Rollup merge of #119369 - bvanjoi:fix-119301, r=petrochenkov

exclude unexported macro bindings from extern crate

Fixes #119301

Macros that aren't exported from an external crate should not be defined.

r? ``@petrochenkov``

compiler/rustc_resolve/src/lib.rs

@@ -55,6 +55,7 @@ use rustc_middle::span_bug;
 use rustc_middle::ty::{self, MainDefinition, RegisteredTools, TyCtxt};
 use rustc_middle::ty::{ResolverGlobalCtxt, ResolverOutputs};
 use rustc_query_system::ich::StableHashingContext;
+use rustc_session::lint::builtin::PRIVATE_MACRO_USE;
 use rustc_session::lint::LintBuffer;
 use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind, SyntaxContext, Transparency};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
@@ -1799,6 +1800,10 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
         }
         if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
+            if let ImportKind::MacroUse { warn_private: true } = import.kind {
+                let msg = format!("macro `{ident}` is private");
+                self.lint_buffer().buffer_lint(PRIVATE_MACRO_USE, import.root_id, ident.span, msg);
+            }
             // Avoid marking `extern crate` items that refer to a name from extern prelude,
             // but not introduce it, as used if they are accessed from lexical scope.
             if is_lexical_scope {