[Flang][openmp][3/5] Make ProcBind clause part of OmpClause

[sameeranjoshi]

Summary

After discussion in D93482 we found that the some of the clauses were not
following the common OmpClause convention.

The benefits of using OmpClause:

• Functionalities from structure checker are mostly aligned to work with llvm::omp::Clause.
• The unparsing as well can take advantage.
• Homogeneity with OpenACC and rest of the clauses in OpenMP.
• Could even generate the parser with TableGen, when there is homogeneity.
• It becomes confusing when to use flangClass and flangClassValue inside TableGen, if incase we generate parser using TableGen we could have only a single let expression.

This patch makes OmpProcBindClause clause part of OmpClause.
The unparse function is dropped as the unparsing is done by WALK_NESTED_ENUM
for OmpProcBindClause.

[clementval]

LGTM

[kiranktp]

LGTM

flang/lib/Lower/OpenMP.cpp

for (const auto &clause : parallelOpClauseList.v) {
           break;
         case Fortran::parser::OmpDefaultClause::Type::None:
           parallelOp.default_valAttr(firOpBuilder.getStringAttr(
               omp::stringifyClauseDefault(omp::ClauseDefault::defnone)));
           break;
         }
       }
       if (const auto &procBindClause =
-              std::get_if<Fortran::parser::OmpProcBindClause>(&clause.u)) {
-        switch (procBindClause->v) {
+              std::get_if<Fortran::parser::OmpClause::ProcBind>(&clause.u)) {
+        const auto &ompProcBindClause{procBindClause->v};
+        switch (ompProcBindClause.v) {
         case Fortran::parser::OmpProcBindClause::Type::Master:
           parallelOp.proc_bind_valAttr(
               firOpBuilder.getStringAttr(omp::stringifyClauseProcBindKind(
                   omp::ClauseProcBindKind::master)));
           break;
         case Fortran::parser::OmpProcBindClause::Type::Close:
           parallelOp.proc_bind_valAttr(
               firOpBuilder.getStringAttr(omp::stringifyClauseProcBindKind(

flang/lib/Parser/openmp-parsers.cpp

TYPE_PARSER(
     "NUM_THREADS" >> construct<OmpClause>(construct<OmpClause::NumThreads>(
                          parenthesized(scalarIntExpr))) ||
     "ORDERED" >> construct<OmpClause>(construct<OmpClause::Ordered>(
                      maybe(parenthesized(scalarIntConstantExpr)))) ||
     "PRIORITY" >> construct<OmpClause>(construct<OmpClause::Priority>(
                       parenthesized(scalarIntExpr))) ||
     "PRIVATE" >> construct<OmpClause>(construct<OmpClause::Private>(
                      parenthesized(Parser<OmpObjectList>{}))) ||
-    "PROC_BIND" >>
-        construct<OmpClause>(parenthesized(Parser<OmpProcBindClause>{})) ||
+    "PROC_BIND" >> construct<OmpClause>(construct<OmpClause::ProcBind>(
+                       parenthesized(Parser<OmpProcBindClause>{}))) ||
     "REDUCTION" >>
         construct<OmpClause>(parenthesized(Parser<OmpReductionClause>{})) ||
     "RELAXED" >> construct<OmpClause>(construct<OmpClause::Relaxed>()) ||
     "RELEASE" >> construct<OmpClause>(construct<OmpClause::Release>()) ||
     "SAFELEN" >> construct<OmpClause>(construct<OmpClause::Safelen>(
                      parenthesized(scalarIntConstantExpr))) ||
     "SCHEDULE" >>
         construct<OmpClause>(parenthesized(Parser<OmpScheduleClause>{})) ||

flang/lib/Parser/unparse.cpp

return std::visit(common::visitors{
                           },
                           [&](const OmpDependClause::InOut &) {
                             Word("DEPEND");
                             return true;
                           },
                       },
         x.u);
   }
-  bool Pre(const OmpProcBindClause &) {
-    Word("PROC_BIND(");
-    return true;
-  }
-  void Post(const OmpProcBindClause &) { Put(")"); }
   void Unparse(const OmpDefaultmapClause &x) {
     Word("DEFAULTMAP(");
     Walk(std::get<OmpDefaultmapClause::ImplicitBehavior>(x.t));
     Walk(":",
         std::get<std::optional<OmpDefaultmapClause::VariableCategory>>(x.t));
     Word(")");
   }
   void Unparse(const OmpNowait &) { Word("NOWAIT"); }

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

#include "llvm/Frontend/OpenMP/OMP.inc"
   void Enter(const parser::OmpClause::Grainsize &);
   void Enter(const parser::OmpClause::Lastprivate &);
   void Enter(const parser::OmpClause::NumTasks &);
   void Enter(const parser::OmpClause::NumTeams &);
   void Enter(const parser::OmpClause::NumThreads &);
   void Enter(const parser::OmpClause::Ordered &);
   void Enter(const parser::OmpClause::Priority &);
   void Enter(const parser::OmpClause::Private &);
+  void Enter(const parser::OmpClause::ProcBind &);
   void Enter(const parser::OmpClause::Safelen &);
   void Enter(const parser::OmpClause::Shared &);
   void Enter(const parser::OmpClause::Simdlen &);
   void Enter(const parser::OmpClause::ThreadLimit &);
   void Enter(const parser::OmpClause::To &);
   void Enter(const parser::OmpClause::Link &);
   void Enter(const parser::OmpClause::Uniform &);
   void Enter(const parser::OmpClause::UseDevicePtr &);
#include "llvm/Frontend/OpenMP/OMP.inc"
   void Leave(const parser::OmpAtomic &);
   void Enter(const parser::OmpAlignedClause &);
   void Enter(const parser::OmpDefaultmapClause &);
   void Enter(const parser::OmpDependClause &);
   void Enter(const parser::OmpDistScheduleClause &);
   void Enter(const parser::OmpIfClause &);
   void Enter(const parser::OmpLinearClause &);
   void Enter(const parser::OmpMapClause &);
-  void Enter(const parser::OmpProcBindClause &);
   void Enter(const parser::OmpReductionClause &);
   void Enter(const parser::OmpScheduleClause &);
 
 private:
   bool HasInvalidWorksharingNesting(
       const parser::CharBlock &, const OmpDirectiveSet &);
 
   // specific clause related

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

 CHECK_SIMPLE_CLAUSE(Untied, OMPC_untied)
 CHECK_SIMPLE_CLAUSE(UseDevicePtr, OMPC_use_device_ptr)
 CHECK_SIMPLE_CLAUSE(AcqRel, OMPC_acq_rel)
 CHECK_SIMPLE_CLAUSE(Acquire, OMPC_acquire)
 CHECK_SIMPLE_CLAUSE(SeqCst, OMPC_seq_cst)
 CHECK_SIMPLE_CLAUSE(Release, OMPC_release)
 CHECK_SIMPLE_CLAUSE(Relaxed, OMPC_relaxed)
 CHECK_SIMPLE_CLAUSE(Hint, OMPC_hint)
+CHECK_SIMPLE_CLAUSE(ProcBind, OMPC_proc_bind)
 
 CHECK_REQ_SCALAR_INT_CLAUSE(Allocator, OMPC_allocator)
 CHECK_REQ_SCALAR_INT_CLAUSE(Grainsize, OMPC_grainsize)
 CHECK_REQ_SCALAR_INT_CLAUSE(NumTasks, OMPC_num_tasks)
 CHECK_REQ_SCALAR_INT_CLAUSE(NumTeams, OMPC_num_teams)
 CHECK_REQ_SCALAR_INT_CLAUSE(NumThreads, OMPC_num_threads)
 CHECK_REQ_SCALAR_INT_CLAUSE(Priority, OMPC_priority)
 CHECK_REQ_SCALAR_INT_CLAUSE(ThreadLimit, OMPC_thread_limit)
std::visit(
             [&](const parser::Name &name) {},
         },
         ompObject.u);
   }
 }
 // Following clauses have a seperate node in parse-tree.h.
 CHECK_SIMPLE_PARSER_CLAUSE(OmpDistScheduleClause, OMPC_dist_schedule)
 CHECK_SIMPLE_PARSER_CLAUSE(OmpNowait, OMPC_nowait)
-CHECK_SIMPLE_PARSER_CLAUSE(OmpProcBindClause, OMPC_proc_bind)
 CHECK_SIMPLE_PARSER_CLAUSE(OmpReductionClause, OMPC_reduction)
 // Atomic-clause
 CHECK_SIMPLE_PARSER_CLAUSE(OmpAtomicRead, OMPC_read)
 CHECK_SIMPLE_PARSER_CLAUSE(OmpAtomicWrite, OMPC_write)
 CHECK_SIMPLE_PARSER_CLAUSE(OmpAtomicUpdate, OMPC_update)
 CHECK_SIMPLE_PARSER_CLAUSE(OmpAtomicCapture, OMPC_capture)
 
 void OmpStructureChecker::Leave(const parser::OmpAtomicRead &) {

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

 }
 def OMP_PROC_BIND_master : ClauseVal<"master",2,1> {}
 def OMP_PROC_BIND_close : ClauseVal<"close",3,1> {}
 def OMP_PROC_BIND_spread : ClauseVal<"spread",4,1> {}
 def OMP_PROC_BIND_default : ClauseVal<"default",5,0> {}
 def OMP_PROC_BIND_unknown : ClauseVal<"unknown",6,0> { let isDefault = true; }
 def OMPC_ProcBind : Clause<"proc_bind"> {
   let clangClass = "OMPProcBindClause";
-  let flangClass = "OmpProcBindClause";
+  let flangClassValue = "OmpProcBindClause";
   let enumClauseValue = "ProcBindKind";
   let allowedClauseValues = [
     OMP_PROC_BIND_master,
     OMP_PROC_BIND_close,
     OMP_PROC_BIND_spread,
     OMP_PROC_BIND_default,
     OMP_PROC_BIND_unknown
   ];