X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/81345200c95645a1b0d2635520f96ad55dfde63f..refs/heads/master:/runtime/JSScope.cpp diff --git a/runtime/JSScope.cpp b/runtime/JSScope.cpp index 57c81c6..32ced61 100644 --- a/runtime/JSScope.cpp +++ b/runtime/JSScope.cpp @@ -1,5 +1,5 @@ /* - * Copyright (C) 2012, 2013, 2014 Apple Inc. All Rights Reserved. + * Copyright (C) 2012-2015 Apple Inc. All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -26,8 +26,8 @@ #include "config.h" #include "JSScope.h" -#include "JSActivation.h" #include "JSGlobalObject.h" +#include "JSLexicalEnvironment.h" #include "JSNameScope.h" #include "JSWithScope.h" #include "JSCInlines.h" @@ -40,9 +40,6 @@ void JSScope::visitChildren(JSCell* cell, SlotVisitor& visitor) { JSScope* thisObject = jsCast(cell); ASSERT_GC_OBJECT_INHERITS(thisObject, info()); - COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag); - ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren()); - Base::visitChildren(thisObject, visitor); visitor.append(&thisObject->m_next); } @@ -50,26 +47,26 @@ void JSScope::visitChildren(JSCell* cell, SlotVisitor& visitor) // Returns true if we found enough information to terminate optimization. static inline bool abstractAccess(ExecState* exec, JSScope* scope, const Identifier& ident, GetOrPut getOrPut, size_t depth, bool& needsVarInjectionChecks, ResolveOp& op) { - if (JSActivation* activation = jsDynamicCast(scope)) { + if (JSLexicalEnvironment* lexicalEnvironment = jsDynamicCast(scope)) { if (ident == exec->propertyNames().arguments) { - // We know the property will be at this activation scope, but we don't know how to cache it. + // We know the property will be at this lexical environment scope, but we don't know how to cache it. op = ResolveOp(Dynamic, 0, 0, 0, 0, 0); return true; } - SymbolTableEntry entry = activation->symbolTable()->get(ident.impl()); + SymbolTableEntry entry = lexicalEnvironment->symbolTable()->get(ident.impl()); if (entry.isReadOnly() && getOrPut == Put) { - // We know the property will be at this activation scope, but we don't know how to cache it. + // We know the property will be at this lexical environment scope, but we don't know how to cache it. op = ResolveOp(Dynamic, 0, 0, 0, 0, 0); return true; } if (!entry.isNull()) { - op = ResolveOp(makeType(ClosureVar, needsVarInjectionChecks), depth, 0, activation, entry.watchpointSet(), entry.getIndex()); + op = ResolveOp(makeType(ClosureVar, needsVarInjectionChecks), depth, 0, lexicalEnvironment, entry.watchpointSet(), entry.scopeOffset().offset()); return true; } - if (activation->symbolTable()->usesNonStrictEval()) + if (lexicalEnvironment->symbolTable()->usesNonStrictEval()) needsVarInjectionChecks = true; return false; } @@ -85,7 +82,7 @@ static inline bool abstractAccess(ExecState* exec, JSScope* scope, const Identif op = ResolveOp( makeType(GlobalVar, needsVarInjectionChecks), depth, 0, 0, entry.watchpointSet(), - reinterpret_cast(globalObject->registerAt(entry.getIndex()).slot())); + reinterpret_cast(globalObject->variableAt(entry.scopeOffset()).slot())); return true; } @@ -99,8 +96,19 @@ static inline bool abstractAccess(ExecState* exec, JSScope* scope, const Identif op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, 0, 0, 0, 0); return true; } - - op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, globalObject->structure(), 0, 0, slot.cachedOffset()); + + WatchpointState state = globalObject->structure()->ensurePropertyReplacementWatchpointSet(exec->vm(), slot.cachedOffset())->state(); + if (state == IsWatched && getOrPut == Put) { + // The field exists, but because the replacement watchpoint is still intact. This is + // kind of dangerous. We have two options: + // 1) Invalidate the watchpoint set. That would work, but it's possible that this code + // path never executes - in which case this would be unwise. + // 2) Have the invalidation happen at run-time. All we have to do is leave the code + // uncached. The only downside is slightly more work when this does execute. + // We go with option (2) here because it seems less evil. + op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, 0, 0, 0, 0); + } else + op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, globalObject->structure(), 0, 0, slot.cachedOffset()); return true; } @@ -125,28 +133,50 @@ int JSScope::depth() return depth; } +// When an exception occurs, the result of isUnscopable becomes false. +static inline bool isUnscopable(ExecState* exec, JSScope* scope, JSObject* object, const Identifier& ident) +{ + if (scope->type() != WithScopeType) + return false; + + JSValue unscopables = object->get(exec, exec->propertyNames().unscopablesSymbol); + if (exec->hadException()) + return false; + if (!unscopables.isObject()) + return false; + JSValue blocked = jsCast(unscopables)->get(exec, ident); + if (exec->hadException()) + return false; + + return blocked.toBoolean(exec); +} + JSValue JSScope::resolve(ExecState* exec, JSScope* scope, const Identifier& ident) { ScopeChainIterator end = scope->end(); ScopeChainIterator it = scope->begin(); while (1) { + JSScope* scope = it.scope(); JSObject* object = it.get(); if (++it == end) // Global scope. return object; - if (object->hasProperty(exec, ident)) - return object; + if (object->hasProperty(exec, ident)) { + if (!isUnscopable(exec, scope, object, ident)) + return object; + ASSERT_WITH_MESSAGE(!exec->hadException(), "When an exception occurs, the result of isUnscopable becomes false"); + } } } -ResolveOp JSScope::abstractResolve(ExecState* exec, JSScope* scope, const Identifier& ident, GetOrPut getOrPut, ResolveType unlinkedType) +ResolveOp JSScope::abstractResolve(ExecState* exec, bool hasTopActivation, JSScope* scope, const Identifier& ident, GetOrPut getOrPut, ResolveType unlinkedType) { ResolveOp op(Dynamic, 0, 0, 0, 0, 0); if (unlinkedType == Dynamic) return op; - size_t depth = 0; + size_t depth = hasTopActivation ? 1 : 0; bool needsVarInjectionChecks = JSC::needsVarInjectionChecks(unlinkedType); for (; scope; scope = scope->next()) { if (abstractAccess(exec, scope, ident, getOrPut, depth, needsVarInjectionChecks, op)) @@ -172,12 +202,12 @@ const char* resolveTypeName(ResolveType type) "GlobalProperty", "GlobalVar", "ClosureVar", + "LocalClosureVar", "GlobalPropertyWithVarInjectionChecks", "GlobalVarWithVarInjectionChecks", "ClosureVarWithVarInjectionChecks", "Dynamic" }; - ASSERT(type < sizeof(names) / sizeof(names[0])); return names[type]; }