Revert "Revert r260388 "[MS ABI] Never reference dllimport'd vtables""
This reverts commit r260449.
We would supress our emission of vftable definitions if we thought
another translation unit would provide the definition because we saw an
explicit instantiation declaration. This is not the case with
dllimport, we want to synthesize a definition of the vftable regardless.
This fixes PR26569.
llvm-svn: 260548
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 620e922..e96a812 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -838,6 +838,11 @@
bool CodeGenVTables::isVTableExternal(const CXXRecordDecl *RD) {
assert(RD->isDynamicClass() && "Non-dynamic classes have no VTable.");
+ // We always synthesize vtables on the import side regardless of whether or
+ // not it is an explicit instantiation declaration.
+ if (CGM.getTarget().getCXXABI().isMicrosoft() && RD->hasAttr<DLLImportAttr>())
+ return false;
+
// If we have an explicit instantiation declaration (and not a
// definition), the vtable is defined elsewhere.
TemplateSpecializationKind TSK = RD->getTemplateSpecializationKind();