[gdb/testsuite]	Rewrite catch-follow-exec.exp using gdb_test

The testcase catch-follow-exec.exp is written use gdb -batch in order to avoid
a GDB SIGTTOU.  After the commit of "Avoid GDB SIGTTOU on catch exec + set
follow-exec-mode new (PR 23368)", that no longer is necessary.

Rewrite the test using regular gdb_test commands.

Tested with x86_64-linux.

2018-10-24  Tom de Vries  <tdevries@suse.de>

	* gdb.base/catch-follow-exec.exp: Rewrite using gdb_test.

---
 gdb/testsuite/gdb.base/catch-follow-exec.exp | 63 ++++++----------------------
 1 file changed, 13 insertions(+), 50 deletions(-)

diff --git a/gdb/testsuite/gdb.base/catch-follow-exec.exp b/gdb/testsuite/gdb.base/catch-follow-exec.exp
index c3c7c7ecdd..5f7db25265 100644
--- a/gdb/testsuite/gdb.base/catch-follow-exec.exp
+++ b/gdb/testsuite/gdb.base/catch-follow-exec.exp
@@ -13,72 +13,35 @@
 # 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 whether finish respects the print pretty user setting when printing the
-# function result.
+# Test whether info prog crashes gdb at a catch point in follow-exec-mode new.
 
 standard_testfile
 
-if { [target_info gdb_protocol] != "" } {
-    # Even though the feature under features being tested are supported by
-    # gdbserver, the way this test is written doesn't make it easy with a
-    # remote target.
-    unsupported "not native"
-    return
-}
-
 if { ![remote_file target exists /bin/ls] } {
     unsupported "no ls"
     return
 }
 
-if { [build_executable "failed to prepare" $testfile $srcfile debug] == -1 } {
-    return -1
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile debug] } {
+    return
 }
 
 proc catch_follow_exec { } {
-    global binfile
-    global gdb_spawn_id
-
-    set test "catch-follow-exec"
-
-    append FLAGS " \"$binfile\""
-    append FLAGS " -batch"
-    append FLAGS " -ex \"catch exec\""
-    append FLAGS " -ex \"set follow-exec-mode new\""
-    append FLAGS " -ex \"run\""
-    append FLAGS " -ex \"info prog\""
-
-    gdb_exit
-    if {[gdb_spawn_with_cmdline_opts "$FLAGS"] != 0} {
-	fail "spawn"
-	return
+    if { ![runto_main] } {
+	untested "could not run to main"
+	return -1
     }
 
-    gdb_test_multiple "" "run til exit" {
-	"runtime error:" {
-	    # Error in case of --enable-ubsan
-	    fail "no runtime error"
-	}
-	eof {
-	    set result [wait -i $gdb_spawn_id]
-	    verbose $result
+    gdb_test "catch exec" \
+	{Catchpoint [0-9]+ \(exec\)}
 
-	    gdb_assert { [lindex $result 2] == 0 }
+    gdb_test_no_output "set follow-exec-mode new"
 
-	    # We suspect this will be zero instead of one after fixing PR23368
-	    # - "gdb goes to into background when hitting exec catchpoint with
-	    # follow-exec-mode new"
-	    gdb_assert { [lindex $result 3] != 0 }
+    gdb_test "continue" \
+	".*hit Catchpoint.*"
 
-	    # Error in case of --disable-ubsan, we get
-	    # "CHILDKILLED SIGSEGV {segmentation violation}" as extra
-	    # argument(s).
-	    gdb_assert { [llength $result] == 4 }
-	}
-
-	remote_close host
-	clear_gdb_spawn_id
-    }
+    gdb_test "info prog" \
+	"No selected thread."
 }
 
 catch_follow_exec