1 //===- MCSectionELF.h - ELF 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 MCSectionELF class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_MC_MCSECTIONELF_H
15 #define LLVM_MC_MCSECTIONELF_H
16 
17 #include "llvm/ADT/Twine.h"
18 #include "llvm/MC/MCSection.h"
19 #include "llvm/MC/MCSymbol.h"
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/ELF.h"
22 #include "llvm/Support/raw_ostream.h"
23 
24 namespace llvm {
25 
26 class MCSymbol;
27 
28 /// MCSectionELF - This represents a section on linux, lots of unix variants
29 /// and some bare metal systems.
30 class MCSectionELF : public MCSection {
31   /// SectionName - This is the name of the section.  The referenced memory is
32   /// owned by TargetLoweringObjectFileELF's ELFUniqueMap.
33   StringRef SectionName;
34 
35   /// Type - This is the sh_type field of a section, drawn from the enums below.
36   unsigned Type;
37 
38   /// Flags - This is the sh_flags field of a section, drawn from the enums.
39   /// below.
40   unsigned Flags;
41 
42   unsigned UniqueID;
43 
44   /// EntrySize - The size of each entry in this section. This size only
45   /// makes sense for sections that contain fixed-sized entries. If a
46   /// section does not contain fixed-sized entries 'EntrySize' will be 0.
47   unsigned EntrySize;
48 
49   const MCSymbol *Group;
50 
51   /// Depending on the type of the section this is sh_link or sh_info.
52   const MCSectionELF *Associated;
53 
54 private:
55   friend class MCContext;
MCSectionELF(StringRef Section,unsigned type,unsigned flags,SectionKind K,unsigned entrySize,const MCSymbol * group,unsigned UniqueID,MCSymbol * Begin,const MCSectionELF * Associated)56   MCSectionELF(StringRef Section, unsigned type, unsigned flags, SectionKind K,
57                unsigned entrySize, const MCSymbol *group, unsigned UniqueID,
58                MCSymbol *Begin, const MCSectionELF *Associated)
59       : MCSection(SV_ELF, K, Begin), SectionName(Section), Type(type),
60         Flags(flags), UniqueID(UniqueID), EntrySize(entrySize), Group(group),
61         Associated(Associated) {}
62   ~MCSectionELF() override;
63 
setSectionName(StringRef Name)64   void setSectionName(StringRef Name) { SectionName = Name; }
65 
66 public:
67 
68   /// ShouldOmitSectionDirective - Decides whether a '.section' directive
69   /// should be printed before the section name
70   bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
71 
getSectionName()72   StringRef getSectionName() const { return SectionName; }
getType()73   unsigned getType() const { return Type; }
getFlags()74   unsigned getFlags() const { return Flags; }
getEntrySize()75   unsigned getEntrySize() const { return EntrySize; }
getGroup()76   const MCSymbol *getGroup() const { return Group; }
77 
78   void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
79                             const MCExpr *Subsection) const override;
80   bool UseCodeAlign() const override;
81   bool isVirtualSection() const override;
82 
isUnique()83   bool isUnique() const { return UniqueID != ~0U; }
getUniqueID()84   unsigned getUniqueID() const { return UniqueID; }
85 
getAssociatedSection()86   const MCSectionELF *getAssociatedSection() const { return Associated; }
87 
classof(const MCSection * S)88   static bool classof(const MCSection *S) {
89     return S->getVariant() == SV_ELF;
90   }
91 };
92 
93 } // end namespace llvm
94 
95 #endif
96