Merge pull request swiftlang#31927 from AnthonyLatsis/assert-type-param-3

GenericSignatureImpl, swiftlang#31712: Plug remaining relevant methods with type param. assertions

Author: AnthonyLatsis

include/swift/AST/GenericSignature.h

@@ -329,12 +329,12 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
   /// Determine whether the given dependent type is equal to a concrete type.
   bool isConcreteType(Type type) const;
 
-  /// Return the concrete type that the given dependent type is constrained to,
+  /// Return the concrete type that the given type parameter is constrained to,
   /// or the null Type if it is not the subject of a concrete same-type
   /// constraint.
   Type getConcreteType(Type type) const;
 
-  /// Return the layout constraint that the given dependent type is constrained
+  /// Return the layout constraint that the given type parameter is constrained
   /// to, or the null LayoutConstraint if it is not the subject of layout
   /// constraint.
   LayoutConstraint getLayoutConstraint(Type type) const;

lib/AST/GenericSignature.cpp

@@ -428,7 +428,7 @@ Type GenericSignatureImpl::getSuperclassBound(Type type) const {
 /// required to conform.
 GenericSignature::RequiredProtocols
 GenericSignatureImpl::getRequiredProtocols(Type type) const {
-  if (!type->isTypeParameter()) return { };
+  assert(type->isTypeParameter() && "Expected a type parameter");
 
   auto &builder = *getGenericSignatureBuilder();
   auto equivClass =
@@ -479,11 +479,11 @@ bool GenericSignatureImpl::isConcreteType(Type type) const {
   return bool(getConcreteType(type));
 }
 
-/// Return the concrete type that the given dependent type is constrained to,
+/// Return the concrete type that the given type parameter is constrained to,
 /// or the null Type if it is not the subject of a concrete same-type
 /// constraint.
 Type GenericSignatureImpl::getConcreteType(Type type) const {
-  if (!type->isTypeParameter()) return Type();
+  assert(type->isTypeParameter() && "Expected a type parameter");
 
   auto &builder = *getGenericSignatureBuilder();
   auto equivClass =
@@ -496,7 +496,8 @@ Type GenericSignatureImpl::getConcreteType(Type type) const {
 }
 
 LayoutConstraint GenericSignatureImpl::getLayoutConstraint(Type type) const {
-  if (!type->isTypeParameter()) return LayoutConstraint();
+  assert(type->isTypeParameter() &&
+         "Only type parameters can have layout constraints");
 
   auto &builder = *getGenericSignatureBuilder();
   auto equivClass =

lib/AST/SubstitutionMap.cpp

@@ -271,7 +271,7 @@ Type SubstitutionMap::lookupSubstitution(CanSubstitutableType type) const {
 
   // The generic parameter may have been made concrete by the generic signature,
   // substitute into the concrete type.
-  if (auto concreteType = genericSig->getConcreteType(genericParam)){
+  if (auto concreteType = genericSig->getConcreteType(genericParam)) {
     // Set the replacement type to an error, to block infinite recursion.
     replacementType = ErrorType::get(concreteType);