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/StringRef.h" 18#include "llvm/MC/MCSection.h" 19#include "llvm/Support/Debug.h" 20#include "llvm/Support/ELF.h" 21#include "llvm/Support/raw_ostream.h" 22 23namespace llvm { 24 25class MCSymbol; 26 27/// MCSectionELF - This represents a section on linux, lots of unix variants 28/// and some bare metal systems. 29class MCSectionELF : public MCSection { 30 /// SectionName - This is the name of the section. The referenced memory is 31 /// owned by TargetLoweringObjectFileELF's ELFUniqueMap. 32 StringRef SectionName; 33 34 /// Type - This is the sh_type field of a section, drawn from the enums below. 35 unsigned Type; 36 37 /// Flags - This is the sh_flags field of a section, drawn from the enums. 38 /// below. 39 unsigned Flags; 40 41 /// EntrySize - The size of each entry in this section. This size only 42 /// makes sense for sections that contain fixed-sized entries. If a 43 /// section does not contain fixed-sized entries 'EntrySize' will be 0. 44 unsigned EntrySize; 45 46 const MCSymbol *Group; 47 48private: 49 friend class MCContext; 50 MCSectionELF(StringRef Section, unsigned type, unsigned flags, 51 SectionKind K, unsigned entrySize, const MCSymbol *group) 52 : MCSection(SV_ELF, K), SectionName(Section), Type(type), Flags(flags), 53 EntrySize(entrySize), Group(group) {} 54 ~MCSectionELF(); 55public: 56 57 /// ShouldOmitSectionDirective - Decides whether a '.section' directive 58 /// should be printed before the section name 59 bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const; 60 61 StringRef getSectionName() const { return SectionName; } 62 virtual std::string getLabelBeginName() const { 63 return SectionName.str() + "_begin"; } 64 virtual std::string getLabelEndName() const { 65 return SectionName.str() + "_end"; 66 } 67 unsigned getType() const { return Type; } 68 unsigned getFlags() const { return Flags; } 69 unsigned getEntrySize() const { return EntrySize; } 70 const MCSymbol *getGroup() const { return Group; } 71 72 void PrintSwitchToSection(const MCAsmInfo &MAI, 73 raw_ostream &OS, 74 const MCExpr *Subsection) const; 75 virtual bool UseCodeAlign() const; 76 virtual bool isVirtualSection() const; 77 78 /// isBaseAddressKnownZero - We know that non-allocatable sections (like 79 /// debug info) have a base of zero. 80 virtual bool isBaseAddressKnownZero() const { 81 return (getFlags() & ELF::SHF_ALLOC) == 0; 82 } 83 84 static bool classof(const MCSection *S) { 85 return S->getVariant() == SV_ELF; 86 } 87 88 // Return the entry size for sections with fixed-width data. 89 static unsigned DetermineEntrySize(SectionKind Kind); 90 91}; 92 93} // end namespace llvm 94 95#endif 96