private Expression GenerateWhileLoop(string loopLabel,
Func<Expression> generateCondition,
Action<List<Expression>, LabelTarget, LabelTarget> generateLoopBody,
PipelineBaseAst continueAst = null)
{
// If continueAst is not null, generate:
// LoopTop:
// if (condition)
// {
// try {
// loop body
// // break -> goto BreakTarget
// // continue -> goto ContinueTarget
// } catch (BreakException be) {
// if (be.MatchLabel(loopLabel)) goto BreakTarget;
// throw;
// } catch (ContinueException ce) {
// if (ce.MatchLabel(loopLabel)) goto ContinueTarget;
// throw;
// }
// ContinueTarget:
// continueAction
// goto LoopTop:
// }
// :BreakTarget
//
// If continueAst is null, generate:
// ContinueTarget:
// if (condition)
// {
// try {
// loop body
// // break -> goto BreakTarget
// // continue -> goto ContinueTarget
// goto ContinueTarget
// } catch (BreakException be) {
// if (be.MatchLabel(loopLabel)) goto BreakTarget;
// throw;
// } catch (ContinueException ce) {
// if (ce.MatchLabel(loopLabel)) goto ContinueTarget;
// throw;
// }
// }
// :BreakTarget
int preStmtCount = _stmtCount;
var exprs = new List<Expression>();
var continueLabel = Expression.Label(!string.IsNullOrEmpty(loopLabel) ? loopLabel + "Continue" : "continue");
var breakLabel = Expression.Label(!string.IsNullOrEmpty(loopLabel) ? loopLabel + "Break" : "break");
var enterLoop = new EnterLoopExpression();
var loopTop = (continueAst != null)
? Expression.Label(!string.IsNullOrEmpty(loopLabel) ? loopLabel + "LoopTop" : "looptop")
: continueLabel;
exprs.Add(Expression.Label(loopTop));
exprs.Add(enterLoop);
var loopBodyExprs = new List<Expression>();
loopBodyExprs.Add(s_callCheckForInterrupts);
_loopTargets.Add(new LoopGotoTargets(loopLabel ?? "", breakLabel, continueLabel));
_generatingWhileOrDoLoop = true;
generateLoopBody(loopBodyExprs, breakLabel, continueLabel);
_generatingWhileOrDoLoop = false;
if (continueAst == null)
{
loopBodyExprs.Add(Expression.Goto(loopTop));
}
_loopTargets.RemoveAt(_loopTargets.Count - 1);
Expression loopBody =
Expression.TryCatch(Expression.Block(loopBodyExprs),
GenerateLoopBreakContinueCatchBlocks(loopLabel, breakLabel, continueLabel));
if (continueAst != null)
{
var x = new List<Expression>();
x.Add(loopBody);
x.Add(Expression.Label(continueLabel));
if (continueAst.GetPureExpression() != null)
{
// Assignments generate the code to update the position automatically,
// but pre/post increments don't, so we add it here explicitly.
x.Add(UpdatePosition(continueAst));
}
// We should not preserve the partial output if exception is thrown when evaluating the continueAst.
x.Add(CaptureStatementResults(continueAst, CaptureAstContext.AssignmentWithoutResultPreservation));
x.Add(Expression.Goto(loopTop));
loopBody = Expression.Block(x);
}
if (generateCondition != null)
{
exprs.Add(Expression.IfThen(generateCondition().Convert(typeof(bool)), loopBody));
}
else
{
exprs.Add(loopBody);
}
exprs.Add(Expression.Label(breakLabel));
enterLoop.LoopStatementCount = _stmtCount - preStmtCount;
return (enterLoop.Loop = new PowerShellLoopExpression(exprs));
}
private Expression GenerateWhileLoop(string loopLabel, Func<Expression> generateCondition, Action<List<Expression>, LabelTarget, LabelTarget> generateLoopBody, PipelineBaseAst continueAst = null)
{
string str;
string str1;
string str2;
LabelTarget labelTarget;
int num = this._stmtCount;
List<Expression> expressions = new List<Expression>();
if (!string.IsNullOrEmpty(loopLabel))
{
str = string.Concat(loopLabel, "Continue");
}
else
{
str = "continue";
}
LabelTarget labelTarget1 = Expression.Label(str);
if (!string.IsNullOrEmpty(loopLabel))
{
str1 = string.Concat(loopLabel, "Break");
}
else
{
str1 = "break";
}
LabelTarget labelTarget2 = Expression.Label(str1);
EnterLoopExpression enterLoopExpression = new EnterLoopExpression();
if (continueAst != null)
{
if (!string.IsNullOrEmpty(loopLabel))
{
str2 = string.Concat(loopLabel, "LoopTop");
}
else
{
str2 = "looptop";
}
labelTarget = Expression.Label(str2);
}
else
{
labelTarget = labelTarget1;
}
LabelTarget labelTarget3 = labelTarget;
expressions.Add(Expression.Label(labelTarget3));
expressions.Add(enterLoopExpression);
List<Expression> expressions1 = new List<Expression>();
expressions1.Add(Compiler._callCheckForInterrupts);
List<Compiler.LoopGotoTargets> loopGotoTargets = this._loopTargets;
string str3 = loopLabel;
string str4 = str3;
if (str3 == null)
{
str4 = "";
}
loopGotoTargets.Add(new Compiler.LoopGotoTargets(str4, labelTarget2, labelTarget1));
generateLoopBody(expressions1, labelTarget2, labelTarget1);
if (continueAst == null)
{
expressions1.Add(Expression.Goto(labelTarget3));
}
this._loopTargets.RemoveAt(this._loopTargets.Count - 1);
Expression expression = Expression.TryCatch(Expression.Block(expressions1), Compiler.GenerateLoopBreakContinueCatchBlocks(loopLabel, labelTarget2, labelTarget1));
if (continueAst != null)
{
List<Expression> expressions2 = new List<Expression>();
expressions2.Add(expression);
expressions2.Add(Expression.Label(labelTarget1));
if (continueAst.GetPureExpression() != null)
{
expressions2.Add(this.UpdatePosition(continueAst));
}
expressions2.Add(this.CaptureStatementResults(continueAst, Compiler.CaptureAstContext.Assignment, null));
expressions2.Add(Expression.Goto(labelTarget3));
expression = Expression.Block(expressions2);
}
if (generateCondition == null)
{
expressions.Add(expression);
}
else
{
expressions.Add(Expression.IfThen(generateCondition().Convert(typeof(bool)), expression));
}
expressions.Add(Expression.Label(labelTarget2));
enterLoopExpression.LoopStatementCount = this._stmtCount - num;
PowerShellLoopExpression powerShellLoopExpression = new PowerShellLoopExpression(expressions);
PowerShellLoopExpression powerShellLoopExpression1 = powerShellLoopExpression;
enterLoopExpression.Loop = powerShellLoopExpression;
return powerShellLoopExpression1;
}