[TypeChecker] Distributed: Verify properties before attempting to synthesize a thunk

Author: xedin

lib/Sema/CodeSynthesisDistributedActor.cpp

@@ -791,6 +791,9 @@ FuncDecl *GetDistributedThunkRequest::evaluate(Evaluator &evaluator,
     if (!var->isDistributed())
       return nullptr;
 
+    if (checkDistributedActorProperty(var, /*diagnose=*/false))
+      return nullptr;
+
     distributedTarget = var->getAccessor(AccessorKind::Get);
   } else {
     distributedTarget = originator.get<AbstractFunctionDecl *>();
@@ -815,7 +818,8 @@ FuncDecl *GetDistributedThunkRequest::evaluate(Evaluator &evaluator,
   // we must avoid synthesis of the thunk because it'd also have errors,
   // giving an ugly user experience (errors in implicit code).
   if (distributedTarget->getInterfaceType()->hasError() ||
-      checkDistributedFunction(distributedTarget)) {
+      (!isa<AccessorDecl>(distributedTarget) &&
+       checkDistributedFunction(distributedTarget))) {
     return nullptr;
   }
 

lib/Sema/TypeCheckDistributed.cpp

@@ -26,6 +26,7 @@
 #include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeVisitor.h"
 #include "swift/AST/ExistentialLayout.h"
+#include "swift/Basic/Defer.h"
 
 using namespace swift;
 
@@ -576,6 +577,13 @@ bool swift::checkDistributedActorProperty(VarDecl *var, bool diagnose) {
   auto &C = var->getASTContext();
   auto DC = var->getDeclContext();
 
+  DiagnosticTransaction transaction(C.Diags);
+
+  SWIFT_DEFER {
+    if (!diagnose)
+      transaction.abort();
+  };
+
   // without the distributed module, we can't check any of these.
   if (!ensureDistributedModuleLoaded(var))
     return true;