[OPENMP] Initial parsing and sema analysis for 'single' directive.

llvm-svn: 211774

clang/include/clang-c/Index.h

@@ -2151,7 +2151,11 @@ enum CXCursorKind {
    */
   CXCursor_OMPSectionDirective           = 236,
 
-  CXCursor_LastStmt                      = CXCursor_OMPSectionDirective,
+  /** \brief OpenMP single directive.
+   */
+  CXCursor_OMPSingleDirective            = 237,
+
+  CXCursor_LastStmt                      = CXCursor_OMPSingleDirective,
 
   /**
    * \brief Cursor that represents the translation unit itself.

clang/include/clang/AST/DataRecursiveASTVisitor.h

@@ -2305,6 +2305,11 @@ DEF_TRAVERSE_STMT(OMPSectionDirective, {
     return false;
 })
 
+DEF_TRAVERSE_STMT(OMPSingleDirective, {
+  if (!TraverseOMPExecutableDirective(S))
+    return false;
+})
+
 // OpenMP clauses.
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseOMPClause(OMPClause *C) {

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -2327,6 +2327,11 @@ DEF_TRAVERSE_STMT(OMPSectionDirective, {
     return false;
 })
 
+DEF_TRAVERSE_STMT(OMPSingleDirective, {
+  if (!TraverseOMPExecutableDirective(S))
+    return false;
+})
+
 // OpenMP clauses.
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseOMPClause(OMPClause *C) {

clang/include/clang/AST/StmtOpenMP.h

@@ -470,6 +470,63 @@ public:
   }
 };
 
+/// \brief This represents '#pragma omp single' directive.
+///
+/// \code
+/// #pragma omp single private(a,b) copyprivate(c,d)
+/// \endcode
+/// In this example directive '#pragma omp single' has clauses 'private' with
+/// the variables 'a' and 'b' and 'copyprivate' with variables 'c' and 'd'.
+///
+class OMPSingleDirective : public OMPExecutableDirective {
+  friend class ASTStmtReader;
+  /// \brief Build directive with the given start and end location.
+  ///
+  /// \param StartLoc Starting location of the directive kind.
+  /// \param EndLoc Ending location of the directive.
+  /// \param NumClauses Number of clauses.
+  ///
+  OMPSingleDirective(SourceLocation StartLoc, SourceLocation EndLoc,
+                     unsigned NumClauses)
+      : OMPExecutableDirective(this, OMPSingleDirectiveClass, OMPD_single,
+                               StartLoc, EndLoc, NumClauses, 1) {}
+
+  /// \brief Build an empty directive.
+  ///
+  /// \param NumClauses Number of clauses.
+  ///
+  explicit OMPSingleDirective(unsigned NumClauses)
+      : OMPExecutableDirective(this, OMPSingleDirectiveClass, OMPD_single,
+                               SourceLocation(), SourceLocation(), NumClauses,
+                               1) {}
+
+public:
+  /// \brief Creates directive with a list of \a Clauses.
+  ///
+  /// \param C AST context.
+  /// \param StartLoc Starting location of the directive kind.
+  /// \param EndLoc Ending Location of the directive.
+  /// \param Clauses List of clauses.
+  /// \param AssociatedStmt Statement, associated with the directive.
+  ///
+  static OMPSingleDirective *
+  Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
+         ArrayRef<OMPClause *> Clauses, Stmt *AssociatedStmt);
+
+  /// \brief Creates an empty directive with the place for \a NumClauses
+  /// clauses.
+  ///
+  /// \param C AST context.
+  /// \param NumClauses Number of clauses.
+  ///
+  static OMPSingleDirective *CreateEmpty(const ASTContext &C,
+                                         unsigned NumClauses, EmptyShell);
+
+  static bool classof(const Stmt *T) {
+    return T->getStmtClass() == OMPSingleDirectiveClass;
+  }
+};
+
 } // end namespace clang
 
 #endif

clang/include/clang/Basic/OpenMPKinds.def

@@ -30,6 +30,9 @@
 #ifndef OPENMP_SECTIONS_CLAUSE
 #  define OPENMP_SECTIONS_CLAUSE(Name)
 #endif
+#ifndef OPENMP_SINGLE_CLAUSE
+#  define OPENMP_SINGLE_CLAUSE(Name)
+#endif
 #ifndef OPENMP_DEFAULT_KIND
 #  define OPENMP_DEFAULT_KIND(Name)
 #endif
@@ -48,6 +51,7 @@ OPENMP_DIRECTIVE(simd)
 OPENMP_DIRECTIVE(for)
 OPENMP_DIRECTIVE(sections)
 OPENMP_DIRECTIVE(section)
+OPENMP_DIRECTIVE(single)
 
 // OpenMP clauses.
 OPENMP_CLAUSE(if, OMPIfClause)
@@ -104,6 +108,11 @@ OPENMP_SECTIONS_CLAUSE(firstprivate)
 OPENMP_SECTIONS_CLAUSE(reduction)
 OPENMP_SECTIONS_CLAUSE(nowait)
 
+// TODO more clauses allowed for directive 'omp single'.
+OPENMP_SINGLE_CLAUSE(private)
+OPENMP_SINGLE_CLAUSE(firstprivate)
+OPENMP_SINGLE_CLAUSE(nowait)
+
 // Static attributes for 'default' clause.
 OPENMP_DEFAULT_KIND(none)
 OPENMP_DEFAULT_KIND(shared)
@@ -125,6 +134,7 @@ OPENMP_SCHEDULE_KIND(runtime)
 #undef OPENMP_DEFAULT_KIND
 #undef OPENMP_DIRECTIVE
 #undef OPENMP_CLAUSE
+#undef OPENMP_SINGLE_CLAUSE
 #undef OPENMP_SECTIONS_CLAUSE
 #undef OPENMP_PARALLEL_CLAUSE
 #undef OPENMP_SIMD_CLAUSE

clang/include/clang/Basic/StmtNodes.td

@@ -182,3 +182,4 @@ def OMPSimdDirective : DStmt<OMPExecutableDirective>;
 def OMPForDirective : DStmt<OMPExecutableDirective>;
 def OMPSectionsDirective : DStmt<OMPExecutableDirective>;
 def OMPSectionDirective : DStmt<OMPExecutableDirective>;
+def OMPSingleDirective : DStmt<OMPExecutableDirective>;

clang/include/clang/Sema/Sema.h

@@ -7331,6 +7331,11 @@ public:
   /// associated statement.
   StmtResult ActOnOpenMPSectionDirective(Stmt *AStmt, SourceLocation StartLoc,
                                          SourceLocation EndLoc);
+  /// \brief Called on well-formed '\#pragma omp single' after parsing of the
+  /// associated statement.
+  StmtResult ActOnOpenMPSingleDirective(ArrayRef<OMPClause *> Clauses,
+                                        Stmt *AStmt, SourceLocation StartLoc,
+                                        SourceLocation EndLoc);
 
   OMPClause *ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
                                          Expr *Expr,

clang/include/clang/Serialization/ASTBitCodes.h

@@ -1344,6 +1344,7 @@ namespace clang {
       STMT_OMP_FOR_DIRECTIVE,
       STMT_OMP_SECTIONS_DIRECTIVE,
       STMT_OMP_SECTION_DIRECTIVE,
+      STMT_OMP_SINGLE_DIRECTIVE,
 
       // ARC
       EXPR_OBJC_BRIDGED_CAST,     // ObjCBridgedCastExpr

clang/lib/AST/Stmt.cpp

@@ -1430,3 +1430,29 @@ OMPSectionDirective *OMPSectionDirective::CreateEmpty(const ASTContext &C,
   return new (Mem) OMPSectionDirective();
 }
 
+OMPSingleDirective *OMPSingleDirective::Create(const ASTContext &C,
+                                               SourceLocation StartLoc,
+                                               SourceLocation EndLoc,
+                                               ArrayRef<OMPClause *> Clauses,
+                                               Stmt *AssociatedStmt) {
+  unsigned Size = llvm::RoundUpToAlignment(sizeof(OMPSingleDirective),
+                                           llvm::alignOf<OMPClause *>());
+  void *Mem =
+      C.Allocate(Size + sizeof(OMPClause *) * Clauses.size() + sizeof(Stmt *));
+  OMPSingleDirective *Dir =
+      new (Mem) OMPSingleDirective(StartLoc, EndLoc, Clauses.size());
+  Dir->setClauses(Clauses);
+  Dir->setAssociatedStmt(AssociatedStmt);
+  return Dir;
+}
+
+OMPSingleDirective *OMPSingleDirective::CreateEmpty(const ASTContext &C,
+                                                    unsigned NumClauses,
+                                                    EmptyShell) {
+  unsigned Size = llvm::RoundUpToAlignment(sizeof(OMPSingleDirective),
+                                           llvm::alignOf<OMPClause *>());
+  void *Mem =
+      C.Allocate(Size + sizeof(OMPClause *) * NumClauses + sizeof(Stmt *));
+  return new (Mem) OMPSingleDirective(NumClauses);
+}
+

clang/lib/AST/StmtPrinter.cpp

@@ -797,6 +797,11 @@ void StmtPrinter::VisitOMPSectionDirective(OMPSectionDirective *Node) {
   PrintOMPExecutableDirective(Node);
 }
 
+void StmtPrinter::VisitOMPSingleDirective(OMPSingleDirective *Node) {
+  Indent() << "#pragma omp single ";
+  PrintOMPExecutableDirective(Node);
+}
+
 //===----------------------------------------------------------------------===//
 //  Expr printing methods.
 //===----------------------------------------------------------------------===//

clang/lib/AST/StmtProfile.cpp

@@ -368,6 +368,10 @@ void StmtProfiler::VisitOMPSectionDirective(const OMPSectionDirective *S) {
   VisitOMPExecutableDirective(S);
 }
 
+void StmtProfiler::VisitOMPSingleDirective(const OMPSingleDirective *S) {
+  VisitOMPExecutableDirective(S);
+}
+
 void StmtProfiler::VisitExpr(const Expr *S) {
   VisitStmt(S);
 }

clang/lib/Basic/OpenMPKinds.cpp

@@ -196,6 +196,16 @@ bool clang::isAllowedClauseForDirective(OpenMPDirectiveKind DKind,
 #define OPENMP_SECTIONS_CLAUSE(Name)                                                \
   case OMPC_##Name:                                                            \
     return true;
+#include "clang/Basic/OpenMPKinds.def"
+    default:
+      break;
+    }
+    break;
+  case OMPD_single:
+    switch (CKind) {
+#define OPENMP_SINGLE_CLAUSE(Name)                                                \
+  case OMPC_##Name:                                                            \
+    return true;
 #include "clang/Basic/OpenMPKinds.def"
     default:
       break;
@@ -215,8 +225,8 @@ bool clang::isOpenMPLoopDirective(OpenMPDirectiveKind DKind) {
 }
 
 bool clang::isOpenMPWorksharingDirective(OpenMPDirectiveKind DKind) {
-  return DKind == OMPD_for || DKind == OMPD_sections ||
-         DKind == OMPD_section; // TODO add next directives.
+  return DKind == OMPD_for || DKind == OMPD_sections || DKind == OMPD_section ||
+         DKind == OMPD_single; // TODO add next directives.
 }
 
 bool clang::isOpenMPParallelDirective(OpenMPDirectiveKind DKind) {

clang/lib/CodeGen/CGStmt.cpp

@@ -188,6 +188,9 @@ void CodeGenFunction::EmitStmt(const Stmt *S) {
   case Stmt::OMPSectionDirectiveClass:
     EmitOMPSectionDirective(cast<OMPSectionDirective>(*S));
     break;
+  case Stmt::OMPSingleDirectiveClass:
+    EmitOMPSingleDirective(cast<OMPSingleDirective>(*S));
+    break;
   }
 }
 

clang/lib/CodeGen/CGStmtOpenMP.cpp

@@ -87,3 +87,7 @@ void CodeGenFunction::EmitOMPSectionDirective(const OMPSectionDirective &) {
   llvm_unreachable("CodeGen for 'omp section' is not supported yet.");
 }
 
+void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &) {
+  llvm_unreachable("CodeGen for 'omp single' is not supported yet.");
+}
+

clang/lib/CodeGen/CodeGenFunction.h

@@ -1905,6 +1905,7 @@ public:
   void EmitOMPForDirective(const OMPForDirective &S);
   void EmitOMPSectionsDirective(const OMPSectionsDirective &S);
   void EmitOMPSectionDirective(const OMPSectionDirective &S);
+  void EmitOMPSingleDirective(const OMPSingleDirective &S);
 
   //===--------------------------------------------------------------------===//
   //                         LValue Expression Emission

clang/lib/Parse/ParseOpenMP.cpp

@@ -65,6 +65,7 @@ Parser::DeclGroupPtrTy Parser::ParseOpenMPDeclarativeDirective() {
   case OMPD_for:
   case OMPD_sections:
   case OMPD_section:
+  case OMPD_single:
     Diag(Tok, diag::err_omp_unexpected_directive)
         << getOpenMPDirectiveName(DKind);
     break;
@@ -80,8 +81,8 @@ Parser::DeclGroupPtrTy Parser::ParseOpenMPDeclarativeDirective() {
 ///         annot_pragma_openmp_end
 ///
 ///       executable-directive:
-///         annot_pragma_openmp 'parallel'|'simd'|'for'|'sections'|'section'
-///         {clause} annot_pragma_openmp_end
+///         annot_pragma_openmp 'parallel' | 'simd' | 'for' | 'sections' |
+///         'section' | 'single' {clause} annot_pragma_openmp_end
 ///
 StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective() {
   assert(Tok.is(tok::annot_pragma_openmp) && "Not an OpenMP directive!");
@@ -121,6 +122,7 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective() {
   case OMPD_simd:
   case OMPD_for:
   case OMPD_sections:
+  case OMPD_single:
   case OMPD_section: {
     ConsumeToken();
 

clang/lib/Sema/SemaOpenMP.cpp

@@ -924,6 +924,13 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, SourceLocation Loc,
     ActOnCapturedRegionStart(Loc, CurScope, CR_OpenMP, Params);
     break;
   }
+  case OMPD_single: {
+    Sema::CapturedParamNameType Params[] = {
+        std::make_pair(StringRef(), QualType()) // __context with shared vars
+    };
+    ActOnCapturedRegionStart(Loc, CurScope, CR_OpenMP, Params);
+    break;
+  }
   case OMPD_threadprivate:
   case OMPD_task:
     llvm_unreachable("OpenMP Directive is not allowed");
@@ -1033,6 +1040,10 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(OpenMPDirectiveKind Kind,
            "No clauses is allowed for 'omp section' directive");
     Res = ActOnOpenMPSectionDirective(AStmt, StartLoc, EndLoc);
     break;
+  case OMPD_single:
+    Res = ActOnOpenMPSingleDirective(ClausesWithImplicit, AStmt, StartLoc,
+                                     EndLoc);
+    break;
   case OMPD_threadprivate:
   case OMPD_task:
     llvm_unreachable("OpenMP Directive is not allowed");
@@ -1647,6 +1658,14 @@ StmtResult Sema::ActOnOpenMPSectionDirective(Stmt *AStmt,
   return OMPSectionDirective::Create(Context, StartLoc, EndLoc, AStmt);
 }
 
+StmtResult Sema::ActOnOpenMPSingleDirective(ArrayRef<OMPClause *> Clauses,
+                                            Stmt *AStmt,
+                                            SourceLocation StartLoc,
+                                            SourceLocation EndLoc) {
+  getCurFunction()->setHasBranchProtectedScope();
+  return OMPSingleDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt);
+}
+
 OMPClause *Sema::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind, Expr *Expr,
                                              SourceLocation StartLoc,
                                              SourceLocation LParenLoc,

clang/lib/Sema/TreeTransform.h

@@ -6449,6 +6449,16 @@ TreeTransform<Derived>::TransformOMPSectionDirective(OMPSectionDirective *D) {
   return Res;
 }
 
+template <typename Derived>
+StmtResult
+TreeTransform<Derived>::TransformOMPSingleDirective(OMPSingleDirective *D) {
+  DeclarationNameInfo DirName;
+  getDerived().getSema().StartOpenMPDSABlock(OMPD_single, DirName, nullptr);
+  StmtResult Res = getDerived().TransformOMPExecutableDirective(D);
+  getDerived().getSema().EndOpenMPDSABlock(Res.get());
+  return Res;
+}
+
 //===----------------------------------------------------------------------===//
 // OpenMP clause transformation
 //===----------------------------------------------------------------------===//

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -1918,6 +1918,13 @@ void ASTStmtReader::VisitOMPSectionDirective(OMPSectionDirective *D) {
   VisitOMPExecutableDirective(D);
 }
 
+void ASTStmtReader::VisitOMPSingleDirective(OMPSingleDirective *D) {
+  VisitStmt(D);
+  // The NumClauses field was read in ReadStmtFromStream.
+  ++Idx;
+  VisitOMPExecutableDirective(D);
+}
+
 //===----------------------------------------------------------------------===//
 // ASTReader Implementation
 //===----------------------------------------------------------------------===//
@@ -2422,6 +2429,11 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = OMPSectionDirective::CreateEmpty(Context, Empty);
       break;
 
+    case STMT_OMP_SINGLE_DIRECTIVE:
+      S = OMPSingleDirective::CreateEmpty(
+          Context, Record[ASTStmtReader::NumStmtFields], Empty);
+      break;
+
     case EXPR_CXX_OPERATOR_CALL:
       S = new (Context) CXXOperatorCallExpr(Context, Empty);
       break;

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -1831,6 +1831,13 @@ void ASTStmtWriter::VisitOMPSectionDirective(OMPSectionDirective *D) {
   Code = serialization::STMT_OMP_SECTION_DIRECTIVE;
 }
 
+void ASTStmtWriter::VisitOMPSingleDirective(OMPSingleDirective *D) {
+  VisitStmt(D);
+  Record.push_back(D->getNumClauses());
+  VisitOMPExecutableDirective(D);
+  Code = serialization::STMT_OMP_SINGLE_DIRECTIVE;
+}
+
 //===----------------------------------------------------------------------===//
 // ASTWriter Implementation
 //===----------------------------------------------------------------------===//

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -735,6 +735,7 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::OMPForDirectiveClass:
     case Stmt::OMPSectionsDirectiveClass:
     case Stmt::OMPSectionDirectiveClass:
+    case Stmt::OMPSingleDirectiveClass:
       llvm_unreachable("Stmt should not be in analyzer evaluation loop");
 
     case Stmt::ObjCSubscriptRefExprClass:

clang/test/OpenMP/nesting_of_regions.cpp

@@ -22,6 +22,9 @@ void foo() {
   {
     bar();
   }
+#pragma omp parallel
+#pragma omp single
+  bar();
 #pragma omp simd
   for (int i = 0; i < 10; ++i) {
 #pragma omp for // expected-error {{OpenMP constructs may not be nested inside a simd region}}
@@ -54,6 +57,13 @@ void foo() {
       bar();
     }
   }
+#pragma omp simd
+  for (int i = 0; i < 10; ++i) {
+#pragma omp single // expected-error {{OpenMP constructs may not be nested inside a simd region}}
+    {
+      bar();
+    }
+  }
 #pragma omp for
   for (int i = 0; i < 10; ++i) {
 #pragma omp for // expected-error {{region cannot be closely nested inside 'for' region; perhaps you forget to enclose 'omp for' directive into a parallel region?}}
@@ -86,6 +96,13 @@ void foo() {
       bar();
     }
   }
+#pragma omp for
+  for (int i = 0; i < 10; ++i) {
+#pragma omp single // expected-error {{region cannot be closely nested inside 'for' region; perhaps you forget to enclose 'omp single' directive into a parallel region?}}
+    {
+      bar();
+    }
+  }
 #pragma omp sections
   {
 #pragma omp for // expected-error {{region cannot be closely nested inside 'sections' region; perhaps you forget to enclose 'omp for' directive into a parallel region?}}
@@ -118,10 +135,50 @@ void foo() {
       bar();
     }
   }
+#pragma omp sections
+  {
+#pragma omp section
+    {
+#pragma omp single // expected-error {{region cannot be closely nested inside 'section' region; perhaps you forget to enclose 'omp single' directive into a parallel region?}}
+      bar();
+    }
+  }
 #pragma omp section // expected-error {{orphaned 'omp section' directives are prohibited, it must be closely nested to a sections region}}
   {
     bar();
   }
+#pragma omp single
+  {
+#pragma omp for // expected-error {{region cannot be closely nested inside 'single' region; perhaps you forget to enclose 'omp for' directive into a parallel region?}}
+    for (int i = 0; i < 10; ++i)
+      ;
+  }
+#pragma omp single
+  {
+#pragma omp simd
+    for (int i = 0; i < 10; ++i)
+      ;
+  }
+#pragma omp single
+  {
+#pragma omp parallel
+    for (int i = 0; i < 10; ++i)
+      ;
+  }
+#pragma omp single
+  {
+#pragma omp single // expected-error {{region cannot be closely nested inside 'single' region; perhaps you forget to enclose 'omp single' directive into a parallel region?}}
+    {
+      bar();
+    }
+  }
+#pragma omp single
+  {
+#pragma omp sections // expected-error {{region cannot be closely nested inside 'single' region; perhaps you forget to enclose 'omp sections' directive into a parallel region?}}
+    {
+      bar();
+    }
+  }
 }
 
 void foo() {
@@ -143,6 +200,14 @@ void foo() {
   {
     bar();
   }
+#pragma omp parallel
+#pragma omp sections
+  {
+    bar();
+  }
+#pragma omp parallel
+#pragma omp single
+  bar();
 #pragma omp simd
   for (int i = 0; i < 10; ++i) {
 #pragma omp for // expected-error {{OpenMP constructs may not be nested inside a simd region}}
@@ -175,6 +240,11 @@ void foo() {
       bar();
     }
   }
+#pragma omp simd
+  for (int i = 0; i < 10; ++i) {
+#pragma omp single // expected-error {{OpenMP constructs may not be nested inside a simd region}}
+    bar();
+  }
 #pragma omp for
   for (int i = 0; i < 10; ++i) {
 #pragma omp for // expected-error {{region cannot be closely nested inside 'for' region; perhaps you forget to enclose 'omp for' directive into a parallel region?}}
@@ -207,6 +277,11 @@ void foo() {
       bar();
     }
   }
+#pragma omp for
+  for (int i = 0; i < 10; ++i) {
+#pragma omp single // expected-error {{region cannot be closely nested inside 'for' region; perhaps you forget to enclose 'omp single' directive into a parallel region?}}
+    bar();
+  }
 #pragma omp sections
   {
 #pragma omp for // expected-error {{region cannot be closely nested inside 'sections' region; perhaps you forget to enclose 'omp for' directive into a parallel region?}}
@@ -239,10 +314,47 @@ void foo() {
       bar();
     }
   }
+#pragma omp sections
+  {
+#pragma omp single // expected-error {{region cannot be closely nested inside 'sections' region; perhaps you forget to enclose 'omp single' directive into a parallel region?}}
+    bar();
+  }
 #pragma omp section // expected-error {{orphaned 'omp section' directives are prohibited, it must be closely nested to a sections region}}
   {
     bar();
   }
+#pragma omp single
+  {
+#pragma omp for // expected-error {{region cannot be closely nested inside 'single' region; perhaps you forget to enclose 'omp for' directive into a parallel region?}}
+    for (int i = 0; i < 10; ++i)
+      ;
+  }
+#pragma omp single
+  {
+#pragma omp simd
+    for (int i = 0; i < 10; ++i)
+      ;
+  }
+#pragma omp single
+  {
+#pragma omp parallel
+    for (int i = 0; i < 10; ++i)
+      ;
+  }
+#pragma omp single
+  {
+#pragma omp single // expected-error {{region cannot be closely nested inside 'single' region; perhaps you forget to enclose 'omp single' directive into a parallel region?}}
+    {
+      bar();
+    }
+  }
+#pragma omp single
+  {
+#pragma omp sections // expected-error {{region cannot be closely nested inside 'single' region; perhaps you forget to enclose 'omp sections' directive into a parallel region?}}
+    {
+      bar();
+    }
+  }
   return foo<int>();
 }
 

clang/test/OpenMP/single_ast_print.cpp

@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 -verify -fopenmp=libiomp5 -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp=libiomp5 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp=libiomp5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+
+void foo() {}
+
+template <class T, int N>
+T tmain(T argc) {
+  T b = argc, c, d, e, f, g;
+  static T a;
+// CHECK: static T a;
+#pragma omp parallel
+#pragma omp single private(argc, b), firstprivate(c, d), nowait
+  foo();
+  // CHECK-NEXT: #pragma omp parallel
+  // CHECK-NEXT: #pragma omp single private(argc,b) firstprivate(c,d) nowait
+  // CHECK-NEXT: foo();
+  return T();
+}
+
+int main(int argc, char **argv) {
+  int b = argc, c, d, e, f, g;
+  static int a;
+// CHECK: static int a;
+#pragma omp parallel
+#pragma omp single private(argc, b), firstprivate(argv, c), nowait
+  foo();
+  // CHECK-NEXT: #pragma omp parallel
+  // CHECK-NEXT: #pragma omp single private(argc,b) firstprivate(argv,c) nowait
+  // CHECK-NEXT: foo();
+  return (tmain<int, 5>(argc) + tmain<char, 1>(argv[0][0]));
+}
+
+#endif

clang/test/OpenMP/single_firstprivate_messages.cpp

@@ -0,0 +1,239 @@
+// RUN: %clang_cc1 -verify -fopenmp=libiomp5 %s
+
+void foo() {
+}
+
+bool foobool(int argc) {
+  return argc;
+}
+
+struct S1; // expected-note 2 {{declared here}} expected-note 2 {{forward declaration of 'S1'}}
+extern S1 a;
+class S2 {
+  mutable int a;
+
+public:
+  S2() : a(0) {}
+  S2(S2 &s2) : a(s2.a) {}
+  static float S2s;
+  static const float S2sc;
+};
+const float S2::S2sc = 0;
+const S2 b;
+const S2 ba[5];
+class S3 {
+  int a;
+  S3 &operator=(const S3 &s3);
+
+public:
+  S3() : a(0) {}
+  S3(S3 &s3) : a(s3.a) {}
+};
+const S3 c;
+const S3 ca[5];
+extern const int f;
+class S4 { // expected-note 2 {{'S4' declared here}}
+  int a;
+  S4();
+  S4(const S4 &s4);
+
+public:
+  S4(int v) : a(v) {}
+};
+class S5 { // expected-note 4 {{'S5' declared here}}
+  int a;
+  S5(const S5 &s5) : a(s5.a) {}
+
+public:
+  S5() : a(0) {}
+  S5(int v) : a(v) {}
+};
+class S6 {
+  int a;
+  S6() : a(0) {}
+
+public:
+  S6(const S6 &s6) : a(s6.a) {}
+  S6(int v) : a(v) {}
+};
+
+S3 h;
+#pragma omp threadprivate(h) // expected-note 2 {{defined as threadprivate or thread local}}
+
+template <class I, class C>
+int foomain(int argc, char **argv) {
+  I e(4); // expected-note {{'e' defined here}}
+  C g(5); // expected-note 2 {{'g' defined here}}
+  int i;
+  int &j = i; // expected-note {{'j' defined here}}
+#pragma omp parallel
+#pragma omp single firstprivate // expected-error {{expected '(' after 'firstprivate'}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate( // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate() // expected-error {{expected expression}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc // expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc, // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc > 0 ? argv[1] : argv[2]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc)
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(S1) // expected-error {{'S1' does not refer to a value}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(a, b) // expected-error {{firstprivate variable with incomplete type 'S1'}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argv[1]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(e, g) // expected-error 2 {{firstprivate variable must have an accessible, unambiguous copy constructor}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(h) // expected-error {{threadprivate or thread local variable cannot be firstprivate}}
+  foo();
+#pragma omp parallel
+#pragma omp single linear(i) // expected-error {{unexpected OpenMP clause 'linear' in directive '#pragma omp single'}}
+  foo();
+#pragma omp parallel
+  {
+    int v = 0;
+    int i;                         // expected-note {{variable with automatic storage duration is predetermined as private; perhaps you forget to enclose 'omp single' directive into a parallel or another task region?}}
+#pragma omp single firstprivate(i) // expected-error {{private variable cannot be firstprivate}}
+    foo();
+    v += i;
+  }
+#pragma omp parallel shared(i)
+#pragma omp parallel private(i)
+#pragma omp single firstprivate(j) // expected-error {{arguments of OpenMP clause 'firstprivate' cannot be of reference type}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(i)
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(g) // expected-error {{firstprivate variable must have an accessible, unambiguous copy constructor}}
+  foo();
+#pragma omp parallel private(i)    // expected-note {{defined as private}}
+#pragma omp single firstprivate(i) // expected-error {{firstprivate variable must be shared}}
+  foo();
+#pragma omp parallel reduction(+ : i) // expected-note {{defined as reduction}}
+#pragma omp single firstprivate(i)    // expected-error {{firstprivate variable must be shared}}
+  foo();
+  return 0;
+}
+
+int main(int argc, char **argv) {
+  const int d = 5;
+  const int da[5] = {0};
+  S4 e(4); // expected-note {{'e' defined here}}
+  S5 g(5); // expected-note 2 {{'g' defined here}}
+  S3 m;
+  S6 n(2);
+  int i;
+  int &j = i; // expected-note {{'j' defined here}}
+#pragma omp parallel
+#pragma omp single firstprivate // expected-error {{expected '(' after 'firstprivate'}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate( // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate() // expected-error {{expected expression}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc // expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc, // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc > 0 ? argv[1] : argv[2]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argc)
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(S1) // expected-error {{'S1' does not refer to a value}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(a, b, c, d, f) // expected-error {{firstprivate variable with incomplete type 'S1'}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(argv[1]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(2 * 2) // expected-error {{expected variable name}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(ba) // OK
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(ca) // OK
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(da) // OK
+  foo();
+  int xa;
+#pragma omp parallel
+#pragma omp single firstprivate(xa) // OK
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(S2::S2s) // OK
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(S2::S2sc) // OK
+  foo();
+#pragma omp parallel
+#pragma omp single safelen(5) // expected-error {{unexpected OpenMP clause 'safelen' in directive '#pragma omp single'}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(e, g) // expected-error 2 {{firstprivate variable must have an accessible, unambiguous copy constructor}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(m) // OK
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(h) // expected-error {{threadprivate or thread local variable cannot be firstprivate}}
+  foo();
+#pragma omp parallel
+#pragma omp single private(xa), firstprivate(xa) // expected-error {{private variable cannot be firstprivate}} expected-note {{defined as private}}
+  foo();
+#pragma omp parallel shared(xa)
+#pragma omp single firstprivate(xa) // OK: may be firstprivate
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(j) // expected-error {{arguments of OpenMP clause 'firstprivate' cannot be of reference type}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(g) // expected-error {{firstprivate variable must have an accessible, unambiguous copy constructor}}
+  foo();
+#pragma omp parallel
+#pragma omp single firstprivate(n) // OK
+  foo();
+#pragma omp parallel
+  {
+    int v = 0;
+    int i;                         // expected-note {{variable with automatic storage duration is predetermined as private; perhaps you forget to enclose 'omp single' directive into a parallel or another task region?}}
+#pragma omp single firstprivate(i) // expected-error {{private variable cannot be firstprivate}}
+    foo();
+    v += i;
+  }
+#pragma omp parallel private(i)    // expected-note {{defined as private}}
+#pragma omp single firstprivate(i) // expected-error {{firstprivate variable must be shared}}
+  foo();
+#pragma omp parallel reduction(+ : i) // expected-note {{defined as reduction}}
+#pragma omp single firstprivate(i)    // expected-error {{firstprivate variable must be shared}}
+  foo();
+
+  return foomain<S4, S5>(argc, argv); // expected-note {{in instantiation of function template specialization 'foomain<S4, S5>' requested here}}
+}

clang/test/OpenMP/single_misc_messages.c

@@ -0,0 +1,151 @@
+// RUN: %clang_cc1 -fsyntax-only -fopenmp=libiomp5 -verify %s
+
+void foo();
+
+// expected-error@+1 {{unexpected OpenMP directive '#pragma omp single'}}
+#pragma omp single
+
+// expected-error@+1 {{unexpected OpenMP directive '#pragma omp single'}}
+#pragma omp single foo
+
+void test_no_clause() {
+  int i;
+#pragma omp single
+  foo();
+
+#pragma omp single
+  ++i;
+}
+
+void test_branch_protected_scope() {
+  int i = 0;
+L1:
+  ++i;
+
+  int x[24];
+
+#pragma omp parallel
+#pragma omp single
+  {
+    if (i == 5)
+      goto L1; // expected-error {{use of undeclared label 'L1'}}
+    else if (i == 6)
+      return; // expected-error {{cannot return from OpenMP region}}
+    else if (i == 7)
+      goto L2;
+    else if (i == 8) {
+    L2:
+      x[i]++;
+    }
+  }
+
+  if (x[0] == 0)
+    goto L2; // expected-error {{use of undeclared label 'L2'}}
+  else if (x[1] == 1)
+    goto L1;
+}
+
+void test_invalid_clause() {
+  int i;
+#pragma omp parallel
+// expected-warning@+1 {{extra tokens at the end of '#pragma omp single' are ignored}}
+#pragma omp single foo bar
+  foo();
+}
+
+void test_non_identifiers() {
+  int i, x;
+
+#pragma omp parallel
+// expected-warning@+1 {{extra tokens at the end of '#pragma omp single' are ignored}}
+#pragma omp single;
+  foo();
+#pragma omp parallel
+// expected-error@+2 {{unexpected OpenMP clause 'linear' in directive '#pragma omp single'}}
+// expected-warning@+1 {{extra tokens at the end of '#pragma omp single' are ignored}}
+#pragma omp single linear(x);
+  foo();
+
+#pragma omp parallel
+// expected-warning@+1 {{extra tokens at the end of '#pragma omp single' are ignored}}
+#pragma omp single private(x);
+  foo();
+
+#pragma omp parallel
+// expected-warning@+1 {{extra tokens at the end of '#pragma omp single' are ignored}}
+#pragma omp single, private(x);
+  foo();
+}
+
+void test_private() {
+  int i;
+#pragma omp parallel
+// expected-error@+2 {{expected expression}}
+// expected-error@+1 {{expected ')'}} expected-note@+1 {{to match this '('}}
+#pragma omp single private(
+  foo();
+#pragma omp parallel
+// expected-error@+2 {{expected ')'}} expected-note@+2 {{to match this '('}}
+// expected-error@+1 2 {{expected expression}}
+#pragma omp single private(,
+  foo();
+#pragma omp parallel
+// expected-error@+1 2 {{expected expression}}
+#pragma omp single private(, )
+  foo();
+#pragma omp parallel
+// expected-error@+1 {{expected expression}}
+#pragma omp single private()
+  foo();
+#pragma omp parallel
+// expected-error@+1 {{expected expression}}
+#pragma omp single private(int)
+  foo();
+#pragma omp parallel
+// expected-error@+1 {{expected variable name}}
+#pragma omp single private(0)
+  foo();
+
+  int x, y, z;
+#pragma omp parallel
+#pragma omp single private(x)
+  foo();
+#pragma omp parallel
+#pragma omp single private(x, y)
+  foo();
+#pragma omp parallel
+#pragma omp single private(x, y, z)
+  foo();
+}
+
+void test_firstprivate() {
+  int i;
+#pragma omp parallel
+// expected-error@+2 {{expected ')'}} expected-note@+2 {{to match this '('}}
+// expected-error@+1 {{expected expression}}
+#pragma omp single firstprivate(
+  foo();
+
+#pragma omp parallel
+// expected-error@+2 {{expected ')'}} expected-note@+2 {{to match this '('}}
+// expected-error@+1 2 {{expected expression}}
+#pragma omp single firstprivate(,
+  foo();
+#pragma omp parallel
+// expected-error@+1 2 {{expected expression}}
+#pragma omp single firstprivate(, )
+  foo();
+#pragma omp parallel
+// expected-error@+1 {{expected expression}}
+#pragma omp single firstprivate()
+  foo();
+#pragma omp parallel
+// expected-error@+1 {{expected expression}}
+#pragma omp single firstprivate(int)
+  foo();
+#pragma omp parallel
+// expected-error@+1 {{expected variable name}}
+#pragma omp single firstprivate(0)
+  foo();
+}
+

clang/test/OpenMP/single_private_messages.cpp

@@ -0,0 +1,140 @@
+// RUN: %clang_cc1 -verify -fopenmp=libiomp5 %s
+
+void foo() {
+}
+
+bool foobool(int argc) {
+  return argc;
+}
+
+struct S1; // expected-note 2 {{declared here}} expected-note 2 {{forward declaration of 'S1'}}
+extern S1 a;
+class S2 {
+  mutable int a;
+
+public:
+  S2() : a(0) {}
+};
+const S2 b;
+const S2 ba[5];
+class S3 {
+  int a;
+
+public:
+  S3() : a(0) {}
+};
+const S3 ca[5];
+class S4 { // expected-note {{'S4' declared here}}
+  int a;
+  S4();
+
+public:
+  S4(int v) : a(v) {}
+};
+class S5 { // expected-note {{'S5' declared here}}
+  int a;
+  S5() : a(0) {}
+
+public:
+  S5(int v) : a(v) {}
+};
+
+S3 h;
+#pragma omp threadprivate(h) // expected-note 2 {{defined as threadprivate or thread local}}
+
+template <class I, class C>
+int foomain(I argc, C **argv) {
+  I e(4);
+  I g(5);
+  int i;
+  int &j = i;                // expected-note {{'j' defined here}}
+#pragma omp single private // expected-error {{expected '(' after 'private'}}
+  foo();
+#pragma omp single private( // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp single private() // expected-error {{expected expression}}
+  foo();
+#pragma omp single private(argc // expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp single private(argc, // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp single private(argc > 0 ? argv[1] : argv[2]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp single private(argc)
+  foo();
+#pragma omp single private(S1) // expected-error {{'S1' does not refer to a value}}
+  foo();
+#pragma omp single private(a, b) // expected-error {{private variable with incomplete type 'S1'}}
+  foo();
+#pragma omp single private(argv[1]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp single private(e, g)
+  foo();
+#pragma omp single private(h) // expected-error {{threadprivate or thread local variable cannot be private}}
+  foo();
+#pragma omp single shared(i) // expected-error {{unexpected OpenMP clause 'shared' in directive '#pragma omp single'}}
+  foo();
+#pragma omp parallel
+  {
+    int v = 0;
+    int i;
+#pragma omp single private(i)
+    foo();
+    v += i;
+  }
+#pragma omp parallel shared(i)
+#pragma omp parallel private(i)
+#pragma omp single private(j) // expected-error {{arguments of OpenMP clause 'private' cannot be of reference type}}
+  foo();
+#pragma omp single private(i)
+  foo();
+  return 0;
+}
+
+int main(int argc, char **argv) {
+  S4 e(4); // expected-note {{'e' defined here}}
+  S5 g(5); // expected-note {{'g' defined here}}
+  int i;
+  int &j = i;                // expected-note {{'j' defined here}}
+#pragma omp single private // expected-error {{expected '(' after 'private'}}
+  foo();
+#pragma omp single private( // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp single private() // expected-error {{expected expression}}
+  foo();
+#pragma omp single private(argc // expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp single private(argc, // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  foo();
+#pragma omp single private(argc > 0 ? argv[1] : argv[2]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp single private(argc)
+  foo();
+#pragma omp single private(S1) // expected-error {{'S1' does not refer to a value}}
+  foo();
+#pragma omp single private(a, b) // expected-error {{private variable with incomplete type 'S1'}}
+  foo();
+#pragma omp single private(argv[1]) // expected-error {{expected variable name}}
+  foo();
+#pragma omp single private(e, g) // expected-error 2 {{private variable must have an accessible, unambiguous default constructor}}
+  foo();
+#pragma omp single private(h) // expected-error {{threadprivate or thread local variable cannot be private}}
+  foo();
+#pragma omp single shared(i) // expected-error {{unexpected OpenMP clause 'shared' in directive '#pragma omp single'}}
+  foo();
+#pragma omp parallel
+  {
+    int i;
+#pragma omp single private(i)
+    foo();
+  }
+#pragma omp parallel shared(i)
+#pragma omp parallel private(i)
+#pragma omp single private(j) // expected-error {{arguments of OpenMP clause 'private' cannot be of reference type}}
+  foo();
+#pragma omp single private(i)
+  foo();
+
+  return 0;
+}
+

clang/tools/libclang/CIndex.cpp

@@ -1854,6 +1854,7 @@ public:
   void VisitOMPForDirective(const OMPForDirective *D);
   void VisitOMPSectionsDirective(const OMPSectionsDirective *D);
   void VisitOMPSectionDirective(const OMPSectionDirective *D);
+  void VisitOMPSingleDirective(const OMPSingleDirective *D);
 
 private:
   void AddDeclarationNameInfo(const Stmt *S);
@@ -2297,6 +2298,10 @@ void EnqueueVisitor::VisitOMPSectionDirective(const OMPSectionDirective *D) {
   VisitOMPExecutableDirective(D);
 }
 
+void EnqueueVisitor::VisitOMPSingleDirective(const OMPSingleDirective *D) {
+  VisitOMPExecutableDirective(D);
+}
+
 void CursorVisitor::EnqueueWorkList(VisitorWorkList &WL, const Stmt *S) {
   EnqueueVisitor(WL, MakeCXCursor(S, StmtParent, TU,RegionOfInterest)).Visit(S);
 }
@@ -3979,6 +3984,8 @@ CXString clang_getCursorKindSpelling(enum CXCursorKind Kind) {
     return cxstring::createRef("OMPSectionsDirective");
   case CXCursor_OMPSectionDirective:
     return cxstring::createRef("OMPSectionDirective");
+  case CXCursor_OMPSingleDirective:
+    return cxstring::createRef("OMPSingleDirective");
   }
 
   llvm_unreachable("Unhandled CXCursorKind");

clang/tools/libclang/CXCursor.cpp

@@ -528,6 +528,9 @@ CXCursor cxcursor::MakeCXCursor(const Stmt *S, const Decl *Parent,
   case Stmt::OMPSectionDirectiveClass:
     K = CXCursor_OMPSectionDirective;
     break;
+  case Stmt::OMPSingleDirectiveClass:
+    K = CXCursor_OMPSingleDirective;
+    break;
   }
 
   CXCursor C = { K, 0, { Parent, S, TU } };