From 655e4e52ef44c1670a3b6f979b85534279c9f6c1 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 17 Aug 2023 08:08:42 -0600 Subject: [PATCH] Avoid crash with Ada and -fdata-sections A user noticed that gdb would crash when showing a backtrace. Investigation showed this to be a crash in the DWARF reader when handling a "pragma export" symbol. The bug here is that earlier code decides to eliminate the symbol, but the export code tries to add it anyway -- but to a NULL list. --- gdb/dwarf2/read.c | 3 +- gdb/testsuite/gdb.ada/data-sections.exp | 34 ++++++++++++++++++++ gdb/testsuite/gdb.ada/data-sections/main.adb | 19 +++++++++++ 3 files changed, 55 insertions(+), 1 deletion(-) create mode 100644 gdb/testsuite/gdb.ada/data-sections.exp create mode 100644 gdb/testsuite/gdb.ada/data-sections/main.adb diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index a538cb55b74..ef7f5708213 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -19203,7 +19203,8 @@ new_symbol (struct die_info *die, struct type *type, struct dwarf2_cu *cu, else list_to_add = cu->list_in_scope; - if (is_ada_import_or_export (cu, name, linkagename)) + if (list_to_add != nullptr + && is_ada_import_or_export (cu, name, linkagename)) { /* This is a Pragma Export. A Pragma Import won't be seen here, because it will not have a location diff --git a/gdb/testsuite/gdb.ada/data-sections.exp b/gdb/testsuite/gdb.ada/data-sections.exp new file mode 100644 index 00000000000..9cc6023686b --- /dev/null +++ b/gdb/testsuite/gdb.ada/data-sections.exp @@ -0,0 +1,34 @@ +# Copyright 2023 Free Software Foundation, Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +load_lib "ada.exp" + +require allow_ada_tests + +standard_ada_testfile main + +if {[gdb_compile_ada "${srcfile}" "${binfile}" executable \ + {debug additional_flags=-fdata-sections ldflags=-Wl,--gc-sections}] \ + != ""} { + return -1 +} + +# The bug was that the DWARF reader would crash when processing a +# certain symbol. +save_vars {GDBFLAGS} { + append GDBFLAGS " --readnow" + + clean_restart ${testfile} +} diff --git a/gdb/testsuite/gdb.ada/data-sections/main.adb b/gdb/testsuite/gdb.ada/data-sections/main.adb new file mode 100644 index 00000000000..a4ca8b6fb57 --- /dev/null +++ b/gdb/testsuite/gdb.ada/data-sections/main.adb @@ -0,0 +1,19 @@ +-- Copyright 2023 Free Software Foundation, Inc. +-- +-- This program is free software; you can redistribute it and/or modify +-- it under the terms of the GNU General Public License as published by +-- the Free Software Foundation; either version 3 of the License, or +-- (at your option) any later version. +-- +-- This program is distributed in the hope that it will be useful, +-- but WITHOUT ANY WARRANTY; without even the implied warranty of +-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +-- GNU General Public License for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with this program. If not, see . + +procedure Main is +begin + null; +end Main; -- 2.30.2