| //===- MCAsmLayout.h - Assembly Layout Object -------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_MC_MCASMLAYOUT_H |
| #define LLVM_MC_MCASMLAYOUT_H |
| |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/SmallVector.h" |
| |
| namespace llvm { |
| class MCAssembler; |
| class MCFragment; |
| class MCSectionData; |
| class MCSymbol; |
| class MCSymbolData; |
| |
| /// Encapsulates the layout of an assembly file at a particular point in time. |
| /// |
| /// Assembly may require computing multiple layouts for a particular assembly |
| /// file as part of the relaxation process. This class encapsulates the layout |
| /// at a single point in time in such a way that it is always possible to |
| /// efficiently compute the exact address of any symbol in the assembly file, |
| /// even during the relaxation process. |
| class MCAsmLayout { |
| public: |
| typedef llvm::SmallVectorImpl<MCSectionData*>::const_iterator const_iterator; |
| typedef llvm::SmallVectorImpl<MCSectionData*>::iterator iterator; |
| |
| private: |
| MCAssembler &Assembler; |
| |
| /// List of sections in layout order. |
| llvm::SmallVector<MCSectionData*, 16> SectionOrder; |
| |
| /// The last fragment which was laid out, or 0 if nothing has been laid |
| /// out. Fragments are always laid out in order, so all fragments with a |
| /// lower ordinal will be valid. |
| mutable DenseMap<const MCSectionData*, MCFragment*> LastValidFragment; |
| |
| /// \brief Make sure that the layout for the given fragment is valid, lazily |
| /// computing it if necessary. |
| void ensureValid(const MCFragment *F) const; |
| |
| /// \brief Is the layout for this fragment valid? |
| bool isFragmentValid(const MCFragment *F) const; |
| |
| /// \brief Compute the amount of padding required before this fragment to |
| /// obey bundling restrictions. |
| uint64_t computeBundlePadding(const MCFragment *F, |
| uint64_t FOffset, uint64_t FSize); |
| |
| public: |
| MCAsmLayout(MCAssembler &_Assembler); |
| |
| /// Get the assembler object this is a layout for. |
| MCAssembler &getAssembler() const { return Assembler; } |
| |
| /// \brief Invalidate the fragments starting with F because it has been |
| /// resized. The fragment's size should have already been updated, but |
| /// its bundle padding will be recomputed. |
| void invalidateFragmentsFrom(MCFragment *F); |
| |
| /// \brief Perform layout for a single fragment, assuming that the previous |
| /// fragment has already been laid out correctly, and the parent section has |
| /// been initialized. |
| void layoutFragment(MCFragment *Fragment); |
| |
| /// @name Section Access (in layout order) |
| /// @{ |
| |
| llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() { |
| return SectionOrder; |
| } |
| const llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() const { |
| return SectionOrder; |
| } |
| |
| /// @} |
| /// @name Fragment Layout Data |
| /// @{ |
| |
| /// \brief Get the offset of the given fragment inside its containing section. |
| uint64_t getFragmentOffset(const MCFragment *F) const; |
| |
| /// @} |
| /// @name Utility Functions |
| /// @{ |
| |
| /// \brief Get the address space size of the given section, as it effects |
| /// layout. This may differ from the size reported by \see getSectionSize() by |
| /// not including section tail padding. |
| uint64_t getSectionAddressSize(const MCSectionData *SD) const; |
| |
| /// \brief Get the data size of the given section, as emitted to the object |
| /// file. This may include additional padding, or be 0 for virtual sections. |
| uint64_t getSectionFileSize(const MCSectionData *SD) const; |
| |
| /// \brief Get the offset of the given symbol, as computed in the current |
| /// layout. |
| /// \result True on success. |
| bool getSymbolOffset(const MCSymbolData *SD, uint64_t &Val) const; |
| |
| /// \brief Variant that reports a fatal error if the offset is not computable. |
| uint64_t getSymbolOffset(const MCSymbolData *SD) const; |
| |
| /// \brief If this symbol is equivalent to A + Constant, return A. |
| const MCSymbol *getBaseSymbol(const MCSymbol &Symbol) const; |
| |
| /// @} |
| }; |
| |
| } // end namespace llvm |
| |
| #endif |