bool LookaheadArray(ref ILReader reader)
{
var fork = reader.Clone();
if (fork.TryGetCall(nameof(Array.Empty)) != null &&
fork.TryGetCall(nameof(Expression.Lambda)) != null &&
fork.TryGetCall("Expression") != null &&
fork.TryGet(OpCodes.Ret) != null)
{
reader.Position = fork.Position;
return(true);
}
return(false);
}
bool LookaheadExpressionThisConstant(ref ILReader reader, TypeReference thisType)
{
var fork = reader.Clone();
if (//Expression.Constant(typeof(ThisType), this)
fork.TryGet(OpCodes.Ldarg, 0) != null &&
fork.TryGet(OpCodes.Ldtoken) is Instruction ldTok && ldTok.Operand.Equals(thisType) &
fork.TryGetCall(nameof(Type.GetTypeFromHandle)) != null &&
fork.TryGetCall(nameof(Expression.Constant)) != null)
{
reader.Position = fork.Position;
return(true);
}
return(false);
}
bool LookaheadClosureAssignment(bool isDup, ref ILReader reader, out ParameterReference parameterReference, out FieldReference fieldReference)
{
fieldReference = null;
parameterReference = null;
var fork = reader.Clone();
if ((isDup || fork.TryGet(OpCodes.Ldloc, 0) != null) &&
fork.TryGet(OpCodes.Ldarg) is Instruction ldarg &&
fork.TryGet(OpCodes.Stfld) is Instruction stfld)
{
parameterReference = (ParameterReference)ldarg.Operand;
fieldReference = (FieldReference)stfld.Operand;
reader.Position = fork.Position;
return(true);
}
return(false);
}
bool LookaheadExpressionFieldConstant(bool isDup, ref ILReader reader, out MetadataToken?fieldToken)
{
fieldToken = null;
var fork = reader.Clone();
if (//Expression.Constant(typeof(<>__DisplayClass>), c)
(isDup || fork.TryGet(OpCodes.Ldloc, 0) != null) &&
fork.TryGet(OpCodes.Ldtoken) != null &&
fork.TryGetCall(nameof(Type.GetTypeFromHandle)) != null &&
fork.TryGetCall(nameof(Expression.Constant)) != null &&
//Expression.Field( , fieldof(c.a));
fork.TryGet(OpCodes.Ldtoken) is Instruction ldtoken &&
fork.TryGetCall(nameof(System.Reflection.FieldInfo.GetFieldFromHandle)) != null &&
fork.TryGetCall(nameof(Expression.Field)) != null)
{
fieldToken = ((FieldReference)ldtoken.Operand).MetadataToken;
reader.Position = fork.Position;
return(true);
}
return(false);
}
