/** Generate the code necessary to allow for runtime type checks */
void generateRuntimeTypeInfo(DartClass x) {
generateRuntimeTypeInfoMethods(x);
ClassElement classElement = x.getSymbol();
if (!classElement.isInterface()) {
injectInterfaceMarkers(classElement, x);
}
}
@Override
public Void visitClass(DartClass node) {
if (node.isInterface()) {
recordRelationship(node, SyntheticLocation.ALL_INTERFACES);
} else {
recordRelationship(node, SyntheticLocation.ALL_CLASSES);
}
return super.visitClass(node);
}
private void generateRTTImplementsMethod(DartClass x) {
ClassElement classElement = x.getSymbol();
// 1) create static type information construction function
// function Foo$lookupOrCreateRTT(rtt, typeArgs) {
//
// // superclass
// FooSuper$addTo(rtt, superTypeArg1, ...);
// // interfaces
// FooInterface1$addTo(rtt, interface1TypeArg1, ...);
//
// // fill in derived types
// rtt.derivedTypes = [
// FirstRef$lookupOrCreateRTT(typearg1, ...),
// ...
// ]
// }
boolean hasTypeParams = classElement.getTypeParameters().size() > 0;
// Build the function
JsFunction implementsFn = new JsFunction(globalScope);
implementsFn.setBody(new JsBlock());
List<JsStatement> body = implementsFn.getBody().getStatements();
JsScope scope = new JsScope(globalScope, "temp");
JsName rtt = scope.declareName("rtt");
implementsFn.getParameters().add(new JsParameter(rtt));
JsName typeArgs = null;
if (hasTypeParams) {
typeArgs = scope.declareName("typeArgs");
implementsFn.getParameters().add(new JsParameter(typeArgs));
}
JsInvocation callAddTo = newInvocation(getRTTAddToMethodName(classElement), rtt.makeRef());
if (hasTypeParams) {
typeArgs = scope.declareName("typeArgs");
callAddTo.getArguments().add(typeArgs.makeRef());
}
body.add(callAddTo.makeStmt());
// Add the derived types
if (hasTypeParams) {
// Populated the list of derived types
JsArrayLiteral derivedTypesArray = new JsArrayLiteral();
// TODO(johnlenz): Add needed types here.
JsExpression addDerivedTypes =
assign(null, nameref(null, rtt.makeRef(), "derivedTypes"), derivedTypesArray);
body.add(addDerivedTypes.makeStmt());
}
// Finally, Add the function
JsExpression fnDecl = assign(null, getRTTImplementsMethodName(classElement), implementsFn);
globalBlock.getStatements().add(fnDecl.makeStmt());
}
/**
* Insert the function or method necessary to implement runtime type information for the provided
* class.
*/
private void generateRuntimeTypeInfoMethods(DartClass x) {
// 1) create static type information lookup function
generateRTTLookupMethod(x);
// 2) create a method to fill in the type information for the class
ClassElement classElement = x.getSymbol();
if (hasRTTImplements(classElement)) {
generateRTTImplementsMethod(x);
}
// 3) create "addTo" method for use by classes or interfaces that inherit from this class
generateRTTAddToMethod(x);
}
private void generateRTTLookupMethod(DartClass x) {
ClassElement classElement = x.getSymbol();
boolean hasTypeParams = hasTypeParameters(classElement);
// 1) create static type information construction function
// function Foo$lookupOrCreateRTT(typeargs) {
// return $createRTT(name, Foo$RTTimplements, typeargs) ;
// }
// Build the function
JsFunction lookupFn = new JsFunction(globalScope);
lookupFn.setBody(new JsBlock());
List<JsStatement> body = lookupFn.getBody().getStatements();
JsScope scope = new JsScope(globalScope, "temp");
JsProgram program = translationContext.getProgram();
JsInvocation invokeCreate =
call(null, newQualifiedNameRef("RTT.create"), getRTTClassId(classElement));
List<JsExpression> callArgs = invokeCreate.getArguments();
if (hasRTTImplements(classElement)) {
callArgs.add(getRTTImplementsMethodName(classElement));
} else if (hasTypeParams) {
// need a placeholder param if the typeArgs are needed.
callArgs.add(program.getNullLiteral());
}
if (hasTypeParams) {
JsName typeArgs = scope.declareName("typeArgs");
lookupFn.getParameters().add(new JsParameter(typeArgs));
callArgs.add(typeArgs.makeRef());
}
body.add(new JsReturn(invokeCreate));
// Finally, Add the function
JsExpression fnDecl = assign(null, getRTTLookupMethodName(classElement), lookupFn);
globalBlock.getStatements().add(fnDecl.makeStmt());
}
private void generateRTTAddToMethod(DartClass x) {
ClassElement classElement = x.getSymbol();
// 2) create "addTo" method
// Foo$Type$addTo(target, typeargs) {
// var rtt = Foo$lookupOrCreateRTT(typeargs)
// target.implementedTypes[rtt.classkey] = rtt;
// }
// Build the function
JsFunction addToFn = new JsFunction(globalScope);
addToFn.setBody(new JsBlock());
JsScope scope = new JsScope(globalScope, "temp");
JsName targetType = scope.declareName("target");
addToFn.getParameters().add(new JsParameter(targetType));
// Get the RTT info object
JsName rtt = scope.declareName("rtt");
List<JsStatement> body = addToFn.getBody().getStatements();
JsInvocation callLookup = newInvocation(getRTTLookupMethodName(classElement));
if (hasTypeParameters(classElement)) {
JsName typeArgs = scope.declareName("typeArgs");
addToFn.getParameters().add(new JsParameter(typeArgs));
callLookup.getArguments().add(new JsNameRef(typeArgs));
}
JsStatement rttLookup = newVar((SourceInfo) null, rtt, callLookup);
body.add(rttLookup);
// store it.
JsExpression addToTypes =
newAssignment(
new JsArrayAccess(
newNameRef(targetType.makeRef(), "implementedTypes"),
newNameRef(rtt.makeRef(), "classKey")),
rtt.makeRef());
body.add(addToTypes.makeStmt());
InterfaceType superType = classElement.getSupertype();
if (superType != null && !superType.getElement().isObject()) {
ClassElement interfaceElement = superType.getElement();
JsInvocation callAddTo =
newInvocation(getRTTAddToMethodName(interfaceElement), targetType.makeRef());
if (hasTypeParameters(interfaceElement) && !superType.hasDynamicTypeArgs()) {
JsArrayLiteral superTypeArgs = new JsArrayLiteral();
List<? extends Type> typeParams = classElement.getTypeParameters();
for (Type arg : superType.getArguments()) {
superTypeArgs
.getExpressions()
.add(
buildTypeLookupExpression(
arg, typeParams, nameref(null, targetType.makeRef(), "typeArgs")));
}
callAddTo.getArguments().add(superTypeArgs);
}
body.add(callAddTo.makeStmt());
}
// Add the interfaces
for (InterfaceType interfaceType : classElement.getInterfaces()) {
ClassElement interfaceElement = interfaceType.getElement();
JsInvocation callAddTo =
call(null, getRTTAddToMethodName(interfaceElement), targetType.makeRef());
if (hasTypeParameters(interfaceElement) && !interfaceType.hasDynamicTypeArgs()) {
JsArrayLiteral interfaceTypeArgs = new JsArrayLiteral();
List<? extends Type> typeParams = classElement.getTypeParameters();
for (Type arg : interfaceType.getArguments()) {
interfaceTypeArgs
.getExpressions()
.add(
buildTypeLookupExpression(
arg, typeParams, nameref(null, targetType.makeRef(), "typeArgs")));
}
callAddTo.getArguments().add(interfaceTypeArgs);
}
body.add(callAddTo.makeStmt());
}
// Add the function statement
JsExpression fnDecl = newAssignment(getRTTAddToMethodName(classElement), addToFn);
globalBlock.getStatements().add(fnDecl.makeStmt());
}