[PATCH] D139400: [clang] Show error when a local variables is passed as default template parameter

[Shafik Yaghmour via Phabricator via cfe-commits]

shafik added inline comments.


================
Comment at: clang/lib/Sema/SemaTemplate.cpp:1594
+      if (VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
+        if (VD->isLocalVarDecl()) {
+          Diag(DRE->getLocation(),
----------------
So if we look at `CheckDefaultArgumentVisitor::VistDeclRefExpr` it has a comment about having to check ODR use due to [cwg 2346](https://cplusplus.github.io/CWG/issues/2346.html) and I believe you should be using that as well.

Which would make your example below pass since the variable is `const` see: https://godbolt.org/z/78Tojh6q5

It looks like neither gcc nor MSVC implement this DR.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D139400/new/

https://reviews.llvm.org/D139400