private GenericExpressionNode BooleanTermPrime(string expression, GenericExpressionNode lhs)
{
if (lexer.IsNext(Token.TokenType.EndOfInput))
{
return(lhs);
}
else if (Same(expression, Token.TokenType.And))
{
GenericExpressionNode rhs = RelationalExpr(expression);
if (null == rhs)
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
OperatorExpressionNode andNode = new AndExpressionNode();
andNode.LeftChild = lhs;
andNode.RightChild = rhs;
return(BooleanTermPrime(expression, andNode));
}
else
{
// Should this be error case?
return(lhs);
}
}
//
// Main entry point for parser.
// You pass in the expression you want to parse, and you get an
// ExpressionTree out the back end.
//
internal GenericExpressionNode Parse(string expression, XmlAttribute conditionAttributeRef, ParserOptions optionSettings)
{
// We currently have no support (and no scenarios) for disallowing property references
// in Conditions.
ErrorUtilities.VerifyThrow(0 != (optionSettings & ParserOptions.AllowProperties),
"Properties should always be allowed.");
this.conditionAttribute = conditionAttributeRef;
this.options = optionSettings;
lexer = new Scanner(expression, options);
if (!lexer.Advance())
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, lexer.GetErrorResource(), expression, errorPosition, lexer.UnexpectedlyFound);
}
GenericExpressionNode node = Expr(expression);
if (!lexer.IsNext(Token.TokenType.EndOfInput))
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
return(node);
}
//
// Top node of grammar
// See grammar for how the following methods relate to each
// other.
//
private GenericExpressionNode Expr(string expression)
{
GenericExpressionNode node = BooleanTerm(expression);
if (!lexer.IsNext(Token.TokenType.EndOfInput))
{
node = ExprPrime(expression, node);
}
#region REMOVE_COMPAT_WARNING
// Check for potential change in behavior
if (LoggingServices != null && !warnedForExpression &&
node.PotentialAndOrConflict())
{
// We only want to warn once even if there multiple () sub expressions
warnedForExpression = true;
// Try to figure out where this expression was located
string projectFile = String.Empty;
int lineNumber = 0;
int columnNumber = 0;
if (this.conditionAttribute != null)
{
projectFile = XmlUtilities.GetXmlNodeFile(this.conditionAttribute, String.Empty /* no project file if XML is purely in-memory */);
XmlSearcher.GetLineColumnByNode(this.conditionAttribute, out lineNumber, out columnNumber);
}
// Log a warning regarding the fact the expression may have been evaluated
// incorrectly in earlier version of MSBuild
LoggingServices.LogWarning(logBuildEventContext, new BuildEventFileInfo(projectFile, lineNumber, columnNumber), "ConditionMaybeEvaluatedIncorrectly", expression);
}
#endregion
return(node);
}
/// <summary>
/// Expands properties and items in the argument, and verifies that the result is consistent
/// with a scalar parameter type.
/// </summary>
/// <param name="function">Function name for errors</param>
/// <param name="argumentNode">Argument to be expanded</param>
/// <returns>Scalar result</returns>
/// <owner>danmose</owner>
private string ExpandArgumentForScalarParameter(string function, GenericExpressionNode argumentNode, ConditionEvaluationState state)
{
string argument = argumentNode.GetUnexpandedValue(state);
List <TaskItem> items = state.expanderToUse.ExpandAllIntoTaskItems(argument, state.conditionAttribute);
string expandedValue = String.Empty;
if (items.Count == 0)
{
// Empty argument, that's fine.
}
else if (items.Count == 1)
{
expandedValue = items[0].ItemSpec;
}
else // too many items for the function
{
// We only allow a single item to be passed into a scalar parameter.
ProjectErrorUtilities.VerifyThrowInvalidProject(false,
state.conditionAttribute,
"CannotPassMultipleItemsIntoScalarFunction", function, argument,
state.expanderToUse.ExpandAllIntoString(argument, state.conditionAttribute));
}
return(expandedValue);
}
/// <summary>
/// Evaluates a string representing a condition from a "condition" attribute.
/// If the condition is a malformed string, it throws an InvalidProjectFileException.
/// This method uses cached expression trees to avoid generating them from scratch every time it's called.
/// This method is thread safe and is called from engine and task execution module threads
/// </summary>
/// <param name="condition">Can be null</param>
/// <param name="conditionAttribute">XML attribute on which the condition is evaluated</param>
/// <param name="expander">All the data available for expanding embedded properties, metadata, and items</param>
/// <param name="conditionedPropertiesTable">Can be null</param>
/// <param name="itemListOptions"></param>
/// <param name="loggingServices">Can be null</param>
/// <param name="buildEventContext"> contains contextual information for logging events</param>
/// <returns>true, if the expression evaluates to true, otherwise false</returns>
internal static bool EvaluateCondition
(
string condition,
XmlAttribute conditionAttribute,
Expander expander,
Hashtable conditionedPropertiesTable,
ParserOptions itemListOptions,
EngineLoggingServices loggingServices,
BuildEventContext buildEventContext
)
{
ErrorUtilities.VerifyThrow((conditionAttribute != null) || (string.IsNullOrEmpty(condition)),
"If condition is non-empty, you must provide the XML node representing the condition.");
// An empty condition is equivalent to a "true" condition.
if (string.IsNullOrEmpty(condition))
{
return(true);
}
Hashtable cachedExpressionTreesForCurrentOptions = cachedExpressionTrees[(int)itemListOptions];
// Try and see if we have an expression tree for this condition already
GenericExpressionNode parsedExpression = (GenericExpressionNode)cachedExpressionTreesForCurrentOptions[condition];
if (parsedExpression == null)
{
Parser conditionParser = new Parser();
#region REMOVE_COMPAT_WARNING
conditionParser.LoggingServices = loggingServices;
conditionParser.LogBuildEventContext = buildEventContext;
#endregion
parsedExpression = conditionParser.Parse(condition, conditionAttribute, itemListOptions);
// It's possible two threads will add a different tree to the same entry in the hashtable,
// but it should be rare and it's not a problem - the previous entry will be thrown away.
// We could ensure no dupes with double check locking but it's not really necessary here.
// Also, we don't want to lock on every read.
lock (cachedExpressionTreesForCurrentOptions)
{
cachedExpressionTreesForCurrentOptions[condition] = parsedExpression;
}
}
ConditionEvaluationState state = new ConditionEvaluationState(conditionAttribute, expander, conditionedPropertiesTable, condition);
bool result;
// We are evaluating this expression now and it can cache some state for the duration,
// so we don't want multiple threads working on the same expression
lock (parsedExpression)
{
result = parsedExpression.Evaluate(state);
parsedExpression.ResetState();
}
return(result);
}
private void Args(string expression, ArrayList arglist)
{
GenericExpressionNode arg = Arg(expression);
arglist.Add(arg);
if (Same(expression, Token.TokenType.Comma))
{
Args(expression, arglist);
}
}
private GenericExpressionNode BooleanTerm(string expression)
{
GenericExpressionNode node = RelationalExpr(expression);
if (null == node)
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
if (!lexer.IsNext(Token.TokenType.EndOfInput))
{
node = BooleanTermPrime(expression, node);
}
return(node);
}
private GenericExpressionNode RelationalExpr(string expression)
{
{
GenericExpressionNode lhs = Factor(expression);
if (null == lhs)
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
OperatorExpressionNode node = RelationalOperation(expression);
if (node == null)
{
return(lhs);
}
GenericExpressionNode rhs = Factor(expression);
node.LeftChild = lhs;
node.RightChild = rhs;
return(node);
}
}
private GenericExpressionNode ExprPrime(string expression, GenericExpressionNode lhs)
{
if (Same(expression, Token.TokenType.EndOfInput))
{
return(lhs);
}
else if (Same(expression, Token.TokenType.Or))
{
OperatorExpressionNode orNode = new OrExpressionNode();
GenericExpressionNode rhs = BooleanTerm(expression);
orNode.LeftChild = lhs;
orNode.RightChild = rhs;
return(ExprPrime(expression, orNode));
}
else
{
// I think this is ok. ExprPrime always shows up at
// the rightmost side of the grammar rhs, the EndOfInput case
// takes care of things
return(lhs);
}
}
private GenericExpressionNode Factor(string expression)
{
// Checks for TokenTypes String, Numeric, Property, ItemMetadata, and ItemList.
GenericExpressionNode arg = this.Arg(expression);
// If it's one of those, return it.
if (arg != null)
{
return(arg);
}
// If it's not one of those, check for other TokenTypes.
Token current = lexer.CurrentToken;
if (Same(expression, Token.TokenType.Function))
{
if (!Same(expression, Token.TokenType.LeftParenthesis))
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", lexer.IsNextString(), errorPosition);
return(null);
}
ArrayList arglist = new ArrayList();
Arglist(expression, arglist);
if (!Same(expression, Token.TokenType.RightParenthesis))
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
return(null);
}
return(new FunctionCallExpressionNode(current.String, arglist));
}
else if (Same(expression, Token.TokenType.LeftParenthesis))
{
GenericExpressionNode child = Expr(expression);
if (Same(expression, Token.TokenType.RightParenthesis))
{
return(child);
}
else
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
}
else if (Same(expression, Token.TokenType.Not))
{
OperatorExpressionNode notNode = new NotExpressionNode();
GenericExpressionNode expr = Factor(expression);
if (expr == null)
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
notNode.LeftChild = expr;
return(notNode);
}
else
{
errorPosition = lexer.GetErrorPosition();
ProjectErrorUtilities.VerifyThrowInvalidProject(false, this.conditionAttribute, "UnexpectedTokenInCondition", expression, lexer.IsNextString(), errorPosition);
}
return(null);
}