Add example of a dependency linked twice.

Author: gendx

.dockerignore

@@ -1,4 +1,6 @@
 .git
+.github
 LICENSE
 *.md
 docker-*.sh
+rustc-build

.github/workflows/docker-build.yml

@@ -29,10 +29,31 @@ jobs:
             --tmpfs /home/dev/build:exec,size=512m \
             --tmpfs /home/dev/.gradle:exec,size=512m \
             --tmpfs /home/dev/.android:size=1m \
-            --tmpfs /home/dev/.cargo/registry:size=16m \
+            --tmpfs /home/dev/.cargo/registry:size=32m \
             --tmpfs /home/dev/.rustup/toolchains:exec,size=1m \
             --entrypoint /home/dev/build-application.sh \
             android-rust-simd
+      - name: Build Android application (re-linked library)
+        run: |
+          docker run \
+            --rm \
+            --cap-drop=all \
+            --security-opt no-new-privileges \
+            --read-only \
+            -u dev \
+            --memory=3g \
+            --memory-swap=3g \
+            --memory-swappiness=0 \
+            --env USER=dev \
+            --tmpfs /tmp:size=16m \
+            --tmpfs /home/dev/build:exec,size=512m \
+            --tmpfs /home/dev/.gradle:exec,size=512m \
+            --tmpfs /home/dev/.android:size=1m \
+            --tmpfs /home/dev/.cargo/registry:size=32m \
+            --tmpfs /home/dev/.cargo/git:size=1m \
+            --tmpfs /home/dev/.rustup/toolchains:exec,size=1m \
+            --entrypoint /home/dev/build-application-relinked.sh \
+            android-rust-simd
       - name: Build Android application (stage 1 Rust)
         run: |
           mkdir -p rustc-build;

.github/workflows/format.yml

@@ -12,5 +12,7 @@ jobs:
           components: rustfmt
       - name: Check Rust formatting (android-simd)
         run: cargo fmt --verbose --manifest-path src/android-simd/Cargo.toml -- --check
+      - name: Check Rust formatting (relinked)
+        run: cargo fmt --verbose --manifest-path src/relinked/Cargo.toml -- --check
       - name: Check Rust formatting (flamedisk)
         run: cargo fmt --verbose --manifest-path tools/flamedisk/Cargo.toml -- --check

Dockerfile

@@ -132,6 +132,7 @@ USER root
 
 COPY \
     scripts/build-application.sh \
+    scripts/build-application-relinked.sh \
     scripts/build-application-stage1.sh \
     scripts/setup.sh \
     scripts/clone-rustlang-head.sh \
@@ -153,9 +154,16 @@ COPY \
     scripts/launch-app-debug.sh \
     scripts/launch-app-release.sh \
     scripts/flamedisk.sh \
+    scripts/android-runner.sh \
+    scripts/build-relinked.sh \
+    scripts/script-relinked.sh \
+    scripts/bench.sh \
+    scripts/bench-haraka.sh \
+    scripts/bench-horcrux.sh \
     /home/dev/
 RUN chmod 555 \
     /home/dev/build-application.sh \
+    /home/dev/build-application-relinked.sh \
     /home/dev/build-application-stage1.sh \
     /home/dev/setup.sh \
     /home/dev/clone-rustlang-head.sh \
@@ -176,11 +184,20 @@ RUN chmod 555 \
     /home/dev/emulator.sh \
     /home/dev/launch-app-debug.sh \
     /home/dev/launch-app-release.sh \
-    /home/dev/flamedisk.sh
+    /home/dev/flamedisk.sh \
+    /home/dev/android-runner.sh \
+    /home/dev/build-relinked.sh \
+    /home/dev/script-relinked.sh \
+    /home/dev/bench.sh \
+    /home/dev/bench-haraka.sh \
+    /home/dev/bench-horcrux.sh
 
 COPY --chown=1000:1000 cargo-config.toml /home/dev/.cargo/config
-COPY --chown=1000:1000 rustbuild-config.toml /home/dev/
-COPY --chown=1000:1000 stdarch.patch /home/dev/
+COPY --chown=1000:1000 \
+    rustbuild-config.toml \
+    stdarch.patch \
+    horcrux.dynamic_detect.patch \
+    /home/dev/
 
 COPY --chown=1000:1000 src /home/dev/src
 COPY --chown=1000:1000 tools /home/dev/tools

README.md

@@ -6,7 +6,8 @@ Additionally, this Rust library demonstrates detecting support for SIMD instruct
 You can find more information in the following blog posts:
 
 - [Compiling Rust libraries for Android apps: a deep dive](https://gendignoux.com/blog/2022/10/24/rust-library-android.html),
-- [Detecting SIMD support on ARM with Android (and patching the Rust compiler for it)](https://gendignoux.com/blog/2022/11/09/rust-simd-detect-arm-android.md).
+- [Detecting SIMD support on ARM with Android (and patching the Rust compiler for it)](https://gendignoux.com/blog/2022/11/09/rust-simd-detect-arm-android.md),
+- [Testing SIMD instructions on ARM with Rust on Android](https://gendignoux.com/blog/2023/01/05/rust-arm-simd-android.html).
 
 ## Usage
 
@@ -16,6 +17,8 @@ To build a Docker container containing all the build tools and the demo applicat
 $ sudo ./docker-build.sh
 ```
 
+### Building and running the demo Android application
+
 You can then launch this Docker container to build the application.
 This comes in various configurations:
 
@@ -35,6 +38,7 @@ You can build various flavors of the Rust library.
 - `script-rust-nightly-nostrip.sh`: same, but without stripping debug symbols.
 - `script-rust-stage1.sh` and `script-rust-stage1-nostrip.sh`: using a locally built `stage1` Rust compiler (see below).
 - `script-rust-default.sh` and `script-rust-default-nostrip.sh`: using the default Rust toolchain (stable).
+- `script-relinked.sh`: more advanced library, which bundles another library linked twice (see the corresponding [blog post](https://gendignoux.com/blog/2023/01/05/rust-arm-simd-android.html#mixing-dynamic-and-static-detection-re-linking-a-dependency)).
 
 Then, multiple ways are provided to build the Java part of the Android app.
 
@@ -44,7 +48,7 @@ Then, multiple ways are provided to build the Java part of the Android app.
 
 You can then spawn an Android emulator with `emulator.sh`, and use the `launch-app-debug.sh` or `launch-app-release.sh` scripts to install+launch the application via ADB to either the emulator or a real device connected via USB.
 
-## Building and using a patched Rust compiler
+### Building and using a patched Rust compiler
 
 This repository also shows how to patch and build the Rust compiler.
 You can launch the Docker container in various scenarios:
@@ -65,3 +69,14 @@ You'll also find the following tool to generate a flame graph of the disk space
 
 - `tools/flamedisk`: small Rust tool to generate an input suitable for `flamegraph.pl`,
 - `scripts/flamedisk.sh`: driver script to generate the flame graph.
+
+### Running unit tests and benchmarks on an Android device
+
+This repository shows how to run Rust unit tests and benchmarks directly on an attached Android device (physical device via USB or emulator), without using a full Android application.
+The `android-runner.sh` script tells Cargo how to do that.
+
+Within the Docker container, you can run the following benchmarks:
+
+- `bench.sh`: demo application, located in `src/android-simd`,
+- `bench-haraka.sh`: my implementation of the Haraka hash function (https://github.com/gendx/haraka-rs),
+- `bench-horcrux.sh`: my implementation of Shamir's Secret Sharing (https://github.com/gendx/horcrux).

cargo-config.toml

@@ -1,11 +1,15 @@
 [target.aarch64-linux-android]
 linker = "/home/dev/opt/android-sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android30-clang"
+runner = "/home/dev/android-runner.sh"
 
 [target.armv7-linux-androideabi]
 linker = "/home/dev/opt/android-sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi30-clang"
+runner = "/home/dev/android-runner.sh"
 
 [target.i686-linux-android]
 linker = "/home/dev/opt/android-sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android30-clang"
+runner = "/home/dev/android-runner.sh"
 
 [target.x86_64-linux-android]
 linker = "/home/dev/opt/android-sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android30-clang"
+runner = "/home/dev/android-runner.sh"

docker-run-all-rustc.sh

@@ -22,6 +22,7 @@ docker run \
     --tmpfs /home/dev/.gradle:exec,size=512m \
     --tmpfs /home/dev/.android:size=3g \
     --tmpfs /home/dev/.cargo/registry:size=512m \
+    --tmpfs /home/dev/.cargo/git:size=1m \
     --tmpfs /home/dev/.rustup/toolchains:exec,size=1m \
     --volume /tmp/.X11-unix:/tmp/.X11-unix \
     --volume ${PWD}/rustc-build:/home/dev/rustc-build \

docker-run-all.sh

@@ -15,7 +15,8 @@ docker run \
     --tmpfs /home/dev/build:exec,size=512m \
     --tmpfs /home/dev/.gradle:exec,size=512m \
     --tmpfs /home/dev/.android:size=3g \
-    --tmpfs /home/dev/.cargo/registry:size=16m \
+    --tmpfs /home/dev/.cargo/registry:size=32m \
+    --tmpfs /home/dev/.cargo/git:size=1m \
     --tmpfs /home/dev/.rustup/toolchains:exec,size=1m \
     --volume /tmp/.X11-unix:/tmp/.X11-unix \
     --device /dev/bus/usb \

docker-run-basic.sh

@@ -14,6 +14,7 @@ docker run \
     --tmpfs /home/dev/build:exec,size=512m \
     --tmpfs /home/dev/.gradle:exec,size=512m \
     --tmpfs /home/dev/.android:size=1m \
-    --tmpfs /home/dev/.cargo/registry:size=16m \
+    --tmpfs /home/dev/.cargo/registry:size=32m \
+    --tmpfs /home/dev/.cargo/git:size=1m \
     --tmpfs /home/dev/.rustup/toolchains:exec,size=1m \
     android-rust-simd

docker-run-emulator.sh

@@ -15,7 +15,8 @@ docker run \
     --tmpfs /home/dev/build:exec,size=512m \
     --tmpfs /home/dev/.gradle:exec,size=512m \
     --tmpfs /home/dev/.android:size=3g \
-    --tmpfs /home/dev/.cargo/registry:size=16m \
+    --tmpfs /home/dev/.cargo/registry:size=32m \
+    --tmpfs /home/dev/.cargo/git:size=1m \
     --tmpfs /home/dev/.rustup/toolchains:exec,size=1m \
     --volume /tmp/.X11-unix:/tmp/.X11-unix \
     --device /dev/dri \