MCSection.h revision 3d2251361171b1a41bdb2ac71882e69d48617f49 
1//===- MCSection.h - Machine Code Sections ----------------------*- 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// This file declares the MCSection class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_MC_MCSECTION_H
15#define LLVM_MC_MCSECTION_H
16
17#include <string>
18#include "llvm/ADT/StringRef.h"
19#include "llvm/MC/SectionKind.h"
20
21namespace llvm {
22  class MCContext;
23  class MCAsmInfo;
24  class raw_ostream;
25
26  /// MCSection - Instances of this class represent a uniqued identifier for a
27  /// section in the current translation unit.  The MCContext class uniques and
28  /// creates these.
29  class MCSection {
30    MCSection(const MCSection&);      // DO NOT IMPLEMENT
31    void operator=(const MCSection&); // DO NOT IMPLEMENT
32  protected:
33    MCSection(SectionKind K) : Kind(K) {}
34    SectionKind Kind;
35  public:
36    virtual ~MCSection();
37
38    SectionKind getKind() const { return Kind; }
39
40    virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
41                                      raw_ostream &OS) const = 0;
42
43    /// isBaseAddressKnownZero - Return true if we know that this section will
44    /// get a base address of zero.  In cases where we know that this is true we
45    /// can emit section offsets as direct references to avoid a subtraction
46    /// from the base of the section, saving a relocation.
47    virtual bool isBaseAddressKnownZero() const {
48      return false;
49    }
50  };
51
52  class MCSectionCOFF : public MCSection {
53    // The memory for this string is stored in the same MCContext as *this.
54    StringRef Name;
55
56    /// IsDirective - This is true if the section name is a directive, not
57    /// something that should be printed with ".section".
58    ///
59    /// FIXME: This is a hack.  Switch to a semantic view of the section instead
60    /// of a syntactic one.
61    bool IsDirective;
62
63    MCSectionCOFF(StringRef name, bool isDirective, SectionKind K)
64      : MCSection(K), Name(name), IsDirective(isDirective) {
65    }
66  public:
67
68    static MCSectionCOFF *Create(StringRef Name, bool IsDirective,
69                                 SectionKind K, MCContext &Ctx);
70
71    StringRef getName() const { return Name; }
72    bool isDirective() const { return IsDirective; }
73
74    virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
75                                      raw_ostream &OS) const;
76  };
77
78} // end namespace llvm
79
80#endif
81