[OPENMP] parsing 'linear' clause (for directive 'omp simd')

Differential Revision: http://reviews.llvm.org/D3272

llvm-svn: 206891

9 files changed, 267 insertions, 12 deletions

diff --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
index a03ef00ce76..8e937fb08b1 100644
--- a/clang/lib/AST/Stmt.cpp
+++ b/clang/lib/AST/Stmt.cpp
@@ -1192,6 +1192,30 @@ OMPSharedClause *OMPSharedClause::CreateEmpty(const ASTContext &C,
   return new (Mem) OMPSharedClause(N);
 }
 
+OMPLinearClause *OMPLinearClause::Create(const ASTContext &C,
+                                         SourceLocation StartLoc,
+                                         SourceLocation LParenLoc,
+                                         SourceLocation ColonLoc,
+                                         SourceLocation EndLoc,
+                                         ArrayRef<Expr *> VL, Expr *Step) {
+  void *Mem = C.Allocate(llvm::RoundUpToAlignment(sizeof(OMPLinearClause),
+                                                  llvm::alignOf<Expr *>()) +
+                         sizeof(Expr *) * (VL.size() + 1));
+  OMPLinearClause *Clause = new (Mem)
+      OMPLinearClause(StartLoc, LParenLoc, ColonLoc, EndLoc, VL.size());
+  Clause->setVarRefs(VL);
+  Clause->setStep(Step);
+  return Clause;
+}
+
+OMPLinearClause *OMPLinearClause::CreateEmpty(const ASTContext &C,
+                                              unsigned NumVars) {
+  void *Mem = C.Allocate(llvm::RoundUpToAlignment(sizeof(OMPLinearClause),
+                                                  llvm::alignOf<Expr *>()) +
+                         sizeof(Expr *) * (NumVars + 1));
+  return new (Mem) OMPLinearClause(NumVars);
+}
+
 OMPCopyinClause *OMPCopyinClause::Create(const ASTContext &C,
                                          SourceLocation StartLoc,
                                          SourceLocation LParenLoc,
diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
index 5cfaab26e53..758db448288 100644
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -664,6 +664,18 @@ void OMPClausePrinter::VisitOMPSharedClause(OMPSharedClause *Node) {
   }
 }
 
+void OMPClausePrinter::VisitOMPLinearClause(OMPLinearClause *Node) {
+  if (!Node->varlist_empty()) {
+    OS << "linear";
+    VisitOMPClauseList(Node, '(');
+    if (Node->getStep() != 0) {
+      OS << ": ";
+      Node->getStep()->printPretty(OS, 0, Policy, 0);
+    }
+    OS << ")";
+  }
+}
+
 void OMPClausePrinter::VisitOMPCopyinClause(OMPCopyinClause *Node) {
   if (!Node->varlist_empty()) {
     OS << "copyin";
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index 07ed86a91cd..1a6d1812dca 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -297,6 +297,10 @@ void OMPClauseProfiler::VisitOMPFirstprivateClause(
 void OMPClauseProfiler::VisitOMPSharedClause(const OMPSharedClause *C) {
   VisitOMPClauseList(C);
 }
+void OMPClauseProfiler::VisitOMPLinearClause(const OMPLinearClause *C) {
+  VisitOMPClauseList(C);
+  Profiler->VisitStmt(C->getStep());
+}
 void OMPClauseProfiler::VisitOMPCopyinClause(const OMPCopyinClause *C) {
   VisitOMPClauseList(C);
 }
diff --git a/clang/lib/Basic/OpenMPKinds.cpp b/clang/lib/Basic/OpenMPKinds.cpp
index ec09de1eb3b..6a7f89069a6 100644
--- a/clang/lib/Basic/OpenMPKinds.cpp
+++ b/clang/lib/Basic/OpenMPKinds.cpp
@@ -83,6 +83,7 @@ unsigned clang::getOpenMPSimpleClauseType(OpenMPClauseKind Kind,
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_shared:
+  case OMPC_linear:
   case OMPC_copyin:
   case NUM_OPENMP_CLAUSES:
     break;
@@ -110,6 +111,7 @@ const char *clang::getOpenMPSimpleClauseTypeName(OpenMPClauseKind Kind,
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_shared:
+  case OMPC_linear:
   case OMPC_copyin:
   case NUM_OPENMP_CLAUSES:
     break;
diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index f1b61077b37..bf3753fd814 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -258,7 +258,7 @@ bool Parser::ParseOpenMPSimpleVarList(OpenMPDirectiveKind Kind,
 ///
 ///    clause:
 ///       if-clause | num_threads-clause | safelen-clause | default-clause |
-///       private-clause | firstprivate-clause | shared-clause
+///       private-clause | firstprivate-clause | shared-clause | linear-clause
 ///
 OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
                                      OpenMPClauseKind CKind, bool FirstClause) {
@@ -301,6 +301,7 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_shared:
+  case OMPC_linear:
   case OMPC_copyin:
     Clause = ParseOpenMPVarListClause(CKind);
     break;
@@ -392,10 +393,13 @@ OMPClause *Parser::ParseOpenMPSimpleClause(OpenMPClauseKind Kind) {
 ///       'firstprivate' '(' list ')'
 ///    shared-clause:
 ///       'shared' '(' list ')'
+///    linear-clause:
+///       'linear' '(' list [ ':' linear-step ] ')'
 ///
 OMPClause *Parser::ParseOpenMPVarListClause(OpenMPClauseKind Kind) {
   SourceLocation Loc = Tok.getLocation();
   SourceLocation LOpen = ConsumeToken();
+  SourceLocation ColonLoc = SourceLocation();
   // Parse '('.
   BalancedDelimiterTracker T(*this, tok::l_paren, tok::annot_pragma_openmp_end);
   if (T.expectAndConsume(diag::err_expected_lparen_after,
@@ -404,8 +408,10 @@ OMPClause *Parser::ParseOpenMPVarListClause(OpenMPClauseKind Kind) {
 
   SmallVector<Expr *, 5> Vars;
   bool IsComma = true;
-  while (IsComma || (Tok.isNot(tok::r_paren) &&
+  const bool MayHaveTail = (Kind == OMPC_linear);
+  while (IsComma || (Tok.isNot(tok::r_paren) && Tok.isNot(tok::colon) &&
                      Tok.isNot(tok::annot_pragma_openmp_end))) {
+    ColonProtectionRAIIObject ColonRAII(*this, MayHaveTail);
     // Parse variable
     ExprResult VarExpr = ParseAssignmentExpression();
     if (VarExpr.isUsable()) {
@@ -416,21 +422,34 @@ OMPClause *Parser::ParseOpenMPVarListClause(OpenMPClauseKind Kind) {
     }
     // Skip ',' if any
     IsComma = Tok.is(tok::comma);
-    if (IsComma) {
+    if (IsComma)
       ConsumeToken();
-    } else if (Tok.isNot(tok::r_paren) &&
-               Tok.isNot(tok::annot_pragma_openmp_end)) {
-      Diag(Tok, diag::err_omp_expected_punc)
-        << getOpenMPClauseName(Kind);
-    }
+    else if (Tok.isNot(tok::r_paren) &&
+             Tok.isNot(tok::annot_pragma_openmp_end) &&
+             (!MayHaveTail || Tok.isNot(tok::colon)))
+      Diag(Tok, diag::err_omp_expected_punc) << getOpenMPClauseName(Kind);
+  }
+
+  // Parse ':' linear-step
+  Expr *TailExpr = 0;
+  const bool MustHaveTail = MayHaveTail && Tok.is(tok::colon);
+  if (MustHaveTail) {
+    ColonLoc = Tok.getLocation();
+    ConsumeToken();
+    ExprResult Tail = ParseAssignmentExpression();
+    if (Tail.isUsable())
+      TailExpr = Tail.take();
+    else
+      SkipUntil(tok::comma, tok::r_paren, tok::annot_pragma_openmp_end,
+                StopBeforeMatch);
   }
 
   // Parse ')'.
   T.consumeClose();
-  if (Vars.empty())
+  if (Vars.empty() || (MustHaveTail && !TailExpr))
     return 0;
 
-  return Actions.ActOnOpenMPVarListClause(Kind, Vars, Loc, LOpen,
-                                          Tok.getLocation());
+  return Actions.ActOnOpenMPVarListClause(Kind, Vars, TailExpr, Loc, LOpen,
+                                          ColonLoc, Tok.getLocation());
 }
 
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index b70a9c8dc2b..0c592a61441 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -294,9 +294,10 @@ DSAStackTy::DSAVarData DSAStackTy::getTopDSA(VarDecl *D) {
   if (Kind != OMPD_parallel) {
     if (isOpenMPLocal(D, std::next(Stack.rbegin())) && D->isLocalVarDecl() &&
         (D->getStorageClass() == SC_Auto ||
-         D->getStorageClass() == SC_None))
+         D->getStorageClass() == SC_None)) {
       DVar.CKind = OMPC_private;
       return DVar;
+    }
   }
 
   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
@@ -774,6 +775,7 @@ OMPClause *Sema::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_shared:
+  case OMPC_linear:
   case OMPC_copyin:
   case OMPC_threadprivate:
   case OMPC_unknown:
@@ -929,6 +931,7 @@ OMPClause *Sema::ActOnOpenMPSimpleClause(OpenMPClauseKind Kind,
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_shared:
+  case OMPC_linear:
   case OMPC_copyin:
   case OMPC_threadprivate:
   case OMPC_unknown:
@@ -986,8 +989,10 @@ OMPClause *Sema::ActOnOpenMPDefaultClause(OpenMPDefaultClauseKind Kind,
 
 OMPClause *Sema::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
                                           ArrayRef<Expr *> VarList,
+                                          Expr *TailExpr,
                                           SourceLocation StartLoc,
                                           SourceLocation LParenLoc,
+                                          SourceLocation ColonLoc,
                                           SourceLocation EndLoc) {
   OMPClause *Res = 0;
   switch (Kind) {
@@ -1000,6 +1005,10 @@ OMPClause *Sema::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
   case OMPC_shared:
     Res = ActOnOpenMPSharedClause(VarList, StartLoc, LParenLoc, EndLoc);
     break;
+  case OMPC_linear:
+    Res = ActOnOpenMPLinearClause(VarList, TailExpr, StartLoc, LParenLoc,
+                                  ColonLoc, EndLoc);
+    break;
   case OMPC_copyin:
     Res = ActOnOpenMPCopyinClause(VarList, StartLoc, LParenLoc, EndLoc);
     break;
@@ -1382,6 +1391,135 @@ OMPClause *Sema::ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
   return OMPSharedClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars);
 }
 
+OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
+                                         SourceLocation StartLoc,
+                                         SourceLocation LParenLoc,
+                                         SourceLocation ColonLoc,
+                                         SourceLocation EndLoc) {
+  SmallVector<Expr *, 8> Vars;
+  for (ArrayRef<Expr *>::iterator I = VarList.begin(), E = VarList.end();
+       I != E; ++I) {
+    assert(*I && "NULL expr in OpenMP linear clause.");
+    if (isa<DependentScopeDeclRefExpr>(*I)) {
+      // It will be analyzed later.
+      Vars.push_back(*I);
+      continue;
+    }
+
+    // OpenMP [2.14.3.7, linear clause]
+    // A list item that appears in a linear clause is subject to the private
+    // clause semantics described in Section 2.14.3.3 on page 159 except as
+    // noted. In addition, the value of the new list item on each iteration
+    // of the associated loop(s) corresponds to the value of the original
+    // list item before entering the construct plus the logical number of
+    // the iteration times linear-step.
+
+    SourceLocation ELoc = (*I)->getExprLoc();
+    // OpenMP [2.1, C/C++]
+    //  A list item is a variable name.
+    // OpenMP  [2.14.3.3, Restrictions, p.1]
+    //  A variable that is part of another variable (as an array or
+    //  structure element) cannot appear in a private clause.
+    DeclRefExpr *DE = dyn_cast<DeclRefExpr>(*I);
+    if (!DE || !isa<VarDecl>(DE->getDecl())) {
+      Diag(ELoc, diag::err_omp_expected_var_name) << (*I)->getSourceRange();
+      continue;
+    }
+
+    VarDecl *VD = cast<VarDecl>(DE->getDecl());
+
+    // OpenMP [2.14.3.7, linear clause]
+    //  A list-item cannot appear in more than one linear clause.
+    //  A list-item that appears in a linear clause cannot appear in any
+    //  other data-sharing attribute clause.
+    DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD);
+    if (DVar.RefExpr) {
+      Diag(ELoc, diag::err_omp_wrong_dsa) << getOpenMPClauseName(DVar.CKind)
+                                          << getOpenMPClauseName(OMPC_linear);
+      Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_explicit_dsa)
+          << getOpenMPClauseName(DVar.CKind);
+      continue;
+    }
+
+    QualType QType = VD->getType();
+    if (QType->isDependentType() || QType->isInstantiationDependentType()) {
+      // It will be analyzed later.
+      Vars.push_back(DE);
+      continue;
+    }
+
+    // A variable must not have an incomplete type or a reference type.
+    if (RequireCompleteType(ELoc, QType,
+                            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;
+    }
+
+    // A list item must not be const-qualified.
+    if (QType.isConstant(Context)) {
+      Diag(ELoc, diag::err_omp_const_variable)
+          << getOpenMPClauseName(OMPC_linear);
+      bool IsDecl =
+          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
+      Diag(VD->getLocation(),
+           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
+          << VD;
+      continue;
+    }
+
+    // A list item must be of integral or pointer type.
+    QType = QType.getUnqualifiedType().getCanonicalType();
+    const Type *Ty = QType.getTypePtrOrNull();
+    if (!Ty || (!Ty->isDependentType() && !Ty->isIntegralType(Context) &&
+                !Ty->isPointerType())) {
+      Diag(ELoc, diag::err_omp_linear_expected_int_or_ptr) << QType;
+      bool IsDecl =
+          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
+      Diag(VD->getLocation(),
+           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
+          << VD;
+      continue;
+    }
+
+    DSAStack->addDSA(VD, DE, OMPC_linear);
+    Vars.push_back(DE);
+  }
+
+  if (Vars.empty())
+    return 0;
+
+  Expr *StepExpr = Step;
+  if (Step && !Step->isValueDependent() && !Step->isTypeDependent() &&
+      !Step->isInstantiationDependent() &&
+      !Step->containsUnexpandedParameterPack()) {
+    SourceLocation StepLoc = Step->getLocStart();
+    ExprResult Val = PerformImplicitIntegerConversion(StepLoc, Step);
+    if (Val.isInvalid())
+      return 0;
+    StepExpr = Val.take();
+
+    // Warn about zero linear step (it would be probably better specified as
+    // making corresponding variables 'const').
+    llvm::APSInt Result;
+    if (StepExpr->isIntegerConstantExpr(Result, Context) &&
+        !Result.isNegative() && !Result.isStrictlyPositive())
+      Diag(StepLoc, diag::warn_omp_linear_step_zero) << Vars[0]
+                                                     << (Vars.size() > 1);
+  }
+
+  return OMPLinearClause::Create(Context, StartLoc, LParenLoc, ColonLoc, EndLoc,
+                                 Vars, StepExpr);
+}
+
 OMPClause *Sema::ActOnOpenMPCopyinClause(ArrayRef<Expr *> VarList,
                                          SourceLocation StartLoc,
                                          SourceLocation LParenLoc,
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 22913104d74..f1138918825 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -1382,6 +1382,19 @@ public:
                                              EndLoc);
   }
 
+  /// \brief Build a new OpenMP 'linear' clause.
+  ///
+  /// By default, performs semantic analysis to build the new statement.
+  /// Subclasses may override this routine to provide different behavior.
+  OMPClause *RebuildOMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
+                                    SourceLocation StartLoc,
+                                    SourceLocation LParenLoc,
+                                    SourceLocation ColonLoc,
+                                    SourceLocation EndLoc) {
+    return getSema().ActOnOpenMPLinearClause(VarList, Step, StartLoc, LParenLoc,
+                                             ColonLoc, EndLoc);
+  }
+
   /// \brief Build a new OpenMP 'copyin' clause.
   ///
   /// By default, performs semantic analysis to build the new statement.
@@ -6436,6 +6449,25 @@ TreeTransform<Derived>::TransformOMPSharedClause(OMPSharedClause *C) {
 
 template<typename Derived>
 OMPClause *
+TreeTransform<Derived>::TransformOMPLinearClause(OMPLinearClause *C) {
+  llvm::SmallVector<Expr *, 16> Vars;
+  Vars.reserve(C->varlist_size());
+  for (auto *VE : C->varlists()) {
+    ExprResult EVar = getDerived().TransformExpr(cast<Expr>(VE));
+    if (EVar.isInvalid())
+      return 0;
+    Vars.push_back(EVar.take());
+  }
+  ExprResult Step = getDerived().TransformExpr(C->getStep());
+  if (Step.isInvalid())
+    return 0;
+  return getDerived().RebuildOMPLinearClause(
+      Vars, Step.take(), C->getLocStart(), C->getLParenLoc(), C->getColonLoc(),
+      C->getLocEnd());
+}
+
+template<typename Derived>
+OMPClause *
 TreeTransform<Derived>::TransformOMPCopyinClause(OMPCopyinClause *C) {
   llvm::SmallVector<Expr *, 16> Vars;
   Vars.reserve(C->varlist_size());
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 9a201d0f69b..da652ff8e3f 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -1692,6 +1692,9 @@ OMPClause *OMPClauseReader::readClause() {
   case OMPC_shared:
     C = OMPSharedClause::CreateEmpty(Context, Record[Idx++]);
     break;
+  case OMPC_linear:
+    C = OMPLinearClause::CreateEmpty(Context, Record[Idx++]);
+    break;
   case OMPC_copyin:
     C = OMPCopyinClause::CreateEmpty(Context, Record[Idx++]);
     break;
@@ -1755,6 +1758,18 @@ void OMPClauseReader::VisitOMPSharedClause(OMPSharedClause *C) {
   C->setVarRefs(Vars);
 }
 
+void OMPClauseReader::VisitOMPLinearClause(OMPLinearClause *C) {
+  C->setLParenLoc(Reader->ReadSourceLocation(Record, Idx));
+  C->setColonLoc(Reader->ReadSourceLocation(Record, Idx));
+  unsigned NumVars = C->varlist_size();
+  SmallVector<Expr *, 16> Vars;
+  Vars.reserve(NumVars);
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Reader->Reader.ReadSubExpr());
+  C->setVarRefs(Vars);
+  C->setStep(Reader->Reader.ReadSubExpr());
+}
+
 void OMPClauseReader::VisitOMPCopyinClause(OMPCopyinClause *C) {
   C->setLParenLoc(Reader->ReadSourceLocation(Record, Idx));
   unsigned NumVars = C->varlist_size();
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index bbbd3377cb7..958620636ee 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -1716,6 +1716,15 @@ void OMPClauseWriter::VisitOMPSharedClause(OMPSharedClause *C) {
     Writer->Writer.AddStmt(VE);
 }
 
+void OMPClauseWriter::VisitOMPLinearClause(OMPLinearClause *C) {
+  Record.push_back(C->varlist_size());
+  Writer->Writer.AddSourceLocation(C->getLParenLoc(), Record);
+  Writer->Writer.AddSourceLocation(C->getColonLoc(), Record);
+  for (auto *VE : C->varlists())
+    Writer->Writer.AddStmt(VE);
+  Writer->Writer.AddStmt(C->getStep());
+}
+
 void OMPClauseWriter::VisitOMPCopyinClause(OMPCopyinClause *C) {
   Record.push_back(C->varlist_size());
   Writer->Writer.AddSourceLocation(C->getLParenLoc(), Record);