Don't include revisions in --version output by default #2105
Conversation
No intended functionality change.
Previously, any commit or rebase would force a re-link of the compiler to pick up the updated version number, even if nothing in the compiler changed. That in turn forces an unnecessary rebuild of the standard library. Now, you can opt into this behavior with the build-script-impl option 'swift-include-revisions-in-version' (it's off by default). When not turned on, no revision numbers will be shown in --version output. As far as the standard presets go, this is turned on for non-incremental buildbot builds and package builds, and off in incremental buildbot builds.
|
Low-priority review request for @gribozavr. @swift-ci Please smoke test |
|
@jrose-apple Thank you! I've been thinking about fixing this for quite a while! Thanks for doing it! :-) |
|
on Fri Apr 08 2016, Jordan Rose <notifications-AT-i.8713187.xyz> wrote:
My hero! Thanks. Dave |
|
I'm afraid I'll have to betray you all; Dmitri reminded me that this version string is used to avoid reusing the Clang module cache when something has changed. That means that changing the importer could result in crashes. I could still add this and just have it on by default, but I'm reluctant to even allow turning it off. The most likely symptom of a stale Clang module cache is crashes in clang::ASTReader, but it could also result in changed apinotes or import strategies not being applied, which means tests would just inexplicably fail locally. I think this needs a cleverer solution. |
|
I'll leave the branch around for a while in case anyone wants to do something with it. |
Can you add such a comment to the current version code, so that we aren't tempted to remove it again later while Dmitri isn't looking? |
New build-script-impl option
swift-include-revisions-in-version, which controls whether revision numbers show up in--versionoutput. Turning this on results in the compiler being rebuilt every time the current checked-out revision changes, which then results in the standard library being rebuilt unnecessarily. The default is off.As far as the standard presets go, this is turned on for non-incremental buildbot builds and package builds, and off in incremental buildbot builds.
Present for @dabrahams.
Before merging this pull request to apple/swift repository:
Triggering Swift CI
The swift-ci is triggered by writing a comment on this PR addressed to the GitHub user @swift-ci. Different tests will run depending on the specific comment that you use. The currently available comments are:
Smoke Testing
Validation Testing
Note: Only members of the Apple organization can trigger swift-ci.