2 * dwarf-aux.c : libdw auxiliary interfaces
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.
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.
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.
23 #include "dwarf-aux.h"
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
30 * Find the real(long) path of @fname in @cu_die.
32 const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
36 const char *src = NULL;
42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
46 for (i = 0; i < nfiles; i++) {
47 src = dwarf_filesrc(files, i, NULL, NULL);
48 if (strtailcmp(src, fname) == 0)
57 * cu_get_comp_dir - Get the path of compilation directory
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.
64 const char *cu_get_comp_dir(Dwarf_Die *cu_die)
67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
69 return dwarf_formstring(&attr);
73 * cu_find_lineinfo - Get a line number and file name for given address
76 * @fname: a pointer which returns the file name string
77 * @lineno: a pointer which returns the line number
79 * Find a line number and file name for @addr in @cu_die.
81 int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
82 const char **fname, int *lineno)
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);
92 /* line number is useless without filename */
96 return *lineno ?: -ENOENT;
99 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
102 * cu_walk_functions_at - Walk on function DIEs at given address
105 * @callback: A callback which called with found DIEs
108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
109 * should be subprogram or inlined-subroutines.
111 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
112 int (*callback)(Dwarf_Die *, void *), void *data)
118 /* Inlined function could be recursive. Trace it until fail */
119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
123 ret = callback(sc_die, data);
133 * die_get_linkage_name - Get the linkage name of the object
134 * @dw_die: A DIE of the object
136 * Get the linkage name attiribute of given @dw_die.
137 * For C++ binary, the linkage name will be the mangled symbol.
139 const char *die_get_linkage_name(Dwarf_Die *dw_die)
141 Dwarf_Attribute attr;
143 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
145 return dwarf_formstring(&attr);
149 * die_compare_name - Compare diename and tname
151 * @tname: a string of target name
153 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
155 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
159 name = dwarf_diename(dw_die);
160 return name ? (strcmp(tname, name) == 0) : false;
164 * die_match_name - Match diename/linkage name and glob
166 * @glob: a string of target glob pattern
168 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
169 * This also match linkage name.
171 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
175 name = dwarf_diename(dw_die);
176 if (name && strglobmatch(name, glob))
178 /* fall back to check linkage name */
179 name = die_get_linkage_name(dw_die);
180 if (name && strglobmatch(name, glob))
187 * die_get_call_lineno - Get callsite line number of inline-function instance
188 * @in_die: a DIE of an inlined function instance
190 * Get call-site line number of @in_die. This means from where the inline
191 * function is called.
193 int die_get_call_lineno(Dwarf_Die *in_die)
195 Dwarf_Attribute attr;
198 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
201 dwarf_formudata(&attr, &ret);
206 * die_get_type - Get type DIE
207 * @vr_die: a DIE of a variable
208 * @die_mem: where to store a type DIE
210 * Get a DIE of the type of given variable (@vr_die), and store
211 * it to die_mem. Return NULL if fails to get a type DIE.
213 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
215 Dwarf_Attribute attr;
217 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
218 dwarf_formref_die(&attr, die_mem))
224 /* Get a type die, but skip qualifiers */
225 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
230 vr_die = die_get_type(vr_die, die_mem);
233 tag = dwarf_tag(vr_die);
234 } while (tag == DW_TAG_const_type ||
235 tag == DW_TAG_restrict_type ||
236 tag == DW_TAG_volatile_type ||
237 tag == DW_TAG_shared_type);
243 * die_get_real_type - Get a type die, but skip qualifiers and typedef
244 * @vr_die: a DIE of a variable
245 * @die_mem: where to store a type DIE
247 * Get a DIE of the type of given variable (@vr_die), and store
248 * it to die_mem. Return NULL if fails to get a type DIE.
249 * If the type is qualifiers (e.g. const) or typedef, this skips it
250 * and tries to find real type (structure or basic types, e.g. int).
252 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
255 vr_die = __die_get_real_type(vr_die, die_mem);
256 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
261 /* Get attribute and translate it as a udata */
262 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
265 Dwarf_Attribute attr;
267 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
268 dwarf_formudata(&attr, result) != 0)
274 /* Get attribute and translate it as a sdata */
275 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
278 Dwarf_Attribute attr;
280 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
281 dwarf_formsdata(&attr, result) != 0)
288 * die_is_signed_type - Check whether a type DIE is signed or not
289 * @tp_die: a DIE of a type
291 * Get the encoding of @tp_die and return true if the encoding
294 bool die_is_signed_type(Dwarf_Die *tp_die)
298 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
301 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
302 ret == DW_ATE_signed_fixed);
306 * die_is_func_def - Ensure that this DIE is a subprogram and definition
309 * Ensure that this DIE is a subprogram and NOT a declaration. This
310 * returns true if @dw_die is a function definition.
312 bool die_is_func_def(Dwarf_Die *dw_die)
314 Dwarf_Attribute attr;
316 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
317 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
321 * die_entrypc - Returns entry PC (the lowest address) of a DIE
323 * @addr: where to store entry PC
325 * Since dwarf_entrypc() does not return entry PC if the DIE has only address
326 * range, we have to use this to retrieve the lowest address from the address
329 int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr)
331 Dwarf_Addr base, end;
332 Dwarf_Attribute attr;
337 if (dwarf_entrypc(dw_die, addr) == 0)
341 * Since the dwarf_ranges() will return 0 if there is no
342 * DW_AT_ranges attribute, we should check it first.
344 if (!dwarf_attr(dw_die, DW_AT_ranges, &attr))
347 return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;
351 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
354 * Ensure that this DIE is an instance (which has an entry address).
355 * This returns true if @dw_die is a function instance. If not, the @dw_die
356 * must be a prototype. You can use die_walk_instances() to find actual
359 bool die_is_func_instance(Dwarf_Die *dw_die)
362 Dwarf_Attribute attr_mem;
363 int tag = dwarf_tag(dw_die);
365 if (tag != DW_TAG_subprogram &&
366 tag != DW_TAG_inlined_subroutine)
369 return dwarf_entrypc(dw_die, &tmp) == 0 ||
370 dwarf_attr(dw_die, DW_AT_ranges, &attr_mem) != NULL;
374 * die_get_data_member_location - Get the data-member offset
375 * @mb_die: a DIE of a member of a data structure
376 * @offs: The offset of the member in the data structure
378 * Get the offset of @mb_die in the data structure including @mb_die, and
379 * stores result offset to @offs. If any error occurs this returns errno.
381 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
383 Dwarf_Attribute attr;
388 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
391 if (dwarf_formudata(&attr, offs) != 0) {
392 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
393 ret = dwarf_getlocation(&attr, &expr, &nexpr);
394 if (ret < 0 || nexpr == 0)
397 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
398 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
399 expr[0].atom, nexpr);
402 *offs = (Dwarf_Word)expr[0].number;
407 /* Get the call file index number in CU DIE */
408 static int die_get_call_fileno(Dwarf_Die *in_die)
412 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
418 /* Get the declared file index number in CU DIE */
419 static int die_get_decl_fileno(Dwarf_Die *pdie)
423 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
430 * die_get_call_file - Get callsite file name of inlined function instance
431 * @in_die: a DIE of an inlined function instance
433 * Get call-site file name of @in_die. This means from which file the inline
434 * function is called.
436 const char *die_get_call_file(Dwarf_Die *in_die)
442 idx = die_get_call_fileno(in_die);
443 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
444 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
447 return dwarf_filesrc(files, idx, NULL, NULL);
452 * die_find_child - Generic DIE search function in DIE tree
453 * @rt_die: a root DIE
454 * @callback: a callback function
455 * @data: a user data passed to the callback function
456 * @die_mem: a buffer for result DIE
458 * Trace DIE tree from @rt_die and call @callback for each child DIE.
459 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
460 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
461 * this continues to trace the tree. Optionally, @callback can return
462 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
463 * the children and trace only the siblings respectively.
464 * Returns NULL if @callback can't find any appropriate DIE.
466 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
467 int (*callback)(Dwarf_Die *, void *),
468 void *data, Dwarf_Die *die_mem)
473 ret = dwarf_child(rt_die, die_mem);
478 ret = callback(die_mem, data);
479 if (ret == DIE_FIND_CB_END)
482 if ((ret & DIE_FIND_CB_CHILD) &&
483 die_find_child(die_mem, callback, data, &child_die)) {
484 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
487 } while ((ret & DIE_FIND_CB_SIBLING) &&
488 dwarf_siblingof(die_mem, die_mem) == 0);
493 struct __addr_die_search_param {
498 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
500 struct __addr_die_search_param *ad = data;
503 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
504 !dwarf_highpc(fn_die, &addr) &&
506 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
507 return DWARF_CB_ABORT;
513 * die_find_tailfunc - Search for a non-inlined function with tail call at
515 * @cu_die: a CU DIE which including @addr
516 * @addr: target address
517 * @die_mem: a buffer for result DIE
519 * Search for a non-inlined function DIE with tail call at @addr. Stores the
520 * DIE to @die_mem and returns it if found. Returns NULL if failed.
522 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
525 struct __addr_die_search_param ad;
527 ad.die_mem = die_mem;
528 /* dwarf_getscopes can't find subprogram. */
529 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
535 /* die_find callback for non-inlined function search */
536 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
538 struct __addr_die_search_param *ad = data;
541 * Since a declaration entry doesn't has given pc, this always returns
542 * function definition entry.
544 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
545 dwarf_haspc(fn_die, ad->addr)) {
546 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
547 return DWARF_CB_ABORT;
553 * die_find_realfunc - Search a non-inlined function at given address
554 * @cu_die: a CU DIE which including @addr
555 * @addr: target address
556 * @die_mem: a buffer for result DIE
558 * Search a non-inlined function DIE which includes @addr. Stores the
559 * DIE to @die_mem and returns it if found. Returns NULL if failed.
561 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
564 struct __addr_die_search_param ad;
566 ad.die_mem = die_mem;
567 /* dwarf_getscopes can't find subprogram. */
568 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
574 /* die_find callback for inline function search */
575 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
577 Dwarf_Addr *addr = data;
579 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
580 dwarf_haspc(die_mem, *addr))
581 return DIE_FIND_CB_END;
583 return DIE_FIND_CB_CONTINUE;
587 * die_find_top_inlinefunc - Search the top inlined function at given address
588 * @sp_die: a subprogram DIE which including @addr
589 * @addr: target address
590 * @die_mem: a buffer for result DIE
592 * Search an inlined function DIE which includes @addr. Stores the
593 * DIE to @die_mem and returns it if found. Returns NULL if failed.
594 * Even if several inlined functions are expanded recursively, this
595 * doesn't trace it down, and returns the topmost one.
597 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
600 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
604 * die_find_inlinefunc - Search an inlined function at given address
605 * @sp_die: a subprogram DIE which including @addr
606 * @addr: target address
607 * @die_mem: a buffer for result DIE
609 * Search an inlined function DIE which includes @addr. Stores the
610 * DIE to @die_mem and returns it if found. Returns NULL if failed.
611 * If several inlined functions are expanded recursively, this trace
612 * it down and returns deepest one.
614 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
619 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
623 /* Inlined function could be recursive. Trace it until fail */
625 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
626 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
633 struct __instance_walk_param {
635 int (*callback)(Dwarf_Die *, void *);
640 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
642 struct __instance_walk_param *iwp = data;
643 Dwarf_Attribute attr_mem;
644 Dwarf_Die origin_mem;
645 Dwarf_Attribute *attr;
649 if (!die_is_func_instance(inst))
650 return DIE_FIND_CB_CONTINUE;
652 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
654 return DIE_FIND_CB_CONTINUE;
656 origin = dwarf_formref_die(attr, &origin_mem);
657 if (origin == NULL || origin->addr != iwp->addr)
658 return DIE_FIND_CB_CONTINUE;
660 /* Ignore redundant instances */
661 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
662 dwarf_decl_line(origin, &tmp);
663 if (die_get_call_lineno(inst) == tmp) {
664 tmp = die_get_decl_fileno(origin);
665 if (die_get_call_fileno(inst) == tmp)
666 return DIE_FIND_CB_CONTINUE;
670 iwp->retval = iwp->callback(inst, iwp->data);
672 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
676 * die_walk_instances - Walk on instances of given DIE
677 * @or_die: an abstract original DIE
678 * @callback: a callback function which is called with instance DIE
681 * Walk on the instances of give @in_die. @in_die must be an inlined function
682 * declartion. This returns the return value of @callback if it returns
683 * non-zero value, or -ENOENT if there is no instance.
685 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
690 struct __instance_walk_param iwp = {
691 .addr = or_die->addr,
692 .callback = callback,
697 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
700 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
705 /* Line walker internal parameters */
706 struct __line_walk_param {
708 line_walk_callback_t callback;
713 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
715 struct __line_walk_param *lw = data;
720 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
721 fname = die_get_call_file(in_die);
722 lineno = die_get_call_lineno(in_die);
723 if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) {
724 lw->retval = lw->callback(fname, lineno, addr, lw->data);
726 return DIE_FIND_CB_END;
729 return DIE_FIND_CB_SIBLING;
733 fname = dwarf_decl_file(in_die);
734 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
735 lw->retval = lw->callback(fname, lineno, addr, lw->data);
737 return DIE_FIND_CB_END;
741 /* Continue to search nested inlined function call-sites */
742 return DIE_FIND_CB_CONTINUE;
745 /* Walk on lines of blocks included in given DIE */
746 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
747 line_walk_callback_t callback, void *data)
749 struct __line_walk_param lw = {
750 .recursive = recursive,
751 .callback = callback,
760 /* Handle function declaration line */
761 fname = dwarf_decl_file(sp_die);
762 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
763 die_entrypc(sp_die, &addr) == 0) {
764 lw.retval = callback(fname, lineno, addr, data);
768 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
773 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
775 struct __line_walk_param *lw = data;
778 * Since inlined function can include another inlined function in
779 * the same file, we need to walk in it recursively.
781 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
783 return DWARF_CB_ABORT;
789 * die_walk_lines - Walk on lines inside given DIE
790 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
791 * @callback: callback routine
794 * Walk on all lines inside given @rt_die and call @callback on each line.
795 * If the @rt_die is a function, walk only on the lines inside the function,
796 * otherwise @rt_die must be a CU DIE.
797 * Note that this walks not only dwarf line list, but also function entries
798 * and inline call-site.
800 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
805 const char *fname, *decf = NULL, *inf = NULL;
808 Dwarf_Die die_mem, *cu_die;
813 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
814 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
815 dwarf_decl_line(rt_die, &decl);
816 decf = dwarf_decl_file(rt_die);
820 pr_debug2("Failed to get CU from given DIE.\n");
824 /* Get lines list in the CU */
825 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
826 pr_debug2("Failed to get source lines on this CU.\n");
829 pr_debug2("Get %zd lines from this CU\n", nlines);
831 /* Walk on the lines on lines list */
832 for (i = 0; i < nlines; i++) {
833 line = dwarf_onesrcline(lines, i);
835 dwarf_lineno(line, &lineno) != 0 ||
836 dwarf_lineaddr(line, &addr) != 0) {
837 pr_debug2("Failed to get line info. "
838 "Possible error in debuginfo.\n");
841 /* Skip end-of-sequence */
842 if (dwarf_lineendsequence(line, &flag) != 0 || flag)
844 /* Skip Non statement line-info */
845 if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)
847 /* Filter lines based on address */
848 if (rt_die != cu_die) {
851 * The line is included in given function, and
852 * no inline block includes it.
854 if (!dwarf_haspc(rt_die, addr))
857 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
858 /* Call-site check */
859 inf = die_get_call_file(&die_mem);
860 if ((inf && !strcmp(inf, decf)) &&
861 die_get_call_lineno(&die_mem) == lineno)
864 dwarf_decl_line(&die_mem, &inl);
866 decf != dwarf_decl_file(&die_mem))
871 /* Get source line */
872 fname = dwarf_linesrc(line, NULL, NULL);
874 ret = callback(fname, lineno, addr, data);
880 * Dwarf lines doesn't include function declarations and inlined
881 * subroutines. We have to check functions list or given function.
883 if (rt_die != cu_die)
885 * Don't need walk inlined functions recursively, because
886 * inner inlined functions don't have the lines of the
887 * specified function.
889 ret = __die_walk_funclines(rt_die, false, callback, data);
891 struct __line_walk_param param = {
892 .callback = callback,
896 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
903 struct __find_variable_param {
908 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
910 struct __find_variable_param *fvp = data;
911 Dwarf_Attribute attr;
914 tag = dwarf_tag(die_mem);
915 if ((tag == DW_TAG_formal_parameter ||
916 tag == DW_TAG_variable) &&
917 die_compare_name(die_mem, fvp->name) &&
918 /* Does the DIE have location information or external instance? */
919 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
920 dwarf_attr(die_mem, DW_AT_location, &attr)))
921 return DIE_FIND_CB_END;
922 if (dwarf_haspc(die_mem, fvp->addr))
923 return DIE_FIND_CB_CONTINUE;
925 return DIE_FIND_CB_SIBLING;
929 * die_find_variable_at - Find a given name variable at given address
930 * @sp_die: a function DIE
931 * @name: variable name
933 * @die_mem: a buffer for result DIE
935 * Find a variable DIE called @name at @addr in @sp_die.
937 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
938 Dwarf_Addr addr, Dwarf_Die *die_mem)
940 struct __find_variable_param fvp = { .name = name, .addr = addr};
942 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
946 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
948 const char *name = data;
950 if (dwarf_tag(die_mem) == DW_TAG_member) {
951 if (die_compare_name(die_mem, name))
952 return DIE_FIND_CB_END;
953 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
954 Dwarf_Die type_die, tmp_die;
955 if (die_get_type(die_mem, &type_die) &&
956 die_find_member(&type_die, name, &tmp_die))
957 return DIE_FIND_CB_END;
960 return DIE_FIND_CB_SIBLING;
964 * die_find_member - Find a given name member in a data structure
965 * @st_die: a data structure type DIE
967 * @die_mem: a buffer for result DIE
969 * Find a member DIE called @name in @st_die.
971 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
974 return die_find_child(st_die, __die_find_member_cb, (void *)name,
979 * die_get_typename - Get the name of given variable DIE
980 * @vr_die: a variable DIE
981 * @buf: a strbuf for result type name
983 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
984 * and Return -ENOENT if failed to find type name.
985 * Note that the result will stores typedef name if possible, and stores
986 * "*(function_type)" if the type is a function pointer.
988 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
992 const char *tmp = "";
994 if (__die_get_real_type(vr_die, &type) == NULL)
997 tag = dwarf_tag(&type);
998 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
1000 else if (tag == DW_TAG_subroutine_type) {
1001 /* Function pointer */
1002 return strbuf_add(buf, "(function_type)", 15);
1004 if (!dwarf_diename(&type))
1006 if (tag == DW_TAG_union_type)
1008 else if (tag == DW_TAG_structure_type)
1010 else if (tag == DW_TAG_enumeration_type)
1012 /* Write a base name */
1013 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
1015 ret = die_get_typename(&type, buf);
1016 return ret ? ret : strbuf_addstr(buf, tmp);
1020 * die_get_varname - Get the name and type of given variable DIE
1021 * @vr_die: a variable DIE
1022 * @buf: a strbuf for type and variable name
1024 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1026 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
1030 ret = die_get_typename(vr_die, buf);
1032 pr_debug("Failed to get type, make it unknown.\n");
1033 ret = strbuf_add(buf, " (unknown_type)", 14);
1036 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
1039 #ifdef HAVE_DWARF_GETLOCATIONS
1041 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1042 * @sp_die: a subprogram DIE
1043 * @vr_die: a variable DIE
1044 * @buf: a strbuf for variable byte offset range
1046 * Get the innermost scope range of @vr_die and stores it in @buf as
1047 * "@<function_name+[NN-NN,NN-NN]>".
1049 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
1056 Dwarf_Addr start, end;
1062 ret = die_entrypc(sp_die, &entry);
1066 name = dwarf_diename(sp_die);
1070 count = dwarf_getscopes_die(vr_die, &scopes);
1072 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1078 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1079 &start, &end)) > 0) {
1084 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1088 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1096 ret = strbuf_add(buf, "]>", 2);
1104 * die_get_var_range - Get byte offset range of given variable DIE
1105 * @sp_die: a subprogram DIE
1106 * @vr_die: a variable DIE
1107 * @buf: a strbuf for type and variable name and byte offset range
1109 * Get the byte offset range of @vr_die and stores it in @buf as
1110 * "@<function_name+[NN-NN,NN-NN]>".
1112 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1116 Dwarf_Addr start, end;
1121 Dwarf_Attribute attr;
1125 ret = die_entrypc(sp_die, &entry);
1129 name = dwarf_diename(sp_die);
1133 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1136 while ((offset = dwarf_getlocations(&attr, offset, &base,
1137 &start, &end, &op, &nops)) > 0) {
1139 /* Single Location Descriptions */
1140 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1144 /* Location Lists */
1148 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1152 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1160 ret = strbuf_add(buf, "]>", 2);
1165 int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1166 Dwarf_Die *vr_die __maybe_unused,
1167 struct strbuf *buf __maybe_unused)
1174 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1175 * @vr_die: a variable DIE
1177 static bool die_has_loclist(Dwarf_Die *vr_die)
1179 Dwarf_Attribute loc;
1180 int tag = dwarf_tag(vr_die);
1182 if (tag != DW_TAG_formal_parameter &&
1183 tag != DW_TAG_variable)
1186 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1187 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1191 * die_is_optimized_target - Check if target program is compiled with
1195 * For any object in given CU whose DW_AT_location is a location list,
1196 * target program is compiled with optimization. This is applicable to
1199 bool die_is_optimized_target(Dwarf_Die *cu_die)
1203 if (die_has_loclist(cu_die))
1206 if (!dwarf_child(cu_die, &tmp_die) &&
1207 die_is_optimized_target(&tmp_die))
1210 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1211 die_is_optimized_target(&tmp_die))
1218 * die_search_idx - Search index of given line address
1219 * @lines: Line records of single CU
1220 * @nr_lines: Number of @lines
1221 * @addr: address we are looking for
1222 * @idx: index to be set by this function (return value)
1224 * Search for @addr by looping over every lines of CU. If address
1225 * matches, set index of that line in @idx. Note that single source
1226 * line can have multiple line records. i.e. single source line can
1227 * have multiple index.
1229 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1230 Dwarf_Addr addr, unsigned long *idx)
1235 for (i = 0; i < nr_lines; i++) {
1236 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1248 * die_get_postprologue_addr - Search next address after function prologue
1249 * @entrypc_idx: entrypc index
1250 * @lines: Line records of single CU
1251 * @nr_lines: Number of @lines
1252 * @hignpc: high PC address of function
1253 * @postprologue_addr: Next address after function prologue (return value)
1255 * Look for prologue-end marker. If there is no explicit marker, return
1256 * address of next line record or next source line.
1258 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1260 unsigned long nr_lines,
1262 Dwarf_Addr *postprologue_addr)
1265 int entrypc_lno, lno;
1270 /* entrypc_lno is actual source line number */
1271 line = dwarf_onesrcline(lines, entrypc_idx);
1272 if (dwarf_lineno(line, &entrypc_lno))
1275 for (i = entrypc_idx; i < nr_lines; i++) {
1276 line = dwarf_onesrcline(lines, i);
1278 if (dwarf_lineaddr(line, &addr) ||
1279 dwarf_lineno(line, &lno) ||
1280 dwarf_lineprologueend(line, &p_end))
1283 /* highpc is exclusive. [entrypc,highpc) */
1287 /* clang supports prologue-end marker */
1291 /* Actual next line in source */
1292 if (lno != entrypc_lno)
1296 * Single source line can have multiple line records.
1298 * void foo() { printf("hello\n"); }
1299 * contains two line records. One points to declaration and
1300 * other points to printf() line. Variable 'lno' won't get
1301 * incremented in this case but 'i' will.
1303 if (i != entrypc_idx)
1307 dwarf_lineaddr(line, postprologue_addr);
1308 if (*postprologue_addr >= highpc)
1309 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1316 * die_skip_prologue - Use next address after prologue as probe location
1317 * @sp_die: a subprogram DIE
1319 * @entrypc: entrypc of the function
1321 * Function prologue prepares stack and registers before executing function
1322 * logic. When target program is compiled without optimization, function
1323 * parameter information is only valid after prologue. When we probe entrypc
1324 * of the function, and try to record function parameter, it contains
1327 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1328 Dwarf_Addr *entrypc)
1330 size_t nr_lines = 0;
1331 unsigned long entrypc_idx = 0;
1332 Dwarf_Lines *lines = NULL;
1333 Dwarf_Addr postprologue_addr;
1336 if (dwarf_highpc(sp_die, &highpc))
1339 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1342 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1345 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1346 highpc, &postprologue_addr))
1349 *entrypc = postprologue_addr;