I'm attempting to build our Android shared library (using @Buttaface's fantastic SDK builds) with a static stdlib and some weird things are happening:
Firstly, the final
.so file (
products: [.library(name: "...", type: .dynamic, ...)]) as built by
swift build --static-swift-stdlib still links to
libswiftCore.so and so on dynamically. I tried to work around this manually by running SwiftPM with
-v, copying the final linker invocation, and changing the search path from
That almost works, but leads to the second issue: there are duplicate symbols in
libswift_StringProcessing.a that are also present in
_swift_stdlib_getScript. I worked around this by running
/usr/local/ndk/25.1.8937393//toolchains/llvm/prebuilt/darwin-x86_64/bin/llvm-objcopy -L _swift_stdlib_getScript and
-L _swift_stdlib_getScriptExtensions, as described here. edit: just found this issue which is relevant here.
The final hurdle, and where I'm stuck, is: the final
.so file seems to want to link the objc runtime. I get a
dlopen failed: cannot locate symbol "objc_retainAutoreleasedReturnValue" referenced by [my .so file] when trying to load it. So I feel like something in the build setup of the Android static SDK is probably not correct. The objc runtime should not be referenced at all for Android builds.
I'm mostly posting this to make the issue known, and to gather some thoughts about how this might be improved in the SDK builds. Maybe someone has run into similar issues for Android or another Linux platform and has some ideas?
A working static build for Android would be a pretty amazing improvement. The (not quite working) stripped, statically linked binary is 75% smaller than the dynamically linked equivalent for us. And that is on top of the 50% reduction we already gained by removing Foundation recently.
Getting this working would make a lot of users (and me!) very happy
./swift/utils/build-script -RA --skip-build-cmark --build-llvm=0 --android --android-ndk /home/butta/android-ndk-r25b/ --android-arch aarch64 --android-api-level 24 --build-swift-tools=0 --native-swift-tools-path=/home/butta/swift-5.7-RELEASE-ubuntu20.04/usr/bin/ --native-clang-tools-path=/home/butta/swift-5.7-RELEASE-ubuntu20.04/usr/bin/ --host-cc=/usr/bin/clang-13 --host-cxx=/usr/bin/clang++-13 --cross-compile-hosts=android-aarch64 --cross-compile-deps-path=/home/butta/swift-release-android-aarch64-24-sdk --skip-local-build --xctest --swift-install-components='clang-resource-dir-symlink;license;stdlib;sdk-overlay' --install-swift --install-libdispatch --install-foundation --install-xctest --install-destdir=/home/butta/swift-release-android-aarch64-24-sdk --cross-compile-append-host-target-to-destdir=False --build-swift-static-stdlib -j9