Update to firebird 3.0 - install build

[Lionel Elie Mamane]

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On Sat, Jun 18, 2016 at 01:06:20PM +0200, Bunth Tamás wrote:

> You wrote on gerrit for the line:

> --with-fbplugins=$(INSTDIR)/$(LIBO_LIB_FOLDER) \

> "this will work only with a "dev install" in the build directory. It
> will not work for packaged / normal install builds."

> I have no idea how to solve this. Is there no variables, which points
> to the right folder, depending on which build has been made?

I was imprecise with my vocabulary. There are not two different
builds; all builds build into $(INSTDIR), and we developers use the
built LibreOffice directly from there for testing. But to make a
package, or a local installation, the final product is then copied
from $(INSTDIR) into $(INSTALLDIR), which is chosen by LibreOffice's
autogen.sh's --prefix argument.

So, in my opinion, a solution based on passing a full absolute path to
--with-fb-plugins will not work in both situations. The effect of that
is that the dlopen() call is to
dlopen("/the/full/path/passed/to/with-fplugins/libEngine12.so", ...)

No choice of full path will work in both situations.

My best hunch, whose beginning was in the first part of my email of 2
June with Message-Id <20160602191615.GA32068 at capsaicin.mamane.lu>, but
was not completely developed there, is to arrange for the dlopen()
call to be just:

dlopen("libEngine12.so", ...)

Then dlopen() will do a search in various directories as documented in
the manpage dlopen in section 3, and ld.so in section 8: rpath,
LD_LIBRARY_PATH, runpath, /etc/ld.so.cache, the directories configured
in /etc/ld.so.conf, ...

Since we want to control the first directory searched, we will use the
rpath, which is set at runtime. See e.g.

$ objdump -p instdir/program/libfirebird_sdbclo.so|grep RPATH
  RPATH                $ORIGIN

"$ORIGIN" is a special value that is replaced at *runtime* by (dixit
"man 8 ld.so") the directory containing the application executable.

AFAIK, that's how LibreOffice itself finds its various subpieces, such
as e.g. libfirebird_sdbclo.so, at least on Unix-like systems like
e.g. GNU/Linux. Anybody on the mailing list can teach us what happens
on Microsoft Windows and MacOS X?

But currently:

$ objdump -p instdir/program/libfbclient.so.2|grep RPATH
  RPATH                /usr/local/firebird/lib

So we need to patch the firebird build system (or configure it through
some argument to its ./configure) to put an rpath of "$ORIGIN" (this
exact string, not the contents of the ORIGIN environment variable)
instead of some absolute path.

See also my email of 2 June. I hope the additional information and
development in this email makes my idea clear.

-- 
Lionel