Create a internal, global native context used only for generated code stubs

src/code-stubs.js

Index: src/code-stubs.js
diff --git a/src/code-stubs.js b/src/code-stubs.js
new file mode 100644
index 0000000000000000000000000000000000000000..ab06f6c63b1fb640755f2970121fc13c15262379
--- /dev/null
+++ b/src/code-stubs.js
@@ -0,0 +1,69 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(function(global, code_stubs) {
+
+"use strict";
+
+code_stubs.StringLengthTFStub = function StringLengthTFStub(call_conv, minor_key) {
+  var stub = function(receiver, name, i, v) {
+    // i and v are dummy parameters mandated by the InterfaceDescriptor,
+    // (LoadWithVectorDescriptor).
+    return %_StringGetLength(%_JSValueGetValue(receiver));
+  }
+  return stub;
+}
+
+code_stubs.StringAddTFStub = function StringAddTFStub(call_conv, minor_key) {
+  var stub = function(left, right) {
+    return %StringAdd(left, right);
+  }
+  return stub;
+}
+
+const kTurboFanICCallModeMask = 1;
+const kTurboFanICCallForUnptimizedCode = 0;
+const kTurboFanICCallForOptimizedCode = 1;
+
+code_stubs.MathFloorStub = function MathFloorStub(call_conv, minor_key) {
+  var call_from_optimized_ic = function(f, i, tv, receiver, v) {
+    "use strict";
+    // |f| is this function's JSFunction
+    // |i| is TypeFeedbackVector slot # of callee's CallIC for Math.floor call
+    // |receiver| is receiver, should not be used
+    // |tv| is the calling function's type vector
+    // |v| is the value to floor
+    if (f !== %_FixedArrayGet(tv, i|0)) {
+      return %_CallFunction(receiver, v, f);
+    }
+    var r = %_MathFloor(+v);
+    if (%_IsMinusZero(r)) {
+      // Collect type feedback when the result of the floor is -0. This is
+      // accomplished by storing a sentinel in the second, "extra"
+      // TypeFeedbackVector slot corresponding to the Math.floor CallIC call in
+      // the caller's TypeVector.
+      %_FixedArraySet(tv, ((i|0)+1)|0, 1);
+      return -0;
+    }
+    // Return integers in smi range as smis.
+    var trunc = r|0;
+    if (trunc === r) {
+      return trunc;
+    }
+    return r;
+  }
+  var call_mode = (minor_key & kTurboFanICCallModeMask);
+  if (call_mode == kTurboFanICCallForOptimizedCode) {
+    return call_from_optimized_ic;
+  } else {
+    %SetForceInlineFlag(call_from_optimized_ic);
+    var call_from_unoptimized_ic = function(f, i, receiver, v) {
+      var tv = %_GetTypeFeedbackVector(%_GetCallerJSFunction());
+      return call_from_optimized_ic(f, i, tv, receiver, v);
+    }
+    return call_from_unoptimized_ic;
+  }
+}
+
+})