Fix PR6473.

Clang's support for weakref is now better than llvm-gcc's :-)

We don't introduce a new symbol and we correctly mark undefined references weak only if there is no
definition or regular undefined references in the same file.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97733 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 030d2c9c9f..dc9ecd64f4 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1062,6 +1062,16 @@ static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
   const NamedDecl *ND = E->getDecl();
 
+  if (ND->hasAttr<WeakRefAttr>()) {
+    const ValueDecl* VD = cast<ValueDecl>(ND);
+    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
+
+    Qualifiers Quals = MakeQualifiers(E->getType());
+    LValue LV = LValue::MakeAddr(Aliasee, Quals);
+
+    return LV;
+  }
+
   if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
     
     // Check if this is a global variable.