[NFC] Update calls to assume resolveType never returns null

Author: CodaFi

lib/Sema/CSGen.cpp

@@ -1499,7 +1499,7 @@ namespace {
       options |= TypeResolutionFlags::AllowUnboundGenerics;
       auto result = TypeResolution::forContextual(CS.DC, options)
                         .resolveType(repr);
-      if (!result || result->hasError()) {
+      if (result->hasError()) {
         return Type();
       }
       return result;
@@ -2771,7 +2771,7 @@ namespace {
             Type castType = TypeResolution::forContextual(
                                 CS.DC, TypeResolverContext::InExpression)
                                 .resolveType(isp->getCastTypeRepr());
-            if (!castType) {
+            if (castType->hasError()) {
               return false;
             }
 

lib/Sema/TypeCheckAttr.cpp

@@ -2853,7 +2853,7 @@ void AttributeChecker::visitImplementsAttr(ImplementsAttr *attr) {
   }
 
   // Definite error-types were already diagnosed in resolveType.
-  if (!T || T->hasError())
+  if (T->hasError())
     return;
   attr->setProtocolType(T);
 

lib/Sema/TypeCheckConstraints.cpp

@@ -1397,7 +1397,7 @@ TypeExpr *PreCheckExpression::simplifyNestedTypeExpr(UnresolvedDotExpr *UDE) {
     auto resolution = TypeResolution::forContextual(DC, options);
     auto BaseTy = resolution.resolveType(InnerTypeRepr);
 
-    if (BaseTy && BaseTy->mayHaveMembers()) {
+    if (BaseTy->mayHaveMembers()) {
       auto lookupOptions = defaultMemberLookupOptions;
       if (isa<AbstractFunctionDecl>(DC) ||
           isa<AbstractClosureExpr>(DC))

lib/Sema/TypeCheckPattern.cpp

@@ -705,7 +705,7 @@ static Type validateTypedPattern(TypedPattern *TP, TypeResolution resolution) {
   }
 
   auto ty = resolution.resolveType(Repr);
-  if (!ty || ty->hasError()) {
+  if (ty->hasError()) {
     return ErrorType::get(Context);
   }
 
@@ -1233,7 +1233,7 @@ Pattern *TypeChecker::coercePatternToType(ContextualPattern pattern,
     TypeResolutionOptions paramOptions(TypeResolverContext::InExpression);
     auto castType = TypeResolution::forContextual(dc, paramOptions)
                         .resolveType(IP->getCastTypeRepr());
-    if (!castType || castType->hasError())
+    if (castType->hasError())
       return nullptr;
     IP->setCastType(castType);
 

lib/Sema/TypeCheckType.cpp

@@ -746,7 +746,7 @@ static Type applyGenericArguments(Type type, TypeResolution resolution,
       if (nominal->isOptionalDecl()) {
         // Validate the generic argument.
         Type objectType = resolution.resolveType(genericArgs[0]);
-        if (!objectType || objectType->hasError()) {
+        if (objectType->hasError()) {
           return ErrorType::get(ctx);
         }
 

lib/Sema/TypeCheckType.h

@@ -366,7 +366,7 @@ class TypeResolution {
   ///
   /// \param TyR The type representation to check.
   ///
-  /// \returns a well-formed type or an ErrorType in case of an error.
+  /// \returns A well-formed type that is never null, or an \c ErrorType in case of an error.
   Type resolveType(TypeRepr *TyR);
 
   /// Whether this type resolution uses archetypes (vs. generic parameters).