[PATCH v3 0/4] multiarch support

[Adriaan Schmidt <adriaan.schmidt@siemens.com>]

This adds `<package>-compat` and `<package>-native` bitbake
targets to all recipes inheriting dpkg-base.

The new -compat build variant replaces the old compat mechanism.
Note that `ISAR_ENABLE_COMPAT_ARCH="1"` is still required to
ensure that the bootstrap and buildchroot is prepared correctly.

Regarding testing of the new features:
- we have (limited) testing of compat, by adding `hello-isar-compat` to
  amd64 and arm64 builds.
- currently no testing of native. There are two main use cases for the feature:
  - SDK that needs `<package>-native`. This could be turned into a test
    easily, by setting/appending SDK_INSTALL. Would require a new option
    in testsuite, similar to `image_install` introduced in 57a0ade9a.
  - A build tool that is provided by a recipe, when using it in cross
    compilation. E.g. if someone needed a patched cmake, they would
    write cmake.bb, and applications that need it would (in case cross
    compilation is enabled) DEPEND+="cmake-native". Or, another real-world
    example from a downstream layer: packaging applications with goreleaser,
    which is not found in the Debian apt repos. Instead, I'm fetching it
    via a dpkg-prebuilt recipe, written to support multiple architectures
    (architecture is part of the download URL). Now if I want to cross
    compile go applications, they DEPEND+="goreleaser-native", and
    DEBIAN_BUILD_DEPENDS_append=", goreleaser:native".
    These cases are more complex, but maybe we can find an example along
    those lines and add it to meta-isar.

As testing of the native feature would (in the simple case) need an
extension of the test classes (for SDK_INSTALL), or introduce something
completely new into meta-isar, I'd like to do that after discussion, in
a later series.

Adriaan

changes since v2:
- fixed a bug that completely broke things for targets without a compat
  arch (e.g., i386). The compat variant of packages is now only available
  when it can actually be built.
- the native variant is only generated if it differs from the target.
  If DISTRO_ARCH==HOST_ARCH, then `<package>-native` is automatically
  provided by the target package.
- also do the bitbake-target->debian-package transformation on SDK_INSTALL
- fix compat packages in testsuite: when we add hello-isar-compat, we
  need to remove hello-isar.

changes since v1:
- fixed an issue that prevented arch overrides of
  ISAR_ENABLE_COMPAT_ARCH, which is used in testsuite
- added `-native` expansion to contents of IMAGE_INSTALL
- documentation in user_manual


Adriaan Schmidt (4):
  bitbake.conf: use PACKAGE_ARCH in overrides
  add multiarch support
  remove obsolete compat-arch override
  doc: add compat/native targets to user manual

 doc/user_manual.md                            | 19 ++--
 .../recipes-app/hello-isar/hello-isar.bb      |  3 -
 meta-isar/recipes-app/libhello/libhello.bb    |  3 -
 .../recipes-app/samefile/samefile_2.14.bb     |  2 +-
 meta/classes/compat.bbclass                   | 40 +++++++++
 meta/classes/debianize.bbclass                |  2 +-
 meta/classes/dpkg-base.bbclass                |  1 +
 meta/classes/image.bbclass                    |  4 +-
 meta/classes/multiarch.bbclass                | 88 +++++++++++++++++++
 meta/classes/native.bbclass                   | 10 +++
 meta/classes/sdk.bbclass                      |  2 +-
 meta/conf/bitbake.conf                        |  6 +-
 .../isar-bootstrap/isar-bootstrap.inc         |  2 +
 .../sbuild-chroot/sbuild-chroot.inc           | 14 +--
 testsuite/cibuilder.py                        |  4 +
 15 files changed, 174 insertions(+), 26 deletions(-)
 create mode 100644 meta/classes/compat.bbclass
 create mode 100644 meta/classes/multiarch.bbclass
 create mode 100644 meta/classes/native.bbclass

-- 
2.30.2