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

diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 0cb38f27aa09dcf45f2b19e7e6c054243dca629e..55bd723511234dcd4ba72b016fd548c39263147f 100644 (file)
--- 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 c28adb3f8aa479d4ec900aa69736694704bfefb6..e23ae30397621c3a810120c5a5df6e3232c7dbb6 100644 (file)
--- 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 9f5071d5ffaa97fc63136fbcae23c9eba2715da6..733bf1701683984fdb9024001575079dfb94d043 100644 (file)
--- 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 7b96093869009785bd794638f5b211c22e37da71..9043eb8cfafb439492e1cfead50f91d19d573e62 100644 (file)
--- 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(