Improve internal compiler API so that OSR code is never installed on function.

runtime/vm/object.h

 // 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.
 
 #ifndef RUNTIME_VM_OBJECT_H_
 #define RUNTIME_VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2275 matching lines @@
                                         intptr_t* function_level) const;
 
   // Return true if this function declares type parameters.
   bool IsGeneric() const { return NumTypeParameters(Thread::Current()) > 0; }
 
   // Return true if any parent function of this function is generic.
   bool HasGenericParent() const;
 
   // Not thread-safe; must be called in the main thread.
   // Sets function's code and code's function.
-  void InstallOptimizedCode(const Code& code, bool is_osr) const;
+  void InstallOptimizedCode(const Code& code) const;
   void AttachCode(const Code& value) const;
   void SetInstructions(const Code& value) const;
   void ClearCode() const;
 
   // Disables optimized code and switches to unoptimized code.
   void SwitchToUnoptimizedCode() const;
 
+  // Ensures that the function has code. If there is no code it compiles the
+  // unoptimized version of the code.  If the code contains errors, it calls
+  // Exceptions::PropagateError and does not return.  Normally returns the
+  // current code, whether it is optimized or unoptimized.
+  RawCode* EnsureHasCode() const;
+
   // Disables optimized code and switches to unoptimized code (or the lazy
   // compilation stub).
   void SwitchToLazyCompiledUnoptimizedCode() const;
 
   // Compiles unoptimized code (if necessary) and attaches it to the function.
   void EnsureHasCompiledUnoptimizedCode() const;
 
   // Return the most recently compiled and installed code for this function.
   // It is not the only Code object that points to this function.
   RawCode* CurrentCode() const { return raw_ptr()->code_; }
@@ skipping 6636 matching lines @@
 
 inline void TypeArguments::SetHash(intptr_t value) const {
   // This is only safe because we create a new Smi, which does not cause
   // heap allocation.
   StoreSmi(&raw_ptr()->hash_, Smi::New(value));
 }
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_OBJECT_H_