Merge pull request #7967 from jrose-apple/3.1-to-err-is-human

Make sure ErrorTypes containing type variables are marked as such

Author: tkremenek

include/swift/AST/Types.h

@@ -992,8 +992,10 @@ class alignas(1 << TypeAlignInBits) TypeBase {
 class ErrorType : public TypeBase {
   friend class ASTContext;
   // The Error type is always canonical.
-  ErrorType(ASTContext &C, Type originalType)
-      : TypeBase(TypeKind::Error, &C, RecursiveTypeProperties::HasError) {
+  ErrorType(ASTContext &C, Type originalType,
+            RecursiveTypeProperties properties)
+      : TypeBase(TypeKind::Error, &C, properties) {
+    assert(properties.hasError());
     if (originalType) {
       ErrorTypeBits.HasOriginalType = true;
       *reinterpret_cast<Type *>(this + 1) = originalType;

lib/AST/ASTContext.cpp

@@ -402,7 +402,8 @@ ASTContext::ASTContext(LangOptions &langOpts, SearchPathOptions &SearchPathOpts,
     SwiftShimsModuleName(getIdentifier(SWIFT_SHIMS_NAME)),
     TypeCheckerDebug(new StderrTypeCheckerDebugConsumer()),
     TheErrorType(
-      new (*this, AllocationArena::Permanent) ErrorType(*this, Type())),
+      new (*this, AllocationArena::Permanent)
+        ErrorType(*this, Type(), RecursiveTypeProperties::HasError)),
     TheUnresolvedType(new (*this, AllocationArena::Permanent)
                       UnresolvedType(*this)),
     TheEmptyTupleType(TupleType::get(ArrayRef<TupleTypeElt>(), *this)),
@@ -2435,16 +2436,19 @@ Type ErrorType::get(const ASTContext &C) { return C.TheErrorType; }
 Type ErrorType::get(Type originalType) {
   assert(originalType);
 
-  auto properties = originalType->getRecursiveProperties();
-  auto arena = getArena(properties);
+  auto originalProperties = originalType->getRecursiveProperties();
+  auto arena = getArena(originalProperties);
 
   auto &ctx = originalType->getASTContext();
   auto &entry = ctx.Impl.getArena(arena).ErrorTypesWithOriginal[originalType];
   if (entry) return entry;
 
   void *mem = ctx.Allocate(sizeof(ErrorType) + sizeof(Type),
                            alignof(ErrorType), arena);
-  return entry = new (mem) ErrorType(ctx, originalType);
+  RecursiveTypeProperties properties = RecursiveTypeProperties::HasError;
+  if (originalProperties.hasTypeVariable())
+    properties |= RecursiveTypeProperties::HasTypeVariable;
+  return entry = new (mem) ErrorType(ctx, originalType, properties);
 }
 
 BuiltinIntegerType *BuiltinIntegerType::get(BuiltinIntegerWidth BitWidth,

lib/AST/Type.cpp

@@ -470,7 +470,8 @@ TypeBase::getTypeVariables(SmallVectorImpl<TypeVariableType *> &typeVariables) {
 
       return false;
     });
-    assert(!typeVariables.empty() && "Did not find type variables!");
+    assert((!typeVariables.empty() || hasError()) &&
+           "Did not find type variables!");
   }
 }