예제 #1
0
bool SymbolRegistry::lookupSymbol(SymbolScope* scope, const std::wstring& name, SymbolScope** container, SymbolPtr* ret, bool lazyResolve)
{
    SymbolScope* s = scope;
    for(; s; s = s->parent)
    {
        SymbolPtr symbol = s->lookup(name, lazyResolve);
        if(symbol)
        {
            if(container)
                *container = s;
            if(ret)
                *ret = symbol;
            return true;
        }
    }
    return false;
}
void SemanticAnalyzer::visitValueBinding(const ValueBindingPtr& node)
{
    PatternPtr name = node->getName();
    //tuple was already exploded in declaration analyzer
    if(name->getNodeType() == NodeType::Tuple)
    {
        validateTupleTypeDeclaration(node);
    }
    if (name->getNodeType() != NodeType::Identifier)
        return;
    if(node->getOwner()->isReadOnly() && !node->getInitializer() && ctx->currentType == nullptr)
    {
        error(node, Errors::E_LET_REQUIRES_INITIALIZER);
        return;
    }
    //handle type inference for temporary variable
    if(node->isTemporary() && node->getInitializer())
    {
        //temporary variable always has an initializer
        TypePtr initializerType;
        TypePtr declaredType = node->getType();

        SCOPED_SET(ctx->contextualType, declaredType);
        node->getInitializer()->accept(this);
        initializerType = node->getInitializer()->getType();
        assert(initializerType != nullptr);

        if(declaredType)
        {
            //it has both type definition and initializer, then we need to check if the initializer expression matches the type annotation
            if(!initializerType->canAssignTo(declaredType))
            {
                error(node, Errors::E_CANNOT_CONVERT_EXPRESSION_TYPE_2, initializerType->toString(), declaredType->toString());
                return;
            }
        }
        else
        {
            node->setType(initializerType);
        }
    }
    

    //add implicitly constructor for Optional
    IdentifierPtr id = static_pointer_cast<Identifier>(node->getName());
    SymbolScope* currentScope = symbolRegistry->getCurrentScope();


    TypePtr declaredType = node->getType() ? node->getType() : lookupType(node->getDeclaredType());
    SCOPED_SET(ctx->contextualType, declaredType);
    if(!declaredType && !node->getInitializer())
    {
        error(node, Errors::E_TYPE_ANNOTATION_MISSING_IN_PATTERN);
        return;
    }
    SymbolPtr sym = currentScope->lookup(id->getIdentifier());
    assert(sym != nullptr);
    SymbolPlaceHolderPtr placeholder = std::dynamic_pointer_cast<SymbolPlaceHolder>(sym);
    assert(placeholder != nullptr);
    if(declaredType)
    {
        placeholder->setType(declaredType);
    }
    ExpressionPtr initializer = node->getInitializer();
    if(initializer)
    {
        placeholder->setFlags(SymbolFlagInitializing, true);
        ExpressionPtr initializer = transformExpression(declaredType, node->getInitializer());
        node->setInitializer(initializer);
        TypePtr actualType = initializer->getType();
        assert(actualType != nullptr);
        if(declaredType)
        {
            if(!Type::equals(actualType, declaredType) && !canConvertTo(initializer, declaredType))
            {
                error(initializer, Errors::E_CANNOT_CONVERT_EXPRESSION_TYPE_2, actualType->toString(), declaredType->toString());
                return;
            }
        }

        if(!declaredType)
            placeholder->setType(actualType);
    }
    assert(placeholder->getType() != nullptr);
    placeholder->setFlags(SymbolFlagInitializing, false);
    //optional type always considered initialized, compiler will make it has a default value nil
    TypePtr symbolType = sym->getType();
    GlobalScope* global = symbolRegistry->getGlobalScope();
    if(initializer || global->isOptional(symbolType) || global->isImplicitlyUnwrappedOptional(symbolType))
        markInitialized(placeholder);

    if (initializer)
        placeholder->setFlags(SymbolFlagHasInitializer, true);
    if(node->isTemporary())
    {
        placeholder->setFlags(SymbolFlagTemporary, true);
        markInitialized(placeholder);
    }

    if(!node->isTemporary())
    {
        //check access control level
        DeclarationType decl = ctx->currentType ? DeclarationTypeProperty : DeclarationTypeVariable;
        declarationAnalyzer->verifyAccessLevel(node->getOwner(), placeholder->getType(), decl, ComponentTypeType);
    }
    if(ctx->currentType && ctx->currentType->getCategory() == Type::Protocol)
    {
        error(node, Errors::E_PROTOCOL_VAR_MUST_BE_COMPUTED_PROPERTY_1);
    }
}