- Return 0 in the unreachable case.

vm/heap.h

 // Copyright (c) 2011, 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 VM_HEAP_H_
 #define VM_HEAP_H_
 
 #include "vm/allocation.h"
 #include "vm/assert.h"
 #include "vm/flags.h"
@@ skipping 49 matching lines @@
     switch (space) {
       case kNew:
         return new_space_->TryAllocate(size);
       case kOld:
         return old_space_->TryAllocate(size);
       case kExecutable:
         return code_space_->TryAllocate(size);
       default:
         UNREACHABLE();
     }
+    return 0;
   }
 
   // Heap contains the specified address.
   bool Contains(uword addr) const;
   bool CodeContains(uword addr) const;
 
   // Visit all pointers in the space.
   void IterateNewPointers(ObjectPointerVisitor* visitor);
   void IterateOldPointers(ObjectPointerVisitor* visitor);
   void IterateCodePointers(ObjectPointerVisitor* visitor);
@@ skipping 41 matching lines @@
  public:
   NoGCScope() {}
  private:
   DISALLOW_COPY_AND_ASSIGN(NoGCScope);
 };
 #endif  // defined(DEBUG)
 
 }  // namespace dart
 
 #endif  // VM_HEAP_H_