protected override Completion ExecuteInternal(EvaluationContext context)
{
EnvironmentRecord oldEnv = null;
EnvironmentRecord loopEnv = null;
var engine = context.Engine;
if (_boundNames != null)
{
oldEnv = engine.ExecutionContext.LexicalEnvironment;
loopEnv = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv);
var loopEnvRec = loopEnv;
var kind = _initStatement._statement.Kind;
for (var i = 0; i < _boundNames.Count; i++)
{
var name = _boundNames[i];
if (kind == VariableDeclarationKind.Const)
{
loopEnvRec.CreateImmutableBinding(name, true);
}
else
{
loopEnvRec.CreateMutableBinding(name, false);
}
}
engine.UpdateLexicalEnvironment(loopEnv);
}
try
{
if (_initExpression != null)
{
_initExpression?.GetValue(context);
}
else
{
_initStatement?.Execute(context);
}
return(ForBodyEvaluation(context));
}
finally
{
if (oldEnv is not null)
{
engine.UpdateLexicalEnvironment(oldEnv);
}
}
}
public override Completion GetValue(EvaluationContext context)
{
var engine = context.Engine;
var funcEnv = JintEnvironment.NewDeclarativeEnvironment(engine, engine.ExecutionContext.LexicalEnvironment);
var closure = new ScriptFunctionInstance(
engine,
_function,
funcEnv,
_function.ThisMode);
closure.MakeConstructor();
if (_function.Name != null)
{
funcEnv.CreateMutableBindingAndInitialize(_function.Name, canBeDeleted: false, closure);
}
return(Completion.Normal(closure, _expression.Location));
}
protected override Completion ExecuteInternal(EvaluationContext context)
{
EnvironmentRecord oldEnv = null;
var engine = context.Engine;
if (_lexicalDeclarations != null)
{
oldEnv = engine.ExecutionContext.LexicalEnvironment;
var blockEnv = JintEnvironment.NewDeclarativeEnvironment(engine, engine.ExecutionContext.LexicalEnvironment);
JintStatementList.BlockDeclarationInstantiation(engine, blockEnv, _lexicalDeclarations);
engine.UpdateLexicalEnvironment(blockEnv);
}
var blockValue = _statementList.Execute(context);
if (oldEnv is not null)
{
engine.UpdateLexicalEnvironment(oldEnv);
}
return(blockValue);
}
private void CreatePerIterationEnvironment(EvaluationContext context)
{
if (_boundNames == null || _boundNames.Count == 0)
{
return;
}
var engine = context.Engine;
var lastIterationEnv = engine.ExecutionContext.LexicalEnvironment;
var lastIterationEnvRec = lastIterationEnv;
var outer = lastIterationEnv._outerEnv;
var thisIterationEnv = JintEnvironment.NewDeclarativeEnvironment(engine, outer);
for (var j = 0; j < _boundNames.Count; j++)
{
var bn = _boundNames[j];
var lastValue = lastIterationEnvRec.GetBindingValue(bn, true);
thisIterationEnv.CreateMutableBindingAndInitialize(bn, false, lastValue);
}
engine.UpdateLexicalEnvironment(thisIterationEnv);
}
/// <summary>
/// https://tc39.es/ecma262/#sec-runtime-semantics-forin-div-ofheadevaluation-tdznames-expr-iterationkind
/// </summary>
private bool HeadEvaluation(EvaluationContext context, out IteratorInstance result)
{
var engine = context.Engine;
var oldEnv = engine.ExecutionContext.LexicalEnvironment;
var tdz = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv);
if (_tdzNames != null)
{
var TDZEnvRec = tdz;
foreach (var name in _tdzNames)
{
TDZEnvRec.CreateMutableBinding(name);
}
}
engine.UpdateLexicalEnvironment(tdz);
var exprValue = _right.GetValue(context).Value;
engine.UpdateLexicalEnvironment(oldEnv);
if (_iterationKind == IterationKind.Enumerate)
{
if (exprValue.IsNullOrUndefined())
{
result = null;
return(false);
}
var obj = TypeConverter.ToObject(engine.Realm, exprValue);
result = new ObjectKeyVisitor(engine, obj);
}
else
{
result = exprValue as IteratorInstance ?? exprValue.GetIterator(engine.Realm);
}
return(true);
}
public Completion Execute(EvaluationContext context, JsValue input)
{
if (!_initialized)
{
Initialize(context);
_initialized = true;
}
var engine = context.Engine;
JsValue v = Undefined.Instance;
Location l = context.LastSyntaxNode.Location;
JintSwitchCase defaultCase = null;
bool hit = false;
for (var i = 0; i < (uint)_jintSwitchBlock.Length; i++)
{
var clause = _jintSwitchBlock[i];
EnvironmentRecord oldEnv = null;
if (clause.LexicalDeclarations != null)
{
oldEnv = engine.ExecutionContext.LexicalEnvironment;
var blockEnv = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv);
JintStatementList.BlockDeclarationInstantiation(engine, blockEnv, clause.LexicalDeclarations);
engine.UpdateLexicalEnvironment(blockEnv);
}
if (clause.Test == null)
{
defaultCase = clause;
}
else
{
var clauseSelector = clause.Test.GetValue(context).Value;
if (clauseSelector == input)
{
hit = true;
}
}
if (hit && clause.Consequent != null)
{
var r = clause.Consequent.Execute(context);
if (oldEnv is not null)
{
engine.UpdateLexicalEnvironment(oldEnv);
}
if (r.Type != CompletionType.Normal)
{
return(r);
}
l = r.Location;
v = r.Value ?? Undefined.Instance;
}
}
// do we need to execute the default case ?
if (hit == false && defaultCase != null)
{
EnvironmentRecord oldEnv = null;
if (defaultCase.LexicalDeclarations != null)
{
oldEnv = engine.ExecutionContext.LexicalEnvironment;
var blockEnv = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv);
JintStatementList.BlockDeclarationInstantiation(engine, blockEnv, defaultCase.LexicalDeclarations);
engine.UpdateLexicalEnvironment(blockEnv);
}
var r = defaultCase.Consequent.Execute(context);
if (oldEnv is not null)
{
engine.UpdateLexicalEnvironment(oldEnv);
}
if (r.Type != CompletionType.Normal)
{
return(r);
}
l = r.Location;
v = r.Value ?? Undefined.Instance;
}
return(new Completion(CompletionType.Normal, v, null, l));
}
/// <summary>
/// https://tc39.es/ecma262/#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset
/// </summary>
private Completion BodyEvaluation(
EvaluationContext context,
JintExpression lhs,
JintStatement stmt,
IteratorInstance iteratorRecord,
IterationKind iterationKind,
LhsKind lhsKind,
IteratorKind iteratorKind = IteratorKind.Sync)
{
var engine = context.Engine;
var oldEnv = engine.ExecutionContext.LexicalEnvironment;
var v = Undefined.Instance;
var destructuring = _destructuring;
string lhsName = null;
var completionType = CompletionType.Normal;
var close = false;
try
{
while (true)
{
EnvironmentRecord iterationEnv = null;
if (!iteratorRecord.TryIteratorStep(out var nextResult))
{
close = true;
return(new Completion(CompletionType.Normal, v, null, Location));
}
if (iteratorKind == IteratorKind.Async)
{
// nextResult = await nextResult;
ExceptionHelper.ThrowNotImplementedException("await");
}
var nextValue = nextResult.Get(CommonProperties.Value);
close = true;
var lhsRef = new ExpressionResult();
if (lhsKind != LhsKind.LexicalBinding)
{
if (!destructuring)
{
lhsRef = lhs.Evaluate(context);
}
}
else
{
iterationEnv = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv);
if (_tdzNames != null)
{
BindingInstantiation(iterationEnv);
}
engine.UpdateLexicalEnvironment(iterationEnv);
if (!destructuring)
{
var identifier = (Identifier)((VariableDeclaration)_leftNode).Declarations[0].Id;
lhsName ??= identifier.Name;
lhsRef = new ExpressionResult(ExpressionCompletionType.Normal, engine.ResolveBinding(lhsName), identifier.Location);
}
}
if (context.DebugMode)
{
context.Engine.DebugHandler.OnStep(_leftNode);
}
var status = new Completion();
if (!destructuring)
{
if (lhsRef.IsAbrupt())
{
close = true;
status = new Completion(lhsRef);
}
else if (lhsKind == LhsKind.LexicalBinding)
{
((Reference)lhsRef.Value).InitializeReferencedBinding(nextValue);
}
else
{
engine.PutValue((Reference)lhsRef.Value, nextValue);
}
}
else
{
status = BindingPatternAssignmentExpression.ProcessPatterns(
context,
_assignmentPattern,
nextValue,
iterationEnv,
checkObjectPatternPropertyReference: _lhsKind != LhsKind.VarBinding);
if (lhsKind == LhsKind.Assignment)
{
// DestructuringAssignmentEvaluation of assignmentPattern using nextValue as the argument.
}
else if (lhsKind == LhsKind.VarBinding)
{
// BindingInitialization for lhs passing nextValue and undefined as the arguments.
}
else
{
// BindingInitialization for lhs passing nextValue and iterationEnv as arguments
}
}
if (status.IsAbrupt())
{
engine.UpdateLexicalEnvironment(oldEnv);
if (_iterationKind == IterationKind.AsyncIterate)
{
iteratorRecord.Close(status.Type);
return(status);
}
if (iterationKind == IterationKind.Enumerate)
{
return(status);
}
iteratorRecord.Close(status.Type);
return(status);
}
var result = stmt.Execute(context);
engine.UpdateLexicalEnvironment(oldEnv);
if (!ReferenceEquals(result.Value, null))
{
v = result.Value;
}
if (result.Type == CompletionType.Break && (result.Target == null || result.Target == _statement?.LabelSet?.Name))
{
completionType = CompletionType.Normal;
return(new Completion(CompletionType.Normal, v, null, Location));
}
if (result.Type != CompletionType.Continue || (result.Target != null && result.Target != _statement?.LabelSet?.Name))
{
completionType = result.Type;
if (result.IsAbrupt())
{
close = true;
return(result);
}
}
}
}
catch
{
completionType = CompletionType.Throw;
throw;
}
finally
{
if (close)
{
try
{
iteratorRecord.Close(completionType);
}
catch
{
// if we already have and exception, use it
if (completionType != CompletionType.Throw)
{
throw;
}
}
}
engine.UpdateLexicalEnvironment(oldEnv);
}
}
/// <summary>
/// https://tc39.es/ecma262/#sec-performeval
/// </summary>
public JsValue PerformEval(JsValue x, Realm callerRealm, bool strictCaller, bool direct)
{
if (!x.IsString())
{
return(x);
}
var evalRealm = _realm;
_engine._host.EnsureCanCompileStrings(callerRealm, evalRealm);
var inFunction = false;
var inMethod = false;
var inDerivedConstructor = false;
if (direct)
{
var thisEnvRec = _engine.ExecutionContext.GetThisEnvironment();
if (thisEnvRec is FunctionEnvironmentRecord functionEnvironmentRecord)
{
var F = functionEnvironmentRecord._functionObject;
inFunction = true;
inMethod = thisEnvRec.HasSuperBinding();
if (F._constructorKind == ConstructorKind.Derived)
{
inDerivedConstructor = true;
}
}
}
var parser = new JavaScriptParser(x.ToString(), ParserOptions);
Script script = null;
try
{
script = parser.ParseScript(strictCaller);
}
catch (ParserException e)
{
if (e.Description == Messages.InvalidLHSInAssignment)
{
ExceptionHelper.ThrowReferenceError(callerRealm, (string)null);
}
else
{
ExceptionHelper.ThrowSyntaxError(callerRealm, e.Message);
}
}
var body = script.Body;
if (body.Count == 0)
{
return(Undefined);
}
if (!inFunction)
{
// if body Contains NewTarget, throw a SyntaxError exception.
}
if (!inMethod)
{
// if body Contains SuperProperty, throw a SyntaxError exception.
}
if (!inDerivedConstructor)
{
// if body Contains SuperCall, throw a SyntaxError exception.
}
var strictEval = script.Strict || _engine._isStrict;
var ctx = _engine.ExecutionContext;
using (new StrictModeScope(strictEval))
{
EnvironmentRecord lexEnv;
EnvironmentRecord varEnv;
PrivateEnvironmentRecord privateEnv;
if (direct)
{
lexEnv = JintEnvironment.NewDeclarativeEnvironment(_engine, ctx.LexicalEnvironment);
varEnv = ctx.VariableEnvironment;
privateEnv = ctx.PrivateEnvironment;
}
else
{
lexEnv = JintEnvironment.NewDeclarativeEnvironment(_engine, evalRealm.GlobalEnv);
varEnv = evalRealm.GlobalEnv;
privateEnv = null;
}
if (strictEval)
{
varEnv = lexEnv;
}
// If ctx is not already suspended, suspend ctx.
Engine.EnterExecutionContext(lexEnv, varEnv, evalRealm, privateEnv);
try
{
Engine.EvalDeclarationInstantiation(script, varEnv, lexEnv, privateEnv, strictEval);
var statement = new JintScript(script);
var result = statement.Execute(_engine._activeEvaluationContext);
var value = result.GetValueOrDefault();
if (result.Type == CompletionType.Throw)
{
var ex = new JavaScriptException(value).SetCallstack(_engine, result.Location);
throw ex;
}
else
{
return(value);
}
}
finally
{
Engine.LeaveExecutionContext();
}
}
}
protected override Completion ExecuteInternal(EvaluationContext context)
{
var engine = context.Engine;
int callStackSizeBeforeExecution = engine.CallStack.Count;
var b = _block.Execute(context);
if (b.Type == CompletionType.Throw)
{
// initialize lazily
if (_statement.Handler is not null && _catch is null)
{
_catch = Build(_statement.Handler.Body);
}
// execute catch
if (_statement.Handler is not null)
{
// Quick-patch for call stack not being unwinded when an exception is caught.
// Ideally, this should instead be solved by always popping the stack when returning
// from a call, regardless of whether it throws (i.e. CallStack.Pop() in finally clause
// in Engine.Call/Engine.Construct - however, that method currently breaks stack traces
// in error messages.
while (callStackSizeBeforeExecution < engine.CallStack.Count)
{
engine.CallStack.Pop();
}
// https://tc39.es/ecma262/#sec-runtime-semantics-catchclauseevaluation
var thrownValue = b.Value;
var oldEnv = engine.ExecutionContext.LexicalEnvironment;
var catchEnv = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv, catchEnvironment: true);
var boundNames = new List <string>();
_statement.Handler.Param.GetBoundNames(boundNames);
foreach (var argName in boundNames)
{
catchEnv.CreateMutableBinding(argName, false);
}
engine.UpdateLexicalEnvironment(catchEnv);
var catchParam = _statement.Handler?.Param;
catchParam.BindingInitialization(context, thrownValue, catchEnv);
b = _catch.Execute(context);
engine.UpdateLexicalEnvironment(oldEnv);
}
}
if (_finalizer != null)
{
var f = _finalizer.Execute(context);
if (f.Type == CompletionType.Normal)
{
return(b);
}
return(f.UpdateEmpty(Undefined.Instance));
}
return(b.UpdateEmpty(Undefined.Instance));
}