rsmith added inline comments.
================
Comment at: clang/lib/Sema/SemaTemplate.cpp:8694-8696
+ Diag(NewDecl->getLocation(), isa<ConceptDecl>(Old)
+ ? diag::err_redefinition
+ : diag::err_redefinition_different_kind)
----------------
It'd be nice to have a third diagnostic for the case where there's a known
declaration that doesn't match. That is:
* If the name is used for something that's not a concept, diagnose with
err_redefinition_different_kind.
* If the name is used for a visible and matching concept, diagnose with
err_redefinition.
* If the name is used for a non-matching concept, regardless of whether it's
visible or even reachable, produce some new mismatch error.
* Otherwise, if the name is used for a matching concept that's not visible,
merge.
================
Comment at: clang/lib/Sema/SemaTemplate.cpp:8679
+ Previous.isSingleResult() ? Previous.getAsSingle<ConceptDecl>() :
nullptr;
+ if (PrevDef && !hasVisibleDefinition(PrevDef) &&
+ Context.isSameEntity(NewDecl, PrevDef)) {
----------------
ChuanqiXu wrote:
>
I don't think that's right: [the C++20 modules
rule](http://eel.is/c++draft/basic.def.odr#2) is that at most one definition is
permitted per translation unit, and the Clang header modules rule is that a
definition is only permissible if no definition is visible (Clang header
modules effectively behave as if they're part of the same translation unit for
the purposes of this check). For now, checking for a visible definition seems
better than checking for a reachable one, until we implement the C++20 rule in
general.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D128921/new/
https://reviews.llvm.org/D128921
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
