Rollup merge of #143280 - xizheyin:143152-1, r=compiler-errors

Remove duplicate error about raw underscore lifetime

Fixes rust-lang/rust#143152

r? ```@fee1-dead```

3 files changed, 30 insertions, 1 deletions

diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 753b9365cd8..93cec8daa5a 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -2899,9 +2899,21 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 }
 
                 if param.ident.name == kw::UnderscoreLifetime {
+                    // To avoid emitting two similar errors,
+                    // we need to check if the span is a raw underscore lifetime, see issue #143152
+                    let is_raw_underscore_lifetime = self
+                        .r
+                        .tcx
+                        .sess
+                        .psess
+                        .raw_identifier_spans
+                        .iter()
+                        .any(|span| span == param.span());
+
                     self.r
                         .dcx()
-                        .emit_err(errors::UnderscoreLifetimeIsReserved { span: param.ident.span });
+                        .create_err(errors::UnderscoreLifetimeIsReserved { span: param.ident.span })
+                        .emit_unless(is_raw_underscore_lifetime);
                     // Record lifetime res, so lowering knows there is something fishy.
                     self.record_lifetime_param(param.id, LifetimeRes::Error);
                     continue;
diff --git a/tests/ui/underscore-lifetime/raw-underscore-lifetime.rs b/tests/ui/underscore-lifetime/raw-underscore-lifetime.rs
new file mode 100644
index 00000000000..874b3d2c48d
--- /dev/null
+++ b/tests/ui/underscore-lifetime/raw-underscore-lifetime.rs
@@ -0,0 +1,9 @@
+// This test is to ensure that the raw underscore lifetime won't emit two duplicate errors.
+// See issue #143152
+
+//@ edition: 2021
+
+fn f<'r#_>(){}
+//~^ ERROR `_` cannot be a raw lifetime
+
+fn main() {}
diff --git a/tests/ui/underscore-lifetime/raw-underscore-lifetime.stderr b/tests/ui/underscore-lifetime/raw-underscore-lifetime.stderr
new file mode 100644
index 00000000000..bdb357a47f4
--- /dev/null
+++ b/tests/ui/underscore-lifetime/raw-underscore-lifetime.stderr
@@ -0,0 +1,8 @@
+error: `_` cannot be a raw lifetime
+  --> $DIR/raw-underscore-lifetime.rs:6:6
+   |
+LL | fn f<'r#_>(){}
+   |      ^^^^
+
+error: aborting due to 1 previous error
+