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author | Tom de Vries <tdevries@suse.de> | 2021-11-29 16:19:16 +0100 |
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committer | Tom de Vries <tdevries@suse.de> | 2021-11-29 16:19:16 +0100 |
commit | 49fa1332a69bc4b09d2cc7db587e27ea30f2a29d (patch) | |
tree | 1bf3c62ec0c6c9a9220221906aeb24c1bc322ce7 /gdb/testsuite | |
parent | 8fee99c3c8e25f2708bddde345c192dd2f3e7e08 (diff) | |
download | gdb-49fa1332a69bc4b09d2cc7db587e27ea30f2a29d.zip gdb-49fa1332a69bc4b09d2cc7db587e27ea30f2a29d.tar.gz gdb-49fa1332a69bc4b09d2cc7db587e27ea30f2a29d.tar.bz2 |
[gdb/symtab] Fix segfault in search_one_symtab
PR28539 describes a segfault in lambda function search_one_symtab due to
psymbol_functions::expand_symtabs_matching calling expansion_notify with a
nullptr symtab:
...
struct compunit_symtab *symtab =
psymtab_to_symtab (objfile, ps);
if (expansion_notify != NULL)
if (!expansion_notify (symtab))
return false;
...
This happens as follows. The partial symtab ps is a dwarf2_include_psymtab
for some header file:
...
(gdb) p ps.filename
$5 = 0x64fcf80 "/usr/include/c++/11/bits/stl_construct.h"
...
The includer of ps is a shared symtab for a partial unit, with as user:
...
(gdb) p ps.includer().user.filename
$11 = 0x64fc9f0 \
"/usr/src/debug/llvm13-13.0.0-1.2.x86_64/tools/clang/lib/AST/Decl.cpp"
...
The call to psymtab_to_symtab expands the Decl.cpp symtab (and consequently
the shared symtab), but returns nullptr because:
...
struct dwarf2_include_psymtab : public partial_symtab
{
...
compunit_symtab *get_compunit_symtab (struct objfile *objfile) const override
{
return nullptr;
}
...
Fix this by returning the Decl.cpp symtab instead, which fixes the segfault
in the PR.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28539
Diffstat (limited to 'gdb/testsuite')
-rw-r--r-- | gdb/testsuite/gdb.dwarf2/dw2-symtab-includes-lookup.exp | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-symtab-includes-lookup.exp b/gdb/testsuite/gdb.dwarf2/dw2-symtab-includes-lookup.exp new file mode 100644 index 0000000..ec3371d --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-symtab-includes-lookup.exp @@ -0,0 +1,99 @@ +# Copyright 2021 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/>. + +# Lookup a type in a partial unit with DW_AT_stmt_list. +# +# The test-case is setup such that the partial symtab expansion route is +# .h partial symtab -> shared partial symtab -> toplevel symtab. +# +# That is, the partial symtabs (as displayed by maint print objfiles) are: +# +# ../sysdeps/x86_64/crtn.S at 0x3d944e0^M +# elf-init.c at 0x3d94440^M +# dw2-symtab-includes.h at 0x3d7c7a0^M +# <unknown> at 0x31ef870^M +# bla.c at 0x33985f0^M +# ../sysdeps/x86_64/crti.S at 0x33e9a00^M +# init.c at 0x33fa600^M +# ../sysdeps/x86_64/start.S at 0x33f3fd0^M +# +# and the expansion of dw2-symtab-includes.h triggers the expansion of its +# includer <unknown>, which triggers expansion of user bla.c. +# +# The problem in PR28539 was that after expansion of dw2-symtab-includes.h +# the expansion_notify function in psymbol_functions::expand_symtabs_matching +# should be called with the bla.c symtab, but instead it got called with +# nullptr, which caused a segfault. + +load_lib dwarf.exp + +# This test can only be run on targets which support DWARF-2 and use gas. +require dwarf2_support 1 + +standard_testfile main.c .S + +# Create the DWARF. +set asm_file [standard_output_file $srcfile2] +Dwarf::assemble $asm_file { + declare_labels partial_label lines_label + global srcdir subdir srcfile + + cu {} { + partial_label: partial_unit { + {stmt_list ${lines_label} DW_FORM_sec_offset} + } { + DW_TAG_base_type { + {DW_AT_byte_size 4 DW_FORM_sdata} + {DW_AT_encoding @DW_ATE_signed} + {DW_AT_name myint} + } + } + } + + cu {} { + compile_unit { + {language @DW_LANG_C} + {DW_AT_name bla.c} + } { + imported_unit { + {import $partial_label ref_addr} + } + } + } + + lines {version 2} lines_label { + include_dir "${srcdir}/${subdir}" + file_name "dw2-symtab-includes.h" 1 + program { + {DW_LNS_advance_line 1} + } + } +} + +if { [prepare_for_testing "failed to prepare" $testfile \ + "${asm_file} ${srcfile}" {}] } { + return -1 +} + +# Check that no symtabs are expanded. +set test "no symtabs expanded" +if { [readnow] } { + unsupported $test +} else { + gdb_test_no_output "maint info symtabs" $test +} + +# Lookup myint. Regression test for PR28539. +gdb_test "ptype myint" "type = myint" |