| //===- MCAsmLayout.h - Assembly Layout Object -------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #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 MCSection; |
| class MCSymbol; |
| |
| /// 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 { |
| MCAssembler &Assembler; |
| |
| /// List of sections in layout order. |
| llvm::SmallVector<MCSection *, 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 MCSection *, MCFragment *> LastValidFragment; |
| |
| /// Make sure that the layout for the given fragment is valid, lazily |
| /// computing it if necessary. |
| void ensureValid(const MCFragment *F) const; |
| |
| /// Is the layout for this fragment valid? |
| bool isFragmentValid(const MCFragment *F) const; |
| |
| public: |
| MCAsmLayout(MCAssembler &Assembler); |
| |
| /// Get the assembler object this is a layout for. |
| MCAssembler &getAssembler() const { return Assembler; } |
| |
| /// 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); |
| |
| /// 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<MCSection *> &getSectionOrder() { return SectionOrder; } |
| const llvm::SmallVectorImpl<MCSection *> &getSectionOrder() const { |
| return SectionOrder; |
| } |
| |
| /// @} |
| /// \name Fragment Layout Data |
| /// @{ |
| |
| /// Get the offset of the given fragment inside its containing section. |
| uint64_t getFragmentOffset(const MCFragment *F) const; |
| |
| /// @} |
| /// \name Utility Functions |
| /// @{ |
| |
| /// 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 MCSection *Sec) const; |
| |
| /// 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 MCSection *Sec) const; |
| |
| /// Get the offset of the given symbol, as computed in the current |
| /// layout. |
| /// \return True on success. |
| bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const; |
| |
| /// Variant that reports a fatal error if the offset is not computable. |
| uint64_t getSymbolOffset(const MCSymbol &S) const; |
| |
| /// If this symbol is equivalent to A + Constant, return A. |
| const MCSymbol *getBaseSymbol(const MCSymbol &Symbol) const; |
| |
| /// @} |
| }; |
| |
| } // end namespace llvm |
| |
| #endif |