chore: add Makefile

Update README.md
Update gitignore

.gitignore

@@ -1,14 +1,3 @@
-# Generated by Cargo
-# will have compiled files and executables
-debug/
-target/
+rust
 
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
-# These are backup files generated by rustfmt
-**/*.rs.bk
-
-# MSVC Windows builds of rustc generate these, which store debugging information
-*.pdb
+Makefile.local

Makefile

@@ -0,0 +1,78 @@
+RUST_PREBUILT_VERSION ?= 2023-11-13
+RUST_PREBUILT_COMPONENTS ?= rust-std rustc cargo rustfmt
+RUST_PREBUILT_CHANNELS ?= beta nightly
+RUST_PREBUILT_TARGET ?= x86_64-apple-darwin
+RUST_PREBUILT_OUTPUT_DIR ?= rust/build/cache
+
+RUST_GIT_URL ?= https://github.com/rust-lang/rust.git
+RUST_TOOLS ?= cargo,clippy,rustdoc,rustfmt,rust-analyzer,analysis,src
+RUST_TARGETS ?= aarch64-apple-ios,aarch64-apple-darwin
+RUST_VERBOSE ?= 0
+RUST_CHANNEL ?= dev
+RUST_DESCRIPTION ?= ""
+RUST_INSTALL_DIR ?= install
+RUST_DIST_FORMATS ?= xz
+
+# NOTE: use Makefile.local for customization
+-include Makefile.local
+
+.PHONY: help
+help:			## Show this help
+	@fgrep -h "## " $(MAKEFILE_LIST) | fgrep -v fgrep | sed -e 's/\\$$//' | sed -e 's/##//'
+
+.PHONY: download
+download:		## Download Rust sources
+	git clone --recurse-submodules -j8 ${RUST_GIT_URL}
+
+.PHONY: download-offline
+download-offline: SHELL:=/bin/bash
+download-offline:	## Download prebuilt Rust binaries
+	mkdir -p ${RUST_PREBUILT_OUTPUT_DIR}/${RUST_PREBUILT_VERSION}
+	@for RUST_CHANNEL in ${RUST_PREBUILT_CHANNELS}; do \
+		for RUST_COMPONENT in ${RUST_PREBUILT_COMPONENTS}; do \
+			RUST_FILENAME=${RUST_PREBUILT_VERSION}/$${RUST_COMPONENT}-$${RUST_CHANNEL}-${RUST_PREBUILT_TARGET}.tar.xz ; \
+			curl --fail https://static.rust-lang.org/dist/$${RUST_FILENAME} --output ${RUST_PREBUILT_OUTPUT_DIR}/$${RUST_FILENAME} ; \
+		done; \
+	done;
+
+###
+# Configure: https://github.com/rust-lang/rust/blob/master/src/bootstrap/configure.py
+###
+
+.PHONY: configure
+configure:		## Configure Rust
+	cd rust && ./configure \
+		--enable-option-checking \
+		--enable-verbose-tests \
+		--enable-codegen-tests \
+		--enable-dist-src \
+		--tools=${RUST_TOOLS} \
+		--target=${RUST_TARGETS} \
+		--set llvm.download-ci-llvm=true \
+		--set build.verbose=${RUST_VERBOSE} \
+		--set rust.channel=${RUST_CHANNEL} \
+		--set rust.description=${RUST_DESCRIPTION} \
+		--dist-compression-formats=${RUST_DIST_FORMATS} \
+		--prefix=${RUST_INSTALL_DIR}
+
+.PHONY: configure-offline
+configure-offline:	## Configure Rust and LLVM
+	cd rust && ./configure \
+		--enable-option-checking \
+		--enable-sccache \
+		--enable-ninja \
+		--enable-verbose-tests \
+		--enable-codegen-tests \
+		--enable-dist-src \
+		--tools=${RUST_TOOLS} \
+		--target=${RUST_TARGETS} \
+		--set llvm.download-ci-llvm=false \
+		--set llvm.targets="AArch64;X86" \
+		--set llvm.experimental-targets="" \
+		--set llvm.tests=true \
+		--set build.verbose=${RUST_VERBOSE} \
+		--set rust.channel=${RUST_CHANNEL} \
+		--set rust.description=${RUST_DESCRIPTION} \
+		--set rust.omit-git-hash=true \
+		--dist-compression-formats=${RUST_DIST_FORMATS} \
+		--prefix=${RUST_INSTALL_DIR}

Makefile.example.local

@@ -0,0 +1,4 @@
+# RUST_TOOLS = cargo,rustfmt
+# RUST_TARGETS = arm64e-apple-ios,arm64e-apple-darwin
+# RUST_CHANNEL = stable
+# RUST_VERBOSE = 3

README.md

@@ -1 +1,16 @@
-# rust-builder
+# Rust Compiler Builder
+
+[![Rust](https://img.shields.io/badge/Rust-Dev-orange.svg)](https://github.com/rust-lang/rust)
+
+Builds the *Rust* compiler and [Tier 3 targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html) using *GitHub Actions*.
+
+## Usage
+
+```sh
+$ make
+help:                    Show this help
+download:                Download Rust sources
+download-offline:        Download prebuilt Rust binaries
+configure:               Configure Rust
+configure-offline:       Configure Rust and LLVM
+```