Auto merge of #102732 - RalfJung:assert_unsafe_precondition2, r=bjorn3

nicer errors from assert_unsafe_precondition

This makes the errors shown by cargo-careful nicer, and since `panic_no_unwind` is `nounwind noreturn` it hopefully doesn't have bad codegen impact. Thanks to `@bjorn3` for the hint!

Would be nice if we could somehow supply our own (static) message to print, currently it always prints `panic in a function that cannot unwind`. But still, this is better than before.

3 files changed, 3 insertions, 10 deletions

diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 5ee6c9f2387..92d0fb1aec8 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -536,7 +536,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // ==========================================================================
 
     rustc_attr!(rustc_allocator, Normal, template!(Word), WarnFollowing, IMPL_DETAIL),
-    rustc_attr!(rustc_allocator_nounwind, Normal, template!(Word), WarnFollowing, IMPL_DETAIL),
+    rustc_attr!(rustc_nounwind, Normal, template!(Word), WarnFollowing, IMPL_DETAIL),
     rustc_attr!(rustc_reallocator, Normal, template!(Word), WarnFollowing, IMPL_DETAIL),
     rustc_attr!(rustc_deallocator, Normal, template!(Word), WarnFollowing, IMPL_DETAIL),
     rustc_attr!(rustc_allocator_zeroed, Normal, template!(Word), WarnFollowing, IMPL_DETAIL),
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 98bcdcf6520..5c76016c662 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -1582,13 +1582,6 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
         codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER;
     }
 
-    // The panic_no_unwind function called by TerminatorKind::Abort will never
-    // unwind. If the panic handler that it invokes unwind then it will simply
-    // call the panic handler again.
-    if Some(did.to_def_id()) == tcx.lang_items().panic_no_unwind() {
-        codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND;
-    }
-
     let supported_target_features = tcx.supported_target_features(LOCAL_CRATE);
 
     let mut inline_span = None;
@@ -1649,7 +1642,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
                 )
                 .emit();
             }
-        } else if attr.has_name(sym::rustc_allocator_nounwind) {
+        } else if attr.has_name(sym::rustc_nounwind) {
             codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND;
         } else if attr.has_name(sym::rustc_reallocator) {
             codegen_fn_attrs.flags |= CodegenFnAttrFlags::REALLOCATOR;
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index fe4fd33bdba..c6711b603b6 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1231,7 +1231,6 @@ symbols! {
         rust_oom,
         rustc,
         rustc_allocator,
-        rustc_allocator_nounwind,
         rustc_allocator_zeroed,
         rustc_allow_const_fn_unstable,
         rustc_allow_incoherent_impl,
@@ -1278,6 +1277,7 @@ symbols! {
         rustc_mir,
         rustc_must_implement_one_of,
         rustc_nonnull_optimization_guaranteed,
+        rustc_nounwind,
         rustc_object_lifetime_default,
         rustc_on_unimplemented,
         rustc_outlives,