Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 1777 deletions

diff --git a/gnu/llvm/tools/clang/lib/Sema/SemaLambda.cpp b/gnu/llvm/tools/clang/lib/Sema/SemaLambda.cpp
deleted file mode 100644
index 4e002a853dc..00000000000
--- a/gnu/llvm/tools/clang/lib/Sema/SemaLambda.cpp
+++ /dev/null
@@ -1,1777 +0,0 @@
-//===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file implements semantic analysis for C++ lambda expressions.
-//
-//===----------------------------------------------------------------------===//
-#include "clang/Sema/DeclSpec.h"
-#include "TypeLocBuilder.h"
-#include "clang/AST/ASTLambda.h"
-#include "clang/AST/ExprCXX.h"
-#include "clang/Basic/TargetInfo.h"
-#include "clang/Sema/Initialization.h"
-#include "clang/Sema/Lookup.h"
-#include "clang/Sema/Scope.h"
-#include "clang/Sema/ScopeInfo.h"
-#include "clang/Sema/SemaInternal.h"
-#include "clang/Sema/SemaLambda.h"
-using namespace clang;
-using namespace sema;
-
-/// Examines the FunctionScopeInfo stack to determine the nearest
-/// enclosing lambda (to the current lambda) that is 'capture-ready' for
-/// the variable referenced in the current lambda (i.e. \p VarToCapture).
-/// If successful, returns the index into Sema's FunctionScopeInfo stack
-/// of the capture-ready lambda's LambdaScopeInfo.
-///
-/// Climbs down the stack of lambdas (deepest nested lambda - i.e. current
-/// lambda - is on top) to determine the index of the nearest enclosing/outer
-/// lambda that is ready to capture the \p VarToCapture being referenced in
-/// the current lambda.
-/// As we climb down the stack, we want the index of the first such lambda -
-/// that is the lambda with the highest index that is 'capture-ready'.
-///
-/// A lambda 'L' is capture-ready for 'V' (var or this) if:
-///  - its enclosing context is non-dependent
-///  - and if the chain of lambdas between L and the lambda in which
-///    V is potentially used (i.e. the lambda at the top of the scope info
-///    stack), can all capture or have already captured V.
-/// If \p VarToCapture is 'null' then we are trying to capture 'this'.
-///
-/// Note that a lambda that is deemed 'capture-ready' still needs to be checked
-/// for whether it is 'capture-capable' (see
-/// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly
-/// capture.
-///
-/// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
-///  LambdaScopeInfo inherits from).  The current/deepest/innermost lambda
-///  is at the top of the stack and has the highest index.
-/// \param VarToCapture - the variable to capture.  If NULL, capture 'this'.
-///
-/// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
-/// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
-/// which is capture-ready.  If the return value evaluates to 'false' then
-/// no lambda is capture-ready for \p VarToCapture.
-
-static inline Optional<unsigned>
-getStackIndexOfNearestEnclosingCaptureReadyLambda(
-    ArrayRef<const clang::sema::FunctionScopeInfo *> FunctionScopes,
-    VarDecl *VarToCapture) {
-  // Label failure to capture.
-  const Optional<unsigned> NoLambdaIsCaptureReady;
-
-  // Ignore all inner captured regions.
-  unsigned CurScopeIndex = FunctionScopes.size() - 1;
-  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
-                                  FunctionScopes[CurScopeIndex]))
-    --CurScopeIndex;
-  assert(
-      isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
-      "The function on the top of sema's function-info stack must be a lambda");
-
-  // If VarToCapture is null, we are attempting to capture 'this'.
-  const bool IsCapturingThis = !VarToCapture;
-  const bool IsCapturingVariable = !IsCapturingThis;
-
-  // Start with the current lambda at the top of the stack (highest index).
-  DeclContext *EnclosingDC =
-      cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
-
-  do {
-    const clang::sema::LambdaScopeInfo *LSI =
-        cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]);
-    // IF we have climbed down to an intervening enclosing lambda that contains
-    // the variable declaration - it obviously can/must not capture the
-    // variable.
-    // Since its enclosing DC is dependent, all the lambdas between it and the
-    // innermost nested lambda are dependent (otherwise we wouldn't have
-    // arrived here) - so we don't yet have a lambda that can capture the
-    // variable.
-    if (IsCapturingVariable &&
-        VarToCapture->getDeclContext()->Equals(EnclosingDC))
-      return NoLambdaIsCaptureReady;
-
-    // For an enclosing lambda to be capture ready for an entity, all
-    // intervening lambda's have to be able to capture that entity. If even
-    // one of the intervening lambda's is not capable of capturing the entity
-    // then no enclosing lambda can ever capture that entity.
-    // For e.g.
-    // const int x = 10;
-    // [=](auto a) {    #1
-    //   [](auto b) {   #2 <-- an intervening lambda that can never capture 'x'
-    //    [=](auto c) { #3
-    //       f(x, c);  <-- can not lead to x's speculative capture by #1 or #2
-    //    }; }; };
-    // If they do not have a default implicit capture, check to see
-    // if the entity has already been explicitly captured.
-    // If even a single dependent enclosing lambda lacks the capability
-    // to ever capture this variable, there is no further enclosing
-    // non-dependent lambda that can capture this variable.
-    if (LSI->ImpCaptureStyle == sema::LambdaScopeInfo::ImpCap_None) {
-      if (IsCapturingVariable && !LSI->isCaptured(VarToCapture))
-        return NoLambdaIsCaptureReady;
-      if (IsCapturingThis && !LSI->isCXXThisCaptured())
-        return NoLambdaIsCaptureReady;
-    }
-    EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
-
-    assert(CurScopeIndex);
-    --CurScopeIndex;
-  } while (!EnclosingDC->isTranslationUnit() &&
-           EnclosingDC->isDependentContext() &&
-           isLambdaCallOperator(EnclosingDC));
-
-  assert(CurScopeIndex < (FunctionScopes.size() - 1));
-  // If the enclosingDC is not dependent, then the immediately nested lambda
-  // (one index above) is capture-ready.
-  if (!EnclosingDC->isDependentContext())
-    return CurScopeIndex + 1;
-  return NoLambdaIsCaptureReady;
-}
-
-/// Examines the FunctionScopeInfo stack to determine the nearest
-/// enclosing lambda (to the current lambda) that is 'capture-capable' for
-/// the variable referenced in the current lambda (i.e. \p VarToCapture).
-/// If successful, returns the index into Sema's FunctionScopeInfo stack
-/// of the capture-capable lambda's LambdaScopeInfo.
-///
-/// Given the current stack of lambdas being processed by Sema and
-/// the variable of interest, to identify the nearest enclosing lambda (to the
-/// current lambda at the top of the stack) that can truly capture
-/// a variable, it has to have the following two properties:
-///  a) 'capture-ready' - be the innermost lambda that is 'capture-ready':
-///     - climb down the stack (i.e. starting from the innermost and examining
-///       each outer lambda step by step) checking if each enclosing
-///       lambda can either implicitly or explicitly capture the variable.
-///       Record the first such lambda that is enclosed in a non-dependent
-///       context. If no such lambda currently exists return failure.
-///  b) 'capture-capable' - make sure the 'capture-ready' lambda can truly
-///  capture the variable by checking all its enclosing lambdas:
-///     - check if all outer lambdas enclosing the 'capture-ready' lambda
-///       identified above in 'a' can also capture the variable (this is done
-///       via tryCaptureVariable for variables and CheckCXXThisCapture for
-///       'this' by passing in the index of the Lambda identified in step 'a')
-///
-/// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
-/// LambdaScopeInfo inherits from).  The current/deepest/innermost lambda
-/// is at the top of the stack.
-///
-/// \param VarToCapture - the variable to capture.  If NULL, capture 'this'.
-///
-///
-/// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
-/// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
-/// which is capture-capable.  If the return value evaluates to 'false' then
-/// no lambda is capture-capable for \p VarToCapture.
-
-Optional<unsigned> clang::getStackIndexOfNearestEnclosingCaptureCapableLambda(
-    ArrayRef<const sema::FunctionScopeInfo *> FunctionScopes,
-    VarDecl *VarToCapture, Sema &S) {
-
-  const Optional<unsigned> NoLambdaIsCaptureCapable;
-
-  const Optional<unsigned> OptionalStackIndex =
-      getStackIndexOfNearestEnclosingCaptureReadyLambda(FunctionScopes,
-                                                        VarToCapture);
-  if (!OptionalStackIndex)
-    return NoLambdaIsCaptureCapable;
-
-  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
-  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
-          S.getCurGenericLambda()) &&
-         "The capture ready lambda for a potential capture can only be the "
-         "current lambda if it is a generic lambda");
-
-  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
-      cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
-
-  // If VarToCapture is null, we are attempting to capture 'this'
-  const bool IsCapturingThis = !VarToCapture;
-  const bool IsCapturingVariable = !IsCapturingThis;
-
-  if (IsCapturingVariable) {
-    // Check if the capture-ready lambda can truly capture the variable, by
-    // checking whether all enclosing lambdas of the capture-ready lambda allow
-    // the capture - i.e. make sure it is capture-capable.
-    QualType CaptureType, DeclRefType;
-    const bool CanCaptureVariable =
-        !S.tryCaptureVariable(VarToCapture,
-                              /*ExprVarIsUsedInLoc*/ SourceLocation(),
-                              clang::Sema::TryCapture_Implicit,
-                              /*EllipsisLoc*/ SourceLocation(),
-                              /*BuildAndDiagnose*/ false, CaptureType,
-                              DeclRefType, &IndexOfCaptureReadyLambda);
-    if (!CanCaptureVariable)
-      return NoLambdaIsCaptureCapable;
-  } else {
-    // Check if the capture-ready lambda can truly capture 'this' by checking
-    // whether all enclosing lambdas of the capture-ready lambda can capture
-    // 'this'.
-    const bool CanCaptureThis =
-        !S.CheckCXXThisCapture(
-             CaptureReadyLambdaLSI->PotentialThisCaptureLocation,
-             /*Explicit*/ false, /*BuildAndDiagnose*/ false,
-             &IndexOfCaptureReadyLambda);
-    if (!CanCaptureThis)
-      return NoLambdaIsCaptureCapable;
-  }
-  return IndexOfCaptureReadyLambda;
-}
-
-static inline TemplateParameterList *
-getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef) {
-  if (LSI->GLTemplateParameterList)
-    return LSI->GLTemplateParameterList;
-
-  if (!LSI->AutoTemplateParams.empty()) {
-    SourceRange IntroRange = LSI->IntroducerRange;
-    SourceLocation LAngleLoc = IntroRange.getBegin();
-    SourceLocation RAngleLoc = IntroRange.getEnd();
-    LSI->GLTemplateParameterList = TemplateParameterList::Create(
-        SemaRef.Context,
-        /*Template kw loc*/ SourceLocation(), LAngleLoc,
-        llvm::makeArrayRef((NamedDecl *const *)LSI->AutoTemplateParams.data(),
-                           LSI->AutoTemplateParams.size()),
-        RAngleLoc, nullptr);
-  }
-  return LSI->GLTemplateParameterList;
-}
-
-CXXRecordDecl *Sema::createLambdaClosureType(SourceRange IntroducerRange,
-                                             TypeSourceInfo *Info,
-                                             bool KnownDependent,
-                                             LambdaCaptureDefault CaptureDefault) {
-  DeclContext *DC = CurContext;
-  while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
-    DC = DC->getParent();
-  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
-                                                               *this);
-  // Start constructing the lambda class.
-  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
-                                                     IntroducerRange.getBegin(),
-                                                     KnownDependent,
-                                                     IsGenericLambda,
-                                                     CaptureDefault);
-  DC->addDecl(Class);
-
-  return Class;
-}
-
-/// Determine whether the given context is or is enclosed in an inline
-/// function.
-static bool isInInlineFunction(const DeclContext *DC) {
-  while (!DC->isFileContext()) {
-    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
-      if (FD->isInlined())
-        return true;
-
-    DC = DC->getLexicalParent();
-  }
-
-  return false;
-}
-
-MangleNumberingContext *
-Sema::getCurrentMangleNumberContext(const DeclContext *DC,
-                                    Decl *&ManglingContextDecl) {
-  // Compute the context for allocating mangling numbers in the current
-  // expression, if the ABI requires them.
-  ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
-
-  enum ContextKind {
-    Normal,
-    DefaultArgument,
-    DataMember,
-    StaticDataMember,
-    InlineVariable,
-    VariableTemplate
-  } Kind = Normal;
-
-  // Default arguments of member function parameters that appear in a class
-  // definition, as well as the initializers of data members, receive special
-  // treatment. Identify them.
-  if (ManglingContextDecl) {
-    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
-      if (const DeclContext *LexicalDC
-          = Param->getDeclContext()->getLexicalParent())
-        if (LexicalDC->isRecord())
-          Kind = DefaultArgument;
-    } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
-      if (Var->getDeclContext()->isRecord())
-        Kind = StaticDataMember;
-      else if (Var->getMostRecentDecl()->isInline())
-        Kind = InlineVariable;
-      else if (Var->getDescribedVarTemplate())
-        Kind = VariableTemplate;
-      else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
-        if (!VTS->isExplicitSpecialization())
-          Kind = VariableTemplate;
-      }
-    } else if (isa<FieldDecl>(ManglingContextDecl)) {
-      Kind = DataMember;
-    }
-  }
-
-  // Itanium ABI [5.1.7]:
-  //   In the following contexts [...] the one-definition rule requires closure
-  //   types in different translation units to "correspond":
-  bool IsInNonspecializedTemplate =
-      inTemplateInstantiation() || CurContext->isDependentContext();
-  switch (Kind) {
-  case Normal: {
-    //  -- the bodies of non-exported nonspecialized template functions
-    //  -- the bodies of inline functions
-    if ((IsInNonspecializedTemplate &&
-         !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) ||
-        isInInlineFunction(CurContext)) {
-      ManglingContextDecl = nullptr;
-      while (auto *CD = dyn_cast<CapturedDecl>(DC))
-        DC = CD->getParent();
-      return &Context.getManglingNumberContext(DC);
-    }
-
-    ManglingContextDecl = nullptr;
-    return nullptr;
-  }
-
-  case StaticDataMember:
-    //  -- the initializers of nonspecialized static members of template classes
-    if (!IsInNonspecializedTemplate) {
-      ManglingContextDecl = nullptr;
-      return nullptr;
-    }
-    // Fall through to get the current context.
-    LLVM_FALLTHROUGH;
-
-  case DataMember:
-    //  -- the in-class initializers of class members
-  case DefaultArgument:
-    //  -- default arguments appearing in class definitions
-  case InlineVariable:
-    //  -- the initializers of inline variables
-  case VariableTemplate:
-    //  -- the initializers of templated variables
-    return &ExprEvalContexts.back().getMangleNumberingContext(Context);
-  }
-
-  llvm_unreachable("unexpected context");
-}
-
-MangleNumberingContext &
-Sema::ExpressionEvaluationContextRecord::getMangleNumberingContext(
-    ASTContext &Ctx) {
-  assert(ManglingContextDecl && "Need to have a context declaration");
-  if (!MangleNumbering)
-    MangleNumbering = Ctx.createMangleNumberingContext();
-  return *MangleNumbering;
-}
-
-CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
-                                           SourceRange IntroducerRange,
-                                           TypeSourceInfo *MethodTypeInfo,
-                                           SourceLocation EndLoc,
-                                           ArrayRef<ParmVarDecl *> Params,
-                                           const bool IsConstexprSpecified) {
-  QualType MethodType = MethodTypeInfo->getType();
-  TemplateParameterList *TemplateParams =
-            getGenericLambdaTemplateParameterList(getCurLambda(), *this);
-  // If a lambda appears in a dependent context or is a generic lambda (has
-  // template parameters) and has an 'auto' return type, deduce it to a
-  // dependent type.
-  if (Class->isDependentContext() || TemplateParams) {
-    const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
-    QualType Result = FPT->getReturnType();
-    if (Result->isUndeducedType()) {
-      Result = SubstAutoType(Result, Context.DependentTy);
-      MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
-                                           FPT->getExtProtoInfo());
-    }
-  }
-
-  // C++11 [expr.prim.lambda]p5:
-  //   The closure type for a lambda-expression has a public inline function
-  //   call operator (13.5.4) whose parameters and return type are described by
-  //   the lambda-expression's parameter-declaration-clause and
-  //   trailing-return-type respectively.
-  DeclarationName MethodName
-    = Context.DeclarationNames.getCXXOperatorName(OO_Call);
-  DeclarationNameLoc MethodNameLoc;
-  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
-    = IntroducerRange.getBegin().getRawEncoding();
-  MethodNameLoc.CXXOperatorName.EndOpNameLoc
-    = IntroducerRange.getEnd().getRawEncoding();
-  CXXMethodDecl *Method
-    = CXXMethodDecl::Create(Context, Class, EndLoc,
-                            DeclarationNameInfo(MethodName,
-                                                IntroducerRange.getBegin(),
-                                                MethodNameLoc),
-                            MethodType, MethodTypeInfo,
-                            SC_None,
-                            /*isInline=*/true,
-                            IsConstexprSpecified,
-                            EndLoc);
-  Method->setAccess(AS_public);
-
-  // Temporarily set the lexical declaration context to the current
-  // context, so that the Scope stack matches the lexical nesting.
-  Method->setLexicalDeclContext(CurContext);
-  // Create a function template if we have a template parameter list
-  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
-            FunctionTemplateDecl::Create(Context, Class,
-                                         Method->getLocation(), MethodName,
-                                         TemplateParams,
-                                         Method) : nullptr;
-  if (TemplateMethod) {
-    TemplateMethod->setLexicalDeclContext(CurContext);
-    TemplateMethod->setAccess(AS_public);
-    Method->setDescribedFunctionTemplate(TemplateMethod);
-  }
-
-  // Add parameters.
-  if (!Params.empty()) {
-    Method->setParams(Params);
-    CheckParmsForFunctionDef(Params,
-                             /*CheckParameterNames=*/false);
-
-    for (auto P : Method->parameters())
-      P->setOwningFunction(Method);
-  }
-
-  Decl *ManglingContextDecl;
-  if (MangleNumberingContext *MCtx =
-          getCurrentMangleNumberContext(Class->getDeclContext(),
-                                        ManglingContextDecl)) {
-    unsigned ManglingNumber = MCtx->getManglingNumber(Method);
-    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl);
-  }
-
-  return Method;
-}
-
-void Sema::buildLambdaScope(LambdaScopeInfo *LSI,
-                                        CXXMethodDecl *CallOperator,
-                                        SourceRange IntroducerRange,
-                                        LambdaCaptureDefault CaptureDefault,
-                                        SourceLocation CaptureDefaultLoc,
-                                        bool ExplicitParams,
-                                        bool ExplicitResultType,
-                                        bool Mutable) {
-  LSI->CallOperator = CallOperator;
-  CXXRecordDecl *LambdaClass = CallOperator->getParent();
-  LSI->Lambda = LambdaClass;
-  if (CaptureDefault == LCD_ByCopy)
-    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval;
-  else if (CaptureDefault == LCD_ByRef)
-    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref;
-  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
-  LSI->IntroducerRange = IntroducerRange;
-  LSI->ExplicitParams = ExplicitParams;
-  LSI->Mutable = Mutable;
-
-  if (ExplicitResultType) {
-    LSI->ReturnType = CallOperator->getReturnType();
-
-    if (!LSI->ReturnType->isDependentType() &&
-        !LSI->ReturnType->isVoidType()) {
-      if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
-                              diag::err_lambda_incomplete_result)) {
-        // Do nothing.
-      }
-    }
-  } else {
-    LSI->HasImplicitReturnType = true;
-  }
-}
-
-void Sema::finishLambdaExplicitCaptures(LambdaScopeInfo *LSI) {
-  LSI->finishedExplicitCaptures();
-}
-
-void Sema::addLambdaParameters(
-    ArrayRef<LambdaIntroducer::LambdaCapture> Captures,
-    CXXMethodDecl *CallOperator, Scope *CurScope) {
-  // Introduce our parameters into the function scope
-  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
-       p < NumParams; ++p) {
-    ParmVarDecl *Param = CallOperator->getParamDecl(p);
-
-    // If this has an identifier, add it to the scope stack.
-    if (CurScope && Param->getIdentifier()) {
-      bool Error = false;
-      // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
-      // retroactively apply it.
-      for (const auto &Capture : Captures) {
-        if (Capture.Id == Param->getIdentifier()) {
-          Error = true;
-          Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
-          Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
-              << Capture.Id << true;
-        }
-      }
-      if (!Error)
-        CheckShadow(CurScope, Param);
-
-      PushOnScopeChains(Param, CurScope);
-    }
-  }
-}
-
-/// If this expression is an enumerator-like expression of some type
-/// T, return the type T; otherwise, return null.
-///
-/// Pointer comparisons on the result here should always work because
-/// it's derived from either the parent of an EnumConstantDecl
-/// (i.e. the definition) or the declaration returned by
-/// EnumType::getDecl() (i.e. the definition).
-static EnumDecl *findEnumForBlockReturn(Expr *E) {
-  // An expression is an enumerator-like expression of type T if,
-  // ignoring parens and parens-like expressions:
-  E = E->IgnoreParens();
-
-  //  - it is an enumerator whose enum type is T or
-  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
-    if (EnumConstantDecl *D
-          = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
-      return cast<EnumDecl>(D->getDeclContext());
-    }
-    return nullptr;
-  }
-
-  //  - it is a comma expression whose RHS is an enumerator-like
-  //    expression of type T or
-  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
-    if (BO->getOpcode() == BO_Comma)
-      return findEnumForBlockReturn(BO->getRHS());
-    return nullptr;
-  }
-
-  //  - it is a statement-expression whose value expression is an
-  //    enumerator-like expression of type T or
-  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
-    if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
-      return findEnumForBlockReturn(last);
-    return nullptr;
-  }
-
-  //   - it is a ternary conditional operator (not the GNU ?:
-  //     extension) whose second and third operands are
-  //     enumerator-like expressions of type T or
-  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
-    if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
-      if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
-        return ED;
-    return nullptr;
-  }
-
-  // (implicitly:)
-  //   - it is an implicit integral conversion applied to an
-  //     enumerator-like expression of type T or
-  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
-    // We can sometimes see integral conversions in valid
-    // enumerator-like expressions.
-    if (ICE->getCastKind() == CK_IntegralCast)
-      return findEnumForBlockReturn(ICE->getSubExpr());
-
-    // Otherwise, just rely on the type.
-  }
-
-  //   - it is an expression of that formal enum type.
-  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
-    return ET->getDecl();
-  }
-
-  // Otherwise, nope.
-  return nullptr;
-}
-
-/// Attempt to find a type T for which the returned expression of the
-/// given statement is an enumerator-like expression of that type.
-static EnumDecl *findEnumForBlockReturn(ReturnStmt *ret) {
-  if (Expr *retValue = ret->getRetValue())
-    return findEnumForBlockReturn(retValue);
-  return nullptr;
-}
-
-/// Attempt to find a common type T for which all of the returned
-/// expressions in a block are enumerator-like expressions of that
-/// type.
-static EnumDecl *findCommonEnumForBlockReturns(ArrayRef<ReturnStmt*> returns) {
-  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
-
-  // Try to find one for the first return.
-  EnumDecl *ED = findEnumForBlockReturn(*i);
-  if (!ED) return nullptr;
-
-  // Check that the rest of the returns have the same enum.
-  for (++i; i != e; ++i) {
-    if (findEnumForBlockReturn(*i) != ED)
-      return nullptr;
-  }
-
-  // Never infer an anonymous enum type.
-  if (!ED->hasNameForLinkage()) return nullptr;
-
-  return ED;
-}
-
-/// Adjust the given return statements so that they formally return
-/// the given type.  It should require, at most, an IntegralCast.
-static void adjustBlockReturnsToEnum(Sema &S, ArrayRef<ReturnStmt*> returns,
-                                     QualType returnType) {
-  for (ArrayRef<ReturnStmt*>::iterator
-         i = returns.begin(), e = returns.end(); i != e; ++i) {
-    ReturnStmt *ret = *i;
-    Expr *retValue = ret->getRetValue();
-    if (S.Context.hasSameType(retValue->getType(), returnType))
-      continue;
-
-    // Right now we only support integral fixup casts.
-    assert(returnType->isIntegralOrUnscopedEnumerationType());
-    assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
-
-    ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
-
-    Expr *E = (cleanups ? cleanups->getSubExpr() : retValue);
-    E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast,
-                                 E, /*base path*/ nullptr, VK_RValue);
-    if (cleanups) {
-      cleanups->setSubExpr(E);
-    } else {
-      ret->setRetValue(E);
-    }
-  }
-}
-
-void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) {
-  assert(CSI.HasImplicitReturnType);
-  // If it was ever a placeholder, it had to been deduced to DependentTy.
-  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
-  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
-         "lambda expressions use auto deduction in C++14 onwards");
-
-  // C++ core issue 975:
-  //   If a lambda-expression does not include a trailing-return-type,
-  //   it is as if the trailing-return-type denotes the following type:
-  //     - if there are no return statements in the compound-statement,
-  //       or all return statements return either an expression of type
-  //       void or no expression or braced-init-list, the type void;
-  //     - otherwise, if all return statements return an expression
-  //       and the types of the returned expressions after
-  //       lvalue-to-rvalue conversion (4.1 [conv.lval]),
-  //       array-to-pointer conversion (4.2 [conv.array]), and
-  //       function-to-pointer conversion (4.3 [conv.func]) are the
-  //       same, that common type;
-  //     - otherwise, the program is ill-formed.
-  //
-  // C++ core issue 1048 additionally removes top-level cv-qualifiers
-  // from the types of returned expressions to match the C++14 auto
-  // deduction rules.
-  //
-  // In addition, in blocks in non-C++ modes, if all of the return
-  // statements are enumerator-like expressions of some type T, where
-  // T has a name for linkage, then we infer the return type of the
-  // block to be that type.
-
-  // First case: no return statements, implicit void return type.
-  ASTContext &Ctx = getASTContext();
-  if (CSI.Returns.empty()) {
-    // It's possible there were simply no /valid/ return statements.
-    // In this case, the first one we found may have at least given us a type.
-    if (CSI.ReturnType.isNull())
-      CSI.ReturnType = Ctx.VoidTy;
-    return;
-  }
-
-  // Second case: at least one return statement has dependent type.
-  // Delay type checking until instantiation.
-  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
-  if (CSI.ReturnType->isDependentType())
-    return;
-
-  // Try to apply the enum-fuzz rule.
-  if (!getLangOpts().CPlusPlus) {
-    assert(isa<BlockScopeInfo>(CSI));
-    const EnumDecl *ED = findCommonEnumForBlockReturns(CSI.Returns);
-    if (ED) {
-      CSI.ReturnType = Context.getTypeDeclType(ED);
-      adjustBlockReturnsToEnum(*this, CSI.Returns, CSI.ReturnType);
-      return;
-    }
-  }
-
-  // Third case: only one return statement. Don't bother doing extra work!
-  if (CSI.Returns.size() == 1)
-    return;
-
-  // General case: many return statements.
-  // Check that they all have compatible return types.
-
-  // We require the return types to strictly match here.
-  // Note that we've already done the required promotions as part of
-  // processing the return statement.
-  for (const ReturnStmt *RS : CSI.Returns) {
-    const Expr *RetE = RS->getRetValue();
-
-    QualType ReturnType =
-        (RetE ? RetE->getType() : Context.VoidTy).getUnqualifiedType();
-    if (Context.getCanonicalFunctionResultType(ReturnType) ==
-          Context.getCanonicalFunctionResultType(CSI.ReturnType)) {
-      // Use the return type with the strictest possible nullability annotation.
-      auto RetTyNullability = ReturnType->getNullability(Ctx);
-      auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
-      if (BlockNullability &&
-          (!RetTyNullability ||
-           hasWeakerNullability(*RetTyNullability, *BlockNullability)))
-        CSI.ReturnType = ReturnType;
-      continue;
-    }
-
-    // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
-    // TODO: It's possible that the *first* return is the divergent one.
-    Diag(RS->getBeginLoc(),
-         diag::err_typecheck_missing_return_type_incompatible)
-        << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
-    // Continue iterating so that we keep emitting diagnostics.
-  }
-}
-
-QualType Sema::buildLambdaInitCaptureInitialization(SourceLocation Loc,
-                                                    bool ByRef,
-                                                    IdentifierInfo *Id,
-                                                    bool IsDirectInit,
-                                                    Expr *&Init) {
-  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
-  // deduce against.
-  QualType DeductType = Context.getAutoDeductType();
-  TypeLocBuilder TLB;
-  TLB.pushTypeSpec(DeductType).setNameLoc(Loc);
-  if (ByRef) {
-    DeductType = BuildReferenceType(DeductType, true, Loc, Id);
-    assert(!DeductType.isNull() && "can't build reference to auto");
-    TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
-  }
-  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
-
-  // Deduce the type of the init capture.
-  Expr *DeduceInit = Init;
-  QualType DeducedType = deduceVarTypeFromInitializer(
-      /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
-      SourceRange(Loc, Loc), IsDirectInit, DeduceInit);
-  if (DeducedType.isNull())
-    return QualType();
-
-  // Are we a non-list direct initialization?
-  bool CXXDirectInit = isa<ParenListExpr>(Init);
-
-  // Perform initialization analysis and ensure any implicit conversions
-  // (such as lvalue-to-rvalue) are enforced.
-  InitializedEntity Entity =
-      InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
-  InitializationKind Kind =
-      IsDirectInit
-          ? (CXXDirectInit ? InitializationKind::CreateDirect(
-                                 Loc, Init->getBeginLoc(), Init->getEndLoc())
-                           : InitializationKind::CreateDirectList(Loc))
-          : InitializationKind::CreateCopy(Loc, Init->getBeginLoc());
-
-  MultiExprArg Args = DeduceInit;
-  QualType DclT;
-  InitializationSequence InitSeq(*this, Entity, Kind, Args);
-  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
-
-  if (Result.isInvalid())
-    return QualType();
-
-  Init = Result.getAs<Expr>();
-  return DeducedType;
-}
-
-VarDecl *Sema::createLambdaInitCaptureVarDecl(SourceLocation Loc,
-                                              QualType InitCaptureType,
-                                              IdentifierInfo *Id,
-                                              unsigned InitStyle, Expr *Init) {
-  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType,
-      Loc);
-  // Create a dummy variable representing the init-capture. This is not actually
-  // used as a variable, and only exists as a way to name and refer to the
-  // init-capture.
-  // FIXME: Pass in separate source locations for '&' and identifier.
-  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
-                                   Loc, Id, InitCaptureType, TSI, SC_Auto);
-  NewVD->setInitCapture(true);
-  NewVD->setReferenced(true);
-  // FIXME: Pass in a VarDecl::InitializationStyle.
-  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
-  NewVD->markUsed(Context);
-  NewVD->setInit(Init);
-  return NewVD;
-}
-
-FieldDecl *Sema::buildInitCaptureField(LambdaScopeInfo *LSI, VarDecl *Var) {
-  FieldDecl *Field = FieldDecl::Create(
-      Context, LSI->Lambda, Var->getLocation(), Var->getLocation(),
-      nullptr, Var->getType(), Var->getTypeSourceInfo(), nullptr, false,
-      ICIS_NoInit);
-  Field->setImplicit(true);
-  Field->setAccess(AS_private);
-  LSI->Lambda->addDecl(Field);
-
-  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
-                  /*isNested*/false, Var->getLocation(), SourceLocation(),
-                  Var->getType(), Var->getInit());
-  return Field;
-}
-
-void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
-                                        Declarator &ParamInfo,
-                                        Scope *CurScope) {
-  // Determine if we're within a context where we know that the lambda will
-  // be dependent, because there are template parameters in scope.
-  bool KnownDependent = false;
-  LambdaScopeInfo *const LSI = getCurLambda();
-  assert(LSI && "LambdaScopeInfo should be on stack!");
-
-  // The lambda-expression's closure type might be dependent even if its
-  // semantic context isn't, if it appears within a default argument of a
-  // function template.
-  if (CurScope->getTemplateParamParent())
-    KnownDependent = true;
-
-  // Determine the signature of the call operator.
-  TypeSourceInfo *MethodTyInfo;
-  bool ExplicitParams = true;
-  bool ExplicitResultType = true;
-  bool ContainsUnexpandedParameterPack = false;
-  SourceLocation EndLoc;
-  SmallVector<ParmVarDecl *, 8> Params;
-  if (ParamInfo.getNumTypeObjects() == 0) {
-    // C++11 [expr.prim.lambda]p4:
-    //   If a lambda-expression does not include a lambda-declarator, it is as
-    //   if the lambda-declarator were ().
-    FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
-        /*IsVariadic=*/false, /*IsCXXMethod=*/true));
-    EPI.HasTrailingReturn = true;
-    EPI.TypeQuals.addConst();
-    // C++1y [expr.prim.lambda]:
-    //   The lambda return type is 'auto', which is replaced by the
-    //   trailing-return type if provided and/or deduced from 'return'
-    //   statements
-    // We don't do this before C++1y, because we don't support deduced return
-    // types there.
-    QualType DefaultTypeForNoTrailingReturn =
-        getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
-                                  : Context.DependentTy;
-    QualType MethodTy =
-        Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
-    MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
-    ExplicitParams = false;
-    ExplicitResultType = false;
-    EndLoc = Intro.Range.getEnd();
-  } else {
-    assert(ParamInfo.isFunctionDeclarator() &&
-           "lambda-declarator is a function");
-    DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getFunctionTypeInfo();
-
-    // C++11 [expr.prim.lambda]p5:
-    //   This function call operator is declared const (9.3.1) if and only if
-    //   the lambda-expression's parameter-declaration-clause is not followed
-    //   by mutable. It is neither virtual nor declared volatile. [...]
-    if (!FTI.hasMutableQualifier()) {
-      FTI.getOrCreateMethodQualifiers().SetTypeQual(DeclSpec::TQ_const,
-                                                    SourceLocation());
-    }
-
-    MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
-    assert(MethodTyInfo && "no type from lambda-declarator");
-    EndLoc = ParamInfo.getSourceRange().getEnd();
-
-    ExplicitResultType = FTI.hasTrailingReturnType();
-
-    if (FTIHasNonVoidParameters(FTI)) {
-      Params.reserve(FTI.NumParams);
-      for (unsigned i = 0, e = FTI.NumParams; i != e; ++i)
-        Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
-    }
-
-    // Check for unexpanded parameter packs in the method type.
-    if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
-      ContainsUnexpandedParameterPack = true;
-  }
-
-  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
-                                                 KnownDependent, Intro.Default);
-
-  CXXMethodDecl *Method =
-      startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
-                            ParamInfo.getDeclSpec().isConstexprSpecified());
-  if (ExplicitParams)
-    CheckCXXDefaultArguments(Method);
-
-  // This represents the function body for the lambda function, check if we
-  // have to apply optnone due to a pragma.
-  AddRangeBasedOptnone(Method);
-
-  // code_seg attribute on lambda apply to the method.
-  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
-    Method->addAttr(A);
-
-  // Attributes on the lambda apply to the method.
-  ProcessDeclAttributes(CurScope, Method, ParamInfo);
-
-  // CUDA lambdas get implicit attributes based on the scope in which they're
-  // declared.
-  if (getLangOpts().CUDA)
-    CUDASetLambdaAttrs(Method);
-
-  // Introduce the function call operator as the current declaration context.
-  PushDeclContext(CurScope, Method);
-
-  // Build the lambda scope.
-  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
-                   ExplicitParams, ExplicitResultType, !Method->isConst());
-
-  // C++11 [expr.prim.lambda]p9:
-  //   A lambda-expression whose smallest enclosing scope is a block scope is a
-  //   local lambda expression; any other lambda expression shall not have a
-  //   capture-default or simple-capture in its lambda-introducer.
-  //
-  // For simple-captures, this is covered by the check below that any named
-  // entity is a variable that can be captured.
-  //
-  // For DR1632, we also allow a capture-default in any context where we can
-  // odr-use 'this' (in particular, in a default initializer for a non-static
-  // data member).
-  if (Intro.Default != LCD_None && !Class->getParent()->isFunctionOrMethod() &&
-      (getCurrentThisType().isNull() ||
-       CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
-                           /*BuildAndDiagnose*/false)))
-    Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
-
-  // Distinct capture names, for diagnostics.
-  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
-
-  // Handle explicit captures.
-  SourceLocation PrevCaptureLoc
-    = Intro.Default == LCD_None? Intro.Range.getBegin() : Intro.DefaultLoc;
-  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
-       PrevCaptureLoc = C->Loc, ++C) {
-    if (C->Kind == LCK_This || C->Kind == LCK_StarThis) {
-      if (C->Kind == LCK_StarThis)
-        Diag(C->Loc, !getLangOpts().CPlusPlus17
-                             ? diag::ext_star_this_lambda_capture_cxx17
-                             : diag::warn_cxx14_compat_star_this_lambda_capture);
-
-      // C++11 [expr.prim.lambda]p8:
-      //   An identifier or this shall not appear more than once in a
-      //   lambda-capture.
-      if (LSI->isCXXThisCaptured()) {
-        Diag(C->Loc, diag::err_capture_more_than_once)
-            << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
-            << FixItHint::CreateRemoval(
-                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
-        continue;
-      }
-
-      // C++2a [expr.prim.lambda]p8:
-      //  If a lambda-capture includes a capture-default that is =,
-      //  each simple-capture of that lambda-capture shall be of the form
-      //  "&identifier", "this", or "* this". [ Note: The form [&,this] is
-      //  redundant but accepted for compatibility with ISO C++14. --end note ]
-      if (Intro.Default == LCD_ByCopy && C->Kind != LCK_StarThis)
-        Diag(C->Loc, !getLangOpts().CPlusPlus2a
-                         ? diag::ext_equals_this_lambda_capture_cxx2a
-                         : diag::warn_cxx17_compat_equals_this_lambda_capture);
-
-      // C++11 [expr.prim.lambda]p12:
-      //   If this is captured by a local lambda expression, its nearest
-      //   enclosing function shall be a non-static member function.
-      QualType ThisCaptureType = getCurrentThisType();
-      if (ThisCaptureType.isNull()) {
-        Diag(C->Loc, diag::err_this_capture) << true;
-        continue;
-      }
-
-      CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
-                          /*FunctionScopeIndexToStopAtPtr*/ nullptr,
-                          C->Kind == LCK_StarThis);
-      if (!LSI->Captures.empty())
-        LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
-      continue;
-    }
-
-    assert(C->Id && "missing identifier for capture");
-
-    if (C->Init.isInvalid())
-      continue;
-
-    VarDecl *Var = nullptr;
-    if (C->Init.isUsable()) {
-      Diag(C->Loc, getLangOpts().CPlusPlus14
-                       ? diag::warn_cxx11_compat_init_capture
-                       : diag::ext_init_capture);
-
-      if (C->Init.get()->containsUnexpandedParameterPack())
-        ContainsUnexpandedParameterPack = true;
-      // If the initializer expression is usable, but the InitCaptureType
-      // is not, then an error has occurred - so ignore the capture for now.
-      // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
-      // FIXME: we should create the init capture variable and mark it invalid
-      // in this case.
-      if (C->InitCaptureType.get().isNull())
-        continue;
-
-      unsigned InitStyle;
-      switch (C->InitKind) {
-      case LambdaCaptureInitKind::NoInit:
-        llvm_unreachable("not an init-capture?");
-      case LambdaCaptureInitKind::CopyInit:
-        InitStyle = VarDecl::CInit;
-        break;
-      case LambdaCaptureInitKind::DirectInit:
-        InitStyle = VarDecl::CallInit;
-        break;
-      case LambdaCaptureInitKind::ListInit:
-        InitStyle = VarDecl::ListInit;
-        break;
-      }
-      Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
-                                           C->Id, InitStyle, C->Init.get());
-      // C++1y [expr.prim.lambda]p11:
-      //   An init-capture behaves as if it declares and explicitly
-      //   captures a variable [...] whose declarative region is the
-      //   lambda-expression's compound-statement
-      if (Var)
-        PushOnScopeChains(Var, CurScope, false);
-    } else {
-      assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
-             "init capture has valid but null init?");
-
-      // C++11 [expr.prim.lambda]p8:
-      //   If a lambda-capture includes a capture-default that is &, the
-      //   identifiers in the lambda-capture shall not be preceded by &.
-      //   If a lambda-capture includes a capture-default that is =, [...]
-      //   each identifier it contains shall be preceded by &.
-      if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) {
-        Diag(C->Loc, diag::err_reference_capture_with_reference_default)
-            << FixItHint::CreateRemoval(
-                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
-        continue;
-      } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) {
-        Diag(C->Loc, diag::err_copy_capture_with_copy_default)
-            << FixItHint::CreateRemoval(
-                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
-        continue;
-      }
-
-      // C++11 [expr.prim.lambda]p10:
-      //   The identifiers in a capture-list are looked up using the usual
-      //   rules for unqualified name lookup (3.4.1)
-      DeclarationNameInfo Name(C->Id, C->Loc);
-      LookupResult R(*this, Name, LookupOrdinaryName);
-      LookupName(R, CurScope);
-      if (R.isAmbiguous())
-        continue;
-      if (R.empty()) {
-        // FIXME: Disable corrections that would add qualification?
-        CXXScopeSpec ScopeSpec;
-        if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R,
-                                llvm::make_unique<DeclFilterCCC<VarDecl>>()))
-          continue;
-      }
-
-      Var = R.getAsSingle<VarDecl>();
-      if (Var && DiagnoseUseOfDecl(Var, C->Loc))
-        continue;
-    }
-
-    // C++11 [expr.prim.lambda]p8:
-    //   An identifier or this shall not appear more than once in a
-    //   lambda-capture.
-    if (!CaptureNames.insert(C->Id).second) {
-      if (Var && LSI->isCaptured(Var)) {
-        Diag(C->Loc, diag::err_capture_more_than_once)
-            << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
-            << FixItHint::CreateRemoval(
-                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
-      } else
-        // Previous capture captured something different (one or both was
-        // an init-cpature): no fixit.
-        Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
-      continue;
-    }
-
-    // C++11 [expr.prim.lambda]p10:
-    //   [...] each such lookup shall find a variable with automatic storage
-    //   duration declared in the reaching scope of the local lambda expression.
-    // Note that the 'reaching scope' check happens in tryCaptureVariable().
-    if (!Var) {
-      Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
-      continue;
-    }
-
-    // Ignore invalid decls; they'll just confuse the code later.
-    if (Var->isInvalidDecl())
-      continue;
-
-    if (!Var->hasLocalStorage()) {
-      Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
-      Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
-      continue;
-    }
-
-    // C++11 [expr.prim.lambda]p23:
-    //   A capture followed by an ellipsis is a pack expansion (14.5.3).
-    SourceLocation EllipsisLoc;
-    if (C->EllipsisLoc.isValid()) {
-      if (Var->isParameterPack()) {
-        EllipsisLoc = C->EllipsisLoc;
-      } else {
-        Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
-          << SourceRange(C->Loc);
-
-        // Just ignore the ellipsis.
-      }
-    } else if (Var->isParameterPack()) {
-      ContainsUnexpandedParameterPack = true;
-    }
-
-    if (C->Init.isUsable()) {
-      buildInitCaptureField(LSI, Var);
-    } else {
-      TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
-                                                   TryCapture_ExplicitByVal;
-      tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
-    }
-    if (!LSI->Captures.empty())
-      LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
-  }
-  finishLambdaExplicitCaptures(LSI);
-
-  LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
-
-  // Add lambda parameters into scope.
-  addLambdaParameters(Intro.Captures, Method, CurScope);
-
-  // Enter a new evaluation context to insulate the lambda from any
-  // cleanups from the enclosing full-expression.
-  PushExpressionEvaluationContext(
-      ExpressionEvaluationContext::PotentiallyEvaluated);
-}
-
-void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
-                            bool IsInstantiation) {
-  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
-
-  // Leave the expression-evaluation context.
-  DiscardCleanupsInEvaluationContext();
-  PopExpressionEvaluationContext();
-
-  // Leave the context of the lambda.
-  if (!IsInstantiation)
-    PopDeclContext();
-
-  // Finalize the lambda.
-  CXXRecordDecl *Class = LSI->Lambda;
-  Class->setInvalidDecl();
-  SmallVector<Decl*, 4> Fields(Class->fields());
-  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
-              SourceLocation(), ParsedAttributesView());
-  CheckCompletedCXXClass(Class);
-
-  PopFunctionScopeInfo();
-}
-
-QualType Sema::getLambdaConversionFunctionResultType(
-    const FunctionProtoType *CallOpProto) {
-  // The function type inside the pointer type is the same as the call
-  // operator with some tweaks. The calling convention is the default free
-  // function convention, and the type qualifications are lost.
-  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
-      CallOpProto->getExtProtoInfo();
-  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
-  CallingConv CC = Context.getDefaultCallingConvention(
-      CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
-  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
-  InvokerExtInfo.TypeQuals = Qualifiers();
-  assert(InvokerExtInfo.RefQualifier == RQ_None &&
-      "Lambda's call operator should not have a reference qualifier");
-  return Context.getFunctionType(CallOpProto->getReturnType(),
-                                 CallOpProto->getParamTypes(), InvokerExtInfo);
-}
-
-/// Add a lambda's conversion to function pointer, as described in
-/// C++11 [expr.prim.lambda]p6.
-static void addFunctionPointerConversion(Sema &S,
-                                         SourceRange IntroducerRange,
-                                         CXXRecordDecl *Class,
-                                         CXXMethodDecl *CallOperator) {
-  // This conversion is explicitly disabled if the lambda's function has
-  // pass_object_size attributes on any of its parameters.
-  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
-    return P->hasAttr<PassObjectSizeAttr>();
-  };
-  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
-    return;
-
-  // Add the conversion to function pointer.
-  QualType InvokerFunctionTy = S.getLambdaConversionFunctionResultType(
-      CallOperator->getType()->castAs<FunctionProtoType>());
-  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
-
-  // Create the type of the conversion function.
-  FunctionProtoType::ExtProtoInfo ConvExtInfo(
-      S.Context.getDefaultCallingConvention(
-      /*IsVariadic=*/false, /*IsCXXMethod=*/true));
-  // The conversion function is always const.
-  ConvExtInfo.TypeQuals = Qualifiers();
-  ConvExtInfo.TypeQuals.addConst();
-  QualType ConvTy =
-      S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
-
-  SourceLocation Loc = IntroducerRange.getBegin();
-  DeclarationName ConversionName
-    = S.Context.DeclarationNames.getCXXConversionFunctionName(
-        S.Context.getCanonicalType(PtrToFunctionTy));
-  DeclarationNameLoc ConvNameLoc;
-  // Construct a TypeSourceInfo for the conversion function, and wire
-  // all the parameters appropriately for the FunctionProtoTypeLoc
-  // so that everything works during transformation/instantiation of
-  // generic lambdas.
-  // The main reason for wiring up the parameters of the conversion
-  // function with that of the call operator is so that constructs
-  // like the following work:
-  // auto L = [](auto b) {                <-- 1
-  //   return [](auto a) -> decltype(a) { <-- 2
-  //      return a;
-  //   };
-  // };
-  // int (*fp)(int) = L(5);
-  // Because the trailing return type can contain DeclRefExprs that refer
-  // to the original call operator's variables, we hijack the call
-  // operators ParmVarDecls below.
-  TypeSourceInfo *ConvNamePtrToFunctionTSI =
-      S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
-  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
-
-  // The conversion function is a conversion to a pointer-to-function.
-  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
-  FunctionProtoTypeLoc ConvTL =
-      ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
-  // Get the result of the conversion function which is a pointer-to-function.
-  PointerTypeLoc PtrToFunctionTL =
-      ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
-  // Do the same for the TypeSourceInfo that is used to name the conversion
-  // operator.
-  PointerTypeLoc ConvNamePtrToFunctionTL =
-      ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
-
-  // Get the underlying function types that the conversion function will
-  // be converting to (should match the type of the call operator).
-  FunctionProtoTypeLoc CallOpConvTL =
-      PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
-  FunctionProtoTypeLoc CallOpConvNameTL =
-    ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
-
-  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
-  // These parameter's are essentially used to transform the name and
-  // the type of the conversion operator.  By using the same parameters
-  // as the call operator's we don't have to fix any back references that
-  // the trailing return type of the call operator's uses (such as
-  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
-  // - we can simply use the return type of the call operator, and
-  // everything should work.
-  SmallVector<ParmVarDecl *, 4> InvokerParams;
-  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
-    ParmVarDecl *From = CallOperator->getParamDecl(I);
-
-    InvokerParams.push_back(ParmVarDecl::Create(
-        S.Context,
-        // Temporarily add to the TU. This is set to the invoker below.
-        S.Context.getTranslationUnitDecl(), From->getBeginLoc(),
-        From->getLocation(), From->getIdentifier(), From->getType(),
-        From->getTypeSourceInfo(), From->getStorageClass(),
-        /*DefaultArg=*/nullptr));
-    CallOpConvTL.setParam(I, From);
-    CallOpConvNameTL.setParam(I, From);
-  }
-
-  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
-      S.Context, Class, Loc,
-      DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
-      /*isInline=*/true, /*isExplicit=*/false,
-      /*isConstexpr=*/S.getLangOpts().CPlusPlus17,
-      CallOperator->getBody()->getEndLoc());
-  Conversion->setAccess(AS_public);
-  Conversion->setImplicit(true);
-
-  if (Class->isGenericLambda()) {
-    // Create a template version of the conversion operator, using the template
-    // parameter list of the function call operator.
-    FunctionTemplateDecl *TemplateCallOperator =
-            CallOperator->getDescribedFunctionTemplate();
-    FunctionTemplateDecl *ConversionTemplate =
-                  FunctionTemplateDecl::Create(S.Context, Class,
-                                      Loc, ConversionName,
-                                      TemplateCallOperator->getTemplateParameters(),
-                                      Conversion);
-    ConversionTemplate->setAccess(AS_public);
-    ConversionTemplate->setImplicit(true);
-    Conversion->setDescribedFunctionTemplate(ConversionTemplate);
-    Class->addDecl(ConversionTemplate);
-  } else
-    Class->addDecl(Conversion);
-  // Add a non-static member function that will be the result of
-  // the conversion with a certain unique ID.
-  DeclarationName InvokerName = &S.Context.Idents.get(
-                                                 getLambdaStaticInvokerName());
-  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
-  // we should get a prebuilt TrivialTypeSourceInfo from Context
-  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
-  // then rewire the parameters accordingly, by hoisting up the InvokeParams
-  // loop below and then use its Params to set Invoke->setParams(...) below.
-  // This would avoid the 'const' qualifier of the calloperator from
-  // contaminating the type of the invoker, which is currently adjusted
-  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments.  Fixing the
-  // trailing return type of the invoker would require a visitor to rebuild
-  // the trailing return type and adjusting all back DeclRefExpr's to refer
-  // to the new static invoker parameters - not the call operator's.
-  CXXMethodDecl *Invoke = CXXMethodDecl::Create(
-      S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
-      InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
-      /*IsInline=*/true,
-      /*IsConstexpr=*/false, CallOperator->getBody()->getEndLoc());
-  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I)
-    InvokerParams[I]->setOwningFunction(Invoke);
-  Invoke->setParams(InvokerParams);
-  Invoke->setAccess(AS_private);
-  Invoke->setImplicit(true);
-  if (Class->isGenericLambda()) {
-    FunctionTemplateDecl *TemplateCallOperator =
-            CallOperator->getDescribedFunctionTemplate();
-    FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
-                          S.Context, Class, Loc, InvokerName,
-                          TemplateCallOperator->getTemplateParameters(),
-                          Invoke);
-    StaticInvokerTemplate->setAccess(AS_private);
-    StaticInvokerTemplate->setImplicit(true);
-    Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
-    Class->addDecl(StaticInvokerTemplate);
-  } else
-    Class->addDecl(Invoke);
-}
-
-/// Add a lambda's conversion to block pointer.
-static void addBlockPointerConversion(Sema &S,
-                                      SourceRange IntroducerRange,
-                                      CXXRecordDecl *Class,
-                                      CXXMethodDecl *CallOperator) {
-  QualType FunctionTy = S.getLambdaConversionFunctionResultType(
-      CallOperator->getType()->castAs<FunctionProtoType>());
-  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
-
-  FunctionProtoType::ExtProtoInfo ConversionEPI(
-      S.Context.getDefaultCallingConvention(
-          /*IsVariadic=*/false, /*IsCXXMethod=*/true));
-  ConversionEPI.TypeQuals = Qualifiers();
-  ConversionEPI.TypeQuals.addConst();
-  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
-
-  SourceLocation Loc = IntroducerRange.getBegin();
-  DeclarationName Name
-    = S.Context.DeclarationNames.getCXXConversionFunctionName(
-        S.Context.getCanonicalType(BlockPtrTy));
-  DeclarationNameLoc NameLoc;
-  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
-  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
-      S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
-      S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
-      /*isInline=*/true, /*isExplicit=*/false,
-      /*isConstexpr=*/false, CallOperator->getBody()->getEndLoc());
-  Conversion->setAccess(AS_public);
-  Conversion->setImplicit(true);
-  Class->addDecl(Conversion);
-}
-
-static ExprResult performLambdaVarCaptureInitialization(
-    Sema &S, const Capture &Capture, FieldDecl *Field,
-    SourceLocation ImplicitCaptureLoc, bool IsImplicitCapture) {
-  assert(Capture.isVariableCapture() && "not a variable capture");
-
-  auto *Var = Capture.getVariable();
-  SourceLocation Loc =
-      IsImplicitCapture ? ImplicitCaptureLoc : Capture.getLocation();
-
-  // C++11 [expr.prim.lambda]p21:
-  //   When the lambda-expression is evaluated, the entities that
-  //   are captured by copy are used to direct-initialize each
-  //   corresponding non-static data member of the resulting closure
-  //   object. (For array members, the array elements are
-  //   direct-initialized in increasing subscript order.) These
-  //   initializations are performed in the (unspecified) order in
-  //   which the non-static data members are declared.
-
-  // C++ [expr.prim.lambda]p12:
-  //   An entity captured by a lambda-expression is odr-used (3.2) in
-  //   the scope containing the lambda-expression.
-  ExprResult RefResult = S.BuildDeclarationNameExpr(
-      CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
-  if (RefResult.isInvalid())
-    return ExprError();
-  Expr *Ref = RefResult.get();
-
-  auto Entity = InitializedEntity::InitializeLambdaCapture(
-      Var->getIdentifier(), Field->getType(), Loc);
-  InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc);
-  InitializationSequence Init(S, Entity, InitKind, Ref);
-  return Init.Perform(S, Entity, InitKind, Ref);
-}
-
-ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
-                                 Scope *CurScope) {
-  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
-  ActOnFinishFunctionBody(LSI.CallOperator, Body);
-  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
-}
-
-static LambdaCaptureDefault
-mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS) {
-  switch (ICS) {
-  case CapturingScopeInfo::ImpCap_None:
-    return LCD_None;
-  case CapturingScopeInfo::ImpCap_LambdaByval:
-    return LCD_ByCopy;
-  case CapturingScopeInfo::ImpCap_CapturedRegion:
-  case CapturingScopeInfo::ImpCap_LambdaByref:
-    return LCD_ByRef;
-  case CapturingScopeInfo::ImpCap_Block:
-    llvm_unreachable("block capture in lambda");
-  }
-  llvm_unreachable("Unknown implicit capture style");
-}
-
-bool Sema::CaptureHasSideEffects(const Capture &From) {
-  if (!From.isVLATypeCapture()) {
-    Expr *Init = From.getInitExpr();
-    if (Init && Init->HasSideEffects(Context))
-      return true;
-  }
-
-  if (!From.isCopyCapture())
-    return false;
-
-  const QualType T = From.isThisCapture()
-                         ? getCurrentThisType()->getPointeeType()
-                         : From.getCaptureType();
-
-  if (T.isVolatileQualified())
-    return true;
-
-  const Type *BaseT = T->getBaseElementTypeUnsafe();
-  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
-    return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
-           !RD->hasTrivialDestructor();
-
-  return false;
-}
-
-bool Sema::DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
-                                       const Capture &From) {
-  if (CaptureHasSideEffects(From))
-    return false;
-
-  if (From.isVLATypeCapture())
-    return false;
-
-  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
-  if (From.isThisCapture())
-    diag << "'this'";
-  else
-    diag << From.getVariable();
-  diag << From.isNonODRUsed();
-  diag << FixItHint::CreateRemoval(CaptureRange);
-  return true;
-}
-
-ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
-                                 LambdaScopeInfo *LSI) {
-  // Collect information from the lambda scope.
-  SmallVector<LambdaCapture, 4> Captures;
-  SmallVector<Expr *, 4> CaptureInits;
-  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
-  LambdaCaptureDefault CaptureDefault =
-      mapImplicitCaptureStyle(LSI->ImpCaptureStyle);
-  CXXRecordDecl *Class;
-  CXXMethodDecl *CallOperator;
-  SourceRange IntroducerRange;
-  bool ExplicitParams;
-  bool ExplicitResultType;
-  CleanupInfo LambdaCleanup;
-  bool ContainsUnexpandedParameterPack;
-  bool IsGenericLambda;
-  {
-    CallOperator = LSI->CallOperator;
-    Class = LSI->Lambda;
-    IntroducerRange = LSI->IntroducerRange;
-    ExplicitParams = LSI->ExplicitParams;
-    ExplicitResultType = !LSI->HasImplicitReturnType;
-    LambdaCleanup = LSI->Cleanup;
-    ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
-    IsGenericLambda = Class->isGenericLambda();
-
-    CallOperator->setLexicalDeclContext(Class);
-    Decl *TemplateOrNonTemplateCallOperatorDecl =
-        CallOperator->getDescribedFunctionTemplate()
-        ? CallOperator->getDescribedFunctionTemplate()
-        : cast<Decl>(CallOperator);
-
-    TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
-    Class->addDecl(TemplateOrNonTemplateCallOperatorDecl);
-
-    PopExpressionEvaluationContext();
-
-    // Translate captures.
-    auto CurField = Class->field_begin();
-    // True if the current capture has a used capture or default before it.
-    bool CurHasPreviousCapture = CaptureDefault != LCD_None;
-    SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
-        CaptureDefaultLoc : IntroducerRange.getBegin();
-
-    for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I, ++CurField) {
-      const Capture &From = LSI->Captures[I];
-
-      assert(!From.isBlockCapture() && "Cannot capture __block variables");
-      bool IsImplicit = I >= LSI->NumExplicitCaptures;
-
-      // Use source ranges of explicit captures for fixits where available.
-      SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
-
-      // Warn about unused explicit captures.
-      bool IsCaptureUsed = true;
-      if (!CurContext->isDependentContext() && !IsImplicit && !From.isODRUsed()) {
-        // Initialized captures that are non-ODR used may not be eliminated.
-        bool NonODRUsedInitCapture =
-            IsGenericLambda && From.isNonODRUsed() && From.getInitExpr();
-        if (!NonODRUsedInitCapture) {
-          bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
-          SourceRange FixItRange;
-          if (CaptureRange.isValid()) {
-            if (!CurHasPreviousCapture && !IsLast) {
-              // If there are no captures preceding this capture, remove the
-              // following comma.
-              FixItRange = SourceRange(CaptureRange.getBegin(),
-                                       getLocForEndOfToken(CaptureRange.getEnd()));
-            } else {
-              // Otherwise, remove the comma since the last used capture.
-              FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
-                                       CaptureRange.getEnd());
-            }
-          }
-
-          IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
-        }
-      }
-
-      if (CaptureRange.isValid()) {
-        CurHasPreviousCapture |= IsCaptureUsed;
-        PrevCaptureLoc = CaptureRange.getEnd();
-      }
-
-      // Handle 'this' capture.
-      if (From.isThisCapture()) {
-        // Capturing 'this' implicitly with a default of '[=]' is deprecated,
-        // because it results in a reference capture. Don't warn prior to
-        // C++2a; there's nothing that can be done about it before then.
-        if (getLangOpts().CPlusPlus2a && IsImplicit &&
-            CaptureDefault == LCD_ByCopy) {
-          Diag(From.getLocation(), diag::warn_deprecated_this_capture);
-          Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
-              << FixItHint::CreateInsertion(
-                     getLocForEndOfToken(CaptureDefaultLoc), ", this");
-        }
-
-        Captures.push_back(
-            LambdaCapture(From.getLocation(), IsImplicit,
-                          From.isCopyCapture() ? LCK_StarThis : LCK_This));
-        CaptureInits.push_back(From.getInitExpr());
-        continue;
-      }
-      if (From.isVLATypeCapture()) {
-        Captures.push_back(
-            LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType));
-        CaptureInits.push_back(nullptr);
-        continue;
-      }
-
-      VarDecl *Var = From.getVariable();
-      LambdaCaptureKind Kind = From.isCopyCapture() ? LCK_ByCopy : LCK_ByRef;
-      Captures.push_back(LambdaCapture(From.getLocation(), IsImplicit, Kind,
-                                       Var, From.getEllipsisLoc()));
-      Expr *Init = From.getInitExpr();
-      if (!Init) {
-        auto InitResult = performLambdaVarCaptureInitialization(
-            *this, From, *CurField, CaptureDefaultLoc, IsImplicit);
-        if (InitResult.isInvalid())
-          return ExprError();
-        Init = InitResult.get();
-      }
-      CaptureInits.push_back(Init);
-    }
-
-    // C++11 [expr.prim.lambda]p6:
-    //   The closure type for a lambda-expression with no lambda-capture
-    //   has a public non-virtual non-explicit const conversion function
-    //   to pointer to function having the same parameter and return
-    //   types as the closure type's function call operator.
-    if (Captures.empty() && CaptureDefault == LCD_None)
-      addFunctionPointerConversion(*this, IntroducerRange, Class,
-                                   CallOperator);
-
-    // Objective-C++:
-    //   The closure type for a lambda-expression has a public non-virtual
-    //   non-explicit const conversion function to a block pointer having the
-    //   same parameter and return types as the closure type's function call
-    //   operator.
-    // FIXME: Fix generic lambda to block conversions.
-    if (getLangOpts().Blocks && getLangOpts().ObjC && !IsGenericLambda)
-      addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
-
-    // Finalize the lambda class.
-    SmallVector<Decl*, 4> Fields(Class->fields());
-    ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
-                SourceLocation(), ParsedAttributesView());
-    CheckCompletedCXXClass(Class);
-  }
-
-  Cleanup.mergeFrom(LambdaCleanup);
-
-  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
-                                          CaptureDefault, CaptureDefaultLoc,
-                                          Captures,
-                                          ExplicitParams, ExplicitResultType,
-                                          CaptureInits, EndLoc,
-                                          ContainsUnexpandedParameterPack);
-  // If the lambda expression's call operator is not explicitly marked constexpr
-  // and we are not in a dependent context, analyze the call operator to infer
-  // its constexpr-ness, suppressing diagnostics while doing so.
-  if (getLangOpts().CPlusPlus17 && !CallOperator->isInvalidDecl() &&
-      !CallOperator->isConstexpr() &&
-      !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
-      !Class->getDeclContext()->isDependentContext()) {
-    TentativeAnalysisScope DiagnosticScopeGuard(*this);
-    CallOperator->setConstexpr(
-        CheckConstexprFunctionDecl(CallOperator) &&
-        CheckConstexprFunctionBody(CallOperator, CallOperator->getBody()));
-  }
-
-  // Emit delayed shadowing warnings now that the full capture list is known.
-  DiagnoseShadowingLambdaDecls(LSI);
-
-  if (!CurContext->isDependentContext()) {
-    switch (ExprEvalContexts.back().Context) {
-    // C++11 [expr.prim.lambda]p2:
-    //   A lambda-expression shall not appear in an unevaluated operand
-    //   (Clause 5).
-    case ExpressionEvaluationContext::Unevaluated:
-    case ExpressionEvaluationContext::UnevaluatedList:
-    case ExpressionEvaluationContext::UnevaluatedAbstract:
-    // C++1y [expr.const]p2:
-    //   A conditional-expression e is a core constant expression unless the
-    //   evaluation of e, following the rules of the abstract machine, would
-    //   evaluate [...] a lambda-expression.
-    //
-    // This is technically incorrect, there are some constant evaluated contexts
-    // where this should be allowed.  We should probably fix this when DR1607 is
-    // ratified, it lays out the exact set of conditions where we shouldn't
-    // allow a lambda-expression.
-    case ExpressionEvaluationContext::ConstantEvaluated:
-      // We don't actually diagnose this case immediately, because we
-      // could be within a context where we might find out later that
-      // the expression is potentially evaluated (e.g., for typeid).
-      ExprEvalContexts.back().Lambdas.push_back(Lambda);
-      break;
-
-    case ExpressionEvaluationContext::DiscardedStatement:
-    case ExpressionEvaluationContext::PotentiallyEvaluated:
-    case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
-      break;
-    }
-  }
-
-  return MaybeBindToTemporary(Lambda);
-}
-
-ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
-                                               SourceLocation ConvLocation,
-                                               CXXConversionDecl *Conv,
-                                               Expr *Src) {
-  // Make sure that the lambda call operator is marked used.
-  CXXRecordDecl *Lambda = Conv->getParent();
-  CXXMethodDecl *CallOperator
-    = cast<CXXMethodDecl>(
-        Lambda->lookup(
-          Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
-  CallOperator->setReferenced();
-  CallOperator->markUsed(Context);
-
-  ExprResult Init = PerformCopyInitialization(
-      InitializedEntity::InitializeLambdaToBlock(ConvLocation, Src->getType(),
-                                                 /*NRVO=*/false),
-      CurrentLocation, Src);
-  if (!Init.isInvalid())
-    Init = ActOnFinishFullExpr(Init.get());
-
-  if (Init.isInvalid())
-    return ExprError();
-
-  // Create the new block to be returned.
-  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
-
-  // Set the type information.
-  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
-  Block->setIsVariadic(CallOperator->isVariadic());
-  Block->setBlockMissingReturnType(false);
-
-  // Add parameters.
-  SmallVector<ParmVarDecl *, 4> BlockParams;
-  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
-    ParmVarDecl *From = CallOperator->getParamDecl(I);
-    BlockParams.push_back(ParmVarDecl::Create(
-        Context, Block, From->getBeginLoc(), From->getLocation(),
-        From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
-        From->getStorageClass(),
-        /*DefaultArg=*/nullptr));
-  }
-  Block->setParams(BlockParams);
-
-  Block->setIsConversionFromLambda(true);
-
-  // Add capture. The capture uses a fake variable, which doesn't correspond
-  // to any actual memory location. However, the initializer copy-initializes
-  // the lambda object.
-  TypeSourceInfo *CapVarTSI =
-      Context.getTrivialTypeSourceInfo(Src->getType());
-  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
-                                    ConvLocation, nullptr,
-                                    Src->getType(), CapVarTSI,
-                                    SC_None);
-  BlockDecl::Capture Capture(/*Variable=*/CapVar, /*ByRef=*/false,
-                             /*Nested=*/false, /*Copy=*/Init.get());
-  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
-
-  // Add a fake function body to the block. IR generation is responsible
-  // for filling in the actual body, which cannot be expressed as an AST.
-  Block->setBody(new (Context) CompoundStmt(ConvLocation));
-
-  // Create the block literal expression.
-  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
-  ExprCleanupObjects.push_back(Block);
-  Cleanup.setExprNeedsCleanups(true);
-
-  return BuildBlock;
-}