[OPENMP]Initial support for severity clause

[jyu2]

Summary

Initial support for severity clause

[ABataev]

llvm/include/llvm/Frontend/OpenMP/OMP.td

538–539

Add a version where these clauses were introduced

[jyu2]

Thanks Alexey for code review! Address his comment.

llvm/include/llvm/Frontend/OpenMP/OMP.td

538–539

Thanks. Changed.

[ABataev]

clang/test/OpenMP/error_message.cpp

85

Di you have a test for tge directive with 2 or more severity clauses?

[jyu2]

Thanks Alexey! Address his comment.

clang/test/OpenMP/error_message.cpp

85

Sorry, added.

[ABataev]

clang/test/OpenMP/error_ast_print.cpp

16

Missed )

clang/test/OpenMP/error_message.cpp

79

What about a test for severity with the same severity kind?

[jyu2]

Thanks Alexey!

clang/test/OpenMP/error_ast_print.cpp

16

Thanks. Changed.

clang/test/OpenMP/error_message.cpp

79

I added one. Thanks.

[ABataev]

LG

clang/include/clang/AST/OpenMPClause.h

const_child_range used_children() const {
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 
   static bool classof(const OMPClause *T) {
     return T->getClauseKind() == llvm::omp::OMPC_at;
   }
 };
 
+/// This represents 'severity' clause in the '#pragma omp error' directive
+///
+/// \code
+/// #pragma omp error severity(fatal)
+/// \endcode
+/// In this example directive '#pragma omp error' has simple
+/// 'severity' clause with kind 'fatal'.
+class OMPSeverityClause final : public OMPClause {
+  friend class OMPClauseReader;
+
+  /// Location of '('
+  SourceLocation LParenLoc;
+
+  /// A kind of the 'severity' clause.
+  OpenMPSeverityClauseKind Kind = OMPC_SEVERITY_unknown;
+
+  /// Start location of the kind in source code.
+  SourceLocation KindKwLoc;
+
+  /// Set kind of the clause.
+  ///
+  /// \param K Kind of clause.
+  void setSeverityKind(OpenMPSeverityClauseKind K) { Kind = K; }
+
+  /// Set clause kind location.
+  ///
+  /// \param KLoc Kind location.
+  void setSeverityKindKwLoc(SourceLocation KLoc) { KindKwLoc = KLoc; }
+
+  /// Sets the location of '('.
+  void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
+
+public:
+  /// Build 'severity' clause with argument \a A ('fatal' or 'warning').
+  ///
+  /// \param A Argument of the clause ('fatal' or 'warning').
+  /// \param ALoc Starting location of the argument.
+  /// \param StartLoc Starting location of the clause.
+  /// \param LParenLoc Location of '('.
+  /// \param EndLoc Ending location of the clause.
+  OMPSeverityClause(OpenMPSeverityClauseKind A, SourceLocation ALoc,
+                    SourceLocation StartLoc, SourceLocation LParenLoc,
+                    SourceLocation EndLoc)
+      : OMPClause(llvm::omp::OMPC_severity, StartLoc, EndLoc),
+        LParenLoc(LParenLoc), Kind(A), KindKwLoc(ALoc) {}
+
+  /// Build an empty clause.
+  OMPSeverityClause()
+      : OMPClause(llvm::omp::OMPC_severity, SourceLocation(),
+                  SourceLocation()) {}
+
+  /// Returns the locaiton of '('.
+  SourceLocation getLParenLoc() const { return LParenLoc; }
+
+  /// Returns kind of the clause.
+  OpenMPSeverityClauseKind getSeverityKind() const { return Kind; }
+
+  /// Returns location of clause kind.
+  SourceLocation getSeverityKindKwLoc() const { return KindKwLoc; }
+
+  child_range children() {
+    return child_range(child_iterator(), child_iterator());
+  }
+
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+
+  child_range used_children() {
+    return child_range(child_iterator(), child_iterator());
+  }
+  const_child_range used_children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+
+  static bool classof(const OMPClause *T) {
+    return T->getClauseKind() == llvm::omp::OMPC_severity;
+  }
+};
+
 /// This represents 'schedule' clause in the '#pragma omp ...' directive.
 ///
 /// \code
 /// #pragma omp for schedule(static, 3)
 /// \endcode
 /// In this example directive '#pragma omp for' has 'schedule' clause with
 /// arguments 'static' and '3'.
 class OMPScheduleClause : public OMPClause, public OMPClauseWithPreInit {

clang/include/clang/AST/RecursiveASTVisitor.h

 }
 
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::VisitOMPAtClause(OMPAtClause *) {
   return true;
 }
 
 template <typename Derived>
+bool RecursiveASTVisitor<Derived>::VisitOMPSeverityClause(OMPSeverityClause *) {
+  return true;
+}
+
+template <typename Derived>
 bool
 RecursiveASTVisitor<Derived>::VisitOMPScheduleClause(OMPScheduleClause *C) {
   TRY_TO(VisitOMPClauseWithPreInit(C));
   TRY_TO(TraverseStmt(C->getChunkSize()));
   return true;
 }
 
 template <typename Derived>

clang/include/clang/Basic/OpenMPKinds.h

 
 /// OpenMP attributes for 'at' clause.
 enum OpenMPAtClauseKind {
 #define OPENMP_AT_KIND(Name) OMPC_AT_##Name,
 #include "clang/Basic/OpenMPKinds.def"
   OMPC_AT_unknown
 };
 
+/// OpenMP attributes for 'severity' clause.
+enum OpenMPSeverityClauseKind {
+#define OPENMP_SEVERITY_KIND(Name) OMPC_SEVERITY_##Name,
+#include "clang/Basic/OpenMPKinds.def"
+  OMPC_SEVERITY_unknown
+};
+
 /// OpenMP device type for 'device_type' clause.
 enum OpenMPDeviceType {
 #define OPENMP_DEVICE_TYPE_KIND(Name) \
   OMPC_DEVICE_TYPE_##Name,
 #include "clang/Basic/OpenMPKinds.def"
   OMPC_DEVICE_TYPE_unknown
 };
 

clang/include/clang/Basic/OpenMPKinds.def

 #define OPENMP_DEFAULTMAP_KIND(Name)
 #endif
 #ifndef OPENMP_ATOMIC_DEFAULT_MEM_ORDER_KIND
 #define OPENMP_ATOMIC_DEFAULT_MEM_ORDER_KIND(Name)
 #endif
 #ifndef OPENMP_AT_KIND
 #define OPENMP_AT_KIND(Name)
 #endif
+#ifndef OPENMP_SEVERITY_KIND
+#define OPENMP_SEVERITY_KIND(Name)
+#endif
 #ifndef OPENMP_DEFAULTMAP_MODIFIER
 #define OPENMP_DEFAULTMAP_MODIFIER(Name)
 #endif
 #ifndef OPENMP_DEVICE_TYPE_KIND
 #define OPENMP_DEVICE_TYPE_KIND(Name)
 #endif
 #ifndef OPENMP_LASTPRIVATE_KIND
 #define OPENMP_LASTPRIVATE_KIND(Name)

 OPENMP_ATOMIC_DEFAULT_MEM_ORDER_KIND(seq_cst)
 OPENMP_ATOMIC_DEFAULT_MEM_ORDER_KIND(acq_rel)
 OPENMP_ATOMIC_DEFAULT_MEM_ORDER_KIND(relaxed)
 
 // Modifiers for 'at' clause.
 OPENMP_AT_KIND(compilation)
 OPENMP_AT_KIND(execution)
 
+// Modifiers for 'severity' clause.
+OPENMP_SEVERITY_KIND(fatal)
+OPENMP_SEVERITY_KIND(warning)
+
 // Map types for 'map' clause.
 OPENMP_MAP_KIND(alloc)
 OPENMP_MAP_KIND(to)
 OPENMP_MAP_KIND(from)
 OPENMP_MAP_KIND(tofrom)
 OPENMP_MAP_KIND(delete)
 OPENMP_MAP_KIND(release)
 

 #undef OPENMP_LASTPRIVATE_KIND
 #undef OPENMP_DEVICE_TYPE_KIND
 #undef OPENMP_LINEAR_KIND
 #undef OPENMP_DEPEND_KIND
 #undef OPENMP_SCHEDULE_MODIFIER
 #undef OPENMP_SCHEDULE_KIND
 #undef OPENMP_ATOMIC_DEFAULT_MEM_ORDER_KIND
 #undef OPENMP_AT_KIND
+#undef OPENMP_SEVERITY_KIND
 #undef OPENMP_MAP_KIND
 #undef OPENMP_MAP_MODIFIER_KIND
 #undef OPENMP_MOTION_MODIFIER_KIND
 #undef OPENMP_DIST_SCHEDULE_KIND
 #undef OPENMP_DEFAULTMAP_KIND
 #undef OPENMP_DEFAULTMAP_MODIFIER
 

clang/include/clang/Sema/Sema.h

public:
 
   /// Called on well-formed 'at' clause.
   OMPClause *ActOnOpenMPAtClause(OpenMPAtClauseKind Kind,
                                  SourceLocation KindLoc,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
 
+  /// Called on well-formed 'severity' clause.
+  OMPClause *ActOnOpenMPSeverityClause(OpenMPSeverityClauseKind Kind,
+                                       SourceLocation KindLoc,
+                                       SourceLocation StartLoc,
+                                       SourceLocation LParenLoc,
+                                       SourceLocation EndLoc);
+
   /// Data used for processing a list of variables in OpenMP clauses.
   struct OpenMPVarListDataTy final {
     Expr *DepModOrTailExpr = nullptr;
     SourceLocation ColonLoc;
     SourceLocation RLoc;
     CXXScopeSpec ReductionOrMapperIdScopeSpec;
     DeclarationNameInfo ReductionOrMapperId;
     int ExtraModifier = -1; ///< Additional modifier for linear, map, depend or

clang/lib/AST/OpenMPClause.cpp

const OMPClauseWithPreInit *OMPClauseWithPreInit::get(const OMPClause *C) {
   case OMPC_is_device_ptr:
   case OMPC_has_device_addr:
   case OMPC_unified_address:
   case OMPC_unified_shared_memory:
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_destroy:
   case OMPC_detach:
   case OMPC_inclusive:
   case OMPC_exclusive:
const OMPClauseWithPostUpdate *OMPClauseWithPostUpdate::get(const OMPClause *C) {
   case OMPC_is_device_ptr:
   case OMPC_has_device_addr:
   case OMPC_unified_address:
   case OMPC_unified_shared_memory:
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_destroy:
   case OMPC_novariants:
   case OMPC_nocontext:
   case OMPC_detach:
OS << "atomic_default_mem_order("
      << ")";
 }
 
 void OMPClausePrinter::VisitOMPAtClause(OMPAtClause *Node) {
   OS << "at(" << getOpenMPSimpleClauseTypeName(OMPC_at, Node->getAtKind())
      << ")";
 }
 
+void OMPClausePrinter::VisitOMPSeverityClause(OMPSeverityClause *Node) {
+  OS << "severity("
+     << getOpenMPSimpleClauseTypeName(OMPC_severity, Node->getSeverityKind())
+     << ")";
+}
+
 void OMPClausePrinter::VisitOMPScheduleClause(OMPScheduleClause *Node) {
   OS << "schedule(";
   if (Node->getFirstScheduleModifier() != OMPC_SCHEDULE_MODIFIER_unknown) {
     OS << getOpenMPSimpleClauseTypeName(OMPC_schedule,
                                         Node->getFirstScheduleModifier());
     if (Node->getSecondScheduleModifier() != OMPC_SCHEDULE_MODIFIER_unknown) {
       OS << ", ";
       OS << getOpenMPSimpleClauseTypeName(OMPC_schedule,

clang/lib/AST/StmtProfile.cpp

 void OMPClauseProfiler::VisitOMPDynamicAllocatorsClause(
     const OMPDynamicAllocatorsClause *C) {}
 
 void OMPClauseProfiler::VisitOMPAtomicDefaultMemOrderClause(
     const OMPAtomicDefaultMemOrderClause *C) {}
 
 void OMPClauseProfiler::VisitOMPAtClause(const OMPAtClause *C) {}
 
+void OMPClauseProfiler::VisitOMPSeverityClause(const OMPSeverityClause *C) {}
+
 void OMPClauseProfiler::VisitOMPScheduleClause(const OMPScheduleClause *C) {
   VistOMPClauseWithPreInit(C);
   if (auto *S = C->getChunkSize())
     Profiler->VisitStmt(S);
 }
 
 void OMPClauseProfiler::VisitOMPOrderedClause(const OMPOrderedClause *C) {
   if (auto *Num = C->getNumForLoops())

clang/lib/Basic/OpenMPKinds.cpp

 #define OPENMP_DEVICE_TYPE_KIND(Name) .Case(#Name, OMPC_DEVICE_TYPE_##Name)
 #include "clang/Basic/OpenMPKinds.def"
         .Default(OMPC_DEVICE_TYPE_unknown);
   case OMPC_at:
     return llvm::StringSwitch<OpenMPAtClauseKind>(Str)
 #define OPENMP_AT_KIND(Name) .Case(#Name, OMPC_AT_##Name)
 #include "clang/Basic/OpenMPKinds.def"
         .Default(OMPC_AT_unknown);
+  case OMPC_severity:
+    return llvm::StringSwitch<OpenMPSeverityClauseKind>(Str)
+#define OPENMP_SEVERITY_KIND(Name) .Case(#Name, OMPC_SEVERITY_##Name)
+#include "clang/Basic/OpenMPKinds.def"
+        .Default(OMPC_SEVERITY_unknown);
   case OMPC_lastprivate:
     return llvm::StringSwitch<OpenMPLastprivateModifier>(Str)
 #define OPENMP_LASTPRIVATE_KIND(Name) .Case(#Name, OMPC_LASTPRIVATE_##Name)
 #include "clang/Basic/OpenMPKinds.def"
         .Default(OMPC_LASTPRIVATE_unknown);
   case OMPC_order:
     return llvm::StringSwitch<OpenMPOrderClauseKind>(Str)
 #define OPENMP_ORDER_KIND(Name) .Case(#Name, OMPC_ORDER_##Name)
case OMPC_at:
     case OMPC_AT_unknown:
       return "unknown";
 #define OPENMP_AT_KIND(Name)                                                   \
   case OMPC_AT_##Name:                                                         \
     return #Name;
 #include "clang/Basic/OpenMPKinds.def"
     }
     llvm_unreachable("Invalid OpenMP 'at' clause type");
-    llvm_unreachable("Invalid OpenMP 'at' clause type");
+  case OMPC_severity:
+    switch (Type) {
+    case OMPC_SEVERITY_unknown:
+      return "unknown";
+#define OPENMP_SEVERITY_KIND(Name)                                             \
+  case OMPC_SEVERITY_##Name:                                                   \
+    return #Name;
+#include "clang/Basic/OpenMPKinds.def"
+    }
+    llvm_unreachable("Invalid OpenMP 'severity' clause type");
   case OMPC_lastprivate:
     switch (Type) {
     case OMPC_LASTPRIVATE_unknown:
       return "unknown";
 #define OPENMP_LASTPRIVATE_KIND(Name)                                          \
     case OMPC_LASTPRIVATE_##Name:                                              \
       return #Name;
 #include "clang/Basic/OpenMPKinds.def"

clang/lib/CodeGen/CGStmtOpenMP.cpp

static void emitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
   case OMPC_is_device_ptr:
   case OMPC_has_device_addr:
   case OMPC_unified_address:
   case OMPC_unified_shared_memory:
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_destroy:
   case OMPC_detach:
   case OMPC_inclusive:
   case OMPC_exclusive:

clang/lib/Parse/ParseOpenMP.cpp

if ((CKind == OMPC_ordered || CKind == OMPC_partial) &&
       Clause = ParseOpenMPClause(CKind, WrongDirective);
     else
       Clause = ParseOpenMPSingleExprClause(CKind, WrongDirective);
     break;
   case OMPC_default:
   case OMPC_proc_bind:
   case OMPC_atomic_default_mem_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_order:
   case OMPC_bind:
     // OpenMP [2.14.3.1, Restrictions]
     //  Only a single default clause may be specified on a parallel, task or
     //  teams directive.
     // OpenMP [2.5, parallel Construct, Restrictions]
     //  At most one proc_bind clause can appear on the directive.
     // OpenMP [5.0, Requires directive, Restrictions]
     //  At most one atomic_default_mem_order clause can appear
     //  on the directive
-    // OpenMP [5.1, Requires directive, Restrictions]
+    // OpenMP [5.1, error directive, Restrictions]
     //  At most one at clause can appear on the directive
+    //  At most one severity clause can appear on the directive
     // OpenMP 5.1, 2.11.7 loop Construct, Restrictions.
     // At most one bind clause can appear on a loop directive.
     if (!FirstClause && CKind != OMPC_order) {
       Diag(Tok, diag::err_omp_more_one_clause)
           << getOpenMPDirectiveName(DKind) << getOpenMPClauseName(CKind) << 0;
       ErrorFound = true;
     }
 

clang/lib/Sema/SemaOpenMP.cpp

for (OMPClause *C : Clauses) {
       case OMPC_unified_shared_memory:
       case OMPC_reverse_offload:
       case OMPC_dynamic_allocators:
       case OMPC_atomic_default_mem_order:
       case OMPC_device_type:
       case OMPC_match:
       case OMPC_when:
       case OMPC_at:
+      case OMPC_severity:
       default:
         llvm_unreachable("Unexpected clause");
       }
       for (Stmt *CC : C->children()) {
         if (CC)
           DSAChecker.Visit(CC);
       }
     }
StmtResult Sema::ActOnOpenMPErrorDirective(ArrayRef<OMPClause *> Clauses,
   auto AtClauses =
       OMPExecutableDirective::getClausesOfKind<OMPAtClause>(Clauses);
   const OMPAtClause *AtC = AtClauses.empty() ? nullptr : (*AtClauses.begin());
 
   if (AtC && !InExContext && AtC->getAtKind() == OMPC_AT_execution) {
     Diag(AtC->getAtKindKwLoc(), diag::err_omp_unexpected_execution_modifier);
     return StmtError();
   }
+  auto SeverityClauses =
+      OMPExecutableDirective::getClausesOfKind<OMPSeverityClause>(Clauses);
+  const OMPSeverityClause *SeverityC =
+      SeverityClauses.empty() ? nullptr : (*SeverityClauses.begin());
+
   if (!AtC || AtC->getAtKind() == OMPC_AT_compilation) {
-    Diag(AtC ? AtC->getBeginLoc() : StartLoc, diag::err_diagnose_if_succeeded)
-        << "ERROR";
+    if (SeverityC && SeverityC->getSeverityKind() == OMPC_SEVERITY_warning)
+      Diag(SeverityC->getSeverityKindKwLoc(), diag::warn_diagnose_if_succeeded)
+          << "WARNING";
+    else
+      Diag(StartLoc, diag::err_diagnose_if_succeeded) << "ERROR";
+    if (!SeverityC || SeverityC->getSeverityKind() != OMPC_SEVERITY_warning)
       return StmtError();
   }
   return OMPErrorDirective::Create(Context, StartLoc, EndLoc, Clauses);
 }
 
 StmtResult Sema::ActOnOpenMPTaskwaitDirective(ArrayRef<OMPClause *> Clauses,
                                               SourceLocation StartLoc,
                                               SourceLocation EndLoc) {
   return OMPTaskwaitDirective::Create(Context, StartLoc, EndLoc, Clauses);
OMPClause *Sema::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind, Expr *Expr,
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_destroy:
   case OMPC_inclusive:
   case OMPC_exclusive:
   case OMPC_uses_allocators:
   case OMPC_affinity:
   case OMPC_when:
   case OMPC_bind:
   default:
static OpenMPDirectiveKind getOpenMPCaptureRegionForClause(
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_destroy:
   case OMPC_detach:
   case OMPC_inclusive:
   case OMPC_exclusive:
   case OMPC_uses_allocators:
   case OMPC_affinity:
   case OMPC_bind:
   default:
OMPClause *Sema::ActOnOpenMPSimpleClause(
   case OMPC_bind:
     Res = ActOnOpenMPBindClause(static_cast<OpenMPBindClauseKind>(Argument),
                                 ArgumentLoc, StartLoc, LParenLoc, EndLoc);
     break;
   case OMPC_at:
     Res = ActOnOpenMPAtClause(static_cast<OpenMPAtClauseKind>(Argument),
                               ArgumentLoc, StartLoc, LParenLoc, EndLoc);
     break;
+  case OMPC_severity:
+    Res = ActOnOpenMPSeverityClause(
+        static_cast<OpenMPSeverityClauseKind>(Argument), ArgumentLoc, StartLoc,
+        LParenLoc, EndLoc);
+    break;
   case OMPC_if:
   case OMPC_final:
   case OMPC_num_threads:
   case OMPC_safelen:
   case OMPC_simdlen:
   case OMPC_sizes:
   case OMPC_allocator:
   case OMPC_collapse:
Diag(KindKwLoc, diag::err_omp_unexpected_clause_value)
                                    /*Last=*/OMPC_AT_unknown)
         << getOpenMPClauseName(OMPC_at);
     return nullptr;
   }
   return new (Context)
       OMPAtClause(Kind, KindKwLoc, StartLoc, LParenLoc, EndLoc);
 }
 
+OMPClause *Sema::ActOnOpenMPSeverityClause(OpenMPSeverityClauseKind Kind,
+                                           SourceLocation KindKwLoc,
+                                           SourceLocation StartLoc,
+                                           SourceLocation LParenLoc,
+                                           SourceLocation EndLoc) {
+  if (Kind == OMPC_SEVERITY_unknown) {
+    Diag(KindKwLoc, diag::err_omp_unexpected_clause_value)
+        << getListOfPossibleValues(OMPC_severity, /*First=*/0,
+                                   /*Last=*/OMPC_SEVERITY_unknown)
+        << getOpenMPClauseName(OMPC_severity);
+    return nullptr;
+  }
+  return new (Context)
+      OMPSeverityClause(Kind, KindKwLoc, StartLoc, LParenLoc, EndLoc);
+}
+
 OMPClause *Sema::ActOnOpenMPOrderClause(OpenMPOrderClauseKind Kind,
                                         SourceLocation KindKwLoc,
                                         SourceLocation StartLoc,
                                         SourceLocation LParenLoc,
                                         SourceLocation EndLoc) {
   if (Kind == OMPC_ORDER_unknown) {
     static_assert(OMPC_ORDER_unknown > 0,
                   "OMPC_ORDER_unknown not greater than 0");
OMPClause *Sema::ActOnOpenMPSingleExprWithArgClause(
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_destroy:
   case OMPC_novariants:
   case OMPC_nocontext:
   case OMPC_detach:
   case OMPC_inclusive:
   case OMPC_exclusive:
   case OMPC_uses_allocators:
   case OMPC_affinity:
OMPClause *Sema::ActOnOpenMPClause(OpenMPClauseKind Kind,
   case OMPC_is_device_ptr:
   case OMPC_has_device_addr:
   case OMPC_atomic_default_mem_order:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
   case OMPC_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_novariants:
   case OMPC_nocontext:
   case OMPC_detach:
   case OMPC_inclusive:
   case OMPC_exclusive:
   case OMPC_uses_allocators:
   case OMPC_affinity:
   case OMPC_when:
OMPClause *Sema::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
   case OMPC_unified_shared_memory:
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_order:
   case OMPC_at:
+  case OMPC_severity:
   case OMPC_destroy:
   case OMPC_novariants:
   case OMPC_nocontext:
   case OMPC_detach:
   case OMPC_uses_allocators:
   case OMPC_when:
   case OMPC_bind:
   default:

clang/lib/Sema/TreeTransform.h

   /// Subclasses may override this routine to provide different behavior.
   OMPClause *RebuildOMPAtClause(OpenMPAtClauseKind Kind, SourceLocation KwLoc,
                                 SourceLocation StartLoc,
                                 SourceLocation LParenLoc,
                                 SourceLocation EndLoc) {
     return getSema().ActOnOpenMPAtClause(Kind, KwLoc, StartLoc, LParenLoc,
                                          EndLoc);
   }
+
+  /// Build a new OpenMP 'severity' clause.
+  ///
+  /// By default, performs semantic analysis to build the new OpenMP clause.
+  /// Subclasses may override this routine to provide different behavior.
+  OMPClause *RebuildOMPSeverityClause(OpenMPSeverityClauseKind Kind,
+                                      SourceLocation KwLoc,
+                                      SourceLocation StartLoc,
+                                      SourceLocation LParenLoc,
+                                      SourceLocation EndLoc) {
+    return getSema().ActOnOpenMPSeverityClause(Kind, KwLoc, StartLoc, LParenLoc,
+                                               EndLoc);
+  }
+
   /// Rebuild the operand to an Objective-C \@synchronized statement.
   ///
   /// By default, performs semantic analysis to build the new statement.
   /// Subclasses may override this routine to provide different behavior.
   ExprResult RebuildObjCAtSynchronizedOperand(SourceLocation atLoc,
                                               Expr *object) {
     return getSema().ActOnObjCAtSynchronizedOperand(atLoc, object);
   }

 OMPClause *TreeTransform<Derived>::TransformOMPAtClause(OMPAtClause *C) {
   return getDerived().RebuildOMPAtClause(C->getAtKind(), C->getAtKindKwLoc(),
                                          C->getBeginLoc(), C->getLParenLoc(),
                                          C->getEndLoc());
 }
 
 template <typename Derived>
 OMPClause *
+TreeTransform<Derived>::TransformOMPSeverityClause(OMPSeverityClause *C) {
+  return getDerived().RebuildOMPSeverityClause(
+      C->getSeverityKind(), C->getSeverityKindKwLoc(), C->getBeginLoc(),
+      C->getLParenLoc(), C->getEndLoc());
+}
+
+template <typename Derived>
+OMPClause *
 TreeTransform<Derived>::TransformOMPPrivateClause(OMPPrivateClause *C) {
   llvm::SmallVector<Expr *, 16> Vars;
   Vars.reserve(C->varlist_size());
   for (auto *VE : C->varlists()) {
     ExprResult EVar = getDerived().TransformExpr(cast<Expr>(VE));
     if (EVar.isInvalid())
       return nullptr;
     Vars.push_back(EVar.get());

clang/lib/Serialization/ASTReader.cpp

case llvm::omp::OMPC_dynamic_allocators:
     C = new (Context) OMPDynamicAllocatorsClause();
     break;
   case llvm::omp::OMPC_atomic_default_mem_order:
     C = new (Context) OMPAtomicDefaultMemOrderClause();
     break;
   case llvm::omp::OMPC_at:
     C = new (Context) OMPAtClause();
     break;
+  case llvm::omp::OMPC_severity:
+    C = new (Context) OMPSeverityClause();
+    break;
   case llvm::omp::OMPC_private:
     C = OMPPrivateClause::CreateEmpty(Context, Record.readInt());
     break;
   case llvm::omp::OMPC_firstprivate:
     C = OMPFirstprivateClause::CreateEmpty(Context, Record.readInt());
     break;
   case llvm::omp::OMPC_lastprivate:
     C = OMPLastprivateClause::CreateEmpty(Context, Record.readInt());

 }
 
 void OMPClauseReader::VisitOMPAtClause(OMPAtClause *C) {
   C->setAtKind(static_cast<OpenMPAtClauseKind>(Record.readInt()));
   C->setLParenLoc(Record.readSourceLocation());
   C->setAtKindKwLoc(Record.readSourceLocation());
 }
 
+void OMPClauseReader::VisitOMPSeverityClause(OMPSeverityClause *C) {
+  C->setSeverityKind(static_cast<OpenMPSeverityClauseKind>(Record.readInt()));
+  C->setLParenLoc(Record.readSourceLocation());
+  C->setSeverityKindKwLoc(Record.readSourceLocation());
+}
+
 void OMPClauseReader::VisitOMPPrivateClause(OMPPrivateClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
   unsigned NumVars = C->varlist_size();
   SmallVector<Expr *, 16> Vars;
   Vars.reserve(NumVars);
   for (unsigned i = 0; i != NumVars; ++i)
     Vars.push_back(Record.readSubExpr());
   C->setVarRefs(Vars);

clang/lib/Serialization/ASTWriter.cpp

 }
 
 void OMPClauseWriter::VisitOMPAtClause(OMPAtClause *C) {
   Record.push_back(C->getAtKind());
   Record.AddSourceLocation(C->getLParenLoc());
   Record.AddSourceLocation(C->getAtKindKwLoc());
 }
 
+void OMPClauseWriter::VisitOMPSeverityClause(OMPSeverityClause *C) {
+  Record.push_back(C->getSeverityKind());
+  Record.AddSourceLocation(C->getLParenLoc());
+  Record.AddSourceLocation(C->getSeverityKindKwLoc());
+}
+
 void OMPClauseWriter::VisitOMPNontemporalClause(OMPNontemporalClause *C) {
   Record.push_back(C->varlist_size());
   Record.AddSourceLocation(C->getLParenLoc());
   for (auto *VE : C->varlists())
     Record.AddStmt(VE);
   for (auto *E : C->private_refs())
     Record.AddStmt(E);
 }

clang/test/OpenMP/error_ast_print.cpp

 // RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
 // expected-no-diagnostics
 
 #ifndef HEADER
 #define HEADER
 
 void foo() {}
 // CHECK: template <typename T, int N> int tmain(T argc, char **argv)
 // CHECK: static int a;
-// CHECK-NEXT: #pragma omp error at(execution)
+// CHECK-NEXT: #pragma omp error at(execution) severity(fatal
 // CHECK-NEXT: a = argv[0][0];
 // CHECK-NEXT: ++a;
-// CHECK-NEXT: #pragma omp error at(execution)
+// CHECK-NEXT: #pragma omp error at(execution) severity(warning)
 // CHECK-NEXT: {
 // CHECK-NEXT: int b = 10;
 // CHECK-NEXT: T c = 100;
 // CHECK-NEXT: a = b + c;
 // CHECK-NEXT: }
-// CHECK-NEXT: #pragma omp error at(execution)
+// CHECK-NEXT: #pragma omp error at(execution) severity(fatal)
 // CHECK-NEXT: foo();
 // CHECK-NEXT: return N;
 
 template <typename T, int N>
 int tmain(T argc, char **argv) {
   T b = argc, c, d, e, f, g;
   static int a;
-#pragma omp error at(execution)
+#pragma omp error at(execution) severity(fatal)
   a = argv[0][0];
   ++a;
-#pragma omp error at(execution)
+#pragma omp error at(execution) severity(warning)
   {
     int b = 10;
     T c = 100;
     a = b + c;
   }
-#pragma omp  error at(execution)
+#pragma omp  error at(execution) severity(fatal)
   foo();
 return N;
 }
 
 // CHECK: int main(int argc, char **argv)
 // CHECK-NEXT: int b = argc, c, d, e, f, g;
 // CHECK-NEXT: static int a;
-// CHECK-NEXT: #pragma omp error at(execution)
+// CHECK-NEXT: #pragma omp error at(execution) severity(fatal)
 // CHECK-NEXT: a = 2;
-// CHECK-NEXT: #pragma omp error at(execution)
+// CHECK-NEXT: #pragma omp error at(execution) severity(warning)
 // CHECK-NEXT: foo();
 int main (int argc, char **argv) {
   int b = argc, c, d, e, f, g;
   static int a;
-#pragma omp error at(execution)
+#pragma omp error at(execution) severity(fatal)
    a=2;
-#pragma omp error at(execution)
+#pragma omp error at(execution) severity(warning)
   foo();
 }
 #endif

clang/test/OpenMP/error_message.cpp

 // expected-error@+3 {{ERROR}}
 // expected-error@+2 {{expected ')'}}
 // expected-note@+1 {{to match this '('}}
 #pragma omp error at(up(a)) // expected-error {{expected 'compilation' or 'execution' in OpenMP clause 'at'}}
 
 #pragma omp error at(execution) // no error
 
 #pragma omp error at(compilation) // expected-error {{ERROR}}
+
+// expected-error@+1 {{ERROR}}
+#pragma omp error severity() // expected-error {{expected 'fatal' or 'warning' in OpenMP clause 'severity'}}
+// expected-error@+1 {{ERROR}}
+#pragma omp error severity(xyz) // expected-error {{expected 'fatal' or 'warning' in OpenMP clause 'severity'}}
+// expected-warning@+1 {{WARNING}}
+#pragma omp error severity(warning) // expected-warning {{WARNING}}
+#pragma omp error severity(fatal) // expected-error {{ERROR}}
+
+// expected-warning@+1 {{WARNING}}
+#pragma omp error at(compilation) severity(warning) // expected-warning {{WARNING}}
+#pragma omp error at(execution) severity(warning) // no error, diagnosic at runtime
+#pragma omp error at(compilation) severity(fatal) // expected-error {{ERROR}}
+#pragma omp error at(execution) severity(fatal) // no error, error at runtime
   return T();
 }
 
 #pragma omp error at(execution) // expected-error {{unexpected 'execution' modifier in non-executable context}}
 
 #pragma omp error at(compilation) // expected-error {{ERROR}}
 class A {
 
 #pragma omp error at(compilation) // expected-error {{ERROR}}
 

 label1 : {
 // expected-error@+1 {{ERROR}}
 #pragma omp error
 }
 if (1)
   label2:
 #pragma omp error // expected-error {{'#pragma omp error' cannot be an immediate substatement}}
 
-  return tmain(argc);
+  return tmain(argc);// expected-note {{in instantiation of function template specialization 'tmain<int>' requested here}}
 }

clang/tools/libclang/CIndex.cpp

 void OMPClauseEnqueue::VisitOMPDynamicAllocatorsClause(
     const OMPDynamicAllocatorsClause *) {}
 
 void OMPClauseEnqueue::VisitOMPAtomicDefaultMemOrderClause(
     const OMPAtomicDefaultMemOrderClause *) {}
 
 void OMPClauseEnqueue::VisitOMPAtClause(const OMPAtClause *) {}
 
+void OMPClauseEnqueue::VisitOMPSeverityClause(const OMPSeverityClause *) {}
+
 void OMPClauseEnqueue::VisitOMPDeviceClause(const OMPDeviceClause *C) {
   Visitor->AddStmt(C->getDevice());
 }
 
 void OMPClauseEnqueue::VisitOMPNumTeamsClause(const OMPNumTeamsClause *C) {
   VisitOMPClauseWithPreInit(C);
   Visitor->AddStmt(C->getNumTeams());
 }

flang/lib/Semantics/check-omp-structure.cpp

 CHECK_SIMPLE_CLAUSE(Update, OMPC_update)
 CHECK_SIMPLE_CLAUSE(UseDeviceAddr, OMPC_use_device_addr)
 CHECK_SIMPLE_CLAUSE(Write, OMPC_write)
 CHECK_SIMPLE_CLAUSE(Init, OMPC_init)
 CHECK_SIMPLE_CLAUSE(Use, OMPC_use)
 CHECK_SIMPLE_CLAUSE(Novariants, OMPC_novariants)
 CHECK_SIMPLE_CLAUSE(Nocontext, OMPC_nocontext)
 CHECK_SIMPLE_CLAUSE(At, OMPC_at)
+CHECK_SIMPLE_CLAUSE(Severity, OMPC_severity)
 CHECK_SIMPLE_CLAUSE(Filter, OMPC_filter)
 CHECK_SIMPLE_CLAUSE(When, OMPC_when)
 CHECK_SIMPLE_CLAUSE(AdjustArgs, OMPC_adjust_args)
 CHECK_SIMPLE_CLAUSE(AppendArgs, OMPC_append_args)
 CHECK_SIMPLE_CLAUSE(MemoryOrder, OMPC_memory_order)
 CHECK_SIMPLE_CLAUSE(Bind, OMPC_bind)
 CHECK_SIMPLE_CLAUSE(Align, OMPC_align)
 CHECK_SIMPLE_CLAUSE(Compare, OMPC_compare)

llvm/include/llvm/Frontend/OpenMP/OMP.td

 }
 def OMPC_AtomicDefaultMemOrder : Clause<"atomic_default_mem_order"> {
   let clangClass = "OMPAtomicDefaultMemOrderClause";
   let flangClass = "OmpAtomicDefaultMemOrderClause";
 }
 def OMPC_At : Clause<"at"> {
   let clangClass = "OMPAtClause";
 }
+def OMPC_Severity : Clause<"severity"> {
+  let clangClass = "OMPSeverityClause";
+}
 def OMPC_Allocate : Clause<"allocate"> {
   let clangClass = "OMPAllocateClause";
   let flangClass = "OmpAllocateClause";
 }
 def OMPC_NonTemporal : Clause<"nontemporal"> {
   let clangClass = "OMPNontemporalClause";
   let flangClass = "Name";
   let isValueList = true;
def OMP_Critical : Directive<"critical"> {
   let allowedClauses = [
     VersionedClause<OMPC_Hint>
   ];
 }
 def OMP_TaskYield : Directive<"taskyield"> {}
 def OMP_Barrier : Directive<"barrier"> {}
 def OMP_Error : Directive<"error"> {
   let allowedClauses = [
-    VersionedClause<OMPC_At>
+    VersionedClause<OMPC_At>,
+    VersionedClause<OMPC_Severity>
   ];
 }
 def OMP_TaskWait : Directive<"taskwait"> {
   let allowedClauses = [
     VersionedClause<OMPC_Depend, 50>
   ];
 }
 def OMP_TaskGroup : Directive<"taskgroup"> {