//---------------------------------------------------------------------------------------
// ParseStatements
//
// statements :
// <empty> |
// statement statements
//
//---------------------------------------------------------------------------------------
private Block ParseStatements()
{
var program = new Block(CurrentPositionContext(), this);
m_blockType.Add(BlockType.Block);
m_useCurrentForNext = false;
try
{
// get the first token
GetNextToken();
// if the block doesn't have a proper file context, then let's set it from the
// first token -- that token might have had a ///#source directive!
if (string.IsNullOrEmpty(program.Context.Document.FileContext))
{
program.Context.Document.FileContext = m_currentToken.Document.FileContext;
}
m_noSkipTokenSet.Add(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
m_noSkipTokenSet.Add(NoSkipTokenSet.s_TopLevelNoSkipTokenSet);
try
{
var possibleDirectivePrologue = true;
int lastEndPosition = m_currentToken.EndPosition;
while (m_currentToken.Token != JSToken.EndOfFile)
{
AstNode ast = null;
try
{
// parse a statement -- pass true because we really want a SourceElement,
// which is a Statement OR a FunctionDeclaration. Technically, FunctionDeclarations
// are not statements!
ast = ParseStatement(true);
// if we are still possibly looking for directive prologues
if (possibleDirectivePrologue)
{
var constantWrapper = ast as ConstantWrapper;
if (constantWrapper != null && constantWrapper.PrimitiveType == PrimitiveType.String)
{
if (!(constantWrapper is DirectivePrologue))
{
// use a directive prologue node instead
ast = new DirectivePrologue(constantWrapper.Value.ToString(), ast.Context, ast.Parser)
{
MayHaveIssues = constantWrapper.MayHaveIssues
};
}
}
else if (!m_newModule)
{
// nope -- no longer finding directive prologues
possibleDirectivePrologue = false;
}
}
else if (m_newModule)
{
// we aren't looking for directive prologues anymore, but we did scan
// into a new module after that last AST, so reset the flag because that
// new module might have directive prologues for next time
possibleDirectivePrologue = true;
}
}
catch (RecoveryTokenException exc)
{
if (TokenInList(NoSkipTokenSet.s_TopLevelNoSkipTokenSet, exc)
|| TokenInList(NoSkipTokenSet.s_StartStatementNoSkipTokenSet, exc))
{
ast = exc._partiallyComputedNode;
GetNextToken();
}
else
{
m_useCurrentForNext = false;
do
{
GetNextToken();
} while (m_currentToken.Token != JSToken.EndOfFile && !TokenInList(NoSkipTokenSet.s_TopLevelNoSkipTokenSet, m_currentToken.Token)
&& !TokenInList(NoSkipTokenSet.s_StartStatementNoSkipTokenSet, m_currentToken.Token));
}
}
if (null != ast)
{
// append the token to the program
program.Append(ast);
// set the last end position to be the start of the current token.
// if we parse the next statement and the end is still the start, we know
// something is up and might get into an infinite loop.
lastEndPosition = m_currentToken.EndPosition;
}
else if (!m_scanner.IsEndOfFile && m_currentToken.StartLinePosition == lastEndPosition)
{
// didn't parse a statement, we're not at the EOF, and we didn't move
// anywhere in the input stream. If we just keep looping around, we're going
// to get into an infinite loop. Break it.
m_currentToken.HandleError(JSError.ApplicationError, true);
break;
}
}
if (m_importantComments.Count > 0
&& m_settings.PreserveImportantComments
&& m_settings.IsModificationAllowed(TreeModifications.PreserveImportantComments))
{
// we have important comments before the EOF. Add the comment(s) to the program.
foreach(var importantComment in m_importantComments)
{
program.Append(new ImportantComment(importantComment, this));
}
m_importantComments.Clear();
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_TopLevelNoSkipTokenSet);
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
}
}
catch (EndOfFileException)
{
}
catch (ScannerException se)
{
// a scanner exception implies that the end of file has been reached with an error.
// Mark the end of file as the error location
EOFError(se.Error);
}
program.UpdateWith(CurrentPositionContext());
return program;
}
/// <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;
}
