Setup preliminary rust infrastructure

.gitmodules

@@ -40,3 +40,6 @@
 [submodule "zopfli"]
 	path = native/jni/external/zopfli
 	url = https://github.com/google/zopfli.git
+[submodule "cxx-rs"]
+	path = native/jni/external/cxx-rs
+	url = https://github.com/topjohnwu/cxx.git

README.MD

@@ -51,7 +51,7 @@ For Magisk app crashes, record and upload the logcat when the crash occurs.
 - Run `./build.py ndk` to let the script download and install NDK for you
 - To start building, run `build.py` to see your options. \
   For each action, use `-h` to access help (e.g. `./build.py all -h`)
-- To start development, open the project with Android Studio. The IDE can be used for both app (Kotlin/Java) and native (C++/C) sources.
+- To start development, open the project with Android Studio. The IDE can be used for both app (Kotlin/Java) and native sources.
 - Optionally, set custom configs with `config.prop`. A sample `config.prop.sample` is provided.
 
 ## Signing and Distribution

build.py

@@ -37,10 +37,10 @@ def vprint(str):
 
 is_windows = os.name == 'nt'
 is_ci = 'CI' in os.environ and os.environ['CI'] == 'true'
+EXE_EXT = '.exe' if is_windows else ''
 
 if not is_ci and is_windows:
     import colorama
-
     colorama.init()
 
 # Environment checks
@@ -58,16 +58,20 @@ except FileNotFoundError:
 
 cpu_count = multiprocessing.cpu_count()
 archs = ['armeabi-v7a', 'x86', 'arm64-v8a', 'x86_64']
+triples = ['armv7a-linux-androideabi', 'i686-linux-android', 'aarch64-linux-android', 'x86_64-linux-android']
 default_targets = ['magisk', 'magiskinit', 'magiskboot', 'magiskpolicy', 'busybox']
 support_targets = default_targets + ['resetprop', 'test']
+rust_targets = ['magisk', 'magiskinit', 'magiskboot', 'magiskpolicy']
 
 sdk_path = os.environ['ANDROID_SDK_ROOT']
 ndk_root = op.join(sdk_path, 'ndk')
 ndk_path = op.join(ndk_root, 'magisk')
 ndk_build = op.join(ndk_path, 'ndk-build')
+rust_bin = op.join(ndk_path, 'toolchains', 'rust', 'bin')
+cargo = op.join(rust_bin, 'cargo' + EXE_EXT)
 gradlew = op.join('.', 'gradlew' + ('.bat' if is_windows else ''))
-adb_path = op.join(sdk_path, 'platform-tools', 'adb' + ('.exe' if is_windows else ''))
-native_gen_path = op.join('native', 'out', 'generated')
+adb_path = op.join(sdk_path, 'platform-tools', 'adb' + EXE_EXT)
+native_gen_path = op.realpath(op.join('native', 'out', 'generated'))
 
 # Global vars
 config = {}
@@ -123,16 +127,17 @@ def mkdir_p(path, mode=0o755):
     os.makedirs(path, mode, exist_ok=True)
 
 
-def execv(cmd):
-    return subprocess.run(cmd, stdout=STDOUT)
+def execv(cmd, env=None):
+    return subprocess.run(cmd, stdout=STDOUT, env=env)
 
 
 def system(cmd):
     return subprocess.run(cmd, shell=True, stdout=STDOUT)
 
 
-def cmd_out(cmd):
-    return subprocess.check_output(cmd).strip().decode('utf-8')
+def cmd_out(cmd, env=None):
+    return subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL, env=env) \
+                     .stdout.strip().decode('utf-8')
 
 
 def xz(data):
@@ -180,15 +185,6 @@ def load_config(args):
     STDOUT = None if args.verbose else subprocess.DEVNULL
 
 
-def collect_binary():
-    for arch in archs:
-        mkdir_p(op.join('native', 'out', arch))
-        for bin in support_targets + ['libpreload.so']:
-            source = op.join('native', 'libs', arch, bin)
-            target = op.join('native', 'out', arch, bin)
-            mv(source, target)
-
-
 def clean_elf():
     if is_windows:
         elf_cleaner = op.join('tools', 'elf-cleaner.exe')
@@ -203,48 +199,6 @@ def clean_elf():
     execv(args)
 
 
-def find_build_tools():
-    global build_tools
-    if build_tools:
-        return build_tools
-    build_tools_root = op.join(os.environ['ANDROID_SDK_ROOT'], 'build-tools')
-    ls = os.listdir(build_tools_root)
-    # Use the latest build tools available
-    ls.sort()
-    build_tools = op.join(build_tools_root, ls[-1])
-    return build_tools
-
-
-# Unused but keep this code
-def sign_zip(unsigned):
-    if 'keyStore' not in config:
-        return
-
-    msg = '* Signing APK'
-    apksigner = op.join(find_build_tools(), 'apksigner' + ('.bat' if is_windows else ''))
-
-    exec_args = [apksigner, 'sign',
-                 '--ks', config['keyStore'],
-                 '--ks-pass', f'pass:{config["keyStorePass"]}',
-                 '--ks-key-alias', config['keyAlias'],
-                 '--key-pass', f'pass:{config["keyPass"]}',
-                 '--v1-signer-name', 'CERT',
-                 '--v4-signing-enabled', 'false']
-
-    if unsigned.endswith('.zip'):
-        msg = '* Signing zip'
-        exec_args.extend(['--min-sdk-version', '17',
-                          '--v2-signing-enabled', 'false',
-                          '--v3-signing-enabled', 'false'])
-
-    exec_args.append(unsigned)
-
-    header(msg)
-    proc = execv(exec_args)
-    if proc.returncode != 0:
-        error('Signing failed!')
-
-
 def binary_dump(src, var_name):
     out_str = f'constexpr unsigned char {var_name}[] = {{'
     for i, c in enumerate(xz(src.read())):
@@ -261,7 +215,70 @@ def run_ndk_build(flags):
     if proc.returncode != 0:
         error('Build binary failed!')
     os.chdir('..')
-    collect_binary()
+    for arch in archs:
+        for tgt in support_targets + ['libpreload.so']:
+            source = op.join('native', 'libs', arch, tgt)
+            target = op.join('native', 'out', arch, tgt)
+            mv(source, target)
+
+
+def run_cargo_build(args):
+    os.chdir(op.join('native', 'rust'))
+    targets = set(args.target) & set(rust_targets)
+
+    env = os.environ.copy()
+    env['PATH'] = f'{rust_bin}:{env["PATH"]}'
+
+    # Install cxxbridge and generate C++ bindings
+    native_out = op.join('..', '..', 'native', 'out')
+    local_cargo_root = op.join(native_out, '.cargo')
+    mkdir_p(local_cargo_root)
+    cmds = [cargo, 'install', '--root', local_cargo_root, 'cxxbridge-cmd']
+    if not args.verbose:
+        cmds.append('-q')
+    proc = execv(cmds, env)
+    if proc.returncode != 0:
+        error('cxxbridge-cmd installation failed!')
+    cxxbridge = op.join(local_cargo_root, 'bin', 'cxxbridge' + EXE_EXT)
+    mkdir(native_gen_path)
+    for p in ['base', 'boot', 'core', 'init', 'sepolicy']:
+        text = cmd_out([cxxbridge, op.join(p, 'src', 'lib.rs')])
+        write_if_diff(op.join(native_gen_path, f'{p}-rs.cpp'), text)
+        text = cmd_out([cxxbridge, '--header', op.join(p, 'src', 'lib.rs')])
+        write_if_diff(op.join(native_gen_path, f'{p}-rs.hpp'), text)
+
+    # Start building the actual build commands
+    cmds = [cargo, 'build', '-Z', 'build-std=std,panic_abort',
+           '-Z', 'build-std-features=panic_immediate_abort']
+    for target in targets:
+        cmds.append('-p')
+        cmds.append(target)
+    rust_out = 'debug'
+    if args.release:
+        cmds.append('-r')
+        rust_out = 'release'
+    if not args.verbose:
+        cmds.append('-q')
+
+    os_name = platform.system().lower()
+    llvm_bin = op.join(ndk_path, 'toolchains', 'llvm', 'prebuilt', f'{os_name}-x86_64', 'bin')
+    env['TARGET_CC'] = op.join(llvm_bin, 'clang' + EXE_EXT)
+    env['RUSTFLAGS'] = '-Clinker-plugin-lto'
+    for (arch, triple) in zip(archs, triples):
+        env['TARGET_CFLAGS'] = f'--target={triple}21'
+        rust_triple = 'thumbv7neon-linux-androideabi' if triple.startswith('armv7') else triple
+        proc = execv([*cmds, '--target', rust_triple], env)
+        if proc.returncode != 0:
+            error('Build binary failed!')
+
+        arch_out = op.join(native_out, arch)
+        mkdir(arch_out)
+        for tgt in targets:
+            source = op.join('target', rust_triple, rust_out, f'lib{tgt}.a')
+            target = op.join(arch_out, f'lib{tgt}-rs.a')
+            mv(source, target)
+
+    os.chdir(op.join('..', '..'))
 
 
 def write_if_diff(file_name, text):
@@ -326,6 +343,8 @@ def build_binary(args):
 
     header('* Building binaries: ' + ' '.join(args.target))
 
+    run_cargo_build(args)
+
     dump_flag_header()
 
     flag = ''
@@ -402,6 +421,7 @@ def cleanup(args):
         rm_rf(op.join('native', 'out'))
         rm_rf(op.join('native', 'libs'))
         rm_rf(op.join('native', 'obj'))
+        rm_rf(op.join('native', 'rust', 'target'))
 
     if 'java' in args.target:
         header('* Cleaning java')

native/README.md

@@ -0,0 +1,34 @@
+# Native Development
+
+## Prerequisite
+
+Install the NDK required to build and develop Magisk with `./build.py ndk`. The NDK will be installed to `$ANDROID_SDK_ROOT/ndk/magisk`. You don't need to manually install a Rust toolchain with `rustup`, as the NDK installed already has a Rust toolchain bundled.
+
+## Code Paths
+
+- `jni`: Magisk's code in C++
+- `jni/external`: external dependencies, mostly submodules
+- `rust`: Magisk's code in Rust
+- `src`: irrelevant, only exists to setup a native Android Studio project
+
+## Build Configs
+
+All C/C++ code and its dependencies are built with [`ndk-build`](https://developer.android.com/ndk/guides/ndk-build) and configured with several `*.mk` files scatterred in many places.
+
+The `rust` folder is a proper Cargo workspace, and all Rust code is built with `cargo` just like any other Rust projects.
+
+## Rust + C/C++
+
+To reduce complexity involved in linking, all Rust code is built as `staticlib` and linked to C++ targets to ensure our final product is built with an officially supported NDK build system. Each C++ target can at most link to **one** Rust `staticlib` or else multiple definitions error will occur.
+
+We use the [`cxx`](https://cxx.rs) project for interop between Rust and C++. Although cxx supports interop in both directions, for Magisk, it is strongly advised to avoid calling C++ functions in Rust; if some functionality required in Rust is already implemented in C++, the desired solution is to port the C++ implementation into Rust and export the migrated function back to C++.
+
+## Development / IDE
+
+All C++ code should be recognized and properly indexed by Android Studio out of the box. For Rust:
+
+- Install the [Rust plugin](https://www.jetbrains.com/rust/) in Android Studio
+- In Preferences > Languages & Frameworks > Rust, set `$ANDROID_SDK_ROOT/ndk/magisk/toolchains/rust/bin` as the toolchain location
+- Open `native/rust/Cargo.toml`, and select "Attach" in the "No Cargo projects found" banner
+
+Note: run `./build.py binary` before developing to make sure generated code is created.

native/jni/Android-rs.mk

@@ -0,0 +1,25 @@
+LOCAL_PATH := $(call my-dir)
+
+###########################
+# Rust compilation outputs
+###########################
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := magisk-rs
+LOCAL_SRC_FILES := ../out/$(TARGET_ARCH_ABI)/libmagisk-rs.a
+include $(PREBUILT_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := boot-rs
+LOCAL_SRC_FILES := ../out/$(TARGET_ARCH_ABI)/libmagiskboot-rs.a
+include $(PREBUILT_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := init-rs
+LOCAL_SRC_FILES := ../out/$(TARGET_ARCH_ABI)/libmagiskinit-rs.a
+include $(PREBUILT_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := policy-rs
+LOCAL_SRC_FILES := ../out/$(TARGET_ARCH_ABI)/libmagiskpolicy-rs.a
+include $(PREBUILT_STATIC_LIBRARY)

native/jni/Android.mk

@@ -14,7 +14,8 @@ LOCAL_STATIC_LIBRARIES := \
     libsystemproperties \
     libphmap \
     libxhook \
-    libmincrypt
+    libmincrypt \
+    libmagisk-rs
 
 LOCAL_SRC_FILES := \
     core/applets.cpp \
@@ -68,7 +69,8 @@ LOCAL_STATIC_LIBRARIES := \
     libbase \
     libcompat \
     libpolicy \
-    libxz
+    libxz \
+    libinit-rs
 
 LOCAL_SRC_FILES := \
     init/init.cpp \
@@ -95,7 +97,8 @@ LOCAL_STATIC_LIBRARIES := \
     libbz2 \
     libfdt \
     libz \
-    libzopfli
+    libzopfli \
+    libboot-rs
 
 LOCAL_SRC_FILES := \
     boot/main.cpp \
@@ -119,7 +122,8 @@ LOCAL_MODULE := magiskpolicy
 LOCAL_STATIC_LIBRARIES := \
     libbase \
     libbase \
-    libpolicy
+    libpolicy \
+    libpolicy-rs
 
 LOCAL_SRC_FILES := sepolicy/main.cpp
 
@@ -135,7 +139,8 @@ LOCAL_STATIC_LIBRARIES := \
     libbase \
     libcompat \
     libnanopb \
-    libsystemproperties
+    libsystemproperties \
+    libmagisk-rs
 
 LOCAL_SRC_FILES := \
     core/applet_stub.cpp \
@@ -181,6 +186,7 @@ LOCAL_SRC_FILES := \
     sepolicy/statement.cpp
 include $(BUILD_STATIC_LIBRARY)
 
+include jni/Android-rs.mk
 include jni/base/Android.mk
 include jni/external/Android.mk
 

native/jni/base/Android.mk

@@ -15,7 +15,8 @@ LOCAL_SRC_FILES := \
     selinux.cpp \
     logging.cpp \
     xwrap.cpp \
-    stream.cpp
+    stream.cpp \
+    ../external/cxx-rs/src/cxx.cc
 include $(BUILD_STATIC_LIBRARY)
 
 # All static executables should link with libcompat

native/jni/external/cxx-rs

@@ -0,0 +1 @@
+Subproject commit 650e64bc3970625f580a61ad9cfc65faa5cdd948

native/rust/.gitignore

@@ -0,0 +1 @@
+target/

native/rust/Cargo.lock

@@ -0,0 +1,99 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "base"
+version = "0.1.0"
+
+[[package]]
+name = "cc"
+version = "1.0.73"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
+
+[[package]]
+name = "cxx"
+version = "1.0.69"
+dependencies = [
+ "cc",
+ "cxxbridge-flags",
+ "cxxbridge-macro",
+]
+
+[[package]]
+name = "cxxbridge-flags"
+version = "1.0.69"
+
+[[package]]
+name = "cxxbridge-macro"
+version = "1.0.69"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "magisk"
+version = "0.1.0"
+dependencies = [
+ "base",
+ "cxx",
+]
+
+[[package]]
+name = "magiskboot"
+version = "0.1.0"
+dependencies = [
+ "base",
+]
+
+[[package]]
+name = "magiskinit"
+version = "0.1.0"
+dependencies = [
+ "base",
+]
+
+[[package]]
+name = "magiskpolicy"
+version = "0.1.0"
+dependencies = [
+ "base",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd96a1e8ed2596c337f8eae5f24924ec83f5ad5ab21ea8e455d3566c69fbcaf7"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3bcdf212e9776fbcb2d23ab029360416bb1706b1aea2d1a5ba002727cbcab804"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.98"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c50aef8a904de4c23c788f104b7dddc7d6f79c647c7c8ce4cc8f73eb0ca773dd"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5bd2fe26506023ed7b5e1e315add59d6f584c621d037f9368fea9cfb988f368c"

native/rust/Cargo.toml

@@ -0,0 +1,26 @@
+[workspace]
+
+members = [
+    "base",
+    "boot",
+    "core",
+    "init",
+    "sepolicy",
+]
+
+[profile.dev]
+opt-level = "z"
+lto = true
+codegen-units = 1
+panic = "abort"
+strip = true
+
+[profile.release]
+opt-level = "z"
+lto = true
+codegen-units = 1
+panic = "abort"
+strip = true
+
+[patch.crates-io]
+cxx = { path = "../jni/external/cxx-rs" }

native/rust/base/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "base"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

native/rust/boot/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "magiskboot"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+base = { path = "../base" }

native/rust/core/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "magisk"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+base = { path = "../base" }
+cxx = "1.0.69"

native/rust/init/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "magiskinit"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+base = { path = "../base" }

native/rust/sepolicy/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "magiskpolicy"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["staticlib", "rlib"]
+
+[dependencies]
+base = { path = "../base" }