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, 38 insertions, 42 deletions

diff --git a/support/support_capture_subprocess.c b/support/support_capture_subprocess.c
index 167514faf1..948ce5a0c6 100644
--- a/support/support_capture_subprocess.c
+++ b/support/support_capture_subprocess.c
@@ -16,6 +16,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <support/subprocess.h>
 #include <support/capture_subprocess.h>
 
 #include <errno.h>
@@ -23,6 +24,7 @@
 #include <support/check.h>
 #include <support/xunistd.h>
 #include <support/xsocket.h>
+#include <support/xspawn.h>
 
 static void
 transfer (const char *what, struct pollfd *pfd, struct xmemstream *stream)
@@ -50,59 +52,53 @@ transfer (const char *what, struct pollfd *pfd, struct xmemstream *stream)
     }
 }
 
-struct support_capture_subprocess
-support_capture_subprocess (void (*callback) (void *), void *closure)
+static void
+support_capture_poll (struct support_capture_subprocess *result,
+		      struct support_subprocess *proc)
 {
-  struct support_capture_subprocess result;
-  xopen_memstream (&result.out);
-  xopen_memstream (&result.err);
-
-  int stdout_pipe[2];
-  xpipe (stdout_pipe);
-  TEST_VERIFY (stdout_pipe[0] > STDERR_FILENO);
-  TEST_VERIFY (stdout_pipe[1] > STDERR_FILENO);
-  int stderr_pipe[2];
-  xpipe (stderr_pipe);
-  TEST_VERIFY (stderr_pipe[0] > STDERR_FILENO);
-  TEST_VERIFY (stderr_pipe[1] > STDERR_FILENO);
-
-  TEST_VERIFY (fflush (stdout) == 0);
-  TEST_VERIFY (fflush (stderr) == 0);
-
-  pid_t pid = xfork ();
-  if (pid == 0)
-    {
-      xclose (stdout_pipe[0]);
-      xclose (stderr_pipe[0]);
-      xdup2 (stdout_pipe[1], STDOUT_FILENO);
-      xdup2 (stderr_pipe[1], STDERR_FILENO);
-      xclose (stdout_pipe[1]);
-      xclose (stderr_pipe[1]);
-      callback (closure);
-      _exit (0);
-    }
-  xclose (stdout_pipe[1]);
-  xclose (stderr_pipe[1]);
-
   struct pollfd fds[2] =
     {
-      { .fd = stdout_pipe[0], .events = POLLIN },
-      { .fd = stderr_pipe[0], .events = POLLIN },
+      { .fd = proc->stdout_pipe[0], .events = POLLIN },
+      { .fd = proc->stderr_pipe[0], .events = POLLIN },
     };
 
   do
     {
       xpoll (fds, 2, -1);
-      transfer ("stdout", &fds[0], &result.out);
-      transfer ("stderr", &fds[1], &result.err);
+      transfer ("stdout", &fds[0], &result->out);
+      transfer ("stderr", &fds[1], &result->err);
     }
   while (fds[0].events != 0 || fds[1].events != 0);
-  xclose (stdout_pipe[0]);
-  xclose (stderr_pipe[0]);
 
-  xfclose_memstream (&result.out);
-  xfclose_memstream (&result.err);
-  xwaitpid (pid, &result.status, 0);
+  xfclose_memstream (&result->out);
+  xfclose_memstream (&result->err);
+
+  result->status = support_process_wait (proc);
+}
+
+struct support_capture_subprocess
+support_capture_subprocess (void (*callback) (void *), void *closure)
+{
+  struct support_capture_subprocess result;
+  xopen_memstream (&result.out);
+  xopen_memstream (&result.err);
+
+  struct support_subprocess proc = support_subprocess (callback, closure);
+
+  support_capture_poll (&result, &proc);
+  return result;
+}
+
+struct support_capture_subprocess
+support_capture_subprogram (const char *file, char *const argv[])
+{
+  struct support_capture_subprocess result;
+  xopen_memstream (&result.out);
+  xopen_memstream (&result.err);
+
+  struct support_subprocess proc = support_subprogram (file, argv);
+
+  support_capture_poll (&result, &proc);
   return result;
 }