private ParseErrorExpression ExecuteAchievementExpression(ExpressionBase expression, InterpreterScope scope)
{
ExpressionBase operand;
switch (expression.Type)
{
case ExpressionType.FunctionCall:
return(ExecuteAchievementFunction((FunctionCallExpression)expression, scope));
case ExpressionType.Conditional:
return(ExecuteAchievementConditional((ConditionalExpression)expression, scope));
case ExpressionType.Comparison:
return(ExecuteAchievementComparison((ComparisonExpression)expression, scope));
case ExpressionType.Mathematic:
return(ExecuteAchievementMathematic((MathematicExpression)expression, scope));
case ExpressionType.Variable:
if (!expression.ReplaceVariables(scope, out operand))
{
return(new ParseErrorExpression(operand, expression));
}
if (expression is FunctionReferenceExpression)
{
return(new ParseErrorExpression("Function used like a variable", expression));
}
return(ExecuteAchievementExpression(operand, scope));
case ExpressionType.BooleanConstant:
{
var context = scope.GetContext <TriggerBuilderContext>();
if (((BooleanConstantExpression)expression).Value == true)
{
context.Trigger.Add(AlwaysTrueFunction.CreateAlwaysTrueRequirement());
}
else
{
context.Trigger.Add(AlwaysFalseFunction.CreateAlwaysFalseRequirement());
}
return(null);
}
}
return(new ParseErrorExpression("Cannot generate trigger from " + expression.Type, expression));
}
private ParseErrorExpression ExecuteAchievementComparison(ComparisonExpression comparison, InterpreterScope scope)
{
var left = comparison.Left;
var right = comparison.Right;
if (left.Type == ExpressionType.Comparison || right.Type == ExpressionType.Comparison)
{
return(new ParseErrorExpression("comparison did not evaluate to a valid comparison", comparison));
}
var context = scope.GetContext <TriggerBuilderContext>();
var op = GetRequirementOperator(comparison.Operation);
var leftField = CreateFieldFromExpression(left);
if (leftField.Type != FieldType.None)
{
var rightField = CreateFieldFromExpression(right);
if (rightField.Type != FieldType.None)
{
// comparing two constants, convert to always_true or always_false
var requirement = new Requirement
{
Left = leftField,
Operator = op,
Right = rightField,
};
if (requirement.Evaluate() == true)
{
context.Trigger.Add(AlwaysTrueFunction.CreateAlwaysTrueRequirement());
}
else
{
context.Trigger.Add(AlwaysFalseFunction.CreateAlwaysFalseRequirement());
}
return(null);
}
// swap the operands and operator so the constant is on the right
var temp = left;
left = right;
right = temp;
op = Requirement.GetReversedRequirementOperator(op);
}
var error = ExecuteAchievementExpression(left, scope);
if (error != null)
{
return(ParseErrorExpression.WrapError(error, "Invalid value", left));
}
if (right.Type == ExpressionType.IntegerConstant || right.Type == ExpressionType.FloatConstant)
{
var lastRequirement = context.LastRequirement;
if (lastRequirement.Operator != RequirementOperator.None)
{
// try to rearrange so the last requirement doesn't have a modifier
for (int i = context.Trigger.Count - 2; i >= 0; --i)
{
var requirement = context.Trigger.ElementAt(i);
if (requirement.Type == RequirementType.AddSource && requirement.Operator == RequirementOperator.None)
{
context.Trigger.Remove(lastRequirement);
context.Trigger.Add(new Requirement {
Left = requirement.Left
});
requirement.Left = lastRequirement.Left;
requirement.Operator = lastRequirement.Operator;
requirement.Right = lastRequirement.Right;
lastRequirement = context.LastRequirement;
break;
}
if (requirement.Type != RequirementType.AddSource &&
requirement.Type != RequirementType.SubSource &&
requirement.Type != RequirementType.AddAddress)
{
break;
}
}
if (lastRequirement.Operator != RequirementOperator.None)
{
// last requirement still has a modifier, have to add a dummy condition.
lastRequirement.Type = RequirementType.AddSource;
context.Trigger.Add(new Requirement {
Left = new Field {
Size = lastRequirement.Left.Size, Type = FieldType.Value, Value = 0
}
});
lastRequirement = context.LastRequirement;
}
}
lastRequirement.Operator = op;
lastRequirement.Right = CreateFieldFromExpression(right);
}
else
{
error = ExecuteAchievementExpression(right, scope);
if (error != null)
{
return(ParseErrorExpression.WrapError(error, "Invalid value", right));
}
var extraRequirement = context.LastRequirement;
((IList <Requirement>)context.Trigger).RemoveAt(context.Trigger.Count - 1);
var requirement = context.LastRequirement;
if (requirement != null)
{
if (requirement.Type == RequirementType.AddAddress)
{
return(HandleAddAddressComparison(comparison, (IList <Requirement>)context.Trigger, op, extraRequirement));
}
else if (context.Trigger.Count > 1 && context.Trigger.ElementAt(context.Trigger.Count - 2).Type == RequirementType.AddAddress)
{
// if left side is an AddAddress chain, but right side is a not, we have to keep the
// dummy condition to prevent the AddAddress from modifying the memory address on the
// right side. integers are handled above.
requirement.Type = RequirementType.AddSource;
extraRequirement.Right = extraRequirement.Left;
extraRequirement.Left = new Field {
Type = FieldType.Value, Value = 0
};
extraRequirement.Operator = op;
context.Trigger.Add(extraRequirement);
}
else if (requirement.Operator != RequirementOperator.None)
{
// if left side is a complex expression (a * 4), add a new dummy condition for the comparison
requirement.Type = RequirementType.AddSource;
extraRequirement.Right = extraRequirement.Left;
extraRequirement.Left = new Field {
Type = FieldType.Value, Value = 0
};
extraRequirement.Operator = op;
context.Trigger.Add(extraRequirement);
}
else
{
// no AddAddress on either side, just merge the conditions
requirement.Operator = op;
requirement.Right = extraRequirement.Left;
}
}
}
return(null);
}
private ParseErrorExpression ExecuteAchievementComparison(ComparisonExpression comparison, InterpreterScope scope)
{
_equalityModifiers.Clear();
var context = scope.GetContext <TriggerBuilderContext>();
var insertIndex = context.Trigger.Count;
var left = comparison.Left;
var right = comparison.Right;
var op = GetRequirementOperator(comparison.Operation);
if (left.Type == ExpressionType.IntegerConstant)
{
if (right.Type == ExpressionType.IntegerConstant)
{
// comparing two constants, convert to always_true or always_false
var requirement = new Requirement
{
Left = new Field {
Type = FieldType.Value, Value = (uint)((IntegerConstantExpression)left).Value
},
Operator = op,
Right = new Field {
Type = FieldType.Value, Value = (uint)((IntegerConstantExpression)right).Value
},
};
if (Evaluate(requirement))
{
context.Trigger.Add(AlwaysTrueFunction.CreateAlwaysTrueRequirement());
}
else
{
context.Trigger.Add(AlwaysFalseFunction.CreateAlwaysFalseRequirement());
}
return(null);
}
// swap the operands and operator so the constant is on the right
var temp = left;
left = right;
right = temp;
op = GetReversedRequirementOperator(op);
}
var error = ExecuteAchievementExpression(left, scope);
if (error != null)
{
return(error);
}
var integerRight = right as IntegerConstantExpression;
if (integerRight != null)
{
int newValue = integerRight.Value;
// SubSource of a memory accessor may cause overflow - if comparing for less than,
// modifiers should not be merged into the compare target
if (_equalityModifiers.Count > 0 &&
(op == RequirementOperator.LessThan || op == RequirementOperator.LessThanOrEqual))
{
bool hasSubSource = false;
for (int i = context.Trigger.Count - 2; i >= 0; i++)
{
var requirementType = context.Trigger.ElementAt(i).Type;
if (requirementType == RequirementType.SubSource)
{
hasSubSource = true;
break;
}
else if (requirementType != RequirementType.AddSource &&
requirementType != RequirementType.AddHits)
{
break;
}
}
if (hasSubSource)
{
var last = context.Trigger.Last();
context.Trigger.Remove(last);
foreach (var modifier in _equalityModifiers)
{
if (modifier.Operation != MathematicOperation.Subtract && modifier.Operation != MathematicOperation.Add)
{
return(new ParseErrorExpression("Cannot normalize expression containing SubSource", left));
}
context.Trigger.Add(new Requirement
{
Type = (modifier.Operation == MathematicOperation.Subtract) ? RequirementType.AddSource : RequirementType.SubSource,
Left = new Field {
Type = FieldType.Value, Value = (uint)modifier.Amount
},
Operator = RequirementOperator.None,
Right = new Field()
});
}
context.Trigger.Add(last);
_equalityModifiers.Clear();
}
}
while (_equalityModifiers.Count > 0)
{
var originalValue = newValue;
var modifier = _equalityModifiers.Pop();
newValue = modifier.Apply(newValue);
var restoredValue = modifier.Remove(newValue);
switch (op)
{
case RequirementOperator.Equal:
if (restoredValue != originalValue)
{
return(new ParseErrorExpression("Result can never be true using integer math", comparison));
}
break;
case RequirementOperator.NotEqual:
if (restoredValue != originalValue)
{
return(new ParseErrorExpression("Result is always true using integer math", comparison));
}
break;
case RequirementOperator.GreaterThanOrEqual:
if (restoredValue != originalValue)
{
op = RequirementOperator.GreaterThan;
}
break;
}
}
var requirement = context.LastRequirement;
requirement.Operator = op;
requirement.Right = new Field {
Size = requirement.Left.Size, Type = FieldType.Value, Value = (uint)newValue
};
}
else
{
var leftModifiers = new Stack <ValueModifier>(_equalityModifiers.Reverse());
_equalityModifiers.Clear();
error = ExecuteAchievementExpression(right, scope);
if (error != null)
{
return(error);
}
if (leftModifiers.Count > 0 || _equalityModifiers.Count > 0)
{
var rightValue = 1234567;
var leftValue = rightValue;
while (leftModifiers.Count > 0)
{
var modifier = leftModifiers.Pop();
leftValue = ValueModifier.Apply(leftValue, MathematicExpression.GetOppositeOperation(modifier.Operation), modifier.Amount);
}
while (_equalityModifiers.Count > 0)
{
var modifier = _equalityModifiers.Pop();
rightValue = ValueModifier.Apply(rightValue, MathematicExpression.GetOppositeOperation(modifier.Operation), modifier.Amount);
}
var diff = leftValue - rightValue;
if (diff != 0)
{
var modifier = new Requirement();
if (diff < 0)
{
modifier.Left = new Field {
Type = FieldType.Value, Value = (uint)(-diff)
};
modifier.Type = RequirementType.SubSource;
}
else
{
modifier.Left = new Field {
Type = FieldType.Value, Value = (uint)diff
};
modifier.Type = RequirementType.AddSource;
}
((IList <Requirement>)context.Trigger).Insert(insertIndex, modifier);
}
}
var extraRequirement = context.LastRequirement;
context.Trigger.Remove(extraRequirement);
var requirement = context.LastRequirement;
if (requirement != null)
{
requirement.Operator = op;
requirement.Right = extraRequirement.Left;
}
}
return(null);
}