From f63d03dde00449e71e32fea3496edc69d2e7d386 Mon Sep 17 00:00:00 2001 From: Mark Wielaard Date: Mon, 3 Aug 2020 02:23:44 +0200 Subject: [PATCH] gas: Make sure .debug_line file table contains a zero filename and dir For DWARF5 the zero file list entry in the .debug_line table represents the compile unit main file. It can be set with .file 0 when -gdwarf-5 is given. But since this directive is illegal for older versions, this is almost never set. To make sure it is always set (so DW_AT_name of the compile unit can be set) use file (and dir) 1 if that is defined (otherwise fall back to pwd, to match DW_AT_comp_dir). gas/ChangeLog: * gas/dwarf2dbg.c (out_dir_and_file_list): For DWARF5 emit at least one directory if there is at least one file. Use dirs[1] if dirs[0] is not set, or if there is no dirs[1] the current working directory. Use files[1] filename, when files[0] filename isn't set. --- gas/ChangeLog | 8 ++++++++ gas/dwarf2dbg.c | 35 ++++++++++++++++++++++++++--------- 2 files changed, 34 insertions(+), 9 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index 14be27927a..8895c0c0c7 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,11 @@ +2020-08-02 Mark Wielaard + + * gas/dwarf2dbg.c (out_dir_and_file_list): For DWARF5 emit at + least one directory if there is at least one file. Use dirs[1] + if dirs[0] is not set, or if there is no dirs[1] the current + working directory. Use files[1] filename, when files[0] filename + isn't set. + 2020-08-02 Mark Wielaard * dwarf2dbg.c (out_debug_info): Emit unit type and abbrev offset diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c index b19e057c76..7877c56388 100644 --- a/gas/dwarf2dbg.c +++ b/gas/dwarf2dbg.c @@ -1992,18 +1992,29 @@ out_dir_and_file_list (void) the .debug_line_str section and reference them here. */ out_uleb128 (DW_FORM_string); - /* Now state how many rows there are in the table. */ - out_uleb128 (dirs_in_use); + /* Now state how many rows there are in the table. We need at + least 1 if there is one or more file names to store the + "working directory". */ + if (dirs_in_use == 0 && files_in_use > 0) + out_uleb128 (1); + else + out_uleb128 (dirs_in_use); } /* Emit directory list. */ - if (DWARF2_LINE_VERSION >= 5 && dirs_in_use > 0) + if (DWARF2_LINE_VERSION >= 5 && (dirs_in_use > 0 || files_in_use > 0)) { - if (dirs == NULL || dirs[0] == NULL) - dir = remap_debug_filename ("."); - else + /* DWARF5 uses slot zero, but that is only set explicitly + using a .file 0 directive. If that isn't used, but dir + one is used, then use that as main file directory. + Otherwise use pwd as main file directory. */ + if (dirs_in_use > 0 && dirs != NULL && dirs[0] != NULL) dir = remap_debug_filename (dirs[0]); - + else if (dirs_in_use > 1 && dirs != NULL && dirs[1] != NULL) + dir = remap_debug_filename (dirs[1]); + else + dir = remap_debug_filename (getpwd ()); + size = strlen (dir) + 1; cp = frag_more (size); memcpy (cp, dir, size); @@ -2089,8 +2100,14 @@ out_dir_and_file_list (void) if (files[i].filename == NULL) { - /* Prevent a crash later, particularly for file 1. */ - files[i].filename = ""; + /* Prevent a crash later, particularly for file 1. DWARF5 + uses slot zero, but that is only set explicitly using a + .file 0 directive. If that isn't used, but file 1 is, + then use that as main file name. */ + if (DWARF2_LINE_VERSION >= 5 && i == 0 && files_in_use >= 1) + files[0].filename = files[1].filename; + else + files[i].filename = ""; if (DWARF2_LINE_VERSION < 5 || i != 0) { as_bad (_("unassigned file number %ld"), (long) i); -- 2.34.1