Ejemplo n.º 1
0
        internal override void AnalyzeNode()
        {
            // see if this is a member (we'll need it for a couple checks)
            Member member = m_func as Member;

            if (Parser.Settings.StripDebugStatements && Parser.Settings.IsModificationAllowed(TreeModifications.StripDebugStatements))
            {
                // if this is a member, and it's a debugger object, and it's a constructor....
                if (member != null && member.IsDebuggerStatement && m_isConstructor)
                {
                    // we need to replace our debugger object with a generic Object
                    m_func = new Lookup("Object", m_func.Context, Parser);
                    // and make sure the node list is empty
                    if (m_args != null && m_args.Count > 0)
                    {
                        m_args = new AstNodeList(m_args.Context, Parser);
                    }
                }
            }

            // if this is a constructor and we want to collapse
            // some of them to literals...
            if (m_isConstructor && Parser.Settings.CollapseToLiteral)
            {
                // see if this is a lookup, and if so, if it's pointing to one
                // of the two constructors we want to collapse
                Lookup lookup = m_func as Lookup;
                if (lookup != null)
                {
                    if (lookup.Name == "Object" &&
                        Parser.Settings.IsModificationAllowed(TreeModifications.NewObjectToObjectLiteral))
                    {
                        // no arguments -- the Object constructor with no arguments is the exact same as an empty
                        // object literal
                        if (m_args == null || m_args.Count == 0)
                        {
                            // replace our node with an object literal
                            ObjectLiteral objLiteral = new ObjectLiteral(Context, Parser, null, null);
                            if (Parent.ReplaceChild(this, objLiteral))
                            {
                                // and bail now. No need to recurse -- it's an empty literal
                                return;
                            }
                        }
                        else if (m_args.Count == 1)
                        {
                            // one argument
                            // check to see if it's an object literal.
                            ObjectLiteral objectLiteral = m_args[0] as ObjectLiteral;
                            if (objectLiteral != null)
                            {
                                // the Object constructor with an argument that is a JavaScript object merely returns the
                                // argument. Since the argument is an object literal, it is by definition a JavaScript object
                                // and therefore we can replace the constructor call with the object literal
                                Parent.ReplaceChild(this, objectLiteral);

                                // don't forget to recurse the object now
                                objectLiteral.AnalyzeNode();

                                // and then bail -- we don't want to process this call
                                // operation any more; we've gotten rid of it
                                return;
                            }
                        }
                    }
                    else if (lookup.Name == "Array" &&
                             Parser.Settings.IsModificationAllowed(TreeModifications.NewArrayToArrayLiteral))
                    {
                        // Array is trickier.
                        // If there are no arguments, then just use [].
                        // if there are multiple arguments, then use [arg0,arg1...argN].
                        // but if there is one argument and it's numeric, we can't crunch it.
                        // also can't crunch if it's a function call or a member or something, since we won't
                        // KNOW whether or not it's numeric.
                        //
                        // so first see if it even is a single-argument constant wrapper.
                        ConstantWrapper constWrapper = (m_args != null && m_args.Count == 1 ? m_args[0] as ConstantWrapper : null);

                        // if the argument count is not one, then we crunch.
                        // if the argument count IS one, we only crunch if we have a constant wrapper,
                        // AND it's not numeric.
                        if (m_args == null ||
                            m_args.Count != 1 ||
                            (constWrapper != null && !constWrapper.IsNumericLiteral))
                        {
                            // create the new array literal object
                            ArrayLiteral arrayLiteral = new ArrayLiteral(Context, Parser, m_args);
                            // replace ourself within our parent
                            if (Parent.ReplaceChild(this, arrayLiteral))
                            {
                                // recurse
                                arrayLiteral.AnalyzeNode();
                                // and bail -- we don't want to recurse this node any more
                                return;
                            }
                        }
                    }
                }
            }

            // if we are replacing resource references with strings generated from resource files
            // and this is a brackets call: lookup[args]
            ResourceStrings resourceStrings = Parser.ResourceStrings;

            if (m_inBrackets && resourceStrings != null && resourceStrings.Count > 0)
            {
                // see if the root object is a lookup that corresponds to the
                // global value (not a local field) for our resource object
                // (same name)
                Lookup rootLookup = m_func as Lookup;
                if (rootLookup != null &&
                    rootLookup.LocalField == null &&
                    string.CompareOrdinal(rootLookup.Name, resourceStrings.Name) == 0)
                {
                    // we're going to replace this node with a string constant wrapper
                    // but first we need to make sure that this is a valid lookup.
                    // if the parameter contains anything that would vary at run-time,
                    // then we need to throw an error.
                    // the parser will always have either one or zero nodes in the arguments
                    // arg list. We're not interested in zero args, so just make sure there is one
                    if (m_args.Count == 1)
                    {
                        // must be a constant wrapper
                        ConstantWrapper argConstant = m_args[0] as ConstantWrapper;
                        if (argConstant != null)
                        {
                            string resourceName = argConstant.Value.ToString();

                            // get the localized string from the resources object
                            ConstantWrapper resourceLiteral = new ConstantWrapper(
                                resourceStrings[resourceName],
                                PrimitiveType.String,
                                Context,
                                Parser);

                            // replace this node with localized string, analyze it, and bail
                            // so we don't anaylze the tree we just replaced
                            Parent.ReplaceChild(this, resourceLiteral);
                            resourceLiteral.AnalyzeNode();
                            return;
                        }
                        else
                        {
                            // error! must be a constant
                            Context.HandleError(
                                JSError.ResourceReferenceMustBeConstant,
                                true);
                        }
                    }
                    else
                    {
                        // error! can only be a single constant argument to the string resource object.
                        // the parser will only have zero or one arguments, so this must be zero
                        // (since the parser won't pass multiple args to a [] operator)
                        Context.HandleError(
                            JSError.ResourceReferenceMustBeConstant,
                            true);
                    }
                }
            }

            // and finally, if this is a backets call and the argument is a constantwrapper that can
            // be an identifier, just change us to a member node:  obj["prop"] to obj.prop.
            // but ONLY if the string value is "safe" to be an identifier. Even though the ECMA-262
            // spec says certain Unicode categories are okay, in practice the various major browsers
            // all seem to have problems with certain characters in identifiers. Rather than risking
            // some browsers breaking when we change this syntax, don't do it for those "danger" categories.
            if (m_inBrackets && m_args != null)
            {
                // see if there is a single, constant argument
                string argText = m_args.SingleConstantArgument;
                if (argText != null)
                {
                    // see if we want to replace the name
                    string newName;
                    if (Parser.Settings.HasRenamePairs && Parser.Settings.ManualRenamesProperties &&
                        Parser.Settings.IsModificationAllowed(TreeModifications.PropertyRenaming) &&
                        !string.IsNullOrEmpty(newName = Parser.Settings.GetNewName(argText)))
                    {
                        // yes -- we are going to replace the name, either as a string literal, or by converting
                        // to a member-dot operation.
                        // See if we can't turn it into a dot-operator. If we can't, then we just want to replace the operator with
                        // a new constant wrapper. Otherwise we'll just replace the operator with a new constant wrapper.
                        if (Parser.Settings.IsModificationAllowed(TreeModifications.BracketMemberToDotMember) &&
                            JSScanner.IsSafeIdentifier(newName) &&
                            !JSScanner.IsKeyword(newName))
                        {
                            // the new name is safe to convert to a member-dot operator.
                            // but we don't want to convert the node to the NEW name, because we still need to Analyze the
                            // new member node -- and it might convert the new name to something else. So instead we're
                            // just going to convert this existing string to a member node WITH THE OLD STRING,
                            // and THEN analyze it (which will convert the old string to newName)
                            Member replacementMember = new Member(Context, Parser, m_func, argText);
                            Parent.ReplaceChild(this, replacementMember);

                            // this analyze call will convert the old-name member to the newName value
                            replacementMember.AnalyzeNode();
                            return;
                        }
                        else
                        {
                            // nope; can't convert to a dot-operator.
                            // we're just going to replace the first argument with a new string literal
                            // and continue along our merry way.
                            m_args.ReplaceChild(m_args[0], new ConstantWrapper(newName, PrimitiveType.String, m_args[0].Context, Parser));
                        }
                    }
                    else if (Parser.Settings.IsModificationAllowed(TreeModifications.BracketMemberToDotMember) &&
                             JSScanner.IsSafeIdentifier(argText) &&
                             !JSScanner.IsKeyword(argText))
                    {
                        // not a replacement, but the string literal is a safe identifier. So we will
                        // replace this call node with a Member-dot operation
                        Member replacementMember = new Member(Context, Parser, m_func, argText);
                        Parent.ReplaceChild(this, replacementMember);
                        replacementMember.AnalyzeNode();
                        return;
                    }
                }
            }

            // call the base class to recurse
            base.AnalyzeNode();

            // call this AFTER recursing to give the fields a chance to resolve, because we only
            // want to make this replacement if we are working on the global Date object.
            if (!m_inBrackets && !m_isConstructor &&
                (m_args == null || m_args.Count == 0) &&
                member != null && string.CompareOrdinal(member.Name, "getTime") == 0 &&
                Parser.Settings.IsModificationAllowed(TreeModifications.DateGetTimeToUnaryPlus))
            {
                // this is not a constructor and it's not a brackets call, and there are no arguments.
                // if the function is a member operation to "getTime" and the object of the member is a
                // constructor call to the global "Date" object (not a local), then we want to replace the call
                // with a unary plus on the Date constructor. Converting to numeric type is the same as
                // calling getTime, so it's the equivalent with much fewer bytes.
                CallNode dateConstructor = member.Root as CallNode;
                if (dateConstructor != null &&
                    dateConstructor.IsConstructor)
                {
                    // lookup for the predifined (not local) "Date" field
                    Lookup lookup = dateConstructor.Function as Lookup;
                    if (lookup != null && string.CompareOrdinal(lookup.Name, "Date") == 0 &&
                        lookup.LocalField == null)
                    {
                        // this is in the pattern: (new Date()).getTime()
                        // we want to replace it with +new Date
                        // use the same date constructor node as the operand
                        NumericUnary unary = new NumericUnary(Context, Parser, dateConstructor, JSToken.Plus);

                        // replace us (the call to the getTime method) with this unary operator
                        Parent.ReplaceChild(this, unary);

                        // don't need to AnalyzeNode on the unary operator. The operand has already
                        // been analyzed when we recursed, and the unary operator wouldn't do anything
                        // special anyway (since the operand is not a numeric constant)
                    }
                }
            }
            else if (Parser.Settings.EvalTreatment != EvalTreatment.Ignore)
            {
                // if this is a window.eval call, then we need to mark this scope as unknown just as
                // we would if this was a regular eval call.
                // (unless, of course, the parser settings say evals are safe)
                // call AFTER recursing so we know the left-hand side properties have had a chance to
                // lookup their fields to see if they are local or global
                if (member != null && string.CompareOrdinal(member.Name, "eval") == 0)
                {
                    if (member.LeftHandSide.IsWindowLookup)
                    {
                        // this is a call to window.eval()
                        // mark this scope as unknown so we don't crunch out locals
                        // we might reference in the eval at runtime
                        ScopeStack.Peek().IsKnownAtCompileTime = false;
                    }
                }
                else
                {
                    CallNode callNode = m_func as CallNode;
                    if (callNode != null &&
                        callNode.InBrackets &&
                        callNode.LeftHandSide.IsWindowLookup &&
                        callNode.Arguments.IsSingleConstantArgument("eval"))
                    {
                        // this is a call to window["eval"]
                        // mark this scope as unknown so we don't crunch out locals
                        // we might reference in the eval at runtime
                        ScopeStack.Peek().IsKnownAtCompileTime = false;
                    }
                }
            }

            /* REVIEW: may be too late. lookups may alread have been analyzed and
             * found undefined
             * // check to see if this is an assignment to a window["prop"] structure
             * BinaryOperator binaryOp = Parent as BinaryOperator;
             * if (binaryOp != null && binaryOp.IsAssign
             *  && m_inBrackets
             *  && m_func.IsWindowLookup
             *  && m_args != null)
             * {
             *  // and IF the property is a non-empty constant that isn't currently
             *  // a global field...
             *  string propertyName = m_args.SingleConstantArgument;
             *  if (!string.IsNullOrEmpty(propertyName)
             *      && Parser.GlobalScope[propertyName] == null)
             *  {
             *      // we want to also add it to the global fields so it's not undefined
             *      Parser.GlobalScope.DeclareField(propertyName, null, 0);
             *  }
             * }
             */
        }
Ejemplo n.º 2
0
        internal override void AnalyzeNode()
        {
            // if we don't even have any resource strings, then there's nothing
            // we need to do and we can just perform the base operation
            ResourceStrings resourceStrings = Parser.ResourceStrings;

            if (resourceStrings != null && resourceStrings.Count > 0)
            {
                // see if the root object is a lookup that corresponds to the
                // global value (not a local field) for our resource object
                // (same name)
                Lookup rootLookup = Root as Lookup;
                if (rootLookup != null &&
                    rootLookup.LocalField == null &&
                    string.CompareOrdinal(rootLookup.Name, resourceStrings.Name) == 0)
                {
                    // it is -- we're going to replace this with a string value.
                    // if this member name is a string on the object, we'll replacve it with
                    // the literal. Otherwise we'll replace it with an empty string.
                    // see if the string resource contains this value
                    ConstantWrapper stringLiteral = new ConstantWrapper(
                        resourceStrings[Name],
                        PrimitiveType.String,
                        Context,
                        Parser
                        );

                    Parent.ReplaceChild(this, stringLiteral);
                    // analyze the literal
                    stringLiteral.AnalyzeNode();
                    return;
                }
            }

            // if we are replacing property names and we have something to replace
            if (Parser.Settings.HasRenamePairs && Parser.Settings.ManualRenamesProperties &&
                Parser.Settings.IsModificationAllowed(TreeModifications.PropertyRenaming))
            {
                // see if this name is a target for replacement
                string newName = Parser.Settings.GetNewName(Name);
                if (!string.IsNullOrEmpty(newName))
                {
                    // it is -- set the name to the new name
                    Name = newName;
                }
            }

            // recurse
            base.AnalyzeNode();

            /* REVIEW: might be too late in the parsing -- references to the variable may have
             * already been analyzed and found undefined
             * // see if we are assigning to a member on the global window object
             * BinaryOperator binaryOp = Parent as BinaryOperator;
             * if (binaryOp != null && binaryOp.IsAssign && m_rootObject.IsWindowLookup)
             * {
             *  // make sure the name of this property is a valid global variable, since we
             *  // are now assigning to it.
             *  if (Parser.GlobalScope[Name] == null)
             *  {
             *      // it's not -- we need to add it to our list of known globals
             *      // by defining a global field for it
             *      Parser.GlobalScope.DeclareField(Name, null, 0);
             *  }
             * }
             */
        }