1 //===- MCSection.h - 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 MCSection class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_MC_MCSECTION_H 15 #define LLVM_MC_MCSECTION_H 16 17 #include "llvm/MC/SectionKind.h" 18 #include "llvm/Support/Casting.h" 19 20 namespace llvm { 21 class MCAsmInfo; 22 class raw_ostream; 23 24 /// MCSection - Instances of this class represent a uniqued identifier for a 25 /// section in the current translation unit. The MCContext class uniques and 26 /// creates these. 27 class MCSection { 28 public: 29 enum SectionVariant { 30 SV_COFF = 0, 31 SV_ELF, 32 SV_MachO, 33 SV_LDContext 34 }; 35 36 private: 37 MCSection(const MCSection&); // DO NOT IMPLEMENT 38 void operator=(const MCSection&); // DO NOT IMPLEMENT 39 protected: 40 MCSection(SectionVariant V, SectionKind K) : Variant(V), Kind(K) {} 41 SectionVariant Variant; 42 SectionKind Kind; 43 public: 44 virtual ~MCSection(); 45 46 SectionKind getKind() const { return Kind; } 47 48 SectionVariant getVariant() const { return Variant; } 49 50 virtual void PrintSwitchToSection(const MCAsmInfo &MAI, 51 raw_ostream &OS) const = 0; 52 53 /// isBaseAddressKnownZero - Return true if we know that this section will 54 /// get a base address of zero. In cases where we know that this is true we 55 /// can emit section offsets as direct references to avoid a subtraction 56 /// from the base of the section, saving a relocation. 57 virtual bool isBaseAddressKnownZero() const { 58 return false; 59 } 60 61 // UseCodeAlign - Return true if a .align directive should use 62 // "optimized nops" to fill instead of 0s. 63 virtual bool UseCodeAlign() const = 0; 64 65 /// isVirtualSection - Check whether this section is "virtual", that is 66 /// has no actual object file contents. 67 virtual bool isVirtualSection() const = 0; 68 69 static bool classof(const MCSection *) { return true; } 70 }; 71 72 } // end namespace llvm 73 74 #endif 75
