internal string NextName()
{
string name;
do
{
// advance to the next name
++m_currentName;
name = CurrentName;
// keep advancing until we find one that isn't in the skip list or a keyword
}while (m_skipNames.ContainsKey(name) || JSScanner.IsKeyword(name));
return(name);
}
public override string ToCode(ToCodeFormat format)
{
if (PrimitiveType == PrimitiveType.String)
{
string rawValue = Value.ToString();
// if the raw value is safe to be an identifier, then go ahead and ditch the quotes and just output
// the raw value. Otherwise call ToCode to wrap the string in quotes.
return(JSScanner.IsSafeIdentifier(rawValue) && !JSScanner.IsKeyword(rawValue) ? rawValue : base.ToCode(format));
}
else
{
// call the base to format the value
return(base.ToCode(format));
}
}
public static string CrunchedLabel(int nestLevel)
{
// nestCount is 0-based.
// return null if the nestLevel is invalid (< 0).
string minLabel = null;
if (nestLevel >= 0)
{
minLabel = GenerateNameFromNumber(nestLevel);
if (JSScanner.IsKeyword(minLabel, true))
{
// prepend something to make it NOT a keyword.
// no keywords start with an underscore, so...
minLabel = '_' + minLabel;
}
}
return(minLabel);
}
static string CreateJSFromResourceStrings(ResourceStrings resourceStrings)
{
var sb = StringBuilderPool.Acquire();
try
{
// start the var statement using the requested name and open the initializer object literal
sb.Append("var ");
sb.Append(resourceStrings.Name);
sb.Append("={");
// we're going to need to insert commas between each pair, so we'll use a boolean
// flag to indicate that we're on the first pair. When we output the first pair, we'll
// set the flag to false. When the flag is false, we're about to insert another pair, so
// we'll add the comma just before.
bool firstItem = true;
// loop through all items in the collection
foreach (var keyPair in resourceStrings.NameValuePairs)
{
// if this isn't the first item, we need to add a comma separator
if (!firstItem)
{
sb.Append(',');
}
else
{
// next loop is no longer the first item
firstItem = false;
}
// append the key as the name, a colon to separate the name and value,
// and then the value
// must quote if not valid JS identifier format, or if it is, but it's a keyword
// (use strict mode just to be safe)
string propertyName = keyPair.Key;
if (!JSScanner.IsValidIdentifier(propertyName) || JSScanner.IsKeyword(propertyName, true))
{
sb.Append("\"");
// because we are using quotes for the delimiters, replace any instances
// of a quote character (") with an escaped quote character (\")
sb.Append(propertyName.Replace("\"", "\\\""));
sb.Append("\"");
}
else
{
sb.Append(propertyName);
}
sb.Append(':');
// make sure the Value is properly escaped, quoted, and whatever we
// need to do to make sure it's a proper JS string.
// pass false for whether this string is an argument to a RegExp constructor.
// pass false for whether to use W3Strict formatting for character escapes (use maximum browser compatibility)
// pass true for ecma strict mode
string stringValue = ConstantWrapper.EscapeString(
keyPair.Value,
false,
false,
true
);
sb.Append(stringValue);
}
// close the object literal and return the string
sb.AppendLine("};");
return(sb.ToString());
}
finally
{
sb.Release();
}
}
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);
* }
* }
*/
}