682504 - js-ctypes doesn't handle void callbacks

Status: RESOLVED FIXED

(Core :: js-ctypes, defect)

Description

[Bobby Holley (:bholley)]

We check the void case here: http://hg.mozilla.org/mozilla-central/file/906413a7ae6b/js/src/ctypes/CTypes.cpp#l5365

After that though, we still call ImplicitConvert unconditionally: http://hg.mozilla.org/mozilla-central/file/906413a7ae6b/js/src/ctypes/CTypes.cpp#l5414

The first thing we do within ImplicitConvert is assert IsSizeDefined() on the target type. This is false for a void return value.

Patch and test coverage coming right up.

Comment 1

[Bobby Holley (:bholley)]

Attachment: Don't try to ImplicitConvert a void return value. v1

Attached a patch. Flagging dwitte for review.

Comment 2

[Bobby Holley (:bholley)]

Attachment: Tests. v1

Attached tests. Flagging jorendorff for review.

Comment 3

[Jason Orendorff [:jorendorff]]

Comment on attachment 556211 [details] [diff] [review]
Don't try to ImplicitConvert a void return value. v1

Stealing review. This is correct (but should not land without the tests of course).

Comment 4

[Jason Orendorff [:jorendorff]]

Comment on attachment 556212 [details] [diff] [review]
Tests. v1

I guess there is no such thing as a bad test, but note that this can be tested without touching the C++ library. The simplest test is like this:

  var fnptr_t = ctypes.FunctionType(ctypes.default_abi, ctypes.void_t, []).ptr;
  fnptr_t(function () {})();  // don't crash

It crashes without the patch. I can't overstate how nice it is to have small tests--so please add a test with just this in it, if you can do that.

Otherwise r=me. Thanks.

Comment 5

[Bobby Holley (:bholley)]

Attachment: Tests. v2

> The simplest test is like this:

Ah, good idea! Attaching an updated patch and carrying over review.

Comment 6

[Bobby Holley (:bholley)]

Attachment: Tests. v2

Whoops, small bug in my push-to-bugzilla script. Sorry for the bugspam.

Comment 7

[Bobby Holley (:bholley)]

Attachment: Tests. v2

Still not quite right. This should do it.

Comment 9

[Bobby Holley (:bholley)]

Pushed to mozilla-inbound: http://hg.mozilla.org/integration/mozilla-inbound/rev/f13920d33454

This had a green try run, modulo known oranges: https://tbpl.mozilla.org/?tree=Try&usebuildbot=1&rev=e71f6e3a3771

Comment 10

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

https://hg.mozilla.org/mozilla-central/rev/c5ed26ad5709
https://hg.mozilla.org/mozilla-central/rev/f13920d33454