HHH-14724 Fix generation of problematic metamodel classes which use TYPE_USE annotations

tooling/metamodel-generator/hibernate-jpamodelgen.gradle

@@ -30,7 +30,7 @@ dependencies {
 
     testCompile libraries.junit
     testCompile libraries.jpa
-	testCompile libraries.validation
+    testCompile libraries.validation
     testCompile project( ':hibernate-core' )
 }
 

tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/util/TypeRenderingVisitor.java

@@ -0,0 +1,182 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.jpamodelgen.util;
+
+import java.util.List;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.element.TypeParameterElement;
+import javax.lang.model.type.ArrayType;
+import javax.lang.model.type.DeclaredType;
+import javax.lang.model.type.ExecutableType;
+import javax.lang.model.type.IntersectionType;
+import javax.lang.model.type.NoType;
+import javax.lang.model.type.NullType;
+import javax.lang.model.type.PrimitiveType;
+import javax.lang.model.type.TypeKind;
+import javax.lang.model.type.TypeMirror;
+import javax.lang.model.type.TypeVariable;
+import javax.lang.model.type.UnionType;
+import javax.lang.model.type.WildcardType;
+import javax.lang.model.util.SimpleTypeVisitor8;
+
+/**
+ * @author Christian Beikov
+ */
+public final class TypeRenderingVisitor extends SimpleTypeVisitor8<Object, Object> {
+
+	private final StringBuilder sb = new StringBuilder();
+
+	private TypeRenderingVisitor() {
+	}
+
+	public static String toString(TypeMirror typeMirror) {
+		if ( typeMirror instanceof TypeVariable ) {
+			// Top level type variables don't need to render the upper bound as `T extends Type`
+			final Element typeVariableElement = ( (TypeVariable) typeMirror ).asElement();
+			if ( typeVariableElement instanceof TypeParameterElement ) {
+				final TypeParameterElement typeParameter = (TypeParameterElement) typeVariableElement;
+				if ( typeParameter.getEnclosingElement().getKind() == ElementKind.METHOD ) {
+					// But for method level type variable we return the upper bound
+					// because the type variable has no meaning except for that method
+					typeMirror = ( (TypeVariable) typeMirror ).getUpperBound();
+				}
+				else {
+					return typeParameter.toString();
+				}
+			}
+			else {
+				typeMirror = typeVariableElement.asType();
+			}
+		}
+		else if ( typeMirror instanceof IntersectionType ) {
+			// For top level type only the first type is relevant
+			typeMirror = ( (IntersectionType) typeMirror ).getBounds().get( 0 );
+		}
+		final TypeRenderingVisitor typeRenderingVisitor = new TypeRenderingVisitor();
+		typeMirror.accept( typeRenderingVisitor, null );
+		return typeRenderingVisitor.sb.toString();
+	}
+
+	@Override
+	public Object visitPrimitive(PrimitiveType t, Object o) {
+		final String primitiveTypeName = getPrimitiveTypeName( t.getKind() );
+		if ( primitiveTypeName != null ) {
+			sb.append( primitiveTypeName );
+		}
+		return null;
+	}
+
+	private static String getPrimitiveTypeName(TypeKind kind) {
+		switch ( kind ) {
+			case INT:
+				return "int";
+			case BOOLEAN:
+				return "boolean";
+			case BYTE:
+				return "byte";
+			case CHAR:
+				return "char";
+			case DOUBLE:
+				return "double";
+			case FLOAT:
+				return "float";
+			case LONG:
+				return "long";
+			case SHORT:
+				return "short";
+			case VOID:
+				return "void";
+		}
+		return null;
+	}
+
+	@Override
+	public Object visitNull(NullType t, Object o) {
+		return null;
+	}
+
+	@Override
+	public Object visitArray(ArrayType t, Object o) {
+		t.getComponentType().accept( this, null );
+		sb.append( "[]" );
+		return t;
+	}
+
+	@Override
+	public Object visitDeclared(DeclaredType t, Object o) {
+		sb.append( t.asElement().toString() );
+		List<? extends TypeMirror> typeArguments = t.getTypeArguments();
+		if ( !typeArguments.isEmpty() ) {
+			sb.append( '<' );
+			typeArguments.get( 0 ).accept( this, null );
+			for ( int i = 1; i < typeArguments.size(); i++ ) {
+				sb.append( ", " );
+				typeArguments.get( i ).accept( this, null );
+			}
+			sb.append( '>' );
+		}
+		return null;
+	}
+
+	@Override
+	public Object visitTypeVariable(TypeVariable t, Object o) {
+		final Element typeVariableElement = t.asElement();
+		if ( typeVariableElement instanceof TypeParameterElement ) {
+			final TypeParameterElement typeParameter = (TypeParameterElement) typeVariableElement;
+			sb.append( typeParameter );
+			if ( !"java.lang.Object".equals( t.getUpperBound().toString() ) ) {
+				sb.append( " extends " );
+				t.getUpperBound().accept( this, null );
+			}
+		}
+		else {
+			typeVariableElement.asType().accept( this, null );
+		}
+		return null;
+	}
+
+	@Override
+	public Object visitWildcard(WildcardType t, Object o) {
+		sb.append( '?' );
+		if ( t.getExtendsBound() != null ) {
+			sb.append( " extends " );
+			t.getExtendsBound().accept( this, null );
+		}
+		if ( t.getSuperBound() != null ) {
+			sb.append( " super " );
+			t.getSuperBound().accept( this, null );
+		}
+		return null;
+	}
+
+	@Override
+	public Object visitUnion(UnionType t, Object o) {
+		return null;
+	}
+
+	@Override
+	public Object visitIntersection(IntersectionType t, Object o) {
+		final List<? extends TypeMirror> bounds = t.getBounds();
+		bounds.get( 0 ).accept( this, null );
+		for ( int i = 0; i < bounds.size(); i++ ) {
+			sb.append( " & " );
+			bounds.get( i ).accept( this, null );
+		}
+		return null;
+	}
+
+	@Override
+	public Object visitExecutable(ExecutableType t, Object o) {
+		return null;
+	}
+
+	@Override
+	public Object visitNoType(NoType t, Object o) {
+		return null;
+	}
+}

tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/util/TypeUtils.java

@@ -74,7 +74,7 @@ public final class TypeUtils {
 		if ( type.getKind().isPrimitive() ) {
 			return PRIMITIVE_WRAPPERS.get( type.getKind() );
 		}
-		return type.toString();
+		return TypeRenderingVisitor.toString( type );
 	}
 
 	public static String toArrayTypeString(ArrayType type, Context context) {