Use InsertPosition for insertion in all Instructions and IRBuilder

Author: SLTozer

clang/lib/CodeGen/CGBuilder.h

@@ -35,7 +35,6 @@ class CGBuilderInserter final : public llvm::IRBuilderDefaultInserter {
 
   /// This forwards to CodeGenFunction::InsertHelper.
   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
-                    llvm::BasicBlock *BB,
                     llvm::BasicBlock::iterator InsertPt) const override;
 
 private:

clang/lib/CodeGen/CGExpr.cpp

@@ -120,7 +120,8 @@ llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
     Alloca = Builder.CreateAlloca(Ty, ArraySize, Name);
   else
     Alloca = new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
-                                  ArraySize, Name, AllocaInsertPt);
+                                  ArraySize, Name,
+                                  (llvm::Instruction *)AllocaInsertPt);
   if (Allocas) {
     Allocas->Add(Alloca);
   }

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -2635,19 +2635,18 @@ CodeGenFunction::SanitizerScope::~SanitizerScope() {
 
 void CodeGenFunction::InsertHelper(llvm::Instruction *I,
                                    const llvm::Twine &Name,
-                                   llvm::BasicBlock *BB,
                                    llvm::BasicBlock::iterator InsertPt) const {
   LoopStack.InsertHelper(I);
   if (IsSanitizerScope)
     I->setNoSanitizeMetadata();
 }
 
 void CGBuilderInserter::InsertHelper(
-    llvm::Instruction *I, const llvm::Twine &Name, llvm::BasicBlock *BB,
+    llvm::Instruction *I, const llvm::Twine &Name,
     llvm::BasicBlock::iterator InsertPt) const {
-  llvm::IRBuilderDefaultInserter::InsertHelper(I, Name, BB, InsertPt);
+  llvm::IRBuilderDefaultInserter::InsertHelper(I, Name, InsertPt);
   if (CGF)
-    CGF->InsertHelper(I, Name, BB, InsertPt);
+    CGF->InsertHelper(I, Name, InsertPt);
 }
 
 // Emits an error if we don't have a valid set of target features for the

clang/lib/CodeGen/CodeGenFunction.h

@@ -345,7 +345,6 @@ class CodeGenFunction : public CodeGenTypeCache {
   /// CGBuilder insert helper. This function is called after an
   /// instruction is created using Builder.
   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
-                    llvm::BasicBlock *BB,
                     llvm::BasicBlock::iterator InsertPt) const;
 
   /// CurFuncDecl - Holds the Decl for the current outermost

llvm/include/llvm/IR/IRBuilder.h

@@ -63,10 +63,10 @@ class IRBuilderDefaultInserter {
   virtual ~IRBuilderDefaultInserter();
 
   virtual void InsertHelper(Instruction *I, const Twine &Name,
-                            BasicBlock *BB,
                             BasicBlock::iterator InsertPt) const {
-    if (BB)
-      I->insertInto(BB, InsertPt);
+    if (InsertPt.isValid()) {
+      I->insertInto(InsertPt.getNodeParent(), InsertPt);
+    }
     I->setName(Name);
   }
 };
@@ -83,9 +83,8 @@ class IRBuilderCallbackInserter : public IRBuilderDefaultInserter {
       : Callback(std::move(Callback)) {}
 
   void InsertHelper(Instruction *I, const Twine &Name,
-                    BasicBlock *BB,
                     BasicBlock::iterator InsertPt) const override {
-    IRBuilderDefaultInserter::InsertHelper(I, Name, BB, InsertPt);
+    IRBuilderDefaultInserter::InsertHelper(I, Name, InsertPt);
     Callback(I);
   }
 };
@@ -143,7 +142,7 @@ class IRBuilderBase {
   /// Insert and return the specified instruction.
   template<typename InstTy>
   InstTy *Insert(InstTy *I, const Twine &Name = "") const {
-    Inserter.InsertHelper(I, Name, BB, InsertPt);
+    Inserter.InsertHelper(I, Name, InsertPt);
     AddMetadataToInst(I);
     return I;
   }

llvm/include/llvm/IR/InstrTypes.h

@@ -44,6 +44,23 @@ template <> struct ilist_alloc_traits<Instruction> {
 iterator_range<simple_ilist<DbgRecord>::iterator>
 getDbgRecordRange(DbgMarker *);
 
+class InsertPosition {
+  using InstListType = SymbolTableList<Instruction, ilist_iterator_bits<true>,
+                                       ilist_parent<BasicBlock>>;
+  InstListType::iterator InsertAt;
+
+public:
+  InsertPosition(std::nullopt_t) : InsertAt() {}
+  InsertPosition(std::nullptr_t) : InsertAt() {}
+  // LLVM_DEPRECATED("Use BasicBlock::iterators for insertion instead",
+  // "BasicBlock::iterator")
+  InsertPosition(Instruction *InsertBefore);
+  InsertPosition(BasicBlock *InsertAtEnd);
+  InsertPosition(InstListType::iterator InsertAt) : InsertAt(InsertAt) {}
+  operator InstListType::iterator() const { return InsertAt; }
+  bool IsValid() const { return InsertAt.getNodePtr(); }
+};
+
 class Instruction : public User,
                     public ilist_node_with_parent<Instruction, BasicBlock,
                                                   ilist_iterator_bits<true>,
@@ -1023,11 +1040,7 @@ class Instruction : public User,
   }
 
   Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
-              InstListType::iterator InsertBefore);
-  Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
-              Instruction *InsertBefore = nullptr);
-  Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
-              BasicBlock *InsertAtEnd);
+              InsertPosition InsertBefore = nullptr);
 
 private:
   /// Create a copy of this instruction.