[AIX] Static init frontend recovery and backend support

[Xiangling_L]

Summary

1. Frontend side
2. Recovered AIX static init frontend to use the linkage type and function names Clang chooses for sinit related function;
3. Removed the GlobalUniqueModuleId calculation and usage;
4. Adjusted the FE testcases accordingly;
5. Added one frontend testcase to demonstrate and validate separate initialization on AIX;

2. Backend side on the assembly path only
3. Set correct linkage and function names for sinit/sterm functions
4. Added testcases

[Xiangling_L]

Fix clang-tidy errors;

[jasonliu]

clang/lib/CodeGen/ItaniumCXXABI.cpp

4609

Handling template instantiation seems fairly orthogonal to "moving naming logic from frontend to backend". Could we put it in a separate patch (which could be a child of this one)?

llvm/include/llvm/CodeGen/AsmPrinter.h

486

Remove const from value type (e.g. Priority and index), as there is no real need for it.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

2159

Maybe a naive quesiton, in what situation would we have name collision and need index as suffix to differentiate?
Could we just report_fatal_error in those situation?

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1885

This would have conflict with D84363. You might want to rebase it later.

1955

Changing Function name and linkage underneath looks a bit scary. People would have a hard time to map IR to final assembly that gets produced. Have you thought about creating an alias (with the correct linkage and name) to the original function instead?

[Xiangling_L]

clang/lib/CodeGen/ItaniumCXXABI.cpp

4609

The reason I chose to handle template instantiation and inline variable in this patch is that I want to show the scenarios where we have separate initialization. And this is also the reason why we want to embed array index into sinit/sterm functions. That is, if we move this part into a separate patch, I am worried that ppl will feel it's weird to embed index into function names.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

2159

As far as I know, there are several situations we would have separate initialization without considering priority:

1. template specialization
2. inline variable
3. ctor/dtor attribute functions

By embedding the index, we can group those sinit/sterm with same priority within current file together.

And as I mentioned above, I chose to handle the former two cases in this patch to show why we need to embed the index.

And regarding the third scenario, we've already report_fatal_error on those cases.

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1885

Thanks for the reminder, I will update the patch accordingly.

1955

Good point. I will adjust the implementation here.

[Xiangling_L]

Created alias for sinit and sterm;
Adjusted the testcase accordingly;

[Xiangling_L]

Removed the disablement in IncrementalProcessingTest.cpp cross-target test;

[jasonliu]

clang/lib/CodeGen/CGDeclCXX.cpp

23–24

We are removing the usage of "getUniqueModuleId" in this file, So I assume this include could get removed as well.

clang/lib/CodeGen/CodeGenModule.h

1058

This wrapper seems redundant. Calling AddGlobalDtor(StermFinalizer, Priority); directly from the callee side already convey what we are trying to achieve here.

clang/lib/CodeGen/ItaniumCXXABI.cpp

4602

Could we trigger this error? If so, could we have a test for it?

llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

2131

I think it's still useful to keep these functions around to prevent accidentally calling to these functions on AIX. We could rephrase error message to "static constructor/destructor section is not needed on AIX."

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1875

Have some suggestion on structure backend code change:

1. Remove isSpecialLLVMGlobalArrayForStaticInit and isSpecialLLVMGlobalArrayToSkip, and call emitSpecialLLVMGlobal directly instead. This would handle all the llvm. variable for us. We would need do early return for names start with llvm. in emitGlobalVariable as well, since they are all handled here.

2. We could override emitXXStructorList because how XCOFF handle the list is vastly different than the other target. We could make the common part(i.e. processing and sorting) a utility function, say "preprocessStructorList".

3. It's not necessary to use the same name emitXXStructor if the interface is different. It might not provide much help when we kinda know no other target is going to use this interface. So we could turn it into a lambda inside of the overrided emitXXStructorList, or simply no need for a new function because the logic is fairly straightforward.

[jasonliu]

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1865

We will need to move this part of the if statement to the overrided emitXXStructorList as well. (If we think overriding emitXXStructorList and calling emitSpecialLLVMGlobal directly is a good idea.)

[Xiangling_L]

clang/lib/CodeGen/CodeGenModule.h

1058

I added this wrapper function to keep the symmetry between AddGlobalCtor and AddGlobalDtor. They are private functions within CodeGenModule class. And I feel it's kinda weird to only move AddGlobalDtor to a public function.

clang/lib/CodeGen/ItaniumCXXABI.cpp

4602

I should've put an assertion here. The init priority attribute has been disabled on AIX in the previous patch.

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1875

1. As we discussed offline, we would leave the handling of llvm.used and llvm.metadata later and don't include them in the scope of this patch.

[Xiangling_L]

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1865

getUniqueModuleId takes Module as a parameter, if we want to invoke this function inside of emitXXStructorList through emitSpecialLLVMGlobal, we have to change the interface of them, which seems not ideal.

[Xiangling_L]

Refactor the code by making emitXXStructorList a virtual function;
Added one testcase for .ref;
Addressed other comments;

[jasonliu]

format

1 ↗

(On Diff #283006)

Redundant file?

llvm/include/llvm/CodeGen/AsmPrinter.h

481

The new block is not all Overridable Hooks, seems better belong in Coarse grained IR lowering routines.

482

This struct got moved to header, means it's not an implementation detail any more.
We would need doxygen comment on it.

486

I have a slight preference to leave it as ComdatKey, and change the name when we actually need to handle .ref because without seeing the actual implementation for .ref we don't know if this is the way we want to pursue.

492

A doxygen comment describe what this function does, and what its return value means, and mention Structors is an output argument.
By looking at what this function does, it seems buildStructorList is a better name.

494

Add a blank line above this.

llvm/test/CodeGen/PowerPC/aix-static-init-key-object.ll

7

Adding this test case would looks like we already decided how to handle .ref in clang and llvm. But in fact, we haven't. I would prefer not having this test.

[Xiangling_L]

llvm/include/llvm/CodeGen/AsmPrinter.h

492

I meant to and should've named this function to preprocessXXStructorList, let me know if you still prefer buildStructorList. And if you do, since the underneath of SmallVector is a variable-sized array, maybe we should try buildSortedStructorArray?

llvm/test/CodeGen/PowerPC/aix-static-init-key-object.ll

7

As we discussed offline, I would adjust the error message instead.

[Xiangling_L]

Added descriptions for struct and functions;
Addressed other comments;

[jasonliu]

llvm/include/llvm/CodeGen/AsmPrinter.h

391

This description is not entirely true. We only see if the array is a ConstantArray and returning false. We are not returning false if the array's element is not { i32, void ()*, i8* }.

492

preprocess sounds like we are already having a XXStructorList and now we try to do something on it.
But right now, we are actually passing in an empty StructorList/Array and build it from scratch. So I would still prefer the name of build in it.
I don't mind changing to a more accurate name as you suggested.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

2103

Return of boolean seems unnecessary.
Callee could check the size of the Structors to decide if they want an early return or not (or in this particular case, the for loop would just do nothing and no need for extra condition if you don't mind the call to getPointerPrefAlignment or assign to 0 to Index)?
So we could just return void for this function?

2126

nit: Missing blank line.

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

1966

nit: Use ++Index instead.
https://llvm.org/docs/CodingStandards.html#prefer-preincrement

Or use Index++ at line 1963 so that we don't need this line.

[Xiangling_L]

llvm/include/llvm/CodeGen/AsmPrinter.h

492

I think we do have a XXStructorList here which is the initializer of llvm.gloal_ctorsor llvm.gloal_dtors array? The usage of this term is consistent with other spots.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

2103

Yeah, we could do that. But it looks a boolean return value makes the code flow natural. And if any target does want to control the early return in the future, it's flexbile for them to do that. I am wondering is there any big difference between bool and void return value for this function?

[jasonliu]

llvm/include/llvm/CodeGen/AsmPrinter.h

492

My understanding is that before we enter this preprocessXXStructorList, we do not have a list of XXStructor. We only have a list of Constant. This functions turns a list of Constant to a list of XXStructor.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

2103

If target need to control early return in the future, they could still do so by querying if the output Structors is empty or not.
I just don't want unnecessary returns, as it's one more thing that user of the function need to care about when they examine this function. And the user of this function would have the same question of why we need to return a boolean here.

[Xiangling_L]

llvm/include/llvm/CodeGen/AsmPrinter.h

492

Just leave a record here, as we discussed offline, we agree that the meaning of term XXStructorList is the initializer of llvm.gloal_ctors` or llvm.gloal_dtors array. So I will keep using preprocessXXStructorList as the function name.

[jasonliu]

Thanks. LGTM.

clang/lib/CodeGen/CGDeclCXX.cpp

 #include "CGOpenMPRuntime.h"
 #include "CodeGenFunction.h"
 #include "TargetInfo.h"
 #include "clang/AST/Attr.h"
 #include "clang/Basic/LangOptions.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/Support/Path.h"
-#include "llvm/Transforms/Utils/ModuleUtils.h"
 
 using namespace clang;
 using namespace CodeGen;
 
 static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
                          ConstantAddress DeclPtr) {
   assert(
       (D.hasGlobalStorage() ||
        (D.hasLocalStorage() && CGF.getContext().getLangOpts().OpenCLCPlusPlus)) &&
if (Kind == GuardKind::VariableGuard && !D->isLocalVarDecl()) {
     Weights = MDHelper.createBranchWeights(1, NumInits - 1);
   }
 
   Builder.CreateCondBr(NeedsInit, InitBlock, NoInitBlock, Weights);
 }
 
 llvm::Function *CodeGenModule::CreateGlobalInitOrCleanUpFunction(
     llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI,
-    SourceLocation Loc, bool TLS, bool IsExternalLinkage) {
+    SourceLocation Loc, bool TLS) {
   llvm::Function *Fn = llvm::Function::Create(
-      FTy,
-      IsExternalLinkage ? llvm::GlobalValue::ExternalLinkage
-                        : llvm::GlobalValue::InternalLinkage,
-      Name, &getModule());
+      FTy, llvm::GlobalValue::InternalLinkage, Name, &getModule());
 
   if (!getLangOpts().AppleKext && !TLS) {
     // Set the section if needed.
     if (const char *Section = getTarget().getStaticInitSectionSpecifier())
       Fn->setSection(Section);
   }
 
-  if (Fn->hasInternalLinkage())
-    SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
 
   Fn->setCallingConv(getRuntimeCC());
 
   if (!getLangOpts().Exceptions)
     Fn->setDoesNotThrow();
 
   if (getLangOpts().Sanitize.has(SanitizerKind::Address) &&
       !isInSanitizerBlacklist(SanitizerKind::Address, Fn, Loc))

 void
 CodeGenModule::EmitCXXGlobalInitFunc() {
   while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
     CXXGlobalInits.pop_back();
 
   if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
     return;
 
-  const bool UseSinitAndSterm = getCXXABI().useSinitAndSterm();
-  if (UseSinitAndSterm) {
-    GlobalUniqueModuleId = getUniqueModuleId(&getModule());
-
-    // FIXME: We need to figure out what to hash on or encode into the unique ID
-    // we need.
-    if (GlobalUniqueModuleId.compare("") == 0)
-      llvm::report_fatal_error(
-          "cannot produce a unique identifier for this module"
-          " based on strong external symbols");
-    GlobalUniqueModuleId = GlobalUniqueModuleId.substr(1);
-  }
-
   llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
   const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
 
+  const bool UseSinitAndSterm = getCXXABI().useSinitAndSterm();
   // Create our global prioritized initialization function.
   if (!PrioritizedCXXGlobalInits.empty()) {
     assert(!UseSinitAndSterm && "Prioritized sinit and sterm functions are not"
                                 " supported yet.");
 
     SmallVector<llvm::Function *, 8> LocalCXXGlobalInits;
     llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(),
                          PrioritizedCXXGlobalInits.end());
for (SmallVectorImpl<GlobalInitData >::iterator
       AddGlobalCtor(Fn, Priority);
     }
     PrioritizedCXXGlobalInits.clear();
   }
 
   if (UseSinitAndSterm && CXXGlobalInits.empty())
     return;
 
-  // Create our global initialization function.
-  SmallString<128> FuncName;
-  bool IsExternalLinkage = false;
-  if (UseSinitAndSterm) {
-    llvm::Twine("__sinit80000000_clang_", GlobalUniqueModuleId)
-        .toVector(FuncName);
-    IsExternalLinkage = true;
-  } else {
-    // Include the filename in the symbol name. Including "sub_" matches gcc
-    // and makes sure these symbols appear lexicographically behind the symbols
-    // with priority emitted above.
-    llvm::Twine("_GLOBAL__sub_I_", getTransformedFileName(getModule()))
-        .toVector(FuncName);
-  }
-
   llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(
-      FTy, FuncName, FI, SourceLocation(), false /* TLS */,
-      IsExternalLinkage);
+      FTy, llvm::Twine("_GLOBAL__sub_I_", getTransformedFileName(getModule())),
+      FI);
 
   CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
   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.

 void CodeGenModule::EmitCXXGlobalCleanUpFunc() {
   if (CXXGlobalDtorsOrStermFinalizers.empty())
     return;
 
   llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
   const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
 
   // Create our global cleanup function.
-  llvm::Function *Fn = nullptr;
-  if (getCXXABI().useSinitAndSterm()) {
-    if (GlobalUniqueModuleId.empty()) {
-      GlobalUniqueModuleId = getUniqueModuleId(&getModule());
-      // FIXME: We need to figure out what to hash on or encode into the unique
-      // ID we need.
-      if (GlobalUniqueModuleId.compare("") == 0)
-        llvm::report_fatal_error(
-            "cannot produce a unique identifier for this module"
-            " based on strong external symbols");
-      GlobalUniqueModuleId = GlobalUniqueModuleId.substr(1);
-    }
-
-    Fn = CreateGlobalInitOrCleanUpFunction(
-        FTy, llvm::Twine("__sterm80000000_clang_", GlobalUniqueModuleId), FI,
-        SourceLocation(), false /* TLS */, true /* IsExternalLinkage */);
-  } else {
-    Fn = CreateGlobalInitOrCleanUpFunction(FTy, "_GLOBAL__D_a", FI);
-  }
+  llvm::Function *Fn =
+      CreateGlobalInitOrCleanUpFunction(FTy, "_GLOBAL__D_a", FI);
 
   CodeGenFunction(*this).GenerateCXXGlobalCleanUpFunc(
       Fn, CXXGlobalDtorsOrStermFinalizers);
   AddGlobalDtor(Fn);
   CXXGlobalDtorsOrStermFinalizers.clear();
 }
 
 /// Emit the code necessary to initialize the given global variable.

clang/lib/CodeGen/CodeGenModule.h

private:
   /// Store the list of global constructors and their respective priorities to
   /// be emitted when the translation unit is complete.
   CtorList GlobalCtors;
 
   /// Store the list of global destructors and their respective priorities to be
   /// emitted when the translation unit is complete.
   CtorList GlobalDtors;
 
-  /// A unique trailing identifier as a part of sinit/sterm function when
-  /// UseSinitAndSterm of CXXABI is set as true.
-  std::string GlobalUniqueModuleId;
-
   /// An ordered map of canonical GlobalDecls to their mangled names.
   llvm::MapVector<GlobalDecl, StringRef> MangledDeclNames;
   llvm::StringMap<GlobalDecl, llvm::BumpPtrAllocator> Manglings;
 
   // An ordered map of canonical GlobalDecls paired with the cpu-index for
   // cpu-specific name manglings.
   llvm::MapVector<std::pair<GlobalDecl, unsigned>, StringRef>
       CPUSpecificMangledDeclNames;
public:
   /// bitcast to the new variable.
   llvm::GlobalVariable *
   CreateOrReplaceCXXRuntimeVariable(StringRef Name, llvm::Type *Ty,
                                     llvm::GlobalValue::LinkageTypes Linkage,
                                     unsigned Alignment);
 
   llvm::Function *CreateGlobalInitOrCleanUpFunction(
       llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI,
-      SourceLocation Loc = SourceLocation(), bool TLS = false,
-      bool IsExternalLinkage = false);
+      SourceLocation Loc = SourceLocation(), bool TLS = false);
 
   /// Return the AST address space of the underlying global variable for D, as
   /// determined by its declaration. Normally this is the same as the address
   /// space of D's type, but in CUDA, address spaces are associated with
   /// declarations, not types. If D is nullptr, return the default address
   /// space for global variable.
   ///
   /// For languages without explicit address spaces, if D has default address
public:
   }
 
   /// Add an sterm finalizer to the C++ global cleanup function.
   void AddCXXStermFinalizerEntry(llvm::FunctionCallee DtorFn) {
     CXXGlobalDtorsOrStermFinalizers.emplace_back(DtorFn.getFunctionType(),
                                                  DtorFn.getCallee(), nullptr);
   }
 
+  /// Add an sterm finalizer to its own llvm.global_dtors entry.
+  void AddCXXStermFinalizerToGlobalDtor(llvm::Function *StermFinalizer,
+                                        int Priority) {
+    AddGlobalDtor(StermFinalizer, Priority);
+  }
+
   /// Create or return a runtime function declaration with the specified type
   /// and name. If \p AssumeConvergent is true, the call will have the
   /// convergent attribute added.
   llvm::FunctionCallee
   CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name,
                         llvm::AttributeList ExtraAttrs = llvm::AttributeList(),
                         bool Local = false, bool AssumeConvergent = false);
 

clang/lib/CodeGen/ItaniumCXXABI.cpp

void XLCXXABI::emitCXXStermFinalizer(const VarDecl &D, llvm::Function *dtorStub,
 
   // Make sure the call and the callee agree on calling convention.
   CI->setCallingConv(dtorStub->getCallingConv());
 
   CGF.EmitBlock(EndBlock);
 
   CGF.FinishFunction();
 
+  assert(!D.getAttr<InitPriorityAttr>() &&
+         "Prioritized sinit and sterm functions are not yet supported.");
+
+  if (isTemplateInstantiation(D.getTemplateSpecializationKind()) ||
+      getContext().GetGVALinkageForVariable(&D) == GVA_DiscardableODR)
+    // According to C++ [basic.start.init]p2, class template static data
+    // members (i.e., implicitly or explicitly instantiated specializations)
+    // have unordered initialization. As a consequence, we can put them into
+    // their own llvm.global_dtors entry.
+    CGM.AddCXXStermFinalizerToGlobalDtor(StermFinalizer, 65535);
+  else
     CGM.AddCXXStermFinalizerEntry(StermFinalizer);
 }

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

 // CHECK: destruct.call:
 // CHECK:   call void @__dtor_v(), !dbg ![[DBGVAR24]]
 // CHECK:   br label %destruct.end, !dbg ![[DBGVAR24]]
 
 // CHECK: destruct.end:
 // CHECK:   ret void, !dbg ![[DBGVAR24]]
 // CHECK: }
 
-// CHECK: define void @__sinit80000000_clang_c3236cbaa79f2bae3a15e6379a05f625() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR25:[0-9]+]] {
+// CHECK: define internal void @_GLOBAL__sub_I__() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR25:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @__cxx_global_var_init(), !dbg ![[DBGVAR26:[0-9]+]]
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define void @__sterm80000000_clang_c3236cbaa79f2bae3a15e6379a05f625() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR27:[0-9]+]] {
+// 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: }
 
 // CHECK: ![[DBGVAR16]] = distinct !DISubprogram(name: "__cxx_global_var_init", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR19]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR16]])
 // CHECK: ![[DBGVAR20]] = distinct !DISubprogram(name: "__dtor_v", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // 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: "__sinit80000000_clang_c3236cbaa79f2bae3a15e6379a05f625", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, type: !{{[0-9]+}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
+// 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: "__sterm80000000_clang_c3236cbaa79f2bae3a15e6379a05f625", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, type: !{{[0-9]+}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
+// 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

+// RUN: %clang_cc1 -triple powerpc-ibm-aix-xcoff -S -emit-llvm -x c++ \
+// RUN:     -std=c++2a < %s | \
+// RUN:   FileCheck --check-prefixes=CHECK,CHECK32 %s
+
+// RUN: %clang_cc1 -triple powerpc64-ibm-aix-xcoff -S -emit-llvm -x c++ \
+// RUN:     -std=c++2a < %s | \
+// RUN:   FileCheck --check-prefixes=CHECK,CHECK64 %s
+
+namespace test1 {
+struct Test1 {
+  Test1(int) {}
+  ~Test1() {}
+};
+
+Test1 t0 = 2;
+
+template <typename T>
+Test1 t1 = 2;
+
+inline Test1 t2 = 2;
+
+void foo() {
+  (void)&t1<int>;
+}
+} // namespace test1
+
+namespace test2 {
+template <typename = void>
+struct A {
+  A() {}
+  ~A() {}
+  static A instance;
+};
+
+template <typename T>
+A<T> A<T>::instance;
+template A<> A<>::instance;
+
+A<int> &bar() {
+  A<int> *a = new A<int>;
+  return *a;
+}
+template <>
+A<int> A<int>::instance = bar();
+} // namespace test2
+
+// CHECK: @llvm.global_ctors = appending global [4 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @__cxx_global_var_init.1, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @__cxx_global_var_init.2, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @__cxx_global_var_init.4, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I__, i8* null }]
+// CHECK: @llvm.global_dtors = appending global [4 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @__finalize__ZN5test12t2E, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @__finalize__ZN5test21AIvE8instanceE, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @__finalize__ZN5test12t1IiEE, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__D_a, i8* null }]
+
+// CHECK: define internal void @__cxx_global_var_init() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK32: call void @_ZN5test15Test1C1Ei(%"struct.test1::Test1"* @_ZN5test12t0E, i32 2)
+// CHECK64: call void @_ZN5test15Test1C1Ei(%"struct.test1::Test1"* @_ZN5test12t0E, i32 signext 2)
+// CHECK:   %0 = call i32 @atexit(void ()* @__dtor__ZN5test12t0E)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__dtor__ZN5test12t0E() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   call void @_ZN5test15Test1D1Ev(%"struct.test1::Test1"* @_ZN5test12t0E)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__finalize__ZN5test12t0E() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = call i32 @unatexit(void ()* @__dtor__ZN5test12t0E)
+// CHECK:   %needs_destruct = icmp eq i32 %0, 0
+// CHECK:   br i1 %needs_destruct, label %destruct.call, label %destruct.end
+
+// CHECK: destruct.call:
+// CHECK:   call void @__dtor__ZN5test12t0E()
+// CHECK:   br label %destruct.end
+
+// CHECK: destruct.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__cxx_global_var_init.1() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = load atomic i8, i8* bitcast (i64* @_ZGVN5test12t2E to i8*) acquire
+// CHECK:   %guard.uninitialized = icmp eq i8 %0, 0
+// CHECK:   br i1 %guard.uninitialized, label %init.check, label %init.end
+
+// CHECK: init.check:
+// CHECK:   %1 = call i32 @__cxa_guard_acquire(i64* @_ZGVN5test12t2E)
+// CHECK:   %tobool = icmp ne i32 %1, 0
+// CHECK:   br i1 %tobool, label %init, label %init.end
+
+// CHECK: init:
+// CHECK32: call void @_ZN5test15Test1C1Ei(%"struct.test1::Test1"* @_ZN5test12t2E, i32 2)
+// CHECK64: call void @_ZN5test15Test1C1Ei(%"struct.test1::Test1"* @_ZN5test12t2E, i32 signext 2)
+// CHECK:   %2 = call i32 @atexit(void ()* @__dtor__ZN5test12t2E)
+// CHECK:   call void @__cxa_guard_release(i64* @_ZGVN5test12t2E)
+// CHECK:   br label %init.end
+
+// CHECK: init.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__dtor__ZN5test12t2E() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   call void @_ZN5test15Test1D1Ev(%"struct.test1::Test1"* @_ZN5test12t2E)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__finalize__ZN5test12t2E() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = call i32 @unatexit(void ()* @__dtor__ZN5test12t2E)
+// CHECK:   %needs_destruct = icmp eq i32 %0, 0
+// CHECK:   br i1 %needs_destruct, label %destruct.call, label %destruct.end
+
+// CHECK: destruct.call:
+// CHECK:   call void @__dtor__ZN5test12t2E()
+// CHECK:   br label %destruct.end
+
+// CHECK: destruct.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__cxx_global_var_init.2() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = load i8, i8* bitcast (i64* @_ZGVN5test21AIvE8instanceE to i8*)
+// CHECK:   %guard.uninitialized = icmp eq i8 %0, 0
+// CHECK:   br i1 %guard.uninitialized, label %init.check, label %init.end
+
+// CHECK: init.check:
+// CHECK:   call void @_ZN5test21AIvEC1Ev(%"struct.test2::A"* @_ZN5test21AIvE8instanceE)
+// CHECK:   %1 = call i32 @atexit(void ()* @__dtor__ZN5test21AIvE8instanceE)
+// CHECK:   store i64 1, i64* @_ZGVN5test21AIvE8instanceE
+// CHECK:   br label %init.end
+
+// CHECK: init.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__dtor__ZN5test21AIvE8instanceE() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   call void @_ZN5test21AIvED1Ev(%"struct.test2::A"* @_ZN5test21AIvE8instanceE)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__finalize__ZN5test21AIvE8instanceE() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = call i32 @unatexit(void ()* @__dtor__ZN5test21AIvE8instanceE)
+// CHECK:   %needs_destruct = icmp eq i32 %0, 0
+// CHECK:   br i1 %needs_destruct, label %destruct.call, label %destruct.end
+
+// CHECK: destruct.call:
+// CHECK:   call void @__dtor__ZN5test21AIvE8instanceE()
+// CHECK:   br label %destruct.end
+
+// CHECK: destruct.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__cxx_global_var_init.3() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %call = call nonnull align 1 dereferenceable(1) %"struct.test2::A.0"* @_ZN5test23barEv()
+// CHECK:   %0 = call i32 @atexit(void ()* @__dtor__ZN5test21AIiE8instanceE)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__dtor__ZN5test21AIiE8instanceE() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   call void @_ZN5test21AIiED1Ev(%"struct.test2::A.0"* @_ZN5test21AIiE8instanceE)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__finalize__ZN5test21AIiE8instanceE() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = call i32 @unatexit(void ()* @__dtor__ZN5test21AIiE8instanceE)
+// CHECK:   %needs_destruct = icmp eq i32 %0, 0
+// CHECK:   br i1 %needs_destruct, label %destruct.call, label %destruct.end
+
+// CHECK: destruct.call:
+// CHECK:   call void @__dtor__ZN5test21AIiE8instanceE()
+// CHECK:   br label %destruct.end
+
+// CHECK: destruct.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__cxx_global_var_init.4() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = load i8, i8* bitcast (i64* @_ZGVN5test12t1IiEE to i8*)
+// CHECK:   %guard.uninitialized = icmp eq i8 %0, 0
+// CHECK:   br i1 %guard.uninitialized, label %init.check, label %init.end
+
+// CHECK: init.check:
+// CHECK32: call void @_ZN5test15Test1C1Ei(%"struct.test1::Test1"* @_ZN5test12t1IiEE, i32 2)
+// CHECK64: call void @_ZN5test15Test1C1Ei(%"struct.test1::Test1"* @_ZN5test12t1IiEE, i32 signext 2)
+// CHECK:   %1 = call i32 @atexit(void ()* @__dtor__ZN5test12t1IiEE)
+// CHECK:   store i64 1, i64* @_ZGVN5test12t1IiEE
+// CHECK:   br label %init.end
+
+// CHECK: init.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__dtor__ZN5test12t1IiEE() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   call void @_ZN5test15Test1D1Ev(%"struct.test1::Test1"* @_ZN5test12t1IiEE)
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @__finalize__ZN5test12t1IiEE() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   %0 = call i32 @unatexit(void ()* @__dtor__ZN5test12t1IiEE)
+// CHECK:   %needs_destruct = icmp eq i32 %0, 0
+// CHECK:   br i1 %needs_destruct, label %destruct.call, label %destruct.end
+
+// CHECK: destruct.call:
+// CHECK:   call void @__dtor__ZN5test12t1IiEE()
+// CHECK:   br label %destruct.end
+
+// CHECK: destruct.end:
+// CHECK:   ret void
+// CHECK: }
+
+// CHECK: define internal void @_GLOBAL__sub_I__() [[ATTR:#[0-9]+]] {
+// CHECK: entry:
+// CHECK:   call void @__cxx_global_var_init()
+// CHECK:   call void @__cxx_global_var_init.3()
+// CHECK:   ret void
+// CHECK: }
+
+// 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: }

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

struct Test4 {
     ~Test4();
   };
 
   void f() {
     static Test4 staticLocal;
   }
 } // namespace test4
 
-// CHECK: @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @__sinit80000000_clang_1145401da454a7baad10bfe313c46638, i8* null }]
-// CHECK: @llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @__sterm80000000_clang_1145401da454a7baad10bfe313c46638, i8* null }]
+// CHECK: @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I__, i8* null }]
+// CHECK: @llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__D_a, i8* null }]
 
 // CHECK: define internal void @__cxx_global_var_init() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN5test15Test1C1Ev(%"struct.test1::Test1"* @_ZN5test12t1E)
 // CHECK:   %0 = call i32 @atexit(void ()* @__dtor__ZN5test12t1E)
 // CHECK:   ret void
 // CHECK: }
 

 // CHECK: destruct.call:
 // CHECK:   call void @__dtor__ZZN5test41fEvE11staticLocal()
 // CHECK:   br label %destruct.end
 
 // CHECK: destruct.end:
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define void @__sinit80000000_clang_1145401da454a7baad10bfe313c46638() [[ATTR:#[0-9]+]] {
+// CHECK: define internal void @_GLOBAL__sub_I__() [[ATTR:#[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @__cxx_global_var_init()
 // CHECK:   call void @__cxx_global_var_init.1()
 // CHECK:   call void @__cxx_global_var_init.2()
 // CHECK:   call void @__cxx_global_var_init.3()
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: define void @__sterm80000000_clang_1145401da454a7baad10bfe313c46638() [[ATTR:#[0-9]+]] {
+// CHECK: define internal void @_GLOBAL__D_a() [[ATTR:#[0-9]+]] {
 // 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: }

clang/unittests/CodeGen/IncrementalProcessingTest.cpp

TEST(IncrementalProcessing, EmitCXXGlobalInitFunc) {
     ASSERT_TRUE(M[1]->getFunction("funcForProg1"));
 
     M[2] = IncrementalParseAST(compiler, P, *CG, TestProgram2);
     ASSERT_TRUE(M[2]);
     ASSERT_TRUE(M[2]->getFunction("funcForProg2"));
     // First code should not end up in second module:
     ASSERT_FALSE(M[2]->getFunction("funcForProg1"));
 
-    // TODO: Remove this after the static initialization frontend implementation
-    // is recovered on AIX.
-    if (compiler.getTarget().getTriple().isOSAIX())
-      return;
-
     // Make sure global inits exist and are unique:
     const Function* GlobalInit1 = getGlobalInit(*M[1]);
     ASSERT_TRUE(GlobalInit1);
 
     const Function* GlobalInit2 = getGlobalInit(*M[2]);
     ASSERT_TRUE(GlobalInit2);
 
     ASSERT_FALSE(GlobalInit1->getName() == GlobalInit2->getName());
 
 }
 
 } // end anonymous namespace

llvm/include/llvm/CodeGen/AsmPrinter.h

public:
 
   /// Emit the specified global variable to the .s file.
   virtual void emitGlobalVariable(const GlobalVariable *GV);
 
   /// Check to see if the specified global is a special global used by LLVM. If
   /// so, emit it and return true, otherwise do nothing and return false.
   bool emitSpecialLLVMGlobal(const GlobalVariable *GV);
 
+  /// `llvm.global_ctors` and `llvm.global_dtors` are arrays of Structor
+  /// structs.
+  ///
+  /// Priority - init priority
+  /// Func - global initialization or global clean-up function
+  /// ComdatKey - associated data
+  struct Structor {
+    int Priority = 0;
+    Constant *Func = nullptr;
+    GlobalValue *ComdatKey = nullptr;
+
+    Structor() = default;
+  };
+
+  /// This method gathers an array of Structors and then sorts them out by
+  /// Priority.
+  /// @param List The initializer of `llvm.global_ctors` or `llvm.global_dtors`
+  /// array.
+  /// @param[out] Structors Sorted Structor structs by Priority.
+  void preprocessXXStructorList(const DataLayout &DL, const Constant *List,
+                                SmallVector<Structor, 8> &Structors);
+
+  /// This method emits `llvm.global_ctors` or `llvm.global_dtors` list.
+  virtual void emitXXStructorList(const DataLayout &DL, const Constant *List,
+                                  bool IsCtor);
+
   /// Emit an alignment directive to the specified power of two boundary. If a
   /// global value is specified, and if that global has an explicit alignment
   /// requested, it will override the alignment request if required for
   /// correctness.
   void emitAlignment(Align Alignment, const GlobalObject *GV = nullptr) const;
 
   /// Lower the specified LLVM Constant to an MCExpr.
   virtual const MCExpr *lowerConstant(const Constant *CV);
public:
 
   virtual void emitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
 
   /// Targets can override this to change how global constants that are part of
   /// a C++ static/global constructor list are emitted.
   virtual void emitXXStructor(const DataLayout &DL, const Constant *CV) {
     emitGlobalConstant(DL, CV);
   }
 
   /// Return true if the basic block has exactly one predecessor and the control
   /// transfer mechanism between the predecessor and this block is a
   /// fall-through.
   virtual bool
   isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
 
   /// Targets can override this to customize the output of IMPLICIT_DEF
   /// instructions in verbose mode.
   virtual void emitImplicitDef(const MachineInstr *MI) const;
 
   /// Emit N NOP instructions.
   void emitNops(unsigned N);
 
   //===------------------------------------------------------------------===//
   // Symbol Lowering Routines.
   //===------------------------------------------------------------------===//
 
   MCSymbol *createTempSymbol(const Twine &Name) const;
 
   /// Return the MCSymbol for a private symbol with global value name as its
   /// base, with the specified suffix.
private:
 
   void emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
                           const MachineBasicBlock *MBB, unsigned uid) const;
   void emitLLVMUsedList(const ConstantArray *InitList);
   /// Emit llvm.ident metadata in an '.ident' directive.
   void emitModuleIdents(Module &M);
   /// Emit bytes for llvm.commandline metadata.
   void emitModuleCommandLines(Module &M);
-  void emitXXStructorList(const DataLayout &DL, const Constant *List,
-                          bool isCtor);
 
   GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy &S);
   /// Emit GlobalAlias or GlobalIFunc.
   void emitGlobalIndirectSymbol(Module &M, const GlobalIndirectSymbol &GIS);
 };
 
 } // end namespace llvm
 
 #endif // LLVM_CODEGEN_ASMPRINTER_H

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

void AsmPrinter::emitLLVMUsedList(const ConstantArray *InitList) {
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
     const GlobalValue *GV =
       dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
     if (GV)
       OutStreamer->emitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
   }
 }
 
-namespace {
-
-struct Structor {
-  int Priority = 0;
-  Constant *Func = nullptr;
-  GlobalValue *ComdatKey = nullptr;
-
-  Structor() = default;
-};
-
-} // end anonymous namespace
-
-/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
-/// priority.
-void AsmPrinter::emitXXStructorList(const DataLayout &DL, const Constant *List,
-                                    bool isCtor) {
-  // Should be an array of '{ i32, void ()*, i8* }' structs.  The first value is the
-  // init priority.
-  if (!isa<ConstantArray>(List)) return;
+void AsmPrinter::preprocessXXStructorList(const DataLayout &DL,
+                                          const Constant *List,
+                                          SmallVector<Structor, 8> &Structors) {
+  // Should be an array of '{ i32, void ()*, i8* }' structs.  The first value is
+  // the init priority.
+  if (!isa<ConstantArray>(List))
+    return;
 
   // Gather the structors in a form that's convenient for sorting by priority.
-  SmallVector<Structor, 8> Structors;
   for (Value *O : cast<ConstantArray>(List)->operands()) {
     auto *CS = cast<ConstantStruct>(O);
     if (CS->getOperand(1)->isNullValue())
-      break;  // Found a null terminator, skip the rest.
+      break; // Found a null terminator, skip the rest.
     ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
-    if (!Priority) continue; // Malformed.
+    if (!Priority)
+      continue; // Malformed.
     Structors.push_back(Structor());
     Structor &S = Structors.back();
     S.Priority = Priority->getLimitedValue(65535);
     S.Func = CS->getOperand(1);
-    if (!CS->getOperand(2)->isNullValue())
+    if (!CS->getOperand(2)->isNullValue()) {
+      if (TM.getTargetTriple().isOSAIX())
+        llvm::report_fatal_error(
+            "associated data of XXStructor list is not yet supported on AIX");
       S.ComdatKey =
           dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
     }
+  }
 
   // Emit the function pointers in the target-specific order
   llvm::stable_sort(Structors, [](const Structor &L, const Structor &R) {
     return L.Priority < R.Priority;
   });
+}
+
+/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
+/// priority.
+void AsmPrinter::emitXXStructorList(const DataLayout &DL, const Constant *List,
+                                    bool IsCtor) {
+  SmallVector<Structor, 8> Structors;
+  preprocessXXStructorList(DL, List, Structors);
+  if (Structors.empty())
+    return;
+
   const Align Align = DL.getPointerPrefAlignment();
   for (Structor &S : Structors) {
     const TargetLoweringObjectFile &Obj = getObjFileLowering();
     const MCSymbol *KeySym = nullptr;
     if (GlobalValue *GV = S.ComdatKey) {
       if (GV->isDeclarationForLinker())
         // If the associated variable is not defined in this module
         // (it might be available_externally, or have been an
         // available_externally definition that was dropped by the
         // EliminateAvailableExternally pass), some other TU
         // will provide its dynamic initializer.
         continue;
 
       KeySym = getSymbol(GV);
     }
+
     MCSection *OutputSection =
-        (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
+        (IsCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
                 : Obj.getStaticDtorSection(S.Priority, KeySym));
     OutStreamer->SwitchSection(OutputSection);
     if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
       emitAlignment(Align);
     emitXXStructor(DL, S.Func);
   }
 }
 
 void AsmPrinter::emitModuleIdents(Module &M) {

llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

void TargetLoweringObjectFileXCOFF::Initialize(MCContext &Ctx,
                                                const TargetMachine &TgtM) {
   TargetLoweringObjectFile::Initialize(Ctx, TgtM);
   TTypeEncoding = 0;
   PersonalityEncoding = 0;
   LSDAEncoding = 0;
 }
 
 MCSection *TargetLoweringObjectFileXCOFF::getStaticCtorSection(
-    unsigned Priority, const MCSymbol *KeySym) const {
-  report_fatal_error("XCOFF ctor section not yet implemented.");
+  unsigned Priority, const MCSymbol *KeySym) const {
+  report_fatal_error("no static constructor section on AIX");
 }
 
 MCSection *TargetLoweringObjectFileXCOFF::getStaticDtorSection(
-    unsigned Priority, const MCSymbol *KeySym) const {
-  report_fatal_error("XCOFF dtor section not yet implemented.");
+  unsigned Priority, const MCSymbol *KeySym) const {
+  report_fatal_error("no static destructor section on AIX");
 }
 
 const MCExpr *TargetLoweringObjectFileXCOFF::lowerRelativeReference(
     const GlobalValue *LHS, const GlobalValue *RHS,
     const TargetMachine &TM) const {
   report_fatal_error("XCOFF not yet implemented.");
 }
 

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

 #include "llvm/MC/SectionKind.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CodeGen.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
 #include <memory>
 #include <new>
 
 using namespace llvm;
 

 };
 
 class PPCAIXAsmPrinter : public PPCAsmPrinter {
 private:
   /// Symbols lowered from ExternalSymbolSDNodes, we will need to emit extern
   /// linkage for them in AIX.
   SmallPtrSet<MCSymbol *, 8> ExtSymSDNodeSymbols;
 
+  /// A unique trailing identifier as a part of sinit/sterm functions.
+  std::string GlobalUniqueModuleId;
+
   static void ValidateGV(const GlobalVariable *GV);
   // Record a list of GlobalAlias associated with a GlobalObject.
   // This is used for AIX's extra-label-at-definition aliasing strategy.
   DenseMap<const GlobalObject *, SmallVector<const GlobalAlias *, 1>>
       GOAliasMap;
 
 public:
   PPCAIXAsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
       : PPCAsmPrinter(TM, std::move(Streamer)) {
     if (MAI->isLittleEndian())
       report_fatal_error(
           "cannot create AIX PPC Assembly Printer for a little-endian target");
   }
 
   StringRef getPassName() const override { return "AIX PPC Assembly Printer"; }
 
   bool doInitialization(Module &M) override;
 
+  void emitXXStructorList(const DataLayout &DL, const Constant *List,
+                          bool IsCtor) override;
+
   void SetupMachineFunction(MachineFunction &MF) override;
 
   void emitGlobalVariable(const GlobalVariable *GV) override;
 
   void emitFunctionDescriptor() override;
 
   void emitFunctionEntryLabel() override;
 
void PPCAIXAsmPrinter::ValidateGV(const GlobalVariable *GV) {
 
   if (GV->hasComdat())
     report_fatal_error("COMDAT not yet supported by AIX.");
 }
 
 static bool isSpecialLLVMGlobalArrayToSkip(const GlobalVariable *GV) {
   return GV->hasAppendingLinkage() &&
          StringSwitch<bool>(GV->getName())
-             // TODO: Update the handling of global arrays for static init when
-             // we support the ".ref" directive.
-             // Otherwise, we can skip these arrays, because the AIX linker
-             // collects static init functions simply based on their name.
-             .Cases("llvm.global_ctors", "llvm.global_dtors", true)
              // TODO: Linker could still eliminate the GV if we just skip
              // handling llvm.used array. Skipping them for now until we or the
              // AIX OS team come up with a good solution.
              .Case("llvm.used", true)
              // It's correct to just skip llvm.compiler.used array here.
              .Case("llvm.compiler.used", true)
              .Default(false);
 }
 
+static bool isSpecialLLVMGlobalArrayForStaticInit(const GlobalVariable *GV) {
+  return StringSwitch<bool>(GV->getName())
+      .Cases("llvm.global_ctors", "llvm.global_dtors", true)
+      .Default(false);
+}
+
 void PPCAIXAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
-  if (isSpecialLLVMGlobalArrayToSkip(GV))
+  // Special LLVM global arrays have been handled at the initialization.
+  if (isSpecialLLVMGlobalArrayToSkip(GV) || isSpecialLLVMGlobalArrayForStaticInit(GV))
     return;
 
   assert(!GV->getName().startswith("llvm.") &&
          "Unhandled intrinsic global variable.");
   ValidateGV(GV);
 
   // Create the symbol, set its storage class.
   MCSymbolXCOFF *GVSym = cast<MCSymbolXCOFF>(getSymbol(GV));
bool PPCAIXAsmPrinter::doInitialization(Module &M) {
   };
 
   // We need to know, up front, the alignment of csects for the assembly path,
   // because once a .csect directive gets emitted, we could not change the
   // alignment value on it.
   for (const auto &G : M.globals()) {
     if (isSpecialLLVMGlobalArrayToSkip(&G))
       continue;
+
+    if (isSpecialLLVMGlobalArrayForStaticInit(&G)) {
+      // Generate a unique module id which is a part of sinit and sterm function
+      // names.
+      if (GlobalUniqueModuleId.empty()) {
+        GlobalUniqueModuleId = getUniqueModuleId(&M);
+        // FIXME: We need to figure out what to hash on or encode into the
+        // unique ID we need.
+        if (GlobalUniqueModuleId.compare("") == 0)
+          llvm::report_fatal_error(
+              "cannot produce a unique identifier for this module based on"
+              " strong external symbols");
+        GlobalUniqueModuleId = GlobalUniqueModuleId.substr(1);
+      }
+
+      emitSpecialLLVMGlobal(&G);
+      continue;
+    }
+
     setCsectAlignment(&G);
   }
 
   for (const auto &F : M)
     setCsectAlignment(&F);
 
   // Construct an aliasing list for each GlobalObject.
   for (const auto &Alias : M.aliases()) {
     const GlobalObject *Base = Alias.getBaseObject();
     if (!Base)
       report_fatal_error(
           "alias without a base object is not yet supported on AIX");
     GOAliasMap[Base].push_back(&Alias);
   }

 
 bool PPCAIXAsmPrinter::doFinalization(Module &M) {
   bool Ret = PPCAsmPrinter::doFinalization(M);
   for (MCSymbol *Sym : ExtSymSDNodeSymbols)
     OutStreamer->emitSymbolAttribute(Sym, MCSA_Extern);
   return Ret;
 }
 
+void PPCAIXAsmPrinter::emitXXStructorList(const DataLayout &DL,
+                                          const Constant *List, bool IsCtor) {
+  SmallVector<Structor, 8> Structors;
+  preprocessXXStructorList(DL, List, Structors);
+  if (Structors.empty())
+    return;
+
+  unsigned Index = 0;
+  for (Structor &S : Structors) {
+    if (S.Priority != 65535)
+      report_fatal_error(
+          "prioritized sinit and sterm functions are not yet supported on AIX");
+
+    llvm::GlobalAlias::create(
+        GlobalValue::ExternalLinkage,
+        (IsCtor ? llvm::Twine("__sinit") : llvm::Twine("__sterm")) +
+            llvm::Twine("80000000_clang_", GlobalUniqueModuleId) +
+            llvm::Twine("_", llvm::utostr(Index++)),
+        cast<Function>(S.Func));
+  }
+}
+
 /// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
 /// for a MachineFunction to the given output stream, in a format that the
 /// Darwin assembler can deal with.
 ///
 static AsmPrinter *
 createPPCAsmPrinterPass(TargetMachine &tm,
                         std::unique_ptr<MCStreamer> &&Streamer) {
   if (tm.getTargetTriple().isOSAIX())

llvm/test/CodeGen/PowerPC/aix-static-init-default-priority.ll

+; RUN: llc -mtriple powerpc-ibm-aix-xcoff < %s | FileCheck %s
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff < %s | FileCheck %s
+
[e-mail]_ctors = appending global [2 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @init1, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @init2, i8* null }]
[e-mail]_dtors = appending global [2 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @destruct1, i8* null }, { i32, void ()*, i8* } { i32 65535, void ()* @destruct2, i8* null }]
+
+define i32 @extFunc() {
+entry:
+  ret i32 3
+}
+
+define internal void @init1() {
+  ret void
+}
+
+define internal void @destruct1() {
+  ret void
+}
+
+define internal void @init2() {
+  ret void
+}
+
+define internal void @destruct2() {
+  ret void
+}
+
+; CHECK:       .lglobl  init1[DS]
+; CHECK:       .lglobl  .init1
+; CHECK:       .csect init1[DS]
+; CHECK: __sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0: # @init1
+; CHECK: .init1:
+; CHECK: .__sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0:
+; CHECK:       .lglobl  destruct1[DS]
+; CHECK:       .lglobl  .destruct1
+; CHECK:       .csect destruct1[DS]
+; CHECK: __sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0: # @destruct1
+; CHECK: .destruct1:
+; CHECK: .__sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0:
+; CHECK:       .lglobl  init2[DS]
+; CHECK:       .lglobl  .init2
+; CHECK:       .csect init2[DS]
+; CHECK: __sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1: # @init2
+; CHECK: .init2:
+; CHECK: .__sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1:
+; CHECK:       .lglobl  destruct2[DS]
+; CHECK:       .lglobl  .destruct2
+; CHECK:       .csect destruct2[DS]
+; CHECK: __sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1: # @destruct2
+; CHECK: .destruct2:
+; CHECK: .__sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1:
+
+; CHECK:  .globl  __sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0
+; CHECK:  .globl  .__sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0
+; CHECK:  .globl  __sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1
+; CHECK:  .globl  .__sinit80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1
+; CHECK:  .globl  __sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0
+; CHECK:  .globl  .__sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_0
+; CHECK:  .globl  __sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1
+; CHECK:  .globl  .__sterm80000000_clang_ac404299654d2af7eae71e75c17f7c9b_1

llvm/test/CodeGen/PowerPC/aix-static-init-key-object.ll

+; RUN: not --crash llc -mtriple powerpc-ibm-aix-xcoff < %s 2>&1 | FileCheck %s
+; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff < %s 2>&1 | FileCheck %s
+
+@v = global i8 0
+
[e-mail]_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @foo, i8* @v}]
+
+define void @foo() {
+  ret void
+}
+
+; CHECK: LLVM ERROR: associated data of XXStructor list is not yet supported on AIX

llvm/test/CodeGen/PowerPC/aix-static-init-no-unique-module-id.ll

+; RUN: not --crash llc -mtriple powerpc-ibm-aix-xcoff %s 2>&1 | FileCheck %s
+; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff %s 2>&1 | FileCheck %s
+
[e-mail]_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @foo, i8* null }]
+
+define internal void @foo() {
+  ret void
+}
+
+; CHECK: LLVM ERROR: cannot produce a unique identifier for this module based on strong external symbols

llvm/test/CodeGen/PowerPC/aix-static-init-non-default-priority.ll

+; RUN: not --crash llc -mtriple powerpc-ibm-aix-xcoff < %s 2>&1 | FileCheck %s
+; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff < %s 2>&1 | FileCheck %s
+
[e-mail]_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 655, void ()* @foo, i8* null }]
+
+define void @foo() {
+  ret void
+}
+
+; CHECK: LLVM ERROR: prioritized sinit and sterm functions are not yet supported