2 * dwarf-aux.c : libdw auxiliary interfaces
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 #include "dwarf-aux.h"
26 * cu_find_realpath - Find the realpath of the target file
27 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
28 * @fname: The tail filename of the target file
30 * Find the real(long) path of @fname in @cu_die.
32 const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
36 const char *src = NULL;
42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
46 for (i = 0; i < nfiles; i++) {
47 src = dwarf_filesrc(files, i, NULL, NULL);
48 if (strtailcmp(src, fname) == 0)
57 * cu_get_comp_dir - Get the path of compilation directory
60 * Get the path of compilation directory of given @cu_die.
61 * Since this depends on DW_AT_comp_dir, older gcc will not
62 * embedded it. In that case, this returns NULL.
64 const char *cu_get_comp_dir(Dwarf_Die *cu_die)
67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
69 return dwarf_formstring(&attr);
73 * cu_find_lineinfo - Get a line number and file name for given address
76 * @fname: a pointer which returns the file name string
77 * @lineno: a pointer which returns the line number
79 * Find a line number and file name for @addr in @cu_die.
81 int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
82 const char **fname, int *lineno)
87 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
88 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
89 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
90 *fname = dwarf_linesrc(line, NULL, NULL);
92 /* line number is useless without filename */
96 return *lineno ?: -ENOENT;
99 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
102 * cu_walk_functions_at - Walk on function DIEs at given address
105 * @callback: A callback which called with found DIEs
108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
109 * should be subprogram or inlined-subroutines.
111 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
112 int (*callback)(Dwarf_Die *, void *), void *data)
118 /* Inlined function could be recursive. Trace it until fail */
119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
123 ret = callback(sc_die, data);
133 * die_compare_name - Compare diename and tname
135 * @tname: a string of target name
137 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
139 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
142 name = dwarf_diename(dw_die);
143 return name ? (strcmp(tname, name) == 0) : false;
147 * die_get_call_lineno - Get callsite line number of inline-function instance
148 * @in_die: a DIE of an inlined function instance
150 * Get call-site line number of @in_die. This means from where the inline
151 * function is called.
153 int die_get_call_lineno(Dwarf_Die *in_die)
155 Dwarf_Attribute attr;
158 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
161 dwarf_formudata(&attr, &ret);
166 * die_get_type - Get type DIE
167 * @vr_die: a DIE of a variable
168 * @die_mem: where to store a type DIE
170 * Get a DIE of the type of given variable (@vr_die), and store
171 * it to die_mem. Return NULL if fails to get a type DIE.
173 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
175 Dwarf_Attribute attr;
177 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
178 dwarf_formref_die(&attr, die_mem))
184 /* Get a type die, but skip qualifiers */
185 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
190 vr_die = die_get_type(vr_die, die_mem);
193 tag = dwarf_tag(vr_die);
194 } while (tag == DW_TAG_const_type ||
195 tag == DW_TAG_restrict_type ||
196 tag == DW_TAG_volatile_type ||
197 tag == DW_TAG_shared_type);
203 * die_get_real_type - Get a type die, but skip qualifiers and typedef
204 * @vr_die: a DIE of a variable
205 * @die_mem: where to store a type DIE
207 * Get a DIE of the type of given variable (@vr_die), and store
208 * it to die_mem. Return NULL if fails to get a type DIE.
209 * If the type is qualifiers (e.g. const) or typedef, this skips it
210 * and tries to find real type (structure or basic types, e.g. int).
212 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
215 vr_die = __die_get_real_type(vr_die, die_mem);
216 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
221 /* Get attribute and translate it as a udata */
222 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
225 Dwarf_Attribute attr;
227 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
228 dwarf_formudata(&attr, result) != 0)
234 /* Get attribute and translate it as a sdata */
235 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
238 Dwarf_Attribute attr;
240 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
241 dwarf_formsdata(&attr, result) != 0)
248 * die_is_signed_type - Check whether a type DIE is signed or not
249 * @tp_die: a DIE of a type
251 * Get the encoding of @tp_die and return true if the encoding
254 bool die_is_signed_type(Dwarf_Die *tp_die)
258 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
261 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
262 ret == DW_ATE_signed_fixed);
266 * die_get_data_member_location - Get the data-member offset
267 * @mb_die: a DIE of a member of a data structure
268 * @offs: The offset of the member in the data structure
270 * Get the offset of @mb_die in the data structure including @mb_die, and
271 * stores result offset to @offs. If any error occurs this returns errno.
273 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
275 Dwarf_Attribute attr;
280 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
283 if (dwarf_formudata(&attr, offs) != 0) {
284 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
285 ret = dwarf_getlocation(&attr, &expr, &nexpr);
286 if (ret < 0 || nexpr == 0)
289 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
290 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
291 expr[0].atom, nexpr);
294 *offs = (Dwarf_Word)expr[0].number;
299 /* Get the call file index number in CU DIE */
300 static int die_get_call_fileno(Dwarf_Die *in_die)
304 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
311 * die_get_call_file - Get callsite file name of inlined function instance
312 * @in_die: a DIE of an inlined function instance
314 * Get call-site file name of @in_die. This means from which file the inline
315 * function is called.
317 const char *die_get_call_file(Dwarf_Die *in_die)
323 idx = die_get_call_fileno(in_die);
324 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
325 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
328 return dwarf_filesrc(files, idx, NULL, NULL);
333 * die_find_child - Generic DIE search function in DIE tree
334 * @rt_die: a root DIE
335 * @callback: a callback function
336 * @data: a user data passed to the callback function
337 * @die_mem: a buffer for result DIE
339 * Trace DIE tree from @rt_die and call @callback for each child DIE.
340 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
341 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
342 * this continues to trace the tree. Optionally, @callback can return
343 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
344 * the children and trace only the siblings respectively.
345 * Returns NULL if @callback can't find any appropriate DIE.
347 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
348 int (*callback)(Dwarf_Die *, void *),
349 void *data, Dwarf_Die *die_mem)
354 ret = dwarf_child(rt_die, die_mem);
359 ret = callback(die_mem, data);
360 if (ret == DIE_FIND_CB_END)
363 if ((ret & DIE_FIND_CB_CHILD) &&
364 die_find_child(die_mem, callback, data, &child_die)) {
365 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
368 } while ((ret & DIE_FIND_CB_SIBLING) &&
369 dwarf_siblingof(die_mem, die_mem) == 0);
374 struct __addr_die_search_param {
379 /* die_find callback for non-inlined function search */
380 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
382 struct __addr_die_search_param *ad = data;
384 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
385 dwarf_haspc(fn_die, ad->addr)) {
386 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
387 return DWARF_CB_ABORT;
393 * die_find_realfunc - Search a non-inlined function at given address
394 * @cu_die: a CU DIE which including @addr
395 * @addr: target address
396 * @die_mem: a buffer for result DIE
398 * Search a non-inlined function DIE which includes @addr. Stores the
399 * DIE to @die_mem and returns it if found. Returns NULl if failed.
401 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
404 struct __addr_die_search_param ad;
406 ad.die_mem = die_mem;
407 /* dwarf_getscopes can't find subprogram. */
408 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
414 /* die_find callback for inline function search */
415 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
417 Dwarf_Addr *addr = data;
419 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
420 dwarf_haspc(die_mem, *addr))
421 return DIE_FIND_CB_END;
423 return DIE_FIND_CB_CONTINUE;
427 * die_find_inlinefunc - Search an inlined function at given address
428 * @cu_die: a CU DIE which including @addr
429 * @addr: target address
430 * @die_mem: a buffer for result DIE
432 * Search an inlined function DIE which includes @addr. Stores the
433 * DIE to @die_mem and returns it if found. Returns NULl if failed.
434 * If several inlined functions are expanded recursively, this trace
435 * it and returns deepest one.
437 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
442 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
446 /* Inlined function could be recursive. Trace it until fail */
448 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
449 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
456 /* Line walker internal parameters */
457 struct __line_walk_param {
459 line_walk_callback_t callback;
464 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
466 struct __line_walk_param *lw = data;
471 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
472 fname = die_get_call_file(in_die);
473 lineno = die_get_call_lineno(in_die);
474 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
475 lw->retval = lw->callback(fname, lineno, addr, lw->data);
477 return DIE_FIND_CB_END;
481 /* Don't need to search recursively */
482 return DIE_FIND_CB_SIBLING;
485 fname = dwarf_decl_file(in_die);
486 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
487 lw->retval = lw->callback(fname, lineno, addr, lw->data);
489 return DIE_FIND_CB_END;
493 /* Continue to search nested inlined function call-sites */
494 return DIE_FIND_CB_CONTINUE;
497 /* Walk on lines of blocks included in given DIE */
498 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
499 line_walk_callback_t callback, void *data)
501 struct __line_walk_param lw = {
502 .recursive = recursive,
503 .callback = callback,
512 /* Handle function declaration line */
513 fname = dwarf_decl_file(sp_die);
514 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
515 dwarf_entrypc(sp_die, &addr) == 0) {
516 lw.retval = callback(fname, lineno, addr, data);
520 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
525 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
527 struct __line_walk_param *lw = data;
529 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
531 return DWARF_CB_ABORT;
537 * die_walk_lines - Walk on lines inside given DIE
538 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
539 * @callback: callback routine
542 * Walk on all lines inside given @rt_die and call @callback on each line.
543 * If the @rt_die is a function, walk only on the lines inside the function,
544 * otherwise @rt_die must be a CU DIE.
545 * Note that this walks not only dwarf line list, but also function entries
546 * and inline call-site.
548 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
555 Dwarf_Die die_mem, *cu_die;
559 if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
560 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
564 pr_debug2("Failed to get CU from given DIE.\n");
568 /* Get lines list in the CU */
569 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
570 pr_debug2("Failed to get source lines on this CU.\n");
573 pr_debug2("Get %zd lines from this CU\n", nlines);
575 /* Walk on the lines on lines list */
576 for (i = 0; i < nlines; i++) {
577 line = dwarf_onesrcline(lines, i);
579 dwarf_lineno(line, &lineno) != 0 ||
580 dwarf_lineaddr(line, &addr) != 0) {
581 pr_debug2("Failed to get line info. "
582 "Possible error in debuginfo.\n");
585 /* Filter lines based on address */
586 if (rt_die != cu_die)
589 * The line is included in given function, and
590 * no inline block includes it.
592 if (!dwarf_haspc(rt_die, addr) ||
593 die_find_inlinefunc(rt_die, addr, &die_mem))
595 /* Get source line */
596 fname = dwarf_linesrc(line, NULL, NULL);
598 ret = callback(fname, lineno, addr, data);
604 * Dwarf lines doesn't include function declarations and inlined
605 * subroutines. We have to check functions list or given function.
607 if (rt_die != cu_die)
609 * Don't need walk functions recursively, because nested
610 * inlined functions don't have lines of the specified DIE.
612 ret = __die_walk_funclines(rt_die, false, callback, data);
614 struct __line_walk_param param = {
615 .callback = callback,
619 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
626 struct __find_variable_param {
631 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
633 struct __find_variable_param *fvp = data;
636 tag = dwarf_tag(die_mem);
637 if ((tag == DW_TAG_formal_parameter ||
638 tag == DW_TAG_variable) &&
639 die_compare_name(die_mem, fvp->name))
640 return DIE_FIND_CB_END;
642 if (dwarf_haspc(die_mem, fvp->addr))
643 return DIE_FIND_CB_CONTINUE;
645 return DIE_FIND_CB_SIBLING;
649 * die_find_variable_at - Find a given name variable at given address
650 * @sp_die: a function DIE
651 * @name: variable name
653 * @die_mem: a buffer for result DIE
655 * Find a variable DIE called @name at @addr in @sp_die.
657 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
658 Dwarf_Addr addr, Dwarf_Die *die_mem)
660 struct __find_variable_param fvp = { .name = name, .addr = addr};
662 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
666 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
668 const char *name = data;
670 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
671 die_compare_name(die_mem, name))
672 return DIE_FIND_CB_END;
674 return DIE_FIND_CB_SIBLING;
678 * die_find_member - Find a given name member in a data structure
679 * @st_die: a data structure type DIE
681 * @die_mem: a buffer for result DIE
683 * Find a member DIE called @name in @st_die.
685 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
688 return die_find_child(st_die, __die_find_member_cb, (void *)name,
693 * die_get_typename - Get the name of given variable DIE
694 * @vr_die: a variable DIE
695 * @buf: a buffer for result type name
696 * @len: a max-length of @buf
698 * Get the name of @vr_die and stores it to @buf. Return the actual length
699 * of type name if succeeded. Return -E2BIG if @len is not enough long, and
700 * Return -ENOENT if failed to find type name.
701 * Note that the result will stores typedef name if possible, and stores
702 * "*(function_type)" if the type is a function pointer.
704 int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
708 const char *tmp = "";
710 if (__die_get_real_type(vr_die, &type) == NULL)
713 tag = dwarf_tag(&type);
714 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
716 else if (tag == DW_TAG_subroutine_type) {
717 /* Function pointer */
718 ret = snprintf(buf, len, "(function_type)");
719 return (ret >= len) ? -E2BIG : ret;
721 if (!dwarf_diename(&type))
723 if (tag == DW_TAG_union_type)
725 else if (tag == DW_TAG_structure_type)
727 /* Write a base name */
728 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
729 return (ret >= len) ? -E2BIG : ret;
731 ret = die_get_typename(&type, buf, len);
733 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
734 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
740 * die_get_varname - Get the name and type of given variable DIE
741 * @vr_die: a variable DIE
742 * @buf: a buffer for type and variable name
743 * @len: the max-length of @buf
745 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
747 int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
751 ret = die_get_typename(vr_die, buf, len);
753 pr_debug("Failed to get type, make it unknown.\n");
754 ret = snprintf(buf, len, "(unknown_type)");
757 ret2 = snprintf(buf + ret, len - ret, "\t%s",
758 dwarf_diename(vr_die));
759 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;