Improve key-function computation for templates. In particular:
- All classes can have a key function; templates don't change that.
non-template classes when computing the key function.
- We always mark all of the virtual member functions of class
template instantiations.
- The vtable for an instantiation of a class template has weak
linkage.
We could probably use available_externally linkage for vtables of
classes instantiated by explicit instantiation declarations (extern
templates), but GCC doesn't do this and I'm not 100% that the ABI
permits it.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@92753 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
index ba5a0c3..ca148da 100644
--- a/lib/CodeGen/CGVtable.cpp
+++ b/lib/CodeGen/CGVtable.cpp
@@ -1493,8 +1493,22 @@
llvm::GlobalVariable::LinkageTypes Linkage;
if (RD->isInAnonymousNamespace() || !RD->hasLinkage())
Linkage = llvm::GlobalVariable::InternalLinkage;
- else if (KeyFunction && !MD->isInlined())
- Linkage = llvm::GlobalVariable::ExternalLinkage;
+ else if (KeyFunction && !MD->isInlined()) {
+ switch (MD->getTemplateSpecializationKind()) {
+ case TSK_Undeclared:
+ case TSK_ExplicitSpecialization:
+ Linkage = llvm::GlobalVariable::ExternalLinkage;
+ break;
+
+ case TSK_ImplicitInstantiation:
+ case TSK_ExplicitInstantiationDeclaration:
+ // FIXME: could an explicit instantiation declaration imply
+ // available_externally linkage?
+ case TSK_ExplicitInstantiationDefinition:
+ Linkage = llvm::GlobalVariable::WeakODRLinkage;
+ break;
+ }
+ }
else
Linkage = llvm::GlobalVariable::WeakODRLinkage;