Re: [Tarantool-patches] [PATCH luajit 1/3] build: pass sysroot to MacOS SDK

[Sergey Kaplun via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Igor,

On 17.05.21, Igor Munkin wrote:
> Sergey,
> 
> On 14.05.21, Sergey Kaplun wrote:
> > Igor,
> > 
> > Thanks for the fixes!
> > 
> > Please fix the nit below. Otherwise, LGTM.
> 
> Thanks for your review. Unfortunately, this is not a nit (at least I
> have no idea how to handle it). Consider the answers below.
> 
> > 
> > On 13.05.21, Igor Munkin wrote:
> > > Sergey,
> > > 
> > > Thanks for such precise review! I've answered the questions below and
> > > re-implemented the fix (the new patch is at the end), so hold your LGTM
> > > for a while.
> > > 
> > > On 11.05.21, Sergey Kaplun wrote:
> > 
> > <snipped>
> > 
> > > > Side note: Also I've seen that Mike uses OSX_DEPLOYMENT_TARGET variable.
> > > > Moreover, CMAKE_OSX_SYSROOT should "computed based on the
> > > > CMAKE_OSX_DEPLOYMENT_TARGET or the host platform" according to [4].
> > > > And by itself, it means the minimum possible IOS version, where an
> > > > application may run [5]. May be we should fix this too with a separate
> > > > issue and patch (to protect users from building LuaJIT on ancient
> > > > devices)?
> > > 
> > > Sorry, I don't get this one. What exactly is bothering you here?
> > 
> > Just friendly reminder. It's not related to the patch. Just a side
> > note. :) I remembered about it only because it is part of OSX twists.
> > There is no need to do it in this patch, but maybe later?
> 
> But I still don't get what we need to do...

I suppose it will be nice to add CMAKE_OSX_DEPLOYMENT_TARGET. Like Mike
does in Makefile: MACOSX_DEPLOYMENT_TARGET is set to 10.4. In the
separate patch, of course.

> 
> > 
> 
> <snipped>
> 
> > 
> > > > 
> > > > [1]: https://cmake.org/cmake/help/latest/manual/cmake-variables.7.html
> > > > [2]: https://cmake.org/cmake/help/v3.1/manual/cmake-variables.7.html
> > > > [3]: https://github.com/LuaJIT/LuaJIT/blob/8dc3cd6c84dfc81539604340b7884408e1c71d55/doc/install.html#L437
> > > > [4]: https://cmake.org/cmake/help/v3.1/variable/CMAKE_OSX_SYSROOT.html
> > > > [5]: https://developer.apple.com/library/archive/documentation/ToolsLanguages/Conceptual/Xcode_Overview/WorkingwithTargets.html
> > > > 
> > > > -- 
> > > > Best regards,
> > > > Sergey Kaplun
> > > 
> > > ================================================================================
> > > 
> > > build: pass sysroot to MacOS SDK
> > > 
> > > There were issues with configuring LuaJIT on Apple machines, since
> > > <LuaJITTestArch> CMake auxiliary routine fails to locate system headers
> > > (e.g. assert.h in case when LUA_USE_ASSERT is enabled). As a result
> > > platform detection fails and LuaJIT configuration ends with the fatal
> > > error. This patch adds the necessary flags to help the routine to find
> > > the required system headers.
> > > 
> > > Needed for tarantool/tarantool#6065
> > > Relates to tarantool/tarantool#5629
> > > Follows up tarantool/tarantool#4862
> > 
> > What's about 5983? Shouldn't it be mentioned too?
> 
> No, since there is a separate issue this patch is needed for (#6065).
> 
> > 
> > > 
> > > Signed-off-by: Igor Munkin <imun@tarantool.org>
> > > ---
> > >  cmake/LuaJITUtils.cmake | 8 ++++++++
> > >  1 file changed, 8 insertions(+)
> > > 
> > > diff --git a/cmake/LuaJITUtils.cmake b/cmake/LuaJITUtils.cmake
> > > index d9f8b12a..3497edc4 100644
> > > --- a/cmake/LuaJITUtils.cmake
> > > +++ b/cmake/LuaJITUtils.cmake
> > > @@ -1,4 +1,12 @@
> > >  function(LuaJITTestArch outvar strflags)
> > > +  # XXX: This routine uses external headers (e.g. system ones),
> > > +  # which location is specified either implicitly (within CMake
> > > +  # machinery) or explicitly (manually by configuration options).
> > > +  # Need -isysroot flag on recentish MacOS after command line
> > > +  # tools no longer provide headers in /usr/include.
> > > +  if(CMAKE_OSX_SYSROOT)
> > 
> > Nit: This variable should be taken into account only for OS X
> > platforms [1]. I suppose not only by CMake, but by our build system too.
> > 
> > I've got the error on Linux if I try to build LuaJIT like the following
> > (by mistake of course):
> > 
> > | $ uname -s
> > | Linux
> > | $ cmake . -DCMAKE_OSX_SYSROOT="/tmp/blablabalblablbalalbla" -DLUA_USE_ASSERT=ON -DCMAKE_BUILD_TYPE=Debug
> 
> Sigh. After all, I've tried for three patches, seems like ninety...
> 
> BTW, I see failures even on MacOS:
> | $ uname -msr
> | Darwin 20.3.0 arm64
> | $ cmake . -DCMAKE_OSX_SYSROOT="/tmp"
> | -- The C compiler identification is AppleClang 12.0.0.12000032
> | -- Detecting C compiler ABI info
> | -- Detecting C compiler ABI info - failed
> | -- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc
> | -- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc - broken
> | CMake Error at /opt/homebrew/Cellar/cmake/3.20.1/share/cmake/Modules/CMakeTestCCompiler.cmake:66 (message):
> |   The C compiler
> |
> |     "/Library/Developer/CommandLineTools/usr/bin/cc"
> |
> |   is not able to compile a simple test program.
> |
> |   It fails with the following output:
> |
> |     Change Dir: /Users/tntmac07.tarantool.i/imun/tarantool-luajit/CMakeFiles/CMakeTmp
> |
> |     Run Build Command(s):/usr/bin/make -f Makefile cmTC_da00c/fast && /Library/Developer/CommandLineTools/usr/bin/make  -f CMakeFiles/cmTC_da00c.dir/build.make CMakeFiles/cmTC_da00c.dir/build
> |     Building C object CMakeFiles/cmTC_da00c.dir/testCCompiler.c.o
> |     /Library/Developer/CommandLineTools/usr/bin/cc   -arch arm64 -isysroot /tmp -mmacosx-version-min=11.1 -MD -MT CMakeFiles/cmTC_da00c.dir/testCCompiler.c.o -MF CMakeFiles/cmTC_da00c.dir/testCCompiler.c.o.d -o CMakeFiles/cmTC_da00c.dir/testCCompiler.c.o -c /Users/tntmac07.tarantool.i/imun/tarantool-luajit/CMakeFiles/CMakeTmp/testCCompiler.c
> |     Linking C executable cmTC_da00c
> |     /opt/homebrew/Cellar/cmake/3.20.1/bin/cmake -E cmake_link_script CMakeFiles/cmTC_da00c.dir/link.txt --verbose=1
> |     /Library/Developer/CommandLineTools/usr/bin/cc  -arch arm64 -isysroot /tmp -mmacosx-version-min=11.1 -Wl,-search_paths_first -Wl,-headerpad_max_install_names CMakeFiles/cmTC_da00c.dir/testCCompiler.c.o -o cmTC_da00c
> |     ld: library not found for -lSystem
> |     clang: error: linker command failed with exit code 1 (use -v to see invocation)
> |     make[1]: *** [cmTC_da00c] Error 1
> |     make: *** [cmTC_da00c/fast] Error 2
> |
> |
> |
> |
> |
> |   CMake will not be able to correctly generate this project.
> | Call Stack (most recent call first):
> |   CMakeLists.txt:12 (project)
> |
> |
> | -- Configuring incomplete, errors occurred!
> | See also "/Users/tntmac07.tarantool.i/imun/tarantool-luajit/CMakeFiles/CMakeOutput.log".
> | See also "/Users/tntmac07.tarantool.i/imun/tarantool-luajit/CMakeFiles/CMakeError.log".
> 
> I have no idea how to fix this, so I propose to classify manual
> definition of CMAKE_OSX_SYSROOT as PEBKAC and move on. Thoughts?

Why we can't just change the check to the following?

| if(CMAKE_SYSTEM_NAME STREQUAL "Darwin" AND CMAKE_OSX_SYSROOT)

At least it fixes the case I mentioned above, doesn't it? And we
definitely can't protect users from wrong sysroot paths on OS X systems
like in your example. This case looks like "Сам себе злобный Буратино".

> 
> > | In file included from lua.h:14,
> > |                  from lj_arch.h:9:
> > | /usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/include/stdint.h:9:16: fatal error: stdint.h: No such file or directory
> > |     9 | # include_next <stdint.h>
> > |       |                ^~~~~~~~~~
> > | compilation terminated.
> > | CMake Error at cmake/LuaJITUtils.cmake:48 (message):
> > |   [LuaJITArch] Unsupported target architecture
> > | Call Stack (most recent call first):
> > |   cmake/SetTargetFlags.cmake:16 (LuaJITArch)
> > |   src/CMakeLists.txt:17 (include)
> > 
> > > +    set(strflags "${strflags} -isysroot ${CMAKE_OSX_SYSROOT}")
> > > +  endif()
> > >    # XXX: <execute_process> simply splits the COMMAND argument by
> > >    # spaces with no further parsing. At the same time GCC is bad in
> > >    # argument handling, so let's help it a bit.
> > > 
> > > ================================================================================
> > > 
> > > [1]: https://gitlab.kitware.com/cmake/cmake/-/blob/master/Source/cmLocalGenerator.cxx#L1911-1916
> > > [2]: https://gitlab.kitware.com/cmake/cmake/-/blob/master/Tests/FindPackageModeMakefileTest/CMakeLists.txt#L24-28
> > > 
> > > 
> > > -- 
> > > Best regards,
> > > IM
> > 
> > [1]: https://cmake.org/cmake/help/v3.0/variable/CMAKE_OSX_SYSROOT.html
> > 
> > -- 
> > Best regards,
> > Sergey Kaplun
> 
> -- 
> Best regards,
> IM

-- 
Best regards,
Sergey Kaplun