Remove terrible awful no-good evil hack

The breakage is being addressed in rust itself.

Cargo.toml

@@ -31,7 +31,6 @@ compiletest_rs = { version = "0.3", optional = true }
 
 [build-dependencies]
 gcc = { version = "0.3.52", optional = true }
-rustc_version = { version = "0.2" }
 
 [dev-dependencies]
 rustyline = "1.0.0"

build.rs

@@ -1,29 +1,14 @@
 #[cfg(feature = "builtin-lua")]
 extern crate gcc;
-extern crate rustc_version;
-
-use std::env;
 
 fn main() {
-    let target_os = env::var("CARGO_CFG_TARGET_OS");
-    let target_family = env::var("CARGO_CFG_TARGET_FAMILY");
-    if target_family == Ok("windows".to_string())
-        && rustc_version::version().unwrap() == rustc_version::Version::parse("1.24.0").unwrap()
-    {
-        // Error handling is completely broken on windows with
-        // https://github.com/rust-lang/rust/pull/46833 merged, and this includes stable rustc
-        // 1.24.0+.  `#[unwind]` fixes error handling on windows, but requires nightly!  This
-        // HORRIBLE HACK enables `#[unwind]` on stable rust by setting RUSTC_BOOTSTRAP=1 during
-        // build.  This is very evil, don't do this kids.
-        //
-        // See https://github.com/rust-lang/rust/issues/48251 and
-        // https://github.com/chucklefish/rlua/issues/71 for more details.
-        println!("cargo:rustc-env=RUSTC_BOOTSTRAP=1");
-        println!("cargo:rustc-cfg=unwind");
-    }
-
     #[cfg(feature = "builtin-lua")]
     {
+        use std::env;
+
+        let target_os = env::var("CARGO_CFG_TARGET_OS");
+        let target_family = env::var("CARGO_CFG_TARGET_FAMILY");
+
         let mut config = gcc::Build::new();
 
         if target_os == Ok("linux".to_string()) {

src/function.rs

@@ -122,7 +122,6 @@ impl<'lua> Function<'lua> {
     /// # }
     /// ```
     pub fn bind<A: ToLuaMulti<'lua>>(&self, args: A) -> Result<Function<'lua>> {
-        #[cfg_attr(unwind, unwind)]
         unsafe extern "C" fn bind_call_impl(state: *mut ffi::lua_State) -> c_int {
             let nargs = ffi::lua_gettop(state);
             let nbinds = ffi::lua_tointeger(state, ffi::lua_upvalueindex(2)) as c_int;

src/lib.rs

@@ -1,5 +1,3 @@
-#![cfg_attr(unwind, feature(unwind_attributes))]
-
 //! # High-level bindings to Lua
 //!
 //! The `rlua` crate provides safe high-level bindings to the [Lua programming language].

src/lua.rs

@@ -759,7 +759,6 @@ impl Lua {
     pub(crate) unsafe fn userdata_metatable<T: UserData>(&self) -> Result<c_int> {
         // Used if both an __index metamethod is set and regular methods, checks methods table
         // first, then __index metamethod.
-        #[cfg_attr(unwind, unwind)]
         unsafe extern "C" fn meta_index_impl(state: *mut ffi::lua_State) -> c_int {
             ffi::luaL_checkstack(state, 2, ptr::null());
 
@@ -997,7 +996,6 @@ impl Lua {
         &'lua self,
         func: Callback<'callback, 'static>,
     ) -> Result<Function<'lua>> {
-        #[cfg_attr(unwind, unwind)]
         unsafe extern "C" fn callback_call_impl(state: *mut ffi::lua_State) -> c_int {
             callback_error(state, || {
                 let lua = Lua {

src/util.rs

@@ -119,7 +119,6 @@ where
         nresults: c_int,
     }
 
-    #[cfg_attr(unwind, unwind)]
     unsafe extern "C" fn do_call<F, R>(state: *mut ffi::lua_State) -> c_int
     where
         F: FnOnce(*mut ffi::lua_State) -> R,
@@ -270,7 +269,6 @@ pub unsafe fn take_userdata<T>(state: *mut ffi::lua_State) -> T {
     ptr::read(ud)
 }
 
-#[cfg_attr(unwind, unwind)]
 pub unsafe extern "C" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c_int {
     callback_error(state, || {
         take_userdata::<T>(state);
@@ -308,7 +306,6 @@ where
 // Takes an error at the top of the stack, and if it is a WrappedError, converts it to an
 // Error::CallbackError with a traceback, if it is some lua type, prints the error along with a
 // traceback, and if it is a WrappedPanic, does not modify it.
-#[cfg_attr(unwind, unwind)]
 pub unsafe extern "C" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
     // I believe luaL_traceback requires this much free stack to not error.
     const LUA_TRACEBACK_STACK: c_int = 11;
@@ -355,7 +352,6 @@ pub unsafe extern "C" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
 }
 
 // A variant of pcall that does not allow lua to catch panic errors from callback_error
-#[cfg_attr(unwind, unwind)]
 pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
     ffi::luaL_checkstack(state, 2, ptr::null());
 
@@ -378,9 +374,7 @@ pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
 }
 
 // A variant of xpcall that does not allow lua to catch panic errors from callback_error
-#[cfg_attr(unwind, unwind)]
 pub unsafe extern "C" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
-    #[cfg_attr(unwind, unwind)]
     unsafe extern "C" fn xpcall_msgh(state: *mut ffi::lua_State) -> c_int {
         ffi::luaL_checkstack(state, 2, ptr::null());
 
@@ -480,7 +474,6 @@ pub unsafe fn init_error_metatables(state: *mut ffi::lua_State) {
 
     // Create error metatable
 
-    #[cfg_attr(unwind, unwind)]
     unsafe extern "C" fn error_tostring(state: *mut ffi::lua_State) -> c_int {
         ffi::luaL_checkstack(state, 2, ptr::null());
 
@@ -544,7 +537,6 @@ pub unsafe fn init_error_metatables(state: *mut ffi::lua_State) {
 
     // Create destructed userdata metatable
 
-    #[cfg_attr(unwind, unwind)]
     unsafe extern "C" fn destructed_error(state: *mut ffi::lua_State) -> c_int {
         ffi::luaL_checkstack(state, 2, ptr::null());
         push_wrapped_error(state, Error::CallbackDestructed);