Update build system

[waebbl]

The patches pick up some ideas from issue #100

• Consequently use the variables provided by GNUInstallDirs
• Simplify finding OpenEXR and IlmBase / Imath. OpenEXR looks for either IlmBase (<OpenEXR-3) or Imath (>=OpenEXR-3), so we don't find these dependencies explicitly and only search for OpenEXR with a version provided
• Testing is enabled globally (enable_testing), but we have a CMAKE_BUILD_TESTS variable. Guard the call of this function by the cmake option.

Bug: #100
Signed-off-by: Bernd Waibel waebbl-gentoo@posteo.net

[michaeldsmith]

@waebbl thanks for the contribution, this looks really good and I like the simpler process. The only issue is it looks like the CI is failing to build under MacOs

The valgrind and Windows-vcpkg-test CIs are failing due to issue #109 that I'm working on

[michaeldsmith]

It looks like the compiler can't find half when building with OpenEXR 2 under MacOs

[waebbl]

Is it possible that it's not recognizing the noexcept keyword? Would it help to pass a certain C++ standard to use?

[michaeldsmith]

@waebbl your suggestion worked, requiring C++ 11 fixed the MacOs OpenEXR 2 build issue.

[michaeldsmith]

@waebbl do you think this PR also addresses the GNUInstallDirs issue mentioned in PR #67 ?

[waebbl]

@waebbl do you think this PR also addresses the GNUInstallDirs issue mentioned in PR #67 ?

Yes it should, at least mostly. Some of that PR is outdated, some is fixed with my PR in conjunction with your changes to use GNUInstallDirs.
What my PR doesn't address yet, is the configuration and installation of pkg-config and cmake config files, which is currently not done by the build system. PR #67 includes some patches for the pkg-config files as well, but I'm not sure if the changes are still up-to-date.
That patch was from another Gentoo fellow dev and we used it for a long time, but with the latest patch, supporting OpenEXR-3 / Imath, I no longer need that patch.

[michaeldsmith]

one more build system question @waebbl, do you think we still need the files in \CTL\config directory and the following lines in \OpenEXR_CTL\CMakeLists.txt ?

if ( PKG_CONFIG_FOUND )
    configure_file(../config/OpenEXR_CTL.pc.in "${PROJECT_BINARY_DIR}/OpenEXR_CTL.pc" @ONLY)
    install( FILES "${PROJECT_BINARY_DIR}/OpenEXR_CTL.pc" DESTINATION lib/pkgconfig COMPONENT dev )
endif()

[waebbl]

It depends.
Many packages which provide new cmake config files, still provide their old pkg-config files as well. So it's up to you, if you still want to distribute the pkg-config files together with cmake config files, we should keep the portion from the CMakeLists.txt file you quoted. But those lines should be prepended by a find_package call for pkg-config.

For the files in CTL/config. If you want to install the pkg-config files, you als need the *.pc.in files. The *.cmake.in files, however, are not needed IMO, as the cmake config files should preferably be created using cmake functions from CMakeConfigPackageHelpers.

[waebbl]

How could I preserve your additions and still edit the files I've changed, i.e. to clean up. Can I just pull your changes into my local branch?

[michaeldsmith]

@waebbl I pushed my additions to your forked repo waebbl/CTL update-build branch https://github.com/waebbl/CTL/tree/update-build so I think you can just do git pull on your update-build branch https://github.com/waebbl/CTL/tree/update-build

[michaeldsmith]

@waebbl do you use the pkg-config files in your gentoo package? If not, I'd rather simplify and remove the pkg-config stuff.

[waebbl]

@waebbl I pushed my additions to your forked repo waebbl/CTL update-build branch https://github.com/waebbl/CTL/tree/update-build so I think you can just do git pull on your update-build branch https://github.com/waebbl/CTL/tree/update-build

Thanks, I could just update it in the browser interface.

@waebbl do you use the pkg-config files in your gentoo package? If not, I'd rather simplify and remove the pkg-config stuff.

We currently don't have consumers of the ctl package, so we don't need the pkg-config files. I'm ok with dropping those.

[michaeldsmith]

@waebbl i pushed a commit to your update-build branch that removes the \CTL\config directory and removes the following code from \OpenEXR_CTL\CMakeLists.txt

if ( PKG_CONFIG_FOUND )
    configure_file(../config/OpenEXR_CTL.pc.in "${PROJECT_BINARY_DIR}/OpenEXR_CTL.pc" @ONLY)
    install( FILES "${PROJECT_BINARY_DIR}/OpenEXR_CTL.pc" DESTINATION lib/pkgconfig COMPONENT dev )
endif()

If you don't see any issues with this, let me know and I'll merge the PR

[waebbl]

@michaeldsmith I cleaned up the code somewhat and actually removed the previously only commented lines of code.
In don't see any issues removing the directory and the pkg-config related code from the CMakeLists.txt file.

[waebbl]

Thanks!