private Block BuildTryStatement(TryStatementSyntax tryStatement, Block currentBlock)
{
// successor - either finally of next block after try statement
var catchSuccessor = currentBlock;
var hasFinally = tryStatement.Finally?.Block != null;
if (hasFinally)
{
// Wire exit in case we have a return inside the try/catch block
catchSuccessor = BuildBlock(tryStatement.Finally.Block,
CreateBranchBlock(tryStatement.Finally, new[] { catchSuccessor, ExitTarget.Peek() }));
ExitTarget.Push(catchSuccessor);
}
var catchBlocks = tryStatement.Catches
.Reverse()
.Select(catchClause => BuildBlock(catchClause.Block, CreateBlock(catchSuccessor)))
.ToList();
// If there is a catch with no Exception filter or equivalent we don't want to
// join the tryStatement start/end blocks with the exit block because all
// exceptions will be caught before going to finally
var areAllExceptionsCaught = tryStatement.Catches.Any(SyntaxHelper.IsCatchingAllExceptions);
// try end
var tryEndStatementConnections = catchBlocks.ToList();
tryEndStatementConnections.Add(catchSuccessor); // happy path, no exceptions thrown
if (!areAllExceptionsCaught) // unexpected exception thrown, go to exit (through finally if present)
{
tryEndStatementConnections.Add(ExitTarget.Peek());
}
var tryBody = BuildBlock(tryStatement.Block,
CreateBranchBlock(tryStatement, tryEndStatementConnections.Distinct()));
var tryStartStatementConnections = catchBlocks.ToList();
tryStartStatementConnections.Add(tryBody); // try body
if (!areAllExceptionsCaught) // unexpected exception thrown, go to exit (through finally if present)
{
tryStartStatementConnections.Add(ExitTarget.Peek());
}
var tryStartBlock = CreateBranchBlock(tryStatement, tryStartStatementConnections.Distinct());
if (hasFinally)
{
ExitTarget.Pop();
}
return(tryStartBlock);
}
private Block BuildJumpToExitStatement(StatementSyntax statement, Block currentBlock, ExpressionSyntax expression = null)
{
return(BuildExpression(expression, CreateJumpBlock(statement, ExitTarget.Peek(), currentBlock)));
}
