linux-x64/clang/include/llvm/MC/MCExpr.h - hafnium/prebuilts - Git at Google

 //===- MCExpr.h - Assembly Level Expressions --------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_MC_MCEXPR_H
 #define LLVM_MC_MCEXPR_H

 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/SMLoc.h"
 #include <cstdint>

 namespace llvm {

 class MCAsmInfo;
 class MCAsmLayout;
 class MCAssembler;
 class MCContext;
 class MCFixup;
 class MCFragment;
 class MCSection;
 class MCStreamer;
 class MCSymbol;
 class MCValue;
 class raw_ostream;
 class StringRef;

 using SectionAddrMap = DenseMap<const MCSection *, uint64_t>;

 /// Base class for the full range of assembler expressions which are
 /// needed for parsing.
 class MCExpr {
 public:
   enum ExprKind {
     Binary,    ///< Binary expressions.
     Constant,  ///< Constant expressions.
     SymbolRef, ///< References to labels and assigned expressions.
     Unary,     ///< Unary expressions.
     Target     ///< Target specific expression.
   };

 private:
   ExprKind Kind;
   SMLoc Loc;

   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
                           const MCAsmLayout *Layout,
                           const SectionAddrMap *Addrs) const;

   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
                           const MCAsmLayout *Layout,
                           const SectionAddrMap *Addrs, bool InSet) const;

 protected:
   explicit MCExpr(ExprKind Kind, SMLoc Loc) : Kind(Kind), Loc(Loc) {}

   bool evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
                                  const MCAsmLayout *Layout,
                                  const MCFixup *Fixup,
                                  const SectionAddrMap *Addrs, bool InSet) const;

 public:
   MCExpr(const MCExpr &) = delete;
   MCExpr &operator=(const MCExpr &) = delete;

   /// \name Accessors
   /// @{

   ExprKind getKind() const { return Kind; }
   SMLoc getLoc() const { return Loc; }

   /// @}
   /// \name Utility Methods
   /// @{

   void print(raw_ostream &OS, const MCAsmInfo *MAI,
              bool InParens = false) const;
   void dump() const;

   /// @}
   /// \name Expression Evaluation
   /// @{

   /// Try to evaluate the expression to an absolute value.
   ///
   /// \param Res - The absolute value, if evaluation succeeds.
   /// \param Layout - The assembler layout object to use for evaluating symbol
   /// values. If not given, then only non-symbolic expressions will be
   /// evaluated.
   /// \return - True on success.
   bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
                           const SectionAddrMap &Addrs) const;
   bool evaluateAsAbsolute(int64_t &Res) const;
   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const;
   bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;

   bool evaluateKnownAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;

   /// Try to evaluate the expression to a relocatable value, i.e. an
   /// expression of the fixed form (a - b + constant).
   ///
   /// \param Res - The relocatable value, if evaluation succeeds.
   /// \param Layout - The assembler layout object to use for evaluating values.
   /// \param Fixup - The Fixup object if available.
   /// \return - True on success.
   bool evaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout,
                              const MCFixup *Fixup) const;

   /// Try to evaluate the expression to the form (a - b + constant) where
   /// neither a nor b are variables.
   ///
   /// This is a more aggressive variant of evaluateAsRelocatable. The intended
   /// use is for when relocations are not available, like the .size directive.
   bool evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const;

   /// Find the "associated section" for this expression, which is
   /// currently defined as the absolute section for constants, or
   /// otherwise the section associated with the first defined symbol in the
   /// expression.
   MCFragment *findAssociatedFragment() const;

   /// @}
 };

 inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
   E.print(OS, nullptr);
   return OS;
 }

 ////  Represent a constant integer expression.
 class MCConstantExpr : public MCExpr {
   int64_t Value;

   explicit MCConstantExpr(int64_t Value)
       : MCExpr(MCExpr::Constant, SMLoc()), Value(Value) {}

 public:
   /// \name Construction
   /// @{

   static const MCConstantExpr *create(int64_t Value, MCContext &Ctx);

   /// @}
   /// \name Accessors
   /// @{

   int64_t getValue() const { return Value; }

   /// @}

   static bool classof(const MCExpr *E) {
     return E->getKind() == MCExpr::Constant;
   }
 };

 ///  Represent a reference to a symbol from inside an expression.
 ///
 /// A symbol reference in an expression may be a use of a label, a use of an
 /// assembler variable (defined constant), or constitute an implicit definition
 /// of the symbol as external.
 class MCSymbolRefExpr : public MCExpr {
 public:
   enum VariantKind : uint16_t {
     VK_None,
     VK_Invalid,

     VK_GOT,
     VK_GOTOFF,
     VK_GOTREL,
     VK_GOTPCREL,
     VK_GOTTPOFF,
     VK_INDNTPOFF,
     VK_NTPOFF,
     VK_GOTNTPOFF,
     VK_PLT,
     VK_TLSGD,
     VK_TLSLD,
     VK_TLSLDM,
     VK_TPOFF,
     VK_DTPOFF,
     VK_TLSCALL,   // symbol(tlscall)
     VK_TLSDESC,   // symbol(tlsdesc)
     VK_TLVP,      // Mach-O thread local variable relocations
     VK_TLVPPAGE,
     VK_TLVPPAGEOFF,
     VK_PAGE,
     VK_PAGEOFF,
     VK_GOTPAGE,
     VK_GOTPAGEOFF,
     VK_SECREL,
     VK_SIZE,      // symbol@SIZE
     VK_WEAKREF,   // The link between the symbols in .weakref foo, bar

     VK_X86_ABS8,

     VK_ARM_NONE,
     VK_ARM_GOT_PREL,
     VK_ARM_TARGET1,
     VK_ARM_TARGET2,
     VK_ARM_PREL31,
     VK_ARM_SBREL,          // symbol(sbrel)
     VK_ARM_TLSLDO,         // symbol(tlsldo)
     VK_ARM_TLSDESCSEQ,

     VK_AVR_NONE,
     VK_AVR_LO8,
     VK_AVR_HI8,
     VK_AVR_HLO8,
     VK_AVR_DIFF8,
     VK_AVR_DIFF16,
     VK_AVR_DIFF32,

     VK_PPC_LO,             // symbol@l
     VK_PPC_HI,             // symbol@h
     VK_PPC_HA,             // symbol@ha
     VK_PPC_HIGH,           // symbol@high
     VK_PPC_HIGHA,          // symbol@higha
     VK_PPC_HIGHER,         // symbol@higher
     VK_PPC_HIGHERA,        // symbol@highera
     VK_PPC_HIGHEST,        // symbol@highest
     VK_PPC_HIGHESTA,       // symbol@highesta
     VK_PPC_GOT_LO,         // symbol@got@l
     VK_PPC_GOT_HI,         // symbol@got@h
     VK_PPC_GOT_HA,         // symbol@got@ha
     VK_PPC_TOCBASE,        // symbol@tocbase
     VK_PPC_TOC,            // symbol@toc
     VK_PPC_TOC_LO,         // symbol@toc@l
     VK_PPC_TOC_HI,         // symbol@toc@h
     VK_PPC_TOC_HA,         // symbol@toc@ha
     VK_PPC_DTPMOD,         // symbol@dtpmod
     VK_PPC_TPREL_LO,       // symbol@tprel@l
     VK_PPC_TPREL_HI,       // symbol@tprel@h
     VK_PPC_TPREL_HA,       // symbol@tprel@ha
     VK_PPC_TPREL_HIGH,     // symbol@tprel@high
     VK_PPC_TPREL_HIGHA,    // symbol@tprel@higha
     VK_PPC_TPREL_HIGHER,   // symbol@tprel@higher
     VK_PPC_TPREL_HIGHERA,  // symbol@tprel@highera
     VK_PPC_TPREL_HIGHEST,  // symbol@tprel@highest
     VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
     VK_PPC_DTPREL_LO,      // symbol@dtprel@l
     VK_PPC_DTPREL_HI,      // symbol@dtprel@h
     VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
     VK_PPC_DTPREL_HIGH,    // symbol@dtprel@high
     VK_PPC_DTPREL_HIGHA,   // symbol@dtprel@higha
     VK_PPC_DTPREL_HIGHER,  // symbol@dtprel@higher
     VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
     VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
     VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
     VK_PPC_GOT_TPREL,      // symbol@got@tprel
     VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
     VK_PPC_GOT_TPREL_HI,   // symbol@got@tprel@h
     VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
     VK_PPC_GOT_DTPREL,     // symbol@got@dtprel
     VK_PPC_GOT_DTPREL_LO,  // symbol@got@dtprel@l
     VK_PPC_GOT_DTPREL_HI,  // symbol@got@dtprel@h
     VK_PPC_GOT_DTPREL_HA,  // symbol@got@dtprel@ha
     VK_PPC_TLS,            // symbol@tls
     VK_PPC_GOT_TLSGD,      // symbol@got@tlsgd
     VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
     VK_PPC_GOT_TLSGD_HI,   // symbol@got@tlsgd@h
     VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
     VK_PPC_TLSGD,          // symbol@tlsgd
     VK_PPC_GOT_TLSLD,      // symbol@got@tlsld
     VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
     VK_PPC_GOT_TLSLD_HI,   // symbol@got@tlsld@h
     VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
     VK_PPC_TLSLD,          // symbol@tlsld
     VK_PPC_LOCAL,          // symbol@local

     VK_COFF_IMGREL32, // symbol@imgrel (image-relative)

     VK_Hexagon_PCREL,
     VK_Hexagon_LO16,
     VK_Hexagon_HI16,
     VK_Hexagon_GPREL,
     VK_Hexagon_GD_GOT,
     VK_Hexagon_LD_GOT,
     VK_Hexagon_GD_PLT,
     VK_Hexagon_LD_PLT,
     VK_Hexagon_IE,
     VK_Hexagon_IE_GOT,

     VK_WebAssembly_FUNCTION, // Function table index, rather than virtual addr
     VK_WebAssembly_GLOBAL,   // Global object index
     VK_WebAssembly_TYPEINDEX,// Type table index

     VK_AMDGPU_GOTPCREL32_LO, // symbol@gotpcrel32@lo
     VK_AMDGPU_GOTPCREL32_HI, // symbol@gotpcrel32@hi
     VK_AMDGPU_REL32_LO,      // symbol@rel32@lo
     VK_AMDGPU_REL32_HI,      // symbol@rel32@hi
     VK_AMDGPU_REL64,         // symbol@rel64

     VK_TPREL,
     VK_DTPREL
   };

 private:
   /// The symbol reference modifier.
   const VariantKind Kind;

   /// Specifies how the variant kind should be printed.
   const unsigned UseParensForSymbolVariant : 1;

   // FIXME: Remove this bit.
   const unsigned HasSubsectionsViaSymbols : 1;

   /// The symbol being referenced.
   const MCSymbol *Symbol;

   explicit MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
                            const MCAsmInfo *MAI, SMLoc Loc = SMLoc());

 public:
   /// \name Construction
   /// @{

   static const MCSymbolRefExpr *create(const MCSymbol *Symbol, MCContext &Ctx) {
     return MCSymbolRefExpr::create(Symbol, VK_None, Ctx);
   }

   static const MCSymbolRefExpr *create(const MCSymbol *Symbol, VariantKind Kind,
                                        MCContext &Ctx, SMLoc Loc = SMLoc());
   static const MCSymbolRefExpr *create(StringRef Name, VariantKind Kind,
                                        MCContext &Ctx);

   /// @}
   /// \name Accessors
   /// @{

   const MCSymbol &getSymbol() const { return *Symbol; }

   VariantKind getKind() const { return Kind; }

   void printVariantKind(raw_ostream &OS) const;

   bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }

   /// @}
   /// \name Static Utility Functions
   /// @{

   static StringRef getVariantKindName(VariantKind Kind);

   static VariantKind getVariantKindForName(StringRef Name);

   /// @}

   static bool classof(const MCExpr *E) {
     return E->getKind() == MCExpr::SymbolRef;
   }
 };

 /// Unary assembler expressions.
 class MCUnaryExpr : public MCExpr {
 public:
   enum Opcode {
     LNot,  ///< Logical negation.
     Minus, ///< Unary minus.
     Not,   ///< Bitwise negation.
     Plus   ///< Unary plus.
   };

 private:
   Opcode Op;
   const MCExpr *Expr;

   MCUnaryExpr(Opcode Op, const MCExpr *Expr, SMLoc Loc)
       : MCExpr(MCExpr::Unary, Loc), Op(Op), Expr(Expr) {}

 public:
   /// \name Construction
   /// @{

   static const MCUnaryExpr *create(Opcode Op, const MCExpr *Expr,
                                    MCContext &Ctx, SMLoc Loc = SMLoc());

   static const MCUnaryExpr *createLNot(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
     return create(LNot, Expr, Ctx, Loc);
   }

   static const MCUnaryExpr *createMinus(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
     return create(Minus, Expr, Ctx, Loc);
   }

   static const MCUnaryExpr *createNot(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
     return create(Not, Expr, Ctx, Loc);
   }

   static const MCUnaryExpr *createPlus(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
     return create(Plus, Expr, Ctx, Loc);
   }

   /// @}
   /// \name Accessors
   /// @{

   /// Get the kind of this unary expression.
   Opcode getOpcode() const { return Op; }

   /// Get the child of this unary expression.
   const MCExpr *getSubExpr() const { return Expr; }

   /// @}

   static bool classof(const MCExpr *E) {
     return E->getKind() == MCExpr::Unary;
   }
 };

 /// Binary assembler expressions.
 class MCBinaryExpr : public MCExpr {
 public:
   enum Opcode {
     Add,  ///< Addition.
     And,  ///< Bitwise and.
     Div,  ///< Signed division.
     EQ,   ///< Equality comparison.
     GT,   ///< Signed greater than comparison (result is either 0 or some
           ///< target-specific non-zero value)
     GTE,  ///< Signed greater than or equal comparison (result is either 0 or
           ///< some target-specific non-zero value).
     LAnd, ///< Logical and.
     LOr,  ///< Logical or.
     LT,   ///< Signed less than comparison (result is either 0 or
           ///< some target-specific non-zero value).
     LTE,  ///< Signed less than or equal comparison (result is either 0 or
           ///< some target-specific non-zero value).
     Mod,  ///< Signed remainder.
     Mul,  ///< Multiplication.
     NE,   ///< Inequality comparison.
     Or,   ///< Bitwise or.
     Shl,  ///< Shift left.
     AShr, ///< Arithmetic shift right.
     LShr, ///< Logical shift right.
     Sub,  ///< Subtraction.
     Xor   ///< Bitwise exclusive or.
   };

 private:
   Opcode Op;
   const MCExpr *LHS, *RHS;

   MCBinaryExpr(Opcode Op, const MCExpr *LHS, const MCExpr *RHS,
                SMLoc Loc = SMLoc())
       : MCExpr(MCExpr::Binary, Loc), Op(Op), LHS(LHS), RHS(RHS) {}

 public:
   /// \name Construction
   /// @{

   static const MCBinaryExpr *create(Opcode Op, const MCExpr *LHS,
                                     const MCExpr *RHS, MCContext &Ctx,
                                     SMLoc Loc = SMLoc());

   static const MCBinaryExpr *createAdd(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Add, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createAnd(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(And, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createDiv(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Div, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createEQ(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
     return create(EQ, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createGT(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
     return create(GT, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createGTE(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(GTE, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createLAnd(const MCExpr *LHS, const MCExpr *RHS,
                                         MCContext &Ctx) {
     return create(LAnd, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createLOr(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(LOr, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createLT(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
     return create(LT, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createLTE(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(LTE, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createMod(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Mod, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createMul(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Mul, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createNE(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
     return create(NE, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createOr(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
     return create(Or, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createShl(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Shl, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createAShr(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(AShr, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createLShr(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(LShr, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createSub(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Sub, LHS, RHS, Ctx);
   }

   static const MCBinaryExpr *createXor(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
     return create(Xor, LHS, RHS, Ctx);
   }

   /// @}
   /// \name Accessors
   /// @{

   /// Get the kind of this binary expression.
   Opcode getOpcode() const { return Op; }

   /// Get the left-hand side expression of the binary operator.
   const MCExpr *getLHS() const { return LHS; }

   /// Get the right-hand side expression of the binary operator.
   const MCExpr *getRHS() const { return RHS; }

   /// @}

   static bool classof(const MCExpr *E) {
     return E->getKind() == MCExpr::Binary;
   }
 };

 /// This is an extension point for target-specific MCExpr subclasses to
 /// implement.
 ///
 /// NOTE: All subclasses are required to have trivial destructors because
 /// MCExprs are bump pointer allocated and not destructed.
 class MCTargetExpr : public MCExpr {
   virtual void anchor();

 protected:
   MCTargetExpr() : MCExpr(Target, SMLoc()) {}
   virtual ~MCTargetExpr() = default;

 public:
   virtual void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const = 0;
   virtual bool evaluateAsRelocatableImpl(MCValue &Res,
                                          const MCAsmLayout *Layout,
                                          const MCFixup *Fixup) const = 0;
   // allow Target Expressions to be checked for equality
   virtual bool isEqualTo(const MCExpr *x) const { return false; }
   // This should be set when assigned expressions are not valid ".set"
   // expressions, e.g. registers, and must be inlined.
   virtual bool inlineAssignedExpr() const { return false; }
   virtual void visitUsedExpr(MCStreamer& Streamer) const = 0;
   virtual MCFragment *findAssociatedFragment() const = 0;

   virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;

   static bool classof(const MCExpr *E) {
     return E->getKind() == MCExpr::Target;
   }
 };

 } // end namespace llvm

 #endif // LLVM_MC_MCEXPR_H
	//===- MCExpr.h - Assembly Level Expressions --------------------- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_MC_MCEXPR_H
	#define LLVM_MC_MCEXPR_H

	#include "llvm/ADT/DenseMap.h"
	#include "llvm/Support/SMLoc.h"
	#include <cstdint>

	namespace llvm {

	class MCAsmInfo;
	class MCAsmLayout;
	class MCAssembler;
	class MCContext;
	class MCFixup;
	class MCFragment;
	class MCSection;
	class MCStreamer;
	class MCSymbol;
	class MCValue;
	class raw_ostream;
	class StringRef;

	using SectionAddrMap = DenseMap<const MCSection *, uint64_t>;

	/// Base class for the full range of assembler expressions which are
	/// needed for parsing.
	class MCExpr {
	public:
	enum ExprKind {
	Binary, ///< Binary expressions.
	Constant, ///< Constant expressions.
	SymbolRef, ///< References to labels and assigned expressions.
	Unary, ///< Unary expressions.
	Target ///< Target specific expression.
	};

	private:
	ExprKind Kind;
	SMLoc Loc;

	bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
	const MCAsmLayout *Layout,
	const SectionAddrMap *Addrs) const;

	bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
	const MCAsmLayout *Layout,
	const SectionAddrMap *Addrs, bool InSet) const;

	protected:
	explicit MCExpr(ExprKind Kind, SMLoc Loc) : Kind(Kind), Loc(Loc) {}

	bool evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
	const MCAsmLayout *Layout,
	const MCFixup *Fixup,
	const SectionAddrMap *Addrs, bool InSet) const;

	public:
	MCExpr(const MCExpr &) = delete;
	MCExpr &operator=(const MCExpr &) = delete;

	/// \name Accessors
	/// @{

	ExprKind getKind() const { return Kind; }
	SMLoc getLoc() const { return Loc; }

	/// @}
	/// \name Utility Methods
	/// @{

	void print(raw_ostream &OS, const MCAsmInfo *MAI,
	bool InParens = false) const;
	void dump() const;

	/// @}
	/// \name Expression Evaluation
	/// @{

	/// Try to evaluate the expression to an absolute value.
	///
	/// \param Res - The absolute value, if evaluation succeeds.
	/// \param Layout - The assembler layout object to use for evaluating symbol
	/// values. If not given, then only non-symbolic expressions will be
	/// evaluated.
	/// \return - True on success.
	bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
	const SectionAddrMap &Addrs) const;
	bool evaluateAsAbsolute(int64_t &Res) const;
	bool evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
	bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const;
	bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;

	bool evaluateKnownAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;

	/// Try to evaluate the expression to a relocatable value, i.e. an
	/// expression of the fixed form (a - b + constant).
	///
	/// \param Res - The relocatable value, if evaluation succeeds.
	/// \param Layout - The assembler layout object to use for evaluating values.
	/// \param Fixup - The Fixup object if available.
	/// \return - True on success.
	bool evaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout,
	const MCFixup *Fixup) const;

	/// Try to evaluate the expression to the form (a - b + constant) where
	/// neither a nor b are variables.
	///
	/// This is a more aggressive variant of evaluateAsRelocatable. The intended
	/// use is for when relocations are not available, like the .size directive.
	bool evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const;

	/// Find the "associated section" for this expression, which is
	/// currently defined as the absolute section for constants, or
	/// otherwise the section associated with the first defined symbol in the
	/// expression.
	MCFragment *findAssociatedFragment() const;

	/// @}
	};

	inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
	E.print(OS, nullptr);
	return OS;
	}

	//// Represent a constant integer expression.
	class MCConstantExpr : public MCExpr {
	int64_t Value;

	explicit MCConstantExpr(int64_t Value)
	: MCExpr(MCExpr::Constant, SMLoc()), Value(Value) {}

	public:
	/// \name Construction
	/// @{

	static const MCConstantExpr *create(int64_t Value, MCContext &Ctx);

	/// @}
	/// \name Accessors
	/// @{

	int64_t getValue() const { return Value; }

	/// @}

	static bool classof(const MCExpr *E) {
	return E->getKind() == MCExpr::Constant;
	}
	};

	/// Represent a reference to a symbol from inside an expression.
	///
	/// A symbol reference in an expression may be a use of a label, a use of an
	/// assembler variable (defined constant), or constitute an implicit definition
	/// of the symbol as external.
	class MCSymbolRefExpr : public MCExpr {
	public:
	enum VariantKind : uint16_t {
	VK_None,
	VK_Invalid,

	VK_GOT,
	VK_GOTOFF,
	VK_GOTREL,
	VK_GOTPCREL,
	VK_GOTTPOFF,
	VK_INDNTPOFF,
	VK_NTPOFF,
	VK_GOTNTPOFF,
	VK_PLT,
	VK_TLSGD,
	VK_TLSLD,
	VK_TLSLDM,
	VK_TPOFF,
	VK_DTPOFF,
	VK_TLSCALL, // symbol(tlscall)
	VK_TLSDESC, // symbol(tlsdesc)
	VK_TLVP, // Mach-O thread local variable relocations
	VK_TLVPPAGE,
	VK_TLVPPAGEOFF,
	VK_PAGE,
	VK_PAGEOFF,
	VK_GOTPAGE,
	VK_GOTPAGEOFF,
	VK_SECREL,
	VK_SIZE, // symbol@SIZE
	VK_WEAKREF, // The link between the symbols in .weakref foo, bar

	VK_X86_ABS8,

	VK_ARM_NONE,
	VK_ARM_GOT_PREL,
	VK_ARM_TARGET1,
	VK_ARM_TARGET2,
	VK_ARM_PREL31,
	VK_ARM_SBREL, // symbol(sbrel)
	VK_ARM_TLSLDO, // symbol(tlsldo)
	VK_ARM_TLSDESCSEQ,

	VK_AVR_NONE,
	VK_AVR_LO8,
	VK_AVR_HI8,
	VK_AVR_HLO8,
	VK_AVR_DIFF8,
	VK_AVR_DIFF16,
	VK_AVR_DIFF32,

	VK_PPC_LO, // symbol@l
	VK_PPC_HI, // symbol@h
	VK_PPC_HA, // symbol@ha
	VK_PPC_HIGH, // symbol@high
	VK_PPC_HIGHA, // symbol@higha
	VK_PPC_HIGHER, // symbol@higher
	VK_PPC_HIGHERA, // symbol@highera
	VK_PPC_HIGHEST, // symbol@highest
	VK_PPC_HIGHESTA, // symbol@highesta
	VK_PPC_GOT_LO, // symbol@got@l
	VK_PPC_GOT_HI, // symbol@got@h
	VK_PPC_GOT_HA, // symbol@got@ha
	VK_PPC_TOCBASE, // symbol@tocbase
	VK_PPC_TOC, // symbol@toc
	VK_PPC_TOC_LO, // symbol@toc@l
	VK_PPC_TOC_HI, // symbol@toc@h
	VK_PPC_TOC_HA, // symbol@toc@ha
	VK_PPC_DTPMOD, // symbol@dtpmod
	VK_PPC_TPREL_LO, // symbol@tprel@l
	VK_PPC_TPREL_HI, // symbol@tprel@h
	VK_PPC_TPREL_HA, // symbol@tprel@ha
	VK_PPC_TPREL_HIGH, // symbol@tprel@high
	VK_PPC_TPREL_HIGHA, // symbol@tprel@higha
	VK_PPC_TPREL_HIGHER, // symbol@tprel@higher
	VK_PPC_TPREL_HIGHERA, // symbol@tprel@highera
	VK_PPC_TPREL_HIGHEST, // symbol@tprel@highest
	VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
	VK_PPC_DTPREL_LO, // symbol@dtprel@l
	VK_PPC_DTPREL_HI, // symbol@dtprel@h
	VK_PPC_DTPREL_HA, // symbol@dtprel@ha
	VK_PPC_DTPREL_HIGH, // symbol@dtprel@high
	VK_PPC_DTPREL_HIGHA, // symbol@dtprel@higha
	VK_PPC_DTPREL_HIGHER, // symbol@dtprel@higher
	VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
	VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
	VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
	VK_PPC_GOT_TPREL, // symbol@got@tprel
	VK_PPC_GOT_TPREL_LO, // symbol@got@tprel@l
	VK_PPC_GOT_TPREL_HI, // symbol@got@tprel@h
	VK_PPC_GOT_TPREL_HA, // symbol@got@tprel@ha
	VK_PPC_GOT_DTPREL, // symbol@got@dtprel
	VK_PPC_GOT_DTPREL_LO, // symbol@got@dtprel@l
	VK_PPC_GOT_DTPREL_HI, // symbol@got@dtprel@h
	VK_PPC_GOT_DTPREL_HA, // symbol@got@dtprel@ha
	VK_PPC_TLS, // symbol@tls
	VK_PPC_GOT_TLSGD, // symbol@got@tlsgd
	VK_PPC_GOT_TLSGD_LO, // symbol@got@tlsgd@l
	VK_PPC_GOT_TLSGD_HI, // symbol@got@tlsgd@h
	VK_PPC_GOT_TLSGD_HA, // symbol@got@tlsgd@ha
	VK_PPC_TLSGD, // symbol@tlsgd
	VK_PPC_GOT_TLSLD, // symbol@got@tlsld
	VK_PPC_GOT_TLSLD_LO, // symbol@got@tlsld@l
	VK_PPC_GOT_TLSLD_HI, // symbol@got@tlsld@h
	VK_PPC_GOT_TLSLD_HA, // symbol@got@tlsld@ha
	VK_PPC_TLSLD, // symbol@tlsld
	VK_PPC_LOCAL, // symbol@local

	VK_COFF_IMGREL32, // symbol@imgrel (image-relative)

	VK_Hexagon_PCREL,
	VK_Hexagon_LO16,
	VK_Hexagon_HI16,
	VK_Hexagon_GPREL,
	VK_Hexagon_GD_GOT,
	VK_Hexagon_LD_GOT,
	VK_Hexagon_GD_PLT,
	VK_Hexagon_LD_PLT,
	VK_Hexagon_IE,
	VK_Hexagon_IE_GOT,

	VK_WebAssembly_FUNCTION, // Function table index, rather than virtual addr
	VK_WebAssembly_GLOBAL, // Global object index
	VK_WebAssembly_TYPEINDEX,// Type table index

	VK_AMDGPU_GOTPCREL32_LO, // symbol@gotpcrel32@lo
	VK_AMDGPU_GOTPCREL32_HI, // symbol@gotpcrel32@hi
	VK_AMDGPU_REL32_LO, // symbol@rel32@lo
	VK_AMDGPU_REL32_HI, // symbol@rel32@hi
	VK_AMDGPU_REL64, // symbol@rel64

	VK_TPREL,
	VK_DTPREL
	};

	private:
	/// The symbol reference modifier.
	const VariantKind Kind;

	/// Specifies how the variant kind should be printed.
	const unsigned UseParensForSymbolVariant : 1;

	// FIXME: Remove this bit.
	const unsigned HasSubsectionsViaSymbols : 1;

	/// The symbol being referenced.
	const MCSymbol *Symbol;

	explicit MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
	const MCAsmInfo *MAI, SMLoc Loc = SMLoc());

	public:
	/// \name Construction
	/// @{

	static const MCSymbolRefExpr create(const MCSymbol Symbol, MCContext &Ctx) {
	return MCSymbolRefExpr::create(Symbol, VK_None, Ctx);
	}

	static const MCSymbolRefExpr create(const MCSymbol Symbol, VariantKind Kind,
	MCContext &Ctx, SMLoc Loc = SMLoc());
	static const MCSymbolRefExpr *create(StringRef Name, VariantKind Kind,
	MCContext &Ctx);

	/// @}
	/// \name Accessors
	/// @{

	const MCSymbol &getSymbol() const { return *Symbol; }

	VariantKind getKind() const { return Kind; }

	void printVariantKind(raw_ostream &OS) const;

	bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }

	/// @}
	/// \name Static Utility Functions
	/// @{

	static StringRef getVariantKindName(VariantKind Kind);

	static VariantKind getVariantKindForName(StringRef Name);

	/// @}

	static bool classof(const MCExpr *E) {
	return E->getKind() == MCExpr::SymbolRef;
	}
	};

	/// Unary assembler expressions.
	class MCUnaryExpr : public MCExpr {
	public:
	enum Opcode {
	LNot, ///< Logical negation.
	Minus, ///< Unary minus.
	Not, ///< Bitwise negation.
	Plus ///< Unary plus.
	};

	private:
	Opcode Op;
	const MCExpr *Expr;

	MCUnaryExpr(Opcode Op, const MCExpr *Expr, SMLoc Loc)
	: MCExpr(MCExpr::Unary, Loc), Op(Op), Expr(Expr) {}

	public:
	/// \name Construction
	/// @{

	static const MCUnaryExpr create(Opcode Op, const MCExpr Expr,
	MCContext &Ctx, SMLoc Loc = SMLoc());

	static const MCUnaryExpr createLNot(const MCExpr Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
	return create(LNot, Expr, Ctx, Loc);
	}

	static const MCUnaryExpr createMinus(const MCExpr Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
	return create(Minus, Expr, Ctx, Loc);
	}

	static const MCUnaryExpr createNot(const MCExpr Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
	return create(Not, Expr, Ctx, Loc);
	}

	static const MCUnaryExpr createPlus(const MCExpr Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
	return create(Plus, Expr, Ctx, Loc);
	}

	/// @}
	/// \name Accessors
	/// @{

	/// Get the kind of this unary expression.
	Opcode getOpcode() const { return Op; }

	/// Get the child of this unary expression.
	const MCExpr *getSubExpr() const { return Expr; }

	/// @}

	static bool classof(const MCExpr *E) {
	return E->getKind() == MCExpr::Unary;
	}
	};

	/// Binary assembler expressions.
	class MCBinaryExpr : public MCExpr {
	public:
	enum Opcode {
	Add, ///< Addition.
	And, ///< Bitwise and.
	Div, ///< Signed division.
	EQ, ///< Equality comparison.
	GT, ///< Signed greater than comparison (result is either 0 or some
	///< target-specific non-zero value)
	GTE, ///< Signed greater than or equal comparison (result is either 0 or
	///< some target-specific non-zero value).
	LAnd, ///< Logical and.
	LOr, ///< Logical or.
	LT, ///< Signed less than comparison (result is either 0 or
	///< some target-specific non-zero value).
	LTE, ///< Signed less than or equal comparison (result is either 0 or
	///< some target-specific non-zero value).
	Mod, ///< Signed remainder.
	Mul, ///< Multiplication.
	NE, ///< Inequality comparison.
	Or, ///< Bitwise or.
	Shl, ///< Shift left.
	AShr, ///< Arithmetic shift right.
	LShr, ///< Logical shift right.
	Sub, ///< Subtraction.
	Xor ///< Bitwise exclusive or.
	};

	private:
	Opcode Op;
	const MCExpr LHS, RHS;

	MCBinaryExpr(Opcode Op, const MCExpr LHS, const MCExpr RHS,
	SMLoc Loc = SMLoc())
	: MCExpr(MCExpr::Binary, Loc), Op(Op), LHS(LHS), RHS(RHS) {}

	public:
	/// \name Construction
	/// @{

	static const MCBinaryExpr create(Opcode Op, const MCExpr LHS,
	const MCExpr *RHS, MCContext &Ctx,
	SMLoc Loc = SMLoc());

	static const MCBinaryExpr createAdd(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Add, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createAnd(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(And, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createDiv(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Div, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createEQ(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(EQ, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createGT(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(GT, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createGTE(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(GTE, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createLAnd(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(LAnd, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createLOr(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(LOr, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createLT(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(LT, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createLTE(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(LTE, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createMod(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Mod, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createMul(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Mul, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createNE(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(NE, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createOr(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Or, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createShl(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Shl, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createAShr(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(AShr, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createLShr(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(LShr, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createSub(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Sub, LHS, RHS, Ctx);
	}

	static const MCBinaryExpr createXor(const MCExpr LHS, const MCExpr *RHS,
	MCContext &Ctx) {
	return create(Xor, LHS, RHS, Ctx);
	}

	/// @}
	/// \name Accessors
	/// @{

	/// Get the kind of this binary expression.
	Opcode getOpcode() const { return Op; }

	/// Get the left-hand side expression of the binary operator.
	const MCExpr *getLHS() const { return LHS; }

	/// Get the right-hand side expression of the binary operator.
	const MCExpr *getRHS() const { return RHS; }

	/// @}

	static bool classof(const MCExpr *E) {
	return E->getKind() == MCExpr::Binary;
	}
	};

	/// This is an extension point for target-specific MCExpr subclasses to
	/// implement.
	///
	/// NOTE: All subclasses are required to have trivial destructors because
	/// MCExprs are bump pointer allocated and not destructed.
	class MCTargetExpr : public MCExpr {
	virtual void anchor();

	protected:
	MCTargetExpr() : MCExpr(Target, SMLoc()) {}
	virtual ~MCTargetExpr() = default;

	public:
	virtual void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const = 0;
	virtual bool evaluateAsRelocatableImpl(MCValue &Res,
	const MCAsmLayout *Layout,
	const MCFixup *Fixup) const = 0;
	// allow Target Expressions to be checked for equality
	virtual bool isEqualTo(const MCExpr *x) const { return false; }
	// This should be set when assigned expressions are not valid ".set"
	// expressions, e.g. registers, and must be inlined.
	virtual bool inlineAssignedExpr() const { return false; }
	virtual void visitUsedExpr(MCStreamer& Streamer) const = 0;
	virtual MCFragment *findAssociatedFragment() const = 0;

	virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;

	static bool classof(const MCExpr *E) {
	return E->getKind() == MCExpr::Target;
	}
	};

	} // end namespace llvm

	#endif // LLVM_MC_MCEXPR_H