Add missing type finalization for function literals not assigned to a function

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
@@ skipping 1112 matching lines @@
   ASSERT(IsSignatureClass());
   const Function& function = Function::Handle(signature_function());
   ASSERT(!function.IsNull());
   if (function.signature_class() != raw()) {
     // This class is a function type alias. Return the canonical signature type.
     const Class& canonical_class = Class::Handle(function.signature_class());
     return canonical_class.SignatureType();
   }
   // Return the first canonical signature type if already computed.
   const Array& signature_types = Array::Handle(canonical_types());
+  // The canonical_types array is initialized to the empty array.
+  ASSERT(!signature_types.IsNull());
   if (signature_types.Length() > 0) {
+    // At most one signature type per signature class.
+    ASSERT(signature_types.Length() == 1);
     Type& signature_type = Type::Handle();
     signature_type ^= signature_types.At(0);
-    if (!signature_type.IsNull()) {
-      return signature_type.raw();
-    }
+    ASSERT(!signature_type.IsNull());
+    return signature_type.raw();
   }
   // A signature class extends class Instance and is parameterized in the same
   // way as the owner class of its non-static signature function.
   // It is not type parameterized if its signature function is static.
   // See Class::NewSignatureClass() for the setup of its type parameters.
   // During type finalization, the type arguments of the super class of the
   // owner class of its signature function will be prepended to the type
   // argument vector. Therefore, we only need to set the type arguments
   // matching the type parameters here.
   const TypeArguments& signature_type_arguments =
@@ skipping 9723 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart