lib: Add igt_subtest_group

Useful for creating common setup code in igt_fixture which is only
needed by a subset of tests. And since I'm a good citizen it comes
with a library testcase/example included.

v2: Make testcase nastier to ensure a subtest group SKIPS when it's
parent is skipping already. I accidentally got this right, but let's
make sure.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

NEWS

@@ -1,3 +1,9 @@
+Release 1.15 (XXXX-XX-XX)
+-------------------------
+
+- Add igt_subtest_group to allow igt_fixture for only a subset of subtests
+  without skipping/failing all subsequent subtests.
+
 Release 1.14 (2016-03-01)
 -------------------------
 

lib/igt_core.c

@@ -97,7 +97,9 @@
  *
  * To allow this i-g-t provides #igt_fixture code blocks for setup code outside
  * of subtests and automatically skips the subtest code blocks themselves. For
- * special cases igt_only_list_subtests() is also provided.
+ * special cases igt_only_list_subtests() is also provided. For setup code only
+ * shared by a group of subtest encapsulate the #igt_fixture block and all the
+ * subtestest in a #igt_subtest_group block.
  *
  * # Magic Control Blocks
  *
@@ -889,6 +891,16 @@ bool igt_only_list_subtests(void)
 	return list_subtests;
 }
 
+void __igt_subtest_group_save(int *save)
+{
+	*save = skip_subtests_henceforth;
+}
+
+void __igt_subtest_group_restore(int save)
+{
+	skip_subtests_henceforth = save;
+}
+
 static bool skipped_one = false;
 static bool succeeded_one = false;
 static bool failed_one = false;

lib/igt_core.h

@@ -197,6 +197,30 @@ bool __igt_run_subtest(const char *subtest_name);
 const char *igt_subtest_name(void);
 bool igt_only_list_subtests(void);
 
+void __igt_subtest_group_save(int *);
+void __igt_subtest_group_restore(int);
+/**
+ * igt_subtest_group:
+ *
+ * Group a set of subtests together with their common setup code
+ *
+ * Testcase with subtests often need to set up a bunch of shared state as the
+ * common test fixture. But if there are multiple with different requirements
+ * the commont setup code can't be extracted, since a test condition failure in
+ * e.g. igt_require() would result in all subsequent tests skipping. Even those
+ * from a different group.
+ *
+ * This macro allows to group together a set of #igt_fixture and #igt_subtest
+ * clauses. If any common setup in a fixture fails, only the subtests in this
+ * group will fail or skip. Subtest groups can be arbitrarily nested.
+ */
+#define igt_subtest_group for (int igt_tokencat(__tmpint,__LINE__) = 0, \
+			       igt_tokencat(__save,__LINE__) = 0; \
+			       igt_tokencat(__tmpint,__LINE__) < 1 && \
+			       (__igt_subtest_group_save(& igt_tokencat(__save,__LINE__) ), true); \
+			       igt_tokencat(__tmpint,__LINE__) ++, \
+			       __igt_subtest_group_restore(igt_tokencat(__save,__LINE__) ))
+
 /**
  * igt_main:
  *

lib/tests/.gitignore

@@ -11,4 +11,5 @@ igt_segfault
 igt_simple_test_subtests
 igt_simulation
 igt_stats
+igt_subtest_group
 igt_timeout

lib/tests/Makefile.sources

@@ -10,6 +10,7 @@ check_PROGRAMS = \
 	igt_timeout \
 	igt_invalid_subtest_name \
 	igt_segfault \
+	igt_subtest_group \
 	igt_assert \
 	igt_exit_handler \
 	$(NULL)

lib/tests/igt_subtest_group.c

@@ -0,0 +1,63 @@
+/*
+ * Copyright © 2016 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 "igt_core.h"
+
+igt_main
+{
+	bool t1 = false;
+
+	igt_subtest_group {
+		igt_fixture {
+			igt_require(true);
+		}
+
+		igt_subtest_group {
+			igt_fixture {
+				igt_require(false);
+			}
+
+			igt_subtest("not-run") {
+				assert(0);
+			}
+
+			igt_subtest_group {
+				/* need to make sure we don't accidentally
+				 * restore to "run testcases" when an outer
+				 * group is already in SKIP state. */
+				igt_subtest("still-not-run") {
+					assert(0);
+				}
+			}
+		}
+
+		igt_subtest("run") {
+			t1 = true;
+			assert(1);
+		}
+	}
+
+	assert(t1);
+}