[OpenMP] Parsing and sema support for target update directive

Summary:
This patch is to add parsing and sema support for `target update` directive. Support for the `to` and `from` clauses will be added by a different patch.  This patch also adds support for other clauses that are already implemented upstream and apply to `target update`, e.g. `device` and `if`.

This patch is based on the original post by Kelvin Li.

Reviewers: hfinkel, carlo.bertolli, kkwli0, arpith-jacob, ABataev

Subscribers: caomhin, cfe-commits

Differential Revision: http://reviews.llvm.org/D15944

llvm-svn: 270878

2 files changed, 33 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 57759bcb63b..14830f21557 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -1825,6 +1825,7 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
   case OMPD_declare_simd:
   case OMPD_declare_target:
   case OMPD_end_declare_target:
+  case OMPD_target_update:
     llvm_unreachable("OpenMP Directive is not allowed");
   case OMPD_unknown:
     llvm_unreachable("Unknown OpenMP directive");
@@ -3274,6 +3275,12 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
     Res = ActOnOpenMPDistributeDirective(ClausesWithImplicit, AStmt, StartLoc,
                                          EndLoc, VarsWithInheritedDSA);
     break;
+  case OMPD_target_update:
+    assert(!AStmt && "Statement is not allowed for target update");
+    Res =
+        ActOnOpenMPTargetUpdateDirective(ClausesWithImplicit, StartLoc, EndLoc);
+    AllowedNameModifiers.push_back(OMPD_target_update);
+    break;
   case OMPD_declare_target:
   case OMPD_end_declare_target:
   case OMPD_threadprivate:
@@ -6511,6 +6518,20 @@ Sema::ActOnOpenMPTargetExitDataDirective(ArrayRef<OMPClause *> Clauses,
   return OMPTargetExitDataDirective::Create(Context, StartLoc, EndLoc, Clauses);
 }
 
+StmtResult Sema::ActOnOpenMPTargetUpdateDirective(ArrayRef<OMPClause *> Clauses,
+                                                  SourceLocation StartLoc,
+                                                  SourceLocation EndLoc) {
+  // TODO: Set this flag accordingly when we add support for the 'to' and 'from'
+  // clauses.
+  bool seenMotionClause = false;
+
+  if (!seenMotionClause) {
+    Diag(StartLoc, diag::err_omp_at_least_one_motion_clause_required);
+    return StmtError();
+  }
+  return OMPTargetUpdateDirective::Create(Context, StartLoc, EndLoc, Clauses);
+}
+
 StmtResult Sema::ActOnOpenMPTeamsDirective(ArrayRef<OMPClause *> Clauses,
                                            Stmt *AStmt, SourceLocation StartLoc,
                                            SourceLocation EndLoc) {
@@ -10407,7 +10428,7 @@ Sema::ActOnOpenMPMapClause(OpenMPMapClauseKind MapTypeModifier,
 
     // Save the components and declaration to create the clause. For purposes of
     // the clause creation, any component list that has has base 'this' uses
-    // null has
+    // null as base declaration.
     ClauseComponents.resize(ClauseComponents.size() + 1);
     ClauseComponents.back().append(CurComponents.begin(), CurComponents.end());
     ClauseBaseDeclarations.push_back(isa<MemberExpr>(BE) ? nullptr
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index a2ad14fde01..9aeefd3d4b5 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -7477,6 +7477,17 @@ StmtResult TreeTransform<Derived>::TransformOMPTargetParallelForDirective(
 }
 
 template <typename Derived>
+StmtResult TreeTransform<Derived>::TransformOMPTargetUpdateDirective(
+    OMPTargetUpdateDirective *D) {
+  DeclarationNameInfo DirName;
+  getDerived().getSema().StartOpenMPDSABlock(OMPD_target_update, DirName,
+                                             nullptr, D->getLocStart());
+  StmtResult Res = getDerived().TransformOMPExecutableDirective(D);
+  getDerived().getSema().EndOpenMPDSABlock(Res.get());
+  return Res;
+}
+
+template <typename Derived>
 StmtResult
 TreeTransform<Derived>::TransformOMPTeamsDirective(OMPTeamsDirective *D) {
   DeclarationNameInfo DirName;