find system lua with pkg-config

Cargo.toml

@@ -31,6 +31,7 @@ compiletest_rs = { version = "0.3", optional = true }
 
 [build-dependencies]
 cc = { version = "1.0", optional = true }
+pkg-config = "0.3.11"
 
 [dev-dependencies]
 rustyline = "1.0.0"
@@ -38,4 +39,4 @@ criterion = "0.2.0"
 
 [[bench]]
 name = "benchmark"
-harness = false
+harness = false

build.rs

@@ -1,6 +1,9 @@
 #[cfg(feature = "builtin-lua")]
 extern crate cc;
 
+#[cfg(not(feature = "builtin-lua"))]
+extern crate pkg_config;
+
 fn main() {
     #[cfg(feature = "builtin-lua")]
     {
@@ -62,4 +65,8 @@ fn main() {
             .file("lua/lzio.c")
             .compile("liblua5.3.a");
     }
+    #[cfg(not(feature = "builtin-lua"))]
+    {
+        pkg_config::Config::new().atleast_version("5.3").probe("lua").unwrap();
+    }
 }

src/ffi.rs

@@ -78,7 +78,6 @@ pub const LUA_GCSETPAUSE: c_int = 6;
 pub const LUA_GCSETSTEPMUL: c_int = 7;
 pub const LUA_GCISRUNNING: c_int = 9;
 
-#[link(name = "lua5.3")]
 extern "C" {
     pub fn lua_newstate(alloc: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
     pub fn lua_close(state: *mut lua_State);