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>

1 files changed, 13 insertions, 1 deletions

diff --git a/lib/igt_core.c b/lib/igt_core.c
index 3c092a5f..947a9ca3 100644
--- a/lib/igt_core.c
+++ b/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;