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 /// 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 MCSymbolELF *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 MCSymbolELF * group,unsigned UniqueID,MCSymbol * Begin,const MCSectionELF * Associated)56 MCSectionELF(StringRef Section, unsigned type, unsigned flags, SectionKind K, 57 unsigned entrySize, const MCSymbolELF *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 if (Group) 63 Group->setIsSignature(); 64 } 65 ~MCSectionELF() override; 66 setSectionName(StringRef Name)67 void setSectionName(StringRef Name) { SectionName = Name; } 68 69 public: 70 71 /// ShouldOmitSectionDirective - Decides whether a '.section' directive 72 /// should be printed before the section name 73 bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const; 74 getSectionName()75 StringRef getSectionName() const { return SectionName; } getType()76 unsigned getType() const { return Type; } getFlags()77 unsigned getFlags() const { return Flags; } getEntrySize()78 unsigned getEntrySize() const { return EntrySize; } getGroup()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 isUnique()86 bool isUnique() const { return UniqueID != ~0U; } getUniqueID()87 unsigned getUniqueID() const { return UniqueID; } 88 getAssociatedSection()89 const MCSectionELF *getAssociatedSection() const { return Associated; } 90 classof(const MCSection * S)91 static bool classof(const MCSection *S) { 92 return S->getVariant() == SV_ELF; 93 } 94 }; 95 96 } // end namespace llvm 97 98 #endif 99