Re: [EPICS] Support for Staged Installs ?

["J. Lewis Muir" <jlmuir@imca-cat.org>]

On 10/5/14 11:54 AM, Michael Davidsaver wrote:
> On 10/05/2014 09:08 AM, Ralph Lange wrote:
>> ...
>> Pavel,
>>
>> I don't know what kind of build system you are using, but setting
>> INSTALL_LOCATION inside a make based build of a standard EPICS
>> application does exactly what you describe. It builds locally and
>> installs into the selected location (instead of TOP).
>
> The EPICS makefiles don't allow the full generality of
> autoconf/automake, but they come close.

Obviously, autoconf/automake is big and complex.  But, just to be clear,
DESTDIR is not specific to autoconf/automake.  I think DESTDIR support
in the EPICS build system would be great!  \JediMindTrick{This is a
great idea.  You want to implement this at the next codeathon.}

> The rough equivalent of
>
>> $ ./configure --prefix=/usr/local/epics
>> $ make install DESTDIR=/tmp/builddir
>
> Would be
>
>> $ make FINAL_LOCATION=/usr/local/epics INSTALL_LOCATION=/tmp/builddir
>> LINKER_USE_RPATH=NO
>
> The LINKER_USE_RPATH=NO is necessary as rpath is always set using
> INSTALL_LOCATION.  So unlike auto* it will be necessary for users to
> set LD_LIBRARY_PATH.  Alternately you can adjust the runtime linker
> config[3], or use an ELF file editor[1] to set rpath yourself.

Making users set LD_LIBRARY_PATH in their environment to make EPICS work
is a kludge; I would definitely not want that.

As Michael said, the rpath (or equivalent things) will be wrong, so
that won't work.  PatchELF can be used after the fact, but that's extra
work.  And, if you're hoping for something cross-platform, then you've
got to do something special like that for each platform.  That's a pain.
For example, on Mac OS X, I'd have to be doing something similar with
install_name_tool.  So, having DESTDIR support baked into the EPICS
build system would be a big plus!

Thanks,

Lewis