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.
24 #include "dwarf-aux.h"
27 * cu_find_realpath - Find the realpath of the target file
28 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
29 * @fname: The tail filename of the target file
31 * Find the real(long) path of @fname in @cu_die.
33 const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
37 const char *src = NULL;
43 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
47 for (i = 0; i < nfiles; i++) {
48 src = dwarf_filesrc(files, i, NULL, NULL);
49 if (strtailcmp(src, fname) == 0)
58 * cu_get_comp_dir - Get the path of compilation directory
61 * Get the path of compilation directory of given @cu_die.
62 * Since this depends on DW_AT_comp_dir, older gcc will not
63 * embedded it. In that case, this returns NULL.
65 const char *cu_get_comp_dir(Dwarf_Die *cu_die)
68 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
70 return dwarf_formstring(&attr);
74 * cu_find_lineinfo - Get a line number and file name for given address
77 * @fname: a pointer which returns the file name string
78 * @lineno: a pointer which returns the line number
80 * Find a line number and file name for @addr in @cu_die.
82 int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
83 const char **fname, int *lineno)
88 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
89 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
90 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
91 *fname = dwarf_linesrc(line, NULL, NULL);
93 /* line number is useless without filename */
97 return *lineno ?: -ENOENT;
100 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
103 * cu_walk_functions_at - Walk on function DIEs at given address
106 * @callback: A callback which called with found DIEs
109 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
110 * should be subprogram or inlined-subroutines.
112 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
113 int (*callback)(Dwarf_Die *, void *), void *data)
119 /* Inlined function could be recursive. Trace it until fail */
120 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
122 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
124 ret = callback(sc_die, data);
134 * die_get_linkage_name - Get the linkage name of the object
135 * @dw_die: A DIE of the object
137 * Get the linkage name attiribute of given @dw_die.
138 * For C++ binary, the linkage name will be the mangled symbol.
140 const char *die_get_linkage_name(Dwarf_Die *dw_die)
142 Dwarf_Attribute attr;
144 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
146 return dwarf_formstring(&attr);
150 * die_compare_name - Compare diename and tname
152 * @tname: a string of target name
154 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
156 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
160 name = dwarf_diename(dw_die);
161 return name ? (strcmp(tname, name) == 0) : false;
165 * die_match_name - Match diename/linkage name and glob
167 * @glob: a string of target glob pattern
169 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
170 * This also match linkage name.
172 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
176 name = dwarf_diename(dw_die);
177 if (name && strglobmatch(name, glob))
179 /* fall back to check linkage name */
180 name = die_get_linkage_name(dw_die);
181 if (name && strglobmatch(name, glob))
188 * die_get_call_lineno - Get callsite line number of inline-function instance
189 * @in_die: a DIE of an inlined function instance
191 * Get call-site line number of @in_die. This means from where the inline
192 * function is called.
194 int die_get_call_lineno(Dwarf_Die *in_die)
196 Dwarf_Attribute attr;
199 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
202 dwarf_formudata(&attr, &ret);
207 * die_get_type - Get type DIE
208 * @vr_die: a DIE of a variable
209 * @die_mem: where to store a type DIE
211 * Get a DIE of the type of given variable (@vr_die), and store
212 * it to die_mem. Return NULL if fails to get a type DIE.
214 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
216 Dwarf_Attribute attr;
218 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
219 dwarf_formref_die(&attr, die_mem))
225 /* Get a type die, but skip qualifiers */
226 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
231 vr_die = die_get_type(vr_die, die_mem);
234 tag = dwarf_tag(vr_die);
235 } while (tag == DW_TAG_const_type ||
236 tag == DW_TAG_restrict_type ||
237 tag == DW_TAG_volatile_type ||
238 tag == DW_TAG_shared_type);
244 * die_get_real_type - Get a type die, but skip qualifiers and typedef
245 * @vr_die: a DIE of a variable
246 * @die_mem: where to store a type DIE
248 * Get a DIE of the type of given variable (@vr_die), and store
249 * it to die_mem. Return NULL if fails to get a type DIE.
250 * If the type is qualifiers (e.g. const) or typedef, this skips it
251 * and tries to find real type (structure or basic types, e.g. int).
253 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
256 vr_die = __die_get_real_type(vr_die, die_mem);
257 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
262 /* Get attribute and translate it as a udata */
263 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
266 Dwarf_Attribute attr;
268 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
269 dwarf_formudata(&attr, result) != 0)
275 /* Get attribute and translate it as a sdata */
276 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
279 Dwarf_Attribute attr;
281 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
282 dwarf_formsdata(&attr, result) != 0)
289 * die_is_signed_type - Check whether a type DIE is signed or not
290 * @tp_die: a DIE of a type
292 * Get the encoding of @tp_die and return true if the encoding
295 bool die_is_signed_type(Dwarf_Die *tp_die)
299 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
302 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
303 ret == DW_ATE_signed_fixed);
307 * die_is_func_def - Ensure that this DIE is a subprogram and definition
310 * Ensure that this DIE is a subprogram and NOT a declaration. This
311 * returns true if @dw_die is a function definition.
313 bool die_is_func_def(Dwarf_Die *dw_die)
315 Dwarf_Attribute attr;
317 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
318 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
322 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
325 * Ensure that this DIE is an instance (which has an entry address).
326 * This returns true if @dw_die is a function instance. If not, you need to
327 * call die_walk_instances() to find actual instances.
329 bool die_is_func_instance(Dwarf_Die *dw_die)
333 /* Actually gcc optimizes non-inline as like as inlined */
334 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
337 * die_get_data_member_location - Get the data-member offset
338 * @mb_die: a DIE of a member of a data structure
339 * @offs: The offset of the member in the data structure
341 * Get the offset of @mb_die in the data structure including @mb_die, and
342 * stores result offset to @offs. If any error occurs this returns errno.
344 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
346 Dwarf_Attribute attr;
351 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
354 if (dwarf_formudata(&attr, offs) != 0) {
355 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
356 ret = dwarf_getlocation(&attr, &expr, &nexpr);
357 if (ret < 0 || nexpr == 0)
360 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
361 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
362 expr[0].atom, nexpr);
365 *offs = (Dwarf_Word)expr[0].number;
370 /* Get the call file index number in CU DIE */
371 static int die_get_call_fileno(Dwarf_Die *in_die)
375 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
381 /* Get the declared file index number in CU DIE */
382 static int die_get_decl_fileno(Dwarf_Die *pdie)
386 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
393 * die_get_call_file - Get callsite file name of inlined function instance
394 * @in_die: a DIE of an inlined function instance
396 * Get call-site file name of @in_die. This means from which file the inline
397 * function is called.
399 const char *die_get_call_file(Dwarf_Die *in_die)
405 idx = die_get_call_fileno(in_die);
406 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
407 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
410 return dwarf_filesrc(files, idx, NULL, NULL);
415 * die_find_child - Generic DIE search function in DIE tree
416 * @rt_die: a root DIE
417 * @callback: a callback function
418 * @data: a user data passed to the callback function
419 * @die_mem: a buffer for result DIE
421 * Trace DIE tree from @rt_die and call @callback for each child DIE.
422 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
423 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
424 * this continues to trace the tree. Optionally, @callback can return
425 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
426 * the children and trace only the siblings respectively.
427 * Returns NULL if @callback can't find any appropriate DIE.
429 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
430 int (*callback)(Dwarf_Die *, void *),
431 void *data, Dwarf_Die *die_mem)
436 ret = dwarf_child(rt_die, die_mem);
441 ret = callback(die_mem, data);
442 if (ret == DIE_FIND_CB_END)
445 if ((ret & DIE_FIND_CB_CHILD) &&
446 die_find_child(die_mem, callback, data, &child_die)) {
447 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
450 } while ((ret & DIE_FIND_CB_SIBLING) &&
451 dwarf_siblingof(die_mem, die_mem) == 0);
456 struct __addr_die_search_param {
461 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
463 struct __addr_die_search_param *ad = data;
466 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
467 !dwarf_highpc(fn_die, &addr) &&
469 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
470 return DWARF_CB_ABORT;
476 * die_find_tailfunc - Search for a non-inlined function with tail call at
478 * @cu_die: a CU DIE which including @addr
479 * @addr: target address
480 * @die_mem: a buffer for result DIE
482 * Search for a non-inlined function DIE with tail call at @addr. Stores the
483 * DIE to @die_mem and returns it if found. Returns NULL if failed.
485 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
488 struct __addr_die_search_param ad;
490 ad.die_mem = die_mem;
491 /* dwarf_getscopes can't find subprogram. */
492 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
498 /* die_find callback for non-inlined function search */
499 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
501 struct __addr_die_search_param *ad = data;
504 * Since a declaration entry doesn't has given pc, this always returns
505 * function definition entry.
507 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
508 dwarf_haspc(fn_die, ad->addr)) {
509 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
510 return DWARF_CB_ABORT;
516 * die_find_realfunc - Search a non-inlined function at given address
517 * @cu_die: a CU DIE which including @addr
518 * @addr: target address
519 * @die_mem: a buffer for result DIE
521 * Search a non-inlined function DIE which includes @addr. Stores the
522 * DIE to @die_mem and returns it if found. Returns NULL if failed.
524 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
527 struct __addr_die_search_param ad;
529 ad.die_mem = die_mem;
530 /* dwarf_getscopes can't find subprogram. */
531 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
537 /* die_find callback for inline function search */
538 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
540 Dwarf_Addr *addr = data;
542 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
543 dwarf_haspc(die_mem, *addr))
544 return DIE_FIND_CB_END;
546 return DIE_FIND_CB_CONTINUE;
550 * die_find_top_inlinefunc - Search the top inlined function at given address
551 * @sp_die: a subprogram DIE which including @addr
552 * @addr: target address
553 * @die_mem: a buffer for result DIE
555 * Search an inlined function DIE which includes @addr. Stores the
556 * DIE to @die_mem and returns it if found. Returns NULL if failed.
557 * Even if several inlined functions are expanded recursively, this
558 * doesn't trace it down, and returns the topmost one.
560 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
563 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
567 * die_find_inlinefunc - Search an inlined function at given address
568 * @sp_die: a subprogram DIE which including @addr
569 * @addr: target address
570 * @die_mem: a buffer for result DIE
572 * Search an inlined function DIE which includes @addr. Stores the
573 * DIE to @die_mem and returns it if found. Returns NULL if failed.
574 * If several inlined functions are expanded recursively, this trace
575 * it down and returns deepest one.
577 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
582 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
586 /* Inlined function could be recursive. Trace it until fail */
588 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
589 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
596 struct __instance_walk_param {
598 int (*callback)(Dwarf_Die *, void *);
603 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
605 struct __instance_walk_param *iwp = data;
606 Dwarf_Attribute attr_mem;
607 Dwarf_Die origin_mem;
608 Dwarf_Attribute *attr;
612 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
614 return DIE_FIND_CB_CONTINUE;
616 origin = dwarf_formref_die(attr, &origin_mem);
617 if (origin == NULL || origin->addr != iwp->addr)
618 return DIE_FIND_CB_CONTINUE;
620 /* Ignore redundant instances */
621 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
622 dwarf_decl_line(origin, &tmp);
623 if (die_get_call_lineno(inst) == tmp) {
624 tmp = die_get_decl_fileno(origin);
625 if (die_get_call_fileno(inst) == tmp)
626 return DIE_FIND_CB_CONTINUE;
630 iwp->retval = iwp->callback(inst, iwp->data);
632 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
636 * die_walk_instances - Walk on instances of given DIE
637 * @or_die: an abstract original DIE
638 * @callback: a callback function which is called with instance DIE
641 * Walk on the instances of give @in_die. @in_die must be an inlined function
642 * declartion. This returns the return value of @callback if it returns
643 * non-zero value, or -ENOENT if there is no instance.
645 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
650 struct __instance_walk_param iwp = {
651 .addr = or_die->addr,
652 .callback = callback,
657 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
660 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
665 /* Line walker internal parameters */
666 struct __line_walk_param {
668 line_walk_callback_t callback;
673 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
675 struct __line_walk_param *lw = data;
680 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
681 fname = die_get_call_file(in_die);
682 lineno = die_get_call_lineno(in_die);
683 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
684 lw->retval = lw->callback(fname, lineno, addr, lw->data);
686 return DIE_FIND_CB_END;
690 /* Don't need to search recursively */
691 return DIE_FIND_CB_SIBLING;
694 fname = dwarf_decl_file(in_die);
695 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
696 lw->retval = lw->callback(fname, lineno, addr, lw->data);
698 return DIE_FIND_CB_END;
702 /* Continue to search nested inlined function call-sites */
703 return DIE_FIND_CB_CONTINUE;
706 /* Walk on lines of blocks included in given DIE */
707 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
708 line_walk_callback_t callback, void *data)
710 struct __line_walk_param lw = {
711 .recursive = recursive,
712 .callback = callback,
721 /* Handle function declaration line */
722 fname = dwarf_decl_file(sp_die);
723 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
724 dwarf_entrypc(sp_die, &addr) == 0) {
725 lw.retval = callback(fname, lineno, addr, data);
729 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
734 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
736 struct __line_walk_param *lw = data;
738 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
740 return DWARF_CB_ABORT;
746 * die_walk_lines - Walk on lines inside given DIE
747 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
748 * @callback: callback routine
751 * Walk on all lines inside given @rt_die and call @callback on each line.
752 * If the @rt_die is a function, walk only on the lines inside the function,
753 * otherwise @rt_die must be a CU DIE.
754 * Note that this walks not only dwarf line list, but also function entries
755 * and inline call-site.
757 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
762 const char *fname, *decf = NULL;
765 Dwarf_Die die_mem, *cu_die;
769 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
770 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
771 dwarf_decl_line(rt_die, &decl);
772 decf = dwarf_decl_file(rt_die);
776 pr_debug2("Failed to get CU from given DIE.\n");
780 /* Get lines list in the CU */
781 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
782 pr_debug2("Failed to get source lines on this CU.\n");
785 pr_debug2("Get %zd lines from this CU\n", nlines);
787 /* Walk on the lines on lines list */
788 for (i = 0; i < nlines; i++) {
789 line = dwarf_onesrcline(lines, i);
791 dwarf_lineno(line, &lineno) != 0 ||
792 dwarf_lineaddr(line, &addr) != 0) {
793 pr_debug2("Failed to get line info. "
794 "Possible error in debuginfo.\n");
797 /* Filter lines based on address */
798 if (rt_die != cu_die) {
801 * The line is included in given function, and
802 * no inline block includes it.
804 if (!dwarf_haspc(rt_die, addr))
806 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
807 dwarf_decl_line(&die_mem, &inl);
809 decf != dwarf_decl_file(&die_mem))
813 /* Get source line */
814 fname = dwarf_linesrc(line, NULL, NULL);
816 ret = callback(fname, lineno, addr, data);
822 * Dwarf lines doesn't include function declarations and inlined
823 * subroutines. We have to check functions list or given function.
825 if (rt_die != cu_die)
827 * Don't need walk functions recursively, because nested
828 * inlined functions don't have lines of the specified DIE.
830 ret = __die_walk_funclines(rt_die, false, callback, data);
832 struct __line_walk_param param = {
833 .callback = callback,
837 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
844 struct __find_variable_param {
849 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
851 struct __find_variable_param *fvp = data;
852 Dwarf_Attribute attr;
855 tag = dwarf_tag(die_mem);
856 if ((tag == DW_TAG_formal_parameter ||
857 tag == DW_TAG_variable) &&
858 die_compare_name(die_mem, fvp->name) &&
859 /* Does the DIE have location information or external instance? */
860 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
861 dwarf_attr(die_mem, DW_AT_location, &attr)))
862 return DIE_FIND_CB_END;
863 if (dwarf_haspc(die_mem, fvp->addr))
864 return DIE_FIND_CB_CONTINUE;
866 return DIE_FIND_CB_SIBLING;
870 * die_find_variable_at - Find a given name variable at given address
871 * @sp_die: a function DIE
872 * @name: variable name
874 * @die_mem: a buffer for result DIE
876 * Find a variable DIE called @name at @addr in @sp_die.
878 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
879 Dwarf_Addr addr, Dwarf_Die *die_mem)
881 struct __find_variable_param fvp = { .name = name, .addr = addr};
883 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
887 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
889 const char *name = data;
891 if (dwarf_tag(die_mem) == DW_TAG_member) {
892 if (die_compare_name(die_mem, name))
893 return DIE_FIND_CB_END;
894 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
895 Dwarf_Die type_die, tmp_die;
896 if (die_get_type(die_mem, &type_die) &&
897 die_find_member(&type_die, name, &tmp_die))
898 return DIE_FIND_CB_END;
901 return DIE_FIND_CB_SIBLING;
905 * die_find_member - Find a given name member in a data structure
906 * @st_die: a data structure type DIE
908 * @die_mem: a buffer for result DIE
910 * Find a member DIE called @name in @st_die.
912 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
915 return die_find_child(st_die, __die_find_member_cb, (void *)name,
920 * die_get_typename - Get the name of given variable DIE
921 * @vr_die: a variable DIE
922 * @buf: a strbuf for result type name
924 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
925 * and Return -ENOENT if failed to find type name.
926 * Note that the result will stores typedef name if possible, and stores
927 * "*(function_type)" if the type is a function pointer.
929 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
933 const char *tmp = "";
935 if (__die_get_real_type(vr_die, &type) == NULL)
938 tag = dwarf_tag(&type);
939 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
941 else if (tag == DW_TAG_subroutine_type) {
942 /* Function pointer */
943 return strbuf_add(buf, "(function_type)", 15);
945 if (!dwarf_diename(&type))
947 if (tag == DW_TAG_union_type)
949 else if (tag == DW_TAG_structure_type)
951 else if (tag == DW_TAG_enumeration_type)
953 /* Write a base name */
954 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
956 ret = die_get_typename(&type, buf);
957 return ret ? ret : strbuf_addstr(buf, tmp);
961 * die_get_varname - Get the name and type of given variable DIE
962 * @vr_die: a variable DIE
963 * @buf: a strbuf for type and variable name
965 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
967 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
971 ret = die_get_typename(vr_die, buf);
973 pr_debug("Failed to get type, make it unknown.\n");
974 ret = strbuf_add(buf, " (unknown_type)", 14);
977 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
980 #ifdef HAVE_DWARF_GETLOCATIONS
982 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
983 * @sp_die: a subprogram DIE
984 * @vr_die: a variable DIE
985 * @buf: a strbuf for variable byte offset range
987 * Get the innermost scope range of @vr_die and stores it in @buf as
988 * "@<function_name+[NN-NN,NN-NN]>".
990 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
997 Dwarf_Addr start, end;
1003 ret = dwarf_entrypc(sp_die, &entry);
1007 name = dwarf_diename(sp_die);
1011 count = dwarf_getscopes_die(vr_die, &scopes);
1013 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1019 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1020 &start, &end)) > 0) {
1025 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1029 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1037 ret = strbuf_add(buf, "]>", 2);
1045 * die_get_var_range - Get byte offset range of given variable DIE
1046 * @sp_die: a subprogram DIE
1047 * @vr_die: a variable DIE
1048 * @buf: a strbuf for type and variable name and byte offset range
1050 * Get the byte offset range of @vr_die and stores it in @buf as
1051 * "@<function_name+[NN-NN,NN-NN]>".
1053 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1057 Dwarf_Addr start, end;
1062 Dwarf_Attribute attr;
1066 ret = dwarf_entrypc(sp_die, &entry);
1070 name = dwarf_diename(sp_die);
1074 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1077 while ((offset = dwarf_getlocations(&attr, offset, &base,
1078 &start, &end, &op, &nops)) > 0) {
1080 /* Single Location Descriptions */
1081 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1085 /* Location Lists */
1089 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1093 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1101 ret = strbuf_add(buf, "]>", 2);
1106 int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1107 Dwarf_Die *vr_die __maybe_unused,
1108 struct strbuf *buf __maybe_unused)
1115 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1116 * @vr_die: a variable DIE
1118 static bool die_has_loclist(Dwarf_Die *vr_die)
1120 Dwarf_Attribute loc;
1121 int tag = dwarf_tag(vr_die);
1123 if (tag != DW_TAG_formal_parameter &&
1124 tag != DW_TAG_variable)
1127 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1128 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1132 * die_is_optimized_target - Check if target program is compiled with
1136 * For any object in given CU whose DW_AT_location is a location list,
1137 * target program is compiled with optimization. This is applicable to
1140 bool die_is_optimized_target(Dwarf_Die *cu_die)
1144 if (die_has_loclist(cu_die))
1147 if (!dwarf_child(cu_die, &tmp_die) &&
1148 die_is_optimized_target(&tmp_die))
1151 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1152 die_is_optimized_target(&tmp_die))
1159 * die_search_idx - Search index of given line address
1160 * @lines: Line records of single CU
1161 * @nr_lines: Number of @lines
1162 * @addr: address we are looking for
1163 * @idx: index to be set by this function (return value)
1165 * Search for @addr by looping over every lines of CU. If address
1166 * matches, set index of that line in @idx. Note that single source
1167 * line can have multiple line records. i.e. single source line can
1168 * have multiple index.
1170 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1171 Dwarf_Addr addr, unsigned long *idx)
1176 for (i = 0; i < nr_lines; i++) {
1177 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1189 * die_get_postprologue_addr - Search next address after function prologue
1190 * @entrypc_idx: entrypc index
1191 * @lines: Line records of single CU
1192 * @nr_lines: Number of @lines
1193 * @hignpc: high PC address of function
1194 * @postprologue_addr: Next address after function prologue (return value)
1196 * Look for prologue-end marker. If there is no explicit marker, return
1197 * address of next line record or next source line.
1199 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1201 unsigned long nr_lines,
1203 Dwarf_Addr *postprologue_addr)
1206 int entrypc_lno, lno;
1211 /* entrypc_lno is actual source line number */
1212 line = dwarf_onesrcline(lines, entrypc_idx);
1213 if (dwarf_lineno(line, &entrypc_lno))
1216 for (i = entrypc_idx; i < nr_lines; i++) {
1217 line = dwarf_onesrcline(lines, i);
1219 if (dwarf_lineaddr(line, &addr) ||
1220 dwarf_lineno(line, &lno) ||
1221 dwarf_lineprologueend(line, &p_end))
1224 /* highpc is exclusive. [entrypc,highpc) */
1228 /* clang supports prologue-end marker */
1232 /* Actual next line in source */
1233 if (lno != entrypc_lno)
1237 * Single source line can have multiple line records.
1239 * void foo() { printf("hello\n"); }
1240 * contains two line records. One points to declaration and
1241 * other points to printf() line. Variable 'lno' won't get
1242 * incremented in this case but 'i' will.
1244 if (i != entrypc_idx)
1248 dwarf_lineaddr(line, postprologue_addr);
1249 if (*postprologue_addr >= highpc)
1250 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1257 * die_skip_prologue - Use next address after prologue as probe location
1258 * @sp_die: a subprogram DIE
1260 * @entrypc: entrypc of the function
1262 * Function prologue prepares stack and registers before executing function
1263 * logic. When target program is compiled without optimization, function
1264 * parameter information is only valid after prologue. When we probe entrypc
1265 * of the function, and try to record function parameter, it contains
1268 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1269 Dwarf_Addr *entrypc)
1271 size_t nr_lines = 0;
1272 unsigned long entrypc_idx = 0;
1273 Dwarf_Lines *lines = NULL;
1274 Dwarf_Addr postprologue_addr;
1277 if (dwarf_highpc(sp_die, &highpc))
1280 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1283 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1286 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1287 highpc, &postprologue_addr))
1290 *entrypc = postprologue_addr;