Stack trace API: poison stack frames below the first strict mode frame.

src/messages.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 728 matching lines @@
   var script = %MessageGetScript(message);
   var start_position = %MessageGetStartPosition(message);
   var location = script.locationFromPosition(start_position, false);
   if (location == null) return -1;
   location.restrict();
   return start_position - location.start;
 }
 
 
 function GetStackTraceLine(recv, fun, pos, isGlobal) {
-  return new CallSite(recv, fun, pos).toString();
+  return new CallSite(recv, fun, pos, false).toString();
 }
 
 // ----------------------------------------------------------------------------
 // Error implementation
 
-function CallSite(receiver, fun, pos) {
-  this.receiver = receiver;
-  this.fun = fun;
-  this.pos = pos;
+var CallSiteReceiverKey   = %CreateSymbol("receiver");

[rossberg, 2013/03/28 10:04:33]

Nit: do our coding conventions allow this kind of spacing for alignment?

+var CallSiteFunctionKey   = %CreateSymbol("function");
+var CallSitePositionKey   = %CreateSymbol("position");
+var CallSiteStrictModeKey = %CreateSymbol("strict mode");
+
+function CallSite(receiver, fun, pos, strict_mode) {
+  this[CallSiteReceiverKey]   = receiver;
+  this[CallSiteFunctionKey]   = fun;
+  this[CallSitePositionKey]   = pos;
+  this[CallSiteStrictModeKey] = strict_mode;
 }
 
 function CallSiteGetThis() {
-  return this.receiver;
+  if (this[CallSiteStrictModeKey]) return void 0;

[rossberg, 2013/03/28 10:04:33]

You could use ?: here.

+  return this[CallSiteReceiverKey];
 }
 
 function CallSiteGetTypeName() {
-  return GetTypeName(this, false);
+  return GetTypeName(this[CallSiteReceiverKey], false);
 }
 
 function CallSiteIsToplevel() {
-  if (this.receiver == null) {
+  if (this[CallSiteReceiverKey] == null) {
     return true;
   }
-  return IS_GLOBAL(this.receiver);
+  return IS_GLOBAL(this[CallSiteReceiverKey]);
 }
 
 function CallSiteIsEval() {
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   return script && script.compilation_type == COMPILATION_TYPE_EVAL;
 }
 
 function CallSiteGetEvalOrigin() {
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   return FormatEvalOrigin(script);
 }
 
 function CallSiteGetScriptNameOrSourceURL() {
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   return script ? script.nameOrSourceURL() : null;
 }
 
 function CallSiteGetFunction() {
-  return this.fun;
+  if (this[CallSiteStrictModeKey]) return void 0;

[rossberg, 2013/03/28 10:04:33]

...same here.

+  return this[CallSiteFunctionKey];
 }
 
 function CallSiteGetFunctionName() {
   // See if the function knows its own name
-  var name = this.fun.name;
+  var name = this[CallSiteFunctionKey].name;
   if (name) {
     return name;
   }
-  name = %FunctionGetInferredName(this.fun);
+  name = %FunctionGetInferredName(this[CallSiteFunctionKey]);
   if (name) {
     return name;
   }
   // Maybe this is an evaluation?
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   if (script && script.compilation_type == COMPILATION_TYPE_EVAL) {
     return "eval";
   }
   return null;
 }
 
 function CallSiteGetMethodName() {
   // See if we can find a unique property on the receiver that holds
   // this function.
-  var ownName = this.fun.name;
-  if (ownName && this.receiver &&
-      (%_CallFunction(this.receiver,
-                      ownName,
-                      ObjectLookupGetter) === this.fun ||
-       %_CallFunction(this.receiver,
-                      ownName,
-                      ObjectLookupSetter) === this.fun ||
-       (IS_OBJECT(this.receiver) &&
-        %GetDataProperty(this.receiver, ownName) === this.fun))) {
+  var receiver = this[CallSiteReceiverKey];
+  var fun = this[CallSiteFunctionKey];
+  var ownName = fun.name;
+  if (ownName && receiver &&
+      (%_CallFunction(receiver, ownName, ObjectLookupGetter) === fun ||
+       %_CallFunction(receiver, ownName, ObjectLookupSetter) === fun ||
+       (IS_OBJECT(receiver) && %GetDataProperty(receiver, ownName) === fun))) {
     // To handle DontEnum properties we guess that the method has
     // the same name as the function.
     return ownName;
   }
   var name = null;
-  for (var prop in this.receiver) {
-    if (%_CallFunction(this.receiver, prop, ObjectLookupGetter) === this.fun ||
-        %_CallFunction(this.receiver, prop, ObjectLookupSetter) === this.fun ||
-        (IS_OBJECT(this.receiver) &&
-         %GetDataProperty(this.receiver, prop) === this.fun)) {
+  for (var prop in receiver) {
+    if (%_CallFunction(receiver, prop, ObjectLookupGetter) === fun ||
+        %_CallFunction(receiver, prop, ObjectLookupSetter) === fun ||
+        (IS_OBJECT(receiver) && %GetDataProperty(receiver, prop) === fun)) {
       // If we find more than one match bail out to avoid confusion.
       if (name) {
         return null;
       }
       name = prop;
     }
   }
   if (name) {
     return name;
   }
   return null;
 }
 
 function CallSiteGetFileName() {
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   return script ? script.name : null;
 }
 
 function CallSiteGetLineNumber() {
-  if (this.pos == -1) {
+  if (this[CallSitePositionKey] == -1) {
     return null;
   }
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   var location = null;
   if (script) {
-    location = script.locationFromPosition(this.pos, true);
+    location = script.locationFromPosition(this[CallSitePositionKey], true);
   }
   return location ? location.line + 1 : null;
 }
 
 function CallSiteGetColumnNumber() {
-  if (this.pos == -1) {
+  if (this[CallSitePositionKey] == -1) {
     return null;
   }
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   var location = null;
   if (script) {
-    location = script.locationFromPosition(this.pos, true);
+    location = script.locationFromPosition(this[CallSitePositionKey], true);
   }
   return location ? location.column + 1: null;
 }
 
 function CallSiteIsNative() {
-  var script = %FunctionGetScript(this.fun);
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
   return script ? (script.type == TYPE_NATIVE) : false;
 }
 
 function CallSiteGetPosition() {
-  return this.pos;
+  return this[CallSitePositionKey];
 }
 
 function CallSiteIsConstructor() {
-  var receiver = this.receiver;
+  var receiver = this[CallSiteReceiverKey];
   var constructor =
       IS_OBJECT(receiver) ? %GetDataProperty(receiver, "constructor") : null;
   if (!constructor) return false;
-  return this.fun === constructor;
+  return this[CallSiteFunctionKey] === constructor;
 }
 
 function CallSiteToString() {
   var fileName;
   var fileLocation = "";
   if (this.isNative()) {
     fileLocation = "native";
   } else {
     if (this.isEval()) {
       fileName = this.getScriptNameOrSourceURL();
@@ skipping 22 matching lines @@
       }
     }
   }
 
   var line = "";
   var functionName = this.getFunctionName();
   var addSuffix = true;
   var isConstructor = this.isConstructor();
   var isMethodCall = !(this.isToplevel() || isConstructor);
   if (isMethodCall) {
-    var typeName = GetTypeName(this, true);
+    var typeName = GetTypeName([CallSiteReceiverKey], true);
     var methodName = this.getMethodName();
     if (functionName) {
       if (typeName &&
           %_CallFunction(functionName, typeName, StringIndexOf) != 0) {
         line += typeName + ".";
       }
       line += functionName;
       if (methodName &&
           (%_CallFunction(functionName, "." + methodName, StringIndexOf) !=
            functionName.length - methodName.length - 1)) {
@@ skipping 83 matching lines @@
       return "<error: " + e + ">";
     } catch (ee) {
       return "<error>";
     }
   }
 }
 
 
 function GetStackFrames(raw_stack) {
   var frames = new InternalArray();
-  for (var i = 0; i < raw_stack.length; i += 4) {
+  var non_strict_frames = raw_stack[0];
+  for (var i = 1; i < raw_stack.length; i += 4) {
     var recv = raw_stack[i];
     var fun = raw_stack[i + 1];
     var code = raw_stack[i + 2];
     var pc = raw_stack[i + 3];
     var pos = %FunctionGetPositionForOffset(code, pc);
-    frames.push(new CallSite(recv, fun, pos));
+    non_strict_frames--;
+    var strict_mode = (non_strict_frames < 0);
+    frames.push(new CallSite(recv, fun, pos, strict_mode));

[rossberg, 2013/03/28 10:04:33]

Could inline def of strict_mode here.

   }
   return frames;
 }
 
 
 function FormatStackTrace(error_string, frames) {
   var lines = new InternalArray();
   lines.push(error_string);
   for (var i = 0; i < frames.length; i++) {
     var frame = frames[i];
     var line;
     try {
       line = frame.toString();
     } catch (e) {
       try {
         line = "<error: " + e + ">";
       } catch (ee) {
         // Any code that reaches this point is seriously nasty!
         line = "<error>";
       }
     }
     lines.push("    at " + line);
   }
   return %_CallFunction(lines, "\n", ArrayJoin);
 }
 
 
-function GetTypeName(obj, requireConstructor) {
-  var constructor = obj.receiver.constructor;
+function GetTypeName(receiver, requireConstructor) {
+  var constructor = receiver.constructor;
   if (!constructor) {
     return requireConstructor ? null :
-        %_CallFunction(obj.receiver, ObjectToString);
+        %_CallFunction(receiver, ObjectToString);
   }
   var constructorName = constructor.name;
   if (!constructorName) {
     return requireConstructor ? null :
-        %_CallFunction(obj.receiver, ObjectToString);
+        %_CallFunction(receiver, ObjectToString);
   }
   return constructorName;
 }
 
 
 // Flag to prevent recursive call of Error.prepareStackTrace.
 var formatting_custom_stack_trace = false;
 
 
 function captureStackTrace(obj, cons_opt) {
@@ skipping 210 matching lines @@
     %SetOverflowedStackTrace(this, void 0);
   }
 
   %DefineOrRedefineAccessorProperty(
       boilerplate, 'stack', getter, setter, DONT_ENUM);
 
   return boilerplate;
 }
 
 var kStackOverflowBoilerplate = SetUpStackOverflowBoilerplate();