[Batch Mode] Merge pull request #18489 from davidungar/rdar-42314665-fix-batch-mode-diag-trunctation

[davidungar]

Explanation: Fixes batch mode bug where all diagnostic outputs could be truncated, leaving the user with no diagnostics.
Scope of issue: User gets no diagnostics when all errors are present in non-primaries.
Origination: Initial implementation of batch mode.
Risk: Should be minimal, but I could be wrong.
Reviewed by: Jordan Rose
Testing: Normal regression tests.
Radar: rdar://43033749, clone of rdar://42314665.

rdar://43033749

[davidungar]

@swift-ci please test

[davidungar]

@swift-ci please nominate

[davidungar]

@AnnaZaks & @jrose-apple : I am cherry-picking this as we decided.

[jrose-apple]

Ah, the 5.0 branch doesn't need nomination yet.

[davidungar]

Thanks, @jrose-apple . I'll merge as soon as it passes the tests, then.

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - a14e64e

[davidungar]

@swift-ci please test linux platform

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - a14e64e

[davidungar]

@swift-ci please test linux platform

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - a14e64e

[jrose-apple]

@swift-ci Please clean test Linux

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - a14e64e

[jrose-apple]

@shahmishal Uh oh, does corelibs-foundation not have a 5.0 branch?

[shahmishal]

@jrose-apple No, it does not have a swift-5.0-branch yet. Is this change already on master because we build with the master branch for swift-corelibs-*

[jrose-apple]

The failure isn't related to David's change; it's a change Doug made a week or so ago. We just don't have any public 5.0 bots to catch it, I guess…

[jrose-apple]

Maybe 5.0 branch cherry-picks shouldn't require Linux testing yet?

[shahmishal]

I will drop the Linux requirement for now, until we re-branch swift-5.0-branch.

[davidungar]

Thank a lot, @jrose-apple and @shahmishal !