Revert "[llvm][DebugInfo] DWARFv5: static data members declarations are DW_TAG_variable (#72234)"

This reverts commit 9a9933f.

The OCaml bindings were using `LLVMDIBuilderCreateStaticMemberType`,
causing the API change in `9a9933fae23249fbf6cf5b3c090e630f578b7f98`
to break buildbots that built the bindings. Revert until we figure out
whether to fixup the bindings or just not change the C-API

Author: Michael137

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -1681,8 +1681,7 @@ CGDebugInfo::CreateRecordStaticField(const VarDecl *Var, llvm::DIType *RecordTy,
   llvm::DINode::DIFlags Flags = getAccessFlag(Var->getAccess(), RD);
   auto Align = getDeclAlignIfRequired(Var, CGM.getContext());
   llvm::DIDerivedType *GV = DBuilder.createStaticMemberType(
-      RecordTy, VName, VUnit, LineNumber, VTy, Flags, /* Val */ nullptr,
-      llvm::dwarf::DW_TAG_member, Align);
+      RecordTy, VName, VUnit, LineNumber, VTy, Flags, /* Val */ nullptr, Align);
   StaticDataMemberCache[Var->getCanonicalDecl()].reset(GV);
   StaticDataMemberDefinitionsToEmit.push_back(Var->getCanonicalDecl());
   return GV;

llvm/include/llvm-c/DebugInfo.h

@@ -785,14 +785,14 @@ LLVMMetadataRef LLVMDIBuilderCreateMemberType(
  * \param Type         Type of the static member.
  * \param Flags        Flags to encode member attribute, e.g. private.
  * \param ConstantVal  Const initializer of the member.
- * \param Tag          DWARF tag of the static member.
  * \param AlignInBits  Member alignment.
  */
-LLVMMetadataRef LLVMDIBuilderCreateStaticMemberType(
+LLVMMetadataRef
+LLVMDIBuilderCreateStaticMemberType(
     LLVMDIBuilderRef Builder, LLVMMetadataRef Scope, const char *Name,
     size_t NameLen, LLVMMetadataRef File, unsigned LineNumber,
     LLVMMetadataRef Type, LLVMDIFlags Flags, LLVMValueRef ConstantVal,
-    unsigned Tag, uint32_t AlignInBits);
+    uint32_t AlignInBits);
 
 /**
  * Create debugging information entry for a pointer to member.

llvm/include/llvm/IR/DIBuilder.h

@@ -376,12 +376,11 @@ namespace llvm {
     /// \param Ty         Type of the static member.
     /// \param Flags      Flags to encode member attribute, e.g. private.
     /// \param Val        Const initializer of the member.
-    /// \param Tag        DWARF tag of the static member.
     /// \param AlignInBits  Member alignment.
     DIDerivedType *createStaticMemberType(DIScope *Scope, StringRef Name,
                                           DIFile *File, unsigned LineNo,
                                           DIType *Ty, DINode::DIFlags Flags,
-                                          Constant *Val, unsigned Tag,
+                                          Constant *Val,
                                           uint32_t AlignInBits = 0);
 
     /// Create debugging information entry for Objective-C

llvm/lib/IR/DIBuilder.cpp

@@ -405,11 +405,12 @@ DIDerivedType *
 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
                                   unsigned LineNumber, DIType *Ty,
                                   DINode::DIFlags Flags, llvm::Constant *Val,
-                                  unsigned Tag, uint32_t AlignInBits) {
+                                  uint32_t AlignInBits) {
   Flags |= DINode::FlagStaticMember;
-  return DIDerivedType::get(VMContext, Tag, Name, File, LineNumber,
-                            getNonCompileUnitScope(Scope), Ty, 0, AlignInBits,
-                            0, std::nullopt, Flags, getConstantOrNull(Val));
+  return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
+                            LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
+                            AlignInBits, 0, std::nullopt, Flags,
+                            getConstantOrNull(Val));
 }
 
 DIDerivedType *

llvm/lib/IR/DebugInfo.cpp

@@ -1315,15 +1315,17 @@ LLVMDIBuilderCreateUnspecifiedType(LLVMDIBuilderRef Builder, const char *Name,
   return wrap(unwrap(Builder)->createUnspecifiedType({Name, NameLen}));
 }
 
-LLVMMetadataRef LLVMDIBuilderCreateStaticMemberType(
+LLVMMetadataRef
+LLVMDIBuilderCreateStaticMemberType(
     LLVMDIBuilderRef Builder, LLVMMetadataRef Scope, const char *Name,
     size_t NameLen, LLVMMetadataRef File, unsigned LineNumber,
     LLVMMetadataRef Type, LLVMDIFlags Flags, LLVMValueRef ConstantVal,
-    unsigned Tag, uint32_t AlignInBits) {
+    uint32_t AlignInBits) {
   return wrap(unwrap(Builder)->createStaticMemberType(
-      unwrapDI<DIScope>(Scope), {Name, NameLen}, unwrapDI<DIFile>(File),
-      LineNumber, unwrapDI<DIType>(Type), map_from_llvmDIFlags(Flags),
-      unwrap<Constant>(ConstantVal), Tag, AlignInBits));
+                  unwrapDI<DIScope>(Scope), {Name, NameLen},
+                  unwrapDI<DIFile>(File), LineNumber, unwrapDI<DIType>(Type),
+                  map_from_llvmDIFlags(Flags), unwrap<Constant>(ConstantVal),
+                  AlignInBits));
 }
 
 LLVMMetadataRef

llvm/lib/IR/DebugInfoMetadata.cpp

@@ -711,9 +711,7 @@ Constant *DIDerivedType::getStorageOffsetInBits() const {
 }
 
 Constant *DIDerivedType::getConstant() const {
-  assert((getTag() == dwarf::DW_TAG_member ||
-          getTag() == dwarf::DW_TAG_variable) &&
-         isStaticMember());
+  assert(getTag() == dwarf::DW_TAG_member && isStaticMember());
   if (auto *C = cast_or_null<ConstantAsMetadata>(getExtraData()))
     return C->getValue();
   return nullptr;

llvm/lib/IR/Verifier.cpp

@@ -1172,7 +1172,6 @@ void Verifier::visitDIDerivedType(const DIDerivedType &N) {
               N.getTag() == dwarf::DW_TAG_restrict_type ||
               N.getTag() == dwarf::DW_TAG_atomic_type ||
               N.getTag() == dwarf::DW_TAG_member ||
-              (N.getTag() == dwarf::DW_TAG_variable && N.isStaticMember()) ||
               N.getTag() == dwarf::DW_TAG_inheritance ||
               N.getTag() == dwarf::DW_TAG_friend ||
               N.getTag() == dwarf::DW_TAG_set_type,