//---------------------------------------------------------------------------------------
// ParseFunction
//
// FunctionDeclaration :
// VisibilityModifier 'function' Identifier '('
// FormalParameterList ')' '{' FunctionBody '}'
//
// FormalParameterList :
// <empty> |
// IdentifierList Identifier
//
// IdentifierList :
// <empty> |
// Identifier, IdentifierList
//---------------------------------------------------------------------------------------
private FunctionObject ParseFunction(FunctionType functionType, Context fncCtx)
{
Lookup name = null;
List<ParameterDeclaration> formalParameters = null;
Block body = null;
bool inExpression = (functionType == FunctionType.Expression);
GetNextToken();
// get the function name or make an anonymous function if in expression "position"
if (JSToken.Identifier == m_currentToken.Token)
{
name = new Lookup(m_scanner.GetIdentifier(), m_currentToken.Clone(), this);
GetNextToken();
}
else
{
string identifier = JSKeyword.CanBeIdentifier(m_currentToken.Token);
if (null != identifier)
{
name = new Lookup(identifier, m_currentToken.Clone(), this);
GetNextToken();
}
else
{
if (!inExpression)
{
// if this isn't a function expression, then we need to throw an error because
// function DECLARATIONS always need a valid identifier name
ReportError(JSError.NoIdentifier, true);
// BUT if the current token is a left paren, we don't want to use it as the name.
// (fix for issue #14152)
if (m_currentToken.Token != JSToken.LeftParenthesis
&& m_currentToken.Token != JSToken.LeftCurly)
{
identifier = m_currentToken.Code;
name = new Lookup(identifier, CurrentPositionContext(), this);
GetNextToken();
}
}
}
}
// make a new state and save the old one
List<BlockType> blockType = m_blockType;
m_blockType = new List<BlockType>(16);
Dictionary<string, LabelInfo> labelTable = m_labelTable;
m_labelTable = new Dictionary<string, LabelInfo>();
// create the function scope and stick it onto the scope stack
FunctionScope functionScope = new FunctionScope(
ScopeStack.Peek(),
(functionType != FunctionType.Declaration),
this
);
ScopeStack.Push(functionScope);
try
{
// get the formal parameters
if (JSToken.LeftParenthesis != m_currentToken.Token)
{
// we expect a left paren at this point for standard cross-browser support.
// BUT -- some versions of IE allow an object property expression to be a function name, like window.onclick.
// we still want to throw the error, because it syntax errors on most browsers, but we still want to
// be able to parse it and return the intended results.
// Skip to the open paren and use whatever is in-between as the function name. Doesn't matter that it's
// an invalid identifier; it won't be accessible as a valid field anyway.
bool expandedIndentifier = false;
while (m_currentToken.Token != JSToken.LeftParenthesis
&& m_currentToken.Token != JSToken.LeftCurly
&& m_currentToken.Token != JSToken.Semicolon
&& m_currentToken.Token != JSToken.EndOfFile)
{
name.Context.UpdateWith(m_currentToken);
GetNextToken();
expandedIndentifier = true;
}
// if we actually expanded the identifier context, then we want to report that
// the function name needs to be an indentifier. Otherwise we didn't expand the
// name, so just report that we expected an open parent at this point.
if (expandedIndentifier)
{
name.Name = name.Context.Code;
name.Context.HandleError(JSError.FunctionNameMustBeIdentifier, true);
}
else
{
ReportError(JSError.NoLeftParenthesis, true);
}
}
if (m_currentToken.Token == JSToken.LeftParenthesis)
{
// skip the open paren
GetNextToken();
Context paramArrayContext = null;
formalParameters = new List<ParameterDeclaration>();
// create the list of arguments and update the context
while (JSToken.RightParenthesis != m_currentToken.Token)
{
if (paramArrayContext != null)
{
ReportError(JSError.ParameterListNotLast, paramArrayContext, true);
paramArrayContext = null;
}
String id = null;
m_noSkipTokenSet.Add(NoSkipTokenSet.s_FunctionDeclNoSkipTokenSet);
try
{
if (JSToken.Identifier != m_currentToken.Token && (id = JSKeyword.CanBeIdentifier(m_currentToken.Token)) == null)
{
if (JSToken.LeftCurly == m_currentToken.Token)
{
ReportError(JSError.NoRightParenthesis);
break;
}
else if (JSToken.Comma == m_currentToken.Token)
{
// We're missing an argument (or previous argument was malformed and
// we skipped to the comma.) Keep trying to parse the argument list --
// we will skip the comma below.
ReportError(JSError.SyntaxError, true);
}
else
{
ReportError(JSError.SyntaxError, true);
SkipTokensAndThrow();
}
}
else
{
if (null == id)
{
id = m_scanner.GetIdentifier();
}
Context paramCtx = m_currentToken.Clone();
GetNextToken();
formalParameters.Add(new ParameterDeclaration(paramCtx, this, id, formalParameters.Count));
}
// got an arg, it should be either a ',' or ')'
if (JSToken.RightParenthesis == m_currentToken.Token)
break;
else if (JSToken.Comma != m_currentToken.Token)
{
// deal with error in some "intelligent" way
if (JSToken.LeftCurly == m_currentToken.Token)
{
ReportError(JSError.NoRightParenthesis);
break;
}
else
{
if (JSToken.Identifier == m_currentToken.Token)
{
// it's possible that the guy was writing the type in C/C++ style (i.e. int x)
ReportError(JSError.NoCommaOrTypeDefinitionError);
}
else
ReportError(JSError.NoComma);
}
}
GetNextToken();
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_FunctionDeclNoSkipTokenSet, exc) == -1)
throw;
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_FunctionDeclNoSkipTokenSet);
}
}
fncCtx.UpdateWith(m_currentToken);
GetNextToken();
}
// read the function body of non-abstract functions.
if (JSToken.LeftCurly != m_currentToken.Token)
ReportError(JSError.NoLeftCurly, true);
m_blockType.Add(BlockType.Block);
m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockNoSkipTokenSet);
m_noSkipTokenSet.Add(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
try
{
// parse the block locally to get the exact end of function
body = new Block(m_currentToken.Clone(), this);
GetNextToken();
while (JSToken.RightCurly != m_currentToken.Token)
{
try
{
// function body's are SourceElements (Statements + FunctionDeclarations)
body.Append(ParseStatement(true));
}
catch (RecoveryTokenException exc)
{
if (exc._partiallyComputedNode != null)
{
body.Append(exc._partiallyComputedNode);
}
if (IndexOfToken(NoSkipTokenSet.s_StartStatementNoSkipTokenSet, exc) == -1)
throw;
}
}
body.Context.UpdateWith(m_currentToken);
fncCtx.UpdateWith(m_currentToken);
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_BlockNoSkipTokenSet, exc) == -1)
{
exc._partiallyComputedNode = new FunctionObject(
name,
this,
(inExpression ? FunctionType.Expression : FunctionType.Declaration),
formalParameters == null ? null : formalParameters.ToArray(),
body,
fncCtx,
functionScope
);
throw;
}
}
finally
{
m_blockType.RemoveAt(m_blockType.Count - 1);
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockNoSkipTokenSet);
}
GetNextToken();
}
finally
{
// pop the scope off the stack
ScopeStack.Pop();
// restore state
m_blockType = blockType;
m_labelTable = labelTable;
}
return new FunctionObject(
name,
this,
functionType,
formalParameters == null ? null : formalParameters.ToArray(),
body,
fncCtx,
functionScope);
}
public FunctionObject(Lookup identifier, JSParser parser, FunctionType functionType, ParameterDeclaration[] parameterDeclarations, Block bodyBlock, Context functionContext, FunctionScope functionScope)
: base(functionContext, parser)
{
FunctionType = functionType;
m_functionScope = functionScope;
if (functionScope != null)
{
functionScope.FunctionObject = this;
}
m_name = string.Empty;
Identifier = identifier;
if (Identifier != null) { Identifier.Parent = this; }
m_parameterDeclarations = parameterDeclarations;
Body = bodyBlock;
if (bodyBlock != null) { bodyBlock.Parent = this; }
// now we need to make sure that the enclosing scope has the name of this function defined
// so that any references get properly resolved once we start analyzing the parent scope
// see if this is not anonymnous AND not a getter/setter
bool isGetterSetter = (FunctionType == FunctionType.Getter || FunctionType == FunctionType.Setter);
if (Identifier != null && !isGetterSetter)
{
// yes -- add the function name to the current enclosing
// check whether the function name is in use already
// shouldn't be any duplicate names
ActivationObject enclosingScope = m_functionScope.Parent;
// functions aren't owned by block scopes
while (enclosingScope is BlockScope)
{
enclosingScope = enclosingScope.Parent;
}
// if the enclosing scope already contains this name, then we know we have a dup
string functionName = Identifier.Name;
m_variableField = enclosingScope[functionName];
if (m_variableField != null)
{
// it's pointing to a function
m_variableField.IsFunction = true;
if (FunctionType == FunctionType.Expression)
{
// if the containing scope is itself a named function expression, then just
// continue on as if everything is fine. It will chain and be good.
if (!(m_variableField is JSNamedFunctionExpressionField))
{
if (m_variableField.NamedFunctionExpression != null)
{
// we have a second named function expression in the same scope
// with the same name. Not an error unless someone actually references
// it.
// we are now ambiguous.
m_variableField.IsAmbiguous = true;
// BUT because this field now points to multiple function object, we
// need to break the connection. We'll leave the inner NFEs pointing
// to this field as the outer field so the names all align, however.
DetachFromOuterField(true);
// create a new NFE pointing to the existing field as the outer so
// the names stay in sync, and with a value of our function object.
JSNamedFunctionExpressionField namedExpressionField =
new JSNamedFunctionExpressionField(m_variableField);
namedExpressionField.FieldValue = this;
m_functionScope.AddField(namedExpressionField);
// hook our function object up to the named field
m_variableField = namedExpressionField;
Identifier.VariableField = namedExpressionField;
// we're done; quit.
return;
}
else if (m_variableField.IsAmbiguous)
{
// we're pointing to a field that is already marked as ambiguous.
// just create our own NFE pointing to this one, and hook us up.
JSNamedFunctionExpressionField namedExpressionField =
new JSNamedFunctionExpressionField(m_variableField);
namedExpressionField.FieldValue = this;
m_functionScope.AddField(namedExpressionField);
// hook our function object up to the named field
m_variableField = namedExpressionField;
Identifier.VariableField = namedExpressionField;
// we're done; quit.
return;
}
else
{
// we are a named function expression in a scope that has already
// defined a local variable of the same name. Not good. Throw the
// error but keep them attached because the names have to be synced
// to keep the same meaning in all browsers.
Identifier.Context.HandleError(JSError.AmbiguousNamedFunctionExpression, false);
// if we are preserving function names, then we need to mark this field
// as not crunchable
if (Parser.Settings.PreserveFunctionNames)
{
m_variableField.CanCrunch = false;
}
}
}
/*else
{
// it's okay; just chain the NFEs as normal and everything will work out
// and the names will be properly synced.
}*/
}
else
{
// function declaration -- duplicate name
Identifier.Context.HandleError(JSError.DuplicateName, false);
}
}
else
{
// doesn't exist -- create it now
m_variableField = enclosingScope.DeclareField(functionName, this, 0);
// and it's a pointing to a function object
m_variableField.IsFunction = true;
}
// set the identifier variable field now. We *know* what the field is now, and during
// Analyze mode we aren't going to recurse into the identifier because that would add
// a reference to it.
Identifier.VariableField = m_variableField;
// if we're here, we have a name. if this is a function expression, then we have
// a named function expression and we need to do a little more work to prepare for
// the ambiguities of named function expressions in various browsers.
if (FunctionType == FunctionType.Expression)
{
// now add a field within the function scope that indicates that it's okay to reference
// this named function expression from WITHIN the function itself.
// the inner field points to the outer field since we're going to want to catch ambiguous
// references in the future
JSNamedFunctionExpressionField namedExpressionField = new JSNamedFunctionExpressionField(m_variableField);
m_functionScope.AddField(namedExpressionField);
m_variableField.NamedFunctionExpression = namedExpressionField;
}
else
{
// function declarations are declared by definition
m_variableField.IsDeclared = true;
}
}
}