c-unwind-abi.rs

//@ compile-flags: -C opt-level=0
//@ needs-unwind

// Test that `nounwind` attributes are correctly applied to exported `C` and `C-unwind` extern
// functions. `C-unwind` functions MUST NOT have this attribute. We disable optimizations above
// to prevent LLVM from inferring the attribute.

#![crate_type = "lib"]

// CHECK: @rust_item_that_cannot_unwind() unnamed_addr #0 {
#[no_mangle]
pub extern "C" fn rust_item_that_cannot_unwind() {}

// CHECK: @rust_item_that_can_unwind() unnamed_addr #1 {
#[no_mangle]
pub extern "C-unwind" fn rust_item_that_can_unwind() {}

// Now, make some assertions that the LLVM attributes for these functions are correct.  First, make
// sure that the first item is correctly marked with the `nounwind` attribute:
//
// CHECK: attributes #0 = { {{.*}}nounwind{{.*}} }
//
// Next, let's assert that the second item, which CAN unwind, does not have this attribute.
//
// CHECK: attributes #1 = {
// CHECK-NOT: nounwind
// CHECK: }