1 /*-
2 * Copyright (c) 2007 John Birrell (jb@freebsd.org)
3 * Copyright (c) 2009-2011 Kai Wang
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include "_libdwarf.h"
29
30 ELFTC_VCSID("$Id: libdwarf_die.c 3039 2014-05-18 15:10:56Z kaiwang27 $");
31
32 int
_dwarf_die_alloc(Dwarf_Debug dbg,Dwarf_Die * ret_die,Dwarf_Error * error)33 _dwarf_die_alloc(Dwarf_Debug dbg, Dwarf_Die *ret_die, Dwarf_Error *error)
34 {
35 Dwarf_Die die;
36
37 assert(ret_die != NULL);
38
39 if ((die = calloc(1, sizeof(struct _Dwarf_Die))) == NULL) {
40 DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
41 return (DW_DLE_MEMORY);
42 }
43
44 STAILQ_INIT(&die->die_attr);
45
46 *ret_die = die;
47
48 return (DW_DLE_NONE);
49 }
50
51 static int
_dwarf_die_add(Dwarf_CU cu,uint64_t offset,uint64_t abnum,Dwarf_Abbrev ab,Dwarf_Die * diep,Dwarf_Error * error)52 _dwarf_die_add(Dwarf_CU cu, uint64_t offset, uint64_t abnum, Dwarf_Abbrev ab,
53 Dwarf_Die *diep, Dwarf_Error *error)
54 {
55 Dwarf_Debug dbg;
56 Dwarf_Die die;
57 int ret;
58
59 assert(cu != NULL);
60 assert(ab != NULL);
61
62 dbg = cu->cu_dbg;
63
64 if ((ret = _dwarf_die_alloc(dbg, &die, error)) != DW_DLE_NONE)
65 return (ret);
66
67 die->die_offset = offset;
68 die->die_abnum = abnum;
69 die->die_ab = ab;
70 die->die_cu = cu;
71 die->die_dbg = cu->cu_dbg;
72
73 *diep = die;
74
75 return (DW_DLE_NONE);
76 }
77
78 /* Find die at offset 'off' within the same CU. */
79 Dwarf_Die
_dwarf_die_find(Dwarf_Die die,Dwarf_Unsigned off)80 _dwarf_die_find(Dwarf_Die die, Dwarf_Unsigned off)
81 {
82 Dwarf_Debug dbg;
83 Dwarf_Section *ds;
84 Dwarf_CU cu;
85 Dwarf_Die die1;
86 Dwarf_Error de;
87 int ret;
88
89 cu = die->die_cu;
90 dbg = die->die_dbg;
91 ds = cu->cu_is_info ? dbg->dbg_info_sec : dbg->dbg_types_sec;
92
93 ret = _dwarf_die_parse(dbg, ds, cu, cu->cu_dwarf_size, off,
94 cu->cu_next_offset, &die1, 0, &de);
95
96 if (ret == DW_DLE_NONE)
97 return (die1);
98 else
99 return (NULL);
100 }
101
102 int
_dwarf_die_parse(Dwarf_Debug dbg,Dwarf_Section * ds,Dwarf_CU cu,int dwarf_size,uint64_t offset,uint64_t next_offset,Dwarf_Die * ret_die,int search_sibling,Dwarf_Error * error)103 _dwarf_die_parse(Dwarf_Debug dbg, Dwarf_Section *ds, Dwarf_CU cu,
104 int dwarf_size, uint64_t offset, uint64_t next_offset, Dwarf_Die *ret_die,
105 int search_sibling, Dwarf_Error *error)
106 {
107 Dwarf_Abbrev ab;
108 Dwarf_AttrDef ad;
109 Dwarf_Die die;
110 uint64_t abnum;
111 uint64_t die_offset;
112 int ret, level;
113
114 assert(cu != NULL);
115
116 level = 1;
117 die = NULL;
118
119 while (offset < next_offset && offset < ds->ds_size) {
120
121 die_offset = offset;
122
123 abnum = _dwarf_read_uleb128(ds->ds_data, &offset);
124
125 if (abnum == 0) {
126 if (level == 0 || !search_sibling)
127 return (DW_DLE_NO_ENTRY);
128
129 /*
130 * Return to previous DIE level.
131 */
132 level--;
133 continue;
134 }
135
136 if ((ret = _dwarf_abbrev_find(cu, abnum, &ab, error)) !=
137 DW_DLE_NONE)
138 return (ret);
139
140 if ((ret = _dwarf_die_add(cu, die_offset, abnum, ab, &die,
141 error)) != DW_DLE_NONE)
142 return (ret);
143
144 STAILQ_FOREACH(ad, &ab->ab_attrdef, ad_next) {
145 if ((ret = _dwarf_attr_init(dbg, ds, &offset,
146 dwarf_size, cu, die, ad, ad->ad_form, 0,
147 error)) != DW_DLE_NONE)
148 return (ret);
149 }
150
151 die->die_next_off = offset;
152 if (search_sibling && level > 0) {
153 dwarf_dealloc(dbg, die, DW_DLA_DIE);
154 if (ab->ab_children == DW_CHILDREN_yes) {
155 /* Advance to next DIE level. */
156 level++;
157 }
158 } else {
159 *ret_die = die;
160 return (DW_DLE_NONE);
161 }
162 }
163
164 return (DW_DLE_NO_ENTRY);
165 }
166
167 void
_dwarf_die_link(Dwarf_P_Die die,Dwarf_P_Die parent,Dwarf_P_Die child,Dwarf_P_Die left_sibling,Dwarf_P_Die right_sibling)168 _dwarf_die_link(Dwarf_P_Die die, Dwarf_P_Die parent, Dwarf_P_Die child,
169 Dwarf_P_Die left_sibling, Dwarf_P_Die right_sibling)
170 {
171 Dwarf_P_Die last_child;
172
173 assert(die != NULL);
174
175 if (parent) {
176
177 /* Disconnect from old parent. */
178 if (die->die_parent) {
179 if (die->die_parent != parent) {
180 if (die->die_parent->die_child == die)
181 die->die_parent->die_child = NULL;
182 die->die_parent = NULL;
183 }
184 }
185
186 /* Find the last child of this parent. */
187 last_child = parent->die_child;
188 if (last_child) {
189 while (last_child->die_right != NULL)
190 last_child = last_child->die_right;
191 }
192
193 /* Connect to new parent. */
194 die->die_parent = parent;
195
196 /*
197 * Attach this DIE to the end of sibling list. If new
198 * parent doesn't have any child, set this DIE as the
199 * first child.
200 */
201 if (last_child) {
202 assert(last_child->die_right == NULL);
203 last_child->die_right = die;
204 die->die_left = last_child;
205 } else
206 parent->die_child = die;
207 }
208
209 if (child) {
210
211 /* Disconnect from old child. */
212 if (die->die_child) {
213 if (die->die_child != child) {
214 die->die_child->die_parent = NULL;
215 die->die_child = NULL;
216 }
217 }
218
219 /* Connect to new child. */
220 die->die_child = child;
221 child->die_parent = die;
222 }
223
224 if (left_sibling) {
225
226 /* Disconnect from old left sibling. */
227 if (die->die_left) {
228 if (die->die_left != left_sibling) {
229 die->die_left->die_right = NULL;
230 die->die_left = NULL;
231 }
232 }
233
234 /* Connect to new right sibling. */
235 die->die_left = left_sibling;
236 left_sibling->die_right = die;
237 }
238
239 if (right_sibling) {
240
241 /* Disconnect from old right sibling. */
242 if (die->die_right) {
243 if (die->die_right != right_sibling) {
244 die->die_right->die_left = NULL;
245 die->die_right = NULL;
246 }
247 }
248
249 /* Connect to new right sibling. */
250 die->die_right = right_sibling;
251 right_sibling->die_left = die;
252 }
253 }
254
255 int
_dwarf_die_count_links(Dwarf_P_Die parent,Dwarf_P_Die child,Dwarf_P_Die left_sibling,Dwarf_P_Die right_sibling)256 _dwarf_die_count_links(Dwarf_P_Die parent, Dwarf_P_Die child,
257 Dwarf_P_Die left_sibling, Dwarf_P_Die right_sibling)
258 {
259 int count;
260
261 count = 0;
262
263 if (parent)
264 count++;
265 if (child)
266 count++;
267 if (left_sibling)
268 count++;
269 if (right_sibling)
270 count++;
271
272 return (count);
273 }
274
275 static int
_dwarf_die_gen_recursive(Dwarf_P_Debug dbg,Dwarf_CU cu,Dwarf_Rel_Section drs,Dwarf_P_Die die,int pass2,Dwarf_Error * error)276 _dwarf_die_gen_recursive(Dwarf_P_Debug dbg, Dwarf_CU cu, Dwarf_Rel_Section drs,
277 Dwarf_P_Die die, int pass2, Dwarf_Error *error)
278 {
279 Dwarf_P_Section ds;
280 Dwarf_Abbrev ab;
281 Dwarf_Attribute at;
282 Dwarf_AttrDef ad;
283 int match, ret;
284
285 ds = dbg->dbgp_info;
286 assert(ds != NULL);
287
288 if (pass2)
289 goto attr_gen;
290
291 /*
292 * Add DW_AT_sibling attribute for DIEs with children, so consumers
293 * can quickly scan chains of siblings, while ignoring the children
294 * of individual siblings.
295 */
296 if (die->die_child && die->die_right) {
297 if (_dwarf_attr_find(die, DW_AT_sibling) == NULL)
298 (void) dwarf_add_AT_reference(dbg, die, DW_AT_sibling,
299 die->die_right, error);
300 }
301
302 /*
303 * Search abbrev list to find a matching entry.
304 */
305 die->die_ab = NULL;
306 for (ab = cu->cu_abbrev_hash; ab != NULL; ab = ab->ab_hh.next) {
307 if (die->die_tag != ab->ab_tag)
308 continue;
309 if (ab->ab_children == DW_CHILDREN_no && die->die_child != NULL)
310 continue;
311 if (ab->ab_children == DW_CHILDREN_yes &&
312 die->die_child == NULL)
313 continue;
314 at = STAILQ_FIRST(&die->die_attr);
315 ad = STAILQ_FIRST(&ab->ab_attrdef);
316 match = 1;
317 while (at != NULL && ad != NULL) {
318 if (at->at_attrib != ad->ad_attrib ||
319 at->at_form != ad->ad_form) {
320 match = 0;
321 break;
322 }
323 at = STAILQ_NEXT(at, at_next);
324 ad = STAILQ_NEXT(ad, ad_next);
325 }
326 if ((at == NULL && ad != NULL) || (at != NULL && ad == NULL))
327 match = 0;
328 if (match) {
329 die->die_ab = ab;
330 break;
331 }
332 }
333
334 /*
335 * Create a new abbrev entry if we can not reuse any existing one.
336 */
337 if (die->die_ab == NULL) {
338 ret = _dwarf_abbrev_add(cu, ++cu->cu_abbrev_cnt, die->die_tag,
339 die->die_child != NULL ? DW_CHILDREN_yes : DW_CHILDREN_no,
340 0, &ab, error);
341 if (ret != DW_DLE_NONE)
342 return (ret);
343 STAILQ_FOREACH(at, &die->die_attr, at_next) {
344 ret = _dwarf_attrdef_add(dbg, ab, at->at_attrib,
345 at->at_form, 0, NULL, error);
346 if (ret != DW_DLE_NONE)
347 return (ret);
348 }
349 die->die_ab = ab;
350 }
351
352 die->die_offset = ds->ds_size;
353
354 /*
355 * Transform the DIE to bytes stream.
356 */
357 ret = _dwarf_write_uleb128_alloc(&ds->ds_data, &ds->ds_cap,
358 &ds->ds_size, die->die_ab->ab_entry, error);
359 if (ret != DW_DLE_NONE)
360 return (ret);
361
362 attr_gen:
363
364 /* Transform the attributes of this DIE. */
365 ret = _dwarf_attr_gen(dbg, ds, drs, cu, die, pass2, error);
366 if (ret != DW_DLE_NONE)
367 return (ret);
368
369 /* Proceed to child DIE. */
370 if (die->die_child != NULL) {
371 ret = _dwarf_die_gen_recursive(dbg, cu, drs, die->die_child,
372 pass2, error);
373 if (ret != DW_DLE_NONE)
374 return (ret);
375 }
376
377 /* Proceed to sibling DIE. */
378 if (die->die_right != NULL) {
379 ret = _dwarf_die_gen_recursive(dbg, cu, drs, die->die_right,
380 pass2, error);
381 if (ret != DW_DLE_NONE)
382 return (ret);
383 }
384
385 /* Write a null DIE indicating the end of current level. */
386 if (die->die_right == NULL) {
387 ret = _dwarf_write_uleb128_alloc(&ds->ds_data, &ds->ds_cap,
388 &ds->ds_size, 0, error);
389 if (ret != DW_DLE_NONE)
390 return (ret);
391 }
392
393 return (DW_DLE_NONE);
394 }
395
396 int
_dwarf_die_gen(Dwarf_P_Debug dbg,Dwarf_CU cu,Dwarf_Rel_Section drs,Dwarf_Error * error)397 _dwarf_die_gen(Dwarf_P_Debug dbg, Dwarf_CU cu, Dwarf_Rel_Section drs,
398 Dwarf_Error *error)
399 {
400 Dwarf_Abbrev ab, tab;
401 Dwarf_AttrDef ad, tad;
402 Dwarf_Die die;
403 int ret;
404
405 assert(dbg != NULL && cu != NULL);
406 assert(dbg->dbgp_root_die != NULL);
407
408 die = dbg->dbgp_root_die;
409
410 /*
411 * Insert a DW_AT_stmt_list attribute into root DIE, if there are
412 * line number information.
413 */
414 if (!STAILQ_EMPTY(&dbg->dbgp_lineinfo->li_lnlist))
415 RCHECK(_dwarf_add_AT_dataref(dbg, die, DW_AT_stmt_list, 0, 0,
416 ".debug_line", NULL, error));
417
418 RCHECK(_dwarf_die_gen_recursive(dbg, cu, drs, die, 0, error));
419
420 if (cu->cu_pass2)
421 RCHECK(_dwarf_die_gen_recursive(dbg, cu, drs, die, 1, error));
422
423 return (DW_DLE_NONE);
424
425 gen_fail:
426
427 HASH_ITER(ab_hh, cu->cu_abbrev_hash, ab, tab) {
428 HASH_DELETE(ab_hh, cu->cu_abbrev_hash, ab);
429 STAILQ_FOREACH_SAFE(ad, &ab->ab_attrdef, ad_next, tad) {
430 STAILQ_REMOVE(&ab->ab_attrdef, ad, _Dwarf_AttrDef,
431 ad_next);
432 free(ad);
433 }
434 free(ab);
435 }
436
437 return (ret);
438 }
439
440 void
_dwarf_die_pro_cleanup(Dwarf_P_Debug dbg)441 _dwarf_die_pro_cleanup(Dwarf_P_Debug dbg)
442 {
443 Dwarf_P_Die die, tdie;
444 Dwarf_P_Attribute at, tat;
445
446 assert(dbg != NULL && dbg->dbg_mode == DW_DLC_WRITE);
447
448 STAILQ_FOREACH_SAFE(die, &dbg->dbgp_dielist, die_pro_next, tdie) {
449 STAILQ_FOREACH_SAFE(at, &die->die_attr, at_next, tat) {
450 STAILQ_REMOVE(&die->die_attr, at, _Dwarf_Attribute,
451 at_next);
452 free(at);
453 }
454 free(die);
455 }
456 }
457