public void Visit(VariableDeclaration node)
{
// invalid! ignore
IsValid = false;
}
public void Visit(VariableDeclaration node)
{
if (node != null)
{
if (node.Parent is LexicalDeclaration)
{
// ES6 let or const declaration. Only add to the current lexical scope.
CurrentLexicalScope.LexicallyDeclaredNames.Add(node);
}
else
{
// must be var or const (mozilla-style). Add to both the lexical scope
// and the variable scope. The variable scope will actually use this node
// to create a field; the lexical stack will just use it to detect conflicts
// with lex-decls
CurrentLexicalScope.VarDeclaredNames.Add(node);
CurrentVariableScope.VarDeclaredNames.Add(node);
}
if (node.Initializer != null)
{
// recurse the initializer
node.Initializer.Accept(this);
node.Index = NextOrderIndex;
}
else
{
// no initializer; give it an index of -1 because it doesn't actually
// do anything at execution time.
node.Index = -1;
}
}
}
private static int RelocateVar(Block block, int insertAt, Var varStatement)
{
// if the var statement is at the next position to insert, then we don't need
// to do anything.
if (block[insertAt] != varStatement)
{
// check to see if the current position is a var and we are the NEXT statement.
// if that's the case, we don't need to break out the initializer, just append all the
// vardecls as-is to the current position.
var existingVar = block[insertAt] as Var;
if (existingVar != null && block[insertAt + 1] == varStatement)
{
// just append our vardecls to the insertion point, then delete our statement
existingVar.Append(varStatement);
block.RemoveAt(insertAt + 1);
}
else
{
// iterate through the decls and count how many have initializers
var initializerCount = 0;
for (var ndx = 0; ndx < varStatement.Count; ++ndx)
{
if (varStatement[ndx].Initializer != null)
{
++initializerCount;
}
}
// if there are more than two decls with initializers, then we won't actually
// be gaining anything by moving the var to the top. We'll get rid of the four
// bytes for the "var ", but we'll be adding two bytes for the name and comma
// because name=init will still need to remain behind.
if (initializerCount <= 2)
{
// first iterate through all the declarations in the var statement,
// constructing an expression statement that is made up of assignment
// operators for each of the declarations that have initializers (if any)
// and removing all the initializers
var assignments = new List<AstNode>();
for (var ndx = 0; ndx < varStatement.Count; ++ndx)
{
var varDecl = varStatement[ndx];
if (varDecl.Initializer != null)
{
if (varDecl.IsCCSpecialCase)
{
// create a vardecl with the same name and no initializer
var copyDecl = new VariableDeclaration(varDecl.Context, varDecl.Parser)
{
Identifier = varDecl.Identifier,
NameContext = varDecl.VariableField.OriginalContext,
VariableField = varDecl.VariableField
};
// replace the special vardecl with the copy
varStatement[ndx] = copyDecl;
// add the original vardecl to the list of "assignments"
assignments.Add(varDecl);
// add the new decl to the field's declaration list, and remove the old one
// because we're going to change that to an assignment.
varDecl.VariableField.Declarations.Add(copyDecl);
varDecl.VariableField.Declarations.Remove(varDecl);
}
else
{
// hold on to the object so we don't lose it to the GC
var initializer = varDecl.Initializer;
// remove it from the vardecl
varDecl.Initializer = null;
// create an assignment operator for a lookup to the name
// as the left, and the initializer as the right, and add it to the list
var lookup = new Lookup(varDecl.VariableField.OriginalContext, varDecl.Parser)
{
Name = varDecl.Identifier,
VariableField = varDecl.VariableField,
};
assignments.Add(new BinaryOperator(varDecl.Context, varDecl.Parser)
{
Operand1 = lookup,
Operand2 = initializer,
OperatorToken = JSToken.Assign,
OperatorContext = varDecl.AssignContext
});
// add the new lookup to the field's references
varDecl.VariableField.References.Add(lookup);
}
}
}
// now if there were any initializers...
if (assignments.Count > 0)
{
// we want to create one big expression from all the assignments and replace the
// var statement with the assignment(s) expression. Start at position n=1 and create
// a binary operator of n-1 as the left, n as the right, and using a comma operator.
var expression = assignments[0];
for (var ndx = 1; ndx < assignments.Count; ++ndx)
{
expression = CommaOperator.CombineWithComma(null, expression.Parser, expression, assignments[ndx]);
}
// replace the var with the expression.
// we still have a pointer to the var, so we can insert it back into the proper
// place next.
varStatement.Parent.ReplaceChild(varStatement, expression);
}
else
{
// no initializers.
// if the parent is a for-in statement...
var forInParent = varStatement.Parent as ForIn;
if (forInParent != null)
{
// we want to replace the var statement with a lookup for the var
// there should be only one vardecl
var varDecl = varStatement[0];
var lookup = new Lookup(varDecl.VariableField.OriginalContext, varStatement.Parser)
{
Name = varDecl.Identifier,
VariableField = varDecl.VariableField
};
varStatement.Parent.ReplaceChild(varStatement, lookup);
varDecl.VariableField.References.Add(lookup);
}
else
{
// just remove the var statement altogether
varStatement.Parent.ReplaceChild(varStatement, null);
}
}
// if the statement at the insertion point is a var-statement already,
// then we just need to append our vardecls to it. Otherwise we'll insert our
// var statement at the right point
if (existingVar != null)
{
// append the varstatement we want to move to the existing var, which will
// transfer all the vardecls to it.
existingVar.Append(varStatement);
}
else
{
// move the var to the insert point, incrementing the position or next time
block.Insert(insertAt, varStatement);
}
}
}
}
return insertAt;
}
public void Visit(VariableDeclaration node)
{
Debug.Fail("shouldn't get here");
}
//---------------------------------------------------------------------------------------
// ParseIdentifierInitializer
//
// Does the real work of parsing a single variable declaration.
// inToken is JSToken.In whenever the potential expression that initialize a variable
// cannot contain an 'in', as in the for statement. inToken is JSToken.None otherwise
//---------------------------------------------------------------------------------------
private AstNode ParseIdentifierInitializer(JSToken inToken)
{
string variableName = null;
AstNode assignmentExpr = null;
RecoveryTokenException except = null;
GetNextToken();
if (JSToken.Identifier != m_currentToken.Token)
{
String identifier = JSKeyword.CanBeIdentifier(m_currentToken.Token);
if (null != identifier)
{
variableName = identifier;
}
else
{
// make up an identifier assume we're done with the var statement
if (JSScanner.IsValidIdentifier(m_currentToken.Code))
{
// it's probably just a keyword
ReportError(JSError.NoIdentifier, m_currentToken.Clone(), true);
variableName = m_currentToken.Code;
}
else
{
ReportError(JSError.NoIdentifier);
return null;
}
}
}
else
{
variableName = m_scanner.Identifier;
}
Context idContext = m_currentToken.Clone();
Context context = m_currentToken.Clone();
Context assignContext = null;
bool ccSpecialCase = false;
bool ccOn = false;
GetNextToken();
m_noSkipTokenSet.Add(NoSkipTokenSet.s_VariableDeclNoSkipTokenSet);
try
{
if (m_currentToken.Token == JSToken.ConditionalCommentStart)
{
ccSpecialCase = true;
GetNextToken();
if (m_currentToken.Token == JSToken.ConditionalCompilationOn)
{
GetNextToken();
if (m_currentToken.Token == JSToken.ConditionalCommentEnd)
{
// forget about it; just ignore the whole thing because it's empty
ccSpecialCase = false;
}
else
{
ccOn = true;
}
}
}
if (JSToken.Assign == m_currentToken.Token || JSToken.Equal == m_currentToken.Token)
{
assignContext = m_currentToken.Clone();
if (JSToken.Equal == m_currentToken.Token)
{
ReportError(JSError.NoEqual, true);
}
// move past the equals sign
GetNextToken();
if (m_currentToken.Token == JSToken.ConditionalCommentEnd)
{
// so we have var id/*@ =@*/ or var id//@=<EOL>
// we only support the equal sign inside conditional comments IF
// the initializer value is there as well.
ccSpecialCase = false;
m_currentToken.HandleError(JSError.ConditionalCompilationTooComplex);
GetNextToken();
}
try
{
assignmentExpr = ParseExpression(true, inToken);
}
catch (RecoveryTokenException exc)
{
assignmentExpr = exc._partiallyComputedNode;
throw;
}
finally
{
if (null != assignmentExpr)
{
context.UpdateWith(assignmentExpr.Context);
}
}
}
else if (ccSpecialCase)
{
// so we have "var id /*@" or "var id //@", but the next character is NOT an equal sign.
// we don't support this structure, either.
ccSpecialCase = false;
m_currentToken.HandleError(JSError.ConditionalCompilationTooComplex);
// skip to end of conditional comment
while (m_currentToken.Token != JSToken.EndOfFile && m_currentToken.Token != JSToken.ConditionalCommentEnd)
{
GetNextToken();
}
GetNextToken();
}
// if the current token is not an end-of-conditional-comment token now,
// then we're not in our special case scenario
if (m_currentToken.Token == JSToken.ConditionalCommentEnd)
{
GetNextToken();
}
else if (ccSpecialCase)
{
// we have "var id/*@=expr" but the next token is not the closing comment.
// we don't support this structure, either.
ccSpecialCase = false;
m_currentToken.HandleError(JSError.ConditionalCompilationTooComplex);
// the assignment expression was apparently wiothin the conditional compilation
// comment, but we're going to ignore it. So clear it out.
assignmentExpr = null;
// skip to end of conditional comment
while (m_currentToken.Token != JSToken.EndOfFile && m_currentToken.Token != JSToken.ConditionalCommentEnd)
{
GetNextToken();
}
GetNextToken();
}
}
catch (RecoveryTokenException exc)
{
// If the exception is in the vardecl no-skip set then we successfully
// recovered to the end of the declaration and can just return
// normally. Otherwise we re-throw after constructing the partial result.
if (IndexOfToken(NoSkipTokenSet.s_VariableDeclNoSkipTokenSet, exc) == -1)
except = exc;
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_VariableDeclNoSkipTokenSet);
}
VariableDeclaration result = new VariableDeclaration(context, this)
{
Identifier = variableName,
NameContext = idContext,
AssignContext = assignContext,
Initializer = assignmentExpr
};
result.IsCCSpecialCase = ccSpecialCase;
if (ccSpecialCase)
{
// by default, set the flag depending on whether we encountered a @cc_on statement.
// might be overridden by the node in analyze phase
result.UseCCOn = ccOn;
}
if (null != except)
{
except._partiallyComputedNode = result;
throw except;
}
return result;
}
public void Visit(VariableDeclaration node)
{
// not applicable; terminate
}
private static void ConvertAssignmentsToVarDecls(BinaryOperator binaryOp, List<VariableDeclaration> varDecls, JSParser parser)
{
// we've already checked that the tree only contains simple assignments separate by commas,
// but just in case we'll check for null anyway
if (binaryOp != null)
{
if (binaryOp.OperatorToken == JSToken.Assign)
{
// we've already cleared this as a simple lookup, but run the check just to be sure
Lookup lookup = binaryOp.Operand1 as Lookup;
if (lookup != null)
{
var varDecl = new VariableDeclaration(binaryOp.Context.Clone(), parser)
{
Identifier = lookup.Name,
NameContext = lookup.Context.Clone(),
AssignContext = binaryOp.OperatorContext,
Initializer = binaryOp.Operand2,
VariableField = lookup.VariableField
};
varDecl.VariableField.Declarations.Add(varDecl);
varDecls.Add(varDecl);
}
}
else if (binaryOp.OperatorToken == JSToken.Comma)
{
// recurse both operands
ConvertAssignmentsToVarDecls(binaryOp.Operand1 as BinaryOperator, varDecls, parser);
ConvertAssignmentsToVarDecls(binaryOp.Operand2 as BinaryOperator, varDecls, parser);
}
// shouldn't ever be anything but these two operators
}
}
public override void Visit(VariableDeclaration node)
{
if (node != null)
{
base.Visit(node);
// check the name of the variable for reserved words that aren't allowed
if (JSScanner.IsKeyword(node.Identifier, m_scopeStack.Peek().UseStrict))
{
node.Context.HandleError(JSError.KeywordUsedAsIdentifier, true);
}
else if (m_scopeStack.Peek().UseStrict
&& (string.CompareOrdinal(node.Identifier, "eval") == 0
|| string.CompareOrdinal(node.Identifier, "arguments") == 0))
{
// strict mode cannot declare variables named "eval" or "arguments"
node.NameContext.HandleError(JSError.StrictModeVariableName, true);
}
// if this is a special-case vardecl (var foo/*@cc_on=EXPR@*/), set the flag indicating
// we encountered a @cc_on statement if we found one
if (node.IsCCSpecialCase && m_parser.Settings.IsModificationAllowed(TreeModifications.RemoveUnnecessaryCCOnStatements))
{
node.UseCCOn = !m_encounteredCCOn;
m_encounteredCCOn = true;
}
}
}