https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124278
Bug ID: 124278
Summary: Accepts conflicting scoped/unscoped enum redeclaration
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: suyuchang at whu dot edu.cn
Target Milestone: ---
The code first declares a scoped enumeration (enum struct X0 {}) and then
redeclares it as an unscoped enum (enum X0;). This is ill-formed because a
scoped enum cannot be redeclared as unscoped. Clang rejects it, while GCC
accepts it.
Code:
enum struct X0 {} ; enum X0 ;
Command:
clang++ test.cpp
<source>:1:28: error: enumeration previously declared as scoped
1 | enum struct X0 {} ; enum X0 ;
| ^
<source>:1:13: note: previous declaration is here
1 | enum struct X0 {} ; enum X0 ;
| ^
1 error generated.
See Compiler Explorer:https://godbolt.org/z/xbMeeMdKr
The test case was generated by a fuzzer.
