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author | Tom de Vries <tdevries@suse.de> | 2023-08-16 23:43:25 +0200 |
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committer | Tom de Vries <tdevries@suse.de> | 2023-08-16 23:43:25 +0200 |
commit | eeee4389cf3725e729b0a477515afd830b34b9f0 (patch) | |
tree | eed75798355e070fe995ba38cc1d360abfb51721 /gdb/testsuite | |
parent | 033bc52bb6190393c8eed80925fa78cc35b40c6d (diff) | |
download | gdb-eeee4389cf3725e729b0a477515afd830b34b9f0.zip gdb-eeee4389cf3725e729b0a477515afd830b34b9f0.tar.gz gdb-eeee4389cf3725e729b0a477515afd830b34b9f0.tar.bz2 |
[gdb/symtab] Handle self-reference DIE
While working on a dwarf assembly test-case I accidentally created the
following pathological dwarf:
...
<1><be>: Abbrev Number: 3 (DW_TAG_class_type)
<bf> DW_AT_name : c1
<c2> DW_AT_specification: <0xbe>
...
and noticed gdb segfaulting during cooked index creating due to running out of
stack. This is a regression from gdb-12, where gdb just hung.
Fix this by inhibiting the scan_attributes self-recursion for self-references.
The same test-case with -readnow makes gdb hang, so also fix this in
dwarf2_attr and follow_die_ref.
Note that this doesn't fix the same problems for the more complicated case of:
...
<1><be>: Abbrev Number: 3 (DW_TAG_class_type)
<bf> DW_AT_name : c1
<c2> DW_AT_specification: <0xc6>
<1><c6>: Abbrev Number: 4 (DW_TAG_class_type)
<c7> DW_AT_name : c2
<ca> DW_AT_specification: <0xbe>
...
but the approach for deciding whether to fix pathological dwarf cases is as
per PR27981 comment 3:
...
yes if it is cheap/obvious, and no if it is something complicated or expensive.
...
and at this point I'm not sure whether fixing this will fall in the first
category.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
Diffstat (limited to 'gdb/testsuite')
-rw-r--r-- | gdb/testsuite/gdb.dwarf2/self-spec.exp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/gdb/testsuite/gdb.dwarf2/self-spec.exp b/gdb/testsuite/gdb.dwarf2/self-spec.exp new file mode 100644 index 0000000..71e7c12 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/self-spec.exp @@ -0,0 +1,52 @@ +# 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 <http://www.gnu.org/licenses/>. + +# Check that gdb doesn't hang or segfault on reading a DIE with a +# specification reference to itself. + +load_lib dwarf.exp + +require dwarf2_support + +standard_testfile main.c .S + +# Create the DWARF. +set asm_file [standard_output_file $srcfile2] +Dwarf::assemble $asm_file { + cu {} { + compile_unit {{language @DW_LANG_C_plus_plus}} { + declare_labels c1 + c1: class_type { + {name c1} + {specification :$c1} + } + } + } +} + +if [prepare_for_testing "failed to prepare" $testfile "${asm_file} ${srcfile}" {}] { + return -1 +} + +set index [have_index $binfile] +require {string eq $index ""} + +require !readnow + +gdb_test "maint print objfiles $testfile" \ + "\r\n *qualified: *c1\r\n.*" \ + "class c1 in cooked index" + +gdb_test "maint expand-symtabs" |