llvm on CentOS 7

[Joel Sherrill]

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. 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

>
> Chris