From a7308ce01effdd143bfe5e3c7350fa2d5606d12b Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Sat, 6 Mar 2021 09:26:39 -0700 Subject: Avoid crash on missing dwz file If DWARF contains a reference to a "dwz" file, but there is no .gnu_debugaltlink section, then gdb will crash. This happens because dwarf2_get_dwz_file will return NULL, but some callers do not expect this. This patch changes dwarf2_get_dwz_file so that callers can require a dwz file. Then, it updates the callers that are attempting to process references to the dwz file to require one. This includes a new testcase. The dwarf.exp changes don't handle the new forms exactly correctly -- they are only handled well enough to let this test case complete. gdb/ChangeLog 2021-03-06 Tom Tromey * dwarf2/read.h (dwarf2_get_dwz_file): Add 'require' parameter. * dwarf2/read.c (dwarf2_get_dwz_file): Add 'require' parameter. (get_abbrev_section_for_cu, read_attribute_value) (get_debug_line_section): Update. * dwarf2/macro.c (dwarf_decode_macro_bytes): Update. gdb/testsuite/ChangeLog 2021-03-06 Tom Tromey * lib/dwarf.exp (_handle_DW_FORM): Treat DW_FORM_GNU_ref_alt and DW_FORM_GNU_strp_alt like DW_FORM_sec_offset. * gdb.dwarf2/dwznolink.exp: New file. --- gdb/dwarf2/macro.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'gdb/dwarf2/macro.c') diff --git a/gdb/dwarf2/macro.c b/gdb/dwarf2/macro.c index afe2f91..2ecebe6 100644 --- a/gdb/dwarf2/macro.c +++ b/gdb/dwarf2/macro.c @@ -509,7 +509,8 @@ dwarf_decode_macro_bytes (dwarf2_per_objfile *per_objfile, || macinfo_type == DW_MACRO_undef_sup || section_is_dwz) { - dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd); + dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd, + true); body = dwz->read_string (objfile, str_offset); } @@ -693,7 +694,8 @@ dwarf_decode_macro_bytes (dwarf2_per_objfile *per_objfile, if (macinfo_type == DW_MACRO_import_sup) { - dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd); + dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd, + true); dwz->macro.read (objfile); -- cgit v1.1