tree 1ebd4592041d948cec958ec70c27dcdbe0df4f8c
parent 65cb20c1dbc948113bf26a02487d0ec2647001e1
author Ben Clayton <bclayton@google.com> 1624896597 +0000
committer Tint LUCI CQ <tint-scoped@luci-project-accounts.iam.gserviceaccount.com> 1624896597 +0000

reader/wgsl: Only resync if num errors less than limit

As all loops in the parser require `synchronized_` to be true, don't set this to true if we've hit the maximum number of error diagnostics.
This lets the parser bubble up as soon as the limit was reached, instead of only aborting once we finally reach the top level loop.

ClusterFuzz has uncovered a number of cases where, in a loop, it can produce an error, then resynchronize, then error again on the next loop iteration. This produces more than the max limit of errors, and can stall the tests long enough to time out.

No unit tests for this, as it requires a really contrived input to trigger, and to exhaustively catch all the places we now call maybe_set_synchronized() would result in a large colleciton of horrible tests. Instead, let ClusterFuzz do the testing.

Fixed: chromium:1224031
Fixed: chromium:1224032
Fixed: chromium:1224042
Fixed: chromium:1224049
Fixed: chromium:1224050
Fixed: chromium:1224130
Fixed: chromium:1224131
Fixed: chromium:1224132
Fixed: chromium:1224144
Fixed: chromium:1224191
Change-Id: I63f160e28d13b85ee92e1b921239d7fb8ac22a08
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/56070
Auto-Submit: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>