1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * dwarf-aux.c : libdw auxiliary interfaces
11 #include "dwarf-aux.h"
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
20 * Find the real(long) path of @fname in @cu_die.
22 const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
26 const char *src = NULL;
32 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
36 for (i = 0; i < nfiles; i++) {
37 src = dwarf_filesrc(files, i, NULL, NULL);
38 if (strtailcmp(src, fname) == 0)
47 * cu_get_comp_dir - Get the path of compilation directory
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.
54 const char *cu_get_comp_dir(Dwarf_Die *cu_die)
57 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
59 return dwarf_formstring(&attr);
63 * cu_find_lineinfo - Get a line number and file name for given address
66 * @fname: a pointer which returns the file name string
67 * @lineno: a pointer which returns the line number
69 * Find a line number and file name for @addr in @cu_die.
71 int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
72 const char **fname, int *lineno)
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);
82 /* line number is useless without filename */
86 return *lineno ?: -ENOENT;
89 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
92 * cu_walk_functions_at - Walk on function DIEs at given address
95 * @callback: A callback which called with found DIEs
98 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
99 * should be subprogram or inlined-subroutines.
101 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
102 int (*callback)(Dwarf_Die *, void *), void *data)
108 /* Inlined function could be recursive. Trace it until fail */
109 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
111 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
113 ret = callback(sc_die, data);
123 * die_get_linkage_name - Get the linkage name of the object
124 * @dw_die: A DIE of the object
126 * Get the linkage name attiribute of given @dw_die.
127 * For C++ binary, the linkage name will be the mangled symbol.
129 const char *die_get_linkage_name(Dwarf_Die *dw_die)
131 Dwarf_Attribute attr;
133 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
135 return dwarf_formstring(&attr);
139 * die_compare_name - Compare diename and tname
141 * @tname: a string of target name
143 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
145 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
149 name = dwarf_diename(dw_die);
150 return name ? (strcmp(tname, name) == 0) : false;
154 * die_match_name - Match diename/linkage name and glob
156 * @glob: a string of target glob pattern
158 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
159 * This also match linkage name.
161 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
165 name = dwarf_diename(dw_die);
166 if (name && strglobmatch(name, glob))
168 /* fall back to check linkage name */
169 name = die_get_linkage_name(dw_die);
170 if (name && strglobmatch(name, glob))
177 * die_get_call_lineno - Get callsite line number of inline-function instance
178 * @in_die: a DIE of an inlined function instance
180 * Get call-site line number of @in_die. This means from where the inline
181 * function is called.
183 int die_get_call_lineno(Dwarf_Die *in_die)
185 Dwarf_Attribute attr;
188 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
191 dwarf_formudata(&attr, &ret);
196 * die_get_type - Get type DIE
197 * @vr_die: a DIE of a variable
198 * @die_mem: where to store a type DIE
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.
203 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
205 Dwarf_Attribute attr;
207 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
208 dwarf_formref_die(&attr, die_mem))
214 /* Get a type die, but skip qualifiers */
215 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
220 vr_die = die_get_type(vr_die, die_mem);
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);
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
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).
242 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
245 vr_die = __die_get_real_type(vr_die, die_mem);
246 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
251 /* Get attribute and translate it as a udata */
252 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
255 Dwarf_Attribute attr;
257 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
258 dwarf_formudata(&attr, result) != 0)
264 /* Get attribute and translate it as a sdata */
265 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
268 Dwarf_Attribute attr;
270 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
271 dwarf_formsdata(&attr, result) != 0)
278 * die_is_signed_type - Check whether a type DIE is signed or not
279 * @tp_die: a DIE of a type
281 * Get the encoding of @tp_die and return true if the encoding
284 bool die_is_signed_type(Dwarf_Die *tp_die)
288 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
291 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
292 ret == DW_ATE_signed_fixed);
296 * die_is_func_def - Ensure that this DIE is a subprogram and definition
299 * Ensure that this DIE is a subprogram and NOT a declaration. This
300 * returns true if @dw_die is a function definition.
302 bool die_is_func_def(Dwarf_Die *dw_die)
304 Dwarf_Attribute attr;
306 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
307 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
311 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
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.
318 bool die_is_func_instance(Dwarf_Die *dw_die)
321 Dwarf_Attribute attr_mem;
323 /* Actually gcc optimizes non-inline as like as inlined */
324 return !dwarf_func_inline(dw_die) &&
325 (dwarf_entrypc(dw_die, &tmp) == 0 ||
326 dwarf_attr(dw_die, DW_AT_ranges, &attr_mem) != NULL);
330 * die_get_data_member_location - Get the data-member offset
331 * @mb_die: a DIE of a member of a data structure
332 * @offs: The offset of the member in the data structure
334 * Get the offset of @mb_die in the data structure including @mb_die, and
335 * stores result offset to @offs. If any error occurs this returns errno.
337 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
339 Dwarf_Attribute attr;
344 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
347 if (dwarf_formudata(&attr, offs) != 0) {
348 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
349 ret = dwarf_getlocation(&attr, &expr, &nexpr);
350 if (ret < 0 || nexpr == 0)
353 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
354 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
355 expr[0].atom, nexpr);
358 *offs = (Dwarf_Word)expr[0].number;
363 /* Get the call file index number in CU DIE */
364 static int die_get_call_fileno(Dwarf_Die *in_die)
368 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
374 /* Get the declared file index number in CU DIE */
375 static int die_get_decl_fileno(Dwarf_Die *pdie)
379 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
386 * die_get_call_file - Get callsite file name of inlined function instance
387 * @in_die: a DIE of an inlined function instance
389 * Get call-site file name of @in_die. This means from which file the inline
390 * function is called.
392 const char *die_get_call_file(Dwarf_Die *in_die)
398 idx = die_get_call_fileno(in_die);
399 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
400 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
403 return dwarf_filesrc(files, idx, NULL, NULL);
408 * die_find_child - Generic DIE search function in DIE tree
409 * @rt_die: a root DIE
410 * @callback: a callback function
411 * @data: a user data passed to the callback function
412 * @die_mem: a buffer for result DIE
414 * Trace DIE tree from @rt_die and call @callback for each child DIE.
415 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
416 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
417 * this continues to trace the tree. Optionally, @callback can return
418 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
419 * the children and trace only the siblings respectively.
420 * Returns NULL if @callback can't find any appropriate DIE.
422 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
423 int (*callback)(Dwarf_Die *, void *),
424 void *data, Dwarf_Die *die_mem)
429 ret = dwarf_child(rt_die, die_mem);
434 ret = callback(die_mem, data);
435 if (ret == DIE_FIND_CB_END)
438 if ((ret & DIE_FIND_CB_CHILD) &&
439 die_find_child(die_mem, callback, data, &child_die)) {
440 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
443 } while ((ret & DIE_FIND_CB_SIBLING) &&
444 dwarf_siblingof(die_mem, die_mem) == 0);
449 struct __addr_die_search_param {
454 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
456 struct __addr_die_search_param *ad = data;
459 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
460 !dwarf_highpc(fn_die, &addr) &&
462 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
463 return DWARF_CB_ABORT;
469 * die_find_tailfunc - Search for a non-inlined function with tail call at
471 * @cu_die: a CU DIE which including @addr
472 * @addr: target address
473 * @die_mem: a buffer for result DIE
475 * Search for a non-inlined function DIE with tail call at @addr. Stores the
476 * DIE to @die_mem and returns it if found. Returns NULL if failed.
478 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
481 struct __addr_die_search_param ad;
483 ad.die_mem = die_mem;
484 /* dwarf_getscopes can't find subprogram. */
485 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
491 /* die_find callback for non-inlined function search */
492 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
494 struct __addr_die_search_param *ad = data;
497 * Since a declaration entry doesn't has given pc, this always returns
498 * function definition entry.
500 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
501 dwarf_haspc(fn_die, ad->addr)) {
502 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
503 return DWARF_CB_ABORT;
509 * die_find_realfunc - Search a non-inlined function at given address
510 * @cu_die: a CU DIE which including @addr
511 * @addr: target address
512 * @die_mem: a buffer for result DIE
514 * Search a non-inlined function DIE which includes @addr. Stores the
515 * DIE to @die_mem and returns it if found. Returns NULL if failed.
517 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
520 struct __addr_die_search_param ad;
522 ad.die_mem = die_mem;
523 /* dwarf_getscopes can't find subprogram. */
524 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
530 /* die_find callback for inline function search */
531 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
533 Dwarf_Addr *addr = data;
535 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
536 dwarf_haspc(die_mem, *addr))
537 return DIE_FIND_CB_END;
539 return DIE_FIND_CB_CONTINUE;
543 * die_find_top_inlinefunc - Search the top inlined function at given address
544 * @sp_die: a subprogram DIE which including @addr
545 * @addr: target address
546 * @die_mem: a buffer for result DIE
548 * Search an inlined function DIE which includes @addr. Stores the
549 * DIE to @die_mem and returns it if found. Returns NULL if failed.
550 * Even if several inlined functions are expanded recursively, this
551 * doesn't trace it down, and returns the topmost one.
553 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
556 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
560 * die_find_inlinefunc - Search an inlined function at given address
561 * @sp_die: a subprogram DIE which including @addr
562 * @addr: target address
563 * @die_mem: a buffer for result DIE
565 * Search an inlined function DIE which includes @addr. Stores the
566 * DIE to @die_mem and returns it if found. Returns NULL if failed.
567 * If several inlined functions are expanded recursively, this trace
568 * it down and returns deepest one.
570 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
575 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
579 /* Inlined function could be recursive. Trace it until fail */
581 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
582 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
589 struct __instance_walk_param {
591 int (*callback)(Dwarf_Die *, void *);
596 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
598 struct __instance_walk_param *iwp = data;
599 Dwarf_Attribute attr_mem;
600 Dwarf_Die origin_mem;
601 Dwarf_Attribute *attr;
605 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
607 return DIE_FIND_CB_CONTINUE;
609 origin = dwarf_formref_die(attr, &origin_mem);
610 if (origin == NULL || origin->addr != iwp->addr)
611 return DIE_FIND_CB_CONTINUE;
613 /* Ignore redundant instances */
614 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
615 dwarf_decl_line(origin, &tmp);
616 if (die_get_call_lineno(inst) == tmp) {
617 tmp = die_get_decl_fileno(origin);
618 if (die_get_call_fileno(inst) == tmp)
619 return DIE_FIND_CB_CONTINUE;
623 iwp->retval = iwp->callback(inst, iwp->data);
625 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
629 * die_walk_instances - Walk on instances of given DIE
630 * @or_die: an abstract original DIE
631 * @callback: a callback function which is called with instance DIE
634 * Walk on the instances of give @in_die. @in_die must be an inlined function
635 * declartion. This returns the return value of @callback if it returns
636 * non-zero value, or -ENOENT if there is no instance.
638 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
643 struct __instance_walk_param iwp = {
644 .addr = or_die->addr,
645 .callback = callback,
650 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
653 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
658 /* Line walker internal parameters */
659 struct __line_walk_param {
661 line_walk_callback_t callback;
666 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
668 struct __line_walk_param *lw = data;
673 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
674 fname = die_get_call_file(in_die);
675 lineno = die_get_call_lineno(in_die);
676 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
677 lw->retval = lw->callback(fname, lineno, addr, lw->data);
679 return DIE_FIND_CB_END;
682 return DIE_FIND_CB_SIBLING;
686 fname = dwarf_decl_file(in_die);
687 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
688 lw->retval = lw->callback(fname, lineno, addr, lw->data);
690 return DIE_FIND_CB_END;
694 /* Continue to search nested inlined function call-sites */
695 return DIE_FIND_CB_CONTINUE;
698 /* Walk on lines of blocks included in given DIE */
699 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
700 line_walk_callback_t callback, void *data)
702 struct __line_walk_param lw = {
703 .recursive = recursive,
704 .callback = callback,
713 /* Handle function declaration line */
714 fname = dwarf_decl_file(sp_die);
715 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
716 dwarf_entrypc(sp_die, &addr) == 0) {
717 lw.retval = callback(fname, lineno, addr, data);
721 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
726 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
728 struct __line_walk_param *lw = data;
731 * Since inlined function can include another inlined function in
732 * the same file, we need to walk in it recursively.
734 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
736 return DWARF_CB_ABORT;
742 * die_walk_lines - Walk on lines inside given DIE
743 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
744 * @callback: callback routine
747 * Walk on all lines inside given @rt_die and call @callback on each line.
748 * If the @rt_die is a function, walk only on the lines inside the function,
749 * otherwise @rt_die must be a CU DIE.
750 * Note that this walks not only dwarf line list, but also function entries
751 * and inline call-site.
753 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
758 const char *fname, *decf = NULL;
761 Dwarf_Die die_mem, *cu_die;
765 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
766 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
767 dwarf_decl_line(rt_die, &decl);
768 decf = dwarf_decl_file(rt_die);
772 pr_debug2("Failed to get CU from given DIE.\n");
776 /* Get lines list in the CU */
777 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
778 pr_debug2("Failed to get source lines on this CU.\n");
781 pr_debug2("Get %zd lines from this CU\n", nlines);
783 /* Walk on the lines on lines list */
784 for (i = 0; i < nlines; i++) {
785 line = dwarf_onesrcline(lines, i);
787 dwarf_lineno(line, &lineno) != 0 ||
788 dwarf_lineaddr(line, &addr) != 0) {
789 pr_debug2("Failed to get line info. "
790 "Possible error in debuginfo.\n");
793 /* Filter lines based on address */
794 if (rt_die != cu_die) {
797 * The line is included in given function, and
798 * no inline block includes it.
800 if (!dwarf_haspc(rt_die, addr))
802 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
803 dwarf_decl_line(&die_mem, &inl);
805 decf != dwarf_decl_file(&die_mem))
809 /* Get source line */
810 fname = dwarf_linesrc(line, NULL, NULL);
812 ret = callback(fname, lineno, addr, data);
818 * Dwarf lines doesn't include function declarations and inlined
819 * subroutines. We have to check functions list or given function.
821 if (rt_die != cu_die)
823 * Don't need walk inlined functions recursively, because
824 * inner inlined functions don't have the lines of the
825 * specified function.
827 ret = __die_walk_funclines(rt_die, false, callback, data);
829 struct __line_walk_param param = {
830 .callback = callback,
834 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
841 struct __find_variable_param {
846 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
848 struct __find_variable_param *fvp = data;
849 Dwarf_Attribute attr;
852 tag = dwarf_tag(die_mem);
853 if ((tag == DW_TAG_formal_parameter ||
854 tag == DW_TAG_variable) &&
855 die_compare_name(die_mem, fvp->name) &&
856 /* Does the DIE have location information or external instance? */
857 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
858 dwarf_attr(die_mem, DW_AT_location, &attr)))
859 return DIE_FIND_CB_END;
860 if (dwarf_haspc(die_mem, fvp->addr))
861 return DIE_FIND_CB_CONTINUE;
863 return DIE_FIND_CB_SIBLING;
867 * die_find_variable_at - Find a given name variable at given address
868 * @sp_die: a function DIE
869 * @name: variable name
871 * @die_mem: a buffer for result DIE
873 * Find a variable DIE called @name at @addr in @sp_die.
875 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
876 Dwarf_Addr addr, Dwarf_Die *die_mem)
878 struct __find_variable_param fvp = { .name = name, .addr = addr};
880 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
884 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
886 const char *name = data;
888 if (dwarf_tag(die_mem) == DW_TAG_member) {
889 if (die_compare_name(die_mem, name))
890 return DIE_FIND_CB_END;
891 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
892 Dwarf_Die type_die, tmp_die;
893 if (die_get_type(die_mem, &type_die) &&
894 die_find_member(&type_die, name, &tmp_die))
895 return DIE_FIND_CB_END;
898 return DIE_FIND_CB_SIBLING;
902 * die_find_member - Find a given name member in a data structure
903 * @st_die: a data structure type DIE
905 * @die_mem: a buffer for result DIE
907 * Find a member DIE called @name in @st_die.
909 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
912 return die_find_child(st_die, __die_find_member_cb, (void *)name,
917 * die_get_typename - Get the name of given variable DIE
918 * @vr_die: a variable DIE
919 * @buf: a strbuf for result type name
921 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
922 * and Return -ENOENT if failed to find type name.
923 * Note that the result will stores typedef name if possible, and stores
924 * "*(function_type)" if the type is a function pointer.
926 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
930 const char *tmp = "";
932 if (__die_get_real_type(vr_die, &type) == NULL)
935 tag = dwarf_tag(&type);
936 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
938 else if (tag == DW_TAG_subroutine_type) {
939 /* Function pointer */
940 return strbuf_add(buf, "(function_type)", 15);
942 if (!dwarf_diename(&type))
944 if (tag == DW_TAG_union_type)
946 else if (tag == DW_TAG_structure_type)
948 else if (tag == DW_TAG_enumeration_type)
950 /* Write a base name */
951 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
953 ret = die_get_typename(&type, buf);
954 return ret ? ret : strbuf_addstr(buf, tmp);
958 * die_get_varname - Get the name and type of given variable DIE
959 * @vr_die: a variable DIE
960 * @buf: a strbuf for type and variable name
962 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
964 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
968 ret = die_get_typename(vr_die, buf);
970 pr_debug("Failed to get type, make it unknown.\n");
971 ret = strbuf_add(buf, " (unknown_type)", 14);
974 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
977 #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
979 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
980 * @sp_die: a subprogram DIE
981 * @vr_die: a variable DIE
982 * @buf: a strbuf for variable byte offset range
984 * Get the innermost scope range of @vr_die and stores it in @buf as
985 * "@<function_name+[NN-NN,NN-NN]>".
987 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
994 Dwarf_Addr start, end;
1000 ret = die_entrypc(sp_die, &entry);
1004 name = dwarf_diename(sp_die);
1008 count = dwarf_getscopes_die(vr_die, &scopes);
1010 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1016 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1017 &start, &end)) > 0) {
1022 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1026 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1034 ret = strbuf_add(buf, "]>", 2);
1042 * die_get_var_range - Get byte offset range of given variable DIE
1043 * @sp_die: a subprogram DIE
1044 * @vr_die: a variable DIE
1045 * @buf: a strbuf for type and variable name and byte offset range
1047 * Get the byte offset range of @vr_die and stores it in @buf as
1048 * "@<function_name+[NN-NN,NN-NN]>".
1050 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1054 Dwarf_Addr start, end;
1059 Dwarf_Attribute attr;
1063 ret = die_entrypc(sp_die, &entry);
1067 name = dwarf_diename(sp_die);
1071 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1074 while ((offset = dwarf_getlocations(&attr, offset, &base,
1075 &start, &end, &op, &nops)) > 0) {
1077 /* Single Location Descriptions */
1078 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1082 /* Location Lists */
1086 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1090 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1098 ret = strbuf_add(buf, "]>", 2);
1103 int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1104 Dwarf_Die *vr_die __maybe_unused,
1105 struct strbuf *buf __maybe_unused)
1112 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1113 * @vr_die: a variable DIE
1115 static bool die_has_loclist(Dwarf_Die *vr_die)
1117 Dwarf_Attribute loc;
1118 int tag = dwarf_tag(vr_die);
1120 if (tag != DW_TAG_formal_parameter &&
1121 tag != DW_TAG_variable)
1124 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1125 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1129 * die_is_optimized_target - Check if target program is compiled with
1133 * For any object in given CU whose DW_AT_location is a location list,
1134 * target program is compiled with optimization. This is applicable to
1137 bool die_is_optimized_target(Dwarf_Die *cu_die)
1141 if (die_has_loclist(cu_die))
1144 if (!dwarf_child(cu_die, &tmp_die) &&
1145 die_is_optimized_target(&tmp_die))
1148 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1149 die_is_optimized_target(&tmp_die))
1156 * die_search_idx - Search index of given line address
1157 * @lines: Line records of single CU
1158 * @nr_lines: Number of @lines
1159 * @addr: address we are looking for
1160 * @idx: index to be set by this function (return value)
1162 * Search for @addr by looping over every lines of CU. If address
1163 * matches, set index of that line in @idx. Note that single source
1164 * line can have multiple line records. i.e. single source line can
1165 * have multiple index.
1167 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1168 Dwarf_Addr addr, unsigned long *idx)
1173 for (i = 0; i < nr_lines; i++) {
1174 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1186 * die_get_postprologue_addr - Search next address after function prologue
1187 * @entrypc_idx: entrypc index
1188 * @lines: Line records of single CU
1189 * @nr_lines: Number of @lines
1190 * @hignpc: high PC address of function
1191 * @postprologue_addr: Next address after function prologue (return value)
1193 * Look for prologue-end marker. If there is no explicit marker, return
1194 * address of next line record or next source line.
1196 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1198 unsigned long nr_lines,
1200 Dwarf_Addr *postprologue_addr)
1203 int entrypc_lno, lno;
1208 /* entrypc_lno is actual source line number */
1209 line = dwarf_onesrcline(lines, entrypc_idx);
1210 if (dwarf_lineno(line, &entrypc_lno))
1213 for (i = entrypc_idx; i < nr_lines; i++) {
1214 line = dwarf_onesrcline(lines, i);
1216 if (dwarf_lineaddr(line, &addr) ||
1217 dwarf_lineno(line, &lno) ||
1218 dwarf_lineprologueend(line, &p_end))
1221 /* highpc is exclusive. [entrypc,highpc) */
1225 /* clang supports prologue-end marker */
1229 /* Actual next line in source */
1230 if (lno != entrypc_lno)
1234 * Single source line can have multiple line records.
1236 * void foo() { printf("hello\n"); }
1237 * contains two line records. One points to declaration and
1238 * other points to printf() line. Variable 'lno' won't get
1239 * incremented in this case but 'i' will.
1241 if (i != entrypc_idx)
1245 dwarf_lineaddr(line, postprologue_addr);
1246 if (*postprologue_addr >= highpc)
1247 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1254 * die_skip_prologue - Use next address after prologue as probe location
1255 * @sp_die: a subprogram DIE
1257 * @entrypc: entrypc of the function
1259 * Function prologue prepares stack and registers before executing function
1260 * logic. When target program is compiled without optimization, function
1261 * parameter information is only valid after prologue. When we probe entrypc
1262 * of the function, and try to record function parameter, it contains
1265 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1266 Dwarf_Addr *entrypc)
1268 size_t nr_lines = 0;
1269 unsigned long entrypc_idx = 0;
1270 Dwarf_Lines *lines = NULL;
1271 Dwarf_Addr postprologue_addr;
1274 if (dwarf_highpc(sp_die, &highpc))
1277 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1280 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1283 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1284 highpc, &postprologue_addr))
1287 *entrypc = postprologue_addr;