[MS] Always use base dtors in place of complete/vbase dtors when possible
Summary:
Previously we tried too hard to uphold the fiction that destructor
variants work like they do on Itanium throughout the ABI-neutral parts
of clang. This lead to MS C++ ABI incompatiblities and other bugs. Now,
-mconstructor-aliases will no longer control this ABI detail, and clang
-cc1's LLVM IR output will be this much closer to the clang driver's.
Based on a patch by Zahira Ammarguellat:
https://reviews.llvm.org/D39063
I've tried to move the logic that Zahira added into MicrosoftCXXABI.cpp.
There is only one ABI-specific detail sticking out, and that is in
CodeGenModule::getAddrOfCXXStructor, where we collapse complete dtors to
base dtors in the MS ABI.
This fixes PR32990.
Reviewers: erichkeane, zahiraam, majnemer, rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D44505
llvm-svn: 327732
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 3c503eb..cb1bfc1 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -786,12 +786,10 @@
void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
GlobalDecl GD) const {
const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
+ // C++ destructors have a few C++ ABI specific special cases.
if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
- if (getCXXABI().useThunkForDtorVariant(Dtor, GD.getDtorType())) {
- // Don't dllexport/import destructor thunks.
- GV->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
- return;
- }
+ getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
+ return;
}
setDLLImportDLLExport(GV, D);
}
@@ -1074,14 +1072,8 @@
GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
- if (isa<CXXDestructorDecl>(D) &&
- getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
- GD.getDtorType())) {
- // Destructor variants in the Microsoft C++ ABI are always internal or
- // linkonce_odr thunks emitted on an as-needed basis.
- return Linkage == GVA_Internal ? llvm::GlobalValue::InternalLinkage
- : llvm::GlobalValue::LinkOnceODRLinkage;
- }
+ if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
+ return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
if (isa<CXXConstructorDecl>(D) &&
cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&