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Commit | Line | Data |
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0021b564 | 1 | /* Subroutines needed for unwinding stack frames for exception handling. */ |
3a674ab9 | 2 | /* Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 |
f30278e8 | 3 | Free Software Foundation, Inc. |
0021b564 JM |
4 | Contributed by Jason Merrill <jason@cygnus.com>. |
5 | ||
1322177d | 6 | This file is part of GCC. |
0021b564 | 7 | |
1322177d LB |
8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 2, or (at your option) any later | |
11 | version. | |
0021b564 | 12 | |
f7af368f JL |
13 | In addition to the permissions in the GNU General Public License, the |
14 | Free Software Foundation gives you unlimited permission to link the | |
15 | compiled version of this file into combinations with other programs, | |
16 | and to distribute those combinations without any restriction coming | |
17 | from the use of this file. (The General Public License restrictions | |
18 | do apply in other respects; for example, they cover modification of | |
19 | the file, and distribution when not linked into a combine | |
20 | executable.) | |
21 | ||
1322177d LB |
22 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
23 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
24 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
25 | for more details. | |
0021b564 JM |
26 | |
27 | You should have received a copy of the GNU General Public License | |
1322177d LB |
28 | along with GCC; see the file COPYING. If not, write to the Free |
29 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
30 | 02111-1307, USA. */ | |
0021b564 | 31 | |
275b60d6 | 32 | #ifndef _Unwind_Find_FDE |
52a11cbf RH |
33 | #include "tconfig.h" |
34 | #include "tsystem.h" | |
4977bab6 ZW |
35 | #include "coretypes.h" |
36 | #include "tm.h" | |
e1f9550a RH |
37 | #include "dwarf2.h" |
38 | #include "unwind.h" | |
bda33a6e | 39 | #define NO_BASE_OF_ENCODED_VALUE |
e1f9550a | 40 | #include "unwind-pe.h" |
52a11cbf RH |
41 | #include "unwind-dw2-fde.h" |
42 | #include "gthr.h" | |
275b60d6 | 43 | #endif |
52a11cbf | 44 | |
e1f9550a RH |
45 | /* The unseen_objects list contains objects that have been registered |
46 | but not yet categorized in any way. The seen_objects list has had | |
47 | it's pc_begin and count fields initialized at minimum, and is sorted | |
48 | by decreasing value of pc_begin. */ | |
49 | static struct object *unseen_objects; | |
50 | static struct object *seen_objects; | |
52a11cbf RH |
51 | |
52 | #ifdef __GTHREAD_MUTEX_INIT | |
53 | static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT; | |
54 | #else | |
55 | static __gthread_mutex_t object_mutex; | |
56 | #endif | |
57 | ||
58 | #ifdef __GTHREAD_MUTEX_INIT_FUNCTION | |
41077ce4 | 59 | static void |
52a11cbf RH |
60 | init_object_mutex (void) |
61 | { | |
62 | __GTHREAD_MUTEX_INIT_FUNCTION (&object_mutex); | |
63 | } | |
64 | ||
65 | static void | |
66 | init_object_mutex_once (void) | |
67 | { | |
68 | static __gthread_once_t once = __GTHREAD_ONCE_INIT; | |
69 | __gthread_once (&once, init_object_mutex); | |
70 | } | |
71 | #else | |
72 | #define init_object_mutex_once() | |
73 | #endif | |
74 | ||
75 | /* Called from crtbegin.o to register the unwind info for an object. */ | |
76 | ||
77 | void | |
a30794da | 78 | __register_frame_info_bases (const void *begin, struct object *ob, |
e1f9550a | 79 | void *tbase, void *dbase) |
52a11cbf | 80 | { |
55fae1a9 | 81 | /* If .eh_frame is empty, don't register at all. */ |
7008a11b | 82 | if ((uword *) begin == 0 || *(uword *) begin == 0) |
55fae1a9 JJ |
83 | return; |
84 | ||
e1f9550a RH |
85 | ob->pc_begin = (void *)-1; |
86 | ob->tbase = tbase; | |
87 | ob->dbase = dbase; | |
88 | ob->u.single = begin; | |
89 | ob->s.i = 0; | |
90 | ob->s.b.encoding = DW_EH_PE_omit; | |
3cfe49da GK |
91 | #ifdef DWARF2_OBJECT_END_PTR_EXTENSION |
92 | ob->fde_end = NULL; | |
93 | #endif | |
52a11cbf RH |
94 | |
95 | init_object_mutex_once (); | |
96 | __gthread_mutex_lock (&object_mutex); | |
97 | ||
e1f9550a RH |
98 | ob->next = unseen_objects; |
99 | unseen_objects = ob; | |
52a11cbf RH |
100 | |
101 | __gthread_mutex_unlock (&object_mutex); | |
102 | } | |
103 | ||
e1f9550a | 104 | void |
a30794da | 105 | __register_frame_info (const void *begin, struct object *ob) |
e1f9550a RH |
106 | { |
107 | __register_frame_info_bases (begin, ob, 0, 0); | |
108 | } | |
109 | ||
52a11cbf RH |
110 | void |
111 | __register_frame (void *begin) | |
112 | { | |
55fae1a9 JJ |
113 | struct object *ob; |
114 | ||
115 | /* If .eh_frame is empty, don't register at all. */ | |
e9d1b155 | 116 | if (*(uword *) begin == 0) |
55fae1a9 JJ |
117 | return; |
118 | ||
703ad42b | 119 | ob = malloc (sizeof (struct object)); |
41077ce4 | 120 | __register_frame_info (begin, ob); |
52a11cbf RH |
121 | } |
122 | ||
123 | /* Similar, but BEGIN is actually a pointer to a table of unwind entries | |
124 | for different translation units. Called from the file generated by | |
125 | collect2. */ | |
126 | ||
127 | void | |
e1f9550a RH |
128 | __register_frame_info_table_bases (void *begin, struct object *ob, |
129 | void *tbase, void *dbase) | |
52a11cbf | 130 | { |
e1f9550a RH |
131 | ob->pc_begin = (void *)-1; |
132 | ob->tbase = tbase; | |
133 | ob->dbase = dbase; | |
134 | ob->u.array = begin; | |
135 | ob->s.i = 0; | |
136 | ob->s.b.from_array = 1; | |
137 | ob->s.b.encoding = DW_EH_PE_omit; | |
52a11cbf RH |
138 | |
139 | init_object_mutex_once (); | |
140 | __gthread_mutex_lock (&object_mutex); | |
141 | ||
e1f9550a RH |
142 | ob->next = unseen_objects; |
143 | unseen_objects = ob; | |
52a11cbf RH |
144 | |
145 | __gthread_mutex_unlock (&object_mutex); | |
146 | } | |
147 | ||
e1f9550a RH |
148 | void |
149 | __register_frame_info_table (void *begin, struct object *ob) | |
150 | { | |
151 | __register_frame_info_table_bases (begin, ob, 0, 0); | |
152 | } | |
153 | ||
52a11cbf RH |
154 | void |
155 | __register_frame_table (void *begin) | |
156 | { | |
703ad42b | 157 | struct object *ob = malloc (sizeof (struct object)); |
52a11cbf RH |
158 | __register_frame_info_table (begin, ob); |
159 | } | |
160 | ||
161 | /* Called from crtbegin.o to deregister the unwind info for an object. */ | |
101fa48c RH |
162 | /* ??? Glibc has for a while now exported __register_frame_info and |
163 | __deregister_frame_info. If we call __register_frame_info_bases | |
164 | from crtbegin (wherein it is declared weak), and this object does | |
165 | not get pulled from libgcc.a for other reasons, then the | |
166 | invocation of __deregister_frame_info will be resolved from glibc. | |
79d0dfa3 | 167 | Since the registration did not happen there, we'll die. |
101fa48c RH |
168 | |
169 | Therefore, declare a new deregistration entry point that does the | |
41077ce4 | 170 | exact same thing, but will resolve to the same library as |
101fa48c | 171 | implements __register_frame_info_bases. */ |
52a11cbf RH |
172 | |
173 | void * | |
a30794da | 174 | __deregister_frame_info_bases (const void *begin) |
52a11cbf RH |
175 | { |
176 | struct object **p; | |
e1f9550a | 177 | struct object *ob = 0; |
52a11cbf | 178 | |
55fae1a9 | 179 | /* If .eh_frame is empty, we haven't registered. */ |
7008a11b | 180 | if ((uword *) begin == 0 || *(uword *) begin == 0) |
5d393c8e | 181 | return ob; |
55fae1a9 | 182 | |
52a11cbf RH |
183 | init_object_mutex_once (); |
184 | __gthread_mutex_lock (&object_mutex); | |
185 | ||
e1f9550a RH |
186 | for (p = &unseen_objects; *p ; p = &(*p)->next) |
187 | if ((*p)->u.single == begin) | |
188 | { | |
189 | ob = *p; | |
190 | *p = ob->next; | |
191 | goto out; | |
192 | } | |
193 | ||
194 | for (p = &seen_objects; *p ; p = &(*p)->next) | |
195 | if ((*p)->s.b.sorted) | |
196 | { | |
197 | if ((*p)->u.sort->orig_data == begin) | |
198 | { | |
199 | ob = *p; | |
200 | *p = ob->next; | |
201 | free (ob->u.sort); | |
202 | goto out; | |
203 | } | |
204 | } | |
205 | else | |
206 | { | |
207 | if ((*p)->u.single == begin) | |
208 | { | |
209 | ob = *p; | |
210 | *p = ob->next; | |
211 | goto out; | |
212 | } | |
213 | } | |
52a11cbf | 214 | |
e1f9550a RH |
215 | out: |
216 | __gthread_mutex_unlock (&object_mutex); | |
79d0dfa3 | 217 | gcc_assert (ob); |
e1f9550a | 218 | return (void *) ob; |
52a11cbf RH |
219 | } |
220 | ||
101fa48c | 221 | void * |
a30794da | 222 | __deregister_frame_info (const void *begin) |
101fa48c RH |
223 | { |
224 | return __deregister_frame_info_bases (begin); | |
225 | } | |
101fa48c | 226 | |
52a11cbf RH |
227 | void |
228 | __deregister_frame (void *begin) | |
229 | { | |
55fae1a9 | 230 | /* If .eh_frame is empty, we haven't registered. */ |
e9d1b155 | 231 | if (*(uword *) begin != 0) |
55fae1a9 | 232 | free (__deregister_frame_info (begin)); |
52a11cbf RH |
233 | } |
234 | ||
e1f9550a RH |
235 | \f |
236 | /* Like base_of_encoded_value, but take the base from a struct object | |
237 | instead of an _Unwind_Context. */ | |
238 | ||
239 | static _Unwind_Ptr | |
240 | base_from_object (unsigned char encoding, struct object *ob) | |
241 | { | |
242 | if (encoding == DW_EH_PE_omit) | |
243 | return 0; | |
244 | ||
245 | switch (encoding & 0x70) | |
246 | { | |
247 | case DW_EH_PE_absptr: | |
248 | case DW_EH_PE_pcrel: | |
099c8b17 | 249 | case DW_EH_PE_aligned: |
e1f9550a RH |
250 | return 0; |
251 | ||
252 | case DW_EH_PE_textrel: | |
253 | return (_Unwind_Ptr) ob->tbase; | |
254 | case DW_EH_PE_datarel: | |
255 | return (_Unwind_Ptr) ob->dbase; | |
79d0dfa3 NS |
256 | default: |
257 | gcc_unreachable (); | |
e1f9550a | 258 | } |
e1f9550a RH |
259 | } |
260 | ||
261 | /* Return the FDE pointer encoding from the CIE. */ | |
262 | /* ??? This is a subset of extract_cie_info from unwind-dw2.c. */ | |
263 | ||
264 | static int | |
a30794da | 265 | get_cie_encoding (const struct dwarf_cie *cie) |
e1f9550a RH |
266 | { |
267 | const unsigned char *aug, *p; | |
268 | _Unwind_Ptr dummy; | |
a9985a92 JM |
269 | _Unwind_Word utmp; |
270 | _Unwind_Sword stmp; | |
e1f9550a RH |
271 | |
272 | aug = cie->augmentation; | |
273 | if (aug[0] != 'z') | |
274 | return DW_EH_PE_absptr; | |
275 | ||
ca29916b | 276 | p = aug + strlen ((const char *)aug) + 1; /* Skip the augmentation string. */ |
a9985a92 JM |
277 | p = read_uleb128 (p, &utmp); /* Skip code alignment. */ |
278 | p = read_sleb128 (p, &stmp); /* Skip data alignment. */ | |
0ef54a47 PB |
279 | if (cie->version == 1) /* Skip return address column. */ |
280 | p++; | |
281 | else | |
282 | p = read_uleb128 (p, &utmp); | |
e1f9550a RH |
283 | |
284 | aug++; /* Skip 'z' */ | |
a9985a92 | 285 | p = read_uleb128 (p, &utmp); /* Skip augmentation length. */ |
e1f9550a RH |
286 | while (1) |
287 | { | |
288 | /* This is what we're looking for. */ | |
289 | if (*aug == 'R') | |
290 | return *p; | |
291 | /* Personality encoding and pointer. */ | |
292 | else if (*aug == 'P') | |
099c8b17 RH |
293 | { |
294 | /* ??? Avoid dereferencing indirect pointers, since we're | |
295 | faking the base address. Gotta keep DW_EH_PE_aligned | |
296 | intact, however. */ | |
297 | p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy); | |
298 | } | |
e1f9550a RH |
299 | /* LSDA encoding. */ |
300 | else if (*aug == 'L') | |
301 | p++; | |
302 | /* Otherwise end of string, or unknown augmentation. */ | |
303 | else | |
304 | return DW_EH_PE_absptr; | |
305 | aug++; | |
306 | } | |
307 | } | |
308 | ||
309 | static inline int | |
a30794da | 310 | get_fde_encoding (const struct dwarf_fde *f) |
e1f9550a RH |
311 | { |
312 | return get_cie_encoding (get_cie (f)); | |
313 | } | |
314 | ||
52a11cbf | 315 | \f |
72dd050a BH |
316 | /* Sorting an array of FDEs by address. |
317 | (Ideally we would have the linker sort the FDEs so we don't have to do | |
318 | it at run time. But the linkers are not yet prepared for this.) */ | |
319 | ||
e1f9550a RH |
320 | /* Comparison routines. Three variants of increasing complexity. */ |
321 | ||
bde257ff | 322 | static int |
e1f9550a | 323 | fde_unencoded_compare (struct object *ob __attribute__((unused)), |
a30794da | 324 | const fde *x, const fde *y) |
e1f9550a | 325 | { |
2f9ec5e5 HPN |
326 | _Unwind_Ptr x_ptr = *(_Unwind_Ptr *) x->pc_begin; |
327 | _Unwind_Ptr y_ptr = *(_Unwind_Ptr *) y->pc_begin; | |
328 | ||
329 | if (x_ptr > y_ptr) | |
bde257ff | 330 | return 1; |
2f9ec5e5 | 331 | if (x_ptr < y_ptr) |
bde257ff RH |
332 | return -1; |
333 | return 0; | |
e1f9550a RH |
334 | } |
335 | ||
bde257ff | 336 | static int |
a30794da | 337 | fde_single_encoding_compare (struct object *ob, const fde *x, const fde *y) |
e1f9550a RH |
338 | { |
339 | _Unwind_Ptr base, x_ptr, y_ptr; | |
340 | ||
341 | base = base_from_object (ob->s.b.encoding, ob); | |
342 | read_encoded_value_with_base (ob->s.b.encoding, base, x->pc_begin, &x_ptr); | |
343 | read_encoded_value_with_base (ob->s.b.encoding, base, y->pc_begin, &y_ptr); | |
344 | ||
bde257ff RH |
345 | if (x_ptr > y_ptr) |
346 | return 1; | |
347 | if (x_ptr < y_ptr) | |
348 | return -1; | |
349 | return 0; | |
e1f9550a RH |
350 | } |
351 | ||
bde257ff | 352 | static int |
a30794da | 353 | fde_mixed_encoding_compare (struct object *ob, const fde *x, const fde *y) |
e1f9550a RH |
354 | { |
355 | int x_encoding, y_encoding; | |
356 | _Unwind_Ptr x_ptr, y_ptr; | |
357 | ||
358 | x_encoding = get_fde_encoding (x); | |
359 | read_encoded_value_with_base (x_encoding, base_from_object (x_encoding, ob), | |
360 | x->pc_begin, &x_ptr); | |
361 | ||
362 | y_encoding = get_fde_encoding (y); | |
363 | read_encoded_value_with_base (y_encoding, base_from_object (y_encoding, ob), | |
364 | y->pc_begin, &y_ptr); | |
365 | ||
bde257ff RH |
366 | if (x_ptr > y_ptr) |
367 | return 1; | |
368 | if (x_ptr < y_ptr) | |
369 | return -1; | |
370 | return 0; | |
e1f9550a RH |
371 | } |
372 | ||
a30794da | 373 | typedef int (*fde_compare_t) (struct object *, const fde *, const fde *); |
e1f9550a RH |
374 | |
375 | ||
72dd050a BH |
376 | /* This is a special mix of insertion sort and heap sort, optimized for |
377 | the data sets that actually occur. They look like | |
378 | 101 102 103 127 128 105 108 110 190 111 115 119 125 160 126 129 130. | |
379 | I.e. a linearly increasing sequence (coming from functions in the text | |
380 | section), with additionally a few unordered elements (coming from functions | |
381 | in gnu_linkonce sections) whose values are higher than the values in the | |
382 | surrounding linear sequence (but not necessarily higher than the values | |
383 | at the end of the linear sequence!). | |
384 | The worst-case total run time is O(N) + O(n log (n)), where N is the | |
385 | total number of FDEs and n is the number of erratic ones. */ | |
386 | ||
e1f9550a | 387 | struct fde_accumulator |
72dd050a | 388 | { |
e1f9550a RH |
389 | struct fde_vector *linear; |
390 | struct fde_vector *erratic; | |
391 | }; | |
52a11cbf | 392 | |
d593d1d2 | 393 | static inline int |
e1f9550a | 394 | start_fde_sort (struct fde_accumulator *accu, size_t count) |
72dd050a | 395 | { |
e1f9550a RH |
396 | size_t size; |
397 | if (! count) | |
398 | return 0; | |
399 | ||
a30794da | 400 | size = sizeof (struct fde_vector) + sizeof (const fde *) * count; |
703ad42b | 401 | if ((accu->linear = malloc (size))) |
e1f9550a RH |
402 | { |
403 | accu->linear->count = 0; | |
703ad42b | 404 | if ((accu->erratic = malloc (size))) |
e1f9550a RH |
405 | accu->erratic->count = 0; |
406 | return 1; | |
407 | } | |
408 | else | |
41077ce4 | 409 | return 0; |
72dd050a | 410 | } |
0021b564 | 411 | |
72dd050a | 412 | static inline void |
a30794da | 413 | fde_insert (struct fde_accumulator *accu, const fde *this_fde) |
72dd050a | 414 | { |
e1f9550a RH |
415 | if (accu->linear) |
416 | accu->linear->array[accu->linear->count++] = this_fde; | |
72dd050a BH |
417 | } |
418 | ||
419 | /* Split LINEAR into a linear sequence with low values and an erratic | |
420 | sequence with high values, put the linear one (of longest possible | |
ba540394 | 421 | length) into LINEAR and the erratic one into ERRATIC. This is O(N). |
41077ce4 | 422 | |
ba540394 NS |
423 | Because the longest linear sequence we are trying to locate within the |
424 | incoming LINEAR array can be interspersed with (high valued) erratic | |
425 | entries. We construct a chain indicating the sequenced entries. | |
426 | To avoid having to allocate this chain, we overlay it onto the space of | |
427 | the ERRATIC array during construction. A final pass iterates over the | |
428 | chain to determine what should be placed in the ERRATIC array, and | |
429 | what is the linear sequence. This overlay is safe from aliasing. */ | |
e1f9550a | 430 | |
72dd050a | 431 | static inline void |
e1f9550a RH |
432 | fde_split (struct object *ob, fde_compare_t fde_compare, |
433 | struct fde_vector *linear, struct fde_vector *erratic) | |
72dd050a | 434 | { |
a30794da | 435 | static const fde *marker; |
72dd050a | 436 | size_t count = linear->count; |
a30794da | 437 | const fde **chain_end = ▮ |
ba540394 NS |
438 | size_t i, j, k; |
439 | ||
440 | /* This should optimize out, but it is wise to make sure this assumption | |
441 | is correct. Should these have different sizes, we cannot cast between | |
442 | them and the overlaying onto ERRATIC will not work. */ | |
79d0dfa3 | 443 | gcc_assert (sizeof (const fde *) == sizeof (const fde **)); |
41077ce4 | 444 | |
72dd050a BH |
445 | for (i = 0; i < count; i++) |
446 | { | |
a30794da | 447 | const fde **probe; |
41077ce4 | 448 | |
ba540394 | 449 | for (probe = chain_end; |
41077ce4 KH |
450 | probe != &marker && fde_compare (ob, linear->array[i], *probe) < 0; |
451 | probe = chain_end) | |
452 | { | |
a30794da | 453 | chain_end = (const fde **) erratic->array[probe - linear->array]; |
41077ce4 KH |
454 | erratic->array[probe - linear->array] = NULL; |
455 | } | |
a30794da | 456 | erratic->array[i] = (const fde *) chain_end; |
ba540394 | 457 | chain_end = &linear->array[i]; |
72dd050a BH |
458 | } |
459 | ||
ba540394 NS |
460 | /* Each entry in LINEAR which is part of the linear sequence we have |
461 | discovered will correspond to a non-NULL entry in the chain we built in | |
462 | the ERRATIC array. */ | |
463 | for (i = j = k = 0; i < count; i++) | |
464 | if (erratic->array[i]) | |
72dd050a | 465 | linear->array[j++] = linear->array[i]; |
ba540394 NS |
466 | else |
467 | erratic->array[k++] = linear->array[i]; | |
72dd050a | 468 | linear->count = j; |
ba540394 | 469 | erratic->count = k; |
72dd050a BH |
470 | } |
471 | ||
a30794da | 472 | #define SWAP(x,y) do { const fde * tmp = x; x = y; y = tmp; } while (0) |
80d83b16 JM |
473 | |
474 | /* Convert a semi-heap to a heap. A semi-heap is a heap except possibly | |
475 | for the first (root) node; push it down to its rightful place. */ | |
476 | ||
477 | static void | |
a30794da | 478 | frame_downheap (struct object *ob, fde_compare_t fde_compare, const fde **a, |
80d83b16 JM |
479 | int lo, int hi) |
480 | { | |
481 | int i, j; | |
482 | ||
483 | for (i = lo, j = 2*i+1; | |
484 | j < hi; | |
485 | j = 2*i+1) | |
486 | { | |
487 | if (j+1 < hi && fde_compare (ob, a[j], a[j+1]) < 0) | |
488 | ++j; | |
489 | ||
490 | if (fde_compare (ob, a[i], a[j]) < 0) | |
491 | { | |
492 | SWAP (a[i], a[j]); | |
493 | i = j; | |
494 | } | |
495 | else | |
496 | break; | |
497 | } | |
498 | } | |
499 | ||
99b13ed3 JW |
500 | /* This is O(n log(n)). BSD/OS defines heapsort in stdlib.h, so we must |
501 | use a name that does not conflict. */ | |
e1f9550a RH |
502 | |
503 | static void | |
504 | frame_heapsort (struct object *ob, fde_compare_t fde_compare, | |
505 | struct fde_vector *erratic) | |
72dd050a BH |
506 | { |
507 | /* For a description of this algorithm, see: | |
508 | Samuel P. Harbison, Guy L. Steele Jr.: C, a reference manual, 2nd ed., | |
2d76cb1a | 509 | p. 60-61. */ |
a30794da | 510 | const fde ** a = erratic->array; |
72dd050a BH |
511 | /* A portion of the array is called a "heap" if for all i>=0: |
512 | If i and 2i+1 are valid indices, then a[i] >= a[2i+1]. | |
2d76cb1a | 513 | If i and 2i+2 are valid indices, then a[i] >= a[2i+2]. */ |
72dd050a | 514 | size_t n = erratic->count; |
80d83b16 JM |
515 | int m; |
516 | ||
517 | /* Expand our heap incrementally from the end of the array, heapifying | |
518 | each resulting semi-heap as we go. After each step, a[m] is the top | |
519 | of a heap. */ | |
520 | for (m = n/2-1; m >= 0; --m) | |
521 | frame_downheap (ob, fde_compare, a, m, n); | |
522 | ||
523 | /* Shrink our heap incrementally from the end of the array, first | |
524 | swapping out the largest element a[0] and then re-heapifying the | |
525 | resulting semi-heap. After each step, a[0..m) is a heap. */ | |
526 | for (m = n-1; m >= 1; --m) | |
72dd050a | 527 | { |
80d83b16 JM |
528 | SWAP (a[0], a[m]); |
529 | frame_downheap (ob, fde_compare, a, 0, m); | |
72dd050a BH |
530 | } |
531 | #undef SWAP | |
532 | } | |
533 | ||
2d76cb1a | 534 | /* Merge V1 and V2, both sorted, and put the result into V1. */ |
e1f9550a RH |
535 | static inline void |
536 | fde_merge (struct object *ob, fde_compare_t fde_compare, | |
537 | struct fde_vector *v1, struct fde_vector *v2) | |
0021b564 | 538 | { |
72dd050a | 539 | size_t i1, i2; |
a30794da | 540 | const fde * fde2; |
0021b564 | 541 | |
72dd050a BH |
542 | i2 = v2->count; |
543 | if (i2 > 0) | |
0021b564 | 544 | { |
72dd050a | 545 | i1 = v1->count; |
a01da83b KH |
546 | do |
547 | { | |
548 | i2--; | |
549 | fde2 = v2->array[i2]; | |
550 | while (i1 > 0 && fde_compare (ob, v1->array[i1-1], fde2) > 0) | |
551 | { | |
552 | v1->array[i1+i2] = v1->array[i1-1]; | |
553 | i1--; | |
554 | } | |
41077ce4 | 555 | v1->array[i1+i2] = fde2; |
a01da83b KH |
556 | } |
557 | while (i2 > 0); | |
72dd050a | 558 | v1->count += v2->count; |
0021b564 JM |
559 | } |
560 | } | |
561 | ||
e1f9550a RH |
562 | static inline void |
563 | end_fde_sort (struct object *ob, struct fde_accumulator *accu, size_t count) | |
72dd050a | 564 | { |
e1f9550a RH |
565 | fde_compare_t fde_compare; |
566 | ||
79d0dfa3 | 567 | gcc_assert (!accu->linear || accu->linear->count == count); |
e1f9550a RH |
568 | |
569 | if (ob->s.b.mixed_encoding) | |
570 | fde_compare = fde_mixed_encoding_compare; | |
571 | else if (ob->s.b.encoding == DW_EH_PE_absptr) | |
572 | fde_compare = fde_unencoded_compare; | |
573 | else | |
574 | fde_compare = fde_single_encoding_compare; | |
575 | ||
576 | if (accu->erratic) | |
d593d1d2 | 577 | { |
e1f9550a | 578 | fde_split (ob, fde_compare, accu->linear, accu->erratic); |
79d0dfa3 | 579 | gcc_assert (accu->linear->count + accu->erratic->count == count); |
e1f9550a RH |
580 | frame_heapsort (ob, fde_compare, accu->erratic); |
581 | fde_merge (ob, fde_compare, accu->linear, accu->erratic); | |
582 | free (accu->erratic); | |
d593d1d2 NS |
583 | } |
584 | else | |
585 | { | |
e1f9550a RH |
586 | /* We've not managed to malloc an erratic array, |
587 | so heap sort in the linear one. */ | |
588 | frame_heapsort (ob, fde_compare, accu->linear); | |
d593d1d2 | 589 | } |
72dd050a BH |
590 | } |
591 | ||
52a11cbf | 592 | \f |
41077ce4 | 593 | /* Update encoding, mixed_encoding, and pc_begin for OB for the |
e1f9550a RH |
594 | fde array beginning at THIS_FDE. Return the number of fdes |
595 | encountered along the way. */ | |
596 | ||
52a11cbf | 597 | static size_t |
a30794da | 598 | classify_object_over_fdes (struct object *ob, const fde *this_fde) |
52a11cbf | 599 | { |
a30794da | 600 | const struct dwarf_cie *last_cie = 0; |
e1f9550a RH |
601 | size_t count = 0; |
602 | int encoding = DW_EH_PE_absptr; | |
603 | _Unwind_Ptr base = 0; | |
0021b564 | 604 | |
3cfe49da | 605 | for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) |
e1f9550a | 606 | { |
a30794da | 607 | const struct dwarf_cie *this_cie; |
e1f9550a | 608 | _Unwind_Ptr mask, pc_begin; |
52a11cbf | 609 | |
e1f9550a RH |
610 | /* Skip CIEs. */ |
611 | if (this_fde->CIE_delta == 0) | |
612 | continue; | |
52a11cbf | 613 | |
e1f9550a RH |
614 | /* Determine the encoding for this FDE. Note mixed encoded |
615 | objects for later. */ | |
616 | this_cie = get_cie (this_fde); | |
617 | if (this_cie != last_cie) | |
618 | { | |
619 | last_cie = this_cie; | |
620 | encoding = get_cie_encoding (this_cie); | |
621 | base = base_from_object (encoding, ob); | |
622 | if (ob->s.b.encoding == DW_EH_PE_omit) | |
623 | ob->s.b.encoding = encoding; | |
624 | else if (ob->s.b.encoding != encoding) | |
625 | ob->s.b.mixed_encoding = 1; | |
626 | } | |
0021b564 | 627 | |
e1f9550a RH |
628 | read_encoded_value_with_base (encoding, base, this_fde->pc_begin, |
629 | &pc_begin); | |
0021b564 | 630 | |
e1f9550a RH |
631 | /* Take care to ignore link-once functions that were removed. |
632 | In these cases, the function address will be NULL, but if | |
633 | the encoding is smaller than a pointer a true NULL may not | |
634 | be representable. Assume 0 in the representable bits is NULL. */ | |
635 | mask = size_of_encoded_value (encoding); | |
636 | if (mask < sizeof (void *)) | |
637 | mask = (1L << (mask << 3)) - 1; | |
638 | else | |
639 | mask = -1; | |
640 | ||
641 | if ((pc_begin & mask) == 0) | |
642 | continue; | |
154bba13 | 643 | |
e1f9550a | 644 | count += 1; |
e9d1b155 KH |
645 | if ((void *) pc_begin < ob->pc_begin) |
646 | ob->pc_begin = (void *) pc_begin; | |
52a11cbf | 647 | } |
154bba13 | 648 | |
e1f9550a | 649 | return count; |
0021b564 JM |
650 | } |
651 | ||
e1f9550a | 652 | static void |
a30794da | 653 | add_fdes (struct object *ob, struct fde_accumulator *accu, const fde *this_fde) |
a3fd4e75 | 654 | { |
a30794da | 655 | const struct dwarf_cie *last_cie = 0; |
e1f9550a RH |
656 | int encoding = ob->s.b.encoding; |
657 | _Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob); | |
658 | ||
3cfe49da | 659 | for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) |
52a11cbf | 660 | { |
a30794da | 661 | const struct dwarf_cie *this_cie; |
52a11cbf | 662 | |
e1f9550a RH |
663 | /* Skip CIEs. */ |
664 | if (this_fde->CIE_delta == 0) | |
665 | continue; | |
666 | ||
667 | if (ob->s.b.mixed_encoding) | |
668 | { | |
669 | /* Determine the encoding for this FDE. Note mixed encoded | |
670 | objects for later. */ | |
671 | this_cie = get_cie (this_fde); | |
672 | if (this_cie != last_cie) | |
673 | { | |
674 | last_cie = this_cie; | |
675 | encoding = get_cie_encoding (this_cie); | |
676 | base = base_from_object (encoding, ob); | |
677 | } | |
678 | } | |
679 | ||
680 | if (encoding == DW_EH_PE_absptr) | |
681 | { | |
e9d1b155 | 682 | if (*(_Unwind_Ptr *) this_fde->pc_begin == 0) |
e1f9550a RH |
683 | continue; |
684 | } | |
685 | else | |
686 | { | |
687 | _Unwind_Ptr pc_begin, mask; | |
688 | ||
689 | read_encoded_value_with_base (encoding, base, this_fde->pc_begin, | |
690 | &pc_begin); | |
691 | ||
692 | /* Take care to ignore link-once functions that were removed. | |
693 | In these cases, the function address will be NULL, but if | |
694 | the encoding is smaller than a pointer a true NULL may not | |
695 | be representable. Assume 0 in the representable bits is NULL. */ | |
696 | mask = size_of_encoded_value (encoding); | |
697 | if (mask < sizeof (void *)) | |
698 | mask = (1L << (mask << 3)) - 1; | |
699 | else | |
700 | mask = -1; | |
701 | ||
702 | if ((pc_begin & mask) == 0) | |
703 | continue; | |
704 | } | |
705 | ||
706 | fde_insert (accu, this_fde); | |
52a11cbf | 707 | } |
a3fd4e75 JL |
708 | } |
709 | ||
52a11cbf RH |
710 | /* Set up a sorted array of pointers to FDEs for a loaded object. We |
711 | count up the entries before allocating the array because it's likely to | |
712 | be faster. We can be called multiple times, should we have failed to | |
713 | allocate a sorted fde array on a previous occasion. */ | |
0021b564 | 714 | |
e1f9550a RH |
715 | static inline void |
716 | init_object (struct object* ob) | |
0021b564 | 717 | { |
e1f9550a | 718 | struct fde_accumulator accu; |
52a11cbf | 719 | size_t count; |
0021b564 | 720 | |
e1f9550a RH |
721 | count = ob->s.b.count; |
722 | if (count == 0) | |
52a11cbf | 723 | { |
e1f9550a RH |
724 | if (ob->s.b.from_array) |
725 | { | |
726 | fde **p = ob->u.array; | |
727 | for (count = 0; *p; ++p) | |
728 | count += classify_object_over_fdes (ob, *p); | |
729 | } | |
730 | else | |
731 | count = classify_object_over_fdes (ob, ob->u.single); | |
732 | ||
733 | /* The count field we have in the main struct object is somewhat | |
734 | limited, but should suffice for virtually all cases. If the | |
735 | counted value doesn't fit, re-write a zero. The worst that | |
736 | happens is that we re-count next time -- admittedly non-trivial | |
737 | in that this implies some 2M fdes, but at least we function. */ | |
738 | ob->s.b.count = count; | |
739 | if (ob->s.b.count != count) | |
740 | ob->s.b.count = 0; | |
52a11cbf | 741 | } |
154bba13 | 742 | |
e1f9550a | 743 | if (!start_fde_sort (&accu, count)) |
52a11cbf | 744 | return; |
154bba13 | 745 | |
e1f9550a | 746 | if (ob->s.b.from_array) |
52a11cbf | 747 | { |
e1f9550a RH |
748 | fde **p; |
749 | for (p = ob->u.array; *p; ++p) | |
41077ce4 | 750 | add_fdes (ob, &accu, *p); |
52a11cbf RH |
751 | } |
752 | else | |
e1f9550a RH |
753 | add_fdes (ob, &accu, ob->u.single); |
754 | ||
755 | end_fde_sort (ob, &accu, count); | |
756 | ||
757 | /* Save the original fde pointer, since this is the key by which the | |
758 | DSO will deregister the object. */ | |
759 | accu.linear->orig_data = ob->u.single; | |
760 | ob->u.sort = accu.linear; | |
761 | ||
762 | ob->s.b.sorted = 1; | |
a3fd4e75 JL |
763 | } |
764 | ||
e1f9550a RH |
765 | /* A linear search through a set of FDEs for the given PC. This is |
766 | used when there was insufficient memory to allocate and sort an | |
767 | array. */ | |
768 | ||
a30794da AJ |
769 | static const fde * |
770 | linear_search_fdes (struct object *ob, const fde *this_fde, void *pc) | |
0021b564 | 771 | { |
a30794da | 772 | const struct dwarf_cie *last_cie = 0; |
e1f9550a RH |
773 | int encoding = ob->s.b.encoding; |
774 | _Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob); | |
775 | ||
3cfe49da | 776 | for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) |
e1f9550a | 777 | { |
a30794da | 778 | const struct dwarf_cie *this_cie; |
e1f9550a RH |
779 | _Unwind_Ptr pc_begin, pc_range; |
780 | ||
781 | /* Skip CIEs. */ | |
782 | if (this_fde->CIE_delta == 0) | |
783 | continue; | |
784 | ||
785 | if (ob->s.b.mixed_encoding) | |
786 | { | |
787 | /* Determine the encoding for this FDE. Note mixed encoded | |
788 | objects for later. */ | |
789 | this_cie = get_cie (this_fde); | |
790 | if (this_cie != last_cie) | |
791 | { | |
792 | last_cie = this_cie; | |
793 | encoding = get_cie_encoding (this_cie); | |
794 | base = base_from_object (encoding, ob); | |
795 | } | |
796 | } | |
797 | ||
798 | if (encoding == DW_EH_PE_absptr) | |
799 | { | |
e9d1b155 KH |
800 | pc_begin = ((_Unwind_Ptr *) this_fde->pc_begin)[0]; |
801 | pc_range = ((_Unwind_Ptr *) this_fde->pc_begin)[1]; | |
e1f9550a RH |
802 | if (pc_begin == 0) |
803 | continue; | |
804 | } | |
805 | else | |
806 | { | |
807 | _Unwind_Ptr mask; | |
ca29916b | 808 | const unsigned char *p; |
e1f9550a RH |
809 | |
810 | p = read_encoded_value_with_base (encoding, base, | |
811 | this_fde->pc_begin, &pc_begin); | |
812 | read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); | |
813 | ||
814 | /* Take care to ignore link-once functions that were removed. | |
815 | In these cases, the function address will be NULL, but if | |
816 | the encoding is smaller than a pointer a true NULL may not | |
817 | be representable. Assume 0 in the representable bits is NULL. */ | |
818 | mask = size_of_encoded_value (encoding); | |
819 | if (mask < sizeof (void *)) | |
820 | mask = (1L << (mask << 3)) - 1; | |
821 | else | |
822 | mask = -1; | |
823 | ||
824 | if ((pc_begin & mask) == 0) | |
825 | continue; | |
826 | } | |
827 | ||
e9d1b155 | 828 | if ((_Unwind_Ptr) pc - pc_begin < pc_range) |
41077ce4 | 829 | return this_fde; |
e1f9550a RH |
830 | } |
831 | ||
832 | return NULL; | |
833 | } | |
834 | ||
835 | /* Binary search for an FDE containing the given PC. Here are three | |
836 | implementations of increasing complexity. */ | |
837 | ||
a30794da | 838 | static inline const fde * |
e1f9550a RH |
839 | binary_search_unencoded_fdes (struct object *ob, void *pc) |
840 | { | |
841 | struct fde_vector *vec = ob->u.sort; | |
52a11cbf | 842 | size_t lo, hi; |
41077ce4 | 843 | |
e1f9550a RH |
844 | for (lo = 0, hi = vec->count; lo < hi; ) |
845 | { | |
846 | size_t i = (lo + hi) / 2; | |
a30794da | 847 | const fde *f = vec->array[i]; |
e1f9550a RH |
848 | void *pc_begin; |
849 | uaddr pc_range; | |
850 | ||
e9d1b155 KH |
851 | pc_begin = ((void **) f->pc_begin)[0]; |
852 | pc_range = ((uaddr *) f->pc_begin)[1]; | |
e1f9550a RH |
853 | |
854 | if (pc < pc_begin) | |
855 | hi = i; | |
856 | else if (pc >= pc_begin + pc_range) | |
857 | lo = i + 1; | |
858 | else | |
859 | return f; | |
860 | } | |
0021b564 | 861 | |
e1f9550a RH |
862 | return NULL; |
863 | } | |
154bba13 | 864 | |
a30794da | 865 | static inline const fde * |
e1f9550a RH |
866 | binary_search_single_encoding_fdes (struct object *ob, void *pc) |
867 | { | |
868 | struct fde_vector *vec = ob->u.sort; | |
869 | int encoding = ob->s.b.encoding; | |
870 | _Unwind_Ptr base = base_from_object (encoding, ob); | |
871 | size_t lo, hi; | |
41077ce4 | 872 | |
e1f9550a | 873 | for (lo = 0, hi = vec->count; lo < hi; ) |
0021b564 | 874 | { |
e1f9550a | 875 | size_t i = (lo + hi) / 2; |
a30794da | 876 | const fde *f = vec->array[i]; |
e1f9550a | 877 | _Unwind_Ptr pc_begin, pc_range; |
ca29916b | 878 | const unsigned char *p; |
e1f9550a RH |
879 | |
880 | p = read_encoded_value_with_base (encoding, base, f->pc_begin, | |
881 | &pc_begin); | |
882 | read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); | |
883 | ||
e9d1b155 | 884 | if ((_Unwind_Ptr) pc < pc_begin) |
e1f9550a | 885 | hi = i; |
e9d1b155 | 886 | else if ((_Unwind_Ptr) pc >= pc_begin + pc_range) |
e1f9550a RH |
887 | lo = i + 1; |
888 | else | |
889 | return f; | |
52a11cbf | 890 | } |
0021b564 | 891 | |
e1f9550a RH |
892 | return NULL; |
893 | } | |
894 | ||
a30794da | 895 | static inline const fde * |
e1f9550a RH |
896 | binary_search_mixed_encoding_fdes (struct object *ob, void *pc) |
897 | { | |
898 | struct fde_vector *vec = ob->u.sort; | |
899 | size_t lo, hi; | |
41077ce4 | 900 | |
e1f9550a | 901 | for (lo = 0, hi = vec->count; lo < hi; ) |
52a11cbf | 902 | { |
e1f9550a | 903 | size_t i = (lo + hi) / 2; |
a30794da | 904 | const fde *f = vec->array[i]; |
e1f9550a | 905 | _Unwind_Ptr pc_begin, pc_range; |
ca29916b | 906 | const unsigned char *p; |
e1f9550a RH |
907 | int encoding; |
908 | ||
909 | encoding = get_fde_encoding (f); | |
910 | p = read_encoded_value_with_base (encoding, | |
911 | base_from_object (encoding, ob), | |
912 | f->pc_begin, &pc_begin); | |
913 | read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); | |
914 | ||
e9d1b155 | 915 | if ((_Unwind_Ptr) pc < pc_begin) |
e1f9550a | 916 | hi = i; |
e9d1b155 | 917 | else if ((_Unwind_Ptr) pc >= pc_begin + pc_range) |
e1f9550a RH |
918 | lo = i + 1; |
919 | else | |
920 | return f; | |
52a11cbf | 921 | } |
0021b564 | 922 | |
e1f9550a RH |
923 | return NULL; |
924 | } | |
52a11cbf | 925 | |
a30794da | 926 | static const fde * |
e1f9550a RH |
927 | search_object (struct object* ob, void *pc) |
928 | { | |
929 | /* If the data hasn't been sorted, try to do this now. We may have | |
930 | more memory available than last time we tried. */ | |
931 | if (! ob->s.b.sorted) | |
52a11cbf | 932 | { |
e1f9550a | 933 | init_object (ob); |
52a11cbf | 934 | |
e1f9550a RH |
935 | /* Despite the above comment, the normal reason to get here is |
936 | that we've not processed this object before. A quick range | |
937 | check is in order. */ | |
938 | if (pc < ob->pc_begin) | |
939 | return NULL; | |
940 | } | |
941 | ||
942 | if (ob->s.b.sorted) | |
943 | { | |
944 | if (ob->s.b.mixed_encoding) | |
945 | return binary_search_mixed_encoding_fdes (ob, pc); | |
946 | else if (ob->s.b.encoding == DW_EH_PE_absptr) | |
947 | return binary_search_unencoded_fdes (ob, pc); | |
948 | else | |
949 | return binary_search_single_encoding_fdes (ob, pc); | |
0021b564 | 950 | } |
52a11cbf RH |
951 | else |
952 | { | |
e1f9550a RH |
953 | /* Long slow labourious linear search, cos we've no memory. */ |
954 | if (ob->s.b.from_array) | |
41077ce4 KH |
955 | { |
956 | fde **p; | |
e1f9550a RH |
957 | for (p = ob->u.array; *p ; p++) |
958 | { | |
a30794da | 959 | const fde *f = linear_search_fdes (ob, *p, pc); |
41077ce4 | 960 | if (f) |
e1f9550a | 961 | return f; |
41077ce4 | 962 | } |
e1f9550a RH |
963 | return NULL; |
964 | } | |
52a11cbf | 965 | else |
e1f9550a RH |
966 | return linear_search_fdes (ob, ob->u.single, pc); |
967 | } | |
968 | } | |
969 | ||
a30794da | 970 | const fde * |
e1f9550a RH |
971 | _Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases) |
972 | { | |
973 | struct object *ob; | |
a30794da | 974 | const fde *f = NULL; |
e1f9550a RH |
975 | |
976 | init_object_mutex_once (); | |
977 | __gthread_mutex_lock (&object_mutex); | |
978 | ||
979 | /* Linear search through the classified objects, to find the one | |
e3aafbad | 980 | containing the pc. Note that pc_begin is sorted descending, and |
e1f9550a RH |
981 | we expect objects to be non-overlapping. */ |
982 | for (ob = seen_objects; ob; ob = ob->next) | |
983 | if (pc >= ob->pc_begin) | |
984 | { | |
985 | f = search_object (ob, pc); | |
986 | if (f) | |
987 | goto fini; | |
988 | break; | |
989 | } | |
990 | ||
991 | /* Classify and search the objects we've not yet processed. */ | |
992 | while ((ob = unseen_objects)) | |
993 | { | |
994 | struct object **p; | |
995 | ||
996 | unseen_objects = ob->next; | |
997 | f = search_object (ob, pc); | |
998 | ||
999 | /* Insert the object into the classified list. */ | |
1000 | for (p = &seen_objects; *p ; p = &(*p)->next) | |
1001 | if ((*p)->pc_begin < ob->pc_begin) | |
1002 | break; | |
1003 | ob->next = *p; | |
1004 | *p = ob; | |
1005 | ||
1006 | if (f) | |
1007 | goto fini; | |
1008 | } | |
1009 | ||
1010 | fini: | |
1011 | __gthread_mutex_unlock (&object_mutex); | |
1012 | ||
1013 | if (f) | |
1014 | { | |
1015 | int encoding; | |
950ccbc4 | 1016 | _Unwind_Ptr func; |
e1f9550a RH |
1017 | |
1018 | bases->tbase = ob->tbase; | |
1019 | bases->dbase = ob->dbase; | |
154bba13 | 1020 | |
e1f9550a RH |
1021 | encoding = ob->s.b.encoding; |
1022 | if (ob->s.b.mixed_encoding) | |
1023 | encoding = get_fde_encoding (f); | |
1024 | read_encoded_value_with_base (encoding, base_from_object (encoding, ob), | |
950ccbc4 NS |
1025 | f->pc_begin, &func); |
1026 | bases->func = (void *) func; | |
52a11cbf | 1027 | } |
0021b564 | 1028 | |
e1f9550a | 1029 | return f; |
a3fd4e75 | 1030 | } |