Ignore debug stepin in optimized code for array builtins.

src/array.js

 // Copyright 2012 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 1129 matching lines @@
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
   } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
     receiver = ToObject(receiver);
   }
 
   var result = new $Array();
   var accumulator = new InternalArray();
   var accumulator_length = 0;
-  if (%DebugCallbackSupportsStepping(f)) {
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(f);
-        if (%_CallFunction(receiver, element, i, array, f)) {
-          accumulator[accumulator_length++] = element;
-        }
+  var stepping = %_DebugCallbackSupportsStepping(f);
+  for (var i = 0; i < length; i++) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(f);
+      if (%_CallFunction(receiver, element, i, array, f)) {
+        accumulator[accumulator_length++] = element;
       }
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        if (%_CallFunction(receiver, element, i, array, f)) {
-          accumulator[accumulator_length++] = element;
-        }
-      }
-    }
-    // End of duplicate.
   }
   %MoveArrayContents(accumulator, result);
   return result;
 }
 
 
 function ArrayForEach(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.forEach");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
   } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
     receiver = ToObject(receiver);
   }
 
-  if (%DebugCallbackSupportsStepping(f)) {
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(f);
-        %_CallFunction(receiver, element, i, array, f);
-      }
+  var stepping = %_DebugCallbackSupportsStepping(f);
+  for (var i = 0; i < length; i++) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(f);
+      %_CallFunction(receiver, element, i, array, f);
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        %_CallFunction(receiver, element, i, array, f);
-      }
-    }
-    // End of duplicate.
   }
 }
 
 
 // Executes the function once for each element present in the
 // array until it finds one where callback returns true.
 function ArraySome(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.some");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
   } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
     receiver = ToObject(receiver);
   }
 
-  if (%DebugCallbackSupportsStepping(f)) {
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(f);
-        if (%_CallFunction(receiver, element, i, array, f)) return true;
-      }
+  var stepping = %_DebugCallbackSupportsStepping(f);
+  for (var i = 0; i < length; i++) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(f);
+      if (%_CallFunction(receiver, element, i, array, f)) return true;
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        if (%_CallFunction(receiver, element, i, array, f)) return true;
-      }
-    }
-    // End of duplicate.
   }
   return false;
 }
 
 
 function ArrayEvery(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.every");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
   } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
     receiver = ToObject(receiver);
   }
 
-  if (%DebugCallbackSupportsStepping(f)) {
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(f);
-        if (!%_CallFunction(receiver, element, i, array, f)) return false;
-      }
+  var stepping = %_DebugCallbackSupportsStepping(f);
+  for (var i = 0; i < length; i++) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(f);
+      if (!%_CallFunction(receiver, element, i, array, f)) return false;
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        if (!%_CallFunction(receiver, element, i, array, f)) return false;
-      }
-    }
-    // End of duplicate.
   }
   return true;
 }
 
 function ArrayMap(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.map");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
   } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
     receiver = ToObject(receiver);
   }
 
   var result = new $Array();
   var accumulator = new InternalArray(length);
-  if (%DebugCallbackSupportsStepping(f)) {
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(f);
-        accumulator[i] = %_CallFunction(receiver, element, i, array, f);
-      }
+  var stepping = %_DebugCallbackSupportsStepping(f);
+  for (var i = 0; i < length; i++) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(f);
+      accumulator[i] = %_CallFunction(receiver, element, i, array, f);
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (var i = 0; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        accumulator[i] = %_CallFunction(receiver, element, i, array, f);
-      }
-    }
-    // End of duplicate.
   }
   %MoveArrayContents(accumulator, result);
   return result;
 }
 
 
 function ArrayIndexOf(element, index) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.indexOf");
 
   var length = TO_UINT32(this.length);
@@ skipping 119 matching lines @@
       current = array[i];
       if (!IS_UNDEFINED(current) || i in array) {
         i++;
         break find_initial;
       }
     }
     throw MakeTypeError('reduce_no_initial', []);
   }
 
   var receiver = %GetDefaultReceiver(callback);
-
-  if (%DebugCallbackSupportsStepping(callback)) {
-    for (; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(callback);
-        current =
-          %_CallFunction(receiver, current, element, i, array, callback);
-      }
+  var stepping = %_DebugCallbackSupportsStepping(callback);
+  for (; i < length; i++) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(callback);
+      current = %_CallFunction(receiver, current, element, i, array, callback);
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (; i < length; i++) {
-      if (i in array) {
-        var element = array[i];
-        current =
-          %_CallFunction(receiver, current, element, i, array, callback);
-      }
-    }
-    // End of duplicate.
   }
   return current;
 }
 
 function ArrayReduceRight(callback, current) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reduceRight");
 
   // Pull out the length so that side effects are visible before the
   // callback function is checked.
   var array = ToObject(this);
   var length = ToUint32(array.length);
 
   if (!IS_SPEC_FUNCTION(callback)) {
     throw MakeTypeError('called_non_callable', [callback]);
   }
 
   var i = length - 1;
   find_initial: if (%_ArgumentsLength() < 2) {
     for (; i >= 0; i--) {
       current = array[i];
       if (!IS_UNDEFINED(current) || i in array) {
         i--;
         break find_initial;
       }
     }
     throw MakeTypeError('reduce_no_initial', []);
   }
 
   var receiver = %GetDefaultReceiver(callback);
-
-  if (%DebugCallbackSupportsStepping(callback)) {
-    for (; i >= 0; i--) {
-      if (i in array) {
-        var element = array[i];
-        // Prepare break slots for debugger step in.
-        %DebugPrepareStepInIfStepping(callback);
-        current =
-          %_CallFunction(receiver, current, element, i, array, callback);
-      }
+  var stepping = %_DebugCallbackSupportsStepping(callback);
+  for (; i >= 0; i--) {
+    if (i in array) {
+      var element = array[i];
+      // Prepare break slots for debugger step in.
+      if (stepping) %DebugPrepareStepInIfStepping(callback);
+      current = %_CallFunction(receiver, current, element, i, array, callback);
     }
-  } else {
-    // This is a duplicate of the previous loop sans debug stepping.
-    for (; i >= 0; i--) {
-      if (i in array) {
-        var element = array[i];
-        current =
-          %_CallFunction(receiver, current, element, i, array, callback);
-      }
-    }
-    // End of duplicate.
   }
   return current;
 }
 
 // ES5, 15.4.3.2
 function ArrayIsArray(obj) {
   return IS_ARRAY(obj);
 }
 
 
@@ skipping 67 matching lines @@
   ));
 
   SetUpLockedPrototype(InternalPackedArray, $Array(), $Array(
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),
     "push", getFunction("push", ArrayPush)
   ));
 }
 
 SetUpArray();