commit 3ebbebd666d649240ba7762b7d41816688b017d7
author David Greene <greened@obbligato.org> Fri Feb 22 21:19:48 2019 +0000
committer David Greene <greened@obbligato.org> Fri Feb 22 21:19:48 2019 +0000
tree 3d063da1243b75d91eae10e1f9c9842ad519491d
parent d57d5e8d9c7f085042908e19832d71dc4d9e5889

[CMake] Honor LLVM_EXTERNAL_<proj>_SOURCE_DIR

When LLVM_ENABLE_PROJECTS is set, CMake assumes the project
directories are all side-by-side. This is not always the case and
there's no reason to expect it if LLVM_EXTERNAL_<proj>_SOURCE_DIR is
set. Honor that setting if it exists and allow the build configuration
to continue.

Differential Revision: https://reviews.llvm.org/D49672

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354693 91177308-0d34-0410-b5e6-96231b3b80d8