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_is_func_instance - Ensure that this DIE is an instance of a subprogram
324 * Ensure that this DIE is an instance (which has an entry address).
325 * This returns true if @dw_die is a function instance. If not, you need to
326 * call die_walk_instances() to find actual instances.
328 bool die_is_func_instance(Dwarf_Die *dw_die)
332 /* Actually gcc optimizes non-inline as like as inlined */
333 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
336 * die_get_data_member_location - Get the data-member offset
337 * @mb_die: a DIE of a member of a data structure
338 * @offs: The offset of the member in the data structure
340 * Get the offset of @mb_die in the data structure including @mb_die, and
341 * stores result offset to @offs. If any error occurs this returns errno.
343 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
345 Dwarf_Attribute attr;
350 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
353 if (dwarf_formudata(&attr, offs) != 0) {
354 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
355 ret = dwarf_getlocation(&attr, &expr, &nexpr);
356 if (ret < 0 || nexpr == 0)
359 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
360 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
361 expr[0].atom, nexpr);
364 *offs = (Dwarf_Word)expr[0].number;
369 /* Get the call file index number in CU DIE */
370 static int die_get_call_fileno(Dwarf_Die *in_die)
374 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
380 /* Get the declared file index number in CU DIE */
381 static int die_get_decl_fileno(Dwarf_Die *pdie)
385 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
392 * die_get_call_file - Get callsite file name of inlined function instance
393 * @in_die: a DIE of an inlined function instance
395 * Get call-site file name of @in_die. This means from which file the inline
396 * function is called.
398 const char *die_get_call_file(Dwarf_Die *in_die)
404 idx = die_get_call_fileno(in_die);
405 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
406 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
409 return dwarf_filesrc(files, idx, NULL, NULL);
414 * die_find_child - Generic DIE search function in DIE tree
415 * @rt_die: a root DIE
416 * @callback: a callback function
417 * @data: a user data passed to the callback function
418 * @die_mem: a buffer for result DIE
420 * Trace DIE tree from @rt_die and call @callback for each child DIE.
421 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
422 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
423 * this continues to trace the tree. Optionally, @callback can return
424 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
425 * the children and trace only the siblings respectively.
426 * Returns NULL if @callback can't find any appropriate DIE.
428 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
429 int (*callback)(Dwarf_Die *, void *),
430 void *data, Dwarf_Die *die_mem)
435 ret = dwarf_child(rt_die, die_mem);
440 ret = callback(die_mem, data);
441 if (ret == DIE_FIND_CB_END)
444 if ((ret & DIE_FIND_CB_CHILD) &&
445 die_find_child(die_mem, callback, data, &child_die)) {
446 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
449 } while ((ret & DIE_FIND_CB_SIBLING) &&
450 dwarf_siblingof(die_mem, die_mem) == 0);
455 struct __addr_die_search_param {
460 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
462 struct __addr_die_search_param *ad = data;
465 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
466 !dwarf_highpc(fn_die, &addr) &&
468 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
469 return DWARF_CB_ABORT;
475 * die_find_tailfunc - Search for a non-inlined function with tail call at
477 * @cu_die: a CU DIE which including @addr
478 * @addr: target address
479 * @die_mem: a buffer for result DIE
481 * Search for a non-inlined function DIE with tail call at @addr. Stores the
482 * DIE to @die_mem and returns it if found. Returns NULL if failed.
484 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
487 struct __addr_die_search_param ad;
489 ad.die_mem = die_mem;
490 /* dwarf_getscopes can't find subprogram. */
491 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
497 /* die_find callback for non-inlined function search */
498 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
500 struct __addr_die_search_param *ad = data;
503 * Since a declaration entry doesn't has given pc, this always returns
504 * function definition entry.
506 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
507 dwarf_haspc(fn_die, ad->addr)) {
508 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
509 return DWARF_CB_ABORT;
515 * die_find_realfunc - Search a non-inlined function at given address
516 * @cu_die: a CU DIE which including @addr
517 * @addr: target address
518 * @die_mem: a buffer for result DIE
520 * Search a non-inlined function DIE which includes @addr. Stores the
521 * DIE to @die_mem and returns it if found. Returns NULL if failed.
523 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
526 struct __addr_die_search_param ad;
528 ad.die_mem = die_mem;
529 /* dwarf_getscopes can't find subprogram. */
530 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
536 /* die_find callback for inline function search */
537 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
539 Dwarf_Addr *addr = data;
541 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
542 dwarf_haspc(die_mem, *addr))
543 return DIE_FIND_CB_END;
545 return DIE_FIND_CB_CONTINUE;
549 * die_find_top_inlinefunc - Search the top inlined function at given address
550 * @sp_die: a subprogram DIE which including @addr
551 * @addr: target address
552 * @die_mem: a buffer for result DIE
554 * Search an inlined function DIE which includes @addr. Stores the
555 * DIE to @die_mem and returns it if found. Returns NULL if failed.
556 * Even if several inlined functions are expanded recursively, this
557 * doesn't trace it down, and returns the topmost one.
559 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
562 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
566 * die_find_inlinefunc - Search an inlined function at given address
567 * @sp_die: a subprogram DIE which including @addr
568 * @addr: target address
569 * @die_mem: a buffer for result DIE
571 * Search an inlined function DIE which includes @addr. Stores the
572 * DIE to @die_mem and returns it if found. Returns NULL if failed.
573 * If several inlined functions are expanded recursively, this trace
574 * it down and returns deepest one.
576 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
581 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
585 /* Inlined function could be recursive. Trace it until fail */
587 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
588 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
595 struct __instance_walk_param {
597 int (*callback)(Dwarf_Die *, void *);
602 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
604 struct __instance_walk_param *iwp = data;
605 Dwarf_Attribute attr_mem;
606 Dwarf_Die origin_mem;
607 Dwarf_Attribute *attr;
611 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
613 return DIE_FIND_CB_CONTINUE;
615 origin = dwarf_formref_die(attr, &origin_mem);
616 if (origin == NULL || origin->addr != iwp->addr)
617 return DIE_FIND_CB_CONTINUE;
619 /* Ignore redundant instances */
620 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
621 dwarf_decl_line(origin, &tmp);
622 if (die_get_call_lineno(inst) == tmp) {
623 tmp = die_get_decl_fileno(origin);
624 if (die_get_call_fileno(inst) == tmp)
625 return DIE_FIND_CB_CONTINUE;
629 iwp->retval = iwp->callback(inst, iwp->data);
631 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
635 * die_walk_instances - Walk on instances of given DIE
636 * @or_die: an abstract original DIE
637 * @callback: a callback function which is called with instance DIE
640 * Walk on the instances of give @in_die. @in_die must be an inlined function
641 * declartion. This returns the return value of @callback if it returns
642 * non-zero value, or -ENOENT if there is no instance.
644 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
649 struct __instance_walk_param iwp = {
650 .addr = or_die->addr,
651 .callback = callback,
656 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
659 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
664 /* Line walker internal parameters */
665 struct __line_walk_param {
667 line_walk_callback_t callback;
672 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
674 struct __line_walk_param *lw = data;
679 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
680 fname = die_get_call_file(in_die);
681 lineno = die_get_call_lineno(in_die);
682 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
683 lw->retval = lw->callback(fname, lineno, addr, lw->data);
685 return DIE_FIND_CB_END;
689 /* Don't need to search recursively */
690 return DIE_FIND_CB_SIBLING;
693 fname = dwarf_decl_file(in_die);
694 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
695 lw->retval = lw->callback(fname, lineno, addr, lw->data);
697 return DIE_FIND_CB_END;
701 /* Continue to search nested inlined function call-sites */
702 return DIE_FIND_CB_CONTINUE;
705 /* Walk on lines of blocks included in given DIE */
706 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
707 line_walk_callback_t callback, void *data)
709 struct __line_walk_param lw = {
710 .recursive = recursive,
711 .callback = callback,
720 /* Handle function declaration line */
721 fname = dwarf_decl_file(sp_die);
722 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
723 dwarf_entrypc(sp_die, &addr) == 0) {
724 lw.retval = callback(fname, lineno, addr, data);
728 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
733 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
735 struct __line_walk_param *lw = data;
737 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
739 return DWARF_CB_ABORT;
745 * die_walk_lines - Walk on lines inside given DIE
746 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
747 * @callback: callback routine
750 * Walk on all lines inside given @rt_die and call @callback on each line.
751 * If the @rt_die is a function, walk only on the lines inside the function,
752 * otherwise @rt_die must be a CU DIE.
753 * Note that this walks not only dwarf line list, but also function entries
754 * and inline call-site.
756 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
761 const char *fname, *decf = NULL;
764 Dwarf_Die die_mem, *cu_die;
768 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
769 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
770 dwarf_decl_line(rt_die, &decl);
771 decf = dwarf_decl_file(rt_die);
775 pr_debug2("Failed to get CU from given DIE.\n");
779 /* Get lines list in the CU */
780 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
781 pr_debug2("Failed to get source lines on this CU.\n");
784 pr_debug2("Get %zd lines from this CU\n", nlines);
786 /* Walk on the lines on lines list */
787 for (i = 0; i < nlines; i++) {
788 line = dwarf_onesrcline(lines, i);
790 dwarf_lineno(line, &lineno) != 0 ||
791 dwarf_lineaddr(line, &addr) != 0) {
792 pr_debug2("Failed to get line info. "
793 "Possible error in debuginfo.\n");
796 /* Filter lines based on address */
797 if (rt_die != cu_die) {
800 * The line is included in given function, and
801 * no inline block includes it.
803 if (!dwarf_haspc(rt_die, addr))
805 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
806 dwarf_decl_line(&die_mem, &inl);
808 decf != dwarf_decl_file(&die_mem))
812 /* Get source line */
813 fname = dwarf_linesrc(line, NULL, NULL);
815 ret = callback(fname, lineno, addr, data);
821 * Dwarf lines doesn't include function declarations and inlined
822 * subroutines. We have to check functions list or given function.
824 if (rt_die != cu_die)
826 * Don't need walk functions recursively, because nested
827 * inlined functions don't have lines of the specified DIE.
829 ret = __die_walk_funclines(rt_die, false, callback, data);
831 struct __line_walk_param param = {
832 .callback = callback,
836 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
843 struct __find_variable_param {
848 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
850 struct __find_variable_param *fvp = data;
851 Dwarf_Attribute attr;
854 tag = dwarf_tag(die_mem);
855 if ((tag == DW_TAG_formal_parameter ||
856 tag == DW_TAG_variable) &&
857 die_compare_name(die_mem, fvp->name) &&
858 /* Does the DIE have location information or external instance? */
859 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
860 dwarf_attr(die_mem, DW_AT_location, &attr)))
861 return DIE_FIND_CB_END;
862 if (dwarf_haspc(die_mem, fvp->addr))
863 return DIE_FIND_CB_CONTINUE;
865 return DIE_FIND_CB_SIBLING;
869 * die_find_variable_at - Find a given name variable at given address
870 * @sp_die: a function DIE
871 * @name: variable name
873 * @die_mem: a buffer for result DIE
875 * Find a variable DIE called @name at @addr in @sp_die.
877 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
878 Dwarf_Addr addr, Dwarf_Die *die_mem)
880 struct __find_variable_param fvp = { .name = name, .addr = addr};
882 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
886 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
888 const char *name = data;
890 if (dwarf_tag(die_mem) == DW_TAG_member) {
891 if (die_compare_name(die_mem, name))
892 return DIE_FIND_CB_END;
893 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
894 Dwarf_Die type_die, tmp_die;
895 if (die_get_type(die_mem, &type_die) &&
896 die_find_member(&type_die, name, &tmp_die))
897 return DIE_FIND_CB_END;
900 return DIE_FIND_CB_SIBLING;
904 * die_find_member - Find a given name member in a data structure
905 * @st_die: a data structure type DIE
907 * @die_mem: a buffer for result DIE
909 * Find a member DIE called @name in @st_die.
911 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
914 return die_find_child(st_die, __die_find_member_cb, (void *)name,
919 * die_get_typename - Get the name of given variable DIE
920 * @vr_die: a variable DIE
921 * @buf: a strbuf for result type name
923 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
924 * and Return -ENOENT if failed to find type name.
925 * Note that the result will stores typedef name if possible, and stores
926 * "*(function_type)" if the type is a function pointer.
928 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
932 const char *tmp = "";
934 if (__die_get_real_type(vr_die, &type) == NULL)
937 tag = dwarf_tag(&type);
938 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
940 else if (tag == DW_TAG_subroutine_type) {
941 /* Function pointer */
942 return strbuf_add(buf, "(function_type)", 15);
944 if (!dwarf_diename(&type))
946 if (tag == DW_TAG_union_type)
948 else if (tag == DW_TAG_structure_type)
950 else if (tag == DW_TAG_enumeration_type)
952 /* Write a base name */
953 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
955 ret = die_get_typename(&type, buf);
956 return ret ? ret : strbuf_addstr(buf, tmp);
960 * die_get_varname - Get the name and type of given variable DIE
961 * @vr_die: a variable DIE
962 * @buf: a strbuf for type and variable name
964 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
966 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
970 ret = die_get_typename(vr_die, buf);
972 pr_debug("Failed to get type, make it unknown.\n");
973 ret = strbuf_add(buf, " (unknown_type)", 14);
976 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
979 #ifdef HAVE_DWARF_GETLOCATIONS
981 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
982 * @sp_die: a subprogram DIE
983 * @vr_die: a variable DIE
984 * @buf: a strbuf for variable byte offset range
986 * Get the innermost scope range of @vr_die and stores it in @buf as
987 * "@<function_name+[NN-NN,NN-NN]>".
989 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
996 Dwarf_Addr start, end;
1002 ret = dwarf_entrypc(sp_die, &entry);
1006 name = dwarf_diename(sp_die);
1010 count = dwarf_getscopes_die(vr_die, &scopes);
1012 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1018 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1019 &start, &end)) > 0) {
1024 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1028 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1036 ret = strbuf_add(buf, "]>", 2);
1044 * die_get_var_range - Get byte offset range of given variable DIE
1045 * @sp_die: a subprogram DIE
1046 * @vr_die: a variable DIE
1047 * @buf: a strbuf for type and variable name and byte offset range
1049 * Get the byte offset range of @vr_die and stores it in @buf as
1050 * "@<function_name+[NN-NN,NN-NN]>".
1052 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1056 Dwarf_Addr start, end;
1061 Dwarf_Attribute attr;
1065 ret = dwarf_entrypc(sp_die, &entry);
1069 name = dwarf_diename(sp_die);
1073 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1076 while ((offset = dwarf_getlocations(&attr, offset, &base,
1077 &start, &end, &op, &nops)) > 0) {
1079 /* Single Location Descriptions */
1080 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1084 /* Location Lists */
1088 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1092 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1100 ret = strbuf_add(buf, "]>", 2);
1105 int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1106 Dwarf_Die *vr_die __maybe_unused,
1107 struct strbuf *buf __maybe_unused)
1114 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1115 * @vr_die: a variable DIE
1117 static bool die_has_loclist(Dwarf_Die *vr_die)
1119 Dwarf_Attribute loc;
1120 int tag = dwarf_tag(vr_die);
1122 if (tag != DW_TAG_formal_parameter &&
1123 tag != DW_TAG_variable)
1126 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1127 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1131 * die_is_optimized_target - Check if target program is compiled with
1135 * For any object in given CU whose DW_AT_location is a location list,
1136 * target program is compiled with optimization. This is applicable to
1139 bool die_is_optimized_target(Dwarf_Die *cu_die)
1143 if (die_has_loclist(cu_die))
1146 if (!dwarf_child(cu_die, &tmp_die) &&
1147 die_is_optimized_target(&tmp_die))
1150 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1151 die_is_optimized_target(&tmp_die))
1158 * die_search_idx - Search index of given line address
1159 * @lines: Line records of single CU
1160 * @nr_lines: Number of @lines
1161 * @addr: address we are looking for
1162 * @idx: index to be set by this function (return value)
1164 * Search for @addr by looping over every lines of CU. If address
1165 * matches, set index of that line in @idx. Note that single source
1166 * line can have multiple line records. i.e. single source line can
1167 * have multiple index.
1169 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1170 Dwarf_Addr addr, unsigned long *idx)
1175 for (i = 0; i < nr_lines; i++) {
1176 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1188 * die_get_postprologue_addr - Search next address after function prologue
1189 * @entrypc_idx: entrypc index
1190 * @lines: Line records of single CU
1191 * @nr_lines: Number of @lines
1192 * @hignpc: high PC address of function
1193 * @postprologue_addr: Next address after function prologue (return value)
1195 * Look for prologue-end marker. If there is no explicit marker, return
1196 * address of next line record or next source line.
1198 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1200 unsigned long nr_lines,
1202 Dwarf_Addr *postprologue_addr)
1205 int entrypc_lno, lno;
1210 /* entrypc_lno is actual source line number */
1211 line = dwarf_onesrcline(lines, entrypc_idx);
1212 if (dwarf_lineno(line, &entrypc_lno))
1215 for (i = entrypc_idx; i < nr_lines; i++) {
1216 line = dwarf_onesrcline(lines, i);
1218 if (dwarf_lineaddr(line, &addr) ||
1219 dwarf_lineno(line, &lno) ||
1220 dwarf_lineprologueend(line, &p_end))
1223 /* highpc is exclusive. [entrypc,highpc) */
1227 /* clang supports prologue-end marker */
1231 /* Actual next line in source */
1232 if (lno != entrypc_lno)
1236 * Single source line can have multiple line records.
1238 * void foo() { printf("hello\n"); }
1239 * contains two line records. One points to declaration and
1240 * other points to printf() line. Variable 'lno' won't get
1241 * incremented in this case but 'i' will.
1243 if (i != entrypc_idx)
1247 dwarf_lineaddr(line, postprologue_addr);
1248 if (*postprologue_addr >= highpc)
1249 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1256 * die_skip_prologue - Use next address after prologue as probe location
1257 * @sp_die: a subprogram DIE
1259 * @entrypc: entrypc of the function
1261 * Function prologue prepares stack and registers before executing function
1262 * logic. When target program is compiled without optimization, function
1263 * parameter information is only valid after prologue. When we probe entrypc
1264 * of the function, and try to record function parameter, it contains
1267 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1268 Dwarf_Addr *entrypc)
1270 size_t nr_lines = 0;
1271 unsigned long entrypc_idx = 0;
1272 Dwarf_Lines *lines = NULL;
1273 Dwarf_Addr postprologue_addr;
1276 if (dwarf_highpc(sp_die, &highpc))
1279 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1282 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1285 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1286 highpc, &postprologue_addr))
1289 *entrypc = postprologue_addr;