WholeProgramDevirt: When promoting for single-impl devirt, also rename the comdat.
This is required when targeting COFF, as the comdat name must match
one of the names of the symbols in the comdat.
Differential Revision: https://reviews.llvm.org/D37550
llvm-svn: 312767
diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
index c4e6e39..f2e01b4 100644
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -757,9 +757,24 @@
// to make it visible to thin LTO objects. We can only get here during the
// ThinLTO export phase.
if (TheFn->hasLocalLinkage()) {
+ std::string NewName = (TheFn->getName() + "$merged").str();
+
+ // Since we are renaming the function, any comdats with the same name must
+ // also be renamed. This is required when targeting COFF, as the comdat name
+ // must match one of the names of the symbols in the comdat.
+ if (Comdat *C = TheFn->getComdat()) {
+ if (C->getName() == TheFn->getName()) {
+ Comdat *NewC = M.getOrInsertComdat(NewName);
+ NewC->setSelectionKind(C->getSelectionKind());
+ for (GlobalObject &GO : M.global_objects())
+ if (GO.getComdat() == C)
+ GO.setComdat(NewC);
+ }
+ }
+
TheFn->setLinkage(GlobalValue::ExternalLinkage);
TheFn->setVisibility(GlobalValue::HiddenVisibility);
- TheFn->setName(TheFn->getName() + "$merged");
+ TheFn->setName(NewName);
}
Res->TheKind = WholeProgramDevirtResolution::SingleImpl;