lib/tests: Check that igt_assert forwards correctly through igt_fork

Note that without the igt_waitchildren nothing at all gets forwarded,
maybe we should check for left-behind children somewhere on subtest
exit.

v2: Drop NIH exit status handling (Chris).

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

lib/tests/igt_fork.c

+/*
+ * Copyright © 2019 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "igt_core.h"
+
+/*
+ * We need to hide assert from the cocci igt test refactor spatch.
+ *
+ * IMPORTANT: Test infrastructure tests are the only valid places where using
+ * assert is allowed.
+ */
+#define internal_assert assert
+
+char test[] = "test";
+char *argv_run[] = { test };
+
+static void igt_fork_vs_assert(void)
+{
+	igt_fork(i, 1) {
+		igt_assert(0);
+	}
+
+	igt_waitchildren();
+}
+
+static int do_fork(void (*test_to_run)(void))
+{
+	int pid, status;
+	int argc;
+
+	switch (pid = fork()) {
+	case -1:
+		internal_assert(0);
+	case 0:
+		argc = 1;
+		igt_simple_init(argc, argv_run);
+		test_to_run();
+		igt_exit();
+	default:
+		while (waitpid(pid, &status, 0) == -1 &&
+		       errno == EINTR)
+			;
+
+		return status;
+	}
+}
+
+
+int main(int argc, char **argv)
+{
+	int ret;
+
+	ret = do_fork(igt_fork_vs_assert);
+	internal_assert(WEXITSTATUS(ret) == IGT_EXIT_FAILURE);
+}

lib/tests/meson.build

 lib_tests = [
 	'igt_fork_helper',
+	'igt_fork',
 	'igt_list_only',
 	'igt_simulation',
 	'igt_stats',