ARMMCExpr.h revision cd81d94322a39503e4a3e87b6ee03d4fcb3465fb 
1//===-- ARMMCExpr.h - ARM specific MC expression classes --------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef ARMMCEXPR_H
11#define ARMMCEXPR_H
12
13#include "llvm/MC/MCExpr.h"
14
15namespace llvm {
16
17class ARMMCExpr : public MCTargetExpr {
18public:
19  enum VariantKind {
20    VK_ARM_None,
21    VK_ARM_HI16,  // The R_ARM_MOVT_ABS relocation (:upper16: in the .s file)
22    VK_ARM_LO16   // The R_ARM_MOVW_ABS_NC relocation (:lower16: in the .s file)
23  };
24
25private:
26  const VariantKind Kind;
27  const MCExpr *Expr;
28
29  explicit ARMMCExpr(VariantKind _Kind, const MCExpr *_Expr)
30    : Kind(_Kind), Expr(_Expr) {}
31
32public:
33  /// @name Construction
34  /// @{
35
36  static const ARMMCExpr *Create(VariantKind Kind, const MCExpr *Expr,
37                                      MCContext &Ctx);
38
39  static const ARMMCExpr *CreateUpper16(const MCExpr *Expr, MCContext &Ctx) {
40    return Create(VK_ARM_HI16, Expr, Ctx);
41  }
42
43  static const ARMMCExpr *CreateLower16(const MCExpr *Expr, MCContext &Ctx) {
44    return Create(VK_ARM_LO16, Expr, Ctx);
45  }
46
47  /// @}
48  /// @name Accessors
49  /// @{
50
51  /// getOpcode - Get the kind of this expression.
52  VariantKind getKind() const { return Kind; }
53
54  /// getSubExpr - Get the child of this expression.
55  const MCExpr *getSubExpr() const { return Expr; }
56
57  /// @}
58
59  void PrintImpl(raw_ostream &OS) const override;
60  bool EvaluateAsRelocatableImpl(MCValue &Res,
61                                 const MCAsmLayout *Layout) const override;
62  void visitUsedExpr(MCStreamer &Streamer) const override;
63  const MCSection *FindAssociatedSection() const override {
64    return getSubExpr()->FindAssociatedSection();
65  }
66
67  // There are no TLS ARMMCExprs at the moment.
68  void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override {}
69
70  static bool classof(const MCExpr *E) {
71    return E->getKind() == MCExpr::Target;
72  }
73};
74} // end namespace llvm
75
76#endif
77