/// <summary>
/// Checks the given try statement to make sure that it is needed.
/// </summary>
/// <param name="tryStatement">
/// The try statement to check.
/// </param>
/// <returns>
/// Returns true if the try statement is not needed, false otherwise.
/// </returns>
private static bool IsUnnecessaryTryStatement(TryStatement tryStatement)
{
Param.AssertNotNull(tryStatement, "tryStatement");
// If the body of the try-statement is empty, it is not needed.
if (IsEmptyParentOfBlockStatement(tryStatement))
{
// If the try-statement contains a non-empty finally or a non-empty catch statement, then it is allowed to be empty.
// This is because an empty try-statement can be used to create a critical execution region and the finally or catch areas
// will run even in the case of a ThreadAbortException.
if (tryStatement.FinallyStatement != null && !IsEmptyParentOfBlockStatement(tryStatement.FinallyStatement))
{
return false;
}
if (tryStatement.CatchStatements != null && tryStatement.CatchStatements.Count > 0)
{
foreach (CatchStatement catchStatement in tryStatement.CatchStatements)
{
if (!IsEmptyParentOfBlockStatement(catchStatement))
{
return false;
}
}
}
return true;
}
else
{
// If the try-statement does not contain any catch statements or finally statements, it is not needed.
if (tryStatement.CatchStatements == null || tryStatement.CatchStatements.Count == 0)
{
if (tryStatement.FinallyStatement == null || IsEmptyParentOfBlockStatement(tryStatement.FinallyStatement))
{
return true;
}
}
}
return false;
}
/// <summary>
/// Looks for a catch-statement, and if it is found, parses and returns it.
/// </summary>
/// <param name="tryStatement">
/// The parent try statement.
/// </param>
/// <param name="parentReference">
/// The parent code unit.
/// </param>
/// <param name="unsafeCode">
/// Indicates whether the code being parsed resides in an unsafe code block.
/// </param>
/// <returns>
/// Returns the statement.
/// </returns>
private CatchStatement GetAttachedCatchStatement(TryStatement tryStatement, Reference<ICodePart> parentReference, bool unsafeCode)
{
Param.AssertNotNull(tryStatement, "tryStatement");
Param.AssertNotNull(parentReference, "parentReference");
Param.Ignore(unsafeCode);
CatchStatement catchStatement = null;
// Look for a catch keyword.
Symbol symbol = this.GetNextSymbol(parentReference);
if (symbol.SymbolType == SymbolType.Catch)
{
Reference<ICodePart> statementReference = new Reference<ICodePart>();
// Move up to the catch keyword and add it.
CsToken firstToken = this.GetToken(CsTokenType.Catch, SymbolType.Catch, statementReference);
Node<CsToken> firstTokenNode = this.tokens.InsertLast(firstToken);
Expression catchExpression = null;
// Get the opening parenthesis, if there is one.
symbol = this.GetNextSymbol(statementReference);
if (symbol.SymbolType == SymbolType.OpenParenthesis)
{
Bracket openParenthesis = this.GetBracketToken(CsTokenType.OpenParenthesis, SymbolType.OpenParenthesis, statementReference);
Node<CsToken> openParenthesisNode = this.tokens.InsertLast(openParenthesis);
// Get the type, if there is one.
symbol = this.GetNextSymbol(statementReference);
if (symbol.SymbolType == SymbolType.Other)
{
catchExpression = this.GetNextExpression(ExpressionPrecedence.None, statementReference, unsafeCode, true, true);
}
// Get the closing parenthesis.
Bracket closeParenthesis = this.GetBracketToken(CsTokenType.CloseParenthesis, SymbolType.CloseParenthesis, statementReference);
Node<CsToken> closeParenthesisNode = this.tokens.InsertLast(closeParenthesis);
openParenthesis.MatchingBracketNode = closeParenthesisNode;
closeParenthesis.MatchingBracketNode = openParenthesisNode;
}
// Get the embedded statement. This must be a block statement.
BlockStatement childStatement = this.GetNextStatement(statementReference, unsafeCode) as BlockStatement;
if (childStatement == null)
{
throw new SyntaxException(this.document.SourceCode, firstToken.LineNumber);
}
// Create the token list for the statement.
CsTokenList partialTokens = new CsTokenList(this.tokens, firstTokenNode, this.tokens.Last);
// Create the catch statement.
catchStatement = new CatchStatement(partialTokens, tryStatement, catchExpression, childStatement);
((IWriteableCodeUnit)catchStatement).SetParent(tryStatement);
statementReference.Target = catchStatement;
if (catchStatement.ClassType != null && catchStatement.Identifier != null)
{
// Add the variable.
Variable variable = new Variable(
catchStatement.ClassType,
catchStatement.Identifier.Text,
VariableModifiers.None,
CodeLocation.Join(catchStatement.ClassType.Location, catchStatement.Identifier.Location),
statementReference,
catchStatement.ClassType.Generated);
// If there is already a variable in this scope with the same name, ignore this one.
if (!catchStatement.Variables.Contains(catchStatement.Identifier.Text))
{
catchStatement.Variables.Add(variable);
}
}
}
return catchStatement;
}
/// <summary>
/// Looks for a finally-statement, and if it is found, parses and returns it.
/// </summary>
/// <param name="tryStatement">
/// The parent try statement.
/// </param>
/// <param name="parentReference">
/// The parent code unit.
/// </param>
/// <param name="unsafeCode">
/// Indicates whether the code being parsed resides in an unsafe code block.
/// </param>
/// <returns>
/// Returns the statement.
/// </returns>
private FinallyStatement GetAttachedFinallyStatement(TryStatement tryStatement, Reference<ICodePart> parentReference, bool unsafeCode)
{
Param.AssertNotNull(tryStatement, "tryStatement");
Param.AssertNotNull(parentReference, "parentReference");
Param.Ignore(unsafeCode);
FinallyStatement finallyStatement = null;
// Look for a finally keyword.
Symbol symbol = this.GetNextSymbol(parentReference);
if (symbol.SymbolType == SymbolType.Finally)
{
Reference<ICodePart> statementReference = new Reference<ICodePart>();
// Move up to the finally keyword and add it.
CsToken firstToken = this.GetToken(CsTokenType.Finally, SymbolType.Finally, statementReference);
Node<CsToken> firstTokenNode = this.tokens.InsertLast(firstToken);
// Get the embedded statement. This must be a block statement.
BlockStatement childStatement = this.GetNextStatement(statementReference, unsafeCode) as BlockStatement;
if (childStatement == null)
{
throw new SyntaxException(this.document.SourceCode, firstToken.LineNumber);
}
// Create the token list for the statement.
CsTokenList partialTokens = new CsTokenList(this.tokens, firstTokenNode, this.tokens.Last);
// Create and return the finally statement.
finallyStatement = new FinallyStatement(partialTokens, tryStatement, childStatement);
((IWriteableCodeUnit)finallyStatement).SetParent(tryStatement);
statementReference.Target = finallyStatement;
}
return finallyStatement;
}
/// <summary>
/// Reads the next try-statement from the file and returns it.
/// </summary>
/// <param name="parentReference">
/// The parent code unit.
/// </param>
/// <param name="unsafeCode">
/// Indicates whether the code being parsed resides in an unsafe code block.
/// </param>
/// <returns>
/// Returns the statement.
/// </returns>
private TryStatement ParseTryStatement(Reference<ICodePart> parentReference, bool unsafeCode)
{
Param.AssertNotNull(parentReference, "parentReference");
Param.Ignore(unsafeCode);
Reference<ICodePart> statementReference = new Reference<ICodePart>();
// Move past the try keyword.
CsToken firstToken = this.GetToken(CsTokenType.Try, SymbolType.Try, parentReference, statementReference);
Node<CsToken> firstTokenNode = this.tokens.InsertLast(firstToken);
// Get the embedded statement. It must be a block statement.
BlockStatement childStatement = this.GetNextStatement(statementReference, unsafeCode) as BlockStatement;
if (childStatement == null)
{
throw this.CreateSyntaxException();
}
// Create the try-statement now.
TryStatement statement = new TryStatement(childStatement);
// Get the attached catch statements, if any.
List<CatchStatement> catchStatements = new List<CatchStatement>();
while (true)
{
CatchStatement catchStatement = this.GetAttachedCatchStatement(statement, statementReference, unsafeCode);
if (catchStatement == null)
{
break;
}
catchStatements.Add(catchStatement);
}
// Get the attached finally statement, if any.
FinallyStatement finallyStatement = this.GetAttachedFinallyStatement(statement, statementReference, unsafeCode);
// Create the full token list for the try-statement and add it.
statement.Tokens = new CsTokenList(this.tokens, firstTokenNode, this.tokens.Last);
// Add the catch and finally statements to the try statement.
statement.CatchStatements = catchStatements.ToArray();
statement.FinallyStatement = finallyStatement;
// Return the statement.
statementReference.Target = statement;
return statement;
}
private void CheckStatementCurlyBracketPlacement(CsElement element, Statement statement)
{
Param.AssertNotNull(element, "element");
Param.AssertNotNull(statement, "statement");
switch (statement.StatementType)
{
case StatementType.Else:
// Check that there is nothing between the starting else keyword and the opening bracket.
this.CheckChainedStatementCurlyBracketPlacement(element, statement);
this.CheckBlockStatementsCurlyBracketPlacement(element, statement);
// Check that there is nothing between the closing bracket and the else keyword of the attached else statement.
ElseStatement elseStatement = (ElseStatement)statement;
if (elseStatement.AttachedElseStatement != null)
{
this.CheckTrailingStatementCurlyBracketPlacement(element, statement);
}
break;
case StatementType.Catch:
case StatementType.Finally:
// Check that there is nothing between the starting catch or finally keyword and the opening bracket.
this.CheckChainedStatementCurlyBracketPlacement(element, statement);
this.CheckBlockStatementsCurlyBracketPlacement(element, statement);
break;
case StatementType.If:
this.CheckBlockStatementsCurlyBracketPlacement(element, statement);
// Check that there is nothing between the closing bracket and the else keyword of the attached else statement.
IfStatement ifStatement = (IfStatement)statement;
if (ifStatement.AttachedElseStatement != null)
{
this.CheckTrailingStatementCurlyBracketPlacement(element, statement);
}
break;
case StatementType.Try:
// Check that there is nothing between the starting try keyword and the opening bracket.
this.CheckBlockStatementsCurlyBracketPlacement(element, statement);
TryStatement tryStatement = (TryStatement)statement;
if (tryStatement.FinallyStatement != null || (tryStatement.CatchStatements != null && tryStatement.CatchStatements.Count > 0))
{
// There is something attached to the end of this try statement. Check that there is nothing between
// the closing bracket of the try statement and the start of the attached statement.
this.CheckTrailingStatementCurlyBracketPlacement(element, tryStatement);
}
if (tryStatement.CatchStatements != null && tryStatement.CatchStatements.Count > 0)
{
CatchStatement[] catchStatementArray = new CatchStatement[tryStatement.CatchStatements.Count];
tryStatement.CatchStatements.CopyTo(catchStatementArray, 0);
for (int i = 0; i < catchStatementArray.Length; ++i)
{
if (catchStatementArray.Length > i + 1 || tryStatement.FinallyStatement != null)
{
// There is something attached to the end of this catch statement, either another catch or a finally.
// Check that there is nothing between the closing bracket of this catch statement and the start of the attached
// statement.
this.CheckTrailingStatementCurlyBracketPlacement(element, catchStatementArray[i]);
}
}
}
break;
case StatementType.Checked:
case StatementType.Fixed:
case StatementType.For:
case StatementType.Foreach:
case StatementType.Lock:
case StatementType.Switch:
case StatementType.Unchecked:
case StatementType.Unsafe:
case StatementType.Using:
case StatementType.While:
// Check that there is nothing between the starting keyword and the opening bracket.
this.CheckBlockStatementsCurlyBracketPlacement(element, statement);
break;
case StatementType.DoWhile:
this.CheckBlockStatementsCurlyBracketPlacement(element, statement);
this.CheckTrailingStatementCurlyBracketPlacement(element, statement);
break;
default:
break;
}
}
/// <summary>
/// The save.
/// </summary>
/// <param name="tryStatement">
/// The try statement.
/// </param>
private void Save(TryStatement tryStatement)
{
this.cppWriter.Write("try");
this.Save((Statement)tryStatement.EmbeddedStatement);
}
