[SR-881] Use of WMO produces "unable to open dependencies file" in llbuild

[drewcrawford]

Previous ID	SR-881
Radar	None
Original Reporter	@drewcrawford
Type	Bug

Attachment: Download

Environment

OSX 10.11.3 (15D21)
swift-DEVELOPMENT-SNAPSHOT-2016-03-01-a

Additional Detail from JIRA

Votes	0
Component/s	llbuild
Labels	Bug
Assignee	None
Priority	Medium

md5: e26beffd1e16b8f7ca7071b46c35d2ec

Issue Description:

When WMO is used, swift-llbuild outputs errors of the form:

<unknown>:0: error: unable to open dependencies file '.atllbuild//llbuildtmp/Fisher-Yates_Shuffle.d'

I guess this is because -emit-dependencies doesn't do anything in this case, but it is not clear how to resolve this. My current workaround is to compile twice, both with and without the flag, which I think is illogical.

To reproduce, open the attached project, and run

$ swift-build-tool -f .atllbuild/llbuild.yaml
Compiling Swift Module 'example' (2 sources)
<unknown>:0: error: unable to open dependencies file '.atllbuild//llbuildtmp/Fisher-Yates_Shuffle.d'
<unknown>:0: error: build had 1 command failures

[drewcrawford]

cc: @ddunbar

[aciidgh]

This should probably be fixed by https://github.com/apple/swift-llbuild/pull/28
@drewcrawford can you try using the new flag and confirm

[Dante-Broggi]

@aciidb0mb3r commented that this should be fixed. If it has, this should be closed.