Inlined load of string.length and array.length....

test/cctest/test-debug.cc

 // Copyright 2007-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2493 matching lines @@
   foo->Call(env->Global(), kArgc, args);
 
   // With stepping all break locations are hit.
   CHECK_EQ(22, break_point_hit_count);
 
   v8::Debug::SetDebugEventListener(NULL);
   CheckDebuggerUnloaded();
 }
 
 
+// Test of the stepping mechanism for named load in a loop.
+TEST(DebugStepNamedLoadLoop) {
+  v8::HandleScope scope;
+  DebugLocalContext env;
+
+  // Create a function for testing stepping of named load.
+  v8::Local<v8::Function> foo = CompileFunction(
+      &env,
+      "function foo() {\n"
+          "  var a = [];\n"
+          "  var s = \"\";\n"
+          "  for (var i = 0; i < 10; i++) {\n"
+          "    var v = new V(i, i + 1);\n"
+          "    v.y;\n"
+          "    a.length;\n"  // Special case: array length.
+          "    s.length;\n"  // Special case: string length.
+          "  }\n"
+          "}\n"
+          "function V(x, y) {\n"
+          "  this.x = x;\n"
+          "  this.y = y;\n"
+          "}\n",
+          "foo");
+
+  // Call function without any break points to ensure inlining is in place.
+  foo->Call(env->Global(), 0, NULL);
+
+  // Register a debug event listener which steps and counts.
+  v8::Debug::SetDebugEventListener(DebugEventStep);
+
+  // Setup break point and step through the function.
+  SetBreakPoint(foo, 4);
+  step_action = StepNext;
+  break_point_hit_count = 0;
+  foo->Call(env->Global(), 0, NULL);
+
+  // With stepping all break locations are hit.
+  CHECK_EQ(41, break_point_hit_count);
+
+  v8::Debug::SetDebugEventListener(NULL);
+  CheckDebuggerUnloaded();
+}
+
+
 // Test the stepping mechanism with different ICs.
 TEST(DebugStepLinearMixedICs) {
   v8::HandleScope scope;
   DebugLocalContext env;
 
   // Create a function for testing stepping.
   v8::Local<v8::Function> foo = CompileFunction(&env,
       "function bar() {};"
       "function foo() {"
       "  var x;"
@@ skipping 3625 matching lines @@
 
 TEST(DebugContextIsPreservedBetweenAccesses) {
   v8::HandleScope scope;
   v8::Local<v8::Context> context1 = v8::Debug::GetDebugContext();
   v8::Local<v8::Context> context2 = v8::Debug::GetDebugContext();
   CHECK_EQ(*context1, *context2);
   // Make sure debugger is unloaded before running other tests.
   v8::internal::ForceUnloadDebugger();
   CheckDebuggerUnloaded();
 }