In bug 592202 comment 52 I wrote: > I'd like another follow-up bug to look at the `if (!fn->isFunArg())` block > in Parser::setFunctionKinds. I bet those two blocks of code (the if block and > the else block) can be combined into something shorter and saner. Brendan replied in comment 55: > As mentioned on IRC, that condition is a stricter one than the condition we > need now: that the function isn't induced by a hoisted declaration form. We > cannot flatten non-lambdas. ...which is not total disagreement, so I think I will try it. There's also this, in CanFlattenUpvar: > /* > * If this function is reaching up across an enclosing funarg, then we > * cannot copy dn's value into a flat closure slot (the display stops > * working once the funarg escapes). > */ > if (!afunbox || afunbox->node->isFunArg()) > return false; This looks bogus to me; I think it can be deleted. If setFunctionKinds and CanFlattenUpvar can be simplified this way, then the funarg analysis can be removed.
Created attachment 553986 [details] [diff] [review] v1 This patch makes me happy. As long as the implementation of js::GetUpvar is to walk the stack, we can't get rid of the funarg analysis.
Comment on attachment 553986 [details] [diff] [review] v1 >+ uintN hasUpvars = false; Why is this an int?
(In reply to Ms2ger from comment #3) > Comment on attachment 553986 [details] [diff] [review] > >+ uintN hasUpvars = false; > Why is this an int? Oh, it shouldn't be. The obvious fix is now inbound: http://hg.mozilla.org/integration/mozilla-inbound/rev/0504a441fef7