[lang] Adding Java cast on the returned value into the generated code…

… of the synthetic functions for default-valued parameters.

close #1035

Signed-off-by: Stéphane Galland <galland@arakhne.org>

main/coreplugins/io.sarl.lang/src/io/sarl/lang/jvmmodel/SARLJvmModelInferrer.java

@@ -45,6 +45,8 @@
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import com.google.common.base.Objects;
 import com.google.common.base.Predicate;
@@ -1849,14 +1851,17 @@ protected void transform(final XtendFunction source, final JvmGenericType contai
 									.cloneWithProxies(exception));
 						}
 
+						final JvmTypeReference returnType2;
 						if (selectedReturnType instanceof XComputedTypeReference) {
-							operation2.setReturnType(this.typeReferences.createDelegateTypeReference(selectedReturnType));
+							returnType2 = this.typeReferences.createDelegateTypeReference(selectedReturnType);
 						} else {
-							operation2.setReturnType(cloneWithTypeParametersAndProxies(selectedReturnType, operation2));
+							returnType2 = cloneWithTypeParametersAndProxies(selectedReturnType, operation2);
 						}
+						operation2.setReturnType(returnType2);
 
 						final List<String> args = translateSarlFormalParametersForSyntheticOperation(
-								operation2, container, isVarArgs, otherSignature.getValue());
+								operation2, container, isVarArgs,
+								otherSignature.getValue());
 
 						if (context.isAtLeastJava8()) {
 							operation2.setDefault(container.isInterface());
@@ -1866,6 +1871,16 @@ protected void transform(final XtendFunction source, final JvmGenericType contai
 								if (!SARLJvmModelInferrer.this.typeReferences.is(type, void.class)) {
 									it.append("return "); //$NON-NLS-1$
 								}
+								final LightweightTypeReference ltr = Utils.toLightweightTypeReference(returnType2, this.services);
+								if (Utils.containsGenericType(ltr)) {
+									final String typeId = ltr.getRawTypeReference().getType().getQualifiedName('.');
+									final String javaId = ltr.getRawTypeReference().getJavaIdentifier();
+									final String fullId = ltr.getJavaIdentifier().replaceAll(
+											Pattern.quote(javaId), Matcher.quoteReplacement(typeId));
+									it.append("("); //$NON-NLS-1$
+									it.append(fullId);
+									it.append(")"); //$NON-NLS-1$
+								}
 								it.append(sourceName);
 								it.append("("); //$NON-NLS-1$
 								it.append(IterableExtensions.join(args, ", ")); //$NON-NLS-1$
@@ -3154,7 +3169,8 @@ protected void translateSarlFormalParameters(
 		}
 	}
 
-	/** Generate a list of formal parameters with annotations for the default values.
+	/** Generate a list arguments from the formal parameters in order to be used for a call into
+	 * a synthetic operation, such as default-valued parameter function.
 	 *
 	 * @param owner the JVM element to change.
 	 * @param actionContainer the container of the action.
@@ -3169,7 +3185,8 @@ protected List<String> translateSarlFormalParametersForSyntheticOperation(JvmExe
 			final JvmTypeReference paramType = parameterSpec.getType();
 			if (parameterSpec instanceof InferredValuedParameter) {
 				final StringBuilder argumentValue = new StringBuilder();
-				if (paramType.getType() instanceof JvmTypeParameter) {
+				final JvmType jtype = paramType.getType();
+				if (jtype instanceof JvmTypeParameter) {
 					argumentValue.append("("); //$NON-NLS-1$
 					argumentValue.append(paramType.getSimpleName());
 					argumentValue.append(") "); //$NON-NLS-1$

main/coreplugins/io.sarl.lang/src/io/sarl/lang/util/Utils.java

@@ -1843,5 +1843,40 @@ private static boolean isLocalEntity(XAbstractFeatureCall featureCall, XExpressi
 		return false;
 	}
 
+	/** Replies if a generic type parameter is declared into the given type.
+	 *
+	 * @param type is the type to explore.
+	 * @return {@code code} if the {@code type} contains a generic type.
+	 */
+	public static boolean containsGenericType(LightweightTypeReference type) {
+		if (type == null) {
+			return false;
+		}
+		final JvmType jtype = type.getType();
+		if (jtype instanceof JvmTypeParameter) {
+			return true;
+		}
+		for (final LightweightTypeReference atype : type.getTypeArguments()) {
+			if (containsGenericType(atype)) {
+				return true;
+			}
+		}
+		switch (type.getKind()) {
+		case LightweightTypeReference.KIND_WILDCARD_TYPE_REFERENCE:
+			if (containsGenericType(type.getLowerBoundSubstitute()) || containsGenericType(type.getUpperBoundSubstitute())) {
+				return true;
+			}
+			break;
+		case LightweightTypeReference.KIND_ARRAY_TYPE_REFERENCE:
+			if (containsGenericType(type.getComponentType())) {
+				return true;
+			}
+			break;
+		default:
+			break;
+		}
+		return false;
+	}
+
 }
 

tests/io.sarl.lang.tests/src/test/java/io/sarl/lang/tests/bugs/to00999/Bug723Test.java

@@ -92,7 +92,7 @@ public class Bug723Test extends AbstractSarlTest {
 			"  @SyntheticMember",
 			"  @Pure",
 			"  public static <S extends Object> Class<? extends S> getSystemPropertyAsClass(final Class<S> type, final String name) {",
-			"    return getSystemPropertyAsClass(type, name, $DEFAULT_VALUE$GETSYSTEMPROPERTYASCLASS_0);",
+			"    return (java.lang.Class<? extends S>)getSystemPropertyAsClass(type, name, $DEFAULT_VALUE$GETSYSTEMPROPERTYASCLASS_0);",
 			"  }",
 			"  ",
 			"  @SyntheticMember",
@@ -144,7 +144,7 @@ public class Bug723Test extends AbstractSarlTest {
 			"  @SyntheticMember",
 			"  @Pure",
 			"  public static <S extends Enum<S>> S getSystemPropertyAsEnum(final Class<S> type, final String name) {",
-			"    return getSystemPropertyAsEnum(type, name, (S) $DEFAULT_VALUE$GETSYSTEMPROPERTYASENUM_0);",
+			"    return (S)getSystemPropertyAsEnum(type, name, (S) $DEFAULT_VALUE$GETSYSTEMPROPERTYASENUM_0);",
 			"  }",
 			"  ",
 			"  @SyntheticMember",