public static List <string> Parse(List <string> unchecked_assembly, string InstructionSetName = DefaultInstructionSetName)
{
// Get Instruction Set
InstructionSet iset = OpCodeLoader.GetSet(InstructionSetName);
// *********************************************************************
// Sanitize *
// *********************************************************************
// Remove Blank Lines
unchecked_assembly.RemoveAll(s => s == null);
unchecked_assembly.RemoveAll(s => Regex.IsMatch(s, "^\\s*$"));
// Remove Newline Comments
unchecked_assembly.RemoveAll(s => s[0] == '#');
for (int i = 0; i < unchecked_assembly.Count; i++)
{
// *******************************
// Trim Whitespace *
// *******************************
// Outter Whitespace
unchecked_assembly[i] = unchecked_assembly[i].Trim();
// Inner Whitspace
unchecked_assembly[i] = Regex.Replace(unchecked_assembly[i], "\\s{2,}", " ");
// *******************************
// *******************************
// Remove Inline Comments
// *******************************
unchecked_assembly[i] = Regex.Replace(unchecked_assembly[i], "\\s*#.*$", "");
// *******************************
}
// *********************************************************************
// *********************************************************************
// Validate
// *********************************************************************
//if is not valid, will throw execptions for CLI to catch and display to user
_ = IsValid(unchecked_assembly, iset);
// *********************************************************************
// *********************************************************************
// Assemble
// *********************************************************************
List <string> binary = new List <string>();
int lines_of_asm = unchecked_assembly.Count;
int current_line_number = 0;
foreach (string line in unchecked_assembly)
{
if (line == "...")
{
int nop_count = 16 - lines_of_asm + 1;
for (int i = 0; i < nop_count; i++)
{
binary.Add("00000000");
}
}
else
{
string upper_nibble_asm = line.Split(" ", 2)[0];
string lower_nibble_asm = line.Split(" ", 2)[1];
string upper_nibble_bin = "";
string lower_nibble_bin = "";
// Convert Upper Nibble
if (InstructionValidator.IsValidInstruction(upper_nibble_asm, iset)) // Is instruction
{
upper_nibble_bin = InstructionValidator.GetUpperNibble(line.Substring(0, 3), iset);
}
else if (Regex.IsMatch(upper_nibble_asm, "^0[xX][0-9a-fA-F]$")) // Is Data
{
int value_upper = (int)(Convert.ToUInt32(upper_nibble_asm, 16));
upper_nibble_bin = BinConverter.IntToBin4(value_upper);
}
// Convert Lower Nibble
int value_lower = (int)(Convert.ToUInt32(lower_nibble_asm, 16));
lower_nibble_bin = BinConverter.IntToBin4(value_lower);
binary.Add(upper_nibble_bin + lower_nibble_bin);
}
current_line_number++;
}
// *********************************************************************
//If a program was executed, but didnt fill in every line of RAM then throw an exception. Must have 16 elements!
if (binary.Count != 16)
{
throw new ParseException($"SAP1ASM: Program must have 16 lines.", new ParseException("Use \"NOP 0x0\" for a no-operation command or the \"...\" macro to fill in the rest with NOP 0x0."));
}
return(binary);
}
private static bool IsValid(List <string> unchecked_assembly, InstructionSet iset)
{
bool dot_macro_used = false;
bool contains_hlt = false;
int line_number = 1;
foreach (string line in unchecked_assembly)
{
if (line != "...")
{
string[] nibbles = line.Split(' ', 2);
if (nibbles.Length == 0)
{
throw new ParseException($"SAP1ASM: Line cannot be blank (line: {line_number}).", new ParseException("Use \"NOP 0x0\" for a no-operation command"));
}
string instruction = nibbles[0];
if (instruction.ToUpper() == "HLT")
{
contains_hlt = true;
}
if (nibbles.Length < 2)
{
throw new ParseException($"SAP1ASM: No lower nibble detected (line: {line_number}).", new ParseException($"\"{instruction}\" must be paired with a valid address in the range of 0x0 - 0xF"));
}
string addr = nibbles[1];
// Check Intruction
if (instruction.Length != 3)
{
throw new ParseException($"SAP1ASM: invalid intruction on line {line_number}.", new ParseException($"\"{instruction}\" is not a recognized instruction"));
}
if (!InstructionValidator.IsValidInstruction(instruction.ToUpper(), iset)) // Check if is valid instruction
{
if (!Regex.IsMatch(instruction, "^0[xX][0-9a-fA-F]$")) // Make sure it isnt data
{
throw new ParseException($"SAP1ASM: invalid intruction on line {line_number}.", new ParseException($"\"{instruction}\" is not a recognized instruction or valid data"));
}
}
// Check Address
if (addr.Length != 3) // should be no more than 3
{
throw new ParseException($"SAP1ASM: invalid address on line {line_number}.", new ParseException($"\"{addr}\" is not of the form \"0xX\""));
}
if (!Regex.IsMatch(addr, "^0[xX][0-9a-fA-F]$")) // should be of the form 0xX
{
throw new ParseException($"SAP1ASM: invalid address on line {line_number}.", new ParseException($"\"{addr}\" is not of the form \"0xX\""));
}
int hex_addr = (int)(Convert.ToUInt32(addr.Substring(2, 1), 16));
if (hex_addr < 0 || hex_addr >= 16) // must tbe between 0-15
{
throw new ParseException($"SAP1ASM: address out of range on line {line_number}.", new ParseException($"\"{addr}\" must be betweeen 0x0 and 0xF"));
}
if (line.Contains("..."))
{
throw new ParseException($"SAP1ASM: invalid use of \"...\" on line {line_number}.", new ParseException($"\"{line}\" must only contain \"...\" with no extra charecters or spaces"));
}
}
else
{
if (!dot_macro_used)
{
dot_macro_used = true;
}
else
{
throw new ParseException($"SAP1ASM: invalid use of \"...\" {line_number}.", new ParseException($"\"{line}\" must only contain once instance of \"...\" in the program"));
}
}
line_number++;
}
// If the code does not contain a HLT instruction
if (!contains_hlt)
{
throw new ParseException($"SAP1ASM: program does not contain an endpoint.", new ParseException($"\"HLT\" must be present in the program at least once"));
}
return(true);
}