From 2e57b13f10f537eecf3f5b60d3504beb7714358c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Bargull?= Date: Fri, 1 Sep 2017 20:17:15 +0200 Subject: [PATCH] Check for undeclared private names in eval-scripts after parsing Accessing runtime types like execution contexts isn't allowed during parsing, therefore we need to defer the undeclared private names check for eval-scripts. EvalDeclarationInstantiation seems like the obvious choice, because it already contains checks for duplicate lexicals in non-strict eval-scripts. --- spec.html | 116 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 102 insertions(+), 14 deletions(-) diff --git a/spec.html b/spec.html index df5ed48..8525f71 100644 --- a/spec.html +++ b/spec.html @@ -193,20 +193,13 @@

Static Semantics: Early Errors

Private fields may not be deleted in any case. There are only ever private names defined inside class bodies. Inside of a class body, code will be in strict mode, and the above rule applies. Outside of a class body, there will be no private names defined, so the below rule will apply. - Script : ScriptBody? - - 1. Let _names_ be an empty List. - 1. If |Script| is parsed directly from PerformEval, - 1. Let _env_ be the running execution context's PrivateNameEnvironment. - 1. Repeat while _env_ is not *null*, - 1. For each binding named _N_ in _env_, - 1. If _names_ does not contain _N_, append _N_ to _names_. - 1. Let _env_ be _env_'s outer environment reference. - 1. If AllPrivateNamesValid of |ScriptBody| with the argument _names_ is *false*, throw a *SyntaxError* exception. - - Module : ModuleBody? + ScriptBody : StatementList + + ModuleBody : ModuleItemList References to PrivateNames which are not lexically present cause an early error. @@ -858,7 +851,8 @@

Runtime Semantics: CreateDynamicFunction( _constructor_, _newTarget_, _kind_ 1. If _strict_ is *true*, then 1. If BoundNames of _parameters_ contains any duplicate elements, throw a *SyntaxError* exception. 1. Let _privateNames_ be an empty List. - 1. If AllPrivateNamesValid of |ScriptBody| with the argument _privateNames_ is *false*, throw a *SyntaxError* exception. + 1. If AllPrivateNamesValid of _body_ with the argument _privateNames_ is *false*, throw a *SyntaxError* exception. + 1. If AllPrivateNamesValid of _parameters_ with the argument _privateNames_ is *false*, throw a *SyntaxError* exception. 1. Let _proto_ be ? GetPrototypeFromConstructor(_newTarget_, _fallbackProto_). 1. Let _F_ be FunctionAllocate(_proto_, _strict_, _kind_). 1. Let _realmF_ be _F_.[[Realm]]. @@ -880,6 +874,100 @@

Runtime Semantics: CreateDynamicFunction( _constructor_, _newTarget_, _kind_ + +

eval ( _x_ )

+ +

Runtime Semantics: EvalDeclarationInstantiation( _body_, _varEnv_, _lexEnv_, _strict_ )

+

When the abstract operation EvalDeclarationInstantiation is called with arguments _body_, _varEnv_, _lexEnv_, and _strict_, the following steps are taken:

+ + 1. Let _varNames_ be the VarDeclaredNames of _body_. + 1. Let _varDeclarations_ be the VarScopedDeclarations of _body_. + 1. Let _lexEnvRec_ be _lexEnv_'s EnvironmentRecord. + 1. Let _varEnvRec_ be _varEnv_'s EnvironmentRecord. + 1. If _strict_ is *false*, then + 1. If _varEnvRec_ is a global Environment Record, then + 1. For each _name_ in _varNames_, do + 1. If _varEnvRec_.HasLexicalDeclaration(_name_) is *true*, throw a *SyntaxError* exception. + 1. NOTE: `eval` will not create a global var declaration that would be shadowed by a global lexical declaration. + 1. Let _thisLex_ be _lexEnv_. + 1. Assert: The following loop will terminate. + 1. Repeat while _thisLex_ is not the same as _varEnv_, + 1. Let _thisEnvRec_ be _thisLex_'s EnvironmentRecord. + 1. If _thisEnvRec_ is not an object Environment Record, then + 1. NOTE: The environment of with statements cannot contain any lexical declaration so it doesn't need to be checked for var/let hoisting conflicts. + 1. For each _name_ in _varNames_, do + 1. If _thisEnvRec_.HasBinding(_name_) is *true*, then + 1. Throw a *SyntaxError* exception. + 1. NOTE: Annex defines alternate semantics for the above step. + 1. NOTE: A direct eval will not hoist var declaration over a like-named lexical declaration. + 1. Let _thisLex_ be _thisLex_'s outer environment reference. + 1. Let _privateNames_ be an empty List. + 1. Let _privateEnv_ be the running execution context's PrivateNameEnvironment. + 1. Repeat while _privateEnv_ is not *null*, + 1. For each binding named _N_ in _privateEnv_, + 1. If _privateNames_ does not contain _N_, append _N_ to _privateNames_. + 1. Let _privateEnv_ be _privateEnv_'s outer environment reference. + 1. If AllPrivateNamesValid of _body_ with the argument _privateNames_ is *false*, throw a *SyntaxError* exception. + 1. Let _functionsToInitialize_ be a new empty List. + 1. Let _declaredFunctionNames_ be a new empty List. + 1. For each _d_ in _varDeclarations_, in reverse list order do + 1. If _d_ is neither a |VariableDeclaration| nor a |ForBinding| nor a |BindingIdentifier|, then + 1. Assert: _d_ is either a |FunctionDeclaration|, a |GeneratorDeclaration|, or an |AsyncFunctionDeclaration|. + 1. NOTE If there are multiple function declarations for the same name, the last declaration is used. + 1. Let _fn_ be the sole element of the BoundNames of _d_. + 1. If _fn_ is not an element of _declaredFunctionNames_, then + 1. If _varEnvRec_ is a global Environment Record, then + 1. Let _fnDefinable_ be ? _varEnvRec_.CanDeclareGlobalFunction(_fn_). + 1. If _fnDefinable_ is *false*, throw a *TypeError* exception. + 1. Append _fn_ to _declaredFunctionNames_. + 1. Insert _d_ as the first element of _functionsToInitialize_. + 1. NOTE: Annex adds additional steps at this point. + 1. Let _declaredVarNames_ be a new empty List. + 1. For each _d_ in _varDeclarations_, do + 1. If _d_ is a |VariableDeclaration|, a |ForBinding|, or a |BindingIdentifier|, then + 1. For each String _vn_ in the BoundNames of _d_, do + 1. If _vn_ is not an element of _declaredFunctionNames_, then + 1. If _varEnvRec_ is a global Environment Record, then + 1. Let _vnDefinable_ be ? _varEnvRec_.CanDeclareGlobalVar(_vn_). + 1. If _vnDefinable_ is *false*, throw a *TypeError* exception. + 1. If _vn_ is not an element of _declaredVarNames_, then + 1. Append _vn_ to _declaredVarNames_. + 1. NOTE: No abnormal terminations occur after this algorithm step unless _varEnvRec_ is a global Environment Record and the global object is a Proxy exotic object. + 1. Let _lexDeclarations_ be the LexicallyScopedDeclarations of _body_. + 1. For each element _d_ in _lexDeclarations_ do + 1. NOTE Lexically declared names are only instantiated here but not initialized. + 1. For each element _dn_ of the BoundNames of _d_ do + 1. If IsConstantDeclaration of _d_ is *true*, then + 1. Perform ? _lexEnvRec_.CreateImmutableBinding(_dn_, *true*). + 1. Else, + 1. Perform ? _lexEnvRec_.CreateMutableBinding(_dn_, *false*). + 1. For each Parse Node _f_ in _functionsToInitialize_, do + 1. Let _fn_ be the sole element of the BoundNames of _f_. + 1. Let _fo_ be the result of performing InstantiateFunctionObject for _f_ with argument _lexEnv_. + 1. If _varEnvRec_ is a global Environment Record, then + 1. Perform ? _varEnvRec_.CreateGlobalFunctionBinding(_fn_, _fo_, *true*). + 1. Else, + 1. Let _bindingExists_ be _varEnvRec_.HasBinding(_fn_). + 1. If _bindingExists_ is *false*, then + 1. Let _status_ be ! _varEnvRec_.CreateMutableBinding(_fn_, *true*). + 1. Assert: _status_ is not an abrupt completion because of validation preceding step 12. + 1. Perform ! _varEnvRec_.InitializeBinding(_fn_, _fo_). + 1. Else, + 1. Perform ! _varEnvRec_.SetMutableBinding(_fn_, _fo_, *false*). + 1. For each String _vn_ in _declaredVarNames_, in list order do + 1. If _varEnvRec_ is a global Environment Record, then + 1. Perform ? _varEnvRec_.CreateGlobalVarBinding(_vn_, *true*). + 1. Else, + 1. Let _bindingExists_ be _varEnvRec_.HasBinding(_vn_). + 1. If _bindingExists_ is *false*, then + 1. Let _status_ be ! _varEnvRec_.CreateMutableBinding(_vn_, *true*). + 1. Assert: _status_ is not an abrupt completion because of validation preceding step 12. + 1. Perform ! _varEnvRec_.InitializeBinding(_vn_, *undefined*). + 1. Return NormalCompletion(~empty~). + + + +