fix/improve double typedef exceptions

diff --git a/parser.c b/parser.c
index 37190b0..6cf1a1a 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -4107,12 +4107,16 @@ entity_t *record_entity(entity_t *entity, const bool is_definition)
                                type_t *const type      = skip_typeref(entity->typedefe.type);
                                type_t *const prev_type
                                        = skip_typeref(previous_entity->typedefe.type);
-                               /* gcc extension redef in system headers is allowed */
-                               if ((!(c_mode & _CXX) && !pos->is_system_header)
-                                       || !types_compatible(type, prev_type)) {
-                                       errorf(pos, "redefinition of '%N' (declared %P)",
-                                              entity, ppos);
-                               }
+                               /* gcc extension: redef in system headers is allowed */
+                               if ((pos->is_system_header || ppos->is_system_header)
+                                   && types_compatible(type, prev_type))
+                                       goto finish;
+                               /* c++ allows double typedef if they are identical
+                                * (after skipping typedefs) */
+                               if ((c_mode & _CXX) && type == prev_type)
+                                       goto finish;
+                               errorf(pos, "redefinition of '%N' (declared %P)",
+                                      entity, ppos);
                                goto finish;
                        }