commit 810b28edb3f64569054d49d6ddf18a4d802d9b11
author Martin Storsjö <martin@martin.st> Tue Dec 17 00:20:32 2019 +0200
committer Martin Storsjö <martin@martin.st> Mon Jan 13 23:36:26 2020 +0200
tree 3e6d95ead285209f15626f331e19a0f97d0c03a4
parent 80a094e1348ae850cd996e947d70e34abf331685

[ItaniumCXXABI] Make tls wrappers properly comdat

Just marking a symbol as weak_odr/linkonce_odr isn't enough for
actually tolerating multiple copies of it at linking on windows,
it has to be made a proper comdat; make it comdat for all platforms
for consistency.

This should hopefully fix
https://bugzilla.mozilla.org/show_bug.cgi?id=1566288.

Differential Revision: https://reviews.llvm.org/D71572

clang/lib/CodeGen/ItaniumCXXABI.cpp

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 6ed172bb..b5b8702 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2546,6 +2546,9 @@
       llvm::Function::Create(FnTy, getThreadLocalWrapperLinkage(VD, CGM),
                              WrapperName.str(), &CGM.getModule());
 
+  if (CGM.supportsCOMDAT() && Wrapper->isWeakForLinker())
+    Wrapper->setComdat(CGM.getModule().getOrInsertComdat(Wrapper->getName()));
+
   CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Wrapper);
 
   // Always resolve references to the wrapper at link time.