From b25c4665e4f3d8a6f247c8277daf87783a37fd88 Mon Sep 17 00:00:00 2001
From: Anthony Latsis <aqamoss3fan2010@gmail.com>
Date: Mon, 18 May 2020 23:26:10 +0300
Subject: [PATCH] GenericSignatureImpl, #31712: Plug remaining relevant methods
 with type param. assertions

---
 include/swift/AST/GenericSignature.h | 4 ++--
 lib/AST/GenericSignature.cpp         | 9 +++++----
 lib/AST/SubstitutionMap.cpp          | 2 +-
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/include/swift/AST/GenericSignature.h b/include/swift/AST/GenericSignature.h
index 4d347fae5b9d8..271e07899698f 100644
--- a/include/swift/AST/GenericSignature.h
+++ b/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;
diff --git a/lib/AST/GenericSignature.cpp b/lib/AST/GenericSignature.cpp
index ade97c2355846..a1a36e38096a4 100644
--- a/lib/AST/GenericSignature.cpp
+++ b/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 =
diff --git a/lib/AST/SubstitutionMap.cpp b/lib/AST/SubstitutionMap.cpp
index 61d4695a4d9db..074e432f4893c 100644
--- a/lib/AST/SubstitutionMap.cpp
+++ b/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);