lib: allow igt_skip_on_simulation outside of fixtures.

Thomas noticed that in simulation mode a lot of the tests fall over
instead of skipping properly. This is due to recently added
self-checks which ensure that any call to igt_skip happens either
within a fixture or subtest block (or it's a simple test without
subtests). This is to catch bugs since pretty much always not wrapping
up hardware setup and checks into these blocks is a bug.

Bug simulation skipping is a bit different, so allow that exception.
Otherwise we'd need to fix up piles of tests (and likely need to play
a game of whack-a-mole).

Also add a library testcase for all the different variants to make
sure it really works.

Cc: Thomas Wood <thomas.wood@intel.com>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/igt_core.c

@@ -1117,13 +1117,23 @@ bool igt_run_in_simulation(void)
  *
  * Skip tests when INTEL_SIMULATION environment variable is set. It uses
  * igt_skip() internally and hence is fully subtest aware.
+ *
+ * Note that in contrast to all other functions which use igt_skip() internally
+ * it is allowed to use this outside of an #igt_fixture block in a test with
+ * subtests. This is because in contrast to most other test requirements,
+ * checking for simulation mode doesn't depend upon the present hardware and it
+ * so makes a lot of sense to have this check in the outermost #igt_main block.
  */
 void igt_skip_on_simulation(void)
 {
 	if (igt_only_list_subtests())
 		return;
 
-	igt_require(!igt_run_in_simulation());
+	if (!in_fixture) {
+		igt_fixture
+			igt_require(!igt_run_in_simulation());
+	} else
+		igt_require(!igt_run_in_simulation());
 }
 
 /* structured logging */

tests/.gitignore

@@ -107,6 +107,7 @@ igt_list_only
 igt_no_exit
 igt_no_exit_list_only
 igt_no_subtest
+igt_simulation
 kms_addfb
 kms_cursor_crc
 kms_fbc_crc

tests/Makefile.sources

@@ -179,6 +179,7 @@ TESTS_testsuite = \
 	igt_fork_helper \
 	igt_list_only \
 	igt_no_subtest \
+	igt_simulation \
 	$(NULL)
 
 TESTS = \

tests/igt_simulation.c

@@ -0,0 +1,139 @@
+/*
+ * Copyright © 2014 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.
+ *
+ * Authors:
+ *    Daniel Vetter <daniel.vetter@ffwll.ch>
+ *
+ */
+
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+
+#include "drmtest.h"
+#include "igt_core.h"
+
+bool simple;
+bool list_subtests;
+bool in_fixture;
+
+char test[] = "test";
+char list[] = "--list-subtests";
+char *argv_list[] = { test, list };
+char *argv_run[] = { test };
+
+static int do_fork(void)
+{
+	int pid, status;
+
+	switch (pid = fork()) {
+	case -1:
+		assert(0);
+	case 0:
+		if (simple) {
+			igt_simple_init();
+
+			igt_skip_on_simulation();
+
+			exit(0);
+		} else {
+			if (list_subtests)
+				igt_subtest_init(2, argv_list);
+			else
+				igt_subtest_init(1, argv_run);
+
+			if (in_fixture) {
+				igt_fixture
+					igt_skip_on_simulation();
+			} else
+				igt_skip_on_simulation();
+
+			igt_subtest("foo")
+				;
+
+			printf("baz\n");
+			igt_exit();
+		}
+	default:
+		while (waitpid(pid, &status, 0) == -1 &&
+		       errno == EINTR)
+			;
+
+		assert(WIFEXITED(status));
+
+		return WEXITSTATUS(status);
+	}
+}
+
+int main(int argc, char **argv)
+{
+	/* simple tests */
+	simple = true;
+	assert(setenv("INTEL_SIMULATION", "1", 1) == 0);
+	assert(do_fork() == 77);
+
+	assert(setenv("INTEL_SIMULATION", "0", 1) == 0);
+	assert(do_fork() == 0);
+
+	/* subtests, list mode */
+	simple = false;
+	list_subtests = true;
+
+	in_fixture = false;
+	assert(setenv("INTEL_SIMULATION", "1", 1) == 0);
+	assert(do_fork() == 0);
+
+	in_fixture = false;
+	assert(setenv("INTEL_SIMULATION", "0", 1) == 0);
+	assert(do_fork() == 0);
+
+	in_fixture = true;
+	assert(setenv("INTEL_SIMULATION", "1", 1) == 0);
+	assert(do_fork() == 0);
+
+	in_fixture = true;
+	assert(setenv("INTEL_SIMULATION", "0", 1) == 0);
+	assert(do_fork() == 0);
+
+	/* subtest, run mode */
+	simple = false;
+	list_subtests = false;
+
+	in_fixture = false;
+	assert(setenv("INTEL_SIMULATION", "1", 1) == 0);
+	assert(do_fork() == 77);
+
+	in_fixture = false;
+	assert(setenv("INTEL_SIMULATION", "0", 1) == 0);
+	assert(do_fork() == 0);
+
+	in_fixture = true;
+	assert(setenv("INTEL_SIMULATION", "1", 1) == 0);
+	assert(do_fork() == 77);
+
+	in_fixture = true;
+	assert(setenv("INTEL_SIMULATION", "0", 1) == 0);
+	assert(do_fork() == 0);
+
+
+	return 0;
+}