Restructure the native module

Consolidate all code into the src folder

.gitmodules

@@ -1,45 +1,45 @@
 [submodule "selinux"]
-	path = native/jni/external/selinux
+	path = native/src/external/selinux
 	url = https://github.com/topjohnwu/selinux.git
 [submodule "busybox"]
-	path = native/jni/external/busybox
+	path = native/src/external/busybox
 	url = https://github.com/topjohnwu/ndk-busybox.git
 [submodule "dtc"]
-	path = native/jni/external/dtc
+	path = native/src/external/dtc
 	url = https://github.com/dgibson/dtc.git
 [submodule "lz4"]
-	path = native/jni/external/lz4
+	path = native/src/external/lz4
 	url = https://github.com/lz4/lz4.git
 [submodule "bzip2"]
-	path = native/jni/external/bzip2
+	path = native/src/external/bzip2
 	url = https://github.com/nemequ/bzip2.git
 [submodule "xz"]
-	path = native/jni/external/xz
+	path = native/src/external/xz
 	url = https://github.com/xz-mirror/xz.git
 [submodule "nanopb"]
-	path = native/jni/external/nanopb
+	path = native/src/external/nanopb
 	url = https://github.com/nanopb/nanopb.git
 [submodule "mincrypt"]
-	path = native/jni/external/mincrypt
+	path = native/src/external/mincrypt
 	url = https://github.com/topjohnwu/mincrypt.git
 [submodule "pcre"]
-	path = native/jni/external/pcre
+	path = native/src/external/pcre
 	url = https://android.googlesource.com/platform/external/pcre
 [submodule "libcxx"]
-	path = native/jni/external/libcxx
+	path = native/src/external/libcxx
 	url = https://github.com/topjohnwu/libcxx.git
 [submodule "zlib"]
-	path = native/jni/external/zlib
+	path = native/src/external/zlib
 	url = https://android.googlesource.com/platform/external/zlib
 [submodule "parallel-hashmap"]
-	path = native/jni/external/parallel-hashmap
+	path = native/src/external/parallel-hashmap
 	url = https://github.com/greg7mdp/parallel-hashmap.git
+[submodule "zopfli"]
+	path = native/src/external/zopfli
+	url = https://github.com/google/zopfli.git
+[submodule "cxx-rs"]
+	path = native/src/external/cxx-rs
+	url = https://github.com/topjohnwu/cxx.git
 [submodule "termux-elf-cleaner"]
 	path = tools/termux-elf-cleaner
 	url = https://github.com/termux/termux-elf-cleaner.git
-[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

build.py

@@ -211,6 +211,7 @@ def binary_dump(src, var_name):
 
 def run_ndk_build(flags):
     os.chdir('native')
+    flags = 'NDK_PROJECT_PATH=. NDK_APPLICATION_MK=src/Application.mk ' + flags
     proc = system(f'{ndk_build} {flags} -j{cpu_count}')
     if proc.returncode != 0:
         error('Build binary failed!')
@@ -223,7 +224,7 @@ def run_ndk_build(flags):
 
 
 def run_cargo_build(args):
-    os.chdir(op.join('native', 'rust'))
+    os.chdir(op.join('native', 'src'))
     targets = set(args.target) & set(rust_targets)
 
     env = os.environ.copy()
@@ -242,9 +243,9 @@ def run_cargo_build(args):
     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')])
+        text = cmd_out([cxxbridge, op.join(p, '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')])
+        text = cmd_out([cxxbridge, '--header', op.join(p, 'lib.rs')])
         write_if_diff(op.join(native_gen_path, f'{p}-rs.hpp'), text)
 
     # Start building the actual build commands

native/README.md

@@ -4,24 +4,17 @@
 
 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.
+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 scattered 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.
+The `src` folder is also a proper Cargo workspace, and all Rust code is built with `cargo` just like normal 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++.
+We use the [`cxx`](https://cxx.rs) project for Rust and C++ interop.
 
 ## Development / IDE
 
@@ -29,6 +22,6 @@ All C++ code should be recognized and properly indexed by Android Studio out of
 
 - 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
+- Open `native/src/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/build.gradle.kts

@@ -9,10 +9,14 @@ android {
 
     externalNativeBuild {
         ndkBuild {
-            path("jni/Android.mk")
+            path("src/Android.mk")
         }
     }
 
+    sourceSets.getByName("main") {
+        manifest.srcFile("src/AndroidManifest.xml")
+    }
+
     defaultConfig {
         externalNativeBuild {
             ndkBuild {

native/rust/.gitignore

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

native/src/.gitignore

@@ -1 +1,2 @@
 test.cpp
+target/

native/src/Android.mk

@@ -153,7 +153,7 @@ include $(BUILD_EXECUTABLE)
 endif
 
 ifdef B_TEST
-ifneq (,$(wildcard jni/test.cpp))
+ifneq (,$(wildcard src/test.cpp))
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := test
@@ -176,7 +176,7 @@ LOCAL_MODULE := libpolicy
 LOCAL_STATIC_LIBRARIES := \
     libbase \
     libsepol
-LOCAL_C_INCLUDES := jni/sepolicy/include
+LOCAL_C_INCLUDES := src/sepolicy/include
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
 LOCAL_SRC_FILES := \
     sepolicy/api.cpp \
@@ -186,12 +186,12 @@ 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
+include src/Android-rs.mk
+include src/base/Android.mk
+include src/external/Android.mk
 
 ifdef B_BB
 
-include jni/external/busybox/Android.mk
+include src/external/busybox/Android.mk
 
 endif

native/src/AndroidManifest.xml

@@ -0,0 +1,2 @@
+<!-- This file exists only to make Android Studio happy -->
+<manifest/>

native/src/Application.mk

@@ -1,3 +1,4 @@
+APP_BUILD_SCRIPT := src/Android.mk
 APP_ABI          := armeabi-v7a arm64-v8a x86 x86_64
 APP_CFLAGS       := -Wall -Oz -fomit-frame-pointer -flto
 APP_LDFLAGS      := -flto
@@ -10,7 +11,7 @@ APP_STRIP_MODE   := --strip-all
 # Busybox should use stock libc.a
 ifdef B_BB
 APP_PLATFORM     := android-24
-APP_LDFLAGS      += -T jni/lto_fix.lds
+APP_LDFLAGS      += -T src/lto_fix.lds
 ifeq ($(OS),Windows_NT)
 APP_SHORT_COMMANDS := true
 endif

native/src/Cargo.toml

@@ -23,4 +23,4 @@ panic = "abort"
 strip = true
 
 [patch.crates-io]
-cxx = { path = "../jni/external/cxx-rs" }
+cxx = { path = "../src/external/cxx-rs" }

native/src/base/Android.mk

@@ -4,7 +4,7 @@ LOCAL_PATH := $(call my-dir)
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libbase
-LOCAL_C_INCLUDES := jni/include $(LOCAL_PATH)/include out/generated
+LOCAL_C_INCLUDES := src/include $(LOCAL_PATH)/include out/generated
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
 LOCAL_EXPORT_STATIC_LIBRARIES := libcxx
 LOCAL_STATIC_LIBRARIES := libcxx
@@ -28,5 +28,5 @@ LOCAL_MODULE := libcompat
 LOCAL_SRC_FILES := compat/compat.cpp
 # Fix static variables' ctor/dtor when using LTO
 # See: https://github.com/android/ndk/issues/1461
-LOCAL_EXPORT_LDLIBS := -static -T jni/lto_fix.lds
+LOCAL_EXPORT_LDLIBS := -static -T src/lto_fix.lds
 include $(BUILD_STATIC_LIBRARY)

native/src/base/Cargo.toml

@@ -3,5 +3,8 @@ name = "base"
 version = "0.1.0"
 edition = "2021"
 
+[lib]
+path = "lib.rs"
+
 [dependencies]
 cxx = "1.0.69"

native/src/boot/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [lib]
 crate-type = ["staticlib"]
+path = "lib.rs"
 
 [dependencies]
 base = { path = "../base" }

native/src/core/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [lib]
 crate-type = ["staticlib"]
+path = "lib.rs"
 
 [dependencies]
 base = { path = "../base" }