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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef jsfuninlines_h
#define jsfuninlines_h
#include "jsfun.h"
#include "vm/EnvironmentObject.h"
namespace js {
inline const char*
GetFunctionNameBytes(JSContext* cx, JSFunction* fun, JSAutoByteString* bytes)
{
if (JSAtom* name = fun->explicitName())
return bytes->encodeLatin1(cx, name);
return js_anonymous_str;
}
static inline JSObject*
SkipEnvironmentObjects(JSObject* env)
{
if (!env)
return nullptr;
while (env->is<EnvironmentObject>())
env = &env->as<EnvironmentObject>().enclosingEnvironment();
return env;
}
inline bool
CanReuseFunctionForClone(JSContext* cx, HandleFunction fun)
{
if (!fun->isSingleton())
return false;
if (fun->isInterpretedLazy()) {
LazyScript* lazy = fun->lazyScript();
if (lazy->hasBeenCloned())
return false;
lazy->setHasBeenCloned();
} else {
JSScript* script = fun->nonLazyScript();
if (script->hasBeenCloned())
return false;
script->setHasBeenCloned();
}
return true;
}
inline JSFunction*
CloneFunctionObjectIfNotSingleton(JSContext* cx, HandleFunction fun, HandleObject parent,
HandleObject proto = nullptr,
NewObjectKind newKind = GenericObject)
{
/*
* For attempts to clone functions at a function definition opcode,
* try to avoid the the clone if the function has singleton type. This
* was called pessimistically, and we need to preserve the type's
* property that if it is singleton there is only a single object
* with its type in existence.
*
* For functions inner to run once lambda, it may be possible that
* the lambda runs multiple times and we repeatedly clone it. In these
* cases, fall through to CloneFunctionObject, which will deep clone
* the function's script.
*/
if (CanReuseFunctionForClone(cx, fun)) {
RootedObject obj(cx, SkipEnvironmentObjects(parent));
ObjectOpResult succeeded;
if (proto && !SetPrototype(cx, fun, proto, succeeded))
return nullptr;
MOZ_ASSERT(!proto || succeeded);
fun->setEnvironment(parent);
return fun;
}
// These intermediate variables are needed to avoid link errors on some
// platforms. Sigh.
gc::AllocKind finalizeKind = gc::AllocKind::FUNCTION;
gc::AllocKind extendedFinalizeKind = gc::AllocKind::FUNCTION_EXTENDED;
gc::AllocKind kind = fun->isExtended()
? extendedFinalizeKind
: finalizeKind;
if (CanReuseScriptForClone(cx->compartment(), fun, parent))
return CloneFunctionReuseScript(cx, fun, parent, kind, newKind, proto);
RootedScript script(cx, JSFunction::getOrCreateScript(cx, fun));
if (!script)
return nullptr;
RootedScope enclosingScope(cx, script->enclosingScope());
return CloneFunctionAndScript(cx, fun, parent, enclosingScope, kind, proto);
}
} /* namespace js */
#endif /* jsfuninlines_h */
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