diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 4778dc9d3df88..e7130d2fe68e7 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -1153,6 +1153,7 @@ class Parser : public CodeCompletionHandler {
     virtual void ParseLexedMemberInitializers();
     virtual void ParseLexedMethodDefs();
     virtual void ParseLexedAttributes();
+    virtual void ParseLexedPragmas();
   };
 
   /// Inner node of the LateParsedDeclaration tree that parses
@@ -1166,6 +1167,7 @@ class Parser : public CodeCompletionHandler {
     void ParseLexedMemberInitializers() override;
     void ParseLexedMethodDefs() override;
     void ParseLexedAttributes() override;
+    void ParseLexedPragmas() override;
 
   private:
     Parser *Self;
@@ -1195,6 +1197,26 @@ class Parser : public CodeCompletionHandler {
     void addDecl(Decl *D) { Decls.push_back(D); }
   };
 
+  /// Contains the lexed tokens of a pragma with arguments that
+  /// may reference member variables and so need to be parsed at the
+  /// end of the class declaration after parsing all other member
+  /// member declarations.
+  class LateParsedPragma : public LateParsedDeclaration {
+    Parser *Self = nullptr;
+    AccessSpecifier AS = AS_none;
+    CachedTokens Toks;
+
+  public:
+    explicit LateParsedPragma(Parser *P, AccessSpecifier AS)
+        : Self(P), AS(AS) {}
+
+    void takeToks(CachedTokens &Cached) { Toks.swap(Cached); }
+    const CachedTokens &toks() const { return Toks; }
+    AccessSpecifier getAccessSpecifier() const { return AS; }
+
+    void ParseLexedPragmas() override;
+  };
+
   // A list of late-parsed attributes.  Used by ParseGNUAttributes.
   class LateParsedAttrList: public SmallVector<LateParsedAttribute *, 2> {
   public:
@@ -1454,6 +1476,8 @@ class Parser : public CodeCompletionHandler {
   void ParseLexedMemberInitializers(ParsingClass &Class);
   void ParseLexedMemberInitializer(LateParsedMemberInitializer &MI);
   void ParseLexedObjCMethodDefs(LexedMethod &LM, bool parseMethod);
+  void ParseLexedPragmas(ParsingClass &Class);
+  void ParseLexedPragma(LateParsedPragma &LP);
   bool ConsumeAndStoreFunctionPrologue(CachedTokens &Toks);
   bool ConsumeAndStoreInitializer(CachedTokens &Toks, CachedInitKind CIK);
   bool ConsumeAndStoreConditional(CachedTokens &Toks);
@@ -2875,7 +2899,7 @@ class Parser : public CodeCompletionHandler {
   /// Parses declarative OpenMP directives.
   DeclGroupPtrTy ParseOpenMPDeclarativeDirectiveWithExtDecl(
       AccessSpecifier &AS, ParsedAttributesWithRange &Attrs,
-      DeclSpec::TST TagType = DeclSpec::TST_unspecified,
+      bool Delayed = false, DeclSpec::TST TagType = DeclSpec::TST_unspecified,
       Decl *TagDecl = nullptr);
   /// Parse 'omp declare reduction' construct.
   DeclGroupPtrTy ParseOpenMPDeclareReductionDirective(AccessSpecifier AS);
diff --git a/clang/lib/Parse/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
index aa314da8e5b40..f8b5fec438007 100644
--- a/clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -223,6 +223,7 @@ Parser::LateParsedDeclaration::~LateParsedDeclaration() {}
 void Parser::LateParsedDeclaration::ParseLexedMethodDeclarations() {}
 void Parser::LateParsedDeclaration::ParseLexedMemberInitializers() {}
 void Parser::LateParsedDeclaration::ParseLexedMethodDefs() {}
+void Parser::LateParsedDeclaration::ParseLexedPragmas() {}
 
 Parser::LateParsedClass::LateParsedClass(Parser *P, ParsingClass *C)
   : Self(P), Class(C) {}
@@ -243,6 +244,10 @@ void Parser::LateParsedClass::ParseLexedMethodDefs() {
   Self->ParseLexedMethodDefs(*Class);
 }
 
+void Parser::LateParsedClass::ParseLexedPragmas() {
+  Self->ParseLexedPragmas(*Class);
+}
+
 void Parser::LateParsedMethodDeclaration::ParseLexedMethodDeclarations() {
   Self->ParseLexedMethodDeclaration(*this);
 }
@@ -255,6 +260,10 @@ void Parser::LateParsedMemberInitializer::ParseLexedMemberInitializers() {
   Self->ParseLexedMemberInitializer(*this);
 }
 
+void Parser::LateParsedPragma::ParseLexedPragmas() {
+  Self->ParseLexedPragma(*this);
+}
+
 /// ParseLexedMethodDeclarations - We finished parsing the member
 /// specification of a top (non-nested) C++ class. Now go over the
 /// stack of method declarations with some parts for which parsing was
@@ -651,6 +660,43 @@ void Parser::ParseLexedMemberInitializer(LateParsedMemberInitializer &MI) {
     ConsumeAnyToken();
 }
 
+void Parser::ParseLexedPragmas(ParsingClass &Class) {
+  bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
+  ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
+                                HasTemplateScope);
+  TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
+  if (HasTemplateScope) {
+    Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
+    ++CurTemplateDepthTracker;
+  }
+  bool HasClassScope = !Class.TopLevelClass;
+  ParseScope ClassScope(this, Scope::ClassScope | Scope::DeclScope,
+                        HasClassScope);
+
+  for (LateParsedDeclaration *LPD : Class.LateParsedDeclarations)
+    LPD->ParseLexedPragmas();
+}
+
+void Parser::ParseLexedPragma(LateParsedPragma &LP) {
+  PP.EnterToken(Tok, /*IsReinject=*/true);
+  PP.EnterTokenStream(LP.toks(), /*DisableMacroExpansion=*/true,
+                      /*IsReinject=*/true);
+
+  // Consume the previously pushed token.
+  ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
+  assert(Tok.isAnnotation() && "Expected annotation token.");
+  switch (Tok.getKind()) {
+  case tok::annot_pragma_openmp: {
+    AccessSpecifier AS = LP.getAccessSpecifier();
+    ParsedAttributesWithRange Attrs(AttrFactory);
+    (void)ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, Attrs);
+    break;
+  }
+  default:
+    llvm_unreachable("Unexpected token.");
+  }
+}
+
 /// ConsumeAndStoreUntil - Consume and store the token at the passed token
 /// container until the token 'T' is reached (which gets
 /// consumed/stored too, if ConsumeFinalToken).
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index fe409327bfb4b..ca2497ef6121d 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -3136,8 +3136,8 @@ Parser::DeclGroupPtrTy Parser::ParseCXXClassMemberDeclarationWithPragmas(
   }
 
   case tok::annot_pragma_openmp:
-    return ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, AccessAttrs, TagType,
-                                                      TagDecl);
+    return ParseOpenMPDeclarativeDirectiveWithExtDecl(
+        AS, AccessAttrs, /*Delayed=*/true, TagType, TagDecl);
 
   default:
     if (tok::isPragmaAnnotation(Tok.getKind())) {
@@ -3355,6 +3355,7 @@ void Parser::ParseCXXMemberSpecification(SourceLocation RecordLoc,
     // declarations and the lexed inline method definitions, along with any
     // delayed attributes.
     SourceLocation SavedPrevTokLocation = PrevTokLocation;
+    ParseLexedPragmas(getCurrentClass());
     ParseLexedAttributes(getCurrentClass());
     ParseLexedMethodDeclarations(getCurrentClass());
 
diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index aaef4cd36d3bd..31ae3af70b714 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -1336,14 +1336,45 @@ void Parser::ParseOMPEndDeclareTargetDirective(OpenMPDirectiveKind DKind,
 ///         annot_pragma_openmp_end
 ///
 Parser::DeclGroupPtrTy Parser::ParseOpenMPDeclarativeDirectiveWithExtDecl(
-    AccessSpecifier &AS, ParsedAttributesWithRange &Attrs,
+    AccessSpecifier &AS, ParsedAttributesWithRange &Attrs, bool Delayed,
     DeclSpec::TST TagType, Decl *Tag) {
   assert(Tok.is(tok::annot_pragma_openmp) && "Not an OpenMP directive!");
   ParsingOpenMPDirectiveRAII DirScope(*this);
   ParenBraceBracketBalancer BalancerRAIIObj(*this);
 
-  SourceLocation Loc = ConsumeAnnotationToken();
-  OpenMPDirectiveKind DKind = parseOpenMPDirectiveKind(*this);
+  SourceLocation Loc;
+  OpenMPDirectiveKind DKind;
+  if (Delayed) {
+    TentativeParsingAction TPA(*this);
+    Loc = ConsumeAnnotationToken();
+    DKind = parseOpenMPDirectiveKind(*this);
+    if (DKind == OMPD_declare_reduction || DKind == OMPD_declare_mapper) {
+      // Need to delay parsing until completion of the parent class.
+      TPA.Revert();
+      CachedTokens Toks;
+      unsigned Cnt = 1;
+      Toks.push_back(Tok);
+      while (Cnt && Tok.isNot(tok::eof)) {
+        (void)ConsumeAnyToken();
+        if (Tok.is(tok::annot_pragma_openmp))
+          ++Cnt;
+        else if (Tok.is(tok::annot_pragma_openmp_end))
+          --Cnt;
+        Toks.push_back(Tok);
+      }
+      // Skip last annot_pragma_openmp_end.
+      if (Cnt == 0)
+        (void)ConsumeAnyToken();
+      auto *LP = new LateParsedPragma(this, AS);
+      LP->takeToks(Toks);
+      getCurrentClass().LateParsedDeclarations.push_back(LP);
+      return nullptr;
+    }
+    TPA.Commit();
+  } else {
+    Loc = ConsumeAnnotationToken();
+    DKind = parseOpenMPDirectiveKind(*this);
+  }
 
   switch (DKind) {
   case OMPD_threadprivate: {
@@ -1495,7 +1526,8 @@ Parser::DeclGroupPtrTy Parser::ParseOpenMPDeclarativeDirectiveWithExtDecl(
 
     DeclGroupPtrTy Ptr;
     if (Tok.is(tok::annot_pragma_openmp)) {
-      Ptr = ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, Attrs, TagType, Tag);
+      Ptr = ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, Attrs, Delayed,
+                                                       TagType, Tag);
     } else if (Tok.isNot(tok::r_brace) && !isEofOrEom()) {
       // Here we expect to see some function declaration.
       if (AS == AS_none) {
diff --git a/clang/test/OpenMP/declare_mapper_messages.cpp b/clang/test/OpenMP/declare_mapper_messages.cpp
index 7b50fb2a52c27..bd91cdad8f40d 100644
--- a/clang/test/OpenMP/declare_mapper_messages.cpp
+++ b/clang/test/OpenMP/declare_mapper_messages.cpp
@@ -8,12 +8,12 @@
 
 int temp; // expected-note {{'temp' declared here}}
 
-class vec {                                                             // expected-note {{definition of 'vec' is not complete until the closing '}'}}
+class vec {
 private:
   int p;                                                                // expected-note {{declared private here}}
 public:
   int len;
-#pragma omp declare mapper(id: vec v) map(v.len)                        // expected-error {{member access into incomplete type 'vec'}}
+#pragma omp declare mapper(id: vec v) map(v.len)
   double *data;
 };
 
diff --git a/clang/test/OpenMP/declare_reduction_codegen.cpp b/clang/test/OpenMP/declare_reduction_codegen.cpp
index 1f6fa2bebea36..129823c6bf6a5 100644
--- a/clang/test/OpenMP/declare_reduction_codegen.cpp
+++ b/clang/test/OpenMP/declare_reduction_codegen.cpp
@@ -69,6 +69,8 @@ struct SSS {
   T a;
   SSS() : a() {}
 #pragma omp declare reduction(fun : T : omp_out ^= omp_in) initializer(omp_priv = 24 + omp_orig)
+#pragma omp declare reduction(sssss : T : ssssss(omp_in)) initializer(omp_priv = 18 + omp_orig)
+  static void ssssss(T &x);
 };
 
 SSS<int> d;
@@ -85,6 +87,17 @@ SSS<int> d;
 // CHECK-NEXT: ret void
 // CHECK-NEXT: }
 
+// CHECK: define internal {{.*}}void @{{[^(]+}}(i32* noalias %0, i32* noalias %1)
+// CHECK: call void @_ZN3SSSIiE6ssssssERi(i32* dereferenceable{{.*}})
+// CHECK-NEXT: ret void
+// CHECK-NEXT: }
+
+// CHECK: define internal {{.*}}void @{{[^(]+}}(i32* noalias %0, i32* noalias %1)
+// CHECK: [[ADD:%.+]] = add nsw i32 18,
+// CHECK-NEXT: store i32 [[ADD]], i32*
+// CHECK-NEXT: ret void
+// CHECK-NEXT: }
+
 template <typename T>
 void init(T &lhs, T &rhs) {}
 
diff --git a/clang/test/OpenMP/declare_reduction_messages.cpp b/clang/test/OpenMP/declare_reduction_messages.cpp
index eeafe9032e080..b1e59591d998d 100644
--- a/clang/test/OpenMP/declare_reduction_messages.cpp
+++ b/clang/test/OpenMP/declare_reduction_messages.cpp
@@ -166,6 +166,8 @@ struct S
   void foo(S &x) {};
   // expected-error@+1 {{too many arguments to function call, expected single argument 'x', have 2 arguments}}
   #pragma omp declare reduction (foo : U, S : omp_out.foo(omp_in, false))
+  #pragma omp declare reduction (xxx : U, S : bar(omp_in)) // expected-error {{non-const lvalue reference to type 'S<1>' cannot bind to a value of unrelated type 'U'}}
+  static void bar(S &x); // expected-note {{passing argument to parameter 'x' here}}
 };
 // expected-warning@+2 {{extra tokens at the end of '#pragma omp declare reduction' are ignored}}
 // expected-note@+1 {{in instantiation of template class 'S<1>' requested here}}