[ThinLTO] Always set linkage type to external when converting alias

When converting an alias to a non-alias when the aliasee is not
imported, ensure that the linkage type is set to external so that it is
a valid linkage type. Added a test case that exposed this issue.

llvm-svn: 252054

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Linker/LinkModules.cpp b/llvm/lib/Linker/LinkModules.cpp
index b7aab9e9644..a855ec06d17 100644
--- a/llvm/lib/Linker/LinkModules.cpp
+++ b/llvm/lib/Linker/LinkModules.cpp
@@ -841,10 +841,12 @@ GlobalValue *ModuleLinker::copyGlobalAliasProto(TypeMapTy &TypeMap,
       assert(F);
       NewGV = copyFunctionProto(TypeMap, F);
     }
-    // Set the linkage to ExternalWeak, see also comments in
-    // ModuleLinker::getLinkage.
+    // Set the linkage to External or ExternalWeak (see comments in
+    // ModuleLinker::getLinkage for why WeakAny is converted to ExternalWeak).
     if (SGA->hasWeakAnyLinkage())
       NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
+    else
+      NewGV->setLinkage(GlobalValue::ExternalLinkage);
     // Don't attempt to link body, needs to be a declaration.
     DoNotLinkFromSource.insert(SGA);
     return NewGV;