MCAsmLayout.h revision b69fc044db8c193348b6611f46432bb21b3cbe90
1//===- MCAsmLayout.h - Assembly Layout Object -------------------*- 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#ifndef LLVM_MC_MCASMLAYOUT_H 11#define LLVM_MC_MCASMLAYOUT_H 12 13#include "llvm/ADT/SmallVector.h" 14 15namespace llvm { 16class MCAssembler; 17class MCFragment; 18class MCSectionData; 19class MCSymbolData; 20 21/// Encapsulates the layout of an assembly file at a particular point in time. 22/// 23/// Assembly may requiring compute multiple layouts for a particular assembly 24/// file as part of the relaxation process. This class encapsulates the layout 25/// at a single point in time in such a way that it is always possible to 26/// efficiently compute the exact addresses of any symbol in the assembly file, 27/// even during the relaxation process. 28class MCAsmLayout { 29public: 30 typedef llvm::SmallVectorImpl<MCSectionData*>::const_iterator const_iterator; 31 typedef llvm::SmallVectorImpl<MCSectionData*>::iterator iterator; 32 33private: 34 MCAssembler &Assembler; 35 36 /// List of sections in layout order. 37 llvm::SmallVector<MCSectionData*, 16> SectionOrder; 38 39public: 40 MCAsmLayout(MCAssembler &_Assembler); 41 42 /// Get the assembler object this is a layout for. 43 MCAssembler &getAssembler() const { return Assembler; } 44 45 /// \brief Update the layout because a fragment has been resized. The 46 /// fragments size should have already been updated, the \arg SlideAmount is 47 /// the delta from the old size. 48 void UpdateForSlide(MCFragment *F, int SlideAmount); 49 50 /// \brief Update the layout because a fragment has been replaced. 51 void FragmentReplaced(MCFragment *Src, MCFragment *Dst); 52 53 /// \brief Perform a full layout. 54 void LayoutFile(); 55 56 /// \brief Perform layout for a single fragment, assuming that the previous 57 /// fragment has already been layed out correctly, and the parent section has 58 /// been initialized. 59 void LayoutFragment(MCFragment *Fragment); 60 61 /// \brief Performs layout for a single section, assuming that the previous 62 /// section has already been layed out correctly. 63 void LayoutSection(MCSectionData *SD); 64 65 /// @name Section Access (in layout order) 66 /// @{ 67 68 llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() { 69 return SectionOrder; 70 } 71 const llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() const { 72 return SectionOrder; 73 } 74 75 /// @} 76 /// @name Fragment Layout Data 77 /// @{ 78 79 /// \brief Get the effective size of the given fragment, as computed in the 80 /// current layout. 81 uint64_t getFragmentEffectiveSize(const MCFragment *F) const; 82 83 /// \brief Set the effective size of the given fragment. 84 void setFragmentEffectiveSize(MCFragment *F, uint64_t Value); 85 86 /// \brief Get the offset of the given fragment inside its containing section. 87 uint64_t getFragmentOffset(const MCFragment *F) const; 88 89 /// \brief Set the offset of the given fragment inside its containing section. 90 void setFragmentOffset(MCFragment *F, uint64_t Value); 91 92 /// @} 93 /// @name Section Layout Data 94 /// @{ 95 96 /// \brief Get the computed address of the given section. 97 uint64_t getSectionAddress(const MCSectionData *SD) const; 98 99 /// \brief Set the computed address of the given section. 100 void setSectionAddress(MCSectionData *SD, uint64_t Value); 101 102 /// @} 103 /// @name Utility Functions 104 /// @{ 105 106 /// \brief Get the address of the given fragment, as computed in the current 107 /// layout. 108 uint64_t getFragmentAddress(const MCFragment *F) const; 109 110 /// \brief Get the address space size of the given section, as it effects 111 /// layout. This may differ from the size reported by \see getSectionSize() by 112 /// not including section tail padding. 113 uint64_t getSectionAddressSize(const MCSectionData *SD) const; 114 115 /// \brief Get the data size of the given section, as emitted to the object 116 /// file. This may include additional padding, or be 0 for virtual sections. 117 uint64_t getSectionFileSize(const MCSectionData *SD) const; 118 119 /// \brief Get the logical data size of the given section. 120 uint64_t getSectionSize(const MCSectionData *SD) const; 121 122 /// \brief Get the address of the given symbol, as computed in the current 123 /// layout. 124 uint64_t getSymbolAddress(const MCSymbolData *SD) const; 125 126 /// @} 127}; 128 129} // end namespace llvm 130 131#endif 132