MS ABI: Update the thunk linkage computation
As suggested by Reid:
- class has GVA_Internal linkage -> internal
- thunk has return adjustment -> weak_odr, to handle evil corner case [1]
- all other normal methods -> linkonce_odr
1. Evil corner case:
struct Incomplete;
struct A { int a; virtual A *bar(); };
struct B { int b; virtual B *foo(Incomplete); };
struct C : A, B { int c; virtual C *foo(Incomplete); };
C c;
Here, the thunk for C::foo() will be emitted when C::foo() is defined, which
might be in a different translation unit, so it needs to be weak_odr.
Differential Revision: http://reviews.llvm.org/D3992
llvm-svn: 210368
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 8984a70..91e6a18 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -382,12 +382,14 @@
// FIXME: Do something better here; GenerateVarArgsThunk is extremely ugly.
if (!UseAvailableExternallyLinkage) {
CodeGenFunction(CGM).GenerateVarArgsThunk(ThunkFn, FnInfo, GD, Thunk);
- CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable);
+ CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable, GD,
+ !Thunk.Return.isEmpty());
}
} else {
// Normal thunk body generation.
CodeGenFunction(CGM).GenerateThunk(ThunkFn, FnInfo, GD, Thunk);
- CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable);
+ CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable, GD,
+ !Thunk.Return.isEmpty());
}
}