1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * dwarf-aux.c : libdw auxiliary interfaces
11 #include "dwarf-aux.h"
15 * cu_find_realpath - Find the realpath of the target file
16 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
17 * @fname: The tail filename of the target file
19 * Find the real(long) path of @fname in @cu_die.
21 const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
25 const char *src = NULL;
31 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
35 for (i = 0; i < nfiles; i++) {
36 src = dwarf_filesrc(files, i, NULL, NULL);
37 if (strtailcmp(src, fname) == 0)
46 * cu_get_comp_dir - Get the path of compilation directory
49 * Get the path of compilation directory of given @cu_die.
50 * Since this depends on DW_AT_comp_dir, older gcc will not
51 * embedded it. In that case, this returns NULL.
53 const char *cu_get_comp_dir(Dwarf_Die *cu_die)
56 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
58 return dwarf_formstring(&attr);
62 * cu_find_lineinfo - Get a line number and file name for given address
65 * @fname: a pointer which returns the file name string
66 * @lineno: a pointer which returns the line number
68 * Find a line number and file name for @addr in @cu_die.
70 int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
71 const char **fname, int *lineno)
76 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
77 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
78 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
79 *fname = dwarf_linesrc(line, NULL, NULL);
81 /* line number is useless without filename */
85 return *lineno ?: -ENOENT;
88 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
91 * cu_walk_functions_at - Walk on function DIEs at given address
94 * @callback: A callback which called with found DIEs
97 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
98 * should be subprogram or inlined-subroutines.
100 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
101 int (*callback)(Dwarf_Die *, void *), void *data)
107 /* Inlined function could be recursive. Trace it until fail */
108 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
110 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
112 ret = callback(sc_die, data);
122 * die_get_linkage_name - Get the linkage name of the object
123 * @dw_die: A DIE of the object
125 * Get the linkage name attiribute of given @dw_die.
126 * For C++ binary, the linkage name will be the mangled symbol.
128 const char *die_get_linkage_name(Dwarf_Die *dw_die)
130 Dwarf_Attribute attr;
132 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
134 return dwarf_formstring(&attr);
138 * die_compare_name - Compare diename and tname
140 * @tname: a string of target name
142 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
144 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
148 name = dwarf_diename(dw_die);
149 return name ? (strcmp(tname, name) == 0) : false;
153 * die_match_name - Match diename/linkage name and glob
155 * @glob: a string of target glob pattern
157 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
158 * This also match linkage name.
160 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
164 name = dwarf_diename(dw_die);
165 if (name && strglobmatch(name, glob))
167 /* fall back to check linkage name */
168 name = die_get_linkage_name(dw_die);
169 if (name && strglobmatch(name, glob))
176 * die_get_call_lineno - Get callsite line number of inline-function instance
177 * @in_die: a DIE of an inlined function instance
179 * Get call-site line number of @in_die. This means from where the inline
180 * function is called.
182 int die_get_call_lineno(Dwarf_Die *in_die)
184 Dwarf_Attribute attr;
187 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
190 dwarf_formudata(&attr, &ret);
195 * die_get_type - Get type DIE
196 * @vr_die: a DIE of a variable
197 * @die_mem: where to store a type DIE
199 * Get a DIE of the type of given variable (@vr_die), and store
200 * it to die_mem. Return NULL if fails to get a type DIE.
202 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
204 Dwarf_Attribute attr;
206 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
207 dwarf_formref_die(&attr, die_mem))
213 /* Get a type die, but skip qualifiers */
214 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
219 vr_die = die_get_type(vr_die, die_mem);
222 tag = dwarf_tag(vr_die);
223 } while (tag == DW_TAG_const_type ||
224 tag == DW_TAG_restrict_type ||
225 tag == DW_TAG_volatile_type ||
226 tag == DW_TAG_shared_type);
232 * die_get_real_type - Get a type die, but skip qualifiers and typedef
233 * @vr_die: a DIE of a variable
234 * @die_mem: where to store a type DIE
236 * Get a DIE of the type of given variable (@vr_die), and store
237 * it to die_mem. Return NULL if fails to get a type DIE.
238 * If the type is qualifiers (e.g. const) or typedef, this skips it
239 * and tries to find real type (structure or basic types, e.g. int).
241 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
244 vr_die = __die_get_real_type(vr_die, die_mem);
245 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
250 /* Get attribute and translate it as a udata */
251 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
254 Dwarf_Attribute attr;
256 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
257 dwarf_formudata(&attr, result) != 0)
263 /* Get attribute and translate it as a sdata */
264 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
267 Dwarf_Attribute attr;
269 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
270 dwarf_formsdata(&attr, result) != 0)
277 * die_is_signed_type - Check whether a type DIE is signed or not
278 * @tp_die: a DIE of a type
280 * Get the encoding of @tp_die and return true if the encoding
283 bool die_is_signed_type(Dwarf_Die *tp_die)
287 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
290 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
291 ret == DW_ATE_signed_fixed);
295 * die_is_func_def - Ensure that this DIE is a subprogram and definition
298 * Ensure that this DIE is a subprogram and NOT a declaration. This
299 * returns true if @dw_die is a function definition.
301 bool die_is_func_def(Dwarf_Die *dw_die)
303 Dwarf_Attribute attr;
305 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
306 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
310 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
313 * Ensure that this DIE is an instance (which has an entry address).
314 * This returns true if @dw_die is a function instance. If not, you need to
315 * call die_walk_instances() to find actual instances.
317 bool die_is_func_instance(Dwarf_Die *dw_die)
321 /* Actually gcc optimizes non-inline as like as inlined */
322 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
325 * die_get_data_member_location - Get the data-member offset
326 * @mb_die: a DIE of a member of a data structure
327 * @offs: The offset of the member in the data structure
329 * Get the offset of @mb_die in the data structure including @mb_die, and
330 * stores result offset to @offs. If any error occurs this returns errno.
332 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
334 Dwarf_Attribute attr;
339 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
342 if (dwarf_formudata(&attr, offs) != 0) {
343 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
344 ret = dwarf_getlocation(&attr, &expr, &nexpr);
345 if (ret < 0 || nexpr == 0)
348 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
349 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
350 expr[0].atom, nexpr);
353 *offs = (Dwarf_Word)expr[0].number;
358 /* Get the call file index number in CU DIE */
359 static int die_get_call_fileno(Dwarf_Die *in_die)
363 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
369 /* Get the declared file index number in CU DIE */
370 static int die_get_decl_fileno(Dwarf_Die *pdie)
374 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
381 * die_get_call_file - Get callsite file name of inlined function instance
382 * @in_die: a DIE of an inlined function instance
384 * Get call-site file name of @in_die. This means from which file the inline
385 * function is called.
387 const char *die_get_call_file(Dwarf_Die *in_die)
393 idx = die_get_call_fileno(in_die);
394 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
395 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
398 return dwarf_filesrc(files, idx, NULL, NULL);
403 * die_find_child - Generic DIE search function in DIE tree
404 * @rt_die: a root DIE
405 * @callback: a callback function
406 * @data: a user data passed to the callback function
407 * @die_mem: a buffer for result DIE
409 * Trace DIE tree from @rt_die and call @callback for each child DIE.
410 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
411 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
412 * this continues to trace the tree. Optionally, @callback can return
413 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
414 * the children and trace only the siblings respectively.
415 * Returns NULL if @callback can't find any appropriate DIE.
417 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
418 int (*callback)(Dwarf_Die *, void *),
419 void *data, Dwarf_Die *die_mem)
424 ret = dwarf_child(rt_die, die_mem);
429 ret = callback(die_mem, data);
430 if (ret == DIE_FIND_CB_END)
433 if ((ret & DIE_FIND_CB_CHILD) &&
434 die_find_child(die_mem, callback, data, &child_die)) {
435 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
438 } while ((ret & DIE_FIND_CB_SIBLING) &&
439 dwarf_siblingof(die_mem, die_mem) == 0);
444 struct __addr_die_search_param {
449 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
451 struct __addr_die_search_param *ad = data;
454 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
455 !dwarf_highpc(fn_die, &addr) &&
457 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
458 return DWARF_CB_ABORT;
464 * die_find_tailfunc - Search for a non-inlined function with tail call at
466 * @cu_die: a CU DIE which including @addr
467 * @addr: target address
468 * @die_mem: a buffer for result DIE
470 * Search for a non-inlined function DIE with tail call at @addr. Stores the
471 * DIE to @die_mem and returns it if found. Returns NULL if failed.
473 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
476 struct __addr_die_search_param ad;
478 ad.die_mem = die_mem;
479 /* dwarf_getscopes can't find subprogram. */
480 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
486 /* die_find callback for non-inlined function search */
487 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
489 struct __addr_die_search_param *ad = data;
492 * Since a declaration entry doesn't has given pc, this always returns
493 * function definition entry.
495 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
496 dwarf_haspc(fn_die, ad->addr)) {
497 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
498 return DWARF_CB_ABORT;
504 * die_find_realfunc - Search a non-inlined function at given address
505 * @cu_die: a CU DIE which including @addr
506 * @addr: target address
507 * @die_mem: a buffer for result DIE
509 * Search a non-inlined function DIE which includes @addr. Stores the
510 * DIE to @die_mem and returns it if found. Returns NULL if failed.
512 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
515 struct __addr_die_search_param ad;
517 ad.die_mem = die_mem;
518 /* dwarf_getscopes can't find subprogram. */
519 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
525 /* die_find callback for inline function search */
526 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
528 Dwarf_Addr *addr = data;
530 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
531 dwarf_haspc(die_mem, *addr))
532 return DIE_FIND_CB_END;
534 return DIE_FIND_CB_CONTINUE;
538 * die_find_top_inlinefunc - Search the top inlined function at given address
539 * @sp_die: a subprogram DIE which including @addr
540 * @addr: target address
541 * @die_mem: a buffer for result DIE
543 * Search an inlined function DIE which includes @addr. Stores the
544 * DIE to @die_mem and returns it if found. Returns NULL if failed.
545 * Even if several inlined functions are expanded recursively, this
546 * doesn't trace it down, and returns the topmost one.
548 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
551 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
555 * die_find_inlinefunc - Search an inlined function at given address
556 * @sp_die: a subprogram DIE which including @addr
557 * @addr: target address
558 * @die_mem: a buffer for result DIE
560 * Search an inlined function DIE which includes @addr. Stores the
561 * DIE to @die_mem and returns it if found. Returns NULL if failed.
562 * If several inlined functions are expanded recursively, this trace
563 * it down and returns deepest one.
565 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
570 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
574 /* Inlined function could be recursive. Trace it until fail */
576 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
577 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
584 struct __instance_walk_param {
586 int (*callback)(Dwarf_Die *, void *);
591 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
593 struct __instance_walk_param *iwp = data;
594 Dwarf_Attribute attr_mem;
595 Dwarf_Die origin_mem;
596 Dwarf_Attribute *attr;
600 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
602 return DIE_FIND_CB_CONTINUE;
604 origin = dwarf_formref_die(attr, &origin_mem);
605 if (origin == NULL || origin->addr != iwp->addr)
606 return DIE_FIND_CB_CONTINUE;
608 /* Ignore redundant instances */
609 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
610 dwarf_decl_line(origin, &tmp);
611 if (die_get_call_lineno(inst) == tmp) {
612 tmp = die_get_decl_fileno(origin);
613 if (die_get_call_fileno(inst) == tmp)
614 return DIE_FIND_CB_CONTINUE;
618 iwp->retval = iwp->callback(inst, iwp->data);
620 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
624 * die_walk_instances - Walk on instances of given DIE
625 * @or_die: an abstract original DIE
626 * @callback: a callback function which is called with instance DIE
629 * Walk on the instances of give @in_die. @in_die must be an inlined function
630 * declartion. This returns the return value of @callback if it returns
631 * non-zero value, or -ENOENT if there is no instance.
633 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
638 struct __instance_walk_param iwp = {
639 .addr = or_die->addr,
640 .callback = callback,
645 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
648 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
653 /* Line walker internal parameters */
654 struct __line_walk_param {
656 line_walk_callback_t callback;
661 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
663 struct __line_walk_param *lw = data;
668 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
669 fname = die_get_call_file(in_die);
670 lineno = die_get_call_lineno(in_die);
671 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
672 lw->retval = lw->callback(fname, lineno, addr, lw->data);
674 return DIE_FIND_CB_END;
678 /* Don't need to search recursively */
679 return DIE_FIND_CB_SIBLING;
682 fname = dwarf_decl_file(in_die);
683 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
684 lw->retval = lw->callback(fname, lineno, addr, lw->data);
686 return DIE_FIND_CB_END;
690 /* Continue to search nested inlined function call-sites */
691 return DIE_FIND_CB_CONTINUE;
694 /* Walk on lines of blocks included in given DIE */
695 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
696 line_walk_callback_t callback, void *data)
698 struct __line_walk_param lw = {
699 .recursive = recursive,
700 .callback = callback,
709 /* Handle function declaration line */
710 fname = dwarf_decl_file(sp_die);
711 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
712 dwarf_entrypc(sp_die, &addr) == 0) {
713 lw.retval = callback(fname, lineno, addr, data);
717 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
722 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
724 struct __line_walk_param *lw = data;
726 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
728 return DWARF_CB_ABORT;
734 * die_walk_lines - Walk on lines inside given DIE
735 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
736 * @callback: callback routine
739 * Walk on all lines inside given @rt_die and call @callback on each line.
740 * If the @rt_die is a function, walk only on the lines inside the function,
741 * otherwise @rt_die must be a CU DIE.
742 * Note that this walks not only dwarf line list, but also function entries
743 * and inline call-site.
745 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
750 const char *fname, *decf = NULL;
753 Dwarf_Die die_mem, *cu_die;
757 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
758 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
759 dwarf_decl_line(rt_die, &decl);
760 decf = dwarf_decl_file(rt_die);
764 pr_debug2("Failed to get CU from given DIE.\n");
768 /* Get lines list in the CU */
769 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
770 pr_debug2("Failed to get source lines on this CU.\n");
773 pr_debug2("Get %zd lines from this CU\n", nlines);
775 /* Walk on the lines on lines list */
776 for (i = 0; i < nlines; i++) {
777 line = dwarf_onesrcline(lines, i);
779 dwarf_lineno(line, &lineno) != 0 ||
780 dwarf_lineaddr(line, &addr) != 0) {
781 pr_debug2("Failed to get line info. "
782 "Possible error in debuginfo.\n");
785 /* Filter lines based on address */
786 if (rt_die != cu_die) {
789 * The line is included in given function, and
790 * no inline block includes it.
792 if (!dwarf_haspc(rt_die, addr))
794 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
795 dwarf_decl_line(&die_mem, &inl);
797 decf != dwarf_decl_file(&die_mem))
801 /* Get source line */
802 fname = dwarf_linesrc(line, NULL, NULL);
804 ret = callback(fname, lineno, addr, data);
810 * Dwarf lines doesn't include function declarations and inlined
811 * subroutines. We have to check functions list or given function.
813 if (rt_die != cu_die)
815 * Don't need walk functions recursively, because nested
816 * inlined functions don't have lines of the specified DIE.
818 ret = __die_walk_funclines(rt_die, false, callback, data);
820 struct __line_walk_param param = {
821 .callback = callback,
825 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
832 struct __find_variable_param {
837 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
839 struct __find_variable_param *fvp = data;
840 Dwarf_Attribute attr;
843 tag = dwarf_tag(die_mem);
844 if ((tag == DW_TAG_formal_parameter ||
845 tag == DW_TAG_variable) &&
846 die_compare_name(die_mem, fvp->name) &&
847 /* Does the DIE have location information or external instance? */
848 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
849 dwarf_attr(die_mem, DW_AT_location, &attr)))
850 return DIE_FIND_CB_END;
851 if (dwarf_haspc(die_mem, fvp->addr))
852 return DIE_FIND_CB_CONTINUE;
854 return DIE_FIND_CB_SIBLING;
858 * die_find_variable_at - Find a given name variable at given address
859 * @sp_die: a function DIE
860 * @name: variable name
862 * @die_mem: a buffer for result DIE
864 * Find a variable DIE called @name at @addr in @sp_die.
866 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
867 Dwarf_Addr addr, Dwarf_Die *die_mem)
869 struct __find_variable_param fvp = { .name = name, .addr = addr};
871 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
875 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
877 const char *name = data;
879 if (dwarf_tag(die_mem) == DW_TAG_member) {
880 if (die_compare_name(die_mem, name))
881 return DIE_FIND_CB_END;
882 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
883 Dwarf_Die type_die, tmp_die;
884 if (die_get_type(die_mem, &type_die) &&
885 die_find_member(&type_die, name, &tmp_die))
886 return DIE_FIND_CB_END;
889 return DIE_FIND_CB_SIBLING;
893 * die_find_member - Find a given name member in a data structure
894 * @st_die: a data structure type DIE
896 * @die_mem: a buffer for result DIE
898 * Find a member DIE called @name in @st_die.
900 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
903 return die_find_child(st_die, __die_find_member_cb, (void *)name,
908 * die_get_typename - Get the name of given variable DIE
909 * @vr_die: a variable DIE
910 * @buf: a strbuf for result type name
912 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
913 * and Return -ENOENT if failed to find type name.
914 * Note that the result will stores typedef name if possible, and stores
915 * "*(function_type)" if the type is a function pointer.
917 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
921 const char *tmp = "";
923 if (__die_get_real_type(vr_die, &type) == NULL)
926 tag = dwarf_tag(&type);
927 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
929 else if (tag == DW_TAG_subroutine_type) {
930 /* Function pointer */
931 return strbuf_add(buf, "(function_type)", 15);
933 if (!dwarf_diename(&type))
935 if (tag == DW_TAG_union_type)
937 else if (tag == DW_TAG_structure_type)
939 else if (tag == DW_TAG_enumeration_type)
941 /* Write a base name */
942 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
944 ret = die_get_typename(&type, buf);
945 return ret ? ret : strbuf_addstr(buf, tmp);
949 * die_get_varname - Get the name and type of given variable DIE
950 * @vr_die: a variable DIE
951 * @buf: a strbuf for type and variable name
953 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
955 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
959 ret = die_get_typename(vr_die, buf);
961 pr_debug("Failed to get type, make it unknown.\n");
962 ret = strbuf_add(buf, " (unknown_type)", 14);
965 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
968 #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
970 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
971 * @sp_die: a subprogram DIE
972 * @vr_die: a variable DIE
973 * @buf: a strbuf for variable byte offset range
975 * Get the innermost scope range of @vr_die and stores it in @buf as
976 * "@<function_name+[NN-NN,NN-NN]>".
978 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
985 Dwarf_Addr start, end;
991 ret = dwarf_entrypc(sp_die, &entry);
995 name = dwarf_diename(sp_die);
999 count = dwarf_getscopes_die(vr_die, &scopes);
1001 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1007 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1008 &start, &end)) > 0) {
1013 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1017 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1025 ret = strbuf_add(buf, "]>", 2);
1033 * die_get_var_range - Get byte offset range of given variable DIE
1034 * @sp_die: a subprogram DIE
1035 * @vr_die: a variable DIE
1036 * @buf: a strbuf for type and variable name and byte offset range
1038 * Get the byte offset range of @vr_die and stores it in @buf as
1039 * "@<function_name+[NN-NN,NN-NN]>".
1041 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1045 Dwarf_Addr start, end;
1050 Dwarf_Attribute attr;
1054 ret = dwarf_entrypc(sp_die, &entry);
1058 name = dwarf_diename(sp_die);
1062 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1065 while ((offset = dwarf_getlocations(&attr, offset, &base,
1066 &start, &end, &op, &nops)) > 0) {
1068 /* Single Location Descriptions */
1069 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1073 /* Location Lists */
1077 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1081 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1089 ret = strbuf_add(buf, "]>", 2);
1094 int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1095 Dwarf_Die *vr_die __maybe_unused,
1096 struct strbuf *buf __maybe_unused)
1103 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1104 * @vr_die: a variable DIE
1106 static bool die_has_loclist(Dwarf_Die *vr_die)
1108 Dwarf_Attribute loc;
1109 int tag = dwarf_tag(vr_die);
1111 if (tag != DW_TAG_formal_parameter &&
1112 tag != DW_TAG_variable)
1115 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1116 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1120 * die_is_optimized_target - Check if target program is compiled with
1124 * For any object in given CU whose DW_AT_location is a location list,
1125 * target program is compiled with optimization. This is applicable to
1128 bool die_is_optimized_target(Dwarf_Die *cu_die)
1132 if (die_has_loclist(cu_die))
1135 if (!dwarf_child(cu_die, &tmp_die) &&
1136 die_is_optimized_target(&tmp_die))
1139 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1140 die_is_optimized_target(&tmp_die))
1147 * die_search_idx - Search index of given line address
1148 * @lines: Line records of single CU
1149 * @nr_lines: Number of @lines
1150 * @addr: address we are looking for
1151 * @idx: index to be set by this function (return value)
1153 * Search for @addr by looping over every lines of CU. If address
1154 * matches, set index of that line in @idx. Note that single source
1155 * line can have multiple line records. i.e. single source line can
1156 * have multiple index.
1158 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1159 Dwarf_Addr addr, unsigned long *idx)
1164 for (i = 0; i < nr_lines; i++) {
1165 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1177 * die_get_postprologue_addr - Search next address after function prologue
1178 * @entrypc_idx: entrypc index
1179 * @lines: Line records of single CU
1180 * @nr_lines: Number of @lines
1181 * @hignpc: high PC address of function
1182 * @postprologue_addr: Next address after function prologue (return value)
1184 * Look for prologue-end marker. If there is no explicit marker, return
1185 * address of next line record or next source line.
1187 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1189 unsigned long nr_lines,
1191 Dwarf_Addr *postprologue_addr)
1194 int entrypc_lno, lno;
1199 /* entrypc_lno is actual source line number */
1200 line = dwarf_onesrcline(lines, entrypc_idx);
1201 if (dwarf_lineno(line, &entrypc_lno))
1204 for (i = entrypc_idx; i < nr_lines; i++) {
1205 line = dwarf_onesrcline(lines, i);
1207 if (dwarf_lineaddr(line, &addr) ||
1208 dwarf_lineno(line, &lno) ||
1209 dwarf_lineprologueend(line, &p_end))
1212 /* highpc is exclusive. [entrypc,highpc) */
1216 /* clang supports prologue-end marker */
1220 /* Actual next line in source */
1221 if (lno != entrypc_lno)
1225 * Single source line can have multiple line records.
1227 * void foo() { printf("hello\n"); }
1228 * contains two line records. One points to declaration and
1229 * other points to printf() line. Variable 'lno' won't get
1230 * incremented in this case but 'i' will.
1232 if (i != entrypc_idx)
1236 dwarf_lineaddr(line, postprologue_addr);
1237 if (*postprologue_addr >= highpc)
1238 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1245 * die_skip_prologue - Use next address after prologue as probe location
1246 * @sp_die: a subprogram DIE
1248 * @entrypc: entrypc of the function
1250 * Function prologue prepares stack and registers before executing function
1251 * logic. When target program is compiled without optimization, function
1252 * parameter information is only valid after prologue. When we probe entrypc
1253 * of the function, and try to record function parameter, it contains
1256 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1257 Dwarf_Addr *entrypc)
1259 size_t nr_lines = 0;
1260 unsigned long entrypc_idx = 0;
1261 Dwarf_Lines *lines = NULL;
1262 Dwarf_Addr postprologue_addr;
1265 if (dwarf_highpc(sp_die, &highpc))
1268 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1271 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1274 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1275 highpc, &postprologue_addr))
1278 *entrypc = postprologue_addr;