1 files changed, 30 insertions, 0 deletions
diff --git a/tests/ui/lto/thin-lto-inlines.rs b/tests/ui/lto/thin-lto-inlines.rs
new file mode 100644
index 000000000..dca791807
--- /dev/null
+++ b/tests/ui/lto/thin-lto-inlines.rs
@@ -0,0 +1,30 @@
+// run-pass
+
+// compile-flags: -Z thinlto -C codegen-units=8 -O
+// ignore-emscripten can't inspect instructions on emscripten
+
+// We want to assert here that ThinLTO will inline across codegen units. There's
+// not really a great way to do that in general so we sort of hack around it by
+// praying two functions go into separate codegen units and then assuming that
+// if inlining *doesn't* happen the first byte of the functions will differ.
+
+pub fn foo() -> u32 {
+    bar::bar()
+}
+
+mod bar {
+    pub fn bar() -> u32 {
+        3
+    }
+}
+
+fn main() {
+    println!("{} {}", foo(), bar::bar());
+
+    unsafe {
+        let foo = foo as usize as *const u8;
+        let bar = bar::bar as usize as *const u8;
+
+        assert_eq!(*foo, *bar);
+    }
+}