[CMake] rpath problems with kdevplatform

[Brad King]

Andreas Pakulat wrote:
> On 26.06.10 13:26:29, Andreas Pakulat wrote:
>> Ping? Any further ideas on this? Could someone at least point me to the
>> source code in cmake that decides wether to add RPATH_REMOVE or
>> RPATH_REPLACE to the cmake_install.cmake file?

Look at "cmInstallTargetGenerator::AddChrpathPatchRule".  Its job is
to generate the install-time script to fix up the RPATH in the installed
binary.  The default is *no* RPATH, unless the INSTALL_RPATH target
property is set:

  http://www.cmake.org/cmake/help/cmake-2-8-docs.html#prop_tgt:INSTALL_RPATH

Elsewhere in this thread (at least on the kde list) you mention this
seems to be working for some targets and not others.  Look for where
the INSTALL_RPATH gets set on the targets where it is working.

> Found it already, I've patched a cmake checkout here to give some
> diagnostic output and looking at the differences its apparent that for
> kdevplatform the installation prefix is not added to the
> "OrderRuntimeSearchPath" list in cmComputeLinkInformation, but this is
> done for kdevelop targets.

This has nothing to do with RPATH_REMOVE or RPATH_CHANGE calls during
installation.  The only time this code would be used with install-tree
information is during the "relink" step used on non-ELF platforms used
to build a new RPATH into the binaries for installation.

> The reason seems to be that when building kdevplatform there are no
> libraries in the install-prefix that the to-be-built targets link
> against. So it seems that this is rather a cmake bug, hence I'm cc'ing
> to the cmake list (and including all the quotes).
>
> @CMake-List readers: Am I right that cmake simply should add the
> install-prefix to the ORderRuntimeSearchPath at some point during
> initialization?

No, this is intentional behavior.  CMake sets the RPATH up in the build
tree to help the binary find its dependencies at runtime.  If it does
not link to anything in <prefix>/lib then there will be no RPATH entry
for it.

> That should help in this case (I didn't test this yet)

As I said above it won't affect the install tree.  See the INSTALL_RPATH
target property.

-Brad