https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51851
--- Comment #7 from qingzhe huang <nickhuang99 at hotmail dot com> --- Thank you for clarifications! I just found a solution for this 10-year-old issue and preparing a patch. However, the solution is not able to solve more complicated cases which requires more work. This issue is so complicated and I am hesitating to file more complicated bugs which this patch won't work because it requires improvement work of function *resolve_typename_type* to handle recursive case correctly. diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 3414cbdc876..db0d43b2b08 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -14493,7 +14493,16 @@ grokparms (tree parmlist, tree *parms) /* Top-level qualifiers on the parameters are ignored for function types. */ - type = cp_build_qualified_type (type, 0); + int type_quals = 0; + /* Top-level qualifiers are reserved for array type. PR101783 */ + if (TREE_CODE (type) == TYPENAME_TYPE) + { + tree resolved_type = resolve_typename_type(type, false); + if (resolved_type && TREE_CODE(resolved_type) == ARRAY_TYPE) + type_quals = CP_TYPE_CONST_P(type); + } + type = cp_build_qualified_type (type, type_quals); + if (TREE_CODE (type) == METHOD_TYPE) { error ("parameter %qD invalidly declared method type", decl);