private static StackSlot MergeStackElement(StackSlot a, StackSlot b)
{
StackSlot mergedSlot;
if (b.Value == null)
{
mergedSlot = a;
}
else if (a.Value == null)
{
mergedSlot = b;
}
else
{
mergedSlot = new StackSlot(MergePointValue.MergeValues(a.Value, b.Value));
}
return(mergedSlot);
}
private StackSlot PopUnknown(Stack <StackSlot> stack, int count, MethodIL method, int ilOffset)
{
if (count < 1)
{
throw new InvalidOperationException();
}
StackSlot topOfStack = default;
CheckForInvalidStack(stack, count, method, ilOffset);
for (int i = 0; i < count; ++i)
{
StackSlot slot = stack.Pop();
if (i == 0)
{
topOfStack = slot;
}
}
return(topOfStack);
}
public void Scan(MethodIL methodBody)
{
MethodDesc thisMethod = methodBody.OwningMethod;
ValueBasicBlockPair[] locals = new ValueBasicBlockPair[methodBody.GetLocals().Length];
Dictionary <int, Stack <StackSlot> > knownStacks = new Dictionary <int, Stack <StackSlot> >();
Stack <StackSlot> currentStack = new Stack <StackSlot>(methodBody.MaxStack);
ScanExceptionInformation(knownStacks, methodBody);
BasicBlockIterator blockIterator = new BasicBlockIterator(methodBody);
MethodReturnValue = null;
ILReader reader = new ILReader(methodBody.GetILBytes());
while (reader.HasNext)
{
int curBasicBlock = blockIterator.MoveNext(reader.Offset);
if (knownStacks.ContainsKey(reader.Offset))
{
if (currentStack == null)
{
// The stack copy constructor reverses the stack
currentStack = new Stack <StackSlot>(knownStacks[reader.Offset].Reverse());
}
else
{
currentStack = MergeStack(currentStack, knownStacks[reader.Offset]);
}
}
if (currentStack == null)
{
currentStack = new Stack <StackSlot>(methodBody.MaxStack);
}
int offset = reader.Offset;
ILOpcode opcode = reader.ReadILOpcode();
switch (opcode)
{
case ILOpcode.add:
case ILOpcode.add_ovf:
case ILOpcode.add_ovf_un:
case ILOpcode.and:
case ILOpcode.div:
case ILOpcode.div_un:
case ILOpcode.mul:
case ILOpcode.mul_ovf:
case ILOpcode.mul_ovf_un:
case ILOpcode.or:
case ILOpcode.rem:
case ILOpcode.rem_un:
case ILOpcode.sub:
case ILOpcode.sub_ovf:
case ILOpcode.sub_ovf_un:
case ILOpcode.xor:
case ILOpcode.cgt:
case ILOpcode.cgt_un:
case ILOpcode.clt:
case ILOpcode.clt_un:
case ILOpcode.shl:
case ILOpcode.shr:
case ILOpcode.shr_un:
case ILOpcode.ceq:
PopUnknown(currentStack, 2, methodBody, offset);
PushUnknown(currentStack);
reader.Skip(opcode);
break;
case ILOpcode.dup:
currentStack.Push(currentStack.Peek());
break;
case ILOpcode.ldnull:
currentStack.Push(new StackSlot(NullValue.Instance));
break;
case ILOpcode.ldc_i4_0:
case ILOpcode.ldc_i4_1:
case ILOpcode.ldc_i4_2:
case ILOpcode.ldc_i4_3:
case ILOpcode.ldc_i4_4:
case ILOpcode.ldc_i4_5:
case ILOpcode.ldc_i4_6:
case ILOpcode.ldc_i4_7:
case ILOpcode.ldc_i4_8:
{
int value = opcode - ILOpcode.ldc_i4_0;
ConstIntValue civ = new ConstIntValue(value);
StackSlot slot = new StackSlot(civ);
currentStack.Push(slot);
}
break;
case ILOpcode.ldc_i4_m1:
{
ConstIntValue civ = new ConstIntValue(-1);
StackSlot slot = new StackSlot(civ);
currentStack.Push(slot);
}
break;
case ILOpcode.ldc_i4:
{
int value = (int)reader.ReadILUInt32();
ConstIntValue civ = new ConstIntValue(value);
StackSlot slot = new StackSlot(civ);
currentStack.Push(slot);
}
break;
case ILOpcode.ldc_i4_s:
{
int value = (sbyte)reader.ReadILByte();
ConstIntValue civ = new ConstIntValue(value);
StackSlot slot = new StackSlot(civ);
currentStack.Push(slot);
}
break;
case ILOpcode.arglist:
case ILOpcode.ldftn:
case ILOpcode.sizeof_:
case ILOpcode.ldc_i8:
case ILOpcode.ldc_r4:
case ILOpcode.ldc_r8:
PushUnknown(currentStack);
reader.Skip(opcode);
break;
case ILOpcode.ldarg:
case ILOpcode.ldarg_0:
case ILOpcode.ldarg_1:
case ILOpcode.ldarg_2:
case ILOpcode.ldarg_3:
case ILOpcode.ldarg_s:
case ILOpcode.ldarga:
case ILOpcode.ldarga_s:
ScanLdarg(opcode, opcode switch
{
ILOpcode.ldarg => reader.ReadILUInt16(),
ILOpcode.ldarga => reader.ReadILUInt16(),
ILOpcode.ldarg_s => reader.ReadILByte(),
ILOpcode.ldarga_s => reader.ReadILByte(),
_ => opcode - ILOpcode.ldarg_0
}, currentStack, thisMethod);
break;
private static StackSlot MergeStackElement(StackSlot a, StackSlot b)
{
return(new StackSlot(MultiValueLattice.Meet(a.Value, b.Value)));
}