private ILCount EstimateLoop(IBlockContext context, IForInSource source)
{
IBlockContext prepContext = context.CloneCountingContext();
sourceExpression.EmitCode(prepContext, false);
source.EmitInitialize(prepContext);
IBlockContext countingContext = prepContext.CloneCountingContext()
.CreateLoopContext(context.IL.DefineLabel(false), context.IL.DefineLabel(false));
IBlockVariable loopVariable = countingContext.DeclaredVariable(variableName, true, source.ElementType);
LabelRef loop = countingContext.IL.DefineLabel(false);
source.EmitNext(countingContext);
loopVariable.EmitStore(countingContext);
loopExpression.EmitCode(countingContext, true);
source.EmitCheckDone(countingContext, loop);
return(new ILCount {
opCodes = countingContext.IL.ILSize,
stack = countingContext.IL.StackCount
});
}
public override void EmitCode(IBlockContext context, bool dropResult)
{
RealizedType sourceType = sourceExpression.ResultType(context).UnderlyingType(context.ModuleContext);
IForInSource source = sourceType.ForInSource(context.ModuleContext, null);
if (source == null)
{
context.AddError(
new StructuralError(
StructuralError.ErrorType.InvalidType,
$"{sourceType} cannot be use as for ... in source",
Start,
End
)
);
}
foreach (DeclarationParameter declaration in declarations)
{
if (context.FindVariable(declaration.target) != null)
{
context.AddError(new StructuralError(
StructuralError.ErrorType.DuplicateVariableName,
$"Variable '{declaration.target}' already declared in this scope",
Start,
End
));
}
}
if (context.HasErrors)
{
return;
}
switch (source !.ElementType)
{
public override void EmitCode(IBlockContext context, bool dropResult)
{
RealizedType sourceType = sourceExpression.ResultType(context).UnderlyingType(context.ModuleContext);
IForInSource source = sourceType.ForInSource(context.ModuleContext, variableType);
if (source == null)
{
context.AddError(
new StructuralError(
StructuralError.ErrorType.InvalidType,
$"{sourceType} cannot be use as for ... in source",
Start,
End
)
);
}
if (context.FindVariable(variableName) != null)
{
context.AddError(new StructuralError(
StructuralError.ErrorType.DuplicateVariableName,
$"Variable '{variableName}' already declared in this scope",
Start,
End
));
}
if (source != null && variableType != null &&
!variableType.IsAssignableFrom(context.ModuleContext, source.ElementType))
{
context.AddError(
new StructuralError(
StructuralError.ErrorType.InvalidType,
$"{sourceType} has elements of type {source.ElementType}, expected {variableType}",
Start,
End
)
);
}
if (context.HasErrors)
{
return;
}
using ITempLocalRef loopCounter = context.IL.TempLocal(typeof(int));
ILCount loopSize = EstimateLoop(context, source);
LabelRef start = context.IL.DefineLabel(loopSize.opCodes < 110);
LabelRef end = context.IL.DefineLabel(loopSize.opCodes < 110);
LabelRef loop = context.IL.DefineLabel(loopSize.opCodes < 100);
IBlockContext loopContext = context.CreateLoopContext(start, end);
IBlockVariable loopVariable = loopContext.DeclaredVariable(variableName, true, source !.ElementType);
sourceExpression.EmitCode(context, false);
if (context.HasErrors)
{
return;
}
source.EmitInitialize(loopContext);
loopContext.IL.Emit(start.isShort ? OpCodes.Br_S : OpCodes.Br, start);
loopContext.IL.MarkLabel(loop);
// Timeout check
LabelRef skipCheck = context.IL.DefineLabel(true);
loopCounter.EmitLoad(loopContext);
loopContext.IL.Emit(OpCodes.Ldc_I4_1);
loopContext.IL.Emit(OpCodes.Add);
loopContext.IL.Emit(OpCodes.Dup);
loopCounter.EmitStore(loopContext);
loopContext.IL.Emit(OpCodes.Ldc_I4, 10000);
loopContext.IL.Emit(OpCodes.Cgt);
loopContext.IL.Emit(OpCodes.Brfalse, skipCheck);
loopContext.IL.Emit(OpCodes.Ldc_I4_0);
loopCounter.EmitStore(loopContext);
context.IL.EmitCall(OpCodes.Call, typeof(Runtime.ContextHolder).GetMethod("CheckTimeout"), 0);
loopContext.IL.MarkLabel(skipCheck);
source.EmitNext(loopContext);
loopVariable.EmitStore(loopContext);
loopExpression.EmitCode(loopContext, true);
loopContext.IL.MarkLabel(start);
source.EmitCheckDone(loopContext, loop);
loopContext.IL.MarkLabel(end);
if (!dropResult)
{
context.IL.Emit(OpCodes.Ldnull);
}
}
