https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122568
Bug ID: 122568
Summary: -Welaborated-enum-base not applied to
elaborated-type-specifiers in alias-declarations
Product: gcc
Version: 15.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: gulackeg at gmail dot com
Target Milestone: ---
Test code:
// https://godbolt.org/z/7bTn4P7hM
// ✔ - GCC (>=14.1): warning: declaration of enumeration with fixed
// underlying type and no enumerator list is only permitted as a
// standalone declaration [-Welaborated-enum-base]
// ✔ - GCC (<=13.4): error: expected ';' or '{' before 'E1'
typedef enum E : int E1; // #1
// ✗ - GCC: OK
using E2 = enum E : int; // #2
The commit "c++: Accept elaborated-enum-base with pedwarn" (g:b106f11) made #1
accepted by GCC with a warning. However, #2 has been accepted since early
versions of GCC. The treatment of #1 and #2 should be consistent - #2 should
emit the same warning as #1.
Extra test code:
// https://godbolt.org/z/hbKdnGdK5
enum E : int;
// ✔ - GCC: error: expected unqualified-id before ':' token
typedef enum ::E : int E3;
// ✔ - GCC: error: expected ';' before ':' token
using E4 = enum ::E : int;
namespace N {
enum E : int;
}
// ✔ - GCC (>=14.1): warning: declaration of enumeration with fixed
// underlying type and no enumerator list is only permitted as a
// standalone declaration [-Welaborated-enum-base]
// ✔ - GCC (<=13.4): error: expected ';' or '{' before 'E5'
typedef enum N::E : int E5;
// ✔ - GCC: error: opaque-enum-specifier must use a simple identifier
using E6 = enum N::E : int;
