From: Joerg Sonnenberger <joerg@bec.de>
Date: Tue, 16 Oct 2012 17:45:27 +0000 (+0000)
Subject: When using a symbol with attribute weakref, search for it first and
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=4695f91f4302a90ae462cd64dda59b34c3dad821;p=clang

When using a symbol with attribute weakref, search for it first and
don't try the normal GetOrCreateLLVM. The latter could drop the weak
atrtibute on the second reference, if there is no explicit declaration
of the aliasee.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166032 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 6be225c6b5..3353612c90 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -884,6 +884,10 @@ llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
 
   // See if there is already something with the target's name in the module.
   llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
+  if (Entry) {
+    unsigned AS = getContext().getTargetAddressSpace(VD->getType());
+    return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
+  }
 
   llvm::Constant *Aliasee;
   if (isa<llvm::FunctionType>(DeclTy))
@@ -893,11 +897,10 @@ llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
   else
     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
                                     llvm::PointerType::getUnqual(DeclTy), 0);
-  if (!Entry) {
-    llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee);
-    F->setLinkage(llvm::Function::ExternalWeakLinkage);    
-    WeakRefReferences.insert(F);
-  }
+
+  llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee);
+  F->setLinkage(llvm::Function::ExternalWeakLinkage);
+  WeakRefReferences.insert(F);
 
   return Aliasee;
 }
diff --git a/test/CodeGen/attr-weakref.c b/test/CodeGen/attr-weakref.c
index c1cc03b668..560d39141c 100644
--- a/test/CodeGen/attr-weakref.c
+++ b/test/CodeGen/attr-weakref.c
@@ -53,6 +53,12 @@ void test6_foo(void) {
   test6_f();
 }
 
+// CHECK: declare extern_weak void @test8_f()
+static void test8_g(void) __attribute__((weakref("test8_f")));
+void test8_h(void) {
+  if (test8_g)
+    test8_g();
+}
 // CHECK: declare extern_weak void @test7_f()
 void test7_f(void);
 static void test7_g(void) __attribute__((weakref("test7_f")));