testonly in the top-level

[Shuhei Takahashi (nya)]

Hi GN devs,

I see some usages of top-level "testonly = true" in Chromium:

https://source.chromium.org/search?q=%5Etestonly%5C%20%3D%5C%20true&ss=chromium%2Fchromium%2Fsrc

The comment says it marks all targets as testonly, but is it true? I don't see any mention in the GN's reference guide. Although I see a similar description for visibility.

Thanks,

Shuhei / nya

--

Shuhei Takahashi a.k.a nya <n...@google.com>

[Roland McGrath]

Variable propagation from outer scopes to inner scopes is a bit subtle in GN.  Anything that looks for `invoker.testonly` directly will find it when it was defined in a containing scope.  Things that use `forward_variables_from` will not find it with the `"*"` wildcard, but will find it when named explicitly.

[Shuhei Takahashi (nya)]

That makes sense, thanks Roland for explanation! 

Shuhei Takahashi a.k.a nya <n...@google.com>

2025年12月18日(木) 3:21 Roland McGrath <mcgr...@chromium.org>: