[clang] 39d0e41 - [NFC][Clang Improve performance of `DoMarkVarDeclReferenced` (#161648)

[via cfe-commits]

Author: Corentin Jabot
Date: 2025-10-02T13:27:57+02:00
New Revision: 39d0e41a5f3e13b127caea16988d7c69371de6cf

URL: https://github.com/llvm/llvm-project/commit/39d0e41a5f3e13b127caea16988d7c69371de6cf
DIFF: https://github.com/llvm/llvm-project/commit/39d0e41a5f3e13b127caea16988d7c69371de6cf.diff

LOG: [NFC][Clang Improve performance of `DoMarkVarDeclReferenced` (#161648)

Address post commit feedback from #161231

Added: 
    

Modified: 
    clang/lib/Sema/SemaExpr.cpp

Removed: 
    


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diff  --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 06b2529011c74..4d3c7d611f370 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -20107,9 +20107,10 @@ static void DoMarkVarDeclReferenced(
   bool NeededForConstantEvaluation =
       isPotentiallyConstantEvaluatedContext(SemaRef) && UsableInConstantExpr;
 
-  bool NeedDefinition = OdrUse == OdrUseContext::Used ||
-                        NeededForConstantEvaluation ||
-                        Var->getType()->isUndeducedType();
+  bool NeedDefinition =
+      OdrUse == OdrUseContext::Used || NeededForConstantEvaluation ||
+      (TSK != clang::TSK_Undeclared && !UsableInConstantExpr &&
+       Var->getType()->isUndeducedType());
 
   assert(!isa<VarTemplatePartialSpecializationDecl>(Var) &&
          "Can't instantiate a partial template specialization.");