Extend label clause to support. See more

Our label implementation was limited to a string
per task_info. Clang allowed to specify non constant
strings but it was a hacky feature. Also don't work
because every task creation will overwrite the task_info label.

This new implementation keeps the constant string for the task_info
(task type), and introduces a new string that is passed to the
runtime in nanos6_create_* functions. This new string will be
instantiation dependent and will be used to improve tracing.

clang/include/clang/AST/OmpSsClause.h

@@ -379,44 +379,53 @@ class OSSPriorityClause : public OSSClause {
 /// \endcode
 /// In this example directive '#pragma oss task' T1 has a 'label' 'string-literal' and
 /// a T2 a 'label' the string contained in variable 's'
-class OSSLabelClause : public OSSClause {
-  friend class OSSClauseReader;
-
-  /// Location of '('.
-  SourceLocation LParenLoc;
-
-  /// Expression of the 'label' clause.
-  Stmt *Expression = nullptr;
-
-  /// Set expression.
-  void setExpression(Expr *E) { Expression = E; }
+class OSSLabelClause final
+    : public OSSVarListClause<OSSLabelClause>,
+      private llvm::TrailingObjects<OSSLabelClause, Expr *> {
+  friend OSSVarListClause;
+  friend TrailingObjects;
 
-public:
-  /// Build 'label' clause with expression \a E.
+  /// Build clause with number of variables \a N.
   ///
   /// \param StartLoc Starting location of the clause.
   /// \param LParenLoc Location of '('.
-  /// \param E Expression of the clause.
   /// \param EndLoc Ending location of the clause.
-  OSSLabelClause(Expr *E, SourceLocation StartLoc, SourceLocation LParenLoc,
-                SourceLocation EndLoc)
-      : OSSClause(OSSC_label, StartLoc, EndLoc), LParenLoc(LParenLoc),
-        Expression(E) {}
+  /// \param N Number of the variables in the clause.
+  OSSLabelClause(SourceLocation StartLoc, SourceLocation LParenLoc,
+                  SourceLocation EndLoc, unsigned N)
+      : OSSVarListClause<OSSLabelClause>(OSSC_label, StartLoc, LParenLoc,
+                                          EndLoc, N) {}
 
   /// Build an empty clause.
-  OSSLabelClause()
-      : OSSClause(OSSC_label, SourceLocation(), SourceLocation()) {}
-
-  /// Sets the location of '('.
-  void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
+  ///
+  /// \param N Number of variables.
+  explicit OSSLabelClause(unsigned N)
+      : OSSVarListClause<OSSLabelClause>(OSSC_label, SourceLocation(),
+                                          SourceLocation(), SourceLocation(),
+                                          N) {}
 
-  /// Returns the location of '('.
-  SourceLocation getLParenLoc() const { return LParenLoc; }
+public:
+  /// Creates clause with a list of variables \a VL.
+  ///
+  /// \param C AST context.
+  /// \param StartLoc Starting location of the clause.
+  /// \param LParenLoc Location of '('.
+  /// \param EndLoc Ending location of the clause.
+  /// \param VL List of references to the variables.
+  static OSSLabelClause *Create(const ASTContext &C, SourceLocation StartLoc,
+                                 SourceLocation LParenLoc,
+                                 SourceLocation EndLoc, ArrayRef<Expr *> VL);
 
-  /// Returns expression.
-  Expr *getExpression() const { return cast_or_null<Expr>(Expression); }
+  /// Creates an empty clause with \a N variables.
+  ///
+  /// \param C AST context.
+  /// \param N The number of variables.
+  static OSSLabelClause *CreateEmpty(const ASTContext &C, unsigned N);
 
-  child_range children() { return child_range(&Expression, &Expression + 1); }
+  child_range children() {
+    return child_range(reinterpret_cast<Stmt **>(varlist_begin()),
+                       reinterpret_cast<Stmt **>(varlist_end()));
+  }
 
   static bool classof(const OSSClause *T) {
     return T->getClauseKind() == OSSC_label;

clang/include/clang/Basic/Attr.td

@@ -3672,9 +3672,9 @@ def OSSTaskDecl : Attr {
   let Args = [
     ExprArgument<"IfExpr">, ExprArgument<"FinalExpr">,
     ExprArgument<"CostExpr">, ExprArgument<"PriorityExpr">,
-    ExprArgument<"LabelExpr">,
     BoolArgument<"Wait", 0>,
     ExprArgument<"OnreadyExpr">,
+    VariadicExprArgument<"LabelExprs">,
     // in()
     VariadicExprArgument<"Ins">, VariadicExprArgument<"Outs">,
     VariadicExprArgument<"Inouts">,

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -11385,6 +11385,8 @@ def err_oss_expected_base_var_name : Error<
 def err_oss_reduction_wrong_type : Error<"reduction type cannot be %select{qualified with 'const', 'volatile' or 'restrict'|a function|a reference|an array}0 type">;
 def err_oss_declare_reduction_redefinition : Error<"redefinition of user-defined reduction for type %0">;
 
+def err_oss_non_const_variable : Error<
+  "this variable cannot be used here">;
 def err_oss_const_variable : Error<
   "const-qualified variable cannot be %0">;
 def err_oss_const_not_mutable_variable : Error<

clang/include/clang/Parse/Parser.h

@@ -3210,6 +3210,18 @@ class Parser : public CodeCompletionHandler {
   OSSClause *ParseOmpSsClause(OmpSsDirectiveKind DKind,
                               OmpSsClauseKind CKind, bool FirstClause);
 
+  /// Parses clause with the list of variables of a kind \a Kind with a
+  /// max limit of N
+  ///
+  /// \param Kind Kind of current clause.
+  /// \param ParseOnly true to skip the clause's semantic actions and return
+  /// \param N Specifies the maximum number of variables to be parsed.
+  /// nullptr.
+  ///
+  template<int N>
+  OSSClause *ParseOmpSsFixedListClause(
+    OmpSsDirectiveKind DKind, OmpSsClauseKind Kind, bool ParseOnly);
+
   /// Parses clause with the list of variables of a kind \a Kind.
   ///
   /// \param Kind Kind of current clause.
@@ -3270,6 +3282,12 @@ class Parser : public CodeCompletionHandler {
     DeclarationNameInfo ReductionId;
   };
 
+  /// Parses clauses with list with a max limit of N
+  template<int N>
+  bool ParseOmpSsFixedList(
+    OmpSsDirectiveKind DKind, OmpSsClauseKind Kind,
+    SmallVectorImpl<Expr *> &Vars, SourceLocation &RLoc);
+
   /// Parses clauses with list.
   bool ParseOmpSsVarList(OmpSsDirectiveKind DKind, OmpSsClauseKind Kind,
                          SmallVectorImpl<Expr *> &Vars,

clang/include/clang/Sema/Sema.h

@@ -11624,7 +11624,7 @@ class Sema final {
   ExprResult
   CheckSignedIntegerValue(Expr *ValExpr);
   ExprResult
-  CheckIsConstCharPtrConvertibleExpr(Expr *E);
+  CheckIsConstCharPtrConvertibleExpr(Expr *E, bool ConstConstraint = false);
   ExprResult
   VerifyPositiveIntegerConstant(Expr *E,
                                 OmpSsClauseKind CKind,
@@ -11731,8 +11731,8 @@ class Sema final {
   DeclGroupPtrTy ActOnOmpSsDeclareTaskDirective(
       DeclGroupPtrTy DG,
       Expr *If, Expr *Final, Expr *Cost, Expr *Priority,
-      Expr *Label, Expr *Onready,
-      bool Wait,
+      Expr *Onready, bool Wait,
+      ArrayRef<Expr *> Labels,
       ArrayRef<Expr *> Ins, ArrayRef<Expr *> Outs, ArrayRef<Expr *> Inouts,
       ArrayRef<Expr *> Concurrents, ArrayRef<Expr *> Commutatives,
       ArrayRef<Expr *> WeakIns, ArrayRef<Expr *> WeakOuts,
@@ -11754,6 +11754,11 @@ class Sema final {
       CXXScopeSpec &ReductionIdScopeSpec,
       DeclarationNameInfo &ReductionId);
 
+  OSSClause *ActOnOmpSsFixedListClause(
+      OmpSsClauseKind Kind, ArrayRef<Expr *> Vars,
+      SourceLocation StartLoc, SourceLocation LParenLoc,
+      SourceLocation EndLoc);
+
   OSSClause *ActOnOmpSsSimpleClause(OmpSsClauseKind Kind,
                                     unsigned Argument,
                                     SourceLocation ArgumentLoc,
@@ -11836,7 +11841,7 @@ class Sema final {
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
   /// Called on well-formed 'label' clause.
-  OSSClause *ActOnOmpSsLabelClause(Expr *E, SourceLocation StartLoc,
+  OSSClause *ActOnOmpSsLabelClause(ArrayRef<Expr *> VarList, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
   /// Called on well-formed 'onready' clause.

clang/lib/AST/AttrImpl.cpp

@@ -149,6 +149,7 @@ void OSSTaskDeclAttr::printPrettyPragma(
       OS << ")";
     }
   };
+  l("label", "(", labelExprs_size(), labelExprs_begin(), labelExprs_end(), OS, Policy);
   l("in", "(", ins_size(), ins_begin(), ins_end(), OS, Policy);
   l("out", "(", outs_size(), outs_begin(), outs_end(), OS, Policy);
   l("inout", "(", inouts_size(), inouts_begin(), inouts_end(), OS, Policy);
@@ -189,11 +190,6 @@ void OSSTaskDeclAttr::printPrettyPragma(
     E->printPretty(OS, nullptr, Policy);
     OS << ")";
   }
-  if (auto *E = getLabelExpr()) {
-    OS << " label(";
-    E->printPretty(OS, nullptr, Policy);
-    OS << ")";
-  }
   if (getWait())
       OS << " wait";
   if (auto *E = getOnreadyExpr()) {

clang/lib/AST/OmpSsClause.cpp

@@ -35,6 +35,23 @@ OSSClause::child_range OSSClause::children() {
   llvm_unreachable("unknown OSSClause");
 }
 
+OSSLabelClause *OSSLabelClause::Create(const ASTContext &C,
+                                         SourceLocation StartLoc,
+                                         SourceLocation LParenLoc,
+                                         SourceLocation EndLoc,
+                                         ArrayRef<Expr *> VL) {
+  void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(VL.size()));
+  OSSLabelClause *Clause =
+      new (Mem) OSSLabelClause(StartLoc, LParenLoc, EndLoc, VL.size());
+  Clause->setVarRefs(VL);
+  return Clause;
+}
+
+OSSLabelClause *OSSLabelClause::CreateEmpty(const ASTContext &C, unsigned N) {
+  void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(N));
+  return new (Mem) OSSLabelClause(N);
+}
+
 void OSSPrivateClause::setPrivateCopies(ArrayRef<Expr *> VL) {
   assert(VL.size() == varlist_size() &&
          "Number of private copies is not the same as the preallocated buffer");

clang/lib/AST/StmtPrinter.cpp

@@ -714,9 +714,11 @@ void OSSClausePrinter::VisitOSSPriorityClause(OSSPriorityClause *Node) {
 }
 
 void OSSClausePrinter::VisitOSSLabelClause(OSSLabelClause *Node) {
-  OS << "label(";
-  Node->getExpression()->printPretty(OS, nullptr, Policy, 0);
-  OS << ")";
+  if (!Node->varlist_empty()) {
+    OS << "label";
+    VisitOSSClauseList(Node, '(');
+    OS << ")";
+  }
 }
 
 void OSSClausePrinter::VisitOSSChunksizeClause(OSSChunksizeClause *Node) {

clang/lib/CodeGen/CGOmpSsRuntime.cpp

@@ -2586,9 +2586,11 @@ void CGOmpSsRuntime::EmitDirectiveData(
     EmitScalarWrapperCallBundle(
       getBundleStr(OSSB_priority), "compute_priority", CGF, Data.Priority, TaskInfo);
   }
-  if (Data.Label) {
-    llvm::Value *V = CGF.EmitScalarExpr(Data.Label);
-    TaskInfo.emplace_back(getBundleStr(OSSB_label), V);
+  if (!Data.Labels.empty()) {
+    SmallVector<llvm::Value *, 2> LabelValues;
+    for (const Expr *E : Data.Labels)
+      LabelValues.push_back(CGF.EmitScalarExpr(E));
+    TaskInfo.emplace_back(getBundleStr(OSSB_label), LabelValues);
   }
   if (Data.Wait) {
     TaskInfo.emplace_back(
@@ -2905,7 +2907,7 @@ RValue CGOmpSsRuntime::emitTaskFunction(CodeGenFunction &CGF,
       EmitScalarWrapperCallBundle(
         getBundleStr(OSSB_priority), "compute_priority", CGF, E, TaskInfo);
     }
-    if (const Expr *E = Attr->getLabelExpr()) {
+    for (const Expr *E : Attr->labelExprs()) {
       llvm::Value *V = CGF.EmitScalarExpr(E);
       TaskInfo.emplace_back(getBundleStr(OSSB_label), V);
     }

clang/lib/CodeGen/CGOmpSsRuntime.h

@@ -105,15 +105,15 @@ struct OSSTaskDataTy final {
   const Expr *Final = nullptr;
   const Expr *Cost = nullptr;
   const Expr *Priority = nullptr;
-  const Expr *Label = nullptr;
+  SmallVector<const Expr *, 2> Labels;
   bool Wait = false;
   const Expr *Onready = nullptr;
 
   bool empty() const {
     return DSAs.empty() && Deps.empty() &&
       Reductions.empty() &&
       !If && !Final && !Cost && !Priority &&
-      !Label && !Onready;
+      Labels.empty() && !Onready;
   }
 };
 

clang/lib/CodeGen/CGStmtOmpSs.cpp

@@ -151,12 +151,13 @@ static void AddPriorityData(const OSSExecutableDirective &S, const Expr * &Prior
   }
 }
 
-static void AddLabelData(const OSSExecutableDirective &S, const Expr * &LabelExpr) {
+static void AddLabelData(
+    const OSSExecutableDirective &S, SmallVectorImpl<const Expr *> &Labels) {
   bool Found = false;
   for (const auto *C : S.getClausesOfKind<OSSLabelClause>()) {
     assert(!Found);
     Found = true;
-    LabelExpr = C->getExpression();
+    Labels.append(C->varlist_begin(), C->varlist_end());
   }
 }
 
@@ -202,7 +203,7 @@ static void AddTaskData(const OSSExecutableDirective &S, OSSTaskDataTy &TaskData
   AddFinalData(S, TaskData.Final);
   AddCostData(S, TaskData.Cost);
   AddPriorityData(S, TaskData.Priority);
-  AddLabelData(S, TaskData.Label);
+  AddLabelData(S, TaskData.Labels);
   AddWaitData(S, TaskData.Wait);
   AddOnreadyData(S, TaskData.Onready);
   AddReductionData(S, TaskData.Reductions);