[clang][OpenMP] Add 'allocator' modifier for 'allocate' clause.

The 'allocator' modifier is now accepted in the 'allocate' clause.
Added LIT tests covering codegen, PCH, template handling, and
serialization for 'allocator' modifier.

Added support for allocator-modifier to release notes.

Testing
- New allocate modifier LIT tests.
- OpenMP LIT tests.
- check-all
- relevant sollve_vv test cases
    tests/5.2/scope/test_scope_allocate_construct.c

Author: ddpagan

clang/docs/ReleaseNotes.rst

@@ -888,6 +888,7 @@ OpenMP Support
 --------------
 - Added support for 'omp assume' directive.
 - Added support for 'omp scope' directive.
+- Added support for allocator-modifier in 'allocate' clause.
 
 Improvements
 ^^^^^^^^^^^^

clang/include/clang/AST/OpenMPClause.h

@@ -486,7 +486,8 @@ class OMPAlignClause final
 /// #pragma omp parallel private(a) allocate(omp_default_mem_alloc :a)
 /// \endcode
 /// In this example directive '#pragma omp parallel' has clause 'private'
-/// and clause 'allocate' for the variable 'a'.
+/// and clause 'allocate' for the variable 'a', which specifies an explicit
+/// memory allocator.
 class OMPAllocateClause final
     : public OMPVarListClause<OMPAllocateClause>,
       private llvm::TrailingObjects<OMPAllocateClause, Expr *> {
@@ -499,6 +500,10 @@ class OMPAllocateClause final
   Expr *Allocator = nullptr;
   /// Position of the ':' delimiter in the clause;
   SourceLocation ColonLoc;
+  /// Modifier of 'allocate' clause.
+  OpenMPAllocateClauseModifier AllocatorModifier = OMPC_ALLOCATE_unknown;
+  /// Location of allocator modifier if any.
+  SourceLocation AllocatorModifierLoc;
 
   /// Build clause with number of variables \a N.
   ///
@@ -510,10 +515,14 @@ class OMPAllocateClause final
   /// \param N Number of the variables in the clause.
   OMPAllocateClause(SourceLocation StartLoc, SourceLocation LParenLoc,
                     Expr *Allocator, SourceLocation ColonLoc,
-                    SourceLocation EndLoc, unsigned N)
+                    OpenMPAllocateClauseModifier AllocatorModifier,
+                    SourceLocation AllocatorModifierLoc, SourceLocation EndLoc,
+                    unsigned N)
       : OMPVarListClause<OMPAllocateClause>(llvm::omp::OMPC_allocate, StartLoc,
                                             LParenLoc, EndLoc, N),
-        Allocator(Allocator), ColonLoc(ColonLoc) {}
+        Allocator(Allocator), ColonLoc(ColonLoc),
+        AllocatorModifier(AllocatorModifier),
+        AllocatorModifierLoc(AllocatorModifierLoc) {}
 
   /// Build an empty clause.
   ///
@@ -527,6 +536,9 @@ class OMPAllocateClause final
   void setColonLoc(SourceLocation CL) { ColonLoc = CL; }
 
   void setAllocator(Expr *A) { Allocator = A; }
+  void setAllocatorModifier(OpenMPAllocateClauseModifier AM) {
+    AllocatorModifier = AM;
+  }
 
 public:
   /// Creates clause with a list of variables \a VL.
@@ -536,18 +548,31 @@ class OMPAllocateClause final
   /// \param LParenLoc Location of '('.
   /// \param Allocator Allocator expression.
   /// \param ColonLoc Location of ':' delimiter.
+  /// \param AllocatorModifier Allocator modifier.
+  /// \param SourceLocation Allocator modifier location.
   /// \param EndLoc Ending location of the clause.
   /// \param VL List of references to the variables.
-  static OMPAllocateClause *Create(const ASTContext &C, SourceLocation StartLoc,
-                                   SourceLocation LParenLoc, Expr *Allocator,
-                                   SourceLocation ColonLoc,
-                                   SourceLocation EndLoc, ArrayRef<Expr *> VL);
+  static OMPAllocateClause *
+  Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc,
+         Expr *Allocator, SourceLocation ColonLoc,
+         OpenMPAllocateClauseModifier AllocatorModifier,
+         SourceLocation AllocatorModifierLoc, SourceLocation EndLoc,
+         ArrayRef<Expr *> VL);
 
   /// Returns the allocator expression or nullptr, if no allocator is specified.
   Expr *getAllocator() const { return Allocator; }
 
+  /// Return 'allocate' modifier.
+  OpenMPAllocateClauseModifier getAllocatorModifier() const {
+    return AllocatorModifier;
+  }
+
   /// Returns the location of the ':' delimiter.
   SourceLocation getColonLoc() const { return ColonLoc; }
+  /// Return the location of the modifier.
+  SourceLocation getAllocatorModifierLoc() const {
+    return AllocatorModifierLoc;
+  }
 
   /// Creates an empty clause with the place for \a N variables.
   ///

clang/include/clang/Basic/OpenMPKinds.def

@@ -86,6 +86,9 @@
 #ifndef OPENMP_DOACROSS_MODIFIER
 #define OPENMP_DOACROSS_MODIFIER(Name)
 #endif
+#ifndef OPENMP_ALLOCATE_MODIFIER
+#define OPENMP_ALLOCATE_MODIFIER(Name)
+#endif
 
 // Static attributes for 'schedule' clause.
 OPENMP_SCHEDULE_KIND(static)
@@ -214,6 +217,9 @@ OPENMP_GRAINSIZE_MODIFIER(strict)
 // Modifiers for the 'num_tasks' clause.
 OPENMP_NUMTASKS_MODIFIER(strict)
 
+// Modifiers for 'allocate' clause.
+OPENMP_ALLOCATE_MODIFIER(allocator)
+
 // Modifiers for the 'doacross' clause.
 OPENMP_DOACROSS_MODIFIER(source)
 OPENMP_DOACROSS_MODIFIER(sink)
@@ -245,4 +251,5 @@ OPENMP_DOACROSS_MODIFIER(source_omp_cur_iteration)
 #undef OPENMP_DEFAULTMAP_KIND
 #undef OPENMP_DEFAULTMAP_MODIFIER
 #undef OPENMP_DOACROSS_MODIFIER
+#undef OPENMP_ALLOCATE_MODIFIER
 

clang/include/clang/Basic/OpenMPKinds.h

@@ -223,6 +223,13 @@ enum OpenMPDoacrossClauseModifier {
   OMPC_DOACROSS_unknown
 };
 
+/// OpenMP modifiers for 'allocate' clause.
+enum OpenMPAllocateClauseModifier {
+#define OPENMP_ALLOCATE_MODIFIER(Name) OMPC_ALLOCATE_##Name,
+#include "clang/Basic/OpenMPKinds.def"
+  OMPC_ALLOCATE_unknown
+};
+
 /// Contains 'interop' data for 'append_args' and 'init' clauses.
 class Expr;
 struct OMPInteropInfo final {

clang/include/clang/Sema/SemaOpenMP.h

@@ -1148,6 +1148,7 @@ class SemaOpenMP : public SemaBase {
     SourceLocation OmpAllMemoryLoc;
     SourceLocation
         StepModifierLoc; /// 'step' modifier location for linear clause
+    OpenMPAllocateClauseModifier AllocClauseModifier = OMPC_ALLOCATE_unknown;
   };
 
   OMPClause *ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
@@ -1165,10 +1166,10 @@ class SemaOpenMP : public SemaBase {
                                         SourceLocation LParenLoc,
                                         SourceLocation EndLoc);
   /// Called on well-formed 'allocate' clause.
-  OMPClause *
-  ActOnOpenMPAllocateClause(Expr *Allocator, ArrayRef<Expr *> VarList,
-                            SourceLocation StartLoc, SourceLocation ColonLoc,
-                            SourceLocation LParenLoc, SourceLocation EndLoc);
+  OMPClause *ActOnOpenMPAllocateClause(
+      Expr *Allocator, OpenMPAllocateClauseModifier ACModifier,
+      ArrayRef<Expr *> VarList, SourceLocation StartLoc,
+      SourceLocation ColonLoc, SourceLocation LParenLoc, SourceLocation EndLoc);
   /// Called on well-formed 'private' clause.
   OMPClause *ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
                                       SourceLocation StartLoc,

clang/lib/AST/OpenMPClause.cpp

@@ -1023,12 +1023,17 @@ OMPPartialClause *OMPPartialClause::CreateEmpty(const ASTContext &C) {
 OMPAllocateClause *
 OMPAllocateClause::Create(const ASTContext &C, SourceLocation StartLoc,
                           SourceLocation LParenLoc, Expr *Allocator,
-                          SourceLocation ColonLoc, SourceLocation EndLoc,
-                          ArrayRef<Expr *> VL) {
+                          SourceLocation ColonLoc,
+                          OpenMPAllocateClauseModifier AllocatorModifier,
+                          SourceLocation AllocatorModifierLoc,
+                          SourceLocation EndLoc, ArrayRef<Expr *> VL) {
+
   // Allocate space for private variables and initializer expressions.
   void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(VL.size()));
-  auto *Clause = new (Mem) OMPAllocateClause(StartLoc, LParenLoc, Allocator,
-                                             ColonLoc, EndLoc, VL.size());
+  auto *Clause = new (Mem) OMPAllocateClause(
+      StartLoc, LParenLoc, Allocator, ColonLoc, AllocatorModifier,
+      AllocatorModifierLoc, EndLoc, VL.size());
+
   Clause->setVarRefs(VL);
   return Clause;
 }
@@ -2242,9 +2247,16 @@ void OMPClausePrinter::VisitOMPAllocateClause(OMPAllocateClause *Node) {
   if (Node->varlist_empty())
     return;
   OS << "allocate";
+  OpenMPAllocateClauseModifier Modifier = Node->getAllocatorModifier();
   if (Expr *Allocator = Node->getAllocator()) {
     OS << "(";
-    Allocator->printPretty(OS, nullptr, Policy, 0);
+    if (Modifier == OMPC_ALLOCATE_allocator) {
+      OS << getOpenMPSimpleClauseTypeName(Node->getClauseKind(), Modifier);
+      OS << "(";
+      Allocator->printPretty(OS, nullptr, Policy, 0);
+      OS << ")";
+    } else
+      Allocator->printPretty(OS, nullptr, Policy, 0);
     OS << ":";
     VisitOMPClauseList(Node, ' ');
   } else {

clang/lib/Basic/OpenMPKinds.cpp

@@ -180,6 +180,11 @@ unsigned clang::getOpenMPSimpleClauseType(OpenMPClauseKind Kind, StringRef Str,
       return OMPC_NUMTASKS_unknown;
     return Type;
   }
+  case OMPC_allocate:
+    return llvm::StringSwitch<OpenMPAllocateClauseModifier>(Str)
+#define OPENMP_ALLOCATE_MODIFIER(Name) .Case(#Name, OMPC_ALLOCATE_##Name)
+#include "clang/Basic/OpenMPKinds.def"
+        .Default(OMPC_ALLOCATE_unknown);
   case OMPC_unknown:
   case OMPC_threadprivate:
   case OMPC_if:
@@ -190,7 +195,6 @@ unsigned clang::getOpenMPSimpleClauseType(OpenMPClauseKind Kind, StringRef Str,
   case OMPC_sizes:
   case OMPC_permutation:
   case OMPC_allocator:
-  case OMPC_allocate:
   case OMPC_collapse:
   case OMPC_private:
   case OMPC_firstprivate:
@@ -505,6 +509,16 @@ const char *clang::getOpenMPSimpleClauseTypeName(OpenMPClauseKind Kind,
 #include "clang/Basic/OpenMPKinds.def"
     }
     llvm_unreachable("Invalid OpenMP 'num_tasks' clause modifier");
+  case OMPC_allocate:
+    switch (Type) {
+    case OMPC_ALLOCATE_unknown:
+      return "unknown";
+#define OPENMP_ALLOCATE_MODIFIER(Name)                                         \
+  case OMPC_ALLOCATE_##Name:                                                   \
+    return #Name;
+#include "clang/Basic/OpenMPKinds.def"
+    }
+    llvm_unreachable("Invalid OpenMP 'allocate' clause modifier");
   case OMPC_unknown:
   case OMPC_threadprivate:
   case OMPC_if:
@@ -515,7 +529,6 @@ const char *clang::getOpenMPSimpleClauseTypeName(OpenMPClauseKind Kind,
   case OMPC_sizes:
   case OMPC_permutation:
   case OMPC_allocator:
-  case OMPC_allocate:
   case OMPC_collapse:
   case OMPC_private:
   case OMPC_firstprivate:

clang/lib/Parse/ParseOpenMP.cpp

@@ -4539,6 +4539,8 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
   bool NeedRParenForLinear = false;
   BalancedDelimiterTracker LinearT(*this, tok::l_paren,
                                    tok::annot_pragma_openmp_end);
+  BalancedDelimiterTracker AllocateT(*this, tok::l_paren,
+                                     tok::annot_pragma_openmp_end);
   // Handle reduction-identifier for reduction clause.
   if (Kind == OMPC_reduction || Kind == OMPC_task_reduction ||
       Kind == OMPC_in_reduction) {
@@ -4800,7 +4802,21 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
     // iterator(iterators-definition)
     ExprResult Tail;
     if (Kind == OMPC_allocate) {
-      Tail = ParseAssignmentExpression();
+      auto Modifier = static_cast<OpenMPAllocateClauseModifier>(
+          getOpenMPSimpleClauseType(Kind, PP.getSpelling(Tok), getLangOpts()));
+      if (Modifier == OMPC_ALLOCATE_allocator) {
+        Data.AllocClauseModifier = Modifier;
+        ConsumeToken();
+        if (Tok.is(tok::l_paren)) {
+          AllocateT.consumeOpen();
+          Tail = ParseAssignmentExpression();
+          AllocateT.consumeClose();
+        } else {
+          Diag(Tok, diag::err_expected) << tok::l_paren;
+        }
+      } else {
+        Tail = ParseAssignmentExpression();
+      }
     } else {
       HasIterator = true;
       EnterScope(Scope::OpenMPDirectiveScope | Scope::DeclScope);
@@ -4817,6 +4833,12 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
       } else {
         // Colon not found, parse only list of variables.
         TPA.Revert();
+        if (Kind == OMPC_allocate &&
+            Data.AllocClauseModifier == OMPC_ALLOCATE_allocator) {
+          SkipUntil(tok::r_paren, tok::annot_pragma_openmp_end,
+                    StopBeforeMatch);
+          Diag(Tok, diag::err_modifier_expected_colon) << "allocator";
+        }
       }
     } else {
       // Parsing was unsuccessfull, revert and skip to the end of clause or
@@ -4886,7 +4908,6 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
   // Parse ')' for linear clause with modifier.
   if (NeedRParenForLinear)
     LinearT.consumeClose();
-
   // Parse ':' linear modifiers (val, uval, ref or step(step-size))
   // or parse ':' alignment.
   const bool MustHaveTail = MayHaveTail && Tok.is(tok::colon);
@@ -5018,6 +5039,9 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
 ///       'has_device_addr' '(' list ')'
 ///    allocate-clause:
 ///       'allocate' '(' [ allocator ':' ] list ')'
+///       As of OpenMP 5.1 there's also
+///         'allocate' '(' allocate-modifier: list ')'
+///         where allocate-modifier is: 'allocator' '(' allocator ')'
 ///    nontemporal-clause:
 ///       'nontemporal' '(' list ')'
 ///    inclusive-clause:

clang/lib/Sema/SemaOpenMP.cpp

@@ -17156,7 +17156,8 @@ OMPClause *SemaOpenMP::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
     Res = ActOnOpenMPHasDeviceAddrClause(VarList, Locs);
     break;
   case OMPC_allocate:
-    Res = ActOnOpenMPAllocateClause(Data.DepModOrTailExpr, VarList, StartLoc,
+    Res = ActOnOpenMPAllocateClause(Data.DepModOrTailExpr,
+                                    Data.AllocClauseModifier, VarList, StartLoc,
                                     LParenLoc, ColonLoc, EndLoc);
     break;
   case OMPC_nontemporal:
@@ -23162,9 +23163,17 @@ SemaOpenMP::ActOnOpenMPHasDeviceAddrClause(ArrayRef<Expr *> VarList,
 }
 
 OMPClause *SemaOpenMP::ActOnOpenMPAllocateClause(
-    Expr *Allocator, ArrayRef<Expr *> VarList, SourceLocation StartLoc,
-    SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc) {
+    Expr *Allocator, OpenMPAllocateClauseModifier AllocClauseModifier,
+    ArrayRef<Expr *> VarList, SourceLocation StartLoc, SourceLocation LParenLoc,
+    SourceLocation ColonLoc, SourceLocation EndLoc) {
+
   if (Allocator) {
+    // Allocator expression is dependent - skip it for now and build the
+    // allocator when instantiated.
+    if (Allocator->isTypeDependent() || Allocator->isValueDependent() ||
+        Allocator->isInstantiationDependent() ||
+        Allocator->containsUnexpandedParameterPack())
+      return nullptr;
     // OpenMP [2.11.4 allocate Clause, Description]
     // allocator is an expression of omp_allocator_handle_t type.
     if (!findOMPAllocatorHandleT(SemaRef, Allocator->getExprLoc(), DSAStack))
@@ -23220,8 +23229,12 @@ OMPClause *SemaOpenMP::ActOnOpenMPAllocateClause(
 
   if (Allocator)
     DSAStack->addInnerAllocatorExpr(Allocator);
+
+  OpenMPAllocateClauseModifier AllocatorModifier = AllocClauseModifier;
+  SourceLocation AllocatorModifierLoc;
   return OMPAllocateClause::Create(getASTContext(), StartLoc, LParenLoc,
-                                   Allocator, ColonLoc, EndLoc, Vars);
+                                   Allocator, ColonLoc, AllocatorModifier,
+                                   AllocatorModifierLoc, EndLoc, Vars);
 }
 
 OMPClause *SemaOpenMP::ActOnOpenMPNontemporalClause(ArrayRef<Expr *> VarList,

clang/lib/Sema/TreeTransform.h

@@ -2075,13 +2075,15 @@ class TreeTransform {
   ///
   /// By default, performs semantic analysis to build the new OpenMP clause.
   /// Subclasses may override this routine to provide different behavior.
-  OMPClause *RebuildOMPAllocateClause(Expr *Allocate, ArrayRef<Expr *> VarList,
+  OMPClause *RebuildOMPAllocateClause(Expr *Allocate,
+                                      OpenMPAllocateClauseModifier ACModifier,
+                                      ArrayRef<Expr *> VarList,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation ColonLoc,
                                       SourceLocation EndLoc) {
     return getSema().OpenMP().ActOnOpenMPAllocateClause(
-        Allocate, VarList, StartLoc, LParenLoc, ColonLoc, EndLoc);
+        Allocate, ACModifier, VarList, StartLoc, LParenLoc, ColonLoc, EndLoc);
   }
 
   /// Build a new OpenMP 'num_teams' clause.
@@ -11128,8 +11130,8 @@ TreeTransform<Derived>::TransformOMPAllocateClause(OMPAllocateClause *C) {
     Vars.push_back(EVar.get());
   }
   return getDerived().RebuildOMPAllocateClause(
-      Allocator, Vars, C->getBeginLoc(), C->getLParenLoc(), C->getColonLoc(),
-      C->getEndLoc());
+      Allocator, C->getAllocatorModifier(), Vars, C->getBeginLoc(),
+      C->getLParenLoc(), C->getColonLoc(), C->getEndLoc());
 }
 
 template <typename Derived>