[LTO] Don't internalize declarations
Summary:
Some links were failing with "Global is external, but doesn't have
external or weak linkage!" in ThinLTO builds with debug
information. This happened when we elide the body of a global that is
referenced by debug info. This results in a declaration, which we
would then internalize - but declarations cannot be internal. This
change avoids the problem by not internalizing these declarations.
Fixes PR38046.
Reviewers: pcc, tejohnson
Subscribers: mehdi_amini, aprantl, hiraditya, JDevlieghere, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49777
llvm-svn: 338100
diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index 32b48dd..68d210c 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -872,7 +872,8 @@
GlobalValue *GV =
RegularLTO.CombinedModule->getNamedValue(R.second.IRName);
// Ignore symbols defined in other partitions.
- if (!GV || GV->hasLocalLinkage())
+ // Also skip declarations, which are not allowed to have internal linkage.
+ if (!GV || GV->hasLocalLinkage() || GV->isDeclaration())
continue;
GV->setUnnamedAddr(R.second.UnnamedAddr ? GlobalValue::UnnamedAddr::Global
: GlobalValue::UnnamedAddr::None);