static void
CloseLiveIterators(JSContext *cx, const InlineFrameIterator &frame)
{
JSScript *script = frame.script();
jsbytecode *pc = frame.pc();
if (!script->hasTrynotes())
return;
JSTryNote *tn = script->trynotes()->vector;
JSTryNote *tnEnd = tn + script->trynotes()->length;
uint32 pcOffset = uint32(pc - script->main());
for (; tn != tnEnd; ++tn) {
if (pcOffset < tn->start)
continue;
if (pcOffset >= tn->start + tn->length)
continue;
if (tn->kind != JSTRY_ITER)
continue;
JS_ASSERT(JSOp(*(script->main() + tn->start + tn->length)) == JSOP_ENDITER);
JS_ASSERT(tn->stackDepth > 0);
uint32 localSlot = tn->stackDepth;
CloseLiveIterator(cx, frame, localSlot);
}
}
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;
}
