public void Execute(NotNullAttribute attribute, PropertyDefinition property, IlProcessorAppender ilProcessor)
{
GenerateNullCheck(
property.SetMethod.Parameters.First(),
ilProcessor,
"value"
);
}
private void GenerateCheck(ParameterDefinition parameter, IlProcessorAppender ilProcessor, string name)
{
var endInstruction = Instruction.Create(OpCodes.Nop);
// Null Check
var whiteSpaceCheckInitializer = Instruction.Create(OpCodes.Ldc_I4_0);
ilProcessor.Append(OpCodes.Ldarg, parameter);
ilProcessor.Append(OpCodes.Brtrue_S, whiteSpaceCheckInitializer);
ilProcessor.Append(OpCodes.Ldstr, name);
ilProcessor.Append(OpCodes.Newobj, GetArgumentNullExceptionConstructor());
ilProcessor.Append(OpCodes.Throw);
// Whitespace Check
ilProcessor.Append(whiteSpaceCheckInitializer);
var counter = ilProcessor.DeclareLocal(ModuleDefinition.TypeSystem.Int32, "<>__" + parameter.Name + "__WhiteSpaceCheckCounter");
ilProcessor.Append(OpCodes.Stloc, counter);
var loopCondition = Instruction.Create(OpCodes.Ldloc, counter);
ilProcessor.Append(OpCodes.Br, loopCondition);
// Loop body
var loopBody = ilProcessor.Append(OpCodes.Ldarg, parameter);
ilProcessor.Append(OpCodes.Ldloc, counter);
ilProcessor.Append(GetElement(parameter));
ilProcessor.Append(OpCodes.Call, GetIsWhiteSpace());
ilProcessor.Append(OpCodes.Brfalse, endInstruction);
// i++
ilProcessor.Append(OpCodes.Ldloc, counter);
ilProcessor.Append(OpCodes.Ldc_I4_1);
ilProcessor.Append(OpCodes.Add);
ilProcessor.Append(OpCodes.Stloc, counter);
// Loop condition
ilProcessor.Append(loopCondition); // Ldloc counter
ilProcessor.Append(OpCodes.Ldarg, parameter);
ilProcessor.Append(OpCodes.Call, GetLength(parameter));
ilProcessor.Append(OpCodes.Clt);
ilProcessor.Append(OpCodes.Brtrue, loopBody);
// Fall through if we got to the end of the string without detecting non-whitespace
ilProcessor.Append(OpCodes.Ldstr, "The given string cannot be empty or only contain whitespace");
ilProcessor.Append(OpCodes.Ldstr, name);
ilProcessor.Append(OpCodes.Newobj, GetArgumentExceptionConstructor());
ilProcessor.Append(OpCodes.Throw);
ilProcessor.Append(endInstruction);
}
private void GenerateCheck(ParameterDefinition parameter, IlProcessorAppender ilProcessor, string name)
{
var endInstruction = Instruction.Create(OpCodes.Nop);
// Null Check
var emptyCheckLdArg = Instruction.Create(OpCodes.Ldarg, parameter);
ilProcessor.Append(OpCodes.Ldarg, parameter);
ilProcessor.Append(OpCodes.Brtrue_S, emptyCheckLdArg);
ilProcessor.Append(OpCodes.Ldstr, name);
ilProcessor.Append(OpCodes.Newobj, GetArgumentNullExceptionConstructor());
ilProcessor.Append(OpCodes.Throw);
// Empty Check
ilProcessor.Append(emptyCheckLdArg);
if (parameter.ParameterType.FullName == "System.String")
{
var stringLength = ModuleDefinition.Import(typeof(string)).Resolve()
.Properties.Single(p => p.Name == "Length")
.GetMethod;
ilProcessor.Append(OpCodes.Call, ModuleDefinition.Import(stringLength));
}
else if (parameter.ParameterType.FullName == "System.Char[]")
{
var arrayLength = ModuleDefinition.Import(typeof(Array)).Resolve()
.Properties.Single(p => p.Name == "Length")
.GetMethod;
ilProcessor.Append(OpCodes.Call, ModuleDefinition.Import(arrayLength));
}
ilProcessor.Append(OpCodes.Ldc_I4_0);
ilProcessor.Append(OpCodes.Bne_Un_S, endInstruction);
ilProcessor.Append(OpCodes.Ldstr, "The given string cannot be empty");
ilProcessor.Append(OpCodes.Ldstr, name);
ilProcessor.Append(OpCodes.Newobj, GetArgumentExceptionConstructor());
ilProcessor.Append(OpCodes.Throw);
ilProcessor.Append(endInstruction);
}
private void GenerateNullCheck(ParameterDefinition parameter, IlProcessorAppender ilProcessor, string name)
{
var endInstruction = Instruction.Create(OpCodes.Nop);
if (parameter.ParameterType.IsValueType)
{
ilProcessor.Append(OpCodes.Ldarga_S, parameter);
ilProcessor.Append(OpCodes.Call, ModuleDefinition.NullableHasValue(parameter.ParameterType.GetNullableInnerType()));
}
else
{
ilProcessor.Append(OpCodes.Ldarg, parameter);
}
ilProcessor.Append(OpCodes.Brtrue_S, endInstruction);
ilProcessor.Append(OpCodes.Ldstr, name);
ilProcessor.Append(OpCodes.Newobj, GetArgumentNullExceptionConstructor());
ilProcessor.Append(OpCodes.Throw);
ilProcessor.Append(endInstruction);
}
public void Execute(NotNullOrWhiteSpaceAttribute attribute, ParameterDefinition parameter, IlProcessorAppender ilProcessor)
{
GenerateCheck(
parameter,
ilProcessor,
parameter.Name
);
}
