Merge pull request #66697 from ktoso/pick-wip-distributed-harden-empty-impls

🍒[5.9][Distributed] Harden typechecker against completely empty DAS types

Author: DougGregor

lib/AST/ASTContext.cpp

@@ -1387,6 +1387,9 @@ FuncDecl *ASTContext::getMakeInvocationEncoderOnDistributedActorSystem(
 FuncDecl *
 ASTContext::getRecordGenericSubstitutionOnDistributedInvocationEncoder(
     NominalTypeDecl *nominal) const {
+  if (!nominal)
+    return nullptr;
+
   for (auto result : nominal->lookupDirect(Id_recordGenericSubstitution)) {
     auto *func = dyn_cast<FuncDecl>(result);
     if (func &&
@@ -1400,6 +1403,9 @@ ASTContext::getRecordGenericSubstitutionOnDistributedInvocationEncoder(
 
 AbstractFunctionDecl *ASTContext::getRecordArgumentOnDistributedInvocationEncoder(
     NominalTypeDecl *nominal) const {
+  if (!nominal)
+    return nullptr;
+
   return evaluateOrDefault(
       nominal->getASTContext().evaluator,
       GetDistributedTargetInvocationEncoderRecordArgumentFunctionRequest{nominal},
@@ -1408,6 +1414,9 @@ AbstractFunctionDecl *ASTContext::getRecordArgumentOnDistributedInvocationEncode
 
 AbstractFunctionDecl *ASTContext::getRecordReturnTypeOnDistributedInvocationEncoder(
     NominalTypeDecl *nominal) const {
+  if (!nominal)
+    return nullptr;
+
   return evaluateOrDefault(
       nominal->getASTContext().evaluator,
       GetDistributedTargetInvocationEncoderRecordReturnTypeFunctionRequest{nominal},
@@ -1416,6 +1425,9 @@ AbstractFunctionDecl *ASTContext::getRecordReturnTypeOnDistributedInvocationEnco
 
 AbstractFunctionDecl *ASTContext::getRecordErrorTypeOnDistributedInvocationEncoder(
     NominalTypeDecl *nominal) const {
+  if (!nominal)
+    return nullptr;
+
   return evaluateOrDefault(
       nominal->getASTContext().evaluator,
       GetDistributedTargetInvocationEncoderRecordErrorTypeFunctionRequest{nominal},
@@ -1424,6 +1436,9 @@ AbstractFunctionDecl *ASTContext::getRecordErrorTypeOnDistributedInvocationEncod
 
 AbstractFunctionDecl *ASTContext::getDecodeNextArgumentOnDistributedInvocationDecoder(
     NominalTypeDecl *nominal) const {
+  if (!nominal)
+    return nullptr;
+
   return evaluateOrDefault(
       nominal->getASTContext().evaluator,
       GetDistributedTargetInvocationDecoderDecodeNextArgumentFunctionRequest{nominal},
@@ -1432,6 +1447,9 @@ AbstractFunctionDecl *ASTContext::getDecodeNextArgumentOnDistributedInvocationDe
 
 AbstractFunctionDecl *ASTContext::getOnReturnOnDistributedTargetInvocationResultHandler(
     NominalTypeDecl *nominal) const {
+  if (!nominal)
+    return nullptr;
+
   return evaluateOrDefault(
       nominal->getASTContext().evaluator,
       GetDistributedTargetInvocationResultHandlerOnReturnFunctionRequest{nominal},

test/Distributed/distributed_imcomplete_system_dont_crash.swift

@@ -36,4 +36,12 @@ public final class CompletelyHollowActorSystem: DistributedActorSystem {
     // expected-error@-1{{type 'CompletelyHollowActorSystem.ResultHandler' does not conform to protocol 'DistributedTargetInvocationResultHandler'}}
   }
 
+}
+
+public final class CompletelyHollowActorSystem_NotEvenTypes: DistributedActorSystem {
+  // expected-error@-1{{type 'CompletelyHollowActorSystem_NotEvenTypes' does not conform to protocol 'DistributedActorSystem'}}
+  // expected-error@-2{{class 'CompletelyHollowActorSystem_NotEvenTypes' is missing witness for protocol requirement 'remoteCallVoid'}}
+  // expected-error@-3{{class 'CompletelyHollowActorSystem_NotEvenTypes' is missing witness for protocol requirement 'remoteCall'}}
+  // expected-note@-4{{protocol 'DistributedActorSystem' requires function 'remoteCall' with signature:}}
+  // expected-note@-5{{protocol 'DistributedActorSystem' requires function 'remoteCallVoid' with signature:}}
 }