[Clang][P1061] Remove ResolvedUnexpandedPackExpr

Author: ricejasonf

clang/include/clang/AST/ExprCXX.h

@@ -5318,59 +5318,6 @@ class BuiltinBitCastExpr final
   }
 };
 
-// Represents an unexpanded pack where the list of expressions are
-// known. These are used when structured bindings introduce a pack.
-class ResolvedUnexpandedPackExpr final
-    : public Expr,
-      private llvm::TrailingObjects<ResolvedUnexpandedPackExpr, Expr *> {
-  friend class ASTStmtReader;
-  friend class ASTStmtWriter;
-  friend TrailingObjects;
-
-  SourceLocation BeginLoc;
-  unsigned NumExprs;
-
-  ResolvedUnexpandedPackExpr(SourceLocation BL, QualType QT, unsigned NumExprs);
-
-public:
-  static ResolvedUnexpandedPackExpr *CreateDeserialized(ASTContext &C,
-                                                        unsigned NumExprs);
-  static ResolvedUnexpandedPackExpr *
-  Create(ASTContext &C, SourceLocation BeginLoc, QualType T, unsigned NumExprs);
-  static ResolvedUnexpandedPackExpr *Create(ASTContext &C,
-                                            SourceLocation BeginLoc, QualType T,
-                                            llvm::ArrayRef<Expr *> Exprs);
-
-  unsigned getNumExprs() const { return NumExprs; }
-
-  llvm::MutableArrayRef<Expr *> getExprs() {
-    return {getTrailingObjects<Expr *>(), NumExprs};
-  }
-
-  llvm::ArrayRef<Expr *> getExprs() const {
-    return {getTrailingObjects<Expr *>(), NumExprs};
-  }
-
-  Expr *getExpansion(unsigned Idx) { return getExprs()[Idx]; }
-  Expr *getExpansion(unsigned Idx) const { return getExprs()[Idx]; }
-
-  // Iterators
-  child_range children() {
-    return child_range((Stmt **)getTrailingObjects<Expr *>(),
-                       (Stmt **)getTrailingObjects<Expr *>() + getNumExprs());
-  }
-
-  SourceLocation getBeginLoc() const LLVM_READONLY { return BeginLoc; }
-  SourceLocation getEndLoc() const LLVM_READONLY { return BeginLoc; }
-
-  // Returns the resolved pack of a decl or nullptr
-  static ResolvedUnexpandedPackExpr *getFromDecl(Decl *);
-
-  static bool classof(const Stmt *T) {
-    return T->getStmtClass() == ResolvedUnexpandedPackExprClass;
-  }
-};
-
 } // namespace clang
 
 #endif // LLVM_CLANG_AST_EXPRCXX_H

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -2950,7 +2950,6 @@ DEF_TRAVERSE_STMT(FunctionParmPackExpr, {})
 DEF_TRAVERSE_STMT(CXXFoldExpr, {})
 DEF_TRAVERSE_STMT(AtomicExpr, {})
 DEF_TRAVERSE_STMT(CXXParenListInitExpr, {})
-DEF_TRAVERSE_STMT(ResolvedUnexpandedPackExpr, {})
 
 DEF_TRAVERSE_STMT(MaterializeTemporaryExpr, {
   if (S->getLifetimeExtendedTemporaryDecl()) {

clang/include/clang/Basic/StmtNodes.td

@@ -163,7 +163,6 @@ def MaterializeTemporaryExpr : StmtNode<Expr>;
 def LambdaExpr : StmtNode<Expr>;
 def CXXFoldExpr : StmtNode<Expr>;
 def CXXParenListInitExpr: StmtNode<Expr>;
-def ResolvedUnexpandedPackExpr : StmtNode<Expr>;
 
 // C++ Coroutines expressions
 def CoroutineSuspendExpr : StmtNode<Expr, 1>;

clang/include/clang/Sema/Sema.h

@@ -232,8 +232,7 @@ void threadSafetyCleanup(BeforeSet *Cache);
 
 // FIXME: No way to easily map from TemplateTypeParmTypes to
 // TemplateTypeParmDecls, so we have this horrible PointerUnion.
-typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType *, NamedDecl *,
-                                     ResolvedUnexpandedPackExpr *>,
+typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType *, NamedDecl *>,
                   SourceLocation>
     UnexpandedParameterPack;
 

clang/include/clang/Serialization/ASTBitCodes.h

@@ -1908,7 +1908,6 @@ enum StmtCode {
   EXPR_PACK_EXPANSION,                    // PackExpansionExpr
   EXPR_PACK_INDEXING,                     // PackIndexingExpr
   EXPR_SIZEOF_PACK,                       // SizeOfPackExpr
-  EXPR_RESOLVED_UNEXPANDED_PACK,          // ResolvedUnexpandedPackExpr
   EXPR_SUBST_NON_TYPE_TEMPLATE_PARM,      // SubstNonTypeTemplateParmExpr
   EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK, // SubstNonTypeTemplateParmPackExpr
   EXPR_FUNCTION_PARM_PACK,                // FunctionParmPackExpr

clang/lib/AST/Expr.cpp

@@ -3659,7 +3659,6 @@ bool Expr::HasSideEffects(const ASTContext &Ctx,
   case PackIndexingExprClass:
   case HLSLOutArgExprClass:
   case OpenACCAsteriskSizeExprClass:
-  case ResolvedUnexpandedPackExprClass:
     // These never have a side-effect.
     return false;
 

clang/lib/AST/ExprCXX.cpp

@@ -1965,52 +1965,3 @@ CXXFoldExpr::CXXFoldExpr(QualType T, UnresolvedLookupExpr *Callee,
   SubExprs[SubExpr::RHS] = RHS;
   setDependence(computeDependence(this));
 }
-
-ResolvedUnexpandedPackExpr::ResolvedUnexpandedPackExpr(SourceLocation BL,
-                                                       QualType QT,
-                                                       unsigned NumExprs)
-    : Expr(ResolvedUnexpandedPackExprClass, QT, VK_PRValue, OK_Ordinary),
-      BeginLoc(BL), NumExprs(NumExprs) {
-  // C++ [temp.dep.expr]p3
-  // An id-expression is type-dependent if it is
-  //    - associated by name lookup with a pack
-  setDependence(ExprDependence::TypeValueInstantiation |
-                ExprDependence::UnexpandedPack);
-}
-
-ResolvedUnexpandedPackExpr *
-ResolvedUnexpandedPackExpr::CreateDeserialized(ASTContext &Ctx,
-                                               unsigned NumExprs) {
-  void *Mem = Ctx.Allocate(totalSizeToAlloc<Expr *>(NumExprs),
-                           alignof(ResolvedUnexpandedPackExpr));
-  return new (Mem)
-      ResolvedUnexpandedPackExpr(SourceLocation(), QualType(), NumExprs);
-}
-
-ResolvedUnexpandedPackExpr *
-ResolvedUnexpandedPackExpr::Create(ASTContext &Ctx, SourceLocation BL,
-                                   QualType T, unsigned NumExprs) {
-  void *Mem = Ctx.Allocate(totalSizeToAlloc<Expr *>(NumExprs),
-                           alignof(ResolvedUnexpandedPackExpr));
-  ResolvedUnexpandedPackExpr *New =
-      new (Mem) ResolvedUnexpandedPackExpr(BL, T, NumExprs);
-
-  auto Exprs = New->getExprs();
-  std::uninitialized_fill(Exprs.begin(), Exprs.end(), nullptr);
-
-  return New;
-}
-
-ResolvedUnexpandedPackExpr *
-ResolvedUnexpandedPackExpr::Create(ASTContext &Ctx, SourceLocation BL,
-                                   QualType T, ArrayRef<Expr *> Exprs) {
-  auto *New = Create(Ctx, BL, T, Exprs.size());
-  std::uninitialized_copy(Exprs.begin(), Exprs.end(), New->getExprs().begin());
-  return New;
-}
-
-ResolvedUnexpandedPackExpr *ResolvedUnexpandedPackExpr::getFromDecl(Decl *D) {
-  if (auto *BD = dyn_cast<BindingDecl>(D))
-    return dyn_cast_if_present<ResolvedUnexpandedPackExpr>(BD->getBinding());
-  return nullptr;
-}

clang/lib/AST/ExprClassification.cpp

@@ -451,13 +451,6 @@ static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
   case Expr::PackExpansionExprClass:
     return ClassifyInternal(Ctx, cast<PackExpansionExpr>(E)->getPattern());
 
-  case Expr::ResolvedUnexpandedPackExprClass: {
-    if (cast<ResolvedUnexpandedPackExpr>(E)->getNumExprs() > 0)
-      return ClassifyInternal(
-          Ctx, cast<ResolvedUnexpandedPackExpr>(E)->getExpansion(0));
-    return Cl::CL_LValue;
-  }
-
   case Expr::MaterializeTemporaryExprClass:
     return cast<MaterializeTemporaryExpr>(E)->isBoundToLvalueReference()
               ? Cl::CL_LValue

clang/lib/AST/ExprConstant.cpp

@@ -17253,7 +17253,6 @@ static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
   case Expr::SYCLUniqueStableNameExprClass:
   case Expr::CXXParenListInitExprClass:
   case Expr::HLSLOutArgExprClass:
-  case Expr::ResolvedUnexpandedPackExprClass:
     return ICEDiag(IK_NotICE, E->getBeginLoc());
 
   case Expr::InitListExprClass: {

clang/lib/AST/ItaniumMangle.cpp

@@ -4932,8 +4932,7 @@ void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity,
   case Expr::AtomicExprClass:
   case Expr::SourceLocExprClass:
   case Expr::EmbedExprClass:
-  case Expr::BuiltinBitCastExprClass:
-  case Expr::ResolvedUnexpandedPackExprClass: {
+  case Expr::BuiltinBitCastExprClass: {
     NotPrimaryExpr();
     if (!NullOut) {
       // As bad as this diagnostic is, it's better than crashing.

clang/lib/AST/StmtPrinter.cpp

@@ -2595,15 +2595,6 @@ void StmtPrinter::VisitPackIndexingExpr(PackIndexingExpr *E) {
   OS << "]";
 }
 
-void StmtPrinter::VisitResolvedUnexpandedPackExpr(
-    ResolvedUnexpandedPackExpr *E) {
-  OS << "<<resolved pack(";
-  llvm::interleave(
-      E->getExprs().begin(), E->getExprs().end(),
-      [this](auto *X) { PrintExpr(X); }, [this] { OS << ", "; });
-  OS << ")>>";
-}
-
 void StmtPrinter::VisitSubstNonTypeTemplateParmPackExpr(
                                        SubstNonTypeTemplateParmPackExpr *Node) {
   OS << *Node->getParameterPack();

clang/lib/AST/StmtProfile.cpp

@@ -2280,10 +2280,6 @@ void StmtProfiler::VisitSizeOfPackExpr(const SizeOfPackExpr *S) {
     ID.AddInteger(0);
   }
 }
-void StmtProfiler::VisitResolvedUnexpandedPackExpr(
-    const ResolvedUnexpandedPackExpr *S) {
-  VisitExpr(S);
-}
 
 void StmtProfiler::VisitPackIndexingExpr(const PackIndexingExpr *E) {
   VisitExpr(E);

clang/lib/Sema/SemaExceptionSpec.cpp

@@ -1286,7 +1286,6 @@ CanThrowResult Sema::canThrow(const Stmt *S) {
   case Expr::ConvertVectorExprClass:
   case Expr::VAArgExprClass:
   case Expr::CXXParenListInitExprClass:
-  case Expr::ResolvedUnexpandedPackExprClass:
     return canSubStmtsThrow(*this, S);
 
   case Expr::CompoundLiteralExprClass:

clang/lib/Sema/SemaTemplateInstantiate.cpp

@@ -1584,10 +1584,6 @@ namespace {
     /// pack.
     ExprResult TransformFunctionParmPackExpr(FunctionParmPackExpr *E);
 
-    // Transform a ResolvedUnexpandedPackExpr
-    ExprResult
-    TransformResolvedUnexpandedPackExpr(ResolvedUnexpandedPackExpr *E);
-
     QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
                                         FunctionProtoTypeLoc TL) {
       // Call the base version; it will forward to our overridden version below.
@@ -2644,19 +2640,6 @@ TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB,
   return Result;
 }
 
-ExprResult TemplateInstantiator::TransformResolvedUnexpandedPackExpr(
-    ResolvedUnexpandedPackExpr *E) {
-  if (getSema().ArgumentPackSubstitutionIndex != -1) {
-    assert(static_cast<unsigned>(getSema().ArgumentPackSubstitutionIndex) <
-               E->getNumExprs() &&
-           "ArgumentPackSubstitutionIndex is out of range");
-    return TransformExpr(
-        E->getExpansion(getSema().ArgumentPackSubstitutionIndex));
-  }
-
-  return inherited::TransformResolvedUnexpandedPackExpr(E);
-}
-
 QualType TemplateInstantiator::TransformSubstTemplateTypeParmPackType(
     TypeLocBuilder &TLB, SubstTemplateTypeParmPackTypeLoc TL,
     bool SuppressObjCLifetime) {

clang/lib/Sema/SemaTemplateVariadic.cpp

@@ -64,10 +64,6 @@ class CollectUnexpandedParameterPacksVisitor
         Unexpanded.push_back({T, Loc});
     }
 
-    void addUnexpanded(ResolvedUnexpandedPackExpr *E) {
-      Unexpanded.push_back({E, E->getBeginLoc()});
-    }
-
   public:
     explicit CollectUnexpandedParameterPacksVisitor(
         SmallVectorImpl<UnexpandedParameterPack> &Unexpanded)
@@ -110,12 +106,6 @@ class CollectUnexpandedParameterPacksVisitor
       return true;
     }
 
-    bool
-    VisitResolvedUnexpandedPackExpr(ResolvedUnexpandedPackExpr *E) override {
-      addUnexpanded(E);
-      return true;
-    }
-
     /// Record occurrences of template template parameter packs.
     bool TraverseTemplateName(TemplateName Template) override {
       if (auto *TTP = dyn_cast_or_null<TemplateTemplateParmDecl>(
@@ -1193,12 +1183,8 @@ ExprResult Sema::ActOnSizeofParameterPackExpr(Scope *S,
 
   MarkAnyDeclReferenced(OpLoc, ParameterPack, true);
 
-  std::optional<unsigned> Length;
-  if (auto *RP = ResolvedUnexpandedPackExpr::getFromDecl(ParameterPack))
-    Length = RP->getNumExprs();
-
   return SizeOfPackExpr::Create(Context, OpLoc, ParameterPack, NameLoc,
-                                RParenLoc, Length);
+                                RParenLoc);
 }
 
 static bool isParameterPack(Expr *PackExpression) {

clang/lib/Sema/TreeTransform.h

@@ -3680,13 +3680,6 @@ class TreeTransform {
                                            FullySubstituted);
   }
 
-  ExprResult RebuildResolvedUnexpandedPackExpr(SourceLocation BeginLoc,
-                                               QualType T,
-                                               ArrayRef<Expr *> Exprs) {
-    return ResolvedUnexpandedPackExpr::Create(SemaRef.Context, BeginLoc, T,
-                                              Exprs);
-  }
-
   /// Build a new expression representing a call to a source location
   ///  builtin.
   ///
@@ -16133,24 +16126,6 @@ TreeTransform<Derived>::TransformFunctionParmPackExpr(FunctionParmPackExpr *E) {
   return E;
 }
 
-template <typename Derived>
-ExprResult TreeTransform<Derived>::TransformResolvedUnexpandedPackExpr(
-    ResolvedUnexpandedPackExpr *E) {
-  bool ArgumentChanged = false;
-  SmallVector<Expr *, 12> NewExprs;
-  if (TransformExprs(E->getExprs().begin(), E->getNumExprs(),
-                     /*IsCall=*/false, NewExprs, &ArgumentChanged))
-    return ExprError();
-
-  if (!AlwaysRebuild() && !ArgumentChanged)
-    return E;
-
-  // NOTE: The type is just a superficial PackExpansionType
-  //       that needs no substitution.
-  return RebuildResolvedUnexpandedPackExpr(E->getBeginLoc(), E->getType(),
-                                           NewExprs);
-}
-
 template<typename Derived>
 ExprResult
 TreeTransform<Derived>::TransformMaterializeTemporaryExpr(

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -2208,16 +2208,6 @@ void ASTStmtReader::VisitPackIndexingExpr(PackIndexingExpr *E) {
     Exprs[I] = Record.readExpr();
 }
 
-void ASTStmtReader::VisitResolvedUnexpandedPackExpr(
-    ResolvedUnexpandedPackExpr *E) {
-  VisitExpr(E);
-  E->NumExprs = Record.readInt();
-  E->BeginLoc = readSourceLocation();
-  auto **Exprs = E->getTrailingObjects<Expr *>();
-  for (unsigned I = 0; I < E->NumExprs; ++I)
-    Exprs[I] = Record.readExpr();
-}
-
 void ASTStmtReader::VisitSubstNonTypeTemplateParmExpr(
                                               SubstNonTypeTemplateParmExpr *E) {
   VisitExpr(E);
@@ -4301,12 +4291,6 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
           /*TransformedExprs=*/Record[ASTStmtReader::NumExprFields]);
       break;
 
-    case EXPR_RESOLVED_UNEXPANDED_PACK:
-      S = ResolvedUnexpandedPackExpr::CreateDeserialized(
-          Context,
-          /*NumExprs=*/Record[ASTStmtReader::NumExprFields]);
-      break;
-
     case EXPR_SUBST_NON_TYPE_TEMPLATE_PARM:
       S = new (Context) SubstNonTypeTemplateParmExpr(Empty);
       break;

clang/lib/Serialization/ASTWriter.cpp

@@ -874,7 +874,6 @@ static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
   RECORD(EXPR_PACK_EXPANSION);
   RECORD(EXPR_SIZEOF_PACK);
   RECORD(EXPR_PACK_INDEXING);
-  RECORD(EXPR_RESOLVED_UNEXPANDED_PACK);
   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM);
   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
   RECORD(EXPR_FUNCTION_PARM_PACK);

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -2210,16 +2210,6 @@ void ASTStmtWriter::VisitPackIndexingExpr(PackIndexingExpr *E) {
   Code = serialization::EXPR_PACK_INDEXING;
 }
 
-void ASTStmtWriter::VisitResolvedUnexpandedPackExpr(
-    ResolvedUnexpandedPackExpr *E) {
-  VisitExpr(E);
-  Record.push_back(E->getNumExprs());
-  Record.AddSourceLocation(E->getBeginLoc());
-  for (Expr *Sub : E->getExprs())
-    Record.AddStmt(Sub);
-  Code = serialization::EXPR_RESOLVED_UNEXPANDED_PACK;
-}
-
 void ASTStmtWriter::VisitSubstNonTypeTemplateParmExpr(
                                               SubstNonTypeTemplateParmExpr *E) {
   VisitExpr(E);

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -1743,7 +1743,6 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::DependentCoawaitExprClass:
     case Stmt::CoreturnStmtClass:
     case Stmt::CoyieldExprClass:
-    case Stmt::ResolvedUnexpandedPackExprClass:
     case Stmt::SEHTryStmtClass:
     case Stmt::SEHExceptStmtClass:
     case Stmt::SEHLeaveStmtClass: