[Buildroot] [PATCH v6 1/4] package/clang: new package

Valentin Korenblit valentin.korenblit at smile.fr
Mon Apr 30 07:20:44 UTC 2018


Hi Thomas,

On 28/04/2018 14:51, Thomas Petazzoni wrote:
> Hello Valentin,
>
> On Wed, 11 Apr 2018 18:14:49 +0200, Valentin Korenblit wrote:
>> This patch provides Clang tools and libraries for the host and libclang
>> for the target.
>>
>> host-clang is needed to build libclc, which is also provided in a follup patch.
>>
>> We need libclang for the target because it is used by most of OpenCL implementations.
>>
>> A later patch in this series will enable Clover, the OpenCl implementation part
>> of Mesa3D, which requires libclang.
>>
>> clang-tblgen must be copied to HOST_DIR as it is not installed by default but is needed
>> for cross-compilation: http://lists.llvm.org/pipermail/cfe-dev/2015-June/043318.html
>>
>> Signed-off-by: Valentin Korenblit <valentin.korenblit at smile.fr>
>> ---
>>   DEVELOPERS               |  1 +
>>   package/Config.in        |  1 +
>>   package/clang/Config.in  | 22 +++++++++++++++
>>   package/clang/clang.hash |  3 ++
>>   package/clang/clang.mk   | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
>>   5 files changed, 99 insertions(+)
>>   create mode 100644 package/clang/Config.in
>>   create mode 100644 package/clang/clang.hash
>>   create mode 100644 package/clang/clang.mk
> I've applied to master, after doing the following changes:
>
>      [Thomas:
>       - Add Config.in comment about BR2_TOOLCHAIN_HAS_GCC_BUG_64735
>       - Minor reformatting/rewrapping of comments in .mk file]
>
> However, I've noticed that a lot of stuff gets installed in the target,
> which doesn't seem very useful (see below). At least the heders
> in /usr/lib/clang don't see very useful. There's a bunch of Python
> script and Javascript files as well. Do you think some of these could
> be removed, perhaps through post-install target hooks ?

I'll check this today, I think the binaries and scripts shouldn't be necessary,
but I am not completely sure about the includes when using OpenCL. I will test what
happens at runtime.

>
> `-- usr
>      |-- bin
>      |   |-- c-index-test
>      |   |-- git-clang-format
>      |   |-- scan-build
>      |   `-- scan-view
>      |-- lib
>      |   |-- LLVMHello.so
>      |   |-- clang
>      |   |   `-- 5.0.1
>      |   |       `-- include
>      |   |           |-- __clang_cuda_builtin_vars.h
>      |   |           |-- __clang_cuda_cmath.h
>      |   |           |-- __clang_cuda_complex_builtins.h
>      |   |           |-- __clang_cuda_intrinsics.h
>      |   |           |-- __clang_cuda_math_forward_declares.h
>      |   |           |-- __clang_cuda_runtime_wrapper.h
>      |   |           |-- __stddef_max_align_t.h
>      |   |           |-- __wmmintrin_aes.h
>      |   |           |-- __wmmintrin_pclmul.h
>      |   |           |-- adxintrin.h
>      |   |           |-- altivec.h
>      |   |           |-- ammintrin.h
>      |   |           |-- arm_acle.h
>      |   |           |-- arm_neon.h
>      |   |           |-- armintr.h
>      |   |           |-- avx2intrin.h
>      |   |           |-- avx512bwintrin.h
>      |   |           |-- avx512cdintrin.h
>      |   |           |-- avx512dqintrin.h
>      |   |           |-- avx512erintrin.h
>      |   |           |-- avx512fintrin.h
>      |   |           |-- avx512ifmaintrin.h
>      |   |           |-- avx512ifmavlintrin.h
>      |   |           |-- avx512pfintrin.h
>      |   |           |-- avx512vbmiintrin.h
>      |   |           |-- avx512vbmivlintrin.h
>      |   |           |-- avx512vlbwintrin.h
>      |   |           |-- avx512vlcdintrin.h
>      |   |           |-- avx512vldqintrin.h
>      |   |           |-- avx512vlintrin.h
>      |   |           |-- avx512vpopcntdqintrin.h
>      |   |           |-- avxintrin.h
>      |   |           |-- bmi2intrin.h
>      |   |           |-- bmiintrin.h
>      |   |           |-- clflushoptintrin.h
>      |   |           |-- clzerointrin.h
>      |   |           |-- cpuid.h
>      |   |           |-- cuda_wrappers
>      |   |           |   |-- algorithm
>      |   |           |   |-- complex
>      |   |           |   `-- new
>      |   |           |-- emmintrin.h
>      |   |           |-- f16cintrin.h
>      |   |           |-- float.h
>      |   |           |-- fma4intrin.h
>      |   |           |-- fmaintrin.h
>      |   |           |-- fxsrintrin.h
>      |   |           |-- htmintrin.h
>      |   |           |-- htmxlintrin.h
>      |   |           |-- ia32intrin.h
>      |   |           |-- immintrin.h
>      |   |           |-- intrin.h
>      |   |           |-- inttypes.h
>      |   |           |-- iso646.h
>      |   |           |-- limits.h
>      |   |           |-- lwpintrin.h
>      |   |           |-- lzcntintrin.h
>      |   |           |-- mm3dnow.h
>      |   |           |-- mm_malloc.h
>      |   |           |-- mmintrin.h
>      |   |           |-- module.modulemap
>      |   |           |-- msa.h
>      |   |           |-- mwaitxintrin.h
>      |   |           |-- nmmintrin.h
>      |   |           |-- opencl-c.h
>      |   |           |-- pkuintrin.h
>      |   |           |-- pmmintrin.h
>      |   |           |-- popcntintrin.h
>      |   |           |-- prfchwintrin.h
>      |   |           |-- rdseedintrin.h
>      |   |           |-- rtmintrin.h
>      |   |           |-- s390intrin.h
>      |   |           |-- shaintrin.h
>      |   |           |-- smmintrin.h
>      |   |           |-- stdalign.h
>      |   |           |-- stdarg.h
>      |   |           |-- stdatomic.h
>      |   |           |-- stdbool.h
>      |   |           |-- stddef.h
>      |   |           |-- stdint.h
>      |   |           |-- stdnoreturn.h
>      |   |           |-- tbmintrin.h
>      |   |           |-- tgmath.h
>      |   |           |-- tmmintrin.h
>      |   |           |-- unwind.h
>      |   |           |-- vadefs.h
>      |   |           |-- varargs.h
>      |   |           |-- vecintrin.h
>      |   |           |-- wmmintrin.h
>      |   |           |-- x86intrin.h
>      |   |           |-- xmmintrin.h
>      |   |           |-- xopintrin.h
>      |   |           |-- xsavecintrin.h
>      |   |           |-- xsaveintrin.h
>      |   |           |-- xsaveoptintrin.h
>      |   |           |-- xsavesintrin.h
>      |   |           `-- xtestintrin.h
>      |   |-- libLLVM-5.0.1.so -> libLLVM-5.0.so
>      |   |-- libLLVM-5.0.so
>      |   |-- libLLVM.so -> libLLVM-5.0.so
>      |   |-- libLTO.so -> libLTO.so.5
>      |   |-- libLTO.so.5 -> libLTO.so.5.0.1
>      |   |-- libLTO.so.5.0.1
>      |   |-- libclang.so -> libclang.so.5
>      |   |-- libclang.so.5 -> libclang.so.5.0
>      |   |-- libclang.so.5.0
>      |   |-- libstdc++.so.6 -> libstdc++.so.6.0.22
>      |   |-- libstdc++.so.6.0.22
>      |   |-- libstdc++.so.6.0.22-gdb.py
>      |   `-- os-release
>      |-- lib64 -> lib
>      |-- libexec
>      |   |-- c++-analyzer
>      |   `-- ccc-analyzer
>      |-- sbin
>      `-- share
>          |-- clang
>          |   |-- bash-autocomplete.sh
>          |   |-- clang-format-bbedit.applescript
>          |   |-- clang-format-diff.py
>          |   |-- clang-format-sublime.py
>          |   |-- clang-format.el
>          |   |-- clang-format.py
>          |   |-- clang-rename.el
>          |   `-- clang-rename.py
>          |-- opt-viewer
>          |   |-- opt-diff.py
>          |   |-- opt-stats.py
>          |   |-- opt-viewer.py
>          |   |-- optpmap.py
>          |   |-- optrecord.py
>          |   `-- style.css
>          |-- scan-build
>          |   |-- scanview.css
>          |   `-- sorttable.js
>          `-- scan-view
>              |-- FileRadar.scpt
>              |-- GetRadarVersion.scpt
>              |-- Reporter.py
>              |-- ScanView.py
>              |-- bugcatcher.ico
>              `-- startfile.py
>
> Also, I must say I was impressed by the size of the libLLVM and
> libclang libraries. libLLVM is 23MB, while libclang is 22MB. What seems
> weird however is that libclang is not linked against libLLVM:
>
> $ readelf -d libclang.so.5.0
>
> Dynamic section at offset 0x15ebbd0 contains 31 entries:
>    Tag        Type                         Name/Value
>   0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
>   0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]
>   0x0000000000000001 (NEEDED)             Shared library: [libc.so.0]
>   0x0000000000000001 (NEEDED)             Shared library: [ld64-uClibc.so.1]
>   0x000000000000000e (SONAME)             Library soname: [libclang.so.5]
>   0x000000000000001d (RUNPATH)            Library runpath: []
>
> Is libclang statically linked against libLLVM, causing a huge
> duplication of code size ?
>
> Looking at the build output of libclang, it indeed seems like it uses
> the .a libraries from LLVM, and not the dynamic library. So the LLVM
> code is present twice: once in libLLVM.so, and a second time in
> libclang.so. This isn't nice at all. Could you look into this ?

Yes, I've just checked with nm that functions are duplicated. I'll try to
fix this.

> I've pasted the command line used by the clang package to produce its
> libclang.so library at http://code.bulix.org/li1n6r-325499?raw. You can
> see it uses the LLVM .a files directly.
>
> My defconfig was:
>
> BR2_x86_64=y
> BR2_x86_core2=y
> BR2_TOOLCHAIN_EXTERNAL=y
> BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
> BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/br-x86-64-core2-full-2018.02-891-g046c5e2.tar.bz2"
> BR2_TOOLCHAIN_EXTERNAL_GCC_6=y
> BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_16=y
> BR2_TOOLCHAIN_EXTERNAL_LOCALE=y
> # BR2_TOOLCHAIN_EXTERNAL_HAS_THREADS_DEBUG is not set
> BR2_TOOLCHAIN_EXTERNAL_CXX=y
> BR2_INIT_NONE=y
> BR2_SYSTEM_BIN_SH_NONE=y
> # BR2_PACKAGE_BUSYBOX is not set
> BR2_PACKAGE_CLANG=y
> # BR2_TARGET_ROOTFS_TAR is not set
>
> Thanks!
>
> Thomas

Best regards,

Valentin




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