internal AstNodeList Append(AstNode astNode)
{
astNode.Parent = this;
m_list.Add(astNode);
Context.UpdateWith(astNode.Context);
return(this);
}
public void Append(AstNode statement)
{
if (statement != null)
{
Context.UpdateWith(statement.Context);
m_statements.Append(statement);
}
}
/// <summary>
/// Create a new context by combining the current and other contexts
/// </summary>
/// <param name="other">other context</param>
/// <returns>new context instance</returns>
public Context CombineWith(Context other)
{
var clone = new Context();
clone.SetData(this);
return(clone.UpdateWith(other));
}
/// <summary>
/// Append the given statement node to the end of the block
/// </summary>
/// <param name="item">node to add to the block</param>
public void Append(AstNode item)
{
if (item != null)
{
if (this.IsConcise)
{
// this WAS concise -- make it not a concise block now because adding another
// statement totally changes the semantics.
Unconcise();
}
item.Parent = this;
m_list.Add(item);
Context.UpdateWith(item.Context);
}
}
public ImportExportStatement Append(AstNode node)
{
var specifierList = node as ImportExportStatement;
if (specifierList != null)
{
// another secifier list -- move each specifier from the other list to ours
for (var ndx = 0; ndx < specifierList.Count; ++ndx)
{
Append(specifierList[ndx]);
}
}
else if (node != null)
{
// not another list; just add it
node.Parent = this;
m_list.Add(node);
Context.UpdateWith(node.Context);
}
return this;
}
public ImportExportStatement Insert(int position, AstNode node)
{
var specifierList = node as ImportExportStatement;
if (specifierList != null)
{
// another secifier list -- move each specifier from the other list to ours
for (var ndx = 0; ndx < specifierList.Count; ++ndx)
{
Insert(position + ndx, specifierList[ndx]);
}
}
else if (node != null)
{
// not another list
node.Parent = this;
m_list.Insert(position, node);
Context.UpdateWith(node.Context);
}
return this;
}
public AstNodeList Insert(int position, AstNode node)
{
var list = node as AstNodeList;
if (list != null)
{
// another list.
for (var ndx = 0; ndx < list.Count; ++ndx)
{
Insert(position + ndx, list[ndx]);
}
}
else if (node != null)
{
// not another list
node.Parent = this;
m_list.Insert(position, node);
Context.UpdateWith(node.Context);
}
return(this);
}
internal AstNodeList Append(AstNode node)
{
var list = node as AstNodeList;
if (list != null)
{
// another list -- append each item, not the whole list
for (var ndx = 0; ndx < list.Count; ++ndx)
{
Append(list[ndx]);
}
}
else if (node != null)
{
// not another list
node.Parent = this;
m_list.Add(node);
Context.UpdateWith(node.Context);
}
return(this);
}
//---------------------------------------------------------------------------------------
// 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);
}
internal override void AnalyzeNode()
{
// javascript doesn't have block scope, so there really is no point
// in nesting blocks. Unnest any now, before we start combining var statements
UnnestBlocks();
// if we want to remove debug statements...
if (Parser.Settings.StripDebugStatements && Parser.Settings.IsModificationAllowed(TreeModifications.StripDebugStatements))
{
// do it now before we try doing other things
StripDebugStatements();
}
// these variables are used to check for combining a particular type of
// for-statement with preceding var-statements.
ForNode targetForNode = null;
string targetName = null;
// check to see if we want to combine adjacent var statements
bool combineVarStatements = Parser.Settings.IsModificationAllowed(TreeModifications.CombineVarStatements);
// check to see if we want to combine a preceding var with a for-statement
bool moveVarIntoFor = Parser.Settings.IsModificationAllowed(TreeModifications.MoveVarIntoFor);
// look at the statements in the block.
// if there are multiple var statements adjacent to each other, combine them.
// walk BACKWARDS down the list because we'll be removing items when we encounter
// multiple vars.
// we also don't need to check the first one, since there is nothing before it.
for (int ndx = m_list.Count - 1; ndx > 0; --ndx)
{
// if the previous node is not a Var, then we don't need to try and combine
// it withthe current node
Var previousVar = m_list[ndx - 1] as Var;
if (previousVar != null)
{
// see if THIS item is also a Var...
if (m_list[ndx] is Var && combineVarStatements)
{
// add the items in this VAR to the end of the previous
previousVar.Append(m_list[ndx]);
// delete this item from the block
m_list.RemoveAt(ndx);
// if we have a target for-node waiting for another comparison....
if (targetForNode != null)
{
// check to see if the variable we are looking for is in the new list
if (previousVar.Contains(targetName))
{
// IT DOES! we can combine the var statement with the initializer in the for-statement
// we already know it's a binaryop, or it wouldn't be a target for-statement
BinaryOperator binaryOp = targetForNode.Initializer as BinaryOperator;
// create a vardecl that matches our assignment initializer
// ignore duplicates because this scope will already have the variable defined.
VariableDeclaration varDecl = new VariableDeclaration(
binaryOp.Context.Clone(),
Parser,
targetName,
binaryOp.Operand1.Context.Clone(),
binaryOp.Operand2,
0,
true
);
// append it to the preceding var-statement
previousVar.Append(varDecl);
// move the previous vardecl to our initializer
targetForNode.ReplaceChild(targetForNode.Initializer, previousVar);
// and remove the previous var from the list.
m_list.RemoveAt(ndx - 1);
// this will bump the for node up one position in the list, so the next iteration
// will be right back on this node, but the initializer will not be null
// but now we no longer need the target mechanism -- the for-statement is
// not the current node again
targetForNode = null;
}
}
}
else if (moveVarIntoFor)
{
// see if this item is a ForNode
ForNode forNode = m_list[ndx] as ForNode;
if (forNode != null)
{
// and see if the forNode's initializer is empty
if (forNode.Initializer != null)
{
// not empty -- see if it is a Var node
Var varInitializer = forNode.Initializer as Var;
if (varInitializer != null)
{
// we want to PREPEND the initializers in the previous var statement
// to our for-statement's initializer list
varInitializer.InsertAt(0, previousVar);
// then remove the previous var statement
m_list.RemoveAt(ndx - 1);
// this will bump the for node up one position in the list, so the next iteration
// will be right back on this node in case there are other var statements we need
// to combine
}
else
{
// see if the initializer is a simple assignment
BinaryOperator binaryOp = forNode.Initializer as BinaryOperator;
if (binaryOp != null && binaryOp.OperatorToken == JSToken.Assign)
{
// it is. See if it's a simple lookup
Lookup lookup = binaryOp.Operand1 as Lookup;
if (lookup != null)
{
// it is. see if that variable is in the previous var statement
if (previousVar.Contains(lookup.Name))
{
// create a vardecl that matches our assignment initializer
// ignore duplicates because this scope will already have the variable defined.
VariableDeclaration varDecl = new VariableDeclaration(
binaryOp.Context.Clone(),
Parser,
lookup.Name,
lookup.Context.Clone(),
binaryOp.Operand2,
0,
true
);
// append it to the var statement before us
previousVar.Append(varDecl);
// move the previous vardecl to our initializer
forNode.ReplaceChild(forNode.Initializer, previousVar);
// and remove the previous var from the list.
m_list.RemoveAt(ndx - 1);
// this will bump the for node up one position in the list, so the next iteration
// will be right back on this node, but the initializer will not be null
}
else
{
// it's not in the immediately preceding var-statement, but that doesn't mean it won't be in
// a var-statement immediately preceding that one -- in which case they'll get combined and
// then it WILL be in the immediately preceding var-statement. So hold on to this
// for statement and we'll check after we do a combine.
targetForNode = forNode;
targetName = lookup.Name;
}
}
}
}
}
else
{
// if it's empty, then we're free to add the previous var statement
// to this for statement's initializer. remove it from it's current
// position and add it as the initializer
m_list.RemoveAt(ndx - 1);
forNode.ReplaceChild(forNode.Initializer, previousVar);
// this will bump the for node up one position in the list, so the next iteration
// will be right back on this node, but the initializer will not be null
}
}
}
}
else
{
// not a var statement. make sure the target for-node is cleared.
targetForNode = null;
ConditionalCompilationComment previousComment = m_list[ndx - 1] as ConditionalCompilationComment;
if (previousComment != null)
{
ConditionalCompilationComment thisComment = m_list[ndx] as ConditionalCompilationComment;
if (thisComment != null)
{
// two adjacent conditional comments -- combine them into the first.
// this will actually make the second block a nested block within the first block,
// but they'll be flattened when the comment's block gets recursed.
previousComment.Statements.Append(thisComment.Statements);
// and remove the second one (which is now a duplicate)
m_list.RemoveAt(ndx);
}
}
}
}
if (m_blockScope != null)
{
ScopeStack.Push(m_blockScope);
}
try
{
// call the base class to recurse
base.AnalyzeNode();
}
finally
{
if (m_blockScope != null)
{
ScopeStack.Pop();
}
}
// NOW that we've recursively analyzed all the child nodes in this block, let's see
// if we can further reduce the statements by checking for a couple good opportunities
if (Parser.Settings.RemoveUnneededCode)
{
// Transform: {var foo=expression;return foo;} to: {return expression;}
if (m_list.Count == 2 && Parser.Settings.IsModificationAllowed(TreeModifications.VarInitializeReturnToReturnInitializer))
{
Var varStatement = m_list[0] as Var;
ReturnNode returnStatement = m_list[1] as ReturnNode;
// see if we have two statements in our block: a var with a single declaration, and a return
if (returnStatement != null && varStatement != null &&
varStatement.Count == 1 && varStatement[0].Initializer != null)
{
// now see if the return is returning a lookup for the same var we are declaring in the
// previous statement
Lookup lookup = returnStatement.Operand as Lookup;
if (lookup != null &&
string.Compare(lookup.Name, varStatement[0].Identifier, StringComparison.Ordinal) == 0)
{
// it's a match!
// create a combined context starting with the var and adding in the return
Context context = varStatement.Context.Clone();
context.UpdateWith(returnStatement.Context);
// create a new return statement
ReturnNode newReturn = new ReturnNode(context, Parser, varStatement[0].Initializer);
// clear out the existing statements
m_list.Clear();
// and add our new one
Append(newReturn);
}
}
}
// we do things differently if these statements are the last in a function
// because we can assume the implicit return
bool isFunctionLevel = (Parent is FunctionObject);
// see if we want to change if-statement that forces a return to a return conditional
if (Parser.Settings.IsModificationAllowed(TreeModifications.IfElseReturnToReturnConditional))
{
// transform: {...; if(cond1)return;} to {...;cond;}
// transform: {...; if(cond1)return exp1;else return exp2;} to {...;return cond1?exp1:exp2;}
if (m_list.Count >= 1)
{
// see if the last statement is an if-statement with a true-block containing only one statement
IfNode ifStatement = m_list[m_list.Count - 1] as IfNode;
if (ifStatement != null &&
ifStatement.TrueBlock != null)
{
// see if this if-statement is structured such that we can convert it to a
// Conditional node that is the operand of a return statement
Conditional returnOperand = ifStatement.CanBeReturnOperand(null, isFunctionLevel);
if (returnOperand != null)
{
// it can! change it.
ReturnNode returnNode = new ReturnNode(
(Context == null ? null : Context.Clone()),
Parser,
returnOperand);
// replace the if-statement with the return statement
ReplaceChild(ifStatement, returnNode);
}
}
// else last statement is not an if-statement, or true block is not a single statement
}
// transform: {...; if(cond1)return exp1;return exp2;} to {...; return cond1?exp1:exp2;}
// my cascade! changing the two statements to a return may cause us to run this again if the
// third statement up becomes the penultimate and is an if-statement
while (m_list.Count > 1)
{
int lastIndex = m_list.Count - 1;
// end in a return statement?
ReturnNode finalReturn = m_list[lastIndex] as ReturnNode;
if (finalReturn != null)
{
// it does -- see if the penultimate statement is an if-block
IfNode ifNode = m_list[lastIndex - 1] as IfNode;
if (ifNode != null)
{
// if followed by return. See if the if statement can be changed to a
// return of a conditional, using the operand of the following return
// as the ultimate expression
Conditional returnConditional = ifNode.CanBeReturnOperand(finalReturn.Operand, isFunctionLevel);
if (returnConditional != null)
{
// it can! so create the new return statement.
// the context of this new return statement should start with a clone of
// the if-statement and updated with the return statement
Context context = ifNode.Context.Clone();
context.UpdateWith(finalReturn.Context);
// create the new return node
ReturnNode newReturn = new ReturnNode(
context,
Parser,
returnConditional);
// remove the last node (the old return)
m_list.RemoveAt(lastIndex--);
// and replace the if-statement with the new return
m_list[lastIndex] = newReturn;
newReturn.Parent = this;
// we collapsed the last two statements, and we KNOW the last one is a
// return -- go back up to the top of the loop to see if we can keep going.
continue;
}
}
}
// if we get here, then something went wrong, we didn't collapse the last
// two statements, so break out of the loop
break;
}
// now we may have converted the last functional statement
// from if(cond)return expr to return cond?expr:void 0, which is four
// extra bytes. So let's check to see if the last statement in the function
// now fits this pattern, and if so, change it back.
// We didn't just NOT change it in the first place because changing it could've
// enabled even more changes that would save a lot more space. But apparently
// those subsequent changes didn't pan out.
if (m_list.Count >= 1)
{
int lastIndex = m_list.Count - 1;
ReturnNode returnNode = m_list[lastIndex] as ReturnNode;
if (returnNode != null)
{
Conditional conditional = returnNode.Operand as Conditional;
if (conditional != null)
{
VoidNode falseVoid = conditional.FalseExpression as VoidNode;
if (falseVoid != null && falseVoid.Operand is ConstantWrapper)
{
// we have the required pattern: "return cond?expr:void 0"
// (well, the object of the void is a constant, at least).
// undo it back to "if(cond)return expr" because that takes fewer bytes.
// by default, the operand of the return operator will be the
// true branch of the conditional
AstNode returnOperand = conditional.TrueExpression;
VoidNode trueVoid = conditional.TrueExpression as VoidNode;
if (trueVoid != null && trueVoid.Operand is ConstantWrapper)
{
// the true branch of the conditional is a void operator acting
// on a constant! So really, there is no operand to the return statement
returnOperand = null;
if (Parser.Settings.IsModificationAllowed(TreeModifications.IfConditionReturnToCondition))
{
// actually, we have return cond?void 0:void 0,
// which would get changed back to function{...;if(cond)return}
// BUT we can just shorten it to function{...;cond}
m_list[lastIndex] = conditional.Condition;
conditional.Condition.Parent = this;
return;
}
}
IfNode ifNode = new IfNode(
returnNode.Context.Clone(),
Parser,
conditional.Condition,
new ReturnNode(returnNode.Context.Clone(), Parser, returnOperand),
null);
m_list[lastIndex] = ifNode;
ifNode.Parent = this;
}
}
}
}
}
}
}
