From 1228719f312c22a3ce4ade10d175b80ac5cedb08 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 2 Mar 2021 11:57:01 -0700 Subject: [PATCH] Check objfile->sf in ada-lang.c Most places in gdb that reference objfile->sf also check that it is not null. It is valid for it to be null, because find_sym_fns can return null for some kinds of object file. However, it's rare to encounter this scenario with Ada code. I only encountered it when looking at a fork of gdb that, I believe, makes its own objfiles without setting 'sf'. This patch changes ada-lang.c to check this field before using it. This avoids any potential crash here. There's no test case because I'm not even sure this is possible to trip over with an unmodified gdb. There are some other unchecked uses in gdb, but at a quick glance they all seem to be involved with symbol reading, which of course won't happen when sf==null. gdb/ChangeLog 2021-03-02 Tom Tromey * ada-lang.c (add_nonlocal_symbols): Handle case where objfile->sf is null. --- gdb/ChangeLog | 5 +++++ gdb/ada-lang.c | 16 +++++++++------- 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index bb7b2de0b58..d9d5b4f9cb7 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2021-03-02 Tom Tromey + + * ada-lang.c (add_nonlocal_symbols): Handle case where objfile->sf + is null. + 2021-02-27 Lancelot Six PR gdb/27393 diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c index 419347f776d..91a2a5ce1df 100644 --- a/gdb/ada-lang.c +++ b/gdb/ada-lang.c @@ -5629,10 +5629,11 @@ add_nonlocal_symbols (struct obstack *obstackp, { data.objfile = objfile; - objfile->sf->qf->map_matching_symbols (objfile, lookup_name, - domain, global, callback, - (is_wild_match - ? NULL : compare_names)); + if (objfile->sf != nullptr) + objfile->sf->qf->map_matching_symbols (objfile, lookup_name, + domain, global, callback, + (is_wild_match + ? NULL : compare_names)); for (compunit_symtab *cu : objfile->compunits ()) { @@ -5654,9 +5655,10 @@ add_nonlocal_symbols (struct obstack *obstackp, for (objfile *objfile : current_program_space->objfiles ()) { data.objfile = objfile; - objfile->sf->qf->map_matching_symbols (objfile, name1, - domain, global, callback, - compare_names); + if (objfile->sf != nullptr) + objfile->sf->qf->map_matching_symbols (objfile, name1, + domain, global, callback, + compare_names); } } } -- 2.30.2