https://github.com/mozilla/gecko-dev
Tip revision: 945cdd538ae094d78cc23a323b271038a71c9f09 authored by ffxbld on 06 August 2015, 07:06:26 UTC
Added FIREFOX_39_0_3_RELEASE FIREFOX_39_0_3_BUILD2 tag(s) for changeset 5a41909266e5. DONTBUILD CLOSED TREE a=release
Added FIREFOX_39_0_3_RELEASE FIREFOX_39_0_3_BUILD2 tag(s) for changeset 5a41909266e5. DONTBUILD CLOSED TREE a=release
Tip revision: 945cdd5
jsfun.h
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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 jsfun_h
#define jsfun_h
/*
* JS function definitions.
*/
#include "jsobj.h"
#include "jsscript.h"
#include "jstypes.h"
namespace js {
class FunctionExtended;
typedef JSNative Native;
}
struct JSAtomState;
class JSFunction : public js::NativeObject
{
public:
static const js::Class class_;
enum Flags {
INTERPRETED = 0x0001, /* function has a JSScript and environment. */
NATIVE_CTOR = 0x0002, /* native that can be called as a constructor */
EXTENDED = 0x0004, /* structure is FunctionExtended */
IS_FUN_PROTO = 0x0010, /* function is Function.prototype for some global object */
EXPR_CLOSURE = 0x0020, /* expression closure: function(x) x*x */
HAS_GUESSED_ATOM = 0x0040, /* function had no explicit name, but a
name was guessed for it anyway */
LAMBDA = 0x0080, /* function comes from a FunctionExpression, ArrowFunction, or
Function() call (not a FunctionDeclaration or nonstandard
function-statement) */
SELF_HOSTED = 0x0100, /* function is self-hosted builtin and must not be
decompilable nor constructible. */
SELF_HOSTED_CTOR = 0x0200, /* function is self-hosted builtin constructor and
must be constructible but not decompilable. */
HAS_REST = 0x0400, /* function has a rest (...) parameter */
ASMJS = 0x0800, /* function is an asm.js module or exported function */
INTERPRETED_LAZY = 0x1000, /* function is interpreted but doesn't have a script yet */
ARROW = 0x2000, /* ES6 '(args) => body' syntax */
RESOLVED_LENGTH = 0x4000, /* f.length has been resolved (see js::fun_resolve). */
RESOLVED_NAME = 0x8000, /* f.name has been resolved (see js::fun_resolve). */
/* Derived Flags values for convenience: */
NATIVE_FUN = 0,
ASMJS_CTOR = ASMJS | NATIVE_CTOR,
ASMJS_LAMBDA_CTOR = ASMJS | NATIVE_CTOR | LAMBDA,
INTERPRETED_LAMBDA = INTERPRETED | LAMBDA,
INTERPRETED_LAMBDA_ARROW = INTERPRETED | LAMBDA | ARROW,
STABLE_ACROSS_CLONES = NATIVE_CTOR | IS_FUN_PROTO | EXPR_CLOSURE | HAS_GUESSED_ATOM |
LAMBDA | SELF_HOSTED | SELF_HOSTED_CTOR | HAS_REST | ASMJS | ARROW
};
static_assert((INTERPRETED | INTERPRETED_LAZY) == js::JS_FUNCTION_INTERPRETED_BITS,
"jsfriendapi.h's JSFunction::INTERPRETED-alike is wrong");
private:
uint16_t nargs_; /* number of formal arguments
(including defaults and the rest parameter unlike f.length) */
uint16_t flags_; /* bitfield composed of the above Flags enum */
union U {
class Native {
friend class JSFunction;
js::Native native; /* native method pointer or null */
const JSJitInfo* jitinfo; /* Information about this function to be
used by the JIT;
use the accessor! */
} n;
struct Scripted {
union {
JSScript* script_; /* interpreted bytecode descriptor or null;
use the accessor! */
js::LazyScript* lazy_; /* lazily compiled script, or nullptr */
} s;
JSObject* env_; /* environment for new activations;
use the accessor! */
} i;
void* nativeOrScript;
} u;
js::HeapPtrAtom atom_; /* name for diagnostics and decompiling */
public:
/* Call objects must be created for each invocation of a heavyweight function. */
bool isHeavyweight() const {
MOZ_ASSERT(!isInterpretedLazy());
if (isNative())
return false;
// Note: this should be kept in sync with FunctionBox::isHeavyweight().
return nonLazyScript()->hasAnyAliasedBindings() ||
nonLazyScript()->funHasExtensibleScope() ||
nonLazyScript()->funNeedsDeclEnvObject() ||
isGenerator();
}
size_t nargs() const {
return nargs_;
}
uint16_t flags() const {
return flags_;
}
/* A function can be classified as either native (C++) or interpreted (JS): */
bool isInterpreted() const { return flags() & (INTERPRETED | INTERPRETED_LAZY); }
bool isNative() const { return !isInterpreted(); }
/* Possible attributes of a native function: */
bool isNativeConstructor() const { return flags() & NATIVE_CTOR; }
bool isAsmJSNative() const { return flags() & ASMJS; }
/* Possible attributes of an interpreted function: */
bool isFunctionPrototype() const { return flags() & IS_FUN_PROTO; }
bool isExprClosure() const { return flags() & EXPR_CLOSURE; }
bool hasGuessedAtom() const { return flags() & HAS_GUESSED_ATOM; }
bool isLambda() const { return flags() & LAMBDA; }
bool isSelfHostedBuiltin() const { return flags() & SELF_HOSTED; }
bool isSelfHostedConstructor() const { return flags() & SELF_HOSTED_CTOR; }
bool hasRest() const { return flags() & HAS_REST; }
bool isInterpretedLazy() const { return flags() & INTERPRETED_LAZY; }
bool hasScript() const { return flags() & INTERPRETED; }
// Arrow functions store their lexical |this| in the first extended slot.
bool isArrow() const { return flags() & ARROW; }
bool hasResolvedLength() const { return flags() & RESOLVED_LENGTH; }
bool hasResolvedName() const { return flags() & RESOLVED_NAME; }
bool hasJITCode() const {
if (!hasScript())
return false;
return nonLazyScript()->hasBaselineScript() || nonLazyScript()->hasIonScript();
}
/* Compound attributes: */
bool isBuiltin() const {
return (isNative() && !isAsmJSNative()) || isSelfHostedBuiltin();
}
bool isInterpretedConstructor() const {
// Note: the JITs inline this check, so be careful when making changes
// here. See MacroAssembler::branchIfNotInterpretedConstructor.
return isInterpreted() && !isFunctionPrototype() && !isArrow() &&
(!isSelfHostedBuiltin() || isSelfHostedConstructor());
}
bool isNamedLambda() const {
return isLambda() && displayAtom() && !hasGuessedAtom();
}
bool isBuiltinFunctionConstructor();
/* Returns the strictness of this function, which must be interpreted. */
bool strict() const {
MOZ_ASSERT(isInterpreted());
return isInterpretedLazy() ? lazyScript()->strict() : nonLazyScript()->strict();
}
void setFlags(uint16_t flags) {
this->flags_ = flags;
}
// Can be called multiple times by the parser.
void setArgCount(uint16_t nargs) {
this->nargs_ = nargs;
}
// Can be called multiple times by the parser.
void setHasRest() {
flags_ |= HAS_REST;
}
void setIsSelfHostedBuiltin() {
MOZ_ASSERT(!isSelfHostedBuiltin());
flags_ |= SELF_HOSTED;
}
void setIsSelfHostedConstructor() {
MOZ_ASSERT(!isSelfHostedConstructor());
flags_ |= SELF_HOSTED_CTOR;
}
void setIsFunctionPrototype() {
MOZ_ASSERT(!isFunctionPrototype());
flags_ |= IS_FUN_PROTO;
}
// Can be called multiple times by the parser.
void setIsExprClosure() {
flags_ |= EXPR_CLOSURE;
}
void setArrow() {
flags_ |= ARROW;
}
void setResolvedLength() {
flags_ |= RESOLVED_LENGTH;
}
void setResolvedName() {
flags_ |= RESOLVED_NAME;
}
JSAtom* atom() const { return hasGuessedAtom() ? nullptr : atom_.get(); }
js::PropertyName* name() const {
return hasGuessedAtom() || !atom_ ? nullptr : atom_->asPropertyName();
}
void initAtom(JSAtom* atom) { atom_.init(atom); }
JSAtom* displayAtom() const {
return atom_;
}
void setGuessedAtom(JSAtom* atom) {
MOZ_ASSERT(!atom_);
MOZ_ASSERT(atom);
MOZ_ASSERT(!hasGuessedAtom());
atom_ = atom;
flags_ |= HAS_GUESSED_ATOM;
}
/* uint16_t representation bounds number of call object dynamic slots. */
enum { MAX_ARGS_AND_VARS = 2 * ((1U << 16) - 1) };
/*
* For an interpreted function, accessors for the initial scope object of
* activations (stack frames) of the function.
*/
JSObject* environment() const {
MOZ_ASSERT(isInterpreted());
return u.i.env_;
}
void setEnvironment(JSObject* obj) {
MOZ_ASSERT(isInterpreted());
*(js::HeapPtrObject*)&u.i.env_ = obj;
}
void initEnvironment(JSObject* obj) {
MOZ_ASSERT(isInterpreted());
((js::HeapPtrObject*)&u.i.env_)->init(obj);
}
static inline size_t offsetOfNargs() { return offsetof(JSFunction, nargs_); }
static inline size_t offsetOfFlags() { return offsetof(JSFunction, flags_); }
static inline size_t offsetOfEnvironment() { return offsetof(JSFunction, u.i.env_); }
static inline size_t offsetOfAtom() { return offsetof(JSFunction, atom_); }
static bool createScriptForLazilyInterpretedFunction(JSContext* cx, js::HandleFunction fun);
void relazify(JSTracer* trc);
// Function Scripts
//
// Interpreted functions may either have an explicit JSScript (hasScript())
// or be lazy with sufficient information to construct the JSScript if
// necessary (isInterpretedLazy()).
//
// A lazy function will have a LazyScript if the function came from parsed
// source, or nullptr if the function is a clone of a self hosted function.
//
// There are several methods to get the script of an interpreted function:
//
// - For all interpreted functions, getOrCreateScript() will get the
// JSScript, delazifying the function if necessary. This is the safest to
// use, but has extra checks, requires a cx and may trigger a GC.
//
// - For inlined functions which may have a LazyScript but whose JSScript
// is known to exist, existingScriptForInlinedFunction() will get the
// script and delazify the function if necessary.
//
// - For functions known to have a JSScript, nonLazyScript() will get it.
JSScript* getOrCreateScript(JSContext* cx) {
MOZ_ASSERT(isInterpreted());
MOZ_ASSERT(cx);
if (isInterpretedLazy()) {
JS::RootedFunction self(cx, this);
if (!createScriptForLazilyInterpretedFunction(cx, self))
return nullptr;
return self->nonLazyScript();
}
return nonLazyScript();
}
JSScript* existingScriptForInlinedFunction() {
MOZ_ASSERT(isInterpreted());
if (isInterpretedLazy()) {
// Get the script from the canonical function. Ion used the
// canonical function to inline the script and because it has
// Baseline code it has not been relazified. Note that we can't
// use lazyScript->script_ here as it may be null in some cases,
// see bug 976536.
js::LazyScript* lazy = lazyScript();
JSFunction* fun = lazy->functionNonDelazifying();
MOZ_ASSERT(fun);
JSScript* script = fun->nonLazyScript();
if (shadowZone()->needsIncrementalBarrier())
js::LazyScript::writeBarrierPre(lazy);
flags_ &= ~INTERPRETED_LAZY;
flags_ |= INTERPRETED;
initScript(script);
}
return nonLazyScript();
}
// The state of a JSFunction whose script errored out during bytecode
// compilation. Such JSFunctions are only reachable via GC iteration and
// not from script.
bool hasUncompiledScript() const {
MOZ_ASSERT(hasScript());
return !u.i.s.script_;
}
JSScript* nonLazyScript() const {
MOZ_ASSERT(!hasUncompiledScript());
return u.i.s.script_;
}
bool getLength(JSContext* cx, uint16_t* length) {
JS::RootedFunction self(cx, this);
if (self->isInterpretedLazy() && !self->getOrCreateScript(cx))
return false;
*length = self->hasScript() ? self->nonLazyScript()->funLength()
: (self->nargs() - self->hasRest());
return true;
}
js::LazyScript* lazyScript() const {
MOZ_ASSERT(isInterpretedLazy() && u.i.s.lazy_);
return u.i.s.lazy_;
}
js::LazyScript* lazyScriptOrNull() const {
MOZ_ASSERT(isInterpretedLazy());
return u.i.s.lazy_;
}
js::GeneratorKind generatorKind() const {
if (!isInterpreted())
return js::NotGenerator;
if (hasScript())
return nonLazyScript()->generatorKind();
if (js::LazyScript* lazy = lazyScriptOrNull())
return lazy->generatorKind();
MOZ_ASSERT(isSelfHostedBuiltin());
return js::NotGenerator;
}
bool isGenerator() const { return generatorKind() != js::NotGenerator; }
bool isLegacyGenerator() const { return generatorKind() == js::LegacyGenerator; }
bool isStarGenerator() const { return generatorKind() == js::StarGenerator; }
void setScript(JSScript* script_) {
mutableScript() = script_;
}
void initScript(JSScript* script_) {
mutableScript().init(script_);
}
void setUnlazifiedScript(JSScript* script) {
// Note: createScriptForLazilyInterpretedFunction triggers a barrier on
// lazy script before it is overwritten here.
MOZ_ASSERT(isInterpretedLazy());
if (!lazyScript()->maybeScript())
lazyScript()->initScript(script);
flags_ &= ~INTERPRETED_LAZY;
flags_ |= INTERPRETED;
initScript(script);
}
void initLazyScript(js::LazyScript* lazy) {
MOZ_ASSERT(isInterpreted());
flags_ &= ~INTERPRETED;
flags_ |= INTERPRETED_LAZY;
u.i.s.lazy_ = lazy;
}
JSNative native() const {
MOZ_ASSERT(isNative());
return u.n.native;
}
JSNative maybeNative() const {
return isInterpreted() ? nullptr : native();
}
void initNative(js::Native native, const JSJitInfo* jitinfo) {
MOZ_ASSERT(native);
u.n.native = native;
u.n.jitinfo = jitinfo;
}
const JSJitInfo* jitInfo() const {
MOZ_ASSERT(isNative());
return u.n.jitinfo;
}
void setJitInfo(const JSJitInfo* data) {
MOZ_ASSERT(isNative());
u.n.jitinfo = data;
}
static unsigned offsetOfNativeOrScript() {
static_assert(offsetof(U, n.native) == offsetof(U, i.s.script_),
"native and script pointers must be in the same spot "
"for offsetOfNativeOrScript() have any sense");
static_assert(offsetof(U, n.native) == offsetof(U, nativeOrScript),
"U::nativeOrScript must be at the same offset as "
"native");
return offsetof(JSFunction, u.nativeOrScript);
}
#if JS_BITS_PER_WORD == 32
static const js::gc::AllocKind FinalizeKind = js::gc::AllocKind::OBJECT2_BACKGROUND;
static const js::gc::AllocKind ExtendedFinalizeKind = js::gc::AllocKind::OBJECT4_BACKGROUND;
#else
static const js::gc::AllocKind FinalizeKind = js::gc::AllocKind::OBJECT4_BACKGROUND;
static const js::gc::AllocKind ExtendedFinalizeKind = js::gc::AllocKind::OBJECT8_BACKGROUND;
#endif
inline void trace(JSTracer* trc);
/* Bound function accessors. */
inline bool initBoundFunction(JSContext* cx, js::HandleObject target, js::HandleValue thisArg,
const js::Value* args, unsigned argslen);
JSObject* getBoundFunctionTarget() const;
const js::Value& getBoundFunctionThis() const;
const js::Value& getBoundFunctionArgument(unsigned which) const;
size_t getBoundFunctionArgumentCount() const;
private:
js::HeapPtrScript& mutableScript() {
MOZ_ASSERT(hasScript());
return *(js::HeapPtrScript*)&u.i.s.script_;
}
inline js::FunctionExtended* toExtended();
inline const js::FunctionExtended* toExtended() const;
public:
inline bool isExtended() const {
MOZ_ASSERT_IF(isTenured(), !!(flags() & EXTENDED) == (asTenured().getAllocKind() == ExtendedFinalizeKind));
return !!(flags() & EXTENDED);
}
/*
* Accessors for data stored in extended functions. Use setExtendedSlot if
* the function has already been initialized. Otherwise use
* initExtendedSlot.
*/
inline void initializeExtended();
inline void initExtendedSlot(size_t which, const js::Value& val);
inline void setExtendedSlot(size_t which, const js::Value& val);
inline const js::Value& getExtendedSlot(size_t which) const;
/* Constructs a new type for the function if necessary. */
static bool setTypeForScriptedFunction(js::ExclusiveContext* cx, js::HandleFunction fun,
bool singleton = false);
/* GC support. */
js::gc::AllocKind getAllocKind() const {
static_assert(FinalizeKind != ExtendedFinalizeKind,
"extended/non-extended AllocKinds have to be different "
"for getAllocKind() to have a reason to exist");
js::gc::AllocKind kind = FinalizeKind;
if (isExtended())
kind = ExtendedFinalizeKind;
MOZ_ASSERT_IF(isTenured(), kind == asTenured().getAllocKind());
return kind;
}
};
static_assert(sizeof(JSFunction) == sizeof(js::shadow::Function),
"shadow interface must match actual interface");
extern JSString*
fun_toStringHelper(JSContext* cx, js::HandleObject obj, unsigned indent);
namespace js {
extern bool
Function(JSContext* cx, unsigned argc, Value* vp);
extern bool
Generator(JSContext* cx, unsigned argc, Value* vp);
// Allocate a new function backed by a JSNative.
extern JSFunction*
NewNativeFunction(ExclusiveContext* cx, JSNative native, unsigned nargs, HandleAtom atom,
gc::AllocKind allocKind = JSFunction::FinalizeKind,
NewObjectKind newKind = GenericObject);
// Allocate a new constructor backed by a JSNative.
extern JSFunction*
NewNativeConstructor(ExclusiveContext* cx, JSNative native, unsigned nargs, HandleAtom atom,
gc::AllocKind allocKind = JSFunction::FinalizeKind,
NewObjectKind newKind = GenericObject,
JSFunction::Flags flags = JSFunction::NATIVE_CTOR);
// Allocate a new scripted function. If enclosingDynamicScope is null, the
// global will be used. In all cases the parent of the resulting object will be
// the global.
extern JSFunction*
NewScriptedFunction(ExclusiveContext* cx, unsigned nargs, JSFunction::Flags flags,
HandleAtom atom, gc::AllocKind allocKind = JSFunction::FinalizeKind,
NewObjectKind newKind = GenericObject,
HandleObject enclosingDynamicScope = NullPtr());
// If proto is nullptr, Function.prototype is used instead. If
// enclosingDynamicScope is null, the function will have a null environment()
// (yes, null, not the global). In all cases, the global will be used as the
// parent.
extern JSFunction*
NewFunctionWithProto(ExclusiveContext* cx, JSNative native, unsigned nargs,
JSFunction::Flags flags, HandleObject enclosingDynamicScope, HandleAtom atom,
HandleObject proto, gc::AllocKind allocKind = JSFunction::FinalizeKind,
NewObjectKind newKind = GenericObject);
extern JSAtom*
IdToFunctionName(JSContext* cx, HandleId id);
extern JSFunction*
DefineFunction(JSContext* cx, HandleObject obj, HandleId id, JSNative native,
unsigned nargs, unsigned flags,
gc::AllocKind allocKind = JSFunction::FinalizeKind,
NewObjectKind newKind = GenericObject);
bool
FunctionHasResolveHook(const JSAtomState& atomState, jsid id);
extern bool
fun_resolve(JSContext* cx, HandleObject obj, HandleId id, bool* resolvedp);
extern bool
fun_toString(JSContext* cx, unsigned argc, Value* vp);
extern bool
fun_bind(JSContext* cx, unsigned argc, Value* vp);
/*
* Function extended with reserved slots for use by various kinds of functions.
* Most functions do not have these extensions, but enough do that efficient
* storage is required (no malloc'ed reserved slots).
*/
class FunctionExtended : public JSFunction
{
public:
static const unsigned NUM_EXTENDED_SLOTS = 2;
/* Arrow functions store their lexical |this| in the first extended slot. */
static const unsigned ARROW_THIS_SLOT = 0;
static inline size_t offsetOfExtendedSlot(unsigned which) {
MOZ_ASSERT(which < NUM_EXTENDED_SLOTS);
return offsetof(FunctionExtended, extendedSlots) + which * sizeof(HeapValue);
}
static inline size_t offsetOfArrowThisSlot() {
return offsetOfExtendedSlot(ARROW_THIS_SLOT);
}
private:
friend class JSFunction;
/* Reserved slots available for storage by particular native functions. */
HeapValue extendedSlots[NUM_EXTENDED_SLOTS];
};
extern bool
CloneFunctionObjectUseSameScript(JSCompartment* compartment, HandleFunction fun,
HandleObject newParent);
extern JSFunction*
CloneFunctionObject(JSContext* cx, HandleFunction fun, HandleObject parent,
gc::AllocKind kind = JSFunction::FinalizeKind,
NewObjectKind newKindArg = GenericObject,
HandleObject proto = NullPtr());
extern bool
FindBody(JSContext* cx, HandleFunction fun, HandleLinearString src, size_t* bodyStart,
size_t* bodyEnd);
} // namespace js
inline js::FunctionExtended*
JSFunction::toExtended()
{
MOZ_ASSERT(isExtended());
return static_cast<js::FunctionExtended*>(this);
}
inline const js::FunctionExtended*
JSFunction::toExtended() const
{
MOZ_ASSERT(isExtended());
return static_cast<const js::FunctionExtended*>(this);
}
inline void
JSFunction::initializeExtended()
{
MOZ_ASSERT(isExtended());
MOZ_ASSERT(mozilla::ArrayLength(toExtended()->extendedSlots) == 2);
toExtended()->extendedSlots[0].init(js::UndefinedValue());
toExtended()->extendedSlots[1].init(js::UndefinedValue());
}
inline void
JSFunction::initExtendedSlot(size_t which, const js::Value& val)
{
MOZ_ASSERT(which < mozilla::ArrayLength(toExtended()->extendedSlots));
toExtended()->extendedSlots[which].init(val);
}
inline void
JSFunction::setExtendedSlot(size_t which, const js::Value& val)
{
MOZ_ASSERT(which < mozilla::ArrayLength(toExtended()->extendedSlots));
toExtended()->extendedSlots[which] = val;
}
inline const js::Value&
JSFunction::getExtendedSlot(size_t which) const
{
MOZ_ASSERT(which < mozilla::ArrayLength(toExtended()->extendedSlots));
return toExtended()->extendedSlots[which];
}
namespace js {
JSString* FunctionToString(JSContext* cx, HandleFunction fun, bool bodyOnly, bool lambdaParen);
template<XDRMode mode>
bool
XDRInterpretedFunction(XDRState<mode>* xdr, HandleObject enclosingScope,
HandleScript enclosingScript, MutableHandleFunction objp);
extern JSObject*
CloneFunctionAndScript(JSContext* cx, HandleObject enclosingScope, HandleFunction fun,
PollutedGlobalScopeOption polluted);
/*
* Report an error that call.thisv is not compatible with the specified class,
* assuming that the method (clasp->name).prototype.<name of callee function>
* is what was called.
*/
extern void
ReportIncompatibleMethod(JSContext* cx, CallReceiver call, const Class* clasp);
/*
* Report an error that call.thisv is not an acceptable this for the callee
* function.
*/
extern void
ReportIncompatible(JSContext* cx, CallReceiver call);
bool
CallOrConstructBoundFunction(JSContext*, unsigned, js::Value*);
extern const JSFunctionSpec function_methods[];
extern bool
fun_apply(JSContext* cx, unsigned argc, Value* vp);
extern bool
fun_call(JSContext* cx, unsigned argc, Value* vp);
extern JSObject*
fun_bind(JSContext* cx, HandleObject target, HandleValue thisArg,
Value* boundArgs, unsigned argslen);
} /* namespace js */
#ifdef DEBUG
namespace JS {
namespace detail {
JS_PUBLIC_API(void)
CheckIsValidConstructible(Value calleev);
} // namespace detail
} // namespace JS
#endif
#endif /* jsfun_h */