private static int RelocateFunction(Block block, int insertAt, FunctionObject funcDecl)
{
if (block[insertAt] != funcDecl)
{
// technically function declarations can only be direct children of the program or a function block.
// and since we are passing in such a block, the parent of the function declaration better be that
// block. If it isn't, we don't want to move it because it's not in an allowed place, and different
// browsers treat that situation differently. Some browsers would process such funcdecls as if
// they were a direct child of the main block. Others will treat it like a function expression with
// an external name, and only assign the function to the name if that line of code is actually
// executed. So since there's a difference, just leave them as-is and only move valid funcdecls.
if (funcDecl.Parent == block)
{
// remove the function from it's parent, which will take it away from where it is right now.
funcDecl.Parent.ReplaceChild(funcDecl, null);
// now insert it into the block at the new location, incrementing the location so the next function
// will be inserted after it. It is important that they be in the same order as the source, or the semantics
// will change when there are functions with the same name.
block.Insert(insertAt++, funcDecl);
}
}
else
{
// we're already in the right place. Just increment the pointer to move to the next position
// for next time
++insertAt;
}
// return the new position
return(insertAt);
}
internal FunctionScope(ActivationObject parent, bool isExpression, CodeSettings settings, FunctionObject funcObj)
: base(parent, settings)
{
m_refScopes = new HashSet<ActivationObject>();
if (isExpression)
{
// parent scopes automatically reference enclosed function expressions
AddReference(Parent);
}
FunctionObject = funcObj;
}
internal FunctionScope(ActivationObject parent, bool isExpression, CodeSettings settings, FunctionObject funcObj)
: base(parent, settings)
{
m_refScopes = new HashSet <ActivationObject>();
if (isExpression)
{
// parent scopes automatically reference enclosed function expressions
AddReference(Parent);
}
FunctionObject = funcObj;
}
public override void Visit(FunctionObject node)
{
if (node != null)
{
// if we are reordering ANYTHING, then we need to do the reordering on a scope level.
// so if that's the case, we need to create a list of all the child functions and NOT
// recurse at this point. Then we'll reorder, then we'll use the lists to recurse.
// BUT if we are not reordering anything, no sense making the lists and recursing later.
// if that's the case, we can just recurse now and not have to worry about anything later.
if (m_moveVarStatements || m_moveFunctionDecls)
{
// add the node to the appropriate list: either function expression or function declaration.
// assume if it's not a function declaration, it must be an expression since the other types
// are not declaration (getter, setter) and we want to treat declarations special.
// if the conditional comment level isn't zero, then something funky is going on with
// the conditional-compilation statements, and we don't want to move the declarations, so
// don't add them to the declaration list. But we still want to recurse them, so add them
// to the expression list (which get recursed but not moved).
if (node.FunctionType == FunctionType.Declaration && m_conditionalCommentLevel == 0)
{
if (m_functionDeclarations == null)
{
m_functionDeclarations = new List <FunctionObject>();
}
m_functionDeclarations.Add(node);
}
else
{
if (m_functionExpressions == null)
{
m_functionExpressions = new List <FunctionObject>();
}
m_functionExpressions.Add(node);
}
// BUT DO NOT RECURSE!!!!
// we only want the functions and variables in THIS scope, not child function scopes.
//base.Visit(node);
}
else
{
// we're not reordering, so just recurse now to save the hassle
base.Visit(node);
}
}
}
private void UnreferencedFunction(JSVariableField variableField, FunctionObject functionObject)
{
// if there is no name, then ignore this declaration because it's malformed.
// (won't be a function expression because those are automatically referenced).
// also ignore ghosted function fields.
if (functionObject.Name != null && variableField.FieldType != FieldType.GhostFunction)
{
// if the function name isn't a simple identifier, then leave it there and mark it as
// not renamable because it's probably one of those darn IE-extension event handlers or something.
if (JSScanner.IsValidIdentifier(functionObject.Name))
{
// unreferenced function declaration. fire a warning.
var ctx = functionObject.IdContext ?? variableField.OriginalContext;
ctx.HandleError(JSError.FunctionNotReferenced, false);
// hide it from the output if our settings say we can.
// we don't want to delete it, per se, because we still want it to
// show up in the scope report so the user can see that it was unreachable
// in case they are wondering where it went.
// ES6 has the notion of block-scoped function declarations. ES5 says functions can't
// be defined inside blocks -- only at the root level of the global scope or function scopes.
// so if this is a block scope, don't hide the function, even if it is unreferenced because
// of the cross-browser difference.
if (this.IsKnownAtCompileTime &&
m_settings.MinifyCode &&
m_settings.RemoveUnneededCode &&
!(this is BlockScope))
{
functionObject.HideFromOutput = true;
}
}
else
{
// not a valid identifier name for this function. Don't rename it because it's
// malformed and we don't want to mess up the developer's intent.
variableField.CanCrunch = false;
}
}
}
private static int RelocateFunction(Block block, int insertAt, FunctionObject funcDecl)
{
if (block[insertAt] != funcDecl)
{
// technically function declarations can only be direct children of the program or a function block.
// and since we are passing in such a block, the parent of the function declaration better be that
// block. If it isn't, we don't want to move it because it's not in an allowed place, and different
// browsers treat that situation differently. Some browsers would process such funcdecls as if
// they were a direct child of the main block. Others will treat it like a function expression with
// an external name, and only assign the function to the name if that line of code is actually
// executed. So since there's a difference, just leave them as-is and only move valid funcdecls.
if (funcDecl.Parent == block)
{
// remove the function from it's parent, which will take it away from where it is right now.
funcDecl.Parent.ReplaceChild(funcDecl, null);
// now insert it into the block at the new location, incrementing the location so the next function
// will be inserted after it. It is important that they be in the same order as the source, or the semantics
// will change when there are functions with the same name.
block.Insert(insertAt++, funcDecl);
}
}
else
{
// we're already in the right place. Just increment the pointer to move to the next position
// for next time
++insertAt;
}
// return the new position
return insertAt;
}
public void Visit(FunctionObject node)
{
if (node != null)
{
// it's a declaration; put the index to -1.
node.Index = -1;
// create a function scope, assign it to the function object,
// and push it on the stack
var parentScope = CurrentLexicalScope;
if (node.FunctionType == FunctionType.Expression &&
!string.IsNullOrEmpty(node.Name))
{
// function expressions have an intermediate scope between the parent and the
// function's scope that contains just the function name so the function can
// be self-referencing without the function expression polluting the parent scope.
// don't add the function name field yet, because it's not a decl per se.
parentScope = new FunctionScope(parentScope, true, m_settings, node)
{
IsInWithScope = m_withDepth > 0
};
// add this function object to the list of function objects the variable scope
// will need to ghost later
CurrentVariableScope.GhostedFunctions.Add(node);
}
node.FunctionScope = new FunctionScope(parentScope, node.FunctionType != FunctionType.Declaration, m_settings, node)
{
IsInWithScope = m_withDepth > 0
};
m_lexicalStack.Push(node.FunctionScope);
m_variableStack.Push(node.FunctionScope);
var savedIndex = m_orderIndex;
try
{
// recurse into the function to handle it after saving the current index and resetting it
if (node.Body != null)
{
m_orderIndex = 0;
node.Body.Accept(this);
}
}
finally
{
Debug.Assert(CurrentLexicalScope == node.FunctionScope);
m_lexicalStack.Pop();
m_variableStack.Pop();
m_orderIndex = savedIndex;
}
// nothing to add to the var-decl list.
// but add the function name to the current lex-decl list
// IF it is a declaration and it has a name (and it SHOULD unless there was an error)
if (node.FunctionType == FunctionType.Declaration &&
!string.IsNullOrEmpty(node.Name))
{
var lexicalScope = CurrentLexicalScope;
lexicalScope.LexicallyDeclaredNames.Add(node);
if (lexicalScope != CurrentVariableScope)
{
// the current lexical scope is the variable scope.
// this is ES6 syntax: a function declaration inside a block scope. Not allowed
// in ES5 code, so throw a warning and ghost this function in the outer variable scope
// to make sure that we don't generate any naming collisions.
node.NameContext.HandleError(JSError.MisplacedFunctionDeclaration, false);
CurrentVariableScope.GhostedFunctions.Add(node);
}
}
}
}
private void DefineField(INameDeclaration nameDecl, FunctionObject fieldValue)
{
var field = this[nameDecl.Name];
if (nameDecl is ParameterDeclaration)
{
// function parameters are handled separately, so if this is a parameter declaration,
// then it must be a catch variable.
if (field == null)
{
// no collision - create the catch-error field
field = new JSVariableField(FieldType.CatchError, nameDecl.Name, 0, null)
{
OriginalContext = nameDecl.NameContext.Clone(),
IsDeclared = true
};
this.AddField(field);
}
else
{
// it's an error to declare anything in the catch scope with the same name as the
// error variable
field.OriginalContext.HandleError(JSError.DuplicateCatch, true);
}
}
else
{
if (field == null)
{
// could be global or local depending on the scope, so let the scope create it.
field = this.CreateField(nameDecl.Name, null, 0);
field.OriginalContext = nameDecl.NameContext.Clone();
field.IsDeclared = true;
field.IsFunction = (nameDecl is FunctionObject);
field.FieldValue = fieldValue;
// if this field is a constant, mark it now
var lexDeclaration = nameDecl.Parent as LexicalDeclaration;
field.InitializationOnly = nameDecl.Parent is ConstStatement
|| (lexDeclaration != null && lexDeclaration.StatementToken == JSToken.Const);
this.AddField(field);
}
else
{
// already defined!
// if this is a lexical declaration, then it's an error because we have two
// lexical declarations with the same name in the same scope.
if (nameDecl.Parent is LexicalDeclaration)
{
nameDecl.NameContext.HandleError(JSError.DuplicateLexicalDeclaration, true);
}
if (nameDecl.Initializer != null)
{
// if this is an initialized declaration, then the var part is
// superfluous and the "initializer" is really a lookup assignment.
// So bump up the ref-count for those cases.
var nameReference = nameDecl as INameReference;
if (nameReference != null)
{
field.AddReference(nameReference);
}
}
// don't clobber an existing field value with null. For instance, the last
// function declaration is the winner, so always set the value if we have something,
// but a var following a function shouldn't reset it to null.
if (fieldValue != null)
{
field.FieldValue = fieldValue;
}
}
}
nameDecl.VariableField = field;
field.Declarations.Add(nameDecl);
// if this scope is within a with-statement, or if the declaration was flagged
// as not being renamable, then mark the field as not crunchable
if (IsInWithScope || nameDecl.RenameNotAllowed)
{
field.CanCrunch = false;
}
}
public void Visit(FunctionObject node)
{
// invalid! ignore
IsValid = false;
}
public void Visit(FunctionObject node)
{
// we're good
}
/// <summary>
/// Parse the source code using the given settings, getting back an abstract syntax tree Block node as the root
/// representing the list of statements in the source code.
/// </summary>
/// <param name="settings">code settings to use to process the source code</param>
/// <returns>root Block node representing the top-level statements</returns>
public Block Parse(CodeSettings settings)
{
// initialize the scanner with our settings
// make sure the RawTokens setting is OFF or we won't be able to create our AST
InitializeScanner(settings);
// make sure we initialize the global scope's strict mode to our flag, whether or not it
// is true. This means if the setting is false, we will RESET the flag to false if we are
// reusing the scope and a previous Parse call had code that set it to strict with a
// program directive.
GlobalScope.UseStrict = m_settings.StrictMode;
// make sure the global scope knows about our known global names
GlobalScope.SetAssumedGlobals(m_settings);
// start of a new module
m_newModule = true;
Block scriptBlock;
Block returnBlock;
switch (m_settings.SourceMode)
{
case JavaScriptSourceMode.Program:
// simply parse a block of statements
returnBlock = scriptBlock = ParseStatements();
break;
case JavaScriptSourceMode.Expression:
// create a block, get the first token, add in the parse of a single expression,
// and we'll go fron there.
returnBlock = scriptBlock = new Block(CurrentPositionContext(), this);
GetNextToken();
try
{
var expr = ParseExpression();
if (expr != null)
{
scriptBlock.Append(expr);
scriptBlock.UpdateWith(expr.Context);
}
}
catch (EndOfFileException)
{
Debug.WriteLine("EOF");
}
break;
case JavaScriptSourceMode.EventHandler:
// we're going to create the global block, add in a function expression with a single
// parameter named "event", and then we're going to parse the input as the body of that
// function expression. We're going to resolve the global block, but only return the body
// of the function.
scriptBlock = new Block(null, this);
var parameters = new AstNodeList(null, this);
parameters.Append(new ParameterDeclaration(null, this)
{
Name = "event",
RenameNotAllowed = true
});
var funcExpression = new FunctionObject(null, this)
{
FunctionType = FunctionType.Expression,
ParameterDeclarations = parameters
};
scriptBlock.Append(funcExpression);
returnBlock = ParseStatements();
funcExpression.Body = returnBlock;
break;
default:
Debug.Fail("Unexpected source mode enumeration");
return null;
}
// resolve everything
ResolutionVisitor.Apply(scriptBlock, GlobalScope, m_settings);
if (scriptBlock != null && Settings.MinifyCode)
{
// this visitor doesn't just reorder scopes. It also combines the adjacent var variables,
// unnests blocks, identifies prologue directives, and sets the strict mode on scopes.
ReorderScopeVisitor.Apply(scriptBlock, this);
// analyze the entire node tree (needed for hypercrunch)
// root to leaf (top down)
var analyzeVisitor = new AnalyzeNodeVisitor(this);
scriptBlock.Accept(analyzeVisitor);
// analyze the scope chain (also needed for hypercrunch)
// root to leaf (top down)
m_globalScope.AnalyzeScope();
// if we want to crunch any names....
if (m_settings.LocalRenaming != LocalRenaming.KeepAll
&& m_settings.IsModificationAllowed(TreeModifications.LocalRenaming))
{
// then do a top-down traversal of the scope tree. For each field that had not
// already been crunched (globals and outers will already be crunched), crunch
// the name with a crunch iterator that does not use any names in the verboten set.
m_globalScope.AutoRenameFields();
}
// if we want to evaluate literal expressions, do so now
if (m_settings.EvalLiteralExpressions)
{
var visitor = new EvaluateLiteralVisitor(this);
scriptBlock.Accept(visitor);
}
// if any of the conditions we check for in the final pass are available, then
// make the final pass
if (m_settings.IsModificationAllowed(TreeModifications.BooleanLiteralsToNotOperators))
{
var visitor = new FinalPassVisitor(this);
scriptBlock.Accept(visitor);
}
// we want to walk all the scopes to make sure that any generated
// variables that haven't been crunched have been assigned valid
// variable names that don't collide with any existing variables.
m_globalScope.ValidateGeneratedNames();
}
if (returnBlock.Parent != null)
{
returnBlock.Parent = null;
}
return returnBlock;
}
public void Visit(FunctionObject node)
{
// not applicable; terminate
}
private static string GetPropertyType(FunctionObject funcObj)
{
// should never be a function declaration....
return funcObj == null || funcObj.FunctionType == FunctionType.Expression
? "data"
: funcObj.FunctionType == FunctionType.Getter ? "get" : "set";
}
public override void Visit(FunctionObject node)
{
if (node != null)
{
// get the name of this function, calculate something if it's anonymous or if
// the name isn't actually referenced
if (node.Name.IsNullOrWhiteSpace()
|| (node.IsExpression
&& node.RefCount == 0
&& m_parser.Settings.RemoveFunctionExpressionNames
&& m_parser.Settings.IsModificationAllowed(TreeModifications.RemoveFunctionExpressionNames)))
{
node.NameGuess = GuessAtName(node);
}
// don't analyze the identifier or we'll add an extra reference to it.
// and we don't need to analyze the parameters because they were fielded-up
// back when the function object was created, too
if (m_scopeStack.Peek().UseStrict)
{
// if this is a function delcaration, it better be a source element.
// if not, we want to throw a warning that different browsers will treat this function declaration
// differently. Technically, this location is not allowed. IE and most other browsers will
// simply treat it like every other function declaration in this scope. Firefox, however, won't
// add this function declaration's name to the containing scope until the function declaration
// is actually "executed." So if you try to call it BEFORE, you will get a "not defined" error.
// TODO: take this out for now, because we will throw this error in the resolution process
// until we can get this worked out properly.
//if (!node.IsSourceElement && node.FunctionType == FunctionType.Declaration)
//{
// (node.NameContext ?? node.Context).HandleError(JSError.MisplacedFunctionDeclaration, true);
//}
// we need to make sure the function isn't named "eval" or "arguments"
if (string.CompareOrdinal(node.Name, "eval") == 0
|| string.CompareOrdinal(node.Name, "arguments") == 0)
{
if (node.IdContext != null)
{
node.IdContext.HandleError(JSError.StrictModeFunctionName, true);
}
else if (node.Context != null)
{
node.Context.HandleError(JSError.StrictModeFunctionName, true);
}
}
// we need to make sure:
// 1. there are no duplicate argument names, and
// 2. none of them are named "eval" or "arguments"
// create map that we'll use to determine if there are any dups
if (node.ParameterDeclarations != null
&& node.ParameterDeclarations.Count > 0)
{
var parameterMap = new HashSet<string>();
foreach (var parameter in node.ParameterDeclarations)
{
// if it already exists in the map, then it's a dup
var parameterName = (parameter as ParameterDeclaration).IfNotNull(p => p.Name);
if (parameterMap.Add(parameterName))
{
// now check to see if it's one of the two forbidden names
if (string.CompareOrdinal(parameterName, "eval") == 0
|| string.CompareOrdinal(parameterName, "arguments") == 0)
{
parameter.Context.HandleError(JSError.StrictModeArgumentName, true);
}
}
else
{
// already exists -- throw an error
parameter.Context.HandleError(JSError.StrictModeDuplicateArgument, true);
}
}
}
}
else if (node.ParameterDeclarations != null
&& node.ParameterDeclarations.Count > 0)
{
// not strict
// if there are duplicate parameter names, throw a warning
var parameterMap = new HashSet<string>();
foreach (var parameter in node.ParameterDeclarations)
{
// if it already exists in the map, then it's a dup
var parameterName = (parameter as ParameterDeclaration).IfNotNull(p => p.Name);
if (!parameterMap.Add(parameterName))
{
// already exists -- throw an error
parameter.Context.HandleError(JSError.DuplicateName, false);
}
}
}
if (node.Body != null)
{
// push the stack and analyze the body
m_scopeStack.Push(node.FunctionScope);
try
{
// recurse the body
node.Body.Accept(this);
}
finally
{
m_scopeStack.Pop();
}
}
}
}
public override void Visit(FunctionObject node)
{
if (node != null)
{
// if we are reordering ANYTHING, then we need to do the reordering on a scope level.
// so if that's the case, we need to create a list of all the child functions and NOT
// recurse at this point. Then we'll reorder, then we'll use the lists to recurse.
// BUT if we are not reordering anything, no sense making the lists and recursing later.
// if that's the case, we can just recurse now and not have to worry about anything later.
if (m_moveVarStatements || m_moveFunctionDecls)
{
// add the node to the appropriate list: either function expression or function declaration.
// assume if it's not a function declaration, it must be an expression since the other types
// are not declaration (getter, setter) and we want to treat declarations special.
// if the conditional comment level isn't zero, then something funky is going on with
// the conditional-compilation statements, and we don't want to move the declarations, so
// don't add them to the declaration list. But we still want to recurse them, so add them
// to the expression list (which get recursed but not moved).
if (node.FunctionType == FunctionType.Declaration && m_conditionalCommentLevel == 0)
{
if (m_functionDeclarations == null)
{
m_functionDeclarations = new List<FunctionObject>();
}
m_functionDeclarations.Add(node);
}
else
{
if (m_functionExpressions == null)
{
m_functionExpressions = new List<FunctionObject>();
}
m_functionExpressions.Add(node);
}
// BUT DO NOT RECURSE!!!!
// we only want the functions and variables in THIS scope, not child function scopes.
//base.Visit(node);
}
else
{
// we're not reordering, so just recurse now to save the hassle
base.Visit(node);
}
}
}
private void DefineField(INameDeclaration nameDecl, FunctionObject fieldValue)
{
var field = this[nameDecl.Name];
if (nameDecl is ParameterDeclaration)
{
// function parameters are handled separately, so if this is a parameter declaration,
// then it must be a catch variable.
if (field == null)
{
// no collision - create the catch-error field
field = new JSVariableField(FieldType.CatchError, nameDecl.Name, 0, null)
{
OriginalContext = nameDecl.NameContext.Clone(),
IsDeclared = true
};
this.AddField(field);
}
else
{
// it's an error to declare anything in the catch scope with the same name as the
// error variable
field.OriginalContext.HandleError(JSError.DuplicateCatch, true);
}
}
else
{
if (field == null)
{
// could be global or local depending on the scope, so let the scope create it.
field = this.CreateField(nameDecl.Name, null, 0);
field.OriginalContext = nameDecl.NameContext.Clone();
field.IsDeclared = true;
field.IsFunction = (nameDecl is FunctionObject);
field.FieldValue = fieldValue;
// if this field is a constant, mark it now
var lexDeclaration = nameDecl.Parent as LexicalDeclaration;
field.InitializationOnly = nameDecl.Parent is ConstStatement ||
(lexDeclaration != null && lexDeclaration.StatementToken == JSToken.Const);
this.AddField(field);
}
else
{
// already defined!
// if this is a lexical declaration, then it's an error because we have two
// lexical declarations with the same name in the same scope.
if (nameDecl.Parent is LexicalDeclaration)
{
nameDecl.NameContext.HandleError(JSError.DuplicateLexicalDeclaration, true);
}
if (nameDecl.Initializer != null)
{
// if this is an initialized declaration, then the var part is
// superfluous and the "initializer" is really a lookup assignment.
// So bump up the ref-count for those cases.
var nameReference = nameDecl as INameReference;
if (nameReference != null)
{
field.AddReference(nameReference);
}
}
// don't clobber an existing field value with null. For instance, the last
// function declaration is the winner, so always set the value if we have something,
// but a var following a function shouldn't reset it to null.
if (fieldValue != null)
{
field.FieldValue = fieldValue;
}
}
}
nameDecl.VariableField = field;
field.Declarations.Add(nameDecl);
// if this scope is within a with-statement, or if the declaration was flagged
// as not being renamable, then mark the field as not crunchable
if (IsInWithScope || nameDecl.RenameNotAllowed)
{
field.CanCrunch = false;
}
}
private static void ResolveGhostedFunctions(ActivationObject scope, FunctionObject funcObject)
{
var functionField = funcObject.VariableField;
// let's check on ghosted names in the outer variable scope
var ghostField = scope[funcObject.Name];
if (ghostField == null)
{
// nothing; good to go. Add a ghosted field to keep track of it.
ghostField = new JSVariableField(FieldType.GhostFunction, funcObject.Name, 0, funcObject)
{
OriginalContext = functionField.OriginalContext.Clone(),
CanCrunch = funcObject.VariableField.IfNotNull(v => v.CanCrunch)
};
scope.AddField(ghostField);
}
else if (ghostField.FieldType == FieldType.GhostFunction)
{
// there is, but it's another ghosted function expression.
// what if a lookup is resolved to this field later? We probably still need to
// at least flag it as ambiguous. We will only need to throw an error, though,
// if someone actually references the outer ghost variable.
ghostField.IsAmbiguous = true;
}
else
{
// something already exists. Could be a naming collision for IE or at least a
// a cross-browser behavior difference if it's not coded properly.
// mark this field as a function, even if it wasn't before
ghostField.IsFunction = true;
if (ghostField.OuterField != null)
{
// if the pre-existing field we are ghosting is a reference to
// an OUTER field, then we actually have a problem that creates a BIG
// difference between older IE browsers and everything else.
// modern browsers will have the link to the outer field, but older
// IE browsers will link to this function expression!
// fire a cross-browser error warning
ghostField.IsAmbiguous = true;
funcObject.IdContext.HandleError(JSError.AmbiguousNamedFunctionExpression);
}
else if (ghostField.IsReferenced)
{
// if the ghosted field isn't even referenced, then who cares?
// but it is referenced. Let's see if it matters.
// something like: var nm = function nm() {}
// is TOTALLY cool common cross-browser syntax.
var parentVarDecl = funcObject.Parent as VariableDeclaration;
if (parentVarDecl == null
|| parentVarDecl.Name != funcObject.Name)
{
// see if it's a simple assignment.
// something like: var nm; nm = function nm(){},
// would also be cool, although less-common than the vardecl version.
Lookup lookup;
var parentAssignment = funcObject.Parent as BinaryOperator;
if (parentAssignment == null || parentAssignment.OperatorToken != JSToken.Assign
|| parentAssignment.Operand2 != funcObject
|| (lookup = parentAssignment.Operand1 as Lookup) == null
|| lookup.Name != funcObject.Name)
{
// something else. Flag it as ambiguous.
ghostField.IsAmbiguous = true;
}
}
}
}
// link them so they all keep the same name going forward
// (since they are named the same in the sources)
functionField.OuterField = ghostField;
// TODO: this really should be a LIST of ghosted fields, since multiple
// elements can ghost to the same field.
ghostField.GhostedField = functionField;
// if the actual field has references, we want to bubble those up
// since we're now linking those fields
if (functionField.RefCount > 0)
{
// add the function's references to the ghost field
ghostField.AddReferences(functionField.References);
}
}
public void Visit(FunctionObject node)
{
// we're good
}
public void Visit(FunctionObject node)
{
if (node != null)
{
// it's a declaration; put the index to -1.
node.Index = -1;
// create a function scope, assign it to the function object,
// and push it on the stack
var parentScope = CurrentLexicalScope;
if (node.FunctionType == FunctionType.Expression
&& !string.IsNullOrEmpty(node.Name))
{
// function expressions have an intermediate scope between the parent and the
// function's scope that contains just the function name so the function can
// be self-referencing without the function expression polluting the parent scope.
// don't add the function name field yet, because it's not a decl per se.
parentScope = new FunctionScope(parentScope, true, m_settings, node)
{
IsInWithScope = m_withDepth > 0
};
// add this function object to the list of function objects the variable scope
// will need to ghost later
CurrentVariableScope.GhostedFunctions.Add(node);
}
node.FunctionScope = new FunctionScope(parentScope, node.FunctionType != FunctionType.Declaration, m_settings, node)
{
IsInWithScope = m_withDepth > 0
};
m_lexicalStack.Push(node.FunctionScope);
m_variableStack.Push(node.FunctionScope);
var savedIndex = m_orderIndex;
try
{
// recurse into the function to handle it after saving the current index and resetting it
if (node.Body != null)
{
m_orderIndex = 0;
node.Body.Accept(this);
}
}
finally
{
Debug.Assert(CurrentLexicalScope == node.FunctionScope);
m_lexicalStack.Pop();
m_variableStack.Pop();
m_orderIndex = savedIndex;
}
// nothing to add to the var-decl list.
// but add the function name to the current lex-decl list
// IF it is a declaration and it has a name (and it SHOULD unless there was an error)
if (node.FunctionType == FunctionType.Declaration &&
!string.IsNullOrEmpty(node.Name))
{
var lexicalScope = CurrentLexicalScope;
lexicalScope.LexicallyDeclaredNames.Add(node);
if (lexicalScope != CurrentVariableScope)
{
// the current lexical scope is the variable scope.
// this is ES6 syntax: a function declaration inside a block scope. Not allowed
// in ES5 code, so throw a warning and ghost this function in the outer variable scope
// to make sure that we don't generate any naming collisions.
node.NameContext.HandleError(JSError.MisplacedFunctionDeclaration, false);
CurrentVariableScope.GhostedFunctions.Add(node);
}
}
}
}
public void Visit(FunctionObject node)
{
// invalid! ignore
IsValid = false;
}
public void Visit(FunctionObject node)
{
// not applicable; terminate
}
private void UnreferencedFunction(JSVariableField variableField, FunctionObject functionObject)
{
// if there is no name, then ignore this declaration because it's malformed.
// (won't be a function expression because those are automatically referenced).
// also ignore ghosted function fields.
if (functionObject.Name != null && variableField.FieldType != FieldType.GhostFunction)
{
// if the function name isn't a simple identifier, then leave it there and mark it as
// not renamable because it's probably one of those darn IE-extension event handlers or something.
if (JSScanner.IsValidIdentifier(functionObject.Name))
{
// unreferenced function declaration. fire a warning.
var ctx = functionObject.IdContext ?? variableField.OriginalContext;
ctx.HandleError(JSError.FunctionNotReferenced, false);
// hide it from the output if our settings say we can.
// we don't want to delete it, per se, because we still want it to
// show up in the scope report so the user can see that it was unreachable
// in case they are wondering where it went.
// ES6 has the notion of block-scoped function declarations. ES5 says functions can't
// be defined inside blocks -- only at the root level of the global scope or function scopes.
// so if this is a block scope, don't hide the function, even if it is unreferenced because
// of the cross-browser difference.
if (this.IsKnownAtCompileTime
&& m_settings.MinifyCode
&& m_settings.RemoveUnneededCode
&& !(this is BlockScope))
{
functionObject.HideFromOutput = true;
}
}
else
{
// not a valid identifier name for this function. Don't rename it because it's
// malformed and we don't want to mess up the developer's intent.
variableField.CanCrunch = false;
}
}
}
private static void ResolveGhostedFunctions(ActivationObject scope, FunctionObject funcObject)
{
var functionField = funcObject.VariableField;
// let's check on ghosted names in the outer variable scope
var ghostField = scope[funcObject.Name];
if (ghostField == null)
{
// nothing; good to go. Add a ghosted field to keep track of it.
ghostField = new JSVariableField(FieldType.GhostFunction, funcObject.Name, 0, funcObject)
{
OriginalContext = functionField.OriginalContext.Clone(),
CanCrunch = funcObject.VariableField.IfNotNull(v => v.CanCrunch)
};
scope.AddField(ghostField);
}
else if (ghostField.FieldType == FieldType.GhostFunction)
{
// there is, but it's another ghosted function expression.
// what if a lookup is resolved to this field later? We probably still need to
// at least flag it as ambiguous. We will only need to throw an error, though,
// if someone actually references the outer ghost variable.
ghostField.IsAmbiguous = true;
}
else
{
// something already exists. Could be a naming collision for IE or at least a
// a cross-browser behavior difference if it's not coded properly.
// mark this field as a function, even if it wasn't before
ghostField.IsFunction = true;
if (ghostField.OuterField != null)
{
// if the pre-existing field we are ghosting is a reference to
// an OUTER field, then we actually have a problem that creates a BIG
// difference between older IE browsers and everything else.
// modern browsers will have the link to the outer field, but older
// IE browsers will link to this function expression!
// fire a cross-browser error warning
ghostField.IsAmbiguous = true;
funcObject.IdContext.HandleError(JSError.AmbiguousNamedFunctionExpression);
}
else if (ghostField.IsReferenced)
{
// if the ghosted field isn't even referenced, then who cares?
// but it is referenced. Let's see if it matters.
// something like: var nm = function nm() {}
// is TOTALLY cool common cross-browser syntax.
var parentVarDecl = funcObject.Parent as VariableDeclaration;
if (parentVarDecl == null ||
parentVarDecl.Name != funcObject.Name)
{
// see if it's a simple assignment.
// something like: var nm; nm = function nm(){},
// would also be cool, although less-common than the vardecl version.
Lookup lookup;
var parentAssignment = funcObject.Parent as BinaryOperator;
if (parentAssignment == null || parentAssignment.OperatorToken != JSToken.Assign ||
parentAssignment.Operand2 != funcObject ||
(lookup = parentAssignment.Operand1 as Lookup) == null ||
lookup.Name != funcObject.Name)
{
// something else. Flag it as ambiguous.
ghostField.IsAmbiguous = true;
}
}
}
}
// link them so they all keep the same name going forward
// (since they are named the same in the sources)
functionField.OuterField = ghostField;
// TODO: this really should be a LIST of ghosted fields, since multiple
// elements can ghost to the same field.
ghostField.GhostedField = functionField;
// if the actual field has references, we want to bubble those up
// since we're now linking those fields
if (functionField.RefCount > 0)
{
// add the function's references to the ghost field
ghostField.AddReferences(functionField.References);
}
}