core: EvalValidate calls appropriate validator for resource mode

data resources are a separate namespace of resources than managed
resources, so we need to call a different provider method depending on
what mode of resource we're visiting.

Managed resources use ValidateResource, while data resources use
ValidateDataSource, since at the provider level of abstraction each
provider has separate sets of resources and data sources respectively.

terraform/eval_validate.go

@@ -107,6 +107,7 @@ type EvalValidateResource struct {
 	Config       **ResourceConfig
 	ResourceName string
 	ResourceType string
+	ResourceMode config.ResourceMode
 }
 
 func (n *EvalValidateResource) Eval(ctx EvalContext) (interface{}, error) {
@@ -114,7 +115,17 @@ func (n *EvalValidateResource) Eval(ctx EvalContext) (interface{}, error) {
 
 	provider := *n.Provider
 	cfg := *n.Config
-	warns, errs := provider.ValidateResource(n.ResourceType, cfg)
+	var warns []string
+	var errs []error
+	// Provider entry point varies depending on resource mode, because
+	// managed resources and data resources are two distinct concepts
+	// in the provider abstraction.
+	switch n.ResourceMode {
+	case config.ManagedResourceMode:
+		warns, errs = provider.ValidateResource(n.ResourceType, cfg)
+	case config.DataResourceMode:
+		warns, errs = provider.ValidateDataSource(n.ResourceType, cfg)
+	}
 
 	// If the resouce name doesn't match the name regular
 	// expression, show a warning.

terraform/transform_resource.go

@@ -230,6 +230,7 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 		Config:       &resourceConfig,
 		ResourceName: n.Resource.Name,
 		ResourceType: n.Resource.Type,
+		ResourceMode: n.Resource.Mode,
 	})
 
 	// Validate all the provisioners