[clang][OpenMP] Add 'allocator' modifier for 'allocate' clause. (llvm#114883)

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 +2247,17 @@ 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

@@ -4800,7 +4800,23 @@ 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();
+        BalancedDelimiterTracker AllocateT(*this, tok::l_paren,
+                                           tok::annot_pragma_openmp_end);
+        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>