From eb75d20a55e7c6416592a6e9d4d2e7e21e08ce14 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 28 Sep 2024 14:16:05 -0400 Subject: Relax a debug assertion in codegen --- compiler/rustc_codegen_cranelift/src/unsize.rs | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'compiler/rustc_codegen_cranelift/src') diff --git a/compiler/rustc_codegen_cranelift/src/unsize.rs b/compiler/rustc_codegen_cranelift/src/unsize.rs index 339628053a9..5c297ebfadb 100644 --- a/compiler/rustc_codegen_cranelift/src/unsize.rs +++ b/compiler/rustc_codegen_cranelift/src/unsize.rs @@ -2,6 +2,7 @@ //! //! [`PointerCoercion::Unsize`]: `rustc_middle::ty::adjustment::PointerCoercion::Unsize` +use rustc_codegen_ssa::base::validate_trivial_unsize; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; use crate::base::codegen_panic_nounwind; @@ -34,20 +35,8 @@ pub(crate) fn unsized_info<'tcx>( let old_info = old_info.expect("unsized_info: missing old info for trait upcasting coercion"); if data_a.principal_def_id() == data_b.principal_def_id() { - // Codegen takes advantage of the additional assumption, where if the - // principal trait def id of what's being casted doesn't change, - // then we don't need to adjust the vtable at all. This - // corresponds to the fact that `dyn Tr: Unsize>` - // requires that `A = B`; we don't allow *upcasting* objects - // between the same trait with different args. If we, for - // some reason, were to relax the `Unsize` trait, it could become - // unsound, so let's assert here that the trait refs are *equal*. - // - // We can use `assert_eq` because the binders should have been anonymized, - // and because higher-ranked equality now requires the binders are equal. - debug_assert_eq!( - data_a.principal(), - data_b.principal(), + debug_assert!( + validate_trivial_unsize(fx.tcx, data_a, data_b), "NOP unsize vtable changed principal trait ref: {data_a} -> {data_b}" ); return old_info; -- cgit 1.4.1-3-g733a5