private void EmitMethodExitChecks(
[NotNull] MethodDefinition methodDefinition, [NotNull] HashSet <int> positions)
{
var outputChecks = new Queue <Instruction[]>();
Instruction lastInstruction = null;
// walk over parameters in reverse order to build checks stack
var parameters = methodDefinition.Parameters;
for (var index1 = parameters.Count - 1; index1 >= 0; index1--)
{
var parameterDefinition = parameters[index1];
if (!positions.Contains(parameterDefinition.Index))
{
continue;
}
var parameterType = parameterDefinition.ParameterType;
if (parameterType.IsByReference)
{
if (!ChecksEmitUtil.IsNullableType(parameterType))
{
LogInfo(string.Format(
"Invalid annotation usage in member {0} at parameter '{1}'.",
methodDefinition.GetXmlDocId(), parameterDefinition.Name));
continue;
}
lastInstruction = lastInstruction ?? Instruction.Create(OpCodes.Ret);
var target = (outputChecks.Count > 0) ? outputChecks.Peek()[0] : lastInstruction;
var checkInstructions = ChecksEmitUtil.EmitNullCheckInstructions(
parameterDefinition, parameterType, ArgumentNullCtor, target,
parameterDefinition.Name, "Output parameter [NotNull] contract violation");
outputChecks.Enqueue(checkInstructions);
}
}
var returnType = methodDefinition.MethodReturnType;
var checkReturnValue = false;
if (positions.Contains(-1)) // check annotated return
{
if (ChecksEmitUtil.IsNullableType(returnType.ReturnType) && !returnType.ReturnType.IsByReference)
{
lastInstruction = lastInstruction ?? Instruction.Create(OpCodes.Ret);
var target = (outputChecks.Count > 0) ? outputChecks.Peek()[0] : lastInstruction;
var checkInstructions = ChecksEmitUtil.EmitNullCheckInstructions(
null, returnType.ReturnType, ArgumentNullCtor, target,
"$return$", "Return value [NotNull] contract violation");
outputChecks.Enqueue(checkInstructions);
checkReturnValue = true;
}
else
{
LogInfo(string.Format(
"Invalid annotation usage in member {0} at return value.",
methodDefinition.GetXmlDocId()));
}
}
if (outputChecks.Count == 0)
{
return;
}
var instructions = methodDefinition.Body.Instructions;
var retInstruction = instructions[instructions.Count - 1];
// replace ret with nop or dup (if return value check required)
retInstruction.OpCode = checkReturnValue ? OpCodes.Dup : OpCodes.Nop;
retInstruction.Operand = null;
foreach (var instruction in outputChecks.Dequeue())
{
instructions.Add(instruction);
}
instructions.Add(lastInstruction);
}
// todo: what about checks field for null?
private void EmitFieldChecks([NotNull] MethodDefinition methodDefinition)
{
var methodBody = methodDefinition.Body;
if (methodBody == null)
{
return;
}
var instructions = methodBody.Instructions;
if (instructions.Count == 0)
{
return;
}
List <Instruction> modifiedBody = null;
for (var index = 0; index < instructions.Count; index++)
{
var instruction = instructions[index];
var opCode = instruction.OpCode;
switch (opCode.Code)
{
case Code.Ldfld:
case Code.Stfld:
case Code.Ldsfld:
case Code.Stsfld: {
var fieldReference = instruction.Operand as FieldReference;
if (fieldReference == null)
{
break;
}
if (!Attributes.IsNotNullAnnotated(fieldReference))
{
break;
}
if (!ChecksEmitUtil.IsNullableType(fieldReference.FieldType))
{
LogInfo(string.Format(
"Invalid annotation usage at field {0}.", fieldReference.GetXmlDocId()));
break;
}
if (modifiedBody == null)
{
modifiedBody = new List <Instruction>(instructions.Count);
for (var index2 = 0; index2 < index; index2++)
{
modifiedBody.Add(instructions[index2]);
}
}
var readAccess = (opCode == OpCodes.Ldfld || opCode == OpCodes.Ldsfld);
if (readAccess)
{
modifiedBody.Add(instruction); // ldfld
}
modifiedBody.Add(Instruction.Create(OpCodes.Dup));
var nextInstruction = instructions[index + 1];
var checkInstructions = ChecksEmitUtil.EmitNullCheckInstructions(
null, fieldReference.FieldType, ArgumentNullCtor,
nextInstruction, fieldReference.Name, "Field [NotNull] contract violation");
foreach (var instr in checkInstructions)
{
modifiedBody.Add(instr);
}
if (!readAccess)
{
modifiedBody.Add(instruction); // stfld
}
continue; // yes, we handled
}
}
if (modifiedBody != null)
{
modifiedBody.Add(instruction);
}
}
if (modifiedBody != null)
{
instructions.Clear();
foreach (var x in modifiedBody)
{
instructions.Add(x);
}
}
}
private void EmitMethodEnterChecks(
[NotNull] MethodDefinition methodDefinition, [NotNull] HashSet <int> positions)
{
var inputСhecks = new Stack <Instruction[]>();
Instruction firstInstruction = null;
// walk over parameters in reverse order to build checks stack
var parameters = methodDefinition.Parameters;
for (var index1 = parameters.Count - 1; index1 >= 0; index1--)
{
var parameterDefinition = parameters[index1];
if (parameterDefinition.IsOut)
{
continue;
}
if (!positions.Contains(parameterDefinition.Index))
{
continue;
}
var parameterType = parameterDefinition.ParameterType;
if (!ChecksEmitUtil.IsNullableType(parameterType))
{
LogInfo(string.Format(
"Invalid annotation usage in member {0} at parameter '{1}'.",
methodDefinition.GetXmlDocId(), parameterDefinition.Name));
continue;
}
if (firstInstruction == null)
{
var instrictions = methodDefinition.Body.Instructions;
if (instrictions.Count == 0)
{
return; // shit happens
}
firstInstruction = instrictions[0];
}
var checkInstructions = ChecksEmitUtil.EmitNullCheckInstructions(
parameterDefinition, parameterType, ArgumentNullCtor, firstInstruction,
parameterDefinition.Name, "Input parameter [NotNull] contract violation");
inputСhecks.Push(checkInstructions);
firstInstruction = checkInstructions[0];
}
if (inputСhecks.Count == 0)
{
return;
}
var instructions = methodDefinition.Body.Instructions;
var oldBody = instructions.ToArray();
instructions.Clear();
while (inputСhecks.Count > 0)
{
foreach (var instruction in inputСhecks.Pop())
{
instructions.Add(instruction);
}
}
foreach (var instruction in oldBody)
{
instructions.Add(instruction);
}
}