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/MC/MCSection.h" 18 #include "llvm/Support/ELF.h" 19 #include "llvm/ADT/StringRef.h" 20 21 namespace llvm { 22 23 class MCSymbol; 24 25 /// MCSectionELF - This represents a section on linux, lots of unix variants 26 /// and some bare metal systems. 27 class MCSectionELF : public MCSection { 28 /// SectionName - This is the name of the section. The referenced memory is 29 /// owned by TargetLoweringObjectFileELF's ELFUniqueMap. 30 StringRef SectionName; 31 32 /// Type - This is the sh_type field of a section, drawn from the enums below. 33 unsigned Type; 34 35 /// Flags - This is the sh_flags field of a section, drawn from the enums. 36 /// below. 37 unsigned Flags; 38 39 /// EntrySize - The size of each entry in this section. This size only 40 /// makes sense for sections that contain fixed-sized entries. If a 41 /// section does not contain fixed-sized entries 'EntrySize' will be 0. 42 unsigned EntrySize; 43 44 const MCSymbol *Group; 45 46 private: 47 friend class MCContext; MCSectionELF(StringRef Section,unsigned type,unsigned flags,SectionKind K,unsigned entrySize,const MCSymbol * group)48 MCSectionELF(StringRef Section, unsigned type, unsigned flags, 49 SectionKind K, unsigned entrySize, const MCSymbol *group) 50 : MCSection(SV_ELF, K), SectionName(Section), Type(type), Flags(flags), 51 EntrySize(entrySize), Group(group) {} 52 ~MCSectionELF(); 53 public: 54 55 /// ShouldOmitSectionDirective - Decides whether a '.section' directive 56 /// should be printed before the section name 57 bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const; 58 getSectionName()59 StringRef getSectionName() const { return SectionName; } getType()60 unsigned getType() const { return Type; } getFlags()61 unsigned getFlags() const { return Flags; } getEntrySize()62 unsigned getEntrySize() const { return EntrySize; } getGroup()63 const MCSymbol *getGroup() const { return Group; } 64 65 void PrintSwitchToSection(const MCAsmInfo &MAI, 66 raw_ostream &OS) const; 67 virtual bool UseCodeAlign() const; 68 virtual bool isVirtualSection() const; 69 70 /// isBaseAddressKnownZero - We know that non-allocatable sections (like 71 /// debug info) have a base of zero. isBaseAddressKnownZero()72 virtual bool isBaseAddressKnownZero() const { 73 return (getFlags() & ELF::SHF_ALLOC) == 0; 74 } 75 classof(const MCSection * S)76 static bool classof(const MCSection *S) { 77 return S->getVariant() == SV_ELF; 78 } classof(const MCSectionELF *)79 static bool classof(const MCSectionELF *) { return true; } 80 81 // Return the entry size for sections with fixed-width data. 82 static unsigned DetermineEntrySize(SectionKind Kind); 83 84 }; 85 86 } // end namespace llvm 87 88 #endif 89