Indicate batch mode failures by exiting with nonzero status

This commit causes GDB in batch mode to exit with nonzero status
if the last command to be executed fails.

gdb/ChangeLog:

	PR gdb/13000:
	* gdb/main.c (captured_main_1): Exit with nonzero status
	in batch mode if the last command to be executed failed.
	* NEWS: Mention the above.

gdb/testsuite/ChangeLog:

	PR gdb/13000:
	* gdb.base/batch-exit-status.exp: New file.
	* gdb.base/batch-exit-status.good-commands: Likewise.
	* gdb.base/batch-exit-status.bad-commands: Likewise.

3 files changed, 65 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/batch-exit-status.bad-commands b/gdb/testsuite/gdb.base/batch-exit-status.bad-commands
new file mode 100644
index 00000000000..4793acb2fad
--- /dev/null
+++ b/gdb/testsuite/gdb.base/batch-exit-status.bad-commands
@@ -0,0 +1 @@
+bork
diff --git a/gdb/testsuite/gdb.base/batch-exit-status.exp b/gdb/testsuite/gdb.base/batch-exit-status.exp
new file mode 100644
index 00000000000..bee4d724e6d
--- /dev/null
+++ b/gdb/testsuite/gdb.base/batch-exit-status.exp
@@ -0,0 +1,63 @@
+# Copyright (C) 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/>.
+
+# Check that "gdb -batch" exits with appropriate status.
+
+standard_testfile
+
+set good_commands "$srcdir/$subdir/batch-exit-status.good-commands"
+set bad_commands "$srcdir/$subdir/batch-exit-status.bad-commands"
+
+proc _test_exit_status {expect_status cmdline_opts} {
+    global gdb_spawn_id
+
+    gdb_exit
+    if {[gdb_spawn_with_cmdline_opts $cmdline_opts] != 0} {
+	fail "spawn"
+	return
+    }
+
+    set result [wait -i $gdb_spawn_id]
+    verbose $result
+    gdb_assert { [lindex $result 2] == 0 }
+    set actual_status [lindex $result 3]
+    gdb_assert { $actual_status == $expect_status }
+}
+
+proc test_exit_status {expect_status cmdline_opts} {
+    with_test_prefix $cmdline_opts {
+	_test_exit_status $expect_status $cmdline_opts
+    }
+}
+
+# gdb -batch with nothing to do should exit 0.
+test_exit_status 0 "-batch"
+
+# Bad command-line options should cause exit 1.
+test_exit_status 1 "-batch -jslkflsdjlkfjlksdjf"
+
+# gdb -batch with good commands should exit 0.
+test_exit_status 0 "-batch -ex \"info source\""
+test_exit_status 0 "-batch -x $good_commands"
+
+# gdb -batch with bad commands should exit 1.
+test_exit_status 1 "-batch -ex \"set not-a-thing 4\""
+test_exit_status 1 "-batch -x $bad_commands"
+
+# Success or failure of the last thing determines the exit code.
+test_exit_status 0 "-batch -ex \"set not-a-thing 4\" -x $good_commands"
+test_exit_status 0 "-batch -x $bad_commands -ex \"info source\""
+test_exit_status 1 "-batch -x $good_commands -x $bad_commands"
+test_exit_status 1 "-batch -x $good_commands -ex \"set not-a-thing 4\""
diff --git a/gdb/testsuite/gdb.base/batch-exit-status.good-commands b/gdb/testsuite/gdb.base/batch-exit-status.good-commands
new file mode 100644
index 00000000000..80708a96534
--- /dev/null
+++ b/gdb/testsuite/gdb.base/batch-exit-status.good-commands
@@ -0,0 +1 @@
+info mem