tree 0bcc39e8ddf16b116383a088d450cf14fe9b35a3
parent f5f8d86dc4c91ef492b919edf98335d4d09188a8
author Jonas Hahnfeld <hahnjo@hahnjo.de> 1607169158 +0100
committer Tom Stellard <tstellar@redhat.com> 1608220280 -0500

[CMake] Avoid __FakeVCSRevision.h with no git repository

Set the return variable to "" in find_first_existing_vc_file to
say that there is a repository, but no file to depend on. This works
transparently for all other callers that handle undefinedness and
equality to an empty string the same way.

Use the knowledge to avoid depending on __FakeVCSRevision.h if there
is no git repository at all (for example when building a release) as
there is no point in regenerating an empty VCSRevision.h.

Differential Revision: https://reviews.llvm.org/D92718

(cherry picked from commit 6e890ec7beb0874464a0af9f84e41a987f968b23)