Configure LLVM

Author: ascopes

.github/workflows/test.yml

@@ -8,15 +8,34 @@ on:
 
 env:
   CARGO_TERM_COLOR: always
+  LLVM_VERSION: 21
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Install LLVM
+      run: |-        
+        LLVM_MAJOR_VERSION=21
+        
+        sudo apt-cache update
+        
+        wget https://apt.llvm.org/llvm.sh
+        chmod +x llvm.sh
+        sudo ./llvm.sh "${LLVM_VERSION}"
+        rm llvm.sh
+
+        # Point llvm-config to llvm-config-$LLVM_VERSION so Rust doesn't whinge about it 
+        sudo ln -sf "$(command -v "llvm-config-${LLVM_VERSION}")" /usr/bin/llvm-config
+        
+        llvm-config --version
+
     - name: Build
       run: cargo build --verbose
+
     - name: Run tests
       run: cargo test --verbose

haikulang_llvm/build.rs

@@ -0,0 +1,35 @@
+// Attempt to avoid pain with LLVM, probably.
+fn main() {
+    let output = std::process::Command::new("llvm-config")
+        .arg("--prefix")
+        .output()
+        .expect(r#"
+            Failed to run llvm-config. Is llvm-devel installed?
+
+            Try one of the following:
+
+                # Fedora
+                - sudo dnf install llvm-devel clang-devel libffi-devel
+
+                # Ubuntu
+                - wget https://apt.llvm.org/llvm.sh
+                  chmod +x llvm.sh
+                  sudo ./llvm.sh 21
+                  rm llvm.sh
+        "#);
+
+    let prefix = std::str::from_utf8(&output.stdout).unwrap().trim();
+
+    let version_output = std::process::Command::new("llvm-config")
+        .arg("--version")
+        .output()
+        .unwrap();
+
+    let version = std::str::from_utf8(&version_output.stdout).unwrap();
+    let major_version = version.split('.').next().unwrap();
+
+    // This turns "21.x.x" into "LLVM_SYS_211_PREFIX"
+    println!("cargo:rustc-env=LLVM_SYS_{}1_PREFIX={}", major_version, prefix);
+
+    println!("cargo:rustc-link-search=native={}/lib", prefix);
+}