MCSectionXCOFF.h revision 360784 
1//===- MCSectionXCOFF.h - XCOFF Machine Code Sections -----------*- 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// This file declares the MCSectionXCOFF class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_MC_MCSECTIONXCOFF_H
14#define LLVM_MC_MCSECTIONXCOFF_H
15
16#include "llvm/ADT/Twine.h"
17#include "llvm/BinaryFormat/XCOFF.h"
18#include "llvm/MC/MCSection.h"
19#include "llvm/MC/MCSymbolXCOFF.h"
20
21namespace llvm {
22
23// This class represents an XCOFF `Control Section`, more commonly referred to
24// as a csect. A csect represents the smallest possible unit of data/code which
25// will be relocated as a single block. A csect can either be:
26// 1) Initialized: The Type will be XTY_SD, and the symbols inside the csect
27//    will have a label definition representing their offset within the csect.
28// 2) Uninitialized: The Type will be XTY_CM, it will contain a single symbol,
29//    and may not contain label definitions.
30// 3) An external reference providing a symbol table entry for a symbol
31//    contained in another XCOFF object file. External reference csects are not
32//    implemented yet.
33class MCSectionXCOFF final : public MCSection {
34  friend class MCContext;
35
36  StringRef Name;
37  XCOFF::StorageMappingClass MappingClass;
38  XCOFF::SymbolType Type;
39  XCOFF::StorageClass StorageClass;
40  MCSymbolXCOFF *const QualName;
41
42  MCSectionXCOFF(StringRef Section, XCOFF::StorageMappingClass SMC,
43                 XCOFF::SymbolType ST, XCOFF::StorageClass SC, SectionKind K,
44                 MCSymbolXCOFF *QualName, MCSymbol *Begin)
45      : MCSection(SV_XCOFF, K, Begin), Name(Section), MappingClass(SMC),
46        Type(ST), StorageClass(SC), QualName(QualName) {
47    assert((ST == XCOFF::XTY_SD || ST == XCOFF::XTY_CM || ST == XCOFF::XTY_ER) &&
48           "Invalid or unhandled type for csect.");
49    assert(QualName != nullptr && "QualName is needed.");
50    QualName->setStorageClass(SC);
51    QualName->setContainingCsect(this);
52  }
53
54public:
55  ~MCSectionXCOFF();
56
57  static bool classof(const MCSection *S) {
58    return S->getVariant() == SV_XCOFF;
59  }
60
61  StringRef getSectionName() const { return Name; }
62  XCOFF::StorageMappingClass getMappingClass() const { return MappingClass; }
63  XCOFF::StorageClass getStorageClass() const { return StorageClass; }
64  XCOFF::SymbolType getCSectType() const { return Type; }
65  MCSymbolXCOFF *getQualNameSymbol() const { return QualName; }
66
67  void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
68                            raw_ostream &OS,
69                            const MCExpr *Subsection) const override;
70  bool UseCodeAlign() const override;
71  bool isVirtualSection() const override;
72};
73
74} // end namespace llvm
75
76#endif
77