btrace: no replay without history

When using a reverse execution command without execution history, GDB
might end up in a state where replaying has been started but remains
at the current instruction.  This state is illegal.

Do not step if there is no execution history to avoid this.

2014-05-20  Markus Metzger  <markus.t.metzger@intel.com>

	* record-btrace.c (record_btrace_step_thread): Check for empty history.

testsuite/
	* gdb.btrace/nohist.exp: New.
This commit is contained in:
Markus Metzger 2014-05-15 10:57:36 +02:00
parent 00b32ff21f
commit e59fa00fa0
4 changed files with 58 additions and 0 deletions

View File

@ -1,3 +1,7 @@
2014-05-20 Markus Metzger <markus.t.metzger@intel.com>
* record-btrace.c (record_btrace_step_thread): Check for empty history.
2014-05-20 Hui Zhu <hui@codesourcery.com>
Yao Qi <yao@codesourcery.com>

View File

@ -1577,6 +1577,10 @@ record_btrace_step_thread (struct thread_info *tp)
enum btrace_thread_flag flags;
unsigned int steps;
/* We can't step without an execution history. */
if (btrace_is_empty (tp))
return btrace_step_no_history ();
btinfo = &tp->btrace;
replay = btinfo->replay;

View File

@ -1,3 +1,7 @@
2014-05-20 Markus Metzger <markus.t.metzger@intel.com>
* gdb.btrace/nohist.exp: New.
2014-05-20 Yao Qi <yao@codesourcery.com>
* lib/gdb.exp (gdb_init): Set timeout if test file is under

View File

@ -0,0 +1,46 @@
# This testcase is part of GDB, the GNU debugger.
#
# Copyright 2014 Free Software Foundation, Inc.
#
# Contributed by Intel Corp. <markus.t.metzger@intel.com>
#
# 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 for btrace support
if { [skip_btrace_tests] } { return -1 }
# start inferior
standard_testfile x86-record_goto.S
if [prepare_for_testing nohist.exp $testfile $srcfile] {
return -1
}
if ![runto_main] {
return -1
}
proc check_not_replaying {} {
gdb_test "info record" [join [list \
"Active record target: record-btrace" \
"Recorded 0 instructions in 0 functions for \[^\\\r\\\n\]*" \
] "\r\n"]
}
gdb_test_no_output "record btrace"
check_not_replaying
gdb_test "reverse-continue" "No more reverse-execution history\.\r\n.*"
check_not_replaying