[Lldb-commits] [PATCH 3/4] cmake build: Fix building of HasAVX.s

[Kuba Ober]

Yes, it is, and if you look closely, you’ll find it elsewhere in LLVM sources IIRC.
Unfortunately, cmake’s assembly support is quite broken.

There are two workarounds here.

1. Providing COMPILE_FLAGS when .S would ordinarily suffice. That’s simply a missing
feature in cmake.

2. Overriding the LANGUAGE with C, instead of specifying ASM (instead of ASM-ATT)
to project() in tools/debugserver/CMakeLists.txt. It’s either a cmake bug or a
cmakelists bug in LLVM.


For a stand-alone testcase project, specifying ASM (as opposed to ASM-ATT)
language in the project() specification works - it will choose gcc or clang-based
assembler instead of as.

Alas, I couldn’t get this to work in llvm, the assembler detection is broken
by something in llvm and CMAKE_ASM_COMPILE_OBJECT is never set.

Cheers, Kuba Ober

On Mar 12, 2014, at 5:49 PM, Jevin Sweval <jevinsweval at gmail.com> wrote:

> On Wed, Mar 12, 2014 at 3:43 PM, Kuba Ober <kuba at mareimbrium.org> wrote:
>> ---
>> tools/debugserver/source/MacOSX/CMakeLists.txt | 6 ++++++
>> 1 file changed, 6 insertions(+)
>> 
>> diff --git a/tools/debugserver/source/MacOSX/CMakeLists.txt b/tools/debugserver/source/MacOSX/CMakeLists.txt
>> index b955917..8e2ec1c 100644
>> --- a/tools/debugserver/source/MacOSX/CMakeLists.txt
>> +++ b/tools/debugserver/source/MacOSX/CMakeLists.txt
>> @@ -40,6 +40,12 @@ add_lldb_executable(debugserver
>>   ${generated_mach_interfaces}
>>   )
>> 
>> +set_source_files_properties(
>> +  HasAVX.s
>> +  # Necessary since compilation will fail with stand-alone assembler
>> +  PROPERTIES LANGUAGE C COMPILE_FLAGS "-x assembler-with-cpp"
>> +  )
>> +
>> add_dependencies(debugserver generate_dnbconfig)
>> target_link_libraries(debugserver ${DEBUGSERVER_USED_LIBS})
>> 
> 
> I noticed this one too. I tried to fix it "cleanly" by renaming it to
> HasAVX.S (note the capital S) but CMake didn't get the hint that it
> was supposed to be passed through cpp. Is this the cleanest way of
> telling CMake what is going on?
> 
> Cheers,
> Jevin