void
ClonedBlockObject::put(JSContext *cx)
{
StackFrame *fp = cx->fp();
JS_ASSERT(maybeStackFrame() == js_FloatingFrameIfGenerator(cx, fp));
uint32_t count = slotCount();
uint32_t depth = stackDepth();
/* The block and its locals must be on the current stack for GC safety. */
JS_ASSERT(depth <= uint32_t(cx->regs().sp - fp->base()));
JS_ASSERT(count <= uint32_t(cx->regs().sp - fp->base() - depth));
/* See comments in CheckDestructuring in frontend/Parser.cpp. */
JS_ASSERT(count >= 1);
copySlotRange(RESERVED_SLOTS, fp->base() + depth, count);
/* We must clear the private slot even with errors. */
setPrivate(NULL);
fp->setScopeChainNoCallObj(enclosingScope());
}
static uint32
ConvertFrames(JSContext *cx, IonActivation *activation, IonBailoutIterator &it)
{
AssertCanGC();
IonSpew(IonSpew_Bailouts, "Bailing out %s:%u, IonScript %p",
it.script()->filename, it.script()->lineno, (void *) it.ionScript());
IonSpew(IonSpew_Bailouts, " reading from snapshot offset %u size %u",
it.snapshotOffset(), it.ionScript()->snapshotsSize());
#ifdef DEBUG
// Use count is reset after invalidation. Log use count on bailouts to
// determine if we have a critical sequence of bailout.
if (it.script()->ion == it.ionScript()) {
IonSpew(IonSpew_Bailouts, " Current script use count is %u",
it.script()->getUseCount());
}
#endif
SnapshotIterator iter(it);
// Set a flag to avoid bailing out on every iteration or function call. Ion can
// compile and run the script again after an invalidation.
it.ionScript()->setBailoutExpected();
// We use OffTheBooks instead of cx because at this time we cannot iterate
// on the stack safely and the reported error attempts to walk the IonMonkey
// frames. We cannot iterate on the stack because we have no exit frame to
// start Ion frames iteratons.
BailoutClosure *br = js_new<BailoutClosure>();
if (!br)
return BAILOUT_RETURN_FATAL_ERROR;
activation->setBailout(br);
StackFrame *fp;
if (it.isEntryJSFrame() && cx->fp()->runningInIon() && activation->entryfp()) {
// Avoid creating duplicate interpreter frames. This is necessary to
// avoid blowing out the interpreter stack, and must be used in
// conjunction with inline-OSR from within bailouts (since each Ion
// activation must be tied to a unique JSStackFrame for StackIter to
// work).
//
// Note: If the entry frame is a placeholder (a stub frame pushed for
// JM -> Ion calls), then we cannot re-use it as it does not have
// enough slots.
JS_ASSERT(cx->fp() == activation->entryfp());
fp = cx->fp();
cx->regs().sp = fp->base();
} else {
br->constructFrame();
if (!cx->stack.pushBailoutArgs(cx, it, br->argsGuard()))
return BAILOUT_RETURN_FATAL_ERROR;
fp = cx->stack.pushBailoutFrame(cx, it, *br->argsGuard(), br->frameGuard());
}
if (!fp)
return BAILOUT_RETURN_OVERRECURSED;
br->setEntryFrame(fp);
JSFunction *callee = it.maybeCallee();
if (callee)
fp->formals()[-2].setObject(*callee);
if (it.isConstructing())
fp->setConstructing();
while (true) {
IonSpew(IonSpew_Bailouts, " restoring frame");
fp->initFromBailout(cx, iter);
if (!iter.moreFrames())
break;
iter.nextFrame();
fp = PushInlinedFrame(cx, fp);
if (!fp)
return BAILOUT_RETURN_OVERRECURSED;
}
jsbytecode *bailoutPc = fp->script()->code + iter.pcOffset();
br->setBailoutPc(bailoutPc);
switch (iter.bailoutKind()) {
case Bailout_Normal:
return BAILOUT_RETURN_OK;
case Bailout_TypeBarrier:
return BAILOUT_RETURN_TYPE_BARRIER;
case Bailout_Monitor:
return BAILOUT_RETURN_MONITOR;
case Bailout_RecompileCheck:
return BAILOUT_RETURN_RECOMPILE_CHECK;
case Bailout_BoundsCheck:
return BAILOUT_RETURN_BOUNDS_CHECK;
case Bailout_Invalidate:
return BAILOUT_RETURN_INVALIDATE;
case Bailout_CachedShapeGuard:
return BAILOUT_RETURN_CACHED_SHAPE_GUARD;
// When bailing out from an argument check, none of the code of the
// function has run yet. When profiling, this means that the function
// hasn't flagged its entry just yet. It has been "entered," however, so
// we flag it here manually that the entry has happened.
case Bailout_ArgumentCheck:
fp->unsetPushedSPSFrame();
Probes::enterScript(cx, fp->script().unsafeGet(), fp->script()->function(), fp);
return BAILOUT_RETURN_ARGUMENT_CHECK;
}
JS_NOT_REACHED("bad bailout kind");
return BAILOUT_RETURN_FATAL_ERROR;
}
static jsbytecode *
FindExceptionHandler(JSContext *cx)
{
StackFrame *fp = cx->fp();
JSScript *script = fp->script();
if (!script->hasTrynotes())
return NULL;
error:
if (cx->isExceptionPending()) {
for (TryNoteIter tni(cx->regs()); !tni.done(); ++tni) {
JSTryNote *tn = *tni;
UnwindScope(cx, tn->stackDepth);
/*
* Set pc to the first bytecode after the the try note to point
* to the beginning of catch or finally or to [enditer] closing
* the for-in loop.
*/
jsbytecode *pc = script->main() + tn->start + tn->length;
cx->regs().pc = pc;
cx->regs().sp = fp->base() + tn->stackDepth;
switch (tn->kind) {
case JSTRY_CATCH:
JS_ASSERT(JSOp(*pc) == JSOP_ENTERBLOCK);
#if JS_HAS_GENERATORS
/* Catch cannot intercept the closing of a generator. */
if (JS_UNLIKELY(cx->getPendingException().isMagic(JS_GENERATOR_CLOSING)))
break;
#endif
/*
* Don't clear cx->throwing to save cx->exception from GC
* until it is pushed to the stack via [exception] in the
* catch block.
*/
return pc;
case JSTRY_FINALLY:
/*
* Push (true, exception) pair for finally to indicate that
* [retsub] should rethrow the exception.
*/
cx->regs().sp[0].setBoolean(true);
cx->regs().sp[1] = cx->getPendingException();
cx->regs().sp += 2;
cx->clearPendingException();
return pc;
case JSTRY_ITER:
{
/*
* This is similar to JSOP_ENDITER in the interpreter loop,
* except the code now uses the stack slot normally used by
* JSOP_NEXTITER, namely regs.sp[-1] before the regs.sp -= 2
* adjustment and regs.sp[1] after, to save and restore the
* pending exception.
*/
JS_ASSERT(JSOp(*pc) == JSOP_ENDITER);
bool ok = UnwindIteratorForException(cx, &cx->regs().sp[-1].toObject());
cx->regs().sp -= 1;
if (!ok)
goto error;
}
}
}
} else {
UnwindForUncatchableException(cx, cx->regs());
}
return NULL;
}
static jsbytecode *
FindExceptionHandler(JSContext *cx)
{
StackFrame *fp = cx->fp();
JSScript *script = fp->script();
top:
if (cx->isExceptionPending() && JSScript::isValidOffset(script->trynotesOffset)) {
// The PC is updated before every stub call, so we can use it here.
unsigned offset = cx->regs().pc - script->main();
JSTryNoteArray *tnarray = script->trynotes();
for (unsigned i = 0; i < tnarray->length; ++i) {
JSTryNote *tn = &tnarray->vector[i];
// The following if condition actually tests two separate conditions:
// (1) offset - tn->start >= tn->length
// means the PC is not in the range of this try note, so we
// should continue searching, after considering:
// (2) offset - tn->start == tn->length
// means the PC is at the first op of the exception handler
// for this try note. This happens when an exception is thrown
// during recording: the interpreter sets the PC to the handler
// and then exits. In this case, we are in fact at the right
// exception handler.
//
// Hypothetically, the op we are at might have thrown an
// exception, in which case this would not be the right handler.
// But the first ops of exception handlers generated by our
// bytecode compiler cannot throw, so this is not possible.
if (offset - tn->start > tn->length)
continue;
if (tn->stackDepth > cx->regs().sp - fp->base())
continue;
UnwindScope(cx, tn->stackDepth);
jsbytecode *pc = script->main() + tn->start + tn->length;
cx->regs().pc = pc;
cx->regs().sp = fp->base() + tn->stackDepth;
switch (tn->kind) {
case JSTRY_CATCH:
JS_ASSERT(JSOp(*pc) == JSOP_ENTERBLOCK);
#if JS_HAS_GENERATORS
/* Catch cannot intercept the closing of a generator. */
if (JS_UNLIKELY(cx->getPendingException().isMagic(JS_GENERATOR_CLOSING)))
break;
#endif
/*
* Don't clear cx->throwing to save cx->exception from GC
* until it is pushed to the stack via [exception] in the
* catch block.
*/
return pc;
case JSTRY_FINALLY:
/*
* Push (true, exception) pair for finally to indicate that
* [retsub] should rethrow the exception.
*/
cx->regs().sp[0].setBoolean(true);
cx->regs().sp[1] = cx->getPendingException();
cx->regs().sp += 2;
cx->clearPendingException();
return pc;
case JSTRY_ITER:
{
/*
* This is similar to JSOP_ENDITER in the interpreter loop,
* except the code now uses the stack slot normally used by
* JSOP_NEXTITER, namely regs.sp[-1] before the regs.sp -= 2
* adjustment and regs.sp[1] after, to save and restore the
* pending exception.
*/
Value v = cx->getPendingException();
JS_ASSERT(JSOp(*pc) == JSOP_ENDITER);
cx->clearPendingException();
bool ok = !!js_CloseIterator(cx, &cx->regs().sp[-1].toObject());
cx->regs().sp -= 1;
if (!ok)
goto top;
cx->setPendingException(v);
}
}
}
}
return NULL;
}
extern "C" void *
js_InternalThrow(VMFrame &f)
{
JSContext *cx = f.cx;
ExpandInlineFrames(cx->compartment);
// The current frame may have an associated orphaned native, if the native
// or SplatApplyArgs threw an exception.
RemoveOrphanedNative(cx, f.fp());
JS_ASSERT(!f.fp()->finishedInInterpreter());
// Make sure sp is up to date.
JS_ASSERT(&cx->regs() == &f.regs);
jsbytecode *pc = NULL;
for (;;) {
if (cx->isExceptionPending()) {
// Call the throw hook if necessary
JSThrowHook handler = cx->debugHooks->throwHook;
if (handler || !cx->compartment->getDebuggees().empty()) {
Value rval;
JSTrapStatus st = Debugger::onExceptionUnwind(cx, &rval);
if (st == JSTRAP_CONTINUE && handler) {
st = handler(cx, cx->fp()->script(), cx->regs().pc, &rval,
cx->debugHooks->throwHookData);
}
switch (st) {
case JSTRAP_ERROR:
cx->clearPendingException();
return NULL;
case JSTRAP_CONTINUE:
break;
case JSTRAP_RETURN:
cx->clearPendingException();
cx->fp()->setReturnValue(rval);
return cx->jaegerCompartment()->forceReturnFromExternC();
case JSTRAP_THROW:
cx->setPendingException(rval);
break;
default:
JS_NOT_REACHED("bad onExceptionUnwind status");
}
}
}
pc = FindExceptionHandler(cx);
if (pc)
break;
// The JIT guarantees that ScriptEpilogue() has always been run
// upon exiting to its caller. This is important for consistency,
// where execution modes make similar guarantees about prologues
// and epilogues. RunTracer(), Interpret(), and Invoke() all
// rely on this property.
JS_ASSERT(!f.fp()->finishedInInterpreter());
UnwindScope(cx, 0);
f.regs.sp = f.fp()->base();
if (cx->compartment->debugMode())
js::ScriptDebugEpilogue(cx, f.fp(), false);
ScriptEpilogue(f.cx, f.fp(), false);
// Don't remove the last frame, this is the responsibility of
// JaegerShot()'s caller. We only guarantee that ScriptEpilogue()
// has been run.
if (f.entryfp == f.fp())
break;
JS_ASSERT(f.regs.sp == cx->regs().sp);
InlineReturn(f);
}
JS_ASSERT(f.regs.sp == cx->regs().sp);
if (!pc)
return NULL;
StackFrame *fp = cx->fp();
JSScript *script = fp->script();
/*
* Fall back to EnterMethodJIT and finish the frame in the interpreter.
* With type inference enabled, we may wipe out all JIT code on the
* stack without patching ncode values to jump to the interpreter, and
* thus can only enter JIT code via EnterMethodJIT (which overwrites
* its entry frame's ncode). See ClearAllFrames.
*/
cx->compartment->jaegerCompartment()->setLastUnfinished(Jaeger_Unfinished);
if (!script->ensureRanAnalysis(cx, NULL)) {
js_ReportOutOfMemory(cx);
return NULL;
}
analyze::AutoEnterAnalysis enter(cx);
cx->regs().pc = pc;
cx->regs().sp = fp->base() + script->analysis()->getCode(pc).stackDepth;
/*
* Interpret the ENTERBLOCK and EXCEPTION opcodes, so that we don't go
* back into the interpreter with a pending exception. This will cause
* it to immediately rethrow.
*/
if (cx->isExceptionPending()) {
JS_ASSERT(JSOp(*pc) == JSOP_ENTERBLOCK);
StaticBlockObject &blockObj = script->getObject(GET_SLOTNO(pc))->asStaticBlock();
Value *vp = cx->regs().sp + blockObj.slotCount();
SetValueRangeToUndefined(cx->regs().sp, vp);
cx->regs().sp = vp;
JS_ASSERT(JSOp(pc[JSOP_ENTERBLOCK_LENGTH]) == JSOP_EXCEPTION);
cx->regs().sp[0] = cx->getPendingException();
cx->clearPendingException();
cx->regs().sp++;
cx->regs().pc = pc + JSOP_ENTERBLOCK_LENGTH + JSOP_EXCEPTION_LENGTH;
cx->regs().fp()->setBlockChain(&blockObj);
}
*f.oldregs = f.regs;
return NULL;
}
