More reliable method of detecting x86-64

Cargo.lock

@@ -135,7 +135,7 @@ dependencies = [
 
 [[package]]
 name = "gmod"
-version = "10.0.0"
+version = "10.1.0"
 dependencies = [
  "cfg_table 1.0.0",
  "cstr",

gmod/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "gmod"
-version = "10.0.0"
+version = "10.1.0"
 authors = ["William Venner <william@venner.io>"]
 edition = "2018"
 license = "MIT"

gmod/src/lib.rs

@@ -39,16 +39,37 @@ pub mod userdata;
 pub mod net;
 
 /// Returns whether this client is running the x86-64 branch
-///
-/// Current implementation checks the contents of the bin/ directory, so this is a blocking operation and requires syscalls, use sparingly
 pub fn is_x86_64() -> bool {
+	#[cfg(target_pointer_width = "64")] {
+		// 64-bit can only be x86-64
+		true
+	}
+	#[cfg(target_pointer_width = "32")] {
+		lazy_static::lazy_static! {
+			static ref IS_X86_64: bool = {
 				use std::path::PathBuf;
+
+				// Check LuaJIT version
+				unsafe {
+					let (lib, _) = lua::LuaShared::find_lua_shared();
+					if lib.get::<()>(b"luaJIT_version_2_0_4\0").is_ok() {
+						false
+					} else if lib.get::<()>(b"luaJIT_version_2_1_0_beta3\0").is_ok() {
+						true
+					} else {
+						// Check bin folder
 						#[cfg(target_os = "linux")] {
 							PathBuf::from("bin/linux64").is_dir()
 						}
 						#[cfg(target_os = "windows")] {
 							PathBuf::from("bin/win64").is_dir()
 						}
+					}
+				}
+			};
+		}
+		*IS_X86_64
+	}
 }
 
 /// Opens & returns a shared library loaded by Garry's Mod using the raw path to the module.

gmod/src/lua/import.rs

@@ -249,27 +249,27 @@ impl LuaShared {
 	}
 
 	#[cfg(all(target_os = "windows", target_pointer_width = "64"))]
-	unsafe fn find_lua_shared() -> (Library, &'static str) {
+	pub unsafe fn find_lua_shared() -> (Library, &'static str) {
 		find_library!("bin/win64/lua_shared.dll")
 		.expect("Failed to load lua_shared.dll")
 	}
 
 	#[cfg(all(target_os = "windows", target_pointer_width = "32"))]
-	unsafe fn find_lua_shared() -> (Library, &'static str) {
+	pub unsafe fn find_lua_shared() -> (Library, &'static str) {
 		find_library!("garrysmod/bin/lua_shared.dll")
 		.or_else(|_| find_library!("bin/lua_shared.dll"))
 		.expect("Failed to load lua_shared.dll")
 	}
 
 	#[cfg(all(target_os = "linux", target_pointer_width = "32"))]
-	unsafe fn find_lua_shared() -> (Library, &'static str) {
+	pub unsafe fn find_lua_shared() -> (Library, &'static str) {
 		find_library!("garrysmod/bin/lua_shared_srv.so")
 		.or_else(|_| find_library!("bin/linux32/lua_shared.so"))
 		.expect("Failed to find lua_shared.so or lua_shared_srv.so")
 	}
 
 	#[cfg(all(target_os = "linux", target_pointer_width = "64"))]
-	unsafe fn find_lua_shared() -> (Library, &'static str) {
+	pub unsafe fn find_lua_shared() -> (Library, &'static str) {
 		find_library!("bin/linux64/lua_shared.so")
 		.expect("Failed to find lua_shared.so")
 	}