aboutsummaryrefslogtreecommitdiff
path: root/include/llvm/MC/MCSection.h
blob: ba5c60d3ba585fec09366b8498c799b4fa54c299 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
//===- MCSection.h - Machine Code Sections ----------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the MCSection class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCSECTION_H
#define LLVM_MC_MCSECTION_H

#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/ilist.h"
#include "llvm/MC/MCFragment.h"
#include "llvm/MC/SectionKind.h"
#include <cassert>
#include <utility>

namespace llvm {

class MCAsmInfo;
class MCContext;
class MCExpr;
class MCSymbol;
class raw_ostream;
class Triple;

template <> struct ilist_alloc_traits<MCFragment> {
  static void deleteNode(MCFragment *V);
};

/// Instances of this class represent a uniqued identifier for a section in the
/// current translation unit.  The MCContext class uniques and creates these.
class MCSection {
public:
  enum SectionVariant { SV_COFF = 0, SV_ELF, SV_MachO, SV_Wasm };

  /// Express the state of bundle locked groups while emitting code.
  enum BundleLockStateType {
    NotBundleLocked,
    BundleLocked,
    BundleLockedAlignToEnd
  };

  using FragmentListType = iplist<MCFragment>;

  using const_iterator = FragmentListType::const_iterator;
  using iterator = FragmentListType::iterator;

  using const_reverse_iterator = FragmentListType::const_reverse_iterator;
  using reverse_iterator = FragmentListType::reverse_iterator;

private:
  MCSymbol *Begin;
  MCSymbol *End = nullptr;
  /// The alignment requirement of this section.
  unsigned Alignment = 1;
  /// The section index in the assemblers section list.
  unsigned Ordinal = 0;
  /// The index of this section in the layout order.
  unsigned LayoutOrder;

  /// Keeping track of bundle-locked state.
  BundleLockStateType BundleLockState = NotBundleLocked;

  /// Current nesting depth of bundle_lock directives.
  unsigned BundleLockNestingDepth = 0;

  /// We've seen a bundle_lock directive but not its first instruction
  /// yet.
  bool BundleGroupBeforeFirstInst : 1;

  /// Whether this section has had instructions emitted into it.
  bool HasInstructions : 1;

  bool IsRegistered : 1;

  MCDummyFragment DummyFragment;

  FragmentListType Fragments;

  /// Mapping from subsection number to insertion point for subsection numbers
  /// below that number.
  SmallVector<std::pair<unsigned, MCFragment *>, 1> SubsectionFragmentMap;

protected:
  SectionVariant Variant;
  SectionKind Kind;

  MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin);
  ~MCSection();

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

  SectionKind getKind() const { return Kind; }

  SectionVariant getVariant() const { return Variant; }

  MCSymbol *getBeginSymbol() { return Begin; }
  const MCSymbol *getBeginSymbol() const {
    return const_cast<MCSection *>(this)->getBeginSymbol();
  }
  void setBeginSymbol(MCSymbol *Sym) {
    assert(!Begin);
    Begin = Sym;
  }
  MCSymbol *getEndSymbol(MCContext &Ctx);
  bool hasEnded() const;

  unsigned getAlignment() const { return Alignment; }
  void setAlignment(unsigned Value) { Alignment = Value; }

  unsigned getOrdinal() const { return Ordinal; }
  void setOrdinal(unsigned Value) { Ordinal = Value; }

  unsigned getLayoutOrder() const { return LayoutOrder; }
  void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }

  BundleLockStateType getBundleLockState() const { return BundleLockState; }
  void setBundleLockState(BundleLockStateType NewState);
  bool isBundleLocked() const { return BundleLockState != NotBundleLocked; }

  bool isBundleGroupBeforeFirstInst() const {
    return BundleGroupBeforeFirstInst;
  }
  void setBundleGroupBeforeFirstInst(bool IsFirst) {
    BundleGroupBeforeFirstInst = IsFirst;
  }

  bool hasInstructions() const { return HasInstructions; }
  void setHasInstructions(bool Value) { HasInstructions = Value; }

  bool isRegistered() const { return IsRegistered; }
  void setIsRegistered(bool Value) { IsRegistered = Value; }

  MCSection::FragmentListType &getFragmentList() { return Fragments; }
  const MCSection::FragmentListType &getFragmentList() const {
    return const_cast<MCSection *>(this)->getFragmentList();
  }

  /// Support for MCFragment::getNextNode().
  static FragmentListType MCSection::*getSublistAccess(MCFragment *) {
    return &MCSection::Fragments;
  }

  const MCDummyFragment &getDummyFragment() const { return DummyFragment; }
  MCDummyFragment &getDummyFragment() { return DummyFragment; }

  iterator begin() { return Fragments.begin(); }
  const_iterator begin() const { return Fragments.begin(); }

  iterator end() { return Fragments.end(); }
  const_iterator end() const { return Fragments.end(); }

  reverse_iterator rbegin() { return Fragments.rbegin(); }
  const_reverse_iterator rbegin() const { return Fragments.rbegin(); }

  reverse_iterator rend() { return Fragments.rend(); }
  const_reverse_iterator rend() const  { return Fragments.rend(); }

  MCSection::iterator getSubsectionInsertionPoint(unsigned Subsection);

  void dump() const;

  virtual void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                                    raw_ostream &OS,
                                    const MCExpr *Subsection) const = 0;

  /// Return true if a .align directive should use "optimized nops" to fill
  /// instead of 0s.
  virtual bool UseCodeAlign() const = 0;

  /// Check whether this section is "virtual", that is has no actual object
  /// file contents.
  virtual bool isVirtualSection() const = 0;
};

} // end namespace llvm

#endif // LLVM_MC_MCSECTION_H