This is mainly for fixes, workarounds, or development/testing of dev-ada/ updates to use system-gcc instead of gnat-gpl (requires ada-overlay to get toolchain Ada language support via USE=ada).
You can (optionally) add this overlay with layman:
$ layman -f -a dev-ada -o https://raw.github.com/sarnold/dev-ada-overlay/master/layman.xml
This overlay contains modified adacore ebuilds (recently added to the portage tree for gnat-gpl only) for use with the system toolchain when built from the above ada-overlay with USE=ada. The toolchain overlay provides the changes and bootstrap gnat compilers for each major version of gcc starting with 5.x (the old gnat-gcc ebuilds stopped at 4.9.x). This has also been tested with crossdev and should provide gnat tools for all supported arches (currently x86, amd64, arm, and arm64).
The modified adacore packages provide relaxed dependencies and a system-gcc USE flag to build with the "standard" system toolchain when built with USE=ada. The primary dependencies for all of the adacore tools are gprbuild and xmlada. Since gprbuild needs itslef to build itslef, there is a bootstrap flag and a rebuild step for gprbuild/xmlada and then all the tools should build from there.
The adacore versions are a bit of a mystery (along with what matches what compared to gnu.org), and the important bit is how up-to-date the Ada RTS (RunTime System) is in the gnu.org source tree compared to the interface expected by the tools.
The versions in this overlay are almost all 2017 and build with both gcc 6.4.0 and 7.2.0 as of this writing. Only two packages had a mismatch with 6.4.0 so the 2016 versions are used in these cases.
Note
You can install these overlays with layman or just clone them somewhere local and add them to PORTDIR_OVERLAYS. Also note the name of this overlay is "dev-ada" and not "dev-ada-overlay".
- Install the ada-overlay and rebuild at least one of the above gcc versions (either 6.4.0 or 7.2.0). See the ada-overlay README file for more details. Add "ada" to your global flags for both gcc and a handful of packages with optional Ada bindings or features.
- Install this overlay (the dev-ada-overlay) and setup as above.
- Set your new toolchain with gcc-config.
- Add system-gcc to your global USE flags (or for each package in package.use). If you're using gcc-6.4.0, then you will need to add both >=dev-ada/gnat_util-2017 and >=dev-ada/asis-2017 to package.mask so it will install the 2016 versions instead
- Emerge gprbuild with USE="bootstrap static", then rebuild gprbuild and xmlada with at least USE="shared". Note the later packages will depend on which shared/static/static-pic flags were used for gprbuild.
- Continue emerging other packages
- Have fun!
These ebuilds are still not working or haven't been updated yet:
- gps-bin
- polyorb
Stay tuned...