llvm dev - Jul 2015 - [LLVMdev] build llvm on CentOS

Hi there,

I was trying to build llvm on CentOS. The problem is that library on CentOS
is always so old (Gcc, python). I managed to install local gcc and let
cmake know. But I couldn't do so with python. I end up comment out the
check in CMakeList.txt which is not good.
I was wondering if anyone has experience building llvm (using cmake) using
a local python?

Thanks,
XIaochu
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Did you specify PYTHON_EXECUTABLE?

See also,
http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/13948/steps/CMake/logs/stdio
It's centos6.

2015年7月22日(水) 14:29 Xiaochu Liu <xiaochu1122 at gmail.com>:
> Hi there,
>
> I was trying to build llvm on CentOS. The problem is that library on
> CentOS is always so old (Gcc, python). I managed to install local gcc and
> let cmake know. But I couldn't do so with python. I end up comment out
the
> check in CMakeList.txt which is not good.
> I was wondering if anyone has experience building llvm (using cmake) using
> a local python?
>
> Thanks,
> XIaochu
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
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For various reasons I have to use an old 5.5 version of CentOS that is fairly
locked down.  Not only are newer versions of ‘gcc’ available, but for
operational reasons we have chosen to keep the set of installed tools frozen
until some more suitable date as there are other teams dependent on the current
configuration.

 

Python is a particular problem because ‘yum’ is written in Python and is very
version sensitive, so ironically you can update Python and find that ‘yum’ no
longer works preventing future updates.

 

My solution was to download the sources for ‘cmake’ [v3.0.2], ‘python’ [v2.7.6]
and ‘gcc’ [v4.8.2], build them locally, and set my PATH, LD_LIBRARY_PATH and
LD_RUN_PATH variables to reference this local version.  Then to configure I
have:

 

CC=`which gcc` CXX=`which g++` $(CMAKE) -G "Unix Makefiles" \

              ../../llvm \

              "-DCMAKE_BUILD_TYPE:STRING=Debug" \

              "-DCMAKE_EXE_LINKER_FLAGS:STRING=-<extra link
flags>" \

              "-DCMAKE_CXX_FLAGS:STRING=<extra C++ flags>" \

              -DLLVM_TARGETS_TO_BUILD="<list of targets>" \

              -DLLVM_DEFAULT_TARGET_TRIPLE=<default target> \

              -DENABLE_TIMESTAMPS=1

 

Having the locally built version of Python on PATH seems to be fine, but I did
have to force ‘CC’ and ‘CXX’ to the intended versions.

 

If you want the version of ‘clang’ you build to run on other Linux distros
(Ubuntu for example), I found that the GCC shared library dependencies could be
a problem, so you might want to include ‘-static-libgcc -static-libstdc++
-static’ in your extra link flags which will use the static libraries and remove
this dependency, although at the expense of large executables.

 

All the best,

 

            MartinO

 

From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of NAKAMURA Takumi
Sent: 22 July 2015 8:25
To: Xiaochu Liu; llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] build llvm on CentOS

 

Did you specify PYTHON_EXECUTABLE?

See also,
http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/13948/steps/CMake/logs/stdio
<https://urldefense.proofpoint.com/v2/url?u=http-3A__bb.pgr.jp_builders_ninja-2Dx64-2Dmsvc-2DRA-2Dcentos6_builds_13948_steps_CMake_logs_stdio&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=Mfk2qtn1LTDThVkh6-oGglNfMADXfJdty4_bhmuhMHA&m=Gtl_nwGu5OHHn-liMx2xEnMf9GcBF7eY3pxfEoOxotY&s=yIGK5ZSYerjjwhdmvn_Gdx6Qn4JlEdpBVIwJ0LA9z_Q&e=>
It's centos6.

 

2015年7月22日(水) 14:29 Xiaochu Liu <xiaochu1122 at gmail.com>:

Hi there,

 

I was trying to build llvm on CentOS. The problem is that library on CentOS is
always so old (Gcc, python). I managed to install local gcc and let cmake know.
But I couldn't do so with python. I end up comment out the check in
CMakeList.txt which is not good.

I was wondering if anyone has experience building llvm (using cmake) using a
local python?

 

Thanks,

XIaochu

 

_______________________________________________
LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

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I tried -DPYTHON_EXECUTABLE but it still says the version is 2.6 (centos
one).

On Wed, Jul 22, 2015 at 12:25 AM NAKAMURA Takumi <geek4civic at gmail.com>
wrote:
> Did you specify PYTHON_EXECUTABLE?
>
> See also,
>
http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/13948/steps/CMake/logs/stdio
> It's centos6.
>
> 2015年7月22日(水) 14:29 Xiaochu Liu <xiaochu1122 at gmail.com>:
>
>> Hi there,
>>
>> I was trying to build llvm on CentOS. The problem is that library on
>> CentOS is always so old (Gcc, python). I managed to install local gcc
and
>> let cmake know. But I couldn't do so with python. I end up comment
out the
>> check in CMakeList.txt which is not good.
>> I was wondering if anyone has experience building llvm (using cmake)
>> using a local python?
>>
>> Thanks,
>> XIaochu
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>
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