public bool HasAnyEffect(StackRelatedInstructionEffect effect) => (Effects & effect) != StackRelatedInstructionEffect.None;
StackRelatedInstructionEffects ClassifyInstruction(StackAnalyzerInstruction insn)
{
string remainingArgs = insn.Arguments;
if (insn.Opcode == "push" || insn.Opcode == "pop")
{
int sign = insn.Opcode == "push" ? 1 : -1;
int listLength = GetRegisterListLength(insn.Arguments, out var hasPC);
StackRelatedInstructionEffect extraEffects = StackRelatedInstructionEffect.None;
if (hasPC)
{
extraEffects |= StackRelatedInstructionEffect.ReturnFromCall;
}
return(new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.MovesStackPointer | extraEffects, StackDelta = sign * WordSize * listLength
});
}
else if (insn.Opcode.StartsWith("mov"))
{
string arg = TakeFirstArgument(ref remainingArgs);
string arg2 = TakeFirstArgument(ref remainingArgs);
if (arg == "sp")
{
if (arg2 == "r7")
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.RestoresStackPointer
}
}
;
else
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.ChangesStackPointerUnpredictably
}
};
}
else if (arg == "r7" && arg2 == "sp")
{
return(new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.SavesStackPointerWithDelta
});
}
}
else if (insn.Opcode == "ldr" || insn.Opcode.StartsWith("ldr.w") || insn.Opcode == "ldrd" || insn.Opcode.StartsWith("ldrd.") ||
insn.Opcode == "str" || insn.Opcode.StartsWith("str.w") || insn.Opcode == "strd" || insn.Opcode.StartsWith("strd."))
{
string arg = TakeFirstArgument(ref remainingArgs);
if (insn.Opcode.StartsWith("ldr") && arg == "sp")
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.ChangesStackPointerUnpredictably
}
}
;
if (insn.Opcode.StartsWith("strd") || insn.Opcode.StartsWith("ldrd"))
{
TakeFirstArgument(ref remainingArgs); //Ignore the second loaded/stored register
}
Match m;
if (remainingArgs.StartsWith("[sp,") && (m = rgSpRelativeAddressing.Match(remainingArgs)).Success)
{
return(new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.MovesStackPointer, StackDelta = -int.Parse(m.Groups[1].Value)
});
}
else
{
string arg2 = TakeFirstArgument(ref remainingArgs);
if (arg2 == "[sp]")
{
if (int.TryParse(remainingArgs.Trim('#', '!'), out int offset))
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.MovesStackPointer, StackDelta = -offset
}
}
;
}
}
}
else if (insn.Opcode == "add" || insn.Opcode == "sub" || insn.Opcode == "adds" || insn.Opcode == "subs" || insn.Opcode == "addw" || insn.Opcode == "subw" || insn.Opcode == "add.w" || insn.Opcode == "sub.w")
{
int sign = insn.Opcode.StartsWith("sub") ? 1 : -1;
string targetRegister = TakeFirstArgument(ref remainingArgs);
string sourceRegister = TakeFirstArgument(ref remainingArgs);
if (remainingArgs == "")
{
remainingArgs = sourceRegister;
sourceRegister = targetRegister;
}
if (targetRegister == "sp")
{
var delta = ParseImmediateValue(remainingArgs);
if (delta.HasValue)
{
if (targetRegister == "sp")
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.MovesStackPointer, StackDelta = sign * delta.Value
}
}
;
else if (targetRegister == "r7")
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.SavesStackPointerWithDelta, StackDelta = sign * delta.Value
}
}
;
}
return(new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.ChangesStackPointerUnpredictably
});
}
else if (targetRegister == "r7")
{
if (sourceRegister == "sp")
{
var delta = ParseImmediateValue(remainingArgs);
if (delta.HasValue)
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.SavesStackPointerWithDelta, StackDelta = sign * delta.Value
}
}
;
}
else
{
var delta = ParseImmediateValue(remainingArgs);
if (delta.HasValue)
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.MovesSavedStackPointer, StackDelta = sign * delta.Value
}
}
;
}
return(new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.ChangesFramePointerUnpredictably
});
}
}
else if (insn.Opcode == "cbz" || insn.Opcode == "cbnz")
{
string arg1 = TakeFirstArgument(ref remainingArgs);
var target = ParseAddress(remainingArgs);
if (target.HasValue)
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.ConditionalJump | StackRelatedInstructionEffect.JumpTargetKnown, JumpTarget = StripThumbBit(target.Value)
}
}
;
else
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.UnpredictableJump
}
};
}
else if (insn.Opcode.StartsWith("b"))
{
string arg = TakeFirstArgument(ref remainingArgs, ' ');
if (insn.Opcode == "bx" && arg == "lr")
{
return new StackRelatedInstructionEffects {
Effects = StackRelatedInstructionEffect.ReturnFromCall | StackRelatedInstructionEffect.JumpsViaLinkRegister
}
}
;
StackRelatedInstructionEffect effect = StackRelatedInstructionEffect.None;
foreach (var cc in ARMConditionCodes)
{
if (insn.Opcode.StartsWith("bl" + cc))
{
effect = StackRelatedInstructionEffect.FunctionCall;
break;
}
}
if (effect == StackRelatedInstructionEffect.None)
{
foreach (var cc in ARMConditionCodes)
{
if (insn.Opcode.StartsWith("b" + cc))
{
effect = StackRelatedInstructionEffect.ConditionalJump;
break;
}
}
}
if (effect == StackRelatedInstructionEffect.None)
{
if (insn.Opcode.StartsWith("bl"))
{
effect = StackRelatedInstructionEffect.FunctionCall;
}
else if (insn.Opcode == "b" || insn.Opcode == "bx" || insn.Opcode.StartsWith("b.") || insn.Opcode.StartsWith("bx."))
{
effect = StackRelatedInstructionEffect.UnconditionalJump;
}
}
if (effect != StackRelatedInstructionEffect.None)
{
var target = ParseAddress(arg);
if (target.HasValue)
{
return new StackRelatedInstructionEffects {
Effects = effect | StackRelatedInstructionEffect.JumpTargetKnown, JumpTarget = StripThumbBit(target.Value)
}
}
;
else
{
if (IsSingleRegister(arg) && remainingArgs == "")
{
return new StackRelatedInstructionEffects {
Effects = effect | StackRelatedInstructionEffect.RegisterJump
}
}
;
else
{
return new StackRelatedInstructionEffects {
Effects = effect | StackRelatedInstructionEffect.UnpredictableJump
}
};
}
}
}
else if (insn.Opcode.StartsWith("ldmia") || insn.Opcode.StartsWith("stmdb"))
{
int sign = insn.Opcode.StartsWith("stmdb") ? 1 : -1;
string arg0 = TakeFirstArgument(ref remainingArgs);
if (arg0 == "sp!")
{
var result = new StackRelatedInstructionEffects
{
Effects = StackRelatedInstructionEffect.MovesStackPointer,
StackDelta = sign * WordSize * GetRegisterListLength(remainingArgs, out var includesPC)
};
if (includesPC)
{
result.Effects |= StackRelatedInstructionEffect.ReturnFromCall;
}
return(result);
}
}
return(default(StackRelatedInstructionEffects));
}
