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 "llvm/MC/SectionKind.h"
18#include "llvm/Support/Compiler.h"
19
20namespace llvm {
21  class MCAsmInfo;
22  class raw_ostream;
23
24  /// MCSection - Instances of this class represent a uniqued identifier for a
25  /// section in the current translation unit.  The MCContext class uniques and
26  /// creates these.
27  class MCSection {
28  public:
29    enum SectionVariant {
30      SV_COFF = 0,
31      SV_ELF,
32      SV_MachO,
33      SV_LDContext
34    };
35
36  private:
37    MCSection(const MCSection&) LLVM_DELETED_FUNCTION;
38    void operator=(const MCSection&) LLVM_DELETED_FUNCTION;
39  protected:
40    MCSection(SectionVariant V, SectionKind K) : Variant(V), Kind(K) {}
41    SectionVariant Variant;
42    SectionKind Kind;
43  public:
44    virtual ~MCSection();
45
46    SectionKind getKind() const { return Kind; }
47
48    SectionVariant getVariant() const { return Variant; }
49
50    virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
51                                      raw_ostream &OS) const = 0;
52
53    /// isBaseAddressKnownZero - Return true if we know that this section will
54    /// get a base address of zero.  In cases where we know that this is true we
55    /// can emit section offsets as direct references to avoid a subtraction
56    /// from the base of the section, saving a relocation.
57    virtual bool isBaseAddressKnownZero() const {
58      return false;
59    }
60
61    // UseCodeAlign - Return true if a .align directive should use
62    // "optimized nops" to fill instead of 0s.
63    virtual bool UseCodeAlign() const = 0;
64
65    /// isVirtualSection - Check whether this section is "virtual", that is
66    /// has no actual object file contents.
67    virtual bool isVirtualSection() const = 0;
68
69    static bool classof(const MCSection *) { return true; }
70  };
71
72} // end namespace llvm
73
74#endif
75