internal static List <VarValue> VisitValueChangeStream(VCDLexer lexer, IDToVarDef idToVariable, SimPass pass, BitAllocator bitAlloc)
{
List <VarValue> changes = new List <VarValue>();
while (!lexer.IsEmpty())
{
ReadOnlyMemory <byte> text = lexer.NextWordAsMem();
ReadOnlySpan <byte> endToken = new byte[] { (byte)'$', (byte)'e', (byte)'n', (byte)'d' };
if (text.Span.SequenceEqual(endToken))
{
break;
}
VisitValueChange(lexer, text, idToVariable, pass, bitAlloc);
if (pass.BinValue.HasValue)
{
changes.Add(pass.BinValue);
}
else if (pass.RealValue.HasValue)
{
changes.Add(pass.RealValue);
}
else
{
throw new Exception("Expected to read a value change but found none.");
}
}
pass.Reset();
return(changes);
}
internal static void VisitSimCmd(VCDLexer lexer, IDToVarDef idToVariable, SimPass pass, BitAllocator bitAlloc)
{
ReadOnlyMemory <byte> declWordMem = lexer.NextWordAsMem();
ReadOnlySpan <byte> declWord = declWordMem.Span;
ReadOnlySpan <byte> endToken = new byte[] { (byte)'$', (byte)'e', (byte)'n', (byte)'d' };
ReadOnlySpan <byte> commentToken = new byte[] { (byte)'$', (byte)'c', (byte)'o', (byte)'m', (byte)'m', (byte)'e', (byte)'n', (byte)'t' };
ReadOnlySpan <byte> dumpAllToken = new byte[] { (byte)'$', (byte)'d', (byte)'u', (byte)'m', (byte)'p', (byte)'a', (byte)'l', (byte)'l' };
ReadOnlySpan <byte> dumpOffToken = new byte[] { (byte)'$', (byte)'d', (byte)'u', (byte)'m', (byte)'p', (byte)'o', (byte)'f', (byte)'f' };
ReadOnlySpan <byte> dumpOnToken = new byte[] { (byte)'$', (byte)'d', (byte)'u', (byte)'m', (byte)'p', (byte)'o', (byte)'n' };
ReadOnlySpan <byte> dumpVarsToken = new byte[] { (byte)'$', (byte)'d', (byte)'u', (byte)'m', (byte)'p', (byte)'v', (byte)'a', (byte)'r', (byte)'s' };
ReadOnlySpan <byte> hashtagToken = new byte[] { (byte)'#' };
//It may be the case that it's first discovered now that
// the end of the file has been reached.
if (declWord.Length == 0)
{
if (lexer.IsWordsRemaining())
{
throw new Exception("Invalid simulation command.");
}
return;
}
if (declWord.SequenceEqual(commentToken))
{
string text = lexer.NextUntil(endToken).ToCharString();
lexer.ExpectNextWord(endToken);
pass.SimCmd = new Comment(text);
}
else if (declWord.SequenceEqual(dumpAllToken))
{
pass.SimCmd = new DumpAll(VisitValueChangeStream(lexer, idToVariable, pass, bitAlloc));
}
else if (declWord.SequenceEqual(dumpOffToken))
{
pass.SimCmd = new DumpOff(VisitValueChangeStream(lexer, idToVariable, pass, bitAlloc));
}
else if (declWord.SequenceEqual(dumpOnToken))
{
pass.SimCmd = new DumpOn(VisitValueChangeStream(lexer, idToVariable, pass, bitAlloc));
}
else if (declWord.SequenceEqual(dumpVarsToken))
{
pass.SimCmd = new DumpVars(VisitValueChangeStream(lexer, idToVariable, pass, bitAlloc));
}
else if (declWord.StartsWith(hashtagToken))
{
pass.SimCmd = VisitSimTime(declWord);
}
else
{
VisitValueChange(lexer, declWordMem, idToVariable, pass, bitAlloc);
}
}
internal static void VisitScalarValueChange(ReadOnlyMemory <byte> text, IDToVarDef idToVariable, SimPass pass, BitAllocator bitAlloc)
{
UnsafeMemory <BitState> bits = bitAlloc.GetBits(1);
BitState bit = ToBitState(text.Span[0]);
var id = text.Slice(1);
bits.Span[0] = bit;
if (idToVariable.TryGetValue(id, out List <VarDef>?variable))
{
pass.BinValue = new BinaryVarValue(bits, variable, ((int)bit & 0b10) == 0);
}
else
{
throw new Exception($"Unknown variable identifier: {id}");
}
}
internal static (List <IDeclCmd> declarations, IDToVarDef idToVariable) VisitDeclCmdStream(VCDLexer lexer)
{
List <IDeclCmd> declarations = new List <IDeclCmd>();
IDToVarDef idToVariable = new IDToVarDef();
Stack <Scope> scopes = new Stack <Scope>();
while (!lexer.IsEmpty())
{
IDeclCmd?decl = VisitDeclCmd(lexer, idToVariable, scopes);
if (decl == null)
{
break;
}
declarations.Add(decl);
}
if (scopes.Count != 0)
{
throw new Exception("Not all declaration scopes were closed.");
}
return(declarations, idToVariable);
}
internal static IDeclCmd?VisitDeclCmd(VCDLexer lexer, IDToVarDef idToVariable, Stack <Scope> scopes)
{
ReadOnlySpan <byte> declWord = lexer.NextWord();
Span <char> chars = stackalloc char[declWord.Length];
declWord.CopyToCharArray(chars);
ReadOnlySpan <byte> endToken = new byte[] { (byte)'$', (byte)'e', (byte)'n', (byte)'d' };
ReadOnlySpan <byte> dollarSign = new byte[] { (byte)'$' };
if (chars.SequenceEqual("$comment"))
{
string text = lexer.NextUntil(endToken).ToCharString();
lexer.ExpectNextWord(endToken);
return(new Comment(text));
}
else if (chars.SequenceEqual("$date"))
{
string text = lexer.NextUntil(endToken).ToCharString();
lexer.ExpectNextWord(endToken);
return(new Date(text));
}
else if (chars.SequenceEqual("$scope"))
{
ScopeType type = VisitScopeType(lexer);
string id = lexer.NextWord().ToCharString();
Scope scope = new Scope(type, id);
scopes.Push(scope);
lexer.ExpectNextWord(endToken);
return(scope);
}
else if (chars.SequenceEqual("$timescale"))
{
int scale = VisitTimeNumber(lexer);
TimeUnit unit = VisitTimeUnit(lexer);
lexer.ExpectNextWord(endToken);
return(new TimeScale(scale, unit));
}
else if (chars.SequenceEqual("$upscope"))
{
scopes.Pop();
lexer.ExpectNextWord(endToken);
return(new UpScope());
}
else if (chars.SequenceEqual("$var"))
{
VarType type = VisitVarType(lexer);
int size = VisitSize(lexer);
string id = lexer.NextWord().ToCharString();
string reference = lexer.NextWord().ToCharString();
VarDef variable = new VarDef(type, size, id, reference, scopes.Reverse().ToArray());
idToVariable.AddVariable(variable);
//Skip this stuff because it's not currently supported
char nextChar = lexer.PeekNextChar();
if (nextChar == '[')
{
ReadOnlySpan <byte> endBracket = new byte[] { (byte)']' };
lexer.NextUntil(endBracket);
lexer.SkipChar();
}
lexer.ExpectNextWord(endToken);
return(variable);
}
else if (chars.SequenceEqual("$version"))
{
string versionTxt = lexer.NextUntil(dollarSign).ToCharString();
string systemTaskString = string.Empty;
ReadOnlySpan <byte> systemTask = lexer.PeekNextWord().Span;
if (systemTask.StartsWith(dollarSign) && !systemTask.SequenceEqual(endToken))
{
lexer.SkipWord(systemTask);
systemTaskString = systemTask.ToCharString();
}
lexer.ExpectNextWord(endToken);
return(new Version(versionTxt, systemTaskString));
}
else if (chars.SequenceEqual("$enddefinitions"))
{
lexer.ExpectNextWord(endToken);
return(null);
}
else
{
throw new Exception($"Invalid declaration command: {declWord.ToCharString()}\nBuffer: {lexer.BufferToString()}");
}
}
internal static void VisitRealVectorValueChange(VCDLexer lexer, ReadOnlySpan <byte> valueText, IDToVarDef idToVariable, SimPass pass, BitAllocator bitAlloc)
{
Span <char> chars = stackalloc char[valueText.Length];
valueText.CopyToCharArray(chars);
double value = double.Parse(chars, NumberStyles.Float, CultureInfo.InvariantCulture);
var id = lexer.NextWordAsMem();
if (idToVariable.TryGetValue(id, out List <VarDef>?variable))
{
pass.RealValue = new RealVarValue(value, variable);
}
else
{
throw new Exception($"Unknown variable identifier: {id}");
}
}
internal static void VisitBinaryVectorValueChange(VCDLexer lexer, ReadOnlySpan <byte> valueText, IDToVarDef idToVariable, SimPass pass, BitAllocator bitAlloc)
{
(UnsafeMemory <BitState> bits, bool isValidBinary) = ToBitStates(valueText, bitAlloc);
var id = lexer.NextWordAsMem();
if (idToVariable.TryGetValue(id, out List <VarDef>?variables))
{
pass.BinValue = new BinaryVarValue(bits, variables, isValidBinary);
}
else
{
throw new Exception($"Unknown variable identifier: {id}");
}
}
internal static void VisitValueChange(VCDLexer lexer, ReadOnlyMemory <byte> text, IDToVarDef idToVariable, SimPass pass, BitAllocator bitAlloc)
{
if (text.Length < 2)
{
throw new Exception($"Invalid value change: {text.ToString()}");
}
ReadOnlySpan <byte> textSpan = text.Span;
if (textSpan[0] == 'b' || textSpan[0] == 'B')
{
VisitBinaryVectorValueChange(lexer, textSpan.Slice(1), idToVariable, pass, bitAlloc);
}
else if (textSpan[0] == 'r' || textSpan[0] == 'R')
{
VisitRealVectorValueChange(lexer, textSpan.Slice(1), idToVariable, pass, bitAlloc);
}
else
{
VisitScalarValueChange(text, idToVariable, pass, bitAlloc);
}
}