CMake config failure

Runtimes OpenMP
1

I am trying to build the runtime on MacOS, but Cmake is failing.

$ git branch
master
release/11.x

  • release/12.x

$ git describe
llvmorg-12.0.0-rc1-51-ge8cdcaeae406

$ cat JimConfig.sh
// Config script

BUILD_SYSTEM=Ninja
BUILD_TAG=ninja
INSTALLDIR=$HOME/software/clang-12.0.0/arm64

cmake …/llvm
-G$BUILD_SYSTEM -B ${BUILD_TAG}_build
-DCMAKE_OSX_ARCHITECTURES=‘arm64’
-DCMAKE_C_COMPILER=which clang
-DCMAKE_CXX_COMPILER=which clang++
-DCMAKE_BUILD_TYPE=Release
-DCMAKE_INSTALL_PREFIX=$INSTALLDIR
-DLLVM_LOCAL_RPATH=$INSTALLDIR/lib
-DLLVM_ENABLE_WERROR=FALSE
-DLLVM_TARGETS_TO_BUILD=‘AArch64’
-DLLVM_DEFAULT_TARGET_TRIPLE=‘aarch64-apple-darwin20.2.0’
-DDEFAULT_SYSROOT=“$(xcrun --show-sdk-path)”
-DLLVM_ENABLE_PROJECTS=‘openmp’

$ sh JimConfig.sh
– clang project is disabled
– clang-tools-extra project is disabled
– compiler-rt project is disabled
– debuginfo-tests project is disabled
– libc project is disabled
– libclc project is disabled
– libcxx project is disabled
– libcxxabi project is disabled
– libunwind project is disabled
– lld project is disabled
– lldb project is disabled
– mlir project is disabled
– openmp project is enabled
– parallel-libs project is disabled
– polly project is disabled
– pstl project is disabled
– flang project is disabled
– Found libtool - /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool
– Native target X86 is not selected; lli will not JIT code
– Threads enabled.
– Doxygen disabled.
– Go bindings disabled.
– Ninja version: 1.10.2
– Found ld64 - /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld
– Could NOT find OCaml (missing: OCAMLFIND OCAML_VERSION OCAML_STDLIB_PATH)
– Could NOT find OCaml (missing: OCAMLFIND OCAML_VERSION OCAML_STDLIB_PATH)
– OCaml bindings disabled.
– LLVM host triple: x86_64-apple-darwin20.2.0
– LLVM default target triple: aarch64-apple-darwin20.2.0
CMake Warning at cmake/modules/HandleLLVMOptions.cmake:261 (message):
-fPIC is not supported.
Call Stack (most recent call first):
cmake/modules/HandleLLVMOptions.cmake:297 (add_flag_or_print_warning)
CMakeLists.txt:698 (include)

– Targeting AArch64
CMake Error at /Users/jcownie/llvm-project/openmp/CMakeLists.txt:93 (add_subdirectory):
The binary directory

/Users/jcownie/llvm-project/build_aarch64/ninja_build/projects/openmp/runtime

is already used to build a source directory. It cannot be used to build
source directory

/Users/jcownie/llvm-project/openmp/runtime

Specify a unique binary directory name.

– Registering Bye as a pass plugin (static build: OFF)
– Failed to find LLVM FileCheck
– Version: 0.0.0
– Performing Test HAVE_THREAD_SAFETY_ATTRIBUTES – failed to compile
– Performing Test HAVE_GNU_POSIX_REGEX – failed to compile
– Performing Test HAVE_POSIX_REGEX – success
– Performing Test HAVE_STEADY_CLOCK – success
– Configuring incomplete, errors occurred!
See also “/Users/jcownie/llvm-project/build_aarch64/ninja_build/CMakeFiles/CMakeOutput.log”.
See also “/Users/jcownie/llvm-project/build_aarch64/ninja_build/CMakeFiles/CMakeError.log”.
$

This previously worked (with an older version of 12.0).

Suggestions, please…

– Jim
James Cownie <jcownie@gmail.com>
Mob: +44 780 637 7146

2

p.s. Note that if I switch to the “master” branch (and add a few more build targets as below), then this failure does not occur.
-DLLVM_ENABLE_PROJECTS=‘clang;openmp;polly;clang-tools-extra;libcxx;libcxxabi’

3

Hi Jim,

In order to support various new "features" we changed the way to build the openmp offload support, it is as runtime not a project now. I thought the old way would still work, especially for non-offload openmp, but maybe that was wrong.

Long story short, we should add more cmake magic to either make the old way work properly or emit an appropriate warning.

I think the problem here is that openmp now wants `clang` to be the compiler (mainly for the GPU runtimes). To guarantee we have a matching and capable `clang` we generally like `clang` to be in the enabled projects and openmp in the enabled runtimes (-DLLVM_ENABLE_RUNTIMES="openmp"). Since you build with clang we could verify if the version is recent enough and use it. We also might not need any of this because you don't build the target stuff (explicitly) so we could disable that part and go with whatever compiler was chosen.

@Shilei, @Jon, could you take a look?

~ Johannes

4

So this is fixed in the 12.0 branch now?

5

I’ve reverted the commit so CMake issue should go.

Regards,
Shilei

6

And yes, in the release/12.x branch.

Regards,
Shilei

7

Thanks. That has now configured OK and is building. (428/4014) :slight_smile: