Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dwarf-aux.c : libdw auxiliary interfaces
4 */
5
6#include <errno.h>
7#include <inttypes.h>
8#include <stdbool.h>
9#include <stdlib.h>
10#include "debug.h"
11#include "dwarf-aux.h"
12#include "strbuf.h"
13#include "string2.h"
14
15/**
16 * cu_find_realpath - Find the realpath of the target file
17 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
18 * @fname: The tail filename of the target file
19 *
20 * Find the real(long) path of @fname in @cu_die.
21 */
22const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
23{
24 Dwarf_Files *files;
25 size_t nfiles, i;
26 const char *src = NULL;
27 int ret;
28
29 if (!fname)
30 return NULL;
31
32 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
33 if (ret != 0)
34 return NULL;
35
36 for (i = 0; i < nfiles; i++) {
37 src = dwarf_filesrc(files, i, NULL, NULL);
38 if (strtailcmp(src, fname) == 0)
39 break;
40 }
41 if (i == nfiles)
42 return NULL;
43 return src;
44}
45
46/**
47 * cu_get_comp_dir - Get the path of compilation directory
48 * @cu_die: a CU DIE
49 *
50 * Get the path of compilation directory of given @cu_die.
51 * Since this depends on DW_AT_comp_dir, older gcc will not
52 * embedded it. In that case, this returns NULL.
53 */
54const char *cu_get_comp_dir(Dwarf_Die *cu_die)
55{
56 Dwarf_Attribute attr;
57 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
58 return NULL;
59 return dwarf_formstring(&attr);
60}
61
62/**
63 * cu_find_lineinfo - Get a line number and file name for given address
64 * @cu_die: a CU DIE
65 * @addr: An address
66 * @fname: a pointer which returns the file name string
67 * @lineno: a pointer which returns the line number
68 *
69 * Find a line number and file name for @addr in @cu_die.
70 */
71int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
72 const char **fname, int *lineno)
73{
74 Dwarf_Line *line;
75 Dwarf_Addr laddr;
76
77 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
78 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
79 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
80 *fname = dwarf_linesrc(line, NULL, NULL);
81 if (!*fname)
82 /* line number is useless without filename */
83 *lineno = 0;
84 }
85
86 return *lineno ?: -ENOENT;
87}
88
89static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
90
91/**
92 * cu_walk_functions_at - Walk on function DIEs at given address
93 * @cu_die: A CU DIE
94 * @addr: An address
95 * @callback: A callback which called with found DIEs
96 * @data: A user data
97 *
98 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
99 * should be subprogram or inlined-subroutines.
100 */
101int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
102 int (*callback)(Dwarf_Die *, void *), void *data)
103{
104 Dwarf_Die die_mem;
105 Dwarf_Die *sc_die;
106 int ret = -ENOENT;
107
108 /* Inlined function could be recursive. Trace it until fail */
109 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
110 sc_die != NULL;
111 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
112 &die_mem)) {
113 ret = callback(sc_die, data);
114 if (ret)
115 break;
116 }
117
118 return ret;
119
120}
121
122/**
123 * die_get_linkage_name - Get the linkage name of the object
124 * @dw_die: A DIE of the object
125 *
126 * Get the linkage name attiribute of given @dw_die.
127 * For C++ binary, the linkage name will be the mangled symbol.
128 */
129const char *die_get_linkage_name(Dwarf_Die *dw_die)
130{
131 Dwarf_Attribute attr;
132
133 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
134 return NULL;
135 return dwarf_formstring(&attr);
136}
137
138/**
139 * die_compare_name - Compare diename and tname
140 * @dw_die: a DIE
141 * @tname: a string of target name
142 *
143 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
144 */
145bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
146{
147 const char *name;
148
149 name = dwarf_diename(dw_die);
150 return name ? (strcmp(tname, name) == 0) : false;
151}
152
153/**
154 * die_match_name - Match diename/linkage name and glob
155 * @dw_die: a DIE
156 * @glob: a string of target glob pattern
157 *
158 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
159 * This also match linkage name.
160 */
161bool die_match_name(Dwarf_Die *dw_die, const char *glob)
162{
163 const char *name;
164
165 name = dwarf_diename(dw_die);
166 if (name && strglobmatch(name, glob))
167 return true;
168 /* fall back to check linkage name */
169 name = die_get_linkage_name(dw_die);
170 if (name && strglobmatch(name, glob))
171 return true;
172
173 return false;
174}
175
176/**
177 * die_get_call_lineno - Get callsite line number of inline-function instance
178 * @in_die: a DIE of an inlined function instance
179 *
180 * Get call-site line number of @in_die. This means from where the inline
181 * function is called.
182 */
183int die_get_call_lineno(Dwarf_Die *in_die)
184{
185 Dwarf_Attribute attr;
186 Dwarf_Word ret;
187
188 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
189 return -ENOENT;
190
191 dwarf_formudata(&attr, &ret);
192 return (int)ret;
193}
194
195/**
196 * die_get_type - Get type DIE
197 * @vr_die: a DIE of a variable
198 * @die_mem: where to store a type DIE
199 *
200 * Get a DIE of the type of given variable (@vr_die), and store
201 * it to die_mem. Return NULL if fails to get a type DIE.
202 */
203Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
204{
205 Dwarf_Attribute attr;
206
207 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
208 dwarf_formref_die(&attr, die_mem))
209 return die_mem;
210 else
211 return NULL;
212}
213
214/* Get a type die, but skip qualifiers */
215static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
216{
217 int tag;
218
219 do {
220 vr_die = die_get_type(vr_die, die_mem);
221 if (!vr_die)
222 break;
223 tag = dwarf_tag(vr_die);
224 } while (tag == DW_TAG_const_type ||
225 tag == DW_TAG_restrict_type ||
226 tag == DW_TAG_volatile_type ||
227 tag == DW_TAG_shared_type);
228
229 return vr_die;
230}
231
232/**
233 * die_get_real_type - Get a type die, but skip qualifiers and typedef
234 * @vr_die: a DIE of a variable
235 * @die_mem: where to store a type DIE
236 *
237 * Get a DIE of the type of given variable (@vr_die), and store
238 * it to die_mem. Return NULL if fails to get a type DIE.
239 * If the type is qualifiers (e.g. const) or typedef, this skips it
240 * and tries to find real type (structure or basic types, e.g. int).
241 */
242Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
243{
244 do {
245 vr_die = __die_get_real_type(vr_die, die_mem);
246 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
247
248 return vr_die;
249}
250
251/* Get attribute and translate it as a udata */
252static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
253 Dwarf_Word *result)
254{
255 Dwarf_Attribute attr;
256
257 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
258 dwarf_formudata(&attr, result) != 0)
259 return -ENOENT;
260
261 return 0;
262}
263
264/* Get attribute and translate it as a sdata */
265static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
266 Dwarf_Sword *result)
267{
268 Dwarf_Attribute attr;
269
270 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
271 dwarf_formsdata(&attr, result) != 0)
272 return -ENOENT;
273
274 return 0;
275}
276
277/**
278 * die_is_signed_type - Check whether a type DIE is signed or not
279 * @tp_die: a DIE of a type
280 *
281 * Get the encoding of @tp_die and return true if the encoding
282 * is signed.
283 */
284bool die_is_signed_type(Dwarf_Die *tp_die)
285{
286 Dwarf_Word ret;
287
288 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
289 return false;
290
291 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
292 ret == DW_ATE_signed_fixed);
293}
294
295/**
296 * die_is_func_def - Ensure that this DIE is a subprogram and definition
297 * @dw_die: a DIE
298 *
299 * Ensure that this DIE is a subprogram and NOT a declaration. This
300 * returns true if @dw_die is a function definition.
301 **/
302bool die_is_func_def(Dwarf_Die *dw_die)
303{
304 Dwarf_Attribute attr;
305
306 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
307 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
308}
309
310/**
311 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
312 * @dw_die: a DIE
313 *
314 * Ensure that this DIE is an instance (which has an entry address).
315 * This returns true if @dw_die is a function instance. If not, you need to
316 * call die_walk_instances() to find actual instances.
317 **/
318bool die_is_func_instance(Dwarf_Die *dw_die)
319{
320 Dwarf_Addr tmp;
321
322 /* Actually gcc optimizes non-inline as like as inlined */
323 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
324}
325/**
326 * die_get_data_member_location - Get the data-member offset
327 * @mb_die: a DIE of a member of a data structure
328 * @offs: The offset of the member in the data structure
329 *
330 * Get the offset of @mb_die in the data structure including @mb_die, and
331 * stores result offset to @offs. If any error occurs this returns errno.
332 */
333int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
334{
335 Dwarf_Attribute attr;
336 Dwarf_Op *expr;
337 size_t nexpr;
338 int ret;
339
340 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
341 return -ENOENT;
342
343 if (dwarf_formudata(&attr, offs) != 0) {
344 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
345 ret = dwarf_getlocation(&attr, &expr, &nexpr);
346 if (ret < 0 || nexpr == 0)
347 return -ENOENT;
348
349 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
350 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
351 expr[0].atom, nexpr);
352 return -ENOTSUP;
353 }
354 *offs = (Dwarf_Word)expr[0].number;
355 }
356 return 0;
357}
358
359/* Get the call file index number in CU DIE */
360static int die_get_call_fileno(Dwarf_Die *in_die)
361{
362 Dwarf_Sword idx;
363
364 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
365 return (int)idx;
366 else
367 return -ENOENT;
368}
369
370/* Get the declared file index number in CU DIE */
371static int die_get_decl_fileno(Dwarf_Die *pdie)
372{
373 Dwarf_Sword idx;
374
375 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
376 return (int)idx;
377 else
378 return -ENOENT;
379}
380
381/**
382 * die_get_call_file - Get callsite file name of inlined function instance
383 * @in_die: a DIE of an inlined function instance
384 *
385 * Get call-site file name of @in_die. This means from which file the inline
386 * function is called.
387 */
388const char *die_get_call_file(Dwarf_Die *in_die)
389{
390 Dwarf_Die cu_die;
391 Dwarf_Files *files;
392 int idx;
393
394 idx = die_get_call_fileno(in_die);
395 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
396 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
397 return NULL;
398
399 return dwarf_filesrc(files, idx, NULL, NULL);
400}
401
402
403/**
404 * die_find_child - Generic DIE search function in DIE tree
405 * @rt_die: a root DIE
406 * @callback: a callback function
407 * @data: a user data passed to the callback function
408 * @die_mem: a buffer for result DIE
409 *
410 * Trace DIE tree from @rt_die and call @callback for each child DIE.
411 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
412 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
413 * this continues to trace the tree. Optionally, @callback can return
414 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
415 * the children and trace only the siblings respectively.
416 * Returns NULL if @callback can't find any appropriate DIE.
417 */
418Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
419 int (*callback)(Dwarf_Die *, void *),
420 void *data, Dwarf_Die *die_mem)
421{
422 Dwarf_Die child_die;
423 int ret;
424
425 ret = dwarf_child(rt_die, die_mem);
426 if (ret != 0)
427 return NULL;
428
429 do {
430 ret = callback(die_mem, data);
431 if (ret == DIE_FIND_CB_END)
432 return die_mem;
433
434 if ((ret & DIE_FIND_CB_CHILD) &&
435 die_find_child(die_mem, callback, data, &child_die)) {
436 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
437 return die_mem;
438 }
439 } while ((ret & DIE_FIND_CB_SIBLING) &&
440 dwarf_siblingof(die_mem, die_mem) == 0);
441
442 return NULL;
443}
444
445struct __addr_die_search_param {
446 Dwarf_Addr addr;
447 Dwarf_Die *die_mem;
448};
449
450static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
451{
452 struct __addr_die_search_param *ad = data;
453 Dwarf_Addr addr = 0;
454
455 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
456 !dwarf_highpc(fn_die, &addr) &&
457 addr == ad->addr) {
458 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
459 return DWARF_CB_ABORT;
460 }
461 return DWARF_CB_OK;
462}
463
464/**
465 * die_find_tailfunc - Search for a non-inlined function with tail call at
466 * given address
467 * @cu_die: a CU DIE which including @addr
468 * @addr: target address
469 * @die_mem: a buffer for result DIE
470 *
471 * Search for a non-inlined function DIE with tail call at @addr. Stores the
472 * DIE to @die_mem and returns it if found. Returns NULL if failed.
473 */
474Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
475 Dwarf_Die *die_mem)
476{
477 struct __addr_die_search_param ad;
478 ad.addr = addr;
479 ad.die_mem = die_mem;
480 /* dwarf_getscopes can't find subprogram. */
481 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
482 return NULL;
483 else
484 return die_mem;
485}
486
487/* die_find callback for non-inlined function search */
488static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
489{
490 struct __addr_die_search_param *ad = data;
491
492 /*
493 * Since a declaration entry doesn't has given pc, this always returns
494 * function definition entry.
495 */
496 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
497 dwarf_haspc(fn_die, ad->addr)) {
498 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
499 return DWARF_CB_ABORT;
500 }
501 return DWARF_CB_OK;
502}
503
504/**
505 * die_find_realfunc - Search a non-inlined function at given address
506 * @cu_die: a CU DIE which including @addr
507 * @addr: target address
508 * @die_mem: a buffer for result DIE
509 *
510 * Search a non-inlined function DIE which includes @addr. Stores the
511 * DIE to @die_mem and returns it if found. Returns NULL if failed.
512 */
513Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
514 Dwarf_Die *die_mem)
515{
516 struct __addr_die_search_param ad;
517 ad.addr = addr;
518 ad.die_mem = die_mem;
519 /* dwarf_getscopes can't find subprogram. */
520 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
521 return NULL;
522 else
523 return die_mem;
524}
525
526/* die_find callback for inline function search */
527static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
528{
529 Dwarf_Addr *addr = data;
530
531 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
532 dwarf_haspc(die_mem, *addr))
533 return DIE_FIND_CB_END;
534
535 return DIE_FIND_CB_CONTINUE;
536}
537
538/**
539 * die_find_top_inlinefunc - Search the top inlined function at given address
540 * @sp_die: a subprogram DIE which including @addr
541 * @addr: target address
542 * @die_mem: a buffer for result DIE
543 *
544 * Search an inlined function DIE which includes @addr. Stores the
545 * DIE to @die_mem and returns it if found. Returns NULL if failed.
546 * Even if several inlined functions are expanded recursively, this
547 * doesn't trace it down, and returns the topmost one.
548 */
549Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
550 Dwarf_Die *die_mem)
551{
552 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
553}
554
555/**
556 * die_find_inlinefunc - Search an inlined function at given address
557 * @sp_die: a subprogram DIE which including @addr
558 * @addr: target address
559 * @die_mem: a buffer for result DIE
560 *
561 * Search an inlined function DIE which includes @addr. Stores the
562 * DIE to @die_mem and returns it if found. Returns NULL if failed.
563 * If several inlined functions are expanded recursively, this trace
564 * it down and returns deepest one.
565 */
566Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
567 Dwarf_Die *die_mem)
568{
569 Dwarf_Die tmp_die;
570
571 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
572 if (!sp_die)
573 return NULL;
574
575 /* Inlined function could be recursive. Trace it until fail */
576 while (sp_die) {
577 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
578 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
579 &tmp_die);
580 }
581
582 return die_mem;
583}
584
585struct __instance_walk_param {
586 void *addr;
587 int (*callback)(Dwarf_Die *, void *);
588 void *data;
589 int retval;
590};
591
592static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
593{
594 struct __instance_walk_param *iwp = data;
595 Dwarf_Attribute attr_mem;
596 Dwarf_Die origin_mem;
597 Dwarf_Attribute *attr;
598 Dwarf_Die *origin;
599 int tmp;
600
601 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
602 if (attr == NULL)
603 return DIE_FIND_CB_CONTINUE;
604
605 origin = dwarf_formref_die(attr, &origin_mem);
606 if (origin == NULL || origin->addr != iwp->addr)
607 return DIE_FIND_CB_CONTINUE;
608
609 /* Ignore redundant instances */
610 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
611 dwarf_decl_line(origin, &tmp);
612 if (die_get_call_lineno(inst) == tmp) {
613 tmp = die_get_decl_fileno(origin);
614 if (die_get_call_fileno(inst) == tmp)
615 return DIE_FIND_CB_CONTINUE;
616 }
617 }
618
619 iwp->retval = iwp->callback(inst, iwp->data);
620
621 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
622}
623
624/**
625 * die_walk_instances - Walk on instances of given DIE
626 * @or_die: an abstract original DIE
627 * @callback: a callback function which is called with instance DIE
628 * @data: user data
629 *
630 * Walk on the instances of give @in_die. @in_die must be an inlined function
631 * declartion. This returns the return value of @callback if it returns
632 * non-zero value, or -ENOENT if there is no instance.
633 */
634int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
635 void *data)
636{
637 Dwarf_Die cu_die;
638 Dwarf_Die die_mem;
639 struct __instance_walk_param iwp = {
640 .addr = or_die->addr,
641 .callback = callback,
642 .data = data,
643 .retval = -ENOENT,
644 };
645
646 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
647 return -ENOENT;
648
649 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
650
651 return iwp.retval;
652}
653
654/* Line walker internal parameters */
655struct __line_walk_param {
656 bool recursive;
657 line_walk_callback_t callback;
658 void *data;
659 int retval;
660};
661
662static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
663{
664 struct __line_walk_param *lw = data;
665 Dwarf_Addr addr = 0;
666 const char *fname;
667 int lineno;
668
669 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
670 fname = die_get_call_file(in_die);
671 lineno = die_get_call_lineno(in_die);
672 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
673 lw->retval = lw->callback(fname, lineno, addr, lw->data);
674 if (lw->retval != 0)
675 return DIE_FIND_CB_END;
676 }
677 }
678 if (!lw->recursive)
679 /* Don't need to search recursively */
680 return DIE_FIND_CB_SIBLING;
681
682 if (addr) {
683 fname = dwarf_decl_file(in_die);
684 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
685 lw->retval = lw->callback(fname, lineno, addr, lw->data);
686 if (lw->retval != 0)
687 return DIE_FIND_CB_END;
688 }
689 }
690
691 /* Continue to search nested inlined function call-sites */
692 return DIE_FIND_CB_CONTINUE;
693}
694
695/* Walk on lines of blocks included in given DIE */
696static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
697 line_walk_callback_t callback, void *data)
698{
699 struct __line_walk_param lw = {
700 .recursive = recursive,
701 .callback = callback,
702 .data = data,
703 .retval = 0,
704 };
705 Dwarf_Die die_mem;
706 Dwarf_Addr addr;
707 const char *fname;
708 int lineno;
709
710 /* Handle function declaration line */
711 fname = dwarf_decl_file(sp_die);
712 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
713 dwarf_entrypc(sp_die, &addr) == 0) {
714 lw.retval = callback(fname, lineno, addr, data);
715 if (lw.retval != 0)
716 goto done;
717 }
718 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
719done:
720 return lw.retval;
721}
722
723static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
724{
725 struct __line_walk_param *lw = data;
726
727 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
728 if (lw->retval != 0)
729 return DWARF_CB_ABORT;
730
731 return DWARF_CB_OK;
732}
733
734/**
735 * die_walk_lines - Walk on lines inside given DIE
736 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
737 * @callback: callback routine
738 * @data: user data
739 *
740 * Walk on all lines inside given @rt_die and call @callback on each line.
741 * If the @rt_die is a function, walk only on the lines inside the function,
742 * otherwise @rt_die must be a CU DIE.
743 * Note that this walks not only dwarf line list, but also function entries
744 * and inline call-site.
745 */
746int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
747{
748 Dwarf_Lines *lines;
749 Dwarf_Line *line;
750 Dwarf_Addr addr;
751 const char *fname, *decf = NULL;
752 int lineno, ret = 0;
753 int decl = 0, inl;
754 Dwarf_Die die_mem, *cu_die;
755 size_t nlines, i;
756
757 /* Get the CU die */
758 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
759 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
760 dwarf_decl_line(rt_die, &decl);
761 decf = dwarf_decl_file(rt_die);
762 } else
763 cu_die = rt_die;
764 if (!cu_die) {
765 pr_debug2("Failed to get CU from given DIE.\n");
766 return -EINVAL;
767 }
768
769 /* Get lines list in the CU */
770 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
771 pr_debug2("Failed to get source lines on this CU.\n");
772 return -ENOENT;
773 }
774 pr_debug2("Get %zd lines from this CU\n", nlines);
775
776 /* Walk on the lines on lines list */
777 for (i = 0; i < nlines; i++) {
778 line = dwarf_onesrcline(lines, i);
779 if (line == NULL ||
780 dwarf_lineno(line, &lineno) != 0 ||
781 dwarf_lineaddr(line, &addr) != 0) {
782 pr_debug2("Failed to get line info. "
783 "Possible error in debuginfo.\n");
784 continue;
785 }
786 /* Filter lines based on address */
787 if (rt_die != cu_die) {
788 /*
789 * Address filtering
790 * The line is included in given function, and
791 * no inline block includes it.
792 */
793 if (!dwarf_haspc(rt_die, addr))
794 continue;
795 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
796 dwarf_decl_line(&die_mem, &inl);
797 if (inl != decl ||
798 decf != dwarf_decl_file(&die_mem))
799 continue;
800 }
801 }
802 /* Get source line */
803 fname = dwarf_linesrc(line, NULL, NULL);
804
805 ret = callback(fname, lineno, addr, data);
806 if (ret != 0)
807 return ret;
808 }
809
810 /*
811 * Dwarf lines doesn't include function declarations and inlined
812 * subroutines. We have to check functions list or given function.
813 */
814 if (rt_die != cu_die)
815 /*
816 * Don't need walk functions recursively, because nested
817 * inlined functions don't have lines of the specified DIE.
818 */
819 ret = __die_walk_funclines(rt_die, false, callback, data);
820 else {
821 struct __line_walk_param param = {
822 .callback = callback,
823 .data = data,
824 .retval = 0,
825 };
826 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
827 ret = param.retval;
828 }
829
830 return ret;
831}
832
833struct __find_variable_param {
834 const char *name;
835 Dwarf_Addr addr;
836};
837
838static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
839{
840 struct __find_variable_param *fvp = data;
841 Dwarf_Attribute attr;
842 int tag;
843
844 tag = dwarf_tag(die_mem);
845 if ((tag == DW_TAG_formal_parameter ||
846 tag == DW_TAG_variable) &&
847 die_compare_name(die_mem, fvp->name) &&
848 /* Does the DIE have location information or external instance? */
849 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
850 dwarf_attr(die_mem, DW_AT_location, &attr)))
851 return DIE_FIND_CB_END;
852 if (dwarf_haspc(die_mem, fvp->addr))
853 return DIE_FIND_CB_CONTINUE;
854 else
855 return DIE_FIND_CB_SIBLING;
856}
857
858/**
859 * die_find_variable_at - Find a given name variable at given address
860 * @sp_die: a function DIE
861 * @name: variable name
862 * @addr: address
863 * @die_mem: a buffer for result DIE
864 *
865 * Find a variable DIE called @name at @addr in @sp_die.
866 */
867Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
868 Dwarf_Addr addr, Dwarf_Die *die_mem)
869{
870 struct __find_variable_param fvp = { .name = name, .addr = addr};
871
872 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
873 die_mem);
874}
875
876static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
877{
878 const char *name = data;
879
880 if (dwarf_tag(die_mem) == DW_TAG_member) {
881 if (die_compare_name(die_mem, name))
882 return DIE_FIND_CB_END;
883 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
884 Dwarf_Die type_die, tmp_die;
885 if (die_get_type(die_mem, &type_die) &&
886 die_find_member(&type_die, name, &tmp_die))
887 return DIE_FIND_CB_END;
888 }
889 }
890 return DIE_FIND_CB_SIBLING;
891}
892
893/**
894 * die_find_member - Find a given name member in a data structure
895 * @st_die: a data structure type DIE
896 * @name: member name
897 * @die_mem: a buffer for result DIE
898 *
899 * Find a member DIE called @name in @st_die.
900 */
901Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
902 Dwarf_Die *die_mem)
903{
904 return die_find_child(st_die, __die_find_member_cb, (void *)name,
905 die_mem);
906}
907
908/**
909 * die_get_typename - Get the name of given variable DIE
910 * @vr_die: a variable DIE
911 * @buf: a strbuf for result type name
912 *
913 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
914 * and Return -ENOENT if failed to find type name.
915 * Note that the result will stores typedef name if possible, and stores
916 * "*(function_type)" if the type is a function pointer.
917 */
918int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
919{
920 Dwarf_Die type;
921 int tag, ret;
922 const char *tmp = "";
923
924 if (__die_get_real_type(vr_die, &type) == NULL)
925 return -ENOENT;
926
927 tag = dwarf_tag(&type);
928 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
929 tmp = "*";
930 else if (tag == DW_TAG_subroutine_type) {
931 /* Function pointer */
932 return strbuf_add(buf, "(function_type)", 15);
933 } else {
934 if (!dwarf_diename(&type))
935 return -ENOENT;
936 if (tag == DW_TAG_union_type)
937 tmp = "union ";
938 else if (tag == DW_TAG_structure_type)
939 tmp = "struct ";
940 else if (tag == DW_TAG_enumeration_type)
941 tmp = "enum ";
942 /* Write a base name */
943 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
944 }
945 ret = die_get_typename(&type, buf);
946 return ret ? ret : strbuf_addstr(buf, tmp);
947}
948
949/**
950 * die_get_varname - Get the name and type of given variable DIE
951 * @vr_die: a variable DIE
952 * @buf: a strbuf for type and variable name
953 *
954 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
955 */
956int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
957{
958 int ret;
959
960 ret = die_get_typename(vr_die, buf);
961 if (ret < 0) {
962 pr_debug("Failed to get type, make it unknown.\n");
963 ret = strbuf_add(buf, " (unknown_type)", 14);
964 }
965
966 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
967}
968
969#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
970/**
971 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
972 * @sp_die: a subprogram DIE
973 * @vr_die: a variable DIE
974 * @buf: a strbuf for variable byte offset range
975 *
976 * Get the innermost scope range of @vr_die and stores it in @buf as
977 * "@<function_name+[NN-NN,NN-NN]>".
978 */
979static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
980 struct strbuf *buf)
981{
982 Dwarf_Die *scopes;
983 int count;
984 size_t offset = 0;
985 Dwarf_Addr base;
986 Dwarf_Addr start, end;
987 Dwarf_Addr entry;
988 int ret;
989 bool first = true;
990 const char *name;
991
992 ret = dwarf_entrypc(sp_die, &entry);
993 if (ret)
994 return ret;
995
996 name = dwarf_diename(sp_die);
997 if (!name)
998 return -ENOENT;
999
1000 count = dwarf_getscopes_die(vr_die, &scopes);
1001
1002 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1003 if (count <= 1) {
1004 ret = -EINVAL;
1005 goto out;
1006 }
1007
1008 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1009 &start, &end)) > 0) {
1010 start -= entry;
1011 end -= entry;
1012
1013 if (first) {
1014 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1015 name, start, end);
1016 first = false;
1017 } else {
1018 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1019 start, end);
1020 }
1021 if (ret < 0)
1022 goto out;
1023 }
1024
1025 if (!first)
1026 ret = strbuf_add(buf, "]>", 2);
1027
1028out:
1029 free(scopes);
1030 return ret;
1031}
1032
1033/**
1034 * die_get_var_range - Get byte offset range of given variable DIE
1035 * @sp_die: a subprogram DIE
1036 * @vr_die: a variable DIE
1037 * @buf: a strbuf for type and variable name and byte offset range
1038 *
1039 * Get the byte offset range of @vr_die and stores it in @buf as
1040 * "@<function_name+[NN-NN,NN-NN]>".
1041 */
1042int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1043{
1044 int ret = 0;
1045 Dwarf_Addr base;
1046 Dwarf_Addr start, end;
1047 Dwarf_Addr entry;
1048 Dwarf_Op *op;
1049 size_t nops;
1050 size_t offset = 0;
1051 Dwarf_Attribute attr;
1052 bool first = true;
1053 const char *name;
1054
1055 ret = dwarf_entrypc(sp_die, &entry);
1056 if (ret)
1057 return ret;
1058
1059 name = dwarf_diename(sp_die);
1060 if (!name)
1061 return -ENOENT;
1062
1063 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1064 return -EINVAL;
1065
1066 while ((offset = dwarf_getlocations(&attr, offset, &base,
1067 &start, &end, &op, &nops)) > 0) {
1068 if (start == 0) {
1069 /* Single Location Descriptions */
1070 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1071 goto out;
1072 }
1073
1074 /* Location Lists */
1075 start -= entry;
1076 end -= entry;
1077 if (first) {
1078 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1079 name, start, end);
1080 first = false;
1081 } else {
1082 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1083 start, end);
1084 }
1085 if (ret < 0)
1086 goto out;
1087 }
1088
1089 if (!first)
1090 ret = strbuf_add(buf, "]>", 2);
1091out:
1092 return ret;
1093}
1094#else
1095int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1096 Dwarf_Die *vr_die __maybe_unused,
1097 struct strbuf *buf __maybe_unused)
1098{
1099 return -ENOTSUP;
1100}
1101#endif
1102
1103/*
1104 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1105 * @vr_die: a variable DIE
1106 */
1107static bool die_has_loclist(Dwarf_Die *vr_die)
1108{
1109 Dwarf_Attribute loc;
1110 int tag = dwarf_tag(vr_die);
1111
1112 if (tag != DW_TAG_formal_parameter &&
1113 tag != DW_TAG_variable)
1114 return false;
1115
1116 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1117 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1118}
1119
1120/*
1121 * die_is_optimized_target - Check if target program is compiled with
1122 * optimization
1123 * @cu_die: a CU DIE
1124 *
1125 * For any object in given CU whose DW_AT_location is a location list,
1126 * target program is compiled with optimization. This is applicable to
1127 * clang as well.
1128 */
1129bool die_is_optimized_target(Dwarf_Die *cu_die)
1130{
1131 Dwarf_Die tmp_die;
1132
1133 if (die_has_loclist(cu_die))
1134 return true;
1135
1136 if (!dwarf_child(cu_die, &tmp_die) &&
1137 die_is_optimized_target(&tmp_die))
1138 return true;
1139
1140 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1141 die_is_optimized_target(&tmp_die))
1142 return true;
1143
1144 return false;
1145}
1146
1147/*
1148 * die_search_idx - Search index of given line address
1149 * @lines: Line records of single CU
1150 * @nr_lines: Number of @lines
1151 * @addr: address we are looking for
1152 * @idx: index to be set by this function (return value)
1153 *
1154 * Search for @addr by looping over every lines of CU. If address
1155 * matches, set index of that line in @idx. Note that single source
1156 * line can have multiple line records. i.e. single source line can
1157 * have multiple index.
1158 */
1159static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1160 Dwarf_Addr addr, unsigned long *idx)
1161{
1162 unsigned long i;
1163 Dwarf_Addr tmp;
1164
1165 for (i = 0; i < nr_lines; i++) {
1166 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1167 return false;
1168
1169 if (tmp == addr) {
1170 *idx = i;
1171 return true;
1172 }
1173 }
1174 return false;
1175}
1176
1177/*
1178 * die_get_postprologue_addr - Search next address after function prologue
1179 * @entrypc_idx: entrypc index
1180 * @lines: Line records of single CU
1181 * @nr_lines: Number of @lines
1182 * @hignpc: high PC address of function
1183 * @postprologue_addr: Next address after function prologue (return value)
1184 *
1185 * Look for prologue-end marker. If there is no explicit marker, return
1186 * address of next line record or next source line.
1187 */
1188static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1189 Dwarf_Lines *lines,
1190 unsigned long nr_lines,
1191 Dwarf_Addr highpc,
1192 Dwarf_Addr *postprologue_addr)
1193{
1194 unsigned long i;
1195 int entrypc_lno, lno;
1196 Dwarf_Line *line;
1197 Dwarf_Addr addr;
1198 bool p_end;
1199
1200 /* entrypc_lno is actual source line number */
1201 line = dwarf_onesrcline(lines, entrypc_idx);
1202 if (dwarf_lineno(line, &entrypc_lno))
1203 return false;
1204
1205 for (i = entrypc_idx; i < nr_lines; i++) {
1206 line = dwarf_onesrcline(lines, i);
1207
1208 if (dwarf_lineaddr(line, &addr) ||
1209 dwarf_lineno(line, &lno) ||
1210 dwarf_lineprologueend(line, &p_end))
1211 return false;
1212
1213 /* highpc is exclusive. [entrypc,highpc) */
1214 if (addr >= highpc)
1215 break;
1216
1217 /* clang supports prologue-end marker */
1218 if (p_end)
1219 break;
1220
1221 /* Actual next line in source */
1222 if (lno != entrypc_lno)
1223 break;
1224
1225 /*
1226 * Single source line can have multiple line records.
1227 * For Example,
1228 * void foo() { printf("hello\n"); }
1229 * contains two line records. One points to declaration and
1230 * other points to printf() line. Variable 'lno' won't get
1231 * incremented in this case but 'i' will.
1232 */
1233 if (i != entrypc_idx)
1234 break;
1235 }
1236
1237 dwarf_lineaddr(line, postprologue_addr);
1238 if (*postprologue_addr >= highpc)
1239 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1240 postprologue_addr);
1241
1242 return true;
1243}
1244
1245/*
1246 * die_skip_prologue - Use next address after prologue as probe location
1247 * @sp_die: a subprogram DIE
1248 * @cu_die: a CU DIE
1249 * @entrypc: entrypc of the function
1250 *
1251 * Function prologue prepares stack and registers before executing function
1252 * logic. When target program is compiled without optimization, function
1253 * parameter information is only valid after prologue. When we probe entrypc
1254 * of the function, and try to record function parameter, it contains
1255 * garbage value.
1256 */
1257void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1258 Dwarf_Addr *entrypc)
1259{
1260 size_t nr_lines = 0;
1261 unsigned long entrypc_idx = 0;
1262 Dwarf_Lines *lines = NULL;
1263 Dwarf_Addr postprologue_addr;
1264 Dwarf_Addr highpc;
1265
1266 if (dwarf_highpc(sp_die, &highpc))
1267 return;
1268
1269 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1270 return;
1271
1272 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1273 return;
1274
1275 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1276 highpc, &postprologue_addr))
1277 return;
1278
1279 *entrypc = postprologue_addr;
1280}
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