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)
47  * cu_get_comp_dir - Get the path of compilation directory
48  * @cu_die: a CU DIE
51  * Since this depends on DW_AT_comp_dir, older gcc will not
76 	l = 0; u = nlines - 1;  in cu_getsrc_die()
78 		n = u - (u - l) / 2;  in cu_getsrc_die()
83 			u = n - 1;  in cu_getsrc_die()
89 		line = dwarf_onesrcline(lines, --l);  in cu_getsrc_die()
108  * cu_find_lineinfo - Get a line number and file name for given address
109  * @cu_die: a CU DIE
140 	return *lineno ?: -ENOENT;  in cu_find_lineinfo()
146  * cu_walk_functions_at - Walk on function DIEs at given address
147  * @cu_die: A CU DIE
152  * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
153  * should be subprogram or inlined-subroutines.
160 	int ret = -ENOENT;  in cu_walk_functions_at()
177  * die_get_linkage_name - Get the linkage name of the object
178  * @dw_die: A DIE of the object
193  * die_compare_name - Compare diename and tname
194  * @dw_die: a DIE
208  * die_match_name - Match diename/linkage name and glob
209  * @dw_die: a DIE
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
243 		return -ENOENT;  in die_get_call_lineno()
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.
268 /* Get a type die, but skip qualifiers */
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.
313 		return -ENOENT;  in die_get_attr_udata()
326 		return -ENOENT;  in die_get_attr_sdata()
332  * die_is_signed_type - Check whether a type DIE is signed or not
333  * @tp_die: a DIE of a type
350  * die_is_func_def - Ensure that this DIE is a subprogram and definition
351  * @dw_die: a DIE
353  * Ensure that this DIE is a subprogram and NOT a declaration. This
370 	 * So we need to check this subprogram DIE has DW_AT_inline  in die_is_func_def()
381  * die_entrypc - Returns entry PC (the lowest address) of a DIE
382  * @dw_die: a DIE
385  * Since dwarf_entrypc() does not return entry PC if the DIE has only address
395 		return -EINVAL;  in die_entrypc()
405 		return -ENOENT;  in die_entrypc()
407 	return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;  in die_entrypc()
411  * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
412  * @dw_die: a DIE
414  * Ensure that this DIE is an instance (which has an entry address).
434  * die_get_data_member_location - Get the data-member offset
435  * @mb_die: a DIE of a member of a data structure
449 		return -ENOENT;  in die_get_data_member_location()
455 			return -ENOENT;  in die_get_data_member_location()
460 			return -ENOTSUP;  in die_get_data_member_location()
467 /* Get the call file index number in CU DIE */
475 		return -ENOENT;  in die_get_call_fileno()
478 /* Get the declared file index number in CU DIE */
486 		return -ENOENT;  in die_get_decl_fileno()
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
512  * die_find_child - Generic DIE search function in DIE tree
513  * @rt_die: a root DIE
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
524  * Returns NULL if @callback can't find any appropriate DIE.
565 	    addr == ad->addr) {  in __die_search_func_tail_cb()
566 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_tail_cb()
573  * die_find_tailfunc - Search for a non-inlined function with tail call at
575  * @cu_die: a CU DIE which including @addr
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.
595 /* die_find callback for non-inlined function search */
605 	    dwarf_haspc(fn_die, ad->addr)) {  in __die_search_func_cb()
606 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_cb()
613  * die_find_realfunc - Search a non-inlined function at given address
614  * @cu_die: a CU DIE which including @addr
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.
647  * die_find_top_inlinefunc - Search the top inlined function at given address
648  * @sp_die: a subprogram DIE which including @addr
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.
664  * die_find_inlinefunc - Search an inlined function at given address
665  * @sp_die: a subprogram DIE which including @addr
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.
717 	if (origin == NULL || origin->addr != iwp->addr)  in __die_walk_instances_cb()
730 	iwp->retval = iwp->callback(inst, iwp->data);  in __die_walk_instances_cb()
732 	return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;  in __die_walk_instances_cb()
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
743  * non-zero value, or -ENOENT if there is no instance.
751 		.addr = or_die->addr,  in die_walk_instances()
754 		.retval = -ENOENT,  in die_walk_instances()
758 		return -ENOENT;  in die_walk_instances()
784 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
785 			if (lw->retval != 0)  in __die_walk_funclines_cb()
788 		if (!lw->recursive)  in __die_walk_funclines_cb()
795 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
796 			if (lw->retval != 0)  in __die_walk_funclines_cb()
801 	/* Continue to search nested inlined function call-sites */  in __die_walk_funclines_cb()
805 /* Walk on lines of blocks included in given DIE */
841 	lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);  in __die_walk_culines_cb()
842 	if (lw->retval != 0)  in __die_walk_culines_cb()
849  * die_walk_lines - Walk on lines inside given DIE
850  * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
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.
858  * and inline call-site.
872 	/* Get the CU die */  in die_walk_lines()
880 		pr_debug2("Failed to get CU from given DIE.\n");  in die_walk_lines()
881 		return -EINVAL;  in die_walk_lines()
886 		pr_debug2("Failed to get source lines on this CU.\n");  in die_walk_lines()
887 		return -ENOENT;  in die_walk_lines()
891 	/* Walk on the lines on lines list */  in die_walk_lines()
901 		/* Skip end-of-sequence */  in die_walk_lines()
904 		/* Skip Non statement line-info */  in die_walk_lines()
907 		/* Filter lines based on address */  in die_walk_lines()
918 				/* Call-site check */  in die_walk_lines()
977 	    die_compare_name(die_mem, fvp->name) &&  in __die_find_variable_cb()
978 	/* Does the DIE have location information or external instance? */  in __die_find_variable_cb()
982 	if (dwarf_haspc(die_mem, fvp->addr))  in __die_find_variable_cb()
989  * die_find_variable_at - Find a given name variable at given address
990  * @sp_die: a function DIE
993  * @die_mem: a buffer for result DIE
995  * Find a variable DIE called @name at @addr in @sp_die.
1024  * die_find_member - Find a given name member in a data structure
1025  * @st_die: a data structure type DIE
1027  * @die_mem: a buffer for result DIE
1029  * Find a member DIE called @name in @st_die.
1039  * die_get_typename - Get the name of given variable DIE
1040  * @vr_die: a variable DIE
1044  * and Return -ENOENT if failed to find type name.
1055 		return -ENOENT;  in die_get_typename()
1065 			return -ENOENT;  in die_get_typename()
1080  * die_get_varname - Get the name and type of given variable DIE
1081  * @vr_die: a variable DIE
1101  * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1102  * @sp_die: a subprogram DIE
1103  * @vr_die: a variable DIE
1107  * "@<function_name+[NN-NN,NN-NN]>".
1128 		return -ENOENT;  in die_get_var_innermost_scope()
1132 	/* (*SCOPES)[1] is the DIE for the scope containing that scope */  in die_get_var_innermost_scope()
1134 		ret = -EINVAL;  in die_get_var_innermost_scope()
1140 		start -= entry;  in die_get_var_innermost_scope()
1141 		end -= entry;  in die_get_var_innermost_scope()
1144 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1148 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1164  * die_get_var_range - Get byte offset range of given variable DIE
1165  * @sp_die: a subprogram DIE
1166  * @vr_die: a variable DIE
1170  * "@<function_name+[NN-NN,NN-NN]>".
1191 		return -ENOENT;  in die_get_var_range()
1194 		return -EINVAL;  in die_get_var_range()
1205 		start -= entry;  in die_get_var_range()
1206 		end -= entry;  in die_get_var_range()
1208 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1212 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1229 	return -ENOTSUP;  in die_get_var_range()
1234  * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1235  * @vr_die: a variable DIE
1251  * die_is_optimized_target - Check if target program is compiled with
1253  * @cu_die: a CU DIE
1278  * die_search_idx - Search index of given line address
1308  * die_get_postprologue_addr - Search next address after function prologue
1315  * Look for prologue-end marker. If there is no explicit marker, return
1347 		/* clang supports prologue-end marker */  in die_get_postprologue_addr()
1369 		dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),  in die_get_postprologue_addr()
1376  * die_skip_prologue - Use next address after prologue as probe location
1377  * @sp_die: a subprogram DIE
1378  * @cu_die: a CU DIE