ndk-build: Link and zipalign all libraries to 16KiB
#76
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https://developer.android.com/guide/practices/page-sizes Since Android 15 devices are allowed to run with 16KiB pages which requires all ELF sections to be 16KiB aligned. In addition, when shared objects are placed uncompressed in the `.apk` Android is able to `mmap()` them directly out of the `.zip` file as long as they are also 16KiB-aligned (otherwise they are decompressed to disk first). The latter step unfortunately requires `zipalign` from `build-tools 35.0.0` as the `-P` flag (to specifically align uncompressed shared objects) did not exist in older releases yet. There is no step that validates that user-libraries from e.g. `package.metadata.android.runtime_libs` have 16KiB-aligned pages internally, but the Rust library from the crate that we compile and link via `cargo` will be configured to link using 16KiB alignment on NDK < r28; it has become the default since r28.
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https://developer.android.com/guide/practices/page-sizes
Since Android 15 devices are allowed to run with 16KiB pages which requires all ELF sections to be 16KiB aligned. In addition, when shared objects are placed uncompressed in the
.apkAndroid is able tommap()them directly out of the.zipfile as long as they are also 16KiB-aligned (otherwise they are decompressed to disk first). The latter step unfortunately requireszipalignfrombuild-tools 35.0.0as the-Pflag (to specifically align uncompressed shared objects) did not exist in older releases yet.There is no step that validates that user-libraries from e.g.
package.metadata.android.runtime_libshave 16KiB-aligned pages internally, but the Rust library from the crate that we compile and link viacargowill be configured to link using 16KiB alignment on NDK < r28; it has become the default since r28.