Merge clang, llvm, lld, lldb, compiler-rt and libc++ 5.0.0 release.

MFC r309126 (by emaste):

  Correct lld llvm-tblgen dependency file name

MFC r309169:

  Get rid of separate Subversion mergeinfo properties for llvm-dwarfdump
  and llvm-lto.  The mergeinfo confuses Subversion enormously, and these
  directories will just use the mergeinfo for llvm itself.

MFC r312765:

  Pull in r276136 from upstream llvm trunk (by Wei Mi):

    Use ValueOffsetPair to enhance value reuse during SCEV expansion.

    In D12090, the ExprValueMap was added to reuse existing value during
    SCEV expansion. However, const folding and sext/zext distribution can
    make the reuse still difficult.

    A simplified case is: suppose we know S1 expands to V1 in
    ExprValueMap, and
      S1 = S2 + C_a
      S3 = S2 + C_b
    where C_a and C_b are different SCEVConstants. Then we'd like to
    expand S3 as V1 - C_a + C_b instead of expanding S2 literally. It is
    helpful when S2 is a complex SCEV expr and S2 has no entry in
    ExprValueMap, which is usually caused by the fact that S3 is
    generated from S1 after const folding.

    In order to do that, we represent ExprValueMap as a mapping from SCEV
    to ValueOffsetPair. We will save both S1->{V1, 0} and S2->{V1, C_a}
    into the ExprValueMap when we create SCEV for V1. When S3 is
    expanded, it will first expand S2 to V1 - C_a because of S2->{V1,
    C_a} in the map, then expand S3 to V1 - C_a + C_b.

    Differential Revision: https://reviews.llvm.org/D21313

  This should fix assertion failures when building OpenCV >= 3.1.

  PR:		215649

MFC r312831:

  Revert r312765 for now, since it causes assertions when building
  lang/spidermonkey24.

  Reported by:	antoine
  PR:		215649

MFC r316511 (by jhb):

  Add an implementation of __ffssi2() derived from __ffsdi2().

  Newer versions of GCC include an __ffssi2() symbol in libgcc and the
  compiler can emit calls to it in generated code.  This is true for at
  least GCC 6.2 when compiling world for mips and mips64.

  Reviewed by:	jmallett, dim
  Sponsored by:	DARPA / AFRL
  Differential Revision:	https://reviews.freebsd.org/D10086

MFC r318601 (by adrian):

  [libcompiler-rt] add bswapdi2/bswapsi2

  This is required for mips gcc 6.3 userland to build/run.

  Reviewed by:	emaste, dim
  Approved by:	emaste
  Differential Revision:	https://reviews.freebsd.org/D10838

MFC r318884 (by emaste):

  lldb: map TRAP_CAP to a trace trap

  In the absense of a more specific handler for TRAP_CAP (generated by
  ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
  trap.

  Example usage (testing the bug in PR219173):

  % proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
  ...
  (lldb) run
  Process 12980 launching
  Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
  Process 12980 stopped
  * thread #1, stop reason = trace
      frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
  ...

  In the future we should have LLDB control the trapcap procctl itself
  (as it does with ASLR), as well as report a specific stop reason.
  This change eliminates an assertion failure from LLDB for now.

MFC r319796:

  Remove a few unneeded files from libllvm, libclang and liblldb.

MFC r319885 (by emaste):

  lld: ELF: Fix ICF crash on absolute symbol relocations.

  If two sections contained relocations to absolute symbols with the same
  value we would crash when trying to access their sections. Add a check that
  both symbols point to sections before accessing their sections, and treat
  absolute symbols as equal if their values are equal.

  Obtained from:	LLD commit r292578

MFC r319918:

  Revert r319796 for now, it can cause undefined references when linking
  in some circumstances.

  Reported by:	Shawn Webb <shawn.webb@hardenedbsd.org>

MFC r319957 (by emaste):

  lld: Add armelf emulation mode

  Obtained from:	LLD r305375

MFC r321369:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 (trunk r308421).  Upstream has branched for the 5.0.0 release,
  which should be in about a month.  Please report bugs and regressions,
  so we can get them into the release.

  Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
  support to build; see UPDATING for more information.

MFC r321420:

  Add a few more object files to liblldb, which should solve errors when
  linking the lldb executable in some cases.  In particular, when the
  -ffunction-sections -fdata-sections options are turned off, or
  ineffective.

  Reported by:	Shawn Webb, Mark Millard

MFC r321433:

  Cleanup stale Options.inc files from the previous libllvm build for
  clang 4.0.0.  Otherwise, these can get included before the two newly
  generated ones (which are different) for clang 5.0.0.

  Reported by:	Mark Millard

MFC r321439 (by bdrewery):

  Move llvm Options.inc hack from r321433 for NO_CLEAN to lib/clang/libllvm.

  The files are only ever generated to .OBJDIR, not to WORLDTMP (as a
  sysroot) and are only ever included from a compilation.  So using
  a beforebuild target here removes the file before the compilation
  tries to include it.

MFC r321664:

  Pull in r308891 from upstream llvm trunk (by Benjamin Kramer):

    [CodeGenPrepare] Cut off FindAllMemoryUses if there are too many uses.

    This avoids excessive compile time. The case I'm looking at is
    Function.cpp from an old version of LLVM that still had the giant
    memcmp string matcher in it. Before r308322 this compiled in about 2
    minutes, after it, clang takes infinite* time to compile it. With
    this patch we're at 5 min, which is still bad but this is a
    pathological case.

    The cut off at 20 uses was chosen by looking at other cut-offs in LLVM
    for user scanning. It's probably too high, but does the job and is
    very unlikely to regress anything.

    Fixes PR33900.

    * I'm impatient and aborted after 15 minutes, on the bug report it was
      killed after 2h.

  Pull in r308986 from upstream llvm trunk (by Simon Pilgrim):

    [X86][CGP] Reduce memcmp() expansion to 2 load pairs (PR33914)

    D35067/rL308322 attempted to support up to 4 load pairs for memcmp
    inlining which resulted in regressions for some optimized libc memcmp
    implementations (PR33914).

    Until we can match these more optimal cases, this patch reduces the
    memcmp expansion to a maximum of 2 load pairs (which matches what we
    do for -Os).

    This patch should be considered for the 5.0.0 release branch as well

    Differential Revision: https://reviews.llvm.org/D35830

  These fix a hang (or extremely long compile time) when building older
  LLVM ports.

  Reported by:    antoine
  PR:             219139

MFC r321719:

  Pull in r309503 from upstream clang trunk (by Richard Smith):

    PR33902: Invalidate line number cache when adding more text to
    existing buffer.

    This led to crashes as the line number cache would report a bogus
    line number for a line of code, and we'd try to find a nonexistent
    column within the line when printing diagnostics.

  This fixes an assertion when building the graphics/champlain port.

  Reported by:	antoine, kwm
  PR:		219139

MFC r321723:

  Upgrade our copies of clang, llvm, lld and lldb to r309439 from the
  upstream release_50 branch.  This is just after upstream's 5.0.0-rc1.

MFC r322320:

  Upgrade our copies of clang, llvm and libc++ to r310316 from the
  upstream release_50 branch.

MFC r322326 (by emaste):

  lldb: Make i386-*-freebsd expression work on JIT path

  * Enable i386 ABI creation for freebsd
  * Added an extra argument in ABISysV_i386::PrepareTrivialCall for mmap
    syscall
  * Unlike linux, the last argument of mmap is actually 64-bit(off_t).
    This requires us to push an additional word for the higher order bits.
  * Prior to this change, ktrace dump will show mmap failures due to
    invalid argument coming from the 6th mmap argument.

  Submitted by:	Karnajit Wangkhem
  Differential Revision:	https://reviews.llvm.org/D34776

MFC r322360 (by emaste):

  lldb: Report inferior signals as signals, not exceptions, on FreeBSD

  This is the FreeBSD equivalent of LLVM r238549.

  This serves 2 purposes:

  * LLDB should handle inferior process signals SIGSEGV/SIGILL/SIGBUS/
    SIGFPE the way it is suppose to be handled. Prior to this fix these
    signals will neither create a coredump, nor exit from the debugger
    or work for signal handling scenario.
  * eInvalidCrashReason need not report "unknown crash reason" if we have
    a valid si_signo

  llvm.org/pr23699

  Patch by Karnajit Wangkhem

  Differential Revision:  https://reviews.llvm.org/D35223

  Submitted by:	Karnajit Wangkhem
  Obtained from:	LLVM r310591

MFC r322474 (by emaste):

  lld: Add `-z muldefs` option.

  Obtained from:	LLVM r310757

MFC r322740:

  Upgrade our copies of clang, llvm, lld and libc++ to r311219 from the
  upstream release_50 branch.

MFC r322855:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r311606 from
  the upstream release_50 branch.

  As of this version, lib/msun's trig test should also work correctly
  again (see bug 220989 for more information).

  PR:		220989

MFC r323112:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r312293 from
  the upstream release_50 branch.  This corresponds to 5.0.0 rc4.

  As of this version, the cad/stepcode port should now compile in a more
  reasonable time on i386 (see bug 221836 for more information).

  PR:		221836

MFC r323245:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 release (upstream r312559).

  Release notes for llvm, clang and lld will be available here soon:
  <http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/clang/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/lld/docs/ReleaseNotes.html>

  Relnotes:	yes

1 files changed, 1101 insertions, 326 deletions

diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaOpenMP.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaOpenMP.cpp
index dcd19c8..01f574b 100644
--- a/contrib/llvm/tools/clang/lib/Sema/SemaOpenMP.cpp
+++ b/contrib/llvm/tools/clang/lib/Sema/SemaOpenMP.cpp
@@ -118,7 +118,9 @@ private:
   typedef SmallVector<SharingMapTy, 4> StackTy;
 
   /// \brief Stack of used declaration and their data-sharing attributes.
-  StackTy Stack;
+  DeclSAMapTy Threadprivates;
+  const FunctionScopeInfo *CurrentNonCapturingFunctionScope = nullptr;
+  SmallVector<std::pair<StackTy, const FunctionScopeInfo *>, 4> Stack;
   /// \brief true, if check for DSA must be from parent directive, false, if
   /// from current directive.
   OpenMPClauseKind ClauseKindMode = OMPC_unknown;
@@ -133,8 +135,14 @@ private:
   /// \brief Checks if the variable is a local for OpenMP region.
   bool isOpenMPLocal(VarDecl *D, StackTy::reverse_iterator Iter);
 
+  bool isStackEmpty() const {
+    return Stack.empty() ||
+           Stack.back().second != CurrentNonCapturingFunctionScope ||
+           Stack.back().first.empty();
+  }
+
 public:
-  explicit DSAStackTy(Sema &S) : Stack(1), SemaRef(S) {}
+  explicit DSAStackTy(Sema &S) : SemaRef(S) {}
 
   bool isClauseParsingMode() const { return ClauseKindMode != OMPC_unknown; }
   void setClauseParsingMode(OpenMPClauseKind K) { ClauseKindMode = K; }
@@ -144,13 +152,38 @@ public:
 
   void push(OpenMPDirectiveKind DKind, const DeclarationNameInfo &DirName,
             Scope *CurScope, SourceLocation Loc) {
-    Stack.push_back(SharingMapTy(DKind, DirName, CurScope, Loc));
-    Stack.back().DefaultAttrLoc = Loc;
+    if (Stack.empty() ||
+        Stack.back().second != CurrentNonCapturingFunctionScope)
+      Stack.emplace_back(StackTy(), CurrentNonCapturingFunctionScope);
+    Stack.back().first.emplace_back(DKind, DirName, CurScope, Loc);
+    Stack.back().first.back().DefaultAttrLoc = Loc;
   }
 
   void pop() {
-    assert(Stack.size() > 1 && "Data-sharing attributes stack is empty!");
-    Stack.pop_back();
+    assert(!Stack.back().first.empty() &&
+           "Data-sharing attributes stack is empty!");
+    Stack.back().first.pop_back();
+  }
+
+  /// Start new OpenMP region stack in new non-capturing function.
+  void pushFunction() {
+    const FunctionScopeInfo *CurFnScope = SemaRef.getCurFunction();
+    assert(!isa<CapturingScopeInfo>(CurFnScope));
+    CurrentNonCapturingFunctionScope = CurFnScope;
+  }
+  /// Pop region stack for non-capturing function.
+  void popFunction(const FunctionScopeInfo *OldFSI) {
+    if (!Stack.empty() && Stack.back().second == OldFSI) {
+      assert(Stack.back().first.empty());
+      Stack.pop_back();
+    }
+    CurrentNonCapturingFunctionScope = nullptr;
+    for (const FunctionScopeInfo *FSI : llvm::reverse(SemaRef.FunctionScopes)) {
+      if (!isa<CapturingScopeInfo>(FSI)) {
+        CurrentNonCapturingFunctionScope = FSI;
+        break;
+      }
+    }
   }
 
   void addCriticalWithHint(OMPCriticalDirective *D, llvm::APSInt Hint) {
@@ -229,31 +262,35 @@ public:
 
   /// \brief Returns currently analyzed directive.
   OpenMPDirectiveKind getCurrentDirective() const {
-    return Stack.back().Directive;
+    return isStackEmpty() ? OMPD_unknown : Stack.back().first.back().Directive;
   }
   /// \brief Returns parent directive.
   OpenMPDirectiveKind getParentDirective() const {
-    if (Stack.size() > 2)
-      return Stack[Stack.size() - 2].Directive;
-    return OMPD_unknown;
+    if (isStackEmpty() || Stack.back().first.size() == 1)
+      return OMPD_unknown;
+    return std::next(Stack.back().first.rbegin())->Directive;
   }
 
   /// \brief Set default data sharing attribute to none.
   void setDefaultDSANone(SourceLocation Loc) {
-    Stack.back().DefaultAttr = DSA_none;
-    Stack.back().DefaultAttrLoc = Loc;
+    assert(!isStackEmpty());
+    Stack.back().first.back().DefaultAttr = DSA_none;
+    Stack.back().first.back().DefaultAttrLoc = Loc;
   }
   /// \brief Set default data sharing attribute to shared.
   void setDefaultDSAShared(SourceLocation Loc) {
-    Stack.back().DefaultAttr = DSA_shared;
-    Stack.back().DefaultAttrLoc = Loc;
+    assert(!isStackEmpty());
+    Stack.back().first.back().DefaultAttr = DSA_shared;
+    Stack.back().first.back().DefaultAttrLoc = Loc;
   }
 
   DefaultDataSharingAttributes getDefaultDSA() const {
-    return Stack.back().DefaultAttr;
+    return isStackEmpty() ? DSA_unspecified
+                          : Stack.back().first.back().DefaultAttr;
   }
   SourceLocation getDefaultDSALocation() const {
-    return Stack.back().DefaultAttrLoc;
+    return isStackEmpty() ? SourceLocation()
+                          : Stack.back().first.back().DefaultAttrLoc;
   }
 
   /// \brief Checks if the specified variable is a threadprivate.
@@ -264,52 +301,64 @@ public:
 
   /// \brief Marks current region as ordered (it has an 'ordered' clause).
   void setOrderedRegion(bool IsOrdered, Expr *Param) {
-    Stack.back().OrderedRegion.setInt(IsOrdered);
-    Stack.back().OrderedRegion.setPointer(Param);
+    assert(!isStackEmpty());
+    Stack.back().first.back().OrderedRegion.setInt(IsOrdered);
+    Stack.back().first.back().OrderedRegion.setPointer(Param);
   }
   /// \brief Returns true, if parent region is ordered (has associated
   /// 'ordered' clause), false - otherwise.
   bool isParentOrderedRegion() const {
-    if (Stack.size() > 2)
-      return Stack[Stack.size() - 2].OrderedRegion.getInt();
-    return false;
+    if (isStackEmpty() || Stack.back().first.size() == 1)
+      return false;
+    return std::next(Stack.back().first.rbegin())->OrderedRegion.getInt();
   }
   /// \brief Returns optional parameter for the ordered region.
   Expr *getParentOrderedRegionParam() const {
-    if (Stack.size() > 2)
-      return Stack[Stack.size() - 2].OrderedRegion.getPointer();
-    return nullptr;
+    if (isStackEmpty() || Stack.back().first.size() == 1)
+      return nullptr;
+    return std::next(Stack.back().first.rbegin())->OrderedRegion.getPointer();
   }
   /// \brief Marks current region as nowait (it has a 'nowait' clause).
   void setNowaitRegion(bool IsNowait = true) {
-    Stack.back().NowaitRegion = IsNowait;
+    assert(!isStackEmpty());
+    Stack.back().first.back().NowaitRegion = IsNowait;
   }
   /// \brief Returns true, if parent region is nowait (has associated
   /// 'nowait' clause), false - otherwise.
   bool isParentNowaitRegion() const {
-    if (Stack.size() > 2)
-      return Stack[Stack.size() - 2].NowaitRegion;
-    return false;
+    if (isStackEmpty() || Stack.back().first.size() == 1)
+      return false;
+    return std::next(Stack.back().first.rbegin())->NowaitRegion;
   }
   /// \brief Marks parent region as cancel region.
   void setParentCancelRegion(bool Cancel = true) {
-    if (Stack.size() > 2)
-      Stack[Stack.size() - 2].CancelRegion =
-          Stack[Stack.size() - 2].CancelRegion || Cancel;
+    if (!isStackEmpty() && Stack.back().first.size() > 1) {
+      auto &StackElemRef = *std::next(Stack.back().first.rbegin());
+      StackElemRef.CancelRegion |= StackElemRef.CancelRegion || Cancel;
+    }
   }
   /// \brief Return true if current region has inner cancel construct.
-  bool isCancelRegion() const { return Stack.back().CancelRegion; }
+  bool isCancelRegion() const {
+    return isStackEmpty() ? false : Stack.back().first.back().CancelRegion;
+  }
 
   /// \brief Set collapse value for the region.
-  void setAssociatedLoops(unsigned Val) { Stack.back().AssociatedLoops = Val; }
+  void setAssociatedLoops(unsigned Val) {
+    assert(!isStackEmpty());
+    Stack.back().first.back().AssociatedLoops = Val;
+  }
   /// \brief Return collapse value for region.
-  unsigned getAssociatedLoops() const { return Stack.back().AssociatedLoops; }
+  unsigned getAssociatedLoops() const {
+    return isStackEmpty() ? 0 : Stack.back().first.back().AssociatedLoops;
+  }
 
   /// \brief Marks current target region as one with closely nested teams
   /// region.
   void setParentTeamsRegionLoc(SourceLocation TeamsRegionLoc) {
-    if (Stack.size() > 2)
-      Stack[Stack.size() - 2].InnerTeamsRegionLoc = TeamsRegionLoc;
+    if (!isStackEmpty() && Stack.back().first.size() > 1) {
+      std::next(Stack.back().first.rbegin())->InnerTeamsRegionLoc =
+          TeamsRegionLoc;
+    }
   }
   /// \brief Returns true, if current region has closely nested teams region.
   bool hasInnerTeamsRegion() const {
@@ -317,14 +366,20 @@ public:
   }
   /// \brief Returns location of the nested teams region (if any).
   SourceLocation getInnerTeamsRegionLoc() const {
-    if (Stack.size() > 1)
-      return Stack.back().InnerTeamsRegionLoc;
-    return SourceLocation();
+    return isStackEmpty() ? SourceLocation()
+                          : Stack.back().first.back().InnerTeamsRegionLoc;
   }
 
-  Scope *getCurScope() const { return Stack.back().CurScope; }
-  Scope *getCurScope() { return Stack.back().CurScope; }
-  SourceLocation getConstructLoc() { return Stack.back().ConstructLoc; }
+  Scope *getCurScope() const {
+    return isStackEmpty() ? nullptr : Stack.back().first.back().CurScope;
+  }
+  Scope *getCurScope() {
+    return isStackEmpty() ? nullptr : Stack.back().first.back().CurScope;
+  }
+  SourceLocation getConstructLoc() {
+    return isStackEmpty() ? SourceLocation()
+                          : Stack.back().first.back().ConstructLoc;
+  }
 
   /// Do the check specified in \a Check to all component lists and return true
   /// if any issue is found.
@@ -333,8 +388,10 @@ public:
       const llvm::function_ref<
           bool(OMPClauseMappableExprCommon::MappableExprComponentListRef,
                OpenMPClauseKind)> &Check) {
-    auto SI = Stack.rbegin();
-    auto SE = Stack.rend();
+    if (isStackEmpty())
+      return false;
+    auto SI = Stack.back().first.rbegin();
+    auto SE = Stack.back().first.rend();
 
     if (SI == SE)
       return false;
@@ -355,15 +412,39 @@ public:
     return false;
   }
 
+  /// Do the check specified in \a Check to all component lists at a given level
+  /// and return true if any issue is found.
+  bool checkMappableExprComponentListsForDeclAtLevel(
+      ValueDecl *VD, unsigned Level,
+      const llvm::function_ref<
+          bool(OMPClauseMappableExprCommon::MappableExprComponentListRef,
+               OpenMPClauseKind)> &Check) {
+    if (isStackEmpty())
+      return false;
+
+    auto StartI = Stack.back().first.begin();
+    auto EndI = Stack.back().first.end();
+    if (std::distance(StartI, EndI) <= (int)Level)
+      return false;
+    std::advance(StartI, Level);
+
+    auto MI = StartI->MappedExprComponents.find(VD);
+    if (MI != StartI->MappedExprComponents.end())
+      for (auto &L : MI->second.Components)
+        if (Check(L, MI->second.Kind))
+          return true;
+    return false;
+  }
+
   /// Create a new mappable expression component list associated with a given
   /// declaration and initialize it with the provided list of components.
   void addMappableExpressionComponents(
       ValueDecl *VD,
       OMPClauseMappableExprCommon::MappableExprComponentListRef Components,
       OpenMPClauseKind WhereFoundClauseKind) {
-    assert(Stack.size() > 1 &&
+    assert(!isStackEmpty() &&
            "Not expecting to retrieve components from a empty stack!");
-    auto &MEC = Stack.back().MappedExprComponents[VD];
+    auto &MEC = Stack.back().first.back().MappedExprComponents[VD];
     // Create new entry and append the new components there.
     MEC.Components.resize(MEC.Components.size() + 1);
     MEC.Components.back().append(Components.begin(), Components.end());
@@ -371,23 +452,25 @@ public:
   }
 
   unsigned getNestingLevel() const {
-    assert(Stack.size() > 1);
-    return Stack.size() - 2;
+    assert(!isStackEmpty());
+    return Stack.back().first.size() - 1;
   }
   void addDoacrossDependClause(OMPDependClause *C, OperatorOffsetTy &OpsOffs) {
-    assert(Stack.size() > 2);
-    assert(isOpenMPWorksharingDirective(Stack[Stack.size() - 2].Directive));
-    Stack[Stack.size() - 2].DoacrossDepends.insert({C, OpsOffs});
+    assert(!isStackEmpty() && Stack.back().first.size() > 1);
+    auto &StackElem = *std::next(Stack.back().first.rbegin());
+    assert(isOpenMPWorksharingDirective(StackElem.Directive));
+    StackElem.DoacrossDepends.insert({C, OpsOffs});
   }
   llvm::iterator_range<DoacrossDependMapTy::const_iterator>
   getDoacrossDependClauses() const {
-    assert(Stack.size() > 1);
-    if (isOpenMPWorksharingDirective(Stack[Stack.size() - 1].Directive)) {
-      auto &Ref = Stack[Stack.size() - 1].DoacrossDepends;
+    assert(!isStackEmpty());
+    auto &StackElem = Stack.back().first.back();
+    if (isOpenMPWorksharingDirective(StackElem.Directive)) {
+      auto &Ref = StackElem.DoacrossDepends;
       return llvm::make_range(Ref.begin(), Ref.end());
     }
-    return llvm::make_range(Stack[0].DoacrossDepends.end(),
-                            Stack[0].DoacrossDepends.end());
+    return llvm::make_range(StackElem.DoacrossDepends.end(),
+                            StackElem.DoacrossDepends.end());
   }
 };
 bool isParallelOrTaskRegion(OpenMPDirectiveKind DKind) {
@@ -416,7 +499,7 @@ DSAStackTy::DSAVarData DSAStackTy::getDSA(StackTy::reverse_iterator &Iter,
   auto *VD = dyn_cast<VarDecl>(D);
   auto *FD = dyn_cast<FieldDecl>(D);
   DSAVarData DVar;
-  if (Iter == std::prev(Stack.rend())) {
+  if (isStackEmpty() || Iter == Stack.back().first.rend()) {
     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
     // in a region but not in construct]
     //  File-scope or namespace-scope variables referenced in called routines
@@ -490,8 +573,9 @@ DSAStackTy::DSAVarData DSAStackTy::getDSA(StackTy::reverse_iterator &Iter,
     //  bound to the current team is shared.
     if (isOpenMPTaskingDirective(DVar.DKind)) {
       DSAVarData DVarTemp;
-      for (StackTy::reverse_iterator I = std::next(Iter), EE = Stack.rend();
-           I != EE; ++I) {
+      auto I = Iter, E = Stack.back().first.rend();
+      do {
+        ++I;
         // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables
         // Referenced in a Construct, implicitly determined, p.6]
         //  In a task construct, if no default clause is present, a variable
@@ -503,9 +587,7 @@ DSAStackTy::DSAVarData DSAStackTy::getDSA(StackTy::reverse_iterator &Iter,
           DVar.CKind = OMPC_firstprivate;
           return DVar;
         }
-        if (isParallelOrTaskRegion(I->Directive))
-          break;
-      }
+      } while (I != E && !isParallelOrTaskRegion(I->Directive));
       DVar.CKind =
           (DVarTemp.CKind == OMPC_unknown) ? OMPC_firstprivate : OMPC_shared;
       return DVar;
@@ -520,12 +602,13 @@ DSAStackTy::DSAVarData DSAStackTy::getDSA(StackTy::reverse_iterator &Iter,
 }
 
 Expr *DSAStackTy::addUniqueAligned(ValueDecl *D, Expr *NewDE) {
-  assert(Stack.size() > 1 && "Data sharing attributes stack is empty");
+  assert(!isStackEmpty() && "Data sharing attributes stack is empty");
   D = getCanonicalDecl(D);
-  auto It = Stack.back().AlignedMap.find(D);
-  if (It == Stack.back().AlignedMap.end()) {
+  auto &StackElem = Stack.back().first.back();
+  auto It = StackElem.AlignedMap.find(D);
+  if (It == StackElem.AlignedMap.end()) {
     assert(NewDE && "Unexpected nullptr expr to be added into aligned map");
-    Stack.back().AlignedMap[D] = NewDE;
+    StackElem.AlignedMap[D] = NewDE;
     return nullptr;
   } else {
     assert(It->second && "Unexpected nullptr expr in the aligned map");
@@ -535,35 +618,43 @@ Expr *DSAStackTy::addUniqueAligned(ValueDecl *D, Expr *NewDE) {
 }
 
 void DSAStackTy::addLoopControlVariable(ValueDecl *D, VarDecl *Capture) {
-  assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
+  assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
   D = getCanonicalDecl(D);
-  Stack.back().LCVMap.insert(
-      std::make_pair(D, LCDeclInfo(Stack.back().LCVMap.size() + 1, Capture)));
+  auto &StackElem = Stack.back().first.back();
+  StackElem.LCVMap.insert(
+      {D, LCDeclInfo(StackElem.LCVMap.size() + 1, Capture)});
 }
 
 DSAStackTy::LCDeclInfo DSAStackTy::isLoopControlVariable(ValueDecl *D) {
-  assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
+  assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
   D = getCanonicalDecl(D);
-  return Stack.back().LCVMap.count(D) > 0 ? Stack.back().LCVMap[D]
-                                          : LCDeclInfo(0, nullptr);
+  auto &StackElem = Stack.back().first.back();
+  auto It = StackElem.LCVMap.find(D);
+  if (It != StackElem.LCVMap.end())
+    return It->second;
+  return {0, nullptr};
 }
 
 DSAStackTy::LCDeclInfo DSAStackTy::isParentLoopControlVariable(ValueDecl *D) {
-  assert(Stack.size() > 2 && "Data-sharing attributes stack is empty");
+  assert(!isStackEmpty() && Stack.back().first.size() > 1 &&
+         "Data-sharing attributes stack is empty");
   D = getCanonicalDecl(D);
-  return Stack[Stack.size() - 2].LCVMap.count(D) > 0
-             ? Stack[Stack.size() - 2].LCVMap[D]
-             : LCDeclInfo(0, nullptr);
+  auto &StackElem = *std::next(Stack.back().first.rbegin());
+  auto It = StackElem.LCVMap.find(D);
+  if (It != StackElem.LCVMap.end())
+    return It->second;
+  return {0, nullptr};
 }
 
 ValueDecl *DSAStackTy::getParentLoopControlVariable(unsigned I) {
-  assert(Stack.size() > 2 && "Data-sharing attributes stack is empty");
-  if (Stack[Stack.size() - 2].LCVMap.size() < I)
+  assert(!isStackEmpty() && Stack.back().first.size() > 1 &&
+         "Data-sharing attributes stack is empty");
+  auto &StackElem = *std::next(Stack.back().first.rbegin());
+  if (StackElem.LCVMap.size() < I)
     return nullptr;
-  for (auto &Pair : Stack[Stack.size() - 2].LCVMap) {
+  for (auto &Pair : StackElem.LCVMap)
     if (Pair.second.first == I)
       return Pair.first;
-  }
   return nullptr;
 }
 
@@ -571,13 +662,13 @@ void DSAStackTy::addDSA(ValueDecl *D, Expr *E, OpenMPClauseKind A,
                         DeclRefExpr *PrivateCopy) {
   D = getCanonicalDecl(D);
   if (A == OMPC_threadprivate) {
-    auto &Data = Stack[0].SharingMap[D];
+    auto &Data = Threadprivates[D];
     Data.Attributes = A;
     Data.RefExpr.setPointer(E);
     Data.PrivateCopy = nullptr;
   } else {
-    assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
-    auto &Data = Stack.back().SharingMap[D];
+    assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
+    auto &Data = Stack.back().first.back().SharingMap[D];
     assert(Data.Attributes == OMPC_unknown || (A == Data.Attributes) ||
            (A == OMPC_firstprivate && Data.Attributes == OMPC_lastprivate) ||
            (A == OMPC_lastprivate && Data.Attributes == OMPC_firstprivate) ||
@@ -592,7 +683,7 @@ void DSAStackTy::addDSA(ValueDecl *D, Expr *E, OpenMPClauseKind A,
     Data.RefExpr.setPointerAndInt(E, IsLastprivate);
     Data.PrivateCopy = PrivateCopy;
     if (PrivateCopy) {
-      auto &Data = Stack.back().SharingMap[PrivateCopy->getDecl()];
+      auto &Data = Stack.back().first.back().SharingMap[PrivateCopy->getDecl()];
       Data.Attributes = A;
       Data.RefExpr.setPointerAndInt(PrivateCopy, IsLastprivate);
       Data.PrivateCopy = nullptr;
@@ -602,19 +693,17 @@ void DSAStackTy::addDSA(ValueDecl *D, Expr *E, OpenMPClauseKind A,
 
 bool DSAStackTy::isOpenMPLocal(VarDecl *D, StackTy::reverse_iterator Iter) {
   D = D->getCanonicalDecl();
-  if (Stack.size() > 2) {
-    reverse_iterator I = Iter, E = std::prev(Stack.rend());
+  if (!isStackEmpty() && Stack.back().first.size() > 1) {
+    reverse_iterator I = Iter, E = Stack.back().first.rend();
     Scope *TopScope = nullptr;
-    while (I != E && !isParallelOrTaskRegion(I->Directive)) {
+    while (I != E && !isParallelOrTaskRegion(I->Directive))
       ++I;
-    }
     if (I == E)
       return false;
     TopScope = I->CurScope ? I->CurScope->getParent() : nullptr;
     Scope *CurScope = getCurScope();
-    while (CurScope != TopScope && !CurScope->isDeclScope(D)) {
+    while (CurScope != TopScope && !CurScope->isDeclScope(D))
       CurScope = CurScope->getParent();
-    }
     return CurScope != TopScope;
   }
   return false;
@@ -665,16 +754,16 @@ DSAStackTy::DSAVarData DSAStackTy::getTopDSA(ValueDecl *D, bool FromParent) {
                                D->getLocation()),
            OMPC_threadprivate);
   }
-  if (Stack[0].SharingMap.count(D)) {
-    DVar.RefExpr = Stack[0].SharingMap[D].RefExpr.getPointer();
+  auto TI = Threadprivates.find(D);
+  if (TI != Threadprivates.end()) {
+    DVar.RefExpr = TI->getSecond().RefExpr.getPointer();
     DVar.CKind = OMPC_threadprivate;
     return DVar;
   }
 
-  if (Stack.size() == 1) {
+  if (isStackEmpty())
     // Not in OpenMP execution region and top scope was already checked.
     return DVar;
-  }
 
   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
   // in a Construct, C/C++, predetermined, p.4]
@@ -722,11 +811,10 @@ DSAStackTy::DSAVarData DSAStackTy::getTopDSA(ValueDecl *D, bool FromParent) {
 
   // Explicitly specified attributes and local variables with predetermined
   // attributes.
-  auto StartI = std::next(Stack.rbegin());
-  auto EndI = std::prev(Stack.rend());
-  if (FromParent && StartI != EndI) {
+  auto StartI = std::next(Stack.back().first.rbegin());
+  auto EndI = Stack.back().first.rend();
+  if (FromParent && StartI != EndI)
     StartI = std::next(StartI);
-  }
   auto I = std::prev(StartI);
   if (I->SharingMap.count(D)) {
     DVar.RefExpr = I->SharingMap[D].RefExpr.getPointer();
@@ -740,12 +828,15 @@ DSAStackTy::DSAVarData DSAStackTy::getTopDSA(ValueDecl *D, bool FromParent) {
 
 DSAStackTy::DSAVarData DSAStackTy::getImplicitDSA(ValueDecl *D,
                                                   bool FromParent) {
+  if (isStackEmpty()) {
+    StackTy::reverse_iterator I;
+    return getDSA(I, D);
+  }
   D = getCanonicalDecl(D);
-  auto StartI = Stack.rbegin();
-  auto EndI = std::prev(Stack.rend());
-  if (FromParent && StartI != EndI) {
+  auto StartI = Stack.back().first.rbegin();
+  auto EndI = Stack.back().first.rend();
+  if (FromParent && StartI != EndI)
     StartI = std::next(StartI);
-  }
   return getDSA(StartI, D);
 }
 
@@ -754,33 +845,37 @@ DSAStackTy::hasDSA(ValueDecl *D,
                    const llvm::function_ref<bool(OpenMPClauseKind)> &CPred,
                    const llvm::function_ref<bool(OpenMPDirectiveKind)> &DPred,
                    bool FromParent) {
+  if (isStackEmpty())
+    return {};
   D = getCanonicalDecl(D);
-  auto StartI = std::next(Stack.rbegin());
-  auto EndI = Stack.rend();
-  if (FromParent && StartI != EndI) {
-    StartI = std::next(StartI);
-  }
-  for (auto I = StartI, EE = EndI; I != EE; ++I) {
+  auto I = (FromParent && Stack.back().first.size() > 1)
+               ? std::next(Stack.back().first.rbegin())
+               : Stack.back().first.rbegin();
+  auto EndI = Stack.back().first.rend();
+  while (std::distance(I, EndI) > 1) {
+    std::advance(I, 1);
     if (!DPred(I->Directive) && !isParallelOrTaskRegion(I->Directive))
       continue;
     DSAVarData DVar = getDSA(I, D);
     if (CPred(DVar.CKind))
       return DVar;
   }
-  return DSAVarData();
+  return {};
 }
 
 DSAStackTy::DSAVarData DSAStackTy::hasInnermostDSA(
     ValueDecl *D, const llvm::function_ref<bool(OpenMPClauseKind)> &CPred,
     const llvm::function_ref<bool(OpenMPDirectiveKind)> &DPred,
     bool FromParent) {
+  if (isStackEmpty())
+    return {};
   D = getCanonicalDecl(D);
-  auto StartI = std::next(Stack.rbegin());
-  auto EndI = Stack.rend();
+  auto StartI = std::next(Stack.back().first.rbegin());
+  auto EndI = Stack.back().first.rend();
   if (FromParent && StartI != EndI)
     StartI = std::next(StartI);
   if (StartI == EndI || !DPred(StartI->Directive))
-    return DSAVarData();
+    return {};
   DSAVarData DVar = getDSA(StartI, D);
   return CPred(DVar.CKind) ? DVar : DSAVarData();
 }
@@ -790,9 +885,11 @@ bool DSAStackTy::hasExplicitDSA(
     unsigned Level, bool NotLastprivate) {
   if (CPred(ClauseKindMode))
     return true;
+  if (isStackEmpty())
+    return false;
   D = getCanonicalDecl(D);
-  auto StartI = std::next(Stack.begin());
-  auto EndI = Stack.end();
+  auto StartI = Stack.back().first.begin();
+  auto EndI = Stack.back().first.end();
   if (std::distance(StartI, EndI) <= (int)Level)
     return false;
   std::advance(StartI, Level);
@@ -805,8 +902,10 @@ bool DSAStackTy::hasExplicitDSA(
 bool DSAStackTy::hasExplicitDirective(
     const llvm::function_ref<bool(OpenMPDirectiveKind)> &DPred,
     unsigned Level) {
-  auto StartI = std::next(Stack.begin());
-  auto EndI = Stack.end();
+  if (isStackEmpty())
+    return false;
+  auto StartI = Stack.back().first.begin();
+  auto EndI = Stack.back().first.end();
   if (std::distance(StartI, EndI) <= (int)Level)
     return false;
   std::advance(StartI, Level);
@@ -819,13 +918,12 @@ bool DSAStackTy::hasDirective(
         &DPred,
     bool FromParent) {
   // We look only in the enclosing region.
-  if (Stack.size() < 2)
+  if (isStackEmpty())
     return false;
-  auto StartI = std::next(Stack.rbegin());
-  auto EndI = std::prev(Stack.rend());
-  if (FromParent && StartI != EndI) {
+  auto StartI = std::next(Stack.back().first.rbegin());
+  auto EndI = Stack.back().first.rend();
+  if (FromParent && StartI != EndI)
     StartI = std::next(StartI);
-  }
   for (auto I = StartI, EE = EndI; I != EE; ++I) {
     if (DPred(I->Directive, I->DirectiveName, I->ConstructLoc))
       return true;
@@ -839,6 +937,14 @@ void Sema::InitDataSharingAttributesStack() {
 
 #define DSAStack static_cast<DSAStackTy *>(VarDataSharingAttributesStack)
 
+void Sema::pushOpenMPFunctionRegion() {
+  DSAStack->pushFunction();
+}
+
+void Sema::popOpenMPFunctionRegion(const FunctionScopeInfo *OldFSI) {
+  DSAStack->popFunction(OldFSI);
+}
+
 bool Sema::IsOpenMPCapturedByRef(ValueDecl *D, unsigned Level) {
   assert(LangOpts.OpenMP && "OpenMP is not allowed");
 
@@ -912,9 +1018,8 @@ bool Sema::IsOpenMPCapturedByRef(ValueDecl *D, unsigned Level) {
     bool IsVariableUsedInMapClause = false;
     bool IsVariableAssociatedWithSection = false;
 
-    DSAStack->checkMappableExprComponentListsForDecl(
-        D, /*CurrentRegionOnly=*/true,
-        [&](OMPClauseMappableExprCommon::MappableExprComponentListRef
+    DSAStack->checkMappableExprComponentListsForDeclAtLevel(
+        D, Level, [&](OMPClauseMappableExprCommon::MappableExprComponentListRef
                 MapExprComponents,
             OpenMPClauseKind WhereFoundClauseKind) {
           // Only the map clause information influences how a variable is
@@ -1050,7 +1155,8 @@ void Sema::StartOpenMPDSABlock(OpenMPDirectiveKind DKind,
                                const DeclarationNameInfo &DirName,
                                Scope *CurScope, SourceLocation Loc) {
   DSAStack->push(DKind, DirName, CurScope, Loc);
-  PushExpressionEvaluationContext(PotentiallyEvaluated);
+  PushExpressionEvaluationContext(
+      ExpressionEvaluationContext::PotentiallyEvaluated);
 }
 
 void Sema::StartOpenMPClause(OpenMPClauseKind K) {
@@ -1594,8 +1700,7 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
   case OMPD_parallel_for:
   case OMPD_parallel_for_simd:
   case OMPD_parallel_sections:
-  case OMPD_teams:
-  case OMPD_target_teams: {
+  case OMPD_teams: {
     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
     QualType KmpInt32PtrTy =
         Context.getPointerType(KmpInt32Ty).withConst().withRestrict();
@@ -1608,6 +1713,28 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
                              Params);
     break;
   }
+  case OMPD_target_teams:
+  case OMPD_target_parallel: {
+    Sema::CapturedParamNameType ParamsTarget[] = {
+        std::make_pair(StringRef(), QualType()) // __context with shared vars
+    };
+    // Start a captured region for 'target' with no implicit parameters.
+    ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
+                             ParamsTarget);
+    QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
+    QualType KmpInt32PtrTy =
+        Context.getPointerType(KmpInt32Ty).withConst().withRestrict();
+    Sema::CapturedParamNameType ParamsTeamsOrParallel[] = {
+        std::make_pair(".global_tid.", KmpInt32PtrTy),
+        std::make_pair(".bound_tid.", KmpInt32PtrTy),
+        std::make_pair(StringRef(), QualType()) // __context with shared vars
+    };
+    // Start a captured region for 'teams' or 'parallel'.  Both regions have
+    // the same implicit parameters.
+    ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
+                             ParamsTeamsOrParallel);
+    break;
+  }
   case OMPD_simd:
   case OMPD_for:
   case OMPD_for_simd:
@@ -1622,7 +1749,6 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
   case OMPD_atomic:
   case OMPD_target_data:
   case OMPD_target:
-  case OMPD_target_parallel:
   case OMPD_target_parallel_for:
   case OMPD_target_parallel_for_simd:
   case OMPD_target_simd: {
@@ -1681,6 +1807,8 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
         std::make_pair(".lb.", KmpUInt64Ty),
         std::make_pair(".ub.", KmpUInt64Ty), std::make_pair(".st.", KmpInt64Ty),
         std::make_pair(".liter.", KmpInt32Ty),
+        std::make_pair(".reductions.",
+                       Context.VoidPtrTy.withConst().withRestrict()),
         std::make_pair(StringRef(), QualType()) // __context with shared vars
     };
     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
@@ -1737,6 +1865,12 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
   }
 }
 
+int Sema::getOpenMPCaptureLevels(OpenMPDirectiveKind DKind) {
+  SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
+  getOpenMPCaptureRegions(CaptureRegions, DKind);
+  return CaptureRegions.size();
+}
+
 static OMPCapturedExprDecl *buildCaptureDecl(Sema &S, IdentifierInfo *Id,
                                              Expr *CaptureExpr, bool WithInit,
                                              bool AsExpression) {
@@ -1796,16 +1930,49 @@ static ExprResult buildCapture(Sema &S, Expr *CaptureExpr, DeclRefExpr *&Ref) {
   return CaptureExpr->isGLValue() ? Res : S.DefaultLvalueConversion(Res.get());
 }
 
+namespace {
+// OpenMP directives parsed in this section are represented as a
+// CapturedStatement with an associated statement.  If a syntax error
+// is detected during the parsing of the associated statement, the
+// compiler must abort processing and close the CapturedStatement.
+//
+// Combined directives such as 'target parallel' have more than one
+// nested CapturedStatements.  This RAII ensures that we unwind out
+// of all the nested CapturedStatements when an error is found.
+class CaptureRegionUnwinderRAII {
+private:
+  Sema &S;
+  bool &ErrorFound;
+  OpenMPDirectiveKind DKind;
+
+public:
+  CaptureRegionUnwinderRAII(Sema &S, bool &ErrorFound,
+                            OpenMPDirectiveKind DKind)
+      : S(S), ErrorFound(ErrorFound), DKind(DKind) {}
+  ~CaptureRegionUnwinderRAII() {
+    if (ErrorFound) {
+      int ThisCaptureLevel = S.getOpenMPCaptureLevels(DKind);
+      while (--ThisCaptureLevel >= 0)
+        S.ActOnCapturedRegionError();
+    }
+  }
+};
+} // namespace
+
 StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
                                       ArrayRef<OMPClause *> Clauses) {
+  bool ErrorFound = false;
+  CaptureRegionUnwinderRAII CaptureRegionUnwinder(
+      *this, ErrorFound, DSAStack->getCurrentDirective());
   if (!S.isUsable()) {
-    ActOnCapturedRegionError();
+    ErrorFound = true;
     return StmtError();
   }
 
   OMPOrderedClause *OC = nullptr;
   OMPScheduleClause *SC = nullptr;
   SmallVector<OMPLinearClause *, 4> LCs;
+  SmallVector<OMPClauseWithPreInit *, 8> PICs;
   // This is required for proper codegen.
   for (auto *Clause : Clauses) {
     if (isOpenMPPrivate(Clause->getClauseKind()) ||
@@ -1822,15 +1989,8 @@ StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
       }
       DSAStack->setForceVarCapturing(/*V=*/false);
     } else if (isParallelOrTaskRegion(DSAStack->getCurrentDirective())) {
-      // Mark all variables in private list clauses as used in inner region.
-      // Required for proper codegen of combined directives.
-      // TODO: add processing for other clauses.
-      if (auto *C = OMPClauseWithPreInit::get(Clause)) {
-        if (auto *DS = cast_or_null<DeclStmt>(C->getPreInitStmt())) {
-          for (auto *D : DS->decls())
-            MarkVariableReferenced(D->getLocation(), cast<VarDecl>(D));
-        }
-      }
+      if (auto *C = OMPClauseWithPreInit::get(Clause))
+        PICs.push_back(C);
       if (auto *C = OMPClauseWithPostUpdate::get(Clause)) {
         if (auto *E = C->getPostUpdateExpr())
           MarkDeclarationsReferencedInExpr(E);
@@ -1843,7 +2003,6 @@ StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
     else if (Clause->getClauseKind() == OMPC_linear)
       LCs.push_back(cast<OMPLinearClause>(Clause));
   }
-  bool ErrorFound = false;
   // OpenMP, 2.7.1 Loop Construct, Restrictions
   // The nonmonotonic modifier cannot be specified if an ordered clause is
   // specified.
@@ -1874,13 +2033,54 @@ StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
     ErrorFound = true;
   }
   if (ErrorFound) {
-    ActOnCapturedRegionError();
     return StmtError();
   }
-  return ActOnCapturedRegionEnd(S.get());
+  StmtResult SR = S;
+  SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
+  getOpenMPCaptureRegions(CaptureRegions, DSAStack->getCurrentDirective());
+  for (auto ThisCaptureRegion : llvm::reverse(CaptureRegions)) {
+    // Mark all variables in private list clauses as used in inner region.
+    // Required for proper codegen of combined directives.
+    // TODO: add processing for other clauses.
+    if (isParallelOrTaskRegion(DSAStack->getCurrentDirective())) {
+      for (auto *C : PICs) {
+        OpenMPDirectiveKind CaptureRegion = C->getCaptureRegion();
+        // Find the particular capture region for the clause if the
+        // directive is a combined one with multiple capture regions.
+        // If the directive is not a combined one, the capture region
+        // associated with the clause is OMPD_unknown and is generated
+        // only once.
+        if (CaptureRegion == ThisCaptureRegion ||
+            CaptureRegion == OMPD_unknown) {
+          if (auto *DS = cast_or_null<DeclStmt>(C->getPreInitStmt())) {
+            for (auto *D : DS->decls())
+              MarkVariableReferenced(D->getLocation(), cast<VarDecl>(D));
+          }
+        }
+      }
+    }
+    SR = ActOnCapturedRegionEnd(SR.get());
+  }
+  return SR;
+}
+
+static bool checkCancelRegion(Sema &SemaRef, OpenMPDirectiveKind CurrentRegion,
+                              OpenMPDirectiveKind CancelRegion,
+                              SourceLocation StartLoc) {
+  // CancelRegion is only needed for cancel and cancellation_point.
+  if (CurrentRegion != OMPD_cancel && CurrentRegion != OMPD_cancellation_point)
+    return false;
+
+  if (CancelRegion == OMPD_parallel || CancelRegion == OMPD_for ||
+      CancelRegion == OMPD_sections || CancelRegion == OMPD_taskgroup)
+    return false;
+
+  SemaRef.Diag(StartLoc, diag::err_omp_wrong_cancel_region)
+      << getOpenMPDirectiveName(CancelRegion);
+  return true;
 }
 
-static bool CheckNestingOfRegions(Sema &SemaRef, DSAStackTy *Stack,
+static bool checkNestingOfRegions(Sema &SemaRef, DSAStackTy *Stack,
                                   OpenMPDirectiveKind CurrentRegion,
                                   const DeclarationNameInfo &CurrentName,
                                   OpenMPDirectiveKind CancelRegion,
@@ -2180,7 +2380,9 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
     OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
     Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc) {
   StmtResult Res = StmtError();
-  if (CheckNestingOfRegions(*this, DSAStack, Kind, DirName, CancelRegion,
+  // First check CancelRegion which is then used in checkNestingOfRegions.
+  if (checkCancelRegion(*this, Kind, CancelRegion, StartLoc) ||
+      checkNestingOfRegions(*this, DSAStack, Kind, DirName, CancelRegion,
                             StartLoc))
     return StmtError();
 
@@ -2193,7 +2395,11 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
 
     // Check default data sharing attributes for referenced variables.
     DSAAttrChecker DSAChecker(DSAStack, *this, cast<CapturedStmt>(AStmt));
-    DSAChecker.Visit(cast<CapturedStmt>(AStmt)->getCapturedStmt());
+    int ThisCaptureLevel = getOpenMPCaptureLevels(Kind);
+    Stmt *S = AStmt;
+    while (--ThisCaptureLevel >= 0)
+      S = cast<CapturedStmt>(S)->getCapturedStmt();
+    DSAChecker.Visit(S);
     if (DSAChecker.isErrorFound())
       return StmtError();
     // Generate list of implicitly defined firstprivate variables.
@@ -2294,9 +2500,8 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
     Res = ActOnOpenMPTaskwaitDirective(StartLoc, EndLoc);
     break;
   case OMPD_taskgroup:
-    assert(ClausesWithImplicit.empty() &&
-           "No clauses are allowed for 'omp taskgroup' directive");
-    Res = ActOnOpenMPTaskgroupDirective(AStmt, StartLoc, EndLoc);
+    Res = ActOnOpenMPTaskgroupDirective(ClausesWithImplicit, AStmt, StartLoc,
+                                        EndLoc);
     break;
   case OMPD_flush:
     assert(AStmt == nullptr &&
@@ -3969,7 +4174,7 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
   SourceLocation InitLoc = IterSpaces[0].InitSrcRange.getBegin();
 
   // Build variables passed into runtime, necessary for worksharing directives.
-  ExprResult LB, UB, IL, ST, EUB, PrevLB, PrevUB;
+  ExprResult LB, UB, IL, ST, EUB, CombLB, CombUB, PrevLB, PrevUB, CombEUB;
   if (isOpenMPWorksharingDirective(DKind) || isOpenMPTaskLoopDirective(DKind) ||
       isOpenMPDistributeDirective(DKind)) {
     // Lower bound variable, initialized with zero.
@@ -4017,8 +4222,32 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
     // enclosing region. E.g. in 'distribute parallel for' the bounds obtained
     // by scheduling 'distribute' have to be passed to the schedule of 'for'.
     if (isOpenMPLoopBoundSharingDirective(DKind)) {
-      auto *CD = cast<CapturedStmt>(AStmt)->getCapturedDecl();
 
+      // Lower bound variable, initialized with zero.
+      VarDecl *CombLBDecl =
+          buildVarDecl(SemaRef, InitLoc, VType, ".omp.comb.lb");
+      CombLB = buildDeclRefExpr(SemaRef, CombLBDecl, VType, InitLoc);
+      SemaRef.AddInitializerToDecl(
+          CombLBDecl, SemaRef.ActOnIntegerConstant(InitLoc, 0).get(),
+          /*DirectInit*/ false);
+
+      // Upper bound variable, initialized with last iteration number.
+      VarDecl *CombUBDecl =
+          buildVarDecl(SemaRef, InitLoc, VType, ".omp.comb.ub");
+      CombUB = buildDeclRefExpr(SemaRef, CombUBDecl, VType, InitLoc);
+      SemaRef.AddInitializerToDecl(CombUBDecl, LastIteration.get(),
+                                   /*DirectInit*/ false);
+
+      ExprResult CombIsUBGreater = SemaRef.BuildBinOp(
+          CurScope, InitLoc, BO_GT, CombUB.get(), LastIteration.get());
+      ExprResult CombCondOp =
+          SemaRef.ActOnConditionalOp(InitLoc, InitLoc, CombIsUBGreater.get(),
+                                     LastIteration.get(), CombUB.get());
+      CombEUB = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, CombUB.get(),
+                                   CombCondOp.get());
+      CombEUB = SemaRef.ActOnFinishFullExpr(CombEUB.get());
+
+      auto *CD = cast<CapturedStmt>(AStmt)->getCapturedDecl();
       // We expect to have at least 2 more parameters than the 'parallel'
       // directive does - the lower and upper bounds of the previous schedule.
       assert(CD->getNumParams() >= 4 &&
@@ -4040,7 +4269,7 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
 
   // Build the iteration variable and its initialization before loop.
   ExprResult IV;
-  ExprResult Init;
+  ExprResult Init, CombInit;
   {
     VarDecl *IVDecl = buildVarDecl(SemaRef, InitLoc, RealVType, ".omp.iv");
     IV = buildDeclRefExpr(SemaRef, IVDecl, RealVType, InitLoc);
@@ -4051,6 +4280,18 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
             : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();
     Init = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), RHS);
     Init = SemaRef.ActOnFinishFullExpr(Init.get());
+
+    if (isOpenMPLoopBoundSharingDirective(DKind)) {
+      Expr *CombRHS =
+          (isOpenMPWorksharingDirective(DKind) ||
+           isOpenMPTaskLoopDirective(DKind) ||
+           isOpenMPDistributeDirective(DKind))
+              ? CombLB.get()
+              : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();
+      CombInit =
+          SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), CombRHS);
+      CombInit = SemaRef.ActOnFinishFullExpr(CombInit.get());
+    }
   }
 
   // Loop condition (IV < NumIterations) or (IV <= UB) for worksharing loops.
@@ -4061,7 +4302,11 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
           ? SemaRef.BuildBinOp(CurScope, CondLoc, BO_LE, IV.get(), UB.get())
           : SemaRef.BuildBinOp(CurScope, CondLoc, BO_LT, IV.get(),
                                NumIterations.get());
-
+  ExprResult CombCond;
+  if (isOpenMPLoopBoundSharingDirective(DKind)) {
+    CombCond =
+        SemaRef.BuildBinOp(CurScope, CondLoc, BO_LE, IV.get(), CombUB.get());
+  }
   // Loop increment (IV = IV + 1)
   SourceLocation IncLoc;
   ExprResult Inc =
@@ -4076,7 +4321,9 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
 
   // Increments for worksharing loops (LB = LB + ST; UB = UB + ST).
   // Used for directives with static scheduling.
-  ExprResult NextLB, NextUB;
+  // In combined construct, add combined version that use CombLB and CombUB
+  // base variables for the update
+  ExprResult NextLB, NextUB, CombNextLB, CombNextUB;
   if (isOpenMPWorksharingDirective(DKind) || isOpenMPTaskLoopDirective(DKind) ||
       isOpenMPDistributeDirective(DKind)) {
     // LB + ST
@@ -4099,6 +4346,59 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
     NextUB = SemaRef.ActOnFinishFullExpr(NextUB.get());
     if (!NextUB.isUsable())
       return 0;
+    if (isOpenMPLoopBoundSharingDirective(DKind)) {
+      CombNextLB =
+          SemaRef.BuildBinOp(CurScope, IncLoc, BO_Add, CombLB.get(), ST.get());
+      if (!NextLB.isUsable())
+        return 0;
+      // LB = LB + ST
+      CombNextLB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, CombLB.get(),
+                                      CombNextLB.get());
+      CombNextLB = SemaRef.ActOnFinishFullExpr(CombNextLB.get());
+      if (!CombNextLB.isUsable())
+        return 0;
+      // UB + ST
+      CombNextUB =
+          SemaRef.BuildBinOp(CurScope, IncLoc, BO_Add, CombUB.get(), ST.get());
+      if (!CombNextUB.isUsable())
+        return 0;
+      // UB = UB + ST
+      CombNextUB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, CombUB.get(),
+                                      CombNextUB.get());
+      CombNextUB = SemaRef.ActOnFinishFullExpr(CombNextUB.get());
+      if (!CombNextUB.isUsable())
+        return 0;
+    }
+  }
+
+  // Create increment expression for distribute loop when combined in a same
+  // directive with for as IV = IV + ST; ensure upper bound expression based
+  // on PrevUB instead of NumIterations - used to implement 'for' when found
+  // in combination with 'distribute', like in 'distribute parallel for'
+  SourceLocation DistIncLoc;
+  ExprResult DistCond, DistInc, PrevEUB;
+  if (isOpenMPLoopBoundSharingDirective(DKind)) {
+    DistCond = SemaRef.BuildBinOp(CurScope, CondLoc, BO_LE, IV.get(), UB.get());
+    assert(DistCond.isUsable() && "distribute cond expr was not built");
+
+    DistInc =
+        SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Add, IV.get(), ST.get());
+    assert(DistInc.isUsable() && "distribute inc expr was not built");
+    DistInc = SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Assign, IV.get(),
+                                 DistInc.get());
+    DistInc = SemaRef.ActOnFinishFullExpr(DistInc.get());
+    assert(DistInc.isUsable() && "distribute inc expr was not built");
+
+    // Build expression: UB = min(UB, prevUB) for #for in composite or combined
+    // construct
+    SourceLocation DistEUBLoc;
+    ExprResult IsUBGreater =
+        SemaRef.BuildBinOp(CurScope, DistEUBLoc, BO_GT, UB.get(), PrevUB.get());
+    ExprResult CondOp = SemaRef.ActOnConditionalOp(
+        DistEUBLoc, DistEUBLoc, IsUBGreater.get(), PrevUB.get(), UB.get());
+    PrevEUB = SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Assign, UB.get(),
+                                 CondOp.get());
+    PrevEUB = SemaRef.ActOnFinishFullExpr(PrevEUB.get());
   }
 
   // Build updates and final values of the loop counters.
@@ -4215,6 +4515,15 @@ CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
   Built.NUB = NextUB.get();
   Built.PrevLB = PrevLB.get();
   Built.PrevUB = PrevUB.get();
+  Built.DistInc = DistInc.get();
+  Built.PrevEUB = PrevEUB.get();
+  Built.DistCombinedFields.LB = CombLB.get();
+  Built.DistCombinedFields.UB = CombUB.get();
+  Built.DistCombinedFields.EUB = CombEUB.get();
+  Built.DistCombinedFields.Init = CombInit.get();
+  Built.DistCombinedFields.Cond = CombCond.get();
+  Built.DistCombinedFields.NLB = CombNextLB.get();
+  Built.DistCombinedFields.NUB = CombNextUB.get();
 
   Expr *CounterVal = SemaRef.DefaultLvalueConversion(IV.get()).get();
   // Fill data for doacross depend clauses.
@@ -4759,7 +5068,8 @@ StmtResult Sema::ActOnOpenMPTaskwaitDirective(SourceLocation StartLoc,
   return OMPTaskwaitDirective::Create(Context, StartLoc, EndLoc);
 }
 
-StmtResult Sema::ActOnOpenMPTaskgroupDirective(Stmt *AStmt,
+StmtResult Sema::ActOnOpenMPTaskgroupDirective(ArrayRef<OMPClause *> Clauses,
+                                               Stmt *AStmt,
                                                SourceLocation StartLoc,
                                                SourceLocation EndLoc) {
   if (!AStmt)
@@ -4769,7 +5079,8 @@ StmtResult Sema::ActOnOpenMPTaskgroupDirective(Stmt *AStmt,
 
   getCurFunction()->setHasBranchProtectedScope();
 
-  return OMPTaskgroupDirective::Create(Context, StartLoc, EndLoc, AStmt);
+  return OMPTaskgroupDirective::Create(Context, StartLoc, EndLoc, Clauses,
+                                       AStmt);
 }
 
 StmtResult Sema::ActOnOpenMPFlushDirective(ArrayRef<OMPClause *> Clauses,
@@ -5644,16 +5955,17 @@ StmtResult Sema::ActOnOpenMPTargetParallelForDirective(
                                                B, DSAStack->isCancelRegion());
 }
 
-/// \brief Check for existence of a map clause in the list of clauses.
-static bool HasMapClause(ArrayRef<OMPClause *> Clauses) {
-  for (ArrayRef<OMPClause *>::iterator I = Clauses.begin(), E = Clauses.end();
-       I != E; ++I) {
-    if (*I != nullptr && (*I)->getClauseKind() == OMPC_map) {
-      return true;
-    }
-  }
+/// Check for existence of a map clause in the list of clauses.
+static bool hasClauses(ArrayRef<OMPClause *> Clauses,
+                       const OpenMPClauseKind K) {
+  return llvm::any_of(
+      Clauses, [K](const OMPClause *C) { return C->getClauseKind() == K; });
+}
 
-  return false;
+template <typename... Params>
+static bool hasClauses(ArrayRef<OMPClause *> Clauses, const OpenMPClauseKind K,
+                       const Params... ClauseTypes) {
+  return hasClauses(Clauses, K) || hasClauses(Clauses, ClauseTypes...);
 }
 
 StmtResult Sema::ActOnOpenMPTargetDataDirective(ArrayRef<OMPClause *> Clauses,
@@ -5667,8 +5979,9 @@ StmtResult Sema::ActOnOpenMPTargetDataDirective(ArrayRef<OMPClause *> Clauses,
 
   // OpenMP [2.10.1, Restrictions, p. 97]
   // At least one map clause must appear on the directive.
-  if (!HasMapClause(Clauses)) {
-    Diag(StartLoc, diag::err_omp_no_map_for_directive)
+  if (!hasClauses(Clauses, OMPC_map, OMPC_use_device_ptr)) {
+    Diag(StartLoc, diag::err_omp_no_clause_for_directive)
+        << "'map' or 'use_device_ptr'"
         << getOpenMPDirectiveName(OMPD_target_data);
     return StmtError();
   }
@@ -5685,9 +5998,9 @@ Sema::ActOnOpenMPTargetEnterDataDirective(ArrayRef<OMPClause *> Clauses,
                                           SourceLocation EndLoc) {
   // OpenMP [2.10.2, Restrictions, p. 99]
   // At least one map clause must appear on the directive.
-  if (!HasMapClause(Clauses)) {
-    Diag(StartLoc, diag::err_omp_no_map_for_directive)
-        << getOpenMPDirectiveName(OMPD_target_enter_data);
+  if (!hasClauses(Clauses, OMPC_map)) {
+    Diag(StartLoc, diag::err_omp_no_clause_for_directive)
+        << "'map'" << getOpenMPDirectiveName(OMPD_target_enter_data);
     return StmtError();
   }
 
@@ -5701,9 +6014,9 @@ Sema::ActOnOpenMPTargetExitDataDirective(ArrayRef<OMPClause *> Clauses,
                                          SourceLocation EndLoc) {
   // OpenMP [2.10.3, Restrictions, p. 102]
   // At least one map clause must appear on the directive.
-  if (!HasMapClause(Clauses)) {
-    Diag(StartLoc, diag::err_omp_no_map_for_directive)
-        << getOpenMPDirectiveName(OMPD_target_exit_data);
+  if (!hasClauses(Clauses, OMPC_map)) {
+    Diag(StartLoc, diag::err_omp_no_clause_for_directive)
+        << "'map'" << getOpenMPDirectiveName(OMPD_target_exit_data);
     return StmtError();
   }
 
@@ -5713,12 +6026,7 @@ Sema::ActOnOpenMPTargetExitDataDirective(ArrayRef<OMPClause *> Clauses,
 StmtResult Sema::ActOnOpenMPTargetUpdateDirective(ArrayRef<OMPClause *> Clauses,
                                                   SourceLocation StartLoc,
                                                   SourceLocation EndLoc) {
-  bool seenMotionClause = false;
-  for (auto *C : Clauses) {
-    if (C->getClauseKind() == OMPC_to || C->getClauseKind() == OMPC_from)
-      seenMotionClause = true;
-  }
-  if (!seenMotionClause) {
+  if (!hasClauses(Clauses, OMPC_to, OMPC_from)) {
     Diag(StartLoc, diag::err_omp_at_least_one_motion_clause_required);
     return StmtError();
   }
@@ -5748,12 +6056,6 @@ StmtResult
 Sema::ActOnOpenMPCancellationPointDirective(SourceLocation StartLoc,
                                             SourceLocation EndLoc,
                                             OpenMPDirectiveKind CancelRegion) {
-  if (CancelRegion != OMPD_parallel && CancelRegion != OMPD_for &&
-      CancelRegion != OMPD_sections && CancelRegion != OMPD_taskgroup) {
-    Diag(StartLoc, diag::err_omp_wrong_cancel_region)
-        << getOpenMPDirectiveName(CancelRegion);
-    return StmtError();
-  }
   if (DSAStack->isParentNowaitRegion()) {
     Diag(StartLoc, diag::err_omp_parent_cancel_region_nowait) << 0;
     return StmtError();
@@ -5770,12 +6072,6 @@ StmtResult Sema::ActOnOpenMPCancelDirective(ArrayRef<OMPClause *> Clauses,
                                             SourceLocation StartLoc,
                                             SourceLocation EndLoc,
                                             OpenMPDirectiveKind CancelRegion) {
-  if (CancelRegion != OMPD_parallel && CancelRegion != OMPD_for &&
-      CancelRegion != OMPD_sections && CancelRegion != OMPD_taskgroup) {
-    Diag(StartLoc, diag::err_omp_wrong_cancel_region)
-        << getOpenMPDirectiveName(CancelRegion);
-    return StmtError();
-  }
   if (DSAStack->isParentNowaitRegion()) {
     Diag(StartLoc, diag::err_omp_parent_cancel_region_nowait) << 1;
     return StmtError();
@@ -5813,6 +6109,33 @@ static bool checkGrainsizeNumTasksClauses(Sema &S,
   return ErrorFound;
 }
 
+static bool checkReductionClauseWithNogroup(Sema &S,
+                                            ArrayRef<OMPClause *> Clauses) {
+  OMPClause *ReductionClause = nullptr;
+  OMPClause *NogroupClause = nullptr;
+  for (auto *C : Clauses) {
+    if (C->getClauseKind() == OMPC_reduction) {
+      ReductionClause = C;
+      if (NogroupClause)
+        break;
+      continue;
+    }
+    if (C->getClauseKind() == OMPC_nogroup) {
+      NogroupClause = C;
+      if (ReductionClause)
+        break;
+      continue;
+    }
+  }
+  if (ReductionClause && NogroupClause) {
+    S.Diag(ReductionClause->getLocStart(), diag::err_omp_reduction_with_nogroup)
+        << SourceRange(NogroupClause->getLocStart(),
+                       NogroupClause->getLocEnd());
+    return true;
+  }
+  return false;
+}
+
 StmtResult Sema::ActOnOpenMPTaskLoopDirective(
     ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
     SourceLocation EndLoc,
@@ -5839,6 +6162,11 @@ StmtResult Sema::ActOnOpenMPTaskLoopDirective(
   // not appear on the same taskloop directive.
   if (checkGrainsizeNumTasksClauses(*this, Clauses))
     return StmtError();
+  // OpenMP, [2.9.2 taskloop Construct, Restrictions]
+  // If a reduction clause is present on the taskloop directive, the nogroup
+  // clause must not be specified.
+  if (checkReductionClauseWithNogroup(*this, Clauses))
+    return StmtError();
 
   getCurFunction()->setHasBranchProtectedScope();
   return OMPTaskLoopDirective::Create(Context, StartLoc, EndLoc,
@@ -5882,6 +6210,11 @@ StmtResult Sema::ActOnOpenMPTaskLoopSimdDirective(
   // not appear on the same taskloop directive.
   if (checkGrainsizeNumTasksClauses(*this, Clauses))
     return StmtError();
+  // OpenMP, [2.9.2 taskloop Construct, Restrictions]
+  // If a reduction clause is present on the taskloop directive, the nogroup
+  // clause must not be specified.
+  if (checkReductionClauseWithNogroup(*this, Clauses))
+    return StmtError();
 
   getCurFunction()->setHasBranchProtectedScope();
   return OMPTaskLoopSimdDirective::Create(Context, StartLoc, EndLoc,
@@ -6519,6 +6852,7 @@ OMPClause *Sema::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind, Expr *Expr,
   case OMPC_lastprivate:
   case OMPC_shared:
   case OMPC_reduction:
+  case OMPC_task_reduction:
   case OMPC_linear:
   case OMPC_aligned:
   case OMPC_copyin:
@@ -6551,6 +6885,323 @@ OMPClause *Sema::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind, Expr *Expr,
   return Res;
 }
 
+// An OpenMP directive such as 'target parallel' has two captured regions:
+// for the 'target' and 'parallel' respectively.  This function returns
+// the region in which to capture expressions associated with a clause.
+// A return value of OMPD_unknown signifies that the expression should not
+// be captured.
+static OpenMPDirectiveKind getOpenMPCaptureRegionForClause(
+    OpenMPDirectiveKind DKind, OpenMPClauseKind CKind,
+    OpenMPDirectiveKind NameModifier = OMPD_unknown) {
+  OpenMPDirectiveKind CaptureRegion = OMPD_unknown;
+
+  switch (CKind) {
+  case OMPC_if:
+    switch (DKind) {
+    case OMPD_target_parallel:
+      // If this clause applies to the nested 'parallel' region, capture within
+      // the 'target' region, otherwise do not capture.
+      if (NameModifier == OMPD_unknown || NameModifier == OMPD_parallel)
+        CaptureRegion = OMPD_target;
+      break;
+    case OMPD_cancel:
+    case OMPD_parallel:
+    case OMPD_parallel_sections:
+    case OMPD_parallel_for:
+    case OMPD_parallel_for_simd:
+    case OMPD_target:
+    case OMPD_target_simd:
+    case OMPD_target_parallel_for:
+    case OMPD_target_parallel_for_simd:
+    case OMPD_target_teams:
+    case OMPD_target_teams_distribute:
+    case OMPD_target_teams_distribute_simd:
+    case OMPD_target_teams_distribute_parallel_for:
+    case OMPD_target_teams_distribute_parallel_for_simd:
+    case OMPD_teams_distribute_parallel_for:
+    case OMPD_teams_distribute_parallel_for_simd:
+    case OMPD_distribute_parallel_for:
+    case OMPD_distribute_parallel_for_simd:
+    case OMPD_task:
+    case OMPD_taskloop:
+    case OMPD_taskloop_simd:
+    case OMPD_target_data:
+    case OMPD_target_enter_data:
+    case OMPD_target_exit_data:
+    case OMPD_target_update:
+      // Do not capture if-clause expressions.
+      break;
+    case OMPD_threadprivate:
+    case OMPD_taskyield:
+    case OMPD_barrier:
+    case OMPD_taskwait:
+    case OMPD_cancellation_point:
+    case OMPD_flush:
+    case OMPD_declare_reduction:
+    case OMPD_declare_simd:
+    case OMPD_declare_target:
+    case OMPD_end_declare_target:
+    case OMPD_teams:
+    case OMPD_simd:
+    case OMPD_for:
+    case OMPD_for_simd:
+    case OMPD_sections:
+    case OMPD_section:
+    case OMPD_single:
+    case OMPD_master:
+    case OMPD_critical:
+    case OMPD_taskgroup:
+    case OMPD_distribute:
+    case OMPD_ordered:
+    case OMPD_atomic:
+    case OMPD_distribute_simd:
+    case OMPD_teams_distribute:
+    case OMPD_teams_distribute_simd:
+      llvm_unreachable("Unexpected OpenMP directive with if-clause");
+    case OMPD_unknown:
+      llvm_unreachable("Unknown OpenMP directive");
+    }
+    break;
+  case OMPC_num_threads:
+    switch (DKind) {
+    case OMPD_target_parallel:
+      CaptureRegion = OMPD_target;
+      break;
+    case OMPD_cancel:
+    case OMPD_parallel:
+    case OMPD_parallel_sections:
+    case OMPD_parallel_for:
+    case OMPD_parallel_for_simd:
+    case OMPD_target:
+    case OMPD_target_simd:
+    case OMPD_target_parallel_for:
+    case OMPD_target_parallel_for_simd:
+    case OMPD_target_teams:
+    case OMPD_target_teams_distribute:
+    case OMPD_target_teams_distribute_simd:
+    case OMPD_target_teams_distribute_parallel_for:
+    case OMPD_target_teams_distribute_parallel_for_simd:
+    case OMPD_teams_distribute_parallel_for:
+    case OMPD_teams_distribute_parallel_for_simd:
+    case OMPD_distribute_parallel_for:
+    case OMPD_distribute_parallel_for_simd:
+    case OMPD_task:
+    case OMPD_taskloop:
+    case OMPD_taskloop_simd:
+    case OMPD_target_data:
+    case OMPD_target_enter_data:
+    case OMPD_target_exit_data:
+    case OMPD_target_update:
+      // Do not capture num_threads-clause expressions.
+      break;
+    case OMPD_threadprivate:
+    case OMPD_taskyield:
+    case OMPD_barrier:
+    case OMPD_taskwait:
+    case OMPD_cancellation_point:
+    case OMPD_flush:
+    case OMPD_declare_reduction:
+    case OMPD_declare_simd:
+    case OMPD_declare_target:
+    case OMPD_end_declare_target:
+    case OMPD_teams:
+    case OMPD_simd:
+    case OMPD_for:
+    case OMPD_for_simd:
+    case OMPD_sections:
+    case OMPD_section:
+    case OMPD_single:
+    case OMPD_master:
+    case OMPD_critical:
+    case OMPD_taskgroup:
+    case OMPD_distribute:
+    case OMPD_ordered:
+    case OMPD_atomic:
+    case OMPD_distribute_simd:
+    case OMPD_teams_distribute:
+    case OMPD_teams_distribute_simd:
+      llvm_unreachable("Unexpected OpenMP directive with num_threads-clause");
+    case OMPD_unknown:
+      llvm_unreachable("Unknown OpenMP directive");
+    }
+    break;
+  case OMPC_num_teams:
+    switch (DKind) {
+    case OMPD_target_teams:
+      CaptureRegion = OMPD_target;
+      break;
+    case OMPD_cancel:
+    case OMPD_parallel:
+    case OMPD_parallel_sections:
+    case OMPD_parallel_for:
+    case OMPD_parallel_for_simd:
+    case OMPD_target:
+    case OMPD_target_simd:
+    case OMPD_target_parallel:
+    case OMPD_target_parallel_for:
+    case OMPD_target_parallel_for_simd:
+    case OMPD_target_teams_distribute:
+    case OMPD_target_teams_distribute_simd:
+    case OMPD_target_teams_distribute_parallel_for:
+    case OMPD_target_teams_distribute_parallel_for_simd:
+    case OMPD_teams_distribute_parallel_for:
+    case OMPD_teams_distribute_parallel_for_simd:
+    case OMPD_distribute_parallel_for:
+    case OMPD_distribute_parallel_for_simd:
+    case OMPD_task:
+    case OMPD_taskloop:
+    case OMPD_taskloop_simd:
+    case OMPD_target_data:
+    case OMPD_target_enter_data:
+    case OMPD_target_exit_data:
+    case OMPD_target_update:
+    case OMPD_teams:
+    case OMPD_teams_distribute:
+    case OMPD_teams_distribute_simd:
+      // Do not capture num_teams-clause expressions.
+      break;
+    case OMPD_threadprivate:
+    case OMPD_taskyield:
+    case OMPD_barrier:
+    case OMPD_taskwait:
+    case OMPD_cancellation_point:
+    case OMPD_flush:
+    case OMPD_declare_reduction:
+    case OMPD_declare_simd:
+    case OMPD_declare_target:
+    case OMPD_end_declare_target:
+    case OMPD_simd:
+    case OMPD_for:
+    case OMPD_for_simd:
+    case OMPD_sections:
+    case OMPD_section:
+    case OMPD_single:
+    case OMPD_master:
+    case OMPD_critical:
+    case OMPD_taskgroup:
+    case OMPD_distribute:
+    case OMPD_ordered:
+    case OMPD_atomic:
+    case OMPD_distribute_simd:
+      llvm_unreachable("Unexpected OpenMP directive with num_teams-clause");
+    case OMPD_unknown:
+      llvm_unreachable("Unknown OpenMP directive");
+    }
+    break;
+  case OMPC_thread_limit:
+    switch (DKind) {
+    case OMPD_target_teams:
+      CaptureRegion = OMPD_target;
+      break;
+    case OMPD_cancel:
+    case OMPD_parallel:
+    case OMPD_parallel_sections:
+    case OMPD_parallel_for:
+    case OMPD_parallel_for_simd:
+    case OMPD_target:
+    case OMPD_target_simd:
+    case OMPD_target_parallel:
+    case OMPD_target_parallel_for:
+    case OMPD_target_parallel_for_simd:
+    case OMPD_target_teams_distribute:
+    case OMPD_target_teams_distribute_simd:
+    case OMPD_target_teams_distribute_parallel_for:
+    case OMPD_target_teams_distribute_parallel_for_simd:
+    case OMPD_teams_distribute_parallel_for:
+    case OMPD_teams_distribute_parallel_for_simd:
+    case OMPD_distribute_parallel_for:
+    case OMPD_distribute_parallel_for_simd:
+    case OMPD_task:
+    case OMPD_taskloop:
+    case OMPD_taskloop_simd:
+    case OMPD_target_data:
+    case OMPD_target_enter_data:
+    case OMPD_target_exit_data:
+    case OMPD_target_update:
+    case OMPD_teams:
+    case OMPD_teams_distribute:
+    case OMPD_teams_distribute_simd:
+      // Do not capture thread_limit-clause expressions.
+      break;
+    case OMPD_threadprivate:
+    case OMPD_taskyield:
+    case OMPD_barrier:
+    case OMPD_taskwait:
+    case OMPD_cancellation_point:
+    case OMPD_flush:
+    case OMPD_declare_reduction:
+    case OMPD_declare_simd:
+    case OMPD_declare_target:
+    case OMPD_end_declare_target:
+    case OMPD_simd:
+    case OMPD_for:
+    case OMPD_for_simd:
+    case OMPD_sections:
+    case OMPD_section:
+    case OMPD_single:
+    case OMPD_master:
+    case OMPD_critical:
+    case OMPD_taskgroup:
+    case OMPD_distribute:
+    case OMPD_ordered:
+    case OMPD_atomic:
+    case OMPD_distribute_simd:
+      llvm_unreachable("Unexpected OpenMP directive with thread_limit-clause");
+    case OMPD_unknown:
+      llvm_unreachable("Unknown OpenMP directive");
+    }
+    break;
+  case OMPC_schedule:
+  case OMPC_dist_schedule:
+  case OMPC_firstprivate:
+  case OMPC_lastprivate:
+  case OMPC_reduction:
+  case OMPC_task_reduction:
+  case OMPC_linear:
+  case OMPC_default:
+  case OMPC_proc_bind:
+  case OMPC_final:
+  case OMPC_safelen:
+  case OMPC_simdlen:
+  case OMPC_collapse:
+  case OMPC_private:
+  case OMPC_shared:
+  case OMPC_aligned:
+  case OMPC_copyin:
+  case OMPC_copyprivate:
+  case OMPC_ordered:
+  case OMPC_nowait:
+  case OMPC_untied:
+  case OMPC_mergeable:
+  case OMPC_threadprivate:
+  case OMPC_flush:
+  case OMPC_read:
+  case OMPC_write:
+  case OMPC_update:
+  case OMPC_capture:
+  case OMPC_seq_cst:
+  case OMPC_depend:
+  case OMPC_device:
+  case OMPC_threads:
+  case OMPC_simd:
+  case OMPC_map:
+  case OMPC_priority:
+  case OMPC_grainsize:
+  case OMPC_nogroup:
+  case OMPC_num_tasks:
+  case OMPC_hint:
+  case OMPC_defaultmap:
+  case OMPC_unknown:
+  case OMPC_uniform:
+  case OMPC_to:
+  case OMPC_from:
+  case OMPC_use_device_ptr:
+  case OMPC_is_device_ptr:
+    llvm_unreachable("Unexpected OpenMP clause.");
+  }
+  return CaptureRegion;
+}
+
 OMPClause *Sema::ActOnOpenMPIfClause(OpenMPDirectiveKind NameModifier,
                                      Expr *Condition, SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
@@ -6558,6 +7209,8 @@ OMPClause *Sema::ActOnOpenMPIfClause(OpenMPDirectiveKind NameModifier,
                                      SourceLocation ColonLoc,
                                      SourceLocation EndLoc) {
   Expr *ValExpr = Condition;
+  Stmt *HelperValStmt = nullptr;
+  OpenMPDirectiveKind CaptureRegion = OMPD_unknown;
   if (!Condition->isValueDependent() && !Condition->isTypeDependent() &&
       !Condition->isInstantiationDependent() &&
       !Condition->containsUnexpandedParameterPack()) {
@@ -6566,10 +7219,20 @@ OMPClause *Sema::ActOnOpenMPIfClause(OpenMPDirectiveKind NameModifier,
       return nullptr;
 
     ValExpr = MakeFullExpr(Val.get()).get();
+
+    OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
+    CaptureRegion =
+        getOpenMPCaptureRegionForClause(DKind, OMPC_if, NameModifier);
+    if (CaptureRegion != OMPD_unknown) {
+      llvm::MapVector<Expr *, DeclRefExpr *> Captures;
+      ValExpr = tryBuildCapture(*this, ValExpr, Captures).get();
+      HelperValStmt = buildPreInits(Context, Captures);
+    }
   }
 
-  return new (Context) OMPIfClause(NameModifier, ValExpr, StartLoc, LParenLoc,
-                                   NameModifierLoc, ColonLoc, EndLoc);
+  return new (Context)
+      OMPIfClause(NameModifier, ValExpr, HelperValStmt, CaptureRegion, StartLoc,
+                  LParenLoc, NameModifierLoc, ColonLoc, EndLoc);
 }
 
 OMPClause *Sema::ActOnOpenMPFinalClause(Expr *Condition,
@@ -6665,6 +7328,8 @@ OMPClause *Sema::ActOnOpenMPNumThreadsClause(Expr *NumThreads,
                                              SourceLocation LParenLoc,
                                              SourceLocation EndLoc) {
   Expr *ValExpr = NumThreads;
+  Stmt *HelperValStmt = nullptr;
+  OpenMPDirectiveKind CaptureRegion = OMPD_unknown;
 
   // OpenMP [2.5, Restrictions]
   //  The num_threads expression must evaluate to a positive integer value.
@@ -6672,8 +7337,16 @@ OMPClause *Sema::ActOnOpenMPNumThreadsClause(Expr *NumThreads,
                                  /*StrictlyPositive=*/true))
     return nullptr;
 
-  return new (Context)
-      OMPNumThreadsClause(ValExpr, StartLoc, LParenLoc, EndLoc);
+  OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
+  CaptureRegion = getOpenMPCaptureRegionForClause(DKind, OMPC_num_threads);
+  if (CaptureRegion != OMPD_unknown) {
+    llvm::MapVector<Expr *, DeclRefExpr *> Captures;
+    ValExpr = tryBuildCapture(*this, ValExpr, Captures).get();
+    HelperValStmt = buildPreInits(Context, Captures);
+  }
+
+  return new (Context) OMPNumThreadsClause(
+      ValExpr, HelperValStmt, CaptureRegion, StartLoc, LParenLoc, EndLoc);
 }
 
 ExprResult Sema::VerifyPositiveIntegerConstantInClause(Expr *E,
@@ -6799,6 +7472,7 @@ OMPClause *Sema::ActOnOpenMPSimpleClause(
   case OMPC_lastprivate:
   case OMPC_shared:
   case OMPC_reduction:
+  case OMPC_task_reduction:
   case OMPC_linear:
   case OMPC_aligned:
   case OMPC_copyin:
@@ -6956,6 +7630,7 @@ OMPClause *Sema::ActOnOpenMPSingleExprWithArgClause(
   case OMPC_lastprivate:
   case OMPC_shared:
   case OMPC_reduction:
+  case OMPC_task_reduction:
   case OMPC_linear:
   case OMPC_aligned:
   case OMPC_copyin:
@@ -7153,6 +7828,7 @@ OMPClause *Sema::ActOnOpenMPClause(OpenMPClauseKind Kind,
   case OMPC_lastprivate:
   case OMPC_shared:
   case OMPC_reduction:
+  case OMPC_task_reduction:
   case OMPC_linear:
   case OMPC_aligned:
   case OMPC_copyin:
@@ -7265,6 +7941,11 @@ OMPClause *Sema::ActOnOpenMPVarListClause(
     Res = ActOnOpenMPReductionClause(VarList, StartLoc, LParenLoc, ColonLoc,
                                      EndLoc, ReductionIdScopeSpec, ReductionId);
     break;
+  case OMPC_task_reduction:
+    Res = ActOnOpenMPTaskReductionClause(VarList, StartLoc, LParenLoc, ColonLoc,
+                                         EndLoc, ReductionIdScopeSpec,
+                                         ReductionId);
+    break;
   case OMPC_linear:
     Res = ActOnOpenMPLinearClause(VarList, TailExpr, StartLoc, LParenLoc,
                                   LinKind, DepLinMapLoc, ColonLoc, EndLoc);
@@ -8233,15 +8914,66 @@ buildDeclareReductionRef(Sema &SemaRef, SourceLocation Loc, SourceRange Range,
   return ExprEmpty();
 }
 
-OMPClause *Sema::ActOnOpenMPReductionClause(
+namespace {
+/// Data for the reduction-based clauses.
+struct ReductionData {
+  /// List of original reduction items.
+  SmallVector<Expr *, 8> Vars;
+  /// List of private copies of the reduction items.
+  SmallVector<Expr *, 8> Privates;
+  /// LHS expressions for the reduction_op expressions.
+  SmallVector<Expr *, 8> LHSs;
+  /// RHS expressions for the reduction_op expressions.
+  SmallVector<Expr *, 8> RHSs;
+  /// Reduction operation expression.
+  SmallVector<Expr *, 8> ReductionOps;
+  /// List of captures for clause.
+  SmallVector<Decl *, 4> ExprCaptures;
+  /// List of postupdate expressions.
+  SmallVector<Expr *, 4> ExprPostUpdates;
+  ReductionData() = delete;
+  /// Reserves required memory for the reduction data.
+  ReductionData(unsigned Size) {
+    Vars.reserve(Size);
+    Privates.reserve(Size);
+    LHSs.reserve(Size);
+    RHSs.reserve(Size);
+    ReductionOps.reserve(Size);
+    ExprCaptures.reserve(Size);
+    ExprPostUpdates.reserve(Size);
+  }
+  /// Stores reduction item and reduction operation only (required for dependent
+  /// reduction item).
+  void push(Expr *Item, Expr *ReductionOp) {
+    Vars.emplace_back(Item);
+    Privates.emplace_back(nullptr);
+    LHSs.emplace_back(nullptr);
+    RHSs.emplace_back(nullptr);
+    ReductionOps.emplace_back(ReductionOp);
+  }
+  /// Stores reduction data.
+  void push(Expr *Item, Expr *Private, Expr *LHS, Expr *RHS,
+            Expr *ReductionOp) {
+    Vars.emplace_back(Item);
+    Privates.emplace_back(Private);
+    LHSs.emplace_back(LHS);
+    RHSs.emplace_back(RHS);
+    ReductionOps.emplace_back(ReductionOp);
+  }
+};
+} // namespace
+
+static bool ActOnOMPReductionKindClause(
+    Sema &S, DSAStackTy *Stack, OpenMPClauseKind ClauseKind,
     ArrayRef<Expr *> VarList, SourceLocation StartLoc, SourceLocation LParenLoc,
     SourceLocation ColonLoc, SourceLocation EndLoc,
     CXXScopeSpec &ReductionIdScopeSpec, const DeclarationNameInfo &ReductionId,
-    ArrayRef<Expr *> UnresolvedReductions) {
+    ArrayRef<Expr *> UnresolvedReductions, ReductionData &RD) {
   auto DN = ReductionId.getName();
   auto OOK = DN.getCXXOverloadedOperator();
   BinaryOperatorKind BOK = BO_Comma;
 
+  ASTContext &Context = S.Context;
   // OpenMP [2.14.3.6, reduction clause]
   // C
   // reduction-identifier is either an identifier or one of the following
@@ -8325,13 +9057,6 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     ReductionIdRange.setBegin(ReductionIdScopeSpec.getBeginLoc());
   ReductionIdRange.setEnd(ReductionId.getEndLoc());
 
-  SmallVector<Expr *, 8> Vars;
-  SmallVector<Expr *, 8> Privates;
-  SmallVector<Expr *, 8> LHSs;
-  SmallVector<Expr *, 8> RHSs;
-  SmallVector<Expr *, 8> ReductionOps;
-  SmallVector<Decl *, 4> ExprCaptures;
-  SmallVector<Expr *, 4> ExprPostUpdates;
   auto IR = UnresolvedReductions.begin(), ER = UnresolvedReductions.end();
   bool FirstIter = true;
   for (auto RefExpr : VarList) {
@@ -8349,27 +9074,23 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     SourceLocation ELoc;
     SourceRange ERange;
     Expr *SimpleRefExpr = RefExpr;
-    auto Res = getPrivateItem(*this, SimpleRefExpr, ELoc, ERange,
+    auto Res = getPrivateItem(S, SimpleRefExpr, ELoc, ERange,
                               /*AllowArraySection=*/true);
     if (Res.second) {
-      // It will be analyzed later.
-      Vars.push_back(RefExpr);
-      Privates.push_back(nullptr);
-      LHSs.push_back(nullptr);
-      RHSs.push_back(nullptr);
       // Try to find 'declare reduction' corresponding construct before using
       // builtin/overloaded operators.
       QualType Type = Context.DependentTy;
       CXXCastPath BasePath;
       ExprResult DeclareReductionRef = buildDeclareReductionRef(
-          *this, ELoc, ERange, DSAStack->getCurScope(), ReductionIdScopeSpec,
+          S, ELoc, ERange, Stack->getCurScope(), ReductionIdScopeSpec,
           ReductionId, Type, BasePath, IR == ER ? nullptr : *IR);
-      if (CurContext->isDependentContext() &&
+      Expr *ReductionOp = nullptr;
+      if (S.CurContext->isDependentContext() &&
           (DeclareReductionRef.isUnset() ||
            isa<UnresolvedLookupExpr>(DeclareReductionRef.get())))
-        ReductionOps.push_back(DeclareReductionRef.get());
-      else
-        ReductionOps.push_back(nullptr);
+        ReductionOp = DeclareReductionRef.get();
+      // It will be analyzed later.
+      RD.push(RefExpr, ReductionOp);
     }
     ValueDecl *D = Res.first;
     if (!D)
@@ -8394,21 +9115,19 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     // OpenMP [2.9.3.3, Restrictions, C/C++, p.3]
     //  A variable that appears in a private clause must not have an incomplete
     //  type or a reference type.
-    if (RequireCompleteType(ELoc, Type,
-                            diag::err_omp_reduction_incomplete_type))
+    if (S.RequireCompleteType(ELoc, Type,
+                              diag::err_omp_reduction_incomplete_type))
       continue;
     // OpenMP [2.14.3.6, reduction clause, Restrictions]
     // A list item that appears in a reduction clause must not be
     // const-qualified.
     if (Type.getNonReferenceType().isConstant(Context)) {
-      Diag(ELoc, diag::err_omp_const_reduction_list_item)
-          << getOpenMPClauseName(OMPC_reduction) << Type << ERange;
+      S.Diag(ELoc, diag::err_omp_const_reduction_list_item) << ERange;
       if (!ASE && !OASE) {
-        bool IsDecl = !VD ||
-                      VD->isThisDeclarationADefinition(Context) ==
-                          VarDecl::DeclarationOnly;
-        Diag(D->getLocation(),
-             IsDecl ? diag::note_previous_decl : diag::note_defined_here)
+        bool IsDecl = !VD || VD->isThisDeclarationADefinition(Context) ==
+                                 VarDecl::DeclarationOnly;
+        S.Diag(D->getLocation(),
+               IsDecl ? diag::note_previous_decl : diag::note_defined_here)
             << D;
       }
       continue;
@@ -8419,10 +9138,11 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     if (!ASE && !OASE && VD) {
       VarDecl *VDDef = VD->getDefinition();
       if (VD->getType()->isReferenceType() && VDDef && VDDef->hasInit()) {
-        DSARefChecker Check(DSAStack);
+        DSARefChecker Check(Stack);
         if (Check.Visit(VDDef->getInit())) {
-          Diag(ELoc, diag::err_omp_reduction_ref_type_arg) << ERange;
-          Diag(VDDef->getLocation(), diag::note_defined_here) << VDDef;
+          S.Diag(ELoc, diag::err_omp_reduction_ref_type_arg)
+              << getOpenMPClauseName(ClauseKind) << ERange;
+          S.Diag(VDDef->getLocation(), diag::note_defined_here) << VDDef;
           continue;
         }
       }
@@ -8440,17 +9160,17 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     //  but a list item can appear only once in the reduction clauses for that
     //  directive.
     DSAStackTy::DSAVarData DVar;
-    DVar = DSAStack->getTopDSA(D, false);
+    DVar = Stack->getTopDSA(D, false);
     if (DVar.CKind == OMPC_reduction) {
-      Diag(ELoc, diag::err_omp_once_referenced)
-          << getOpenMPClauseName(OMPC_reduction);
+      S.Diag(ELoc, diag::err_omp_once_referenced)
+          << getOpenMPClauseName(ClauseKind);
       if (DVar.RefExpr)
-        Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_referenced);
+        S.Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_referenced);
     } else if (DVar.CKind != OMPC_unknown) {
-      Diag(ELoc, diag::err_omp_wrong_dsa)
+      S.Diag(ELoc, diag::err_omp_wrong_dsa)
           << getOpenMPClauseName(DVar.CKind)
           << getOpenMPClauseName(OMPC_reduction);
-      ReportOriginalDSA(*this, DSAStack, D, DVar);
+      ReportOriginalDSA(S, Stack, D, DVar);
       continue;
     }
 
@@ -8458,16 +9178,16 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     //  A list item that appears in a reduction clause of a worksharing
     //  construct must be shared in the parallel regions to which any of the
     //  worksharing regions arising from the worksharing construct bind.
-    OpenMPDirectiveKind CurrDir = DSAStack->getCurrentDirective();
+    OpenMPDirectiveKind CurrDir = Stack->getCurrentDirective();
     if (isOpenMPWorksharingDirective(CurrDir) &&
         !isOpenMPParallelDirective(CurrDir) &&
         !isOpenMPTeamsDirective(CurrDir)) {
-      DVar = DSAStack->getImplicitDSA(D, true);
+      DVar = Stack->getImplicitDSA(D, true);
       if (DVar.CKind != OMPC_shared) {
-        Diag(ELoc, diag::err_omp_required_access)
+        S.Diag(ELoc, diag::err_omp_required_access)
             << getOpenMPClauseName(OMPC_reduction)
             << getOpenMPClauseName(OMPC_shared);
-        ReportOriginalDSA(*this, DSAStack, D, DVar);
+        ReportOriginalDSA(S, Stack, D, DVar);
         continue;
       }
     }
@@ -8476,24 +9196,20 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     // builtin/overloaded operators.
     CXXCastPath BasePath;
     ExprResult DeclareReductionRef = buildDeclareReductionRef(
-        *this, ELoc, ERange, DSAStack->getCurScope(), ReductionIdScopeSpec,
+        S, ELoc, ERange, Stack->getCurScope(), ReductionIdScopeSpec,
         ReductionId, Type, BasePath, IR == ER ? nullptr : *IR);
     if (DeclareReductionRef.isInvalid())
       continue;
-    if (CurContext->isDependentContext() &&
+    if (S.CurContext->isDependentContext() &&
         (DeclareReductionRef.isUnset() ||
          isa<UnresolvedLookupExpr>(DeclareReductionRef.get()))) {
-      Vars.push_back(RefExpr);
-      Privates.push_back(nullptr);
-      LHSs.push_back(nullptr);
-      RHSs.push_back(nullptr);
-      ReductionOps.push_back(DeclareReductionRef.get());
+      RD.push(RefExpr, DeclareReductionRef.get());
       continue;
     }
     if (BOK == BO_Comma && DeclareReductionRef.isUnset()) {
       // Not allowed reduction identifier is found.
-      Diag(ReductionId.getLocStart(),
-           diag::err_omp_unknown_reduction_identifier)
+      S.Diag(ReductionId.getLocStart(),
+             diag::err_omp_unknown_reduction_identifier)
           << Type << ReductionIdRange;
       continue;
     }
@@ -8509,28 +9225,27 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     if (DeclareReductionRef.isUnset()) {
       if ((BOK == BO_GT || BOK == BO_LT) &&
           !(Type->isScalarType() ||
-            (getLangOpts().CPlusPlus && Type->isArithmeticType()))) {
-        Diag(ELoc, diag::err_omp_clause_not_arithmetic_type_arg)
-            << getLangOpts().CPlusPlus;
+            (S.getLangOpts().CPlusPlus && Type->isArithmeticType()))) {
+        S.Diag(ELoc, diag::err_omp_clause_not_arithmetic_type_arg)
+            << getOpenMPClauseName(ClauseKind) << S.getLangOpts().CPlusPlus;
         if (!ASE && !OASE) {
-          bool IsDecl = !VD ||
-                        VD->isThisDeclarationADefinition(Context) ==
-                            VarDecl::DeclarationOnly;
-          Diag(D->getLocation(),
-               IsDecl ? diag::note_previous_decl : diag::note_defined_here)
+          bool IsDecl = !VD || VD->isThisDeclarationADefinition(Context) ==
+                                   VarDecl::DeclarationOnly;
+          S.Diag(D->getLocation(),
+                 IsDecl ? diag::note_previous_decl : diag::note_defined_here)
               << D;
         }
         continue;
       }
       if ((BOK == BO_OrAssign || BOK == BO_AndAssign || BOK == BO_XorAssign) &&
-          !getLangOpts().CPlusPlus && Type->isFloatingType()) {
-        Diag(ELoc, diag::err_omp_clause_floating_type_arg);
+          !S.getLangOpts().CPlusPlus && Type->isFloatingType()) {
+        S.Diag(ELoc, diag::err_omp_clause_floating_type_arg)
+            << getOpenMPClauseName(ClauseKind);
         if (!ASE && !OASE) {
-          bool IsDecl = !VD ||
-                        VD->isThisDeclarationADefinition(Context) ==
-                            VarDecl::DeclarationOnly;
-          Diag(D->getLocation(),
-               IsDecl ? diag::note_previous_decl : diag::note_defined_here)
+          bool IsDecl = !VD || VD->isThisDeclarationADefinition(Context) ==
+                                   VarDecl::DeclarationOnly;
+          S.Diag(D->getLocation(),
+                 IsDecl ? diag::note_previous_decl : diag::note_defined_here)
               << D;
         }
         continue;
@@ -8538,9 +9253,9 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     }
 
     Type = Type.getNonLValueExprType(Context).getUnqualifiedType();
-    auto *LHSVD = buildVarDecl(*this, ELoc, Type, ".reduction.lhs",
+    auto *LHSVD = buildVarDecl(S, ELoc, Type, ".reduction.lhs",
                                D->hasAttrs() ? &D->getAttrs() : nullptr);
-    auto *RHSVD = buildVarDecl(*this, ELoc, Type, D->getName(),
+    auto *RHSVD = buildVarDecl(S, ELoc, Type, D->getName(),
                                D->hasAttrs() ? &D->getAttrs() : nullptr);
     auto PrivateTy = Type;
     if (OASE ||
@@ -8552,19 +9267,20 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
       // For array subscripts or single variables Private Ty is the same as Type
       // (type of the variable or single array element).
       PrivateTy = Context.getVariableArrayType(
-          Type, new (Context) OpaqueValueExpr(SourceLocation(),
-                                              Context.getSizeType(), VK_RValue),
+          Type,
+          new (Context) OpaqueValueExpr(SourceLocation(), Context.getSizeType(),
+                                        VK_RValue),
           ArrayType::Normal, /*IndexTypeQuals=*/0, SourceRange());
     } else if (!ASE && !OASE &&
                Context.getAsArrayType(D->getType().getNonReferenceType()))
       PrivateTy = D->getType().getNonReferenceType();
     // Private copy.
-    auto *PrivateVD = buildVarDecl(*this, ELoc, PrivateTy, D->getName(),
+    auto *PrivateVD = buildVarDecl(S, ELoc, PrivateTy, D->getName(),
                                    D->hasAttrs() ? &D->getAttrs() : nullptr);
     // Add initializer for private variable.
     Expr *Init = nullptr;
-    auto *LHSDRE = buildDeclRefExpr(*this, LHSVD, Type, ELoc);
-    auto *RHSDRE = buildDeclRefExpr(*this, RHSVD, Type, ELoc);
+    auto *LHSDRE = buildDeclRefExpr(S, LHSVD, Type, ELoc);
+    auto *RHSDRE = buildDeclRefExpr(S, RHSVD, Type, ELoc);
     if (DeclareReductionRef.isUsable()) {
       auto *DRDRef = DeclareReductionRef.getAs<DeclRefExpr>();
       auto *DRD = cast<OMPDeclareReductionDecl>(DRDRef->getDecl());
@@ -8581,13 +9297,13 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
       case BO_LOr:
         // '+', '-', '^', '|', '||' reduction ops - initializer is '0'.
         if (Type->isScalarType() || Type->isAnyComplexType())
-          Init = ActOnIntegerConstant(ELoc, /*Val=*/0).get();
+          Init = S.ActOnIntegerConstant(ELoc, /*Val=*/0).get();
         break;
       case BO_Mul:
       case BO_LAnd:
         if (Type->isScalarType() || Type->isAnyComplexType()) {
           // '*' and '&&' reduction ops - initializer is '1'.
-          Init = ActOnIntegerConstant(ELoc, /*Val=*/1).get();
+          Init = S.ActOnIntegerConstant(ELoc, /*Val=*/1).get();
         }
         break;
       case BO_And: {
@@ -8610,7 +9326,7 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
         if (Init && OrigType->isAnyComplexType()) {
           // Init = 0xFFFF + 0xFFFFi;
           auto *Im = new (Context) ImaginaryLiteral(Init, OrigType);
-          Init = CreateBuiltinBinOp(ELoc, BO_Add, Init, Im).get();
+          Init = S.CreateBuiltinBinOp(ELoc, BO_Add, Init, Im).get();
         }
         Type = OrigType;
         break;
@@ -8627,15 +9343,14 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
           QualType IntTy =
               Context.getIntTypeForBitwidth(Size, /*Signed=*/IsSigned);
           llvm::APInt InitValue =
-              (BOK != BO_LT)
-                  ? IsSigned ? llvm::APInt::getSignedMinValue(Size)
-                             : llvm::APInt::getMinValue(Size)
-                  : IsSigned ? llvm::APInt::getSignedMaxValue(Size)
-                             : llvm::APInt::getMaxValue(Size);
+              (BOK != BO_LT) ? IsSigned ? llvm::APInt::getSignedMinValue(Size)
+                                        : llvm::APInt::getMinValue(Size)
+                             : IsSigned ? llvm::APInt::getSignedMaxValue(Size)
+                                        : llvm::APInt::getMaxValue(Size);
           Init = IntegerLiteral::Create(Context, InitValue, IntTy, ELoc);
           if (Type->isPointerType()) {
             // Cast to pointer type.
-            auto CastExpr = BuildCStyleCastExpr(
+            auto CastExpr = S.BuildCStyleCastExpr(
                 SourceLocation(), Context.getTrivialTypeSourceInfo(Type, ELoc),
                 SourceLocation(), Init);
             if (CastExpr.isInvalid())
@@ -8676,20 +9391,19 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
         llvm_unreachable("Unexpected reduction operation");
       }
     }
-    if (Init && DeclareReductionRef.isUnset()) {
-      AddInitializerToDecl(RHSVD, Init, /*DirectInit=*/false);
-    } else if (!Init)
-      ActOnUninitializedDecl(RHSVD);
+    if (Init && DeclareReductionRef.isUnset())
+      S.AddInitializerToDecl(RHSVD, Init, /*DirectInit=*/false);
+    else if (!Init)
+      S.ActOnUninitializedDecl(RHSVD);
     if (RHSVD->isInvalidDecl())
       continue;
     if (!RHSVD->hasInit() && DeclareReductionRef.isUnset()) {
-      Diag(ELoc, diag::err_omp_reduction_id_not_compatible) << Type
-                                                            << ReductionIdRange;
-      bool IsDecl =
-          !VD ||
-          VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
-      Diag(D->getLocation(),
-           IsDecl ? diag::note_previous_decl : diag::note_defined_here)
+      S.Diag(ELoc, diag::err_omp_reduction_id_not_compatible)
+          << Type << ReductionIdRange;
+      bool IsDecl = !VD || VD->isThisDeclarationADefinition(Context) ==
+                               VarDecl::DeclarationOnly;
+      S.Diag(D->getLocation(),
+             IsDecl ? diag::note_previous_decl : diag::note_defined_here)
           << D;
       continue;
     }
@@ -8697,16 +9411,16 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
     // codegen.
     PrivateVD->setInit(RHSVD->getInit());
     PrivateVD->setInitStyle(RHSVD->getInitStyle());
-    auto *PrivateDRE = buildDeclRefExpr(*this, PrivateVD, PrivateTy, ELoc);
+    auto *PrivateDRE = buildDeclRefExpr(S, PrivateVD, PrivateTy, ELoc);
     ExprResult ReductionOp;
     if (DeclareReductionRef.isUsable()) {
       QualType RedTy = DeclareReductionRef.get()->getType();
       QualType PtrRedTy = Context.getPointerType(RedTy);
-      ExprResult LHS = CreateBuiltinUnaryOp(ELoc, UO_AddrOf, LHSDRE);
-      ExprResult RHS = CreateBuiltinUnaryOp(ELoc, UO_AddrOf, RHSDRE);
+      ExprResult LHS = S.CreateBuiltinUnaryOp(ELoc, UO_AddrOf, LHSDRE);
+      ExprResult RHS = S.CreateBuiltinUnaryOp(ELoc, UO_AddrOf, RHSDRE);
       if (!BasePath.empty()) {
-        LHS = DefaultLvalueConversion(LHS.get());
-        RHS = DefaultLvalueConversion(RHS.get());
+        LHS = S.DefaultLvalueConversion(LHS.get());
+        RHS = S.DefaultLvalueConversion(RHS.get());
         LHS = ImplicitCastExpr::Create(Context, PtrRedTy,
                                        CK_UncheckedDerivedToBase, LHS.get(),
                                        &BasePath, LHS.get()->getValueKind());
@@ -8719,27 +9433,27 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
       QualType FnTy = Context.getFunctionType(Context.VoidTy, Params, EPI);
       auto *OVE = new (Context) OpaqueValueExpr(
           ELoc, Context.getPointerType(FnTy), VK_RValue, OK_Ordinary,
-          DefaultLvalueConversion(DeclareReductionRef.get()).get());
+          S.DefaultLvalueConversion(DeclareReductionRef.get()).get());
       Expr *Args[] = {LHS.get(), RHS.get()};
       ReductionOp = new (Context)
           CallExpr(Context, OVE, Args, Context.VoidTy, VK_RValue, ELoc);
     } else {
-      ReductionOp = BuildBinOp(DSAStack->getCurScope(),
-                               ReductionId.getLocStart(), BOK, LHSDRE, RHSDRE);
+      ReductionOp = S.BuildBinOp(
+          Stack->getCurScope(), ReductionId.getLocStart(), BOK, LHSDRE, RHSDRE);
       if (ReductionOp.isUsable()) {
         if (BOK != BO_LT && BOK != BO_GT) {
           ReductionOp =
-              BuildBinOp(DSAStack->getCurScope(), ReductionId.getLocStart(),
-                         BO_Assign, LHSDRE, ReductionOp.get());
+              S.BuildBinOp(Stack->getCurScope(), ReductionId.getLocStart(),
+                           BO_Assign, LHSDRE, ReductionOp.get());
         } else {
           auto *ConditionalOp = new (Context) ConditionalOperator(
               ReductionOp.get(), SourceLocation(), LHSDRE, SourceLocation(),
               RHSDRE, Type, VK_LValue, OK_Ordinary);
           ReductionOp =
-              BuildBinOp(DSAStack->getCurScope(), ReductionId.getLocStart(),
-                         BO_Assign, LHSDRE, ConditionalOp);
+              S.BuildBinOp(Stack->getCurScope(), ReductionId.getLocStart(),
+                           BO_Assign, LHSDRE, ConditionalOp);
         }
-        ReductionOp = ActOnFinishFullExpr(ReductionOp.get());
+        ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get());
       }
       if (ReductionOp.isInvalid())
         continue;
@@ -8747,48 +9461,86 @@ OMPClause *Sema::ActOnOpenMPReductionClause(
 
     DeclRefExpr *Ref = nullptr;
     Expr *VarsExpr = RefExpr->IgnoreParens();
-    if (!VD && !CurContext->isDependentContext()) {
+    if (!VD && !S.CurContext->isDependentContext()) {
       if (ASE || OASE) {
-        TransformExprToCaptures RebuildToCapture(*this, D);
+        TransformExprToCaptures RebuildToCapture(S, D);
         VarsExpr =
             RebuildToCapture.TransformExpr(RefExpr->IgnoreParens()).get();
         Ref = RebuildToCapture.getCapturedExpr();
       } else {
-        VarsExpr = Ref =
-            buildCapture(*this, D, SimpleRefExpr, /*WithInit=*/false);
+        VarsExpr = Ref = buildCapture(S, D, SimpleRefExpr, /*WithInit=*/false);
       }
-      if (!IsOpenMPCapturedDecl(D)) {
-        ExprCaptures.push_back(Ref->getDecl());
+      if (!S.IsOpenMPCapturedDecl(D)) {
+        RD.ExprCaptures.emplace_back(Ref->getDecl());
         if (Ref->getDecl()->hasAttr<OMPCaptureNoInitAttr>()) {
-          ExprResult RefRes = DefaultLvalueConversion(Ref);
+          ExprResult RefRes = S.DefaultLvalueConversion(Ref);
           if (!RefRes.isUsable())
             continue;
           ExprResult PostUpdateRes =
-              BuildBinOp(DSAStack->getCurScope(), ELoc, BO_Assign,
-                         SimpleRefExpr, RefRes.get());
+              S.BuildBinOp(Stack->getCurScope(), ELoc, BO_Assign, SimpleRefExpr,
+                           RefRes.get());
           if (!PostUpdateRes.isUsable())
             continue;
-          ExprPostUpdates.push_back(
-              IgnoredValueConversions(PostUpdateRes.get()).get());
+          if (isOpenMPTaskingDirective(Stack->getCurrentDirective()) ||
+              Stack->getCurrentDirective() == OMPD_taskgroup) {
+            S.Diag(RefExpr->getExprLoc(),
+                   diag::err_omp_reduction_non_addressable_expression)
+                << RefExpr->getSourceRange();
+            continue;
+          }
+          RD.ExprPostUpdates.emplace_back(
+              S.IgnoredValueConversions(PostUpdateRes.get()).get());
         }
       }
     }
-    DSAStack->addDSA(D, RefExpr->IgnoreParens(), OMPC_reduction, Ref);
-    Vars.push_back(VarsExpr);
-    Privates.push_back(PrivateDRE);
-    LHSs.push_back(LHSDRE);
-    RHSs.push_back(RHSDRE);
-    ReductionOps.push_back(ReductionOp.get());
+    // All reduction items are still marked as reduction (to do not increase
+    // code base size).
+    Stack->addDSA(D, RefExpr->IgnoreParens(), OMPC_reduction, Ref);
+    RD.push(VarsExpr, PrivateDRE, LHSDRE, RHSDRE, ReductionOp.get());
   }
+  return RD.Vars.empty();
+}
 
-  if (Vars.empty())
+OMPClause *Sema::ActOnOpenMPReductionClause(
+    ArrayRef<Expr *> VarList, SourceLocation StartLoc, SourceLocation LParenLoc,
+    SourceLocation ColonLoc, SourceLocation EndLoc,
+    CXXScopeSpec &ReductionIdScopeSpec, const DeclarationNameInfo &ReductionId,
+    ArrayRef<Expr *> UnresolvedReductions) {
+  ReductionData RD(VarList.size());
+
+  if (ActOnOMPReductionKindClause(*this, DSAStack, OMPC_reduction, VarList,
+                                  StartLoc, LParenLoc, ColonLoc, EndLoc,
+                                  ReductionIdScopeSpec, ReductionId,
+                                  UnresolvedReductions, RD))
     return nullptr;
 
   return OMPReductionClause::Create(
-      Context, StartLoc, LParenLoc, ColonLoc, EndLoc, Vars,
-      ReductionIdScopeSpec.getWithLocInContext(Context), ReductionId, Privates,
-      LHSs, RHSs, ReductionOps, buildPreInits(Context, ExprCaptures),
-      buildPostUpdate(*this, ExprPostUpdates));
+      Context, StartLoc, LParenLoc, ColonLoc, EndLoc, RD.Vars,
+      ReductionIdScopeSpec.getWithLocInContext(Context), ReductionId,
+      RD.Privates, RD.LHSs, RD.RHSs, RD.ReductionOps,
+      buildPreInits(Context, RD.ExprCaptures),
+      buildPostUpdate(*this, RD.ExprPostUpdates));
+}
+
+OMPClause *Sema::ActOnOpenMPTaskReductionClause(
+    ArrayRef<Expr *> VarList, SourceLocation StartLoc, SourceLocation LParenLoc,
+    SourceLocation ColonLoc, SourceLocation EndLoc,
+    CXXScopeSpec &ReductionIdScopeSpec, const DeclarationNameInfo &ReductionId,
+    ArrayRef<Expr *> UnresolvedReductions) {
+  ReductionData RD(VarList.size());
+
+  if (ActOnOMPReductionKindClause(*this, DSAStack, OMPC_task_reduction,
+                                  VarList, StartLoc, LParenLoc, ColonLoc,
+                                  EndLoc, ReductionIdScopeSpec, ReductionId,
+                                  UnresolvedReductions, RD))
+    return nullptr;
+
+  return OMPTaskReductionClause::Create(
+      Context, StartLoc, LParenLoc, ColonLoc, EndLoc, RD.Vars,
+      ReductionIdScopeSpec.getWithLocInContext(Context), ReductionId,
+      RD.Privates, RD.LHSs, RD.RHSs, RD.ReductionOps,
+      buildPreInits(Context, RD.ExprCaptures),
+      buildPostUpdate(*this, RD.ExprPostUpdates));
 }
 
 bool Sema::CheckOpenMPLinearModifier(OpenMPLinearClauseKind LinKind,
@@ -10451,7 +11203,8 @@ void Sema::ActOnOpenMPDeclareReductionCombinerStart(Scope *S, Decl *D) {
   else
     CurContext = DRD;
 
-  PushExpressionEvaluationContext(PotentiallyEvaluated);
+  PushExpressionEvaluationContext(
+      ExpressionEvaluationContext::PotentiallyEvaluated);
 
   QualType ReductionType = DRD->getType();
   // Create 'T* omp_parm;T omp_in;'. All references to 'omp_in' will
@@ -10505,7 +11258,8 @@ void Sema::ActOnOpenMPDeclareReductionInitializerStart(Scope *S, Decl *D) {
   else
     CurContext = DRD;
 
-  PushExpressionEvaluationContext(PotentiallyEvaluated);
+  PushExpressionEvaluationContext(
+      ExpressionEvaluationContext::PotentiallyEvaluated);
 
   QualType ReductionType = DRD->getType();
   // Create 'T* omp_parm;T omp_priv;'. All references to 'omp_priv' will
@@ -10566,6 +11320,8 @@ OMPClause *Sema::ActOnOpenMPNumTeamsClause(Expr *NumTeams,
                                            SourceLocation LParenLoc,
                                            SourceLocation EndLoc) {
   Expr *ValExpr = NumTeams;
+  Stmt *HelperValStmt = nullptr;
+  OpenMPDirectiveKind CaptureRegion = OMPD_unknown;
 
   // OpenMP [teams Constrcut, Restrictions]
   // The num_teams expression must evaluate to a positive integer value.
@@ -10573,7 +11329,16 @@ OMPClause *Sema::ActOnOpenMPNumTeamsClause(Expr *NumTeams,
                                  /*StrictlyPositive=*/true))
     return nullptr;
 
-  return new (Context) OMPNumTeamsClause(ValExpr, StartLoc, LParenLoc, EndLoc);
+  OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
+  CaptureRegion = getOpenMPCaptureRegionForClause(DKind, OMPC_num_teams);
+  if (CaptureRegion != OMPD_unknown) {
+    llvm::MapVector<Expr *, DeclRefExpr *> Captures;
+    ValExpr = tryBuildCapture(*this, ValExpr, Captures).get();
+    HelperValStmt = buildPreInits(Context, Captures);
+  }
+
+  return new (Context) OMPNumTeamsClause(ValExpr, HelperValStmt, CaptureRegion,
+                                         StartLoc, LParenLoc, EndLoc);
 }
 
 OMPClause *Sema::ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,
@@ -10581,6 +11346,8 @@ OMPClause *Sema::ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,
                                               SourceLocation LParenLoc,
                                               SourceLocation EndLoc) {
   Expr *ValExpr = ThreadLimit;
+  Stmt *HelperValStmt = nullptr;
+  OpenMPDirectiveKind CaptureRegion = OMPD_unknown;
 
   // OpenMP [teams Constrcut, Restrictions]
   // The thread_limit expression must evaluate to a positive integer value.
@@ -10588,8 +11355,16 @@ OMPClause *Sema::ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,
                                  /*StrictlyPositive=*/true))
     return nullptr;
 
-  return new (Context)
-      OMPThreadLimitClause(ValExpr, StartLoc, LParenLoc, EndLoc);
+  OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
+  CaptureRegion = getOpenMPCaptureRegionForClause(DKind, OMPC_thread_limit);
+  if (CaptureRegion != OMPD_unknown) {
+    llvm::MapVector<Expr *, DeclRefExpr *> Captures;
+    ValExpr = tryBuildCapture(*this, ValExpr, Captures).get();
+    HelperValStmt = buildPreInits(Context, Captures);
+  }
+
+  return new (Context) OMPThreadLimitClause(
+      ValExpr, HelperValStmt, CaptureRegion, StartLoc, LParenLoc, EndLoc);
 }
 
 OMPClause *Sema::ActOnOpenMPPriorityClause(Expr *Priority,