compiler-rt doesn't build with cmake

[MagaTailor]

Trying to use system LLVM 3.8 located in /usr fails:

CMake Error at CMakeLists.txt:113 (include):
  include could not find load file:

    /usr/lib/llvm-3.8/build/share/llvm/cmake/LLVMConfig.cmake

CMake Error at cmake/Modules/AddCompilerRT.cmake:1 (include):
  include could not find load file:

    AddLLVM
Call Stack (most recent call first):
  lib/CMakeLists.txt:4 (include)

because it's located in /usr/share/llvm-3.8/cmake/LLVMConfig.cmake

This particular aarch64 Ubuntu 16.04 image used to work fine 3 weeks ago but, IIRC, cmake wasn't used at the time.

[sanxiyn]

Yes, this is unfortunate. Copying or symbolic linking cmake directory works. See src/etc/Dockerfile for an example.

[MagaTailor]

I'd tried symlinking but it didn't work either:

CMake Error at /usr/lib/llvm-3.8/build/share/llvm/cmake/LLVMExports.cmake:1034 (message):
  The imported target "LLVMSupport" references the file

     "/usr/lib/llvm-3.8/build/lib/libLLVMSupport.a"

  but this file does not exist.  Possible reasons include:

  * The file was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and contained

     "/usr/lib/llvm-3.8/build/share/llvm/cmake/LLVMExports.cmake"

  but not all the files it references.

Call Stack (most recent call first):
  /usr/lib/llvm-3.8/build/share/llvm/cmake/LLVMConfig.cmake:178 (include)
  CMakeLists.txt:113 (include)

The file is found in /usr/lib/llvm-3.8/lib/ or /usr/lib/llvm-3.8/build/Release/lib so after adding two more symlinks to bin and lib in build, I got this:

CMake Error at /usr/lib/llvm-3.8/build/share/llvm/cmake/LLVMExports.cmake:1034 (message):
  The imported target "PollyISL" references the file

     "/usr/lib/llvm-3.8/build/lib/libPollyISL.a"

This library doesn't exist period.

[MagaTailor]

#34873

[japaric]

@petevine #34873 landed. Can this be closed?