Make GlobalValues with non-default visibilility dso_local.

This is similar to r322317, but for visibility. It is not as neat
because we have to special case extern_weak.

The idea is the same as the previous change, make the transition to
explicit dso_local easier for the frontends. With this they only have
to add dso_local to symbols where we need some external information to
decide if it is dso_local (like it being part of an ELF executable).

llvm-svn: 322806

2 files changed, 9 insertions, 2 deletions

diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 27a75927832..7c647605894 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -2499,8 +2499,11 @@ static void PrintVisibility(GlobalValue::VisibilityTypes Vis,
 
 static void PrintDSOLocation(const GlobalValue &GV,
                              formatted_raw_ostream &Out) {
-  // GVs with local linkage are implicitly dso_local, so we don't print it.
-  if (GV.isDSOLocal() && !GV.hasLocalLinkage())
+  // GVs with local linkage or non default visibility are implicitly dso_local,
+  // so we don't print it.
+  bool Implicit = GV.hasLocalLinkage() ||
+                  (!GV.hasExternalWeakLinkage() && !GV.hasDefaultVisibility());
+  if (GV.isDSOLocal() && !Implicit)
     Out << "dso_local ";
 }
 
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 42fec7e3d98..f7775be6961 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -575,6 +575,10 @@ void Verifier::visitGlobalValue(const GlobalValue &GV) {
            "GlobalValue with private or internal linkage must be dso_local!",
            &GV);
 
+  if (!GV.hasDefaultVisibility() && !GV.hasExternalWeakLinkage())
+    Assert(GV.isDSOLocal(),
+           "GlobalValue with non default visibility must be dso_local!", &GV);
+
   forEachUser(&GV, GlobalValueVisited, [&](const Value *V) -> bool {
     if (const Instruction *I = dyn_cast<Instruction>(V)) {
       if (!I->getParent() || !I->getParent()->getParent())