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1/*
2 * dwarf-aux.c : libdw auxiliary interfaces
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 */
19
20#include <errno.h>
21#include <inttypes.h>
22#include <stdbool.h>
23#include "util.h"
24#include "debug.h"
25#include "dwarf-aux.h"
26#include "string2.h"
27
28/**
29 * cu_find_realpath - Find the realpath of the target file
30 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
31 * @fname: The tail filename of the target file
32 *
33 * Find the real(long) path of @fname in @cu_die.
34 */
35const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
36{
37 Dwarf_Files *files;
38 size_t nfiles, i;
39 const char *src = NULL;
40 int ret;
41
42 if (!fname)
43 return NULL;
44
45 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
46 if (ret != 0)
47 return NULL;
48
49 for (i = 0; i < nfiles; i++) {
50 src = dwarf_filesrc(files, i, NULL, NULL);
51 if (strtailcmp(src, fname) == 0)
52 break;
53 }
54 if (i == nfiles)
55 return NULL;
56 return src;
57}
58
59/**
60 * cu_get_comp_dir - Get the path of compilation directory
61 * @cu_die: a CU DIE
62 *
63 * Get the path of compilation directory of given @cu_die.
64 * Since this depends on DW_AT_comp_dir, older gcc will not
65 * embedded it. In that case, this returns NULL.
66 */
67const char *cu_get_comp_dir(Dwarf_Die *cu_die)
68{
69 Dwarf_Attribute attr;
70 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
71 return NULL;
72 return dwarf_formstring(&attr);
73}
74
75/**
76 * cu_find_lineinfo - Get a line number and file name for given address
77 * @cu_die: a CU DIE
78 * @addr: An address
79 * @fname: a pointer which returns the file name string
80 * @lineno: a pointer which returns the line number
81 *
82 * Find a line number and file name for @addr in @cu_die.
83 */
84int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
85 const char **fname, int *lineno)
86{
87 Dwarf_Line *line;
88 Dwarf_Addr laddr;
89
90 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
91 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
92 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
93 *fname = dwarf_linesrc(line, NULL, NULL);
94 if (!*fname)
95 /* line number is useless without filename */
96 *lineno = 0;
97 }
98
99 return *lineno ?: -ENOENT;
100}
101
102static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
103
104/**
105 * cu_walk_functions_at - Walk on function DIEs at given address
106 * @cu_die: A CU DIE
107 * @addr: An address
108 * @callback: A callback which called with found DIEs
109 * @data: A user data
110 *
111 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
112 * should be subprogram or inlined-subroutines.
113 */
114int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
115 int (*callback)(Dwarf_Die *, void *), void *data)
116{
117 Dwarf_Die die_mem;
118 Dwarf_Die *sc_die;
119 int ret = -ENOENT;
120
121 /* Inlined function could be recursive. Trace it until fail */
122 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
123 sc_die != NULL;
124 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
125 &die_mem)) {
126 ret = callback(sc_die, data);
127 if (ret)
128 break;
129 }
130
131 return ret;
132
133}
134
135/**
136 * die_get_linkage_name - Get the linkage name of the object
137 * @dw_die: A DIE of the object
138 *
139 * Get the linkage name attiribute of given @dw_die.
140 * For C++ binary, the linkage name will be the mangled symbol.
141 */
142const char *die_get_linkage_name(Dwarf_Die *dw_die)
143{
144 Dwarf_Attribute attr;
145
146 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
147 return NULL;
148 return dwarf_formstring(&attr);
149}
150
151/**
152 * die_compare_name - Compare diename and tname
153 * @dw_die: a DIE
154 * @tname: a string of target name
155 *
156 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
157 */
158bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
159{
160 const char *name;
161
162 name = dwarf_diename(dw_die);
163 return name ? (strcmp(tname, name) == 0) : false;
164}
165
166/**
167 * die_match_name - Match diename/linkage name and glob
168 * @dw_die: a DIE
169 * @glob: a string of target glob pattern
170 *
171 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
172 * This also match linkage name.
173 */
174bool die_match_name(Dwarf_Die *dw_die, const char *glob)
175{
176 const char *name;
177
178 name = dwarf_diename(dw_die);
179 if (name && strglobmatch(name, glob))
180 return true;
181 /* fall back to check linkage name */
182 name = die_get_linkage_name(dw_die);
183 if (name && strglobmatch(name, glob))
184 return true;
185
186 return false;
187}
188
189/**
190 * die_get_call_lineno - Get callsite line number of inline-function instance
191 * @in_die: a DIE of an inlined function instance
192 *
193 * Get call-site line number of @in_die. This means from where the inline
194 * function is called.
195 */
196int die_get_call_lineno(Dwarf_Die *in_die)
197{
198 Dwarf_Attribute attr;
199 Dwarf_Word ret;
200
201 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
202 return -ENOENT;
203
204 dwarf_formudata(&attr, &ret);
205 return (int)ret;
206}
207
208/**
209 * die_get_type - Get type DIE
210 * @vr_die: a DIE of a variable
211 * @die_mem: where to store a type DIE
212 *
213 * Get a DIE of the type of given variable (@vr_die), and store
214 * it to die_mem. Return NULL if fails to get a type DIE.
215 */
216Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
217{
218 Dwarf_Attribute attr;
219
220 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
221 dwarf_formref_die(&attr, die_mem))
222 return die_mem;
223 else
224 return NULL;
225}
226
227/* Get a type die, but skip qualifiers */
228static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
229{
230 int tag;
231
232 do {
233 vr_die = die_get_type(vr_die, die_mem);
234 if (!vr_die)
235 break;
236 tag = dwarf_tag(vr_die);
237 } while (tag == DW_TAG_const_type ||
238 tag == DW_TAG_restrict_type ||
239 tag == DW_TAG_volatile_type ||
240 tag == DW_TAG_shared_type);
241
242 return vr_die;
243}
244
245/**
246 * die_get_real_type - Get a type die, but skip qualifiers and typedef
247 * @vr_die: a DIE of a variable
248 * @die_mem: where to store a type DIE
249 *
250 * Get a DIE of the type of given variable (@vr_die), and store
251 * it to die_mem. Return NULL if fails to get a type DIE.
252 * If the type is qualifiers (e.g. const) or typedef, this skips it
253 * and tries to find real type (structure or basic types, e.g. int).
254 */
255Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
256{
257 do {
258 vr_die = __die_get_real_type(vr_die, die_mem);
259 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
260
261 return vr_die;
262}
263
264/* Get attribute and translate it as a udata */
265static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
266 Dwarf_Word *result)
267{
268 Dwarf_Attribute attr;
269
270 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
271 dwarf_formudata(&attr, result) != 0)
272 return -ENOENT;
273
274 return 0;
275}
276
277/* Get attribute and translate it as a sdata */
278static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
279 Dwarf_Sword *result)
280{
281 Dwarf_Attribute attr;
282
283 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
284 dwarf_formsdata(&attr, result) != 0)
285 return -ENOENT;
286
287 return 0;
288}
289
290/**
291 * die_is_signed_type - Check whether a type DIE is signed or not
292 * @tp_die: a DIE of a type
293 *
294 * Get the encoding of @tp_die and return true if the encoding
295 * is signed.
296 */
297bool die_is_signed_type(Dwarf_Die *tp_die)
298{
299 Dwarf_Word ret;
300
301 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
302 return false;
303
304 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
305 ret == DW_ATE_signed_fixed);
306}
307
308/**
309 * die_is_func_def - Ensure that this DIE is a subprogram and definition
310 * @dw_die: a DIE
311 *
312 * Ensure that this DIE is a subprogram and NOT a declaration. This
313 * returns true if @dw_die is a function definition.
314 **/
315bool die_is_func_def(Dwarf_Die *dw_die)
316{
317 Dwarf_Attribute attr;
318
319 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
320 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
321}
322
323/**
324 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
325 * @dw_die: a DIE
326 *
327 * Ensure that this DIE is an instance (which has an entry address).
328 * This returns true if @dw_die is a function instance. If not, you need to
329 * call die_walk_instances() to find actual instances.
330 **/
331bool die_is_func_instance(Dwarf_Die *dw_die)
332{
333 Dwarf_Addr tmp;
334
335 /* Actually gcc optimizes non-inline as like as inlined */
336 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
337}
338/**
339 * die_get_data_member_location - Get the data-member offset
340 * @mb_die: a DIE of a member of a data structure
341 * @offs: The offset of the member in the data structure
342 *
343 * Get the offset of @mb_die in the data structure including @mb_die, and
344 * stores result offset to @offs. If any error occurs this returns errno.
345 */
346int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
347{
348 Dwarf_Attribute attr;
349 Dwarf_Op *expr;
350 size_t nexpr;
351 int ret;
352
353 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
354 return -ENOENT;
355
356 if (dwarf_formudata(&attr, offs) != 0) {
357 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
358 ret = dwarf_getlocation(&attr, &expr, &nexpr);
359 if (ret < 0 || nexpr == 0)
360 return -ENOENT;
361
362 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
363 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
364 expr[0].atom, nexpr);
365 return -ENOTSUP;
366 }
367 *offs = (Dwarf_Word)expr[0].number;
368 }
369 return 0;
370}
371
372/* Get the call file index number in CU DIE */
373static int die_get_call_fileno(Dwarf_Die *in_die)
374{
375 Dwarf_Sword idx;
376
377 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
378 return (int)idx;
379 else
380 return -ENOENT;
381}
382
383/* Get the declared file index number in CU DIE */
384static int die_get_decl_fileno(Dwarf_Die *pdie)
385{
386 Dwarf_Sword idx;
387
388 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
389 return (int)idx;
390 else
391 return -ENOENT;
392}
393
394/**
395 * die_get_call_file - Get callsite file name of inlined function instance
396 * @in_die: a DIE of an inlined function instance
397 *
398 * Get call-site file name of @in_die. This means from which file the inline
399 * function is called.
400 */
401const char *die_get_call_file(Dwarf_Die *in_die)
402{
403 Dwarf_Die cu_die;
404 Dwarf_Files *files;
405 int idx;
406
407 idx = die_get_call_fileno(in_die);
408 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
409 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
410 return NULL;
411
412 return dwarf_filesrc(files, idx, NULL, NULL);
413}
414
415
416/**
417 * die_find_child - Generic DIE search function in DIE tree
418 * @rt_die: a root DIE
419 * @callback: a callback function
420 * @data: a user data passed to the callback function
421 * @die_mem: a buffer for result DIE
422 *
423 * Trace DIE tree from @rt_die and call @callback for each child DIE.
424 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
425 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
426 * this continues to trace the tree. Optionally, @callback can return
427 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
428 * the children and trace only the siblings respectively.
429 * Returns NULL if @callback can't find any appropriate DIE.
430 */
431Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
432 int (*callback)(Dwarf_Die *, void *),
433 void *data, Dwarf_Die *die_mem)
434{
435 Dwarf_Die child_die;
436 int ret;
437
438 ret = dwarf_child(rt_die, die_mem);
439 if (ret != 0)
440 return NULL;
441
442 do {
443 ret = callback(die_mem, data);
444 if (ret == DIE_FIND_CB_END)
445 return die_mem;
446
447 if ((ret & DIE_FIND_CB_CHILD) &&
448 die_find_child(die_mem, callback, data, &child_die)) {
449 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
450 return die_mem;
451 }
452 } while ((ret & DIE_FIND_CB_SIBLING) &&
453 dwarf_siblingof(die_mem, die_mem) == 0);
454
455 return NULL;
456}
457
458struct __addr_die_search_param {
459 Dwarf_Addr addr;
460 Dwarf_Die *die_mem;
461};
462
463static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
464{
465 struct __addr_die_search_param *ad = data;
466 Dwarf_Addr addr = 0;
467
468 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
469 !dwarf_highpc(fn_die, &addr) &&
470 addr == ad->addr) {
471 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
472 return DWARF_CB_ABORT;
473 }
474 return DWARF_CB_OK;
475}
476
477/**
478 * die_find_tailfunc - Search for a non-inlined function with tail call at
479 * given address
480 * @cu_die: a CU DIE which including @addr
481 * @addr: target address
482 * @die_mem: a buffer for result DIE
483 *
484 * Search for a non-inlined function DIE with tail call at @addr. Stores the
485 * DIE to @die_mem and returns it if found. Returns NULL if failed.
486 */
487Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
488 Dwarf_Die *die_mem)
489{
490 struct __addr_die_search_param ad;
491 ad.addr = addr;
492 ad.die_mem = die_mem;
493 /* dwarf_getscopes can't find subprogram. */
494 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
495 return NULL;
496 else
497 return die_mem;
498}
499
500/* die_find callback for non-inlined function search */
501static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
502{
503 struct __addr_die_search_param *ad = data;
504
505 /*
506 * Since a declaration entry doesn't has given pc, this always returns
507 * function definition entry.
508 */
509 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
510 dwarf_haspc(fn_die, ad->addr)) {
511 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
512 return DWARF_CB_ABORT;
513 }
514 return DWARF_CB_OK;
515}
516
517/**
518 * die_find_realfunc - Search a non-inlined function at given address
519 * @cu_die: a CU DIE which including @addr
520 * @addr: target address
521 * @die_mem: a buffer for result DIE
522 *
523 * Search a non-inlined function DIE which includes @addr. Stores the
524 * DIE to @die_mem and returns it if found. Returns NULL if failed.
525 */
526Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
527 Dwarf_Die *die_mem)
528{
529 struct __addr_die_search_param ad;
530 ad.addr = addr;
531 ad.die_mem = die_mem;
532 /* dwarf_getscopes can't find subprogram. */
533 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
534 return NULL;
535 else
536 return die_mem;
537}
538
539/* die_find callback for inline function search */
540static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
541{
542 Dwarf_Addr *addr = data;
543
544 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
545 dwarf_haspc(die_mem, *addr))
546 return DIE_FIND_CB_END;
547
548 return DIE_FIND_CB_CONTINUE;
549}
550
551/**
552 * die_find_top_inlinefunc - Search the top inlined function at given address
553 * @sp_die: a subprogram DIE which including @addr
554 * @addr: target address
555 * @die_mem: a buffer for result DIE
556 *
557 * Search an inlined function DIE which includes @addr. Stores the
558 * DIE to @die_mem and returns it if found. Returns NULL if failed.
559 * Even if several inlined functions are expanded recursively, this
560 * doesn't trace it down, and returns the topmost one.
561 */
562Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
563 Dwarf_Die *die_mem)
564{
565 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
566}
567
568/**
569 * die_find_inlinefunc - Search an inlined function at given address
570 * @sp_die: a subprogram DIE which including @addr
571 * @addr: target address
572 * @die_mem: a buffer for result DIE
573 *
574 * Search an inlined function DIE which includes @addr. Stores the
575 * DIE to @die_mem and returns it if found. Returns NULL if failed.
576 * If several inlined functions are expanded recursively, this trace
577 * it down and returns deepest one.
578 */
579Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
580 Dwarf_Die *die_mem)
581{
582 Dwarf_Die tmp_die;
583
584 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
585 if (!sp_die)
586 return NULL;
587
588 /* Inlined function could be recursive. Trace it until fail */
589 while (sp_die) {
590 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
591 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
592 &tmp_die);
593 }
594
595 return die_mem;
596}
597
598struct __instance_walk_param {
599 void *addr;
600 int (*callback)(Dwarf_Die *, void *);
601 void *data;
602 int retval;
603};
604
605static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
606{
607 struct __instance_walk_param *iwp = data;
608 Dwarf_Attribute attr_mem;
609 Dwarf_Die origin_mem;
610 Dwarf_Attribute *attr;
611 Dwarf_Die *origin;
612 int tmp;
613
614 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
615 if (attr == NULL)
616 return DIE_FIND_CB_CONTINUE;
617
618 origin = dwarf_formref_die(attr, &origin_mem);
619 if (origin == NULL || origin->addr != iwp->addr)
620 return DIE_FIND_CB_CONTINUE;
621
622 /* Ignore redundant instances */
623 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
624 dwarf_decl_line(origin, &tmp);
625 if (die_get_call_lineno(inst) == tmp) {
626 tmp = die_get_decl_fileno(origin);
627 if (die_get_call_fileno(inst) == tmp)
628 return DIE_FIND_CB_CONTINUE;
629 }
630 }
631
632 iwp->retval = iwp->callback(inst, iwp->data);
633
634 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
635}
636
637/**
638 * die_walk_instances - Walk on instances of given DIE
639 * @or_die: an abstract original DIE
640 * @callback: a callback function which is called with instance DIE
641 * @data: user data
642 *
643 * Walk on the instances of give @in_die. @in_die must be an inlined function
644 * declartion. This returns the return value of @callback if it returns
645 * non-zero value, or -ENOENT if there is no instance.
646 */
647int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
648 void *data)
649{
650 Dwarf_Die cu_die;
651 Dwarf_Die die_mem;
652 struct __instance_walk_param iwp = {
653 .addr = or_die->addr,
654 .callback = callback,
655 .data = data,
656 .retval = -ENOENT,
657 };
658
659 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
660 return -ENOENT;
661
662 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
663
664 return iwp.retval;
665}
666
667/* Line walker internal parameters */
668struct __line_walk_param {
669 bool recursive;
670 line_walk_callback_t callback;
671 void *data;
672 int retval;
673};
674
675static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
676{
677 struct __line_walk_param *lw = data;
678 Dwarf_Addr addr = 0;
679 const char *fname;
680 int lineno;
681
682 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
683 fname = die_get_call_file(in_die);
684 lineno = die_get_call_lineno(in_die);
685 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
686 lw->retval = lw->callback(fname, lineno, addr, lw->data);
687 if (lw->retval != 0)
688 return DIE_FIND_CB_END;
689 }
690 }
691 if (!lw->recursive)
692 /* Don't need to search recursively */
693 return DIE_FIND_CB_SIBLING;
694
695 if (addr) {
696 fname = dwarf_decl_file(in_die);
697 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
698 lw->retval = lw->callback(fname, lineno, addr, lw->data);
699 if (lw->retval != 0)
700 return DIE_FIND_CB_END;
701 }
702 }
703
704 /* Continue to search nested inlined function call-sites */
705 return DIE_FIND_CB_CONTINUE;
706}
707
708/* Walk on lines of blocks included in given DIE */
709static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
710 line_walk_callback_t callback, void *data)
711{
712 struct __line_walk_param lw = {
713 .recursive = recursive,
714 .callback = callback,
715 .data = data,
716 .retval = 0,
717 };
718 Dwarf_Die die_mem;
719 Dwarf_Addr addr;
720 const char *fname;
721 int lineno;
722
723 /* Handle function declaration line */
724 fname = dwarf_decl_file(sp_die);
725 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
726 dwarf_entrypc(sp_die, &addr) == 0) {
727 lw.retval = callback(fname, lineno, addr, data);
728 if (lw.retval != 0)
729 goto done;
730 }
731 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
732done:
733 return lw.retval;
734}
735
736static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
737{
738 struct __line_walk_param *lw = data;
739
740 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
741 if (lw->retval != 0)
742 return DWARF_CB_ABORT;
743
744 return DWARF_CB_OK;
745}
746
747/**
748 * die_walk_lines - Walk on lines inside given DIE
749 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
750 * @callback: callback routine
751 * @data: user data
752 *
753 * Walk on all lines inside given @rt_die and call @callback on each line.
754 * If the @rt_die is a function, walk only on the lines inside the function,
755 * otherwise @rt_die must be a CU DIE.
756 * Note that this walks not only dwarf line list, but also function entries
757 * and inline call-site.
758 */
759int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
760{
761 Dwarf_Lines *lines;
762 Dwarf_Line *line;
763 Dwarf_Addr addr;
764 const char *fname, *decf = NULL;
765 int lineno, ret = 0;
766 int decl = 0, inl;
767 Dwarf_Die die_mem, *cu_die;
768 size_t nlines, i;
769
770 /* Get the CU die */
771 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
772 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
773 dwarf_decl_line(rt_die, &decl);
774 decf = dwarf_decl_file(rt_die);
775 } else
776 cu_die = rt_die;
777 if (!cu_die) {
778 pr_debug2("Failed to get CU from given DIE.\n");
779 return -EINVAL;
780 }
781
782 /* Get lines list in the CU */
783 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
784 pr_debug2("Failed to get source lines on this CU.\n");
785 return -ENOENT;
786 }
787 pr_debug2("Get %zd lines from this CU\n", nlines);
788
789 /* Walk on the lines on lines list */
790 for (i = 0; i < nlines; i++) {
791 line = dwarf_onesrcline(lines, i);
792 if (line == NULL ||
793 dwarf_lineno(line, &lineno) != 0 ||
794 dwarf_lineaddr(line, &addr) != 0) {
795 pr_debug2("Failed to get line info. "
796 "Possible error in debuginfo.\n");
797 continue;
798 }
799 /* Filter lines based on address */
800 if (rt_die != cu_die) {
801 /*
802 * Address filtering
803 * The line is included in given function, and
804 * no inline block includes it.
805 */
806 if (!dwarf_haspc(rt_die, addr))
807 continue;
808 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
809 dwarf_decl_line(&die_mem, &inl);
810 if (inl != decl ||
811 decf != dwarf_decl_file(&die_mem))
812 continue;
813 }
814 }
815 /* Get source line */
816 fname = dwarf_linesrc(line, NULL, NULL);
817
818 ret = callback(fname, lineno, addr, data);
819 if (ret != 0)
820 return ret;
821 }
822
823 /*
824 * Dwarf lines doesn't include function declarations and inlined
825 * subroutines. We have to check functions list or given function.
826 */
827 if (rt_die != cu_die)
828 /*
829 * Don't need walk functions recursively, because nested
830 * inlined functions don't have lines of the specified DIE.
831 */
832 ret = __die_walk_funclines(rt_die, false, callback, data);
833 else {
834 struct __line_walk_param param = {
835 .callback = callback,
836 .data = data,
837 .retval = 0,
838 };
839 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
840 ret = param.retval;
841 }
842
843 return ret;
844}
845
846struct __find_variable_param {
847 const char *name;
848 Dwarf_Addr addr;
849};
850
851static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
852{
853 struct __find_variable_param *fvp = data;
854 Dwarf_Attribute attr;
855 int tag;
856
857 tag = dwarf_tag(die_mem);
858 if ((tag == DW_TAG_formal_parameter ||
859 tag == DW_TAG_variable) &&
860 die_compare_name(die_mem, fvp->name) &&
861 /* Does the DIE have location information or external instance? */
862 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
863 dwarf_attr(die_mem, DW_AT_location, &attr)))
864 return DIE_FIND_CB_END;
865 if (dwarf_haspc(die_mem, fvp->addr))
866 return DIE_FIND_CB_CONTINUE;
867 else
868 return DIE_FIND_CB_SIBLING;
869}
870
871/**
872 * die_find_variable_at - Find a given name variable at given address
873 * @sp_die: a function DIE
874 * @name: variable name
875 * @addr: address
876 * @die_mem: a buffer for result DIE
877 *
878 * Find a variable DIE called @name at @addr in @sp_die.
879 */
880Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
881 Dwarf_Addr addr, Dwarf_Die *die_mem)
882{
883 struct __find_variable_param fvp = { .name = name, .addr = addr};
884
885 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
886 die_mem);
887}
888
889static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
890{
891 const char *name = data;
892
893 if (dwarf_tag(die_mem) == DW_TAG_member) {
894 if (die_compare_name(die_mem, name))
895 return DIE_FIND_CB_END;
896 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
897 Dwarf_Die type_die, tmp_die;
898 if (die_get_type(die_mem, &type_die) &&
899 die_find_member(&type_die, name, &tmp_die))
900 return DIE_FIND_CB_END;
901 }
902 }
903 return DIE_FIND_CB_SIBLING;
904}
905
906/**
907 * die_find_member - Find a given name member in a data structure
908 * @st_die: a data structure type DIE
909 * @name: member name
910 * @die_mem: a buffer for result DIE
911 *
912 * Find a member DIE called @name in @st_die.
913 */
914Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
915 Dwarf_Die *die_mem)
916{
917 return die_find_child(st_die, __die_find_member_cb, (void *)name,
918 die_mem);
919}
920
921/**
922 * die_get_typename - Get the name of given variable DIE
923 * @vr_die: a variable DIE
924 * @buf: a strbuf for result type name
925 *
926 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
927 * and Return -ENOENT if failed to find type name.
928 * Note that the result will stores typedef name if possible, and stores
929 * "*(function_type)" if the type is a function pointer.
930 */
931int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
932{
933 Dwarf_Die type;
934 int tag, ret;
935 const char *tmp = "";
936
937 if (__die_get_real_type(vr_die, &type) == NULL)
938 return -ENOENT;
939
940 tag = dwarf_tag(&type);
941 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
942 tmp = "*";
943 else if (tag == DW_TAG_subroutine_type) {
944 /* Function pointer */
945 return strbuf_add(buf, "(function_type)", 15);
946 } else {
947 if (!dwarf_diename(&type))
948 return -ENOENT;
949 if (tag == DW_TAG_union_type)
950 tmp = "union ";
951 else if (tag == DW_TAG_structure_type)
952 tmp = "struct ";
953 else if (tag == DW_TAG_enumeration_type)
954 tmp = "enum ";
955 /* Write a base name */
956 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
957 }
958 ret = die_get_typename(&type, buf);
959 return ret ? ret : strbuf_addstr(buf, tmp);
960}
961
962/**
963 * die_get_varname - Get the name and type of given variable DIE
964 * @vr_die: a variable DIE
965 * @buf: a strbuf for type and variable name
966 *
967 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
968 */
969int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
970{
971 int ret;
972
973 ret = die_get_typename(vr_die, buf);
974 if (ret < 0) {
975 pr_debug("Failed to get type, make it unknown.\n");
976 ret = strbuf_add(buf, " (unknown_type)", 14);
977 }
978
979 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
980}
981
982#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
983/**
984 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
985 * @sp_die: a subprogram DIE
986 * @vr_die: a variable DIE
987 * @buf: a strbuf for variable byte offset range
988 *
989 * Get the innermost scope range of @vr_die and stores it in @buf as
990 * "@<function_name+[NN-NN,NN-NN]>".
991 */
992static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
993 struct strbuf *buf)
994{
995 Dwarf_Die *scopes;
996 int count;
997 size_t offset = 0;
998 Dwarf_Addr base;
999 Dwarf_Addr start, end;
1000 Dwarf_Addr entry;
1001 int ret;
1002 bool first = true;
1003 const char *name;
1004
1005 ret = dwarf_entrypc(sp_die, &entry);
1006 if (ret)
1007 return ret;
1008
1009 name = dwarf_diename(sp_die);
1010 if (!name)
1011 return -ENOENT;
1012
1013 count = dwarf_getscopes_die(vr_die, &scopes);
1014
1015 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1016 if (count <= 1) {
1017 ret = -EINVAL;
1018 goto out;
1019 }
1020
1021 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1022 &start, &end)) > 0) {
1023 start -= entry;
1024 end -= entry;
1025
1026 if (first) {
1027 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1028 name, start, end);
1029 first = false;
1030 } else {
1031 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1032 start, end);
1033 }
1034 if (ret < 0)
1035 goto out;
1036 }
1037
1038 if (!first)
1039 ret = strbuf_add(buf, "]>", 2);
1040
1041out:
1042 free(scopes);
1043 return ret;
1044}
1045
1046/**
1047 * die_get_var_range - Get byte offset range of given variable DIE
1048 * @sp_die: a subprogram DIE
1049 * @vr_die: a variable DIE
1050 * @buf: a strbuf for type and variable name and byte offset range
1051 *
1052 * Get the byte offset range of @vr_die and stores it in @buf as
1053 * "@<function_name+[NN-NN,NN-NN]>".
1054 */
1055int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1056{
1057 int ret = 0;
1058 Dwarf_Addr base;
1059 Dwarf_Addr start, end;
1060 Dwarf_Addr entry;
1061 Dwarf_Op *op;
1062 size_t nops;
1063 size_t offset = 0;
1064 Dwarf_Attribute attr;
1065 bool first = true;
1066 const char *name;
1067
1068 ret = dwarf_entrypc(sp_die, &entry);
1069 if (ret)
1070 return ret;
1071
1072 name = dwarf_diename(sp_die);
1073 if (!name)
1074 return -ENOENT;
1075
1076 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1077 return -EINVAL;
1078
1079 while ((offset = dwarf_getlocations(&attr, offset, &base,
1080 &start, &end, &op, &nops)) > 0) {
1081 if (start == 0) {
1082 /* Single Location Descriptions */
1083 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1084 goto out;
1085 }
1086
1087 /* Location Lists */
1088 start -= entry;
1089 end -= entry;
1090 if (first) {
1091 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1092 name, start, end);
1093 first = false;
1094 } else {
1095 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1096 start, end);
1097 }
1098 if (ret < 0)
1099 goto out;
1100 }
1101
1102 if (!first)
1103 ret = strbuf_add(buf, "]>", 2);
1104out:
1105 return ret;
1106}
1107#else
1108int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1109 Dwarf_Die *vr_die __maybe_unused,
1110 struct strbuf *buf __maybe_unused)
1111{
1112 return -ENOTSUP;
1113}
1114#endif
1115
1116/*
1117 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1118 * @vr_die: a variable DIE
1119 */
1120static bool die_has_loclist(Dwarf_Die *vr_die)
1121{
1122 Dwarf_Attribute loc;
1123 int tag = dwarf_tag(vr_die);
1124
1125 if (tag != DW_TAG_formal_parameter &&
1126 tag != DW_TAG_variable)
1127 return false;
1128
1129 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1130 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1131}
1132
1133/*
1134 * die_is_optimized_target - Check if target program is compiled with
1135 * optimization
1136 * @cu_die: a CU DIE
1137 *
1138 * For any object in given CU whose DW_AT_location is a location list,
1139 * target program is compiled with optimization. This is applicable to
1140 * clang as well.
1141 */
1142bool die_is_optimized_target(Dwarf_Die *cu_die)
1143{
1144 Dwarf_Die tmp_die;
1145
1146 if (die_has_loclist(cu_die))
1147 return true;
1148
1149 if (!dwarf_child(cu_die, &tmp_die) &&
1150 die_is_optimized_target(&tmp_die))
1151 return true;
1152
1153 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1154 die_is_optimized_target(&tmp_die))
1155 return true;
1156
1157 return false;
1158}
1159
1160/*
1161 * die_search_idx - Search index of given line address
1162 * @lines: Line records of single CU
1163 * @nr_lines: Number of @lines
1164 * @addr: address we are looking for
1165 * @idx: index to be set by this function (return value)
1166 *
1167 * Search for @addr by looping over every lines of CU. If address
1168 * matches, set index of that line in @idx. Note that single source
1169 * line can have multiple line records. i.e. single source line can
1170 * have multiple index.
1171 */
1172static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1173 Dwarf_Addr addr, unsigned long *idx)
1174{
1175 unsigned long i;
1176 Dwarf_Addr tmp;
1177
1178 for (i = 0; i < nr_lines; i++) {
1179 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1180 return false;
1181
1182 if (tmp == addr) {
1183 *idx = i;
1184 return true;
1185 }
1186 }
1187 return false;
1188}
1189
1190/*
1191 * die_get_postprologue_addr - Search next address after function prologue
1192 * @entrypc_idx: entrypc index
1193 * @lines: Line records of single CU
1194 * @nr_lines: Number of @lines
1195 * @hignpc: high PC address of function
1196 * @postprologue_addr: Next address after function prologue (return value)
1197 *
1198 * Look for prologue-end marker. If there is no explicit marker, return
1199 * address of next line record or next source line.
1200 */
1201static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1202 Dwarf_Lines *lines,
1203 unsigned long nr_lines,
1204 Dwarf_Addr highpc,
1205 Dwarf_Addr *postprologue_addr)
1206{
1207 unsigned long i;
1208 int entrypc_lno, lno;
1209 Dwarf_Line *line;
1210 Dwarf_Addr addr;
1211 bool p_end;
1212
1213 /* entrypc_lno is actual source line number */
1214 line = dwarf_onesrcline(lines, entrypc_idx);
1215 if (dwarf_lineno(line, &entrypc_lno))
1216 return false;
1217
1218 for (i = entrypc_idx; i < nr_lines; i++) {
1219 line = dwarf_onesrcline(lines, i);
1220
1221 if (dwarf_lineaddr(line, &addr) ||
1222 dwarf_lineno(line, &lno) ||
1223 dwarf_lineprologueend(line, &p_end))
1224 return false;
1225
1226 /* highpc is exclusive. [entrypc,highpc) */
1227 if (addr >= highpc)
1228 break;
1229
1230 /* clang supports prologue-end marker */
1231 if (p_end)
1232 break;
1233
1234 /* Actual next line in source */
1235 if (lno != entrypc_lno)
1236 break;
1237
1238 /*
1239 * Single source line can have multiple line records.
1240 * For Example,
1241 * void foo() { printf("hello\n"); }
1242 * contains two line records. One points to declaration and
1243 * other points to printf() line. Variable 'lno' won't get
1244 * incremented in this case but 'i' will.
1245 */
1246 if (i != entrypc_idx)
1247 break;
1248 }
1249
1250 dwarf_lineaddr(line, postprologue_addr);
1251 if (*postprologue_addr >= highpc)
1252 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1253 postprologue_addr);
1254
1255 return true;
1256}
1257
1258/*
1259 * die_skip_prologue - Use next address after prologue as probe location
1260 * @sp_die: a subprogram DIE
1261 * @cu_die: a CU DIE
1262 * @entrypc: entrypc of the function
1263 *
1264 * Function prologue prepares stack and registers before executing function
1265 * logic. When target program is compiled without optimization, function
1266 * parameter information is only valid after prologue. When we probe entrypc
1267 * of the function, and try to record function parameter, it contains
1268 * garbage value.
1269 */
1270void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1271 Dwarf_Addr *entrypc)
1272{
1273 size_t nr_lines = 0;
1274 unsigned long entrypc_idx = 0;
1275 Dwarf_Lines *lines = NULL;
1276 Dwarf_Addr postprologue_addr;
1277 Dwarf_Addr highpc;
1278
1279 if (dwarf_highpc(sp_die, &highpc))
1280 return;
1281
1282 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1283 return;
1284
1285 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1286 return;
1287
1288 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1289 highpc, &postprologue_addr))
1290 return;
1291
1292 *entrypc = postprologue_addr;
1293}
1/*
2 * dwarf-aux.c : libdw auxiliary interfaces
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 */
19
20#include <stdbool.h>
21#include "util.h"
22#include "debug.h"
23#include "dwarf-aux.h"
24
25/**
26 * cu_find_realpath - Find the realpath of the target file
27 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
28 * @fname: The tail filename of the target file
29 *
30 * Find the real(long) path of @fname in @cu_die.
31 */
32const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
33{
34 Dwarf_Files *files;
35 size_t nfiles, i;
36 const char *src = NULL;
37 int ret;
38
39 if (!fname)
40 return NULL;
41
42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
43 if (ret != 0)
44 return NULL;
45
46 for (i = 0; i < nfiles; i++) {
47 src = dwarf_filesrc(files, i, NULL, NULL);
48 if (strtailcmp(src, fname) == 0)
49 break;
50 }
51 if (i == nfiles)
52 return NULL;
53 return src;
54}
55
56/**
57 * cu_get_comp_dir - Get the path of compilation directory
58 * @cu_die: a CU DIE
59 *
60 * Get the path of compilation directory of given @cu_die.
61 * Since this depends on DW_AT_comp_dir, older gcc will not
62 * embedded it. In that case, this returns NULL.
63 */
64const char *cu_get_comp_dir(Dwarf_Die *cu_die)
65{
66 Dwarf_Attribute attr;
67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
68 return NULL;
69 return dwarf_formstring(&attr);
70}
71
72/**
73 * cu_find_lineinfo - Get a line number and file name for given address
74 * @cu_die: a CU DIE
75 * @addr: An address
76 * @fname: a pointer which returns the file name string
77 * @lineno: a pointer which returns the line number
78 *
79 * Find a line number and file name for @addr in @cu_die.
80 */
81int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
82 const char **fname, int *lineno)
83{
84 Dwarf_Line *line;
85 Dwarf_Addr laddr;
86
87 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
88 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
89 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
90 *fname = dwarf_linesrc(line, NULL, NULL);
91 if (!*fname)
92 /* line number is useless without filename */
93 *lineno = 0;
94 }
95
96 return *lineno ?: -ENOENT;
97}
98
99static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
100
101/**
102 * cu_walk_functions_at - Walk on function DIEs at given address
103 * @cu_die: A CU DIE
104 * @addr: An address
105 * @callback: A callback which called with found DIEs
106 * @data: A user data
107 *
108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
109 * should be subprogram or inlined-subroutines.
110 */
111int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
112 int (*callback)(Dwarf_Die *, void *), void *data)
113{
114 Dwarf_Die die_mem;
115 Dwarf_Die *sc_die;
116 int ret = -ENOENT;
117
118 /* Inlined function could be recursive. Trace it until fail */
119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
120 sc_die != NULL;
121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
122 &die_mem)) {
123 ret = callback(sc_die, data);
124 if (ret)
125 break;
126 }
127
128 return ret;
129
130}
131
132/**
133 * die_compare_name - Compare diename and tname
134 * @dw_die: a DIE
135 * @tname: a string of target name
136 *
137 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
138 */
139bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
140{
141 const char *name;
142
143 name = dwarf_diename(dw_die);
144 return name ? (strcmp(tname, name) == 0) : false;
145}
146
147/**
148 * die_match_name - Match diename and glob
149 * @dw_die: a DIE
150 * @glob: a string of target glob pattern
151 *
152 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
153 */
154bool die_match_name(Dwarf_Die *dw_die, const char *glob)
155{
156 const char *name;
157
158 name = dwarf_diename(dw_die);
159 return name ? strglobmatch(name, glob) : false;
160}
161
162/**
163 * die_get_call_lineno - Get callsite line number of inline-function instance
164 * @in_die: a DIE of an inlined function instance
165 *
166 * Get call-site line number of @in_die. This means from where the inline
167 * function is called.
168 */
169int die_get_call_lineno(Dwarf_Die *in_die)
170{
171 Dwarf_Attribute attr;
172 Dwarf_Word ret;
173
174 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
175 return -ENOENT;
176
177 dwarf_formudata(&attr, &ret);
178 return (int)ret;
179}
180
181/**
182 * die_get_type - Get type DIE
183 * @vr_die: a DIE of a variable
184 * @die_mem: where to store a type DIE
185 *
186 * Get a DIE of the type of given variable (@vr_die), and store
187 * it to die_mem. Return NULL if fails to get a type DIE.
188 */
189Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
190{
191 Dwarf_Attribute attr;
192
193 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
194 dwarf_formref_die(&attr, die_mem))
195 return die_mem;
196 else
197 return NULL;
198}
199
200/* Get a type die, but skip qualifiers */
201static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
202{
203 int tag;
204
205 do {
206 vr_die = die_get_type(vr_die, die_mem);
207 if (!vr_die)
208 break;
209 tag = dwarf_tag(vr_die);
210 } while (tag == DW_TAG_const_type ||
211 tag == DW_TAG_restrict_type ||
212 tag == DW_TAG_volatile_type ||
213 tag == DW_TAG_shared_type);
214
215 return vr_die;
216}
217
218/**
219 * die_get_real_type - Get a type die, but skip qualifiers and typedef
220 * @vr_die: a DIE of a variable
221 * @die_mem: where to store a type DIE
222 *
223 * Get a DIE of the type of given variable (@vr_die), and store
224 * it to die_mem. Return NULL if fails to get a type DIE.
225 * If the type is qualifiers (e.g. const) or typedef, this skips it
226 * and tries to find real type (structure or basic types, e.g. int).
227 */
228Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
229{
230 do {
231 vr_die = __die_get_real_type(vr_die, die_mem);
232 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
233
234 return vr_die;
235}
236
237/* Get attribute and translate it as a udata */
238static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
239 Dwarf_Word *result)
240{
241 Dwarf_Attribute attr;
242
243 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
244 dwarf_formudata(&attr, result) != 0)
245 return -ENOENT;
246
247 return 0;
248}
249
250/* Get attribute and translate it as a sdata */
251static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
252 Dwarf_Sword *result)
253{
254 Dwarf_Attribute attr;
255
256 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
257 dwarf_formsdata(&attr, result) != 0)
258 return -ENOENT;
259
260 return 0;
261}
262
263/**
264 * die_is_signed_type - Check whether a type DIE is signed or not
265 * @tp_die: a DIE of a type
266 *
267 * Get the encoding of @tp_die and return true if the encoding
268 * is signed.
269 */
270bool die_is_signed_type(Dwarf_Die *tp_die)
271{
272 Dwarf_Word ret;
273
274 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
275 return false;
276
277 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
278 ret == DW_ATE_signed_fixed);
279}
280
281/**
282 * die_is_func_def - Ensure that this DIE is a subprogram and definition
283 * @dw_die: a DIE
284 *
285 * Ensure that this DIE is a subprogram and NOT a declaration. This
286 * returns true if @dw_die is a function definition.
287 **/
288bool die_is_func_def(Dwarf_Die *dw_die)
289{
290 Dwarf_Attribute attr;
291
292 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
293 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
294}
295
296/**
297 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
298 * @dw_die: a DIE
299 *
300 * Ensure that this DIE is an instance (which has an entry address).
301 * This returns true if @dw_die is a function instance. If not, you need to
302 * call die_walk_instances() to find actual instances.
303 **/
304bool die_is_func_instance(Dwarf_Die *dw_die)
305{
306 Dwarf_Addr tmp;
307
308 /* Actually gcc optimizes non-inline as like as inlined */
309 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
310}
311/**
312 * die_get_data_member_location - Get the data-member offset
313 * @mb_die: a DIE of a member of a data structure
314 * @offs: The offset of the member in the data structure
315 *
316 * Get the offset of @mb_die in the data structure including @mb_die, and
317 * stores result offset to @offs. If any error occurs this returns errno.
318 */
319int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
320{
321 Dwarf_Attribute attr;
322 Dwarf_Op *expr;
323 size_t nexpr;
324 int ret;
325
326 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
327 return -ENOENT;
328
329 if (dwarf_formudata(&attr, offs) != 0) {
330 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
331 ret = dwarf_getlocation(&attr, &expr, &nexpr);
332 if (ret < 0 || nexpr == 0)
333 return -ENOENT;
334
335 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
336 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
337 expr[0].atom, nexpr);
338 return -ENOTSUP;
339 }
340 *offs = (Dwarf_Word)expr[0].number;
341 }
342 return 0;
343}
344
345/* Get the call file index number in CU DIE */
346static int die_get_call_fileno(Dwarf_Die *in_die)
347{
348 Dwarf_Sword idx;
349
350 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
351 return (int)idx;
352 else
353 return -ENOENT;
354}
355
356/* Get the declared file index number in CU DIE */
357static int die_get_decl_fileno(Dwarf_Die *pdie)
358{
359 Dwarf_Sword idx;
360
361 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
362 return (int)idx;
363 else
364 return -ENOENT;
365}
366
367/**
368 * die_get_call_file - Get callsite file name of inlined function instance
369 * @in_die: a DIE of an inlined function instance
370 *
371 * Get call-site file name of @in_die. This means from which file the inline
372 * function is called.
373 */
374const char *die_get_call_file(Dwarf_Die *in_die)
375{
376 Dwarf_Die cu_die;
377 Dwarf_Files *files;
378 int idx;
379
380 idx = die_get_call_fileno(in_die);
381 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
382 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
383 return NULL;
384
385 return dwarf_filesrc(files, idx, NULL, NULL);
386}
387
388
389/**
390 * die_find_child - Generic DIE search function in DIE tree
391 * @rt_die: a root DIE
392 * @callback: a callback function
393 * @data: a user data passed to the callback function
394 * @die_mem: a buffer for result DIE
395 *
396 * Trace DIE tree from @rt_die and call @callback for each child DIE.
397 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
398 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
399 * this continues to trace the tree. Optionally, @callback can return
400 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
401 * the children and trace only the siblings respectively.
402 * Returns NULL if @callback can't find any appropriate DIE.
403 */
404Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
405 int (*callback)(Dwarf_Die *, void *),
406 void *data, Dwarf_Die *die_mem)
407{
408 Dwarf_Die child_die;
409 int ret;
410
411 ret = dwarf_child(rt_die, die_mem);
412 if (ret != 0)
413 return NULL;
414
415 do {
416 ret = callback(die_mem, data);
417 if (ret == DIE_FIND_CB_END)
418 return die_mem;
419
420 if ((ret & DIE_FIND_CB_CHILD) &&
421 die_find_child(die_mem, callback, data, &child_die)) {
422 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
423 return die_mem;
424 }
425 } while ((ret & DIE_FIND_CB_SIBLING) &&
426 dwarf_siblingof(die_mem, die_mem) == 0);
427
428 return NULL;
429}
430
431struct __addr_die_search_param {
432 Dwarf_Addr addr;
433 Dwarf_Die *die_mem;
434};
435
436static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
437{
438 struct __addr_die_search_param *ad = data;
439 Dwarf_Addr addr = 0;
440
441 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
442 !dwarf_highpc(fn_die, &addr) &&
443 addr == ad->addr) {
444 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
445 return DWARF_CB_ABORT;
446 }
447 return DWARF_CB_OK;
448}
449
450/**
451 * die_find_tailfunc - Search for a non-inlined function with tail call at
452 * given address
453 * @cu_die: a CU DIE which including @addr
454 * @addr: target address
455 * @die_mem: a buffer for result DIE
456 *
457 * Search for a non-inlined function DIE with tail call at @addr. Stores the
458 * DIE to @die_mem and returns it if found. Returns NULL if failed.
459 */
460Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
461 Dwarf_Die *die_mem)
462{
463 struct __addr_die_search_param ad;
464 ad.addr = addr;
465 ad.die_mem = die_mem;
466 /* dwarf_getscopes can't find subprogram. */
467 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
468 return NULL;
469 else
470 return die_mem;
471}
472
473/* die_find callback for non-inlined function search */
474static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
475{
476 struct __addr_die_search_param *ad = data;
477
478 /*
479 * Since a declaration entry doesn't has given pc, this always returns
480 * function definition entry.
481 */
482 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
483 dwarf_haspc(fn_die, ad->addr)) {
484 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
485 return DWARF_CB_ABORT;
486 }
487 return DWARF_CB_OK;
488}
489
490/**
491 * die_find_realfunc - Search a non-inlined function at given address
492 * @cu_die: a CU DIE which including @addr
493 * @addr: target address
494 * @die_mem: a buffer for result DIE
495 *
496 * Search a non-inlined function DIE which includes @addr. Stores the
497 * DIE to @die_mem and returns it if found. Returns NULL if failed.
498 */
499Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
500 Dwarf_Die *die_mem)
501{
502 struct __addr_die_search_param ad;
503 ad.addr = addr;
504 ad.die_mem = die_mem;
505 /* dwarf_getscopes can't find subprogram. */
506 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
507 return NULL;
508 else
509 return die_mem;
510}
511
512/* die_find callback for inline function search */
513static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
514{
515 Dwarf_Addr *addr = data;
516
517 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
518 dwarf_haspc(die_mem, *addr))
519 return DIE_FIND_CB_END;
520
521 return DIE_FIND_CB_CONTINUE;
522}
523
524/**
525 * die_find_top_inlinefunc - Search the top inlined function at given address
526 * @sp_die: a subprogram DIE which including @addr
527 * @addr: target address
528 * @die_mem: a buffer for result DIE
529 *
530 * Search an inlined function DIE which includes @addr. Stores the
531 * DIE to @die_mem and returns it if found. Returns NULL if failed.
532 * Even if several inlined functions are expanded recursively, this
533 * doesn't trace it down, and returns the topmost one.
534 */
535Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
536 Dwarf_Die *die_mem)
537{
538 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
539}
540
541/**
542 * die_find_inlinefunc - Search an inlined function at given address
543 * @sp_die: a subprogram DIE which including @addr
544 * @addr: target address
545 * @die_mem: a buffer for result DIE
546 *
547 * Search an inlined function DIE which includes @addr. Stores the
548 * DIE to @die_mem and returns it if found. Returns NULL if failed.
549 * If several inlined functions are expanded recursively, this trace
550 * it down and returns deepest one.
551 */
552Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
553 Dwarf_Die *die_mem)
554{
555 Dwarf_Die tmp_die;
556
557 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
558 if (!sp_die)
559 return NULL;
560
561 /* Inlined function could be recursive. Trace it until fail */
562 while (sp_die) {
563 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
564 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
565 &tmp_die);
566 }
567
568 return die_mem;
569}
570
571struct __instance_walk_param {
572 void *addr;
573 int (*callback)(Dwarf_Die *, void *);
574 void *data;
575 int retval;
576};
577
578static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
579{
580 struct __instance_walk_param *iwp = data;
581 Dwarf_Attribute attr_mem;
582 Dwarf_Die origin_mem;
583 Dwarf_Attribute *attr;
584 Dwarf_Die *origin;
585 int tmp;
586
587 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
588 if (attr == NULL)
589 return DIE_FIND_CB_CONTINUE;
590
591 origin = dwarf_formref_die(attr, &origin_mem);
592 if (origin == NULL || origin->addr != iwp->addr)
593 return DIE_FIND_CB_CONTINUE;
594
595 /* Ignore redundant instances */
596 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
597 dwarf_decl_line(origin, &tmp);
598 if (die_get_call_lineno(inst) == tmp) {
599 tmp = die_get_decl_fileno(origin);
600 if (die_get_call_fileno(inst) == tmp)
601 return DIE_FIND_CB_CONTINUE;
602 }
603 }
604
605 iwp->retval = iwp->callback(inst, iwp->data);
606
607 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
608}
609
610/**
611 * die_walk_instances - Walk on instances of given DIE
612 * @or_die: an abstract original DIE
613 * @callback: a callback function which is called with instance DIE
614 * @data: user data
615 *
616 * Walk on the instances of give @in_die. @in_die must be an inlined function
617 * declartion. This returns the return value of @callback if it returns
618 * non-zero value, or -ENOENT if there is no instance.
619 */
620int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
621 void *data)
622{
623 Dwarf_Die cu_die;
624 Dwarf_Die die_mem;
625 struct __instance_walk_param iwp = {
626 .addr = or_die->addr,
627 .callback = callback,
628 .data = data,
629 .retval = -ENOENT,
630 };
631
632 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
633 return -ENOENT;
634
635 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
636
637 return iwp.retval;
638}
639
640/* Line walker internal parameters */
641struct __line_walk_param {
642 bool recursive;
643 line_walk_callback_t callback;
644 void *data;
645 int retval;
646};
647
648static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
649{
650 struct __line_walk_param *lw = data;
651 Dwarf_Addr addr = 0;
652 const char *fname;
653 int lineno;
654
655 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
656 fname = die_get_call_file(in_die);
657 lineno = die_get_call_lineno(in_die);
658 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
659 lw->retval = lw->callback(fname, lineno, addr, lw->data);
660 if (lw->retval != 0)
661 return DIE_FIND_CB_END;
662 }
663 }
664 if (!lw->recursive)
665 /* Don't need to search recursively */
666 return DIE_FIND_CB_SIBLING;
667
668 if (addr) {
669 fname = dwarf_decl_file(in_die);
670 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
671 lw->retval = lw->callback(fname, lineno, addr, lw->data);
672 if (lw->retval != 0)
673 return DIE_FIND_CB_END;
674 }
675 }
676
677 /* Continue to search nested inlined function call-sites */
678 return DIE_FIND_CB_CONTINUE;
679}
680
681/* Walk on lines of blocks included in given DIE */
682static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
683 line_walk_callback_t callback, void *data)
684{
685 struct __line_walk_param lw = {
686 .recursive = recursive,
687 .callback = callback,
688 .data = data,
689 .retval = 0,
690 };
691 Dwarf_Die die_mem;
692 Dwarf_Addr addr;
693 const char *fname;
694 int lineno;
695
696 /* Handle function declaration line */
697 fname = dwarf_decl_file(sp_die);
698 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
699 dwarf_entrypc(sp_die, &addr) == 0) {
700 lw.retval = callback(fname, lineno, addr, data);
701 if (lw.retval != 0)
702 goto done;
703 }
704 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
705done:
706 return lw.retval;
707}
708
709static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
710{
711 struct __line_walk_param *lw = data;
712
713 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
714 if (lw->retval != 0)
715 return DWARF_CB_ABORT;
716
717 return DWARF_CB_OK;
718}
719
720/**
721 * die_walk_lines - Walk on lines inside given DIE
722 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
723 * @callback: callback routine
724 * @data: user data
725 *
726 * Walk on all lines inside given @rt_die and call @callback on each line.
727 * If the @rt_die is a function, walk only on the lines inside the function,
728 * otherwise @rt_die must be a CU DIE.
729 * Note that this walks not only dwarf line list, but also function entries
730 * and inline call-site.
731 */
732int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
733{
734 Dwarf_Lines *lines;
735 Dwarf_Line *line;
736 Dwarf_Addr addr;
737 const char *fname, *decf = NULL;
738 int lineno, ret = 0;
739 int decl = 0, inl;
740 Dwarf_Die die_mem, *cu_die;
741 size_t nlines, i;
742
743 /* Get the CU die */
744 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
745 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
746 dwarf_decl_line(rt_die, &decl);
747 decf = dwarf_decl_file(rt_die);
748 } else
749 cu_die = rt_die;
750 if (!cu_die) {
751 pr_debug2("Failed to get CU from given DIE.\n");
752 return -EINVAL;
753 }
754
755 /* Get lines list in the CU */
756 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
757 pr_debug2("Failed to get source lines on this CU.\n");
758 return -ENOENT;
759 }
760 pr_debug2("Get %zd lines from this CU\n", nlines);
761
762 /* Walk on the lines on lines list */
763 for (i = 0; i < nlines; i++) {
764 line = dwarf_onesrcline(lines, i);
765 if (line == NULL ||
766 dwarf_lineno(line, &lineno) != 0 ||
767 dwarf_lineaddr(line, &addr) != 0) {
768 pr_debug2("Failed to get line info. "
769 "Possible error in debuginfo.\n");
770 continue;
771 }
772 /* Filter lines based on address */
773 if (rt_die != cu_die) {
774 /*
775 * Address filtering
776 * The line is included in given function, and
777 * no inline block includes it.
778 */
779 if (!dwarf_haspc(rt_die, addr))
780 continue;
781 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
782 dwarf_decl_line(&die_mem, &inl);
783 if (inl != decl ||
784 decf != dwarf_decl_file(&die_mem))
785 continue;
786 }
787 }
788 /* Get source line */
789 fname = dwarf_linesrc(line, NULL, NULL);
790
791 ret = callback(fname, lineno, addr, data);
792 if (ret != 0)
793 return ret;
794 }
795
796 /*
797 * Dwarf lines doesn't include function declarations and inlined
798 * subroutines. We have to check functions list or given function.
799 */
800 if (rt_die != cu_die)
801 /*
802 * Don't need walk functions recursively, because nested
803 * inlined functions don't have lines of the specified DIE.
804 */
805 ret = __die_walk_funclines(rt_die, false, callback, data);
806 else {
807 struct __line_walk_param param = {
808 .callback = callback,
809 .data = data,
810 .retval = 0,
811 };
812 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
813 ret = param.retval;
814 }
815
816 return ret;
817}
818
819struct __find_variable_param {
820 const char *name;
821 Dwarf_Addr addr;
822};
823
824static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
825{
826 struct __find_variable_param *fvp = data;
827 Dwarf_Attribute attr;
828 int tag;
829
830 tag = dwarf_tag(die_mem);
831 if ((tag == DW_TAG_formal_parameter ||
832 tag == DW_TAG_variable) &&
833 die_compare_name(die_mem, fvp->name) &&
834 /* Does the DIE have location information or external instance? */
835 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
836 dwarf_attr(die_mem, DW_AT_location, &attr)))
837 return DIE_FIND_CB_END;
838 if (dwarf_haspc(die_mem, fvp->addr))
839 return DIE_FIND_CB_CONTINUE;
840 else
841 return DIE_FIND_CB_SIBLING;
842}
843
844/**
845 * die_find_variable_at - Find a given name variable at given address
846 * @sp_die: a function DIE
847 * @name: variable name
848 * @addr: address
849 * @die_mem: a buffer for result DIE
850 *
851 * Find a variable DIE called @name at @addr in @sp_die.
852 */
853Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
854 Dwarf_Addr addr, Dwarf_Die *die_mem)
855{
856 struct __find_variable_param fvp = { .name = name, .addr = addr};
857
858 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
859 die_mem);
860}
861
862static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
863{
864 const char *name = data;
865
866 if (dwarf_tag(die_mem) == DW_TAG_member) {
867 if (die_compare_name(die_mem, name))
868 return DIE_FIND_CB_END;
869 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
870 Dwarf_Die type_die, tmp_die;
871 if (die_get_type(die_mem, &type_die) &&
872 die_find_member(&type_die, name, &tmp_die))
873 return DIE_FIND_CB_END;
874 }
875 }
876 return DIE_FIND_CB_SIBLING;
877}
878
879/**
880 * die_find_member - Find a given name member in a data structure
881 * @st_die: a data structure type DIE
882 * @name: member name
883 * @die_mem: a buffer for result DIE
884 *
885 * Find a member DIE called @name in @st_die.
886 */
887Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
888 Dwarf_Die *die_mem)
889{
890 return die_find_child(st_die, __die_find_member_cb, (void *)name,
891 die_mem);
892}
893
894/**
895 * die_get_typename - Get the name of given variable DIE
896 * @vr_die: a variable DIE
897 * @buf: a strbuf for result type name
898 *
899 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
900 * and Return -ENOENT if failed to find type name.
901 * Note that the result will stores typedef name if possible, and stores
902 * "*(function_type)" if the type is a function pointer.
903 */
904int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
905{
906 Dwarf_Die type;
907 int tag, ret;
908 const char *tmp = "";
909
910 if (__die_get_real_type(vr_die, &type) == NULL)
911 return -ENOENT;
912
913 tag = dwarf_tag(&type);
914 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
915 tmp = "*";
916 else if (tag == DW_TAG_subroutine_type) {
917 /* Function pointer */
918 strbuf_add(buf, "(function_type)", 15);
919 return 0;
920 } else {
921 if (!dwarf_diename(&type))
922 return -ENOENT;
923 if (tag == DW_TAG_union_type)
924 tmp = "union ";
925 else if (tag == DW_TAG_structure_type)
926 tmp = "struct ";
927 else if (tag == DW_TAG_enumeration_type)
928 tmp = "enum ";
929 /* Write a base name */
930 strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
931 return 0;
932 }
933 ret = die_get_typename(&type, buf);
934 if (ret == 0)
935 strbuf_addstr(buf, tmp);
936
937 return ret;
938}
939
940/**
941 * die_get_varname - Get the name and type of given variable DIE
942 * @vr_die: a variable DIE
943 * @buf: a strbuf for type and variable name
944 *
945 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
946 */
947int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
948{
949 int ret;
950
951 ret = die_get_typename(vr_die, buf);
952 if (ret < 0) {
953 pr_debug("Failed to get type, make it unknown.\n");
954 strbuf_add(buf, " (unknown_type)", 14);
955 }
956
957 strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
958
959 return 0;
960}
961
962#ifdef HAVE_DWARF_GETLOCATIONS
963/**
964 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
965 * @sp_die: a subprogram DIE
966 * @vr_die: a variable DIE
967 * @buf: a strbuf for variable byte offset range
968 *
969 * Get the innermost scope range of @vr_die and stores it in @buf as
970 * "@<function_name+[NN-NN,NN-NN]>".
971 */
972static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
973 struct strbuf *buf)
974{
975 Dwarf_Die *scopes;
976 int count;
977 size_t offset = 0;
978 Dwarf_Addr base;
979 Dwarf_Addr start, end;
980 Dwarf_Addr entry;
981 int ret;
982 bool first = true;
983 const char *name;
984
985 ret = dwarf_entrypc(sp_die, &entry);
986 if (ret)
987 return ret;
988
989 name = dwarf_diename(sp_die);
990 if (!name)
991 return -ENOENT;
992
993 count = dwarf_getscopes_die(vr_die, &scopes);
994
995 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
996 if (count <= 1) {
997 ret = -EINVAL;
998 goto out;
999 }
1000
1001 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1002 &start, &end)) > 0) {
1003 start -= entry;
1004 end -= entry;
1005
1006 if (first) {
1007 strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1008 name, start, end);
1009 first = false;
1010 } else {
1011 strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1012 start, end);
1013 }
1014 }
1015
1016 if (!first)
1017 strbuf_add(buf, "]>", 2);
1018
1019out:
1020 free(scopes);
1021 return ret;
1022}
1023
1024/**
1025 * die_get_var_range - Get byte offset range of given variable DIE
1026 * @sp_die: a subprogram DIE
1027 * @vr_die: a variable DIE
1028 * @buf: a strbuf for type and variable name and byte offset range
1029 *
1030 * Get the byte offset range of @vr_die and stores it in @buf as
1031 * "@<function_name+[NN-NN,NN-NN]>".
1032 */
1033int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1034{
1035 int ret = 0;
1036 Dwarf_Addr base;
1037 Dwarf_Addr start, end;
1038 Dwarf_Addr entry;
1039 Dwarf_Op *op;
1040 size_t nops;
1041 size_t offset = 0;
1042 Dwarf_Attribute attr;
1043 bool first = true;
1044 const char *name;
1045
1046 ret = dwarf_entrypc(sp_die, &entry);
1047 if (ret)
1048 return ret;
1049
1050 name = dwarf_diename(sp_die);
1051 if (!name)
1052 return -ENOENT;
1053
1054 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1055 return -EINVAL;
1056
1057 while ((offset = dwarf_getlocations(
1058 &attr, offset, &base,
1059 &start, &end, &op, &nops)) > 0) {
1060 if (start == 0) {
1061 /* Single Location Descriptions */
1062 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1063 return ret;
1064 }
1065
1066 /* Location Lists */
1067 start -= entry;
1068 end -= entry;
1069 if (first) {
1070 strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1071 name, start, end);
1072 first = false;
1073 } else {
1074 strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1075 start, end);
1076 }
1077 }
1078
1079 if (!first)
1080 strbuf_add(buf, "]>", 2);
1081
1082 return ret;
1083}
1084#else
1085int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1086 Dwarf_Die *vr_die __maybe_unused,
1087 struct strbuf *buf __maybe_unused)
1088{
1089 return -ENOTSUP;
1090}
1091#endif