scanner: add validators for enums

Right now compositors need to manually check that enum values sent
by the client are valid. In particular:

- Check that the value sent by the client is not outside of the enum.
- Check that the version of the enum entry is consistent with the
  object version.

Automatically generate validator functions to perform these tasks.

Signed-off-by: Simon Ser <contact@emersion.fr>
Closes: https://gitlab.freedesktop.org/wayland/wayland/-/issues/104

1 files changed, 31 insertions, 0 deletions

diff --git a/tests/data/small-server.h b/tests/data/small-server.h
index 22b8113..13fd1ed 100644
--- a/tests/data/small-server.h
+++ b/tests/data/small-server.h
@@ -83,11 +83,42 @@ enum intf_A_foo {
 	 * @since 2
 	 */
 	INTF_A_FOO_THIRD = 2,
+	/**
+	 * this is a negative value
+	 * @since 2
+	 */
+	INTF_A_FOO_NEGATIVE = -1,
 };
 /**
  * @ingroup iface_intf_A
  */
 #define INTF_A_FOO_THIRD_SINCE_VERSION 2
+/**
+ * @ingroup iface_intf_A
+ */
+#define INTF_A_FOO_NEGATIVE_SINCE_VERSION 2
+/**
+ * @ingroup iface_intf_A
+ * Validate a intf_A foo value.
+ *
+ * @return true on success, false on error.
+ * @ref intf_A_foo
+ */
+static inline bool
+intf_A_foo_is_valid(uint32_t value, uint32_t version) {
+	switch (value) {
+	case INTF_A_FOO_FIRST:
+		return version >= 1;
+	case INTF_A_FOO_SECOND:
+		return version >= 1;
+	case INTF_A_FOO_THIRD:
+		return version >= 2;
+	case (uint32_t)INTF_A_FOO_NEGATIVE:
+		return version >= 2;
+	default:
+		return false;
+	}
+}
 #endif /* INTF_A_FOO_ENUM */
 
 /**