Improve CTFE validation error message

1 files changed, 12 insertions, 8 deletions

diff --git a/compiler/rustc_mir/src/interpret/validity.rs b/compiler/rustc_mir/src/interpret/validity.rs
index c9ebffe8d1c..7511890090b 100644
--- a/compiler/rustc_mir/src/interpret/validity.rs
+++ b/compiler/rustc_mir/src/interpret/validity.rs
@@ -26,23 +26,27 @@ use super::{
 
 macro_rules! throw_validation_failure {
     ($where:expr, { $( $what_fmt:expr ),+ } $( expected { $( $expected_fmt:expr ),+ } )?) => {{
-        let msg = rustc_middle::ty::print::with_no_trimmed_paths(|| {
+        let (path, msg) = rustc_middle::ty::print::with_no_trimmed_paths(|| {
             let mut msg = String::new();
             msg.push_str("encountered ");
             write!(&mut msg, $($what_fmt),+).unwrap();
-            let where_ = &$where;
-            if !where_.is_empty() {
-                msg.push_str(" at ");
-                write_path(&mut msg, where_);
-            }
             $(
                 msg.push_str(", but expected ");
                 write!(&mut msg, $($expected_fmt),+).unwrap();
             )?
 
-            msg
+            let where_ = &$where;
+            let path = if !where_.is_empty() {
+                let mut path = String::new();
+                write_path(&mut path, where_);
+                Some(path)
+            } else {
+                None
+            };
+
+            (path, msg)
         });
-        throw_ub!(ValidationFailure(msg))
+        throw_ub!(ValidationFailure { path, msg })
     }};
 }