summary refs log tree commit diff
path: root/compiler/rustc_codegen_cranelift
diff options
context:
space:
mode:
authorMichael Goulet <michael@errs.io>2023-08-09 00:31:26 +0000
committerMaybe Lapkin <waffle.lapkin@gmail.com>2024-10-17 20:43:31 +0200
commite3800a1a04f338ce69bd403f230a019cebc54ece (patch)
tree45940f80da51d580dbb2e2451c9be4bd1cd06168 /compiler/rustc_codegen_cranelift
parent3a85d3fa785d95a7b7bcf4f160b67bffba7afd4a (diff)
downloadrust-e3800a1a04f338ce69bd403f230a019cebc54ece.tar.gz
rust-e3800a1a04f338ce69bd403f230a019cebc54ece.zip
Allow dropping dyn principal
Diffstat (limited to 'compiler/rustc_codegen_cranelift')
-rw-r--r--compiler/rustc_codegen_cranelift/src/unsize.rs4
1 files changed, 3 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/unsize.rs b/compiler/rustc_codegen_cranelift/src/unsize.rs
index 5c297ebfadb..336934354e1 100644
--- a/compiler/rustc_codegen_cranelift/src/unsize.rs
+++ b/compiler/rustc_codegen_cranelift/src/unsize.rs
@@ -34,7 +34,9 @@ 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() {
+            let b_principal_def_id = data_b.principal_def_id();
+            if data_a.principal_def_id() == b_principal_def_id || b_principal_def_id.is_none() {
+                // A NOP cast that doesn't actually change anything, should be allowed even with invalid vtables.
                 debug_assert!(
                     validate_trivial_unsize(fx.tcx, data_a, data_b),
                     "NOP unsize vtable changed principal trait ref: {data_a} -> {data_b}"