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/MCSymbolELF.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 /// This represents a section on linux, lots of unix variants and some bare 29 /// metal systems. 30 class MCSectionELF final : public MCSection { 31 /// This is the name of the section. The referenced memory is owned by 32 /// TargetLoweringObjectFileELF's ELFUniqueMap. 33 StringRef SectionName; 34 35 /// This is the sh_type field of a section, drawn from the enums below. 36 unsigned Type; 37 38 /// This is the sh_flags field of a section, drawn from the enums below. 39 unsigned Flags; 40 41 unsigned UniqueID; 42 43 /// The size of each entry in this section. This size only makes sense for 44 /// sections that contain fixed-sized entries. If a section does not contain 45 /// fixed-sized entries 'EntrySize' will be 0. 46 unsigned EntrySize; 47 48 const MCSymbolELF *Group; 49 50 /// Depending on the type of the section this is sh_link or sh_info. 51 const MCSectionELF *Associated; 52 53 private: 54 friend class MCContext; 55 MCSectionELF(StringRef Section, unsigned type, unsigned flags, SectionKind K, 56 unsigned entrySize, const MCSymbolELF *group, unsigned UniqueID, 57 MCSymbol *Begin, const MCSectionELF *Associated) 58 : MCSection(SV_ELF, K, Begin), SectionName(Section), Type(type), 59 Flags(flags), UniqueID(UniqueID), EntrySize(entrySize), Group(group), 60 Associated(Associated) { 61 if (Group) 62 Group->setIsSignature(); 63 } 64 65 void setSectionName(StringRef Name) { SectionName = Name; } 66 67 public: 68 ~MCSectionELF(); 69 70 /// Decides whether a '.section' directive should be printed before the 71 /// section name 72 bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const; 73 74 StringRef getSectionName() const { return SectionName; } 75 unsigned getType() const { return Type; } 76 unsigned getFlags() const { return Flags; } 77 unsigned getEntrySize() const { return EntrySize; } 78 void setFlags(unsigned F) { Flags = F; } 79 const MCSymbolELF *getGroup() const { return Group; } 80 81 void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS, 82 const MCExpr *Subsection) const override; 83 bool UseCodeAlign() const override; 84 bool isVirtualSection() const override; 85 86 bool isUnique() const { return UniqueID != ~0U; } 87 unsigned getUniqueID() const { return UniqueID; } 88 89 const MCSectionELF *getAssociatedSection() const { return Associated; } 90 91 static bool classof(const MCSection *S) { 92 return S->getVariant() == SV_ELF; 93 } 94 }; 95 96 } // end namespace llvm 97 98 #endif 99
