wip: arm64 builds

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    name: ${{ matrix.kind }} ${{ matrix.os }}
+    name: ${{ matrix.arch }} ${{ matrix.os }}
     if: |
       github.event_name == 'push' ||
       !startsWith(github.event.pull_request.head.label, 'denoland:')
@@ -18,6 +18,15 @@ jobs:
           - macos-latest
           - ubuntu-16.04
           - windows-2019
+        arch:
+          - 'x86_64'
+          - 'arm64'
+
+        exclude:
+          - os: windows-2019
+            arch: 'arm64'
+          - os: macOS-latest
+            arch: 'arm64'
 
     steps:
       - name: Configure git
@@ -39,6 +48,14 @@ jobs:
         with:
           python-version: "2.7.x"
           architecture: x64
+
+      - name: Install cross compile deps
+        if: matrix.arch == 'arm64'
+        run: |
+          apt -yq --no-install-suggests --no-install-recommends install \
+          g++-aarch64-linux-gnu gcc-aarch64-linux-gnu g++-multilib \
+          libc6-arm64-cross
+          export CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER="/usr/bin/aarch64-linux-gnu-gcc"
 
       - name: Install and start sccache
         shell: pwsh

.gn

@@ -18,7 +18,6 @@ secondary_source = "//v8/"
 
 default_args = {
   linux_use_bundled_binutils = false
-  use_sysroot = false
 
   # TODO(ry) We may want to turn on CFI at some point. Disabling for simplicity
   # for now. See http://clang.llvm.org/docs/ControlFlowIntegrity.html

build.rs

@@ -83,6 +83,21 @@ fn build_v8() {
     }
   }
 
+  dbg!(env::var("CARGO_CFG_TARGET_ARCH").unwrap().as_str());
+
+  match env::var("CARGO_CFG_TARGET_ARCH").unwrap().as_str() {
+    "aarch64" => {
+      gn_args.push("target_cpu=\"arm64\"".to_string());
+      if need_sysroot_download("arm64") {
+        install_sysroot("arm64");
+      }
+    }
+    "x86_64" => {
+      gn_args.push("use_sysroot=false".to_string());
+    }
+    _ => unimplemented!(),
+  };
+
   let gn_root = env::var("CARGO_MANIFEST_DIR").unwrap();
 
   let gn_out = cargo_gn::maybe_gen(&gn_root, gn_args);
@@ -91,6 +106,21 @@ fn build_v8() {
   cargo_gn::build("rusty_v8", None);
 }
 
+fn install_sysroot(arch: &str) {
+  let status = Command::new("python")
+    .arg("./build/linux/sysroot_scripts/install-sysroot.py")
+    .arg(format!("--arch={}", arch))
+    .status()
+    .expect(&format!("sysroot download failed: {}", arch));
+  assert!(status.success());
+}
+
+fn need_sysroot_download(arch: &str) -> bool {
+  let sysroot_path =
+    PathBuf::from(format!("build/linux/debian_sid_{}-sysroot", arch));
+  !sysroot_path.is_dir()
+}
+
 fn platform() -> &'static str {
   #[cfg(target_os = "windows")]
   {