[flang][OpenMP]Add support for OpenMP ERROR directive

flang/include/flang/Parser/dump-parse-tree.h

@@ -488,6 +488,9 @@ class ParseTreeDumper {
   NODE(parser, OmpAlignment)
   NODE(parser, OmpAlignedClause)
   NODE(OmpAlignedClause, Modifier)
+  NODE(parser, OmpAtClause)
+  NODE_ENUM(OmpAtClause, ActionTime)
+  NODE_ENUM(OmpSeverityClause, Severity)
   NODE(parser, OmpAtomic)
   NODE(parser, OmpAtomicCapture)
   NODE(OmpAtomicCapture, Stmt1)
@@ -564,6 +567,7 @@ class ParseTreeDumper {
   NODE_ENUM(OmpLinearModifier, Value)
   NODE(parser, OmpLoopDirective)
   NODE(parser, OmpMapClause)
+  NODE(parser, OmpMessageClause)
   NODE(OmpMapClause, Modifier)
   static std::string GetNodeName(const llvm::omp::Clause &x) {
     return llvm::Twine(
@@ -604,6 +608,7 @@ class ParseTreeDumper {
   NODE(parser, OmpScheduleClause)
   NODE(OmpScheduleClause, Modifier)
   NODE_ENUM(OmpScheduleClause, Kind)
+  NODE(parser, OmpSeverityClause)
   NODE(parser, OmpDeviceClause)
   NODE(OmpDeviceClause, Modifier)
   NODE(parser, OmpDeviceModifier)
@@ -652,6 +657,7 @@ class ParseTreeDumper {
   NODE(parser, OmpAtomicDefaultMemOrderClause)
   NODE_ENUM(common, OmpAtomicDefaultMemOrderType)
   NODE(parser, OpenMPDepobjConstruct)
+  NODE(parser, OpenMPErrorConstruct)
   NODE(parser, OpenMPFlushConstruct)
   NODE(parser, OpenMPLoopConstruct)
   NODE(parser, OpenMPExecutableAllocate)

flang/include/flang/Parser/parse-tree.h

@@ -3761,6 +3761,13 @@ struct OmpAllocateClause {
   std::tuple<MODIFIERS(), OmpObjectList> t;
 };
 
+// Ref: [5.2:216-217 (sort of, as it's only mentioned in passing)
+// AT(compilation|execution)
+struct OmpAtClause {
+  ENUM_CLASS(ActionTime, Compilation, Execution);
+  WRAPPER_CLASS_BOILERPLATE(OmpAtClause, ActionTime);
+};
+
 // Ref: [5.0:60-63], [5.1:83-86], [5.2:210-213]
 //
 // atomic-default-mem-order-clause ->
@@ -4008,6 +4015,13 @@ struct OmpMapClause {
   std::tuple<MODIFIERS(), OmpObjectList, bool> t;
 };
 
+// Ref: [5.2:217-218]
+// message-clause ->
+//    MESSAGE("message-text")
+struct OmpMessageClause {
+  WRAPPER_CLASS_BOILERPLATE(OmpMessageClause, Expr);
+};
+
 // Ref: [4.5:87-91], [5.0:140-146], [5.1:166-171], [5.2:270]
 //
 // num-tasks-clause ->
@@ -4070,6 +4084,14 @@ struct OmpScheduleClause {
   std::tuple<MODIFIERS(), Kind, std::optional<ScalarIntExpr>> t;
 };
 
+// REF: [5.2:217]
+// severity-clause ->
+//    SEVERITY(warning|fatal)
+struct OmpSeverityClause {
+  ENUM_CLASS(Severity, Fatal, Warning);
+  WRAPPER_CLASS_BOILERPLATE(OmpSeverityClause, Severity);
+};
+
 // Ref: [4.5:107-109], [5.0:176-180], [5.1:205-210], [5.2:167-168]
 //
 // to-clause (in DECLARE TARGET) ->
@@ -4445,6 +4467,14 @@ struct OpenMPDepobjConstruct {
   std::tuple<Verbatim, OmpObject, OmpClause> t;
 };
 
+// Ref: OpenMP [5.2:216-218]
+// ERROR AT(compilation|execution) SEVERITY(fatal|warning) MESSAGE("msg-str)
+struct OpenMPErrorConstruct {
+  TUPLE_CLASS_BOILERPLATE(OpenMPErrorConstruct);
+  CharBlock source;
+  std::tuple<Verbatim, OmpClauseList> t;
+};
+
 // 2.17.8 flush -> FLUSH [memory-order-clause] [(variable-name-list)]
 struct OpenMPFlushConstruct {
   TUPLE_CLASS_BOILERPLATE(OpenMPFlushConstruct);
@@ -4517,7 +4547,7 @@ struct OpenMPConstruct {
   UNION_CLASS_BOILERPLATE(OpenMPConstruct);
   std::variant<OpenMPStandaloneConstruct, OpenMPSectionsConstruct,
       OpenMPSectionConstruct, OpenMPLoopConstruct, OpenMPBlockConstruct,
-      OpenMPAtomicConstruct, OpenMPDeclarativeAllocate,
+      OpenMPAtomicConstruct, OpenMPDeclarativeAllocate, OpenMPErrorConstruct,
       OpenMPExecutableAllocate, OpenMPAllocatorsConstruct,
       OpenMPCriticalConstruct>
       u;

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -2905,6 +2905,13 @@ static void genOMP(lower::AbstractConverter &converter, lower::SymMap &symTable,
                 queue.begin(), name);
 }
 
+static void genOMP(lower::AbstractConverter &converter, lower::SymMap &symTable,
+                   semantics::SemanticsContext &semaCtx,
+                   lower::pft::Evaluation &eval,
+                   const parser::OpenMPErrorConstruct &) {
+  TODO(converter.getCurrentLocation(), "OpenMPErrorConstruct");
+}
+
 static void genOMP(lower::AbstractConverter &converter, lower::SymMap &symTable,
                    semantics::SemanticsContext &semaCtx,
                    lower::pft::Evaluation &eval,

flang/lib/Parser/openmp-parsers.cpp

@@ -507,6 +507,16 @@ TYPE_PARSER(construct<OmpBindClause>(
     "TEAMS" >> pure(OmpBindClause::Binding::Teams) ||
     "THREAD" >> pure(OmpBindClause::Binding::Thread)))
 
+TYPE_PARSER(construct<OmpAtClause>(
+    "EXECUTION" >> pure(OmpAtClause::ActionTime::Execution) ||
+    "COMPILATION" >> pure(OmpAtClause::ActionTime::Compilation)))
+
+TYPE_PARSER(construct<OmpSeverityClause>(
+    "FATAL" >> pure(OmpSeverityClause::Severity::Fatal) ||
+    "WARNING" >> pure(OmpSeverityClause::Severity::Warning)))
+
+TYPE_PARSER(construct<OmpMessageClause>(expr))
+
 TYPE_PARSER(
     "ACQUIRE" >> construct<OmpClause>(construct<OmpClause::Acquire>()) ||
     "ACQ_REL" >> construct<OmpClause>(construct<OmpClause::AcqRel>()) ||
@@ -518,6 +528,8 @@ TYPE_PARSER(
                       parenthesized(Parser<OmpAllocateClause>{}))) ||
     "ALLOCATOR" >> construct<OmpClause>(construct<OmpClause::Allocator>(
                        parenthesized(scalarIntExpr))) ||
+    "AT" >> construct<OmpClause>(construct<OmpClause::At>(
+                parenthesized(Parser<OmpAtClause>{}))) ||
     "ATOMIC_DEFAULT_MEM_ORDER" >>
         construct<OmpClause>(construct<OmpClause::AtomicDefaultMemOrder>(
             parenthesized(Parser<OmpAtomicDefaultMemOrderClause>{}))) ||
@@ -585,6 +597,8 @@ TYPE_PARSER(
     "MAP" >> construct<OmpClause>(construct<OmpClause::Map>(
                  parenthesized(Parser<OmpMapClause>{}))) ||
     "MERGEABLE" >> construct<OmpClause>(construct<OmpClause::Mergeable>()) ||
+    "MESSAGE" >> construct<OmpClause>(construct<OmpClause::Message>(
+                     parenthesized(Parser<OmpMessageClause>{}))) ||
     "NOGROUP" >> construct<OmpClause>(construct<OmpClause::Nogroup>()) ||
     "NONTEMPORAL" >> construct<OmpClause>(construct<OmpClause::Nontemporal>(
                          parenthesized(nonemptyList(name)))) ||
@@ -627,6 +641,8 @@ TYPE_PARSER(
     "SCHEDULE" >> construct<OmpClause>(construct<OmpClause::Schedule>(
                       parenthesized(Parser<OmpScheduleClause>{}))) ||
     "SEQ_CST" >> construct<OmpClause>(construct<OmpClause::SeqCst>()) ||
+    "SEVERITY" >> construct<OmpClause>(construct<OmpClause::Severity>(
+                      parenthesized(Parser<OmpSeverityClause>{}))) ||
     "SHARED" >> construct<OmpClause>(construct<OmpClause::Shared>(
                     parenthesized(Parser<OmpObjectList>{}))) ||
     "SIMD"_id >> construct<OmpClause>(construct<OmpClause::Simd>()) ||
@@ -946,6 +962,9 @@ TYPE_PARSER(sourced(construct<OmpCriticalDirective>(verbatim("CRITICAL"_tok),
 TYPE_PARSER(construct<OpenMPCriticalConstruct>(
     Parser<OmpCriticalDirective>{}, block, Parser<OmpEndCriticalDirective>{}))
 
+TYPE_PARSER(sourced(construct<OpenMPErrorConstruct>(
+    verbatim("ERROR"_tok), Parser<OmpClauseList>{})))
+
 // 2.11.3 Executable Allocate directive
 TYPE_PARSER(
     sourced(construct<OpenMPExecutableAllocate>(verbatim("ALLOCATE"_tok),
@@ -1043,6 +1062,7 @@ TYPE_CONTEXT_PARSER("OpenMP construct"_en_US,
                 // OpenMPStandaloneConstruct to resolve !$OMP ORDERED
                 construct<OpenMPConstruct>(Parser<OpenMPStandaloneConstruct>{}),
                 construct<OpenMPConstruct>(Parser<OpenMPAtomicConstruct>{}),
+                construct<OpenMPConstruct>(Parser<OpenMPErrorConstruct>{}),
                 construct<OpenMPConstruct>(Parser<OpenMPExecutableAllocate>{}),
                 construct<OpenMPConstruct>(Parser<OpenMPAllocatorsConstruct>{}),
                 construct<OpenMPConstruct>(Parser<OpenMPDeclarativeAllocate>{}),

flang/lib/Parser/unparse.cpp

@@ -2651,6 +2651,15 @@ class UnparseVisitor {
     Put(")\n");
     EndOpenMP();
   }
+  bool Pre(const OmpMessageClause &x) {
+    Walk(x.v);
+    return false;
+  }
+  void Unparse(const OpenMPErrorConstruct &x) {
+    Word("!$OMP ERROR ");
+    Walk(x.t);
+    Put("\n");
+  }
   void Unparse(const OmpSectionsDirective &x) {
     switch (x.v) {
     case llvm::omp::Directive::OMPD_sections:
@@ -2835,6 +2844,7 @@ class UnparseVisitor {
   WALK_NESTED_ENUM(InquireSpec::LogVar, Kind)
   WALK_NESTED_ENUM(ProcedureStmt, Kind) // R1506
   WALK_NESTED_ENUM(UseStmt, ModuleNature) // R1410
+  WALK_NESTED_ENUM(OmpAtClause, ActionTime) // OMP at
   WALK_NESTED_ENUM(OmpBindClause, Binding) // OMP bind
   WALK_NESTED_ENUM(OmpProcBindClause, AffinityPolicy) // OMP proc_bind
   WALK_NESTED_ENUM(OmpDefaultClause, DataSharingAttribute) // OMP default
@@ -2846,6 +2856,7 @@ class UnparseVisitor {
   WALK_NESTED_ENUM(OmpOrderingModifier, Value) // OMP ordering-modifier
   WALK_NESTED_ENUM(OmpTaskDependenceType, Value) // OMP task-dependence-type
   WALK_NESTED_ENUM(OmpScheduleClause, Kind) // OMP schedule-kind
+  WALK_NESTED_ENUM(OmpSeverityClause, Severity) // OMP severity
   WALK_NESTED_ENUM(OmpDeviceModifier, Value) // OMP device modifier
   WALK_NESTED_ENUM(
       OmpDeviceTypeClause, DeviceTypeDescription) // OMP device_type

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

@@ -1662,6 +1662,15 @@ void OmpStructureChecker::Leave(const parser::OpenMPDeclareTargetConstruct &x) {
   dirContext_.pop_back();
 }
 
+void OmpStructureChecker::Enter(const parser::OpenMPErrorConstruct &x) {
+  const auto &dir{std::get<parser::Verbatim>(x.t)};
+  PushContextAndClauseSets(dir.source, llvm::omp::Directive::OMPD_error);
+}
+
+void OmpStructureChecker::Leave(const parser::OpenMPErrorConstruct &x) {
+  dirContext_.pop_back();
+}
+
 void OmpStructureChecker::Enter(const parser::OpenMPExecutableAllocate &x) {
   isPredefinedAllocator = true;
   const auto &dir{std::get<parser::Verbatim>(x.t)};

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

@@ -102,6 +102,8 @@ class OmpStructureChecker
   void Enter(const parser::OmpDeclareTargetWithList &);
   void Enter(const parser::OmpDeclareTargetWithClause &);
   void Leave(const parser::OmpDeclareTargetWithClause &);
+  void Enter(const parser::OpenMPErrorConstruct &);
+  void Leave(const parser::OpenMPErrorConstruct &);
   void Enter(const parser::OpenMPExecutableAllocate &);
   void Leave(const parser::OpenMPExecutableAllocate &);
   void Enter(const parser::OpenMPAllocatorsConstruct &);

flang/test/Lower/OpenMP/Todo/error.f90

@@ -0,0 +1,7 @@
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -fopenmp-version=51 -o - %s 2>&1 | FileCheck %s
+
+! CHECK: not yet implemented: OpenMPErrorConstruct
+program p
+  integer, allocatable :: x
+  !$omp error at(compilation) severity(warning) message("an error")
+end program p

flang/test/Parser/OpenMP/error-unparse.f90

@@ -0,0 +1,23 @@
+! RUN: %flang_fc1  -fopenmp-version=51 -fopenmp -fdebug-unparse-no-sema %s 2>&1 | FileCheck %s
+! RUN: %flang_fc1  -fopenmp-version=51 -fopenmp -fdebug-dump-parse-tree-no-sema %s 2>&1 | FileCheck %s --check-prefix="PARSE-TREE"
+program main
+  character(*), parameter :: message = "This is an error"
+  !CHECK: !$OMP ERROR AT(COMPILATION) SEVERITY(WARNING) MESSAGE("some message here")
+  !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPErrorConstruct
+  !PARSE-TREE: OmpClauseList -> OmpClause -> At -> OmpAtClause -> ActionTime = Compilation
+  !PARSE-TREE: OmpClause -> Severity -> OmpSeverityClause -> Severity = Warning
+  !PARSE-TREE:  OmpClause -> Message -> OmpMessageClause -> Expr -> LiteralConstant -> CharLiteralConstant
+  !$omp error at(compilation) severity(warning) message("some message here")
+  !CHECK: !$OMP ERROR AT(COMPILATION) SEVERITY(FATAL) MESSAGE(message)
+  !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPErrorConstruct
+  !PARSE-TREE: OmpClauseList -> OmpClause -> At -> OmpAtClause -> ActionTime = Compilation
+  !PARSE-TREE: OmpClause -> Severity -> OmpSeverityClause -> Severity = Fatal
+  !PARSE-TREE:  OmpClause -> Message -> OmpMessageClause -> Expr -> Designator -> DataRef -> Name = 'message'
+  !$omp error at(compilation) severity(fatal) message(message)
+  !CHECK: !$OMP ERROR AT(EXECUTION) SEVERITY(FATAL) MESSAGE(message)
+  !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPErrorConstruct
+  !PARSE-TREE: OmpClauseList -> OmpClause -> At -> OmpAtClause -> ActionTime = Execution
+  !PARSE-TREE: OmpClause -> Severity -> OmpSeverityClause -> Severity = Fatal
+  !PARSE-TREE:  OmpClause -> Message -> OmpMessageClause -> Expr -> Designator ->  DataRef -> Name = 'message'
+  !$omp error at(EXECUTION) severity(fatal) message(message)
+end program main

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

@@ -66,6 +66,7 @@ def OMPC_AppendArgs : Clause<"append_args"> {
 }
 def OMPC_At : Clause<"at"> {
   let clangClass = "OMPAtClause";
+  let flangClass = "OmpAtClause";
 }
 def OMPC_AtomicDefaultMemOrder : Clause<"atomic_default_mem_order"> {
   let clangClass = "OMPAtomicDefaultMemOrderClause";
@@ -287,6 +288,7 @@ def OMPC_Mergeable : Clause<"mergeable"> {
 }
 def OMPC_Message : Clause<"message"> {
   let clangClass = "OMPMessageClause";
+  let flangClass = "OmpMessageClause";
 }
 def OMPC_NoOpenMP : Clause<"no_openmp"> {
   let clangClass = "OMPNoOpenMPClause";
@@ -444,6 +446,7 @@ def OMPC_SeqCst : Clause<"seq_cst"> {
 }
 def OMPC_Severity : Clause<"severity"> {
   let clangClass = "OMPSeverityClause";
+  let flangClass = "OmpSeverityClause";
 }
 def OMPC_Shared : Clause<"shared"> {
   let clangClass = "OMPSharedClause";