[PATCH v2 2/4] add multiarch support

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

This adds support for building packages for native and compat architectures
to dpdk-base.bbclass.
Thus, all package recipes automatically have a *-native and *-compat target,
which can be used in DEPENDS/RDEPENDS definitions.
Additionally those targets can be used in IMAGE_INSTALL, where they
are automatically converted to install the correct debian package:
  foo-compat -> foo:${COMPAT_DISTRO_ARCH}
  foo-native -> foo:${HOST_ARCH}

Note that the switch ISAR_ENABLE_COMPAT_ARCH still exist and controls
addition of the compat architecture during bootstrapping.

Signed-off-by: Adriaan Schmidt <adriaan.schmidt@siemens.com>
---
 .../recipes-app/samefile/samefile_2.14.bb     |  2 +-
 meta/classes/compat.bbclass                   | 46 ++++++++++++++
 meta/classes/debianize.bbclass                |  2 +-
 meta/classes/dpkg-base.bbclass                |  1 +
 meta/classes/image.bbclass                    |  4 +-
 meta/classes/multiarch.bbclass                | 60 +++++++++++++++++++
 meta/classes/native.bbclass                   | 10 ++++
 meta/conf/bitbake.conf                        |  1 +
 8 files changed, 123 insertions(+), 3 deletions(-)
 create mode 100644 meta/classes/compat.bbclass
 create mode 100644 meta/classes/multiarch.bbclass
 create mode 100644 meta/classes/native.bbclass

diff --git a/meta-isar/recipes-app/samefile/samefile_2.14.bb b/meta-isar/recipes-app/samefile/samefile_2.14.bb
index 5e36a2ac..c53c9445 100644
--- a/meta-isar/recipes-app/samefile/samefile_2.14.bb
+++ b/meta-isar/recipes-app/samefile/samefile_2.14.bb
@@ -21,7 +21,7 @@ do_prepare_build() {
     # deb_debianize. Pre-exisiting files will not be recreated, changelog
     # will be prepended unless its latest entry is for CHANGELOG_V.
     cat << EOF > ${WORKDIR}/changelog
-${PN} (0.1) unstable; urgency=low
+${BPN} (0.1) unstable; urgency=low
 
   * a long long time ago there was an early version
 
diff --git a/meta/classes/compat.bbclass b/meta/classes/compat.bbclass
new file mode 100644
index 00000000..2221bbf7
--- /dev/null
+++ b/meta/classes/compat.bbclass
@@ -0,0 +1,46 @@
+# This software is a part of ISAR.
+# Copyright (C) 2023 Siemens AG
+#
+# SPDX-License-Identifier: MIT
+
+# this class is "dual-use": it can be inherited (e.g., by bootstrap and image
+# classes) to access variables and functions, and it's also addedd via BBCLASSEXTEND
+# when inheriting multiconfig.bbclass.
+
+################################################################################
+# generic functions
+################################################################################
+
+# calculate COMPAT_DISTRO_ARCH and ISAR_ENABLE_COMPAT_ARCH
+# this must always use the DISTRO_ARCH override (not PACKAGE_ARCH), so needs
+# to happen in a modified environment
+python() {
+    distro_arch = d.getVar('DISTRO_ARCH', True)
+    package_arch = d.getVar('PACKAGE_ARCH', True)
+    overrides = d.getVar('OVERRIDES', True).split(':')
+
+    localdata = bb.data.createCopy(d)
+    new_overrides = [distro_arch] + [o for o in overrides if not o == package_arch]
+    localdata.setVar('OVERRIDES', ':'.join(new_overrides))
+    isar_enable_compat_arch = localdata.getVar('ISAR_ENABLE_COMPAT_ARCH', True)
+    compat_distro_arch = localdata.getVar('COMPAT_DISTRO_ARCH', True)
+
+    if compat_distro_arch is None and 'class-compat' in d.getVar('OVERRIDES').split(':'):
+        bb.fatal(f"{distro_arch} does not have a compat arch")
+
+    d.setVar('COMPAT_DISTRO_ARCH', compat_distro_arch)
+    d.setVar('ISAR_ENABLE_COMPAT_ARCH', isar_enable_compat_arch)
+}
+
+
+################################################################################
+# package recipe modifications when actually building *-compat:
+################################################################################
+
+# check that we can actually build compat (ISAR_ENABLE_COMPAT_ARCH is set)
+python do_fetch:prepend:class-compat() {
+    if not d.getVar('ISAR_ENABLE_COMPAT_ARCH', True) == '1':
+        bb.fatal("compat package requested, but ISAR_ENABLE_COMPAT_ARCH is not set.")
+}
+
+PACKAGE_ARCH:class-compat = "${COMPAT_DISTRO_ARCH}"
diff --git a/meta/classes/debianize.bbclass b/meta/classes/debianize.bbclass
index a6694a00..1b98c02d 100644
--- a/meta/classes/debianize.bbclass
+++ b/meta/classes/debianize.bbclass
@@ -31,7 +31,7 @@ deb_add_changelog() {
 
 	date=$(LANG=C date -R -d @${timestamp})
 	cat <<EOF > ${S}/debian/changelog
-${PN} (${changelog_v}) UNRELEASED; urgency=low
+${BPN} (${changelog_v}) UNRELEASED; urgency=low
 
   * generated by Isar
 
diff --git a/meta/classes/dpkg-base.bbclass b/meta/classes/dpkg-base.bbclass
index ad28f7b3..55cc6655 100644
--- a/meta/classes/dpkg-base.bbclass
+++ b/meta/classes/dpkg-base.bbclass
@@ -5,6 +5,7 @@
 # SPDX-License-Identifier: MIT
 
 inherit sbuild
+inherit multiarch
 inherit debianize
 inherit terminal
 inherit repository
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index ef7d5a2a..ce7c549c 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -79,9 +79,11 @@ image_do_mounts() {
     buildchroot_do_mounts
 }
 
+inherit multiarch
+
 ROOTFSDIR = "${IMAGE_ROOTFS}"
 ROOTFS_FEATURES += "clean-package-cache clean-pycache generate-manifest export-dpkg-status clean-log-files clean-debconf-cache"
-ROOTFS_PACKAGES += "${IMAGE_PREINSTALL} ${IMAGE_INSTALL}"
+ROOTFS_PACKAGES += "${IMAGE_PREINSTALL} ${@isar_multiarch_packages('IMAGE_INSTALL', d)}"
 ROOTFS_MANIFEST_DEPLOY_DIR ?= "${DEPLOY_DIR_IMAGE}"
 ROOTFS_DPKGSTATUS_DEPLOY_DIR ?= "${DEPLOY_DIR_IMAGE}"
 ROOTFS_PACKAGE_SUFFIX ?= "${PN}-${DISTRO}-${MACHINE}"
diff --git a/meta/classes/multiarch.bbclass b/meta/classes/multiarch.bbclass
new file mode 100644
index 00000000..09aaff52
--- /dev/null
+++ b/meta/classes/multiarch.bbclass
@@ -0,0 +1,60 @@
+# This software is a part of ISAR.
+# Copyright (C) 2021-2022 Siemens AG
+#
+# SPDX-License-Identifier: MIT
+
+BBCLASSEXTEND += "native compat"
+BPN = "${PN}"
+
+python multiarch_virtclass_handler() {
+    def fixup_pn_in_vars(d):
+        vars = 'SRC_URI FILESPATH'.split()
+        for var in vars:
+            v = d.getVar(var, False)
+            if v is not None:
+                d.setVar(var, v.replace('${PN}', '${BPN}'))
+
+    def fixup_depends(suffix, d):
+        vars = 'PROVIDES RPROVIDES DEPENDS RDEPENDS'.split()
+        for var in vars:
+            multiarch_var = []
+            val = d.getVar(var, True)
+            if val is None:
+                continue
+            for v in val.split():
+                if v.endswith('-compat') or v.endswith('-native'):
+                    multiarch_var.append(v)
+                else:
+                    multiarch_var.append(v + suffix)
+            d.setVar(var, ' '.join(multiarch_var))
+
+    pn = e.data.getVar('PN')
+    if pn.endswith('-compat'):
+        e.data.setVar('BPN', pn[:-len('-compat')])
+        e.data.appendVar('OVERRIDES', ':class-compat')
+        fixup_pn_in_vars(e.data)
+        fixup_depends('-compat', e.data)
+    elif pn.endswith('-native'):
+        e.data.setVar('BPN', pn[:-len('-native')])
+        e.data.appendVar('OVERRIDES', ':class-native')
+        fixup_pn_in_vars(e.data)
+        fixup_depends('-native', e.data)
+}
+addhandler multiarch_virtclass_handler
+multiarch_virtclass_handler[eventmask] = "bb.event.RecipePreFinalise"
+
+# function to convert bitbake targets to installable debian packages,
+# e.g., "hello-compat" to "hello:i386".
+def isar_multiarch_packages(var, d):
+    bb_targets = (d.getVar(var, True) or '').split()
+    packages = []
+    compat_distro_arch = d.getVar('COMPAT_DISTRO_ARCH', True)
+    host_arch = d.getVar('HOST_ARCH', True)
+    for t in bb_targets:
+        if t.endswith('-compat'):
+            packages.append(t[:-len('-compat')] + ':' + compat_distro_arch)
+        elif t.endswith('-native'):
+            packages.append(t[:-len('-native')] + ':' + host_arch)
+        else:
+            packages.append(t)
+    return ' '.join(packages)
diff --git a/meta/classes/native.bbclass b/meta/classes/native.bbclass
new file mode 100644
index 00000000..ef20e8bc
--- /dev/null
+++ b/meta/classes/native.bbclass
@@ -0,0 +1,10 @@
+# This software is a part of ISAR.
+# Copyright (C) 2023 Siemens AG
+#
+# SPDX-License-Identifier: MIT
+
+################################################################################
+# package recipe modifications when actually building *-native:
+################################################################################
+
+PACKAGE_ARCH:class-native = "${HOST_ARCH}"
diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 05ccb7b8..dd21319a 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -81,6 +81,7 @@ QEMU_ARCH:riscv64 = "riscv64"
 
 # Codename of the repository created by the caching class
 DEBDISTRONAME ?= "isar"
+NATIVELSBSTRING ?= "isarnative"
 
 # Strings used in sstate signature files
 TARGET_VENDOR = ""
-- 
2.30.2