[flang][OpenMP] Use OmpDirectiveSpecification in DECLARE_TARGET (llvm#160573)

Author: kparzysz

flang/examples/FeatureList/FeatureList.cpp

@@ -451,9 +451,6 @@ struct NodeVisitor {
   READ_FEATURE(OmpBlockConstruct)
   READ_FEATURE(OmpClause)
   READ_FEATURE(OmpClauseList)
-  READ_FEATURE(OmpDeclareTargetSpecifier)
-  READ_FEATURE(OmpDeclareTargetWithClause)
-  READ_FEATURE(OmpDeclareTargetWithList)
   READ_FEATURE(OmpDefaultClause)
   READ_FEATURE(OmpDefaultClause::DataSharingAttribute)
   READ_FEATURE(OmpDefaultmapClause)

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

@@ -538,9 +538,6 @@ class ParseTreeDumper {
   NODE_ENUM(OmpCloseModifier, Value)
   NODE(parser, OmpContainsClause)
   NODE(parser, OmpContextSelectorSpecification)
-  NODE(parser, OmpDeclareTargetSpecifier)
-  NODE(parser, OmpDeclareTargetWithClause)
-  NODE(parser, OmpDeclareTargetWithList)
   NODE(parser, OmpDeclareVariantDirective)
   NODE(parser, OmpDefaultClause)
   NODE_ENUM(OmpDefaultClause, DataSharingAttribute)

flang/include/flang/Parser/openmp-utils.h

@@ -41,7 +41,6 @@ struct ConstructId {
 MAKE_CONSTR_ID(OpenMPDeclarativeAllocate, D::OMPD_allocate);
 MAKE_CONSTR_ID(OpenMPDeclarativeAssumes, D::OMPD_assumes);
 MAKE_CONSTR_ID(OpenMPDeclareReductionConstruct, D::OMPD_declare_reduction);
-MAKE_CONSTR_ID(OpenMPDeclareTargetConstruct, D::OMPD_declare_target);
 MAKE_CONSTR_ID(OpenMPExecutableAllocate, D::OMPD_allocate);
 MAKE_CONSTR_ID(OpenMPRequiresConstruct, D::OMPD_requires);
 
@@ -97,7 +96,6 @@ struct DirectiveNameScope {
       } else if constexpr (std::is_same_v<T, OpenMPDeclarativeAllocate> ||
           std::is_same_v<T, OpenMPDeclarativeAssumes> ||
           std::is_same_v<T, OpenMPDeclareReductionConstruct> ||
-          std::is_same_v<T, OpenMPDeclareTargetConstruct> ||
           std::is_same_v<T, OpenMPExecutableAllocate> ||
           std::is_same_v<T, OpenMPRequiresConstruct>) {
         return MakeName(std::get<Verbatim>(x.t).source, ConstructId<T>::id);

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

@@ -4943,28 +4943,16 @@ struct OmpDeclareVariantDirective {
   CharBlock source;
 };
 
-// 2.10.6 declare-target -> DECLARE TARGET (extended-list) |
-//                          DECLARE TARGET [declare-target-clause[ [,]
-//                                          declare-target-clause]...]
-struct OmpDeclareTargetWithList {
-  WRAPPER_CLASS_BOILERPLATE(OmpDeclareTargetWithList, OmpObjectList);
-  CharBlock source;
-};
-
-struct OmpDeclareTargetWithClause {
-  WRAPPER_CLASS_BOILERPLATE(OmpDeclareTargetWithClause, OmpClauseList);
-  CharBlock source;
-};
-
-struct OmpDeclareTargetSpecifier {
-  UNION_CLASS_BOILERPLATE(OmpDeclareTargetSpecifier);
-  std::variant<OmpDeclareTargetWithList, OmpDeclareTargetWithClause> u;
-};
-
+// Ref: [4.5:110-113], [5.0:180-185], [5.1:210-216], [5.2:206-207],
+//      [6.0:346-348]
+//
+// declare-target-directive ->                      // since 4.5
+//    DECLARE_TARGET[(extended-list)] |
+//    DECLARE_TARGET clause-list
 struct OpenMPDeclareTargetConstruct {
-  TUPLE_CLASS_BOILERPLATE(OpenMPDeclareTargetConstruct);
+  WRAPPER_CLASS_BOILERPLATE(
+      OpenMPDeclareTargetConstruct, OmpDirectiveSpecification);
   CharBlock source;
-  std::tuple<Verbatim, OmpDeclareTargetSpecifier> t;
 };
 
 // OMP v5.2: 5.8.8

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -761,19 +761,17 @@ static void promoteNonCPtrUseDevicePtrArgsToUseDeviceAddr(
 static void getDeclareTargetInfo(
     lower::AbstractConverter &converter, semantics::SemanticsContext &semaCtx,
     lower::pft::Evaluation &eval,
-    const parser::OpenMPDeclareTargetConstruct &declareTargetConstruct,
+    const parser::OpenMPDeclareTargetConstruct &construct,
     mlir::omp::DeclareTargetOperands &clauseOps,
     llvm::SmallVectorImpl<DeclareTargetCaptureInfo> &symbolAndClause) {
-  const auto &spec =
-      std::get<parser::OmpDeclareTargetSpecifier>(declareTargetConstruct.t);
-  if (const auto *objectList{parser::Unwrap<parser::OmpObjectList>(spec.u)}) {
-    ObjectList objects{makeObjects(*objectList, semaCtx)};
+
+  if (!construct.v.Arguments().v.empty()) {
+    ObjectList objects{makeObjects(construct.v.Arguments(), semaCtx)};
     // Case: declare target(func, var1, var2)
     gatherFuncAndVarSyms(objects, mlir::omp::DeclareTargetCaptureClause::to,
                          symbolAndClause, /*automap=*/false);
-  } else if (const auto *clauseList{
-                 parser::Unwrap<parser::OmpClauseList>(spec.u)}) {
-    List<Clause> clauses = makeClauses(*clauseList, semaCtx);
+  } else {
+    List<Clause> clauses = makeClauses(construct.v.Clauses(), semaCtx);
     if (clauses.empty()) {
       Fortran::lower::pft::FunctionLikeUnit *owningProc =
           eval.getOwningProcedure();

flang/lib/Parser/openmp-parsers.cpp

@@ -1773,23 +1773,11 @@ TYPE_PARSER(sourced(construct<OpenMPDeclareReductionConstruct>(
         IsDirective(llvm::omp::Directive::OMPD_declare_reduction)) >=
     Parser<OmpDirectiveSpecification>{})))
 
-// declare-target with list
-TYPE_PARSER(sourced(construct<OmpDeclareTargetWithList>(
-    parenthesized(Parser<OmpObjectList>{}))))
-
-// declare-target with clause
-TYPE_PARSER(
-    sourced(construct<OmpDeclareTargetWithClause>(Parser<OmpClauseList>{})))
-
-// declare-target-specifier
-TYPE_PARSER(
-    construct<OmpDeclareTargetSpecifier>(Parser<OmpDeclareTargetWithList>{}) ||
-    construct<OmpDeclareTargetSpecifier>(Parser<OmpDeclareTargetWithClause>{}))
-
 // 2.10.6 Declare Target Construct
 TYPE_PARSER(sourced(construct<OpenMPDeclareTargetConstruct>(
-    verbatim("DECLARE TARGET"_tok) || verbatim("DECLARE_TARGET"_tok),
-    Parser<OmpDeclareTargetSpecifier>{})))
+    predicated(Parser<OmpDirectiveName>{},
+        IsDirective(llvm::omp::Directive::OMPD_declare_target)) >=
+    Parser<OmpDirectiveSpecification>{})))
 
 static OmpMapperSpecifier ConstructOmpMapperSpecifier(
     std::optional<Name> &&mapperName, TypeSpec &&typeSpec, Name &&varName) {

flang/lib/Parser/unparse.cpp

@@ -2492,9 +2492,6 @@ class UnparseVisitor {
   void Unparse(const OpenMPCriticalConstruct &x) {
     Unparse(static_cast<const OmpBlockConstruct &>(x));
   }
-  void Unparse(const OmpDeclareTargetWithList &x) {
-    Put("("), Walk(x.v), Put(")");
-  }
   void Unparse(const OmpInitializerProc &x) {
     Walk(std::get<ProcedureDesignator>(x.t));
     Put("(");
@@ -2582,8 +2579,8 @@ class UnparseVisitor {
   }
   void Unparse(const OpenMPDeclareTargetConstruct &x) {
     BeginOpenMP();
-    Word("!$OMP DECLARE TARGET ");
-    Walk(std::get<parser::OmpDeclareTargetSpecifier>(x.t));
+    Word("!$OMP ");
+    Walk(x.v);
     Put("\n");
     EndOpenMP();
   }