2 files changed, 52 insertions, 13 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ad4fea84d3e..f7756ba606c 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1602,10 +1602,8 @@ Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
       }
 
   bool refersToEnclosingScope =
-    (CurContext != D->getDeclContext() &&
-     D->getDeclContext()->isFunctionOrMethod()) ||
-    (isa<VarDecl>(D) &&
-     cast<VarDecl>(D)->isInitCapture());
+      isa<VarDecl>(D) &&
+      NeedToCaptureVariable(cast<VarDecl>(D), NameInfo.getLoc());
 
   DeclRefExpr *E;
   if (isa<VarTemplateSpecializationDecl>(D)) {
@@ -11799,7 +11797,7 @@ static DeclContext *getParentOfCapturingContextOrNull(DeclContext *DC, VarDecl *
                                  const bool Diagnose, Sema &S) {
   if (isa<BlockDecl>(DC) || isa<CapturedDecl>(DC) || isLambdaCallOperator(DC))
     return getLambdaAwareParentOfDeclContext(DC);
-  else {
+  else if (Var->hasLocalStorage()) {
     if (Diagnose)
        diagnoseUncapturableValueReference(S, Loc, Var, DC);
   }
@@ -12241,7 +12239,7 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc,
                               QualType &CaptureType,
                               QualType &DeclRefType,
 						                const unsigned *const FunctionScopeIndexToStopAt) {
-  bool Nested = false;
+  bool Nested = Var->isInitCapture();
   
   DeclContext *DC = CurContext;
   const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt 
@@ -12259,8 +12257,13 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc,
   
   // If the variable is declared in the current context (and is not an 
   // init-capture), there is no need to capture it.
-  if (!Var->isInitCapture() && Var->getDeclContext() == DC) return true;
-  if (!Var->hasLocalStorage()) return true;
+  if (!Nested && Var->getDeclContext() == DC) return true;
+
+  // Capture global variables if it is required to use private copy of this
+  // variable.
+  bool IsGlobal = !Var->hasLocalStorage();
+  if (IsGlobal && !(LangOpts.OpenMP && IsOpenMPCapturedVar(Var)))
+    return true;
 
   // Walk up the stack to determine whether we can capture the variable,
   // performing the "simple" checks that don't depend on type. We stop when
@@ -12281,8 +12284,17 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc,
                                                               ExprLoc, 
                                                               BuildAndDiagnose,
                                                               *this);
-    if (!ParentDC) return true;
-    
+    // We need to check for the parent *first* because, if we *have*
+    // private-captured a global variable, we need to recursively capture it in
+    // intermediate blocks, lambdas, etc.
+    if (!ParentDC) {
+      if (IsGlobal) {
+        FunctionScopesIndex = MaxFunctionScopesIndex - 1;
+        break;
+      }
+      return true;
+    }
+
     FunctionScopeInfo  *FSI = FunctionScopes[FunctionScopesIndex];
     CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FSI);
 
@@ -12508,6 +12520,14 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation Loc,
                             DeclRefType, nullptr);
 }
 
+bool Sema::NeedToCaptureVariable(VarDecl *Var, SourceLocation Loc) {
+  QualType CaptureType;
+  QualType DeclRefType;
+  return !tryCaptureVariable(Var, Loc, TryCapture_Implicit, SourceLocation(),
+                             /*BuildAndDiagnose=*/false, CaptureType,
+                             DeclRefType, nullptr);
+}
+
 QualType Sema::getCapturedDeclRefType(VarDecl *Var, SourceLocation Loc) {
   QualType CaptureType;
   QualType DeclRefType;
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 995054321d3..a1064d68b05 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -551,6 +551,19 @@ void Sema::InitDataSharingAttributesStack() {
 
 #define DSAStack static_cast<DSAStackTy *>(VarDataSharingAttributesStack)
 
+bool Sema::IsOpenMPCapturedVar(VarDecl *VD) {
+  assert(LangOpts.OpenMP && "OpenMP is not allowed");
+  if (DSAStack->getCurrentDirective() != OMPD_unknown) {
+    auto DVarPrivate = DSAStack->getTopDSA(VD, /*FromParent=*/false);
+    if (DVarPrivate.CKind != OMPC_unknown && isOpenMPPrivate(DVarPrivate.CKind))
+      return true;
+    DVarPrivate = DSAStack->hasDSA(VD, isOpenMPPrivate, MatchesAlways(),
+                                   /*FromParent=*/false);
+    return DVarPrivate.CKind != OMPC_unknown;
+  }
+  return false;
+}
+
 void Sema::DestroyDataSharingAttributesStack() { delete DSAStack; }
 
 void Sema::StartOpenMPDSABlock(OpenMPDirectiveKind DKind,
@@ -4378,7 +4391,7 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
       VDInitRefExpr = DeclRefExpr::Create(
           Context, /*QualifierLoc*/ NestedNameSpecifierLoc(),
           /*TemplateKWLoc*/ SourceLocation(), VDInit,
-          /*isEnclosingLocal*/ false, ELoc, Type,
+          /*isEnclosingLocal*/ true, ELoc, Type,
           /*VK*/ VK_LValue);
       VDInit->setIsUsed();
       auto Init = DefaultLvalueConversion(VDInitRefExpr).get();
@@ -4392,8 +4405,14 @@ OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
       else
         VDPrivate->setInit(Result.getAs<Expr>());
     } else {
-      AddInitializerToDecl(VDPrivate, DefaultLvalueConversion(DE).get(),
-                           /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
+      AddInitializerToDecl(
+          VDPrivate, DefaultLvalueConversion(
+                         DeclRefExpr::Create(Context, NestedNameSpecifierLoc(),
+                                             SourceLocation(), DE->getDecl(),
+                                             /*isEnclosingLocal=*/true,
+                                             DE->getExprLoc(), DE->getType(),
+                                             /*VK=*/VK_LValue)).get(),
+          /*DirectInit=*/false, /*TypeMayContainAuto=*/false);
     }
     if (VDPrivate->isInvalidDecl()) {
       if (IsImplicitClause) {