Change msg: impl Into<String> for bug diagnostics.

To `msg: impl Into<DiagnosticMessage>`, like all the other diagnostics.
For consistency.

compiler/rustc_errors/src/lib.rs

@@ -1033,7 +1033,7 @@ impl Handler {
         self.emit_diag_at_span(Diagnostic::new_with_code(Warning(None), Some(code), msg), span);
     }
 
-    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<String>) -> ! {
+    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
         self.inner.borrow_mut().span_bug(span, msg)
     }
 
@@ -1045,7 +1045,7 @@ impl Handler {
     pub fn span_delayed_bug(
         &self,
         sp: impl Into<MultiSpan>,
-        msg: impl Into<String>,
+        msg: impl Into<DiagnosticMessage>,
     ) -> ErrorGuaranteed {
         let mut inner = self.inner.borrow_mut();
 
@@ -1056,10 +1056,10 @@ impl Handler {
             inner.err_count + inner.lint_err_count + inner.delayed_bug_count() + 1 >= c.get()
         }) {
             // FIXME: don't abort here if report_delayed_bugs is off
-            inner.span_bug(sp, msg.into());
+            inner.span_bug(sp, msg);
         }
-        let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg.into());
-        diagnostic.set_span(sp.into());
+        let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg);
+        diagnostic.set_span(sp);
         inner.emit_diagnostic(&mut diagnostic).unwrap()
     }
 
@@ -1589,8 +1589,8 @@ impl HandlerInner {
     }
 
     #[track_caller]
-    fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: impl Into<String>) -> ! {
-        self.emit_diagnostic(Diagnostic::new(Bug, msg.into()).set_span(sp));
+    fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+        self.emit_diagnostic(Diagnostic::new(Bug, msg).set_span(sp));
         panic::panic_any(ExplicitBug);
     }
 

compiler/rustc_expand/src/base.rs

@@ -1145,7 +1145,7 @@ impl<'a> ExtCtxt<'a> {
     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) {
         self.sess.diagnostic().span_err(sp, msg);
     }
-    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<String>) -> ! {
+    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) -> ! {
         self.sess.diagnostic().span_bug(sp, msg);
     }
     pub fn trace_macros_diag(&mut self) {

compiler/rustc_middle/src/ty/sty.rs

@@ -15,7 +15,9 @@ use hir::def::DefKind;
 use polonius_engine::Atom;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::intern::Interned;
-use rustc_errors::{DiagnosticArgValue, ErrorGuaranteed, IntoDiagnosticArg, MultiSpan};
+use rustc_errors::{
+    DiagnosticArgValue, DiagnosticMessage, ErrorGuaranteed, IntoDiagnosticArg, MultiSpan,
+};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::LangItem;
@@ -2005,7 +2007,7 @@ impl<'tcx> Ty<'tcx> {
     pub fn new_error_with_message<S: Into<MultiSpan>>(
         tcx: TyCtxt<'tcx>,
         span: S,
-        msg: impl Into<String>,
+        msg: impl Into<DiagnosticMessage>,
     ) -> Ty<'tcx> {
         let reported = tcx.sess.span_delayed_bug(span, msg);
         Ty::new(tcx, Error(reported))

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -249,8 +249,8 @@ impl<'a> Parser<'a> {
         self.diagnostic().struct_span_err(sp, m)
     }
 
-    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: impl Into<String>) -> ! {
-        self.diagnostic().span_bug(sp, m)
+    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) -> ! {
+        self.diagnostic().span_bug(sp, msg)
     }
 
     pub(super) fn diagnostic(&self) -> &'a Handler {

compiler/rustc_session/src/session.rs

@@ -632,7 +632,7 @@ impl Session {
     pub fn span_delayed_bug<S: Into<MultiSpan>>(
         &self,
         sp: S,
-        msg: impl Into<String>,
+        msg: impl Into<DiagnosticMessage>,
     ) -> ErrorGuaranteed {
         self.diagnostic().span_delayed_bug(sp, msg)
     }