MCAsmLayout.h revision d13a0caf726e05c9bd939d752ef371d6d467ef28 
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  /// @name Section Access (in layout order)
51  /// @{
52
53  llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() {
54    return SectionOrder;
55  }
56  const llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() const {
57    return SectionOrder;
58  }
59
60  /// @}
61  /// @name Fragment Layout Data
62  /// @{
63
64  /// \brief Get the effective size of the given fragment, as computed in the
65  /// current layout.
66  uint64_t getFragmentEffectiveSize(const MCFragment *F) const;
67
68  /// \brief Set the effective size of the given fragment.
69  void setFragmentEffectiveSize(MCFragment *F, uint64_t Value);
70
71  /// \brief Get the offset of the given fragment inside its containing section.
72  uint64_t getFragmentOffset(const MCFragment *F) const;
73
74  /// \brief Set the offset of the given fragment inside its containing section.
75  void setFragmentOffset(MCFragment *F, uint64_t Value);
76
77  /// @}
78  /// @name Section Layout Data
79  /// @{
80
81  /// \brief Get the computed address of the given section.
82  uint64_t getSectionAddress(const MCSectionData *SD) const;
83
84  /// \brief Set the computed address of the given section.
85  void setSectionAddress(MCSectionData *SD, uint64_t Value);
86
87  /// \brief Get the data size of the given section, as emitted to the object
88  /// file. This may include additional padding, or be 0 for virtual sections.
89  uint64_t getSectionFileSize(const MCSectionData *SD) const;
90
91  /// \brief Set the data size of the given section.
92  void setSectionFileSize(MCSectionData *SD, uint64_t Value);
93
94  /// \brief Get the actual data size of the given section.
95  uint64_t getSectionSize(const MCSectionData *SD) const;
96
97  /// \brief Set the actual data size of the given section.
98  void setSectionSize(MCSectionData *SD, uint64_t Value);
99
100  /// @}
101  /// @name Utility Functions
102  /// @{
103
104  /// \brief Get the address of the given fragment, as computed in the current
105  /// layout.
106  uint64_t getFragmentAddress(const MCFragment *F) const;
107
108  /// \brief Get the address of the given symbol, as computed in the current
109  /// layout.
110  uint64_t getSymbolAddress(const MCSymbolData *SD) const;
111
112  /// @}
113};
114
115} // end namespace llvm
116
117#endif
118