1 files changed, 7 insertions, 2 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index f60a68ab011..17b7ddc7683 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2134,7 +2134,8 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
 }
 
 static bool isVarDeclStrongDefinition(const ASTContext &Context,
-                                      const VarDecl *D, bool NoCommon) {
+                                      CodeGenModule &CGM, const VarDecl *D,
+                                      bool NoCommon) {
   // Don't give variables common linkage if -fno-common was specified unless it
   // was overridden by a NoCommon attribute.
   if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
@@ -2159,6 +2160,10 @@ static bool isVarDeclStrongDefinition(const ASTContext &Context,
   if (D->hasAttr<WeakImportAttr>())
     return true;
 
+  // A variable cannot be both common and exist in a comdat.
+  if (shouldBeInCOMDAT(CGM, *D))
+    return true;
+
   // Declarations with a required alignment do not have common linakge in MSVC
   // mode.
   if (Context.getLangOpts().MSVCCompat) {
@@ -2227,7 +2232,7 @@ llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
   // C++ doesn't have tentative definitions and thus cannot have common
   // linkage.
   if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
-      !isVarDeclStrongDefinition(Context, cast<VarDecl>(D),
+      !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
                                  CodeGenOpts.NoCommon))
     return llvm::GlobalVariable::CommonLinkage;