1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
|
/* Get info from stack frames; convert between frames, blocks,
functions and pc values.
Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 Free Software
Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "symtab.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "frame.h"
#include "gdbcore.h"
#include "value.h" /* for read_register */
#include "target.h" /* for target_has_stack */
#include "inferior.h" /* for read_pc */
#include "annotate.h"
#include "regcache.h"
#include "gdb_assert.h"
#include "dummy-frame.h"
#include "command.h"
#include "gdbcmd.h"
#include "block.h"
/* Prototypes for exported functions. */
void _initialize_blockframe (void);
/* Is ADDR inside the startup file? Note that if your machine has a
way to detect the bottom of the stack, there is no need to call
this function from DEPRECATED_FRAME_CHAIN_VALID; the reason for
doing so is that some machines have no way of detecting bottom of
stack.
A PC of zero is always considered to be the bottom of the stack. */
int
inside_entry_file (CORE_ADDR addr)
{
if (addr == 0)
return 1;
if (symfile_objfile == 0)
return 0;
if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
{
/* Do not stop backtracing if the pc is in the call dummy
at the entry point. */
/* FIXME: Won't always work with zeros for the last two arguments */
if (DEPRECATED_PC_IN_CALL_DUMMY (addr, 0, 0))
return 0;
}
return (addr >= symfile_objfile->ei.entry_file_lowpc &&
addr < symfile_objfile->ei.entry_file_highpc);
}
/* Test a specified PC value to see if it is in the range of addresses
that correspond to the main() function. See comments above for why
we might want to do this.
Typically called from DEPRECATED_FRAME_CHAIN_VALID.
A PC of zero is always considered to be the bottom of the stack. */
int
inside_main_func (CORE_ADDR pc)
{
if (pc == 0)
return 1;
if (symfile_objfile == 0)
return 0;
/* If the addr range is not set up at symbol reading time, set it up
now. This is for DEPRECATED_FRAME_CHAIN_VALID_ALTERNATE. I do
this for coff, because it is unable to set it up and symbol
reading time. */
if (symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC &&
symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
{
struct symbol *mainsym;
mainsym = lookup_symbol (main_name (), NULL, VAR_NAMESPACE, NULL, NULL);
if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
{
symfile_objfile->ei.main_func_lowpc =
BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
symfile_objfile->ei.main_func_highpc =
BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
}
}
return (symfile_objfile->ei.main_func_lowpc <= pc &&
symfile_objfile->ei.main_func_highpc > pc);
}
/* Test a specified PC value to see if it is in the range of addresses
that correspond to the process entry point function. See comments
in objfiles.h for why we might want to do this.
Typically called from DEPRECATED_FRAME_CHAIN_VALID.
A PC of zero is always considered to be the bottom of the stack. */
int
inside_entry_func (CORE_ADDR pc)
{
if (pc == 0)
return 1;
if (symfile_objfile == 0)
return 0;
if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
{
/* Do not stop backtracing if the pc is in the call dummy
at the entry point. */
/* FIXME: Won't always work with zeros for the last two arguments */
if (DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0))
return 0;
}
return (symfile_objfile->ei.entry_func_lowpc <= pc &&
symfile_objfile->ei.entry_func_highpc > pc);
}
/* Return nonzero if the function for this frame lacks a prologue. Many
machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
function. */
int
frameless_look_for_prologue (struct frame_info *frame)
{
CORE_ADDR func_start, after_prologue;
func_start = get_frame_func (frame);
if (func_start)
{
func_start += FUNCTION_START_OFFSET;
/* This is faster, since only care whether there *is* a
prologue, not how long it is. */
return PROLOGUE_FRAMELESS_P (func_start);
}
else if (get_frame_pc (frame) == 0)
/* A frame with a zero PC is usually created by dereferencing a
NULL function pointer, normally causing an immediate core dump
of the inferior. Mark function as frameless, as the inferior
has no chance of setting up a stack frame. */
return 1;
else
/* If we can't find the start of the function, we don't really
know whether the function is frameless, but we should be able
to get a reasonable (i.e. best we can do under the
circumstances) backtrace by saying that it isn't. */
return 0;
}
/* return the address of the PC for the given FRAME, ie the current PC value
if FRAME is the innermost frame, or the address adjusted to point to the
call instruction if not. */
CORE_ADDR
frame_address_in_block (struct frame_info *frame)
{
CORE_ADDR pc = get_frame_pc (frame);
/* If we are not in the innermost frame, and we are not interrupted
by a signal, frame->pc points to the instruction following the
call. As a consequence, we need to get the address of the previous
instruction. Unfortunately, this is not straightforward to do, so
we just use the address minus one, which is a good enough
approximation. */
/* FIXME: cagney/2002-11-10: Should this instead test for
NORMAL_FRAME? A dummy frame (in fact all the abnormal frames)
save the PC value in the block. */
if (get_next_frame (frame) != 0
&& get_frame_type (get_next_frame (frame)) != SIGTRAMP_FRAME)
--pc;
return pc;
}
/* Return the innermost lexical block in execution
in a specified stack frame. The frame address is assumed valid.
If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
address we used to choose the block. We use this to find a source
line, to decide which macro definitions are in scope.
The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
PC, and may not really be a valid PC at all. For example, in the
caller of a function declared to never return, the code at the
return address will never be reached, so the call instruction may
be the very last instruction in the block. So the address we use
to choose the block is actually one byte before the return address
--- hopefully pointing us at the call instruction, or its delay
slot instruction. */
struct block *
get_frame_block (struct frame_info *frame, CORE_ADDR *addr_in_block)
{
const CORE_ADDR pc = frame_address_in_block (frame);
if (addr_in_block)
*addr_in_block = pc;
return block_for_pc (pc);
}
CORE_ADDR
get_pc_function_start (CORE_ADDR pc)
{
register struct block *bl;
register struct symbol *symbol;
register struct minimal_symbol *msymbol;
CORE_ADDR fstart;
if ((bl = block_for_pc (pc)) != NULL &&
(symbol = block_function (bl)) != NULL)
{
bl = SYMBOL_BLOCK_VALUE (symbol);
fstart = BLOCK_START (bl);
}
else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL)
{
fstart = SYMBOL_VALUE_ADDRESS (msymbol);
if (!find_pc_section (fstart))
return 0;
}
else
{
fstart = 0;
}
return (fstart);
}
/* Return the symbol for the function executing in frame FRAME. */
struct symbol *
get_frame_function (struct frame_info *frame)
{
register struct block *bl = get_frame_block (frame, 0);
if (bl == 0)
return 0;
return block_function (bl);
}
/* Return the function containing pc value PC in section SECTION.
Returns 0 if function is not known. */
struct symbol *
find_pc_sect_function (CORE_ADDR pc, struct sec *section)
{
register struct block *b = block_for_pc_sect (pc, section);
if (b == 0)
return 0;
return block_function (b);
}
/* Return the function containing pc value PC.
Returns 0 if function is not known. Backward compatibility, no section */
struct symbol *
find_pc_function (CORE_ADDR pc)
{
return find_pc_sect_function (pc, find_pc_mapped_section (pc));
}
/* These variables are used to cache the most recent result
* of find_pc_partial_function. */
static CORE_ADDR cache_pc_function_low = 0;
static CORE_ADDR cache_pc_function_high = 0;
static const char *cache_pc_function_name = 0;
static struct sec *cache_pc_function_section = NULL;
/* Clear cache, e.g. when symbol table is discarded. */
void
clear_pc_function_cache (void)
{
cache_pc_function_low = 0;
cache_pc_function_high = 0;
cache_pc_function_name = (char *) 0;
cache_pc_function_section = NULL;
}
/* Finds the "function" (text symbol) that is smaller than PC but
greatest of all of the potential text symbols in SECTION. Sets
*NAME and/or *ADDRESS conditionally if that pointer is non-null.
If ENDADDR is non-null, then set *ENDADDR to be the end of the
function (exclusive), but passing ENDADDR as non-null means that
the function might cause symbols to be read. This function either
succeeds or fails (not halfway succeeds). If it succeeds, it sets
*NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
returns 0. */
int
find_pc_sect_partial_function (CORE_ADDR pc, asection *section,
const char **name, CORE_ADDR *address,
CORE_ADDR *endaddr)
{
struct partial_symtab *pst;
struct symbol *f;
struct minimal_symbol *msymbol;
struct partial_symbol *psb;
struct obj_section *osect;
int i;
CORE_ADDR mapped_pc;
mapped_pc = overlay_mapped_address (pc, section);
if (mapped_pc >= cache_pc_function_low
&& mapped_pc < cache_pc_function_high
&& section == cache_pc_function_section)
goto return_cached_value;
/* If sigtramp is in the u area, it counts as a function (especially
important for step_1). */
if (SIGTRAMP_START_P () && PC_IN_SIGTRAMP (mapped_pc, (char *) NULL))
{
cache_pc_function_low = SIGTRAMP_START (mapped_pc);
cache_pc_function_high = SIGTRAMP_END (mapped_pc);
cache_pc_function_name = "<sigtramp>";
cache_pc_function_section = section;
goto return_cached_value;
}
msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section);
pst = find_pc_sect_psymtab (mapped_pc, section);
if (pst)
{
/* Need to read the symbols to get a good value for the end address. */
if (endaddr != NULL && !pst->readin)
{
/* Need to get the terminal in case symbol-reading produces
output. */
target_terminal_ours_for_output ();
PSYMTAB_TO_SYMTAB (pst);
}
if (pst->readin)
{
/* Checking whether the msymbol has a larger value is for the
"pathological" case mentioned in print_frame_info. */
f = find_pc_sect_function (mapped_pc, section);
if (f != NULL
&& (msymbol == NULL
|| (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
>= SYMBOL_VALUE_ADDRESS (msymbol))))
{
cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
cache_pc_function_name = DEPRECATED_SYMBOL_NAME (f);
cache_pc_function_section = section;
goto return_cached_value;
}
}
else
{
/* Now that static symbols go in the minimal symbol table, perhaps
we could just ignore the partial symbols. But at least for now
we use the partial or minimal symbol, whichever is larger. */
psb = find_pc_sect_psymbol (pst, mapped_pc, section);
if (psb
&& (msymbol == NULL ||
(SYMBOL_VALUE_ADDRESS (psb)
>= SYMBOL_VALUE_ADDRESS (msymbol))))
{
/* This case isn't being cached currently. */
if (address)
*address = SYMBOL_VALUE_ADDRESS (psb);
if (name)
*name = DEPRECATED_SYMBOL_NAME (psb);
/* endaddr non-NULL can't happen here. */
return 1;
}
}
}
/* Not in the normal symbol tables, see if the pc is in a known section.
If it's not, then give up. This ensures that anything beyond the end
of the text seg doesn't appear to be part of the last function in the
text segment. */
osect = find_pc_sect_section (mapped_pc, section);
if (!osect)
msymbol = NULL;
/* Must be in the minimal symbol table. */
if (msymbol == NULL)
{
/* No available symbol. */
if (name != NULL)
*name = 0;
if (address != NULL)
*address = 0;
if (endaddr != NULL)
*endaddr = 0;
return 0;
}
cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
cache_pc_function_name = DEPRECATED_SYMBOL_NAME (msymbol);
cache_pc_function_section = section;
/* Use the lesser of the next minimal symbol in the same section, or
the end of the section, as the end of the function. */
/* Step over other symbols at this same address, and symbols in
other sections, to find the next symbol in this section with
a different address. */
for (i = 1; DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL; i++)
{
if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
&& SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
break;
}
if (DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL
&& SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
else
/* We got the start address from the last msymbol in the objfile.
So the end address is the end of the section. */
cache_pc_function_high = osect->endaddr;
return_cached_value:
if (address)
{
if (pc_in_unmapped_range (pc, section))
*address = overlay_unmapped_address (cache_pc_function_low, section);
else
*address = cache_pc_function_low;
}
if (name)
*name = cache_pc_function_name;
if (endaddr)
{
if (pc_in_unmapped_range (pc, section))
{
/* Because the high address is actually beyond the end of
the function (and therefore possibly beyond the end of
the overlay), we must actually convert (high - 1) and
then add one to that. */
*endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1,
section);
}
else
*endaddr = cache_pc_function_high;
}
return 1;
}
/* Backward compatibility, no section argument. */
int
find_pc_partial_function (CORE_ADDR pc, const char **name, CORE_ADDR *address,
CORE_ADDR *endaddr)
{
asection *section;
section = find_pc_overlay (pc);
return find_pc_sect_partial_function (pc, section, name, address, endaddr);
}
/* Return the innermost stack frame executing inside of BLOCK,
or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
struct frame_info *
block_innermost_frame (struct block *block)
{
struct frame_info *frame;
register CORE_ADDR start;
register CORE_ADDR end;
CORE_ADDR calling_pc;
if (block == NULL)
return NULL;
start = BLOCK_START (block);
end = BLOCK_END (block);
frame = NULL;
while (1)
{
frame = get_prev_frame (frame);
if (frame == NULL)
return NULL;
calling_pc = frame_address_in_block (frame);
if (calling_pc >= start && calling_pc < end)
return frame;
}
}
/* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
below is for infrun.c, which may give the macro a pc without that
subtracted out. */
/* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
top of the stack frame which we are checking, where "bottom" and
"top" refer to some section of memory which contains the code for
the call dummy. Calls to this macro assume that the contents of
SP_REGNUM and DEPRECATED_FP_REGNUM (or the saved values thereof),
respectively, are the things to pass.
This won't work on the 29k, where SP_REGNUM and
DEPRECATED_FP_REGNUM don't have that meaning, but the 29k doesn't
use ON_STACK. This could be fixed by generalizing this scheme,
perhaps by passing in a frame and adding a few fields, at least on
machines which need them for DEPRECATED_PC_IN_CALL_DUMMY.
Something simpler, like checking for the stack segment, doesn't work,
since various programs (threads implementations, gcc nested function
stubs, etc) may either allocate stack frames in another segment, or
allocate other kinds of code on the stack. */
int
deprecated_pc_in_call_dummy_on_stack (CORE_ADDR pc, CORE_ADDR sp,
CORE_ADDR frame_address)
{
return (INNER_THAN ((sp), (pc))
&& (frame_address != 0)
&& INNER_THAN ((pc), (frame_address)));
}
int
deprecated_pc_in_call_dummy_at_entry_point (CORE_ADDR pc, CORE_ADDR sp,
CORE_ADDR frame_address)
{
return ((pc) >= CALL_DUMMY_ADDRESS ()
&& (pc) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK));
}
/* Returns true for a user frame or a call_function_by_hand dummy
frame, and false for the CRT0 start-up frame. Purpose is to
terminate backtrace. */
int
legacy_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
{
/* Don't prune CALL_DUMMY frames. */
if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
&& DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), 0, 0))
return 1;
/* If the new frame pointer is zero, then it isn't valid. */
if (fp == 0)
return 0;
/* If the new frame would be inside (younger than) the previous frame,
then it isn't valid. */
if (INNER_THAN (fp, get_frame_base (fi)))
return 0;
/* If the architecture has a custom DEPRECATED_FRAME_CHAIN_VALID,
call it now. */
if (DEPRECATED_FRAME_CHAIN_VALID_P ())
return DEPRECATED_FRAME_CHAIN_VALID (fp, fi);
/* If we're already inside the entry function for the main objfile, then it
isn't valid. */
if (inside_entry_func (get_frame_pc (fi)))
return 0;
/* If we're inside the entry file, it isn't valid. */
/* NOTE/drow 2002-12-25: should there be a way to disable this check? It
assumes a single small entry file, and the way some debug readers (e.g.
dbxread) figure out which object is the entry file is somewhat hokey. */
if (inside_entry_file (frame_pc_unwind (fi)))
return 0;
return 1;
}
|