MCSection.h revision ed84062812c7b8a82d0e8128a22aa1aa07a14d79
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/Compiler.h" 19 20namespace 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 }; 34 35 private: 36 MCSection(const MCSection&) LLVM_DELETED_FUNCTION; 37 void operator=(const MCSection&) LLVM_DELETED_FUNCTION; 38 protected: 39 MCSection(SectionVariant V, SectionKind K) : Variant(V), Kind(K) {} 40 SectionVariant Variant; 41 SectionKind Kind; 42 public: 43 virtual ~MCSection(); 44 45 SectionKind getKind() const { return Kind; } 46 47 SectionVariant getVariant() const { return Variant; } 48 49 virtual void PrintSwitchToSection(const MCAsmInfo &MAI, 50 raw_ostream &OS) const = 0; 51 52 /// isBaseAddressKnownZero - Return true if we know that this section will 53 /// get a base address of zero. In cases where we know that this is true we 54 /// can emit section offsets as direct references to avoid a subtraction 55 /// from the base of the section, saving a relocation. 56 virtual bool isBaseAddressKnownZero() const { 57 return false; 58 } 59 60 // UseCodeAlign - Return true if a .align directive should use 61 // "optimized nops" to fill instead of 0s. 62 virtual bool UseCodeAlign() const = 0; 63 64 /// isVirtualSection - Check whether this section is "virtual", that is 65 /// has no actual object file contents. 66 virtual bool isVirtualSection() const = 0; 67 }; 68 69} // end namespace llvm 70 71#endif 72