e9d | 978 | { |
03febf99 AC |
979 | if (this_frame->level > 0) |
980 | return this_frame->next; | |
a94dd1fd AC |
981 | else |
982 | return NULL; | |
4c1e7e9d AC |
983 | } |
984 | ||
985 | /* Flush the entire frame cache. */ | |
986 | ||
987 | void | |
988 | flush_cached_frames (void) | |
989 | { | |
990 | /* Since we can't really be sure what the first object allocated was */ | |
991 | obstack_free (&frame_cache_obstack, 0); | |
992 | obstack_init (&frame_cache_obstack); | |
993 | ||
994 | current_frame = NULL; /* Invalidate cache */ | |
995 | select_frame (NULL); | |
996 | annotate_frames_invalid (); | |
997 | } | |
998 | ||
999 | /* Flush the frame cache, and start a new one if necessary. */ | |
1000 | ||
1001 | void | |
1002 | reinit_frame_cache (void) | |
1003 | { | |
1004 | flush_cached_frames (); | |
1005 | ||
1006 | /* FIXME: The inferior_ptid test is wrong if there is a corefile. */ | |
1007 | if (PIDGET (inferior_ptid) != 0) | |
1008 | { | |
1009 | select_frame (get_current_frame ()); | |
1010 | } | |
1011 | } | |
1012 | ||
eb4f72c5 AC |
1013 | /* Create the previous frame using the deprecated methods |
1014 | INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */ | |
4c1e7e9d | 1015 | |
eb4f72c5 | 1016 | static struct frame_info * |
03febf99 | 1017 | legacy_get_prev_frame (struct frame_info *this_frame) |
4c1e7e9d AC |
1018 | { |
1019 | CORE_ADDR address = 0; | |
1020 | struct frame_info *prev; | |
95adb866 | 1021 | int fromleaf; |
4c1e7e9d | 1022 | |
055bb976 AC |
1023 | /* Allocate the new frame but do not wire it in to the frame chain. |
1024 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along | |
1025 | frame->next to pull some fancy tricks (of course such code is, by | |
1026 | definition, recursive). Try to prevent it. | |
1027 | ||
1028 | There is no reason to worry about memory leaks, should the | |
1029 | remainder of the function fail. The allocated memory will be | |
1030 | quickly reclaimed when the frame cache is flushed, and the `we've | |
1031 | been here before' check, in get_prev_frame will stop repeated | |
1032 | memory allocation calls. */ | |
1033 | prev = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
1034 | prev->level = this_frame->level + 1; | |
1035 | ||
1036 | /* NOTE: cagney/2002-11-18: Should have been correctly setting the | |
1037 | frame's type here, before anything else, and not last, at the | |
1038 | bottom of this function. The various | |
1039 | DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC, | |
1040 | DEPRECATED_INIT_FRAME_PC_FIRST and | |
1041 | DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds | |
1042 | that handle the frame not being correctly set from the start. | |
1043 | Unfortunatly those same work-arounds rely on the type defaulting | |
1044 | to NORMAL_FRAME. Ulgh! The new frame code does not have this | |
1045 | problem. */ | |
1046 | prev->type = NORMAL_FRAME; | |
1047 | ||
06c77151 AC |
1048 | /* A legacy frame's ID is always computed here. Mark it as valid. */ |
1049 | prev->id_p = 1; | |
1050 | ||
055bb976 AC |
1051 | /* Handle sentinel frame unwind as a special case. */ |
1052 | if (this_frame->level < 0) | |
1053 | { | |
1054 | /* Try to unwind the PC. If that doesn't work, assume we've reached | |
1055 | the oldest frame and simply return. Is there a better sentinal | |
1056 | value? The unwound PC value is then used to initialize the new | |
1057 | previous frame's type. | |
1058 | ||
1059 | Note that the pc-unwind is intentionally performed before the | |
1060 | frame chain. This is ok since, for old targets, both | |
618ce49f AC |
1061 | frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and |
1062 | DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures | |
1063 | have already been initialized (using | |
055bb976 AC |
1064 | DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
1065 | doesn't matter. | |
1066 | ||
1067 | By unwinding the PC first, it becomes possible to, in the case of | |
1068 | a dummy frame, avoid also unwinding the frame ID. This is | |
1069 | because (well ignoring the PPC) a dummy frame can be located | |
1070 | using THIS_FRAME's frame ID. */ | |
1071 | ||
1072 | prev->pc = frame_pc_unwind (this_frame); | |
1073 | if (prev->pc == 0) | |
1074 | { | |
1075 | /* The allocated PREV_FRAME will be reclaimed when the frame | |
1076 | obstack is next purged. */ | |
1077 | if (frame_debug) | |
1078 | fprintf_unfiltered (gdb_stdlog, | |
1079 | "Outermost frame - unwound PC zero\n"); | |
1080 | return NULL; | |
1081 | } | |
1082 | prev->type = frame_type_from_pc (prev->pc); | |
1083 | ||
1084 | /* Set the unwind functions based on that identified PC. */ | |
1085 | prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc); | |
1086 | ||
1087 | /* Find the prev's frame's ID. */ | |
1088 | if (prev->type == DUMMY_FRAME | |
1089 | && gdbarch_unwind_dummy_id_p (current_gdbarch)) | |
1090 | { | |
1091 | /* When unwinding a normal frame, the stack structure is | |
1092 | determined by analyzing the frame's function's code (be | |
1093 | it using brute force prologue analysis, or the dwarf2 | |
1094 | CFI). In the case of a dummy frame, that simply isn't | |
1095 | possible. The The PC is either the program entry point, | |
1096 | or some random address on the stack. Trying to use that | |
1097 | PC to apply standard frame ID unwind techniques is just | |
1098 | asking for trouble. */ | |
e8a8712a | 1099 | /* Assume call_function_by_hand(), via SAVE_DUMMY_FRAME_TOS, |
055bb976 AC |
1100 | previously saved the dummy frame's ID. Things only work |
1101 | if the two return the same value. */ | |
1102 | gdb_assert (SAVE_DUMMY_FRAME_TOS_P ()); | |
1103 | /* Use an architecture specific method to extract the prev's | |
1104 | dummy ID from the next frame. Note that this method uses | |
1105 | frame_register_unwind to obtain the register values | |
1106 | needed to determine the dummy frame's ID. */ | |
1107 | prev->id = gdbarch_unwind_dummy_id (current_gdbarch, this_frame); | |
1108 | } | |
1109 | else | |
1110 | { | |
1111 | /* We're unwinding a sentinel frame, the PC of which is | |
1112 | pointing at a stack dummy. Fake up the dummy frame's ID | |
1113 | using the same sequence as is found a traditional | |
1114 | unwinder. Once all architectures supply the | |
1115 | unwind_dummy_id method, this code can go away. */ | |
1116 | prev->id.base = read_fp (); | |
1117 | prev->id.pc = read_pc (); | |
1118 | } | |
1119 | ||
1120 | /* Check that the unwound ID is valid. */ | |
1121 | if (!frame_id_p (prev->id)) | |
1122 | { | |
1123 | if (frame_debug) | |
1124 | fprintf_unfiltered (gdb_stdlog, | |
1125 | "Outermost legacy sentinel frame - unwound frame ID invalid\n"); | |
1126 | return NULL; | |
1127 | } | |
1128 | ||
1129 | /* Check that the new frame isn't inner to (younger, below, | |
1130 | next) the old frame. If that happens the frame unwind is | |
1131 | going backwards. */ | |
1132 | /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since | |
1133 | that doesn't have a valid frame ID. Should instead set the | |
1134 | sentinel frame's frame ID to a `sentinel'. Leave it until | |
1135 | after the switch to storing the frame ID, instead of the | |
1136 | frame base, in the frame object. */ | |
1137 | ||
1138 | /* FIXME: cagney/2002-12-18: Instead of this hack, should only | |
1139 | store the frame ID in PREV_FRAME. Unfortunatly, some | |
1140 | architectures (HP/UX) still reply on EXTRA_FRAME_INFO and, | |
1141 | hence, still poke at the "struct frame_info" object directly. */ | |
1142 | prev->frame = prev->id.base; | |
1143 | ||
1144 | /* Link it in. */ | |
1145 | this_frame->prev = prev; | |
1146 | prev->next = this_frame; | |
1147 | ||
1148 | /* FIXME: cagney/2002-01-19: This call will go away. Instead of | |
1149 | initializing extra info, all frames will use the frame_cache | |
1150 | (passed to the unwind functions) to store additional frame | |
1151 | info. Unfortunatly legacy targets can't use | |
1152 | legacy_get_prev_frame() to unwind the sentinel frame and, | |
1153 | consequently, are forced to take this code path and rely on | |
1154 | the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to | |
1155 | initialize the inner-most frame. */ | |
1156 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) | |
1157 | { | |
1158 | DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev); | |
1159 | } | |
1160 | return prev; | |
1161 | } | |
1162 | ||
eb4f72c5 AC |
1163 | /* This code only works on normal frames. A sentinel frame, where |
1164 | the level is -1, should never reach this code. */ | |
03febf99 | 1165 | gdb_assert (this_frame->level >= 0); |
4c1e7e9d AC |
1166 | |
1167 | /* On some machines it is possible to call a function without | |
1168 | setting up a stack frame for it. On these machines, we | |
1169 | define this macro to take two args; a frameinfo pointer | |
1170 | identifying a frame and a variable to set or clear if it is | |
1171 | or isn't leafless. */ | |
1172 | ||
1173 | /* Still don't want to worry about this except on the innermost | |
03febf99 | 1174 | frame. This macro will set FROMLEAF if THIS_FRAME is a frameless |
95adb866 | 1175 | function invocation. */ |
03febf99 | 1176 | if (this_frame->level == 0) |
95adb866 AC |
1177 | /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
1178 | the frame chain, not just the inner most frame! The generic, | |
1179 | per-architecture, frame code should handle this and the below | |
1180 | should simply be removed. */ | |
03febf99 | 1181 | fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame); |
95adb866 AC |
1182 | else |
1183 | fromleaf = 0; | |
1184 | ||
1185 | if (fromleaf) | |
1186 | /* A frameless inner-most frame. The `FP' (which isn't an | |
1187 | architecture frame-pointer register!) of the caller is the same | |
1188 | as the callee. */ | |
1189 | /* FIXME: 2002-11-09: There isn't any reason to special case this | |
1190 | edge condition. Instead the per-architecture code should hande | |
1191 | it locally. */ | |
03febf99 | 1192 | address = get_frame_base (this_frame); |
95adb866 | 1193 | else |
4c1e7e9d AC |
1194 | { |
1195 | /* Two macros defined in tm.h specify the machine-dependent | |
1196 | actions to be performed here. | |
95adb866 | 1197 | |
4c1e7e9d | 1198 | First, get the frame's chain-pointer. |
95adb866 | 1199 | |
4c1e7e9d AC |
1200 | If that is zero, the frame is the outermost frame or a leaf |
1201 | called by the outermost frame. This means that if start | |
1202 | calls main without a frame, we'll return 0 (which is fine | |
1203 | anyway). | |
1204 | ||
1205 | Nope; there's a problem. This also returns when the current | |
1206 | routine is a leaf of main. This is unacceptable. We move | |
1207 | this to after the ffi test; I'd rather have backtraces from | |
1208 | start go curfluy than have an abort called from main not show | |
1209 | main. */ | |
618ce49f AC |
1210 | gdb_assert (DEPRECATED_FRAME_CHAIN_P ()); |
1211 | address = DEPRECATED_FRAME_CHAIN (this_frame); | |
4c1e7e9d | 1212 | |
03febf99 | 1213 | if (!frame_chain_valid (address, this_frame)) |
4c1e7e9d AC |
1214 | return 0; |
1215 | } | |
1216 | if (address == 0) | |
1217 | return 0; | |
1218 | ||
055bb976 | 1219 | /* Link in the already allocated prev frame. */ |
03febf99 AC |
1220 | this_frame->prev = prev; |
1221 | prev->next = this_frame; | |
4c1e7e9d | 1222 | prev->frame = address; |
4c1e7e9d | 1223 | |
95adb866 | 1224 | /* This change should not be needed, FIXME! We should determine |
a5afb99f | 1225 | whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen |
e9582e71 AC |
1226 | after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple |
1227 | way to express what goes on here. | |
95adb866 | 1228 | |
e9582e71 AC |
1229 | DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places: |
1230 | create_new_frame (where the PC is already set up) and here (where | |
1231 | it isn't). DEPRECATED_INIT_FRAME_PC is only called from here, | |
1232 | always after DEPRECATED_INIT_EXTRA_FRAME_INFO. | |
95adb866 | 1233 | |
e9582e71 AC |
1234 | The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO |
1235 | requires the PC value (which hasn't been set yet). Some other | |
1236 | machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO | |
1237 | before they can do DEPRECATED_INIT_FRAME_PC. Phoo. | |
95adb866 | 1238 | |
2ca6c561 AC |
1239 | We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more |
1240 | complication to an already overcomplicated part of GDB. | |
1241 | gnu@cygnus.com, 15Sep92. | |
95adb866 | 1242 | |
a5afb99f | 1243 | Assuming that some machines need DEPRECATED_INIT_FRAME_PC after |
e9582e71 | 1244 | DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme: |
95adb866 AC |
1245 | |
1246 | SETUP_INNERMOST_FRAME(): Default version is just create_new_frame | |
1247 | (read_fp ()), read_pc ()). Machines with extra frame info would | |
1248 | do that (or the local equivalent) and then set the extra fields. | |
1249 | ||
1250 | SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that | |
1251 | create_new_frame would no longer init extra frame info; | |
1252 | SETUP_ARBITRARY_FRAME would have to do that. | |
1253 | ||
e9582e71 AC |
1254 | INIT_PREV_FRAME(fromleaf, prev) Replace |
1255 | DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC. | |
1256 | This should also return a flag saying whether to keep the new | |
1257 | frame, or whether to discard it, because on some machines (e.g. | |
618ce49f AC |
1258 | mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID |
1259 | called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good | |
1260 | way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID | |
1261 | into the extra fields of the new frame). std_frame_pc(fromleaf, | |
1262 | prev) | |
95adb866 AC |
1263 | |
1264 | This is the default setting for INIT_PREV_FRAME. It just does | |
a5afb99f AC |
1265 | what the default DEPRECATED_INIT_FRAME_PC does. Some machines |
1266 | will call it from INIT_PREV_FRAME (either at the beginning, the | |
1267 | end, or in the middle). Some machines won't use it. | |
95adb866 AC |
1268 | |
1269 | kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */ | |
1270 | ||
1271 | /* NOTE: cagney/2002-11-09: Just ignore the above! There is no | |
1272 | reason for things to be this complicated. | |
1273 | ||
1274 | The trick is to assume that there is always a frame. Instead of | |
1275 | special casing the inner-most frame, create fake frame | |
1276 | (containing the hardware registers) that is inner to the | |
1277 | user-visible inner-most frame (...) and then unwind from that. | |
1278 | That way architecture code can use use the standard | |
1279 | frame_XX_unwind() functions and not differentiate between the | |
1280 | inner most and any other case. | |
1281 | ||
1282 | Since there is always a frame to unwind from, there is always | |
03febf99 | 1283 | somewhere (THIS_FRAME) to store all the info needed to construct |
95adb866 AC |
1284 | a new (previous) frame without having to first create it. This |
1285 | means that the convolution below - needing to carefully order a | |
1286 | frame's initialization - isn't needed. | |
1287 | ||
618ce49f AC |
1288 | The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least |
1289 | for a more up-to-date architecture, always calls | |
1290 | FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but | |
1291 | without first needing the frame! Instead of the convolution | |
1292 | below, we could have simply called FRAME_SAVED_PC() and been done | |
1293 | with it! Note that FRAME_SAVED_PC() is being superseed by | |
1294 | frame_pc_unwind() and that function does have somewhere to cache | |
1295 | that PC value. */ | |
4c1e7e9d | 1296 | |
2ca6c561 | 1297 | if (DEPRECATED_INIT_FRAME_PC_FIRST_P ()) |
97f46953 | 1298 | prev->pc = (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf, prev)); |
4c1e7e9d | 1299 | |
e9582e71 AC |
1300 | if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
1301 | DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev); | |
4c1e7e9d AC |
1302 | |
1303 | /* This entry is in the frame queue now, which is good since | |
95adb866 AC |
1304 | FRAME_SAVED_PC may use that queue to figure out its value (see |
1305 | tm-sparc.h). We want the pc saved in the inferior frame. */ | |
a5afb99f AC |
1306 | if (DEPRECATED_INIT_FRAME_PC_P ()) |
1307 | prev->pc = DEPRECATED_INIT_FRAME_PC (fromleaf, prev); | |
4c1e7e9d | 1308 | |
95adb866 AC |
1309 | /* If ->frame and ->pc are unchanged, we are in the process of |
1310 | getting ourselves into an infinite backtrace. Some architectures | |
618ce49f AC |
1311 | check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems |
1312 | like there is no reason this can't be an architecture-independent | |
1313 | check. */ | |
03febf99 AC |
1314 | if (prev->frame == this_frame->frame |
1315 | && prev->pc == this_frame->pc) | |
4c1e7e9d | 1316 | { |
03febf99 | 1317 | this_frame->prev = NULL; |
95adb866 AC |
1318 | obstack_free (&frame_cache_obstack, prev); |
1319 | return NULL; | |
4c1e7e9d AC |
1320 | } |
1321 | ||
1322 | /* Initialize the code used to unwind the frame PREV based on the PC | |
1323 | (and probably other architectural information). The PC lets you | |
1324 | check things like the debug info at that point (dwarf2cfi?) and | |
1325 | use that to decide how the frame should be unwound. */ | |
494cca16 | 1326 | prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc); |
4c1e7e9d | 1327 | |
5a203e44 AC |
1328 | /* NOTE: cagney/2002-11-18: The code segments, found in |
1329 | create_new_frame and get_prev_frame(), that initializes the | |
1330 | frames type is subtly different. The latter only updates ->type | |
1331 | when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops | |
1332 | get_prev_frame() overriding the frame's type when the INIT code | |
1333 | has previously set it. This is really somewhat bogus. The | |
1334 | initialization, as seen in create_new_frame(), should occur | |
1335 | before the INIT function has been called. */ | |
07555a72 | 1336 | if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
ae45cd16 AC |
1337 | && (DEPRECATED_PC_IN_CALL_DUMMY_P () |
1338 | ? DEPRECATED_PC_IN_CALL_DUMMY (prev->pc, 0, 0) | |
1339 | : pc_in_dummy_frame (prev->pc))) | |
5a203e44 AC |
1340 | prev->type = DUMMY_FRAME; |
1341 | else | |
1342 | { | |
1343 | /* FIXME: cagney/2002-11-10: This should be moved to before the | |
1344 | INIT code above so that the INIT code knows what the frame's | |
1345 | type is (in fact, for a [generic] dummy-frame, the type can | |
1346 | be set and then the entire initialization can be skipped. | |
1347 | Unforunatly, its the INIT code that sets the PC (Hmm, catch | |
1348 | 22). */ | |
1349 | char *name; | |
1350 | find_pc_partial_function (prev->pc, &name, NULL, NULL); | |
1351 | if (PC_IN_SIGTRAMP (prev->pc, name)) | |
1352 | prev->type = SIGTRAMP_FRAME; | |
1353 | /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some | |
1354 | architectures are forcing the frame's type in INIT so we | |
1355 | don't want to override it here. Remember, NORMAL_FRAME == 0, | |
1356 | so it all works (just :-/). Once this initialization is | |
1357 | moved to the start of this function, all this nastness will | |
1358 | go away. */ | |
1359 | } | |
4c1e7e9d AC |
1360 | |
1361 | return prev; | |
1362 | } | |
1363 | ||
eb4f72c5 | 1364 | /* Return a structure containing various interesting information |
03febf99 | 1365 | about the frame that called THIS_FRAME. Returns NULL |
eb4f72c5 AC |
1366 | if there is no such frame. */ |
1367 | ||
1368 | struct frame_info * | |
03febf99 | 1369 | get_prev_frame (struct frame_info *this_frame) |
eb4f72c5 AC |
1370 | { |
1371 | struct frame_info *prev_frame; | |
1372 | ||
1373 | /* Return the inner-most frame, when the caller passes in NULL. */ | |
1374 | /* NOTE: cagney/2002-11-09: Not sure how this would happen. The | |
1375 | caller should have previously obtained a valid frame using | |
1376 | get_selected_frame() and then called this code - only possibility | |
1377 | I can think of is code behaving badly. | |
1378 | ||
1379 | NOTE: cagney/2003-01-10: Talk about code behaving badly. Check | |
1380 | block_innermost_frame(). It does the sequence: frame = NULL; | |
1381 | while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why | |
1382 | it couldn't be written better, I don't know. | |
1383 | ||
1384 | NOTE: cagney/2003-01-11: I suspect what is happening is | |
1385 | block_innermost_frame() is, when the target has no state | |
1386 | (registers, memory, ...), still calling this function. The | |
1387 | assumption being that this function will return NULL indicating | |
1388 | that a frame isn't possible, rather than checking that the target | |
1389 | has state and then calling get_current_frame() and | |
1390 | get_prev_frame(). This is a guess mind. */ | |
03febf99 | 1391 | if (this_frame == NULL) |
eb4f72c5 AC |
1392 | { |
1393 | /* NOTE: cagney/2002-11-09: There was a code segment here that | |
1394 | would error out when CURRENT_FRAME was NULL. The comment | |
1395 | that went with it made the claim ... | |
1396 | ||
1397 | ``This screws value_of_variable, which just wants a nice | |
1398 | clean NULL return from block_innermost_frame if there are no | |
1399 | frames. I don't think I've ever seen this message happen | |
1400 | otherwise. And returning NULL here is a perfectly legitimate | |
1401 | thing to do.'' | |
1402 | ||
1403 | Per the above, this code shouldn't even be called with a NULL | |
03febf99 | 1404 | THIS_FRAME. */ |
eb4f72c5 AC |
1405 | return current_frame; |
1406 | } | |
1407 | ||
1408 | /* There is always a frame. If this assertion fails, suspect that | |
1409 | something should be calling get_selected_frame() or | |
1410 | get_current_frame(). */ | |
03febf99 | 1411 | gdb_assert (this_frame != NULL); |
eb4f72c5 | 1412 | |
03febf99 | 1413 | if (this_frame->level >= 0 |
eb4f72c5 | 1414 | && !backtrace_below_main |
03febf99 | 1415 | && inside_main_func (get_frame_pc (this_frame))) |
eb4f72c5 AC |
1416 | /* Don't unwind past main(), bug always unwind the sentinel frame. |
1417 | Note, this is done _before_ the frame has been marked as | |
1418 | previously unwound. That way if the user later decides to | |
1419 | allow unwinds past main(), that just happens. */ | |
ac2bd0a9 AC |
1420 | { |
1421 | if (frame_debug) | |
1422 | fprintf_unfiltered (gdb_stdlog, | |
1423 | "Outermost frame - inside main func.\n"); | |
1424 | return NULL; | |
1425 | } | |
eb4f72c5 AC |
1426 | |
1427 | /* Only try to do the unwind once. */ | |
03febf99 AC |
1428 | if (this_frame->prev_p) |
1429 | return this_frame->prev; | |
1430 | this_frame->prev_p = 1; | |
eb4f72c5 | 1431 | |
ce0c7262 | 1432 | #if 0 |
b14185ce AC |
1433 | /* If we're inside the entry file, it isn't valid. Don't apply this |
1434 | test to a dummy frame - dummy frame PC's typically land in the | |
1435 | entry file. Don't apply this test to the sentinel frame. | |
1436 | Sentinel frames should always be allowed to unwind. */ | |
eb4f72c5 AC |
1437 | /* NOTE: drow/2002-12-25: should there be a way to disable this |
1438 | check? It assumes a single small entry file, and the way some | |
1439 | debug readers (e.g. dbxread) figure out which object is the | |
1440 | entry file is somewhat hokey. */ | |
1441 | /* NOTE: cagney/2003-01-10: If there is a way of disabling this test | |
1442 | then it should probably be moved to before the ->prev_p test, | |
1443 | above. */ | |
ce0c7262 CV |
1444 | /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call to |
1445 | inside_entry_file destroys a meaningful backtrace under some | |
1446 | conditions. E. g. the backtrace tests in the asm-source testcase | |
1447 | are broken for some targets. In this test the functions are all | |
1448 | implemented as part of one file and the testcase is not necessarily | |
1449 | linked with a start file (depending on the target). What happens is, | |
1450 | that the first frame is printed normaly and following frames are | |
1451 | treated as being inside the enttry file then. This way, only the | |
1452 | #0 frame is printed in the backtrace output. */ | |
03febf99 AC |
1453 | if (this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
1454 | && inside_entry_file (get_frame_pc (this_frame))) | |
ac2bd0a9 AC |
1455 | { |
1456 | if (frame_debug) | |
1457 | fprintf_unfiltered (gdb_stdlog, | |
1458 | "Outermost frame - inside entry file\n"); | |
eb4f72c5 | 1459 | return NULL; |
ac2bd0a9 | 1460 | } |
ce0c7262 | 1461 | #endif |
eb4f72c5 | 1462 | |
b14185ce AC |
1463 | /* If we're already inside the entry function for the main objfile, |
1464 | then it isn't valid. Don't apply this test to a dummy frame - | |
1465 | dummy frame PC's typically land in the entry func. Don't apply | |
1466 | this test to the sentinel frame. Sentinel frames should always | |
1467 | be allowed to unwind. */ | |
1468 | /* NOTE: cagney/2003-02-25: Don't enable until someone has found | |
1469 | hard evidence that this is needed. */ | |
1470 | if (0 | |
03febf99 AC |
1471 | && this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
1472 | && inside_entry_func (get_frame_pc (this_frame))) | |
b14185ce AC |
1473 | { |
1474 | if (frame_debug) | |
1475 | fprintf_unfiltered (gdb_stdlog, | |
1476 | "Outermost frame - inside entry func\n"); | |
1477 | return NULL; | |
1478 | } | |
1479 | ||
eb4f72c5 | 1480 | /* If any of the old frame initialization methods are around, use |
055bb976 AC |
1481 | the legacy get_prev_frame method. */ |
1482 | if (legacy_frame_p (current_gdbarch)) | |
ac2bd0a9 | 1483 | { |
03febf99 | 1484 | prev_frame = legacy_get_prev_frame (this_frame); |
ac2bd0a9 AC |
1485 | if (frame_debug && prev_frame == NULL) |
1486 | fprintf_unfiltered (gdb_stdlog, | |
1487 | "Outermost frame - legacy_get_prev_frame NULL.\n"); | |
1488 | return prev_frame; | |
1489 | } | |
eb4f72c5 | 1490 | |
270c3b1d AC |
1491 | /* Check that this frame's ID was valid. If it wasn't, don't try to |
1492 | unwind to the prev frame. Be careful to not apply this test to | |
1493 | the sentinel frame. */ | |
1494 | if (this_frame->level >= 0 && !frame_id_p (get_frame_id (this_frame))) | |
1495 | { | |
1496 | if (frame_debug) | |
1497 | fprintf_filtered (gdb_stdlog, | |
1498 | "Outermost frame - this ID is NULL\n"); | |
1499 | return NULL; | |
1500 | } | |
1501 | ||
1502 | /* Check that this frame's ID isn't inner to (younger, below, next) | |
1503 | the next frame. This happens when frame unwind goes backwards. | |
1504 | Since the sentinel frame isn't valid, don't apply this if this | |
1505 | frame is entier the inner-most or sentinel frame. */ | |
1506 | if (this_frame->level > 0 | |
1507 | && frame_id_inner (get_frame_id (this_frame), | |
1508 | get_frame_id (this_frame->next))) | |
1509 | error ("This frame inner-to next frame (corrupt stack?)"); | |
1510 | ||
1511 | /* Check that this and the next frame are different. If they are | |
1512 | not, there is most likely a stack cycle. As with the inner-than | |
1513 | test, avoid the inner-most and sentinel frames. */ | |
1514 | /* FIXME: cagney/2003-03-17: Can't yet enable this this check. The | |
1515 | frame_id_eq() method doesn't yet use function addresses when | |
1516 | comparing frame IDs. */ | |
1517 | if (0 | |
1518 | && this_frame->level > 0 | |
1519 | && frame_id_eq (get_frame_id (this_frame), | |
1520 | get_frame_id (this_frame->next))) | |
1521 | error ("This frame identical to next frame (corrupt stack?)"); | |
1522 | ||
eb4f72c5 AC |
1523 | /* Allocate the new frame but do not wire it in to the frame chain. |
1524 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along | |
1525 | frame->next to pull some fancy tricks (of course such code is, by | |
1526 | definition, recursive). Try to prevent it. | |
1527 | ||
1528 | There is no reason to worry about memory leaks, should the | |
1529 | remainder of the function fail. The allocated memory will be | |
1530 | quickly reclaimed when the frame cache is flushed, and the `we've | |
1531 | been here before' check above will stop repeated memory | |
1532 | allocation calls. */ | |
1533 | prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
03febf99 | 1534 | prev_frame->level = this_frame->level + 1; |
eb4f72c5 AC |
1535 | |
1536 | /* Try to unwind the PC. If that doesn't work, assume we've reached | |
1537 | the oldest frame and simply return. Is there a better sentinal | |
1538 | value? The unwound PC value is then used to initialize the new | |
1539 | previous frame's type. | |
1540 | ||
1541 | Note that the pc-unwind is intentionally performed before the | |
1542 | frame chain. This is ok since, for old targets, both | |
618ce49f AC |
1543 | frame_pc_unwind (nee, FRAME_SAVED_PC) and |
1544 | DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures | |
1545 | have already been initialized (using | |
e9582e71 AC |
1546 | DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
1547 | doesn't matter. | |
eb4f72c5 AC |
1548 | |
1549 | By unwinding the PC first, it becomes possible to, in the case of | |
1550 | a dummy frame, avoid also unwinding the frame ID. This is | |
1551 | because (well ignoring the PPC) a dummy frame can be located | |
03febf99 | 1552 | using THIS_FRAME's frame ID. */ |
eb4f72c5 | 1553 | |
03febf99 | 1554 | prev_frame->pc = frame_pc_unwind (this_frame); |
eb4f72c5 | 1555 | if (prev_frame->pc == 0) |
ac2bd0a9 AC |
1556 | { |
1557 | /* The allocated PREV_FRAME will be reclaimed when the frame | |
1558 | obstack is next purged. */ | |
1559 | if (frame_debug) | |
1560 | fprintf_unfiltered (gdb_stdlog, | |
1561 | "Outermost frame - unwound PC zero\n"); | |
1562 | return NULL; | |
1563 | } | |
eb4f72c5 AC |
1564 | prev_frame->type = frame_type_from_pc (prev_frame->pc); |
1565 | ||
1566 | /* Set the unwind functions based on that identified PC. */ | |
1567 | prev_frame->unwind = frame_unwind_find_by_pc (current_gdbarch, | |
1568 | prev_frame->pc); | |
1569 | ||
06c77151 | 1570 | /* The prev's frame's ID is computed by demand in get_frame_id(). */ |
6dc42492 | 1571 | |
270c3b1d AC |
1572 | /* The unwound frame ID is validate at the start of this function, |
1573 | as part of the logic to decide if that frame should be further | |
1574 | unwound, and not here while the prev frame is being created. | |
1575 | Doing this makes it possible for the user to examine a frame that | |
1576 | has an invalid frame ID. | |
1577 | ||
1578 | The very old VAX frame_args_address_correct() method noted: [...] | |
1579 | For the sake of argument, suppose that the stack is somewhat | |
1580 | trashed (which is one reason that "info frame" exists). So, | |
1581 | return 0 (indicating we don't know the address of the arglist) if | |
1582 | we don't know what frame this frame calls. */ | |
6dc42492 | 1583 | |
eb4f72c5 | 1584 | /* Link it in. */ |
03febf99 AC |
1585 | this_frame->prev = prev_frame; |
1586 | prev_frame->next = this_frame; | |
eb4f72c5 | 1587 | |
eb4f72c5 AC |
1588 | return prev_frame; |
1589 | } | |
1590 | ||
4c1e7e9d AC |
1591 | CORE_ADDR |
1592 | get_frame_pc (struct frame_info *frame) | |
1593 | { | |
1594 | return frame->pc; | |
1595 | } | |
1596 | ||
1058bca7 AC |
1597 | static int |
1598 | pc_notcurrent (struct frame_info *frame) | |
1599 | { | |
1600 | /* If FRAME is not the innermost frame, that normally means that | |
1601 | FRAME->pc points at the return instruction (which is *after* the | |
1602 | call instruction), and we want to get the line containing the | |
1603 | call (because the call is where the user thinks the program is). | |
1604 | However, if the next frame is either a SIGTRAMP_FRAME or a | |
1605 | DUMMY_FRAME, then the next frame will contain a saved interrupt | |
1606 | PC and such a PC indicates the current (rather than next) | |
1607 | instruction/line, consequently, for such cases, want to get the | |
1608 | line containing fi->pc. */ | |
1609 | struct frame_info *next = get_next_frame (frame); | |
1610 | int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME); | |
1611 | return notcurrent; | |
1612 | } | |
1613 | ||
1614 | void | |
1615 | find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal) | |
1616 | { | |
1617 | (*sal) = find_pc_line (frame->pc, pc_notcurrent (frame)); | |
1618 | } | |
1619 | ||
c193f6ac AC |
1620 | /* Per "frame.h", return the ``address'' of the frame. Code should |
1621 | really be using get_frame_id(). */ | |
1622 | CORE_ADDR | |
1623 | get_frame_base (struct frame_info *fi) | |
1624 | { | |
06c77151 AC |
1625 | if (!fi->id_p) |
1626 | { | |
1627 | /* HACK: Force the ID code to (indirectly) initialize the | |
1628 | ->frame pointer. */ | |
1629 | get_frame_id (fi); | |
1630 | } | |
c193f6ac AC |
1631 | return fi->frame; |
1632 | } | |
1633 | ||
da62e633 AC |
1634 | /* High-level offsets into the frame. Used by the debug info. */ |
1635 | ||
1636 | CORE_ADDR | |
1637 | get_frame_base_address (struct frame_info *fi) | |
1638 | { | |
1639 | if (fi->type != NORMAL_FRAME) | |
1640 | return 0; | |
1641 | if (fi->base == NULL) | |
1642 | fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi)); | |
1643 | /* Sneaky: If the low-level unwind and high-level base code share a | |
1644 | common unwinder, let them share the prologue cache. */ | |
1645 | if (fi->base->unwind == fi->unwind) | |
1646 | return fi->base->this_base (fi->next, &fi->prologue_cache); | |
1647 | return fi->base->this_base (fi->next, &fi->base_cache); | |
1648 | } | |
1649 | ||
1650 | CORE_ADDR | |
1651 | get_frame_locals_address (struct frame_info *fi) | |
1652 | { | |
1653 | void **cache; | |
1654 | if (fi->type != NORMAL_FRAME) | |
1655 | return 0; | |
1656 | /* If there isn't a frame address method, find it. */ | |
1657 | if (fi->base == NULL) | |
1658 | fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi)); | |
1659 | /* Sneaky: If the low-level unwind and high-level base code share a | |
1660 | common unwinder, let them share the prologue cache. */ | |
1661 | if (fi->base->unwind == fi->unwind) | |
1662 | cache = &fi->prologue_cache; | |
1663 | else | |
1664 | cache = &fi->base_cache; | |
1665 | return fi->base->this_locals (fi->next, cache); | |
1666 | } | |
1667 | ||
1668 | CORE_ADDR | |
1669 | get_frame_args_address (struct frame_info *fi) | |
1670 | { | |
1671 | void **cache; | |
1672 | if (fi->type != NORMAL_FRAME) | |
1673 | return 0; | |
1674 | /* If there isn't a frame address method, find it. */ | |
1675 | if (fi->base == NULL) | |
1676 | fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi)); | |
1677 | /* Sneaky: If the low-level unwind and high-level base code share a | |
1678 | common unwinder, let them share the prologue cache. */ | |
1679 | if (fi->base->unwind == fi->unwind) | |
1680 | cache = &fi->prologue_cache; | |
1681 | else | |
1682 | cache = &fi->base_cache; | |
1683 | return fi->base->this_args (fi->next, cache); | |
1684 | } | |
1685 | ||
85cf597a AC |
1686 | /* Level of the selected frame: 0 for innermost, 1 for its caller, ... |
1687 | or -1 for a NULL frame. */ | |
1688 | ||
1689 | int | |
1690 | frame_relative_level (struct frame_info *fi) | |
1691 | { | |
1692 | if (fi == NULL) | |
1693 | return -1; | |
1694 | else | |
1695 | return fi->level; | |
1696 | } | |
1697 | ||
5a203e44 AC |
1698 | enum frame_type |
1699 | get_frame_type (struct frame_info *frame) | |
1700 | { | |
1701 | /* Some targets still don't use [generic] dummy frames. Catch them | |
1702 | here. */ | |
07555a72 | 1703 | if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
5a203e44 AC |
1704 | && deprecated_frame_in_dummy (frame)) |
1705 | return DUMMY_FRAME; | |
1706 | return frame->type; | |
1707 | } | |
1708 | ||
1709 | void | |
1710 | deprecated_set_frame_type (struct frame_info *frame, enum frame_type type) | |
1711 | { | |
1712 | /* Arrrg! See comment in "frame.h". */ | |
1713 | frame->type = type; | |
1714 | } | |
1715 | ||
4c1e7e9d AC |
1716 | #ifdef FRAME_FIND_SAVED_REGS |
1717 | /* XXX - deprecated. This is a compatibility function for targets | |
f30ee0bc | 1718 | that do not yet implement DEPRECATED_FRAME_INIT_SAVED_REGS. */ |
4c1e7e9d AC |
1719 | /* Find the addresses in which registers are saved in FRAME. */ |
1720 | ||
1721 | void | |
95486978 AC |
1722 | deprecated_get_frame_saved_regs (struct frame_info *frame, |
1723 | struct frame_saved_regs *saved_regs_addr) | |
4c1e7e9d AC |
1724 | { |
1725 | if (frame->saved_regs == NULL) | |
1726 | { | |
1727 | frame->saved_regs = (CORE_ADDR *) | |
479ab5a0 | 1728 | frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
4c1e7e9d AC |
1729 | } |
1730 | if (saved_regs_addr == NULL) | |
1731 | { | |
1732 | struct frame_saved_regs saved_regs; | |
1733 | FRAME_FIND_SAVED_REGS (frame, saved_regs); | |
1734 | memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS); | |
1735 | } | |
1736 | else | |
1737 | { | |
1738 | FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr); | |
1739 | memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS); | |
1740 | } | |
1741 | } | |
1742 | #endif | |
1743 | ||
0394eb2a AC |
1744 | struct frame_extra_info * |
1745 | get_frame_extra_info (struct frame_info *fi) | |
1746 | { | |
1747 | return fi->extra_info; | |
1748 | } | |
1749 | ||
2c517d0e AC |
1750 | struct frame_extra_info * |
1751 | frame_extra_info_zalloc (struct frame_info *fi, long size) | |
1752 | { | |
479ab5a0 | 1753 | fi->extra_info = frame_obstack_zalloc (size); |
2c517d0e AC |
1754 | return fi->extra_info; |
1755 | } | |
1756 | ||
b87efeee | 1757 | void |
2f107107 | 1758 | deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc) |
b87efeee | 1759 | { |
2f107107 AC |
1760 | /* See comment in "frame.h". */ |
1761 | frame->pc = pc; | |
e0d2ae16 AC |
1762 | /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are |
1763 | maintaining a locally allocated frame object. Since such frame's | |
1764 | are not in the frame chain, it isn't possible to assume that the | |
1765 | frame has a next. Sigh. */ | |
1766 | if (frame->next != NULL) | |
1767 | { | |
1768 | /* While we're at it, update this frame's cached PC value, found | |
1769 | in the next frame. Oh for the day when "struct frame_info" | |
1770 | is opaque and this hack on hack can just go away. */ | |
1771 | frame->next->pc_unwind_cache = pc; | |
1772 | frame->next->pc_unwind_cache_p = 1; | |
1773 | } | |
2f107107 AC |
1774 | } |
1775 | ||
1776 | void | |
1777 | deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base) | |
1778 | { | |
1779 | /* See comment in "frame.h". */ | |
1780 | frame->frame = base; | |
b87efeee AC |
1781 | } |
1782 | ||
c8b8a898 AC |
1783 | void |
1784 | deprecated_set_frame_saved_regs_hack (struct frame_info *frame, | |
1785 | CORE_ADDR *saved_regs) | |
1786 | { | |
1787 | frame->saved_regs = saved_regs; | |
1788 | } | |
1789 | ||
1790 | void | |
1791 | deprecated_set_frame_extra_info_hack (struct frame_info *frame, | |
1792 | struct frame_extra_info *extra_info) | |
1793 | { | |
1794 | frame->extra_info = extra_info; | |
1795 | } | |
1796 | ||
483d36b2 AC |
1797 | void |
1798 | deprecated_set_frame_next_hack (struct frame_info *fi, | |
1799 | struct frame_info *next) | |
1800 | { | |
1801 | fi->next = next; | |
1802 | } | |
1803 | ||
1804 | void | |
1805 | deprecated_set_frame_prev_hack (struct frame_info *fi, | |
1806 | struct frame_info *prev) | |
1807 | { | |
1808 | fi->prev = prev; | |
1809 | } | |
1810 | ||
2d75187b AC |
1811 | struct context * |
1812 | deprecated_get_frame_context (struct frame_info *fi) | |
1813 | { | |
1814 | return fi->context; | |
1815 | } | |
1816 | ||
1817 | void | |
1818 | deprecated_set_frame_context (struct frame_info *fi, | |
1819 | struct context *context) | |
1820 | { | |
1821 | fi->context = context; | |
1822 | } | |
1823 | ||
c8b8a898 AC |
1824 | struct frame_info * |
1825 | deprecated_frame_xmalloc (void) | |
1826 | { | |
1827 | struct frame_info *frame = XMALLOC (struct frame_info); | |
1828 | memset (frame, 0, sizeof (struct frame_info)); | |
1829 | return frame; | |
1830 | } | |
1831 | ||
f6c609c4 AC |
1832 | struct frame_info * |
1833 | deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs, | |
1834 | long sizeof_extra_info) | |
1835 | { | |
1836 | struct frame_info *frame = deprecated_frame_xmalloc (); | |
1837 | make_cleanup (xfree, frame); | |
1838 | if (sizeof_saved_regs > 0) | |
1839 | { | |
1840 | frame->saved_regs = xcalloc (1, sizeof_saved_regs); | |
1841 | make_cleanup (xfree, frame->saved_regs); | |
1842 | } | |
1843 | if (sizeof_extra_info > 0) | |
1844 | { | |
1845 | frame->extra_info = xcalloc (1, sizeof_extra_info); | |
1846 | make_cleanup (xfree, frame->extra_info); | |
1847 | } | |
1848 | return frame; | |
1849 | } | |
c8b8a898 | 1850 | |
1594fa56 AC |
1851 | int |
1852 | legacy_frame_p (struct gdbarch *current_gdbarch) | |
1853 | { | |
1854 | return (DEPRECATED_INIT_FRAME_PC_P () | |
1855 | || DEPRECATED_INIT_FRAME_PC_FIRST_P () | |
1856 | || DEPRECATED_INIT_EXTRA_FRAME_INFO_P () | |
618ce49f | 1857 | || DEPRECATED_FRAME_CHAIN_P () |
055bb976 AC |
1858 | || !gdbarch_unwind_dummy_id_p (current_gdbarch) |
1859 | || !SAVE_DUMMY_FRAME_TOS_P ()); | |
1594fa56 AC |
1860 | } |
1861 | ||
4c1e7e9d AC |
1862 | void |
1863 | _initialize_frame (void) | |
1864 | { | |
1865 | obstack_init (&frame_cache_obstack); | |
eb4f72c5 AC |
1866 | |
1867 | /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest | |
1868 | `set backtrace {past,beyond,...}-main'. Also suggest adding `set | |
1869 | backtrace ...-start' to control backtraces past start. The | |
1870 | problem with `below' is that it stops the `up' command. */ | |
1871 | ||
1872 | add_setshow_boolean_cmd ("backtrace-below-main", class_obscure, | |
1873 | &backtrace_below_main, "\ | |
1874 | Set whether backtraces should continue past \"main\".\n\ | |
1875 | Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ | |
1876 | the backtrace at \"main\". Set this variable if you need to see the rest\n\ | |
1877 | of the stack trace.", "\ | |
1878 | Show whether backtraces should continue past \"main\".\n\ | |
1879 | Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ | |
1880 | the backtrace at \"main\". Set this variable if you need to see the rest\n\ | |
1881 | of the stack trace.", | |
1882 | NULL, NULL, &setlist, &showlist); | |
ac2bd0a9 AC |
1883 | |
1884 | ||
1885 | /* Debug this files internals. */ | |
1886 | add_show_from_set (add_set_cmd ("frame", class_maintenance, var_zinteger, | |
1887 | &frame_debug, "Set frame debugging.\n\ | |
1888 | When non-zero, frame specific internal debugging is enabled.", &setdebuglist), | |
1889 | &showdebuglist); | |
4c1e7e9d | 1890 | } |