Use code snippet to get lifetime literal name instead of lifetime.ident

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -3088,6 +3088,15 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         lifetime_ref: &ast::Lifetime,
         outer_lifetime_ref: Option<Ident>,
     ) {
+        // Lifetime may be `'r#fn` or `'a`, so we need to get the actual name by code snippet
+        let lifetime_name = if let Ok(lifetime_name) =
+            self.r.tcx.sess.source_map().span_to_snippet(lifetime_ref.ident.span)
+        {
+            lifetime_name
+        } else {
+            lifetime_ref.ident.to_string()
+        };
+
         debug_assert_ne!(lifetime_ref.ident.name, kw::UnderscoreLifetime);
         let mut err = if let Some(outer) = outer_lifetime_ref {
             struct_span_code_err!(
@@ -3104,13 +3113,13 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                 lifetime_ref.ident.span,
                 E0261,
                 "use of undeclared lifetime name `{}`",
-                lifetime_ref.ident
+                lifetime_name
             )
             .with_span_label(lifetime_ref.ident.span, "undeclared lifetime")
         };
 
         // Check if this is a typo of `'static`.
-        if edit_distance(lifetime_ref.ident.name.as_str(), "'static", 2).is_some() {
+        if edit_distance(lifetime_name.as_str(), "'static", 2).is_some() {
             err.span_suggestion_verbose(
                 lifetime_ref.ident.span,
                 "you may have misspelled the `'static` lifetime",
@@ -3120,7 +3129,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         } else {
             self.suggest_introducing_lifetime(
                 &mut err,
-                Some(lifetime_ref.ident.name.as_str()),
+                Some(lifetime_name.as_str()),
                 |err, _, span, message, suggestion, span_suggs| {
                     err.multipart_suggestion_with_style(
                         message,

tests/ui/lifetimes/lifetime-errors/error-lifetime-name-issue-143150.rs

@@ -1,5 +1,5 @@
 //@ edition: 2021
-fn a(_: dyn Trait + 'r#fn) { //~ ERROR use of undeclared lifetime name `'fn` [E0261]
+fn a(_: dyn Trait + 'r#fn) { //~ ERROR use of undeclared lifetime name `'r#fn` [E0261]
 
 }
 

tests/ui/lifetimes/lifetime-errors/error-lifetime-name-issue-143150.stderr

@@ -1,10 +1,10 @@
-error[E0261]: use of undeclared lifetime name `'fn`
+error[E0261]: use of undeclared lifetime name `'r#fn`
   --> $DIR/error-lifetime-name-issue-143150.rs:2:21
    |
 LL | fn a(_: dyn Trait + 'r#fn) {
    |     -               ^^^^^ undeclared lifetime
    |     |
-   |     help: consider introducing lifetime `'fn` here: `<'fn>`
+   |     help: consider introducing lifetime `'r#fn` here: `<'r#fn>`
 
 error: aborting due to 1 previous error