OpenMP: Data-sharing attributes analysis and clause 'shared'

llvm-svn: 189795

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -2346,12 +2346,17 @@ bool RecursiveASTVisitor<Derived>::VisitOMPDefaultClause(OMPDefaultClause *C) {
     TraverseStmt(*I);
 
 template<typename Derived>
-bool RecursiveASTVisitor<Derived>::VisitOMPPrivateClause(
-                                                      OMPPrivateClause *C) {
+bool RecursiveASTVisitor<Derived>::VisitOMPPrivateClause(OMPPrivateClause *C) {
   PROCESS_OMP_CLAUSE_LIST(OMPPrivateClause, C)
   return true;
 }
 
+template<typename Derived>
+bool RecursiveASTVisitor<Derived>::VisitOMPSharedClause(OMPSharedClause *C) {
+  PROCESS_OMP_CLAUSE_LIST(OMPSharedClause, C)
+  return true;
+}
+
 #undef PROCESS_OMP_CLAUSE_LIST
 
 // FIXME: look at the following tricky-seeming exprs to see if we

clang/include/clang/AST/StmtOpenMP.h

@@ -249,6 +249,63 @@ public:
   }
 };
 
+/// \brief This represents clause 'shared' in the '#pragma omp ...' directives.
+///
+/// \code
+/// #pragma omp parallel shared(a,b)
+/// \endcode
+/// In this example directive '#pragma omp parallel' has clause 'shared'
+/// with the variables 'a' and 'b'.
+///
+class OMPSharedClause : public OMPClause, public OMPVarList<OMPSharedClause> {
+  /// \brief Build clause with number of variables \a N.
+  ///
+  /// \param StartLoc Starting location of the clause.
+  /// \param LParenLoc Location of '('.
+  /// \param EndLoc Ending location of the clause.
+  /// \param N Number of the variables in the clause.
+  ///
+  OMPSharedClause(SourceLocation StartLoc, SourceLocation LParenLoc,
+                  SourceLocation EndLoc, unsigned N)
+    : OMPClause(OMPC_shared, StartLoc, EndLoc),
+      OMPVarList<OMPSharedClause>(LParenLoc, N) { }
+
+  /// \brief Build an empty clause.
+  ///
+  /// \param N Number of variables.
+  ///
+  explicit OMPSharedClause(unsigned N)
+    : OMPClause(OMPC_private, SourceLocation(), SourceLocation()),
+      OMPVarList<OMPSharedClause>(SourceLocation(), N) { }
+public:
+  /// \brief Creates clause with a list of variables \a VL.
+  ///
+  /// \param C AST context.
+  /// \param StartLoc Starting location of the clause.
+  /// \param LParenLoc Location of '('.
+  /// \param EndLoc Ending location of the clause.
+  /// \param VL List of references to the variables.
+  ///
+  static OMPSharedClause *Create(const ASTContext &C, SourceLocation StartLoc,
+                                 SourceLocation LParenLoc,
+                                 SourceLocation EndLoc, ArrayRef<Expr *> VL);
+  /// \brief Creates an empty clause with \a N variables.
+  ///
+  /// \param C AST context.
+  /// \param N The number of variables.
+  ///
+  static OMPSharedClause *CreateEmpty(const ASTContext &C, unsigned N);
+
+  StmtRange children() {
+    return StmtRange(reinterpret_cast<Stmt **>(varlist_begin()),
+                     reinterpret_cast<Stmt **>(varlist_end()));
+  }
+
+  static bool classof(const OMPClause *T) {
+    return T->getClauseKind() == OMPC_shared;
+  }
+};
+
 //===----------------------------------------------------------------------===//
 // AST classes for directives.
 //===----------------------------------------------------------------------===//

clang/include/clang/Basic/CapturedStmt.h

@@ -15,7 +15,8 @@ namespace clang {
 
 /// \brief The different kinds of captured statement.
 enum CapturedRegionKind {
-  CR_Default
+  CR_Default,
+  CR_OpenMP
 };
 
 } // end namespace clang

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -6601,6 +6601,14 @@ def err_omp_clause_ref_type_arg : Error<
   "arguments of OpenMP clause '%0' cannot be of reference type %1">;
 def err_omp_threadprivate_incomplete_type : Error<
   "threadprivate variable with incomplete type %0">;
+def err_omp_no_dsa_for_variable : Error <
+  "variable %0 must have explicitly specified data sharing attributes">;
+def err_omp_wrong_dsa : Error<
+  "%0 variable cannot be %1">;
+def note_omp_explicit_dsa : Note <
+  "defined as %0">;
+def note_omp_predetermined_dsa : Note <
+  "predetermined as %0">;
 } // end of OpenMP category
 
 let CategoryName = "Related Result Type Issue" in {

clang/include/clang/Basic/OpenMPKinds.def

@@ -33,10 +33,12 @@ OPENMP_DIRECTIVE(task)
 // OpenMP clauses.
 OPENMP_CLAUSE(default, OMPDefaultClause)
 OPENMP_CLAUSE(private, OMPPrivateClause)
+OPENMP_CLAUSE(shared,  OMPSharedClause)
 
 // Clauses allowed for OpenMP directives.
 OPENMP_PARALLEL_CLAUSE(default)
 OPENMP_PARALLEL_CLAUSE(private)
+OPENMP_PARALLEL_CLAUSE(shared)
 
 // Static attributes for 'default' clause.
 OPENMP_DEFAULT_KIND(none)

clang/include/clang/Sema/Scope.h

@@ -91,7 +91,10 @@ public:
     TryScope = 0x2000,
 
     /// \brief This is the scope for a function-level C++ try or catch scope.
-    FnTryCatchScope = 0x4000
+    FnTryCatchScope = 0x4000,
+
+    /// \brief This is the scope of OpenMP executable directive
+    OpenMPDirectiveScope = 0x8000
   };
 private:
   /// The parent scope for this scope.  This is null for the translation-unit
@@ -301,7 +304,12 @@ public:
     }
     return false;
   }
-  
+
+  /// \brief Determines whether this scope is the OpenMP directive scope
+  bool isOpenMPDirectiveScope() const {
+    return (getFlags() & Scope::OpenMPDirectiveScope);
+  }
+
   /// \brief Determine whether this scope is a C++ 'try' block.
   bool isTryScope() const { return getFlags() & Scope::TryScope; }
 

clang/include/clang/Sema/ScopeInfo.h

@@ -567,6 +567,8 @@ public:
     switch (CapRegionKind) {
     case CR_Default:
       return "default captured statement";
+    case CR_OpenMP:
+      return "OpenMP region";
     }
     llvm_unreachable("Invalid captured region kind!");
   }

clang/include/clang/Sema/Sema.h

@@ -6883,6 +6883,20 @@ public:
   void AddAlignedAttr(SourceRange AttrRange, Decl *D, TypeSourceInfo *T,
                       unsigned SpellingListIndex, bool IsPackExpansion);
 
+  // OpenMP directives and clauses.
+private:
+  void *VarDataSharingAttributesStack;
+  /// \brief Initialization of data-sharing attributes stack.
+  void InitDataSharingAttributesStack();
+  void DestroyDataSharingAttributesStack();
+public:
+  /// \brief Called on start of new data sharing attribute block.
+  void StartOpenMPDSABlock(OpenMPDirectiveKind K,
+                           const DeclarationNameInfo &DirName,
+                           Scope *CurScope);
+  /// \brief Called on end of data sharing attribute block.
+  void EndOpenMPDSABlock(Stmt *CurDirective);
+
   // OpenMP directives and clauses.
   /// \brief Called on correct id-expression from the '#pragma omp
   /// threadprivate'.
@@ -6933,6 +6947,11 @@ public:
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
+  /// \brief Called on well-formed 'shared' clause.
+  OMPClause *ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
+                                     SourceLocation StartLoc,
+                                     SourceLocation LParenLoc,
+                                     SourceLocation EndLoc);
 
   /// \brief The kind of conversion being performed.
   enum CheckedConversionKind {

clang/lib/AST/Stmt.cpp

@@ -1111,6 +1111,16 @@ bool CapturedStmt::capturesVariable(const VarDecl *Var) const {
   return false;
 }
 
+StmtRange OMPClause::children() {
+  switch(getClauseKind()) {
+  default : break;
+#define OPENMP_CLAUSE(Name, Class)                                       \
+  case OMPC_ ## Name : return static_cast<Class *>(this)->children();
+#include "clang/Basic/OpenMPKinds.def"
+  }
+  llvm_unreachable("unknown OMPClause");
+}
+
 OMPPrivateClause *OMPPrivateClause::Create(const ASTContext &C,
                                            SourceLocation StartLoc,
                                            SourceLocation LParenLoc,
@@ -1131,6 +1141,26 @@ OMPPrivateClause *OMPPrivateClause::CreateEmpty(const ASTContext &C,
   return new (Mem) OMPPrivateClause(N);
 }
 
+OMPSharedClause *OMPSharedClause::Create(const ASTContext &C,
+                                         SourceLocation StartLoc,
+                                         SourceLocation LParenLoc,
+                                         SourceLocation EndLoc,
+                                         ArrayRef<Expr *> VL) {
+  void *Mem = C.Allocate(sizeof(OMPSharedClause) + sizeof(Expr *) * VL.size(),
+                         llvm::alignOf<OMPSharedClause>());
+  OMPSharedClause *Clause = new (Mem) OMPSharedClause(StartLoc, LParenLoc,
+                                                      EndLoc, VL.size());
+  Clause->setVarRefs(VL);
+  return Clause;
+}
+
+OMPSharedClause *OMPSharedClause::CreateEmpty(const ASTContext &C,
+                                              unsigned N) {
+  void *Mem = C.Allocate(sizeof(OMPSharedClause) + sizeof(Expr *) * N,
+                         llvm::alignOf<OMPSharedClause>());
+  return new (Mem) OMPSharedClause(N);
+}
+
 void OMPExecutableDirective::setClauses(ArrayRef<OMPClause *> Clauses) {
   assert(Clauses.size() == this->Clauses.size() &&
          "Number of clauses is not the same as the preallocated buffer");

clang/lib/AST/StmtPrinter.cpp

@@ -614,6 +614,14 @@ void OMPClausePrinter::VisitOMPPrivateClause(OMPPrivateClause *Node) {
   }
 }
 
+void OMPClausePrinter::VisitOMPSharedClause(OMPSharedClause *Node) {
+  if (!Node->varlist_empty()) {
+    OS << "shared";
+    PROCESS_OMP_CLAUSE_LIST(OMPSharedClause, Node, '(')
+    OS << ")";
+  }
+}
+
 #undef PROCESS_OMP_CLAUSE_LIST
 }
 

clang/lib/AST/StmtProfile.cpp

@@ -272,6 +272,9 @@ void OMPClauseProfiler::VisitOMPDefaultClause(const OMPDefaultClause *C) { }
 void OMPClauseProfiler::VisitOMPPrivateClause(const OMPPrivateClause *C) {
   PROCESS_OMP_CLAUSE_LIST(OMPPrivateClause, C)
 }
+void OMPClauseProfiler::VisitOMPSharedClause(const OMPSharedClause *C) {
+  PROCESS_OMP_CLAUSE_LIST(OMPSharedClause, C)
+}
 #undef PROCESS_OMP_CLAUSE_LIST
 }
 

clang/lib/CodeGen/CGStmt.cpp

@@ -136,8 +136,10 @@ void CodeGenFunction::EmitStmt(const Stmt *S) {
   case Stmt::SwitchStmtClass:   EmitSwitchStmt(cast<SwitchStmt>(*S));     break;
   case Stmt::GCCAsmStmtClass:   // Intentional fall-through.
   case Stmt::MSAsmStmtClass:    EmitAsmStmt(cast<AsmStmt>(*S));           break;
-  case Stmt::CapturedStmtClass:
-    EmitCapturedStmt(cast<CapturedStmt>(*S), CR_Default);
+  case Stmt::CapturedStmtClass: {
+    const CapturedStmt *CS = cast<CapturedStmt>(S);
+    EmitCapturedStmt(*CS, CS->getCapturedRegionKind());
+    }
     break;
   case Stmt::ObjCAtTryStmtClass:
     EmitObjCAtTryStmt(cast<ObjCAtTryStmt>(*S));

clang/lib/Parse/ParseOpenMP.cpp

@@ -84,11 +84,14 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective() {
   SmallVector<OMPClause *, 5> Clauses;
   SmallVector<llvm::PointerIntPair<OMPClause *, 1, bool>, NUM_OPENMP_CLAUSES>
                                                FirstClauses(NUM_OPENMP_CLAUSES);
-  const unsigned ScopeFlags = Scope::FnScope | Scope::DeclScope;
+  const unsigned ScopeFlags = Scope::FnScope | Scope::DeclScope |
+                              Scope::OpenMPDirectiveScope;
   SourceLocation Loc = ConsumeToken(), EndLoc;
   OpenMPDirectiveKind DKind = Tok.isAnnotation() ?
                                   OMPD_unknown :
                                   getOpenMPDirectiveKind(PP.getSpelling(Tok));
+  // Name of critical directive.
+  DeclarationNameInfo DirName;
   StmtResult Directive = StmtError();
 
   switch (DKind) {
@@ -111,6 +114,9 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective() {
     break;
   case OMPD_parallel: {
     ConsumeToken();
+
+    Actions.StartOpenMPDSABlock(DKind, DirName, Actions.getCurScope());
+
     while (Tok.isNot(tok::annot_pragma_openmp_end)) {
       OpenMPClauseKind CKind = Tok.isAnnotation() ?
                                   OMPC_unknown :
@@ -138,7 +144,7 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective() {
     {
       // The body is a block scope like in Lambdas and Blocks.
       Sema::CompoundScopeRAII CompoundScope(Actions);
-      Actions.ActOnCapturedRegionStart(Loc, getCurScope(), CR_Default, 1);
+      Actions.ActOnCapturedRegionStart(Loc, getCurScope(), CR_OpenMP, 1);
       Actions.ActOnStartOfCompoundStmt();
       // Parse statement
       AssociatedStmt = ParseStatement();
@@ -157,6 +163,7 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective() {
                                                          Loc, EndLoc);
 
     // Exit scope.
+    Actions.EndOpenMPDSABlock(Directive.get());
     OMPDirectiveScope.Exit();
     }
     break;
@@ -245,7 +252,7 @@ bool Parser::ParseOpenMPSimpleVarList(OpenMPDirectiveKind Kind,
 /// \brief Parsing of OpenMP clauses.
 ///
 ///    clause:
-///       default-clause|private-clause
+///       default-clause|private-clause|shared-clause
 ///
 OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
                                      OpenMPClauseKind CKind, bool FirstClause) {
@@ -271,6 +278,7 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
     Clause = ParseOpenMPSimpleClause(CKind);
     break;
   case OMPC_private:
+  case OMPC_shared:
     Clause = ParseOpenMPVarListClause(CKind);
     break;
   case OMPC_unknown:
@@ -322,6 +330,8 @@ OMPClause *Parser::ParseOpenMPSimpleClause(OpenMPClauseKind Kind) {
 ///
 ///    private-clause:
 ///       'private' '(' list ')'
+///    shared-clause:
+///       'shared' '(' list ')'
 ///
 OMPClause *Parser::ParseOpenMPVarListClause(OpenMPClauseKind Kind) {
   SourceLocation Loc = Tok.getLocation();

clang/lib/Sema/Sema.cpp

@@ -90,7 +90,8 @@ Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
     AccessCheckingSFINAE(false), InNonInstantiationSFINAEContext(false),
     NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1),
     CurrentInstantiationScope(0), TyposCorrected(0),
-    AnalysisWarnings(*this), CurScope(0), Ident_super(0), Ident___float128(0)
+    AnalysisWarnings(*this), VarDataSharingAttributesStack(0), CurScope(0),
+    Ident_super(0), Ident___float128(0)
 {
   TUScope = 0;
 
@@ -113,6 +114,9 @@ Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
                                           false, 0, false));
 
   FunctionScopes.push_back(new FunctionScopeInfo(Diags));
+
+  // Initilization of data sharing attributes stack for OpenMP
+  InitDataSharingAttributesStack();
 }
 
 void Sema::Initialize() {
@@ -199,6 +203,9 @@ Sema::~Sema() {
   // If Sema's ExternalSource is the multiplexer - we own it.
   if (isMultiplexExternalSource)
     delete ExternalSource;
+
+  // Destroys data sharing attributes stack for OpenMP
+  DestroyDataSharingAttributesStack();
 }
 
 /// makeUnavailableInSystemHeader - There is an error in the current

clang/lib/Sema/SemaOpenMP.cpp

@@ -27,6 +27,325 @@
 #include "clang/Sema/ScopeInfo.h"
 using namespace clang;
 
+//===----------------------------------------------------------------------===//
+// Stack of data-sharing attributes for variables
+//===----------------------------------------------------------------------===//
+
+namespace {
+/// \brief Default data sharing attributes, which can be applied to directive.
+enum DefaultDataSharingAttributes {
+  DSA_unspecified = 0,   /// \brief Data sharing attribute not specified.
+  DSA_none = 1 << 0,     /// \brief Default data sharing attribute 'none'.
+  DSA_shared = 1 << 1    /// \brief Default data sharing attribute 'shared'.
+};
+
+/// \brief Stack for tracking declarations used in OpenMP directives and
+/// clauses and their data-sharing attributes.
+class DSAStackTy {
+public:
+  struct DSAVarData {
+    OpenMPDirectiveKind DKind;
+    OpenMPClauseKind CKind;
+    DeclRefExpr *RefExpr;
+    DSAVarData() : DKind(OMPD_unknown), CKind(OMPC_unknown), RefExpr(0) { }
+  };
+private:
+  struct DSAInfo {
+    OpenMPClauseKind Attributes;
+    DeclRefExpr *RefExpr;
+  };
+  typedef llvm::SmallDenseMap<VarDecl *, DSAInfo, 64> DeclSAMapTy;
+
+  struct SharingMapTy {
+    DeclSAMapTy SharingMap;
+    DefaultDataSharingAttributes DefaultAttr;
+    OpenMPDirectiveKind Directive;
+    DeclarationNameInfo DirectiveName;
+    Scope *CurScope;
+    SharingMapTy(OpenMPDirectiveKind DKind,
+                 const DeclarationNameInfo &Name,
+                 Scope *CurScope)
+      : SharingMap(), DefaultAttr(DSA_unspecified), Directive(DKind),
+        DirectiveName(Name), CurScope(CurScope) { }
+    SharingMapTy()
+      : SharingMap(), DefaultAttr(DSA_unspecified),
+        Directive(OMPD_unknown), DirectiveName(),
+        CurScope(0) { }
+  };
+
+  typedef SmallVector<SharingMapTy, 64> StackTy;
+
+  /// \brief Stack of used declaration and their data-sharing attributes.
+  StackTy Stack;
+  Sema &Actions;
+
+  typedef SmallVector<SharingMapTy, 8>::reverse_iterator reverse_iterator;
+
+  DSAVarData getDSA(StackTy::reverse_iterator Iter, VarDecl *D);
+public:
+  explicit DSAStackTy(Sema &S) : Stack(1), Actions(S) { }
+
+  void push(OpenMPDirectiveKind DKind, const DeclarationNameInfo &DirName,
+            Scope *CurScope) {
+    Stack.push_back(SharingMapTy(DKind, DirName, CurScope));
+  }
+
+  void pop() {
+    assert(Stack.size() > 1 && "Data-sharing attributes stack is empty!");
+    Stack.pop_back();
+  }
+
+  /// \brief Adds explicit data sharing attribute to the specified declaration.
+  void addDSA(VarDecl *D, DeclRefExpr *E, OpenMPClauseKind A);
+
+  /// \brief Checks if the variable is a local for OpenMP region.
+  bool isOpenMPLocal(VarDecl *D);
+
+  /// \brief Returns data sharing attributes from top of the stack for the
+  /// specified declaration.
+  DSAVarData getTopDSA(VarDecl *D);
+  /// \brief Returns data-sharing attributes for the specified declaration.
+  DSAVarData getImplicitDSA(VarDecl *D);
+
+  /// \brief Returns currently analyzed directive.
+  OpenMPDirectiveKind getCurrentDirective() const {
+    return Stack.back().Directive;
+  }
+
+  /// \brief Set default data sharing attribute to none.
+  void setDefaultDSANone() { Stack.back().DefaultAttr = DSA_none; }
+  /// \brief Set default data sharing attribute to shared.
+  void setDefaultDSAShared() { Stack.back().DefaultAttr = DSA_shared; }
+
+  DefaultDataSharingAttributes getDefaultDSA() const {
+    return Stack.back().DefaultAttr;
+  }
+
+  Scope *getCurScope() { return Stack.back().CurScope; }
+};
+} // end anonymous namespace.
+
+DSAStackTy::DSAVarData DSAStackTy::getDSA(StackTy::reverse_iterator Iter,
+                                          VarDecl *D) {
+  DSAVarData DVar;
+  if (Iter == Stack.rend() - 1) {
+    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+    // in a region but not in construct]
+    //  File-scope or namespace-scope variables referenced in called routines
+    //  in the region are shared unless they appear in a threadprivate
+    //  directive.
+    // TODO
+    if (!D->isFunctionOrMethodVarDecl())
+      DVar.CKind = OMPC_shared;
+
+    return DVar;
+  }
+  DVar.DKind = Iter->Directive;
+  // Explicitly specified attributes and local variables with predetermined
+  // attributes.
+  if (Iter->SharingMap.count(D)) {
+    DVar.RefExpr = Iter->SharingMap[D].RefExpr;
+    DVar.CKind = Iter->SharingMap[D].Attributes;
+    return DVar;
+  }
+
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, C/C++, implicitly determined, p.1]
+  //  In a parallel or task construct, the data-sharing attributes of these
+  //  variables are determined by the default clause, if present.
+  switch (Iter->DefaultAttr) {
+  case DSA_shared:
+    DVar.CKind = OMPC_shared;
+    return DVar;
+  case DSA_none:
+    return DVar;
+  case DSA_unspecified:
+    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+    // in a Construct, implicitly determined, p.2]
+    //  In a parallel construct, if no default clause is present, these
+    //  variables are shared.
+    if (DVar.DKind == OMPD_parallel) {
+      DVar.CKind = OMPC_shared;
+      return DVar;
+    }
+
+    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+    // in a Construct, implicitly determined, p.4]
+    //  In a task construct, if no default clause is present, a variable that in
+    //  the enclosing context is determined to be shared by all implicit tasks
+    //  bound to the current team is shared.
+    // TODO
+    if (DVar.DKind == OMPD_task) {
+      DSAVarData DVarTemp;
+      for (StackTy::reverse_iterator I = Iter + 1,
+                                     EE = Stack.rend() - 1;
+           I != EE; ++I) {
+        // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+        // in a Construct, implicitly determined, p.6]
+        //  In a task construct, if no default clause is present, a variable
+        //  whose data-sharing attribute is not determined by the rules above is
+        //  firstprivate.
+        DVarTemp = getDSA(I, D);
+        if (DVarTemp.CKind != OMPC_shared) {
+          DVar.RefExpr = 0;
+          DVar.DKind = OMPD_task;
+          DVar.CKind = OMPC_unknown;
+          // TODO: should return OMPC_firstprivate
+          return DVar;
+        }
+        if (I->Directive == OMPD_parallel) break;
+      }
+      DVar.DKind = OMPD_task;
+      // TODO: Should return OMPC_firstprivate instead of OMPC_unknown.
+      DVar.CKind =
+        (DVarTemp.CKind == OMPC_unknown) ? OMPC_unknown : OMPC_shared;
+      return DVar;
+    }
+  }
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, implicitly determined, p.3]
+  //  For constructs other than task, if no default clause is present, these
+  //  variables inherit their data-sharing attributes from the enclosing
+  //  context.
+  return getDSA(Iter + 1, D);
+}
+
+void DSAStackTy::addDSA(VarDecl *D, DeclRefExpr *E, OpenMPClauseKind A) {
+  if (A == OMPC_threadprivate) {
+    Stack[0].SharingMap[D].Attributes = A;
+    Stack[0].SharingMap[D].RefExpr = E;
+  } else {
+    assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
+    Stack.back().SharingMap[D].Attributes = A;
+    Stack.back().SharingMap[D].RefExpr = E;
+  }
+}
+
+bool DSAStackTy::isOpenMPLocal(VarDecl *D) {
+  Scope *CurScope = getCurScope();
+  while (CurScope && !CurScope->isDeclScope(D))
+    CurScope = CurScope->getParent();
+  while (CurScope && !CurScope->isOpenMPDirectiveScope())
+    CurScope = CurScope->getParent();
+  bool isOpenMPLocal = !!CurScope;
+  if (!isOpenMPLocal) {
+    CurScope = getCurScope();
+    while (CurScope && !CurScope->isOpenMPDirectiveScope())
+      CurScope = CurScope->getParent();
+    isOpenMPLocal =
+      CurScope &&
+      isa<CapturedDecl>(D->getDeclContext()) &&
+      static_cast<DeclContext *>(
+        CurScope->getFnParent()->getEntity())->Encloses(D->getDeclContext());
+  }
+  return isOpenMPLocal;
+}
+
+DSAStackTy::DSAVarData DSAStackTy::getTopDSA(VarDecl *D) {
+  DSAVarData DVar;
+
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, C/C++, predetermined, p.1]
+  //  Variables appearing in threadprivate directives are threadprivate.
+  if (D->getTLSKind() != VarDecl::TLS_None) {
+    DVar.CKind = OMPC_threadprivate;
+    return DVar;
+  }
+  if (Stack[0].SharingMap.count(D)) {
+    DVar.RefExpr = Stack[0].SharingMap[D].RefExpr;
+    DVar.CKind = OMPC_threadprivate;
+    return DVar;
+  }
+
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, C/C++, predetermined, p.1]
+  // Variables with automatic storage duration that are declared in a scope
+  // inside the construct are private.
+  if (isOpenMPLocal(D) && D->isLocalVarDecl() &&
+      (D->getStorageClass() == SC_Auto ||
+       D->getStorageClass() == SC_None)) {
+    DVar.CKind = OMPC_private;
+    return DVar;
+  }
+
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, C/C++, predetermined, p.4]
+  //  Static data memebers are shared.
+  if (D->isStaticDataMember()) {
+    // Variables with const-qualified type having no mutable member may be
+    // listed in a firstprivate clause, even if they are static data members.
+    // TODO:
+    DVar.CKind = OMPC_shared;
+    return DVar;
+  }
+
+  QualType Type = D->getType().getNonReferenceType().getCanonicalType();
+  bool IsConstant = Type.isConstant(Actions.getASTContext());
+  while (Type->isArrayType()) {
+    QualType ElemType = cast<ArrayType>(Type.getTypePtr())->getElementType();
+    Type = ElemType.getNonReferenceType().getCanonicalType();
+  }
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, C/C++, predetermined, p.6]
+  //  Variables with const qualified type having no mutable member are
+  //  shared.
+  CXXRecordDecl *RD = Actions.getLangOpts().CPlusPlus ?
+                                Type->getAsCXXRecordDecl() : 0;
+  if (IsConstant &&
+      !(Actions.getLangOpts().CPlusPlus && RD && RD->hasMutableFields())) {
+    // Variables with const-qualified type having no mutable member may be
+    // listed in a firstprivate clause, even if they are static data members.
+    // TODO
+    DVar.CKind = OMPC_shared;
+    return DVar;
+  }
+
+  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+  // in a Construct, C/C++, predetermined, p.7]
+  //  Variables with static storage duration that are declared in a scope
+  //  inside the construct are shared.
+  if (isOpenMPLocal(D) && D->isStaticLocal()) {
+    DVar.CKind = OMPC_shared;
+    return DVar;
+  }
+
+  // Explicitly specified attributes and local variables with predetermined
+  // attributes.
+  if (Stack.back().SharingMap.count(D)) {
+    DVar.RefExpr = Stack.back().SharingMap[D].RefExpr;
+    DVar.CKind = Stack.back().SharingMap[D].Attributes;
+  }
+
+  return DVar;
+}
+
+DSAStackTy::DSAVarData DSAStackTy::getImplicitDSA(VarDecl *D) {
+  return getDSA(Stack.rbegin() + 1, D);
+}
+
+void Sema::InitDataSharingAttributesStack() {
+  VarDataSharingAttributesStack = new DSAStackTy(*this);
+}
+
+#define DSAStack static_cast<DSAStackTy *>(VarDataSharingAttributesStack)
+
+void Sema::DestroyDataSharingAttributesStack() {
+  delete DSAStack;
+}
+
+void Sema::StartOpenMPDSABlock(OpenMPDirectiveKind DKind,
+                               const DeclarationNameInfo &DirName,
+                               Scope *CurScope) {
+  DSAStack->push(DKind, DirName, CurScope);
+  PushExpressionEvaluationContext(PotentiallyEvaluated);
+}
+
+void Sema::EndOpenMPDSABlock(Stmt *CurDirective) {
+  DSAStack->pop();
+  DiscardCleanupsInEvaluationContext();
+  PopExpressionEvaluationContext();
+}
+
 namespace {
 
 class VarDeclFilterCCC : public CorrectionCandidateCallback {
@@ -130,6 +449,7 @@ ExprResult Sema::ActOnOpenMPIdExpression(Scope *CurScope,
 
   QualType ExprType = VD->getType().getNonReferenceType();
   ExprResult DE = BuildDeclRefExpr(VD, ExprType, VK_RValue, Id.getLoc());
+  DSAStack->addDSA(VD, cast<DeclRefExpr>(DE.get()), OMPC_threadprivate);
   return DE;
 }
 
@@ -192,12 +512,93 @@ OMPThreadPrivateDecl *Sema::CheckOMPThreadPrivateDecl(
                                                Loc, Vars);
 }
 
+namespace {
+class DSAAttrChecker : public StmtVisitor<DSAAttrChecker, void> {
+  DSAStackTy *Stack;
+  Sema &Actions;
+  bool ErrorFound;
+  CapturedStmt *CS;
+public:
+  void VisitDeclRefExpr(DeclRefExpr *E) {
+    if(VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) {
+      if (VD->isImplicit() && VD->hasAttr<UnusedAttr>()) return;
+      // Skip internally declared variables.
+      if (VD->isLocalVarDecl() && !CS->capturesVariable(VD)) return;
+
+      SourceLocation ELoc = E->getExprLoc();
+
+      OpenMPDirectiveKind DKind = Stack->getCurrentDirective();
+      DSAStackTy::DSAVarData DVar = Stack->getTopDSA(VD);
+      if (DVar.CKind != OMPC_unknown) {
+        if (DKind == OMPD_task && DVar.CKind != OMPC_shared &&
+            DVar.CKind != OMPC_threadprivate && !DVar.RefExpr)
+          // TODO: should be marked as firstprivate.
+          ;
+        return;
+      }
+      // The default(none) clause requires that each variable that is referenced
+      // in the construct, and does not have a predetermined data-sharing
+      // attribute, must have its data-sharing attribute explicitly determined
+      // by being listed in a data-sharing attribute clause.
+      if (DVar.CKind == OMPC_unknown && Stack->getDefaultDSA() == DSA_none &&
+          (DKind == OMPD_parallel || DKind == OMPD_task)) {
+        ErrorFound = true;
+        Actions.Diag(ELoc, diag::err_omp_no_dsa_for_variable) << VD;
+        return;
+      }
+
+      // OpenMP [2.9.3.6, Restrictions, p.2]
+      //  A list item that appears in a reduction clause of the innermost
+      //  enclosing worksharing or parallel construct may not be accessed in an
+      //  explicit task.
+      // TODO:
+
+      // Define implicit data-sharing attributes for task.
+      DVar = Stack->getImplicitDSA(VD);
+      if (DKind == OMPD_task && DVar.CKind != OMPC_shared) {
+        // TODO: should be marked as firstprivate.
+      }
+    }
+  }
+  void VisitOMPExecutableDirective(OMPExecutableDirective *S) {
+    for (ArrayRef<OMPClause *>::iterator I = S->clauses().begin(),
+                                         E = S->clauses().end();
+         I != E; ++I)
+      if (OMPClause *C = *I)
+        for (StmtRange R = C->children(); R; ++R)
+          if (Stmt *Child = *R)
+            Visit(Child);
+  }
+  void VisitStmt(Stmt *S) {
+    for (Stmt::child_iterator I = S->child_begin(), E = S->child_end();
+         I != E; ++I)
+      if (Stmt *Child = *I)
+        if (!isa<OMPExecutableDirective>(Child))
+          Visit(Child);
+    }
+
+  bool isErrorFound() { return ErrorFound; }
+
+  DSAAttrChecker(DSAStackTy *S, Sema &Actions, CapturedStmt *CS)
+    : Stack(S), Actions(Actions), ErrorFound(false), CS(CS) { }
+};
+}
+
 StmtResult Sema::ActOnOpenMPExecutableDirective(OpenMPDirectiveKind Kind,
                                                 ArrayRef<OMPClause *> Clauses,
                                                 Stmt *AStmt,
                                                 SourceLocation StartLoc,
                                                 SourceLocation EndLoc) {
+  assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
+
   StmtResult Res = StmtError();
+
+  // Check default data sharing attributes for referenced variables.
+  DSAAttrChecker DSAChecker(DSAStack, *this, cast<CapturedStmt>(AStmt));
+  DSAChecker.Visit(cast<CapturedStmt>(AStmt)->getCapturedStmt());
+  if (DSAChecker.isErrorFound())
+    return StmtError();
+
   switch (Kind) {
   case OMPD_parallel:
     Res = ActOnOpenMPParallelDirective(Clauses, AStmt, StartLoc, EndLoc);
@@ -231,11 +632,12 @@ OMPClause *Sema::ActOnOpenMPSimpleClause(OpenMPClauseKind Kind,
   OMPClause *Res = 0;
   switch (Kind) {
   case OMPC_default:
-    Res = ActOnOpenMPDefaultClause(
-                             static_cast<OpenMPDefaultClauseKind>(Argument),
-                             ArgumentLoc, StartLoc, LParenLoc, EndLoc);
+    Res =
+      ActOnOpenMPDefaultClause(static_cast<OpenMPDefaultClauseKind>(Argument),
+                               ArgumentLoc, StartLoc, LParenLoc, EndLoc);
     break;
   case OMPC_private:
+  case OMPC_shared:
   case OMPC_threadprivate:
   case OMPC_unknown:
   case NUM_OPENMP_CLAUSES:
@@ -272,6 +674,16 @@ OMPClause *Sema::ActOnOpenMPDefaultClause(OpenMPDefaultClauseKind Kind,
       << Values << getOpenMPClauseName(OMPC_default);
     return 0;
   }
+  switch (Kind) {
+  case OMPC_DEFAULT_none:
+    DSAStack->setDefaultDSANone();
+    break;
+  case OMPC_DEFAULT_shared:
+    DSAStack->setDefaultDSAShared();
+    break;
+  default:
+    break;
+  }
   return new (Context) OMPDefaultClause(Kind, KindKwLoc, StartLoc, LParenLoc,
                                         EndLoc);
 }
@@ -286,6 +698,9 @@ OMPClause *Sema::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
   case OMPC_private:
     Res = ActOnOpenMPPrivateClause(VarList, StartLoc, LParenLoc, EndLoc);
     break;
+  case OMPC_shared:
+    Res = ActOnOpenMPSharedClause(VarList, StartLoc, LParenLoc, EndLoc);
+    break;
   case OMPC_default:
   case OMPC_threadprivate:
   case OMPC_unknown:
@@ -396,6 +811,29 @@ OMPClause *Sema::ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
       }
     }
 
+    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+    // in a Construct]
+    //  Variables with the predetermined data-sharing attributes may not be
+    //  listed in data-sharing attributes clauses, except for the cases
+    //  listed below. For these exceptions only, listing a predetermined
+    //  variable in a data-sharing attribute clause is allowed and overrides
+    //  the variable's predetermined data-sharing attributes.
+    DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD);
+    if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_private) {
+      Diag(ELoc, diag::err_omp_wrong_dsa)
+         << getOpenMPClauseName(DVar.CKind)
+         << getOpenMPClauseName(OMPC_private);
+      if (DVar.RefExpr) {
+        Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_explicit_dsa)
+             << getOpenMPClauseName(DVar.CKind);
+      } else {
+        Diag(VD->getLocation(), diag::note_omp_predetermined_dsa)
+             << getOpenMPClauseName(DVar.CKind);
+      }
+      continue;
+    }
+
+    DSAStack->addDSA(VD, DE, OMPC_private);
     Vars.push_back(DE);
   }
 
@@ -404,3 +842,65 @@ OMPClause *Sema::ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
   return OMPPrivateClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars);
 }
 
+OMPClause *Sema::ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
+                                         SourceLocation StartLoc,
+                                         SourceLocation LParenLoc,
+                                         SourceLocation EndLoc) {
+  SmallVector<Expr *, 8> Vars;
+  for (ArrayRef<Expr *>::iterator I = VarList.begin(), E = VarList.end();
+       I != E; ++I) {
+    if (*I && isa<DependentScopeDeclRefExpr>(*I)) {
+      // It will be analyzed later.
+      Vars.push_back(*I);
+      continue;
+    }
+
+    SourceLocation ELoc = (*I)->getExprLoc();
+    // OpenMP [2.1, C/C++]
+    //  A list item is a variable name.
+    // OpenMP  [2.9.3.4, Restrictions, p.1]
+    //  A variable that is part of another variable (as an array or
+    //  structure element) cannot appear in a private clause.
+    DeclRefExpr *DE = dyn_cast<DeclRefExpr>(*I);
+    if (!DE || !isa<VarDecl>(DE->getDecl())) {
+      Diag(ELoc, diag::err_omp_expected_var_name)
+        << (*I)->getSourceRange();
+      continue;
+    }
+    Decl *D = DE->getDecl();
+    VarDecl *VD = cast<VarDecl>(D);
+
+    QualType Type = VD->getType();
+    if (Type->isDependentType() || Type->isInstantiationDependentType()) {
+      // It will be analyzed later.
+      Vars.push_back(DE);
+      continue;
+    }
+
+    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
+    // in a Construct]
+    //  Variables with the predetermined data-sharing attributes may not be
+    //  listed in data-sharing attributes clauses, except for the cases
+    //  listed below. For these exceptions only, listing a predetermined
+    //  variable in a data-sharing attribute clause is allowed and overrides
+    //  the variable's predetermined data-sharing attributes.
+    DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD);
+    if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_shared && DVar.RefExpr) {
+      Diag(ELoc, diag::err_omp_wrong_dsa)
+         << getOpenMPClauseName(DVar.CKind)
+         << getOpenMPClauseName(OMPC_shared);
+      Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_explicit_dsa)
+           << getOpenMPClauseName(DVar.CKind);
+      continue;
+    }
+
+    DSAStack->addDSA(VD, DE, OMPC_shared);
+    Vars.push_back(DE);
+  }
+
+  if (Vars.empty()) return 0;
+
+  return OMPSharedClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars);
+}
+
+#undef DSAStack

clang/lib/Sema/TreeTransform.h

@@ -1307,6 +1307,14 @@ public:
                                               EndLoc);
   }
 
+  OMPClause *RebuildOMPSharedClause(ArrayRef<Expr *> VarList,
+                                    SourceLocation StartLoc,
+                                    SourceLocation LParenLoc,
+                                    SourceLocation EndLoc) {
+    return getSema().ActOnOpenMPSharedClause(VarList, StartLoc, LParenLoc,
+                                             EndLoc);
+  }
+
   /// \brief Rebuild the operand to an Objective-C \@synchronized statement.
   ///
   /// By default, performs semantic analysis to build the new statement.
@@ -6249,33 +6257,44 @@ TreeTransform<Derived>::TransformSEHHandler(Stmt *Handler) {
 template<typename Derived>
 StmtResult
 TreeTransform<Derived>::TransformOMPParallelDirective(OMPParallelDirective *D) {
+  DeclarationNameInfo DirName;
+  getSema().StartOpenMPDSABlock(OMPD_parallel, DirName, 0);
+
   // Transform the clauses
-  SmallVector<OMPClause *, 5> TClauses;
+  llvm::SmallVector<OMPClause *, 16> TClauses;
   ArrayRef<OMPClause *> Clauses = D->clauses();
   TClauses.reserve(Clauses.size());
   for (ArrayRef<OMPClause *>::iterator I = Clauses.begin(), E = Clauses.end();
        I != E; ++I) {
     if (*I) {
       OMPClause *Clause = getDerived().TransformOMPClause(*I);
-      if (!Clause)
+      if (!Clause) {
+        getSema().EndOpenMPDSABlock(0);
         return StmtError();
+      }
       TClauses.push_back(Clause);
     }
     else {
       TClauses.push_back(0);
     }
   }
-  if (!D->getAssociatedStmt())
+  if (!D->getAssociatedStmt()) {
+    getSema().EndOpenMPDSABlock(0);
     return StmtError();
+  }
   StmtResult AssociatedStmt =
     getDerived().TransformStmt(D->getAssociatedStmt());
-  if (AssociatedStmt.isInvalid())
+  if (AssociatedStmt.isInvalid()) {
+    getSema().EndOpenMPDSABlock(0);
     return StmtError();
+  }
 
-  return getDerived().RebuildOMPParallelDirective(TClauses,
-                                                  AssociatedStmt.take(),
-                                                  D->getLocStart(),
-                                                  D->getLocEnd());
+  StmtResult Res = getDerived().RebuildOMPParallelDirective(TClauses,
+                                                            AssociatedStmt.take(),
+                                                            D->getLocStart(),
+                                                            D->getLocEnd());
+  getSema().EndOpenMPDSABlock(Res.get());
+  return Res;
 }
 
 template<typename Derived>
@@ -6291,7 +6310,7 @@ TreeTransform<Derived>::TransformOMPDefaultClause(OMPDefaultClause *C) {
 template<typename Derived>
 OMPClause *
 TreeTransform<Derived>::TransformOMPPrivateClause(OMPPrivateClause *C) {
-  SmallVector<Expr *, 5> Vars;
+  llvm::SmallVector<Expr *, 16> Vars;
   Vars.reserve(C->varlist_size());
   for (OMPVarList<OMPPrivateClause>::varlist_iterator I = C->varlist_begin(),
                                                       E = C->varlist_end();
@@ -6307,6 +6326,25 @@ TreeTransform<Derived>::TransformOMPPrivateClause(OMPPrivateClause *C) {
                                               C->getLocEnd());
 }
 
+template<typename Derived>
+OMPClause *
+TreeTransform<Derived>::TransformOMPSharedClause(OMPSharedClause *C) {
+  llvm::SmallVector<Expr *, 16> Vars;
+  Vars.reserve(C->varlist_size());
+  for (OMPVarList<OMPSharedClause>::varlist_iterator I = C->varlist_begin(),
+                                                     E = C->varlist_end();
+       I != E; ++I) {
+    ExprResult EVar = getDerived().TransformExpr(cast<Expr>(*I));
+    if (EVar.isInvalid())
+      return 0;
+    Vars.push_back(EVar.take());
+  }
+  return getDerived().RebuildOMPSharedClause(Vars,
+                                             C->getLocStart(),
+                                             C->getLParenLoc(),
+                                             C->getLocEnd());
+}
+
 //===----------------------------------------------------------------------===//
 // Expression transformation
 //===----------------------------------------------------------------------===//

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -1689,6 +1689,9 @@ OMPClause *OMPClauseReader::readClause() {
   case OMPC_private:
     C = OMPPrivateClause::CreateEmpty(Context, Record[Idx++]);
     break;
+  case OMPC_shared:
+    C = OMPSharedClause::CreateEmpty(Context, Record[Idx++]);
+    break;
   }
   Visit(C);
   C->setLocStart(Reader->ReadSourceLocation(Record, Idx));
@@ -1714,6 +1717,16 @@ void OMPClauseReader::VisitOMPPrivateClause(OMPPrivateClause *C) {
   C->setVarRefs(Vars);
 }
 
+void OMPClauseReader::VisitOMPSharedClause(OMPSharedClause *C) {
+  C->setLParenLoc(Reader->ReadSourceLocation(Record, Idx));
+  unsigned NumVars = C->varlist_size();
+  SmallVector<Expr *, 16> Vars;
+  Vars.reserve(NumVars);
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Reader->Reader.ReadSubExpr());
+  C->setVarRefs(Vars);
+}
+
 //===----------------------------------------------------------------------===//
 // OpenMP Directives.
 //===----------------------------------------------------------------------===//

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -1703,6 +1703,15 @@ void OMPClauseWriter::VisitOMPPrivateClause(OMPPrivateClause *C) {
     Writer->Writer.AddStmt(*I);
 }
 
+void OMPClauseWriter::VisitOMPSharedClause(OMPSharedClause *C) {
+  Record.push_back(C->varlist_size());
+  Writer->Writer.AddSourceLocation(C->getLParenLoc(), Record);
+  for (OMPVarList<OMPSharedClause>::varlist_iterator I = C->varlist_begin(),
+                                                     E = C->varlist_end();
+       I != E; ++I)
+    Writer->Writer.AddStmt(*I);
+}
+
 //===----------------------------------------------------------------------===//
 // OpenMP Directives.
 //===----------------------------------------------------------------------===//

clang/test/OpenMP/openmp_common.c

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify -fopenmp -ferror-limit 100 -o - %s
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 -o - %s
 
 #pragma omp // expected-error {{expected an OpenMP directive}}
 #pragma omp unknown_directive // expected-error {{expected an OpenMP directive}}

clang/test/OpenMP/parallel_default_messages.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify -fopenmp -ferror-limit 100 -o - %s
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 -o - %s
 
 void foo();
 
@@ -11,5 +11,11 @@ int main(int argc, char **argv) {
   #pragma omp parallel default (x) // expected-error {{expected 'none' or 'shared' in OpenMP clause 'default'}}
   foo();
 
+  #pragma omp parallel default(none)
+  ++argc; // expected-error {{variable 'argc' must have explicitly specified data sharing attributes}}
+
+  #pragma omp parallel default(none)
+  #pragma omp parallel default(shared)
+  ++argc;
   return 0;
 }

clang/test/OpenMP/parallel_messages.cpp

@@ -0,0 +1,49 @@
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 -o - %s
+
+void foo() {
+}
+
+#pragma omp parallel // expected-error {{unexpected OpenMP directive '#pragma omp parallel'}}
+
+int main(int argc, char **argv) {
+  #pragma omp parallel
+  #pragma omp parallel unknown() // expected-warning {{extra tokens at the end of '#pragma omp parallel' are ignored}}
+  foo();
+  L1:
+    foo();
+  #pragma omp parallel
+  ;
+  #pragma omp parallel
+  {
+    goto L1; // expected-error {{use of undeclared label 'L1'}}
+    argc++;
+  }
+
+  for (int i = 0; i < 10; ++i) {
+    switch(argc) {
+     case (0):
+      #pragma omp parallel
+      {
+        foo();
+        break; // expected-error {{'break' statement not in loop or switch statement}}
+        continue; // expected-error {{'continue' statement not in loop statement}}
+      }
+      default:
+       break;
+    }
+  }
+  #pragma omp parallel default(none)
+  ++argc; // expected-error {{variable 'argc' must have explicitly specified data sharing attributes}}
+
+  goto L2; // expected-error {{use of undeclared label 'L2'}}
+  #pragma omp parallel
+  L2:
+  foo();
+  #pragma omp parallel
+  {
+    return 1; // expected-error {{cannot return from OpenMP region}}
+  }
+
+  return 0;
+}
+

clang/test/OpenMP/parallel_private_messages.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify -fopenmp -ferror-limit 100 %s
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 %s
 
 void foo() {
 }
@@ -13,7 +13,7 @@ class S2 {
   mutable int a;
 public:
   S2():a(0) { }
-  static float S2s;
+  static float S2s; // expected-note {{predetermined as shared}}
 };
 const S2 b;
 const S2 ba[5];
@@ -22,9 +22,9 @@ class S3 {
 public:
   S3():a(0) { }
 };
-const S3 c;
-const S3 ca[5];
-extern const int f;
+const S3 c; // expected-note {{predetermined as shared}}
+const S3 ca[5]; // expected-note {{predetermined as shared}}
+extern const int f; // expected-note {{predetermined as shared}}
 class S4 { // expected-note {{'S4' declared here}}
   int a;
   S4();
@@ -38,9 +38,12 @@ public:
   S5(int v):a(v) { }
 };
 
+int threadvar;
+#pragma omp threadprivate(threadvar) // expected-note {{defined as threadprivate or thread local}}
+
 int main(int argc, char **argv) {
-  const int d = 5;
-  const int da[5] = { 0 };
+  const int d = 5; // expected-note {{predetermined as shared}}
+  const int da[5] = { 0 }; // expected-note {{predetermined as shared}}
   S4 e(4); // expected-note {{'e' defined here}}
   S5 g(5); // expected-note {{'g' defined here}}
   int i;
@@ -53,13 +56,14 @@ int main(int argc, char **argv) {
   #pragma omp parallel private (argc > 0 ? argv[1] : argv[2]) // expected-error {{expected variable name}}
   #pragma omp parallel private (argc argv) // expected-error {{expected ',' or ')' in 'private' clause}}
   #pragma omp parallel private (S1) // expected-error {{'S1' does not refer to a value}}
-  #pragma omp parallel private (a, b, c, d, f) // expected-error {{a private variable with incomplete type 'S1'}}
+  #pragma omp parallel private (a, b, c, d, f) // expected-error {{a private variable with incomplete type 'S1'}} expected-error 3 {{shared variable cannot be private}}
   #pragma omp parallel private (argv[1]) // expected-error {{expected variable name}}
   #pragma omp parallel private(ba)
-  #pragma omp parallel private(ca)
-  #pragma omp parallel private(da)
-  #pragma omp parallel private(S2::S2s)
+  #pragma omp parallel private(ca) // expected-error {{shared variable cannot be private}}
+  #pragma omp parallel private(da) // expected-error {{shared variable cannot be private}}
+  #pragma omp parallel private(S2::S2s) // expected-error {{shared variable cannot be private}}
   #pragma omp parallel private(e, g) // expected-error 2 {{private variable must have an accessible, unambiguous default constructor}}
+  #pragma omp parallel private(threadvar) // expected-error {{threadprivate or thread local variable cannot be private}}
   foo();
   #pragma omp parallel private(i)
   #pragma omp parallel private(j) // expected-error {{arguments of OpenMP clause 'private' cannot be of reference type 'int &'}}

clang/test/OpenMP/parallel_shared_messages.cpp

@@ -0,0 +1,77 @@
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 %s
+
+void foo() {
+}
+
+bool foobool(int argc) {
+  return argc;
+}
+
+struct S1; // expected-note {{declared here}}
+extern S1 a;
+class S2 {
+  mutable int a;
+public:
+  S2():a(0) { }
+  S2(S2 &s2):a(s2.a) { }
+};
+const S2 b;
+const S2 ba[5];
+class S3 {
+  int a;
+public:
+  S3():a(0) { }
+  S3(S3 &s3):a(s3.a) { }
+};
+const S3 c;
+const S3 ca[5];
+extern const int f;
+class S4 {
+  int a;
+  S4();
+  S4(const S4 &s4);
+public:
+  S4(int v):a(v) { }
+};
+class S5 {
+  int a;
+  S5():a(0) {}
+  S5(const S5 &s5):a(s5.a) { }
+public:
+  S5(int v):a(v) { }
+};
+
+S3 h;
+#pragma omp threadprivate(h) // expected-note {{defined as threadprivate or thread local}}
+
+int main(int argc, char **argv) {
+  const int d = 5;
+  const int da[5] = { 0 };
+  S4 e(4);
+  S5 g(5);
+  int i;
+  int &j = i;
+  #pragma omp parallel shared // expected-error {{expected '(' after 'shared'}}
+  #pragma omp parallel shared ( // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  #pragma omp parallel shared () // expected-error {{expected expression}}
+  #pragma omp parallel shared (argc // expected-error {{expected ')'}} expected-note {{to match this '('}}
+  #pragma omp parallel shared (argc, // expected-error {{expected expression}} expected-error {{expected ')'}} expected-note {{to match this '('}}
+  #pragma omp parallel shared (argc > 0 ? argv[1] : argv[2]) // expected-error {{expected variable name}}
+  #pragma omp parallel shared (argc)
+  #pragma omp parallel shared (S1) // expected-error {{'S1' does not refer to a value}}
+  #pragma omp parallel shared (a, b, c, d, f)
+  #pragma omp parallel shared (argv[1]) // expected-error {{expected variable name}}
+  #pragma omp parallel shared(ba)
+  #pragma omp parallel shared(ca)
+  #pragma omp parallel shared(da)
+  #pragma omp parallel shared(e, g)
+  #pragma omp parallel shared(h) // expected-error {{threadprivate or thread local variable cannot be shared}}
+  #pragma omp parallel private(i), shared(i) // expected-error {{private variable cannot be shared}} expected-note {{defined as private}}
+  foo();
+  #pragma omp parallel private(i)
+  #pragma omp parallel shared(i)
+  #pragma omp parallel shared(j)
+  foo();
+
+  return 0;
+}

clang/test/OpenMP/threadprivate_messages.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify -fopenmp -ferror-limit 100 %s
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 %s
 
 #pragma omp threadprivate // expected-error {{expected '(' after 'threadprivate'}}
 #pragma omp threadprivate( // expected-error {{expected identifier}} expected-error {{expected ')'}} expected-note {{to match this '('}}

clang/tools/libclang/CIndex.cpp

@@ -1936,6 +1936,9 @@ void OMPClauseEnqueue::VisitOMPDefaultClause(const OMPDefaultClause *C) { }
 void OMPClauseEnqueue::VisitOMPPrivateClause(const OMPPrivateClause *C) {
   PROCESS_OMP_CLAUSE_LIST(OMPPrivateClause, C)
 }
+void OMPClauseEnqueue::VisitOMPSharedClause(const OMPSharedClause *C) {
+  PROCESS_OMP_CLAUSE_LIST(OMPSharedClause, C)
+}
 #undef PROCESS_OMP_CLAUSE_LIST
 }
 void EnqueueVisitor::EnqueueChildren(const OMPClause *S) {

clang/tools/libclang/RecursiveASTVisitor.h

@@ -2337,6 +2337,12 @@ bool RecursiveASTVisitor<Derived>::VisitOMPPrivateClause(OMPPrivateClause *C) {
   return true;
 }
 
+template<typename Derived>
+bool RecursiveASTVisitor<Derived>::VisitOMPSharedClause(OMPSharedClause *C) {
+  PROCESS_OMP_CLAUSE_LIST(OMPSharedClause, C)
+  return true;
+}
+
 #undef PROCESS_OMP_CLAUSE_LIST
 
 // FIXME: look at the following tricky-seeming exprs to see if we