[clang-cl] Inherit dllexport to static locals also in template instantiations (PR39496)

In the course of D51340, @takuto.ikuta discovered that Clang fails to put
dllexport/import attributes on static locals during template instantiation.

For regular functions, this happens in Sema::FinalizeDeclaration(), however for
template instantiations we need to do something in or around
TemplateDeclInstantiator::VisitVarDecl(). This patch does that, and extracts
the code to a utility function.

Differential Revision: https://reviews.llvm.org/D53870

llvm-svn: 345699

1 files changed, 20 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 7581433826d..bf15e25d62d 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11924,6 +11924,23 @@ static bool hasDependentAlignment(VarDecl *VD) {
   return false;
 }
 
+/// Check if VD needs to be dllexport/dllimport due to being in a
+/// dllexport/import function.
+void Sema::CheckStaticLocalForDllExport(VarDecl *VD) {
+  assert(VD->isStaticLocal());
+
+  auto *FD = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod());
+  if (!FD)
+    return;
+
+  // Static locals inherit dll attributes from their function.
+  if (Attr *A = getDLLAttr(FD)) {
+    auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext()));
+    NewAttr->setInherited(true);
+    VD->addAttr(NewAttr);
+  }
+}
+
 /// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform
 /// any semantic actions necessary after any initializer has been attached.
 void Sema::FinalizeDeclaration(Decl *ThisDecl) {
@@ -11977,14 +11994,9 @@ void Sema::FinalizeDeclaration(Decl *ThisDecl) {
   }
 
   if (VD->isStaticLocal()) {
-    if (FunctionDecl *FD =
-            dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) {
-      // Static locals inherit dll attributes from their function.
-      if (Attr *A = getDLLAttr(FD)) {
-        auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext()));
-        NewAttr->setInherited(true);
-        VD->addAttr(NewAttr);
-      }
+    CheckStaticLocalForDllExport(VD);
+
+    if (dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) {
       // CUDA 8.0 E.3.9.4: Within the body of a __device__ or __global__
       // function, only __shared__ variables or variables without any device
       // memory qualifiers may be declared with static storage class.