void * JS_FASTCALL
stubs::CompileFunction(VMFrame &f, uint32 nactual)
{
/*
* We have a partially constructed frame. That's not really good enough to
* compile though because we could throw, so get a full, adjusted frame.
*/
JSContext *cx = f.cx;
JSStackFrame *fp = f.fp();
/*
* Since we can only use members set by initCallFrameCallerHalf,
* we must carefully extract the callee from the nactual.
*/
JSObject &callee = fp->formalArgsEnd()[-(int(nactual) + 2)].toObject();
JSFunction *fun = callee.getFunctionPrivate();
JSScript *script = fun->script();
/*
* FixupArity/RemovePartialFrame expect to be called after the early
* prologue.
*/
fp->initCallFrameEarlyPrologue(fun, nactual);
if (nactual != fp->numFormalArgs()) {
fp = (JSStackFrame *)FixupArity(f, nactual);
if (!fp)
return NULL;
}
/* Finish frame initialization. */
fp->initCallFrameLatePrologue();
/* These would have been initialized by the prologue. */
f.regs.fp = fp;
f.regs.sp = fp->base();
f.regs.pc = script->code;
if (fun->isHeavyweight() && !js::CreateFunCallObject(cx, fp))
THROWV(NULL);
CompileStatus status = CanMethodJIT(cx, script, fp, CompileRequest_JIT);
if (status == Compile_Okay)
return script->getJIT(fp->isConstructing())->invokeEntry;
/* Function did not compile... interpret it. */
JSBool ok = Interpret(cx, fp);
InlineReturn(f);
if (!ok)
THROWV(NULL);
return NULL;
}
static jsbytecode *
FindExceptionHandler(JSContext *cx)
{
JSStackFrame *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;
jsbytecode *pc = script->main + tn->start + tn->length;
JSBool ok = js_UnwindScope(cx, tn->stackDepth, JS_TRUE);
JS_ASSERT(cx->regs->sp == fp->base() + tn->stackDepth);
switch (tn->kind) {
case JSTRY_CATCH:
JS_ASSERT(js_GetOpcode(cx, fp->script(), 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(js_GetOpcode(cx, fp->script(), pc) == JSOP_ENDITER);
cx->clearPendingException();
ok = !!js_CloseIterator(cx, &cx->regs->sp[-1].toObject());
cx->regs->sp -= 1;
if (!ok)
goto top;
cx->setPendingException(v);
}
}
}
}
return NULL;
}