In the past, dexpreopt for boot jars was very inflexible, and it was
incredibly hard to make a change that is as simple as adding a jar to a
boot image. Boot image generation was handled by
"platform_bootclasspath" and "bootclasspath_fragment" separately. This
caused not only code duplication but also the inflexiblity as such a
design did not fit today's use cases, where a boot image may take jars
from multiple mainline modules and the platform, and a mainline module
can contribute to multiple boot images. The design casued a huge
maintenance burden as any change to the boot image cost multi-week
efforts.
In recent years, efforts have been made to improve this a bit by a bit.
This change is another step towards making dexpreopt reasonable.
After this change, all boot images are generated by "dex_bootjars",
which is in build/soong and is therefore available on both the full
source tree and the thin manifest (master-art). The change decouples
profile generation/extraction from boot image generation. Profiles for
mainline modules are still handled by "bootclasspath_fragment"
because they need to be packed into APEXes when building mainline
modules and extracted from APEXes whem building the system image from
prebuilt modules. Boot images are not handled by
"bootclasspath_fragment" anymore.
Bug: 290583827
Test: m (all existing tests are still passing)
Test: Manually checked that the boot images are exactly the same as
before.
Change-Id: Ib5a5f401bee334ffcab5c26618e0c8888b84575a
Most of the fields in the bootImageConfig/Variant structs are assigned
inside a Once func so are guaranteed to be only set once. However, some
are assigned outside. This change adds comprehensive tests for those
structs and verifies that the constant fields are preserved and the
mutated fields have the correct value.
The check for the constant fields is added in a new TestBootImageConfig
test.
The check for the mutated fields is added into
TestSnapshotWithBootclasspathFragment_ImageName as that test checks an
art bootclasspath_fragment in the following configurations:
* source on its own
* prebuilt on its own
* source and prebuilt with source preferred
* source and prebuilt with prebuilt
It reveals a couple of interesting facts:
* All the *installs fields are set to the same value irrespective of
whether the source or prebuilt is preferred. The information is
constructed solely from information already within the
bootImageConfig/Variant and so can be moved within Once.
* The licenseMetadataFile is incorrect when prebuilt is preferred.
That is due to both the source and prebuilt modules setting it and
the source module always wins as the source module depends on the
prebuilt so always runs its GenerateAndroidBuildActions after it.
Those issues will be cleaned up in following changes.
Bug: 245956352
Test: m nothing
Change-Id: If917cfbcb3b1c842a8682d51cc1ee1fed1c51add
