private static int GetEndPosition(SyntaxNodeOrToken nodeOrToken)
{
if (nodeOrToken.IsToken)
{
return(nodeOrToken.Span.End);
}
else
{
return(nodeOrToken.AsNode().GetLastToken().Span.End);
}
}
internal SyntaxToken FindTokenInternal(int position)
{
// While maintaining invariant curNode.Position <= position < curNode.FullSpan.End
// go down the tree until a token is found
SyntaxNodeOrToken curNode = this;
while (true)
{
Debug.Assert(curNode.Kind() != SyntaxKind.None);
Debug.Assert(curNode.FullSpan.Contains(position));
var node = curNode.AsNode();
if (node != null)
{
//find a child that includes the position
curNode = node.ChildThatContainsPosition(position);
}
else
{
return(curNode.AsToken());
}
}
}
private BoundStatement RewriteForStatement(
CSharpSyntaxNode syntax,
ImmutableArray <LocalSymbol> outerLocals,
BoundStatement rewrittenInitializer,
ImmutableArray <LocalSymbol> innerLocals,
BoundExpression rewrittenCondition,
SyntaxNodeOrToken conditionSyntax,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(rewrittenBody != null);
// The sequence point behavior exhibited here is different from that of the native compiler. In the native
// compiler, if you have something like
//
// for(int i = 0, j = 0; ; i++, j++)
// ^--------------^ ^------^
//
// then all the initializers are treated as a single sequence point, as are
// all the loop incrementers.
//
// We now make each one individually a sequence point:
//
// for(int i = 0, j = 0; ; i++, j++)
// ^-------^ ^---^ ^-^ ^-^
//
// If we decide that we want to preserve the native compiler stepping behavior
// then we'll need to be a bit fancy here. The initializer and increment statements
// can contain lambdas whose bodies need to have sequence points inserted, so we
// need to make sure we visit the children. But we'll also need to make sure that
// we do not generate one sequence point for each statement in the initializers
// and the incrementers.
var statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
if (!innerLocals.IsDefaultOrEmpty)
{
var walker = new AnyLocalCapturedInALambdaWalker(innerLocals);
if (walker.Analyze(rewrittenCondition) || walker.Analyze(rewrittenIncrement) || walker.Analyze(rewrittenBody))
{
// If any inner local is captured within a lambda, we need to enter scope-block
// always from the top, that is where an instance of a display class will be created.
// The IL will be less optimal, but this shouldn't be a problem, given presence of lambdas.
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// start:
// {
// GotoIfFalse condition break;
// body;
// continue:
// increment;
// goto start;
// }
// break:
// }
// start:
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
var blockBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// GotoIfFalse condition break;
if (rewrittenCondition != null)
{
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
ifNotConditionGotoBreak = new BoundSequencePointWithSpan(syntax, ifNotConditionGotoBreak, conditionSyntax.Span);
}
else
{
ifNotConditionGotoBreak = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), ifNotConditionGotoBreak);
}
}
blockBuilder.Add(ifNotConditionGotoBreak);
}
// body;
blockBuilder.Add(rewrittenBody);
// continue:
// increment;
blockBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
blockBuilder.Add(rewrittenIncrement);
}
// goto start;
blockBuilder.Add(new BoundGotoStatement(syntax, startLabel));
statementBuilder.Add(new BoundBlock(syntax, innerLocals, blockBuilder.ToImmutableAndFree()));
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
return(new BoundBlock(syntax, outerLocals, statementBuilder.ToImmutableAndFree(), hasErrors));
}
}
var endLabel = new GeneratedLabelSymbol("end");
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// goto end;
// start:
// body;
// continue:
// increment;
// end:
// GotoIfTrue condition start;
// break:
// }
// initializer;
// goto end;
//mark the initial jump as hidden.
//We do it to tell that this is not a part of previous statement.
//This jump may be a target of another jump (for example if loops are nested) and that will make
//impression of the previous statement being re-executed
var gotoEnd = new BoundSequencePoint(null, new BoundGotoStatement(syntax, endLabel));
statementBuilder.Add(gotoEnd);
// start:
// body;
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
ArrayBuilder <BoundStatement> saveBuilder = null;
if (!innerLocals.IsDefaultOrEmpty)
{
saveBuilder = statementBuilder;
statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
}
statementBuilder.Add(rewrittenBody);
// continue:
// increment;
statementBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
statementBuilder.Add(rewrittenIncrement);
}
// end:
// GotoIfTrue condition start;
statementBuilder.Add(new BoundLabelStatement(syntax, endLabel));
BoundStatement branchBack = null;
if (rewrittenCondition != null)
{
branchBack = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
}
else
{
branchBack = new BoundGotoStatement(syntax, startLabel);
}
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
branchBack = new BoundSequencePointWithSpan(syntax, branchBack, conditionSyntax.Span);
}
else
{
//if there is no condition, make this a hidden point so that
//it does not count as a part of previous statement
branchBack = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), branchBack);
}
}
statementBuilder.Add(branchBack);
if (!innerLocals.IsDefaultOrEmpty)
{
var block = new BoundBlock(syntax, innerLocals, statementBuilder.ToImmutableAndFree());
statementBuilder = saveBuilder;
statementBuilder.Add(block);
}
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return(new BoundBlock(syntax, outerLocals, statements, hasErrors));
}
private BoundStatement RewriteForStatement(
CSharpSyntaxNode syntax,
ImmutableArray <LocalSymbol> locals,
BoundStatement rewrittenInitializer,
BoundExpression rewrittenCondition,
SyntaxNodeOrToken conditionSyntax,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
// The sequence point behavior exhibited here is different from that of the native compiler. In the native
// compiler, if you have something like
//
// for(int i = 0, j = 0; ; i++, j++)
// ^--------------^ ^------^
//
// then all the initializers are treated as a single sequence point, as are
// all the loop incrementers.
//
// We now make each one individually a sequence point:
//
// for(int i = 0, j = 0; ; i++, j++)
// ^-------^ ^---^ ^-^ ^-^
//
// If we decide that we want to preserve the native compiler stepping behavior
// then we'll need to be a bit fancy here. The initializer and increment statements
// can contain lambdas whose bodies need to have sequence points inserted, so we
// need to make sure we visit the children. But we'll also need to make sure that
// we do not generate one sequence point for each statement in the initializers
// and the incrementers.
var startLabel = new GeneratedLabelSymbol("start");
var endLabel = new GeneratedLabelSymbol("end");
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// goto end;
// start:
// body;
// continue:
// increment;
// end:
// GotoIfTrue condition start;
// break:
// }
// initializer;
// goto end;
var statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
//mark the initial jump as hidden.
//We do it to tell that this is not a part of previous statement.
//This jump may be a target of another jump (for example if loops are nested) and that will make
//impression of the previous statement being re-executed
var gotoEnd = new BoundSequencePoint(null, new BoundGotoStatement(syntax, endLabel));
statementBuilder.Add(gotoEnd);
// start:
// body;
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
Debug.Assert(rewrittenBody != null);
statementBuilder.Add(rewrittenBody);
// continue:
// increment;
statementBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
statementBuilder.Add(rewrittenIncrement);
}
// end:
// GotoIfTrue condition start;
statementBuilder.Add(new BoundLabelStatement(syntax, endLabel));
BoundStatement branchBack = null;
if (rewrittenCondition != null)
{
branchBack = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
}
else
{
branchBack = new BoundGotoStatement(syntax, startLabel);
}
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
branchBack = new BoundSequencePointWithSpan(syntax, branchBack, conditionSyntax.Span);
}
else
{
//if there is no condition, make this a hidden point so that
//it does not count as a part of previous statement
branchBack = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), branchBack);
}
}
statementBuilder.Add(branchBack);
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return(new BoundBlock(syntax, locals, statements, hasErrors));
}
