Auto merge of #144225 - purplesyringa:unwinding-intrinsics, r=nikic

Don't special-case llvm.* as nounwind

Certain LLVM intrinsics, such as `llvm.wasm.throw`, can unwind. Marking them as nounwind causes us to skip cleanup of locals and optimize out `catch_unwind` under inlining or when `llvm.wasm.throw` is used directly by user code.

The motivation for forcibly marking llvm.* as nounwind is no longer present: most intrinsics are linked as `extern "C"` or other non-unwinding ABIs, so we won't codegen `invoke` for them anyway.

Closes rust-lang/rust#132416.

`@rustbot` label +T-compiler +A-panic

1 files changed, 15 insertions, 1 deletions

diff --git a/tests/codegen-llvm/wasm_exceptions.rs b/tests/codegen-llvm/wasm_exceptions.rs
index 07b8ae6e9d7..796b69b722b 100644
--- a/tests/codegen-llvm/wasm_exceptions.rs
+++ b/tests/codegen-llvm/wasm_exceptions.rs
@@ -2,7 +2,7 @@
 //@ compile-flags: -C panic=unwind -Z emscripten-wasm-eh
 
 #![crate_type = "lib"]
-#![feature(core_intrinsics)]
+#![feature(core_intrinsics, wasm_exception_handling_intrinsics)]
 
 extern "C-unwind" {
     fn may_panic();
@@ -57,3 +57,17 @@ pub fn test_rtry() {
     // CHECK: {{.*}} = catchpad within {{.*}} [ptr null]
     // CHECK: catchret
 }
+
+// Make sure the intrinsic is not inferred as nounwind. This is a regression test for #132416.
+// CHECK-LABEL: @test_intrinsic() {{.*}} @__gxx_wasm_personality_v0
+#[no_mangle]
+pub fn test_intrinsic() {
+    let _log_on_drop = LogOnDrop;
+    unsafe {
+        core::arch::wasm32::throw::<0>(core::ptr::null_mut());
+    }
+
+    // CHECK-NOT: call
+    // CHECK: invoke void @llvm.wasm.throw(i32 noundef 0, ptr noundef null)
+    // CHECK: %cleanuppad = cleanuppad within none []
+}