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[PATCH] Fix crash in "finish"
- From: Tom Tromey <tom at tromey dot com>
- To: gdb-patches at sourceware dot org
- Cc: Tom Tromey <tom at tromey dot com>
- Date: Sat, 29 Dec 2018 10:49:22 -0700
- Subject: [PATCH] Fix crash in "finish"
PR gdb/28155 notes a crash in "finish" that occurs with a particular
source file compiled by clang.
The bug is the typical gdb problem of a missing call to check_typedef.
clang emits a function whose return type is a typedef to void.
get_return_value asserts that the return type is not void, but the
callers were not using check_typedef first.
gdb/ChangeLog
2018-12-29 Tom Tromey <tom@tromey.com>
PR gdb/28155:
* python/py-finishbreakpoint.c (bpfinishpy_init): Use
check_typedef.
* infcmd.c (finish_command_fsm_should_stop): Use check_typedef.
(print_return_value): Likewise.
gdb/testsuite/ChangeLog
2018-12-29 Tom Tromey <tom@tromey.com>
PR gdb/28155:
* gdb.dwarf2/typedef-void-finish.exp: New file.
---
gdb/ChangeLog | 8 ++
gdb/infcmd.c | 5 +-
gdb/python/py-finishbreakpoint.c | 2 +-
gdb/testsuite/ChangeLog | 5 ++
.../gdb.dwarf2/typedef-void-finish.exp | 90 +++++++++++++++++++
5 files changed, 107 insertions(+), 3 deletions(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/typedef-void-finish.exp
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 4406f86865..75e9221b9d 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -1706,7 +1706,8 @@ print_return_value_1 (struct ui_out *uiout, struct return_value_info *rv)
void
print_return_value (struct ui_out *uiout, struct return_value_info *rv)
{
- if (rv->type == NULL || TYPE_CODE (rv->type) == TYPE_CODE_VOID)
+ if (rv->type == NULL
+ || TYPE_CODE (check_typedef (rv->type)) == TYPE_CODE_VOID)
return;
TRY
@@ -1800,7 +1801,7 @@ finish_command_fsm_should_stop (struct thread_fsm *self,
internal_error (__FILE__, __LINE__,
_("finish_command: function has no target type"));
- if (TYPE_CODE (rv->type) != TYPE_CODE_VOID)
+ if (TYPE_CODE (check_typedef (rv->type)) != TYPE_CODE_VOID)
{
struct value *func;
diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
index c33b7dd7aa..fbf1537393 100644
--- a/gdb/python/py-finishbreakpoint.c
+++ b/gdb/python/py-finishbreakpoint.c
@@ -253,7 +253,7 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
if (function != NULL)
{
struct type *ret_type =
- TYPE_TARGET_TYPE (SYMBOL_TYPE (function));
+ check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (function)));
/* Remember only non-void return types. */
if (TYPE_CODE (ret_type) != TYPE_CODE_VOID)
diff --git a/gdb/testsuite/gdb.dwarf2/typedef-void-finish.exp b/gdb/testsuite/gdb.dwarf2/typedef-void-finish.exp
new file mode 100644
index 0000000000..729e1e01bc
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/typedef-void-finish.exp
@@ -0,0 +1,90 @@
+# Copyright 2018 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/>.
+
+# PR gdb/21855 concerns a crash in "finish" where the function's
+# return type is a typedef of void.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+standard_testfile void-type.c typedef-void-finish.S
+
+# Make some DWARF for the test.
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+ global srcdir subdir srcfile
+
+ set func_result [function_range func ${srcdir}/${subdir}/${srcfile}]
+ set func_start [lindex $func_result 0]
+ set func_length [lindex $func_result 1]
+
+ set main_result [function_range main ${srcdir}/${subdir}/${srcfile}]
+ set main_start [lindex $main_result 0]
+ set main_length [lindex $main_result 1]
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_producer "GNU C 8.1"}
+ {DW_AT_language @DW_LANG_C}
+ {DW_AT_name void-type.c}
+ {DW_AT_comp_dir /tmp}
+ } {
+ declare_labels main_type void_typedef
+
+ main_type: DW_TAG_base_type {
+ {DW_AT_byte_size 4 DW_FORM_sdata}
+ {DW_AT_encoding @DW_ATE_signed}
+ }
+
+ void_typedef: DW_TAG_typedef {
+ {name foo}
+ }
+
+ DW_TAG_subprogram {
+ {name func}
+ {low_pc $func_start addr}
+ {high_pc "$func_start + $func_length" addr}
+ {type :$void_typedef}
+ }
+ DW_TAG_subprogram {
+ {name main}
+ {low_pc $main_start addr}
+ {high_pc "$main_start + $main_length" addr}
+ {type :$main_type}
+ }
+ }
+ }
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file] {nodebug}] } {
+ return -1
+}
+
+if {![runto_main]} {
+ return -1
+}
+
+gdb_test "break func" "Breakpoint .*" \
+ "set breakpoint in func"
+gdb_continue_to_breakpoint "continue to func"
+
+gdb_test "finish" [multi_line \
+ "Run till exit from #0 $hex in func \\\(\\\)" \
+ "$hex in main \\\(\\\)"]
--
2.17.2