Use private linkage for remaining GlobalVariables with private names.

This patch changes the remaining GlobalVariables using "\01L" and
"\01l" prefixes to use private linkage. What is strange about them is
that they currently use WeakAnyLinkage. There is no comment stating
why and that is really odd since the symbols are completely hidden, so
it doesn't make sense for them to be weak.

Clang revisions like r63329, r63408, r63770, r65761 set the linkage to
weak, but don't say why. I suspect they were just copying llvm-gcc.

In llvm-gcc I found r58599 and r56322 that set DECL_WEAK, but they
were just syncing from the apple gcc. I am not exactly sure what that
means, since the last commit to
svn://gcc.gnu.org/svn/gcc/branches/apple was in 2006, 2 years earlier.

In summary, I have no idea why weak linkage was being used :-(

To quote John McCall, "Let’s try without it and see" :-)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203059 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 18 insertions, 18 deletions

diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 0cb38f27aa..55bd723511 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -5955,11 +5955,11 @@ llvm::Value *CGObjCNonFragileABIMac::GenerateProtocolRef(CodeGenFunction &CGF,
   PTGV = new llvm::GlobalVariable(
     CGM.getModule(),
     Init->getType(), false,
-    llvm::GlobalValue::WeakAnyLinkage,
+    llvm::GlobalValue::PrivateLinkage,
     Init,
     ProtocolName);
+  assertPrivateName(PTGV);
   PTGV->setSection("__DATA, __objc_protorefs, coalesced, no_dead_strip");
-  PTGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
   CGM.AddUsedGlobal(PTGV);
   return CGF.Builder.CreateLoad(PTGV);
 }
@@ -6243,10 +6243,11 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocolRef(
     // contents for protocols which were referenced but never defined.
     Entry =
         new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ProtocolnfABITy,
-                                 false, llvm::GlobalValue::WeakAnyLinkage, 0,
+                                 false, llvm::GlobalValue::PrivateLinkage, 0,
                                  "\01l_OBJC_PROTOCOL_$_" + PD->getName());
     Entry->setSection("__DATA,__datacoal_nt,coalesced");
   }
+  assertPrivateName(Entry);
 
   return Entry;
 }
@@ -6358,12 +6359,11 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocol(
 
   if (Entry) {
     // Already created, update the initializer.
-    assert(Entry->getLinkage() == llvm::GlobalValue::WeakAnyLinkage);
     Entry->setInitializer(Init);
   } else {
     Entry =
       new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ProtocolnfABITy,
-                               false, llvm::GlobalValue::WeakAnyLinkage, Init,
+                               false, llvm::GlobalValue::PrivateLinkage, Init,
                                "\01l_OBJC_PROTOCOL_$_" + PD->getName());
     Entry->setAlignment(
       CGM.getDataLayout().getABITypeAlignment(ObjCTypes.ProtocolnfABITy));
@@ -6371,19 +6371,19 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocol(
 
     Protocols[PD->getIdentifier()] = Entry;
   }
-  Entry->setVisibility(llvm::GlobalValue::HiddenVisibility);
+  assertPrivateName(Entry);
   CGM.AddUsedGlobal(Entry);
 
   // Use this protocol meta-data to build protocol list table in section
   // __DATA, __objc_protolist
   llvm::GlobalVariable *PTGV =
     new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ProtocolnfABIPtrTy,
-                             false, llvm::GlobalValue::WeakAnyLinkage, Entry,
+                             false, llvm::GlobalValue::PrivateLinkage, Entry,
                              "\01l_OBJC_LABEL_PROTOCOL_$_" + PD->getName());
+  assertPrivateName(PTGV);
   PTGV->setAlignment(
     CGM.getDataLayout().getABITypeAlignment(ObjCTypes.ProtocolnfABIPtrTy));
   PTGV->setSection("__DATA, __objc_protolist, coalesced, no_dead_strip");
-  PTGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
   CGM.AddUsedGlobal(PTGV);
   return Entry;
 }
@@ -6592,14 +6592,14 @@ CGObjCNonFragileABIMac::EmitVTableMessageSend(CodeGenFunction &CGF,
     messageRef = new llvm::GlobalVariable(CGM.getModule(),
                                           init->getType(),
                                           /*constant*/ false,
-                                          llvm::GlobalValue::WeakAnyLinkage,
+                                          llvm::GlobalValue::PrivateLinkage,
                                           init,
                                           messageRefName);
-    messageRef->setVisibility(llvm::GlobalValue::HiddenVisibility);
     messageRef->setAlignment(16);
     messageRef->setSection("__DATA, __objc_msgrefs, coalesced");
   }
-  
+  assertPrivateName(messageRef);
+
   bool requiresnullCheck = false;
   if (CGM.getLangOpts().ObjCAutoRefCount && method)
     for (ObjCMethodDecl::param_const_iterator i = method->param_begin(),
diff --git a/test/CodeGenObjC/forward-protocol-metadata-symbols.m b/test/CodeGenObjC/forward-protocol-metadata-symbols.m
index c28adb3f8a..e23ae30397 100644
--- a/test/CodeGenObjC/forward-protocol-metadata-symbols.m
+++ b/test/CodeGenObjC/forward-protocol-metadata-symbols.m
@@ -18,7 +18,7 @@ int main() {
   return 0;
 }
 
-// CHECK: @"\01l_OBJC_PROTOCOL_$_P0" = weak hidden global
+// CHECK: @"\01l_OBJC_PROTOCOL_$_P0" = private global
 // CHECK: @"\01l_OBJC_CLASS_PROTOCOLS_$_A" = private global
-// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P0" = weak hidden global
-// CHECK: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P0" = weak hidden global
+// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P0" = private global
+// CHECK: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P0" = private global
diff --git a/test/CodeGenObjC/hidden-visibility.m b/test/CodeGenObjC/hidden-visibility.m
index 9f5071d5ff..733bf17016 100644
--- a/test/CodeGenObjC/hidden-visibility.m
+++ b/test/CodeGenObjC/hidden-visibility.m
@@ -2,7 +2,7 @@
 // CHECK: @"OBJC_IVAR_$_I.P" = hidden
 // CHECK: @"OBJC_CLASS_$_I" = hidden
 // CHECK: @"OBJC_METACLASS_$_I" = hidden
-// CHECK: @"\01l_OBJC_PROTOCOL_$_Prot0" = weak hidden
+// CHECK: @"\01l_OBJC_PROTOCOL_$_Prot0" = private global
 
 @interface I {
   int P;
diff --git a/test/CodeGenObjC/metadata-symbols-64.m b/test/CodeGenObjC/metadata-symbols-64.m
index 7b96093869..9043eb8cfa 100644
--- a/test/CodeGenObjC/metadata-symbols-64.m
+++ b/test/CodeGenObjC/metadata-symbols-64.m
@@ -11,8 +11,8 @@
 // CHECK: @"\01l_OBJC_$_CLASS_METHODS_A" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_PROTOCOL_INSTANCE_METHODS_P" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_PROTOCOL_CLASS_METHODS_P" = private global {{.*}} section "__DATA, __objc_const", align 8
-// CHECK: @"\01l_OBJC_PROTOCOL_$_P" = weak hidden global {{.*}} section "__DATA,__datacoal_nt,coalesced", align 8
-// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = weak hidden global {{.*}} section "__DATA, __objc_protolist, coalesced, no_dead_strip", align 8
+// CHECK: @"\01l_OBJC_PROTOCOL_$_P" = private global {{.*}} section "__DATA,__datacoal_nt,coalesced", align 8
+// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = private global {{.*}} section "__DATA, __objc_protolist, coalesced, no_dead_strip", align 8
 // CHECK: @"\01l_OBJC_CLASS_PROTOCOLS_$_A" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_METACLASS_RO_$_A" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_INSTANCE_METHODS_A" = private global {{.*}} section "__DATA, __objc_const", align 8
@@ -28,7 +28,7 @@
 // CHECK: @"\01L_OBJC_CLASSLIST_SUP_REFS_$_{{[0-9]*}}" = private global {{.*}} section "__DATA, __objc_superrefs, regular, no_dead_strip", align 8
 // CHECK: @"OBJC_CLASS_$_B" = external global
 // CHECK: @"\01L_OBJC_CLASSLIST_REFERENCES_$_{{[0-9]*}}" = private global {{.*}} section "__DATA, __objc_classrefs, regular, no_dead_strip", align 8
-// CHECK: @"\01l_objc_msgSend_fixup_alloc" = weak hidden global {{.*}} section "__DATA, __objc_msgrefs, coalesced", align 16
+// CHECK: @"\01l_objc_msgSend_fixup_alloc" = private global {{.*}} section "__DATA, __objc_msgrefs, coalesced", align 16
 // CHECK: @"\01L_OBJC_LABEL_CLASS_$" = private global {{.*}} section "__DATA, __objc_classlist, regular, no_dead_strip", align 8
 // CHECK: @"\01L_OBJC_LABEL_CATEGORY_$" = private global {{.*}} section "__DATA, __objc_catlist, regular, no_dead_strip", align 8
 // CHECK: @objc_msgSend_fpret(