produce error if mixing styles (class ref/string) in proxy hints

Fixes #629

Author: aclement

spring-aot/src/main/java/org/springframework/nativex/type/Type.java

@@ -2025,7 +2025,10 @@ private void unpackProxyHint(AnnotationNode typeInfo, HintDeclaration ch) {
 		// Note: Proxies hints will get discarded immediately if types are not around
 		List<String> proxyTypes = new ArrayList<>();
 		boolean typeMissing = false;
+		boolean typesSpecified = false;
+		boolean typenamesSpecified = false;
 		for (org.objectweb.asm.Type type : types) {
+			typesSpecified = true;
 			String typeName = type.getClassName();
 			Type resolvedType = typeSystem.resolveName(typeName, true);
 			if (resolvedType != null) {
@@ -2035,13 +2038,17 @@ private void unpackProxyHint(AnnotationNode typeInfo, HintDeclaration ch) {
 			}
 		}
 		for (String typeName : typeNames) {
+			typenamesSpecified = true;
 			Type resolvedType = typeSystem.resolveName(typeName, true);
 			if (resolvedType != null) {
 				proxyTypes.add(typeName);
 			} else {
 				typeMissing = true;
 			}
 		}
+		if (typesSpecified && typenamesSpecified) {
+			throw new IllegalStateException("ERROR: [Limitation] Don't mix typenames and explicit type references in a ProxyHint on type "+getDottedName());
+		}
 		if (!typeMissing) {
 			ch.addProxyDescriptor(new ProxyDescriptor(proxyTypes.toArray(new String[0])));
 		}

spring-native/src/main/java/org/springframework/nativex/hint/ProxyHint.java

@@ -25,7 +25,9 @@
  * sets of types need proxies.
  * Interface references via the {@link #types} member are the preferred form of use but sometimes due
  * to accessibility restrictions or nested types the type names may need to be specified in the {@link #typeNames}
- * member.
+ * member.  The ordering of types when building a proxy is important, therefore we don't allow mixing the class reference
+ * and string styles as it may not result in the ordering you entered the attributes in at the source level. In these cases
+ * it is best to simple use the typeNames attribute (the ordering within a particular attribute is guaranteed).
  *
  * @see <a href="https://www.graalvm.org/reference-manual/native-image/DynamicProxy/">Dynamic proxy in native image</a>
  * @author Andy Clement