track caller for delay_span_bug

Author: mark-i-m

src/librustc_errors/lib.rs

@@ -5,6 +5,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
 #![feature(crate_visibility_modifier)]
 #![feature(nll)]
+#![feature(track_caller)]
 
 pub use emitter::ColorConfig;
 
@@ -621,6 +622,7 @@ impl Handler {
         self.inner.borrow_mut().span_bug(span, msg)
     }
 
+    #[track_caller]
     pub fn delay_span_bug(&self, span: impl Into<MultiSpan>, msg: &str) {
         self.inner.borrow_mut().delay_span_bug(span, msg)
     }
@@ -873,6 +875,7 @@ impl HandlerInner {
         self.emit_diagnostic(diag.set_span(sp));
     }
 
+    #[track_caller]
     fn delay_span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) {
         // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
         // incrementing `err_count` by one, so we need to +1 the comparing.
@@ -883,6 +886,7 @@ impl HandlerInner {
         }
         let mut diagnostic = Diagnostic::new(Level::Bug, msg);
         diagnostic.set_span(sp.into());
+        diagnostic.note(&format!("delayed at {}", std::panic::Location::caller()));
         self.delay_as_bug(diagnostic)
     }
 

src/librustc_middle/ty/context.rs

@@ -1144,40 +1144,22 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` to ensure it gets used.
     #[track_caller]
     pub fn ty_error(self) -> Ty<'tcx> {
-        self.err_with_message_and_location(
-            DUMMY_SP,
-            "TyKind::Error constructed but no error reported",
-            std::panic::Location::caller(),
-        )
+        self.ty_error_with_message(DUMMY_SP, "TyKind::Error constructed but no error reported")
     }
 
     /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` with the given `msg to
     /// ensure it gets used.
     #[track_caller]
     pub fn ty_error_with_message<S: Into<MultiSpan>>(self, span: S, msg: &str) -> Ty<'tcx> {
-        self.err_with_message_and_location(span, msg, std::panic::Location::caller())
-    }
-
-    pub fn err_with_message_and_location<S: Into<MultiSpan>>(
-        self,
-        span: S,
-        msg: &str,
-        loc: &'static std::panic::Location<'static>,
-    ) -> Ty<'tcx> {
-        self.sess.delay_span_bug(span, &format!("{}: {}", loc, msg));
+        self.sess.delay_span_bug(span, msg);
         self.mk_ty(Error(super::sty::DelaySpanBugEmitted(())))
     }
 
     /// Like `err` but for constants.
     #[track_caller]
     pub fn const_error(self, ty: Ty<'tcx>) -> &'tcx Const<'tcx> {
-        self.sess.delay_span_bug(
-            DUMMY_SP,
-            &format!(
-                "ty::ConstKind::Error constructed but no error reported. {}",
-                std::panic::Location::caller()
-            ),
-        );
+        self.sess
+            .delay_span_bug(DUMMY_SP, "ty::ConstKind::Error constructed but no error reported.");
         self.mk_const(ty::Const {
             val: ty::ConstKind::Error(super::sty::DelaySpanBugEmitted(())),
             ty,