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 
21 namespace 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.
33 class 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 
54 public:
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