Fix redundant import errors for preload extern crate

2024-03-04 10:24:23 +08:00
parent 62415e2a95
commit 5a4ff2779e
10 changed files with 230 additions and 72 deletions
--- a/compiler/rustc_lint/src/context/diagnostics.rs
+++ b/compiler/rustc_lint/src/context/diagnostics.rs
@@ -143,7 +143,11 @@ pub(super) fn builtin(sess: &Session, diagnostic: BuiltinLintDiag, diag: &mut Di
        BuiltinLintDiag::RedundantImport(spans, ident) => {
            for (span, is_imported) in spans {
                let introduced = if is_imported { "imported" } else { "defined" };
-                diag.span_label(span, format!("the item `{ident}` is already {introduced} here"));
+                let span_msg = if span.is_dummy() { "by prelude" } else { "here" };
+                diag.span_label(
+                    span,
+                    format!("the item `{ident}` is already {introduced} {span_msg}"),
+                );
            }
        }
        BuiltinLintDiag::DeprecatedMacro(suggestion, span) => {