public override void EmitGet(InstructionWriter writer, IStackFragment sigBlock, StackSignature sigType,
int sigIndex, bool keepSig)
{
Debug.Assert(_isVararg);
if (sigIndex > 255 || sigBlock.Offset > 255 | sigType.FixedSize > 127)
{
throw new NotImplementedException();
}
//Note that for VARG/VARGC, we are using a different version of R1-R3. See OpCodes doc for details.
Debug.Assert(_funcVarargSig.FixedSize == 0);
if (_funcVarargSig.IsCompatibleWith(sigType))
{
writer.WriteUUS(keepSig ? OpCodes.VARG : OpCodes.VARGC,
sigBlock.Offset, sigIndex, sigType.FixedSize);
}
else
{
writer.WriteUUS(keepSig ? OpCodes.VARG : OpCodes.VARGC,
sigBlock.Offset, sigIndex, -1);
}
}
public override void Emit(InstructionWriter writer)
{
Debug.Assert(_firstLoopVarStack.Offset == _hiddenVariableStack.Offset + 3);
_forBlock.EmitUpvalLists(writer);
var exitLabel = new LabelStatementSyntaxNode();
var loopLabel = new LabelStatementSyntaxNode();
//Insert assignment and FORG instruction (call iterator function and check for exit condition).
_assignment.Emit(writer);
writer.MarkLabel(loopLabel);
if (_hiddenVariableStack.Offset > 255 || _loopVarSig > 255 || _loopVarSigType.FixedSize > 127)
{
throw new NotImplementedException();
}
writer.WriteUSx(OpCodes.FORG, _hiddenVariableStack.Offset, 0);
writer.AddLabelFix(exitLabel, InstructionWriter.FixUSxJump);
//Adjust right parameter: assume EmptyV.
if (_loopVarSigType.IsCompatibleWith(StackSignature.EmptyV))
{
writer.WriteUUS(OpCodes.FORG_CTN,
_loopVarSig, (int)WellKnownStackSignature.EmptyV, _loopVarSigType.FixedSize);
}
else
{
writer.WriteUUS(OpCodes.FORG_CTN, _loopVarSig, 0, 0);
}
//Emit inner block.
_forBlock.EmitStatements(writer);
//Jump back.
writer.WriteUSx(OpCodes.JMP, 0, 0);
writer.AddLabelFix(loopLabel, InstructionWriter.FixUSxJump);
writer.MarkLabel(exitLabel);
}