llvm-14.0.0.src.tar.xz extracts to two directories

[pierre]

The tarball for llvm contains two directories:

$ tar tf /sources/llvm-14.0.0.src.tar.xz
llvm-14.0.0.src/
[...]
llvm-14.0.0.src/utils/yaml-bench/CMakeLists.txt
llvm-14.0.0.src/utils/yaml-bench/YAMLBench.cpp
cmake/
cmake/Modules/
cmake/Modules/EnableLanguageNolink.cmake
[...]

I am not sure we want to do anything about that, but since it is an unusual behavior, I report it.

The main drawback is that it may get unnoticed, and not be removed after running the build.

[pierre]

We could put a note. Or we could move it to some place inside the build directory, and sed some CMakeLists.txt (maybe not worth it, since there are 4 CMakeLists.txt files involved). Problem is that there is a variable for the location of this directory, but it is not cached, so it is redefined in each project that needs it... Stupid upstream, stupid cmake, again...

[pierre]

I guess upstream only builds the full project ​https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.0/llvm-project-14.0.0.src.tar.xz, which extracts to a unique directory.

[Bruce Dubbs]

Sigh. I tried:

rm -rf ./cmake

but the build failed with:

CMake Error at tools/clang/cmake/modules/CMakeLists.txt:1 (include):
  include could not find requested file:

    ExtendPath

CMake Error at tools/clang/cmake/modules/CMakeLists.txt:3 (include):
  include could not find requested file:

    FindPrefixFromConfig


CMake Error at tools/clang/cmake/modules/CMakeLists.txt:42 (find_prefix_from_config):
  Unknown CMake command "find_prefix_from_config".

In my case I build with:

DIR=$PWD
rm -rf /build/llvm
mkdir  /build/llvm
cd     /build/llvm
tar -xf $DIR/llvm-14.0.0.src.tar.xz

so the cmake gets deleted with /build/llvm each time I build it.

[Xi Ruoyao]

Upstream bug report link: ​https://github.com/llvm/llvm-project/issues/54716

[pierre]

Upstream seems not clear about what to do. What we have as instructions work presently. We just need to make users aware of the presence of the cmake directory. I'd say we should just add a note. If usptream change their mind, we may have to change the instructions anyway. Then the note may or may not go away.

[pierre]

Fixed at bceef3d3a5