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

There are two problems with the current catch-follow-exec.exp:
- INTERNAL_GDBFLAGS (containing the datadir setting) is not used
- remote host testing doesn't work

Fix the former by using gdb_spawn_with_cmdline_opts.  Fix the latter by
requiring gdb-native.

Build on x86_64-linux with and without ubsan, and tested.

2018-10-05  Tom de Vries  <tdevries@suse.de>

	PR gdb/23730
	* gdb.base/catch-follow-exec.c: Add copyright notice.
	* gdb.base/catch-follow-exec.exp: Rewrite to use
	gdb_spawn_with_cmdline_opts.  Require gdb-native.

---
 gdb/testsuite/gdb.base/catch-follow-exec.c   | 17 +++++++++
 gdb/testsuite/gdb.base/catch-follow-exec.exp | 52 +++++++++++++++++++++-------
 2 files changed, 56 insertions(+), 13 deletions(-)

diff --git a/gdb/testsuite/gdb.base/catch-follow-exec.c b/gdb/testsuite/gdb.base/catch-follow-exec.c
index fa68a2a34e..1a59f58aa5 100644
--- a/gdb/testsuite/gdb.base/catch-follow-exec.c
+++ b/gdb/testsuite/gdb.base/catch-follow-exec.c
@@ -1,3 +1,20 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   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/>.  */
+
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/gdb/testsuite/gdb.base/catch-follow-exec.exp b/gdb/testsuite/gdb.base/catch-follow-exec.exp
index 0e32ed4a6f..c3c7c7ecdd 100644
--- a/gdb/testsuite/gdb.base/catch-follow-exec.exp
+++ b/gdb/testsuite/gdb.base/catch-follow-exec.exp
@@ -18,12 +18,11 @@
 
 standard_testfile
 
-if {[build_executable "failed to prepare" $testfile $srcfile debug] == -1} {
-    return -1
-}
-
-if { ![remote_file target exists /bin/bash] } {
-    unsupported "no bash"
+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
 }
 
@@ -32,9 +31,13 @@ if { ![remote_file target exists /bin/ls] } {
     return
 }
 
+if { [build_executable "failed to prepare" $testfile $srcfile debug] == -1 } {
+    return -1
+}
+
 proc catch_follow_exec { } {
     global binfile
-    global GDB
+    global gdb_spawn_id
 
     set test "catch-follow-exec"
 
@@ -45,13 +48,36 @@ proc catch_follow_exec { } {
     append FLAGS " -ex \"run\""
     append FLAGS " -ex \"info prog\""
 
-    catch {exec /bin/bash -c "$GDB $FLAGS"} catchlog
-    send_log "$catchlog\n"
+    gdb_exit
+    if {[gdb_spawn_with_cmdline_opts "$FLAGS"] != 0} {
+	fail "spawn"
+	return
+    }
+
+    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_assert { [lindex $result 2] == 0 }
+
+	    # 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 }
+
+	    # Error in case of --disable-ubsan, we get
+	    # "CHILDKILLED SIGSEGV {segmentation violation}" as extra
+	    # argument(s).
+	    gdb_assert { [llength $result] == 4 }
+	}
 
-    if { [regexp {No selected thread} $catchlog] } {
-	pass $test
-    } else {
-	fail $test
+	remote_close host
+	clear_gdb_spawn_id
     }
 }