private bool TryReadFrac(
out FloatLiteral frac,
int fracBase,
Func <BigInteger, char, BigInteger?> tryAccumulateFracDigit)
{
(BigInteger, int)pair;
bool parsed = TryReadNum(out pair, (BigInteger.Zero, 0), (acc, c) =>
{
var(i, n) = acc;
var maybeAcc = tryAccumulateFracDigit(i, c);
if (maybeAcc.HasValue)
{
return(maybeAcc.Value, n + 1);
}
else
{
return(null);
}
});
if (parsed)
{
var(i, n) = pair;
frac = FloatLiteral.Number(i, fracBase, -n);
return(true);
}
else
{
frac = FloatLiteral.Zero(fracBase);
return(false);
}
}
private bool TryAppendExponent(
FloatLiteral floatNum,
out FloatLiteral result)
{
bool negateExp = false;
if (Expect('-'))
{
negateExp = true;
}
else
{
Expect('+');
}
BigInteger exp;
if (!TryReadNum(out exp))
{
result = floatNum;
return(false);
}
else
{
result = floatNum.AddToExponent(MaybeNegate(exp, negateExp));
return(true);
}
}
/// <summary>
/// Losslessly changes a float literal's base. Base changes only work if old base
/// is a power of the new base.
/// </summary>
/// <param name="newBase">The new base.</param>
/// <returns>An equivalent float literal with base <paramref name="newBase"/>.</returns>
public FloatLiteral ChangeBase(int newBase)
{
if (Kind != FloatLiteralKind.Number || Base == newBase)
{
return(this);
}
else if (Exponent == 0)
{
return(FloatLiteral.Number(IsNegative, Significand, newBase, 0));
}
// Note: `x * (n ^ m) ^ k` equals `x * n ^ (m * k)`.
var power = 1;
var resultBase = Base;
while (resultBase != newBase)
{
if (resultBase < newBase || resultBase % newBase != 0)
{
throw new InvalidOperationException(
$"Float literal '{this}' with base '{Base}' cannot be transformed losslessly to float with base '{newBase}'.");
}
resultBase /= newBase;
power++;
}
return(FloatLiteral.Number(IsNegative, Significand, newBase, power * Exponent));
}
private Token ReadKeywordToken()
{
var spanStart = offset;
char c;
if (!TryPeekChar(out c) || c < 'a' || c > 'z')
{
return(ReadReservedToken(spanStart));
}
var builder = new StringBuilder();
while (TryReadIdentifierChar(out c))
{
builder.Append(c);
}
var span = new SourceSpan(document, spanStart, offset - spanStart);
var result = builder.ToString();
// Some floating point tokens look like keywords, so we'll handle
// them here as well as in the FP parsing routine.
if (result == "nan")
{
return(new Token(TokenKind.Float, span, FloatLiteral.NaN(false)));
}
else if (result.StartsWith("nan:0x", StringComparison.Ordinal))
{
var payload = result.Substring("nan:0x".Length);
long newBits = 0;
for (int i = 0; i < payload.Length; i++)
{
int digit;
if (payload[i] == '_')
{
continue;
}
else if (TryParseHexDigit(payload[i], out digit))
{
newBits = newBits * 16 + digit;
}
else
{
return(new Token(TokenKind.Keyword, span, result));
}
}
return(new Token(TokenKind.Float, span, FloatLiteral.NaN(false, newBits)));
}
else if (result == "inf")
{
return(new Token(TokenKind.Float, span, FloatLiteral.PositiveInfinity));
}
else
{
return(new Token(TokenKind.Keyword, span, result));
}
}
private bool TryReadUnsignedNumber(
bool negate,
out object result,
IntegerReader tryReadNum,
FloatReader tryReadFrac,
char exponentChar,
int exponent)
{
BigInteger num;
if (tryReadNum(out num))
{
if (Expect('.'))
{
FloatLiteral frac;
if (!tryReadFrac(out frac))
{
frac = FloatLiteral.Zero(exponent);
}
var floatNum = num + frac;
if (Expect(exponentChar) || Expect(char.ToUpperInvariant(exponentChar)))
{
floatNum = floatNum.ChangeBase(exponent);
if (!TryAppendExponent(floatNum, out floatNum))
{
result = null;
return(false);
}
}
result = MaybeNegate(floatNum, negate);
}
else if (Expect(exponentChar) || Expect(char.ToUpperInvariant(exponentChar)))
{
FloatLiteral floatNum;
if (!TryAppendExponent(FloatLiteral.Number(num, exponent), out floatNum))
{
result = null;
return(false);
}
result = MaybeNegate(floatNum, negate);
}
else
{
result = MaybeNegate(num, negate);
}
return(true);
}
else
{
result = null;
return(false);
}
}
private bool TryReadFrac(out FloatLiteral frac)
{
return(TryReadFrac(out frac, 10, (i, c) =>
{
if (c >= '0' && c <= '9')
{
return i * 10 + (c - '0');
}
else
{
return null;
}
}));
}
private bool TryReadHexFrac(out FloatLiteral frac)
{
return(TryReadFrac(out frac, 16, (i, c) =>
{
int digit;
if (TryParseHexDigit(c, out digit))
{
return i * 16 + digit;
}
else
{
return null;
}
}));
}
private bool TryReadUnsignedNumber(bool negate, out object result)
{
if (Expect("nan:0x"))
{
BigInteger hexNum;
if (TryReadHexNum(out hexNum))
{
result = FloatLiteral.NaN(negate, (long)hexNum);
return(true);
}
else
{
result = FloatLiteral.NaN(negate);
return(false);
}
}
else if (Expect("nan"))
{
result = FloatLiteral.NaN(negate);
return(true);
}
else if (Expect("inf"))
{
result = MaybeNegate(FloatLiteral.PositiveInfinity, negate);
return(true);
}
else if (Expect("0x"))
{
return(TryReadUnsignedNumber(
negate,
out result,
TryReadHexNum,
TryReadHexFrac,
'p',
2));
}
else
{
return(TryReadUnsignedNumber(
negate,
out result,
TryReadNum,
TryReadFrac,
'e',
10));
}
}
private FloatLiteral MaybeNegate(FloatLiteral v, bool negate)
{
return(negate ? -v : v);
}
/// <summary>
/// Runs a single expression in the script.
/// </summary>
/// <param name="expression">The expression to run.</param>
public TestStatistics Run(SExpression expression)
{
if (expression.IsCallTo("module"))
{
var module = Assembler.AssembleModule(expression, out string moduleId);
var instance = Wasm.Interpret.ModuleInstance.Instantiate(
module,
importer,
policy: ExecutionPolicy.Create(maxMemorySize: 0x1000),
compiler: Compiler);
moduleInstances.Add(instance);
if (moduleId != null)
{
moduleInstancesByName[moduleId] = instance;
}
if (module.StartFunctionIndex.HasValue)
{
instance.Functions[(int)module.StartFunctionIndex.Value].Invoke(Array.Empty <object>());
}
return(TestStatistics.Empty);
}
else if (expression.IsCallTo("register"))
{
var tail = expression.Tail;
var name = Assembler.AssembleString(tail[0], Log);
tail = tail.Skip(1).ToArray();
var moduleId = Assembler.AssembleLabelOrNull(ref tail);
if (moduleId == null)
{
importer.RegisterImporter(name, new ModuleExportsImporter(moduleInstances[moduleInstances.Count - 1]));
}
else
{
importer.RegisterImporter(name, new ModuleExportsImporter(moduleInstancesByName[moduleId]));
}
return(TestStatistics.Empty);
}
else if (expression.IsCallTo("invoke") || expression.IsCallTo("get"))
{
RunAction(expression);
return(TestStatistics.SingleSuccess);
}
else if (expression.IsCallTo("assert_return"))
{
var results = RunAction(expression.Tail[0]);
var expected = expression.Tail
.Skip(1)
.Zip(results, (expr, val) => EvaluateConstExpr(expr, val.GetType()))
.ToArray();
if (expected.Length != results.Count)
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action produced result ",
string.Join(", ", results),
"; expected ",
string.Join(", ", expected),
".",
Assembler.Highlight(expression)));
return(TestStatistics.SingleFailure);
}
bool failures = false;
for (int i = 0; i < expected.Length; i++)
{
if (!object.Equals(results[i], expected[i]))
{
if (AlmostEquals(results[i], expected[i]))
{
Log.Log(
new LogEntry(
Severity.Warning,
"rounding error",
"action produced result ",
results[i].ToString(),
"; expected ",
expected[i].ToString(),
".",
Assembler.Highlight(expression)));
}
else
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action produced result ",
results[i].ToString(),
"; expected ",
expected[i].ToString(),
".",
Assembler.Highlight(expression)));
failures = true;
}
}
}
return(failures ? TestStatistics.SingleFailure : TestStatistics.SingleSuccess);
}
else if (expression.IsCallTo("assert_trap") || expression.IsCallTo("assert_exhaustion"))
{
var expected = Assembler.AssembleString(expression.Tail[1], Log);
bool caught = false;
Exception exception = null;
try
{
if (expression.Tail[0].IsCallTo("module"))
{
Run(expression.Tail[0]);
}
else
{
RunAction(expression.Tail[0], false);
}
}
catch (TrapException ex)
{
caught = ex.SpecMessage == expected;
exception = ex;
}
catch (PixieException)
{
throw;
}
catch (Exception ex)
{
caught = false;
exception = ex;
}
if (caught)
{
return(TestStatistics.SingleSuccess);
}
else
{
if (exception == null)
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action should have trapped, but didn't.",
Assembler.Highlight(expression)));
}
else
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action trapped as expected, but with an unexpected exception. ",
exception.ToString(),
Assembler.Highlight(expression)));
}
return(TestStatistics.SingleFailure);
}
}
else if (expression.IsCallTo("assert_return_canonical_nan"))
{
var results = RunAction(expression.Tail[0]);
bool isCanonicalNaN;
if (results.Count != 1)
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action produced ",
results.Count.ToString(),
" results (",
string.Join(", ", results),
"); expected a single canonical NaN.",
Assembler.Highlight(expression)));
return(TestStatistics.SingleFailure);
}
else if (results[0] is double)
{
var val = Interpret.ValueHelpers.ReinterpretAsInt64((double)results[0]);
isCanonicalNaN = val == Interpret.ValueHelpers.ReinterpretAsInt64((double)FloatLiteral.NaN(false)) ||
val == Interpret.ValueHelpers.ReinterpretAsInt64((double)FloatLiteral.NaN(true));
}
else if (results[0] is float)
{
var val = Interpret.ValueHelpers.ReinterpretAsInt32((float)results[0]);
isCanonicalNaN = val == Interpret.ValueHelpers.ReinterpretAsInt32((float)FloatLiteral.NaN(false)) ||
val == Interpret.ValueHelpers.ReinterpretAsInt32((float)FloatLiteral.NaN(true));
}
else
{
isCanonicalNaN = false;
}
if (isCanonicalNaN)
{
return(TestStatistics.SingleSuccess);
}
else
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action produced ",
results[0].ToString(),
"; expected a single canonical NaN.",
Assembler.Highlight(expression)));
return(TestStatistics.SingleFailure);
}
}
else if (expression.IsCallTo("assert_return_arithmetic_nan"))
{
var results = RunAction(expression.Tail[0]);
bool isNaN;
if (results.Count != 1)
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action produced ",
results.Count.ToString(),
" results (",
string.Join(", ", results),
"); expected a single NaN.",
Assembler.Highlight(expression)));
return(TestStatistics.SingleFailure);
}
else if (results[0] is double)
{
isNaN = double.IsNaN((double)results[0]);
}
else if (results[0] is float)
{
isNaN = float.IsNaN((float)results[0]);
}
else
{
isNaN = false;
}
if (isNaN)
{
return(TestStatistics.SingleSuccess);
}
else
{
Log.Log(
new LogEntry(
Severity.Error,
"assertion failed",
"action produced ",
results[0].ToString(),
"; expected a single NaN.",
Assembler.Highlight(expression)));
return(TestStatistics.SingleFailure);
}
}
else
{
Log.Log(
new LogEntry(
Severity.Warning,
"unknown script command",
Quotation.QuoteEvenInBold(
"expression ",
expression.Head.Span.Text,
" was not recognized as a known script command."),
Assembler.Highlight(expression)));
return(TestStatistics.SingleUnknown);
}
}