lib/Target/ARM/MCTargetDesc/ARMMCExpr.h

   1 //===-- ARMMCExpr.h - ARM specific MC expression classes --------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMMCEXPR_H
  10 #define LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMMCEXPR_H
  11
  12 #include "llvm/MC/MCExpr.h"
  13
  14 namespace llvm {
  15
  16 class ARMMCExpr : public MCTargetExpr {
  17 public:
  18   enum VariantKind {
  19     VK_ARM_None,
  20     VK_ARM_HI16,  // The R_ARM_MOVT_ABS relocation (:upper16: in the .s file)
  21     VK_ARM_LO16   // The R_ARM_MOVW_ABS_NC relocation (:lower16: in the .s file)
  22   };
  23
  24 private:
  25   const VariantKind Kind;
  26   const MCExpr *Expr;
  27
  28   explicit ARMMCExpr(VariantKind Kind, const MCExpr *Expr)
  29       : Kind(Kind), Expr(Expr) {}
  30
  31 public:
  32   /// @name Construction
  33   /// @{
  34
  35   static const ARMMCExpr *create(VariantKind Kind, const MCExpr *Expr,
  36                                       MCContext &Ctx);
  37
  38   static const ARMMCExpr *createUpper16(const MCExpr *Expr, MCContext &Ctx) {
  39     return create(VK_ARM_HI16, Expr, Ctx);
  40   }
  41
  42   static const ARMMCExpr *createLower16(const MCExpr *Expr, MCContext &Ctx) {
  43     return create(VK_ARM_LO16, Expr, Ctx);
  44   }
  45
  46   /// @}
  47   /// @name Accessors
  48   /// @{
  49
  50   /// getOpcode - Get the kind of this expression.
  51   VariantKind getKind() const { return Kind; }
  52
  53   /// getSubExpr - Get the child of this expression.
  54   const MCExpr *getSubExpr() const { return Expr; }
  55
  56   /// @}
  57
  58   void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
  59   bool evaluateAsRelocatableImpl(MCValue &Res,
  60                                  const MCAsmLayout *Layout,
  61                                  const MCFixup *Fixup) const override {
  62     return false;
  63   }
  64   void visitUsedExpr(MCStreamer &Streamer) const override;
  65   MCFragment *findAssociatedFragment() const override {
  66     return getSubExpr()->findAssociatedFragment();
  67   }
  68
  69   // There are no TLS ARMMCExprs at the moment.
  70   void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override {}
  71
  72   static bool classof(const MCExpr *E) {
  73     return E->getKind() == MCExpr::Target;
  74   }
  75 };
  76 } // end namespace llvm
  77
  78 #endif