[modules] Do not report missing definitions of demoted constexpr variable templates.

This is a followup to regression introduced in r284284.

This should fix our libstdc++ modules builds.

https://reviews.llvm.org/D25678

Reviewed by Richard Smith!

llvm-svn: 284577

1 files changed, 5 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index af1ac443bae..b483690a03c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -10124,7 +10124,11 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl,
     // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to
     // the definition of a variable [...] or the declaration of a static data
     // member.
-    if (Var->isConstexpr() && !Var->isThisDeclarationADefinition()) {
+    if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() &&
+        !Var->isThisDeclarationADemotedDefinition()) {
+      assert((!Var->isThisDeclarationADemotedDefinition() ||
+              getLangOpts().Modules) &&
+             "Demoting decls is only in the contest of modules!");
       if (Var->isStaticDataMember()) {
         // C++1z removes the relevant rule; the in-class declaration is always
         // a definition there.