Make helper functions static to avoid accidental collision and potentially aid optimization.

runtime/vm/object_graph.cc

 // Copyright (c) 2014, 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_graph.h"
 
 #include "vm/dart.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 354 matching lines @@
 
 intptr_t ObjectGraph::InboundReferences(Object* obj, const Array& references) {
   Object& scratch = Object::Handle();
   NoGCScope no_gc_scope_;
   InboundReferencesVisitor visitor(isolate(), obj->raw(), references, &scratch);
   isolate()->heap()->IterateObjects(&visitor);
   return visitor.length();
 }
 
 
-void WritePtr(RawObject* raw, WriteStream* stream) {
+static void WritePtr(RawObject* raw, WriteStream* stream) {
   ASSERT(raw->IsHeapObject());
   ASSERT(raw->IsOldObject());
   uword addr = RawObject::ToAddr(raw);
   ASSERT(Utils::IsAligned(addr, kObjectAlignment));
   // Using units of kObjectAlignment makes the ids fit into Smis when parsed
   // in the Dart code of the Observatory.
   // TODO(koda): Use delta-encoding/back-references to further compress this.
   stream->WriteUnsigned(addr / kObjectAlignment);
 }
 
@@ skipping 16 matching lines @@
   }
 
   intptr_t count() const { return count_; }
 
  private:
   WriteStream* stream_;
   intptr_t count_;
 };
 
 
-void WriteHeader(RawObject* raw, intptr_t size, intptr_t cid,
+static void WriteHeader(RawObject* raw, intptr_t size, intptr_t cid,
                  WriteStream* stream) {
   WritePtr(raw, stream);
   ASSERT(Utils::IsAligned(size, kObjectAlignment));
   stream->WriteUnsigned(size);
   stream->WriteUnsigned(cid);
 }
 
 
 class WriteGraphVisitor : public ObjectGraph::Visitor {
  public:
@@ skipping 32 matching lines @@
   stream->WriteUnsigned(0);
   {
     WritePointerVisitor ptr_writer(isolate(), stream);
     isolate()->VisitObjectPointers(&ptr_writer, false, false);
   }
   stream->WriteUnsigned(0);
   IterateObjects(&visitor);
 }
 
 }  // namespace dart