Remove dead code from DIBuilder

[jyoti.allur]

Summary

DIBuilder: Delete dead code, NFC

Remove both versions of DIBuilder::createGlobalVariable() as they are not used. Renaming 'DIBuilder::createStaticVariable()' to 'DIBuilder::createGlobalVariable()' .

[friss]

I would have split the removal and the renaming into 2 patches, but that's not a big deal. I don't think I have the authority to approve that, but it LGTM. Let's add some reviewers with more knowledge of the history of that code, they might have something to say.

[dblaikie]

Sure, looks good to me (As Frederik mentioned - could be nice to be two commits, but it's nothing too interesting). Please commit.

[jyoti.allur]

Closed by commit rL218593 (authored by @jyoti.allur).

llvm/include/llvm/IR/DIBuilder.h

     /// implicitly uniques the values returned.
     DISubrange getOrCreateSubrange(int64_t Lo, int64_t Count);
 
-    /// createGlobalVariable - Create a new descriptor for the specified global.
-    /// @param Name        Name of the variable.
-    /// @param File        File where this variable is defined.
-    /// @param LineNo      Line number.
-    /// @param Ty          Variable Type.
-    /// @param isLocalToUnit Boolean flag indicate whether this variable is
-    ///                      externally visible or not.
-    /// @param Val         llvm::Value of the variable.
-    DIGlobalVariable
-    createGlobalVariable(StringRef Name, DIFile File, unsigned LineNo,
-                         DITypeRef Ty, bool isLocalToUnit, llvm::Value *Val);
 
-    /// \brief Create a new descriptor for the specified global.
-    /// @param Name        Name of the variable.
-    /// @param LinkageName Mangled variable name.
-    /// @param File        File where this variable is defined.
-    /// @param LineNo      Line number.
-    /// @param Ty          Variable Type.
-    /// @param isLocalToUnit Boolean flag indicate whether this variable is
-    ///                      externally visible or not.
-    /// @param Val         llvm::Value of the variable.
-    DIGlobalVariable
-    createGlobalVariable(StringRef Name, StringRef LinkageName, DIFile File,
-                         unsigned LineNo, DITypeRef Ty, bool isLocalToUnit,
-                         llvm::Value *Val);
-
-    /// createStaticVariable - Create a new descriptor for the specified
+    /// createGlobalVariable - Create a new descriptor for the specified
     /// variable.
     /// @param Context     Variable scope.
     /// @param Name        Name of the variable.

     /// @param Val         llvm::Value of the variable.
     /// @param Decl        Reference to the corresponding declaration.
     DIGlobalVariable
-    createStaticVariable(DIDescriptor Context, StringRef Name,
+    createGlobalVariable(DIDescriptor Context, StringRef Name,
                          StringRef LinkageName, DIFile File, unsigned LineNo,
                          DITypeRef Ty, bool isLocalToUnit, llvm::Value *Val,
                          MDNode *Decl = nullptr);
 
-    /// createTempStaticVariableFwdDecl - Identical to createStaticVariable
+    /// createTempGlobalVariableFwdDecl - Identical to createGlobalVariable
     /// except that the resulting DbgNode is temporary and meant to be RAUWed.
     DIGlobalVariable
-    createTempStaticVariableFwdDecl(DIDescriptor Context, StringRef Name,
+    createTempGlobalVariableFwdDecl(DIDescriptor Context, StringRef Name,
                                     StringRef LinkageName, DIFile File,
                                     unsigned LineNo, DITypeRef Ty,
                                     bool isLocalToUnit, llvm::Value *Val,

llvm/lib/IR/DIBuilder.cpp

   return DISubrange(MDNode::get(VMContext, Elts));
 }
 
-/// \brief Create a new descriptor for the specified global.
-DIGlobalVariable DIBuilder::createGlobalVariable(StringRef Name,
-                                                 StringRef LinkageName,
-                                                 DIFile F, unsigned LineNumber,
-                                                 DITypeRef Ty, bool isLocalToUnit,
-                                                 Value *Val) {
-  Value *Elts[] = {
-    GetTagConstant(VMContext, dwarf::DW_TAG_variable),
-    Constant::getNullValue(Type::getInt32Ty(VMContext)),
-    nullptr, // TheCU,
-    MDString::get(VMContext, Name),
-    MDString::get(VMContext, Name),
-    MDString::get(VMContext, LinkageName),
-    F,
-    ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
-    Ty,
-    ConstantInt::get(Type::getInt32Ty(VMContext), isLocalToUnit),
-    ConstantInt::get(Type::getInt32Ty(VMContext), 1), /* isDefinition*/
-    Val,
-    DIDescriptor()
-  };
-  MDNode *Node = MDNode::get(VMContext, Elts);
-  AllGVs.push_back(Node);
-  return DIGlobalVariable(Node);
-}
-
-/// \brief Create a new descriptor for the specified global.
-DIGlobalVariable DIBuilder::createGlobalVariable(StringRef Name, DIFile F,
-                                                 unsigned LineNumber,
-                                                 DITypeRef Ty,
-                                                 bool isLocalToUnit,
-                                                 Value *Val) {
-  return createGlobalVariable(Name, Name, F, LineNumber, Ty, isLocalToUnit,
-                              Val);
-}
-
 static DIGlobalVariable
-createStaticVariableHelper(LLVMContext &VMContext, DIDescriptor Context,
+createGlobalVariableHelper(LLVMContext &VMContext, DIDescriptor Context,
                            StringRef Name, StringRef LinkageName, DIFile F,
                            unsigned LineNumber, DITypeRef Ty, bool isLocalToUnit,
                            Value *Val, MDNode *Decl, bool isDefinition,

   return DIGlobalVariable(CreateFunc(Elts));
 }
 
-/// createStaticVariable - Create a new descriptor for the specified
+/// createGlobalVariable - Create a new descriptor for the specified
 /// variable.
-DIGlobalVariable DIBuilder::createStaticVariable(DIDescriptor Context,
+DIGlobalVariable DIBuilder::createGlobalVariable(DIDescriptor Context,
                                                  StringRef Name,
                                                  StringRef LinkageName,
                                                  DIFile F, unsigned LineNumber,

                                                  DITypeRef Ty,
                                                  bool isLocalToUnit,
                                                  Value *Val, MDNode *Decl) {
-  return createStaticVariableHelper(VMContext, Context, Name, LinkageName, F,
+  return createGlobalVariableHelper(VMContext, Context, Name, LinkageName, F,
                                     LineNumber, Ty, isLocalToUnit, Val, Decl, true,
                                     [&] (ArrayRef<Value *> Elts) -> MDNode * {
                                       MDNode *Node = MDNode::get(VMContext, Elts);

                                     });
 }
 
-/// createTempStaticVariableFwdDecl - Create a new temporary descriptor for the
+/// createTempGlobalVariableFwdDecl - Create a new temporary descriptor for the
 /// specified variable declarartion.
 DIGlobalVariable
-DIBuilder::createTempStaticVariableFwdDecl(DIDescriptor Context,
+DIBuilder::createTempGlobalVariableFwdDecl(DIDescriptor Context,
                                            StringRef Name,
                                            StringRef LinkageName,
                                            DIFile F, unsigned LineNumber,

                                            DITypeRef Ty,
                                            bool isLocalToUnit,
                                            Value *Val, MDNode *Decl) {
-  return createStaticVariableHelper(VMContext, Context, Name, LinkageName, F,
+  return createGlobalVariableHelper(VMContext, Context, Name, LinkageName, F,
                                     LineNumber, Ty, isLocalToUnit, Val, Decl, false,
                                     [&] (ArrayRef<Value *> Elts) {
                                       return MDNode::getTemporary(VMContext, Elts);

llvm/tools/clang/lib/CodeGen/CGDebugInfo.cpp

       continue;
     }
     // Use VarDecl's Tag, Scope and Line number.
-    GV = DBuilder.createStaticVariable(DContext, FieldName, LinkageName, Unit,
+    GV = DBuilder.createGlobalVariable(DContext, FieldName, LinkageName, Unit,
                                        LineNo, FieldTy,
                                        Var->hasInternalLinkage(), Var,
                                        llvm::DIDerivedType());

     assert(RD->isAnonymousStructOrUnion() && "unnamed non-anonymous struct or union?");
     GV = CollectAnonRecordDecls(RD, Unit, LineNo, LinkageName, Var, DContext);
   } else {
-      GV = DBuilder.createStaticVariable(
+      GV = DBuilder.createGlobalVariable(
         DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
         Var->hasInternalLinkage(), Var,
         getOrCreateStaticDataMemberDeclarationOrNull(D));

     return;
   llvm::DIDescriptor DContext =
       getContextDescriptor(dyn_cast<Decl>(VD->getDeclContext()));
-  llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
+  llvm::DIGlobalVariable GV = DBuilder.createGlobalVariable(
       DContext, Name, StringRef(), Unit, getLineNumber(VD->getLocation()), Ty,
       true, Init,
       getOrCreateStaticDataMemberDeclarationOrNull(cast<VarDecl>(VD)));