[PATCH] D20992: [CMake] Add LLVM runtimes directory

Wed Jun 8 18:59:55 PDT 2016

On Wed, Jun 8, 2016 at 4:39 PM Justin Bogner via llvm-commits <
llvm-commits at lists.llvm.org> wrote:

> Chris Bieneman <beanz at apple.com> writes:
> > beanz created this revision.
> > beanz added reviewers: chandlerc, bogner.
> > beanz added a subscriber: llvm-commits.
> >
> > There are a few LLVM projects that produce runtime libraries. Ideally
> > runtime libraries should be built differently than other projects,
> > specifically they should be built using the just-built toolchain.
> >
> > There is support for building compiler-rt in this way from the clang
> > build. Moving this logic into the LLVM build is interesting because it
> > provides a simpler way to extend the just-built toolchain to include
> > LLD and the LLVM object file tools.
> >
> > Once this functionality is better fleshed out and tested we’ll want to
> > encapsulate it in a module that can be used for clang standalone
> > builds, and we’ll want to make it the default way to build compiler-rt.
> >
> > With this patch applied there is no immediate change in the build.
> > Moving compiler-rt out from llvm/projects into llvm/runtimes enables
> > the functionality.
>
> This seems reasonable, but I am a little worried about how transitioning
> to the new system will work. Will everyone have to move their
> compiler-rt checkout? Will we continue to support compiler-rt in either
> place? Both of these are workable, but neither is great. Thoughts?
>

I share your concerns, but I also kind of like the direction this is going.

But there is a higher-level meta-point: do we want to keep the 'projects'
directory *at all*.

Every single resident of it I can think of except for the test-suite is
either dead (dragonegg) or a runtime library.

I think we should either have all the build-integrated projects in a single
'projects' directory (including LLD and Clang), or we should have none of
them and use more domain relevant organization (today "tools", you're
adding "runtimes", maybe we move the test-suite to go under one of the test
directories).

I think we should have a consistent plan here before moving stuff. But once
we have it, I think we shouldn't be afraid of re-organizing stuff to make
more sense, and just work to get folks to update their checkouts.

-Chandler

>
> > This code has a few improvements over the method provided by
> > LLVM_BUILD_EXTERNAL_COMPILER_RT. Specifically the sub-ninja command is
> > always invoked, so changes to compiler-rt source files will get built
> > properly, so this patch can be used for iterative development with
> > just-built tools.
> >
> > http://reviews.llvm.org/D20992
> >
> > Files:
> >   CMakeLists.txt
> >   cmake/modules/LLVMExternalProjectUtils.cmake
> >   runtimes/CMakeLists.txt
> >
> > Index: runtimes/CMakeLists.txt
> > ===================================================================
> > --- /dev/null
> > +++ runtimes/CMakeLists.txt
> > @@ -0,0 +1,16 @@
> > +include(LLVMExternalProjectUtils)
> > +
> > +# Discover the projects that use CMake in the subdirectories.
> > +# Note that explicit cmake invocation is required every time a new
> project is
> > +# added or removed.
> > +
> > +add_custom_target(runtimes)
> > +
> > +file(GLOB entries *)
> > +foreach(entry ${entries})
> > +  if(IS_DIRECTORY ${entry} AND EXISTS ${entry}/CMakeLists.txt)
> > +    get_filename_component(projName ${entry} NAME)
> > +    llvm_ExternalProject_Add(${projName} ${entry} USE_TOOLCHAIN)
> > +    add_dependencies(runtimes ${projName})
> > +  endif()
> > +endforeach(entry)
> > Index: cmake/modules/LLVMExternalProjectUtils.cmake
> > ===================================================================
> > --- cmake/modules/LLVMExternalProjectUtils.cmake
> > +++ cmake/modules/LLVMExternalProjectUtils.cmake
> > @@ -29,7 +29,8 @@
> >  #     Extra targets in the subproject to generate targets for
> >  #   )
> >  function(llvm_ExternalProject_Add name source_dir)
> > -  cmake_parse_arguments(ARG "USE_TOOLCHAIN;EXCLUDE_FROM_ALL;NO_INSTALL"
> > +  cmake_parse_arguments(ARG
> > +    "USE_TOOLCHAIN;EXCLUDE_FROM_ALL;NO_INSTALL;ALWAYS_CLEAN"
> >      "SOURCE_DIR"
> >
> "CMAKE_ARGS;TOOLCHAIN_TOOLS;RUNTIME_LIBRARIES;DEPENDS;EXTRA_TARGETS"
> ${ARGN})
> >    canonicalize_tool_name(${name} nameCanon)
> > @@ -52,6 +53,10 @@
> >      endif()
> >    endforeach()
> >
> > +  if(ARG_ALWAYS_CLEAN)
> > +    set(always_clean clean)
> > +  endif()
> > +
> >    list(FIND TOOLCHAIN_TOOLS clang FOUND_CLANG)
> >    if(FOUND_CLANG GREATER -1)
> >      set(CLANG_IN_TOOLCHAIN On)
> > @@ -135,6 +140,14 @@
> >      CMAKE_ARGS ${${nameCanon}_CMAKE_ARGS}
> >                 ${compiler_args}
> >                 -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
> > +
>  -DLLVM_CONFIG_PATH=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-config
> > +
>  -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_OUTPUT_INTDIR}
> > +
>  -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_RUNTIME_OUTPUT_INTDIR}
> > +               -DLLVM_LIBDIR_SUFFIX=${LLVM_LIBDIR_SUFFIX}
> > +               -DLLVM_ENABLE_WERROR=${LLVM_ENABLE_WERROR}
> > +               -DPACKAGE_VERSION=${PACKAGE_VERSION}
> > +               -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
> > +               -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
>
> How did you decide which variables need to be passed through like this?
> The set seems somewhat arbitrary, but I may be missing something
> obvious.
>
> >                 ${ARG_CMAKE_ARGS}
> >                 ${PASSTHROUGH_VARIABLES}
> >      INSTALL_COMMAND ""
> > @@ -152,7 +165,7 @@
> >      ExternalProject_Add_Step(${name} force-rebuild
> >        COMMAND ${run_build}
> >        COMMENT "Forcing rebuild of ${name}"
> > -      DEPENDEES configure clean
> > +      DEPENDEES configure ${always_clean}
>
> I'm not sure I understand what this does. If I had to guess I'd say that
> when ALWAYS_CLEAN is passed the rebuild of the external project always
> invokes clean first, but if it's not passed we'll just invoke the
> external build and allow it to be incremental if appropriate. Is that
> right?
>
> >        DEPENDS ${ALWAYS_REBUILD} ${ARG_DEPENDS} ${TOOLCHAIN_BINS}
> >        ${cmake_3_4_USES_TERMINAL} )
> >    endif()
> > Index: CMakeLists.txt
> > ===================================================================
> > --- CMakeLists.txt
> > +++ CMakeLists.txt
> > @@ -720,6 +720,8 @@
> >    add_subdirectory(tools)
> >  endif()
> >
> > +add_subdirectory(runtimes)
> > +
> >  if( LLVM_INCLUDE_EXAMPLES )
> >    add_subdirectory(examples)
> >  endif()
> > @@ -730,7 +732,8 @@
> >      llvm_ExternalProject_Add(test-suite
> ${LLVM_MAIN_SRC_DIR}/projects/test-suite
> >        USE_TOOLCHAIN
> >        EXCLUDE_FROM_ALL
> > -      NO_INSTALL)
> > +      NO_INSTALL
> > +      ALWAYS_CLEAN)
> >    endif()
> >    add_subdirectory(test)
> >    add_subdirectory(unittests)
> >
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160609/3b8ec91f/attachment.html>