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);
62 /* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */
63 static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr)
68 size_t nlines, l, u, n;
71 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0 ||
75 /* Lines are sorted by address, use binary search */
76 l = 0; u = nlines - 1;
79 line = dwarf_onesrcline(lines, n);
80 if (!line || dwarf_lineaddr(line, &laddr) != 0)
87 /* Going backward to find the lowest line */
89 line = dwarf_onesrcline(lines, --l);
90 if (!line || dwarf_lineaddr(line, &laddr) != 0)
92 } while (laddr == addr);
94 /* Going forward to find the statement line */
96 line = dwarf_onesrcline(lines, l++);
97 if (!line || dwarf_lineaddr(line, &laddr) != 0 ||
98 dwarf_linebeginstatement(line, &flag) != 0)
108 * cu_find_lineinfo - Get a line number and file name for given address
111 * @fname: a pointer which returns the file name string
112 * @lineno: a pointer which returns the line number
114 * Find a line number and file name for @addr in @cu_die.
116 int cu_find_lineinfo(Dwarf_Die *cu_die, Dwarf_Addr addr,
117 const char **fname, int *lineno)
123 if (die_find_realfunc(cu_die, addr, &die_mem)
124 && die_entrypc(&die_mem, &faddr) == 0 &&
126 *fname = dwarf_decl_file(&die_mem);
127 dwarf_decl_line(&die_mem, lineno);
131 line = cu_getsrc_die(cu_die, addr);
132 if (line && dwarf_lineno(line, lineno) == 0) {
133 *fname = dwarf_linesrc(line, NULL, NULL);
135 /* line number is useless without filename */
140 return *lineno ?: -ENOENT;
143 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
146 * cu_walk_functions_at - Walk on function DIEs at given address
149 * @callback: A callback which called with found DIEs
152 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
153 * should be subprogram or inlined-subroutines.
155 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
156 int (*callback)(Dwarf_Die *, void *), void *data)
162 /* Inlined function could be recursive. Trace it until fail */
163 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
165 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
167 ret = callback(sc_die, data);
177 * die_get_linkage_name - Get the linkage name of the object
178 * @dw_die: A DIE of the object
180 * Get the linkage name attribute of given @dw_die.
181 * For C++ binary, the linkage name will be the mangled symbol.
183 const char *die_get_linkage_name(Dwarf_Die *dw_die)
185 Dwarf_Attribute attr;
187 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
189 return dwarf_formstring(&attr);
193 * die_compare_name - Compare diename and tname
195 * @tname: a string of target name
197 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
199 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
203 name = dwarf_diename(dw_die);
204 return name ? (strcmp(tname, name) == 0) : false;
208 * die_match_name - Match diename/linkage name and glob
210 * @glob: a string of target glob pattern
212 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
213 * This also match linkage name.
215 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
219 name = dwarf_diename(dw_die);
220 if (name && strglobmatch(name, glob))
222 /* fall back to check linkage name */
223 name = die_get_linkage_name(dw_die);
224 if (name && strglobmatch(name, glob))
231 * die_get_call_lineno - Get callsite line number of inline-function instance
232 * @in_die: a DIE of an inlined function instance
234 * Get call-site line number of @in_die. This means from where the inline
235 * function is called.
237 int die_get_call_lineno(Dwarf_Die *in_die)
239 Dwarf_Attribute attr;
242 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
245 dwarf_formudata(&attr, &ret);
250 * die_get_type - Get type DIE
251 * @vr_die: a DIE of a variable
252 * @die_mem: where to store a type DIE
254 * Get a DIE of the type of given variable (@vr_die), and store
255 * it to die_mem. Return NULL if fails to get a type DIE.
257 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
259 Dwarf_Attribute attr;
261 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
262 dwarf_formref_die(&attr, die_mem))
268 /* Get a type die, but skip qualifiers */
269 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
274 vr_die = die_get_type(vr_die, die_mem);
277 tag = dwarf_tag(vr_die);
278 } while (tag == DW_TAG_const_type ||
279 tag == DW_TAG_restrict_type ||
280 tag == DW_TAG_volatile_type ||
281 tag == DW_TAG_shared_type);
287 * die_get_real_type - Get a type die, but skip qualifiers and typedef
288 * @vr_die: a DIE of a variable
289 * @die_mem: where to store a type DIE
291 * Get a DIE of the type of given variable (@vr_die), and store
292 * it to die_mem. Return NULL if fails to get a type DIE.
293 * If the type is qualifiers (e.g. const) or typedef, this skips it
294 * and tries to find real type (structure or basic types, e.g. int).
296 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
299 vr_die = __die_get_real_type(vr_die, die_mem);
300 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
305 /* Get attribute and translate it as a udata */
306 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
309 Dwarf_Attribute attr;
311 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
312 dwarf_formudata(&attr, result) != 0)
318 /* Get attribute and translate it as a sdata */
319 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
322 Dwarf_Attribute attr;
324 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
325 dwarf_formsdata(&attr, result) != 0)
332 * die_is_signed_type - Check whether a type DIE is signed or not
333 * @tp_die: a DIE of a type
335 * Get the encoding of @tp_die and return true if the encoding
338 bool die_is_signed_type(Dwarf_Die *tp_die)
342 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
345 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
346 ret == DW_ATE_signed_fixed);
350 * die_is_func_def - Ensure that this DIE is a subprogram and definition
353 * Ensure that this DIE is a subprogram and NOT a declaration. This
354 * returns true if @dw_die is a function definition.
356 bool die_is_func_def(Dwarf_Die *dw_die)
358 Dwarf_Attribute attr;
361 if (dwarf_tag(dw_die) != DW_TAG_subprogram)
364 if (dwarf_attr(dw_die, DW_AT_declaration, &attr))
368 * DW_AT_declaration can be lost from function declaration
369 * by gcc's bug #97060.
370 * So we need to check this subprogram DIE has DW_AT_inline
371 * or an entry address.
373 if (!dwarf_attr(dw_die, DW_AT_inline, &attr) &&
374 die_entrypc(dw_die, &addr) < 0)
381 * die_entrypc - Returns entry PC (the lowest address) of a DIE
383 * @addr: where to store entry PC
385 * Since dwarf_entrypc() does not return entry PC if the DIE has only address
386 * range, we have to use this to retrieve the lowest address from the address
389 int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr)
391 Dwarf_Addr base, end;
392 Dwarf_Attribute attr;
397 if (dwarf_entrypc(dw_die, addr) == 0)
401 * Since the dwarf_ranges() will return 0 if there is no
402 * DW_AT_ranges attribute, we should check it first.
404 if (!dwarf_attr(dw_die, DW_AT_ranges, &attr))
407 return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;
411 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
414 * Ensure that this DIE is an instance (which has an entry address).
415 * This returns true if @dw_die is a function instance. If not, the @dw_die
416 * must be a prototype. You can use die_walk_instances() to find actual
419 bool die_is_func_instance(Dwarf_Die *dw_die)
422 Dwarf_Attribute attr_mem;
423 int tag = dwarf_tag(dw_die);
425 if (tag != DW_TAG_subprogram &&
426 tag != DW_TAG_inlined_subroutine)
429 return dwarf_entrypc(dw_die, &tmp) == 0 ||
430 dwarf_attr(dw_die, DW_AT_ranges, &attr_mem) != NULL;
434 * die_get_data_member_location - Get the data-member offset
435 * @mb_die: a DIE of a member of a data structure
436 * @offs: The offset of the member in the data structure
438 * Get the offset of @mb_die in the data structure including @mb_die, and
439 * stores result offset to @offs. If any error occurs this returns errno.
441 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
443 Dwarf_Attribute attr;
448 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
451 if (dwarf_formudata(&attr, offs) != 0) {
452 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
453 ret = dwarf_getlocation(&attr, &expr, &nexpr);
454 if (ret < 0 || nexpr == 0)
457 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
458 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
459 expr[0].atom, nexpr);
462 *offs = (Dwarf_Word)expr[0].number;
467 /* Get the call file index number in CU DIE */
468 static int die_get_call_fileno(Dwarf_Die *in_die)
472 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
478 /* Get the declared file index number in CU DIE */
479 static int die_get_decl_fileno(Dwarf_Die *pdie)
483 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
490 * die_get_call_file - Get callsite file name of inlined function instance
491 * @in_die: a DIE of an inlined function instance
493 * Get call-site file name of @in_die. This means from which file the inline
494 * function is called.
496 const char *die_get_call_file(Dwarf_Die *in_die)
502 idx = die_get_call_fileno(in_die);
503 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
504 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
507 return dwarf_filesrc(files, idx, NULL, NULL);
512 * die_find_child - Generic DIE search function in DIE tree
513 * @rt_die: a root DIE
514 * @callback: a callback function
515 * @data: a user data passed to the callback function
516 * @die_mem: a buffer for result DIE
518 * Trace DIE tree from @rt_die and call @callback for each child DIE.
519 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
520 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
521 * this continues to trace the tree. Optionally, @callback can return
522 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
523 * the children and trace only the siblings respectively.
524 * Returns NULL if @callback can't find any appropriate DIE.
526 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
527 int (*callback)(Dwarf_Die *, void *),
528 void *data, Dwarf_Die *die_mem)
533 ret = dwarf_child(rt_die, die_mem);
538 ret = callback(die_mem, data);
539 if (ret == DIE_FIND_CB_END)
542 if ((ret & DIE_FIND_CB_CHILD) &&
543 die_find_child(die_mem, callback, data, &child_die)) {
544 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
547 } while ((ret & DIE_FIND_CB_SIBLING) &&
548 dwarf_siblingof(die_mem, die_mem) == 0);
553 struct __addr_die_search_param {
558 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
560 struct __addr_die_search_param *ad = data;
563 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
564 !dwarf_highpc(fn_die, &addr) &&
566 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
567 return DWARF_CB_ABORT;
573 * die_find_tailfunc - Search for a non-inlined function with tail call at
575 * @cu_die: a CU DIE which including @addr
576 * @addr: target address
577 * @die_mem: a buffer for result DIE
579 * Search for a non-inlined function DIE with tail call at @addr. Stores the
580 * DIE to @die_mem and returns it if found. Returns NULL if failed.
582 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
585 struct __addr_die_search_param ad;
587 ad.die_mem = die_mem;
588 /* dwarf_getscopes can't find subprogram. */
589 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
595 /* die_find callback for non-inlined function search */
596 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
598 struct __addr_die_search_param *ad = data;
601 * Since a declaration entry doesn't has given pc, this always returns
602 * function definition entry.
604 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
605 dwarf_haspc(fn_die, ad->addr)) {
606 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
607 return DWARF_CB_ABORT;
613 * die_find_realfunc - Search a non-inlined function at given address
614 * @cu_die: a CU DIE which including @addr
615 * @addr: target address
616 * @die_mem: a buffer for result DIE
618 * Search a non-inlined function DIE which includes @addr. Stores the
619 * DIE to @die_mem and returns it if found. Returns NULL if failed.
621 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
624 struct __addr_die_search_param ad;
626 ad.die_mem = die_mem;
627 /* dwarf_getscopes can't find subprogram. */
628 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
634 /* die_find callback for inline function search */
635 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
637 Dwarf_Addr *addr = data;
639 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
640 dwarf_haspc(die_mem, *addr))
641 return DIE_FIND_CB_END;
643 return DIE_FIND_CB_CONTINUE;
647 * die_find_top_inlinefunc - Search the top inlined function at given address
648 * @sp_die: a subprogram DIE which including @addr
649 * @addr: target address
650 * @die_mem: a buffer for result DIE
652 * Search an inlined function DIE which includes @addr. Stores the
653 * DIE to @die_mem and returns it if found. Returns NULL if failed.
654 * Even if several inlined functions are expanded recursively, this
655 * doesn't trace it down, and returns the topmost one.
657 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
660 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
664 * die_find_inlinefunc - Search an inlined function at given address
665 * @sp_die: a subprogram DIE which including @addr
666 * @addr: target address
667 * @die_mem: a buffer for result DIE
669 * Search an inlined function DIE which includes @addr. Stores the
670 * DIE to @die_mem and returns it if found. Returns NULL if failed.
671 * If several inlined functions are expanded recursively, this trace
672 * it down and returns deepest one.
674 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
679 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
683 /* Inlined function could be recursive. Trace it until fail */
685 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
686 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
693 struct __instance_walk_param {
695 int (*callback)(Dwarf_Die *, void *);
700 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
702 struct __instance_walk_param *iwp = data;
703 Dwarf_Attribute attr_mem;
704 Dwarf_Die origin_mem;
705 Dwarf_Attribute *attr;
709 if (!die_is_func_instance(inst))
710 return DIE_FIND_CB_CONTINUE;
712 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
714 return DIE_FIND_CB_CONTINUE;
716 origin = dwarf_formref_die(attr, &origin_mem);
717 if (origin == NULL || origin->addr != iwp->addr)
718 return DIE_FIND_CB_CONTINUE;
720 /* Ignore redundant instances */
721 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
722 dwarf_decl_line(origin, &tmp);
723 if (die_get_call_lineno(inst) == tmp) {
724 tmp = die_get_decl_fileno(origin);
725 if (die_get_call_fileno(inst) == tmp)
726 return DIE_FIND_CB_CONTINUE;
730 iwp->retval = iwp->callback(inst, iwp->data);
732 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
736 * die_walk_instances - Walk on instances of given DIE
737 * @or_die: an abstract original DIE
738 * @callback: a callback function which is called with instance DIE
741 * Walk on the instances of give @in_die. @in_die must be an inlined function
742 * declaration. This returns the return value of @callback if it returns
743 * non-zero value, or -ENOENT if there is no instance.
745 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
750 struct __instance_walk_param iwp = {
751 .addr = or_die->addr,
752 .callback = callback,
757 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
760 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
765 /* Line walker internal parameters */
766 struct __line_walk_param {
768 line_walk_callback_t callback;
773 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
775 struct __line_walk_param *lw = data;
780 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
781 fname = die_get_call_file(in_die);
782 lineno = die_get_call_lineno(in_die);
783 if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) {
784 lw->retval = lw->callback(fname, lineno, addr, lw->data);
786 return DIE_FIND_CB_END;
789 return DIE_FIND_CB_SIBLING;
793 fname = dwarf_decl_file(in_die);
794 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
795 lw->retval = lw->callback(fname, lineno, addr, lw->data);
797 return DIE_FIND_CB_END;
801 /* Continue to search nested inlined function call-sites */
802 return DIE_FIND_CB_CONTINUE;
805 /* Walk on lines of blocks included in given DIE */
806 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
807 line_walk_callback_t callback, void *data)
809 struct __line_walk_param lw = {
810 .recursive = recursive,
811 .callback = callback,
820 /* Handle function declaration line */
821 fname = dwarf_decl_file(sp_die);
822 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
823 die_entrypc(sp_die, &addr) == 0) {
824 lw.retval = callback(fname, lineno, addr, data);
828 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
833 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
835 struct __line_walk_param *lw = data;
838 * Since inlined function can include another inlined function in
839 * the same file, we need to walk in it recursively.
841 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
843 return DWARF_CB_ABORT;
849 * die_walk_lines - Walk on lines inside given DIE
850 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
851 * @callback: callback routine
854 * Walk on all lines inside given @rt_die and call @callback on each line.
855 * If the @rt_die is a function, walk only on the lines inside the function,
856 * otherwise @rt_die must be a CU DIE.
857 * Note that this walks not only dwarf line list, but also function entries
858 * and inline call-site.
860 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
865 const char *fname, *decf = NULL, *inf = NULL;
868 Dwarf_Die die_mem, *cu_die;
873 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
874 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
875 dwarf_decl_line(rt_die, &decl);
876 decf = dwarf_decl_file(rt_die);
880 pr_debug2("Failed to get CU from given DIE.\n");
884 /* Get lines list in the CU */
885 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
886 pr_debug2("Failed to get source lines on this CU.\n");
889 pr_debug2("Get %zd lines from this CU\n", nlines);
891 /* Walk on the lines on lines list */
892 for (i = 0; i < nlines; i++) {
893 line = dwarf_onesrcline(lines, i);
895 dwarf_lineno(line, &lineno) != 0 ||
896 dwarf_lineaddr(line, &addr) != 0) {
897 pr_debug2("Failed to get line info. "
898 "Possible error in debuginfo.\n");
901 /* Skip end-of-sequence */
902 if (dwarf_lineendsequence(line, &flag) != 0 || flag)
904 /* Skip Non statement line-info */
905 if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)
907 /* Filter lines based on address */
908 if (rt_die != cu_die) {
911 * The line is included in given function, and
912 * no inline block includes it.
914 if (!dwarf_haspc(rt_die, addr))
917 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
918 /* Call-site check */
919 inf = die_get_call_file(&die_mem);
920 if ((inf && !strcmp(inf, decf)) &&
921 die_get_call_lineno(&die_mem) == lineno)
924 dwarf_decl_line(&die_mem, &inl);
926 decf != dwarf_decl_file(&die_mem))
931 /* Get source line */
932 fname = dwarf_linesrc(line, NULL, NULL);
934 ret = callback(fname, lineno, addr, data);
940 * Dwarf lines doesn't include function declarations and inlined
941 * subroutines. We have to check functions list or given function.
943 if (rt_die != cu_die)
945 * Don't need walk inlined functions recursively, because
946 * inner inlined functions don't have the lines of the
947 * specified function.
949 ret = __die_walk_funclines(rt_die, false, callback, data);
951 struct __line_walk_param param = {
952 .callback = callback,
956 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
963 struct __find_variable_param {
968 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
970 struct __find_variable_param *fvp = data;
971 Dwarf_Attribute attr;
974 tag = dwarf_tag(die_mem);
975 if ((tag == DW_TAG_formal_parameter ||
976 tag == DW_TAG_variable) &&
977 die_compare_name(die_mem, fvp->name) &&
979 * Does the DIE have location information or const value
980 * or external instance?
982 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
983 dwarf_attr(die_mem, DW_AT_location, &attr) ||
984 dwarf_attr(die_mem, DW_AT_const_value, &attr)))
985 return DIE_FIND_CB_END;
986 if (dwarf_haspc(die_mem, fvp->addr))
987 return DIE_FIND_CB_CONTINUE;
989 return DIE_FIND_CB_SIBLING;
993 * die_find_variable_at - Find a given name variable at given address
994 * @sp_die: a function DIE
995 * @name: variable name
997 * @die_mem: a buffer for result DIE
999 * Find a variable DIE called @name at @addr in @sp_die.
1001 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
1002 Dwarf_Addr addr, Dwarf_Die *die_mem)
1004 struct __find_variable_param fvp = { .name = name, .addr = addr};
1006 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
1010 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
1012 const char *name = data;
1014 if (dwarf_tag(die_mem) == DW_TAG_member) {
1015 if (die_compare_name(die_mem, name))
1016 return DIE_FIND_CB_END;
1017 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
1018 Dwarf_Die type_die, tmp_die;
1019 if (die_get_type(die_mem, &type_die) &&
1020 die_find_member(&type_die, name, &tmp_die))
1021 return DIE_FIND_CB_END;
1024 return DIE_FIND_CB_SIBLING;
1028 * die_find_member - Find a given name member in a data structure
1029 * @st_die: a data structure type DIE
1030 * @name: member name
1031 * @die_mem: a buffer for result DIE
1033 * Find a member DIE called @name in @st_die.
1035 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
1038 return die_find_child(st_die, __die_find_member_cb, (void *)name,
1043 * die_get_typename - Get the name of given variable DIE
1044 * @vr_die: a variable DIE
1045 * @buf: a strbuf for result type name
1047 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
1048 * and Return -ENOENT if failed to find type name.
1049 * Note that the result will stores typedef name if possible, and stores
1050 * "*(function_type)" if the type is a function pointer.
1052 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
1056 const char *tmp = "";
1058 if (__die_get_real_type(vr_die, &type) == NULL)
1061 tag = dwarf_tag(&type);
1062 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
1064 else if (tag == DW_TAG_subroutine_type) {
1065 /* Function pointer */
1066 return strbuf_add(buf, "(function_type)", 15);
1068 if (!dwarf_diename(&type))
1070 if (tag == DW_TAG_union_type)
1072 else if (tag == DW_TAG_structure_type)
1074 else if (tag == DW_TAG_enumeration_type)
1076 /* Write a base name */
1077 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
1079 ret = die_get_typename(&type, buf);
1080 return ret ? ret : strbuf_addstr(buf, tmp);
1084 * die_get_varname - Get the name and type of given variable DIE
1085 * @vr_die: a variable DIE
1086 * @buf: a strbuf for type and variable name
1088 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1090 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
1094 ret = die_get_typename(vr_die, buf);
1096 pr_debug("Failed to get type, make it unknown.\n");
1097 ret = strbuf_add(buf, " (unknown_type)", 14);
1100 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
1103 #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
1105 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1106 * @sp_die: a subprogram DIE
1107 * @vr_die: a variable DIE
1108 * @buf: a strbuf for variable byte offset range
1110 * Get the innermost scope range of @vr_die and stores it in @buf as
1111 * "@<function_name+[NN-NN,NN-NN]>".
1113 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
1120 Dwarf_Addr start, end;
1126 ret = die_entrypc(sp_die, &entry);
1130 name = dwarf_diename(sp_die);
1134 count = dwarf_getscopes_die(vr_die, &scopes);
1136 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1142 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1143 &start, &end)) > 0) {
1148 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1152 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1160 ret = strbuf_add(buf, "]>", 2);
1168 * die_get_var_range - Get byte offset range of given variable DIE
1169 * @sp_die: a subprogram DIE
1170 * @vr_die: a variable DIE
1171 * @buf: a strbuf for type and variable name and byte offset range
1173 * Get the byte offset range of @vr_die and stores it in @buf as
1174 * "@<function_name+[NN-NN,NN-NN]>".
1176 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1180 Dwarf_Addr start, end;
1185 Dwarf_Attribute attr;
1189 ret = die_entrypc(sp_die, &entry);
1193 name = dwarf_diename(sp_die);
1197 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1200 while ((offset = dwarf_getlocations(&attr, offset, &base,
1201 &start, &end, &op, &nops)) > 0) {
1203 /* Single Location Descriptions */
1204 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1208 /* Location Lists */
1212 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1216 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1224 ret = strbuf_add(buf, "]>", 2);
1229 int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1230 Dwarf_Die *vr_die __maybe_unused,
1231 struct strbuf *buf __maybe_unused)
1238 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1239 * @vr_die: a variable DIE
1241 static bool die_has_loclist(Dwarf_Die *vr_die)
1243 Dwarf_Attribute loc;
1244 int tag = dwarf_tag(vr_die);
1246 if (tag != DW_TAG_formal_parameter &&
1247 tag != DW_TAG_variable)
1250 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1251 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1255 * die_is_optimized_target - Check if target program is compiled with
1259 * For any object in given CU whose DW_AT_location is a location list,
1260 * target program is compiled with optimization. This is applicable to
1263 bool die_is_optimized_target(Dwarf_Die *cu_die)
1267 if (die_has_loclist(cu_die))
1270 if (!dwarf_child(cu_die, &tmp_die) &&
1271 die_is_optimized_target(&tmp_die))
1274 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1275 die_is_optimized_target(&tmp_die))
1282 * die_search_idx - Search index of given line address
1283 * @lines: Line records of single CU
1284 * @nr_lines: Number of @lines
1285 * @addr: address we are looking for
1286 * @idx: index to be set by this function (return value)
1288 * Search for @addr by looping over every lines of CU. If address
1289 * matches, set index of that line in @idx. Note that single source
1290 * line can have multiple line records. i.e. single source line can
1291 * have multiple index.
1293 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1294 Dwarf_Addr addr, unsigned long *idx)
1299 for (i = 0; i < nr_lines; i++) {
1300 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1312 * die_get_postprologue_addr - Search next address after function prologue
1313 * @entrypc_idx: entrypc index
1314 * @lines: Line records of single CU
1315 * @nr_lines: Number of @lines
1316 * @hignpc: high PC address of function
1317 * @postprologue_addr: Next address after function prologue (return value)
1319 * Look for prologue-end marker. If there is no explicit marker, return
1320 * address of next line record or next source line.
1322 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1324 unsigned long nr_lines,
1326 Dwarf_Addr *postprologue_addr)
1329 int entrypc_lno, lno;
1334 /* entrypc_lno is actual source line number */
1335 line = dwarf_onesrcline(lines, entrypc_idx);
1336 if (dwarf_lineno(line, &entrypc_lno))
1339 for (i = entrypc_idx; i < nr_lines; i++) {
1340 line = dwarf_onesrcline(lines, i);
1342 if (dwarf_lineaddr(line, &addr) ||
1343 dwarf_lineno(line, &lno) ||
1344 dwarf_lineprologueend(line, &p_end))
1347 /* highpc is exclusive. [entrypc,highpc) */
1351 /* clang supports prologue-end marker */
1355 /* Actual next line in source */
1356 if (lno != entrypc_lno)
1360 * Single source line can have multiple line records.
1362 * void foo() { printf("hello\n"); }
1363 * contains two line records. One points to declaration and
1364 * other points to printf() line. Variable 'lno' won't get
1365 * incremented in this case but 'i' will.
1367 if (i != entrypc_idx)
1371 dwarf_lineaddr(line, postprologue_addr);
1372 if (*postprologue_addr >= highpc)
1373 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1380 * die_skip_prologue - Use next address after prologue as probe location
1381 * @sp_die: a subprogram DIE
1383 * @entrypc: entrypc of the function
1385 * Function prologue prepares stack and registers before executing function
1386 * logic. When target program is compiled without optimization, function
1387 * parameter information is only valid after prologue. When we probe entrypc
1388 * of the function, and try to record function parameter, it contains
1391 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1392 Dwarf_Addr *entrypc)
1394 size_t nr_lines = 0;
1395 unsigned long entrypc_idx = 0;
1396 Dwarf_Lines *lines = NULL;
1397 Dwarf_Addr postprologue_addr;
1400 if (dwarf_highpc(sp_die, &highpc))
1403 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1406 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1409 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1410 highpc, &postprologue_addr))
1413 *entrypc = postprologue_addr;