Would the maintainers please consider merging the attached patch? Detailed description of my problem is on the commit log.
I tracked down this build-time check back to a commit by Oscar Fuentes in 2008 (https://github.com/llvm-mirror/llvm/commit/6326a0d5090110c334a3a554bfb10b37a6fe4709) and hasn’t been changed since. It seems to be unnecessary to prevent a parent project from doing in-source builds.
I ran my project with
make and it seems to have solved my problem. LLVM now builds out-of-tree while my project can be built in-tree.
I ran ‘make check-llvm’ to test it, which gave me this result.
Testing Time: 121.05s
Expected Passes : 21278
Expected Failures : 220
Unsupported Tests : 788
[100%] Built target check-llvm
However I couldn’t build
make check-llvm using in-tree builds, I had to fall back to out-of-tree builds. So to summarize: now LLVM can be part of a parent project that uses in-source builds, but the tests must still be built out-of-tree. If the maintainers are OK with this limitation, the patch is ready. Otherwise I’d have to track down what changes are necessary on the test targets.