public void Memory(char action, string targetName, int paramCount)
{
uint crush;
switch (action)
{
case 's' when paramCount > 1: //set indexed
_opcodes.Add(NanTags.EncodeVariableRef(targetName, out crush));
AddSymbol(crush, targetName);
_opcodes.Add(NanTags.EncodeOpcode('m', 'S', (ushort)paramCount, 0));
break;
case 'g' when paramCount > 0: // get indexed
_opcodes.Add(NanTags.EncodeVariableRef(targetName, out crush));
AddSymbol(crush, targetName);
_opcodes.Add(NanTags.EncodeOpcode('m', 'G', (ushort)paramCount, 0));
break;
default:
NanTags.EncodeVariableRef(targetName, out crush);
AddSymbol(crush, targetName);
_opcodes.Add(NanTags.EncodeLongOpcode('m', action, crush));
break;
}
}
/// <summary>
/// Inject a compiled sub-unit into this writer
/// References to string constants will be recalculated
/// </summary>
public void Merge(NanCodeWriter fragment)
{
var codes = fragment._opcodes;
var strings = fragment._stringTable;
AddSymbols(fragment._symbols);
foreach (var code in codes)
{
var type = NanTags.TypeOf(code);
switch (type)
{
case DataType.Invalid: throw new Exception("Invalid opcode when merging");
case DataType.ValInt32:
case DataType.ValUInt32:
case DataType.VariableRef:
case DataType.Number:
case DataType.Opcode:
_opcodes.Add(code);
break;
case DataType.PtrString:
case DataType.PtrStaticString:
NanTags.DecodePointer(code, out var target, out _);
LiteralString(strings[(int)target]);
break;
// all other types are only expected at runtime (so far)
default: throw new Exception("Unexpected opcode when merging");
}
}
}
/// <summary>
/// Write opcodes and data section to stream
/// References to string constants will be recalculated
/// </summary>
public void WriteToStream(Stream output)
{
// a string is [NanTag(UInt32): byte length] [string bytes, padded to 8 byte chunks]
// 1) Calculate the string table size
var dataLength = _stringTable.Select(CalculatePaddedSize).Sum() + _stringTable.Count;
// 2) Write a jump command to skip the table
var jumpCode = NanTags.EncodeLongOpcode('c', 's', (uint)dataLength);
WriteCode(output, jumpCode);
// 3) Write the strings, with a mapping dictionary
long location = 1; // counting initial jump as 0
var mapping = new Dictionary <long, long>(); // original index, final memory location
for (var index = 0; index < _stringTable.Count; index++)
{
var staticStr = _stringTable[index];
var bytes = Encoding.ASCII.GetBytes(staticStr);
var chunks = CalculatePaddedSize(staticStr);
var padSize = (chunks * 8) - bytes.Length;
mapping.Add(index, location);
var headerOpCode = NanTags.EncodeUInt32((uint)bytes.Length);
WriteCode(output, headerOpCode);
location++;
output.Write(bytes, 0, bytes.Length);
location += chunks;
for (int p = 0; p < padSize; p++)
{
output.WriteByte(0);
}
}
// 4) Write the op-codes
foreach (var code in _opcodes)
{
var type = NanTags.TypeOf(code);
switch (type)
{
case DataType.PtrString:
case DataType.PtrStaticString:
NanTags.DecodePointer(code, out var original, out _);
var final = mapping[original];
WriteCode(output, NanTags.EncodePointer(final, DataType.PtrStaticString));
break;
default:
WriteCode(output, code);
break;
}
}
output.Flush();
}
/// <summary>
/// Write a static string.
/// Static strings aren't seen by the GC and exist in memory outside of the normal allocation space
/// </summary>
public void LiteralString(string s)
{
// duplication check
if (_stringTable.Contains(s))
{
var idx = _stringTable.IndexOf(s);
_opcodes.Add(NanTags.EncodePointer(idx, DataType.PtrStaticString));
return;
}
// no existing matches
_stringTable.Add(s);
_opcodes.Add(NanTags.EncodePointer(_stringTable.Count - 1, DataType.PtrStaticString));
}
public void LiteralInt32(int i)
{
_opcodes.Add(NanTags.EncodeInt32(i));
}
/// <summary>
/// Jump relative up
/// </summary>
public void UnconditionalJump(uint opCodeCount)
{
_opcodes.Add(NanTags.EncodeLongOpcode('c', 'j', opCodeCount));
}
/// <summary>
/// Jump relative down if top of value-stack is false
/// </summary>
public void CompareJump(uint opCodeCount)
{
_opcodes.Add(NanTags.EncodeLongOpcode('c', 'c', opCodeCount));
}
/// <summary>
/// Encode a compound compare
/// </summary>
/// <param name="operation">compare to do</param>
/// <param name="argCount">number of value-stack args to compare</param>
/// <param name="opCodeCount">opcodes to jump relative down if top if comparison result is false</param>
public void CompoundCompareJump(CmpOp operation, ushort argCount, ushort opCodeCount)
{
_opcodes.Add(NanTags.EncodeOpcode('C', (byte)operation, argCount, opCodeCount));
}
public void Return(int pCount)
{
_opcodes.Add(NanTags.EncodeOpcode('c', 'r', 0, (ushort)pCount));
}
/// <summary>
/// Function return that should not happen
/// </summary>
public void InvalidReturn()
{
_opcodes.Add(NanTags.EncodeOpcode('c', 't', 0, 0));
}
/// <summary>
/// Add a define-and-skip set of opcodes *before* merging in the compiled function opcodes.
/// </summary>
public void FunctionDefine(string functionName, int argCount, uint tokenCount)
{
_opcodes.Add(NanTags.EncodeVariableRef(functionName, out var crushed));
AddSymbol(crushed, functionName);
_opcodes.Add(NanTags.EncodeOpcode('f', 'd', (ushort)argCount, (ushort)tokenCount));
}
public void FunctionCall(string functionName, int parameterCount)
{
_opcodes.Add(NanTags.EncodeVariableRef(functionName, out _));
_opcodes.Add(NanTags.EncodeOpcode('f', 'c', (ushort)parameterCount, 0));
}
public void Memory(char action, double opcode)
{
var crush = NanTags.DecodeUInt32(opcode);
_opcodes.Add(NanTags.EncodeLongOpcode('m', action, crush));
}
public void Increment(sbyte incr, string targetName)
{
NanTags.EncodeVariableRef(targetName, out var crush);
AddSymbol(crush, targetName);
_opcodes.Add(NanTags.EncodeLongOpcode('i', (char)incr, crush));
}
/// <summary>
/// Reference a value name
/// </summary>
public void VariableReference(string valueName)
{
_opcodes.Add(NanTags.EncodeVariableRef(valueName, out var crushed));
AddSymbol(crushed, valueName);
}
