[Clang][OpenMP] Allow num_teams to accept multiple expressions

clang/include/clang/AST/OpenMPClause.h

@@ -6131,60 +6131,77 @@ class OMPMapClause final : public OMPMappableExprListClause<OMPMapClause>,
 /// \endcode
 /// In this example directive '#pragma omp teams' has clause 'num_teams'
 /// with single expression 'n'.
-class OMPNumTeamsClause : public OMPClause, public OMPClauseWithPreInit {
-  friend class OMPClauseReader;
+///
+/// When 'ompx_bare' clause exists on a 'target' directive, 'num_teams' clause
+/// can accept up to three expressions.
+///
+/// \code
+/// #pragma omp target teams ompx_bare num_teams(x, y, z)
+/// \endcode
+class OMPNumTeamsClause final
+    : public OMPVarListClause<OMPNumTeamsClause>,
+      public OMPClauseWithPreInit,
+      private llvm::TrailingObjects<OMPNumTeamsClause, Expr *> {
+  friend OMPVarListClause;
+  friend TrailingObjects;
 
   /// Location of '('.
   SourceLocation LParenLoc;
 
-  /// NumTeams number.
-  Stmt *NumTeams = nullptr;
+  OMPNumTeamsClause(const ASTContext &C, SourceLocation StartLoc,
+                    SourceLocation LParenLoc, SourceLocation EndLoc, unsigned N)
+      : OMPVarListClause(llvm::omp::OMPC_num_teams, StartLoc, LParenLoc, EndLoc,
+                         N),
+        OMPClauseWithPreInit(this) {}
 
-  /// Set the NumTeams number.
-  ///
-  /// \param E NumTeams number.
-  void setNumTeams(Expr *E) { NumTeams = E; }
+  /// Build an empty clause.
+  OMPNumTeamsClause(unsigned N)
+      : OMPVarListClause(llvm::omp::OMPC_num_teams, SourceLocation(),
+                         SourceLocation(), SourceLocation(), N),
+        OMPClauseWithPreInit(this) {}
 
 public:
-  /// Build 'num_teams' clause.
+  /// Creates clause with a list of variables \a VL.
   ///
-  /// \param E Expression associated with this clause.
-  /// \param HelperE Helper Expression associated with this clause.
-  /// \param CaptureRegion Innermost OpenMP region where expressions in this
-  /// clause must be captured.
+  /// \param C AST context.
   /// \param StartLoc Starting location of the clause.
   /// \param LParenLoc Location of '('.
   /// \param EndLoc Ending location of the clause.
-  OMPNumTeamsClause(Expr *E, Stmt *HelperE, OpenMPDirectiveKind CaptureRegion,
-                    SourceLocation StartLoc, SourceLocation LParenLoc,
-                    SourceLocation EndLoc)
-      : OMPClause(llvm::omp::OMPC_num_teams, StartLoc, EndLoc),
-        OMPClauseWithPreInit(this), LParenLoc(LParenLoc), NumTeams(E) {
-    setPreInitStmt(HelperE, CaptureRegion);
-  }
+  /// \param VL List of references to the variables.
+  /// \param PreInit
+  static OMPNumTeamsClause *Create(const ASTContext &C, SourceLocation StartLoc,
+                                   SourceLocation LParenLoc,
+                                   SourceLocation EndLoc, ArrayRef<Expr *> VL,
+                                   Stmt *PreInit);
 
-  /// Build an empty clause.
-  OMPNumTeamsClause()
-      : OMPClause(llvm::omp::OMPC_num_teams, SourceLocation(),
-                  SourceLocation()),
-        OMPClauseWithPreInit(this) {}
+  /// Creates an empty clause with \a N variables.
+  ///
+  /// \param C AST context.
+  /// \param N The number of variables.
+  static OMPNumTeamsClause *CreateEmpty(const ASTContext &C, unsigned N);
 
   /// Sets the location of '('.
   void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
 
   /// Returns the location of '('.
   SourceLocation getLParenLoc() const { return LParenLoc; }
 
-  /// Return NumTeams number.
-  Expr *getNumTeams() { return cast<Expr>(NumTeams); }
+  /// Return NumTeams number. By default, we return the first expression.
+  Expr *getNumTeams() { return getVarRefs().front(); }
 
-  /// Return NumTeams number.
-  Expr *getNumTeams() const { return cast<Expr>(NumTeams); }
+  /// Return NumTeams number. By default, we return the first expression.
+  Expr *getNumTeams() const {
+    return const_cast<OMPNumTeamsClause *>(this)->getNumTeams();
+  }
 
-  child_range children() { return child_range(&NumTeams, &NumTeams + 1); }
+  child_range children() {
+    return child_range(reinterpret_cast<Stmt **>(varlist_begin()),
+                       reinterpret_cast<Stmt **>(varlist_end()));
+  }
 
   const_child_range children() const {
-    return const_child_range(&NumTeams, &NumTeams + 1);
+    auto Children = const_cast<OMPNumTeamsClause *>(this)->children();
+    return const_child_range(Children.begin(), Children.end());
   }
 
   child_range used_children() {

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -3793,8 +3793,8 @@ bool RecursiveASTVisitor<Derived>::VisitOMPMapClause(OMPMapClause *C) {
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::VisitOMPNumTeamsClause(
     OMPNumTeamsClause *C) {
+  TRY_TO(VisitOMPClauseList(C));
   TRY_TO(VisitOMPClauseWithPreInit(C));
-  TRY_TO(TraverseStmt(C->getNumTeams()));
   return true;
 }
 

clang/include/clang/Sema/SemaOpenMP.h

@@ -1227,7 +1227,8 @@ class SemaOpenMP : public SemaBase {
       const OMPVarListLocTy &Locs, bool NoDiagnose = false,
       ArrayRef<Expr *> UnresolvedMappers = std::nullopt);
   /// Called on well-formed 'num_teams' clause.
-  OMPClause *ActOnOpenMPNumTeamsClause(Expr *NumTeams, SourceLocation StartLoc,
+  OMPClause *ActOnOpenMPNumTeamsClause(ArrayRef<Expr *> VarList,
+                                       SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
   /// Called on well-formed 'thread_limit' clause.

clang/lib/AST/OpenMPClause.cpp

@@ -1720,6 +1720,24 @@ const Expr *OMPDoacrossClause::getLoopData(unsigned NumLoop) const {
   return *It;
 }
 
+OMPNumTeamsClause *
+OMPNumTeamsClause::Create(const ASTContext &C, SourceLocation StartLoc,
+                          SourceLocation LParenLoc, SourceLocation EndLoc,
+                          ArrayRef<Expr *> VL, Stmt *PreInit) {
+  void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(VL.size()));
+  OMPNumTeamsClause *Clause =
+      new (Mem) OMPNumTeamsClause(C, StartLoc, LParenLoc, EndLoc, VL.size());
+  Clause->setVarRefs(VL);
+  Clause->setPreInitStmt(PreInit);
+  return Clause;
+}
+
+OMPNumTeamsClause *OMPNumTeamsClause::CreateEmpty(const ASTContext &C,
+                                                  unsigned N) {
+  void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(N));
+  return new (Mem) OMPNumTeamsClause(N);
+}
+
 //===----------------------------------------------------------------------===//
 //  OpenMP clauses printing methods
 //===----------------------------------------------------------------------===//
@@ -1977,9 +1995,11 @@ void OMPClausePrinter::VisitOMPDeviceClause(OMPDeviceClause *Node) {
 }
 
 void OMPClausePrinter::VisitOMPNumTeamsClause(OMPNumTeamsClause *Node) {
-  OS << "num_teams(";
-  Node->getNumTeams()->printPretty(OS, nullptr, Policy, 0);
-  OS << ")";
+  if (!Node->varlist_empty()) {
+    OS << "num_teams";
+    VisitOMPClauseList(Node, '(');
+    OS << ")";
+  }
 }
 
 void OMPClausePrinter::VisitOMPThreadLimitClause(OMPThreadLimitClause *Node) {

clang/lib/AST/StmtProfile.cpp

@@ -843,9 +843,8 @@ void OMPClauseProfiler::VisitOMPAllocateClause(const OMPAllocateClause *C) {
   VisitOMPClauseList(C);
 }
 void OMPClauseProfiler::VisitOMPNumTeamsClause(const OMPNumTeamsClause *C) {
+  VisitOMPClauseList(C);
   VistOMPClauseWithPreInit(C);
-  if (C->getNumTeams())
-    Profiler->VisitStmt(C->getNumTeams());
 }
 void OMPClauseProfiler::VisitOMPThreadLimitClause(
     const OMPThreadLimitClause *C) {

clang/lib/Parse/ParseOpenMP.cpp

@@ -3098,7 +3098,6 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
   case OMPC_simdlen:
   case OMPC_collapse:
   case OMPC_ordered:
-  case OMPC_num_teams:
   case OMPC_thread_limit:
   case OMPC_priority:
   case OMPC_grainsize:
@@ -3252,6 +3251,13 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
                  ? ParseOpenMPSimpleClause(CKind, WrongDirective)
                  : ParseOpenMPClause(CKind, WrongDirective);
     break;
+  case OMPC_num_teams:
+    if (!FirstClause) {
+      Diag(Tok, diag::err_omp_more_one_clause)
+          << getOpenMPDirectiveName(DKind) << getOpenMPClauseName(CKind) << 0;
+      ErrorFound = true;
+    }
+    [[clang::fallthrough]];
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_lastprivate:

clang/lib/Sema/SemaOpenMP.cpp

@@ -13901,6 +13901,20 @@ StmtResult SemaOpenMP::ActOnOpenMPTargetTeamsDirective(
     return StmtError();
   }
 
+  const OMPClause *NumTeamsClause = nullptr;
+  bool HasNumTeamsClause = llvm::any_of(Clauses, [&](const OMPClause *C) {
+    NumTeamsClause = C;
+    return C->getClauseKind() == OMPC_num_teams;
+  });
+
+  if (HasNumTeamsClause) {
+    ArrayRef<const Expr *> NumTeams =
+        cast<OMPNumTeamsClause>(NumTeamsClause)->getVarRefs();
+    if (!HasBareClause && NumTeams.size() > 1) {
+      return StmtError();
+    }
+  }
+
   return OMPTargetTeamsDirective::Create(getASTContext(), StartLoc, EndLoc,
                                          Clauses, AStmt);
 }
@@ -15041,9 +15055,6 @@ OMPClause *SemaOpenMP::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
   case OMPC_ordered:
     Res = ActOnOpenMPOrderedClause(StartLoc, EndLoc, LParenLoc, Expr);
     break;
-  case OMPC_num_teams:
-    Res = ActOnOpenMPNumTeamsClause(Expr, StartLoc, LParenLoc, EndLoc);
-    break;
   case OMPC_thread_limit:
     Res = ActOnOpenMPThreadLimitClause(Expr, StartLoc, LParenLoc, EndLoc);
     break;
@@ -15147,6 +15158,7 @@ OMPClause *SemaOpenMP::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
   case OMPC_affinity:
   case OMPC_when:
   case OMPC_bind:
+  case OMPC_num_teams:
   default:
     llvm_unreachable("Clause is not allowed.");
   }
@@ -17010,6 +17022,9 @@ OMPClause *SemaOpenMP::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
         static_cast<OpenMPDoacrossClauseModifier>(ExtraModifier),
         ExtraModifierLoc, ColonLoc, VarList, StartLoc, LParenLoc, EndLoc);
     break;
+  case OMPC_num_teams:
+    Res = ActOnOpenMPNumTeamsClause(VarList, StartLoc, LParenLoc, EndLoc);
+    break;
   case OMPC_if:
   case OMPC_depobj:
   case OMPC_final:
@@ -17040,7 +17055,6 @@ OMPClause *SemaOpenMP::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
   case OMPC_device:
   case OMPC_threads:
   case OMPC_simd:
-  case OMPC_num_teams:
   case OMPC_thread_limit:
   case OMPC_priority:
   case OMPC_grainsize:
@@ -21703,32 +21717,40 @@ const ValueDecl *SemaOpenMP::getOpenMPDeclareMapperVarName() const {
   return cast<DeclRefExpr>(DSAStack->getDeclareMapperVarRef())->getDecl();
 }
 
-OMPClause *SemaOpenMP::ActOnOpenMPNumTeamsClause(Expr *NumTeams,
+OMPClause *SemaOpenMP::ActOnOpenMPNumTeamsClause(ArrayRef<Expr *> VarList,
                                                  SourceLocation StartLoc,
                                                  SourceLocation LParenLoc,
                                                  SourceLocation EndLoc) {
-  Expr *ValExpr = NumTeams;
-  Stmt *HelperValStmt = nullptr;
-
-  // OpenMP [teams Constrcut, Restrictions]
-  // The num_teams expression must evaluate to a positive integer value.
-  if (!isNonNegativeIntegerValue(ValExpr, SemaRef, OMPC_num_teams,
-                                 /*StrictlyPositive=*/true))
+  if (VarList.empty())
     return nullptr;
 
   OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
   OpenMPDirectiveKind CaptureRegion = getOpenMPCaptureRegionForClause(
       DKind, OMPC_num_teams, getLangOpts().OpenMP);
-  if (CaptureRegion != OMPD_unknown &&
-      !SemaRef.CurContext->isDependentContext()) {
+
+  for (Expr *ValExpr : VarList) {
+    // OpenMP [teams Constrcut, Restrictions]
+    // The num_teams expression must evaluate to a positive integer value.
+    if (!isNonNegativeIntegerValue(ValExpr, SemaRef, OMPC_num_teams,
+                                   /*StrictlyPositive=*/true))
+      return nullptr;
+  }
+
+  if (CaptureRegion == OMPD_unknown || SemaRef.CurContext->isDependentContext())
+    return OMPNumTeamsClause::Create(getASTContext(), StartLoc, LParenLoc,
+                                     EndLoc, VarList, /*PreInit=*/nullptr);
+
+  llvm::MapVector<const Expr *, DeclRefExpr *> Captures;
+  SmallVector<Expr *, 3> Vars;
+  for (Expr *ValExpr : VarList) {
     ValExpr = SemaRef.MakeFullExpr(ValExpr).get();
-    llvm::MapVector<const Expr *, DeclRefExpr *> Captures;
     ValExpr = tryBuildCapture(SemaRef, ValExpr, Captures).get();
-    HelperValStmt = buildPreInits(getASTContext(), Captures);
+    Vars.push_back(ValExpr);
   }
 
-  return new (getASTContext()) OMPNumTeamsClause(
-      ValExpr, HelperValStmt, CaptureRegion, StartLoc, LParenLoc, EndLoc);
+  Stmt *PreInit = buildPreInits(getASTContext(), Captures);
+  return OMPNumTeamsClause::Create(getASTContext(), StartLoc, LParenLoc, EndLoc,
+                                   Vars, PreInit);
 }
 
 OMPClause *SemaOpenMP::ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,

clang/lib/Serialization/ASTReader.cpp

@@ -10562,7 +10562,7 @@ OMPClause *OMPClauseReader::readClause() {
     break;
   }
   case llvm::omp::OMPC_num_teams:
-    C = new (Context) OMPNumTeamsClause();
+    C = OMPNumTeamsClause::CreateEmpty(Context, Record.readInt());
     break;
   case llvm::omp::OMPC_thread_limit:
     C = new (Context) OMPThreadLimitClause();
@@ -11350,8 +11350,13 @@ void OMPClauseReader::VisitOMPAllocateClause(OMPAllocateClause *C) {
 
 void OMPClauseReader::VisitOMPNumTeamsClause(OMPNumTeamsClause *C) {
   VisitOMPClauseWithPreInit(C);
-  C->setNumTeams(Record.readSubExpr());
   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);
 }
 
 void OMPClauseReader::VisitOMPThreadLimitClause(OMPThreadLimitClause *C) {

clang/lib/Serialization/ASTWriter.cpp

@@ -7528,9 +7528,11 @@ void OMPClauseWriter::VisitOMPAllocateClause(OMPAllocateClause *C) {
 }
 
 void OMPClauseWriter::VisitOMPNumTeamsClause(OMPNumTeamsClause *C) {
+  Record.push_back(C->varlist_size());
   VisitOMPClauseWithPreInit(C);
-  Record.AddStmt(C->getNumTeams());
   Record.AddSourceLocation(C->getLParenLoc());
+  for (auto *VE : C->varlists())
+    Record.AddStmt(VE);
 }
 
 void OMPClauseWriter::VisitOMPThreadLimitClause(OMPThreadLimitClause *C) {