[Clang][OpenMP] Add parse and sema for iterator map modifier

[doru1004]

Summary

This patch adds parse and sema support for iterator map modifier.

[ABataev]

clang/include/clang/AST/OpenMPClause.h

5780

We're using tail allocation for such objects.

[ABataev]

Erroneous test are required

clang/include/clang/AST/OpenMPClause.h

310–314

Why do we need it here, if it is specific to map clause?

317

Why ArrayRef if only one expression is expected?

5914–5916

Just getIteratorRef() should be enough.

clang/lib/Sema/SemaOpenMP.cpp

1166–1169

Use llvm::any_of()

[ABataev]

clang/include/clang/AST/OpenMPClause.h

5866–5867

Can we use just a nullptr as a mark that there is no associated iterator?

clang/include/clang/Parse/Parser.h

3474–3475 ↗

(On Diff #489917)

Where is it defined, cannot find it in the patch?

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

Do you really need to store the variable in the stack, is not it enough just to check that the type of this variable is BuiltinType::OMPIterator?

clang/test/OpenMP/target_map_messages.cpp

256–257

Cases with incorrect parsing, wrong variables etc.?

[doru1004]

clang/include/clang/Parse/Parser.h

3474–3475 ↗

(On Diff #489917)

Leftover, removed it.

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

I'm happy to replace this if you think it will work. Is there an example somewhere in the code where I can get from the VarDecl to the build in type you mention?

[ABataev]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

You have already a check IteratorModifier->getType()->isSpecificBuiltinType(BuiltinType::OMPIterator), you can you something similar for the variable

[ABataev]

clang/include/clang/AST/OpenMPClause.h

5779–5780

It can be removed

clang/test/OpenMP/target_map_messages.cpp

970–979

Test cases for wrong variables in mappers?

[doru1004]

clang/test/OpenMP/target_map_messages.cpp

970–979

You mean as part of the iterator ? like iterator(it = 0:UndefVar) ?

[ABataev]

clang/test/OpenMP/target_map_messages.cpp

970–979

I mean, you have a check that in mappers only iterator vars are allowed. Can you add a check for this?

[doru1004]

clang/test/OpenMP/target_map_messages.cpp

970–979

As far as I understand it the additional check I added to the existing mapper checks is needed because of the way the mapper check was written. The mapper checks looks at declarations and if a mapper clause exists then it assumes that the declaration must be coming from that mapper clause. This used to hold in the past since that was the only way you could have a declaration. This is not true anymore since we can now have declarations coming from both the mapper and the iterator modifier. I'll add a test to showcase this.

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

This didn't work and I had to revert to using the stack!

[ABataev]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

Why?

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

I checked the output of the check and it was false when it should have been true! If you check the latest test that I added it showcases the source code and in the case of OpenMP 5.2 you can see that the message "only variable 'vvec' is allowed in map clauses of this 'omp declare mapper' directive" doesn't appear when a legal iteration variable is used.
If I used the check you suggested then the error message appears.
In the example you pasted the check is performed on a Expr *. In the case here, we only have VD which is a VarDecl.

[ABataev]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

Did not get it. It still shall be of type builtintype::OMPIterator.

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

I am not sure how I can force it to have that type when it just doesn't. Do you have any suggestions?

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

The VD that we are checking for this builtin is coming from somewhere else in the code, it is passed into the Sema::DiagnoseUseOfDecl( function. It's not a VarDecl that is under the control of anything added in this patch.

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

This implementation is in line with the current checks for the declaration of the mapper variable. You store the declaration onto the stack so that you can compare it with the incoming VarDecl passed to the diagnose function.

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

1166–1168

Some debug printouts regarding VD:

VD->dump();

VarDecl 0x55b57f81dec8 <test_declare_mapper_iterator.c:26:52> col:52 implicit used it 'int'

This is the type of the variable if you do VD->getType()->dump():

BuiltinType 0x55b57f6d2560 'int'

[doru1004]

clang/lib/Sema/SemaOpenMP.cpp

22400–22413

This input to this function is the VD variable I've been talking about. If you print it all out it's just a simple VarDecl:

if you do VD->dump();

VarDecl 0x55b57f81dec8 <test_declare_mapper_iterator.c:26:52> col:52 implicit used it 'int'

if you do VD->getType()->dump():

BuiltinType 0x55b57f6d2560 'int'

[ABataev]

Can you add positive test for declare mapper?

clang/lib/Sema/SemaExpr.cpp

5423–5426

Can we register this variable only in declare mapper context, i.e. add a check that we add it only for declare mapper?

[doru1004]

clang/test/OpenMP/declare_mapper_messages.c

33–36

Here we have both the positive and the negative declare mapper cases. Please let me know if you meant something different.

[doru1004]

clang/lib/Sema/SemaExpr.cpp

5423–5426

Happy to do that!

[ABataev]

clang/test/OpenMP/declare_mapper_messages.c

33–36

Would be good to have ast print case and codegen

[doru1004]

clang/test/OpenMP/declare_mapper_messages.c

33–36

I can add ast print! Code gen for this map modifier is going to be done in a separate patch.

[ABataev]

clang/test/OpenMP/declare_mapper_messages.c

33–36

Ok, a st print should be enough

[ABataev]

LG

[doru1004]

Commit 49d47c4d2f280d15d1de94c53b72b6ab3c127b35

clang/include/clang/AST/OpenMPClause.h

protected:
   /// Sets the list of variables for this clause.
   void setVarRefs(ArrayRef<Expr *> VL) {
     assert(VL.size() == NumVars &&
            "Number of variables is not the same as the preallocated buffer");
     std::copy(VL.begin(), VL.end(),
               static_cast<T *>(this)->template getTrailingObjects<Expr *>());
   }
 
 public:
   using varlist_iterator = MutableArrayRef<Expr *>::iterator;
   using varlist_const_iterator = ArrayRef<const Expr *>::iterator;
   using varlist_range = llvm::iterator_range<varlist_iterator>;
   using varlist_const_range = llvm::iterator_range<varlist_const_iterator>;
 
   unsigned varlist_size() const { return NumVars; }
   bool varlist_empty() const { return NumVars == 0; }
 
   varlist_range varlists() {
     return varlist_range(varlist_begin(), varlist_end());
   }
   varlist_const_range varlists() const {
     return varlist_const_range(varlist_begin(), varlist_end());
   }
 
class OMPMapClause final : public OMPMappableExprListClause<OMPMapClause>,
   friend OMPVarListClause;
   friend TrailingObjects;
 
   /// Define the sizes of each trailing object array except the last one. This
   /// is required for TrailingObjects to work properly.
   size_t numTrailingObjects(OverloadToken<Expr *>) const {
     // There are varlist_size() of expressions, and varlist_size() of
     // user-defined mappers.
-    return 2 * varlist_size();
+    return 2 * varlist_size() + 1;
   }
   size_t numTrailingObjects(OverloadToken<ValueDecl *>) const {
     return getUniqueDeclarationsNum();
   }
   size_t numTrailingObjects(OverloadToken<unsigned>) const {
     return getUniqueDeclarationsNum() + getTotalComponentListNum();
   }
 
 private:
   /// Map-type-modifiers for the 'map' clause.
   OpenMPMapModifierKind MapTypeModifiers[NumberOfOMPMapClauseModifiers] = {
       OMPC_MAP_MODIFIER_unknown, OMPC_MAP_MODIFIER_unknown,
       OMPC_MAP_MODIFIER_unknown, OMPC_MAP_MODIFIER_unknown,
-      OMPC_MAP_MODIFIER_unknown};
+      OMPC_MAP_MODIFIER_unknown, OMPC_MAP_MODIFIER_unknown};
 
   /// Location of map-type-modifiers for the 'map' clause.
   SourceLocation MapTypeModifiersLoc[NumberOfOMPMapClauseModifiers];
 
   /// Map type for the 'map' clause.
   OpenMPMapClauseKind MapType = OMPC_MAP_unknown;
 
   /// Is this an implicit map type or not.
   bool MapTypeIsImplicit = false;
 
   /// Location of the map type.
   SourceLocation MapLoc;
 
   /// Colon location.
   SourceLocation ColonLoc;
 
   /// Build a clause for \a NumVars listed expressions, \a
   /// NumUniqueDeclarations declarations, \a NumComponentLists total component
   /// lists, and \a NumComponents total expression components.
   ///
   /// \param MapModifiers Map-type-modifiers.
   /// \param MapModifiersLoc Locations of map-type-modifiers.
   /// \param MapperQualifierLoc C++ nested name specifier for the associated
   /// user-defined mapper.
   /// \param MapperIdInfo The identifier of associated user-defined mapper.
   /// \param MapType Map type.
private:
   /// Set type location.
   ///
   /// \param TLoc Type location.
   void setMapLoc(SourceLocation TLoc) { MapLoc = TLoc; }
 
   /// Set colon location.
   void setColonLoc(SourceLocation Loc) { ColonLoc = Loc; }
 
+  /// Set iterator modifier.
+  void setIteratorModifier(Expr *IteratorModifier) {
+    getTrailingObjects<Expr *>()[2 * varlist_size()] = IteratorModifier;
+  }
+
 public:
   /// Creates clause with a list of variables \a VL.
   ///
   /// \param C AST context.
   /// \param Locs Locations needed to build a mappable clause. It includes 1)
   /// StartLoc: starting location of the clause (the clause keyword); 2)
   /// LParenLoc: location of '('; 3) EndLoc: ending location of the clause.
   /// \param Vars The original expression used in the clause.
   /// \param Declarations Declarations used in the clause.
   /// \param ComponentLists Component lists used in the clause.
   /// \param UDMapperRefs References to user-defined mappers associated with
   /// expressions used in the clause.
+  /// \param IteratorModifier Iterator modifier.
   /// \param MapModifiers Map-type-modifiers.
   /// \param MapModifiersLoc Location of map-type-modifiers.
   /// \param UDMQualifierLoc C++ nested name specifier for the associated
   /// user-defined mapper.
   /// \param MapperId The identifier of associated user-defined mapper.
   /// \param Type Map type.
   /// \param TypeIsImplicit Map type is inferred implicitly.
   /// \param TypeLoc Location of the map type.
   static OMPMapClause *
   Create(const ASTContext &C, const OMPVarListLocTy &Locs,
          ArrayRef<Expr *> Vars, ArrayRef<ValueDecl *> Declarations,
          MappableExprComponentListsRef ComponentLists,
-         ArrayRef<Expr *> UDMapperRefs,
+         ArrayRef<Expr *> UDMapperRefs, Expr *IteratorModifier,
          ArrayRef<OpenMPMapModifierKind> MapModifiers,
          ArrayRef<SourceLocation> MapModifiersLoc,
          NestedNameSpecifierLoc UDMQualifierLoc, DeclarationNameInfo MapperId,
          OpenMPMapClauseKind Type, bool TypeIsImplicit, SourceLocation TypeLoc);
 
   /// Creates an empty clause with the place for \a NumVars original
   /// expressions, \a NumUniqueDeclarations declarations, \NumComponentLists
   /// lists, and \a NumComponents expression components.
   ///
   /// \param C AST context.
   /// \param Sizes All required sizes to build a mappable clause. It includes 1)
   /// NumVars: number of expressions listed in this clause; 2)
   /// NumUniqueDeclarations: number of unique base declarations in this clause;
   /// 3) NumComponentLists: number of component lists in this clause; and 4)
   /// NumComponents: total number of expression components in the clause.
   static OMPMapClause *CreateEmpty(const ASTContext &C,
                                    const OMPMappableExprListSizeTy &Sizes);
 
+  /// Fetches Expr * of iterator modifier.
+  Expr *getIteratorModifier() {
+    return getTrailingObjects<Expr *>()[2 * varlist_size()];
+  }
+
   /// Fetches mapping kind for the clause.
   OpenMPMapClauseKind getMapType() const LLVM_READONLY { return MapType; }
 
   /// Is this an implicit map type?
   /// We have to capture 'IsMapTypeImplicit' from the parser for more
   /// informative error messages.  It helps distinguish map(r) from
   /// map(tofrom: r), which is important to print more helpful error
   /// messages for some target directives.

clang/include/clang/Basic/DiagnosticParseKinds.td

 def err_omp_expected_punc_after_iterator : Error<
   "expected ',' or ')' after iterator specifier">;
 def err_omp_decl_in_declare_simd_variant : Error<
   "function declaration is expected after 'declare %select{simd|variant}0' directive">;
 def err_omp_unknown_map_type : Error<
   "incorrect map type, expected one of 'to', 'from', 'tofrom', 'alloc', 'release', or 'delete'">;
 def err_omp_unknown_map_type_modifier : Error<
   "incorrect map type modifier, expected one of: 'always', 'close', 'mapper'"
-  "%select{|, 'present'}0%select{|, 'ompx_hold'}1">;
+  "%select{|, 'present'|, 'present', 'iterator'}0%select{|, 'ompx_hold'}1">;
 def err_omp_map_type_missing : Error<
   "missing map type">;
 def err_omp_map_type_modifier_missing : Error<
   "missing map type modifier">;
 def err_omp_declare_simd_inbranch_notinbranch : Error<
   "unexpected '%0' clause, '%1' is specified already">;
 def err_expected_end_declare_target_or_variant : Error<
   "expected '#pragma omp end declare %select{target|variant}0'">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

 def err_omp_depend_sink_source_not_allowed : Error<
   "'depend(%select{source|sink:vec}0)' clause%select{|s}0 cannot be mixed with 'depend(%select{sink:vec|source}0)' clause%select{s|}0">;
 def err_omp_depend_zero_length_array_section_not_allowed : Error<
   "zero-length array section is not allowed in 'depend' clause">;
 def err_omp_depend_sink_source_with_modifier : Error<
   "depend modifier cannot be used with 'sink' or 'source' depend type">;
 def err_omp_depend_modifier_not_iterator : Error<
   "expected iterator specification as depend modifier">;
+def err_omp_map_modifier_not_iterator : Error<
+  "expected iterator specification as map modifier">;
 def err_omp_linear_ordered : Error<
   "'linear' clause cannot be specified along with 'ordered' clause with a parameter">;
 def err_omp_unexpected_schedule_modifier : Error<
   "modifier '%0' cannot be used along with modifier '%1'">;
 def err_omp_schedule_nonmonotonic_static : Error<
   "'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind">;
 def err_omp_simple_clause_incompatible_with_ordered : Error<
   "'%0' clause with '%1' modifier cannot be specified if an 'ordered' clause is specified">;

clang/include/clang/Basic/OpenMPKinds.h

 enum OpenMPMapModifierKind {
   OMPC_MAP_MODIFIER_unknown = OMPC_MAP_unknown,
 #define OPENMP_MAP_MODIFIER_KIND(Name) \
   OMPC_MAP_MODIFIER_##Name,
 #include "clang/Basic/OpenMPKinds.def"
   OMPC_MAP_MODIFIER_last
 };
 
-  /// Number of allowed map-type-modifiers.
 static constexpr unsigned NumberOfOMPMapClauseModifiers =
     OMPC_MAP_MODIFIER_last - OMPC_MAP_MODIFIER_unknown - 1;
 
 /// OpenMP modifier kind for 'to' or 'from' clause.
 enum OpenMPMotionModifierKind {
 #define OPENMP_MOTION_MODIFIER_KIND(Name) \
   OMPC_MOTION_MODIFIER_##Name,
 #include "clang/Basic/OpenMPKinds.def"

clang/include/clang/Basic/OpenMPKinds.def

 OPENMP_MAP_KIND(tofrom)
 OPENMP_MAP_KIND(delete)
 OPENMP_MAP_KIND(release)
 
 // Map-type-modifiers for 'map' clause.
 OPENMP_MAP_MODIFIER_KIND(always)
 OPENMP_MAP_MODIFIER_KIND(close)
 OPENMP_MAP_MODIFIER_KIND(mapper)
+OPENMP_MAP_MODIFIER_KIND(iterator)
 OPENMP_MAP_MODIFIER_KIND(present)
 // This is an OpenMP extension for the sake of OpenACC support.
 OPENMP_MAP_MODIFIER_KIND(ompx_hold)
 
 // Modifiers for 'to' or 'from' clause.
 OPENMP_MOTION_MODIFIER_KIND(mapper)
 OPENMP_MOTION_MODIFIER_KIND(present)
 

clang/include/clang/Sema/Sema.h

DeclGroupPtrTy ActOnOpenMPDeclareMapperDirective(
       SourceLocation StartLoc, DeclarationName VN, AccessSpecifier AS,
       Expr *MapperVarRef, ArrayRef<OMPClause *> Clauses,
       Decl *PrevDeclInScope = nullptr);
   /// Build the mapper variable of '#pragma omp declare mapper'.
   ExprResult ActOnOpenMPDeclareMapperDirectiveVarDecl(Scope *S,
                                                       QualType MapperType,
                                                       SourceLocation StartLoc,
                                                       DeclarationName VN);
+  void ActOnOpenMPIteratorVarDecl(VarDecl *VD);
   bool isOpenMPDeclareMapperVarDeclAllowed(const VarDecl *VD) const;
   const ValueDecl *getOpenMPDeclareMapperVarName() const;
 
   /// Called on the start of target region i.e. '#pragma omp declare target'.
   bool ActOnStartOpenMPDeclareTargetContext(DeclareTargetContextInfo &DTCI);
 
   /// Called at the end of target region i.e. '#pragma omp end declare target'.
   const DeclareTargetContextInfo ActOnOpenMPEndDeclareTargetDirective();
public:
   /// passing string for message.
   OMPClause *ActOnOpenMPMessageClause(Expr *MS, SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
 
   /// Data used for processing a list of variables in OpenMP clauses.
   struct OpenMPVarListDataTy final {
     Expr *DepModOrTailExpr = nullptr;
+    Expr *IteratorExpr = nullptr;
     SourceLocation ColonLoc;
     SourceLocation RLoc;
     CXXScopeSpec ReductionOrMapperIdScopeSpec;
     DeclarationNameInfo ReductionOrMapperId;
     int ExtraModifier = -1; ///< Additional modifier for linear, map, depend or
                             ///< lastprivate clause.
     SmallVector<OpenMPMapModifierKind, NumberOfOMPMapClauseModifiers>
         MapTypeModifiers;

   /// Called on well-formed 'device' clause.
   OMPClause *ActOnOpenMPDeviceClause(OpenMPDeviceClauseModifier Modifier,
                                      Expr *Device, SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation ModifierLoc,
                                      SourceLocation EndLoc);
   /// Called on well-formed 'map' clause.
   OMPClause *ActOnOpenMPMapClause(
-      ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
+      Expr *IteratorModifier, ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
       ArrayRef<SourceLocation> MapTypeModifiersLoc,
       CXXScopeSpec &MapperIdScopeSpec, DeclarationNameInfo &MapperId,
       OpenMPMapClauseKind MapType, bool IsMapTypeImplicit,
       SourceLocation MapLoc, SourceLocation ColonLoc, ArrayRef<Expr *> VarList,
       const OMPVarListLocTy &Locs, bool NoDiagnose = false,
       ArrayRef<Expr *> UnresolvedMappers = std::nullopt);
   /// Called on well-formed 'num_teams' clause.
   OMPClause *ActOnOpenMPNumTeamsClause(Expr *NumTeams, SourceLocation StartLoc,

clang/lib/AST/OpenMPClause.cpp

unsigned OMPClauseMappableExprCommon::getUniqueDeclarationsTotalNumber(
   }
   return TotalNum;
 }
 
 OMPMapClause *OMPMapClause::Create(
     const ASTContext &C, const OMPVarListLocTy &Locs, ArrayRef<Expr *> Vars,
     ArrayRef<ValueDecl *> Declarations,
     MappableExprComponentListsRef ComponentLists, ArrayRef<Expr *> UDMapperRefs,
-    ArrayRef<OpenMPMapModifierKind> MapModifiers,
+    Expr *IteratorModifier, ArrayRef<OpenMPMapModifierKind> MapModifiers,
     ArrayRef<SourceLocation> MapModifiersLoc,
     NestedNameSpecifierLoc UDMQualifierLoc, DeclarationNameInfo MapperId,
     OpenMPMapClauseKind Type, bool TypeIsImplicit, SourceLocation TypeLoc) {
   OMPMappableExprListSizeTy Sizes;
   Sizes.NumVars = Vars.size();
   Sizes.NumUniqueDeclarations = getUniqueDeclarationsTotalNumber(Declarations);
   Sizes.NumComponentLists = ComponentLists.size();
   Sizes.NumComponents = getComponentsTotalNumber(ComponentLists);
 
   // We need to allocate:
   // 2 x NumVars x Expr* - we have an original list expression and an associated
   // user-defined mapper for each clause list entry.
   // NumUniqueDeclarations x ValueDecl* - unique base declarations associated
   // with each component list.
   // (NumUniqueDeclarations + NumComponentLists) x unsigned - we specify the
   // number of lists for each unique declaration and the size of each component
   // list.
   // NumComponents x MappableComponent - the total of all the components in all
   // the lists.
   void *Mem = C.Allocate(
       totalSizeToAlloc<Expr *, ValueDecl *, unsigned,
                        OMPClauseMappableExprCommon::MappableComponent>(
-          2 * Sizes.NumVars, Sizes.NumUniqueDeclarations,
+          2 * Sizes.NumVars + 1, Sizes.NumUniqueDeclarations,
           Sizes.NumUniqueDeclarations + Sizes.NumComponentLists,
           Sizes.NumComponents));
   OMPMapClause *Clause = new (Mem)
       OMPMapClause(MapModifiers, MapModifiersLoc, UDMQualifierLoc, MapperId,
                    Type, TypeIsImplicit, TypeLoc, Locs, Sizes);
 
   Clause->setVarRefs(Vars);
   Clause->setUDMapperRefs(UDMapperRefs);
+  Clause->setIteratorModifier(IteratorModifier);
   Clause->setClauseInfo(Declarations, ComponentLists);
   Clause->setMapType(Type);
   Clause->setMapLoc(TypeLoc);
   return Clause;
 }
 
 OMPMapClause *
 OMPMapClause::CreateEmpty(const ASTContext &C,
                           const OMPMappableExprListSizeTy &Sizes) {
   void *Mem = C.Allocate(
       totalSizeToAlloc<Expr *, ValueDecl *, unsigned,
                        OMPClauseMappableExprCommon::MappableComponent>(
-          2 * Sizes.NumVars, Sizes.NumUniqueDeclarations,
+          2 * Sizes.NumVars + 1, Sizes.NumUniqueDeclarations,
           Sizes.NumUniqueDeclarations + Sizes.NumComponentLists,
           Sizes.NumComponents));
-  return new (Mem) OMPMapClause(Sizes);
+  OMPMapClause *Clause = new (Mem) OMPMapClause(Sizes);
+  Clause->setIteratorModifier(nullptr);
+  return Clause;
 }
 
 OMPToClause *OMPToClause::Create(
     const ASTContext &C, const OMPVarListLocTy &Locs, ArrayRef<Expr *> Vars,
     ArrayRef<ValueDecl *> Declarations,
     MappableExprComponentListsRef ComponentLists, ArrayRef<Expr *> UDMapperRefs,
     ArrayRef<OpenMPMotionModifierKind> MotionModifiers,
     ArrayRef<SourceLocation> MotionModifiersLoc,
static void PrintMapper(raw_ostream &OS, T *Node,
   OS << '(';
   NestedNameSpecifier *MapperNNS =
       Node->getMapperQualifierLoc().getNestedNameSpecifier();
   if (MapperNNS)
     MapperNNS->print(OS, Policy);
   OS << Node->getMapperIdInfo() << ')';
 }
 
+template <typename T>
+static void PrintIterator(raw_ostream &OS, T *Node,
+                          const PrintingPolicy &Policy) {
+  if (Expr *IteratorModifier = Node->getIteratorModifier())
+    IteratorModifier->printPretty(OS, nullptr, Policy);
+}
+
 void OMPClausePrinter::VisitOMPMapClause(OMPMapClause *Node) {
   if (!Node->varlist_empty()) {
     OS << "map(";
     if (Node->getMapType() != OMPC_MAP_unknown) {
       for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
         if (Node->getMapTypeModifier(I) != OMPC_MAP_MODIFIER_unknown) {
+          if (Node->getMapTypeModifier(I) == OMPC_MAP_MODIFIER_iterator) {
+            PrintIterator(OS, Node, Policy);
+          } else {
             OS << getOpenMPSimpleClauseTypeName(OMPC_map,
                                                 Node->getMapTypeModifier(I));
             if (Node->getMapTypeModifier(I) == OMPC_MAP_MODIFIER_mapper)
               PrintMapper(OS, Node, Policy);
+          }
           OS << ',';
         }
       }
       OS << getOpenMPSimpleClauseTypeName(OMPC_map, Node->getMapType());
       OS << ':';
     }
     VisitOMPClauseList(Node, ' ');
     OS << ")";

clang/lib/Parse/ParseOpenMP.cpp

if (TypeModifier == OMPC_MAP_MODIFIER_always ||
         Diag(Tok, diag::err_omp_map_type_modifier_missing);
         ConsumeToken();
         continue;
       }
       // Potential map-type token as it is followed by a colon.
       if (PP.LookAhead(0).is(tok::colon))
         return false;
       Diag(Tok, diag::err_omp_unknown_map_type_modifier)
-          << (getLangOpts().OpenMP >= 51 ? 1 : 0)
+          << (getLangOpts().OpenMP >= 51 ? (getLangOpts().OpenMP >= 52 ? 2 : 1)
+                                         : 0)
           << getLangOpts().OpenMPExtensions;
       ConsumeToken();
     }
     if (getCurToken().is(tok::comma))
       ConsumeToken();
   }
   return false;
 }
bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
 
   // Parse '('.
   BalancedDelimiterTracker T(*this, tok::l_paren, tok::annot_pragma_openmp_end);
   if (T.expectAndConsume(diag::err_expected_lparen_after,
                          getOpenMPClauseName(Kind).data()))
     return true;
 
   bool HasIterator = false;
+  bool InvalidIterator = false;
   bool NeedRParenForLinear = false;
   BalancedDelimiterTracker LinearT(*this, tok::l_paren,
                                    tok::annot_pragma_openmp_end);
   // Handle reduction-identifier for reduction clause.
   if (Kind == OMPC_reduction || Kind == OMPC_task_reduction ||
       Kind == OMPC_in_reduction) {
     Data.ExtraModifier = OMPC_REDUCTION_unknown;
     if (Kind == OMPC_reduction && getLangOpts().OpenMP >= 50 &&
if ((getLangOpts().OpenMP >= 50 && !isOpenMPDistributeDirective(DKind) &&
       Data.ExtraModifier =
           getOpenMPSimpleClauseType(Kind, PP.getSpelling(Tok), getLangOpts());
       Data.ExtraModifierLoc = Tok.getLocation();
       ConsumeToken();
       assert(Tok.is(tok::colon) && "Expected colon.");
       Data.ColonLoc = ConsumeToken();
     }
   } else if (Kind == OMPC_map) {
+    // Handle optional iterator map modifier.
+    if (Tok.is(tok::identifier) && PP.getSpelling(Tok) == "iterator") {
+      HasIterator = true;
+      EnterScope(Scope::OpenMPDirectiveScope | Scope::DeclScope);
+      Data.MapTypeModifiers.push_back(OMPC_MAP_MODIFIER_iterator);
+      Data.MapTypeModifiersLoc.push_back(Tok.getLocation());
+      ExprResult IteratorRes = ParseOpenMPIteratorsExpr();
+      Data.IteratorExpr = IteratorRes.get();
+      // Parse ','
+      ExpectAndConsume(tok::comma);
+      if (getLangOpts().OpenMP < 52) {
+        Diag(Tok, diag::err_omp_unknown_map_type_modifier)
+            << (getLangOpts().OpenMP >= 51 ? 1 : 0)
+            << getLangOpts().OpenMPExtensions;
+        InvalidIterator = true;
+      }
+    }
     // Handle map type for map clause.
     ColonProtectionRAIIObject ColonRAII(*this);
 
     // The first identifier may be a list item, a map-type or a
     // map-type-modifier. The map-type can also be delete which has the same
     // spelling of the C++ delete keyword.
     Data.ExtraModifier = OMPC_MAP_unknown;
     Data.ExtraModifierLoc = Tok.getLocation();
bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
   Data.RLoc = Tok.getLocation();
   if (!T.consumeClose())
     Data.RLoc = T.getCloseLocation();
   // Exit from scope when the iterator is used in depend clause.
   if (HasIterator)
     ExitScope();
   return (Kind != OMPC_depend && Kind != OMPC_map && Vars.empty()) ||
          (MustHaveTail && !Data.DepModOrTailExpr) || InvalidReductionId ||
-         IsInvalidMapperModifier;
+         IsInvalidMapperModifier || InvalidIterator;
 }
 
 /// Parsing of OpenMP clause 'private', 'firstprivate', 'lastprivate',
 /// 'shared', 'copyin', 'copyprivate', 'flush', 'reduction', 'task_reduction',
 /// 'in_reduction', 'nontemporal', 'exclusive' or 'inclusive'.
 ///
 ///    private-clause:
 ///       'private' '(' list ')'

clang/lib/Sema/SemaExpr.cpp

Diag(Loc, diag::err_omp_wrong_var_in_declare_reduction)
         << getCurFunction()->HasOMPDeclareReductionCombiner;
     Diag(D->getLocation(), diag::note_entity_declared_at) << D;
     return true;
   }
 
   // [OpenMP 5.0], 2.19.7.3. declare mapper Directive, Restrictions
   //  List-items in map clauses on this construct may only refer to the declared
   //  variable var and entities that could be referenced by a procedure defined
-  //  at the same location
+  //  at the same location.
+  // [OpenMP 5.2] Also allow iterator declared variables.
   if (LangOpts.OpenMP && isa<VarDecl>(D) &&
       !isOpenMPDeclareMapperVarDeclAllowed(cast<VarDecl>(D))) {
     Diag(Loc, diag::err_omp_declare_mapper_wrong_var)
         << getOpenMPDeclareMapperVarName();
     Diag(D->getLocation(), diag::note_entity_declared_at) << D;
     return true;
   }
 
if (S) {
         Diag(D.DeclIdentLoc, diag::err_redefinition) << VD->getDeclName();
         Diag(Old->getLocation(), diag::note_previous_definition);
       } else {
         PushOnScopeChains(VD, S);
       }
     } else {
       CurContext->addDecl(VD);
     }
+
+    /// Act on the iterator variable declaration.
+    ActOnOpenMPIteratorVarDecl(VD);
+
     Expr *Begin = D.Range.Begin;
     if (!IsDeclTyDependent && Begin && !Begin->isTypeDependent()) {
       ExprResult BeginRes =
           PerformImplicitConversion(Begin, DeclTy, AA_Converting);
       Begin = BeginRes.get();
     }
     Expr *End = D.Range.End;
     if (!IsDeclTyDependent && End && !End->isTypeDependent()) {

clang/lib/Sema/SemaOpenMP.cpp

struct ImplicitDefaultFDInfoTy {
       ImplicitDefaultFDInfoTy(const FieldDecl *FD, size_t StackLevel,
                               VarDecl *VD)
           : FD(FD), StackLevel(StackLevel), VD(VD) {}
     };
     /// List of captured fields
     llvm::SmallVector<ImplicitDefaultFDInfoTy, 8>
         ImplicitDefaultFirstprivateFDs;
     Expr *DeclareMapperVar = nullptr;
+    SmallVector<VarDecl *, 16> IteratorVarDecls;
     SharingMapTy(OpenMPDirectiveKind DKind, DeclarationNameInfo Name,
                  Scope *CurScope, SourceLocation Loc)
         : Directive(DKind), DirectiveName(Name), CurScope(CurScope),
           ConstructLoc(Loc) {}
     SharingMapTy() = default;
   };
 
   using StackTy = SmallVector<SharingMapTy, 4>;
public:
   void addDeclareMapperVarRef(Expr *Ref) {
     SharingMapTy &StackElem = getTopOfStack();
     StackElem.DeclareMapperVar = Ref;
   }
   const Expr *getDeclareMapperVarRef() const {
     const SharingMapTy *Top = getTopOfStackOrNull();
     return Top ? Top->DeclareMapperVar : nullptr;
   }
+
+  /// Add a new iterator variable.
+  void addIteratorVarDecl(VarDecl *VD) {
+    SharingMapTy &StackElem = getTopOfStack();
+    StackElem.IteratorVarDecls.push_back(VD->getCanonicalDecl());
+  }
+  /// Check if variable declaration is an iterator VarDecl.
+  bool isIteratorVarDecl(const VarDecl *VD) const {
+    const SharingMapTy *Top = getTopOfStackOrNull();
+    if (!Top)
+      return false;
+
+    return llvm::any_of(Top->IteratorVarDecls, [VD](const VarDecl *IteratorVD) {
+      return IteratorVD == VD->getCanonicalDecl();
+    });
+  }
   /// get captured field from ImplicitDefaultFirstprivateFDs
   VarDecl *getImplicitFDCapExprDecl(const FieldDecl *FD) const {
     const_iterator I = begin();
     const_iterator EndI = end();
     size_t StackLevel = getStackSize();
     for (; I != EndI; ++I) {
       if (I->DefaultAttr == DSA_firstprivate || I->DefaultAttr == DSA_private)
         break;
for (auto I = C->varlist_begin(), End = C->varlist_end(); I != End;
         }
       }
     }
     if (SubExprs.empty())
       continue;
     CXXScopeSpec MapperIdScopeSpec;
     DeclarationNameInfo MapperId;
     if (OMPClause *NewClause = S.ActOnOpenMPMapClause(
-            C->getMapTypeModifiers(), C->getMapTypeModifiersLoc(),
+            nullptr, C->getMapTypeModifiers(), C->getMapTypeModifiersLoc(),
             MapperIdScopeSpec, MapperId, C->getMapType(),
             /*IsMapTypeImplicit=*/true, SourceLocation(), SourceLocation(),
             SubExprs, OMPVarListLocTy()))
       Clauses.push_back(NewClause);
   }
 }
 
 StmtResult Sema::ActOnOpenMPExecutableDirective(
if (getLangOpts().OpenMP >= 50 && Kind != OMPD_target &&
             if (!isa<DeclRefExpr>(E->IgnoreParenImpCasts()))
               ImplicitExprs.emplace_back(E);
       }
       if (!ImplicitExprs.empty()) {
         ArrayRef<Expr *> Exprs = ImplicitExprs;
         CXXScopeSpec MapperIdScopeSpec;
         DeclarationNameInfo MapperId;
         if (OMPClause *Implicit = ActOnOpenMPMapClause(
-                OMPC_MAP_MODIFIER_unknown, SourceLocation(), MapperIdScopeSpec,
-                MapperId, OMPC_MAP_tofrom,
+                nullptr, OMPC_MAP_MODIFIER_unknown, SourceLocation(),
+                MapperIdScopeSpec, MapperId, OMPC_MAP_tofrom,
                 /*IsMapTypeImplicit=*/true, SourceLocation(), SourceLocation(),
                 Exprs, OMPVarListLocTy(), /*NoDiagnose=*/true))
           ClausesWithImplicit.emplace_back(Implicit);
       }
     }
     for (unsigned I = 0, E = DefaultmapKindNum; I < E; ++I) {
       int ClauseKindCnt = -1;
       for (ArrayRef<Expr *> ImplicitMap : ImplicitMaps[I]) {
         ++ClauseKindCnt;
         if (ImplicitMap.empty())
           continue;
         CXXScopeSpec MapperIdScopeSpec;
         DeclarationNameInfo MapperId;
         auto Kind = static_cast<OpenMPMapClauseKind>(ClauseKindCnt);
         if (OMPClause *Implicit = ActOnOpenMPMapClause(
-                ImplicitMapModifiers[I], ImplicitMapModifiersLoc[I],
+                nullptr, ImplicitMapModifiers[I], ImplicitMapModifiersLoc[I],
                 MapperIdScopeSpec, MapperId, Kind, /*IsMapTypeImplicit=*/true,
                 SourceLocation(), SourceLocation(), ImplicitMap,
                 OMPVarListLocTy())) {
           ClausesWithImplicit.emplace_back(Implicit);
           ErrorFound |= cast<OMPMapClause>(Implicit)->varlist_size() !=
                         ImplicitMap.size();
         } else {
           ErrorFound = true;
Res = ActOnOpenMPDependClause(
         {static_cast<OpenMPDependClauseKind>(ExtraModifier), ExtraModifierLoc,
          ColonLoc, Data.OmpAllMemoryLoc},
         Data.DepModOrTailExpr, VarList, StartLoc, LParenLoc, EndLoc);
     break;
   case OMPC_map:
     assert(0 <= ExtraModifier && ExtraModifier <= OMPC_MAP_unknown &&
            "Unexpected map modifier.");
     Res = ActOnOpenMPMapClause(
-        Data.MapTypeModifiers, Data.MapTypeModifiersLoc,
+        Data.IteratorExpr, Data.MapTypeModifiers, Data.MapTypeModifiersLoc,
         Data.ReductionOrMapperIdScopeSpec, Data.ReductionOrMapperId,
         static_cast<OpenMPMapClauseKind>(ExtraModifier), Data.IsMapTypeImplicit,
         ExtraModifierLoc, ColonLoc, VarList, Locs);
     break;
   case OMPC_to:
     Res =
         ActOnOpenMPToClause(Data.MotionModifiers, Data.MotionModifiersLoc,
                             Data.ReductionOrMapperIdScopeSpec,
for (Expr *RE : MVLI.VarList) {
     MVLI.VarComponents.back().append(CurComponents.begin(),
                                      CurComponents.end());
     MVLI.VarBaseDeclarations.push_back(isa<MemberExpr>(BE) ? nullptr
                                                            : CurDeclaration);
   }
 }
 
 OMPClause *Sema::ActOnOpenMPMapClause(
-    ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
+    Expr *IteratorModifier, ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
     ArrayRef<SourceLocation> MapTypeModifiersLoc,
     CXXScopeSpec &MapperIdScopeSpec, DeclarationNameInfo &MapperId,
     OpenMPMapClauseKind MapType, bool IsMapTypeImplicit, SourceLocation MapLoc,
     SourceLocation ColonLoc, ArrayRef<Expr *> VarList,
     const OMPVarListLocTy &Locs, bool NoDiagnose,
     ArrayRef<Expr *> UnresolvedMappers) {
   OpenMPMapModifierKind Modifiers[] = {
       OMPC_MAP_MODIFIER_unknown, OMPC_MAP_MODIFIER_unknown,
       OMPC_MAP_MODIFIER_unknown, OMPC_MAP_MODIFIER_unknown,
-      OMPC_MAP_MODIFIER_unknown};
+      OMPC_MAP_MODIFIER_unknown, OMPC_MAP_MODIFIER_unknown};
   SourceLocation ModifiersLoc[NumberOfOMPMapClauseModifiers];
 
+  if (IteratorModifier && !IteratorModifier->getType()->isSpecificBuiltinType(
+                              BuiltinType::OMPIterator))
+    Diag(IteratorModifier->getExprLoc(),
+         diag::err_omp_map_modifier_not_iterator);
+
   // Process map-type-modifiers, flag errors for duplicate modifiers.
   unsigned Count = 0;
   for (unsigned I = 0, E = MapTypeModifiers.size(); I < E; ++I) {
     if (MapTypeModifiers[I] != OMPC_MAP_MODIFIER_unknown &&
         llvm::is_contained(Modifiers, MapTypeModifiers[I])) {
       Diag(MapTypeModifiersLoc[I], diag::err_omp_duplicate_map_type_modifier);
       continue;
     }
     assert(Count < NumberOfOMPMapClauseModifiers &&
            "Modifiers exceed the allowed number of map type modifiers");
     Modifiers[Count] = MapTypeModifiers[I];
     ModifiersLoc[Count] = MapTypeModifiersLoc[I];
     ++Count;
   }
 
   MappableVarListInfo MVLI(VarList);
   checkMappableExpressionList(*this, DSAStack, OMPC_map, MVLI, Locs.StartLoc,
                               MapperIdScopeSpec, MapperId, UnresolvedMappers,
                               MapType, Modifiers, IsMapTypeImplicit,
                               NoDiagnose);
 
   // We need to produce a map clause even if we don't have variables so that
   // other diagnostics related with non-existing map clauses are accurate.
-  return OMPMapClause::Create(Context, Locs, MVLI.ProcessedVarList,
-                              MVLI.VarBaseDeclarations, MVLI.VarComponents,
-                              MVLI.UDMapperList, Modifiers, ModifiersLoc,
-                              MapperIdScopeSpec.getWithLocInContext(Context),
-                              MapperId, MapType, IsMapTypeImplicit, MapLoc);
+  return OMPMapClause::Create(
+      Context, Locs, MVLI.ProcessedVarList, MVLI.VarBaseDeclarations,
+      MVLI.VarComponents, MVLI.UDMapperList, IteratorModifier, Modifiers,
+      ModifiersLoc, MapperIdScopeSpec.getWithLocInContext(Context), MapperId,
+      MapType, IsMapTypeImplicit, MapLoc);
 }
 
 QualType Sema::ActOnOpenMPDeclareReductionType(SourceLocation TyLoc,
                                                TypeResult ParsedType) {
   assert(ParsedType.isUsable());
 
   QualType ReductionType = GetTypeFromParser(ParsedType.get());
   if (ReductionType.isNull())
auto *VD = VarDecl::Create(Context, Context.getTranslationUnitDecl(),
                              MapperType, TInfo, SC_None);
   if (S)
     PushOnScopeChains(VD, S, /*AddToContext=*/false);
   Expr *E = buildDeclRefExpr(*this, VD, MapperType, StartLoc);
   DSAStack->addDeclareMapperVarRef(E);
   return E;
 }
 
+void Sema::ActOnOpenMPIteratorVarDecl(VarDecl *VD) {
+  if (DSAStack->getDeclareMapperVarRef())
+    DSAStack->addIteratorVarDecl(VD);
+}
+
 bool Sema::isOpenMPDeclareMapperVarDeclAllowed(const VarDecl *VD) const {
   assert(LangOpts.OpenMP && "Expected OpenMP mode.");
   const Expr *Ref = DSAStack->getDeclareMapperVarRef();
   if (const auto *DRE = cast_or_null<DeclRefExpr>(Ref)) {
     if (VD->getCanonicalDecl() == DRE->getDecl()->getCanonicalDecl())
       return true;
     if (VD->isUsableInConstantExpressions(Context))
       return true;
+    if (LangOpts.OpenMP >= 52 && DSAStack->isIteratorVarDecl(VD))
+      return true;
     return false;
   }
   return true;
 }
 
 const ValueDecl *Sema::getOpenMPDeclareMapperVarName() const {
   assert(LangOpts.OpenMP && "Expected OpenMP mode.");
   return cast<DeclRefExpr>(DSAStack->getDeclareMapperVarRef())->getDecl();
 }
 
 OMPClause *Sema::ActOnOpenMPNumTeamsClause(Expr *NumTeams,
                                            SourceLocation StartLoc,

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

NestedNameSpecifierLoc NewQualifierLoc =
                                             TemplateArgs);
     CXXScopeSpec SS;
     SS.Adopt(NewQualifierLoc);
     DeclarationNameInfo NewNameInfo =
         SemaRef.SubstDeclarationNameInfo(OldC->getMapperIdInfo(), TemplateArgs);
     OMPVarListLocTy Locs(OldC->getBeginLoc(), OldC->getLParenLoc(),
                          OldC->getEndLoc());
     OMPClause *NewC = SemaRef.ActOnOpenMPMapClause(
-        OldC->getMapTypeModifiers(), OldC->getMapTypeModifiersLoc(), SS,
-        NewNameInfo, OldC->getMapType(), OldC->isImplicitMapType(),
-        OldC->getMapLoc(), OldC->getColonLoc(), NewVars, Locs);
+        OldC->getIteratorModifier(), OldC->getMapTypeModifiers(),
+        OldC->getMapTypeModifiersLoc(), SS, NewNameInfo, OldC->getMapType(),
+        OldC->isImplicitMapType(), OldC->getMapLoc(), OldC->getColonLoc(),
+        NewVars, Locs);
     Clauses.push_back(NewC);
   }
   SemaRef.EndOpenMPDSABlock(nullptr);
   if (!IsCorrect)
     return nullptr;
   Sema::DeclGroupPtrTy DG = SemaRef.ActOnOpenMPDeclareMapperDirective(
       /*S=*/nullptr, Owner, D->getDeclName(), SubstMapperTy, D->getLocation(),
       VN, D->getAccess(), MapperVarRef.get(), Clauses, PrevDeclInScope);

clang/lib/Sema/TreeTransform.h

return getSema().ActOnOpenMPDeviceClause(Modifier, Device, StartLoc,
                                              LParenLoc, ModifierLoc, EndLoc);
   }
 
   /// Build a new OpenMP 'map' clause.
   ///
   /// By default, performs semantic analysis to build the new OpenMP clause.
   /// Subclasses may override this routine to provide different behavior.
   OMPClause *RebuildOMPMapClause(
-      ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
+      Expr *IteratorModifier, ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
       ArrayRef<SourceLocation> MapTypeModifiersLoc,
       CXXScopeSpec MapperIdScopeSpec, DeclarationNameInfo MapperId,
       OpenMPMapClauseKind MapType, bool IsMapTypeImplicit,
       SourceLocation MapLoc, SourceLocation ColonLoc, ArrayRef<Expr *> VarList,
       const OMPVarListLocTy &Locs, ArrayRef<Expr *> UnresolvedMappers) {
     return getSema().ActOnOpenMPMapClause(
-        MapTypeModifiers, MapTypeModifiersLoc, MapperIdScopeSpec, MapperId,
-        MapType, IsMapTypeImplicit, MapLoc, ColonLoc, VarList, Locs,
+        IteratorModifier, MapTypeModifiers, MapTypeModifiersLoc,
+        MapperIdScopeSpec, MapperId, MapType, IsMapTypeImplicit, MapLoc,
+        ColonLoc, VarList, Locs,
         /*NoDiagnose=*/false, UnresolvedMappers);
   }
 
   /// Build a new OpenMP 'allocate' clause.
   ///
   /// By default, performs semantic analysis to build the new OpenMP clause.
   /// Subclasses may override this routine to provide different behavior.
   OMPClause *RebuildOMPAllocateClause(Expr *Allocate, ArrayRef<Expr *> VarList,
bool transformOMPMappableExprListClause(
   }
   return false;
 }
 
 template <typename Derived>
 OMPClause *TreeTransform<Derived>::TransformOMPMapClause(OMPMapClause *C) {
   OMPVarListLocTy Locs(C->getBeginLoc(), C->getLParenLoc(), C->getEndLoc());
   llvm::SmallVector<Expr *, 16> Vars;
+  Expr *IteratorModifier = C->getIteratorModifier();
+  if (IteratorModifier) {
+    ExprResult MapModRes = getDerived().TransformExpr(IteratorModifier);
+    if (MapModRes.isInvalid())
+      return nullptr;
+    IteratorModifier = MapModRes.get();
+  }
   CXXScopeSpec MapperIdScopeSpec;
   DeclarationNameInfo MapperIdInfo;
   llvm::SmallVector<Expr *, 16> UnresolvedMappers;
   if (transformOMPMappableExprListClause<Derived, OMPMapClause>(
           *this, C, Vars, MapperIdScopeSpec, MapperIdInfo, UnresolvedMappers))
     return nullptr;
   return getDerived().RebuildOMPMapClause(
-      C->getMapTypeModifiers(), C->getMapTypeModifiersLoc(), MapperIdScopeSpec,
-      MapperIdInfo, C->getMapType(), C->isImplicitMapType(), C->getMapLoc(),
-      C->getColonLoc(), Vars, Locs, UnresolvedMappers);
+      IteratorModifier, C->getMapTypeModifiers(), C->getMapTypeModifiersLoc(),
+      MapperIdScopeSpec, MapperIdInfo, C->getMapType(), C->isImplicitMapType(),
+      C->getMapLoc(), C->getColonLoc(), Vars, Locs, UnresolvedMappers);
 }
 
 template <typename Derived>
 OMPClause *
 TreeTransform<Derived>::TransformOMPAllocateClause(OMPAllocateClause *C) {
   Expr *Allocator = C->getAllocator();
   if (Allocator) {
     ExprResult AllocatorRes = getDerived().TransformExpr(Allocator);

clang/lib/Serialization/ASTReader.cpp

void OMPClauseReader::VisitOMPDeviceClause(OMPDeviceClause *C) {
   C->setModifier(Record.readEnum<OpenMPDeviceClauseModifier>());
   C->setDevice(Record.readSubExpr());
   C->setModifierLoc(Record.readSourceLocation());
   C->setLParenLoc(Record.readSourceLocation());
 }
 
 void OMPClauseReader::VisitOMPMapClause(OMPMapClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
+  bool HasIteratorModifier = false;
   for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
     C->setMapTypeModifier(
         I, static_cast<OpenMPMapModifierKind>(Record.readInt()));
     C->setMapTypeModifierLoc(I, Record.readSourceLocation());
+    if (C->getMapTypeModifier(I) == OMPC_MAP_MODIFIER_iterator)
+      HasIteratorModifier = true;
   }
   C->setMapperQualifierLoc(Record.readNestedNameSpecifierLoc());
   C->setMapperIdInfo(Record.readDeclarationNameInfo());
   C->setMapType(
      static_cast<OpenMPMapClauseKind>(Record.readInt()));
   C->setMapLoc(Record.readSourceLocation());
   C->setColonLoc(Record.readSourceLocation());
   auto NumVars = C->varlist_size();
   auto UniqueDecls = C->getUniqueDeclarationsNum();
   auto TotalLists = C->getTotalComponentListNum();
   auto TotalComponents = C->getTotalComponentsNum();
 
   SmallVector<Expr *, 16> Vars;
   Vars.reserve(NumVars);
   for (unsigned i = 0; i != NumVars; ++i)
     Vars.push_back(Record.readExpr());
   C->setVarRefs(Vars);
 
   SmallVector<Expr *, 16> UDMappers;
   UDMappers.reserve(NumVars);
   for (unsigned I = 0; I < NumVars; ++I)
     UDMappers.push_back(Record.readExpr());
   C->setUDMapperRefs(UDMappers);
 
+  if (HasIteratorModifier)
+    C->setIteratorModifier(Record.readExpr());
+
   SmallVector<ValueDecl *, 16> Decls;
   Decls.reserve(UniqueDecls);
   for (unsigned i = 0; i < UniqueDecls; ++i)
     Decls.push_back(Record.readDeclAs<ValueDecl>());
   C->setUniqueDecls(Decls);
 
   SmallVector<unsigned, 16> ListsPerDecl;
   ListsPerDecl.reserve(UniqueDecls);

clang/lib/Serialization/ASTWriter.cpp

 }
 
 void OMPClauseWriter::VisitOMPMapClause(OMPMapClause *C) {
   Record.push_back(C->varlist_size());
   Record.push_back(C->getUniqueDeclarationsNum());
   Record.push_back(C->getTotalComponentListNum());
   Record.push_back(C->getTotalComponentsNum());
   Record.AddSourceLocation(C->getLParenLoc());
+  bool HasIteratorModifier = false;
   for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
     Record.push_back(C->getMapTypeModifier(I));
     Record.AddSourceLocation(C->getMapTypeModifierLoc(I));
+    if (C->getMapTypeModifier(I) == OMPC_MAP_MODIFIER_iterator)
+      HasIteratorModifier = true;
   }
   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
   Record.push_back(C->getMapType());
   Record.AddSourceLocation(C->getMapLoc());
   Record.AddSourceLocation(C->getColonLoc());
   for (auto *E : C->varlists())
     Record.AddStmt(E);
   for (auto *E : C->mapperlists())
     Record.AddStmt(E);
+  if (HasIteratorModifier)
+    Record.AddStmt(C->getIteratorModifier());
   for (auto *D : C->all_decls())
     Record.AddDeclRef(D);
   for (auto N : C->all_num_lists())
     Record.push_back(N);
   for (auto N : C->all_lists_sizes())
     Record.push_back(N);
   for (auto &M : C->all_components()) {
     Record.AddStmt(M.getAssociatedExpression());

clang/test/OpenMP/declare_mapper_ast_print.c

 // RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s
 // RUN: %clang_cc1 -fopenmp -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s
 // RUN: %clang_cc1 -fopenmp-simd -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
 
 // RUN: %clang_cc1 -DOMP51 -verify -fopenmp -fopenmp-version=51 -ast-print %s | FileCheck -check-prefixes=CHECK,OMP51 %s
 // RUN: %clang_cc1 -DOMP51 -fopenmp -fopenmp-version=51 -emit-pch -o %t %s
 // RUN: %clang_cc1 -DOMP51 -fopenmp -fopenmp-version=51 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck -check-prefixes=CHECK,OMP51 %s
 
 // RUN: %clang_cc1 -DOMP51 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s | FileCheck -check-prefixes=CHECK,OMP51 %s
 // RUN: %clang_cc1 -DOMP51 -fopenmp-simd -fopenmp-version=51 -emit-pch -o %t %s
 // RUN: %clang_cc1 -DOMP51 -fopenmp-simd -fopenmp-version=51 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck -check-prefixes=CHECK,OMP51 %s
+
+// RUN: %clang_cc1 -DOMP52 -verify -fopenmp -fopenmp-version=52 -ast-print %s | FileCheck -check-prefixes=CHECK,OMP52 %s
+// RUN: %clang_cc1 -DOMP52 -fopenmp -fopenmp-version=52 -emit-pch -o %t %s
+// RUN: %clang_cc1 -DOMP52 -fopenmp -fopenmp-version=52 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck -check-prefixes=CHECK,OMP52 %s
+
+// RUN: %clang_cc1 -DOMP52 -verify -fopenmp-simd -fopenmp-version=52 -ast-print %s | FileCheck -check-prefixes=CHECK,OMP52 %s
+// RUN: %clang_cc1 -DOMP52 -fopenmp-simd -fopenmp-version=52 -emit-pch -o %t %s
+// RUN: %clang_cc1 -DOMP52 -fopenmp-simd -fopenmp-version=52 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck -check-prefixes=CHECK,OMP52 %s
 // expected-no-diagnostics
 
 #ifndef HEADER
 #define HEADER
 
 // CHECK: struct vec {
 struct vec {
   int len;

 // CHECK: #pragma omp target update to(mapper(id): vv) from(mapper(default): dd[0:10])
 #ifdef OMP51
 #pragma omp target update to(mapper(id) present: vv) from(mapper(default), present: dd[0:10])
 // OMP51: #pragma omp target update to(mapper(id), present: vv) from(mapper(default), present: dd[0:10])
 #pragma omp target update to(present mapper(id): vv) from(present, mapper(default): dd[0:10])
 // OMP51: #pragma omp target update to(present, mapper(id): vv) from(present, mapper(default): dd[0:10])
 #endif
   }
+#ifdef OMP52
+#pragma omp declare mapper(id1: struct vec vvec) map(iterator(it=0:vvec.len:2), tofrom:vvec.data[it])
+// OMP52: #pragma omp declare mapper (id1 : struct vec vvec) map(iterator(int it = 0:vvec.len:2),tofrom: vvec.data[it]);
+#endif
   return 0;
 }
 // CHECK: }
 
 #endif

clang/test/OpenMP/declare_mapper_messages.c

 // RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 %s
 
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=52 -ferror-limit 100 -DOMP52 %s
+
 // RUN: %clang_cc1 -verify -fopenmp-simd -ferror-limit 100 %s
 
 int temp; // expected-note {{'temp' declared here}}
 
 struct vec {                                                            // expected-note {{definition of 'struct vec' is not complete until the closing '}'}}
   int len;
 #pragma omp declare mapper(id: struct vec v) map(v.len)                 // expected-error {{incomplete definition of type 'struct vec'}}
   double *data;

 #pragma omp declare mapper(bb:struct vec v) private(v)                  // expected-error {{expected at least one clause on '#pragma omp declare mapper' directive}} // expected-error {{unexpected OpenMP clause 'private' in directive '#pragma omp declare mapper'}}
 #pragma omp declare mapper(cc:struct vec v) map(v) (                    // expected-warning {{extra tokens at the end of '#pragma omp declare mapper' are ignored}}
 
 #pragma omp declare mapper(++: struct vec v) map(v.len)                 // expected-error {{illegal OpenMP user-defined mapper identifier}}
 #pragma omp declare mapper(id1: struct vec v) map(v.len, temp)          // expected-error {{only variable 'v' is allowed in map clauses of this 'omp declare mapper' directive}}
 #pragma omp declare mapper(default : struct vec kk) map(kk.data[0:2])   // expected-note {{previous definition is here}}
 #pragma omp declare mapper(struct vec v) map(v.len)                     // expected-error {{redefinition of user-defined mapper for type 'struct vec' with name 'default'}}
 #pragma omp declare mapper(int v) map(v)                                // expected-error {{mapper type must be of struct, union or class type}}
+#ifdef OMP52
+#pragma omp declare mapper(id2: struct vec vvec) map(iterator(it=0:vvec.len:2), tofrom:vvec.data[it])
+int var; // expected-note {{'var' declared here}}
+// expected-error@+1 {{only variable 'vvec' is allowed in map clauses of this 'omp declare mapper' directive}}
+#pragma omp declare mapper(id3: struct vec vvec) map(iterator(it=0:vvec.len:2), tofrom:vvec.data[var])
+#else
+// expected-error@+4 {{expected at least one clause on '#pragma omp declare mapper' directive}}
+// expected-note@+3 {{'it' declared here}}
+// expected-error@+2 {{only variable 'vvec' is allowed in map clauses of this 'omp declare mapper' directive}}
+// expected-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+#pragma omp declare mapper(id2: struct vec vvec) map(iterator(it=0:vvec.len:2), tofrom:vvec.data[it])
+#endif // OMP52
 
 int fun(int arg) {
 #pragma omp declare mapper(id: struct vec v) map(v.len)
   {
 #pragma omp declare mapper(id: struct vec v) map(v.len)                 // expected-note {{previous definition is here}}
 #pragma omp declare mapper(id: struct vec v) map(v.len)                 // expected-error {{redefinition of user-defined mapper for type 'struct vec' with name 'id'}}
     {
 #pragma omp declare mapper(id: struct vec v) map(v.len) allocate(v)   // expected-error {{unexpected OpenMP clause 'allocate' in directive '#pragma omp declare mapper'}}

 
 #pragma omp target update to(mapper)                                    // expected-error {{expected '(' after 'mapper'}} expected-error {{expected expression}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper()                                   // expected-error {{illegal OpenMP user-defined mapper identifier}} expected-error {{expected expression}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper:vv)                                 // expected-error {{expected '(' after 'mapper'}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper(:vv)                                // expected-error {{illegal OpenMP user-defined mapper identifier}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper(aa :vv)                             // expected-error {{expected ')'}} expected-note {{to match this '('}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper(ab):vv)                             // expected-error {{cannot find a valid user-defined mapper for type 'struct vec' with name 'ab'}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper(ab):arr[0:2])                       // expected-error {{cannot find a valid user-defined mapper for type 'struct vec' with name 'ab'}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
+#ifdef OMP52
+#pragma omp target update to(mapper(aa) a:vv)                           // expected-warning {{missing ':' after motion modifier - ignoring}}
+#else
 #pragma omp target update to(mapper(aa) a:vv)                           // expected-warning {{missing ':' after ) - ignoring}}
+#endif
 #pragma omp target update to(mapper(aa):d)                              // expected-error {{mapper type must be of struct, union or class type}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update to(mapper(aa):vv) to(mapper(aa):arr[0])
 
 #pragma omp target update from(mapper)                                  // expected-error {{expected '(' after 'mapper'}} expected-error {{expected expression}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper()                                 // expected-error {{illegal OpenMP user-defined mapper identifier}} expected-error {{expected expression}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper:vv)                               // expected-error {{expected '(' after 'mapper'}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper(:vv)                              // expected-error {{illegal OpenMP user-defined mapper identifier}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper(aa :vv)                           // expected-error {{expected ')'}} expected-note {{to match this '('}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper(ab):vv)                           // expected-error {{cannot find a valid user-defined mapper for type 'struct vec' with name 'ab'}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper(ab):arr[0:2])                     // expected-error {{cannot find a valid user-defined mapper for type 'struct vec' with name 'ab'}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
+#ifdef OMP52
+#pragma omp target update from(mapper(aa) a:vv)                         // expected-warning {{missing ':' after motion modifier - ignoring}}
+#else
 #pragma omp target update from(mapper(aa) a:vv)                         // expected-warning {{missing ':' after ) - ignoring}}
+#endif
 #pragma omp target update from(mapper(aa):d)                            // expected-error {{mapper type must be of struct, union or class type}} expected-error {{expected at least one 'to' clause or 'from' clause specified to '#pragma omp target update'}}
 #pragma omp target update from(mapper(aa):vv) from(mapper(aa):arr[0])
     }
   }
   return arg;
 }

clang/test/OpenMP/target_ast_print.cpp

 // OMP51-NEXT: #pragma omp target defaultmap(present: pointer)
   foo();
 // OMP51-NEXT: foo();
 
   return tmain<int, 5>(argc, &argc) + tmain<char, 1>(argv[0][0], argv[0]);
 }
 #endif // OMP51
 
+#ifdef OMP52
+
+///==========================================================================///
+// RUN: %clang_cc1 -DOMP52 -verify -fopenmp -fopenmp-version=52 -ast-print %s | FileCheck %s --check-prefix OMP52
+// RUN: %clang_cc1 -DOMP52 -fopenmp -fopenmp-version=52 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -DOMP52 -fopenmp -fopenmp-version=52 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix OMP52
+
+// RUN: %clang_cc1 -DOMP52 -verify -fopenmp-simd -fopenmp-version=52 -ast-print %s | FileCheck %s --check-prefix OMP52
+// RUN: %clang_cc1 -DOMP52 -fopenmp-simd -fopenmp-version=52 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -DOMP52 -fopenmp-simd -fopenmp-version=52 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix OMP52
+
+void foo() {}
+
+template <typename T, int C>
+T tmain(T argc, T *argv) {
+  int N = 100;
+  int v[N];
+  #pragma omp target map(iterator(it = 0:N:2), to: v[it])
+  foo();
+  #pragma omp target map(iterator(it = 0:N:4), from: v[it])
+  foo();
+
+  return 0;
+}
+
+// OMP52: template <typename T, int C> T tmain(T argc, T *argv) {
+// OMP52-NEXT: int N = 100;
+// OMP52-NEXT: int v[N];
+// OMP52-NEXT: #pragma omp target map(iterator(int it = 0:N:2),to: v[it])
+// OMP52-NEXT: foo()
+// OMP52-NEXT: #pragma omp target map(iterator(int it = 0:N:4),from: v[it])
+// OMP52-NEXT: foo()
+
+// OMP52-LABEL: int main(int argc, char **argv) {
+int main (int argc, char **argv) {
+  int i, j, a[20], always, close;
+// OMP52-NEXT: int i, j, a[20]
+#pragma omp target
+// OMP52-NEXT: #pragma omp target
+  foo();
+// OMP52-NEXT: foo();
+#pragma omp target map(iterator(it = 0:20:2), to: a[it])
+// OMP52-NEXT: #pragma omp target map(iterator(int it = 0:20:2),to: a[it])
+  foo();
+// OMP52-NEXT: foo();
+#pragma omp target map(iterator(it = 0:20:4), from: a[it])
+// OMP52-NEXT: #pragma omp target map(iterator(int it = 0:20:4),from: a[it])
+foo();
+// OMP52-NEXT: foo();
+
+  return tmain<int, 5>(argc, &argc) + tmain<char, 1>(argv[0][0], argv[0]);
+}
+#endif // OMP52
+
 #ifdef OMPX
 
 // RUN: %clang_cc1 -DOMPX -verify -fopenmp -fopenmp-extensions -ast-print %s | FileCheck %s --check-prefix=OMPX
 // RUN: %clang_cc1 -DOMPX -fopenmp -fopenmp-extensions -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -DOMPX -fopenmp -fopenmp-extensions -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=OMPX
 
 // RUN: %clang_cc1 -DOMPX -verify -fopenmp-simd -fopenmp-extensions -ast-print %s | FileCheck %s --check-prefix=OMPX
 // RUN: %clang_cc1 -DOMPX -fopenmp-simd -fopenmp-extensions -x c++ -std=c++11 -emit-pch -o %t %s

clang/test/OpenMP/target_map_messages.cpp

 // -fopenmp, -fno-openmp-extensions
 // RUN: %clang_cc1 -verify=expected,ge50,lt51,omp,lt51-omp -fopenmp -fno-openmp-extensions -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,lt50,lt51,omp,lt51-omp -fopenmp -fno-openmp-extensions -fopenmp-version=40 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,lt50,lt51,omp,lt51-omp -fopenmp -fno-openmp-extensions -fopenmp-version=45 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,lt51,omp,lt51-omp -fopenmp -fno-openmp-extensions -fopenmp-version=50 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,ge51,omp,ge51-omp -fopenmp -fno-openmp-extensions -fopenmp-version=51 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,ge50,ge51,ge52,omp,ge52-omp -fopenmp -fno-openmp-extensions -fopenmp-version=52 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -DCCODE -verify -fopenmp -fno-openmp-extensions -ferror-limit 300 -x c %s -Wno-openmp -Wuninitialized
 
 // -fopenmp-simd, -fno-openmp-extensions
 // RUN: %clang_cc1 -verify=expected,ge50,lt51,omp,lt51-omp -fopenmp-simd -fno-openmp-extensions -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,lt50,lt51,omp,lt51-omp -fopenmp-simd -fno-openmp-extensions -fopenmp-version=40 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,lt50,lt51,omp,lt51-omp -fopenmp-simd -fno-openmp-extensions -fopenmp-version=45 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,lt51,omp,lt51-omp -fopenmp-simd -fno-openmp-extensions -fopenmp-version=50 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,ge51,omp,ge51-omp -fopenmp-simd -fno-openmp-extensions -fopenmp-version=51 -ferror-limit 300 %s -Wno-openmp-target -Wuninitialized
void func(int arg) {
     {}
     // expected-error@+2 {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
     // lt51-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(present, tofrom: c,f[:])
     {}
     // expected-error@+1 {{use of undeclared identifier 'present'}}
     #pragma omp target map(present)
     {}
+    // ge52-omp-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(ompx_hold, tofrom: c,f)
     {}
+    // ge52-omp-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(ompx_hold, tofrom: c[1:2],f)
     {}
+    // ge52-omp-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(ompx_hold, tofrom: c,f[1:2])
     {}
+    // ge52-omp-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // expected-error@+3 {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
     // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(ompx_hold, tofrom: c[:],f)
     {}
+    // ge52-omp-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // expected-error@+3 {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
     // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(ompx_hold, tofrom: c,f[:])
     {}
     // expected-error@+1 {{use of undeclared identifier 'ompx_hold'}}
     #pragma omp target map(ompx_hold)
     {}
     #pragma omp target map(close, close, tofrom: a)   // expected-error {{same map type modifier has been specified more than once}}
     {}
     #pragma omp target map(always, close, always, close, tofrom: a)   // expected-error 2 {{same map type modifier has been specified more than once}}
     {}
     // ge51-error@+2 {{same map type modifier has been specified more than once}}
     // lt51-error@+1 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(present, present, tofrom: a)
     {}
+    // ge52-omp-error@+5 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
+    // ge52-omp-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // ompx-error@+3 {{same map type modifier has been specified more than once}}
     // ge51-omp-error@+2 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(ompx_hold, ompx_hold, tofrom: a)
     {}
+    // ge52-omp-error@+9 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
+    // ge52-omp-error@+8 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'iterator'}}
     // expected-error@+7 2 {{same map type modifier has been specified more than once}}
     // ge51-error@+6 {{same map type modifier has been specified more than once}}
     // lt51-ompx-error@+5 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
     // lt51-omp-error@+4 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     // ompx-error@+3 {{same map type modifier has been specified more than once}}
     // ge51-omp-error@+2 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-omp-error@+1 2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(always, close, present, ompx_hold, always, close, present, ompx_hold, tofrom: a)
void func(int arg) {
     // ge51-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
     // lt51-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
     #pragma omp target map(tofrom from: a)
     {}
     #pragma omp target map(close bf: a)   // expected-error {{incorrect map type, expected one of 'to', 'from', 'tofrom', 'alloc', 'release', or 'delete'}}
     {}
     #pragma omp target map(([b[I]][bf])f)  // lt50-error {{expected ',' or ']' in lambda capture list}} lt50-error {{expected ')'}} lt50-note {{to match this '('}}
     {}
+    // ge51-ompx-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'ompx_hold'}}
+    // lt51-ompx-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+    // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
+    // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
+    #pragma omp target map(iterator(it=0:10), tofrom:a)
+    {}
+    // ompx-error@+8 {{redefinition of 'it'}}
+    // ompx-note@+7 {{previous definition is here}}
+    // omp-error@+6 {{redefinition of 'it'}}
+    // omp-note@+5 {{previous definition is here}}
+    // ge51-ompx-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'ompx_hold'}}
+    // lt51-ompx-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+    // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
+    // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
+    #pragma omp target map(iterator(it=0:10, it=0:20), tofrom:a)
+    {}
+    // ge51-ompx-error@+6 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'ompx_hold'}}
+    // lt51-ompx-error@+5 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+    // lt51-error@+4 {{expected '(' after 'iterator'}}
+    // ge51-error@+3 {{expected '(' after 'iterator'}}
+    // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
+    // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
+    #pragma omp target map(iterator, tofrom:a)
+    {}
+    // ge51-ompx-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'ompx_hold'}}
+    // lt51-ompx-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+    // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
+    // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
+    #pragma omp target map(iterator(), tofrom:a)
+    {}
     return;
   }
 };
 
 struct SB {
   unsigned A;
   unsigned B;
   float Arr[100];

 #pragma omp target enter data map(to:pos)
 #pragma omp target enter data map(to:pos.dptr[0:pos.size])
 #pragma omp target teams distribute parallel for
   for(int i=0; i<100; i++) {
     pos(i).x = i;
     pos(i).y = i+1;
   }
 
+  // ge51-ompx-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'ompx_hold'}}
+  // lt51-ompx-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+  // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
+  // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
+  #pragma omp target map(iterator(it=0:10), tofrom:a[it])
+  {}
+
+  // ompx-error@+8 {{use of undeclared identifier 'itt'; did you mean 'it'?}}
+  // ompx-note@+7 {{'it' declared here}}
+  // omp-error@+6 {{use of undeclared identifier 'itt'; did you mean 'it'?}}
+  // omp-note@+5 {{'it' declared here}}
+  // ge51-ompx-error@+4 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present', 'ompx_hold'}}
+  // lt51-ompx-error@+3 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'ompx_hold'}}
+  // ge51-omp-error@+2 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper', 'present'}}
+  // lt51-omp-error@+1 {{incorrect map type modifier, expected one of: 'always', 'close', 'mapper'}}
+  #pragma omp target map(iterator(it=0:10), tofrom:a[itt])
+  {}
+
   return tmain<int, 3>(argc)+tmain<from, 4>(argc); // expected-note {{in instantiation of function template specialization 'tmain<int, 3>' requested here}} expected-note {{in instantiation of function template specialization 'tmain<int, 4>' requested here}}
 }
 #endif