public void ResolveVariables_Adds_Variables_To_Symbol_Table()
{
// arrange
IDictionary<string, int> symbolTable = new Dictionary<string, int>
{
// resolved labels should already be in symbol table
{"LOOP", 4},
{"END", 18}
};
IInstruction[] instructions =
{
new VariableInstruction("i"),
new ComputeInstruction(ComputeDestinationType.Memory, "1"),
new VariableInstruction("sum"),
new ComputeInstruction(ComputeDestinationType.Memory, "0"),
// LOOP label was here
new VariableInstruction("i"),
new ComputeInstruction(ComputeDestinationType.DataRegister, "M"),
new AddressInstruction(100),
new ComputeInstruction(ComputeDestinationType.DataRegister, "D-A"),
new VariableInstruction("END"),
new ComputeInstruction(ComputeDestinationType.None, "D", ComputeJumpType.JGT),
new VariableInstruction("i"),
new ComputeInstruction(ComputeDestinationType.DataRegister, "M"),
new VariableInstruction("sum"),
new ComputeInstruction(ComputeDestinationType.Memory, "M+1"),
new VariableInstruction("LOOP"),
new ComputeInstruction(ComputeDestinationType.None, "0", ComputeJumpType.JMP),
// END label was here
new VariableInstruction("END"),
new ComputeInstruction(ComputeDestinationType.None, "0", ComputeJumpType.JMP),
};
var variableResolver = new HackVariableResolver(new IsVariableVisitor());
// act
variableResolver.ResolveVariables(symbolTable, instructions).ToArray();
// assert
Assert.AreEqual(4, symbolTable.Count);
Assert.AreEqual(16, symbolTable["i"]);
Assert.AreEqual(17, symbolTable["sum"]);
}
public void ResolveVariables_Converts_Variable_Instructions_To_Address_Instructions()
{
// arrange
IDictionary<string, int> symbolTable = new Dictionary<string, int>
{
// resolved labels should already be in symbol table
{"LOOP", 4},
{"END", 18}
};
IInstruction[] instructions =
{
new VariableInstruction("i"),
new ComputeInstruction(ComputeDestinationType.Memory, "1"),
new VariableInstruction("sum"),
new ComputeInstruction(ComputeDestinationType.Memory, "0"),
// LOOP label was here
new VariableInstruction("i"),
new ComputeInstruction(ComputeDestinationType.DataRegister, "M"),
new AddressInstruction(100),
new ComputeInstruction(ComputeDestinationType.DataRegister, "D-A"),
new VariableInstruction("END"),
new ComputeInstruction(ComputeDestinationType.None, "D", ComputeJumpType.JGT),
new VariableInstruction("i"),
new ComputeInstruction(ComputeDestinationType.DataRegister, "M"),
new VariableInstruction("sum"),
new ComputeInstruction(ComputeDestinationType.Memory, "M+1"),
new VariableInstruction("LOOP"),
new ComputeInstruction(ComputeDestinationType.None, "0", ComputeJumpType.JMP),
// END label was here
new VariableInstruction("END"),
new ComputeInstruction(ComputeDestinationType.None, "0", ComputeJumpType.JMP),
};
var variableResolver = new HackVariableResolver(new IsVariableVisitor());
var initialVariableInstructions = instructions.Count(i => i is VariableInstruction);
var initialAddressInstructions = instructions.Count(i => i is AddressInstruction);
// act
var resolvedInstructions = variableResolver.ResolveVariables(symbolTable, instructions).ToArray();
// assert
Assert.AreEqual(0, resolvedInstructions.Count(i => i is VariableInstruction));
int numAddressInstructions = initialAddressInstructions + initialVariableInstructions;
Assert.AreEqual(numAddressInstructions,
resolvedInstructions.Count(i => i is AddressInstruction));
Assert.AreEqual(16, ((AddressInstruction)resolvedInstructions[0]).Address);
Assert.AreEqual(17, ((AddressInstruction)resolvedInstructions[2]).Address);
}