1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jsfuninlines.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,90 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jsfuninlines_h
1.11 +#define jsfuninlines_h
1.12 +
1.13 +#include "jsfun.h"
1.14 +
1.15 +#include "vm/ScopeObject.h"
1.16 +
1.17 +namespace js {
1.18 +
1.19 +inline const char *
1.20 +GetFunctionNameBytes(JSContext *cx, JSFunction *fun, JSAutoByteString *bytes)
1.21 +{
1.22 + JSAtom *atom = fun->atom();
1.23 + if (atom)
1.24 + return bytes->encodeLatin1(cx, atom);
1.25 + return js_anonymous_str;
1.26 +}
1.27 +
1.28 +static inline JSObject *
1.29 +SkipScopeParent(JSObject *parent)
1.30 +{
1.31 + if (!parent)
1.32 + return nullptr;
1.33 + while (parent->is<ScopeObject>())
1.34 + parent = &parent->as<ScopeObject>().enclosingScope();
1.35 + return parent;
1.36 +}
1.37 +
1.38 +inline bool
1.39 +CanReuseFunctionForClone(JSContext *cx, HandleFunction fun)
1.40 +{
1.41 + if (!fun->hasSingletonType())
1.42 + return false;
1.43 + if (fun->isInterpretedLazy()) {
1.44 + LazyScript *lazy = fun->lazyScript();
1.45 + if (lazy->hasBeenCloned())
1.46 + return false;
1.47 + lazy->setHasBeenCloned();
1.48 + } else {
1.49 + JSScript *script = fun->nonLazyScript();
1.50 + if (script->hasBeenCloned())
1.51 + return false;
1.52 + script->setHasBeenCloned();
1.53 + }
1.54 + return true;
1.55 +}
1.56 +
1.57 +inline JSFunction *
1.58 +CloneFunctionObjectIfNotSingleton(JSContext *cx, HandleFunction fun, HandleObject parent,
1.59 + NewObjectKind newKind = GenericObject)
1.60 +{
1.61 + /*
1.62 + * For attempts to clone functions at a function definition opcode,
1.63 + * try to avoid the the clone if the function has singleton type. This
1.64 + * was called pessimistically, and we need to preserve the type's
1.65 + * property that if it is singleton there is only a single object
1.66 + * with its type in existence.
1.67 + *
1.68 + * For functions inner to run once lambda, it may be possible that
1.69 + * the lambda runs multiple times and we repeatedly clone it. In these
1.70 + * cases, fall through to CloneFunctionObject, which will deep clone
1.71 + * the function's script.
1.72 + */
1.73 + if (CanReuseFunctionForClone(cx, fun)) {
1.74 + RootedObject obj(cx, SkipScopeParent(parent));
1.75 + if (!JSObject::setParent(cx, fun, obj))
1.76 + return nullptr;
1.77 + fun->setEnvironment(parent);
1.78 + return fun;
1.79 + }
1.80 +
1.81 + // These intermediate variables are needed to avoid link errors on some
1.82 + // platforms. Sigh.
1.83 + gc::AllocKind finalizeKind = JSFunction::FinalizeKind;
1.84 + gc::AllocKind extendedFinalizeKind = JSFunction::ExtendedFinalizeKind;
1.85 + gc::AllocKind kind = fun->isExtended()
1.86 + ? extendedFinalizeKind
1.87 + : finalizeKind;
1.88 + return CloneFunctionObject(cx, fun, parent, kind, newKind);
1.89 +}
1.90 +
1.91 +} /* namespace js */
1.92 +
1.93 +#endif /* jsfuninlines_h */
