[Clang][AIX] Add .ref in frontend for AIX XCOFF to support `-bcdtors:csect` linker option

[tingwang]

Summary

This is the frontend part of .ref enablement. It works with D122198, and implements below items:

(1) variable to init/term functions (required to add functions to _cdtors array if the variable is included in linker output)
(2) dtor function to term function (required to correctly handle atexit/unatexit registration/unregistration)

[tingwang]

Update the three test cases introduced in this patch to use opaque-pointer
clang/test/CodeGen/PowerPC/aix-init-ref-null.cpp
clang/test/CodeGen/PowerPC/aix-ref-static-var.cpp
clang/test/CodeGen/PowerPC/aix-ref-tls_init.cpp

[tingwang]

Gentle ping.

[shchenz]

Thanks for doing this. I am not familiar with the frontend, so I may be wrong/stupid in the follow comments : )
Hope other experts like @hubert.reinterpretcast can give more meaningful comments.

I tested on AIX, seems for static variable static int x = foo(); in global scope, even compile with -bcdtors:csect, the init function also will not be eliminated. Could you please give an example to show why we need the new associated metadata for this case? Thanks.

And we may need to update the docs for associated metadata too in docs/LangRef.rst

clang/lib/CodeGen/CGDeclCXX.cpp

543

Should we use addVarTermAssoc?

870

FFDtorTermAssoc should store the mapping between dtor and term functions? So why we need to update this container when we generate wrapper function for init function? I think in the init function there should only be ctors related functions?

And why we don't need to update for VarsWithInitTerm, in that container there should be some static variables reply on the wrapper init function?

clang/lib/CodeGen/CodeGenModule.cpp

5088

Why do we need to add mapping between a variable and its address? We already map the global and its init function in above EmitCXXGlobalVarDeclInitFunc?

clang/lib/CodeGen/CodeGenModule.h

488

Is there any reason why we need vector here instead of map? Can you give an example that shows one global variable will be connected with more than one init functions?

[tingwang]

In D125095#3552451, @shchenz wrote:

Thanks for doing this. I am not familiar with the frontend, so I may be wrong/stupid in the follow comments : )
Hope other experts like @hubert.reinterpretcast can give more meaningful comments.

I tested on AIX, seems for static variable static int x = foo(); in global scope, even compile with -bcdtors:csect, the init function also will not be eliminated. Could you please give an example to show why we need the new associated metadata for this case? Thanks.

Here is one example to show:

TEST_FOLDER=/tmp/test
mkdir -p $TEST_FOLDER
cd $TEST_FOLDER
cat > libbar.cc <<EOF
int globalVar = 2;
extern "C" int puts(const char *);
int foo() {
  puts("foo");
  globalVar = 42;
  return 30;
}
static int x = foo();
EOF

cat > libbaz.cc <<EOF
extern "C" int puts(const char *);
template <typename = void>
struct A {
  ~A() { puts("struct A ~A() 2"); }
  static A instance;
};

template <typename T> A<T> A<T>::instance;
void *zap() { return &A<>::instance; }

EOF

cat > uselib.cc <<EOF
#include <dlfcn.h>

int main(void) {
    void *handle = dlopen("./libbaz.so", RTLD_NOW | RTLD_LOCAL);
    dlclose(handle);
}
EOF

• g++

XLC=g++
$XLC -fno-exceptions -c libbar.cc
rm -f libbar.a
ar qs libbar.a libbar.o
ranlib libbar.a
$XLC -fno-exceptions -c libbaz.cc
$XLC -shared -o libbaz.so libbaz.o libbar.a
$XLC -fno-exceptions -ldl uselib.cc -o uselib -ldl
./uselib 
foo
struct A ~A() 2

• XLC 16.1.0

XLC=/gsa/rtpgsa/projects/x/xlcmpbld/run/vacpp/16.1.0/aix/daily/191109/bin/xlclang++
$XLC -g -qnoeh -qfuncsect -c libbar.cc
rm -f libbar.a
ar qs libbar.a libbar.o
ranlib libbar.a
$XLC -g -qnoeh -qfuncsect -c libbaz.cc
$XLC -g -qtwolink -G -o libbaz.so libbaz.o libbar.a
$XLC -g -qnoeh uselib.cc -o uselib
./uselib 
foo
struct A ~A() 2

• clang++ baseline

XLC=/home/tingwa/repo/llvm-project-base/dev/build/bin/clang++
$XLC -g -fignore-exceptions -ffunction-sections -c libbar.cc
rm -f libbar.a
ar qs libbar.a libbar.o
ranlib libbar.a
$XLC -g -fignore-exceptions -ffunction-sections -c libbaz.cc
$XLC -g -bcdtors:csect -shared -Wl,-G -o libbaz.so libbaz.o libbar.a
$XLC -g -fignore-exceptions uselib.cc -o uselib
./uselib
struct A ~A() 2

• clang++ .ref

XLC=/home/tingwa/repo/llvm-project-12514-BE/dev/build/bin/clang++
$XLC -g -fignore-exceptions -ffunction-sections -c libbar.cc
rm -f libbar.a
ar qs libbar.a libbar.o
ranlib libbar.a
$XLC -g -fignore-exceptions -ffunction-sections -c libbaz.cc
$XLC -g -bcdtors:csect -shared -Wl,-G -o libbaz.so libbaz.o libbar.a
$XLC -g -fignore-exceptions uselib.cc -o uselib
./uselib 
foo
struct A ~A() 2

As shown in this example: without .ref association, clang++ baseline case will be wrong, since globalVar is updated in the init function.

[tingwang]

clang/lib/CodeGen/CGDeclCXX.cpp

870

FFDtorTermAssoc should store the mapping between dtor and term functions? So why we need to update this container when we generate wrapper function for init function? I think in the init function there should only be ctors related functions?

Thank you for pointing out! This is redundant.

And why we don't need to update for VarsWithInitTerm, in that container there should be some static variables reply on the wrapper init function?

VarsWithInitTerm keeps track of mapping between variables in clang (Decl*) and the corresponding data structure in llvm (Constant *). To me it's stable, and not like functions which could be wrapped in new functions.

clang/lib/CodeGen/CodeGenModule.cpp

5088

It seems to me that clang most of the time operates on Decl*. However to generate metadata, we refer to llvm::Constant*. I did not find how to get llvm::Constant* from Decl* in clang, so I'm tracking that information. I will check again to see if there is any official way to do that but I'm not aware of.

clang/lib/CodeGen/CodeGenModule.h

488

One variable can have two functions associated: one init and one term, thus used vector for VFInitTermAssoc. Also it is better to use variable as key for the benefit of the inner for loop inside AddMeta.

Dtor-to-Term (FFDtorTermAssoc) could use map, however it shares similar update logic as VFInitTermAssoc (for example the code snippet AddMeta in CodeGenModule::genAssocMeta() is used on both data structure), so I prefer to use vector for both of them.

[tingwang]

Update according to comments:
(1) Update docs
(2) Use addVarTermAssoc
(3) Remove redundant call to updateAssociatedFunc(FFDtorTermAssoc...
(4) Remove unnecessary llvm::array_pod_sort on FFDtorTermAssoc

[tingwang]

Gentle ping.

Verified the patch works with latest code base, all tests green.

[shchenz]

Sorry, I am really not familiar with these FE stuffs. Need approval from other reviewers who know more about this part.

clang/lib/CodeGen/CodeGenModule.cpp

558

Seems this dos not follow other functions call's style. Can we call a function like EmitAssociatedMetadata() here and do the clean up (cleanupAssoc() may not be needed) in the EmitAssociatedMetadata()?

clang/test/CodeGen/PowerPC/aix-init-ref-null.cpp

2

is -debug-info-kind=limited or -O3 necessary in this test? Same as other new added cases.

clang/test/CodeGen/PowerPC/aix-ref-tls_init.cpp

10 ↗

(On Diff #435107)

Not sure if this is right or not. XLC on AIX seems refer to __tls_get_addr instead of __tls_init...

[tingwang]

clang/lib/CodeGen/CodeGenModule.cpp

558

Thanks! I will update the code.

clang/test/CodeGen/PowerPC/aix-init-ref-null.cpp

2

Oh, "-debug-info-kind=limited" is not required. I will remove those. The "-O3" flag is required to show that associated metadata can be nullptr. Without "-O3", normal llvm.global_ctors will be generated.

clang/test/CodeGen/PowerPC/aix-ref-tls_init.cpp

10 ↗

(On Diff #435107)

I saw some case that AIX generated tls related association, and I was postulating that the association should be linked to _tls_init. I will revisit my case and update with more info or correct the association later.

[tingwang]

Update according to comments:
(1) Merged cleanupAssoc() into genAssocMeta(), and renamed genAssocMeta() to EmitAssociatedMetadata().
(2) Removed "-debug-info-kind=limited" from all test cases.

[tingwang]

Drop TLS related .ref for now

[tingwang]

Add guards against TLS variables.

[tingwang]

Currently this patch does not work due to limit set on associated metadata operand count (forced to be single operand).

commit 87f2e9448e82bbed4ac59bb61bea03256aa5f4de
Author: Matt Arsenault <[e-mail]>
Date:   Mon Jan 9 12:17:38 2023 -0500

    Verifier: Add checks for associated metadata
    
    Also add missing assembler test for the valid cases.

I'm working on a patch to relieve this limit for TT.isOSAIX(), and will add that to the stack later.

[tingwang]

Rebase and update patch
(1) Update verifier check on associated metadata to allow multiple operands for AIX.
(2) Update test cases to use opaque pointer.

[tingwang]

As verifier change and baseline test cases have been moved into https://reviews.llvm.org/D145767, update this patch.

clang/lib/CodeGen/CGDecl.cpp

void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
 
   // CUDA's local and local static __shared__ variables should not
   // have any non-empty initializers. This is ensured by Sema.
   // Whatever initializer such variable may have when it gets here is
   // a no-op and should not be emitted.
   bool isCudaSharedVar = getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
                          D.hasAttr<CUDASharedAttr>();
   // If this value has an initializer, emit it.
-  if (D.getInit() && !isCudaSharedVar)
+  if (D.getInit() && !isCudaSharedVar) {
     var = AddInitializerToStaticVarDecl(D, var);
+    if (CGM.getTriple().isOSAIX() && D.getTLSKind() == VarDecl::TLS_None)
+      CGM.addVarWithInitTerm(&D, var);
+  }
 
   var->setAlignment(alignment.getAsAlign());
 
   if (D.hasAttr<AnnotateAttr>())
     CGM.AddGlobalAnnotations(&D, var);
 
   if (auto *SA = D.getAttr<PragmaClangBSSSectionAttr>())
     var->addAttribute("bss-section", SA->getName());

clang/lib/CodeGen/CGDeclCXX.cpp

SmallString<256> FnName;
     llvm::raw_svector_ostream Out(FnName);
     getCXXABI().getMangleContext().mangleDynamicInitializer(D, Out);
   }
 
   // Create a variable initialization function.
   llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(
       FTy, FnName.str(), getTypes().arrangeNullaryFunction(), D->getLocation());
 
+  if (getTriple().isOSAIX() && D->getTLSKind() == VarDecl::TLS_None)
+    addVarTermAssoc(D, Fn);
   auto *ISA = D->getAttr<InitSegAttr>();
   CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr,
                                                           PerformInit);
 
   llvm::GlobalVariable *COMDATKey =
       supportsCOMDAT() && D->isExternallyVisible() ? Addr : nullptr;
 
   if (D->getTLSKind()) {
for (SmallVectorImpl<GlobalInitData >::iterator
         for (auto *F : ModuleInits)
           LocalCXXGlobalInits.push_back(F);
         ModuleInits.clear();
       }
 
       for (; I < PrioE; ++I)
         LocalCXXGlobalInits.push_back(I->second);
 
+      if (getTriple().isOSAIX()) {
+        auto GetElem = [](auto &V, unsigned i) { return V[i]; };
+        updateAssociatedFunc(VFInitTermAssoc, LocalCXXGlobalInits, GetElem, Fn);
+      }
       CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);
       AddGlobalCtor(Fn, Priority);
     }
     PrioritizedCXXGlobalInits.clear();
   }
 
   if (getCXXABI().useSinitAndSterm() && ModuleInits.empty() &&
       CXXGlobalInits.empty())
Fn = CreateGlobalInitOrCleanUpFunction(
         FTy, llvm::Twine(InitFnName), FI, SourceLocation(), false,
         llvm::GlobalVariable::ExternalLinkage);
   } else
     Fn = CreateGlobalInitOrCleanUpFunction(
         FTy,
         llvm::Twine("_GLOBAL__sub_I_", getTransformedFileName(getModule())),
         FI);
 
+  if (getTriple().isOSAIX()) {
+    auto GetElem = [](auto &V, unsigned i) { return V[i]; };
+    updateAssociatedFunc(VFInitTermAssoc, ModuleInits, GetElem, Fn);
+  }
   CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, ModuleInits);
   AddGlobalCtor(Fn);
 
   // In OpenCL global init functions must be converted to kernels in order to
   // be able to launch them from the host.
   // FIXME: Some more work might be needed to handle destructors correctly.
   // Current initialization function makes use of function pointers callbacks.
   // We can't support function pointers especially between host and device.
CodeGenModule::EmitCXXGlobalInitFunc() {
   if (getLangOpts().HIP && getLangOpts().CUDAIsDevice) {
     Fn->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);
     Fn->addFnAttr("device-init");
   }
 
   ModuleInits.clear();
 }
 
+void CodeGenModule::EmitAssociatedMetadata() {
+  auto AddMeta = [this](auto &Assoc, auto &LA) {
+    for (auto I = Assoc.begin(), E = Assoc.end(); I != E;) {
+      llvm::SmallVector<llvm::Metadata *, 2> Metas;
+      auto Src = I->first;
+
+      for (; I < E && I->first == Src; ++I)
+        Metas.push_back(llvm::ValueAsMetadata::get(I->second));
+
+      llvm::MDNode *MD = llvm::MDNode::get(getLLVMContext(), Metas);
+      if (auto *GO = dyn_cast<llvm::GlobalObject>(LA(Src)))
+        GO->addMetadata(llvm::LLVMContext::MD_associated, *MD);
+    }
+  };
+  // Generate dtor to term .ref
+  auto LM1 = [](llvm::Function *C) { return C; };
+  AddMeta(FFDtorTermAssoc, LM1);
+
+  // Generate var to init/term .ref
+  auto LM2 = [this](const Decl *C) {
+    assert((VarsWithInitTerm.find(C) != VarsWithInitTerm.end()) &&
+           "EmitAssociatedMetadata does not have var info");
+    return VarsWithInitTerm[C];
+  };
+  llvm::array_pod_sort(VFInitTermAssoc.begin(), VFInitTermAssoc.end());
+  AddMeta(VFInitTermAssoc, LM2);
+
+  // Cleanup
+  VFInitTermAssoc.clear();
+  FFDtorTermAssoc.clear();
+  VarsWithInitTerm.clear();
+}
+
 void CodeGenModule::EmitCXXGlobalCleanUpFunc() {
   if (CXXGlobalDtorsOrStermFinalizers.empty() &&
       PrioritizedCXXStermFinalizers.empty())
     return;
 
   llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
   const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
 
for (SmallVectorImpl<StermFinalizerData>::iterator
           FTy, "_GLOBAL__a_" + getPrioritySuffix(Priority), FI);
 
       for (; I < PrioE; ++I) {
         llvm::FunctionCallee DtorFn = I->second;
         LocalCXXStermFinalizers.emplace_back(DtorFn.getFunctionType(),
                                              DtorFn.getCallee(), nullptr);
       }
 
+      if (getTriple().isOSAIX()) {
+        auto GetElem = [](auto &V, unsigned i) { return std::get<1>(V[i]); };
+        updateAssociatedFunc(VFInitTermAssoc, LocalCXXStermFinalizers, GetElem,
+                             Fn);
+        updateAssociatedFunc(FFDtorTermAssoc, LocalCXXStermFinalizers, GetElem,
+                             Fn);
+      }
       CodeGenFunction(*this).GenerateCXXGlobalCleanUpFunc(
           Fn, LocalCXXStermFinalizers);
       AddGlobalDtor(Fn, Priority);
     }
     PrioritizedCXXStermFinalizers.clear();
   }
 
   if (CXXGlobalDtorsOrStermFinalizers.empty())
     return;
 
   // Create our global cleanup function.
   llvm::Function *Fn =
       CreateGlobalInitOrCleanUpFunction(FTy, "_GLOBAL__D_a", FI);
 
+  if (getTriple().isOSAIX()) {
+    auto GetElem = [](auto &V, unsigned i) { return std::get<1>(V[i]); };
+    updateAssociatedFunc(VFInitTermAssoc, CXXGlobalDtorsOrStermFinalizers,
+                         GetElem, Fn);
+    updateAssociatedFunc(FFDtorTermAssoc, CXXGlobalDtorsOrStermFinalizers,
+                         GetElem, Fn);
+  }
   CodeGenFunction(*this).GenerateCXXGlobalCleanUpFunc(
       Fn, CXXGlobalDtorsOrStermFinalizers);
   AddGlobalDtor(Fn);
   CXXGlobalDtorsOrStermFinalizers.clear();
 }
 
 /// Emit the code necessary to initialize the given global variable.
 void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,

clang/lib/CodeGen/CodeGenModule.h

bool operator()(const GlobalInitData &LHS,
       return LHS.first.priority < RHS.first.priority;
     }
   };
 
   /// Global variables with initializers whose order of initialization is set by
   /// init_priority attribute.
   SmallVector<GlobalInitData, 8> PrioritizedCXXGlobalInits;
 
+  /// To support `-bcdtors:csect` on AIX, we are adding .ref pseudo-op to
+  /// associate variable with init/term functions, and maintain the dependency
+  /// between dtor and term functions.
+  llvm::SmallVector<std::pair<const Decl *, llvm::Constant *>, 8>
+      VFInitTermAssoc;
+  llvm::SmallVector<std::pair<llvm::Function *, llvm::Constant *>, 8>
+      FFDtorTermAssoc;
+  llvm::DenseMap<const Decl *, llvm::Constant *> VarsWithInitTerm;
+
   /// Global destructor functions and arguments that need to run on termination.
   /// When UseSinitAndSterm is set, it instead contains sterm finalizer
   /// functions, which also run on unloading a shared library.
   typedef std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH,
                      llvm::Constant *>
       CXXGlobalDtorsOrStermFinalizer_t;
   SmallVector<CXXGlobalDtorsOrStermFinalizer_t, 8>
       CXXGlobalDtorsOrStermFinalizers;
CGObjCRuntime &getObjCRuntime() {
     return *ObjCRuntime;
   }
 
   /// Return true iff an Objective-C runtime has been configured.
   bool hasObjCRuntime() { return !!ObjCRuntime; }
 
   const std::string &getModuleNameHash() const { return ModuleNameHash; }
 
+  /// As wrapper functions are generated, update .ref association point to the
+  /// wrapper
+  template <typename TA, typename TB, typename F>
+  void updateAssociatedFunc(
+      llvm::SmallVector<std::pair<TA, llvm::Constant *>, 8> &Assoc, TB &Funcs,
+      F &GetElem, llvm::Function *Fn) {
+    for (auto I = Assoc.begin(), E = Assoc.end(); I != E; ++I) {
+      bool Found = false;
+      for (unsigned i = 0, e = Funcs.size(); i != e; ++i)
+        if (I->second == GetElem(Funcs, i)) {
+          Found = true;
+          break;
+        }
+
+      if (Found)
+        *I = std::make_pair(I->first, Fn);
+    }
+  }
+
+  template <typename T, typename F>
+  void updateInitTermAssociatedFunc(T &Funcs, F &GetElem, llvm::Function *Fn) {
+    updateAssociatedFunc(VFInitTermAssoc, Funcs, GetElem, Fn);
+  }
+
+  void addVarTermAssoc(const Decl *Src, llvm::Constant *Target) {
+    VFInitTermAssoc.push_back(std::make_pair(Src, Target));
+  }
+
+  void addDtorTermAssoc(llvm::Function *Src, llvm::Constant *Target) {
+    FFDtorTermAssoc.push_back(std::make_pair(Src, Target));
+  }
+
+  void addVarWithInitTerm(const Decl *Var, llvm::Constant *C) {
+    VarsWithInitTerm[Var] = C;
+  }
+
   /// Return a reference to the configured OpenCL runtime.
   CGOpenCLRuntime &getOpenCLRuntime() {
     assert(OpenCLRuntime != nullptr);
     return *OpenCLRuntime;
   }
 
   /// Return a reference to the configured OpenMP runtime.
   CGOpenMPRuntime &getOpenMPRuntime() {
private:
   void EmitVTablesOpportunistically();
 
   /// Call replaceAllUsesWith on all pairs in Replacements.
   void applyReplacements();
 
   /// Call replaceAllUsesWith on all pairs in GlobalValReplacements.
   void applyGlobalValReplacements();
 
+  /// Generate associated metadata for static init/term
+  void EmitAssociatedMetadata();
+
   void checkAliases();
 
   std::map<int, llvm::TinyPtrVector<llvm::Function *>> DtorsUsingAtExit;
 
   /// Register functions annotated with __attribute__((destructor)) using
   /// __cxa_atexit, if it is available, or atexit otherwise.
   void registerGlobalDtorsWithAtExit();
 

clang/lib/CodeGen/CodeGenModule.cpp

void CodeGenModule::Release() {
 
   if (CXX20ModuleInits && Primary && Primary->isInterfaceOrPartition())
     EmitCXXModuleInitFunc(Primary);
   else
     EmitCXXGlobalInitFunc();
   EmitCXXGlobalCleanUpFunc();
   registerGlobalDtorsWithAtExit();
   EmitCXXThreadLocalInitFunc();
+  if (getTriple().isOSAIX()) {
+    EmitAssociatedMetadata();
+  }
   if (ObjCRuntime)
     if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
       AddGlobalCtor(ObjCInitFunction);
   if (Context.getLangOpts().CUDA && CUDARuntime) {
     if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
       AddGlobalCtor(CudaCtorFunction);
   }
   if (OpenMPRuntime) {
if (D->getTLSKind() && !GV->isThreadLocal()) {
     if (D->getTLSKind() == VarDecl::TLS_Dynamic)
       CXXThreadLocals.push_back(D);
     setTLSMode(GV, *D);
   }
 
   maybeSetTrivialComdat(*D, *GV);
 
   // Emit the initializer function if necessary.
-  if (NeedsGlobalCtor || NeedsGlobalDtor)
+  if (NeedsGlobalCtor || NeedsGlobalDtor) {
     EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
+    if (getTriple().isOSAIX() && D->getTLSKind() == VarDecl::TLS_None)
+      addVarWithInitTerm(D, GV);
+  }
 
   SanitizerMD->reportGlobal(GV, *D, NeedsGlobalCtor);
 
   // Emit global variable debug information.
   if (CGDebugInfo *DI = getModuleDebugInfo())
     if (getCodeGenOpts().hasReducedDebugInfo())
       DI->EmitGlobalVariable(GV, D);
 }

clang/lib/CodeGen/ItaniumCXXABI.cpp

SmallString<256> FnName;
     getMangleContext().mangleDynamicStermFinalizer(&D, Out);
   }
 
   // Create the finalization action associated with a variable.
   const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
   llvm::Function *StermFinalizer = CGM.CreateGlobalInitOrCleanUpFunction(
       FTy, FnName.str(), FI, D.getLocation());
 
+  if (CGM.getTriple().isOSAIX() && D.getTLSKind() == VarDecl::TLS_None) {
+    CGM.addVarTermAssoc(&D, StermFinalizer);
+    CGM.addDtorTermAssoc(dtorStub, StermFinalizer);
+  }
+
   CodeGenFunction CGF(CGM);
 
   CGF.StartFunction(GlobalDecl(), CGM.getContext().VoidTy, StermFinalizer, FI,
                     FunctionArgList(), D.getLocation(),
                     D.getInit()->getExprLoc());
 
   // The unatexit subroutine unregisters __dtor functions that were previously
   // registered by the atexit subroutine. If the referenced function is found,

clang/test/CodeGen/PowerPC/aix-init-ref-null.cpp

 // RUN: %clang_cc1 -triple powerpc64-ibm-aix-xcoff -emit-llvm -O3 -x c++ < %s | FileCheck %s
 
 // Global Ctors present at -O0, removed by -O3
 typedef enum {
   A, B
 } E;
 
 class base {
 protected:
   base(E v): m(v) { }
 private:
   E m;
 };
 
 struct ext: base {
       ext():base(A){}
 };
 
 ext base_rview;
 
-// CHECK: @base_rview = local_unnamed_addr global %struct.ext zeroinitializer, align [[ALIGN:[0-9]+]]
-// XFAIL-CHECK: @base_rview = local_unnamed_addr global %struct.ext zeroinitializer, align [[ALIGN:[0-9]+]], !associated ![[ASSOC0:[0-9]+]]
+// CHECK: @base_rview = local_unnamed_addr global %struct.ext zeroinitializer, align [[ALIGN:[0-9]+]], !associated ![[ASSOC0:[0-9]+]]
 // CHECK: @llvm.global_ctors = appending global [0 x { i32, ptr, ptr }] zeroinitializer
-// XFAIL-CHECK: ![[ASSOC0]] = distinct !{null}
+// CHECK: ![[ASSOC0]] = distinct !{null}

clang/test/CodeGen/PowerPC/aix-ref-static-var.cpp

 // RUN: %clang_cc1 -triple powerpc64-ibm-aix-xcoff -emit-llvm -x c++ < %s | FileCheck %s
 
 struct S {
   ~S();
 };
 void f() {
   static S s;
 }
 
-// CHECK: @_ZZ1fvE1s = internal global %struct.S zeroinitializer, align [[ALIGN:[0-9]+]]
-// XFAIL-CHECK: @_ZZ1fvE1s = internal global %struct.S zeroinitializer, align [[ALIGN:[0-9]+]], !associated ![[ASSOC0:[0-9]+]]
-// CHECK: define internal void @__dtor__ZZ1fvE1s() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZZ1fvE1s() [[ATTR:#[0-9]+]] !associated ![[ASSOC0:[0-9]+]] {
-// XFAIL-CHECK: ![[ASSOC0]] = !{ptr @_GLOBAL__D_a}
+// CHECK: @_ZZ1fvE1s = internal global %struct.S zeroinitializer, align [[ALIGN:[0-9]+]], !associated ![[ASSOC0:[0-9]+]]
+// CHECK: define internal void @__dtor__ZZ1fvE1s() [[ATTR:#[0-9]+]] !associated ![[ASSOC0:[0-9]+]] {
+// CHECK: ![[ASSOC0]] = !{ptr @_GLOBAL__D_a}

clang/test/CodeGenCXX/aix-static-init-debug-info.cpp

 // RUN: %clang_cc1 -triple powerpc-ibm-aix-xcoff -emit-llvm -x c++ \
 // RUN:     -debug-info-kind=limited < %s | \
 // RUN:   FileCheck %s
 
 // RUN: %clang_cc1 -triple powerpc64-ibm-aix-xcoff -emit-llvm -x c++ \
 // RUN:     -debug-info-kind=limited  < %s | \
 // RUN:   FileCheck %s
 
 struct X {
   X();
   ~X();
 };
 
 X v;
 
-// XFAIL-CHECK: @v = global %struct.X zeroinitializer, align {{[0-9]+}}, !dbg !{{[0-9]+}}, !associated ![[ASSOC1:[0-9]+]]
+// CHECK: @v = global %struct.X zeroinitializer, align {{[0-9]+}}, !dbg !{{[0-9]+}}, !associated ![[ASSOC1:[0-9]+]]
 
 // CHECK: define internal void @__cxx_global_var_init() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR16:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN1XC1Ev(ptr {{[^,]*}} @v), !dbg ![[DBGVAR19:[0-9]+]]
 // CHECK:   %0 = call i32 @atexit(ptr @__dtor_v) [[ATTR:#[0-9]+]], !dbg ![[DBGVAR19b:[0-9]+]]
 // CHECK:   ret void, !dbg ![[DBGVAR19]]
 // CHECK: }
 
-// CHECK: define internal void @__dtor_v() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR20:[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor_v() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR20:[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
+// CHECK: define internal void @__dtor_v() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR20:[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN1XD1Ev(ptr @v), !dbg ![[DBGVAR21b:[0-9]+]]
 // CHECK:   ret void, !dbg ![[DBGVAR21:[0-9]+]]
 // CHECK: }
 
 // CHECK: define internal void @__finalize_v() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR22:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor_v) [[ATTR:#[0-9]+]], !dbg ![[DBGVAR24:[0-9]+]]

 // CHECK: }
 
 // CHECK: define internal void @_GLOBAL__D_a() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR27:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @__finalize_v(), !dbg ![[DBGVAR28:[0-9]+]]
 // CHECK:   ret void
 // CHECK: }
 
-// XFAIL-CHECK: ![[ASSOC1]] = !{ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}, ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}}
+// CHECK: ![[ASSOC1]] = !{ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}, ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}}
 // CHECK: ![[DBGVAR16]] = distinct !DISubprogram(name: "__cxx_global_var_init", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, type: !{{[0-9]+}}, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR19]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR16]])
 // CHECK: ![[DBGVAR19b]] = !DILocation(line: 0, scope: ![[DBGVAR16]])
 // CHECK: ![[DBGVAR20]] = distinct !DISubprogram(name: "__dtor_v", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
-// XFAIL-CHECK: ![[ASSOC2]] = !{ptr @_GLOBAL__D_a}
+// CHECK: ![[ASSOC2]] = !{ptr @_GLOBAL__D_a}
 // CHECK: ![[DBGVAR21b]] = !DILocation(line: 0, scope: ![[DBGVAR20]])
 // CHECK: ![[DBGVAR21]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR20]])
 // CHECK: ![[DBGVAR22]] = distinct !DISubprogram(linkageName: "__finalize_v", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR24]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR22]])
 // CHECK: ![[DBGVAR25]] = distinct !DISubprogram(linkageName: "_GLOBAL__sub_I__", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, type: !{{[0-9]+}}, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR26]] = !DILocation(line: 0, scope: ![[DBGVAR25]])
 // CHECK: ![[DBGVAR27]] = distinct !DISubprogram(linkageName: "_GLOBAL__D_a", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, type: !{{[0-9]+}}, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR28]] = !DILocation(line: 0, scope: ![[DBGVAR27]])

clang/test/CodeGenCXX/aix-static-init-temp-spec-and-inline-var.cpp

 A<int> &bar() {
   A<int> *a = new A<int>;
   return *a;
 }
 template <>
 A<int> A<int>::instance = bar();
 } // namespace test2
 
-// XFAIL-CHECK: @_ZN5test12t0E = global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
-// XFAIL-CHECK: @_ZN5test12t2E = linkonce_odr global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC1:[0-9]+]]
+// CHECK: @_ZN5test12t0E = global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
+// CHECK: @_ZN5test12t2E = linkonce_odr global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC1:[0-9]+]]
 // CHECK: @_ZGVN5test12t2E = linkonce_odr global i64 0, align 8
-// XFAIL-CHECK: @_ZN5test12t1IiEE = linkonce_odr global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC2:[0-9]+]]
-// XFAIL-CHECK: @_ZN5test21AIvE8instanceE = weak_odr global %"struct.test2::A" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC3:[0-9]+]]
+// CHECK: @_ZN5test12t1IiEE = linkonce_odr global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC2:[0-9]+]]
+// CHECK: @_ZN5test21AIvE8instanceE = weak_odr global %"struct.test2::A" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC3:[0-9]+]]
 // CHECK: @_ZGVN5test21AIvE8instanceE = weak_odr global i64 0, align 8
-// XFAIL-CHECK: @_ZN5test21AIiE8instanceE = global %"struct.test2::A.0" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
+// CHECK: @_ZN5test21AIiE8instanceE = global %"struct.test2::A.0" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
 // CHECK: @_ZGVN5test12t1IiEE = linkonce_odr global i64 0, align 8
 // CHECK: @llvm.global_ctors = appending global [4 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @__cxx_global_var_init.1, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @__cxx_global_var_init.2, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @__cxx_global_var_init.4, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__sub_I__, ptr null }]
 // CHECK: @llvm.global_dtors = appending global [4 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @__finalize__ZN5test12t2E, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @__finalize__ZN5test21AIvE8instanceE, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @__finalize__ZN5test12t1IiEE, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__D_a, ptr null }]
 
 // CHECK: define internal void @__cxx_global_var_init() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK32: call void @_ZN5test15Test1C1Ei(ptr noundef{{[^,]*}} @_ZN5test12t0E, i32 noundef 2)
 // CHECK64: call void @_ZN5test15Test1C1Ei(ptr noundef{{[^,]*}} @_ZN5test12t0E, i32 noundef signext 2)
 // CHECK:   %0 = call i32 @atexit(ptr @__dtor__ZN5test12t0E)
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test12t0E() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test12t0E() [[ATTR:#[0-9]+]] !associated ![[ASSOC4:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test12t0E() [[ATTR:#[0-9]+]] !associated ![[ASSOC4:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1D1Ev(ptr @_ZN5test12t0E)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test12t0E() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test12t0E)

 // CHECK:   %2 = call i32 @atexit(ptr @__dtor__ZN5test12t2E)
 // CHECK:   call void @__cxa_guard_release(ptr @_ZGVN5test12t2E)
 // CHECK:   br label %init.end
 
 // CHECK: init.end:
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] !associated ![[ASSOC5:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] !associated ![[ASSOC5:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1D1Ev(ptr @_ZN5test12t2E)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test12t2E() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test12t2E)

 // CHECK:   call void @_ZN5test21AIvEC1Ev(ptr {{[^,]*}} @_ZN5test21AIvE8instanceE)
 // CHECK:   %1 = call i32 @atexit(ptr @__dtor__ZN5test21AIvE8instanceE)
 // CHECK:   br label %init.end
 
 // CHECK: init.end:
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test21AIvE8instanceE() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test21AIvE8instanceE() [[ATTR:#[0-9]+]] !associated ![[ASSOC6:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test21AIvE8instanceE() [[ATTR:#[0-9]+]] !associated ![[ASSOC6:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test21AIvED1Ev(ptr @_ZN5test21AIvE8instanceE)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test21AIvE8instanceE() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test21AIvE8instanceE)

 
 // CHECK: define internal void @__cxx_global_var_init.3() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %call = call noundef nonnull align 1 dereferenceable(1) ptr @_ZN5test23barEv()
 // CHECK:   %0 = call i32 @atexit(ptr @__dtor__ZN5test21AIiE8instanceE)
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test21AIiE8instanceE() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test21AIiE8instanceE() [[ATTR:#[0-9]+]] !associated ![[ASSOC4:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test21AIiE8instanceE() [[ATTR:#[0-9]+]] !associated ![[ASSOC4:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test21AIiED1Ev(ptr @_ZN5test21AIiE8instanceE)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test21AIiE8instanceE() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test21AIiE8instanceE)

 // CHECK64: call void @_ZN5test15Test1C1Ei(ptr {{[^,]*}} @_ZN5test12t1IiEE, i32 noundef signext 2)
 // CHECK:   %1 = call i32 @atexit(ptr @__dtor__ZN5test12t1IiEE)
 // CHECK:   br label %init.end
 
 // CHECK: init.end:
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test12t1IiEE() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test12t1IiEE() [[ATTR:#[0-9]+]] !associated ![[ASSOC7:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test12t1IiEE() [[ATTR:#[0-9]+]] !associated ![[ASSOC7:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1D1Ev(ptr @_ZN5test12t1IiEE)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test12t1IiEE() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test12t1IiEE)

 
 // CHECK: define internal void @_GLOBAL__D_a() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @__finalize__ZN5test21AIiE8instanceE()
 // CHECK:   call void @__finalize__ZN5test12t0E()
 // CHECK:   ret void
 // CHECK: }
 
-// XFAIL-CHECK: ![[ASSOC0]] = !{ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}, ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}}
-// XFAIL-CHECK: ![[ASSOC1]] = !{ptr @{{__cxx_global_var_init.1|__finalize__ZN5test12t2E}}, ptr @{{__cxx_global_var_init.1|__finalize__ZN5test12t2E}}}
-// XFAIL-CHECK: ![[ASSOC2]] = !{ptr @{{__cxx_global_var_init.4|__finalize__ZN5test12t1IiEE}}, ptr @{{__cxx_global_var_init.4|__finalize__ZN5test12t1IiEE}}}
-// XFAIL-CHECK: ![[ASSOC3]] = !{ptr @{{__finalize__ZN5test21AIvE8instanceE|__cxx_global_var_init.2}}, ptr @{{__finalize__ZN5test21AIvE8instanceE|__cxx_global_var_init.2}}}
-// XFAIL-CHECK: ![[ASSOC4]] = !{ptr @_GLOBAL__D_a}
-// XFAIL-CHECK: ![[ASSOC5]] = !{ptr @__finalize__ZN5test12t2E}
-// XFAIL-CHECK: ![[ASSOC6]] = !{ptr @__finalize__ZN5test21AIvE8instanceE}
-// XFAIL-CHECK: ![[ASSOC7]] = !{ptr @__finalize__ZN5test12t1IiEE}
+// CHECK: ![[ASSOC0]] = !{ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}, ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}}
+// CHECK: ![[ASSOC1]] = !{ptr @{{__cxx_global_var_init.1|__finalize__ZN5test12t2E}}, ptr @{{__cxx_global_var_init.1|__finalize__ZN5test12t2E}}}
+// CHECK: ![[ASSOC2]] = !{ptr @{{__cxx_global_var_init.4|__finalize__ZN5test12t1IiEE}}, ptr @{{__cxx_global_var_init.4|__finalize__ZN5test12t1IiEE}}}
+// CHECK: ![[ASSOC3]] = !{ptr @{{__finalize__ZN5test21AIvE8instanceE|__cxx_global_var_init.2}}, ptr @{{__finalize__ZN5test21AIvE8instanceE|__cxx_global_var_init.2}}}
+// CHECK: ![[ASSOC4]] = !{ptr @_GLOBAL__D_a}
+// CHECK: ![[ASSOC5]] = !{ptr @__finalize__ZN5test12t2E}
+// CHECK: ![[ASSOC6]] = !{ptr @__finalize__ZN5test21AIvE8instanceE}
+// CHECK: ![[ASSOC7]] = !{ptr @__finalize__ZN5test12t1IiEE}

clang/test/CodeGenCXX/aix-static-init.cpp

struct Test4 {
     ~Test4();
   };
 
   void f() {
     static Test4 staticLocal;
   }
 } // namespace test4
 
-// XFAIL-CHECK: @_ZN5test12t1E = global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
-// XFAIL-CHECK: @_ZN5test12t2E = global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
-// XFAIL-CHECK: @_ZN5test21xE = global i32 0, align {{[0-9]+}}, !associated ![[ASSOC1:[0-9]+]]
-// XFAIL-CHECK: @_ZN5test31tE = global %"struct.test3::Test3" undef, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
+// CHECK: @_ZN5test12t1E = global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
+// CHECK: @_ZN5test12t2E = global %"struct.test1::Test1" zeroinitializer, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
+// CHECK: @_ZN5test21xE = global i32 0, align {{[0-9]+}}, !associated ![[ASSOC1:[0-9]+]]
+// CHECK: @_ZN5test31tE = global %"struct.test3::Test3" undef, align {{[0-9]+}}, !associated ![[ASSOC0:[0-9]+]]
 // CHECK: @_ZGVZN5test41fEvE11staticLocal = internal global i64 0, align 8
 // CHECK: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__sub_I__, ptr null }]
 // CHECK: @llvm.global_dtors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__D_a, ptr null }]
 
 // CHECK: define internal void @__cxx_global_var_init() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1C1Ev(ptr {{[^,]*}} @_ZN5test12t1E)
 // CHECK:   %0 = call i32 @atexit(ptr @__dtor__ZN5test12t1E)
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test12t1E() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test12t1E() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test12t1E() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1D1Ev(ptr @_ZN5test12t1E)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: declare i32 @atexit(ptr)
 
 // CHECK: define internal void @__finalize__ZN5test12t1E() [[ATTR:#[0-9]+]] {

 
 // CHECK: define internal void @__cxx_global_var_init.1() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1C1Ev(ptr {{[^,]*}} @_ZN5test12t2E)
 // CHECK:   %0 = call i32 @atexit(ptr @__dtor__ZN5test12t2E)
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1D1Ev(ptr @_ZN5test12t2E)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test12t2E() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test12t2E)

 // CHECK: }
 
 // CHECK: define internal void @__cxx_global_var_init.3() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @atexit(ptr @__dtor__ZN5test31tE)
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZN5test31tE() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZN5test31tE() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZN5test31tE() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test35Test3D1Ev(ptr @_ZN5test31tE)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZN5test31tE() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZN5test31tE)

 // CHECK:   %2 = call i32 @atexit(ptr @__dtor__ZZN5test41fEvE11staticLocal)
 // CHECK:   call void @__cxa_guard_release(ptr @_ZGVZN5test41fEvE11staticLocal)
 // CHECK:   br label %init.end
 
 // CHECK: init.end:
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define internal void @__dtor__ZZN5test41fEvE11staticLocal() [[ATTR:#[0-9]+]] {
-// XFAIL-CHECK: define internal void @__dtor__ZZN5test41fEvE11staticLocal() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
+// CHECK: define internal void @__dtor__ZZN5test41fEvE11staticLocal() [[ATTR:#[0-9]+]] !associated ![[ASSOC2:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test45Test4D1Ev(ptr @_ZZN5test41fEvE11staticLocal)
 // CHECK:   ret void
 // CHECK: }
 
 // CHECK: define internal void @__finalize__ZZN5test41fEvE11staticLocal() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   %0 = call i32 @unatexit(ptr @__dtor__ZZN5test41fEvE11staticLocal)

 // CHECK: entry:
 // CHECK:   call void @__finalize__ZZN5test41fEvE11staticLocal()
 // CHECK:   call void @__finalize__ZN5test31tE()
 // CHECK:   call void @__finalize__ZN5test12t2E()
 // CHECK:   call void @__finalize__ZN5test12t1E()
 // CHECK:   ret void
 // CHECK: }
 
-// XFAIL-CHECK: ![[ASSOC0]] = !{ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}, ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}}
-// XFAIL-CHECK: ![[ASSOC1]] = !{ptr @_GLOBAL__sub_I__}
-// XFAIL-CHECK: ![[ASSOC2]] = !{ptr @_GLOBAL__D_a}
+// CHECK: ![[ASSOC0]] = !{ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}, ptr @{{_GLOBAL__sub_I__|_GLOBAL__D_a}}}
+// CHECK: ![[ASSOC1]] = !{ptr @_GLOBAL__sub_I__}
+// CHECK: ![[ASSOC2]] = !{ptr @_GLOBAL__D_a}

llvm/docs/LangRef.rst

 
 .. code-block:: text
 
     $a = comdat any
     @a = global i32 1, comdat $a
     @b = internal global i32 2, comdat $a, section "abc", !associated !0
     !0 = !{ptr @a}
 
-It does not have any effect on non-ELF targets. Non-ELF target may use
-``associated`` metadata for its own purpose. For example, on AIX XCOFF target,
-the ``associated`` metadata may indicate connection among static variables
-(static global variable, static class member etc.) and static init/term
-functions. This kind of association can be one-to-many.
+On AIX XCOFF target, the ``associated`` metadata indicates connection among
+static variables (static global variable, static class member etc.) and static
+init/term functions. This metadata lowers to ``.ref`` assembler pseudo-
+operation which prevents discarding of the functions in linker GC.
+
+It does not have any effect on other non-ELF targets.
 
 '``prof``' Metadata
 ^^^^^^^^^^^^^^^^^^^
 
 The ``prof`` metadata is used to record profile data in the IR.
 The first operand of the metadata node indicates the profile metadata
 type. There are currently 3 types:
 :ref:`branch_weights<prof_node_branch_weights>`,