// scopeReturnStatement scopes a return statement in the SRG.
func (sb *scopeBuilder) scopeReturnStatement(node compilergraph.GraphNode, context scopeContext) proto.ScopeInfo {
var actualReturnType typegraph.TypeReference = sb.sg.tdg.VoidTypeReference()
exprNode, found := node.TryGetNode(parser.NodeReturnStatementValue)
if found {
exprScope := sb.getScope(exprNode, context)
if !exprScope.GetIsValid() {
return newScope().
Invalid().
GetScope()
}
actualReturnType = exprScope.ResolvedTypeRef(sb.sg.tdg)
}
// Ensure the return types match.
expectedReturnType, _ := sb.sg.tdg.LookupReturnType(context.parentImplemented)
if expectedReturnType.IsVoid() {
if !actualReturnType.IsVoid() {
sb.decorateWithError(node, "No return value expected here, found value of type '%v'", actualReturnType)
return newScope().
Invalid().
Returning(actualReturnType, true).
GetScope()
}
} else if actualReturnType.IsVoid() {
sb.decorateWithError(node, "Expected non-void resolved value")
return newScope().
Invalid().
Returning(actualReturnType, true).
GetScope()
} else {
if serr := actualReturnType.CheckSubTypeOf(expectedReturnType); serr != nil {
sb.decorateWithError(node, "Expected return value of type '%v': %v", expectedReturnType, serr)
return newScope().
Invalid().
Returning(actualReturnType, true).
GetScope()
}
}
return newScope().
IsTerminatingStatement().
Valid().
Returning(actualReturnType, true).
GetScope()
}
// scopeSmlDecoratorAttribute scopes a decorator SML expression attribute under a declaration.
func (sb *scopeBuilder) scopeSmlDecorator(node compilergraph.GraphNode, declaredType typegraph.TypeReference, context scopeContext) (typegraph.TypeReference, bool) {
// Resolve the scope of the decorator.
decoratorScope := sb.getScope(node.GetNode(parser.NodeSmlDecoratorPath), context)
if !decoratorScope.GetIsValid() {
return declaredType, false
}
namedScope, _ := sb.getNamedScopeForScope(decoratorScope)
decoratorName := namedScope.Name()
// Register that we make use of the decorator function.
context.staticDependencyCollector.registerNamedDependency(namedScope)
// Ensure the decorator refers to a function.
decoratorType := decoratorScope.ResolvedTypeRef(sb.sg.tdg)
if !decoratorType.IsDirectReferenceTo(sb.sg.tdg.FunctionType()) {
sb.decorateWithError(node, "SML declaration decorator '%v' must refer to a function. Found: %v", decoratorName, decoratorType)
return declaredType, false
}
// Ensure that the decorator doesn't return void.
returnType := decoratorType.Generics()[0]
if returnType.IsVoid() {
sb.decorateWithError(node, "SML declaration decorator '%v' cannot return void", decoratorName)
return declaredType, false
}
// Scope the attribute value (if any).
var attributeValueType = sb.sg.tdg.BoolTypeReference()
valueNode, hasValueNode := node.TryGetNode(parser.NodeSmlDecoratorValue)
if hasValueNode {
attributeValueScope := sb.getScope(valueNode, context)
if !attributeValueScope.GetIsValid() {
return returnType, false
}
attributeValueType = attributeValueScope.ResolvedTypeRef(sb.sg.tdg)
}
// Ensure the decorator takes the decorated type and a value as parameters.
if decoratorType.ParameterCount() != 2 {
sb.decorateWithError(node, "SML declaration decorator '%v' must refer to a function with two parameters. Found: %v", decoratorName, decoratorType)
return returnType, false
}
// Ensure the first parameter is the declared type.
allowedDecoratedType := decoratorType.Parameters()[0]
allowedValueType := decoratorType.Parameters()[1]
if serr := declaredType.CheckSubTypeOf(allowedDecoratedType); serr != nil {
sb.decorateWithError(node, "SML declaration decorator '%v' expects to decorate an instance of type %v: %v", decoratorName, allowedDecoratedType, serr)
return declaredType, false
}
// Ensure that the second parameter is the value type.
if serr := attributeValueType.CheckSubTypeOf(allowedValueType); serr != nil {
sb.decorateWithError(node, "Cannot assign value of type %v for decorator '%v': %v", attributeValueType, decoratorName, serr)
return returnType, false
}
// The returned type is that of the decorator.
return returnType, true
}