From d2e35e8523c012aff9999a2d54a8b889a00ee6bf Mon Sep 17 00:00:00 2001
From: Pierce Thompson <insprill@gmail.com>
Date: Thu, 30 May 2024 23:03:05 -0400
Subject: [PATCH] Simplify build process with cross

Refactors actions builds to use cross for cross-compilation instead of
manually setting up the infrastructure which is extremely fragile, and
makes adding new archs hard.

Builds for armv7hf and armv6hf are now made as well, although they
aren't part of the docker image - they'll only be released in binaries.
If there's no intrest in these they'll probably get removed at some
point.

This also simplifies the Dockerfile a bit, making it plug-n-play with
any rust platform that has first-party host tools.
---
 .cargo/config.toml         |  9 ---------
 .github/workflows/rust.yml | 40 ++++++++++++++++++++------------------
 Dockerfile                 |  9 ++-------
 3 files changed, 23 insertions(+), 35 deletions(-)
 delete mode 100644 .cargo/config.toml

diff --git a/.cargo/config.toml b/.cargo/config.toml
deleted file mode 100644
index bed90e4..0000000
--- a/.cargo/config.toml
+++ /dev/null
@@ -1,9 +0,0 @@
-[target.aarch64-unknown-linux-gnu]
-linker = "aarch64-linux-gnu-gcc"
-
-[target.aarch64-unknown-linux-musl]
-rustflags = [ 
-    "-C", "target-feature=+crt-static", 
-    "-C", "link-arg=-lgcc"
-]
-
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index c3391cf..db99311 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -4,7 +4,6 @@ on: [ push, pull_request ]
 
 env:
   CARGO_TERM_COLOR: always
-  CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER: aarch64-linux-gnu-gcc
 
 jobs:
   build:
@@ -13,44 +12,47 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          # x86_64
           - target: 'x86_64-pc-windows-msvc'
             os: windows
           - target: 'x86_64-unknown-linux-gnu'
             os: ubuntu
           - target: 'x86_64-unknown-linux-musl'
             os: ubuntu
+          # aarch64 (armv8)
           - target: 'aarch64-unknown-linux-gnu'
             os: ubuntu
           - target: 'aarch64-unknown-linux-musl'
             os: ubuntu
+          # armv7
+          - target: 'armv7-unknown-linux-gnueabihf'
+            os: ubuntu
+          - target: 'armv7-unknown-linux-musleabihf'
+            os: ubuntu
+          # armv6
+          - target: 'arm-unknown-linux-gnueabihf'
+            os: ubuntu
+          - target: 'arm-unknown-linux-musleabihf'
+            os: ubuntu
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v4
 
-      - name: Install musl Dependencies
-        if: contains(matrix.target, 'musl')
-        run: sudo apt-get update && sudo apt-get install musl-tools
-
-      - name: Install aarch64 Dependencies
-        if: contains(matrix.target, 'aarch64')
-        run: sudo apt-get update && sudo apt-get install gcc-aarch64-linux-gnu
-
-      - name: Setup aarch64 musl compiler
-        if: contains(matrix.target, 'aarch64') && contains(matrix.target, 'musl')
-        run: |
-          wget https://musl.cc/aarch64-linux-musl-cross.tgz
-          tar -xvzf aarch64-linux-musl-cross.tgz
-          echo "CC=$(pwd)/aarch64-linux-musl-cross/bin/aarch64-linux-musl-gcc" >> "$GITHUB_ENV"
-
-      - name: Install Target
-        run: rustup target add ${{ matrix.target }}
+      - name: Install Cross
+        run: cargo install --git https://github.com/cross-rs/cross cross
 
       - name: Setup Cache
         uses: Swatinem/rust-cache@v2
 
-      - name: Build
+      # cross doesn't support msvc toolchains out-of-the-box (https://github.com/cross-rs/cross-toolchains)
+      - name: Build (Windows)
+        if: matrix.os == 'windows'
         run: cargo build --release --target=${{ matrix.target }}
 
+      - name: Build (Linux)
+        if: matrix.os == 'ubuntu'
+        run: cross build --release --target=${{ matrix.target }}
+
       - name: Upload Artifact
         uses: actions/upload-artifact@v4
         with:
diff --git a/Dockerfile b/Dockerfile
index a52a296..24a07ac 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,19 +3,14 @@
 ####################################################################################################
 FROM rust:alpine AS builder
 
-RUN apk add --no-cache musl-dev gcc # GCC needed for aarch64 builds
+RUN apk add --no-cache musl-dev
 
 WORKDIR /intellectual
 
 COPY . .
 
 # Figure out what arch we're on
-RUN BASE_TARGET=-unknown-linux-musl; \
-    case "$(uname -m)" in \
-        x86_64) TARGET=x86_64$BASE_TARGET ;; \
-        aarch64) TARGET=aarch64$BASE_TARGET ;; \
-        *) echo "Unsupported architecture"; exit 1 ;; \
-    esac; \
+RUN TARGET=$(uname -m)-unknown-linux-musl; \
 # Set environment variables so the build has git info
     export $(cat .env | xargs); \
 # Build the binary