https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99468
Bug ID: 99468
Summary: [modules] awkward diagnostic for named-module inside
header unit
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: nathan at gcc dot gnu.org
Target Milestone: ---
We correctly reject a module-declaration appearing in a header-unit
compilation. But the diagnostic is ... poor
./cc1plus -std=c++20 -fmodule-header -quiet constrained-partial-1_a.C
constrained-partial-1_a.C:3:8: error: module already declared
3 | export module M;
| ^~~~~~
constrained-partial-1_a.C:3:8: note: module 'M' declared here
