[Mesa-dev] [PATCH] configure: Trust LLVM >= 4.0 llvm-config --libs for shared libraries

[Grazvydas Ignotas]

On Mon, Aug 14, 2017 at 11:13 PM, Andy Furniss <adf.lists at gmail.com> wrote:
> Michel Dänzer wrote:
>>
>> On 11/08/17 01:45 AM, Emil Velikov wrote:
>>
>> Thanks, pushed.
>
>
> Don't know if this is expected or not, but llvm built like -
>
> cmake -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Release
> -DLLVM_TARGETS_TO_BUILD="host;AMDGPU" -DLLVM_ENABLE_ASSERTIONS=ON
> -DLLVM_APPEND_VC_REV=OFF -DLLVM_BUILD_LLVM_DYLIB=ON
>
> now fails to build mesa (I also tried without vulkan and it still fails
> raseonsi IIRC).
>
>  CXXLD    libvulkan_radeon.la
> /usr/lib/libLLVMSupport.a(Process.cpp.o): In function
> `llvm::sys::Process::FileDescriptorHasColors(int)':
> Process.cpp:(.text._ZN4llvm3sys7Process23FileDescriptorHasColorsEi+0x4d):
> undefined reference to `setupterm'
> Process.cpp:(.text._ZN4llvm3sys7Process23FileDescriptorHasColorsEi+0x78):
> undefined reference to `tigetnum'
> Process.cpp:(.text._ZN4llvm3sys7Process23FileDescriptorHasColorsEi+0x81):
> undefined reference to `set_curterm'
> Process.cpp:(.text._ZN4llvm3sys7Process23FileDescriptorHasColorsEi+0x89):
> undefined reference to `del_curterm'
> collect2: error: ld returned 1 exit status
>
> Haven't tried llvm with -DLLVM_APPEND_VC_REV=ON yet, mesa still builds OK
> with this commit reverted.

Same problem here, using LLVM-6.0 from a week ago, my cmake is just
-DCMAKE_INSTALL_PREFIX=/opt/xorg -DLLVM_TARGETS_TO_BUILD='AMDGPU;X86'
-DCMAKE_BUILD_TYPE=Release -DLLVM_BUILD_LLVM_DYLIB=TRUE

llvm-config --libs
seems to return tons of output like -lLLVMBitWriter -lLLVMAnalysis
-lLLVMProfileData -lLLVMObject ... which seems to result in static
linking that's supposedly not supported by mesa? The only .so I see is
libLLVM.so , all others are .a files.

Meanwhile
llvm-config --shared-mode
returns "static", which implies it wants be statically linked. There
is BUILD_SHARED_LIBS cmake option, but llvm documentation advices
against using it and suggests LLVM_BUILD_LLVM_DYLIB instead.
Confusing...

Also, llvm-config --version says "6.0.0git-f49c401", which means I had
to manually hack configure.ac every time to "6.0.0svn" to get mesa
building too :(

Gražvydas