Use compiletest to make sure unsafe things do not compile

.travis.yml

@@ -1,10 +1,12 @@
 language: rust
-rust:
-  - stable
-  - beta
-  - nightly
 env:
   - RUSTFLAGS="-D warnings"
 matrix:
+  include:
+    - rust: stable
+      script: cargo test --lib -v
+    - rust: beta
+      script: cargo test --lib -v
+    - rust: nightly
   allow_failures:
     - rust: nightly

Cargo.toml

@@ -29,3 +29,4 @@ gcc = { version = "0.3.52", optional = true }
 
 [dev-dependencies]
 rustyline = "1.0.0"
+compiletest_rs = "0.3.0"

src/tests.rs

@@ -982,28 +982,3 @@ fn test_metatable() {
         _ => panic!(),
     };
 }
-
-// Need to use compiletest-rs or similar to make sure these don't compile.
-/*
-#[test]
-fn should_not_compile() {
-    let lua = Lua::new();
-    let globals = lua.globals();
-
-    // Should not allow userdata borrow to outlive lifetime of AnyUserData handle
-    struct MyUserData;
-    impl UserData for MyUserData {};
-    let userdata_ref;
-    {
-        let touter = globals.get::<_, Table>("touter").unwrap();
-        touter.set("userdata", lua.create_userdata(MyUserData)).unwrap();
-        let userdata = touter.get::<_, AnyUserData>("userdata").unwrap();
-        userdata_ref = userdata.borrow::<MyUserData>();
-    }
-
-    // Should not allow self borrow of lua, it can change addresses
-    globals.set("boom", lua.create_function(|_, _| {
-        lua.eval::<i32>("1 + 1", None)
-    })).unwrap();
-}
-*/

tests/compile-fail.rs

@@ -0,0 +1,18 @@
+extern crate compiletest_rs as compiletest;
+
+use std::path::PathBuf;
+
+fn run_mode(mode: &'static str) {
+    let mut config = compiletest::Config::default();
+
+    config.mode = mode.parse().expect("Invalid mode");
+    config.src_base = PathBuf::from(format!("tests/{}", mode));
+    config.target_rustcflags = Some("-L target/debug -L target/debug/deps".to_string());
+
+    compiletest::run_tests(&config);
+}
+
+#[test]
+fn compile_test() {
+    run_mode("compile-fail");
+}

tests/compile-fail/self-borrow.rs

@@ -0,0 +1,13 @@
+extern crate rlua;
+
+use rlua::*;
+
+fn main() {
+    let lua = Lua::new();
+
+    // Should not allow self borrow of lua, it can change addresses
+    let func = lua.create_function(|_, ()| -> Result<i32> {
+        //~^ error: closure may outlive the current function, but it borrows `lua`, which is owned by the current function
+        lua.eval::<i32>("1 + 1", None)
+    });
+}

tests/compile-fail/userdata-borrow.rs

@@ -0,0 +1,20 @@
+extern crate rlua;
+
+use rlua::*;
+
+fn main() {
+    let lua = Lua::new();
+    let globals = lua.globals();
+
+    // Should not allow userdata borrow to outlive lifetime of AnyUserData handle
+    struct MyUserData;
+    impl UserData for MyUserData {};
+    let userdata_ref;
+    {
+        let touter = globals.get::<_, Table>("touter").unwrap();
+        touter.set("userdata", lua.create_userdata(MyUserData)).unwrap();
+        let userdata = touter.get::<_, AnyUserData>("userdata").unwrap();
+        userdata_ref = userdata.borrow::<MyUserData>();
+    }
+    //~^ error: `userdata` does not live long enough
+}