From 1905178bd28effaf043a6f063ff2db228b6a050f Mon Sep 17 00:00:00 2001
From: Sculas <contact@sculas.xyz>
Date: Sat, 15 Feb 2025 01:25:46 +0100
Subject: [PATCH 1/2] feat: Allow external build scripts to link Lua libraries

---
 Cargo.toml                   |  1 +
 mlua-sys/Cargo.toml          |  1 +
 mlua-sys/build/main_inner.rs | 31 +++++++++++++++++++------------
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index fb432cf8..1fc14c05 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,6 +36,7 @@ luau = ["ffi/luau", "dep:libloading"]
 luau-jit = ["luau", "ffi/luau-codegen"]
 luau-vector4 = ["luau", "ffi/luau-vector4"]
 vendored = ["ffi/vendored"]
+external = ["ffi/external"]
 module = ["dep:mlua_derive", "ffi/module"]
 async = ["dep:futures-util"]
 send = ["parking_lot/send_guard", "error-send"]
diff --git a/mlua-sys/Cargo.toml b/mlua-sys/Cargo.toml
index f4171a15..39b6f276 100644
--- a/mlua-sys/Cargo.toml
+++ b/mlua-sys/Cargo.toml
@@ -30,6 +30,7 @@ luau = ["luau0-src"]
 luau-codegen = ["luau"]
 luau-vector4 = ["luau"]
 vendored = ["lua-src", "luajit-src"]
+external = []
 module = []
 
 [dependencies]
diff --git a/mlua-sys/build/main_inner.rs b/mlua-sys/build/main_inner.rs
index 05ac53b5..dc97f38d 100644
--- a/mlua-sys/build/main_inner.rs
+++ b/mlua-sys/build/main_inner.rs
@@ -14,22 +14,29 @@ fn main() {
     #[cfg(all(feature = "luau", feature = "module", windows))]
     compile_error!("Luau does not support `module` mode on Windows");
 
-    #[cfg(all(feature = "module", feature = "vendored"))]
-    compile_error!("`vendored` and `module` features are mutually exclusive");
+    #[cfg(any(
+        all(feature = "vendored", any(feature = "external", feature = "module")),
+        all(feature = "external", any(feature = "vendored", feature = "module")),
+        all(feature = "module", any(feature = "vendored", feature = "external"))
+    ))]
+    compile_error!("`vendored`, `external` and `module` features are mutually exclusive");
 
     println!("cargo:rerun-if-changed=build");
 
-    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
-    if target_os == "windows" && cfg!(feature = "module") {
-        if !std::env::var("LUA_LIB_NAME").unwrap_or_default().is_empty() {
-            // Don't use raw-dylib linking
-            find::probe_lua();
-            return;
+    // Check if compilation and linking is handled by external crate
+    if !cfg!(feature = "external") {
+        let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+        if target_os == "windows" && cfg!(feature = "module") {
+            if !std::env::var("LUA_LIB_NAME").unwrap_or_default().is_empty() {
+                // Don't use raw-dylib linking
+                find::probe_lua();
+                return;
+            }
+
+            println!("cargo:rustc-cfg=raw_dylib");
         }
 
-        println!("cargo:rustc-cfg=raw_dylib");
+        #[cfg(not(feature = "module"))]
+        find::probe_lua();
     }
-
-    #[cfg(not(feature = "module"))]
-    find::probe_lua();
 }

From 248770e52d9961b8189e23f7672bed26c0af83f2 Mon Sep 17 00:00:00 2001
From: Sculas <contact@sculas.xyz>
Date: Wed, 11 Jun 2025 12:22:15 +0200
Subject: [PATCH 2/2] refactor: remove `external` feature flag

---
 Cargo.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index dd2d2ba5..65ac1ba8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,7 +36,6 @@ luau = ["ffi/luau"]
 luau-jit = ["luau", "ffi/luau-codegen"]
 luau-vector4 = ["luau", "ffi/luau-vector4"]
 vendored = ["ffi/vendored"]
-external = ["ffi/external"]
 module = ["mlua_derive", "ffi/module"]
 async = ["dep:futures-util"]
 send = ["error-send"]