1 //===- MCAsmLayout.h - Assembly Layout Object -------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCASMLAYOUT_H
11 #define LLVM_MC_MCASMLAYOUT_H
13 #include "llvm/ADT/SmallVector.h"
21 /// Encapsulates the layout of an assembly file at a particular point in time.
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.
30 typedef llvm::SmallVectorImpl<MCSectionData*>::const_iterator const_iterator;
31 typedef llvm::SmallVectorImpl<MCSectionData*>::iterator iterator;
34 MCAssembler &Assembler;
36 /// List of sections in layout order.
37 llvm::SmallVector<MCSectionData*, 16> SectionOrder;
39 /// The last fragment which was laid out, or 0 if nothing has been laid
40 /// out. Fragments are always laid out in order, so all fragments with a
41 /// lower ordinal will be up to date.
42 mutable DenseMap<const MCSectionData*, MCFragment *> LastValidFragment;
44 /// \brief Make sure that the layout for the given fragment is valid, lazily
45 /// computing it if necessary.
46 void EnsureValid(const MCFragment *F) const;
48 bool isFragmentUpToDate(const MCFragment *F) const;
51 MCAsmLayout(MCAssembler &_Assembler);
53 /// Get the assembler object this is a layout for.
54 MCAssembler &getAssembler() const { return Assembler; }
56 /// \brief Invalidate all following fragments because a fragment has been
57 /// resized. The fragments size should have already been updated.
58 void Invalidate(MCFragment *F);
60 /// \brief Perform layout for a single fragment, assuming that the previous
61 /// fragment has already been laid out correctly, and the parent section has
63 void LayoutFragment(MCFragment *Fragment);
65 /// @name Section Access (in layout order)
68 llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() {
71 const llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() const {
76 /// @name Fragment Layout Data
79 /// \brief Get the offset of the given fragment inside its containing section.
80 uint64_t getFragmentOffset(const MCFragment *F) const;
83 /// @name Utility Functions
86 /// \brief Get the address space size of the given section, as it effects
87 /// layout. This may differ from the size reported by \see getSectionSize() by
88 /// not including section tail padding.
89 uint64_t getSectionAddressSize(const MCSectionData *SD) const;
91 /// \brief Get the data size of the given section, as emitted to the object
92 /// file. This may include additional padding, or be 0 for virtual sections.
93 uint64_t getSectionFileSize(const MCSectionData *SD) const;
95 /// \brief Get the offset of the given symbol, as computed in the current
97 uint64_t getSymbolOffset(const MCSymbolData *SD) const;
102 } // end namespace llvm