[clang] [RFC][C++20][Modules] Relax ODR check in unnamed modules (PR #111160)

[Chuanqi Xu via cfe-commits]

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@@ -2527,7 +2527,7 @@ class BitsUnpacker {
 
 inline bool shouldSkipCheckingODR(const Decl *D) {
   return D->getASTContext().getLangOpts().SkipODRCheckInGMF &&
-         D->isFromGlobalModule();
+         (D->isFromGlobalModule() || !D->isInNamedModule());
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ChuanqiXu9 wrote:

This may not be wanted. It will skip the ODR checks for the original clang modules. If we really want it, we should use `D->isFromHeaderUnits()`

https://github.com/llvm/llvm-project/pull/111160