private Emitter(NsxModuleBuilder moduleBuilder, SubroutineSymbol subroutine)
{
_module = moduleBuilder;
_subroutine = subroutine;
_checker = new Checker(subroutine, moduleBuilder.Diagnostics);
_compilation = moduleBuilder.Compilation;
_breakScopes = new ValueStack <BreakScope>(initialCapacity: 4);
_code = default;
_textId = 0;
_supressConstantLookup = false;
_clearPage = true;
if (subroutine is FunctionSymbol function && function.Parameters.Length > 0)
{
foreach (ParameterSymbol p in function.Parameters)
{
_ = GetVariableToken(p.Name);
}
}
}
private static void CompileSubroutines(
NsxModuleBuilder moduleBuilder, ImmutableArray <SubroutineSymbol> subroutines,
ref BufferWriter writer, List <int> subroutineOffsets)
{
if (subroutines.Length == 0)
{
return;
}
var dialogueBlockOffsets = new List <int>();
foreach (SubroutineSymbol subroutine in subroutines)
{
subroutineOffsets.Add(writer.Position);
SubroutineDeclaration decl = subroutine.Declaration;
int dialogueBlockCount = decl.DialogueBlocks.Length;
int start = writer.Position;
int offsetBlockSize = sizeof(ushort) + dialogueBlockCount * sizeof(ushort);
writer.Position += 2 + offsetBlockSize;
dialogueBlockOffsets.Clear();
int codeStart = writer.Position;
Emitter.CompileSubroutine(moduleBuilder, subroutine, ref writer, dialogueBlockOffsets);
int codeEnd = writer.Position;
int codeSize = codeEnd - codeStart;
writer.Position = start;
writer.WriteUInt16LE((ushort)(offsetBlockSize + codeSize));
writer.WriteUInt16LE((ushort)dialogueBlockCount);
for (int i = 0; i < dialogueBlockCount; i++)
{
writer.WriteUInt16LE((ushort)dialogueBlockOffsets[i]);
}
writer.Position = codeEnd;
}
}
public static void WriteModule(NsxModuleBuilder builder)
{
SourceFileSymbol sourceFile = builder.SourceFile;
Compilation compilation = builder.Compilation;
ReadOnlySpan <SubroutineSymbol> subroutines = builder.Subroutines;
// Compile subroutines
using var codeBuffer = PooledBuffer <byte> .Allocate(64 * 1024);
var codeWriter = new BufferWriter(codeBuffer);
var subroutineOffsets = new List <int>(subroutines.Length);
CompileSubroutines(
builder,
sourceFile.Chapters.As <SubroutineSymbol>(),
ref codeWriter,
subroutineOffsets
);
CompileSubroutines(
builder,
sourceFile.Scenes.As <SubroutineSymbol>(),
ref codeWriter,
subroutineOffsets
);
CompileSubroutines(
builder,
sourceFile.Functions.As <SubroutineSymbol>(),
ref codeWriter,
subroutineOffsets
);
codeWriter.WriteBytes(NsxConstants.TableEndMarker);
ReadOnlySpan <string> stringHeap = builder.StringHeap;
const int subTableOffset = NsxConstants.NsxHeaderSize;
int subTableSize = NsxConstants.TableHeaderSize + 6 + subroutines.Length * sizeof(int);
int stringTableSize = NsxConstants.TableHeaderSize + 6 + stringHeap.Length * sizeof(int);
// Build the runtime information table (RTI)
int rtiTableOffset = NsxConstants.NsxHeaderSize + subTableSize;
using var rtiBuffer = PooledBuffer <byte> .Allocate(8 * 1024);
var rtiWriter = new BufferWriter(rtiBuffer);
uint rtiOffsetBlockSize = sourceFile.SubroutineCount * sizeof(ushort);
using var rtiEntryOffsets = PooledBuffer <byte> .Allocate(rtiOffsetBlockSize);
var rtiOffsetWriter = new BufferWriter(rtiEntryOffsets);
WriteRuntimeInformation(
sourceFile.Chapters.As <SubroutineSymbol>(),
ref rtiWriter,
ref rtiOffsetWriter
);
WriteRuntimeInformation(
sourceFile.Scenes.As <SubroutineSymbol>(),
ref rtiWriter,
ref rtiOffsetWriter
);
WriteRuntimeInformation(
sourceFile.Functions.As <SubroutineSymbol>(),
ref rtiWriter,
ref rtiOffsetWriter
);
rtiWriter.WriteBytes(NsxConstants.TableEndMarker);
int rtiSize = NsxConstants.TableHeaderSize + rtiOffsetWriter.Position + rtiWriter.Position;
Span <byte> rtiHeader = stackalloc byte[NsxConstants.TableHeaderSize];
var rtiHeaderWriter = new BufferWriter(rtiHeader);
rtiHeaderWriter.WriteBytes(NsxConstants.RtiTableMarker);
rtiHeaderWriter.WriteUInt16LE((ushort)(rtiSize - NsxConstants.TableHeaderSize));
int impTableOffset = rtiTableOffset + rtiSize;
// Build the import table
ReadOnlySpan <SourceFileSymbol> imports = builder.Imports;
using var importTable = PooledBuffer <byte> .Allocate(2048);
var impTableWriter = new BufferWriter(importTable);
impTableWriter.WriteUInt16LE((ushort)imports.Length);
for (int i = 0; i < imports.Length; i++)
{
impTableWriter.WriteLengthPrefixedUtf8String(imports[i].Name);
}
impTableWriter.WriteBytes(NsxConstants.TableEndMarker);
Span <byte> impHeader = stackalloc byte[NsxConstants.TableHeaderSize];
var impHeaderWriter = new BufferWriter(impHeader);
impHeaderWriter.WriteBytes(NsxConstants.ImportTableMarker);
impHeaderWriter.WriteUInt16LE((ushort)impTableWriter.Position);
int impTableSize = impHeaderWriter.Position + impTableWriter.Position;
int stringTableOffset = impTableOffset + impTableSize;
int codeStart = stringTableOffset + stringTableSize;
// Build the subroutine offset table (SUB)
using var subTable = PooledBuffer <byte> .Allocate((uint) subTableSize);
var subWriter = new BufferWriter(subTable);
subWriter.WriteUInt16LE((ushort)subroutines.Length);
for (int i = 0; i < subroutines.Length; i++)
{
subWriter.WriteInt32LE(subroutineOffsets[i] + codeStart);
}
subWriter.WriteBytes(NsxConstants.TableEndMarker);
Span <byte> subHeader = stackalloc byte[NsxConstants.TableHeaderSize];
var subHeaderWriter = new BufferWriter(subHeader);
subHeaderWriter.WriteBytes(NsxConstants.SubTableMarker);
subHeaderWriter.WriteUInt16LE((ushort)subWriter.Position);
// Encode the strings and build the offset table (STR)
int stringHeapStart = codeStart + codeWriter.Position;
using var stringHeapBuffer = PooledBuffer <byte> .Allocate(64 * 1024);
using var stringOffsetTable = PooledBuffer <byte> .Allocate((uint) stringTableSize);
var strTableWriter = new BufferWriter(stringOffsetTable);
strTableWriter.WriteUInt16LE((ushort)stringHeap.Length);
var stringWriter = new BufferWriter(stringHeapBuffer);
foreach (string s in stringHeap)
{
strTableWriter.WriteInt32LE(stringHeapStart + stringWriter.Position);
stringWriter.WriteLengthPrefixedUtf8String(s);
}
strTableWriter.WriteBytes(NsxConstants.TableEndMarker);
Span <byte> strTableHeader = stackalloc byte[NsxConstants.TableHeaderSize];
var strTableHeaderWriter = new BufferWriter(strTableHeader);
strTableHeaderWriter.WriteBytes(NsxConstants.StringTableMarker);
strTableHeaderWriter.WriteUInt16LE((ushort)stringTableSize);
// Build the NSX header
using var headerBuffer = PooledBuffer <byte> .Allocate(NsxConstants.NsxHeaderSize);
var headerWriter = new BufferWriter(headerBuffer);
long modificationTime = compilation.SourceReferenceResolver
.GetModificationTimestamp(sourceFile.FilePath);
headerWriter.WriteBytes(NsxConstants.NsxMagic);
headerWriter.WriteInt64LE(modificationTime);
headerWriter.WriteInt32LE(subTableOffset);
headerWriter.WriteInt32LE(rtiTableOffset);
headerWriter.WriteInt32LE(impTableOffset);
headerWriter.WriteInt32LE(stringTableOffset);
headerWriter.WriteInt32LE(codeStart);
// --- Write everything to the stream ---
string outDir = compilation.OutputDirectory;
string?subDir = Path.GetDirectoryName(sourceFile.Name);
if (!string.IsNullOrEmpty(subDir))
{
subDir = Path.Combine(outDir, subDir);
Directory.CreateDirectory(subDir);
}
string path = Path.Combine(outDir, Path.ChangeExtension(sourceFile.Name, "nsx"));
using FileStream fileStream = File.Create(path);
fileStream.Write(headerWriter.Written);
fileStream.Write(subHeaderWriter.Written);
fileStream.Write(subWriter.Written);
fileStream.Write(rtiHeader);
fileStream.Write(rtiOffsetWriter.Written);
fileStream.Write(rtiWriter.Written);
fileStream.Write(impHeaderWriter.Written);
fileStream.Write(impTableWriter.Written);
fileStream.Write(strTableHeaderWriter.Written);
fileStream.Write(strTableWriter.Written);
fileStream.Write(codeWriter.Written);
fileStream.Write(stringWriter.Written);
}
