[MS] Don't bail on replacing dllimport vbase dtors with base dtors

Fix PR32990 by effectively reverting r283063 and solving it a different
way.

We want to limit the hack to not replace equivalent available_externally
dtors specifically to libc++, which uses always_inline. It seems certain
versions of libc++ do not provide all the symbols that an explicit
template instantiation is expected to provide.

If we get to the code that forms a real alias, only *then* check if this
is available_externally, and do that by asking a better question, which
is "is this a declaration for the linker?", because *that's* what means
we can't form an alias to it.

As a follow-on simplification, remove the InEveryTU parameter. Its last
use guarded this code for forming aliases, but we should never form
aliases to declarations, regardless of what we know about every TU.

llvm-svn: 315656

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 0a3cc306657..e81dedf14da 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -3805,7 +3805,7 @@ static void emitCXXDestructor(CodeGenModule &CGM, const CXXDestructorDecl *dtor,
   if (!dtor->getParent()->getNumVBases() &&
       (dtorType == StructorType::Complete || dtorType == StructorType::Base)) {
     bool ProducedAlias = !CGM.TryEmitDefinitionAsAlias(
-        GlobalDecl(dtor, Dtor_Complete), GlobalDecl(dtor, Dtor_Base), true);
+        GlobalDecl(dtor, Dtor_Complete), GlobalDecl(dtor, Dtor_Base));
     if (ProducedAlias) {
       if (dtorType == StructorType::Complete)
         return;