public void VisitNode(JSWhileLoop wl)
{
SynthesizeLoopLabel(wl);
Formatter.ConditionalNewLine();
Formatter.NewLine();
Comment("while ({0})", wl.Condition);
EmitLabelledBlock(
IndexToLabel(wl.Index),
(__) =>
__.WriteSExpr(
"loop",
(_) => {
var synthetic = new JSIfStatement(
wl.Condition,
new JSNullStatement(),
new JSExpressionStatement(new JSBreakExpression {
TargetLoop = wl.Index
})
);
Visit(synthetic);
_.ConditionalNewLine();
_.NewLine();
Comment("while (...) {{ ");
EmitBlockInterior(wl.Statements);
},
true, true
)
);
}
public void VisitNode(JSWhileLoop wl)
{
CheckLabel(wl);
BlockStack.Push(new EnclosingBlockEntry {
Block = wl,
ParentNode = ParentNode,
Depth = BlockStack.Count
});
try {
VisitChildren(wl);
} finally {
BlockStack.Pop();
}
}
public void VisitNode(JSWhileLoop wl)
{
// Extract the last non-block statement from the body of the while loop
var lastChild = wl.Children.LastOrDefault();
while (lastChild is JSBlockStatement)
{
var bs = lastChild as JSBlockStatement;
if (bs.IsControlFlow)
{
break;
}
else
{
lastChild = bs.Statements.LastOrDefault();
}
}
// Is it a continue expression?
var lastES = lastChild as JSExpressionStatement;
if (lastES != null)
{
var lastContinue = lastES.Expression as JSContinueExpression;
if (
(lastContinue != null) &&
(lastContinue.TargetLoop == wl.Index)
)
{
// Spurious continue, so murder it
wl.ReplaceChildRecursive(lastContinue, new JSNullExpression());
if (TraceLevel >= 1)
{
Console.WriteLine("// Pruning spurious continue expression {0}", lastContinue);
}
MadeChanges = true;
}
}
LoopIndexStack.Push(wl.Index.GetValueOrDefault(-1));
VisitChildren(wl);
LoopIndexStack.Pop();
}
public void VisitNode(JSWhileLoop loop)
{
Output.NewLine();
BlockStack.Push(BlockType.While);
WriteLoopLabel(loop);
Output.WriteRaw("while");
Output.Space();
Output.LPar();
Visit(loop.Condition);
Output.RPar();
Output.Space();
VisitNode((JSBlockStatement)loop, true);
BlockStack.Pop();
}
public void VisitNode(JSWhileLoop whileLoop)
{
JSVariable initVariable = null, lastVariable = null;
JSBinaryOperator initOperator = null;
JSExpression initValue = null;
var prevEStmt = PreviousSibling as JSExpressionStatement;
var prevVDS = PreviousSibling as JSVariableDeclarationStatement;
if (prevEStmt != null)
{
var boe = prevEStmt.Expression as JSBinaryOperatorExpression;
if (
(boe != null) &&
(boe.Operator is JSAssignmentOperator) &&
(boe.Left is JSVariable)
)
{
initVariable = (JSVariable)boe.Left;
initOperator = boe.Operator;
initValue = boe.Right;
}
}
else if (prevVDS != null)
{
var decl = prevVDS.Declarations.FirstOrDefault(
(d) => !d.IsNull
);
if (decl != null)
{
initVariable = (JSVariable)decl.Left;
initOperator = decl.Operator;
initValue = decl.Right;
}
}
var lastStatement = whileLoop.Statements.LastOrDefault();
while ((lastStatement != null) && (lastStatement.GetType() == typeof(JSBlockStatement)))
{
lastStatement = ((JSBlockStatement)lastStatement).Statements.LastOrDefault();
}
var lastExpressionStatement = lastStatement as JSExpressionStatement;
if (lastExpressionStatement != null)
{
var lastUoe = lastExpressionStatement.Expression as JSUnaryOperatorExpression;
var lastBoe = lastExpressionStatement.Expression as JSBinaryOperatorExpression;
if ((lastUoe != null) && (lastUoe.Operator is JSUnaryMutationOperator))
{
lastVariable = lastUoe.Expression as JSVariable;
}
else if ((lastBoe != null) && (lastBoe.Operator is JSAssignmentOperator))
{
lastVariable = lastBoe.Left as JSVariable;
if (
(lastVariable != null) &&
!lastBoe.Right.SelfAndChildrenRecursive.Any(
(n) => lastVariable.Equals(n)
)
)
{
lastVariable = null;
}
}
}
var lastIfStatement = lastStatement as JSIfStatement;
if (
(lastIfStatement != null) &&
whileLoop.Condition is JSBooleanLiteral &&
((JSBooleanLiteral)whileLoop.Condition).Value
)
{
var innerStatement = lastIfStatement.TrueClause;
while (innerStatement is JSBlockStatement)
{
var bs = (JSBlockStatement)innerStatement;
if (bs.Statements.Count != 1)
{
innerStatement = null;
break;
}
innerStatement = bs.Statements[0];
}
var eStmt = innerStatement as JSExpressionStatement;
if (eStmt != null)
{
var breakExpr = eStmt.Expression as JSBreakExpression;
if ((breakExpr != null) && (breakExpr.TargetLoop == whileLoop.Index))
{
whileLoop.ReplaceChildRecursive(lastIfStatement, new JSNullStatement());
var doLoop = new JSDoLoop(
new JSUnaryOperatorExpression(JSOperator.LogicalNot, lastIfStatement.Condition, TypeSystem.Boolean),
whileLoop.Statements.ToArray()
);
doLoop.Index = whileLoop.Index;
ParentNode.ReplaceChild(whileLoop, doLoop);
VisitChildren(doLoop);
return;
}
}
}
bool cantBeFor = false;
if ((initVariable != null) && (lastVariable != null) &&
!initVariable.Equals(lastVariable)
)
{
cantBeFor = true;
}
else if ((initVariable ?? lastVariable) == null)
{
cantBeFor = true;
}
else if (!whileLoop.Condition.SelfAndChildrenRecursive.Any(
(n) => (initVariable ?? lastVariable).Equals(n)
))
{
cantBeFor = true;
}
else if (
!PostSwitchTransform && (
(lastStatement is JSSwitchStatement) ||
(lastStatement is JSLabelGroupStatement)
)
)
{
cantBeFor = true;
}
if (!cantBeFor)
{
JSStatement initializer = null, increment = null;
if (initVariable != null)
{
initializer = PreviousSibling as JSStatement;
ParentNode.ReplaceChild(PreviousSibling, new JSNullStatement());
}
if (lastVariable != null)
{
increment = lastExpressionStatement;
whileLoop.ReplaceChildRecursive(lastExpressionStatement, new JSNullStatement());
}
var forLoop = new JSForLoop(
initializer, whileLoop.Condition, increment,
whileLoop.Statements.ToArray()
);
forLoop.Index = whileLoop.Index;
ParentNode.ReplaceChild(whileLoop, forLoop);
VisitChildren(forLoop);
}
else
{
VisitChildren(whileLoop);
}
}
public void VisitNode(JSWhileLoop wl)
{
var condInvocation = wl.Condition as JSInvocationExpression;
JSVariable enumeratorVariable;
if (
(condInvocation != null) &&
(condInvocation.JSMethod != null) &&
(condInvocation.JSMethod.Identifier == "MoveNext") &&
(condInvocation.JSMethod.Method.DeclaringType.Interfaces.Any((ii) => ii.Item1.FullName == "System.Collections.IEnumerator")) &&
((enumeratorVariable = condInvocation.ThisReference as JSVariable) != null)
)
{
var enumeratorType = condInvocation.JSMethod.Method.DeclaringType;
while (EnableEnumeratorRemoval)
{
var enumeratorAssignmentBeforeLoop = (
from boe in SeenAssignments
let boeLeftVar = (boe.Left as JSVariable)
where (boeLeftVar != null) && (boeLeftVar.Name == enumeratorVariable.Name)
select boe
).LastOrDefault();
if (enumeratorAssignmentBeforeLoop == null)
{
break;
}
var enumeratorValue = enumeratorAssignmentBeforeLoop.Right;
var assignmentInvocation = enumeratorValue as JSInvocationExpression;
if (assignmentInvocation == null)
{
var rre = enumeratorValue as JSResultReferenceExpression;
if (rre != null)
{
assignmentInvocation = rre.Referent as JSInvocationExpression;
}
}
if (assignmentInvocation == null)
{
break;
}
var jsm = assignmentInvocation.JSMethod;
if (jsm == null)
{
break;
}
var attrParams2 = jsm.Method.Metadata.GetAttributeParameters("JSIL.Meta.JSUnderlyingArray");
if (attrParams2 != null)
{
var arrayMember = (string)attrParams2[0].Value;
var lengthMember = (string)attrParams2[1].Value;
var replacement = ReplaceWhileLoopAndEnumerator(
wl, assignmentInvocation.ThisReference,
condInvocation.ThisReference, condInvocation.JSMethod.Method.DeclaringType,
arrayMember, lengthMember
);
ParentNode.ReplaceChild(wl, replacement);
EnumeratorsToKill.Add(enumeratorVariable);
VisitReplacement(replacement);
return;
}
break;
}
var attrParams = enumeratorType.Metadata.GetAttributeParameters("JSIL.Meta.JSIsArrayEnumerator");
if (attrParams != null)
{
var arrayMember = (string)attrParams[0].Value;
var indexMember = (string)attrParams[1].Value;
var lengthMember = (string)attrParams[2].Value;
var replacement = ReplaceWhileLoop(
wl, condInvocation.ThisReference, condInvocation.JSMethod.Method.DeclaringType,
arrayMember, indexMember, lengthMember
);
ParentNode.ReplaceChild(wl, replacement);
VisitReplacement(replacement);
return;
}
}
VisitChildren(wl);
}
private JSForLoop ReplaceWhileLoopAndEnumerator(JSWhileLoop wl, JSExpression backingStore, JSExpression enumerator, TypeInfo enumeratorType, string arrayMember, string lengthMember)
{
var loopId = _NextLoopId++;
var arrayVariableName = String.Format("a${0:x}", loopId);
var indexVariableName = String.Format("i${0:x}", loopId);
var lengthVariableName = String.Format("l${0:x}", loopId);
var currentPropertyReference = enumeratorType.Definition.Properties.First((p) => p.Name == "Current");
var currentPropertyInfo = enumeratorType.Source.GetProperty(currentPropertyReference);
var itemType = currentPropertyInfo.ReturnType;
var arrayType = new ArrayType(itemType);
var arrayVariable = new JSVariable(
arrayVariableName, arrayType, Function.Method.Reference,
JSDotExpression.New(backingStore, new JSStringIdentifier(arrayMember, arrayType))
);
var indexVariable = new JSVariable(
indexVariableName, TypeSystem.Int32, Function.Method.Reference,
JSLiteral.New(0)
);
var lengthVariable = new JSVariable(
lengthVariableName, TypeSystem.Int32, Function.Method.Reference,
JSDotExpression.New(backingStore, new JSStringIdentifier(lengthMember, TypeSystem.Int32))
);
var initializer = new JSVariableDeclarationStatement(
new JSBinaryOperatorExpression(
JSOperator.Assignment, arrayVariable, arrayVariable.DefaultValue, arrayVariable.IdentifierType
),
new JSBinaryOperatorExpression(
JSOperator.Assignment, indexVariable, indexVariable.DefaultValue, indexVariable.IdentifierType
),
new JSBinaryOperatorExpression(
JSOperator.Assignment, lengthVariable, lengthVariable.DefaultValue, lengthVariable.IdentifierType
)
);
var condition = new JSBinaryOperatorExpression(
JSOperator.LessThan,
indexVariable, lengthVariable, TypeSystem.Boolean
);
var increment = new JSUnaryOperatorExpression(
JSOperator.PostIncrement,
indexVariable, TypeSystem.Int32
);
var result = new JSForLoop(
initializer, condition, new JSExpressionStatement(increment),
wl.Statements.ToArray()
);
result.Index = wl.Index;
new PropertyAccessReplacer(
enumerator, new JSProperty(currentPropertyReference, currentPropertyInfo),
new JSIndexerExpression(
arrayVariable, indexVariable,
itemType
)
).Visit(result);
return(result);
}