[Clang][OpenMP] Refactor checking for mutually exclusive clauses. NFC.

[Meinersbur]

Summary

Multiple clauses are mutually exclusive. This patch refactors the functions that check for pairs of mutually exclusive clauses into a generalized function which also also accepts a list of clause types if which at most one can appear.

NFC patch extracted out of D99459 by request.

[ABataev]

LG

clang/lib/Sema/SemaOpenMP.cpp

Sema::ActOnOpenMPParallelSectionsDirective(ArrayRef<OMPClause *> Clauses,
 
   setFunctionHasBranchProtectedScope();
 
   return OMPParallelSectionsDirective::Create(
       Context, StartLoc, EndLoc, Clauses, AStmt,
       DSAStack->getTaskgroupReductionRef(), DSAStack->isCancelRegion());
 }
 
-/// detach and mergeable clauses are mutially exclusive, check for it.
-static bool checkDetachMergeableClauses(Sema &S,
-                                        ArrayRef<OMPClause *> Clauses) {
+/// Find and diagnose mutually exclusive clause kinds.
+static bool checkMutuallyExclusiveClauses(
+    Sema &S, ArrayRef<OMPClause *> Clauses,
+    ArrayRef<OpenMPClauseKind> MutuallyExclusiveClauses) {
   const OMPClause *PrevClause = nullptr;
   bool ErrorFound = false;
   for (const OMPClause *C : Clauses) {
-    if (C->getClauseKind() == OMPC_detach ||
-        C->getClauseKind() == OMPC_mergeable) {
+    if (llvm::is_contained(MutuallyExclusiveClauses, C->getClauseKind())) {
       if (!PrevClause) {
         PrevClause = C;
       } else if (PrevClause->getClauseKind() != C->getClauseKind()) {
         S.Diag(C->getBeginLoc(), diag::err_omp_clauses_mutually_exclusive)
             << getOpenMPClauseName(C->getClauseKind())
             << getOpenMPClauseName(PrevClause->getClauseKind());
         S.Diag(PrevClause->getBeginLoc(), diag::note_omp_previous_clause)
             << getOpenMPClauseName(PrevClause->getClauseKind());
         ErrorFound = true;
       }
     }
   }
   return ErrorFound;
 }
 
 StmtResult Sema::ActOnOpenMPTaskDirective(ArrayRef<OMPClause *> Clauses,
                                           Stmt *AStmt, SourceLocation StartLoc,
                                           SourceLocation EndLoc) {
   if (!AStmt)
     return StmtError();
 
   // OpenMP 5.0, 2.10.1 task Construct
   // If a detach clause appears on the directive, then a mergeable clause cannot
   // appear on the same directive.
-  if (checkDetachMergeableClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_detach, OMPC_mergeable}))
     return StmtError();
 
   auto *CS = cast<CapturedStmt>(AStmt);
   // 1.2.2 OpenMP Language Terminology
   // Structured block - An executable statement with a single entry at the
   // top and a single exit at the bottom.
   // The point of exit cannot be a branch out of the structured block.
   // longjmp() and throw() must not violate the entry/exit criteria.
if (DSAStack->isParentOrderedRegion()) {
     Diag(StartLoc, diag::err_omp_parent_cancel_region_ordered) << 1;
     return StmtError();
   }
   DSAStack->setParentCancelRegion(/*Cancel=*/true);
   return OMPCancelDirective::Create(Context, StartLoc, EndLoc, Clauses,
                                     CancelRegion);
 }
 
-static bool checkGrainsizeNumTasksClauses(Sema &S,
-                                          ArrayRef<OMPClause *> Clauses) {
-  const OMPClause *PrevClause = nullptr;
-  bool ErrorFound = false;
-  for (const OMPClause *C : Clauses) {
-    if (C->getClauseKind() == OMPC_grainsize ||
-        C->getClauseKind() == OMPC_num_tasks) {
-      if (!PrevClause)
-        PrevClause = C;
-      else if (PrevClause->getClauseKind() != C->getClauseKind()) {
-        S.Diag(C->getBeginLoc(), diag::err_omp_clauses_mutually_exclusive)
-            << getOpenMPClauseName(C->getClauseKind())
-            << getOpenMPClauseName(PrevClause->getClauseKind());
-        S.Diag(PrevClause->getBeginLoc(), diag::note_omp_previous_clause)
-            << getOpenMPClauseName(PrevClause->getClauseKind());
-        ErrorFound = true;
-      }
-    }
-  }
-  return ErrorFound;
-}
-
 static bool checkReductionClauseWithNogroup(Sema &S,
                                             ArrayRef<OMPClause *> Clauses) {
   const OMPClause *ReductionClause = nullptr;
   const OMPClause *NogroupClause = nullptr;
   for (const OMPClause *C : Clauses) {
     if (C->getClauseKind() == OMPC_reduction) {
       ReductionClause = C;
       if (NogroupClause)
if (NestedLoopCount == 0)
     return StmtError();
 
   assert((CurContext->isDependentContext() || B.builtAll()) &&
          "omp for loop exprs were not built");
 
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // The grainsize clause and num_tasks clause are mutually exclusive and may
   // not appear on the same taskloop directive.
-  if (checkGrainsizeNumTasksClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_grainsize, OMPC_num_tasks}))
     return StmtError();
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // If a reduction clause is present on the taskloop directive, the nogroup
   // clause must not be specified.
   if (checkReductionClauseWithNogroup(*this, Clauses))
     return StmtError();
 
   setFunctionHasBranchProtectedScope();
for (OMPClause *C : Clauses) {
                                      DSAStack))
           return StmtError();
     }
   }
 
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // The grainsize clause and num_tasks clause are mutually exclusive and may
   // not appear on the same taskloop directive.
-  if (checkGrainsizeNumTasksClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_grainsize, OMPC_num_tasks}))
     return StmtError();
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // If a reduction clause is present on the taskloop directive, the nogroup
   // clause must not be specified.
   if (checkReductionClauseWithNogroup(*this, Clauses))
     return StmtError();
   if (checkSimdlenSafelenSpecified(*this, Clauses))
     return StmtError();
if (NestedLoopCount == 0)
     return StmtError();
 
   assert((CurContext->isDependentContext() || B.builtAll()) &&
          "omp for loop exprs were not built");
 
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // The grainsize clause and num_tasks clause are mutually exclusive and may
   // not appear on the same taskloop directive.
-  if (checkGrainsizeNumTasksClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_grainsize, OMPC_num_tasks}))
     return StmtError();
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // If a reduction clause is present on the taskloop directive, the nogroup
   // clause must not be specified.
   if (checkReductionClauseWithNogroup(*this, Clauses))
     return StmtError();
 
   setFunctionHasBranchProtectedScope();
for (OMPClause *C : Clauses) {
                                      DSAStack))
           return StmtError();
     }
   }
 
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // The grainsize clause and num_tasks clause are mutually exclusive and may
   // not appear on the same taskloop directive.
-  if (checkGrainsizeNumTasksClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_grainsize, OMPC_num_tasks}))
     return StmtError();
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // If a reduction clause is present on the taskloop directive, the nogroup
   // clause must not be specified.
   if (checkReductionClauseWithNogroup(*this, Clauses))
     return StmtError();
   if (checkSimdlenSafelenSpecified(*this, Clauses))
     return StmtError();
if (NestedLoopCount == 0)
     return StmtError();
 
   assert((CurContext->isDependentContext() || B.builtAll()) &&
          "omp for loop exprs were not built");
 
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // The grainsize clause and num_tasks clause are mutually exclusive and may
   // not appear on the same taskloop directive.
-  if (checkGrainsizeNumTasksClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_grainsize, OMPC_num_tasks}))
     return StmtError();
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // If a reduction clause is present on the taskloop directive, the nogroup
   // clause must not be specified.
   if (checkReductionClauseWithNogroup(*this, Clauses))
     return StmtError();
 
   setFunctionHasBranchProtectedScope();
for (OMPClause *C : Clauses) {
                                      DSAStack))
           return StmtError();
     }
   }
 
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // The grainsize clause and num_tasks clause are mutually exclusive and may
   // not appear on the same taskloop directive.
-  if (checkGrainsizeNumTasksClauses(*this, Clauses))
+  if (checkMutuallyExclusiveClauses(*this, Clauses,
+                                    {OMPC_grainsize, OMPC_num_tasks}))
     return StmtError();
   // OpenMP, [2.9.2 taskloop Construct, Restrictions]
   // If a reduction clause is present on the taskloop directive, the nogroup
   // clause must not be specified.
   if (checkReductionClauseWithNogroup(*this, Clauses))
     return StmtError();
   if (checkSimdlenSafelenSpecified(*this, Clauses))
     return StmtError();