Add out of line virtual destructors to all LLVMTargetMachine subclasses

These recently all grew a unique_ptr<TargetLoweringObjectFile> member in
r221878.  When anyone calls a virtual method of a class, clang-cl
requires all virtual methods to be semantically valid. This includes the
implicit virtual destructor, which triggers instantiation of the
unique_ptr destructor, which fails because the type being deleted is
incomplete.

This is just part of the ongoing saga of PR20337, which is affecting
Blink as well. Because the MSVC ABI doesn't have key functions, we end
up referencing the vtable and implicit destructor on any virtual call
through a class. We don't actually end up emitting the dtor, so it'd be
good if we could avoid this unneeded type completion work.

llvm-svn: 222480

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
index 9a35e1f8b75..cd18dfb6305 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
@@ -75,6 +75,8 @@ HexagonTargetMachine::HexagonTargetMachine(const Target &T, StringRef TT,
     initAsmInfo();
 }
 
+HexagonTargetMachine::~HexagonTargetMachine() {}
+
 namespace {
 /// Hexagon Code Generator Pass Configuration Options.
 class HexagonPassConfig : public TargetPassConfig {