From 7739cf5dc3e81cd8cc894d5fba63d3bc9ac721b7 Mon Sep 17 00:00:00 2001
From: adumbidiot <nathaniel.daniel23@outlook.com>
Date: Fri, 30 Oct 2020 20:00:16 -0700
Subject: [PATCH] Respect CARGO_CFG_TARGET_ARCH env var

---
 build/src/lib.rs | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/build/src/lib.rs b/build/src/lib.rs
index 29534b4c..f24578f3 100644
--- a/build/src/lib.rs
+++ b/build/src/lib.rs
@@ -18,8 +18,9 @@ cfg_if! {
         Ok(stdout_str.trim().trim_start_matches('v').to_string())
     }
 
-    fn download_node_lib(dist_url: &str, version: &str) -> Vec<u8> {
-      let url = format!("{dist_url}/v{version}/win-x64/node.lib", dist_url = dist_url, version = version);
+    fn download_node_lib(dist_url: &str, version: &str, arch: &str) -> Vec<u8> {
+      // Assume windows since we know we are building on windows.
+      let url = format!("{dist_url}/v{version}/win-{arch}/node.lib", dist_url = dist_url, version = version, arch = arch);
 
       let response = ureq::get(&url).call();
       if let Some(error) = response.synthetic_error() {
@@ -43,6 +44,24 @@ cfg_if! {
         .or_else(|_| get_node_version())
         .expect("Failed to determine nodejs version");
 
+      // NPM also gives us an arch var, but let's trust cargo more.
+      // We translate from cargo's arch env format into npm/gyps's.
+      // See https://doc.rust-lang.org/reference/conditional-compilation.html#target_arch for rust env values.
+      // Nodejs appears to follow `process.arch`.
+      // See https://nodejs.org/docs/latest/api/process.html#process_process_arch for npm env values.
+      let arch = std::env::var("CARGO_CFG_TARGET_ARCH")
+        .map(|arch| match arch.as_str() {
+          "x86" => "x86", // TODO: x86 appears to also be called ia32 in npm_config_arch sometimes. What is the right value?
+          "x86_64" => "x64",
+          "mips" => "mips",
+          "powerpc" => "ppc",
+          "powerpc64" => "ppc64",
+          "arm" => "arm",
+          "aarch64" => "arm64",
+          arch => panic!("Unknown Architecture: {}", arch),
+        })
+        .expect("Failed to determine target arch");
+
       println!("cargo:rerun-if-env-changed=NPM_CONFIG_DISTURL");
       println!("cargo:rerun-if-env-changed=NPM_CONFIG_TARGET");
 
@@ -65,7 +84,7 @@ cfg_if! {
       node_lib_file_dir.push(format!("node-{}.lib", node_version));
 
       if let Err(_) = metadata(&node_lib_file_dir) {
-        let node_lib = download_node_lib(&dist_url, &node_version);
+        let node_lib = download_node_lib(&dist_url, &node_version, &arch);
         write(&node_lib_file_dir, &node_lib).expect(&format!("Could not save file to {}", node_lib_file_dir.to_str().unwrap()));
       }
       println!(
@@ -73,7 +92,6 @@ cfg_if! {
         &node_lib_file_dir.file_stem().unwrap().to_str().unwrap()
       );
       println!("cargo:rustc-link-search=native={}", link_search_dir.to_str().unwrap());
-      // Link `win_delay_load_hook.obj` for windows electron
       println!("cargo:rustc-cdylib-link-arg=delayimp.lib");
       println!("cargo:rustc-cdylib-link-arg=/DELAYLOAD:node.exe");
       setup_napi_feature();