public void Emit(CompilationContext context)
{
context.EmitComment(";Boolean expression");
((ICodeEmitter)Tokens[0]).Emit(context);
var expressionType = ((IHasType)Tokens[0]).GetExpressionType(context);
if (Tokens.Count > 1)
{
TypeChecking.CheckExpressionTypeIsBoolean(expressionType);
}
for (int i = 1; i < Tokens.Count; i += 2)
{
string op = ((DefaultLanguageTerminalToken)Tokens[i]).Value;
((ICodeEmitter)Tokens[i + 1]).Emit(context);
expressionType = ((IHasType)Tokens[i + 1]).GetExpressionType(context);
TypeChecking.CheckExpressionTypeIsBoolean(expressionType);
context.EmitInstruction(new IRPop()
{
To = "ebx"
});
context.EmitInstruction(new IRPop()
{
To = "eax"
});
var trueLabel = new LabelAddressValue(context.CreateNewLabel());
switch (op)
{
case "&&":
context.EmitInstruction(new IRAnd()
{
Left = "eax", Right = "ebx", To = "ecx"
});
context.EmitInstruction(new IRCompareImmediate()
{
Left = "ecx", Right = new ImmediateValue(0)
});
context.EmitInstruction(new IRJumpNE()
{
Address = trueLabel
});
break;
case "||":
context.EmitInstruction(new IROr()
{
Left = "eax", Right = "ebx", To = "ecx"
});
context.EmitInstruction(new IRCompareImmediate()
{
Left = "ecx", Right = new ImmediateValue(0)
});
context.EmitInstruction(new IRJumpNE()
{
Address = trueLabel
});
break;
}
var skipTrueLabel = new LabelAddressValue(context.CreateNewLabel());
context.EmitInstruction(new IRPushImmediate()
{
Value = new ImmediateValue(0)
});
context.EmitInstruction(new IRJumpImmediate()
{
Address = skipTrueLabel
});
context.EmitLabel(trueLabel.Value);
context.EmitInstruction(new IRPushImmediate()
{
Value = new ImmediateValue(1)
});
context.EmitLabel(skipTrueLabel.Value);
}
}
