support: Add support_capture_subprogram

Its API is similar to support_capture_subprocess, but rather creates a
new process based on the input path and arguments.  Under the hoods it
uses posix_spawn to create the new process.

It also allows the use of other support_capture_* functions to check
for expected results and free the resources.

Checked on x86_64-linux-gnu.

	* support/Makefile (libsupport-routines): Add support_subprocess,
	xposix_spawn, xposix_spawn_file_actions_addclose, and
	xposix_spawn_file_actions_adddup2.
	(tst-support_capture_subprocess-ARGS): New rule.
	* support/capture_subprocess.h (support_capture_subprogram): New
	prototype.
	* support/support_capture_subprocess.c (support_capture_subprocess):
	Refactor to use support_subprocess and support_capture_poll.
	(support_capture_subprogram): New function.
	* support/tst-support_capture_subprocess.c (write_mode_to_str,
	str_to_write_mode, test_common, parse_int, handle_restart,
	do_subprocess, do_subprogram, do_multiple_tests): New functions.
	(do_test): Add support_capture_subprogram tests.
	* support/subprocess.h: New file.
	* support/support_subprocess.c: Likewise.
	* support/xposix_spawn.c: Likewise.
	* support/xposix_spawn_file_actions_addclose.c: Likewise.
	* support/xposix_spawn_file_actions_adddup2.c: Likewise.
	* support/xspawn.h: Likewise.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/support/subprocess.h b/support/subprocess.h
new file mode 100644
index 0000000000..c031878d94
--- /dev/null
+++ b/support/subprocess.h
@@ -0,0 +1,49 @@
+/* Create a subprocess.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_SUBPROCESS_H
+#define SUPPORT_SUBPROCESS_H
+
+#include <sys/types.h>
+
+struct support_subprocess
+{
+  int stdout_pipe[2];
+  int stderr_pipe[2];
+  pid_t pid;
+};
+
+/* Invoke CALLBACK (CLOSURE) in a subprocess created with fork and return
+   its PID, a pipe redirected to STDOUT, and a pipe redirected to STDERR.  */
+struct support_subprocess support_subprocess
+  (void (*callback) (void *), void *closure);
+
+/* Issue FILE with ARGV arguments by using posix_spawn and return is PID, a
+   pipe redirected to STDOUT, and a pipe redirected to STDERR.  */
+struct support_subprocess support_subprogram
+  (const char *file, char *const argv[]);
+
+/* Wait for the subprocess indicated by PROC::PID.  Return the status
+   indicate by waitpid call.  */
+int support_process_wait (struct support_subprocess *proc);
+
+/* Terminate the subprocess indicated by PROC::PID, first with a SIGTERM and
+   then with a SIGKILL.  Return the status as for waitpid call.  */
+int support_process_terminate (struct support_subprocess *proc);
+
+#endif