union-cast: add some testcases

Casts to union type are a GCC extension and are similar to
compound literals.

However, sparse doesn't know about them and treats them like
other casts to non-scalars.

Add some testcases for this and its upcoming warning flag.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>

2 files changed, 49 insertions, 0 deletions

diff --git a/validation/eval/union-cast-no.c b/validation/eval/union-cast-no.c
new file mode 100644
index 00000000..d06b348d
--- /dev/null
+++ b/validation/eval/union-cast-no.c
@@ -0,0 +1,24 @@
+union u {
+	int	i;
+	char	x[8];
+};
+
+static union u foo(int i)
+{
+	return (union u)i;
+}
+
+static union u bar(long l)
+{
+	return (union u)l;
+}
+
+/*
+ * check-name: union-cast-no
+ * check-command: sparse -Wno-union-cast $file
+ * check-known-to-fail
+ *
+ * check-error-start
+eval/union-cast-no.c:13:17: warning: cast to non-scalar
+ * check-error-end
+ */
diff --git a/validation/eval/union-cast.c b/validation/eval/union-cast.c
new file mode 100644
index 00000000..1d816753
--- /dev/null
+++ b/validation/eval/union-cast.c
@@ -0,0 +1,25 @@
+union u {
+	int	i;
+	char	x[8];
+};
+
+static union u foo(int a)
+{
+	return (union u)a;
+}
+
+static union u bar(long a)
+{
+	return (union u)a;
+}
+
+/*
+ * check-name: union-cast
+ * check-command: sparse -Wunion-cast $file
+ * check-known-to-fail
+ *
+ * check-error-start
+eval/union-cast.c:8:17: warning: cast to union type
+eval/union-cast.c:13:17: warning: cast to non-scalar
+ * check-error-end
+ */