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 //===- Stmt.h - Classes for representing statements -------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file defines the Stmt interface and subclasses.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_AST_STMT_H
 #define LLVM_CLANG_AST_STMT_H
 
 #include "clang/AST/APValue.h"
 #include "clang/AST/DeclGroup.h"
 #include "clang/AST/DependenceFlags.h"
 #include "clang/AST/OperationKinds.h"
 #include "clang/AST/StmtIterator.h"
 #include "clang/Basic/CapturedStmt.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/Lambda.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/TypeTraits.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitmaskEnum.h"
 #include "llvm/ADT/PointerIntPair.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/iterator.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
 #include <cassert>
 #include <cstddef>
 #include <iterator>
 #include <optional>
 #include <string>
 
 namespace llvm {
 
 class FoldingSetNodeID;
 
 } // namespace llvm
 
 namespace clang {
 
 class ASTContext;
 class Attr;
 class CapturedDecl;
 class Decl;
 class Expr;
 class AddrLabelExpr;
 class LabelDecl;
 class ODRHash;
 class PrinterHelper;
 struct PrintingPolicy;
 class RecordDecl;
 class SourceManager;
 class StringLiteral;
 class Token;
 class VarDecl;
 enum class CharacterLiteralKind;
 enum class ConstantResultStorageKind;
 enum class CXXConstructionKind;
 enum class CXXNewInitializationStyle;
 enum class PredefinedIdentKind;
 enum class SourceLocIdentKind;
 enum class StringLiteralKind;
 
 //===----------------------------------------------------------------------===//
 // AST classes for statements.
 //===----------------------------------------------------------------------===//
 
 /// Stmt - This represents one statement.
 ///
 class alignas(void *) Stmt {
 public:
   enum StmtClass {
     NoStmtClass = 0,
 #define STMT(CLASS, PARENT) CLASS##Class,
 #define STMT_RANGE(BASE, FIRST, LAST) \
         first##BASE##Constant=FIRST##Class, last##BASE##Constant=LAST##Class,
 #define LAST_STMT_RANGE(BASE, FIRST, LAST) \
         first##BASE##Constant=FIRST##Class, last##BASE##Constant=LAST##Class
 #define ABSTRACT_STMT(STMT)
 #include "clang/AST/StmtNodes.inc"
   };
 
   // Make vanilla 'new' and 'delete' illegal for Stmts.
 protected:
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
 
   void *operator new(size_t bytes) noexcept {
     llvm_unreachable("Stmts cannot be allocated with regular 'new'.");
   }
 
   void operator delete(void *data) noexcept {
     llvm_unreachable("Stmts cannot be released with regular 'delete'.");
   }
 
   //===--- Statement bitfields classes ---===//
 
   #define NumStmtBits 9
 
   class StmtBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class Stmt;
 
     /// The statement class.
     LLVM_PREFERRED_TYPE(StmtClass)
     unsigned sClass : NumStmtBits;
   };
 
   class NullStmtBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class NullStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// True if the null statement was preceded by an empty macro, e.g:
     /// @code
     ///   #define CALL(x)
     ///   CALL(0);
     /// @endcode
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasLeadingEmptyMacro : 1;
 
     /// The location of the semi-colon.
     SourceLocation SemiLoc;
   };
 
   class CompoundStmtBitfields {
     friend class ASTStmtReader;
     friend class CompoundStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// True if the compound statement has one or more pragmas that set some
     /// floating-point features.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFPFeatures : 1;
 
     unsigned NumStmts;
   };
 
   class LabelStmtBitfields {
     friend class LabelStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     SourceLocation IdentLoc;
   };
 
   class AttributedStmtBitfields {
     friend class ASTStmtReader;
     friend class AttributedStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// Number of attributes.
     unsigned NumAttrs : 32 - NumStmtBits;
 
     /// The location of the attribute.
     SourceLocation AttrLoc;
   };
 
   class IfStmtBitfields {
     friend class ASTStmtReader;
     friend class IfStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// Whether this is a constexpr if, or a consteval if, or neither.
     LLVM_PREFERRED_TYPE(IfStatementKind)
     unsigned Kind : 3;
 
     /// True if this if statement has storage for an else statement.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasElse : 1;
 
     /// True if this if statement has storage for a variable declaration.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasVar : 1;
 
     /// True if this if statement has storage for an init statement.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasInit : 1;
 
     /// The location of the "if".
     SourceLocation IfLoc;
   };
 
   class SwitchStmtBitfields {
     friend class SwitchStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// True if the SwitchStmt has storage for an init statement.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasInit : 1;
 
     /// True if the SwitchStmt has storage for a condition variable.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasVar : 1;
 
     /// If the SwitchStmt is a switch on an enum value, records whether all
     /// the enum values were covered by CaseStmts.  The coverage information
     /// value is meant to be a hint for possible clients.
     LLVM_PREFERRED_TYPE(bool)
     unsigned AllEnumCasesCovered : 1;
 
     /// The location of the "switch".
     SourceLocation SwitchLoc;
   };
 
   class WhileStmtBitfields {
     friend class ASTStmtReader;
     friend class WhileStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// True if the WhileStmt has storage for a condition variable.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasVar : 1;
 
     /// The location of the "while".
     SourceLocation WhileLoc;
   };
 
   class DoStmtBitfields {
     friend class DoStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// The location of the "do".
     SourceLocation DoLoc;
   };
 
   class ForStmtBitfields {
     friend class ForStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// The location of the "for".
     SourceLocation ForLoc;
   };
 
   class GotoStmtBitfields {
     friend class GotoStmt;
     friend class IndirectGotoStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// The location of the "goto".
     SourceLocation GotoLoc;
   };
 
   class ContinueStmtBitfields {
     friend class ContinueStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// The location of the "continue".
     SourceLocation ContinueLoc;
   };
 
   class BreakStmtBitfields {
     friend class BreakStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// The location of the "break".
     SourceLocation BreakLoc;
   };
 
   class ReturnStmtBitfields {
     friend class ReturnStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// True if this ReturnStmt has storage for an NRVO candidate.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasNRVOCandidate : 1;
 
     /// The location of the "return".
     SourceLocation RetLoc;
   };
 
   class SwitchCaseBitfields {
     friend class SwitchCase;
     friend class CaseStmt;
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     /// Used by CaseStmt to store whether it is a case statement
     /// of the form case LHS ... RHS (a GNU extension).
     LLVM_PREFERRED_TYPE(bool)
     unsigned CaseStmtIsGNURange : 1;
 
     /// The location of the "case" or "default" keyword.
     SourceLocation KeywordLoc;
   };
 
   //===--- Expression bitfields classes ---===//
 
   class ExprBitfields {
     friend class ASTStmtReader; // deserialization
     friend class AtomicExpr; // ctor
     friend class BlockDeclRefExpr; // ctor
     friend class CallExpr; // ctor
     friend class CXXConstructExpr; // ctor
     friend class CXXDependentScopeMemberExpr; // ctor
     friend class CXXNewExpr; // ctor
     friend class CXXUnresolvedConstructExpr; // ctor
     friend class DeclRefExpr; // computeDependence
     friend class DependentScopeDeclRefExpr; // ctor
     friend class DesignatedInitExpr; // ctor
     friend class Expr;
     friend class InitListExpr; // ctor
     friend class ObjCArrayLiteral; // ctor
     friend class ObjCDictionaryLiteral; // ctor
     friend class ObjCMessageExpr; // ctor
     friend class OffsetOfExpr; // ctor
     friend class OpaqueValueExpr; // ctor
     friend class OverloadExpr; // ctor
     friend class ParenListExpr; // ctor
     friend class PseudoObjectExpr; // ctor
     friend class ShuffleVectorExpr; // ctor
 
     LLVM_PREFERRED_TYPE(StmtBitfields)
     unsigned : NumStmtBits;
 
     LLVM_PREFERRED_TYPE(ExprValueKind)
     unsigned ValueKind : 2;
     LLVM_PREFERRED_TYPE(ExprObjectKind)
     unsigned ObjectKind : 3;
     LLVM_PREFERRED_TYPE(ExprDependence)
     unsigned Dependent : llvm::BitWidth<ExprDependence>;
   };
   enum { NumExprBits = NumStmtBits + 5 + llvm::BitWidth<ExprDependence> };
 
   class ConstantExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class ConstantExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The kind of result that is tail-allocated.
     LLVM_PREFERRED_TYPE(ConstantResultStorageKind)
     unsigned ResultKind : 2;
 
     /// The kind of Result as defined by APValue::ValueKind.
     LLVM_PREFERRED_TYPE(APValue::ValueKind)
     unsigned APValueKind : 4;
 
     /// When ResultKind == ConstantResultStorageKind::Int64, true if the
     /// tail-allocated integer is unsigned.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsUnsigned : 1;
 
     /// When ResultKind == ConstantResultStorageKind::Int64. the BitWidth of the
     /// tail-allocated integer. 7 bits because it is the minimal number of bits
     /// to represent a value from 0 to 64 (the size of the tail-allocated
     /// integer).
     unsigned BitWidth : 7;
 
     /// When ResultKind == ConstantResultStorageKind::APValue, true if the
     /// ASTContext will cleanup the tail-allocated APValue.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasCleanup : 1;
 
     /// True if this ConstantExpr was created for immediate invocation.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsImmediateInvocation : 1;
   };
 
   class PredefinedExprBitfields {
     friend class ASTStmtReader;
     friend class PredefinedExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(PredefinedIdentKind)
     unsigned Kind : 4;
 
     /// True if this PredefinedExpr has a trailing "StringLiteral *"
     /// for the predefined identifier.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFunctionName : 1;
 
     /// True if this PredefinedExpr should be treated as a StringLiteral (for
     /// MSVC compatibility).
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsTransparent : 1;
 
     /// The location of this PredefinedExpr.
     SourceLocation Loc;
   };
 
   class DeclRefExprBitfields {
     friend class ASTStmtReader; // deserialization
     friend class DeclRefExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasQualifier : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasTemplateKWAndArgsInfo : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFoundDecl : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned HadMultipleCandidates : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned RefersToEnclosingVariableOrCapture : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned CapturedByCopyInLambdaWithExplicitObjectParameter : 1;
     LLVM_PREFERRED_TYPE(NonOdrUseReason)
     unsigned NonOdrUseReason : 2;
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsImmediateEscalating : 1;
 
     /// The location of the declaration name itself.
     SourceLocation Loc;
   };
 
 
   class FloatingLiteralBitfields {
     friend class FloatingLiteral;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     static_assert(
         llvm::APFloat::S_MaxSemantics < 32,
         "Too many Semantics enum values to fit in bitfield of size 5");
     LLVM_PREFERRED_TYPE(llvm::APFloat::Semantics)
     unsigned Semantics : 5; // Provides semantics for APFloat construction
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsExact : 1;
   };
 
   class StringLiteralBitfields {
     friend class ASTStmtReader;
     friend class StringLiteral;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The kind of this string literal.
     /// One of the enumeration values of StringLiteral::StringKind.
     LLVM_PREFERRED_TYPE(StringLiteralKind)
     unsigned Kind : 3;
 
     /// The width of a single character in bytes. Only values of 1, 2,
     /// and 4 bytes are supported. StringLiteral::mapCharByteWidth maps
     /// the target + string kind to the appropriate CharByteWidth.
     unsigned CharByteWidth : 3;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsPascal : 1;
 
     /// The number of concatenated token this string is made of.
     /// This is the number of trailing SourceLocation.
     unsigned NumConcatenated;
   };
 
   class CharacterLiteralBitfields {
     friend class CharacterLiteral;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(CharacterLiteralKind)
     unsigned Kind : 3;
   };
 
   class UnaryOperatorBitfields {
     friend class UnaryOperator;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(UnaryOperatorKind)
     unsigned Opc : 5;
     LLVM_PREFERRED_TYPE(bool)
     unsigned CanOverflow : 1;
     //
     /// This is only meaningful for operations on floating point
     /// types when additional values need to be in trailing storage.
     /// It is 0 otherwise.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFPFeatures : 1;
 
     SourceLocation Loc;
   };
 
   class UnaryExprOrTypeTraitExprBitfields {
     friend class UnaryExprOrTypeTraitExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(UnaryExprOrTypeTrait)
     unsigned Kind : 3;
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsType : 1; // true if operand is a type, false if an expression.
   };
 
   class ArrayOrMatrixSubscriptExprBitfields {
     friend class ArraySubscriptExpr;
     friend class MatrixSubscriptExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     SourceLocation RBracketLoc;
   };
 
   class CallExprBitfields {
     friend class CallExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     unsigned NumPreArgs : 1;
 
     /// True if the callee of the call expression was found using ADL.
     LLVM_PREFERRED_TYPE(bool)
     unsigned UsesADL : 1;
 
     /// True if the call expression has some floating-point features.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFPFeatures : 1;
 
     /// True if the call expression is a must-elide call to a coroutine.
     unsigned IsCoroElideSafe : 1;
 
     /// Padding used to align OffsetToTrailingObjects to a byte multiple.
     unsigned : 24 - 4 - NumExprBits;
 
     /// The offset in bytes from the this pointer to the start of the
     /// trailing objects belonging to CallExpr. Intentionally byte sized
     /// for faster access.
     unsigned OffsetToTrailingObjects : 8;
   };
   enum { NumCallExprBits = 32 };
 
   class MemberExprBitfields {
     friend class ASTStmtReader;
     friend class MemberExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// IsArrow - True if this is "X->F", false if this is "X.F".
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsArrow : 1;
 
     /// True if this member expression used a nested-name-specifier to
     /// refer to the member, e.g., "x->Base::f".
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasQualifier : 1;
 
     // True if this member expression found its member via a using declaration.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFoundDecl : 1;
 
     /// True if this member expression specified a template keyword
     /// and/or a template argument list explicitly, e.g., x->f<int>,
     /// x->template f, x->template f<int>.
     /// When true, an ASTTemplateKWAndArgsInfo structure and its
     /// TemplateArguments (if any) are present.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasTemplateKWAndArgsInfo : 1;
 
     /// True if this member expression refers to a method that
     /// was resolved from an overloaded set having size greater than 1.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HadMultipleCandidates : 1;
 
     /// Value of type NonOdrUseReason indicating why this MemberExpr does
     /// not constitute an odr-use of the named declaration. Meaningful only
     /// when naming a static member.
     LLVM_PREFERRED_TYPE(NonOdrUseReason)
     unsigned NonOdrUseReason : 2;
 
     /// This is the location of the -> or . in the expression.
     SourceLocation OperatorLoc;
   };
 
   class CastExprBitfields {
     friend class CastExpr;
     friend class ImplicitCastExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(CastKind)
     unsigned Kind : 7;
     LLVM_PREFERRED_TYPE(bool)
     unsigned PartOfExplicitCast : 1; // Only set for ImplicitCastExpr.
 
     /// True if the call expression has some floating-point features.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFPFeatures : 1;
 
     /// The number of CXXBaseSpecifiers in the cast. 14 bits would be enough
     /// here. ([implimits] Direct and indirect base classes [16384]).
     unsigned BasePathSize;
   };
 
   class BinaryOperatorBitfields {
     friend class BinaryOperator;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(BinaryOperatorKind)
     unsigned Opc : 6;
 
     /// This is only meaningful for operations on floating point
     /// types when additional values need to be in trailing storage.
     /// It is 0 otherwise.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFPFeatures : 1;
 
     /// Whether or not this BinaryOperator should be excluded from integer
     /// overflow sanitization.
     LLVM_PREFERRED_TYPE(bool)
     unsigned ExcludedOverflowPattern : 1;
 
     SourceLocation OpLoc;
   };
 
   class InitListExprBitfields {
     friend class InitListExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether this initializer list originally had a GNU array-range
     /// designator in it. This is a temporary marker used by CodeGen.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HadArrayRangeDesignator : 1;
   };
 
   class ParenListExprBitfields {
     friend class ASTStmtReader;
     friend class ParenListExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The number of expressions in the paren list.
     unsigned NumExprs;
   };
 
   class GenericSelectionExprBitfields {
     friend class ASTStmtReader;
     friend class GenericSelectionExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The location of the "_Generic".
     SourceLocation GenericLoc;
   };
 
   class PseudoObjectExprBitfields {
     friend class ASTStmtReader; // deserialization
     friend class PseudoObjectExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     unsigned NumSubExprs : 16;
     unsigned ResultIndex : 16;
   };
 
   class SourceLocExprBitfields {
     friend class ASTStmtReader;
     friend class SourceLocExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The kind of source location builtin represented by the SourceLocExpr.
     /// Ex. __builtin_LINE, __builtin_FUNCTION, etc.
     LLVM_PREFERRED_TYPE(SourceLocIdentKind)
     unsigned Kind : 3;
   };
 
   class ParenExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class ParenExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned ProducedByFoldExpansion : 1;
   };
 
   class StmtExprBitfields {
     friend class ASTStmtReader;
     friend class StmtExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The number of levels of template parameters enclosing this statement
     /// expression. Used to determine if a statement expression remains
     /// dependent after instantiation.
     unsigned TemplateDepth;
   };
 
   //===--- C++ Expression bitfields classes ---===//
 
   class CXXOperatorCallExprBitfields {
     friend class ASTStmtReader;
     friend class CXXOperatorCallExpr;
 
     LLVM_PREFERRED_TYPE(CallExprBitfields)
     unsigned : NumCallExprBits;
 
     /// The kind of this overloaded operator. One of the enumerator
     /// value of OverloadedOperatorKind.
     LLVM_PREFERRED_TYPE(OverloadedOperatorKind)
     unsigned OperatorKind : 6;
   };
 
   class CXXRewrittenBinaryOperatorBitfields {
     friend class ASTStmtReader;
     friend class CXXRewrittenBinaryOperator;
 
     LLVM_PREFERRED_TYPE(CallExprBitfields)
     unsigned : NumCallExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsReversed : 1;
   };
 
   class CXXBoolLiteralExprBitfields {
     friend class CXXBoolLiteralExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The value of the boolean literal.
     LLVM_PREFERRED_TYPE(bool)
     unsigned Value : 1;
 
     /// The location of the boolean literal.
     SourceLocation Loc;
   };
 
   class CXXNullPtrLiteralExprBitfields {
     friend class CXXNullPtrLiteralExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The location of the null pointer literal.
     SourceLocation Loc;
   };
 
   class CXXThisExprBitfields {
     friend class CXXThisExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether this is an implicit "this".
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsImplicit : 1;
 
     /// Whether there is a lambda with an explicit object parameter that
     /// captures this "this" by copy.
     LLVM_PREFERRED_TYPE(bool)
     unsigned CapturedByCopyInLambdaWithExplicitObjectParameter : 1;
 
     /// The location of the "this".
     SourceLocation Loc;
   };
 
   class CXXThrowExprBitfields {
     friend class ASTStmtReader;
     friend class CXXThrowExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether the thrown variable (if any) is in scope.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsThrownVariableInScope : 1;
 
     /// The location of the "throw".
     SourceLocation ThrowLoc;
   };
 
   class CXXDefaultArgExprBitfields {
     friend class ASTStmtReader;
     friend class CXXDefaultArgExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether this CXXDefaultArgExpr rewrote its argument and stores a copy.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasRewrittenInit : 1;
 
     /// The location where the default argument expression was used.
     SourceLocation Loc;
   };
 
   class CXXDefaultInitExprBitfields {
     friend class ASTStmtReader;
     friend class CXXDefaultInitExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether this CXXDefaultInitExprBitfields rewrote its argument and stores
     /// a copy.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasRewrittenInit : 1;
 
     /// The location where the default initializer expression was used.
     SourceLocation Loc;
   };
 
   class CXXScalarValueInitExprBitfields {
     friend class ASTStmtReader;
     friend class CXXScalarValueInitExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     SourceLocation RParenLoc;
   };
 
   class CXXNewExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class CXXNewExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Was the usage ::new, i.e. is the global new to be used?
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsGlobalNew : 1;
 
     /// Do we allocate an array? If so, the first trailing "Stmt *" is the
     /// size expression.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsArray : 1;
 
     /// Should the alignment be passed to the allocation function?
     LLVM_PREFERRED_TYPE(bool)
     unsigned ShouldPassAlignment : 1;
 
     /// If this is an array allocation, does the usual deallocation
     /// function for the allocated type want to know the allocated size?
     LLVM_PREFERRED_TYPE(bool)
     unsigned UsualArrayDeleteWantsSize : 1;
 
     // Is initializer expr present?
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasInitializer : 1;
 
     /// What kind of initializer syntax used? Could be none, parens, or braces.
     LLVM_PREFERRED_TYPE(CXXNewInitializationStyle)
     unsigned StoredInitializationStyle : 2;
 
     /// True if the allocated type was expressed as a parenthesized type-id.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsParenTypeId : 1;
 
     /// The number of placement new arguments.
     unsigned NumPlacementArgs;
   };
 
   class CXXDeleteExprBitfields {
     friend class ASTStmtReader;
     friend class CXXDeleteExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Is this a forced global delete, i.e. "::delete"?
     LLVM_PREFERRED_TYPE(bool)
     unsigned GlobalDelete : 1;
 
     /// Is this the array form of delete, i.e. "delete[]"?
     LLVM_PREFERRED_TYPE(bool)
     unsigned ArrayForm : 1;
 
     /// ArrayFormAsWritten can be different from ArrayForm if 'delete' is
     /// applied to pointer-to-array type (ArrayFormAsWritten will be false
     /// while ArrayForm will be true).
     LLVM_PREFERRED_TYPE(bool)
     unsigned ArrayFormAsWritten : 1;
 
     /// Does the usual deallocation function for the element type require
     /// a size_t argument?
     LLVM_PREFERRED_TYPE(bool)
     unsigned UsualArrayDeleteWantsSize : 1;
 
     /// Location of the expression.
     SourceLocation Loc;
   };
 
   class TypeTraitExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class TypeTraitExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The kind of type trait, which is a value of a TypeTrait enumerator.
     LLVM_PREFERRED_TYPE(TypeTrait)
     unsigned Kind : 8;
 
     /// If this expression is not value-dependent, this indicates whether
     /// the trait evaluated true or false.
     LLVM_PREFERRED_TYPE(bool)
     unsigned Value : 1;
 
     /// The number of arguments to this type trait. According to [implimits]
     /// 8 bits would be enough, but we require (and test for) at least 16 bits
     /// to mirror FunctionType.
     unsigned NumArgs;
   };
 
   class DependentScopeDeclRefExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class DependentScopeDeclRefExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether the name includes info for explicit template
     /// keyword and arguments.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasTemplateKWAndArgsInfo : 1;
   };
 
   class CXXConstructExprBitfields {
     friend class ASTStmtReader;
     friend class CXXConstructExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned Elidable : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned HadMultipleCandidates : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned ListInitialization : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned StdInitListInitialization : 1;
     LLVM_PREFERRED_TYPE(bool)
     unsigned ZeroInitialization : 1;
     LLVM_PREFERRED_TYPE(CXXConstructionKind)
     unsigned ConstructionKind : 3;
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsImmediateEscalating : 1;
 
     SourceLocation Loc;
   };
 
   class ExprWithCleanupsBitfields {
     friend class ASTStmtReader; // deserialization
     friend class ExprWithCleanups;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     // When false, it must not have side effects.
     LLVM_PREFERRED_TYPE(bool)
     unsigned CleanupsHaveSideEffects : 1;
 
     unsigned NumObjects : 32 - 1 - NumExprBits;
   };
 
   class CXXUnresolvedConstructExprBitfields {
     friend class ASTStmtReader;
     friend class CXXUnresolvedConstructExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The number of arguments used to construct the type.
     unsigned NumArgs;
   };
 
   class CXXDependentScopeMemberExprBitfields {
     friend class ASTStmtReader;
     friend class CXXDependentScopeMemberExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether this member expression used the '->' operator or
     /// the '.' operator.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsArrow : 1;
 
     /// Whether this member expression has info for explicit template
     /// keyword and arguments.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasTemplateKWAndArgsInfo : 1;
 
     /// See getFirstQualifierFoundInScope() and the comment listing
     /// the trailing objects.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasFirstQualifierFoundInScope : 1;
 
     /// The location of the '->' or '.' operator.
     SourceLocation OperatorLoc;
   };
 
   class OverloadExprBitfields {
     friend class ASTStmtReader;
     friend class OverloadExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// Whether the name includes info for explicit template
     /// keyword and arguments.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasTemplateKWAndArgsInfo : 1;
 
     /// Padding used by the derived classes to store various bits. If you
     /// need to add some data here, shrink this padding and add your data
     /// above. NumOverloadExprBits also needs to be updated.
     unsigned : 32 - NumExprBits - 1;
 
     /// The number of results.
     unsigned NumResults;
   };
   enum { NumOverloadExprBits = NumExprBits + 1 };
 
   class UnresolvedLookupExprBitfields {
     friend class ASTStmtReader;
     friend class UnresolvedLookupExpr;
 
     LLVM_PREFERRED_TYPE(OverloadExprBitfields)
     unsigned : NumOverloadExprBits;
 
     /// True if these lookup results should be extended by
     /// argument-dependent lookup if this is the operand of a function call.
     LLVM_PREFERRED_TYPE(bool)
     unsigned RequiresADL : 1;
   };
   static_assert(sizeof(UnresolvedLookupExprBitfields) <= 4,
                 "UnresolvedLookupExprBitfields must be <= than 4 bytes to"
                 "avoid trashing OverloadExprBitfields::NumResults!");
 
   class UnresolvedMemberExprBitfields {
     friend class ASTStmtReader;
     friend class UnresolvedMemberExpr;
 
     LLVM_PREFERRED_TYPE(OverloadExprBitfields)
     unsigned : NumOverloadExprBits;
 
     /// Whether this member expression used the '->' operator or
     /// the '.' operator.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsArrow : 1;
 
     /// Whether the lookup results contain an unresolved using declaration.
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasUnresolvedUsing : 1;
   };
   static_assert(sizeof(UnresolvedMemberExprBitfields) <= 4,
                 "UnresolvedMemberExprBitfields must be <= than 4 bytes to"
                 "avoid trashing OverloadExprBitfields::NumResults!");
 
   class CXXNoexceptExprBitfields {
     friend class ASTStmtReader;
     friend class CXXNoexceptExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned Value : 1;
   };
 
   class SubstNonTypeTemplateParmExprBitfields {
     friend class ASTStmtReader;
     friend class SubstNonTypeTemplateParmExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The location of the non-type template parameter reference.
     SourceLocation NameLoc;
   };
 
   class LambdaExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class LambdaExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The default capture kind, which is a value of type
     /// LambdaCaptureDefault.
     LLVM_PREFERRED_TYPE(LambdaCaptureDefault)
     unsigned CaptureDefault : 2;
 
     /// Whether this lambda had an explicit parameter list vs. an
     /// implicit (and empty) parameter list.
     LLVM_PREFERRED_TYPE(bool)
     unsigned ExplicitParams : 1;
 
     /// Whether this lambda had the result type explicitly specified.
     LLVM_PREFERRED_TYPE(bool)
     unsigned ExplicitResultType : 1;
 
     /// The number of captures.
     unsigned NumCaptures : 16;
   };
 
   class RequiresExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class RequiresExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsSatisfied : 1;
     SourceLocation RequiresKWLoc;
   };
 
   //===--- C++ Coroutines bitfields classes ---===//
 
   class CoawaitExprBitfields {
     friend class CoawaitExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsImplicit : 1;
   };
 
   //===--- Obj-C Expression bitfields classes ---===//
 
   class ObjCIndirectCopyRestoreExprBitfields {
     friend class ObjCIndirectCopyRestoreExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     LLVM_PREFERRED_TYPE(bool)
     unsigned ShouldCopy : 1;
   };
 
   //===--- Clang Extensions bitfields classes ---===//
 
   class OpaqueValueExprBitfields {
     friend class ASTStmtReader;
     friend class OpaqueValueExpr;
 
     LLVM_PREFERRED_TYPE(ExprBitfields)
     unsigned : NumExprBits;
 
     /// The OVE is a unique semantic reference to its source expression if this
     /// bit is set to true.
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsUnique : 1;
 
     SourceLocation Loc;
   };
 
   union {
     // Same order as in StmtNodes.td.
     // Statements
     StmtBitfields StmtBits;
     NullStmtBitfields NullStmtBits;
     CompoundStmtBitfields CompoundStmtBits;
     LabelStmtBitfields LabelStmtBits;
     AttributedStmtBitfields AttributedStmtBits;
     IfStmtBitfields IfStmtBits;
     SwitchStmtBitfields SwitchStmtBits;
     WhileStmtBitfields WhileStmtBits;
     DoStmtBitfields DoStmtBits;
     ForStmtBitfields ForStmtBits;
     GotoStmtBitfields GotoStmtBits;
     ContinueStmtBitfields ContinueStmtBits;
     BreakStmtBitfields BreakStmtBits;
     ReturnStmtBitfields ReturnStmtBits;
     SwitchCaseBitfields SwitchCaseBits;
 
     // Expressions
     ExprBitfields ExprBits;
     ConstantExprBitfields ConstantExprBits;
     PredefinedExprBitfields PredefinedExprBits;
     DeclRefExprBitfields DeclRefExprBits;
     FloatingLiteralBitfields FloatingLiteralBits;
     StringLiteralBitfields StringLiteralBits;
     CharacterLiteralBitfields CharacterLiteralBits;
     UnaryOperatorBitfields UnaryOperatorBits;
     UnaryExprOrTypeTraitExprBitfields UnaryExprOrTypeTraitExprBits;
     ArrayOrMatrixSubscriptExprBitfields ArrayOrMatrixSubscriptExprBits;
     CallExprBitfields CallExprBits;
     MemberExprBitfields MemberExprBits;
     CastExprBitfields CastExprBits;
     BinaryOperatorBitfields BinaryOperatorBits;
     InitListExprBitfields InitListExprBits;
     ParenListExprBitfields ParenListExprBits;
     GenericSelectionExprBitfields GenericSelectionExprBits;
     PseudoObjectExprBitfields PseudoObjectExprBits;
     SourceLocExprBitfields SourceLocExprBits;
     ParenExprBitfields ParenExprBits;
 
     // GNU Extensions.
     StmtExprBitfields StmtExprBits;
 
     // C++ Expressions
     CXXOperatorCallExprBitfields CXXOperatorCallExprBits;
     CXXRewrittenBinaryOperatorBitfields CXXRewrittenBinaryOperatorBits;
     CXXBoolLiteralExprBitfields CXXBoolLiteralExprBits;
     CXXNullPtrLiteralExprBitfields CXXNullPtrLiteralExprBits;
     CXXThisExprBitfields CXXThisExprBits;
     CXXThrowExprBitfields CXXThrowExprBits;
     CXXDefaultArgExprBitfields CXXDefaultArgExprBits;
     CXXDefaultInitExprBitfields CXXDefaultInitExprBits;
     CXXScalarValueInitExprBitfields CXXScalarValueInitExprBits;
     CXXNewExprBitfields CXXNewExprBits;
     CXXDeleteExprBitfields CXXDeleteExprBits;
     TypeTraitExprBitfields TypeTraitExprBits;
     DependentScopeDeclRefExprBitfields DependentScopeDeclRefExprBits;
     CXXConstructExprBitfields CXXConstructExprBits;
     ExprWithCleanupsBitfields ExprWithCleanupsBits;
     CXXUnresolvedConstructExprBitfields CXXUnresolvedConstructExprBits;
     CXXDependentScopeMemberExprBitfields CXXDependentScopeMemberExprBits;
     OverloadExprBitfields OverloadExprBits;
     UnresolvedLookupExprBitfields UnresolvedLookupExprBits;
     UnresolvedMemberExprBitfields UnresolvedMemberExprBits;
     CXXNoexceptExprBitfields CXXNoexceptExprBits;
     SubstNonTypeTemplateParmExprBitfields SubstNonTypeTemplateParmExprBits;
     LambdaExprBitfields LambdaExprBits;
     RequiresExprBitfields RequiresExprBits;
 
     // C++ Coroutines expressions
     CoawaitExprBitfields CoawaitBits;
 
     // Obj-C Expressions
     ObjCIndirectCopyRestoreExprBitfields ObjCIndirectCopyRestoreExprBits;
 
     // Clang Extensions
     OpaqueValueExprBitfields OpaqueValueExprBits;
   };
 
 public:
   // Only allow allocation of Stmts using the allocator in ASTContext
   // or by doing a placement new.
   void* operator new(size_t bytes, const ASTContext& C,
                      unsigned alignment = 8);
 
   void* operator new(size_t bytes, const ASTContext* C,
                      unsigned alignment = 8) {
     return operator new(bytes, *C, alignment);
   }
 
   void *operator new(size_t bytes, void *mem) noexcept { return mem; }
 
   void operator delete(void *, const ASTContext &, unsigned) noexcept {}
   void operator delete(void *, const ASTContext *, unsigned) noexcept {}
   void operator delete(void *, size_t) noexcept {}
   void operator delete(void *, void *) noexcept {}
 
 public:
   /// A placeholder type used to construct an empty shell of a
   /// type, that will be filled in later (e.g., by some
   /// de-serialization).
   struct EmptyShell {};
 
   /// The likelihood of a branch being taken.
   enum Likelihood {
     LH_Unlikely = -1, ///< Branch has the [[unlikely]] attribute.
     LH_None,          ///< No attribute set or branches of the IfStmt have
                       ///< the same attribute.
     LH_Likely         ///< Branch has the [[likely]] attribute.
   };
 
 protected:
   /// Iterator for iterating over Stmt * arrays that contain only T *.
   ///
   /// This is needed because AST nodes use Stmt* arrays to store
   /// references to children (to be compatible with StmtIterator).
   template<typename T, typename TPtr = T *, typename StmtPtr = Stmt *>
   struct CastIterator
       : llvm::iterator_adaptor_base<CastIterator<T, TPtr, StmtPtr>, StmtPtr *,
                                     std::random_access_iterator_tag, TPtr> {
     using Base = typename CastIterator::iterator_adaptor_base;
 
     CastIterator() : Base(nullptr) {}
     CastIterator(StmtPtr *I) : Base(I) {}
 
     typename Base::value_type operator*() const {
       return cast_or_null<T>(*this->I);
     }
   };
 
   /// Const iterator for iterating over Stmt * arrays that contain only T *.
   template <typename T>
   using ConstCastIterator = CastIterator<T, const T *const, const Stmt *const>;
 
   using ExprIterator = CastIterator<Expr>;
   using ConstExprIterator = ConstCastIterator<Expr>;
 
 private:
   /// Whether statistic collection is enabled.
   static bool StatisticsEnabled;
 
 protected:
   /// Construct an empty statement.
   explicit Stmt(StmtClass SC, EmptyShell) : Stmt(SC) {}
 
 public:
   Stmt() = delete;
   Stmt(const Stmt &) = delete;
   Stmt(Stmt &&) = delete;
   Stmt &operator=(const Stmt &) = delete;
   Stmt &operator=(Stmt &&) = delete;
 
   Stmt(StmtClass SC) {
     static_assert(sizeof(*this) <= 8,
                   "changing bitfields changed sizeof(Stmt)");
     static_assert(sizeof(*this) % alignof(void *) == 0,
                   "Insufficient alignment!");
     StmtBits.sClass = SC;
     if (StatisticsEnabled) Stmt::addStmtClass(SC);
   }
 
   StmtClass getStmtClass() const {
     return static_cast<StmtClass>(StmtBits.sClass);
   }
 
   const char *getStmtClassName() const;
 
   /// SourceLocation tokens are not useful in isolation - they are low level
   /// value objects created/interpreted by SourceManager. We assume AST
   /// clients will have a pointer to the respective SourceManager.
   SourceRange getSourceRange() const LLVM_READONLY;
   SourceLocation getBeginLoc() const LLVM_READONLY;
   SourceLocation getEndLoc() const LLVM_READONLY;
 
   // global temp stats (until we have a per-module visitor)
   static void addStmtClass(const StmtClass s);
   static void EnableStatistics();
   static void PrintStats();
 
   /// \returns the likelihood of a set of attributes.
   static Likelihood getLikelihood(ArrayRef<const Attr *> Attrs);
 
   /// \returns the likelihood of a statement.
   static Likelihood getLikelihood(const Stmt *S);
 
   /// \returns the likelihood attribute of a statement.
   static const Attr *getLikelihoodAttr(const Stmt *S);
 
   /// \returns the likelihood of the 'then' branch of an 'if' statement. The
   /// 'else' branch is required to determine whether both branches specify the
   /// same likelihood, which affects the result.
   static Likelihood getLikelihood(const Stmt *Then, const Stmt *Else);
 
   /// \returns whether the likelihood of the branches of an if statement are
   /// conflicting. When the first element is \c true there's a conflict and
   /// the Attr's are the conflicting attributes of the Then and Else Stmt.
   static std::tuple<bool, const Attr *, const Attr *>
   determineLikelihoodConflict(const Stmt *Then, const Stmt *Else);
 
   /// Dumps the specified AST fragment and all subtrees to
   /// \c llvm::errs().
   void dump() const;
   void dump(raw_ostream &OS, const ASTContext &Context) const;
 
   /// \return Unique reproducible object identifier
   int64_t getID(const ASTContext &Context) const;
 
   /// dumpColor - same as dump(), but forces color highlighting.
   void dumpColor() const;
 
   /// dumpPretty/printPretty - These two methods do a "pretty print" of the AST
   /// back to its original source language syntax.
   void dumpPretty(const ASTContext &Context) const;
   void printPretty(raw_ostream &OS, PrinterHelper *Helper,
                    const PrintingPolicy &Policy, unsigned Indentation = 0,
                    StringRef NewlineSymbol = "\n",
                    const ASTContext *Context = nullptr) const;
   void printPrettyControlled(raw_ostream &OS, PrinterHelper *Helper,
                              const PrintingPolicy &Policy,
                              unsigned Indentation = 0,
                              StringRef NewlineSymbol = "\n",
                              const ASTContext *Context = nullptr) const;
 
   /// Pretty-prints in JSON format.
   void printJson(raw_ostream &Out, PrinterHelper *Helper,
                  const PrintingPolicy &Policy, bool AddQuotes) const;
 
   /// viewAST - Visualize an AST rooted at this Stmt* using GraphViz.  Only
   ///   works on systems with GraphViz (Mac OS X) or dot+gv installed.
   void viewAST() const;
 
   /// Skip no-op (attributed, compound) container stmts and skip captured
   /// stmt at the top, if \a IgnoreCaptured is true.
   Stmt *IgnoreContainers(bool IgnoreCaptured = false);
   const Stmt *IgnoreContainers(bool IgnoreCaptured = false) const {
     return const_cast<Stmt *>(this)->IgnoreContainers(IgnoreCaptured);
   }
 
   const Stmt *stripLabelLikeStatements() const;
   Stmt *stripLabelLikeStatements() {
     return const_cast<Stmt*>(
       const_cast<const Stmt*>(this)->stripLabelLikeStatements());
   }
 
   /// Child Iterators: All subclasses must implement 'children'
   /// to permit easy iteration over the substatements/subexpressions of an
   /// AST node.  This permits easy iteration over all nodes in the AST.
   using child_iterator = StmtIterator;
   using const_child_iterator = ConstStmtIterator;
 
   using child_range = llvm::iterator_range<child_iterator>;
   using const_child_range = llvm::iterator_range<const_child_iterator>;
 
   child_range children();
 
   const_child_range children() const {
     auto Children = const_cast<Stmt *>(this)->children();
     return const_child_range(Children.begin(), Children.end());
   }
 
   child_iterator child_begin() { return children().begin(); }
   child_iterator child_end() { return children().end(); }
 
   const_child_iterator child_begin() const { return children().begin(); }
   const_child_iterator child_end() const { return children().end(); }
 
   /// Produce a unique representation of the given statement.
   ///
   /// \param ID once the profiling operation is complete, will contain
   /// the unique representation of the given statement.
   ///
   /// \param Context the AST context in which the statement resides
   ///
   /// \param Canonical whether the profile should be based on the canonical
   /// representation of this statement (e.g., where non-type template
   /// parameters are identified by index/level rather than their
   /// declaration pointers) or the exact representation of the statement as
   /// written in the source.
   /// \param ProfileLambdaExpr whether or not to profile lambda expressions.
   /// When false, the lambda expressions are never considered to be equal to
   /// other lambda expressions. When true, the lambda expressions with the same
   /// implementation will be considered to be the same. ProfileLambdaExpr should
   /// only be true when we try to merge two declarations within modules.
   void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                bool Canonical, bool ProfileLambdaExpr = false) const;
 
   /// Calculate a unique representation for a statement that is
   /// stable across compiler invocations.
   ///
   /// \param ID profile information will be stored in ID.
   ///
   /// \param Hash an ODRHash object which will be called where pointers would
   /// have been used in the Profile function.
   void ProcessODRHash(llvm::FoldingSetNodeID &ID, ODRHash& Hash) const;
 };
 
 /// DeclStmt - Adaptor class for mixing declarations with statements and
 /// expressions. For example, CompoundStmt mixes statements, expressions
 /// and declarations (variables, types). Another example is ForStmt, where
 /// the first statement can be an expression or a declaration.
 class DeclStmt : public Stmt {
   DeclGroupRef DG;
   SourceLocation StartLoc, EndLoc;
 
 public:
   DeclStmt(DeclGroupRef dg, SourceLocation startLoc, SourceLocation endLoc)
       : Stmt(DeclStmtClass), DG(dg), StartLoc(startLoc), EndLoc(endLoc) {}
 
   /// Build an empty declaration statement.
   explicit DeclStmt(EmptyShell Empty) : Stmt(DeclStmtClass, Empty) {}
 
   /// isSingleDecl - This method returns true if this DeclStmt refers
   /// to a single Decl.
   bool isSingleDecl() const { return DG.isSingleDecl(); }
 
   const Decl *getSingleDecl() const { return DG.getSingleDecl(); }
   Decl *getSingleDecl() { return DG.getSingleDecl(); }
 
   const DeclGroupRef getDeclGroup() const { return DG; }
   DeclGroupRef getDeclGroup() { return DG; }
   void setDeclGroup(DeclGroupRef DGR) { DG = DGR; }
 
   void setStartLoc(SourceLocation L) { StartLoc = L; }
   SourceLocation getEndLoc() const { return EndLoc; }
   void setEndLoc(SourceLocation L) { EndLoc = L; }
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return StartLoc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == DeclStmtClass;
   }
 
   // Iterators over subexpressions.
   child_range children() {
     return child_range(child_iterator(DG.begin(), DG.end()),
                        child_iterator(DG.end(), DG.end()));
   }
 
   const_child_range children() const {
     auto Children = const_cast<DeclStmt *>(this)->children();
     return const_child_range(Children);
   }
 
   using decl_iterator = DeclGroupRef::iterator;
   using const_decl_iterator = DeclGroupRef::const_iterator;
   using decl_range = llvm::iterator_range<decl_iterator>;
   using decl_const_range = llvm::iterator_range<const_decl_iterator>;
 
   decl_range decls() { return decl_range(decl_begin(), decl_end()); }
 
   decl_const_range decls() const {
     return decl_const_range(decl_begin(), decl_end());
   }
 
   decl_iterator decl_begin() { return DG.begin(); }
   decl_iterator decl_end() { return DG.end(); }
   const_decl_iterator decl_begin() const { return DG.begin(); }
   const_decl_iterator decl_end() const { return DG.end(); }
 
   using reverse_decl_iterator = std::reverse_iterator<decl_iterator>;
 
   reverse_decl_iterator decl_rbegin() {
     return reverse_decl_iterator(decl_end());
   }
 
   reverse_decl_iterator decl_rend() {
     return reverse_decl_iterator(decl_begin());
   }
 };
 
 /// NullStmt - This is the null statement ";": C99 6.8.3p3.
 ///
 class NullStmt : public Stmt {
 public:
   NullStmt(SourceLocation L, bool hasLeadingEmptyMacro = false)
       : Stmt(NullStmtClass) {
     NullStmtBits.HasLeadingEmptyMacro = hasLeadingEmptyMacro;
     setSemiLoc(L);
   }
 
   /// Build an empty null statement.
   explicit NullStmt(EmptyShell Empty) : Stmt(NullStmtClass, Empty) {}
 
   SourceLocation getSemiLoc() const { return NullStmtBits.SemiLoc; }
   void setSemiLoc(SourceLocation L) { NullStmtBits.SemiLoc = L; }
 
   bool hasLeadingEmptyMacro() const {
     return NullStmtBits.HasLeadingEmptyMacro;
   }
 
   SourceLocation getBeginLoc() const { return getSemiLoc(); }
   SourceLocation getEndLoc() const { return getSemiLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == NullStmtClass;
   }
 
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
 
   const_child_range children() const {
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 };
 
 /// CompoundStmt - This represents a group of statements like { stmt stmt }.
 class CompoundStmt final
     : public Stmt,
       private llvm::TrailingObjects<CompoundStmt, Stmt *, FPOptionsOverride> {
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   /// The location of the opening "{".
   SourceLocation LBraceLoc;
 
   /// The location of the closing "}".
   SourceLocation RBraceLoc;
 
   CompoundStmt(ArrayRef<Stmt *> Stmts, FPOptionsOverride FPFeatures,
                SourceLocation LB, SourceLocation RB);
   explicit CompoundStmt(EmptyShell Empty) : Stmt(CompoundStmtClass, Empty) {}
 
   void setStmts(ArrayRef<Stmt *> Stmts);
 
   /// Set FPOptionsOverride in trailing storage. Used only by Serialization.
   void setStoredFPFeatures(FPOptionsOverride F) {
     assert(hasStoredFPFeatures());
     *getTrailingObjects<FPOptionsOverride>() = F;
   }
 
   size_t numTrailingObjects(OverloadToken<Stmt *>) const {
     return CompoundStmtBits.NumStmts;
   }
 
 public:
   static CompoundStmt *Create(const ASTContext &C, ArrayRef<Stmt *> Stmts,
                               FPOptionsOverride FPFeatures, SourceLocation LB,
                               SourceLocation RB);
 
   // Build an empty compound statement with a location.
   explicit CompoundStmt(SourceLocation Loc) : CompoundStmt(Loc, Loc) {}
 
   CompoundStmt(SourceLocation Loc, SourceLocation EndLoc)
       : Stmt(CompoundStmtClass), LBraceLoc(Loc), RBraceLoc(EndLoc) {
     CompoundStmtBits.NumStmts = 0;
     CompoundStmtBits.HasFPFeatures = 0;
   }
 
   // Build an empty compound statement.
   static CompoundStmt *CreateEmpty(const ASTContext &C, unsigned NumStmts,
                                    bool HasFPFeatures);
 
   bool body_empty() const { return CompoundStmtBits.NumStmts == 0; }
   unsigned size() const { return CompoundStmtBits.NumStmts; }
 
   bool hasStoredFPFeatures() const { return CompoundStmtBits.HasFPFeatures; }
 
   /// Get FPOptionsOverride from trailing storage.
   FPOptionsOverride getStoredFPFeatures() const {
     assert(hasStoredFPFeatures());
     return *getTrailingObjects<FPOptionsOverride>();
   }
 
   /// Get the store FPOptionsOverride or default if not stored.
   FPOptionsOverride getStoredFPFeaturesOrDefault() const {
     return hasStoredFPFeatures() ? getStoredFPFeatures() : FPOptionsOverride();
   }
 
   using body_iterator = Stmt **;
   using body_range = llvm::iterator_range<body_iterator>;
 
   body_range body() { return body_range(body_begin(), body_end()); }
   body_iterator body_begin() { return getTrailingObjects<Stmt *>(); }
   body_iterator body_end() { return body_begin() + size(); }
   Stmt *body_front() { return !body_empty() ? body_begin()[0] : nullptr; }
 
   Stmt *body_back() {
     return !body_empty() ? body_begin()[size() - 1] : nullptr;
   }
 
   using const_body_iterator = Stmt *const *;
   using body_const_range = llvm::iterator_range<const_body_iterator>;
 
   body_const_range body() const {
     return body_const_range(body_begin(), body_end());
   }
 
   const_body_iterator body_begin() const {
     return getTrailingObjects<Stmt *>();
   }
 
   const_body_iterator body_end() const { return body_begin() + size(); }
 
   const Stmt *body_front() const {
     return !body_empty() ? body_begin()[0] : nullptr;
   }
 
   const Stmt *body_back() const {
     return !body_empty() ? body_begin()[size() - 1] : nullptr;
   }
 
   using reverse_body_iterator = std::reverse_iterator<body_iterator>;
 
   reverse_body_iterator body_rbegin() {
     return reverse_body_iterator(body_end());
   }
 
   reverse_body_iterator body_rend() {
     return reverse_body_iterator(body_begin());
   }
 
   using const_reverse_body_iterator =
       std::reverse_iterator<const_body_iterator>;
 
   const_reverse_body_iterator body_rbegin() const {
     return const_reverse_body_iterator(body_end());
   }
 
   const_reverse_body_iterator body_rend() const {
     return const_reverse_body_iterator(body_begin());
   }
 
   // Get the Stmt that StmtExpr would consider to be the result of this
   // compound statement. This is used by StmtExpr to properly emulate the GCC
   // compound expression extension, which ignores trailing NullStmts when
   // getting the result of the expression.
   // i.e. ({ 5;;; })
   //           ^^ ignored
   // If we don't find something that isn't a NullStmt, just return the last
   // Stmt.
   Stmt *getStmtExprResult() {
     for (auto *B : llvm::reverse(body())) {
       if (!isa<NullStmt>(B))
         return B;
     }
     return body_back();
   }
 
   const Stmt *getStmtExprResult() const {
     return const_cast<CompoundStmt *>(this)->getStmtExprResult();
   }
 
   SourceLocation getBeginLoc() const { return LBraceLoc; }
   SourceLocation getEndLoc() const { return RBraceLoc; }
 
   SourceLocation getLBracLoc() const { return LBraceLoc; }
   SourceLocation getRBracLoc() const { return RBraceLoc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CompoundStmtClass;
   }
 
   // Iterators
   child_range children() { return child_range(body_begin(), body_end()); }
 
   const_child_range children() const {
     return const_child_range(body_begin(), body_end());
   }
 };
 
 // SwitchCase is the base class for CaseStmt and DefaultStmt,
 class SwitchCase : public Stmt {
 protected:
   /// The location of the ":".
   SourceLocation ColonLoc;
 
   // The location of the "case" or "default" keyword. Stored in SwitchCaseBits.
   // SourceLocation KeywordLoc;
 
   /// A pointer to the following CaseStmt or DefaultStmt class,
   /// used by SwitchStmt.
   SwitchCase *NextSwitchCase = nullptr;
 
   SwitchCase(StmtClass SC, SourceLocation KWLoc, SourceLocation ColonLoc)
       : Stmt(SC), ColonLoc(ColonLoc) {
     setKeywordLoc(KWLoc);
   }
 
   SwitchCase(StmtClass SC, EmptyShell) : Stmt(SC) {}
 
 public:
   const SwitchCase *getNextSwitchCase() const { return NextSwitchCase; }
   SwitchCase *getNextSwitchCase() { return NextSwitchCase; }
   void setNextSwitchCase(SwitchCase *SC) { NextSwitchCase = SC; }
 
   SourceLocation getKeywordLoc() const { return SwitchCaseBits.KeywordLoc; }
   void setKeywordLoc(SourceLocation L) { SwitchCaseBits.KeywordLoc = L; }
   SourceLocation getColonLoc() const { return ColonLoc; }
   void setColonLoc(SourceLocation L) { ColonLoc = L; }
 
   inline Stmt *getSubStmt();
   const Stmt *getSubStmt() const {
     return const_cast<SwitchCase *>(this)->getSubStmt();
   }
 
   SourceLocation getBeginLoc() const { return getKeywordLoc(); }
   inline SourceLocation getEndLoc() const LLVM_READONLY;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CaseStmtClass ||
            T->getStmtClass() == DefaultStmtClass;
   }
 };
 
 /// CaseStmt - Represent a case statement. It can optionally be a GNU case
 /// statement of the form LHS ... RHS representing a range of cases.
 class CaseStmt final
     : public SwitchCase,
       private llvm::TrailingObjects<CaseStmt, Stmt *, SourceLocation> {
   friend TrailingObjects;
 
   // CaseStmt is followed by several trailing objects, some of which optional.
   // Note that it would be more convenient to put the optional trailing objects
   // at the end but this would impact children().
   // The trailing objects are in order:
   //
   // * A "Stmt *" for the LHS of the case statement. Always present.
   //
   // * A "Stmt *" for the RHS of the case statement. This is a GNU extension
   //   which allow ranges in cases statement of the form LHS ... RHS.
   //   Present if and only if caseStmtIsGNURange() is true.
   //
   // * A "Stmt *" for the substatement of the case statement. Always present.
   //
   // * A SourceLocation for the location of the ... if this is a case statement
   //   with a range. Present if and only if caseStmtIsGNURange() is true.
   enum { LhsOffset = 0, SubStmtOffsetFromRhs = 1 };
   enum { NumMandatoryStmtPtr = 2 };
 
   unsigned numTrailingObjects(OverloadToken<Stmt *>) const {
     return NumMandatoryStmtPtr + caseStmtIsGNURange();
   }
 
   unsigned numTrailingObjects(OverloadToken<SourceLocation>) const {
     return caseStmtIsGNURange();
   }
 
   unsigned lhsOffset() const { return LhsOffset; }
   unsigned rhsOffset() const { return LhsOffset + caseStmtIsGNURange(); }
   unsigned subStmtOffset() const { return rhsOffset() + SubStmtOffsetFromRhs; }
 
   /// Build a case statement assuming that the storage for the
   /// trailing objects has been properly allocated.
   CaseStmt(Expr *lhs, Expr *rhs, SourceLocation caseLoc,
            SourceLocation ellipsisLoc, SourceLocation colonLoc)
       : SwitchCase(CaseStmtClass, caseLoc, colonLoc) {
     // Handle GNU case statements of the form LHS ... RHS.
     bool IsGNURange = rhs != nullptr;
     SwitchCaseBits.CaseStmtIsGNURange = IsGNURange;
     setLHS(lhs);
     setSubStmt(nullptr);
     if (IsGNURange) {
       setRHS(rhs);
       setEllipsisLoc(ellipsisLoc);
     }
   }
 
   /// Build an empty switch case statement.
   explicit CaseStmt(EmptyShell Empty, bool CaseStmtIsGNURange)
       : SwitchCase(CaseStmtClass, Empty) {
     SwitchCaseBits.CaseStmtIsGNURange = CaseStmtIsGNURange;
   }
 
 public:
   /// Build a case statement.
   static CaseStmt *Create(const ASTContext &Ctx, Expr *lhs, Expr *rhs,
                           SourceLocation caseLoc, SourceLocation ellipsisLoc,
                           SourceLocation colonLoc);
 
   /// Build an empty case statement.
   static CaseStmt *CreateEmpty(const ASTContext &Ctx, bool CaseStmtIsGNURange);
 
   /// True if this case statement is of the form case LHS ... RHS, which
   /// is a GNU extension. In this case the RHS can be obtained with getRHS()
   /// and the location of the ellipsis can be obtained with getEllipsisLoc().
   bool caseStmtIsGNURange() const { return SwitchCaseBits.CaseStmtIsGNURange; }
 
   SourceLocation getCaseLoc() const { return getKeywordLoc(); }
   void setCaseLoc(SourceLocation L) { setKeywordLoc(L); }
 
   /// Get the location of the ... in a case statement of the form LHS ... RHS.
   SourceLocation getEllipsisLoc() const {
     return caseStmtIsGNURange() ? *getTrailingObjects<SourceLocation>()
                                 : SourceLocation();
   }
 
   /// Set the location of the ... in a case statement of the form LHS ... RHS.
   /// Assert that this case statement is of this form.
   void setEllipsisLoc(SourceLocation L) {
     assert(
         caseStmtIsGNURange() &&
         "setEllipsisLoc but this is not a case stmt of the form LHS ... RHS!");
     *getTrailingObjects<SourceLocation>() = L;
   }
 
   Expr *getLHS() {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[lhsOffset()]);
   }
 
   const Expr *getLHS() const {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[lhsOffset()]);
   }
 
   void setLHS(Expr *Val) {
     getTrailingObjects<Stmt *>()[lhsOffset()] = reinterpret_cast<Stmt *>(Val);
   }
 
   Expr *getRHS() {
     return caseStmtIsGNURange() ? reinterpret_cast<Expr *>(
                                       getTrailingObjects<Stmt *>()[rhsOffset()])
                                 : nullptr;
   }
 
   const Expr *getRHS() const {
     return caseStmtIsGNURange() ? reinterpret_cast<Expr *>(
                                       getTrailingObjects<Stmt *>()[rhsOffset()])
                                 : nullptr;
   }
 
   void setRHS(Expr *Val) {
     assert(caseStmtIsGNURange() &&
            "setRHS but this is not a case stmt of the form LHS ... RHS!");
     getTrailingObjects<Stmt *>()[rhsOffset()] = reinterpret_cast<Stmt *>(Val);
   }
 
   Stmt *getSubStmt() { return getTrailingObjects<Stmt *>()[subStmtOffset()]; }
   const Stmt *getSubStmt() const {
     return getTrailingObjects<Stmt *>()[subStmtOffset()];
   }
 
   void setSubStmt(Stmt *S) {
     getTrailingObjects<Stmt *>()[subStmtOffset()] = S;
   }
 
   SourceLocation getBeginLoc() const { return getKeywordLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY {
     // Handle deeply nested case statements with iteration instead of recursion.
     const CaseStmt *CS = this;
     while (const auto *CS2 = dyn_cast<CaseStmt>(CS->getSubStmt()))
       CS = CS2;
 
     return CS->getSubStmt()->getEndLoc();
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CaseStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(getTrailingObjects<Stmt *>(),
                        getTrailingObjects<Stmt *>() +
                            numTrailingObjects(OverloadToken<Stmt *>()));
   }
 
   const_child_range children() const {
     return const_child_range(getTrailingObjects<Stmt *>(),
                              getTrailingObjects<Stmt *>() +
                                  numTrailingObjects(OverloadToken<Stmt *>()));
   }
 };
 
 class DefaultStmt : public SwitchCase {
   Stmt *SubStmt;
 
 public:
   DefaultStmt(SourceLocation DL, SourceLocation CL, Stmt *substmt)
       : SwitchCase(DefaultStmtClass, DL, CL), SubStmt(substmt) {}
 
   /// Build an empty default statement.
   explicit DefaultStmt(EmptyShell Empty)
       : SwitchCase(DefaultStmtClass, Empty) {}
 
   Stmt *getSubStmt() { return SubStmt; }
   const Stmt *getSubStmt() const { return SubStmt; }
   void setSubStmt(Stmt *S) { SubStmt = S; }
 
   SourceLocation getDefaultLoc() const { return getKeywordLoc(); }
   void setDefaultLoc(SourceLocation L) { setKeywordLoc(L); }
 
   SourceLocation getBeginLoc() const { return getKeywordLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY {
     return SubStmt->getEndLoc();
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == DefaultStmtClass;
   }
 
   // Iterators
   child_range children() { return child_range(&SubStmt, &SubStmt + 1); }
 
   const_child_range children() const {
     return const_child_range(&SubStmt, &SubStmt + 1);
   }
 };
 
 SourceLocation SwitchCase::getEndLoc() const {
   if (const auto *CS = dyn_cast<CaseStmt>(this))
     return CS->getEndLoc();
   else if (const auto *DS = dyn_cast<DefaultStmt>(this))
     return DS->getEndLoc();
   llvm_unreachable("SwitchCase is neither a CaseStmt nor a DefaultStmt!");
 }
 
 Stmt *SwitchCase::getSubStmt() {
   if (auto *CS = dyn_cast<CaseStmt>(this))
     return CS->getSubStmt();
   else if (auto *DS = dyn_cast<DefaultStmt>(this))
     return DS->getSubStmt();
   llvm_unreachable("SwitchCase is neither a CaseStmt nor a DefaultStmt!");
 }
 
 /// Represents a statement that could possibly have a value and type. This
 /// covers expression-statements, as well as labels and attributed statements.
 ///
 /// Value statements have a special meaning when they are the last non-null
 /// statement in a GNU statement expression, where they determine the value
 /// of the statement expression.
 class ValueStmt : public Stmt {
 protected:
   using Stmt::Stmt;
 
 public:
   const Expr *getExprStmt() const;
   Expr *getExprStmt() {
     const ValueStmt *ConstThis = this;
     return const_cast<Expr*>(ConstThis->getExprStmt());
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() >= firstValueStmtConstant &&
            T->getStmtClass() <= lastValueStmtConstant;
   }
 };
 
 /// LabelStmt - Represents a label, which has a substatement.  For example:
 ///    foo: return;
 class LabelStmt : public ValueStmt {
   LabelDecl *TheDecl;
   Stmt *SubStmt;
   bool SideEntry = false;
 
 public:
   /// Build a label statement.
   LabelStmt(SourceLocation IL, LabelDecl *D, Stmt *substmt)
       : ValueStmt(LabelStmtClass), TheDecl(D), SubStmt(substmt) {
     setIdentLoc(IL);
   }
 
   /// Build an empty label statement.
   explicit LabelStmt(EmptyShell Empty) : ValueStmt(LabelStmtClass, Empty) {}
 
   SourceLocation getIdentLoc() const { return LabelStmtBits.IdentLoc; }
   void setIdentLoc(SourceLocation L) { LabelStmtBits.IdentLoc = L; }
 
   LabelDecl *getDecl() const { return TheDecl; }
   void setDecl(LabelDecl *D) { TheDecl = D; }
 
   const char *getName() const;
   Stmt *getSubStmt() { return SubStmt; }
 
   const Stmt *getSubStmt() const { return SubStmt; }
   void setSubStmt(Stmt *SS) { SubStmt = SS; }
 
   SourceLocation getBeginLoc() const { return getIdentLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY { return SubStmt->getEndLoc();}
 
   child_range children() { return child_range(&SubStmt, &SubStmt + 1); }
 
   const_child_range children() const {
     return const_child_range(&SubStmt, &SubStmt + 1);
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == LabelStmtClass;
   }
   bool isSideEntry() const { return SideEntry; }
   void setSideEntry(bool SE) { SideEntry = SE; }
 };
 
 /// Represents an attribute applied to a statement.
 ///
 /// Represents an attribute applied to a statement. For example:
 ///   [[omp::for(...)]] for (...) { ... }
 class AttributedStmt final
     : public ValueStmt,
       private llvm::TrailingObjects<AttributedStmt, const Attr *> {
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   Stmt *SubStmt;
 
   AttributedStmt(SourceLocation Loc, ArrayRef<const Attr *> Attrs,
                  Stmt *SubStmt)
       : ValueStmt(AttributedStmtClass), SubStmt(SubStmt) {
     AttributedStmtBits.NumAttrs = Attrs.size();
     AttributedStmtBits.AttrLoc = Loc;
     std::copy(Attrs.begin(), Attrs.end(), getAttrArrayPtr());
   }
 
   explicit AttributedStmt(EmptyShell Empty, unsigned NumAttrs)
       : ValueStmt(AttributedStmtClass, Empty) {
     AttributedStmtBits.NumAttrs = NumAttrs;
     AttributedStmtBits.AttrLoc = SourceLocation{};
     std::fill_n(getAttrArrayPtr(), NumAttrs, nullptr);
   }
 
   const Attr *const *getAttrArrayPtr() const {
     return getTrailingObjects<const Attr *>();
   }
   const Attr **getAttrArrayPtr() { return getTrailingObjects<const Attr *>(); }
 
 public:
   static AttributedStmt *Create(const ASTContext &C, SourceLocation Loc,
                                 ArrayRef<const Attr *> Attrs, Stmt *SubStmt);
 
   // Build an empty attributed statement.
   static AttributedStmt *CreateEmpty(const ASTContext &C, unsigned NumAttrs);
 
   SourceLocation getAttrLoc() const { return AttributedStmtBits.AttrLoc; }
   ArrayRef<const Attr *> getAttrs() const {
     return llvm::ArrayRef(getAttrArrayPtr(), AttributedStmtBits.NumAttrs);
   }
 
   Stmt *getSubStmt() { return SubStmt; }
   const Stmt *getSubStmt() const { return SubStmt; }
 
   SourceLocation getBeginLoc() const { return getAttrLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY { return SubStmt->getEndLoc();}
 
   child_range children() { return child_range(&SubStmt, &SubStmt + 1); }
 
   const_child_range children() const {
     return const_child_range(&SubStmt, &SubStmt + 1);
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == AttributedStmtClass;
   }
 };
 
 /// IfStmt - This represents an if/then/else.
 class IfStmt final
     : public Stmt,
       private llvm::TrailingObjects<IfStmt, Stmt *, SourceLocation> {
   friend TrailingObjects;
 
   // IfStmt is followed by several trailing objects, some of which optional.
   // Note that it would be more convenient to put the optional trailing
   // objects at then end but this would change the order of the children.
   // The trailing objects are in order:
   //
   // * A "Stmt *" for the init statement.
   //    Present if and only if hasInitStorage().
   //
   // * A "Stmt *" for the condition variable.
   //    Present if and only if hasVarStorage(). This is in fact a "DeclStmt *".
   //
   // * A "Stmt *" for the condition.
   //    Always present. This is in fact a "Expr *".
   //
   // * A "Stmt *" for the then statement.
   //    Always present.
   //
   // * A "Stmt *" for the else statement.
   //    Present if and only if hasElseStorage().
   //
   // * A "SourceLocation" for the location of the "else".
   //    Present if and only if hasElseStorage().
   enum { InitOffset = 0, ThenOffsetFromCond = 1, ElseOffsetFromCond = 2 };
   enum { NumMandatoryStmtPtr = 2 };
   SourceLocation LParenLoc;
   SourceLocation RParenLoc;
 
   unsigned numTrailingObjects(OverloadToken<Stmt *>) const {
     return NumMandatoryStmtPtr + hasElseStorage() + hasVarStorage() +
            hasInitStorage();
   }
 
   unsigned numTrailingObjects(OverloadToken<SourceLocation>) const {
     return hasElseStorage();
   }
 
   unsigned initOffset() const { return InitOffset; }
   unsigned varOffset() const { return InitOffset + hasInitStorage(); }
   unsigned condOffset() const {
     return InitOffset + hasInitStorage() + hasVarStorage();
   }
   unsigned thenOffset() const { return condOffset() + ThenOffsetFromCond; }
   unsigned elseOffset() const { return condOffset() + ElseOffsetFromCond; }
 
   /// Build an if/then/else statement.
   IfStmt(const ASTContext &Ctx, SourceLocation IL, IfStatementKind Kind,
          Stmt *Init, VarDecl *Var, Expr *Cond, SourceLocation LParenLoc,
          SourceLocation RParenLoc, Stmt *Then, SourceLocation EL, Stmt *Else);
 
   /// Build an empty if/then/else statement.
   explicit IfStmt(EmptyShell Empty, bool HasElse, bool HasVar, bool HasInit);
 
 public:
   /// Create an IfStmt.
   static IfStmt *Create(const ASTContext &Ctx, SourceLocation IL,
                         IfStatementKind Kind, Stmt *Init, VarDecl *Var,
                         Expr *Cond, SourceLocation LPL, SourceLocation RPL,
                         Stmt *Then, SourceLocation EL = SourceLocation(),
                         Stmt *Else = nullptr);
 
   /// Create an empty IfStmt optionally with storage for an else statement,
   /// condition variable and init expression.
   static IfStmt *CreateEmpty(const ASTContext &Ctx, bool HasElse, bool HasVar,
                              bool HasInit);
 
   /// True if this IfStmt has the storage for an init statement.
   bool hasInitStorage() const { return IfStmtBits.HasInit; }
 
   /// True if this IfStmt has storage for a variable declaration.
   bool hasVarStorage() const { return IfStmtBits.HasVar; }
 
   /// True if this IfStmt has storage for an else statement.
   bool hasElseStorage() const { return IfStmtBits.HasElse; }
 
   Expr *getCond() {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[condOffset()]);
   }
 
   const Expr *getCond() const {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[condOffset()]);
   }
 
   void setCond(Expr *Cond) {
     getTrailingObjects<Stmt *>()[condOffset()] = reinterpret_cast<Stmt *>(Cond);
   }
 
   Stmt *getThen() { return getTrailingObjects<Stmt *>()[thenOffset()]; }
   const Stmt *getThen() const {
     return getTrailingObjects<Stmt *>()[thenOffset()];
   }
 
   void setThen(Stmt *Then) {
     getTrailingObjects<Stmt *>()[thenOffset()] = Then;
   }
 
   Stmt *getElse() {
     return hasElseStorage() ? getTrailingObjects<Stmt *>()[elseOffset()]
                             : nullptr;
   }
 
   const Stmt *getElse() const {
     return hasElseStorage() ? getTrailingObjects<Stmt *>()[elseOffset()]
                             : nullptr;
   }
 
   void setElse(Stmt *Else) {
     assert(hasElseStorage() &&
            "This if statement has no storage for an else statement!");
     getTrailingObjects<Stmt *>()[elseOffset()] = Else;
   }
 
   /// Retrieve the variable declared in this "if" statement, if any.
   ///
   /// In the following example, "x" is the condition variable.
   /// \code
   /// if (int x = foo()) {
   ///   printf("x is %d", x);
   /// }
   /// \endcode
   VarDecl *getConditionVariable();
   const VarDecl *getConditionVariable() const {
     return const_cast<IfStmt *>(this)->getConditionVariable();
   }
 
   /// Set the condition variable for this if statement.
   /// The if statement must have storage for the condition variable.
   void setConditionVariable(const ASTContext &Ctx, VarDecl *V);
 
   /// If this IfStmt has a condition variable, return the faux DeclStmt
   /// associated with the creation of that condition variable.
   DeclStmt *getConditionVariableDeclStmt() {
     return hasVarStorage() ? static_cast<DeclStmt *>(
                                  getTrailingObjects<Stmt *>()[varOffset()])
                            : nullptr;
   }
 
   const DeclStmt *getConditionVariableDeclStmt() const {
     return hasVarStorage() ? static_cast<DeclStmt *>(
                                  getTrailingObjects<Stmt *>()[varOffset()])
                            : nullptr;
   }
 
   void setConditionVariableDeclStmt(DeclStmt *CondVar) {
     assert(hasVarStorage());
     getTrailingObjects<Stmt *>()[varOffset()] = CondVar;
   }
 
   Stmt *getInit() {
     return hasInitStorage() ? getTrailingObjects<Stmt *>()[initOffset()]
                             : nullptr;
   }
 
   const Stmt *getInit() const {
     return hasInitStorage() ? getTrailingObjects<Stmt *>()[initOffset()]
                             : nullptr;
   }
 
   void setInit(Stmt *Init) {
     assert(hasInitStorage() &&
            "This if statement has no storage for an init statement!");
     getTrailingObjects<Stmt *>()[initOffset()] = Init;
   }
 
   SourceLocation getIfLoc() const { return IfStmtBits.IfLoc; }
   void setIfLoc(SourceLocation IfLoc) { IfStmtBits.IfLoc = IfLoc; }
 
   SourceLocation getElseLoc() const {
     return hasElseStorage() ? *getTrailingObjects<SourceLocation>()
                             : SourceLocation();
   }
 
   void setElseLoc(SourceLocation ElseLoc) {
     assert(hasElseStorage() &&
            "This if statement has no storage for an else statement!");
     *getTrailingObjects<SourceLocation>() = ElseLoc;
   }
 
   bool isConsteval() const {
     return getStatementKind() == IfStatementKind::ConstevalNonNegated ||
            getStatementKind() == IfStatementKind::ConstevalNegated;
   }
 
   bool isNonNegatedConsteval() const {
     return getStatementKind() == IfStatementKind::ConstevalNonNegated;
   }
 
   bool isNegatedConsteval() const {
     return getStatementKind() == IfStatementKind::ConstevalNegated;
   }
 
   bool isConstexpr() const {
     return getStatementKind() == IfStatementKind::Constexpr;
   }
 
   void setStatementKind(IfStatementKind Kind) {
     IfStmtBits.Kind = static_cast<unsigned>(Kind);
   }
 
   IfStatementKind getStatementKind() const {
     return static_cast<IfStatementKind>(IfStmtBits.Kind);
   }
 
   /// If this is an 'if constexpr', determine which substatement will be taken.
   /// Otherwise, or if the condition is value-dependent, returns std::nullopt.
   std::optional<const Stmt *> getNondiscardedCase(const ASTContext &Ctx) const;
   std::optional<Stmt *> getNondiscardedCase(const ASTContext &Ctx);
 
   bool isObjCAvailabilityCheck() const;
 
   SourceLocation getBeginLoc() const { return getIfLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY {
     if (getElse())
       return getElse()->getEndLoc();
     return getThen()->getEndLoc();
   }
   SourceLocation getLParenLoc() const { return LParenLoc; }
   void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation Loc) { RParenLoc = Loc; }
 
   // Iterators over subexpressions.  The iterators will include iterating
   // over the initialization expression referenced by the condition variable.
   child_range children() {
     // We always store a condition, but there is none for consteval if
     // statements, so skip it.
     return child_range(getTrailingObjects<Stmt *>() +
                            (isConsteval() ? thenOffset() : 0),
                        getTrailingObjects<Stmt *>() +
                            numTrailingObjects(OverloadToken<Stmt *>()));
   }
 
   const_child_range children() const {
     // We always store a condition, but there is none for consteval if
     // statements, so skip it.
     return const_child_range(getTrailingObjects<Stmt *>() +
                                  (isConsteval() ? thenOffset() : 0),
                              getTrailingObjects<Stmt *>() +
                                  numTrailingObjects(OverloadToken<Stmt *>()));
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == IfStmtClass;
   }
 };
 
 /// SwitchStmt - This represents a 'switch' stmt.
 class SwitchStmt final : public Stmt,
                          private llvm::TrailingObjects<SwitchStmt, Stmt *> {
   friend TrailingObjects;
 
   /// Points to a linked list of case and default statements.
   SwitchCase *FirstCase = nullptr;
 
   // SwitchStmt is followed by several trailing objects,
   // some of which optional. Note that it would be more convenient to
   // put the optional trailing objects at the end but this would change
   // the order in children().
   // The trailing objects are in order:
   //
   // * A "Stmt *" for the init statement.
   //    Present if and only if hasInitStorage().
   //
   // * A "Stmt *" for the condition variable.
   //    Present if and only if hasVarStorage(). This is in fact a "DeclStmt *".
   //
   // * A "Stmt *" for the condition.
   //    Always present. This is in fact an "Expr *".
   //
   // * A "Stmt *" for the body.
   //    Always present.
   enum { InitOffset = 0, BodyOffsetFromCond = 1 };
   enum { NumMandatoryStmtPtr = 2 };
   SourceLocation LParenLoc;
   SourceLocation RParenLoc;
 
   unsigned numTrailingObjects(OverloadToken<Stmt *>) const {
     return NumMandatoryStmtPtr + hasInitStorage() + hasVarStorage();
   }
 
   unsigned initOffset() const { return InitOffset; }
   unsigned varOffset() const { return InitOffset + hasInitStorage(); }
   unsigned condOffset() const {
     return InitOffset + hasInitStorage() + hasVarStorage();
   }
   unsigned bodyOffset() const { return condOffset() + BodyOffsetFromCond; }
 
   /// Build a switch statement.
   SwitchStmt(const ASTContext &Ctx, Stmt *Init, VarDecl *Var, Expr *Cond,
              SourceLocation LParenLoc, SourceLocation RParenLoc);
 
   /// Build a empty switch statement.
   explicit SwitchStmt(EmptyShell Empty, bool HasInit, bool HasVar);
 
 public:
   /// Create a switch statement.
   static SwitchStmt *Create(const ASTContext &Ctx, Stmt *Init, VarDecl *Var,
                             Expr *Cond, SourceLocation LParenLoc,
                             SourceLocation RParenLoc);
 
   /// Create an empty switch statement optionally with storage for
   /// an init expression and a condition variable.
   static SwitchStmt *CreateEmpty(const ASTContext &Ctx, bool HasInit,
                                  bool HasVar);
 
   /// True if this SwitchStmt has storage for an init statement.
   bool hasInitStorage() const { return SwitchStmtBits.HasInit; }
 
   /// True if this SwitchStmt has storage for a condition variable.
   bool hasVarStorage() const { return SwitchStmtBits.HasVar; }
 
   Expr *getCond() {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[condOffset()]);
   }
 
   const Expr *getCond() const {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[condOffset()]);
   }
 
   void setCond(Expr *Cond) {
     getTrailingObjects<Stmt *>()[condOffset()] = reinterpret_cast<Stmt *>(Cond);
   }
 
   Stmt *getBody() { return getTrailingObjects<Stmt *>()[bodyOffset()]; }
   const Stmt *getBody() const {
     return getTrailingObjects<Stmt *>()[bodyOffset()];
   }
 
   void setBody(Stmt *Body) {
     getTrailingObjects<Stmt *>()[bodyOffset()] = Body;
   }
 
   Stmt *getInit() {
     return hasInitStorage() ? getTrailingObjects<Stmt *>()[initOffset()]
                             : nullptr;
   }
 
   const Stmt *getInit() const {
     return hasInitStorage() ? getTrailingObjects<Stmt *>()[initOffset()]
                             : nullptr;
   }
 
   void setInit(Stmt *Init) {
     assert(hasInitStorage() &&
            "This switch statement has no storage for an init statement!");
     getTrailingObjects<Stmt *>()[initOffset()] = Init;
   }
 
   /// Retrieve the variable declared in this "switch" statement, if any.
   ///
   /// In the following example, "x" is the condition variable.
   /// \code
   /// switch (int x = foo()) {
   ///   case 0: break;
   ///   // ...
   /// }
   /// \endcode
   VarDecl *getConditionVariable();
   const VarDecl *getConditionVariable() const {
     return const_cast<SwitchStmt *>(this)->getConditionVariable();
   }
 
   /// Set the condition variable in this switch statement.
   /// The switch statement must have storage for it.
   void setConditionVariable(const ASTContext &Ctx, VarDecl *VD);
 
   /// If this SwitchStmt has a condition variable, return the faux DeclStmt
   /// associated with the creation of that condition variable.
   DeclStmt *getConditionVariableDeclStmt() {
     return hasVarStorage() ? static_cast<DeclStmt *>(
                                  getTrailingObjects<Stmt *>()[varOffset()])
                            : nullptr;
   }
 
   const DeclStmt *getConditionVariableDeclStmt() const {
     return hasVarStorage() ? static_cast<DeclStmt *>(
                                  getTrailingObjects<Stmt *>()[varOffset()])
                            : nullptr;
   }
 
   void setConditionVariableDeclStmt(DeclStmt *CondVar) {
     assert(hasVarStorage());
     getTrailingObjects<Stmt *>()[varOffset()] = CondVar;
   }
 
   SwitchCase *getSwitchCaseList() { return FirstCase; }
   const SwitchCase *getSwitchCaseList() const { return FirstCase; }
   void setSwitchCaseList(SwitchCase *SC) { FirstCase = SC; }
 
   SourceLocation getSwitchLoc() const { return SwitchStmtBits.SwitchLoc; }
   void setSwitchLoc(SourceLocation L) { SwitchStmtBits.SwitchLoc = L; }
   SourceLocation getLParenLoc() const { return LParenLoc; }
   void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation Loc) { RParenLoc = Loc; }
 
   void setBody(Stmt *S, SourceLocation SL) {
     setBody(S);
     setSwitchLoc(SL);
   }
 
   void addSwitchCase(SwitchCase *SC) {
     assert(!SC->getNextSwitchCase() &&
            "case/default already added to a switch");
     SC->setNextSwitchCase(FirstCase);
     FirstCase = SC;
   }
 
   /// Set a flag in the SwitchStmt indicating that if the 'switch (X)' is a
   /// switch over an enum value then all cases have been explicitly covered.
   void setAllEnumCasesCovered() { SwitchStmtBits.AllEnumCasesCovered = true; }
 
   /// Returns true if the SwitchStmt is a switch of an enum value and all cases
   /// have been explicitly covered.
   bool isAllEnumCasesCovered() const {
     return SwitchStmtBits.AllEnumCasesCovered;
   }
 
   SourceLocation getBeginLoc() const { return getSwitchLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY {
     return getBody() ? getBody()->getEndLoc()
                      : reinterpret_cast<const Stmt *>(getCond())->getEndLoc();
   }
 
   // Iterators
   child_range children() {
     return child_range(getTrailingObjects<Stmt *>(),
                        getTrailingObjects<Stmt *>() +
                            numTrailingObjects(OverloadToken<Stmt *>()));
   }
 
   const_child_range children() const {
     return const_child_range(getTrailingObjects<Stmt *>(),
                              getTrailingObjects<Stmt *>() +
                                  numTrailingObjects(OverloadToken<Stmt *>()));
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == SwitchStmtClass;
   }
 };
 
 /// WhileStmt - This represents a 'while' stmt.
 class WhileStmt final : public Stmt,
                         private llvm::TrailingObjects<WhileStmt, Stmt *> {
   friend TrailingObjects;
 
   // WhileStmt is followed by several trailing objects,
   // some of which optional. Note that it would be more
   // convenient to put the optional trailing object at the end
   // but this would affect children().
   // The trailing objects are in order:
   //
   // * A "Stmt *" for the condition variable.
   //    Present if and only if hasVarStorage(). This is in fact a "DeclStmt *".
   //
   // * A "Stmt *" for the condition.
   //    Always present. This is in fact an "Expr *".
   //
   // * A "Stmt *" for the body.
   //    Always present.
   //
   enum { VarOffset = 0, BodyOffsetFromCond = 1 };
   enum { NumMandatoryStmtPtr = 2 };
 
   SourceLocation LParenLoc, RParenLoc;
 
   unsigned varOffset() const { return VarOffset; }
   unsigned condOffset() const { return VarOffset + hasVarStorage(); }
   unsigned bodyOffset() const { return condOffset() + BodyOffsetFromCond; }
 
   unsigned numTrailingObjects(OverloadToken<Stmt *>) const {
     return NumMandatoryStmtPtr + hasVarStorage();
   }
 
   /// Build a while statement.
   WhileStmt(const ASTContext &Ctx, VarDecl *Var, Expr *Cond, Stmt *Body,
             SourceLocation WL, SourceLocation LParenLoc,
             SourceLocation RParenLoc);
 
   /// Build an empty while statement.
   explicit WhileStmt(EmptyShell Empty, bool HasVar);
 
 public:
   /// Create a while statement.
   static WhileStmt *Create(const ASTContext &Ctx, VarDecl *Var, Expr *Cond,
                            Stmt *Body, SourceLocation WL,
                            SourceLocation LParenLoc, SourceLocation RParenLoc);
 
   /// Create an empty while statement optionally with storage for
   /// a condition variable.
   static WhileStmt *CreateEmpty(const ASTContext &Ctx, bool HasVar);
 
   /// True if this WhileStmt has storage for a condition variable.
   bool hasVarStorage() const { return WhileStmtBits.HasVar; }
 
   Expr *getCond() {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[condOffset()]);
   }
 
   const Expr *getCond() const {
     return reinterpret_cast<Expr *>(getTrailingObjects<Stmt *>()[condOffset()]);
   }
 
   void setCond(Expr *Cond) {
     getTrailingObjects<Stmt *>()[condOffset()] = reinterpret_cast<Stmt *>(Cond);
   }
 
   Stmt *getBody() { return getTrailingObjects<Stmt *>()[bodyOffset()]; }
   const Stmt *getBody() const {
     return getTrailingObjects<Stmt *>()[bodyOffset()];
   }
 
   void setBody(Stmt *Body) {
     getTrailingObjects<Stmt *>()[bodyOffset()] = Body;
   }
 
   /// Retrieve the variable declared in this "while" statement, if any.
   ///
   /// In the following example, "x" is the condition variable.
   /// \code
   /// while (int x = random()) {
   ///   // ...
   /// }
   /// \endcode
   VarDecl *getConditionVariable();
   const VarDecl *getConditionVariable() const {
     return const_cast<WhileStmt *>(this)->getConditionVariable();
   }
 
   /// Set the condition variable of this while statement.
   /// The while statement must have storage for it.
   void setConditionVariable(const ASTContext &Ctx, VarDecl *V);
 
   /// If this WhileStmt has a condition variable, return the faux DeclStmt
   /// associated with the creation of that condition variable.
   DeclStmt *getConditionVariableDeclStmt() {
     return hasVarStorage() ? static_cast<DeclStmt *>(
                                  getTrailingObjects<Stmt *>()[varOffset()])
                            : nullptr;
   }
 
   const DeclStmt *getConditionVariableDeclStmt() const {
     return hasVarStorage() ? static_cast<DeclStmt *>(
                                  getTrailingObjects<Stmt *>()[varOffset()])
                            : nullptr;
   }
 
   void setConditionVariableDeclStmt(DeclStmt *CondVar) {
     assert(hasVarStorage());
     getTrailingObjects<Stmt *>()[varOffset()] = CondVar;
   }
 
   SourceLocation getWhileLoc() const { return WhileStmtBits.WhileLoc; }
   void setWhileLoc(SourceLocation L) { WhileStmtBits.WhileLoc = L; }
 
   SourceLocation getLParenLoc() const { return LParenLoc; }
   void setLParenLoc(SourceLocation L) { LParenLoc = L; }
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
   SourceLocation getBeginLoc() const { return getWhileLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY {
     return getBody()->getEndLoc();
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == WhileStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(getTrailingObjects<Stmt *>(),
                        getTrailingObjects<Stmt *>() +
                            numTrailingObjects(OverloadToken<Stmt *>()));
   }
 
   const_child_range children() const {
     return const_child_range(getTrailingObjects<Stmt *>(),
                              getTrailingObjects<Stmt *>() +
                                  numTrailingObjects(OverloadToken<Stmt *>()));
   }
 };
 
 /// DoStmt - This represents a 'do/while' stmt.
 class DoStmt : public Stmt {
   enum { BODY, COND, END_EXPR };
   Stmt *SubExprs[END_EXPR];
   SourceLocation WhileLoc;
   SourceLocation RParenLoc; // Location of final ')' in do stmt condition.
 
 public:
   DoStmt(Stmt *Body, Expr *Cond, SourceLocation DL, SourceLocation WL,
          SourceLocation RP)
       : Stmt(DoStmtClass), WhileLoc(WL), RParenLoc(RP) {
     setCond(Cond);
     setBody(Body);
     setDoLoc(DL);
   }
 
   /// Build an empty do-while statement.
   explicit DoStmt(EmptyShell Empty) : Stmt(DoStmtClass, Empty) {}
 
   Expr *getCond() { return reinterpret_cast<Expr *>(SubExprs[COND]); }
   const Expr *getCond() const {
     return reinterpret_cast<Expr *>(SubExprs[COND]);
   }
 
   void setCond(Expr *Cond) { SubExprs[COND] = reinterpret_cast<Stmt *>(Cond); }
 
   Stmt *getBody() { return SubExprs[BODY]; }
   const Stmt *getBody() const { return SubExprs[BODY]; }
   void setBody(Stmt *Body) { SubExprs[BODY] = Body; }
 
   SourceLocation getDoLoc() const { return DoStmtBits.DoLoc; }
   void setDoLoc(SourceLocation L) { DoStmtBits.DoLoc = L; }
   SourceLocation getWhileLoc() const { return WhileLoc; }
   void setWhileLoc(SourceLocation L) { WhileLoc = L; }
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
   SourceLocation getBeginLoc() const { return getDoLoc(); }
   SourceLocation getEndLoc() const { return getRParenLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == DoStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
   }
 
   const_child_range children() const {
     return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
   }
 };
 
 /// ForStmt - This represents a 'for (init;cond;inc)' stmt.  Note that any of
 /// the init/cond/inc parts of the ForStmt will be null if they were not
 /// specified in the source.
 class ForStmt : public Stmt {
   friend class ASTStmtReader;
 
   enum { INIT, CONDVAR, COND, INC, BODY, END_EXPR };
   Stmt* SubExprs[END_EXPR]; // SubExprs[INIT] is an expression or declstmt.
   SourceLocation LParenLoc, RParenLoc;
 
 public:
   ForStmt(const ASTContext &C, Stmt *Init, Expr *Cond, VarDecl *condVar,
           Expr *Inc, Stmt *Body, SourceLocation FL, SourceLocation LP,
           SourceLocation RP);
 
   /// Build an empty for statement.
   explicit ForStmt(EmptyShell Empty) : Stmt(ForStmtClass, Empty) {}
 
   Stmt *getInit() { return SubExprs[INIT]; }
 
   /// Retrieve the variable declared in this "for" statement, if any.
   ///
   /// In the following example, "y" is the condition variable.
   /// \code
   /// for (int x = random(); int y = mangle(x); ++x) {
   ///   // ...
   /// }
   /// \endcode
   VarDecl *getConditionVariable() const;
   void setConditionVariable(const ASTContext &C, VarDecl *V);
 
   /// If this ForStmt has a condition variable, return the faux DeclStmt
   /// associated with the creation of that condition variable.
   DeclStmt *getConditionVariableDeclStmt() {
     return reinterpret_cast<DeclStmt*>(SubExprs[CONDVAR]);
   }
 
   const DeclStmt *getConditionVariableDeclStmt() const {
     return reinterpret_cast<DeclStmt*>(SubExprs[CONDVAR]);
   }
 
   void setConditionVariableDeclStmt(DeclStmt *CondVar) {
     SubExprs[CONDVAR] = CondVar;
   }
 
   Expr *getCond() { return reinterpret_cast<Expr*>(SubExprs[COND]); }
   Expr *getInc()  { return reinterpret_cast<Expr*>(SubExprs[INC]); }
   Stmt *getBody() { return SubExprs[BODY]; }
 
   const Stmt *getInit() const { return SubExprs[INIT]; }
   const Expr *getCond() const { return reinterpret_cast<Expr*>(SubExprs[COND]);}
   const Expr *getInc()  const { return reinterpret_cast<Expr*>(SubExprs[INC]); }
   const Stmt *getBody() const { return SubExprs[BODY]; }
 
   void setInit(Stmt *S) { SubExprs[INIT] = S; }
   void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
   void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
   void setBody(Stmt *S) { SubExprs[BODY] = S; }
 
   SourceLocation getForLoc() const { return ForStmtBits.ForLoc; }
   void setForLoc(SourceLocation L) { ForStmtBits.ForLoc = L; }
   SourceLocation getLParenLoc() const { return LParenLoc; }
   void setLParenLoc(SourceLocation L) { LParenLoc = L; }
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
   SourceLocation getBeginLoc() const { return getForLoc(); }
   SourceLocation getEndLoc() const { return getBody()->getEndLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == ForStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
   }
 
   const_child_range children() const {
     return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
   }
 };
 
 /// GotoStmt - This represents a direct goto.
 class GotoStmt : public Stmt {
   LabelDecl *Label;
   SourceLocation LabelLoc;
 
 public:
   GotoStmt(LabelDecl *label, SourceLocation GL, SourceLocation LL)
       : Stmt(GotoStmtClass), Label(label), LabelLoc(LL) {
     setGotoLoc(GL);
   }
 
   /// Build an empty goto statement.
   explicit GotoStmt(EmptyShell Empty) : Stmt(GotoStmtClass, Empty) {}
 
   LabelDecl *getLabel() const { return Label; }
   void setLabel(LabelDecl *D) { Label = D; }
 
   SourceLocation getGotoLoc() const { return GotoStmtBits.GotoLoc; }
   void setGotoLoc(SourceLocation L) { GotoStmtBits.GotoLoc = L; }
   SourceLocation getLabelLoc() const { return LabelLoc; }
   void setLabelLoc(SourceLocation L) { LabelLoc = L; }
 
   SourceLocation getBeginLoc() const { return getGotoLoc(); }
   SourceLocation getEndLoc() const { return getLabelLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == GotoStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
 
   const_child_range children() const {
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 };
 
 /// IndirectGotoStmt - This represents an indirect goto.
 class IndirectGotoStmt : public Stmt {
   SourceLocation StarLoc;
   Stmt *Target;
 
 public:
   IndirectGotoStmt(SourceLocation gotoLoc, SourceLocation starLoc, Expr *target)
       : Stmt(IndirectGotoStmtClass), StarLoc(starLoc) {
     setTarget(target);
     setGotoLoc(gotoLoc);
   }
 
   /// Build an empty indirect goto statement.
   explicit IndirectGotoStmt(EmptyShell Empty)
       : Stmt(IndirectGotoStmtClass, Empty) {}
 
   void setGotoLoc(SourceLocation L) { GotoStmtBits.GotoLoc = L; }
   SourceLocation getGotoLoc() const { return GotoStmtBits.GotoLoc; }
   void setStarLoc(SourceLocation L) { StarLoc = L; }
   SourceLocation getStarLoc() const { return StarLoc; }
 
   Expr *getTarget() { return reinterpret_cast<Expr *>(Target); }
   const Expr *getTarget() const {
     return reinterpret_cast<const Expr *>(Target);
   }
   void setTarget(Expr *E) { Target = reinterpret_cast<Stmt *>(E); }
 
   /// getConstantTarget - Returns the fixed target of this indirect
   /// goto, if one exists.
   LabelDecl *getConstantTarget();
   const LabelDecl *getConstantTarget() const {
     return const_cast<IndirectGotoStmt *>(this)->getConstantTarget();
   }
 
   SourceLocation getBeginLoc() const { return getGotoLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY { return Target->getEndLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == IndirectGotoStmtClass;
   }
 
   // Iterators
   child_range children() { return child_range(&Target, &Target + 1); }
 
   const_child_range children() const {
     return const_child_range(&Target, &Target + 1);
   }
 };
 
 /// ContinueStmt - This represents a continue.
 class ContinueStmt : public Stmt {
 public:
   ContinueStmt(SourceLocation CL) : Stmt(ContinueStmtClass) {
     setContinueLoc(CL);
   }
 
   /// Build an empty continue statement.
   explicit ContinueStmt(EmptyShell Empty) : Stmt(ContinueStmtClass, Empty) {}
 
   SourceLocation getContinueLoc() const { return ContinueStmtBits.ContinueLoc; }
   void setContinueLoc(SourceLocation L) { ContinueStmtBits.ContinueLoc = L; }
 
   SourceLocation getBeginLoc() const { return getContinueLoc(); }
   SourceLocation getEndLoc() const { return getContinueLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == ContinueStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
 
   const_child_range children() const {
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 };
 
 /// BreakStmt - This represents a break.
 class BreakStmt : public Stmt {
 public:
   BreakStmt(SourceLocation BL) : Stmt(BreakStmtClass) {
     setBreakLoc(BL);
   }
 
   /// Build an empty break statement.
   explicit BreakStmt(EmptyShell Empty) : Stmt(BreakStmtClass, Empty) {}
 
   SourceLocation getBreakLoc() const { return BreakStmtBits.BreakLoc; }
   void setBreakLoc(SourceLocation L) { BreakStmtBits.BreakLoc = L; }
 
   SourceLocation getBeginLoc() const { return getBreakLoc(); }
   SourceLocation getEndLoc() const { return getBreakLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == BreakStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
 
   const_child_range children() const {
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 };
 
 /// ReturnStmt - This represents a return, optionally of an expression:
 ///   return;
 ///   return 4;
 ///
 /// Note that GCC allows return with no argument in a function declared to
 /// return a value, and it allows returning a value in functions declared to
 /// return void.  We explicitly model this in the AST, which means you can't
 /// depend on the return type of the function and the presence of an argument.
 class ReturnStmt final
     : public Stmt,
       private llvm::TrailingObjects<ReturnStmt, const VarDecl *> {
   friend TrailingObjects;
 
   /// The return expression.
   Stmt *RetExpr;
 
   // ReturnStmt is followed optionally by a trailing "const VarDecl *"
   // for the NRVO candidate. Present if and only if hasNRVOCandidate().
 
   /// True if this ReturnStmt has storage for an NRVO candidate.
   bool hasNRVOCandidate() const { return ReturnStmtBits.HasNRVOCandidate; }
 
   unsigned numTrailingObjects(OverloadToken<const VarDecl *>) const {
     return hasNRVOCandidate();
   }
 
   /// Build a return statement.
   ReturnStmt(SourceLocation RL, Expr *E, const VarDecl *NRVOCandidate);
 
   /// Build an empty return statement.
   explicit ReturnStmt(EmptyShell Empty, bool HasNRVOCandidate);
 
 public:
   /// Create a return statement.
   static ReturnStmt *Create(const ASTContext &Ctx, SourceLocation RL, Expr *E,
                             const VarDecl *NRVOCandidate);
 
   /// Create an empty return statement, optionally with
   /// storage for an NRVO candidate.
   static ReturnStmt *CreateEmpty(const ASTContext &Ctx, bool HasNRVOCandidate);
 
   Expr *getRetValue() { return reinterpret_cast<Expr *>(RetExpr); }
   const Expr *getRetValue() const { return reinterpret_cast<Expr *>(RetExpr); }
   void setRetValue(Expr *E) { RetExpr = reinterpret_cast<Stmt *>(E); }
 
   /// Retrieve the variable that might be used for the named return
   /// value optimization.
   ///
   /// The optimization itself can only be performed if the variable is
   /// also marked as an NRVO object.
   const VarDecl *getNRVOCandidate() const {
     return hasNRVOCandidate() ? *getTrailingObjects<const VarDecl *>()
                               : nullptr;
   }
 
   /// Set the variable that might be used for the named return value
   /// optimization. The return statement must have storage for it,
   /// which is the case if and only if hasNRVOCandidate() is true.
   void setNRVOCandidate(const VarDecl *Var) {
     assert(hasNRVOCandidate() &&
            "This return statement has no storage for an NRVO candidate!");
     *getTrailingObjects<const VarDecl *>() = Var;
   }
 
   SourceLocation getReturnLoc() const { return ReturnStmtBits.RetLoc; }
   void setReturnLoc(SourceLocation L) { ReturnStmtBits.RetLoc = L; }
 
   SourceLocation getBeginLoc() const { return getReturnLoc(); }
   SourceLocation getEndLoc() const LLVM_READONLY {
     return RetExpr ? RetExpr->getEndLoc() : getReturnLoc();
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == ReturnStmtClass;
   }
 
   // Iterators
   child_range children() {
     if (RetExpr)
       return child_range(&RetExpr, &RetExpr + 1);
     return child_range(child_iterator(), child_iterator());
   }
 
   const_child_range children() const {
     if (RetExpr)
       return const_child_range(&RetExpr, &RetExpr + 1);
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 };
 
 /// AsmStmt is the base class for GCCAsmStmt and MSAsmStmt.
 class AsmStmt : public Stmt {
 protected:
   friend class ASTStmtReader;
 
   SourceLocation AsmLoc;
 
   /// True if the assembly statement does not have any input or output
   /// operands.
   bool IsSimple;
 
   /// If true, treat this inline assembly as having side effects.
   /// This assembly statement should not be optimized, deleted or moved.
   bool IsVolatile;
 
   unsigned NumOutputs;
   unsigned NumInputs;
   unsigned NumClobbers;
 
   Stmt **Exprs = nullptr;
 
   AsmStmt(StmtClass SC, SourceLocation asmloc, bool issimple, bool isvolatile,
           unsigned numoutputs, unsigned numinputs, unsigned numclobbers)
       : Stmt (SC), AsmLoc(asmloc), IsSimple(issimple), IsVolatile(isvolatile),
         NumOutputs(numoutputs), NumInputs(numinputs),
         NumClobbers(numclobbers) {}
 
 public:
   /// Build an empty inline-assembly statement.
   explicit AsmStmt(StmtClass SC, EmptyShell Empty) : Stmt(SC, Empty) {}
 
   SourceLocation getAsmLoc() const { return AsmLoc; }
   void setAsmLoc(SourceLocation L) { AsmLoc = L; }
 
   bool isSimple() const { return IsSimple; }
   void setSimple(bool V) { IsSimple = V; }
 
   bool isVolatile() const { return IsVolatile; }
   void setVolatile(bool V) { IsVolatile = V; }
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return {}; }
   SourceLocation getEndLoc() const LLVM_READONLY { return {}; }
 
   //===--- Asm String Analysis ---===//
 
   /// Assemble final IR asm string.
   std::string generateAsmString(const ASTContext &C) const;
 
   //===--- Output operands ---===//
 
   unsigned getNumOutputs() const { return NumOutputs; }
 
   /// getOutputConstraint - Return the constraint string for the specified
   /// output operand.  All output constraints are known to be non-empty (either
   /// '=' or '+').
   StringRef getOutputConstraint(unsigned i) const;
 
   /// isOutputPlusConstraint - Return true if the specified output constraint
   /// is a "+" constraint (which is both an input and an output) or false if it
   /// is an "=" constraint (just an output).
   bool isOutputPlusConstraint(unsigned i) const {
     return getOutputConstraint(i)[0] == '+';
   }
 
   const Expr *getOutputExpr(unsigned i) const;
 
   /// getNumPlusOperands - Return the number of output operands that have a "+"
   /// constraint.
   unsigned getNumPlusOperands() const;
 
   //===--- Input operands ---===//
 
   unsigned getNumInputs() const { return NumInputs; }
 
   /// getInputConstraint - Return the specified input constraint.  Unlike output
   /// constraints, these can be empty.
   StringRef getInputConstraint(unsigned i) const;
 
   const Expr *getInputExpr(unsigned i) const;
 
   //===--- Other ---===//
 
   unsigned getNumClobbers() const { return NumClobbers; }
   StringRef getClobber(unsigned i) const;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == GCCAsmStmtClass ||
       T->getStmtClass() == MSAsmStmtClass;
   }
 
   // Input expr iterators.
 
   using inputs_iterator = ExprIterator;
   using const_inputs_iterator = ConstExprIterator;
   using inputs_range = llvm::iterator_range<inputs_iterator>;
   using inputs_const_range = llvm::iterator_range<const_inputs_iterator>;
 
   inputs_iterator begin_inputs() {
     return &Exprs[0] + NumOutputs;
   }
 
   inputs_iterator end_inputs() {
     return &Exprs[0] + NumOutputs + NumInputs;
   }
 
   inputs_range inputs() { return inputs_range(begin_inputs(), end_inputs()); }
 
   const_inputs_iterator begin_inputs() const {
     return &Exprs[0] + NumOutputs;
   }
 
   const_inputs_iterator end_inputs() const {
     return &Exprs[0] + NumOutputs + NumInputs;
   }
 
   inputs_const_range inputs() const {
     return inputs_const_range(begin_inputs(), end_inputs());
   }
 
   // Output expr iterators.
 
   using outputs_iterator = ExprIterator;
   using const_outputs_iterator = ConstExprIterator;
   using outputs_range = llvm::iterator_range<outputs_iterator>;
   using outputs_const_range = llvm::iterator_range<const_outputs_iterator>;
 
   outputs_iterator begin_outputs() {
     return &Exprs[0];
   }
 
   outputs_iterator end_outputs() {
     return &Exprs[0] + NumOutputs;
   }
 
   outputs_range outputs() {
     return outputs_range(begin_outputs(), end_outputs());
   }
 
   const_outputs_iterator begin_outputs() const {
     return &Exprs[0];
   }
 
   const_outputs_iterator end_outputs() const {
     return &Exprs[0] + NumOutputs;
   }
 
   outputs_const_range outputs() const {
     return outputs_const_range(begin_outputs(), end_outputs());
   }
 
   child_range children() {
     return child_range(&Exprs[0], &Exprs[0] + NumOutputs + NumInputs);
   }
 
   const_child_range children() const {
     return const_child_range(&Exprs[0], &Exprs[0] + NumOutputs + NumInputs);
   }
 };
 
 /// This represents a GCC inline-assembly statement extension.
 class GCCAsmStmt : public AsmStmt {
   friend class ASTStmtReader;
 
   SourceLocation RParenLoc;
   StringLiteral *AsmStr;
 
   // FIXME: If we wanted to, we could allocate all of these in one big array.
   StringLiteral **Constraints = nullptr;
   StringLiteral **Clobbers = nullptr;
   IdentifierInfo **Names = nullptr;
   unsigned NumLabels = 0;
 
 public:
   GCCAsmStmt(const ASTContext &C, SourceLocation asmloc, bool issimple,
              bool isvolatile, unsigned numoutputs, unsigned numinputs,
              IdentifierInfo **names, StringLiteral **constraints, Expr **exprs,
              StringLiteral *asmstr, unsigned numclobbers,
              StringLiteral **clobbers, unsigned numlabels,
              SourceLocation rparenloc);
 
   /// Build an empty inline-assembly statement.
   explicit GCCAsmStmt(EmptyShell Empty) : AsmStmt(GCCAsmStmtClass, Empty) {}
 
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
   //===--- Asm String Analysis ---===//
 
   const StringLiteral *getAsmString() const { return AsmStr; }
   StringLiteral *getAsmString() { return AsmStr; }
   void setAsmString(StringLiteral *E) { AsmStr = E; }
 
   /// AsmStringPiece - this is part of a decomposed asm string specification
   /// (for use with the AnalyzeAsmString function below).  An asm string is
   /// considered to be a concatenation of these parts.
   class AsmStringPiece {
   public:
     enum Kind {
       String,  // String in .ll asm string form, "$" -> "$$" and "%%" -> "%".
       Operand  // Operand reference, with optional modifier %c4.
     };
 
   private:
     Kind MyKind;
     std::string Str;
     unsigned OperandNo;
 
     // Source range for operand references.
     CharSourceRange Range;
 
   public:
     AsmStringPiece(const std::string &S) : MyKind(String), Str(S) {}
     AsmStringPiece(unsigned OpNo, const std::string &S, SourceLocation Begin,
                    SourceLocation End)
         : MyKind(Operand), Str(S), OperandNo(OpNo),
           Range(CharSourceRange::getCharRange(Begin, End)) {}
 
     bool isString() const { return MyKind == String; }
     bool isOperand() const { return MyKind == Operand; }
 
     const std::string &getString() const { return Str; }
 
     unsigned getOperandNo() const {
       assert(isOperand());
       return OperandNo;
     }
 
     CharSourceRange getRange() const {
       assert(isOperand() && "Range is currently used only for Operands.");
       return Range;
     }
 
     /// getModifier - Get the modifier for this operand, if present.  This
     /// returns '\0' if there was no modifier.
     char getModifier() const;
   };
 
   /// AnalyzeAsmString - Analyze the asm string of the current asm, decomposing
   /// it into pieces.  If the asm string is erroneous, emit errors and return
   /// true, otherwise return false.  This handles canonicalization and
   /// translation of strings from GCC syntax to LLVM IR syntax, and handles
   //// flattening of named references like %[foo] to Operand AsmStringPiece's.
   unsigned AnalyzeAsmString(SmallVectorImpl<AsmStringPiece> &Pieces,
                             const ASTContext &C, unsigned &DiagOffs) const;
 
   /// Assemble final IR asm string.
   std::string generateAsmString(const ASTContext &C) const;
 
   //===--- Output operands ---===//
 
   IdentifierInfo *getOutputIdentifier(unsigned i) const { return Names[i]; }
 
   StringRef getOutputName(unsigned i) const {
     if (IdentifierInfo *II = getOutputIdentifier(i))
       return II->getName();
 
     return {};
   }
 
   StringRef getOutputConstraint(unsigned i) const;
 
   const StringLiteral *getOutputConstraintLiteral(unsigned i) const {
     return Constraints[i];
   }
   StringLiteral *getOutputConstraintLiteral(unsigned i) {
     return Constraints[i];
   }
 
   Expr *getOutputExpr(unsigned i);
 
   const Expr *getOutputExpr(unsigned i) const {
     return const_cast<GCCAsmStmt*>(this)->getOutputExpr(i);
   }
 
   //===--- Input operands ---===//
 
   IdentifierInfo *getInputIdentifier(unsigned i) const {
     return Names[i + NumOutputs];
   }
 
   StringRef getInputName(unsigned i) const {
     if (IdentifierInfo *II = getInputIdentifier(i))
       return II->getName();
 
     return {};
   }
 
   StringRef getInputConstraint(unsigned i) const;
 
   const StringLiteral *getInputConstraintLiteral(unsigned i) const {
     return Constraints[i + NumOutputs];
   }
   StringLiteral *getInputConstraintLiteral(unsigned i) {
     return Constraints[i + NumOutputs];
   }
 
   Expr *getInputExpr(unsigned i);
   void setInputExpr(unsigned i, Expr *E);
 
   const Expr *getInputExpr(unsigned i) const {
     return const_cast<GCCAsmStmt*>(this)->getInputExpr(i);
   }
 
   //===--- Labels ---===//
 
   bool isAsmGoto() const {
     return NumLabels > 0;
   }
 
   unsigned getNumLabels() const {
     return NumLabels;
   }
 
   IdentifierInfo *getLabelIdentifier(unsigned i) const {
     return Names[i + NumOutputs + NumInputs];
   }
 
   AddrLabelExpr *getLabelExpr(unsigned i) const;
   StringRef getLabelName(unsigned i) const;
   using labels_iterator = CastIterator<AddrLabelExpr>;
   using const_labels_iterator = ConstCastIterator<AddrLabelExpr>;
   using labels_range = llvm::iterator_range<labels_iterator>;
   using labels_const_range = llvm::iterator_range<const_labels_iterator>;
 
   labels_iterator begin_labels() {
     return &Exprs[0] + NumOutputs + NumInputs;
   }
 
   labels_iterator end_labels() {
     return &Exprs[0] + NumOutputs + NumInputs + NumLabels;
   }
 
   labels_range labels() {
     return labels_range(begin_labels(), end_labels());
   }
 
   const_labels_iterator begin_labels() const {
     return &Exprs[0] + NumOutputs + NumInputs;
   }
 
   const_labels_iterator end_labels() const {
     return &Exprs[0] + NumOutputs + NumInputs + NumLabels;
   }
 
   labels_const_range labels() const {
     return labels_const_range(begin_labels(), end_labels());
   }
 
 private:
   void setOutputsAndInputsAndClobbers(const ASTContext &C,
                                       IdentifierInfo **Names,
                                       StringLiteral **Constraints,
                                       Stmt **Exprs,
                                       unsigned NumOutputs,
                                       unsigned NumInputs,
                                       unsigned NumLabels,
                                       StringLiteral **Clobbers,
                                       unsigned NumClobbers);
 
 public:
   //===--- Other ---===//
 
   /// getNamedOperand - Given a symbolic operand reference like %[foo],
   /// translate this into a numeric value needed to reference the same operand.
   /// This returns -1 if the operand name is invalid.
   int getNamedOperand(StringRef SymbolicName) const;
 
   StringRef getClobber(unsigned i) const;
 
   StringLiteral *getClobberStringLiteral(unsigned i) { return Clobbers[i]; }
   const StringLiteral *getClobberStringLiteral(unsigned i) const {
     return Clobbers[i];
   }
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return AsmLoc; }
   SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == GCCAsmStmtClass;
   }
 };
 
 /// This represents a Microsoft inline-assembly statement extension.
 class MSAsmStmt : public AsmStmt {
   friend class ASTStmtReader;
 
   SourceLocation LBraceLoc, EndLoc;
   StringRef AsmStr;
 
   unsigned NumAsmToks = 0;
 
   Token *AsmToks = nullptr;
   StringRef *Constraints = nullptr;
   StringRef *Clobbers = nullptr;
 
 public:
   MSAsmStmt(const ASTContext &C, SourceLocation asmloc,
             SourceLocation lbraceloc, bool issimple, bool isvolatile,
             ArrayRef<Token> asmtoks, unsigned numoutputs, unsigned numinputs,
             ArrayRef<StringRef> constraints,
             ArrayRef<Expr*> exprs, StringRef asmstr,
             ArrayRef<StringRef> clobbers, SourceLocation endloc);
 
   /// Build an empty MS-style inline-assembly statement.
   explicit MSAsmStmt(EmptyShell Empty) : AsmStmt(MSAsmStmtClass, Empty) {}
 
   SourceLocation getLBraceLoc() const { return LBraceLoc; }
   void setLBraceLoc(SourceLocation L) { LBraceLoc = L; }
   SourceLocation getEndLoc() const { return EndLoc; }
   void setEndLoc(SourceLocation L) { EndLoc = L; }
 
   bool hasBraces() const { return LBraceLoc.isValid(); }
 
   unsigned getNumAsmToks() { return NumAsmToks; }
   Token *getAsmToks() { return AsmToks; }
 
   //===--- Asm String Analysis ---===//
   StringRef getAsmString() const { return AsmStr; }
 
   /// Assemble final IR asm string.
   std::string generateAsmString(const ASTContext &C) const;
 
   //===--- Output operands ---===//
 
   StringRef getOutputConstraint(unsigned i) const {
     assert(i < NumOutputs);
     return Constraints[i];
   }
 
   Expr *getOutputExpr(unsigned i);
 
   const Expr *getOutputExpr(unsigned i) const {
     return const_cast<MSAsmStmt*>(this)->getOutputExpr(i);
   }
 
   //===--- Input operands ---===//
 
   StringRef getInputConstraint(unsigned i) const {
     assert(i < NumInputs);
     return Constraints[i + NumOutputs];
   }
 
   Expr *getInputExpr(unsigned i);
   void setInputExpr(unsigned i, Expr *E);
 
   const Expr *getInputExpr(unsigned i) const {
     return const_cast<MSAsmStmt*>(this)->getInputExpr(i);
   }
 
   //===--- Other ---===//
 
   ArrayRef<StringRef> getAllConstraints() const {
     return llvm::ArrayRef(Constraints, NumInputs + NumOutputs);
   }
 
   ArrayRef<StringRef> getClobbers() const {
     return llvm::ArrayRef(Clobbers, NumClobbers);
   }
 
   ArrayRef<Expr*> getAllExprs() const {
     return llvm::ArrayRef(reinterpret_cast<Expr **>(Exprs),
                           NumInputs + NumOutputs);
   }
 
   StringRef getClobber(unsigned i) const { return getClobbers()[i]; }
 
 private:
   void initialize(const ASTContext &C, StringRef AsmString,
                   ArrayRef<Token> AsmToks, ArrayRef<StringRef> Constraints,
                   ArrayRef<Expr*> Exprs, ArrayRef<StringRef> Clobbers);
 
 public:
   SourceLocation getBeginLoc() const LLVM_READONLY { return AsmLoc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == MSAsmStmtClass;
   }
 
   child_range children() {
     return child_range(&Exprs[0], &Exprs[NumInputs + NumOutputs]);
   }
 
   const_child_range children() const {
     return const_child_range(&Exprs[0], &Exprs[NumInputs + NumOutputs]);
   }
 };
 
 class SEHExceptStmt : public Stmt {
   friend class ASTReader;
   friend class ASTStmtReader;
 
   SourceLocation  Loc;
   Stmt *Children[2];
 
   enum { FILTER_EXPR, BLOCK };
 
   SEHExceptStmt(SourceLocation Loc, Expr *FilterExpr, Stmt *Block);
   explicit SEHExceptStmt(EmptyShell E) : Stmt(SEHExceptStmtClass, E) {}
 
 public:
   static SEHExceptStmt* Create(const ASTContext &C,
                                SourceLocation ExceptLoc,
                                Expr *FilterExpr,
                                Stmt *Block);
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return getExceptLoc(); }
 
   SourceLocation getExceptLoc() const { return Loc; }
   SourceLocation getEndLoc() const { return getBlock()->getEndLoc(); }
 
   Expr *getFilterExpr() const {
     return reinterpret_cast<Expr*>(Children[FILTER_EXPR]);
   }
 
   CompoundStmt *getBlock() const {
     return cast<CompoundStmt>(Children[BLOCK]);
   }
 
   child_range children() {
     return child_range(Children, Children+2);
   }
 
   const_child_range children() const {
     return const_child_range(Children, Children + 2);
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == SEHExceptStmtClass;
   }
 };
 
 class SEHFinallyStmt : public Stmt {
   friend class ASTReader;
   friend class ASTStmtReader;
 
   SourceLocation  Loc;
   Stmt *Block;
 
   SEHFinallyStmt(SourceLocation Loc, Stmt *Block);
   explicit SEHFinallyStmt(EmptyShell E) : Stmt(SEHFinallyStmtClass, E) {}
 
 public:
   static SEHFinallyStmt* Create(const ASTContext &C,
                                 SourceLocation FinallyLoc,
                                 Stmt *Block);
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return getFinallyLoc(); }
 
   SourceLocation getFinallyLoc() const { return Loc; }
   SourceLocation getEndLoc() const { return Block->getEndLoc(); }
 
   CompoundStmt *getBlock() const { return cast<CompoundStmt>(Block); }
 
   child_range children() {
     return child_range(&Block,&Block+1);
   }
 
   const_child_range children() const {
     return const_child_range(&Block, &Block + 1);
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == SEHFinallyStmtClass;
   }
 };
 
 class SEHTryStmt : public Stmt {
   friend class ASTReader;
   friend class ASTStmtReader;
 
   bool IsCXXTry;
   SourceLocation  TryLoc;
   Stmt *Children[2];
 
   enum { TRY = 0, HANDLER = 1 };
 
   SEHTryStmt(bool isCXXTry, // true if 'try' otherwise '__try'
              SourceLocation TryLoc,
              Stmt *TryBlock,
              Stmt *Handler);
 
   explicit SEHTryStmt(EmptyShell E) : Stmt(SEHTryStmtClass, E) {}
 
 public:
   static SEHTryStmt* Create(const ASTContext &C, bool isCXXTry,
                             SourceLocation TryLoc, Stmt *TryBlock,
                             Stmt *Handler);
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return getTryLoc(); }
 
   SourceLocation getTryLoc() const { return TryLoc; }
   SourceLocation getEndLoc() const { return Children[HANDLER]->getEndLoc(); }
 
   bool getIsCXXTry() const { return IsCXXTry; }
 
   CompoundStmt* getTryBlock() const {
     return cast<CompoundStmt>(Children[TRY]);
   }
 
   Stmt *getHandler() const { return Children[HANDLER]; }
 
   /// Returns 0 if not defined
   SEHExceptStmt  *getExceptHandler() const;
   SEHFinallyStmt *getFinallyHandler() const;
 
   child_range children() {
     return child_range(Children, Children+2);
   }
 
   const_child_range children() const {
     return const_child_range(Children, Children + 2);
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == SEHTryStmtClass;
   }
 };
 
 /// Represents a __leave statement.
 class SEHLeaveStmt : public Stmt {
   SourceLocation LeaveLoc;
 
 public:
   explicit SEHLeaveStmt(SourceLocation LL)
       : Stmt(SEHLeaveStmtClass), LeaveLoc(LL) {}
 
   /// Build an empty __leave statement.
   explicit SEHLeaveStmt(EmptyShell Empty) : Stmt(SEHLeaveStmtClass, Empty) {}
 
   SourceLocation getLeaveLoc() const { return LeaveLoc; }
   void setLeaveLoc(SourceLocation L) { LeaveLoc = L; }
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return LeaveLoc; }
   SourceLocation getEndLoc() const LLVM_READONLY { return LeaveLoc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == SEHLeaveStmtClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
 
   const_child_range children() const {
     return const_child_range(const_child_iterator(), const_child_iterator());
   }
 };
 
 /// This captures a statement into a function. For example, the following
 /// pragma annotated compound statement can be represented as a CapturedStmt,
 /// and this compound statement is the body of an anonymous outlined function.
 /// @code
 /// #pragma omp parallel
 /// {
 ///   compute();
 /// }
 /// @endcode
 class CapturedStmt : public Stmt {
 public:
   /// The different capture forms: by 'this', by reference, capture for
   /// variable-length array type etc.
   enum VariableCaptureKind {
     VCK_This,
     VCK_ByRef,
     VCK_ByCopy,
     VCK_VLAType,
   };
 
   /// Describes the capture of either a variable, or 'this', or
   /// variable-length array type.
   class Capture {
     llvm::PointerIntPair<VarDecl *, 2, VariableCaptureKind> VarAndKind;
     SourceLocation Loc;
 
     Capture() = default;
 
   public:
     friend class ASTStmtReader;
     friend class CapturedStmt;
 
     /// Create a new capture.
     ///
     /// \param Loc The source location associated with this capture.
     ///
     /// \param Kind The kind of capture (this, ByRef, ...).
     ///
     /// \param Var The variable being captured, or null if capturing this.
     Capture(SourceLocation Loc, VariableCaptureKind Kind,
             VarDecl *Var = nullptr);
 
     /// Determine the kind of capture.
     VariableCaptureKind getCaptureKind() const;
 
     /// Retrieve the source location at which the variable or 'this' was
     /// first used.
     SourceLocation getLocation() const { return Loc; }
 
     /// Determine whether this capture handles the C++ 'this' pointer.
     bool capturesThis() const { return getCaptureKind() == VCK_This; }
 
     /// Determine whether this capture handles a variable (by reference).
     bool capturesVariable() const { return getCaptureKind() == VCK_ByRef; }
 
     /// Determine whether this capture handles a variable by copy.
     bool capturesVariableByCopy() const {
       return getCaptureKind() == VCK_ByCopy;
     }
 
     /// Determine whether this capture handles a variable-length array
     /// type.
     bool capturesVariableArrayType() const {
       return getCaptureKind() == VCK_VLAType;
     }
 
     /// Retrieve the declaration of the variable being captured.
     ///
     /// This operation is only valid if this capture captures a variable.
     VarDecl *getCapturedVar() const;
   };
 
 private:
   /// The number of variable captured, including 'this'.
   unsigned NumCaptures;
 
   /// The pointer part is the implicit the outlined function and the
   /// int part is the captured region kind, 'CR_Default' etc.
   llvm::PointerIntPair<CapturedDecl *, 2, CapturedRegionKind> CapDeclAndKind;
 
   /// The record for captured variables, a RecordDecl or CXXRecordDecl.
   RecordDecl *TheRecordDecl = nullptr;
 
   /// Construct a captured statement.
   CapturedStmt(Stmt *S, CapturedRegionKind Kind, ArrayRef<Capture> Captures,
                ArrayRef<Expr *> CaptureInits, CapturedDecl *CD, RecordDecl *RD);
 
   /// Construct an empty captured statement.
   CapturedStmt(EmptyShell Empty, unsigned NumCaptures);
 
   Stmt **getStoredStmts() { return reinterpret_cast<Stmt **>(this + 1); }
 
   Stmt *const *getStoredStmts() const {
     return reinterpret_cast<Stmt *const *>(this + 1);
   }
 
   Capture *getStoredCaptures() const;
 
   void setCapturedStmt(Stmt *S) { getStoredStmts()[NumCaptures] = S; }
 
 public:
   friend class ASTStmtReader;
 
   static CapturedStmt *Create(const ASTContext &Context, Stmt *S,
                               CapturedRegionKind Kind,
                               ArrayRef<Capture> Captures,
                               ArrayRef<Expr *> CaptureInits,
                               CapturedDecl *CD, RecordDecl *RD);
 
   static CapturedStmt *CreateDeserialized(const ASTContext &Context,
                                           unsigned NumCaptures);
 
   /// Retrieve the statement being captured.
   Stmt *getCapturedStmt() { return getStoredStmts()[NumCaptures]; }
   const Stmt *getCapturedStmt() const { return getStoredStmts()[NumCaptures]; }
 
   /// Retrieve the outlined function declaration.
   CapturedDecl *getCapturedDecl();
   const CapturedDecl *getCapturedDecl() const;
 
   /// Set the outlined function declaration.
   void setCapturedDecl(CapturedDecl *D);
 
   /// Retrieve the captured region kind.
   CapturedRegionKind getCapturedRegionKind() const;
 
   /// Set the captured region kind.
   void setCapturedRegionKind(CapturedRegionKind Kind);
 
   /// Retrieve the record declaration for captured variables.
   const RecordDecl *getCapturedRecordDecl() const { return TheRecordDecl; }
 
   /// Set the record declaration for captured variables.
   void setCapturedRecordDecl(RecordDecl *D) {
     assert(D && "null RecordDecl");
     TheRecordDecl = D;
   }
 
   /// True if this variable has been captured.
   bool capturesVariable(const VarDecl *Var) const;
 
   /// An iterator that walks over the captures.
   using capture_iterator = Capture *;
   using const_capture_iterator = const Capture *;
   using capture_range = llvm::iterator_range<capture_iterator>;
   using capture_const_range = llvm::iterator_range<const_capture_iterator>;
 
   capture_range captures() {
     return capture_range(capture_begin(), capture_end());
   }
   capture_const_range captures() const {
     return capture_const_range(capture_begin(), capture_end());
   }
 
   /// Retrieve an iterator pointing to the first capture.
   capture_iterator capture_begin() { return getStoredCaptures(); }
   const_capture_iterator capture_begin() const { return getStoredCaptures(); }
 
   /// Retrieve an iterator pointing past the end of the sequence of
   /// captures.
   capture_iterator capture_end() const {
     return getStoredCaptures() + NumCaptures;
   }
 
   /// Retrieve the number of captures, including 'this'.
   unsigned capture_size() const { return NumCaptures; }
 
   /// Iterator that walks over the capture initialization arguments.
   using capture_init_iterator = Expr **;
   using capture_init_range = llvm::iterator_range<capture_init_iterator>;
 
   /// Const iterator that walks over the capture initialization
   /// arguments.
   using const_capture_init_iterator = Expr *const *;
   using const_capture_init_range =
       llvm::iterator_range<const_capture_init_iterator>;
 
   capture_init_range capture_inits() {
     return capture_init_range(capture_init_begin(), capture_init_end());
   }
 
   const_capture_init_range capture_inits() const {
     return const_capture_init_range(capture_init_begin(), capture_init_end());
   }
 
   /// Retrieve the first initialization argument.
   capture_init_iterator capture_init_begin() {
     return reinterpret_cast<Expr **>(getStoredStmts());
   }
 
   const_capture_init_iterator capture_init_begin() const {
     return reinterpret_cast<Expr *const *>(getStoredStmts());
   }
 
   /// Retrieve the iterator pointing one past the last initialization
   /// argument.
   capture_init_iterator capture_init_end() {
     return capture_init_begin() + NumCaptures;
   }
 
   const_capture_init_iterator capture_init_end() const {
     return capture_init_begin() + NumCaptures;
   }
 
   SourceLocation getBeginLoc() const LLVM_READONLY {
     return getCapturedStmt()->getBeginLoc();
   }
 
   SourceLocation getEndLoc() const LLVM_READONLY {
     return getCapturedStmt()->getEndLoc();
   }
 
   SourceRange getSourceRange() const LLVM_READONLY {
     return getCapturedStmt()->getSourceRange();
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CapturedStmtClass;
   }
 
   child_range children();
 
   const_child_range children() const;
 };
 
 } // namespace clang
 
 #endif // LLVM_CLANG_AST_STMT_H