Auto merge of #105997 - RalfJung:immediate-abort, r=eholk

abort immediately on bad mem::zeroed/uninit

Now that we have non-unwinding panics, let's use them for these assertions. This re-establishes the property that `mem::uninitialized` and `mem::zeroed` will never unwind -- the earlier approach of causing panics here sometimes led to hard-to-debug segfaults when the surrounding code was not able to cope with the unexpected unwinding.

Cc `@bjorn3` I did not touch cranelift but I assume it needs a similar patch. However it has a `codegen_panic` abstraction that I did not want to touch since I didn't know how else it is used.

1 files changed, 4 insertions, 5 deletions

diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index cff72048ead..978aff511bf 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -637,7 +637,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         self.set_debug_loc(bx, terminator.source_info);
 
         // Obtain the panic entry point.
-        let (fn_abi, llfn) = common::build_langcall(bx, Some(span), LangItem::PanicNoUnwind);
+        let (fn_abi, llfn) = common::build_langcall(bx, Some(span), LangItem::PanicCannotUnwind);
 
         // Codegen the actual panic invoke/call.
         let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &[], None, None, &[], false);
@@ -698,11 +698,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     })
                 });
                 let msg = bx.const_str(&msg_str);
-                let location = self.get_caller_location(bx, source_info).immediate();
 
                 // Obtain the panic entry point.
                 let (fn_abi, llfn) =
-                    common::build_langcall(bx, Some(source_info.span), LangItem::Panic);
+                    common::build_langcall(bx, Some(source_info.span), LangItem::PanicNounwind);
 
                 // Codegen the actual panic invoke/call.
                 helper.do_call(
@@ -710,7 +709,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     bx,
                     fn_abi,
                     llfn,
-                    &[msg.0, msg.1, location],
+                    &[msg.0, msg.1],
                     target.as_ref().map(|bb| (ReturnDest::Nothing, *bb)),
                     cleanup,
                     &[],
@@ -1665,7 +1664,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             let llpersonality = self.cx.eh_personality();
             bx.cleanup_landing_pad(llpersonality);
 
-            let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, LangItem::PanicNoUnwind);
+            let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, LangItem::PanicCannotUnwind);
             let fn_ty = bx.fn_decl_backend_type(&fn_abi);
 
             let llret = bx.call(fn_ty, Some(&fn_abi), fn_ptr, &[], None);