public static void EraseMethodInvocationFromInstructions(ILProcessor ilProcessor, Instruction callInstruction)
{
var argumentPushingInstructions = new List <Instruction>();
int succesfullyEraseArguments = 0;
if (!(callInstruction.Operand is MethodReference methodReference))
{
return;
}
bool isMethodThatReturnsItsFirstArgument = !methodReference.HasThis && (methodReference.Parameters.FirstOrDefault()?.ParameterType.TypeReferenceEquals(methodReference.ReturnType) ?? false);
var parametersCount = methodReference.Parameters.Count + (methodReference.HasThis ? 1 : 0);
for (int i = 0; i != parametersCount; i++)
{
if (isMethodThatReturnsItsFirstArgument && i == 0)
{
continue;
}
var instructionThatPushedArg = FindInstructionThatPushedArg(ilProcessor.Body.Method, i, callInstruction);
if (instructionThatPushedArg == null)
{
continue;
}
if (InstructionExtensions.IsInvocation(instructionThatPushedArg))
{
continue;
}
var pushDelta = InstructionExtensions.GetPushDelta(instructionThatPushedArg);
var popDelta = InstructionExtensions.GetPopDelta(instructionThatPushedArg);
if (pushDelta == 1 && popDelta == 0)
{
argumentPushingInstructions.Add(instructionThatPushedArg);
succesfullyEraseArguments++;
continue;
}
if (pushDelta == 1 && popDelta == 1)
{
var whoPushedThat = FindInstructionThatPushedArg(ilProcessor.Body.Method, 0, instructionThatPushedArg);
if (InstructionExtensions.GetPopDelta(whoPushedThat) == 0 && InstructionExtensions.GetPushDelta(whoPushedThat) == 1)
{
argumentPushingInstructions.Add(instructionThatPushedArg);
argumentPushingInstructions.Add(whoPushedThat);
succesfullyEraseArguments++;
continue;
}
}
}
foreach (var i in argumentPushingInstructions)
{
i.MakeNOP();
}
//we're going to remove the invocation. While we do this we want to remain stack neutral. The stackbehaviour going in is that the jobdescription itself will be on the stack,
//plus any arguments the method might have. After the function, it will put the same jobdescription on the stack as the return value.
//we're going to pop all the arguments, but leave the jobdescription itself on the stack, since that the behaviour of the original method.
var parametersToErase = parametersCount - (isMethodThatReturnsItsFirstArgument ? 1 : 0);
var popInstructions = Enumerable.Repeat(Instruction.Create(OpCodes.Pop), parametersToErase - succesfullyEraseArguments);
ilProcessor.InsertBefore(callInstruction, popInstructions);
//instead of removing the call instruction, we'll replace it with a NOP opcode. This is safer as this instruction
//might be the target of a branch instruction that we don't want to become invalid.
callInstruction.MakeNOP();
if (!methodReference.ReturnType.TypeReferenceEquals(methodReference.Module.TypeSystem.Void) && !isMethodThatReturnsItsFirstArgument)
{
callInstruction.OpCode = OpCodes.Ldnull;
}
}
public static Instruction FindInstructionThatPushedArg(MethodDefinition containingMethod, int argNumber,
Instruction callInstructionsWhoseArgumentsWeWantToFind)
{
containingMethod.Body.EnsurePreviousAndNextAreSet();
var cursor = callInstructionsWhoseArgumentsWeWantToFind.Previous;
int stackSlotWhoseWriteWeAreLookingFor = argNumber;
int stackSlotWhereNextPushWouldBeWrittenTo = InstructionExtensions.GetPopDelta(callInstructionsWhoseArgumentsWeWantToFind);
var seenInstructions = new HashSet <Instruction>()
{
callInstructionsWhoseArgumentsWeWantToFind, cursor
};
while (cursor != null)
{
var pushAmount = cursor.GetPushDelta();
var popAmount = cursor.GetPopDelta();
var result = CecilHelpers.MatchesDelegateProducingPattern(containingMethod, cursor, CecilHelpers.DelegateProducingPattern.MatchSide.End);
if (result != null)
{
//so we are crawling backwards through isntructions. if we find a "this is roslyn caching a delegate" sequence,
//we're going to pretend it is a single instruction, that pushes the delegate on the stack, and pops nothing.
cursor = result.Instructions.First();
pushAmount = 1;
popAmount = 0;
}
else if (cursor.IsBranch())
{
var target = (Instruction)cursor.Operand;
if (!seenInstructions.Contains(target))
{
if (IsUnsupportedBranch(cursor))
{
UserError.DC0010(containingMethod, cursor).Throw();
}
}
}
for (int i = 0; i != pushAmount; i++)
{
stackSlotWhereNextPushWouldBeWrittenTo--;
if (stackSlotWhereNextPushWouldBeWrittenTo == stackSlotWhoseWriteWeAreLookingFor)
{
return(cursor);
}
}
for (int i = 0; i != popAmount; i++)
{
stackSlotWhereNextPushWouldBeWrittenTo++;
}
cursor = cursor.Previous;
seenInstructions.Add(cursor);
}
return(null);
}
private void ApplyPostProcessingOnJobCode(MethodDefinition[] methodUsedByLambdaJobs,
LambdaParameterValueInformations lambdaParameterValueInformations)
{
var forEachInvocations = new List <(MethodDefinition, Instruction)>();
var methodDefinition = methodUsedByLambdaJobs.First();
forEachInvocations.AddRange(methodDefinition.Body.Instructions.Where(IsChunkEntitiesForEachInvocation).Select(i => (methodDefinition, i)));
foreach (var methodUsedByLambdaJob in methodUsedByLambdaJobs)
{
var methodBody = methodUsedByLambdaJob.Body;
var displayClassVariable = methodBody.Variables.SingleOrDefault(v => v.VariableType.Name.Contains("DisplayClass"));
if (displayClassVariable != null)
{
TypeDefinition displayClass = displayClassVariable.VariableType.Resolve();
bool allDelegatesAreGuaranteedNotToOutliveMethod =
displayClass.IsValueType ||
CecilHelpers.AllDelegatesAreGuaranteedNotToOutliveMethodFor(methodUsedByLambdaJob);
if (!displayClass.IsValueType && allDelegatesAreGuaranteedNotToOutliveMethod)
{
CecilHelpers.PatchMethodThatUsedDisplayClassToTreatItAsAStruct(methodBody,
displayClassVariable, displayClass);
CecilHelpers.PatchDisplayClassToBeAStruct(displayClass);
}
}
}
int counter = 1;
foreach (var(methodUsedByLambdaJob, instruction) in forEachInvocations)
{
var methodBody = methodUsedByLambdaJob.Body;
var(ldFtn, newObj) = FindClosureCreatingInstructions(methodBody, instruction);
var newType = new TypeDefinition("", "InlineEntitiesForEachInvocation" + counter++, TypeAttributes.NestedPublic | TypeAttributes.SequentialLayout, methodUsedByLambdaJob.Module.ImportReference(typeof(ValueType)))
{
DeclaringType = methodUsedByLambdaJob.DeclaringType
};
methodUsedByLambdaJob.DeclaringType.NestedTypes.Add(newType);
CloneLambdaMethodAndItsLocalMethods();
var iterateEntitiesMethod = CreateIterateEntitiesMethod(lambdaParameterValueInformations);
var variable = new VariableDefinition(newType);
methodBody.Variables.Add(variable);
InstructionExtensions.MakeNOP(ldFtn.Previous);
InstructionExtensions.MakeNOP(ldFtn);
newObj.OpCode = OpCodes.Ldnull;
newObj.Operand = null;
var displayClassVariable = methodBody.Variables.SingleOrDefault(v => v.VariableType.Name.Contains("DisplayClass"));
if (displayClassVariable == null)
{
continue;
}
var ilProcessor = methodBody.GetILProcessor();
ilProcessor.InsertAfter(instruction, new List <Instruction>
{
//no need to drop the delegate from the stack, because we just removed the function that placed it on the stack in the first place.
//do not drop the description from the stack, as the original method returns it, and we want to maintain stack behaviour.
//call our new method
Instruction.Create(OpCodes.Ldloca, variable),
Instruction.Create(OpCodes.Initobj, newType),
Instruction.Create(OpCodes.Ldloca, variable),
Instruction.Create(OpCodes.Ldloca, displayClassVariable),
Instruction.Create(OpCodes.Call, ReadFromDisplayClassMethod),
Instruction.Create(OpCodes.Ldloca, variable),
Instruction.Create(OpCodes.Ldarga, methodBody.Method.Parameters.First(p => p.ParameterType.Name == nameof(ArchetypeChunk))),
Instruction.Create(OpCodes.Ldarg_0),
Instruction.Create(OpCodes.Ldfld, lambdaParameterValueInformations._runtimesField),
Instruction.Create(OpCodes.Call, (MethodReference)iterateEntitiesMethod),
});
#if ENABLE_DOTS_COMPILER_CHUNKS
var chunkEntitiesInvocation = LambdaJobDescriptionConstruction.FindInstructionThatPushedArg(methodBody.Method, 0, instruction);
if (chunkEntitiesInvocation.Operand is MethodReference mr && mr.Name == "get_" + nameof(ArchetypeChunk.Entities) && mr.DeclaringType.Name == nameof(ArchetypeChunk))
{
CecilHelpers.EraseMethodInvocationFromInstructions(ilProcessor, chunkEntitiesInvocation);
}
#endif
CecilHelpers.EraseMethodInvocationFromInstructions(ilProcessor, instruction);
}
}