Simplify build setup by adding a setup script

2 files changed, 124 insertions, 15 deletions

diff --git a/README.md b/README.md
index 9a8179fa..0b5ccbfd 100644
--- a/README.md
+++ b/README.md
@@ -122,32 +122,54 @@ Just like other game decompilations, this project is probably in a legal gray zo
 
 ### Alright, how do I start contributing?
 
-First, set up the build environment by following the instructions below. Then follow the [contributing guidelines here](Contributing.md).
+First, set up the build environment by following the instructions below.
 
 ## Building
 
-### Dependencies
+Reminder: **this will not produce a playable game.** This project will not allow you to play the game if you don't already own it on a Switch.
+
+### For Windows users
+
+While Linux is not a hard requirement, it is strongly advised to [set up WSL](https://docs.microsoft.com/en-us/windows/wsl/install-win10) to simplify the setup process. Ubuntu 20.04 is usually a good choice.
 
-* Clang 4.0.1
-    * Download [Clang 4.0.1](https://releases.llvm.org/download.html#4.0.1) and extract the archive to a convenient location of your choice.
-    * You might also need libtinfo5. For Ubuntu or Debian users, install it with `sudo apt install libtinfo5`
+The instructions below assume that you are using Linux (native or WSL) or macOS.
+
+### 1. Set up dependencies
+
+* Python 3.6 or newer
 * Ninja
-    * For Ubuntu or Debian users, install it with `sudo apt install ninja-build`
 * CMake 3.13+
-    * If you are on Ubuntu 18.04, you must [update CMake by using the official CMake APT repository](https://apt.kitware.com/).
+    * If you are on Ubuntu 18.04, you must first [update CMake by using the official CMake APT repository](https://apt.kitware.com/).
+* [Optional] ccache (to speed up builds)
 
-Using Linux (or WSL) is recommended but not required. The rest of this guide assumes that you are using a Linux environment, though.
+Ubuntu users can install those dependencies by running:
 
-### Building for Switch
+```shell
+sudo apt install python3 ninja-build cmake ccache
+```
 
-1. After cloning this repository, run: `git submodule update --init --recursive`
-2. Run: `env UKING_CLANG=$$$$$ cmake -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_TOOLCHAIN_FILE=toolchain/ToolchainNX64.cmake -B build`
-    * Replace `$$$$$` with the path to the extracted Clang archive, such that `$1/bin/clang` exists. This should be an absolute path; use `/home/<name>` instead of `~`.
-3. Start the build by running: `ninja -C build`
+### 2. Set up the repository
 
-On subsequent builds, just run `ninja -C build` from the project root.
+1. Clone this repository.
+2. Run `git submodule update --init --recursive`
+3. Run `tools/setup.py`
+    * This will set up [Clang 4.0.1](https://releases.llvm.org/download.html#4.0.1) and create a build directory in `build/`.
 
-Reminder: **this will not produce a playable game.** This project will not allow you to play the game if you don't already own it on a Switch.
+### 3. Build
+
+To start the build, just run
+
+```shell
+ninja -C build
+```
+
+By default, Ninja will perform a multithreaded build. There is no need to pass -j manually.
+
+To check whether everything built correctly, just run `tools/check.py` after the build completes.
+
+## Contributing
+
+Follow the [contributing guidelines here](Contributing.md).
 
 ## Resources
 
diff --git a/tools/setup.py b/tools/setup.py
new file mode 100755
index 00000000..b495e89a
--- /dev/null
+++ b/tools/setup.py
@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+
+import os
+import platform
+from pathlib import Path
+import sys
+import tarfile
+import tempfile
+import urllib.request
+
+ROOT = Path(__file__).parent.parent
+
+
+def fail(error: str):
+    print(error)
+    sys.exit(1)
+
+
+def set_up_compiler():
+    compiler_dir = ROOT / "toolchain" / "clang"
+    if compiler_dir.is_dir():
+        print("clang is already set up: nothing to do")
+        return
+
+    system = platform.system()
+    machine = platform.machine()
+
+    builds = {
+        # Linux
+        ("Linux", "x86_64"): {
+            "url": "https://releases.llvm.org/4.0.1/clang+llvm-4.0.1-x86_64-linux-gnu-Fedora-25.tar.xz",
+            "dir_name": "clang+llvm-4.0.1-x86_64-linux-gnu-Fedora-25",
+        },
+        ("Linux", "aarch64"): {
+            "url": "https://releases.llvm.org/4.0.1/clang+llvm-4.0.1-aarch64-linux-gnu.tar.xz",
+            "dir_name": "clang+llvm-4.0.1-aarch64-linux-gnu",
+        },
+
+        # macOS
+        ("Darwin", "x86_64"): {
+            "url": "https://releases.llvm.org/4.0.1/clang+llvm-4.0.1-x86_64-apple-darwin.tar.xz",
+            "dir_name": "clang+llvm-4.0.1-x86_64-apple-darwin",
+        },
+        ("Darwin", "aarch64"): {
+            "url": "https://releases.llvm.org/4.0.1/clang+llvm-4.0.1-x86_64-apple-darwin.tar.xz",
+            "dir_name": "clang+llvm-4.0.1-x86_64-apple-darwin",
+        },
+    }
+
+    build_info = builds.get((system, machine))
+    if build_info is None:
+        fail(
+            f"unknown platform: {platform.platform()} (please report if you are on Linux and macOS)")
+
+    url: str = build_info["url"]
+    dir_name: str = build_info["dir_name"]
+
+    print(f"downloading Clang from {url}...")
+    with tempfile.TemporaryDirectory() as tmpdir:
+        path = tmpdir + "/" + url.split("/")[-1]
+        urllib.request.urlretrieve(url, path)
+
+        print(f"extracting Clang...")
+        with tarfile.open(path) as f:
+            f.extractall(compiler_dir.parent)
+            (compiler_dir.parent / dir_name).rename(compiler_dir)
+
+    print(">>> successfully set up Clang")
+
+
+def create_build_dir():
+    build_dir = ROOT / "build"
+    if build_dir.is_dir():
+        print("build directory already exists: nothing to do")
+        return
+
+    os.system("cmake -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_TOOLCHAIN_FILE=toolchain/ToolchainNX64.cmake -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -B build/")
+    print(">>> created build directory")
+
+
+def main():
+    set_up_compiler()
+    create_build_dir()
+
+
+if __name__ == "__main__":
+    main()