[OPENMP 4.1] Allow variables with reference types in private clauses.

OpenMP 4.1 allows to use variables with reference types in all private clauses (private, firstprivate, lastprivate, linear etc.). Patch allows to use such variables and fixes codegen for linear variables with reference types.

llvm-svn: 245268

1 files changed, 21 insertions, 54 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index da808371987..ddfb2d246e2 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -715,7 +715,7 @@ void Sema::EndOpenMPDSABlock(Stmt *CurDirective) {
             continue;
           }
           auto *VD = cast<VarDecl>(cast<DeclRefExpr>(DE)->getDecl());
-          QualType Type = VD->getType();
+          QualType Type = VD->getType().getNonReferenceType();
           auto DVar = DSAStack->getTopDSA(VD, false);
           if (DVar.CKind == OMPC_lastprivate) {
             // Generate helper private variable and initialize it with the
@@ -5363,16 +5363,7 @@ OMPClause *Sema::ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
                             diag::err_omp_private_incomplete_type)) {
       continue;
     }
-    if (Type->isReferenceType()) {
-      Diag(ELoc, diag::err_omp_clause_ref_type_arg)
-          << getOpenMPClauseName(OMPC_private) << Type;
-      bool IsDecl =
-          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
-      Diag(VD->getLocation(),
-           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
-          << VD;
-      continue;
-    }
+    Type = Type.getNonReferenceType();
 
     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
     // in a Construct]
@@ -5507,23 +5498,7 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
                             diag::err_omp_firstprivate_incomplete_type)) {
       continue;
     }
-    if (Type->isReferenceType()) {
-      if (IsImplicitClause) {
-        Diag(ImplicitClauseLoc,
-             diag::err_omp_task_predetermined_firstprivate_ref_type_arg)
-            << Type;
-        Diag(RefExpr->getExprLoc(), diag::note_used_here);
-      } else {
-        Diag(ELoc, diag::err_omp_clause_ref_type_arg)
-            << getOpenMPClauseName(OMPC_firstprivate) << Type;
-      }
-      bool IsDecl =
-          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
-      Diag(VD->getLocation(),
-           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
-          << VD;
-      continue;
-    }
+    Type = Type.getNonReferenceType();
 
     // OpenMP [2.9.3.4, Restrictions, C/C++, p.1]
     //  A variable of class type (or array thereof) that appears in a private
@@ -5741,16 +5716,7 @@ OMPClause *Sema::ActOnOpenMPLastprivateClause(ArrayRef<Expr *> VarList,
                             diag::err_omp_lastprivate_incomplete_type)) {
       continue;
     }
-    if (Type->isReferenceType()) {
-      Diag(ELoc, diag::err_omp_clause_ref_type_arg)
-          << getOpenMPClauseName(OMPC_lastprivate) << Type;
-      bool IsDecl =
-          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
-      Diag(VD->getLocation(),
-           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
-          << VD;
-      continue;
-    }
+    Type = Type.getNonReferenceType();
 
     // OpenMP [2.14.1.1, Data-sharing Attribute Rules for Variables Referenced
     // in a Construct]
@@ -6353,12 +6319,14 @@ OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
                                          SourceLocation ColonLoc,
                                          SourceLocation EndLoc) {
   SmallVector<Expr *, 8> Vars;
+  SmallVector<Expr *, 8> Privates;
   SmallVector<Expr *, 8> Inits;
   for (auto &RefExpr : VarList) {
     assert(RefExpr && "NULL expr in OpenMP linear clause.");
     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
       // It will be analyzed later.
       Vars.push_back(RefExpr);
+      Privates.push_back(nullptr);
       Inits.push_back(nullptr);
       continue;
     }
@@ -6401,6 +6369,7 @@ OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
     if (QType->isDependentType() || QType->isInstantiationDependentType()) {
       // It will be analyzed later.
       Vars.push_back(DE);
+      Privates.push_back(nullptr);
       Inits.push_back(nullptr);
       continue;
     }
@@ -6410,16 +6379,7 @@ OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
                             diag::err_omp_linear_incomplete_type)) {
       continue;
     }
-    if (QType->isReferenceType()) {
-      Diag(ELoc, diag::err_omp_clause_ref_type_arg)
-          << getOpenMPClauseName(OMPC_linear) << QType;
-      bool IsDecl =
-          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
-      Diag(VD->getLocation(),
-           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
-          << VD;
-      continue;
-    }
+    QType = QType.getNonReferenceType();
 
     // A list item must not be const-qualified.
     if (QType.isConstant(Context)) {
@@ -6447,6 +6407,10 @@ OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
       continue;
     }
 
+    // Build private copy of original var.
+    auto *Private = buildVarDecl(*this, ELoc, QType, VD->getName());
+    auto *PrivateRef = buildDeclRefExpr(
+        *this, Private, DE->getType().getUnqualifiedType(), DE->getExprLoc());
     // Build var to save initial value.
     VarDecl *Init = buildVarDecl(*this, ELoc, QType, ".linear.start");
     AddInitializerToDecl(Init, DefaultLvalueConversion(DE).get(),
@@ -6455,6 +6419,7 @@ OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
         *this, Init, DE->getType().getUnqualifiedType(), DE->getExprLoc());
     DSAStack->addDSA(VD, DE, OMPC_linear);
     Vars.push_back(DE);
+    Privates.push_back(PrivateRef);
     Inits.push_back(InitRef);
   }
 
@@ -6495,7 +6460,7 @@ OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
   }
 
   return OMPLinearClause::Create(Context, StartLoc, LParenLoc, ColonLoc, EndLoc,
-                                 Vars, Inits, StepExpr, CalcStepExpr);
+                                 Vars, Privates, Inits, StepExpr, CalcStepExpr);
 }
 
 static bool FinishOpenMPLinearClause(OMPLinearClause &Clause, DeclRefExpr *IV,
@@ -6514,25 +6479,26 @@ static bool FinishOpenMPLinearClause(OMPLinearClause &Clause, DeclRefExpr *IV,
     Step = cast<BinaryOperator>(CalcStep)->getLHS();
   bool HasErrors = false;
   auto CurInit = Clause.inits().begin();
+  auto CurPrivate = Clause.privates().begin();
   for (auto &RefExpr : Clause.varlists()) {
     Expr *InitExpr = *CurInit;
 
     // Build privatized reference to the current linear var.
     auto DE = cast<DeclRefExpr>(RefExpr);
-    auto PrivateRef =
+    auto CapturedRef =
         buildDeclRefExpr(SemaRef, cast<VarDecl>(DE->getDecl()),
                          DE->getType().getUnqualifiedType(), DE->getExprLoc(),
                          /*RefersToCapture=*/true);
 
     // Build update: Var = InitExpr + IV * Step
     ExprResult Update =
-        BuildCounterUpdate(SemaRef, S, RefExpr->getExprLoc(), PrivateRef,
+        BuildCounterUpdate(SemaRef, S, RefExpr->getExprLoc(), *CurPrivate,
                            InitExpr, IV, Step, /* Subtract */ false);
     Update = SemaRef.ActOnFinishFullExpr(Update.get());
 
     // Build final: Var = InitExpr + NumIterations * Step
     ExprResult Final =
-        BuildCounterUpdate(SemaRef, S, RefExpr->getExprLoc(), PrivateRef,
+        BuildCounterUpdate(SemaRef, S, RefExpr->getExprLoc(), CapturedRef,
                            InitExpr, NumIterations, Step, /* Subtract */ false);
     Final = SemaRef.ActOnFinishFullExpr(Final.get());
     if (!Update.isUsable() || !Final.isUsable()) {
@@ -6543,7 +6509,7 @@ static bool FinishOpenMPLinearClause(OMPLinearClause &Clause, DeclRefExpr *IV,
       Updates.push_back(Update.get());
       Finals.push_back(Final.get());
     }
-    ++CurInit;
+    ++CurInit, ++CurPrivate;
   }
   Clause.setUpdates(Updates);
   Clause.setFinals(Finals);
@@ -6802,7 +6768,8 @@ OMPClause *Sema::ActOnOpenMPCopyprivateClause(ArrayRef<Expr *> VarList,
     //  A variable of class type (or array thereof) that appears in a
     //  copyin clause requires an accessible, unambiguous copy assignment
     //  operator for the class type.
-    Type = Context.getBaseElementType(Type).getUnqualifiedType();
+    Type = Context.getBaseElementType(Type.getNonReferenceType())
+               .getUnqualifiedType();
     auto *SrcVD =
         buildVarDecl(*this, DE->getLocStart(), Type, ".copyprivate.src");
     auto *PseudoSrcExpr =