Break out WeakCodeReferences to own file in preparation to use it outside object.cc.

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 40629)
+++ runtime/vm/object.cc	(working copy)
@@ -44,6 +44,7 @@
 #include "vm/tags.h"
 #include "vm/timer.h"
 #include "vm/unicode.h"
+#include "vm/weak_code.h"
 
 namespace dart {
 
@@ -2590,122 +2591,6 @@
 }
 
 
-// Helper class to handle an array of code weak properties. Implements
-// registration and disabling of stored code objects.
-class WeakCodeReferences : public ValueObject {
- public:
-  explicit WeakCodeReferences(const Array& value) : array_(value) {}
-  virtual ~WeakCodeReferences() {}
-
-  void Register(const Code& value) {
-    if (!array_.IsNull()) {
-      // Try to find and reuse cleared WeakProperty to avoid allocating new one.
-      WeakProperty& weak_property = WeakProperty::Handle();
-      for (intptr_t i = 0; i < array_.Length(); i++) {
-        weak_property ^= array_.At(i);
-        if (weak_property.key() == Code::null()) {
-          // Empty property found. Reuse it.
-          weak_property.set_key(value);
-          return;
-        }
-      }
-    }
-
-    const WeakProperty& weak_property = WeakProperty::Handle(
-        WeakProperty::New(Heap::kOld));
-    weak_property.set_key(value);
-
-    intptr_t length = array_.IsNull() ? 0 : array_.Length();
-    const Array& new_array = Array::Handle(
-        Array::Grow(array_, length + 1, Heap::kOld));
-    new_array.SetAt(length, weak_property);
-    UpdateArrayTo(new_array);
-  }
-
-  virtual void UpdateArrayTo(const Array& array) = 0;
-  virtual void ReportDeoptimization(const Code& code) = 0;
-  virtual void ReportSwitchingCode(const Code& code) = 0;
-
-  static bool IsOptimizedCode(const Array& dependent_code, const Code& code) {
-    if (!code.is_optimized()) {
-      return false;
-    }
-    WeakProperty& weak_property = WeakProperty::Handle();
-    for (intptr_t i = 0; i < dependent_code.Length(); i++) {
-      weak_property ^= dependent_code.At(i);
-      if (code.raw() == weak_property.key()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  void DisableCode() {
-    const Array& code_objects = Array::Handle(array_.raw());
-    if (code_objects.IsNull()) {
-      return;
-    }
-    UpdateArrayTo(Object::null_array());
-    // Disable all code on stack.
-    Code& code = Code::Handle();
-    {
-      DartFrameIterator iterator;
-      StackFrame* frame = iterator.NextFrame();
-      while (frame != NULL) {
-        code = frame->LookupDartCode();
-        if (IsOptimizedCode(code_objects, code)) {
-          ReportDeoptimization(code);
-          DeoptimizeAt(code, frame->pc());
-        }
-        frame = iterator.NextFrame();
-      }
-    }
-
-    // Switch functions that use dependent code to unoptimized code.
-    WeakProperty& weak_property = WeakProperty::Handle();
-    Function& function = Function::Handle();
-    for (intptr_t i = 0; i < code_objects.Length(); i++) {
-      weak_property ^= code_objects.At(i);
-      code ^= weak_property.key();
-      if (code.IsNull()) {
-        // Code was garbage collected already.
-        continue;
-      }
-
-      function ^= code.function();
-      // If function uses dependent code switch it to unoptimized.
-      if (code.is_optimized() && (function.CurrentCode() == code.raw())) {
-        ReportSwitchingCode(code);
-        function.SwitchToUnoptimizedCode();
-      } else if (function.unoptimized_code() == code.raw()) {
-        ReportSwitchingCode(code);
-        function.ClearICData();
-        // Remove the code object from the function. The next time the
-        // function is invoked, it will be compiled again.
-        function.ClearCode();
-        // Invalidate the old code object so existing references to it
-        // (from optimized code) will fail when invoked.
-        if (!CodePatcher::IsEntryPatched(code)) {
-          CodePatcher::PatchEntry(code);
-        }
-      } else {
-        // Make non-OSR code non-entrant.
-        if (code.GetEntryPatchPc() != 0) {
-          if (!CodePatcher::IsEntryPatched(code)) {
-            ReportSwitchingCode(code);
-            CodePatcher::PatchEntry(code);
-          }
-        }
-      }
-    }
-  }
-
- private:
-  const Array& array_;
-  DISALLOW_COPY_AND_ASSIGN(WeakCodeReferences);
-};
-
-
 class CHACodeArray : public WeakCodeReferences {
  public:
   explicit CHACodeArray(const Class& cls)