Revert "[clang] NRVO: Improvements and handling of more cases."

This change caused build errors related to move-only __block variables,
see discussion on https://reviews.llvm.org/D99696

> This expands NRVO propagation for more cases:
>
> Parse analysis improvement:
> * Lambdas and Blocks with dependent return type can have their variables
>   marked as NRVO Candidates.
>
> Variable instantiation improvements:
> * Fixes crash when instantiating NRVO variables in Blocks.
> * Functions, Lambdas, and Blocks which have auto return type have their
>   variables' NRVO status propagated. For Blocks with non-auto return type,
>   as a limitation, this propagation does not consider the actual return
>   type.
>
> This also implements exclusion of VarDecls which are references to
> dependent types.
>
> Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
>
> Reviewed By: Quuxplusone
>
> Differential Revision: https://reviews.llvm.org/D99696

This also reverts the follow-on change which was hard to tease apart
form the one above:

> "[clang] Implement P2266 Simpler implicit move"
>
> This Implements [[http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2266r1.html|P2266 Simpler implicit move]].
>
> Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
>
> Reviewed By: Quuxplusone
>
> Differential Revision: https://reviews.llvm.org/D99005

This reverts commits 1e50c3d785 and
bf20631782.

clang/include/clang/Sema/Sema.h

@@ -3455,6 +3455,12 @@ public:
   bool DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType);
   bool isSameOrCompatibleFunctionType(CanQualType Param, CanQualType Arg);
 
+  ExprResult PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
+                                             const VarDecl *NRVOCandidate,
+                                             QualType ResultType,
+                                             Expr *Value,
+                                             bool AllowNRVO = true);
+
   bool CanPerformAggregateInitializationForOverloadResolution(
       const InitializedEntity &Entity, InitListExpr *From);
 
@@ -4754,30 +4760,28 @@ public:
                                            SourceLocation Loc,
                                            unsigned NumParams);
 
-  struct NamedReturnInfo {
+  enum CopyElisionSemanticsKind {
-    const VarDecl *Candidate;
+    CES_Strict = 0,
-
+    CES_AllowParameters = 1,
-    enum Status : uint8_t { None, MoveEligible, MoveEligibleAndCopyElidable };
+    CES_AllowDifferentTypes = 2,
-    Status S;
+    CES_AllowExceptionVariables = 4,
-
+    CES_AllowRValueReferenceType = 8,
-    bool isMoveEligible() const { return S != None; };
+    CES_ImplicitlyMovableCXX11CXX14CXX17 =
-    bool isCopyElidable() const { return S == MoveEligibleAndCopyElidable; }
+        (CES_AllowParameters | CES_AllowDifferentTypes),
+    CES_ImplicitlyMovableCXX20 =
+        (CES_AllowParameters | CES_AllowDifferentTypes |
+         CES_AllowExceptionVariables | CES_AllowRValueReferenceType),
   };
-  NamedReturnInfo getNamedReturnInfo(Expr *&E, bool ForceCXX2b = false);
-  NamedReturnInfo getNamedReturnInfo(const VarDecl *VD,
-                                     bool ForceCXX20 = false);
-  const VarDecl *getCopyElisionCandidate(NamedReturnInfo &Info,
-                                         QualType ReturnType);
 
-  ExprResult PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
+  VarDecl *getCopyElisionCandidate(QualType ReturnType, Expr *E,
-                                             const NamedReturnInfo &NRInfo,
+                                   CopyElisionSemanticsKind CESK);
-                                             Expr *Value);
+  bool isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD,
+                              CopyElisionSemanticsKind CESK);
 
   StmtResult ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
                              Scope *CurScope);
   StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp);
-  StmtResult ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
+  StmtResult ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp);
-                                     NamedReturnInfo &NRInfo);
 
   StmtResult ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
                              bool IsVolatile, unsigned NumOutputs,

clang/lib/Sema/Sema.cpp

@@ -1962,10 +1962,9 @@ static void checkEscapingByref(VarDecl *VD, Sema &S) {
   SourceLocation Loc = VD->getLocation();
   Expr *VarRef =
       new (S.Context) DeclRefExpr(S.Context, VD, false, T, VK_LValue, Loc);
-  ExprResult Result = S.PerformCopyInitialization(
+  ExprResult Result = S.PerformMoveOrCopyInitialization(
-      InitializedEntity::InitializeBlock(Loc, T, false), SourceLocation(),
+      InitializedEntity::InitializeBlock(Loc, T, false), VD, VD->getType(),
-      VarRef);
+      VarRef, /*AllowNRVO=*/true);
-
   if (!Result.isInvalid()) {
     Result = S.MaybeCreateExprWithCleanups(Result);
     Expr *Init = Result.getAs<Expr>();

clang/lib/Sema/SemaCoroutine.cpp

@@ -994,10 +994,26 @@ StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
     E = R.get();
   }
 
+  // Move the return value if we can
+  if (E) {
+    const VarDecl *NRVOCandidate = this->getCopyElisionCandidate(
+        E->getType(), E, CES_ImplicitlyMovableCXX20);
+    if (NRVOCandidate) {
+      InitializedEntity Entity =
+          InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
+      ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
+          Entity, NRVOCandidate, E->getType(), E);
+      if (MoveResult.get())
+        E = MoveResult.get();
+    }
+  }
+
+  // FIXME: If the operand is a reference to a variable that's about to go out
+  // of scope, we should treat the operand as an xvalue for this overload
+  // resolution.
   VarDecl *Promise = FSI->CoroutinePromise;
   ExprResult PC;
   if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
-    getNamedReturnInfo(E, /*ForceCXX2b=*/true);
     PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
   } else {
     E = MakeFullDiscardedValueExpr(E).get();
@@ -1554,7 +1570,7 @@ bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
     // Trigger a nice error message.
     InitializedEntity Entity =
         InitializedEntity::InitializeResult(Loc, FnRetType, false);
-    S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue);
+    S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
     noteMemberDeclaredHere(S, ReturnValue, Fn);
     return false;
   }
@@ -1570,8 +1586,8 @@ bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
     return false;
 
   InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
-  ExprResult Res =
+  ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
-      S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue);
+                                                     this->ReturnValue);
   if (Res.isInvalid())
     return false;
 

clang/lib/Sema/SemaExprCXX.cpp

@@ -854,6 +854,10 @@ ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
     Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";
 
   if (Ex && !Ex->isTypeDependent()) {
+    QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
+    if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
+      return ExprError();
+
     // Initialize the exception result.  This implicitly weeds out
     // abstract types or types with inaccessible copy constructors.
 
@@ -869,17 +873,15 @@ ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
     //       operation from the operand to the exception object (15.1) can be
     //       omitted by constructing the automatic object directly into the
     //       exception object
-    NamedReturnInfo NRInfo =
+    const VarDecl *NRVOVariable = nullptr;
-        IsThrownVarInScope ? getNamedReturnInfo(Ex) : NamedReturnInfo();
+    if (IsThrownVarInScope)
-
+      NRVOVariable = getCopyElisionCandidate(QualType(), Ex, CES_Strict);
-    QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
-    if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
-      return ExprError();
 
     InitializedEntity Entity = InitializedEntity::InitializeException(
         OpLoc, ExceptionObjectTy,
-        /*NRVO=*/NRInfo.isCopyElidable());
+        /*NRVO=*/NRVOVariable != nullptr);
-    ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, Ex);
+    ExprResult Res = PerformMoveOrCopyInitialization(
+        Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope);
     if (Res.isInvalid())
       return ExprError();
     Ex = Res.get();

clang/lib/Sema/SemaStmt.cpp

@@ -3307,161 +3307,99 @@ Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
   return new (Context) BreakStmt(BreakLoc);
 }
 
-/// Determine whether the given expression might be move-eligible or
+/// Determine whether the given expression is a candidate for
-/// copy-elidable in either a (co_)return statement or throw expression,
+/// copy elision in either a return statement or a throw expression.
-/// without considering function return type, if applicable.
 ///
-/// \param E The expression being returned from the function or block,
+/// \param ReturnType If we're determining the copy elision candidate for
-/// being thrown, or being co_returned from a coroutine. This expression
+/// a return statement, this is the return type of the function. If we're
-/// might be modified by the implementation.
+/// determining the copy elision candidate for a throw expression, this will
+/// be a NULL type.
 ///
-/// \param ForceCXX2b Overrides detection of current language mode
+/// \param E The expression being returned from the function or block, or
-/// and uses the rules for C++2b.
+/// being thrown.
 ///
-/// \returns An aggregate which contains the Candidate and isMoveEligible
+/// \param CESK Whether we allow function parameters or
-/// and isCopyElidable methods. If Candidate is non-null, it means
+/// id-expressions that could be moved out of the function to be considered NRVO
-/// isMoveEligible() would be true under the most permissive language standard.
+/// candidates. C++ prohibits these for NRVO itself, but we re-use this logic to
-Sema::NamedReturnInfo Sema::getNamedReturnInfo(Expr *&E, bool ForceCXX2b) {
+/// determine whether we should try to move as part of a return or throw (which
-  if (!E)
+/// does allow function parameters).
-    return NamedReturnInfo();
+///
+/// \returns The NRVO candidate variable, if the return statement may use the
+/// NRVO, or NULL if there is no such candidate.
+VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, Expr *E,
+                                       CopyElisionSemanticsKind CESK) {
   // - in a return statement in a function [where] ...
   // ... the expression is the name of a non-volatile automatic object ...
-  const auto *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
+  DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
   if (!DR || DR->refersToEnclosingVariableOrCapture())
-    return NamedReturnInfo();
+    return nullptr;
-  const auto *VD = dyn_cast<VarDecl>(DR->getDecl());
+  VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
   if (!VD)
-    return NamedReturnInfo();
+    return nullptr;
-  NamedReturnInfo Res = getNamedReturnInfo(VD, /*ForceCXX20=*/ForceCXX2b);
+
-  if (Res.Candidate && !E->isXValue() &&
+  if (isCopyElisionCandidate(ReturnType, VD, CESK))
-      (ForceCXX2b || getLangOpts().CPlusPlus2b)) {
+    return VD;
-    E = ImplicitCastExpr::Create(Context, VD->getType().getNonReferenceType(),
+  return nullptr;
-                                 CK_NoOp, E, nullptr, VK_XValue,
-                                 FPOptionsOverride());
-  }
-  return Res;
 }
 
-/// Updates the status in the given NamedReturnInfo object to disallow
+bool Sema::isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD,
-/// copy elision, and optionally also implicit move.
+                                  CopyElisionSemanticsKind CESK) {
-///
+  QualType VDType = VD->getType();
-/// \param Info The NamedReturnInfo object to update.
-///
-/// \param CanMove If true, disallow only copy elision.
-/// If false, also disallow implcit move.
-static void disallowNRVO(Sema::NamedReturnInfo &Info, bool CanMove) {
-  Info.S = std::min(Info.S, CanMove ? Sema::NamedReturnInfo::MoveEligible
-                                    : Sema::NamedReturnInfo::None);
-}
-
-/// Determine whether the given NRVO candidate variable is move-eligible or
-/// copy-elidable, without considering function return type.
-///
-/// \param VD The NRVO candidate variable.
-///
-/// \param ForceCXX20 Overrides detection of current language mode
-/// and uses the rules for C++20.
-///
-/// \returns An aggregate which contains the Candidate and isMoveEligible
-/// and isCopyElidable methods. If Candidate is non-null, it means
-/// isMoveEligible() would be true under the most permissive language standard.
-Sema::NamedReturnInfo Sema::getNamedReturnInfo(const VarDecl *VD,
-                                               bool ForceCXX20) {
-  bool hasCXX11 = getLangOpts().CPlusPlus11 || ForceCXX20;
-  bool hasCXX20 = getLangOpts().CPlusPlus20 || ForceCXX20;
-  NamedReturnInfo Info{VD, NamedReturnInfo::MoveEligibleAndCopyElidable};
-
-  // C++20 [class.copy.elision]p3:
   // - in a return statement in a function with ...
-  // (other than a function ... parameter)
+  // ... a class return type ...
-  if (VD->getKind() == Decl::ParmVar)
+  if (!ReturnType.isNull() && !ReturnType->isDependentType()) {
-    disallowNRVO(Info, hasCXX11);
+    if (!ReturnType->isRecordType())
-  else if (VD->getKind() != Decl::Var)
+      return false;
-    return NamedReturnInfo();
+    // ... the same cv-unqualified type as the function return type ...
+    // When considering moving this expression out, allow dissimilar types.
+    if (!(CESK & CES_AllowDifferentTypes) && !VDType->isDependentType() &&
+        !Context.hasSameUnqualifiedType(ReturnType, VDType))
+      return false;
+  }
 
-  // (other than ... a catch-clause parameter)
+  // ...object (other than a function or catch-clause parameter)...
-  if (VD->isExceptionVariable())
+  if (VD->getKind() != Decl::Var &&
-    disallowNRVO(Info, hasCXX20);
+      !((CESK & CES_AllowParameters) && VD->getKind() == Decl::ParmVar))
+    return false;
+  if (!(CESK & CES_AllowExceptionVariables) && VD->isExceptionVariable())
+    return false;
 
   // ...automatic...
-  if (!VD->hasLocalStorage())
+  if (!VD->hasLocalStorage()) return false;
-    return NamedReturnInfo();
 
-  // We don't want to implicitly move out of a __block variable during a return
+  // Return false if VD is a __block variable. We don't want to implicitly move
-  // because we cannot assume the variable will no longer be used.
+  // out of a __block variable during a return because we cannot assume the
+  // variable will no longer be used.
   if (VD->hasAttr<BlocksAttr>())
-    return NamedReturnInfo();
+    return false;
 
-  QualType VDType = VD->getType();
   if (VDType->isObjectType()) {
     // C++17 [class.copy.elision]p3:
     // ...non-volatile automatic object...
     if (VDType.isVolatileQualified())
-      return NamedReturnInfo();
+      return false;
   } else if (VDType->isRValueReferenceType()) {
     // C++20 [class.copy.elision]p3:
-    // ...either a non-volatile object or an rvalue reference to a non-volatile
+    // ...either a non-volatile object or an rvalue reference to a non-volatile object type...
-    // object type...
+    if (!(CESK & CES_AllowRValueReferenceType))
+      return false;
     QualType VDReferencedType = VDType.getNonReferenceType();
-    if (VDReferencedType.isVolatileQualified() ||
+    if (VDReferencedType.isVolatileQualified() || !VDReferencedType->isObjectType())
-        !VDReferencedType->isObjectType())
+      return false;
-      return NamedReturnInfo();
-    disallowNRVO(Info, hasCXX20);
   } else {
-    return NamedReturnInfo();
+    return false;
   }
 
+  if (CESK & CES_AllowDifferentTypes)
+    return true;
+
   // Variables with higher required alignment than their type's ABI
   // alignment cannot use NRVO.
   if (!VDType->isDependentType() && VD->hasAttr<AlignedAttr>() &&
       Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VDType))
-    disallowNRVO(Info, hasCXX11);
+    return false;
 
-  return Info;
+  return true;
-}
-
-/// Updates given NamedReturnInfo's move-eligible and
-/// copy-elidable statuses, considering the function
-/// return type criteria as applicable to return statements.
-///
-/// \param Info The NamedReturnInfo object to update.
-///
-/// \param ReturnType This is the return type of the function.
-/// \returns The copy elision candidate, in case the initial return expression
-/// was copy elidable, or nullptr otherwise.
-const VarDecl *Sema::getCopyElisionCandidate(NamedReturnInfo &Info,
-                                             QualType ReturnType) {
-  if (!Info.Candidate)
-    return nullptr;
-
-  auto invalidNRVO = [&] {
-    Info = NamedReturnInfo();
-    return nullptr;
-  };
-
-  // If we got a non-deduced auto ReturnType, we are in a dependent context and
-  // there is no point in allowing copy elision since we won't have it deduced
-  // by the point the VardDecl is instantiated, which is the last chance we have
-  // of deciding if the candidate is really copy elidable.
-  if ((ReturnType->getTypeClass() == Type::TypeClass::Auto &&
-       ReturnType->isCanonicalUnqualified()) ||
-      ReturnType->isSpecificBuiltinType(BuiltinType::Dependent))
-    return invalidNRVO();
-
-  if (!ReturnType->isDependentType()) {
-    // - in a return statement in a function with ...
-    // ... a class return type ...
-    if (!ReturnType->isRecordType())
-      return invalidNRVO();
-
-    QualType VDType = Info.Candidate->getType();
-    // ... the same cv-unqualified type as the function return type ...
-    // When considering moving this expression out, allow dissimilar types.
-    if (!VDType->isDependentType() &&
-        !Context.hasSameUnqualifiedType(ReturnType, VDType))
-      disallowNRVO(Info, getLangOpts().CPlusPlus11);
-  }
-  return Info.isCopyElidable() ? Info.Candidate : nullptr;
 }
 
 /// Try to perform the initialization of a potentially-movable value,
@@ -3486,7 +3424,8 @@ const VarDecl *Sema::getCopyElisionCandidate(NamedReturnInfo &Info,
 /// the selected constructor/operator doesn't match the additional criteria, we
 /// need to do the second overload resolution.
 static bool TryMoveInitialization(Sema &S, const InitializedEntity &Entity,
-                                  const VarDecl *NRVOCandidate, Expr *&Value,
+                                  const VarDecl *NRVOCandidate,
+                                  QualType ResultType, Expr *&Value,
                                   bool ConvertingConstructorsOnly,
                                   bool IsDiagnosticsCheck, ExprResult &Res) {
   ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, Value->getType(),
@@ -3569,41 +3508,63 @@ static bool TryMoveInitialization(Sema &S, const InitializedEntity &Entity,
 /// This routine implements C++20 [class.copy.elision]p3, which attempts to
 /// treat returned lvalues as rvalues in certain cases (to prefer move
 /// construction), then falls back to treating them as lvalues if that failed.
-ExprResult
+ExprResult Sema::PerformMoveOrCopyInitialization(
-Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
+    const InitializedEntity &Entity, const VarDecl *NRVOCandidate,
-                                      const NamedReturnInfo &NRInfo,
+    QualType ResultType, Expr *Value, bool AllowNRVO) {
-                                      Expr *Value) {
+  ExprResult Res = ExprError();
+  bool NeedSecondOverloadResolution = true;
 
-  if (NRInfo.Candidate && !getLangOpts().CPlusPlus2b) {
+  if (AllowNRVO) {
-    if (NRInfo.isMoveEligible()) {
+    CopyElisionSemanticsKind CESK = CES_Strict;
-      ExprResult Res;
+    if (getLangOpts().CPlusPlus20) {
-      if (!TryMoveInitialization(*this, Entity, NRInfo.Candidate, Value,
+      CESK = CES_ImplicitlyMovableCXX20;
-                                 !getLangOpts().CPlusPlus20, false, Res))
+    } else if (getLangOpts().CPlusPlus11) {
-        return Res;
+      CESK = CES_ImplicitlyMovableCXX11CXX14CXX17;
     }
-    if (!getDiagnostics().isIgnored(diag::warn_return_std_move,
+
+    if (!NRVOCandidate) {
+      NRVOCandidate = getCopyElisionCandidate(ResultType, Value, CESK);
+    }
+
+    if (NRVOCandidate) {
+      NeedSecondOverloadResolution =
+          TryMoveInitialization(*this, Entity, NRVOCandidate, ResultType, Value,
+                                !getLangOpts().CPlusPlus20, false, Res);
+    }
+
+    if (!getLangOpts().CPlusPlus20 && NeedSecondOverloadResolution &&
+        !getDiagnostics().isIgnored(diag::warn_return_std_move,
                                     Value->getExprLoc())) {
-      QualType QT = NRInfo.Candidate->getType();
+      const VarDecl *FakeNRVOCandidate = getCopyElisionCandidate(
-      if (QT.getNonReferenceType().getUnqualifiedType().isTriviallyCopyableType(
+          QualType(), Value, CES_ImplicitlyMovableCXX20);
-              Context)) {
+      if (FakeNRVOCandidate) {
-        // Adding 'std::move' around a trivially copyable variable is probably
+        QualType QT = FakeNRVOCandidate->getType();
-        // pointless. Don't suggest it.
+        if (QT->isLValueReferenceType()) {
-      } else {
+          // Adding 'std::move' around an lvalue reference variable's name is
-        ExprResult FakeRes = ExprError();
+          // dangerous. Don't suggest it.
-        Expr *FakeValue = Value;
+        } else if (QT.getNonReferenceType()
-        TryMoveInitialization(*this, Entity, NRInfo.Candidate, FakeValue, false,
+                       .getUnqualifiedType()
-                              true, FakeRes);
+                       .isTriviallyCopyableType(Context)) {
-        if (!FakeRes.isInvalid()) {
+          // Adding 'std::move' around a trivially copyable variable is probably
-          bool IsThrow = (Entity.getKind() == InitializedEntity::EK_Exception);
+          // pointless. Don't suggest it.
-          SmallString<32> Str;
+        } else {
-          Str += "std::move(";
+          ExprResult FakeRes = ExprError();
-          Str += NRInfo.Candidate->getDeclName().getAsString();
+          Expr *FakeValue = Value;
-          Str += ")";
+          TryMoveInitialization(*this, Entity, FakeNRVOCandidate, ResultType,
-          Diag(Value->getExprLoc(), diag::warn_return_std_move)
+                                FakeValue, false, true, FakeRes);
-              << Value->getSourceRange() << NRInfo.Candidate->getDeclName()
+          if (!FakeRes.isInvalid()) {
-              << IsThrow;
+            bool IsThrow =
-          Diag(Value->getExprLoc(), diag::note_add_std_move)
+                (Entity.getKind() == InitializedEntity::EK_Exception);
-              << FixItHint::CreateReplacement(Value->getSourceRange(), Str);
+            SmallString<32> Str;
+            Str += "std::move(";
+            Str += FakeNRVOCandidate->getDeclName().getAsString();
+            Str += ")";
+            Diag(Value->getExprLoc(), diag::warn_return_std_move)
+                << Value->getSourceRange()
+                << FakeNRVOCandidate->getDeclName() << IsThrow;
+            Diag(Value->getExprLoc(), diag::note_add_std_move)
+                << FixItHint::CreateReplacement(Value->getSourceRange(), Str);
+          }
         }
       }
     }
@@ -3612,7 +3573,10 @@ Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
   // Either we didn't meet the criteria for treating an lvalue as an rvalue,
   // above, or overload resolution failed. Either way, we need to try
   // (again) now with the return value expression as written.
-  return PerformCopyInitialization(Entity, SourceLocation(), Value);
+  if (NeedSecondOverloadResolution)
+    Res = PerformCopyInitialization(Entity, SourceLocation(), Value);
+
+  return Res;
 }
 
 /// Determine whether the declared return type of the specified function
@@ -3626,9 +3590,8 @@ static bool hasDeducedReturnType(FunctionDecl *FD) {
 /// ActOnCapScopeReturnStmt - Utility routine to type-check return statements
 /// for capturing scopes.
 ///
-StmtResult Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc,
+StmtResult
-                                         Expr *RetValExp,
+Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
-                                         NamedReturnInfo &NRInfo) {
   // If this is the first return we've seen, infer the return type.
   // [expr.prim.lambda]p4 in C++11; block literals follow the same rules.
   CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
@@ -3707,7 +3670,7 @@ StmtResult Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc,
     if (CurCap->ReturnType.isNull())
       CurCap->ReturnType = FnRetType;
   }
-  const VarDecl *NRVOCandidate = getCopyElisionCandidate(NRInfo, FnRetType);
+  assert(!FnRetType.isNull());
 
   if (auto *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) {
     if (CurBlock->FunctionType->castAs<FunctionType>()->getNoReturnAttr()) {
@@ -3730,6 +3693,7 @@ StmtResult Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc,
   // Otherwise, verify that this result type matches the previous one.  We are
   // pickier with blocks than for normal functions because we don't have GCC
   // compatibility to worry about here.
+  const VarDecl *NRVOCandidate = nullptr;
   if (FnRetType->isDependentType()) {
     // Delay processing for now.  TODO: there are lots of dependent
     // types we can conclusively prove aren't void.
@@ -3757,15 +3721,20 @@ StmtResult Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc,
 
     // In C++ the return statement is handled via a copy initialization.
     // the C version of which boils down to CheckSingleAssignmentConstraints.
-    InitializedEntity Entity = InitializedEntity::InitializeResult(
+    NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
-        ReturnLoc, FnRetType, NRVOCandidate != nullptr);
+    InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
-    ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, RetValExp);
+                                                                   FnRetType,
+                                                      NRVOCandidate != nullptr);
+    ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
+                                                     FnRetType, RetValExp);
     if (Res.isInvalid()) {
       // FIXME: Cleanup temporaries here, anyway?
       return StmtError();
     }
     RetValExp = Res.get();
     CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc);
+  } else {
+    NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
   }
 
   if (RetValExp) {
@@ -3974,10 +3943,8 @@ StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
   if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
     return StmtError();
 
-  NamedReturnInfo NRInfo = getNamedReturnInfo(RetValExp);
-
   if (isa<CapturingScopeInfo>(getCurFunction()))
-    return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp, NRInfo);
+    return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp);
 
   QualType FnRetType;
   QualType RelatedRetType;
@@ -4049,7 +4016,6 @@ StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
       }
     }
   }
-  const VarDecl *NRVOCandidate = getCopyElisionCandidate(NRInfo, FnRetType);
 
   bool HasDependentReturnType = FnRetType->isDependentType();
 
@@ -4156,6 +4122,8 @@ StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
                                 /* NRVOCandidate=*/nullptr);
   } else {
     assert(RetValExp || HasDependentReturnType);
+    const VarDecl *NRVOCandidate = nullptr;
+
     QualType RetType = RelatedRetType.isNull() ? FnRetType : RelatedRetType;
 
     // C99 6.8.6.4p3(136): The return statement is not an assignment. The
@@ -4164,12 +4132,15 @@ StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
 
     // In C++ the return statement is handled via a copy initialization,
     // the C version of which boils down to CheckSingleAssignmentConstraints.
+    if (RetValExp)
+      NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
     if (!HasDependentReturnType && !RetValExp->isTypeDependent()) {
       // we have a non-void function with an expression, continue checking
-      InitializedEntity Entity = InitializedEntity::InitializeResult(
+      InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
-          ReturnLoc, RetType, NRVOCandidate != nullptr);
+                                                                     RetType,
-      ExprResult Res =
+                                                      NRVOCandidate != nullptr);
-          PerformMoveOrCopyInitialization(Entity, NRInfo, RetValExp);
+      ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
+                                                       RetType, RetValExp);
       if (Res.isInvalid()) {
         // FIXME: Clean up temporaries here anyway?
         return StmtError();

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -23,7 +23,6 @@
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/Sema/Lookup.h"
-#include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/SemaInternal.h"
 #include "clang/Sema/Template.h"
 #include "clang/Sema/TemplateInstCallback.h"
@@ -1086,30 +1085,11 @@ Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
 
   SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
                                      StartingScope, InstantiatingVarTemplate);
-  if (D->isNRVOVariable()) {
-    QualType RT;
-    if (auto *F = dyn_cast<FunctionDecl>(DC))
-      RT = F->getReturnType();
-    else if (isa<BlockDecl>(DC))
-      RT = cast<FunctionType>(SemaRef.getCurBlock()->FunctionType)
-               ->getReturnType();
-    else
-      llvm_unreachable("Unknown context type");
 
-    // This is the last chance we have of checking copy elision eligibility
+  if (D->isNRVOVariable()) {
-    // for functions in depdendent contexts. The sema actions for building
+    QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
-    // the return statement during template instantiation will have no effect
+    if (SemaRef.isCopyElisionCandidate(ReturnType, Var, Sema::CES_Strict))
-    // regarding copy elision, since NRVO propagation runs on the scope exit
+      Var->setNRVOVariable(true);
-    // actions, and these are not run on instantiation.
-    // This might run through some VarDecls which were returned from non-taken
-    // 'if constexpr' branches, and these will end up being constructed on the
-    // return slot even if they will never be returned, as a sort of accidental
-    // 'optimization'. Notably, functions with 'auto' return types won't have it
-    // deduced by this point. Coupled with the limitation described
-    // previously, this makes it very hard to support copy elision for these.
-    Sema::NamedReturnInfo Info = SemaRef.getNamedReturnInfo(Var);
-    bool NRVO = SemaRef.getCopyElisionCandidate(Info, RT) != nullptr;
-    Var->setNRVOVariable(NRVO);
   }
 
   Var->setImplicit(D->isImplicit());

clang/lib/Sema/SemaType.cpp

@@ -8899,10 +8899,6 @@ static QualType getDecltypeForExpr(Sema &S, Expr *E) {
   if (E->isTypeDependent())
     return S.Context.DependentTy;
 
-  Expr *IDExpr = E;
-  if (auto *ImplCastExpr = dyn_cast<ImplicitCastExpr>(E))
-    IDExpr = ImplCastExpr->getSubExpr();
-
   // C++11 [dcl.type.simple]p4:
   //   The type denoted by decltype(e) is defined as follows:
 
@@ -8913,7 +8909,7 @@ static QualType getDecltypeForExpr(Sema &S, Expr *E) {
   // Note that this does not pick up the implicit 'const' for a template
   // parameter object. This rule makes no difference before C++20 so we apply
   // it unconditionally.
-  if (const auto *SNTTPE = dyn_cast<SubstNonTypeTemplateParmExpr>(IDExpr))
+  if (const auto *SNTTPE = dyn_cast<SubstNonTypeTemplateParmExpr>(E))
     return SNTTPE->getParameterType(S.Context);
 
   //     - if e is an unparenthesized id-expression or an unparenthesized class
@@ -8922,22 +8918,21 @@ static QualType getDecltypeForExpr(Sema &S, Expr *E) {
   //       functions, the program is ill-formed;
   //
   // We apply the same rules for Objective-C ivar and property references.
-  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(IDExpr)) {
+  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
     const ValueDecl *VD = DRE->getDecl();
     if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(VD))
       return TPO->getType().getUnqualifiedType();
     return VD->getType();
-  } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(IDExpr)) {
+  } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
     if (const ValueDecl *VD = ME->getMemberDecl())
       if (isa<FieldDecl>(VD) || isa<VarDecl>(VD))
         return VD->getType();
-  } else if (const ObjCIvarRefExpr *IR = dyn_cast<ObjCIvarRefExpr>(IDExpr)) {
+  } else if (const ObjCIvarRefExpr *IR = dyn_cast<ObjCIvarRefExpr>(E)) {
     return IR->getDecl()->getType();
-  } else if (const ObjCPropertyRefExpr *PR =
+  } else if (const ObjCPropertyRefExpr *PR = dyn_cast<ObjCPropertyRefExpr>(E)) {
-                 dyn_cast<ObjCPropertyRefExpr>(IDExpr)) {
     if (PR->isExplicitProperty())
       return PR->getExplicitProperty()->getType();
-  } else if (auto *PE = dyn_cast<PredefinedExpr>(IDExpr)) {
+  } else if (auto *PE = dyn_cast<PredefinedExpr>(E)) {
     return PE->getType();
   }
 
@@ -8950,8 +8945,8 @@ static QualType getDecltypeForExpr(Sema &S, Expr *E) {
   //   entity.
   using namespace sema;
   if (S.getCurLambda()) {
-    if (isa<ParenExpr>(IDExpr)) {
+    if (isa<ParenExpr>(E)) {
-      if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(IDExpr->IgnoreParens())) {
+      if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParens())) {
         if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
           QualType T = S.getCapturedDeclRefType(Var, DRE->getLocation());
           if (!T.isNull())

clang/test/CXX/class/class.init/class.copy.elision/p3.cpp

@@ -1,8 +1,8 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -fcxx-exceptions -verify=expected,cxx20_2b,cxx2b %s
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -fcxx-exceptions -verify=expected,cxx20_2b %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_20,cxx20_2b %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -verify=expected,cxx20_2b %s
-// RUN: %clang_cc1 -std=c++17 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_17,cxx11_20 %s
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_17 %s
-// RUN: %clang_cc1 -std=c++14 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_17,cxx11_20 %s
+// RUN: %clang_cc1 -std=c++14 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_17 %s
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_17,cxx11_20 %s
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -fcxx-exceptions -verify=expected,cxx11_17 %s
 
 namespace test_delete_function {
 struct A1 {
@@ -409,10 +409,8 @@ Target t4() {
 namespace test_simpler_implicit_move {
 
 struct CopyOnly {
-  CopyOnly(); // cxx2b-note {{candidate constructor not viable: requires 0 arguments, but 1 was provided}}
+  CopyOnly();
-  // cxx2b-note@-1 {{candidate constructor not viable: requires 0 arguments, but 1 was provided}}
+  CopyOnly(CopyOnly &);
-  CopyOnly(CopyOnly &); // cxx2b-note {{candidate constructor not viable: expects an lvalue for 1st argument}}
-  // cxx2b-note@-1 {{candidate constructor not viable: expects an lvalue for 1st argument}}
 };
 struct MoveOnly {
   MoveOnly();
@@ -421,7 +419,7 @@ struct MoveOnly {
 MoveOnly &&rref();
 
 MoveOnly &&test1(MoveOnly &&w) {
-  return w; // cxx11_20-error {{cannot bind to lvalue of type}}
+  return w; // expected-error {{cannot bind to lvalue of type}}
 }
 
 CopyOnly test2(bool b) {
@@ -430,22 +428,22 @@ CopyOnly test2(bool b) {
   if (b) {
     return w1;
   } else {
-    return w2; // cxx2b-error {{no matching constructor for initialization}}
+    return w2;
   }
 }
 
-template <class T> T &&test3(T &&x) { return x; } // cxx11_20-error {{cannot bind to lvalue of type}}
+template <class T> T &&test3(T &&x) { return x; } // expected-error {{cannot bind to lvalue of type}}
 template MoveOnly& test3<MoveOnly&>(MoveOnly&);
-template MoveOnly &&test3<MoveOnly>(MoveOnly &&); // cxx11_20-note {{in instantiation of function template specialization}}
+template MoveOnly&& test3<MoveOnly>(MoveOnly&&); // expected-note {{in instantiation of function template specialization}}
 
 MoveOnly &&test4() {
   MoveOnly &&x = rref();
-  return x; // cxx11_20-error {{cannot bind to lvalue of type}}
+  return x; // expected-error {{cannot bind to lvalue of type}}
 }
 
 void test5() try {
   CopyOnly x;
-  throw x; // cxx2b-error {{no matching constructor for initialization}}
+  throw x;
 } catch (...) {
 }
 

clang/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.spec.auto/p7-cxx14.cpp

@@ -1,6 +1,6 @@
-// RUN: %clang_cc1 -verify -std=c++2b -verify=expected,cxx2b    %s
+// RUN: %clang_cc1 -verify -std=c++2b -verify %s
-// RUN: %clang_cc1 -verify -std=c++20 -verify=expected,cxx14_20 %s
+// RUN: %clang_cc1 -verify -std=c++20 -verify %s
-// RUN: %clang_cc1 -verify -std=c++14 -verify=expected,cxx14_20 %s
+// RUN: %clang_cc1 -verify -std=c++14 -verify %s
 
 namespace std {
   template<typename T> struct initializer_list {
@@ -30,7 +30,7 @@ using Int = decltype(x3d);
 auto x4a = (i);
 decltype(auto) x4d = (i);
 using Int = decltype(x4a);
-using IntLRef = decltype(x4d); // cxx2b-note {{previous definition is here}}
+using IntLRef = decltype(x4d);
 
 auto x5a = f();
 decltype(auto) x5d = f();
@@ -81,7 +81,7 @@ using Int = decltype(f2d(0));
 auto f3a(int n) { return (n); }
 decltype(auto) f3d(int n) { return (n); } // expected-warning {{reference to stack memory}}
 using Int = decltype(f3a(0));
-using IntLRef = decltype(f3d(0)); // cxx2b-error {{type alias redefinition with different types ('decltype(f3d(0))' (aka 'int &&') vs 'decltype(x4d)' (aka 'int &'))}}
+using IntLRef = decltype(f3d(0));
 
 auto f4a(int n) { return f(); }
 decltype(auto) f4d(int n) { return f(); }
@@ -91,7 +91,7 @@ using IntRRef = decltype(f4d(0));
 auto f5aa(int n) { auto x = f(); return x; }
 auto f5ad(int n) { decltype(auto) x = f(); return x; }
 decltype(auto) f5da(int n) { auto x = f(); return x; }
-decltype(auto) f5dd(int n) { decltype(auto) x = f(); return x; } // cxx14_20-error {{rvalue reference to type 'int' cannot bind to lvalue}}
+decltype(auto) f5dd(int n) { decltype(auto) x = f(); return x; } // expected-error {{rvalue reference to type 'int' cannot bind to lvalue}}
 using Int = decltype(f5aa(0));
 using Int = decltype(f5ad(0));
 using Int = decltype(f5da(0));

clang/test/CXX/drs/dr3xx.cpp

@@ -1,9 +1,9 @@
-// RUN: %clang_cc1 -std=c++2b -verify=expected,cxx20_2b,cxx2b    -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++2b -verify=expected,cxx20_2b -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++20 -verify=expected,cxx98_20,cxx20_2b -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++20 -verify=expected,cxx20_2b -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++17 -verify=expected,cxx98_17,cxx98_20 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++17 -verify=expected,cxx98_17 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++14 -verify=expected,cxx98_17,cxx98_20 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++14 -verify=expected,cxx98_17 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++11 -verify=expected,cxx98_17,cxx98_20 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++11 -verify=expected,cxx98_17 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++98 -verify=expected,cxx98_17,cxx98_20 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++98 -verify=expected,cxx98_17 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
 
 namespace dr300 { // dr300: yes
   template<typename R, typename A> void f(R (&)(A)) {}
@@ -628,8 +628,7 @@ namespace dr349 { // dr349: no
   struct A {
     template <class T> operator T ***() {
       int ***p = 0;
-      return p; // cxx98_20-error {{cannot initialize return object of type 'const int ***' with an lvalue of type 'int ***'}}
+      return p; // expected-error {{cannot initialize return object of type 'const int ***' with an lvalue of type 'int ***'}}
-      // cxx2b-error@-1 {{cannot initialize return object of type 'const int ***' with an rvalue of type 'int ***'}}
     }
   };
 

clang/test/CXX/expr/expr.prim/expr.prim.lambda/p4-cxx14.cpp

@@ -1,6 +1,6 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx2b    %s
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx14_20 %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14_20 %s
+// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify %s
 
 int a;
 int &b = [] (int &r) -> decltype(auto) { return r; } (a);
@@ -9,15 +9,13 @@ int &d = [] (int &r) -> auto & { return r; } (a);
 int &e = [] (int &r) -> auto { return r; } (a); // expected-error {{cannot bind to a temporary}}
 int &f = [] (int r) -> decltype(auto) { return r; } (a); // expected-error {{cannot bind to a temporary}}
 int &g = [] (int r) -> decltype(auto) { return (r); } (a); // expected-warning {{reference to stack}}
-// cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
 
 int test_explicit_auto_return()
 {
     struct X {};
     auto L = [](auto F, auto a) { return F(a); };
     auto M = [](auto a) -> auto { return a; }; // OK
-    auto MRef = [](auto b) -> auto & { return b; }; //cxx14_20-warning{{reference to stack}}
+    auto MRef = [](auto b) -> auto& { return b; }; //expected-warning{{reference to stack}}
-    // cxx2b-error@-1 {{non-const lvalue reference to type 'X' cannot bind to a temporary of type 'X'}}
     auto MPtr = [](auto c) -> auto* { return &c; }; //expected-warning{{address of stack}}
     auto MDeclType = [](auto&& d) -> decltype(auto) { return static_cast<decltype(d)>(d); }; //OK
     M(3);

clang/test/CXX/temp/temp.decls/temp.mem/p5.cpp

@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx2b    %s
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx98_20 %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++98 -fsyntax-only -verify=expected,cxx98_20 %s
+// RUN: %clang_cc1 -std=c++98 -fsyntax-only -verify %s
-// RUN: %clang_cc1            -fsyntax-only -verify=expected,cxx98_20 %s
+// RUN: %clang_cc1            -fsyntax-only -verify %s
 
 struct A {
   template <class T> operator T*();
@@ -67,10 +67,8 @@ struct X0 {
 
   template<typename T> operator const T*() const {
     T x = T();
-    return x; // cxx98_20-error{{cannot initialize return object of type 'const char *' with an lvalue of type 'char'}} \
+    return x; // expected-error{{cannot initialize return object of type 'const char *' with an lvalue of type 'char'}} \
-    // cxx98_20-error{{cannot initialize return object of type 'const int *' with an lvalue of type 'int'}} \
+    // expected-error{{cannot initialize return object of type 'const int *' with an lvalue of type 'int'}}
-    // cxx2b-error{{cannot initialize return object of type 'const char *' with an rvalue of type 'char'}} \
-    // cxx2b-error{{cannot initialize return object of type 'const int *' with an rvalue of type 'int'}}
   }
 };
 

clang/test/CodeGen/nrvo-tracking.cpp

@@ -29,6 +29,8 @@ L(2, t, X&);
 
 // CHECK-LABEL: define{{.*}} void @_Z2l3v
 // CHECK:       call {{.*}} @_ZN1XC1Ev
+// CHECK-NEXT:  call {{.*}} @_ZN1XC1EOS_
+// CHECK-NEXT:  call void @llvm.lifetime.end
 // CHECK-NEXT:  call void @llvm.lifetime.end
 // CHECK-NEXT:  ret void
 L(3, t, T);
@@ -150,11 +152,7 @@ F(8, (t), decltype(auto));
   }; }()();                                    \
 }
 
-// CHECK-LABEL: define{{.*}} void @_Z2b1v
+//B(1, X); // Uncomment this line at your own peril ;)
-// CHECK:       call {{.*}} @_ZN1XC1Ev
-// CHECK-NEXT:  call void @llvm.lifetime.end
-// CHECK-NEXT:  ret void
-B(1, X);
 
 // CHECK-LABEL: define{{.*}} void @_Z2b2v
 // CHECK:       call {{.*}} @_ZN1XC1Ev
@@ -166,6 +164,8 @@ B(2, X&);
 
 // CHECK-LABEL: define{{.*}} void @_Z2b3v
 // CHECK:       call {{.*}} @_ZN1XC1Ev
+// CHECK-NEXT:  call {{.*}} @_ZN1XC1EOS_
+// CHECK-NEXT:  call void @llvm.lifetime.end
 // CHECK-NEXT:  call void @llvm.lifetime.end
 // CHECK-NEXT:  ret void
 B(3, T);
@@ -187,24 +187,3 @@ B(4, T&);
 B(5, );
 
 #undef B
-
-// CHECK-LABEL: define{{.*}} void @_Z6f_attrv
-// CHECK:       call {{.*}} @_ZN1XC1Ev
-// CHECK-NEXT:  call void @llvm.lifetime.end
-// CHECK-NEXT:  ret void
-template<class T = X> [[gnu::cdecl]] static inline auto tf_attr() -> X {
-    T t;
-    return t;
-}
-void f_attr() { auto t = tf_attr(); }
-
-// CHECK-LABEL: define{{.*}} void @_Z6b_attrv
-// CHECK:       call {{.*}} @_ZN1XC1Ev
-// CHECK-NEXT:  call void @llvm.lifetime.end
-// CHECK-NEXT:  ret void
-void b_attr() {
-  auto t = []<class T = X>() { return ^ X () [[clang::vectorcall]] {
-      T t;
-      return t;
-  }; }()();
-}

clang/test/SemaCXX/constant-expression-cxx11.cpp

@@ -1,6 +1,6 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b,cxx2b    -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -Wno-c99-designator -fcxx-exceptions -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -Wno-c99-designator -fcxx-exceptions -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx11_20,cxx20_2b -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -Wno-c99-designator -fcxx-exceptions -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx20_2b -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -Wno-c99-designator -fcxx-exceptions -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify=expected,cxx11_20,cxx11    -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -Wno-c99-designator -fcxx-exceptions -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify=expected,cxx11 -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -Wno-c99-designator -fcxx-exceptions -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion
 
 namespace StaticAssertFoldTest {
 
@@ -1938,18 +1938,13 @@ namespace Lifetime {
   }
 
   constexpr int &get(int &&n) { return n; }
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
-  // cxx2b-error@-2 {{no return statement in constexpr function}} See PR40598
   constexpr int &&get_rv(int &&n) { return static_cast<int&&>(n); }
   struct S {
     int &&r;
     int &s;
     int t;
     constexpr S() : r(get_rv(0)), s(get(0)), t(r) {} // expected-note {{read of object outside its lifetime}}
-    constexpr S(int) : r(get_rv(0)), s(get(0)), t(s) {}
+    constexpr S(int) : r(get_rv(0)), s(get(0)), t(s) {} // expected-note {{read of object outside its lifetime}}
-    // cxx2b-warning@-1 {{reference 's' is not yet bound to a value when used here}}
-    // cxx2b-note@-2    {{read of uninitialized object is not allowed in a constant expression}}
-    // cxx11_20-note@-3 {{read of object outside its lifetime}}
   };
   constexpr int k1 = S().t; // expected-error {{constant expression}} expected-note {{in call}}
   constexpr int k2 = S(0).t; // expected-error {{constant expression}} expected-note {{in call}}

clang/test/SemaCXX/constant-expression-cxx14.cpp

@@ -1,6 +1,6 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b,cxx2b          %s -fcxx-exceptions -triple=x86_64-linux-gnu
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b %s -fcxx-exceptions -triple=x86_64-linux-gnu
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx14_20,cxx20_2b,cxx20 %s -fcxx-exceptions -triple=x86_64-linux-gnu
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx20_2b %s -fcxx-exceptions -triple=x86_64-linux-gnu
-// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14_20,cxx14          %s -fcxx-exceptions -triple=x86_64-linux-gnu
+// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14    %s -fcxx-exceptions -triple=x86_64-linux-gnu
 
 struct S {
   // dummy ctor to make this a literal type
@@ -269,23 +269,16 @@ namespace null {
 
 namespace incdec {
   template<typename T> constexpr T &ref(T &&r) { return r; }
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
   template<typename T> constexpr T postinc(T &&r) { return (r++, r); }
   template<typename T> constexpr T postdec(T &&r) { return (r--, r); }
 
-  template int &ref<int>(int &&);
-  // cxx2b-note@-1  {{in instantiation of function template specialization}}
-
-  static_assert(postinc(0) == 1, "");
-  static_assert(postdec(0) == -1, "");
-#if __cplusplus <= 202002L
   static_assert(++ref(0) == 1, "");
   static_assert(ref(0)++ == 0, "");
+  static_assert(postinc(0) == 1, "");
   static_assert(--ref(0) == -1, "");
   static_assert(ref(0)-- == 0, "");
-#endif
+  static_assert(postdec(0) == -1, "");
 
-#if __cplusplus <= 202002L
   constexpr int overflow_int_inc_1 = ref(0x7fffffff)++; // expected-error {{constant}} expected-note {{2147483648}}
   constexpr int overflow_int_inc_1_ok = ref(0x7ffffffe)++;
   constexpr int overflow_int_inc_2 = ++ref(0x7fffffff); // expected-error {{constant}} expected-note {{2147483648}}
@@ -298,42 +291,37 @@ namespace incdec {
   // inc on bool sets to true
   static_assert(++ref(false), "");
   // cxx14-warning@-1  {{incrementing expression of type bool}}
-  // cxx20-error@-2 {{incrementing expression of type bool}}
+  // cxx20_2b-error@-2 {{incrementing expression of type bool}}
   static_assert(++ref(true), "");
   // cxx14-warning@-1  {{incrementing expression of type bool}}
-  // cxx20-error@-2 {{incrementing expression of type bool}}
+  // cxx20_2b-error@-2 {{incrementing expression of type bool}}
-#endif
 
   int arr[10];
-  static_assert(postinc(&arr[0]) == &arr[1], "");
-  static_assert(postdec(&arr[1]) == &arr[0], "");
-#if __cplusplus <= 202002L
   static_assert(++ref(&arr[0]) == &arr[1], "");
   static_assert(++ref(&arr[9]) == &arr[10], "");
   static_assert(++ref(&arr[10]) == &arr[11], ""); // expected-error {{constant}} expected-note {{cannot refer to element 11}}
   static_assert(ref(&arr[0])++ == &arr[0], "");
   static_assert(ref(&arr[10])++ == &arr[10], ""); // expected-error {{constant}} expected-note {{cannot refer to element 11}}
+  static_assert(postinc(&arr[0]) == &arr[1], "");
   static_assert(--ref(&arr[10]) == &arr[9], "");
   static_assert(--ref(&arr[1]) == &arr[0], "");
   static_assert(--ref(&arr[0]) != &arr[0], ""); // expected-error {{constant}} expected-note {{cannot refer to element -1}}
   static_assert(ref(&arr[1])-- == &arr[1], "");
   static_assert(ref(&arr[0])-- == &arr[0], ""); // expected-error {{constant}} expected-note {{cannot refer to element -1}}
-#endif
+  static_assert(postdec(&arr[1]) == &arr[0], "");
 
-  static_assert(postinc(0.0) == 1.0, "");
-  static_assert(postdec(0.0) == -1.0, "");
-#if __cplusplus <= 202002L
   int x;
   static_assert(++ref(&x) == &x + 1, "");
 
   static_assert(++ref(0.0) == 1.0, "");
   static_assert(ref(0.0)++ == 0.0, "");
+  static_assert(postinc(0.0) == 1.0, "");
   static_assert(--ref(0.0) == -1.0, "");
   static_assert(ref(0.0)-- == 0.0, "");
+  static_assert(postdec(0.0) == -1.0, "");
 
   static_assert(++ref(1e100) == 1e100, "");
   static_assert(--ref(1e100) == 1e100, "");
-#endif
 
   union U {
     int a, b;
@@ -875,13 +863,9 @@ namespace VirtualFromBase {
 
 namespace Lifetime {
   constexpr int &get(int &&r) { return r; }
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
-  // cxx2b-error@-2 {{no return statement in constexpr function}} See PR40598
   constexpr int f() {
     int &r = get(123);
-    return r;
+    return r; // expected-note {{read of object outside its lifetime}}
-    // cxx2b-note@-1 {{use of reference outside its lifetime is not allowed in a constant expression}}
-    // cxx14_20-note@-2 {{read of object outside its lifetime}}
   }
   static_assert(f() == 123, ""); // expected-error {{constant expression}} expected-note {{in call}}
 

clang/test/SemaCXX/coroutine-rvo.cpp

@@ -39,14 +39,15 @@ struct suspend_never {
 };
 
 struct MoveOnly {
-  MoveOnly() = default;
+  MoveOnly() {};
   MoveOnly(const MoveOnly&) = delete;
-  MoveOnly(MoveOnly &&) = default;
+  MoveOnly(MoveOnly&&) noexcept {};
+  ~MoveOnly() {};
 };
 
 struct NoCopyNoMove {
   NoCopyNoMove() = default;
-  NoCopyNoMove(const NoCopyNoMove &) = delete;
+  NoCopyNoMove(const NoCopyNoMove &) = delete; // expected-note 4{{'NoCopyNoMove' has been explicitly marked deleted here}}
 };
 
 template <typename T>
@@ -62,12 +63,13 @@ struct task {
 
 task<NoCopyNoMove> local2val() {
   NoCopyNoMove value;
-  co_return value;
+  co_return value; // expected-error {{call to deleted constructor of 'NoCopyNoMove'}}
+  // expected-error@-1 {{value reference to type 'NoCopyNoMove' cannot bind to lvalue of type 'NoCopyNoMove'}}
 }
 
 task<NoCopyNoMove &> local2ref() {
   NoCopyNoMove value;
-  co_return value; // expected-error {{non-const lvalue reference to type 'NoCopyNoMove' cannot bind to a temporary of type 'NoCopyNoMove'}}
+  co_return value; // expected-error {{call to deleted constructor of 'NoCopyNoMove'}}
 }
 
 // We need the move constructor for construction of the coroutine.
@@ -80,7 +82,8 @@ task<NoCopyNoMove> lvalue2val(NoCopyNoMove &value) {
 }
 
 task<NoCopyNoMove> rvalue2val(NoCopyNoMove &&value) {
-  co_return value;
+  co_return value; // expected-error {{rvalue reference to type 'NoCopyNoMove' cannot bind to lvalue of type 'NoCopyNoMove'}}
+  // expected-error@-1 {{call to deleted constructor of 'NoCopyNoMove'}}
 }
 
 task<NoCopyNoMove &> lvalue2ref(NoCopyNoMove &value) {
@@ -88,7 +91,7 @@ task<NoCopyNoMove &> lvalue2ref(NoCopyNoMove &value) {
 }
 
 task<NoCopyNoMove &> rvalue2ref(NoCopyNoMove &&value) {
-  co_return value; // expected-error {{non-const lvalue reference to type 'NoCopyNoMove' cannot bind to a temporary of type 'NoCopyNoMove'}}
+  co_return value; // expected-error {{call to deleted constructor of 'NoCopyNoMove'}}
 }
 
 struct To {

clang/test/SemaCXX/coroutines.cpp

@@ -1,9 +1,9 @@
 // This file contains references to sections of the Coroutines TS, which can be
 // found at http://wg21.link/coroutines.
 
-// RUN: %clang_cc1 -std=c++2b                 -fsyntax-only -verify=expected,cxx20_2b,cxx2b    %s -fcxx-exceptions -fexceptions -Wunused-result
+// RUN: %clang_cc1 -std=c++2b                 -fsyntax-only -verify=expected,cxx20_2b %s -fcxx-exceptions -fexceptions -Wunused-result
-// RUN: %clang_cc1 -std=c++20                 -fsyntax-only -verify=expected,cxx14_20,cxx20_2b %s -fcxx-exceptions -fexceptions -Wunused-result
+// RUN: %clang_cc1 -std=c++20                 -fsyntax-only -verify=expected,cxx20_2b %s -fcxx-exceptions -fexceptions -Wunused-result
-// RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -fsyntax-only -verify=expected,cxx14_20          %s -fcxx-exceptions -fexceptions -Wunused-result
+// RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -fsyntax-only -verify=expected          %s -fcxx-exceptions -fexceptions -Wunused-result
 
 void no_coroutine_traits_bad_arg_await() {
   co_await a; // expected-error {{include <experimental/coroutine>}}
@@ -934,8 +934,7 @@ struct std::experimental::coroutine_traits<int, mismatch_gro_type_tag2> {
 };
 
 extern "C" int f(mismatch_gro_type_tag2) {
-  // cxx2b-error@-1 {{cannot initialize return object of type 'int' with an rvalue of type 'void *'}}
+  // expected-error@-1 {{cannot initialize return object of type 'int' with an lvalue of type 'void *'}}
-  // cxx14_20-error@-2 {{cannot initialize return object of type 'int' with an lvalue of type 'void *'}}
   co_return; //expected-note {{function is a coroutine due to use of 'co_return' here}}
 }
 

clang/test/SemaCXX/deduced-return-type-cxx14.cpp

@@ -1,11 +1,11 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b,cxx2b    %s
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b %s
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b,cxx2b    %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx20_2b %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
 
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx14_20,cxx20_2b %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx20_2b %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx14_20,cxx20_2b %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx20_2b %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
 
-// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14_20,cxx14    %s
+// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14    %s
-// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14_20,cxx14    %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
+// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=expected,cxx14    %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
 
 auto f(); // expected-note {{previous}}
 int f(); // expected-error {{differ only in their return type}}
@@ -129,14 +129,10 @@ namespace Templates {
     return T() + 1;
   }
   template<typename T> auto &f2(T &&v) { return v; }
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
-  // cxx2b-error@-2 {{non-const lvalue reference to type 'double' cannot bind to a temporary of type 'double'}}
-  // cxx2b-note@-3  {{candidate template ignored: substitution failure [with T = double]}}
   int a = f1<int>();
-  const int &b = f2(0); // cxx2b-note {{in instantiation of function template specialization 'Templates::f2<int>' requested here}}
+  const int &b = f2(0);
   double d;
   float &c = f2(0.0); // expected-error {{non-const lvalue reference to type 'float' cannot bind to a value of unrelated type 'double'}}
-  // cxx2b-note@-1 {{in instantiation of function template specialization 'Templates::f2<double>' requested here}}
 
   template<typename T> auto fwd_decl(); // expected-note {{declared here}}
   int e = fwd_decl<int>(); // expected-error {{cannot be used before it is defined}}
@@ -149,9 +145,8 @@ namespace Templates {
   auto (*p)() = f1; // expected-error {{incompatible initializer}}
   auto (*q)() = f1<int>; // ok
 
-  typedef decltype(f2(1.2)) dbl; // cxx14_20-note {{previous}}
+  typedef decltype(f2(1.2)) dbl; // expected-note {{previous}}
-  // cxx2b-error@-1 {{no matching function for call to 'f2'}}
+  typedef float dbl; // expected-error {{typedef redefinition with different types ('float' vs 'decltype(f2(1.2))' (aka 'double &'))}}
-  typedef float dbl; // cxx14_20-error {{typedef redefinition with different types ('float' vs 'decltype(f2(1.2))' (aka 'double &'))}}
 
   extern template auto fwd_decl<double>();
   int k1 = fwd_decl<double>();

clang/test/SemaCXX/return-stack-addr.cpp

@@ -1,6 +1,6 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected,cxx2b          %s
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=expected       %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected,cxx11_20       %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=expected       %s
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify=expected,cxx11_20,cxx11 %s
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify=expected,cxx11 %s
 
 int* ret_local() {
   int x = 1;
@@ -29,8 +29,7 @@ int* ret_local_array_element_const_index() {
 
 int& ret_local_ref() {
   int x = 1;
-  return x; // cxx11_20-warning {{reference to stack memory}}
+  return x;  // expected-warning {{reference to stack memory}}
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
 }
 
 int* ret_local_addrOf() {
@@ -155,10 +154,8 @@ void ret_from_lambda() {
   (void) [&]() -> int& { return b; };
   (void) [=]() mutable -> int& { return a; };
   (void) [=]() mutable -> int& { return b; };
-  (void) [&]() -> int& { int a; return a; }; // cxx11_20-warning {{reference to stack}}
+  (void) [&]() -> int& { int a; return a; }; // expected-warning {{reference to stack}}
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
+  (void) [=]() -> int& { int a; return a; }; // expected-warning {{reference to stack}}
-  (void) [=]() -> int& { int a; return a; }; // cxx11_20-warning {{reference to stack}}
-  // cxx2b-error@-1 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
   (void) [&]() -> int& { int &a = b; return a; };
   (void) [=]() mutable -> int& { int &a = b; return a; };
 

clang/test/SemaCXX/warn-return-std-move.cpp

@@ -1,8 +1,8 @@
-// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=cxx20_2b,cxx2b -fcxx-exceptions -Wreturn-std-move %s
+// RUN: %clang_cc1 -std=c++2b -fsyntax-only -verify=cxx20_2b -fcxx-exceptions -Wreturn-std-move %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=cxx20_2b       -fcxx-exceptions -Wreturn-std-move %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=cxx20_2b -fcxx-exceptions -Wreturn-std-move %s
-// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify=cxx11_17       -fcxx-exceptions -Wreturn-std-move %s
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify=cxx11_17 -fcxx-exceptions -Wreturn-std-move %s
-// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=cxx11_17       -fcxx-exceptions -Wreturn-std-move %s
+// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify=cxx11_17 -fcxx-exceptions -Wreturn-std-move %s
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify=cxx11_17       -fcxx-exceptions -Wreturn-std-move %s
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify=cxx11_17 -fcxx-exceptions -Wreturn-std-move %s
 
 // RUN: %clang_cc1 -std=c++17 -fsyntax-only -fcxx-exceptions -Wreturn-std-move -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s -check-prefix=CHECK
 // RUN: %clang_cc1 -std=c++14 -fsyntax-only -fcxx-exceptions -Wreturn-std-move -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s -check-prefix=CHECK
@@ -217,8 +217,8 @@ ConvertFromBase testRParam6(Derived&& d) {
 }
 
 // But if the return type is a reference type, then moving would be wrong.
-Derived &testRetRef1(Derived &&d) { return d; } // cxx2b-error {{non-const lvalue reference to type 'Derived' cannot bind to a temporary of type 'Derived'}}
+Derived& testRetRef1(Derived&& d) { return d; }
-Base &testRetRef2(Derived &&d) { return d; }    // cxx2b-error {{non-const lvalue reference to type 'Base' cannot bind to a temporary of type 'Derived'}}
+Base& testRetRef2(Derived&& d) { return d; }
 #if __cplusplus >= 201402L
 auto&& testRetRef3(Derived&& d) { return d; }
 decltype(auto) testRetRef4(Derived&& d) { return (d); }