AST: Check subject type in ProtocolConformanceRef::forAbstract()

Author: slavapestov

lib/AST/ASTContext.cpp

@@ -5748,10 +5748,28 @@ ProtocolConformanceRef ProtocolConformanceRef::forAbstract(
     Type conformingType, ProtocolDecl *proto) {
   ASTContext &ctx = proto->getASTContext();
 
+  auto kind = conformingType->getDesugaredType()->getKind();
+  switch (kind) {
+  case TypeKind::GenericTypeParam:
+  case TypeKind::TypeVariable:
+  case TypeKind::DependentMember:
+  case TypeKind::Unresolved:
+  case TypeKind::Placeholder:
+  case TypeKind::PrimaryArchetype:
+  case TypeKind::PackArchetype:
+  case TypeKind::OpaqueTypeArchetype:
+  case TypeKind::ExistentialArchetype:
+  case TypeKind::ElementArchetype:
+    break;
+
+  default:
+    llvm::errs() << "Abstract conformance with bad subject type:\n";
+    conformingType->dump(llvm::errs());
+    abort();
+  }
+
   // Figure out which arena this should go in.
-  RecursiveTypeProperties properties;
-  if (conformingType)
-    properties |= conformingType->getRecursiveProperties();
+  auto properties = conformingType->getRecursiveProperties();
   auto arena = getArena(properties);
 
   // Profile the substitution map.

lib/AST/ProtocolConformanceRef.cpp

@@ -312,10 +312,8 @@ bool ProtocolConformanceRef::isCanonical() const {
   if (isPack())
     return getPack()->isCanonical();
 
-  if (isAbstract()) {
-    Type conformingType = getType();
-    return !conformingType || conformingType->isCanonical();
-  }
+  if (isAbstract())
+    return getType()->isCanonical();
 
   return getConcrete()->isCanonical();
 }
@@ -328,12 +326,8 @@ ProtocolConformanceRef::getCanonicalConformanceRef() const {
   if (isPack())
     return ProtocolConformanceRef(getPack()->getCanonicalConformance());
 
-  if (isAbstract()) {
-    Type conformingType = getType();
-    if (conformingType)
-      conformingType = conformingType->getCanonicalType();
-    return forAbstract(conformingType, getProtocol());
-  }
+  if (isAbstract())
+    return forAbstract(getType()->getCanonicalType(), getProtocol());
 
   return ProtocolConformanceRef(getConcrete()->getCanonicalConformance());
 }