> > 1) Pick a directory as your sysroot
> > 2) Install the libc headers there (without having built it)
> What I did was mv musl-*/include ~/arm-sysroot/usr/include.
I think you need to copy them, not move them.
On a new directories and fresh untar of musl, I don't think there's a difference
> > 3) Build clang w/ baremetal cache, pointing it at the partially built
> > sysroot.
> cmake -G 'Unix Makefiles' -DBAREMETAL_ARMV7EM_SYSROOT=~/arm-sysroot -C ../../code/clang/cmake/caches/BaremetalARM.cmake ../../code/clang
Sorry, I wasn't explicit enough. You need to define all of the variables
that the cache is looking for.
> loading initial cache file ../../code/clang/cmake/caches/BaremetalARM.cmake
> -- Found LLVM_CONFIG as /usr/local/bin/llvm-config
> -- Building with -fPIC
> -- Could NOT find Z3 (missing: Z3_LIBRARIES Z3_INCLUDE_DIR) (Required is at least version "4.5")
> -- Clang version: 4.0.1
> CMake Error at /usr/local/llvm40/lib/cmake/llvm/LLVM-Config.cmake:203 (message):
> Library `BinaryFormat' not found in list of llvm libraries.
> Call Stack (most recent call first):
> /usr/local/llvm40/lib/cmake/llvm/AddLLVM.cmake:508 (llvm_map_components_to_libnames)
> cmake/modules/AddClang.cmake:86 (llvm_add_library)
> lib/AST/CMakeLists.txt:6 (add_clang_library)
> -- Configuring incomplete, errors occurred!
> See also "/usr/home/meka/repos/clang/build/clang/CMakeFiles/CMakeOutput.log".
I think it found an installed llvm, and is trying to use that to build clang
against. First, the clang and llvm's versions have to match. Second, when I
mentioned building clang, I really meant building llvm+clang... sorry.
$ cmake -G 'Unix Makefiles' -DBAREMETAL_ARMV7EM_SYSROOT=~/arm-sysroot -C
Where your path/to/llvm has the symlinks:
* path/to/llvm/tools/clang -> path/to/clang
ln -s `which clang40` path/to/llvm/tools/clang
* path/to/llvm/runtimes/compiler_rt path/to/compiler_rt
ln -s path/to/llvm/projects/compiler-rt path/to/llvm/runtimes/compiler_rt
Is that right?
And by "edited BaremetalARM.cmake" I mean you can strip out the other
targets in there that you don't need.
So I have copied BaremetalARM.cmake into llvm/cmake/caches/BaremetalARM.cmake to be able to alter it, I've put all other repos in llvm/projects and the command is:
# cmake -G 'Unix Makefiles' -DBAREMETAL_ARMV7EM_SYSROOT=~/arm-sysroot -DBAREMETAL_ARMV6M_SYSROOT=~/arm-sysroot -DBAREMETAL_ARMV7M_SYSROOT=~/arm-sysroot -C ../../code/llvm/cmake/caches/BaremetalARM.cmake ../../code/llvm
Before adding all repos into llvm/projects, it complained about 'Specified distribution component 'clang' doesn't have a target' (just an example). Now I have 'Specified distribution component 'builtins-armv6m-none-eabi' doesn't have a target' as error.