618197 - Turn the JS recursive descent parser into a coroutine

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, enhancement)

Description

[Chris Leary [:cdleary] (not checking bugmail)]

Firefox.next placeholder bug. The idea is to do incremental parsing corresponding to the network-selector chunks with a yield when the last available character is extinguished. Heap-allocate a stack, mprotect the correct number of pages after it to avoid heaped-stack overflows, and let it ride!

This would also require compiler support to determine (or limit) the maximum size frame under a node in the callgraph, so we could guarantee that mprotect was protecting a safe number of pages. (This also assumes that no nodes in the subgraph use alloca.) That way, you couldn't have stack accesses jump over the known heaped-stack region into arbitrary heap space.

Comment 1

[Till Schneidereit [:till]]

Mass-reassigning cdleary's bugs to default. He won't work on any of them, anymore. I guess, at least.

@cdleary: shout if you take issue with this.

Comment 2

[Matthew Gaudet (he/him) [:mgaudet]]

We may want to do this eventually, but this bug isn't the right way forward methinks.