[OPENMP50]Add initial support for OpenMP 5.0 iterator.

Added basic parsing/semantic analysis/(de)serialization support for
iterator expression introduced in OpenMP 5.0.

Author: alexey-bataev

clang/include/clang-c/Index.h

@@ -2180,7 +2180,12 @@ enum CXCursorKind {
    */
   CXCursor_OMPArrayShapingExpr = 150,
 
-  CXCursor_LastExpr = CXCursor_OMPArrayShapingExpr,
+  /**
+   * OpenMP 5.0 [2.1.6 Iterators]
+   */
+  CXCursor_OMPIteratorExpr = 151,
+
+  CXCursor_LastExpr = CXCursor_OMPIteratorExpr,
 
   /* Statements */
   CXCursor_FirstStmt = 200,

clang/include/clang/AST/ASTContext.h

@@ -970,7 +970,7 @@ class ASTContext : public RefCountedBase<ASTContext> {
 #include "clang/Basic/OpenCLImageTypes.def"
   CanQualType OCLSamplerTy, OCLEventTy, OCLClkEventTy;
   CanQualType OCLQueueTy, OCLReserveIDTy;
-  CanQualType OMPArraySectionTy, OMPArrayShapingTy;
+  CanQualType OMPArraySectionTy, OMPArrayShapingTy, OMPIteratorTy;
 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
   CanQualType Id##Ty;
 #include "clang/Basic/OpenCLExtensionTypes.def"

clang/include/clang/AST/BuiltinTypes.def

@@ -316,8 +316,11 @@ PLACEHOLDER_TYPE(OMPArraySection, OMPArraySectionTy)
 // A placeholder type for OpenMP array shaping operation.
 PLACEHOLDER_TYPE(OMPArrayShaping, OMPArrayShapingTy)
 
+// A placeholder type for OpenMP iterators.
+PLACEHOLDER_TYPE(OMPIterator, OMPIteratorTy)
+
 #ifdef LAST_BUILTIN_TYPE
-LAST_BUILTIN_TYPE(OMPArrayShaping)
+LAST_BUILTIN_TYPE(OMPIterator)
 #undef LAST_BUILTIN_TYPE
 #endif
 

clang/include/clang/AST/ComputeDependence.h

@@ -88,6 +88,7 @@ class PseudoObjectExpr;
 class AtomicExpr;
 class OMPArraySectionExpr;
 class OMPArrayShapingExpr;
+class OMPIteratorExpr;
 class ObjCArrayLiteral;
 class ObjCDictionaryLiteral;
 class ObjCBoxedExpr;
@@ -174,6 +175,7 @@ ExprDependence computeDependence(AtomicExpr *E);
 
 ExprDependence computeDependence(OMPArraySectionExpr *E);
 ExprDependence computeDependence(OMPArrayShapingExpr *E);
+ExprDependence computeDependence(OMPIteratorExpr *E);
 
 ExprDependence computeDependence(ObjCArrayLiteral *E);
 ExprDependence computeDependence(ObjCDictionaryLiteral *E);

clang/include/clang/AST/ExprOpenMP.h

@@ -205,6 +205,169 @@ class OMPArrayShapingExpr final
     return const_child_range(Begin, Begin + NumDims + 1);
   }
 };
+
+/// OpenMP 5.0 [2.1.6 Iterators]
+/// Iterators are identifiers that expand to multiple values in the clause on
+/// which they appear.
+/// The syntax of the iterator modifier is as follows:
+/// \code
+/// iterator(iterators-definition)
+/// \endcode
+/// where iterators-definition is one of the following:
+/// \code
+/// iterator-specifier [, iterators-definition ]
+/// \endcode
+/// where iterator-specifier is one of the following:
+/// \code
+/// [ iterator-type ] identifier = range-specification
+/// \endcode
+/// where identifier is a base language identifier.
+/// iterator-type is a type name.
+/// range-specification is of the form begin:end[:step], where begin and end are
+/// expressions for which their types can be converted to iterator-type and step
+/// is an integral expression.
+/// In an iterator-specifier, if the iterator-type is not specified then the
+/// type of that iterator is of int type.
+/// The iterator-type must be an integral or pointer type.
+/// The iterator-type must not be const qualified.
+class OMPIteratorExpr final
+    : public Expr,
+      private llvm::TrailingObjects<OMPIteratorExpr, Decl *, Expr *,
+                                    SourceLocation> {
+public:
+  /// Iterator range representation begin:end[:step].
+  struct IteratorRange {
+    Expr *Begin = nullptr;
+    Expr *End = nullptr;
+    Expr *Step = nullptr;
+  };
+  /// Iterator definition representation.
+  struct IteratorDefinition {
+    Decl *IteratorDecl = nullptr;
+    IteratorRange Range;
+    SourceLocation AssignmentLoc;
+    SourceLocation ColonLoc, SecondColonLoc;
+  };
+
+private:
+  friend TrailingObjects;
+  friend class ASTStmtReader;
+  friend class ASTStmtWriter;
+
+  /// Offset in the list of expressions for subelements of the ranges.
+  enum class RangeExprOffset {
+    Begin = 0,
+    End = 1,
+    Step = 2,
+    Total = 3,
+  };
+  /// Offset in the list of locations for subelements of colon symbols
+  /// locations.
+  enum class RangeLocOffset {
+    AssignLoc = 0,
+    FirstColonLoc = 1,
+    SecondColonLoc = 2,
+    Total = 3,
+  };
+  /// Location of 'iterator' keyword.
+  SourceLocation IteratorKwLoc;
+  /// Location of '('.
+  SourceLocation LPLoc;
+  /// Location of ')'.
+  SourceLocation RPLoc;
+  /// Number of iterator definitions.
+  unsigned NumIterators = 0;
+
+  OMPIteratorExpr(QualType ExprTy, SourceLocation IteratorKwLoc,
+                  SourceLocation L, SourceLocation R,
+                  ArrayRef<OMPIteratorExpr::IteratorDefinition> Data);
+
+  /// Construct an empty expression.
+  explicit OMPIteratorExpr(EmptyShell Shell, unsigned NumIterators)
+      : Expr(OMPIteratorExprClass, Shell), NumIterators(NumIterators) {}
+
+  /// Sets basic declaration for the specified iterator definition.
+  void setIteratorDeclaration(unsigned I, Decl *D);
+
+  /// Sets the location of the assignment symbol for the specified iterator
+  /// definition.
+  void setAssignmentLoc(unsigned I, SourceLocation Loc);
+
+  /// Sets begin, end and optional step expressions for specified iterator
+  /// definition.
+  void setIteratorRange(unsigned I, Expr *Begin, SourceLocation ColonLoc,
+                        Expr *End, SourceLocation SecondColonLoc, Expr *Step);
+
+  unsigned numTrailingObjects(OverloadToken<Decl *>) const {
+    return NumIterators;
+  }
+
+  unsigned numTrailingObjects(OverloadToken<Expr *>) const {
+    return NumIterators * static_cast<int>(RangeExprOffset::Total);
+  }
+
+public:
+  static OMPIteratorExpr *Create(const ASTContext &Context, QualType T,
+                                 SourceLocation IteratorKwLoc, SourceLocation L,
+                                 SourceLocation R,
+                                 ArrayRef<IteratorDefinition> Data);
+
+  static OMPIteratorExpr *CreateEmpty(const ASTContext &Context,
+                                      unsigned NumIterators);
+
+  SourceLocation getLParenLoc() const { return LPLoc; }
+  void setLParenLoc(SourceLocation L) { LPLoc = L; }
+
+  SourceLocation getRParenLoc() const { return RPLoc; }
+  void setRParenLoc(SourceLocation L) { RPLoc = L; }
+
+  SourceLocation getIteratorKwLoc() const { return IteratorKwLoc; }
+  void setIteratorKwLoc(SourceLocation L) { IteratorKwLoc = L; }
+  SourceLocation getBeginLoc() const LLVM_READONLY { return IteratorKwLoc; }
+  SourceLocation getEndLoc() const LLVM_READONLY { return RPLoc; }
+
+  /// Gets the iterator declaration for the given iterator.
+  Decl *getIteratorDecl(unsigned I);
+  const Decl *getIteratorDecl(unsigned I) const {
+    return const_cast<OMPIteratorExpr *>(this)->getIteratorDecl(I);
+  }
+
+  /// Gets the iterator range for the given iterator.
+  IteratorRange getIteratorRange(unsigned I);
+  const IteratorRange getIteratorRange(unsigned I) const {
+    return const_cast<OMPIteratorExpr *>(this)->getIteratorRange(I);
+  }
+
+  /// Gets the location of '=' for the given iterator definition.
+  SourceLocation getAssignLoc(unsigned I) const;
+  /// Gets the location of the first ':' in the range for the given iterator
+  /// definition.
+  SourceLocation getColonLoc(unsigned I) const;
+  /// Gets the location of the second ':' (if any) in the range for the given
+  /// iteratori definition.
+  SourceLocation getSecondColonLoc(unsigned I) const;
+
+  /// Returns number of iterator definitions.
+  unsigned numOfIterators() const { return NumIterators; }
+
+  static bool classof(const Stmt *T) {
+    return T->getStmtClass() == OMPIteratorExprClass;
+  }
+
+  // Iterators
+  child_range children() {
+    Stmt **Begin = reinterpret_cast<Stmt **>(getTrailingObjects<Expr *>());
+    return child_range(
+        Begin, Begin + NumIterators * static_cast<int>(RangeExprOffset::Total));
+  }
+  const_child_range children() const {
+    Stmt *const *Begin =
+        reinterpret_cast<Stmt *const *>(getTrailingObjects<Expr *>());
+    return const_child_range(
+        Begin, Begin + NumIterators * static_cast<int>(RangeExprOffset::Total));
+  }
+};
+
 } // end namespace clang
 
 #endif

clang/include/clang/AST/OpenMPClause.h

@@ -4372,6 +4372,9 @@ class OMPDependClause final
   /// Set colon location.
   void setColonLoc(SourceLocation Loc) { ColonLoc = Loc; }
 
+  /// Sets optional dependency modifier.
+  void setModifier(Expr *DepModifier);
+
 public:
   /// Creates clause with a list of variables \a VL.
   ///
@@ -4387,7 +4390,7 @@ class OMPDependClause final
   /// clause.
   static OMPDependClause *Create(const ASTContext &C, SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
-                                 SourceLocation EndLoc,
+                                 SourceLocation EndLoc, Expr *DepModifier,
                                  OpenMPDependClauseKind DepKind,
                                  SourceLocation DepLoc, SourceLocation ColonLoc,
                                  ArrayRef<Expr *> VL, unsigned NumLoops);
@@ -4404,6 +4407,12 @@ class OMPDependClause final
   /// Get dependency type.
   OpenMPDependClauseKind getDependencyKind() const { return DepKind; }
 
+  /// Return optional depend modifier.
+  Expr *getModifier();
+  const Expr *getModifier() const {
+    return const_cast<OMPDependClause *>(this)->getModifier();
+  }
+
   /// Get dependency type location.
   SourceLocation getDependencyLoc() const { return DepLoc; }
 

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -2552,6 +2552,7 @@ DEF_TRAVERSE_STMT(AddrLabelExpr, {})
 DEF_TRAVERSE_STMT(ArraySubscriptExpr, {})
 DEF_TRAVERSE_STMT(OMPArraySectionExpr, {})
 DEF_TRAVERSE_STMT(OMPArrayShapingExpr, {})
+DEF_TRAVERSE_STMT(OMPIteratorExpr, {})
 
 DEF_TRAVERSE_STMT(BlockExpr, {
   TRY_TO(TraverseDecl(S->getBlockDecl()));

clang/include/clang/AST/TextNodeDumper.h

@@ -274,6 +274,7 @@ class TextNodeDumper
   void VisitObjCSubscriptRefExpr(const ObjCSubscriptRefExpr *Node);
   void VisitObjCIvarRefExpr(const ObjCIvarRefExpr *Node);
   void VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *Node);
+  void VisitOMPIteratorExpr(const OMPIteratorExpr *Node);
 
   void VisitRValueReferenceType(const ReferenceType *T);
   void VisitArrayType(const ArrayType *T);

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -1220,6 +1220,10 @@ def err_omp_expected_identifier_for_critical : Error<
   "expected identifier specifying the name of the 'omp critical' directive">;
 def err_omp_expected_reduction_identifier : Error<
   "expected identifier or one of the following operators: '+', '-', '*', '&', '|', '^', '&&', or '||'">;
+def err_omp_expected_equal_in_iterator : Error<
+  "expected '=' in iterator specifier">;
+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<

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -9760,6 +9760,14 @@ def note_omp_conversion_here : Note<
 def err_omp_ambiguous_conversion : Error<
   "ambiguous conversion from type %0 to an integral or unscoped "
   "enumeration type">;
+def err_omp_iterator_not_integral_or_pointer : Error<
+  "expected integral or pointer type as the iterator-type, not %0">;
+def err_omp_iterator_constant : Error<
+  "expected non-constant type as the iterator-type, constant %0 is provided">;
+def err_omp_iterator_step_not_integral : Error<
+  "iterator step expression %0 is not the integral expression">;
+def err_omp_iterator_step_constant_zero : Error<
+  "iterator step expression %0 evaluates to 0">;
 def err_omp_required_access : Error<
   "%0 variable must be %1">;
 def err_omp_const_variable : Error<
@@ -9953,6 +9961,7 @@ def err_omp_invalid_mapper: Error<
   "cannot find a valid user-defined mapper for type %0 with name %1">;
 def err_omp_array_section_use : Error<"OpenMP array section is not allowed here">;
 def err_omp_array_shaping_use : Error<"OpenMP array shaping operation is not allowed here">;
+def err_omp_iterator_use : Error<"OpenMP iterator is not allowed here">;
 def err_omp_typecheck_section_value : Error<
   "subscripted value is not an array or pointer">;
 def err_omp_typecheck_section_not_integer : Error<
@@ -10031,6 +10040,10 @@ 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_linear_ordered : Error<
   "'linear' clause cannot be specified along with 'ordered' clause with a parameter">;
 def err_omp_unexpected_schedule_modifier : Error<