[OPENMP] Codegen for 'firstprivate' clause.

This patch generates some helper variables that used as private copies of the corresponding original variables inside an OpenMP 'parallel' directive. These generated variables are initialized by copy using values of the original variables (with the copy constructor, if any). For arrays, initializator is generated for single element and in the codegen procedure this initial value is automatically propagated between all elements of the private copy.
In outlined function, references to original variables are replaced by the references to these private helper variables. At the end of the initialization of the private variables an implicit barier is generated by calling __kmpc_barrier(...) runtime function to be sure that all threads were initialized using original values of the variables.
Differential Revision: http://reviews.llvm.org/D5140

llvm-svn: 219306

1 files changed, 84 insertions, 62 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index ff2b2826092..159f1bb08ed 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3902,11 +3902,36 @@ OMPClause *Sema::ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
   return OMPPrivateClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars);
 }
 
+namespace {
+class DiagsUninitializedSeveretyRAII {
+private:
+  DiagnosticsEngine &Diags;
+  SourceLocation SavedLoc;
+  bool IsIgnored;
+
+public:
+  DiagsUninitializedSeveretyRAII(DiagnosticsEngine &Diags, SourceLocation Loc,
+                                 bool IsIgnored)
+      : Diags(Diags), SavedLoc(Loc), IsIgnored(IsIgnored) {
+    if (!IsIgnored) {
+      Diags.setSeverity(/*Diag*/ diag::warn_uninit_self_reference_in_init,
+                        /*Map*/ diag::Severity::Ignored, Loc);
+    }
+  }
+  ~DiagsUninitializedSeveretyRAII() {
+    if (!IsIgnored)
+      Diags.popMappings(SavedLoc);
+  }
+};
+}
+
 OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
                                                SourceLocation StartLoc,
                                                SourceLocation LParenLoc,
                                                SourceLocation EndLoc) {
   SmallVector<Expr *, 8> Vars;
+  SmallVector<Expr *, 8> PrivateCopies;
+  SmallVector<Expr *, 8> Inits;
   bool IsImplicitClause =
       StartLoc.isInvalid() && LParenLoc.isInvalid() && EndLoc.isInvalid();
   auto ImplicitClauseLoc = DSAStack->getConstructLoc();
@@ -3916,11 +3941,13 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
       // It will be analyzed later.
       Vars.push_back(RefExpr);
+      PrivateCopies.push_back(nullptr);
+      Inits.push_back(nullptr);
       continue;
     }
 
-    SourceLocation ELoc = IsImplicitClause ? ImplicitClauseLoc
-                                           : RefExpr->getExprLoc();
+    SourceLocation ELoc =
+        IsImplicitClause ? ImplicitClauseLoc : RefExpr->getExprLoc();
     // OpenMP [2.1, C/C++]
     //  A list item is a variable name.
     // OpenMP  [2.9.3.3, Restrictions, p.1]
@@ -3938,6 +3965,8 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
       // It will be analyzed later.
       Vars.push_back(DE);
+      PrivateCopies.push_back(nullptr);
+      Inits.push_back(nullptr);
       continue;
     }
 
@@ -3971,65 +4000,6 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
     //  clause requires an accessible, unambiguous copy constructor for the
     //  class type.
     Type = Context.getBaseElementType(Type);
-    CXXRecordDecl *RD = getLangOpts().CPlusPlus
-                            ? Type.getNonReferenceType()->getAsCXXRecordDecl()
-                            : nullptr;
-    // FIXME This code must be replaced by actual constructing/destructing of
-    // the firstprivate variable.
-    if (RD) {
-      CXXConstructorDecl *CD = LookupCopyingConstructor(RD, 0);
-      PartialDiagnostic PD =
-          PartialDiagnostic(PartialDiagnostic::NullDiagnostic());
-      if (!CD ||
-          CheckConstructorAccess(ELoc, CD,
-                                 InitializedEntity::InitializeTemporary(Type),
-                                 CD->getAccess(), PD) == AR_inaccessible ||
-          CD->isDeleted()) {
-        if (IsImplicitClause) {
-          Diag(ImplicitClauseLoc,
-               diag::err_omp_task_predetermined_firstprivate_required_method)
-              << 0;
-          Diag(RefExpr->getExprLoc(), diag::note_used_here);
-        } else {
-          Diag(ELoc, diag::err_omp_required_method)
-              << getOpenMPClauseName(OMPC_firstprivate) << 1;
-        }
-        bool IsDecl = VD->isThisDeclarationADefinition(Context) ==
-                      VarDecl::DeclarationOnly;
-        Diag(VD->getLocation(),
-             IsDecl ? diag::note_previous_decl : diag::note_defined_here)
-            << VD;
-        Diag(RD->getLocation(), diag::note_previous_decl) << RD;
-        continue;
-      }
-      MarkFunctionReferenced(ELoc, CD);
-      DiagnoseUseOfDecl(CD, ELoc);
-
-      CXXDestructorDecl *DD = RD->getDestructor();
-      if (DD) {
-        if (CheckDestructorAccess(ELoc, DD, PD) == AR_inaccessible ||
-            DD->isDeleted()) {
-          if (IsImplicitClause) {
-            Diag(ImplicitClauseLoc,
-                 diag::err_omp_task_predetermined_firstprivate_required_method)
-                << 1;
-            Diag(RefExpr->getExprLoc(), diag::note_used_here);
-          } else {
-            Diag(ELoc, diag::err_omp_required_method)
-                << getOpenMPClauseName(OMPC_firstprivate) << 4;
-          }
-          bool IsDecl = VD->isThisDeclarationADefinition(Context) ==
-                        VarDecl::DeclarationOnly;
-          Diag(VD->getLocation(),
-               IsDecl ? diag::note_previous_decl : diag::note_defined_here)
-              << VD;
-          Diag(RD->getLocation(), diag::note_previous_decl) << RD;
-          continue;
-        }
-        MarkFunctionReferenced(ELoc, DD);
-        DiagnoseUseOfDecl(DD, ELoc);
-      }
-    }
 
     // If an implicit firstprivate variable found it was checked already.
     if (!IsImplicitClause) {
@@ -4119,15 +4089,67 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
       }
     }
 
+    Type = Type.getUnqualifiedType();
+    auto VDPrivate = VarDecl::Create(Context, CurContext, DE->getLocStart(),
+                                     ELoc, VD->getIdentifier(), VD->getType(),
+                                     VD->getTypeSourceInfo(), /*S*/ SC_Auto);
+    // Generate helper private variable and initialize it with the value of the
+    // original variable. The address of the original variable is replaced by
+    // the address of the new private variable in the CodeGen. This new variable
+    // is not added to IdResolver, so the code in the OpenMP region uses
+    // original variable for proper diagnostics and variable capturing.
+    Expr *VDInitRefExpr = nullptr;
+    // For arrays generate initializer for single element and replace it by the
+    // original array element in CodeGen.
+    if (DE->getType()->isArrayType()) {
+      auto VDInit = VarDecl::Create(Context, CurContext, DE->getLocStart(),
+                                    ELoc, VD->getIdentifier(), Type,
+                                    VD->getTypeSourceInfo(), /*S*/ SC_Auto);
+      CurContext->addHiddenDecl(VDInit);
+      VDInitRefExpr = DeclRefExpr::Create(
+          Context, /*QualifierLoc*/ NestedNameSpecifierLoc(),
+          /*TemplateKWLoc*/ SourceLocation(), VDInit,
+          /*isEnclosingLocal*/ false, ELoc, Type,
+          /*VK*/ VK_LValue);
+      VDInit->setIsUsed();
+      auto Init = DefaultLvalueConversion(VDInitRefExpr).get();
+      InitializedEntity Entity = InitializedEntity::InitializeVariable(VDInit);
+      InitializationKind Kind = InitializationKind::CreateCopy(ELoc, ELoc);
+
+      InitializationSequence InitSeq(*this, Entity, Kind, Init);
+      ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Init);
+      if (Result.isInvalid())
+        VDPrivate->setInvalidDecl();
+      else
+        VDPrivate->setInit(Result.getAs<Expr>());
+    } else {
+      AddInitializerToDecl(VDPrivate, DefaultLvalueConversion(DE).get(),
+                           /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
+    }
+    if (VDPrivate->isInvalidDecl()) {
+      if (IsImplicitClause) {
+        Diag(DE->getExprLoc(),
+             diag::note_omp_task_predetermined_firstprivate_here);
+      }
+      continue;
+    }
+    CurContext->addDecl(VDPrivate);
+    auto VDPrivateRefExpr = DeclRefExpr::Create(
+        Context, /*QualifierLoc*/ NestedNameSpecifierLoc(),
+        /*TemplateKWLoc*/ SourceLocation(), VDPrivate,
+        /*isEnclosingLocal*/ false, DE->getLocStart(), DE->getType(),
+        /*VK*/ VK_LValue);
     DSAStack->addDSA(VD, DE, OMPC_firstprivate);
     Vars.push_back(DE);
+    PrivateCopies.push_back(VDPrivateRefExpr);
+    Inits.push_back(VDInitRefExpr);
   }
 
   if (Vars.empty())
     return nullptr;
 
   return OMPFirstprivateClause::Create(Context, StartLoc, LParenLoc, EndLoc,
-                                       Vars);
+                                       Vars, PrivateCopies, Inits);
 }
 
 OMPClause *Sema::ActOnOpenMPLastprivateClause(ArrayRef<Expr *> VarList,