llvm on CentOS 7

[Chris Johns]

On 17/9/19 8:09 am, Joel Sherrill wrote:
> On Mon, Sep 16, 2019 at 4:57 PM Chris Johns <chrisj at rtems.org> wrote:
>>
>> On 17/9/19 7:52 am, Joel Sherrill wrote:
>>> I need to install that! In the mean time, I used the machine I test
>>> odd new gcc versions on and this happened:
>>>
>>> -- Check for working CXX compiler: /usr/bin/c++
>>> -- Check for working CXX compiler: /usr/bin/c++ -- works
>>> -- Detecting CXX compiler ABI info
>>> -- Detecting CXX compiler ABI info - done
>>> -- Detecting CXX compile features
>>> -- Detecting CXX compile features - done
>>>
>>> $ type gcc
>>> gcc is hashed (/home/joel/test-gcc/install-master/bin/gcc)
>>> $ type c++
>>> c++ is /home/joel/test-gcc/install-master/bin/c++
>>>
>>> It looks like something has hard-coded c++ to use /usr/bin which is not nice.
>>>
>>
>> I suspect you would need to see what cmake is doing to understand this.
>>
>> Try adding to the cmake command line
>> 'CXX=/home/joel/test-gcc/install-master/bin/c++'
>> CC=/home/joel/test-gcc/install-master/bin/cc'.
> 
> I went down in .../build and had to remove the cmake cache file. Then the
> following built to completion. 

Oh hmm, best of luck playing with those files.

> Not sure if there are other steps:
> 
> CXX=/home/joel/test-gcc/install-master/bin/c++
> CC=/home/joel/test-gcc/install-master/bin/gcc /usr/bin/cmake -Wno-dev
> -G 'Unix Makefiles' -DCMAKE_BUILD_TYPE=Release
> -DCMAKE_INSTALL_PREFIX=/home/joel/rtems-work/tools/5
> '-DPACKAGE_VERSION=8.0.1 (RTEMS 5, RSB
> d6d8e1df57492e81d971316b36cff019cb8541fc)'
> -DLLDB_CODESIGN_IDENTITY=llvm ../llvm-8.0.1
> 
> Something should be using the compiler from my PATH

The only sure way is to clean and run cmake again. My experience with cmake over
the last 5 years is playing with the cache requires follow up therapy.

Chris