Add musl build

Author: xoofx

.github/workflows/native.yml

@@ -32,15 +32,28 @@ jobs:
     - name: Build Linux
       if: matrix.os == 'ubuntu-22.04'
       run: |
+          sudo apt-get update
           chmod 755 *.sh
           echo "building linux-x64"
           ./build-linux-x64.sh
           echo "building linux-arm64"
-          sudo apt-get install gcc-aarch64-linux-gnu      
+          sudo apt-get install -y gcc-aarch64-linux-gnu
           ./build-linux-arm64.sh
           echo "building linux-arm"
-          sudo apt-get install gcc-arm-linux-gnueabihf      
+          sudo apt-get install -y gcc-arm-linux-gnueabihf
           ./build-linux-arm.sh
+
+          # musl
+          echo "building linux-musl-x64"
+          sudo apt-get install -y musl-tools
+          CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER=musl-gcc ./build-linux-musl-x64.sh
+
+          echo "building linux-musl-arm64"
+          # Use cross (Docker-based) to avoid installing a full aarch64 musl toolchain on the runner.
+          cargo install cross --locked
+          RUSTFLAGS="-C target-feature=-crt-static" cross build --release --target aarch64-unknown-linux-musl
+          mkdir -p build/linux-musl-arm64/native
+          cp target/aarch64-unknown-linux-musl/release/libblake3_dotnet.so build/linux-musl-arm64/native
     - name: Build macOS
       if: matrix.os == 'macos-latest'
       run: |

lib/blake3_dotnet/.cargo/config.toml

@@ -4,7 +4,13 @@ rustflags = ["-Ctarget-feature=+crt-static"]
 rustflags = ["-Ctarget-feature=+crt-static"]
 [target.x86_64-unknown-linux-gnu]
 rustflags = ["-Ctarget-feature=-crt-static"]
+[target.x86_64-unknown-linux-musl]
+linker = "x86_64-linux-musl-gcc"
+rustflags = ["-Ctarget-feature=-crt-static"]
 [target.aarch64-unknown-linux-gnu]
 linker = "aarch64-linux-gnu-gcc"
+[target.aarch64-unknown-linux-musl]
+linker = "aarch64-linux-musl-gcc"
+rustflags = ["-Ctarget-feature=-crt-static"]
 [target.arm-unknown-linux-gnueabihf]
 linker = "arm-linux-gnueabihf-gcc"

lib/blake3_dotnet/build-linux-musl-arm64.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+set -eu
+
+TARGET="aarch64-unknown-linux-musl"
+BUILD="linux-musl-arm64"
+
+rustup target add "$TARGET"
+
+# Some toolchains/environments require disabling crt static linking for musl.
+# If you already set RUSTFLAGS, this appends the flag.
+EXTRA_RUSTFLAGS="-C target-feature=-crt-static"
+if [ "${RUSTFLAGS:-}" = "" ]; then
+  export RUSTFLAGS="$EXTRA_RUSTFLAGS"
+else
+  export RUSTFLAGS="$RUSTFLAGS $EXTRA_RUSTFLAGS"
+fi
+
+cargo build --release --target "$TARGET"
+
+mkdir -p "build/$BUILD/native"
+cp "target/$TARGET/release/libblake3_dotnet.so" "build/$BUILD/native"
+
+# Prefer a target-specific strip if available, otherwise fall back.
+if command -v aarch64-linux-musl-strip >/dev/null 2>&1; then
+  aarch64-linux-musl-strip "build/$BUILD/native"/*.so
+elif command -v llvm-strip >/dev/null 2>&1; then
+  llvm-strip "build/$BUILD/native"/*.so || true
+elif command -v strip >/dev/null 2>&1; then
+  strip "build/$BUILD/native"/*.so || true
+fi

lib/blake3_dotnet/build-linux-musl-x64.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+set -eu
+
+TARGET="x86_64-unknown-linux-musl"
+BUILD="linux-musl-x64"
+
+rustup target add "$TARGET"
+
+# Some toolchains/environments require disabling crt static linking for musl.
+# If you already set RUSTFLAGS, this appends the flag.
+EXTRA_RUSTFLAGS="-C target-feature=-crt-static"
+if [ "${RUSTFLAGS:-}" = "" ]; then
+  export RUSTFLAGS="$EXTRA_RUSTFLAGS"
+else
+  export RUSTFLAGS="$RUSTFLAGS $EXTRA_RUSTFLAGS"
+fi
+
+cargo build --release --target "$TARGET"
+
+mkdir -p "build/$BUILD/native"
+cp "target/$TARGET/release/libblake3_dotnet.so" "build/$BUILD/native"
+
+if command -v strip >/dev/null 2>&1; then
+  strip "build/$BUILD/native"/*.so || true
+fi

lib/blake3_dotnet/readme.md

@@ -6,4 +6,8 @@ BLAKE3 Rust libraries compiled to native and exposed as plain shared libraries.
 
 You need to have [`rustup`](https://rustup.rs/) installed
 
-Run one of the `build*` scripts (e.g `build-win-x64.ps1` or `build-linux-x64.sh`).
+Run one of the `build*` scripts (e.g `build-win-x64.ps1` or `build-linux-x64.sh`).
+
+Musl targets are supported via:
+- `build-linux-musl-x64.sh` (`x86_64-unknown-linux-musl`)
+- `build-linux-musl-arm64.sh` (`aarch64-unknown-linux-musl`)