From 3094c89e9ce3ae656ac56147ee34bf1f65e63d04 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Wed, 21 Sep 2022 14:54:49 +0930 Subject: [PATCH] PR29573, addr2line doesn't display file/line for local symbols The DWARF standard is clear that DW_AT_linkage_name is optional. Compilers may not provide the attribute on functions and variables, even though the language mangles names. g++ does not for local variables and functions. Without DW_AT_linkage_name, mangled object file symbols can't be directly matched against the source-level DW_AT_name in DWARF info. One possibility is demangling the object file symbols, but that comes with its own set of problems: 1) A demangler might not be available for the compiler/language. 2) Demangling doesn't give the source function name as stored in DW_AT_name. Class and template parameters must be stripped at least. So this patch takes a simpler approach. A symbol matches DWARF info if the DWARF address matches the symbol address, and if the symbol name contains the DWARF name as a sub-string. Very likely the name matching is entirely superfluous. PR 29573 * dwarf.c (lookup_symbol_in_function_table): Match a symbol containing the DWARF source name as a substring. (lookup_symbol_in_variable_table): Likewise. (_bfd_dwarf2_find_nearest_line_with_alt): If stash_find_line_fast returns false, fall back to comp_unit_find_line. --- bfd/dwarf2.c | 34 ++++++++++++++++------------------ 1 file changed, 16 insertions(+), 18 deletions(-) diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c index b8dad5cb3f4..4a6a1e40185 100644 --- a/bfd/dwarf2.c +++ b/bfd/dwarf2.c @@ -3379,7 +3379,7 @@ lookup_symbol_in_function_table (struct comp_unit *unit, && arange->high - arange->low < best_fit_len && each->file && each->name - && strcmp (name, each->name) == 0) + && strstr (name, each->name) != NULL) { best_fit = each; best_fit_len = arange->high - arange->low; @@ -3415,7 +3415,7 @@ lookup_symbol_in_variable_table (struct comp_unit *unit, && !each->stack && each->file != NULL && each->name != NULL - && strcmp (name, each->name) == 0) + && strstr (name, each->name) != NULL) break; if (each) @@ -5867,25 +5867,23 @@ _bfd_dwarf2_find_nearest_line_with_alt if (stash->info_hash_status == STASH_INFO_HASH_ON) { - found = stash_find_line_fast (stash, symbol, addr, filename_ptr, - linenumber_ptr); + found = stash_find_line_fast (stash, symbol, addr, + filename_ptr, linenumber_ptr); if (found) goto done; } - else - { - /* Check the previously read comp. units first. */ - for (each = stash->f.all_comp_units; each; each = each->next_unit) - if ((symbol->flags & BSF_FUNCTION) == 0 - || each->arange.high == 0 - || comp_unit_contains_address (each, addr)) - { - found = comp_unit_find_line (each, symbol, addr, filename_ptr, - linenumber_ptr); - if (found) - goto done; - } - } + + /* Check the previously read comp. units first. */ + for (each = stash->f.all_comp_units; each; each = each->next_unit) + if ((symbol->flags & BSF_FUNCTION) == 0 + || each->arange.high == 0 + || comp_unit_contains_address (each, addr)) + { + found = comp_unit_find_line (each, symbol, addr, filename_ptr, + linenumber_ptr); + if (found) + goto done; + } } else { -- 2.30.2