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