Would you answer me about relation of agp and ndk version and .so file size.

[ciwhiz]

I couldn't find the right answer anywhere. please lead me on the way...

https://github.com/google-home/sample-app-for-matter-android
I built this project on two different PCs.

One is a mac(m1), the other is an intel CPU PC.
Among the .so files included in the sample app project above, the largest file, libCHIPController.so, is about 340MB.
When this .so file is built as a release APK on each PC,
When I opened the apk,
On the mac it was reduced to about 25 MB, while on the intel it stayed the same at 340 MB.

I struggled a bit at first, but I found the clue.
There is no difference between the CPU of the build PC.
The cause is that the above project is built with AGP (android gradle plugin), and AGP has a basic NDK version for each version.
The AGP of the above project is 7.4 and the default NDK version is 23.1.7779620.

The above NDK version, 23.1.7779620, was installed on the Mac,
NDK 21.4.xx, 25.2.xxx were installed on the Intel PC.

Due to this difference, the size of the .so file packaged in the apk was such a difference.

As far as I know, there is no need to install NDK when building a prebuilt .so file as an apk.
In fact, the build itself doesn't fail. However, there is only a difference in the size of the .so file.

When packaging the .so file in the android project, should the NDK version suitable for the so file be installed?
Has anyone seen a guide or document about this? am i missing something?

[enh-google]

if you run strip on the large file, does it end up the same size as the small file? strip is in the ndk, so if you don't have that installed, maybe your build skips that step?

…

On Mon, Feb 20, 2023, 23:20 ciwhiz ***@***.***> wrote: I couldn't find the right answer anywhere. please lead me on the way... https://github.com/google-home/sample-app-for-matter-android I built this project on two different PCs. One is a mac(m1), the other is an intel CPU PC. Among the .so files included in the sample app project above, the largest file, libCHIPController.so, is about 340MB. When this .so file is built as a release APK on each PC, When I opened the apk, On the mac it was reduced to about 25 MB, while on the intel it stayed the same at 340 MB. I struggled a bit at first, but I found the clue. There is no difference between the CPU of the build PC. The cause is that the above project is built with AGP (android gradle plugin), and AGP has a basic NDK version for each version. The AGP of the above project is 7.4 and the default NDK version is 23.1.7779620. The above NDK version, 23.1.7779620, was installed on the Mac, NDK 21.4.xx, 25.2.xxx were installed on the Intel PC. Due to this difference, the size of the .so file packaged in the apk was such a difference. As far as I know, there is no need to install NDK when building a prebuilt .so file as an apk. In fact, the build itself doesn't fail. However, there is only a difference in the size of the .so file. When packaging the .so file in the android project, should the NDK version suitable for the so file be installed? Has anyone seen a guide or document about this? am i missing something? — Reply to this email directly, view it on GitHub <#1844>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AMVLEWEAOP7SAGMPTTW5YRDWYRUDZANCNFSM6AAAAAAVCVNPA4> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[DanAlbert]

As far as I know, there is no need to install NDK when building a prebuilt .so file as an apk.

There is if you want AGP to strip those libraries. llvm-strip is shipped in the NDK. If you have no NDK installed AGP cannot strip prebuilt libraries during APK packaging. If you read the warnings from your AGP build you should see this: https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:build-system/gradle-core/src/main/java/com/android/build/gradle/internal/cxx/stripping/SymbolStripExecutableFinder.kt;l=54-58;drc=58c237e7f2a2cbb89b1011a384d63a5f64195845

I (unsuccessfully) argued against this behavior, FWIW. A real user might have more luck getting it changed than I did. You'd need to file an AGP bug. I expect the only way this can have the behavior that users want (if I've understood correctly, "leave me alone and strip the damn libraries") is for build-tools to bundle llvm-strip. The argument against it was that it could potentially be problematic for a project with an old version of build-tools to strip prebuilt libraries that came from a newer NDK.

[ciwhiz]

@enh-google , @DanAlbert ,
yes, Thank you very much,~
Both of you are right.
".so files" strip handling was the problem.
Thanks also for Dan's comments on AGP!!