Port backtrace's cpp_smoke to rustc repo

Author: Pyr0de

tests/auxiliary/rust_test_helpers.c

@@ -451,3 +451,11 @@ uint16_t issue_97463_leak_uninit_data(uint32_t a, uint32_t b, uint32_t c) {
 
     return data->b; /* leak data */
 }
+
+void templated_trampoline(void (*func)()) {
+    func();
+}
+
+void cpp_trampoline(void (*func)()) {
+    templated_trampoline(func);
+}

tests/ui/backtrace/smoke.rs

@@ -0,0 +1,40 @@
+//Part of porting backtrace-rs tests to rustc repo:
+//Original test: <https://github.com/rust-lang/rust/issues/122899>
+//<https://github.com/rust-lang/backtrace-rs/tree/6fa4b85b9962c3e1be8c2e5cc605cd078134152b/crates/cpp_smoke_test>
+// ignore-tidy-linelength
+//@ run-pass
+//@ compile-flags: -Cstrip=none
+//@ needs-unwind
+
+#![allow(improper_ctypes)]
+#![allow(improper_ctypes_definitions)]
+#![feature(backtrace_frames)]
+
+use std::{backtrace::Backtrace, sync::atomic::{AtomicBool, Ordering}};
+
+#[link(name = "rust_test_helpers", kind = "static")]
+extern "C" {
+    fn cpp_trampoline(func: extern "C" fn()) -> ();
+}
+
+fn main() {
+    std::env::set_var("RUST_BACKTRACE", "1");
+    static RAN_ASSERTS: AtomicBool = AtomicBool::new(false);
+    extern "C" fn assert_cpp_frames() {
+        let trace = Backtrace::capture();
+        let actual = format!("{:?}", trace.frames());
+        let expected = [
+            "templated_trampoline",
+            "cpp_trampoline",
+        ];
+        for e in expected {
+            assert!(actual.contains(e));
+        }
+        RAN_ASSERTS.store(true, Ordering::SeqCst);
+    }
+    assert!(!RAN_ASSERTS.load(Ordering::SeqCst));
+    unsafe {
+        cpp_trampoline(assert_cpp_frames);
+    }
+    assert!(RAN_ASSERTS.load(Ordering::SeqCst));
+}