Function createTraceMethod

src/cpp-syntax-utils.ts:36–68

(type: Type, members: ClassElement[])

 * Create the Trace method required by cppgc::GarbageCollected.
 */
export function createTraceMethod(type: Type, members: ClassElement[]): MethodDeclaration | undefined {
  // Collect all the GCed members from the class.
  const body = new Block();
  for (const member of members) {
    if (member instanceof PropertyDeclaration) {
      let traceMethod: string | undefined;
      if (member.type.hasObject())
        traceMethod = 'compilets::TraceMember';
      else if (member.type.hasTemplate())
        traceMethod = 'compilets::TracePossibleMember';
      if (traceMethod) {
        body.statements.push(
          new ExpressionStatement(
            new RawExpression(Type.createVoidType(),
                              `${traceMethod}(visitor, ${member.name})`)));
      }
    }
  }
  if (body.statements.length == 0)
    return;
  if (type.base) {
    body.statements.push(
      new ExpressionStatement(
        new RawExpression(new Type('void', 'void'),
                          `${type.base.name}::Trace(visitor)`)));
  }
  // Create the visitor parameter.
  const visitorType = new Type('cppgc::Visitor*', 'external');
  const visitor = new ParameterDeclaration('visitor', visitorType);
  // Create the method.
  const methodType = new FunctionType('method', Type.createVoidType(), [ visitorType ]);
  return new MethodDeclaration(methodType, 'Trace', [ 'public', 'override', 'const' ], [ visitor ], body);
}

/**
 * Convert the expression of source type to target type if necessary.