compile-android.sh

#!/bin/bash

set -e
platform="$(uname -s | tr '[:upper:]' '[:lower:]')"

# if args, use them to select targets (x86_64, arm64, etc)
if [ $# -gt 0 ]; then
    targets="$@"
else
    # otherwise, default to all targets
    targets="arm64 x86_64 x86 arm"
fi

ORIG_PATH="$PATH"
ORIG_RUSTFLAGS="$RUSTFLAGS"

if [ -z "$ANDROID_NDK_HOME" ]; then
    if [ -d `pwd`/"NDK" ]; then
        echo "Found NDK folder in root, using."
        ANDROID_NDK_HOME=`pwd`/NDK
    else
        # NOTE: I had some issues with this and cargo that magically resolved themselves when I made the path absolute.
        echo "Environment variable ANDROID_NDK_HOME not set, please set to location of Android NDK."
        exit 1
    fi
fi
export ANDROID_NDK_HOME

if [ "$RELEASE" = "true" ]; then
    echo "Building in release mode... (slow)";
else
    echo "Building in debug mode... (fast)"
    RELEASE=false;
fi

# Workaround for "error: unable to find library -lgcc"
# See: https://stackoverflow.com/questions/68873570/how-do-i-fix-ld-error-unable-to-find-library-lgcc-when-cross-compiling-rust
find "${ANDROID_NDK_HOME}" -name "libunwind.a" -execdir bash -c 'echo "INPUT(-lunwind)" > libgcc.a' \;

for archtargetstr in \
    'arm64 aarch64-linux-android' \
    'x86_64 x86_64-linux-android' \
    'x86 i686-linux-android' \
    'arm armv7-linux-androideabi' \
; do
    arch=$(echo $archtargetstr | cut -d " " -f 1)
    target=$(echo $archtargetstr | cut -d " " -f 2)
    target_underscore=$(echo $target | sed 's/-/_/g')

    echo ARCH $arch
    echo TARGET $target
    if ! echo "$targets" | grep -q "$arch"; then
        echo "Skipping $arch..."
        continue
    fi

    NDK_ARCH_DIR="$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/$platform-x86_64/bin"
    if [ ! -d "$NDK_ARCH_DIR" ]; then
        echo "Couldn't find directory $NDK_ARCH_DIR"
        exit 1
    fi

    echo "Building for $arch..."

    export PATH="$NDK_ARCH_DIR:$ORIG_PATH"
    export RUSTFLAGS="$ORIG_RUSTFLAGS"
    # Need to set AR for target since NDK 21+:
    #   https://github.com/rust-lang/cc-rs/issues/636#issuecomment-1075352495
    declare -x "AR_${target_underscore}"="$NDK_ARCH_DIR/llvm-ar"
    declare -x "CC_${target_underscore}"="$NDK_ARCH_DIR/${target}-clang"
    declare -x "RANLIB_${target_underscore}"="$NDK_ARCH_DIR/llvm-ranlib"

    # Needed for runtime error: https://github.com/termux/termux-packages/issues/8029
    #   java.lang.UnsatisfiedLinkError: dlopen failed: cannot locate symbol "__extenddftf2"
    export RUSTFLAGS+=" -C link-arg=$($NDK_ARCH_DIR/${target}-clang -print-libgcc-file-name)"
    echo RUSTFLAGS=$RUSTFLAGS

    # fix armv7 -> arm
    if [ "$arch" = "arm" ]; then
        declare -x "CC_${target_underscore}"="$NDK_ARCH_DIR/arm-linux-androideabi-clang"
    fi

    # check that they exist
    for var in AR_${target_underscore} CC_${target_underscore} RANLIB_${target_underscore}; do
        if [ ! -f "${!var}" ]; then
            echo "Couldn't find ${!var} set for variable $var"
            exit 1
        fi
    done

    # People suggest to use this, but ime it needs all the same workarounds anyway :shrug:
    #cargo ndk build -p aw-server --target $target --lib $($RELEASE && echo '--release')
    cargo build -p aw-server --target $target --lib $($RELEASE && echo '--release')
done