LLVM 19.0.0git
MCAsmLayout.h
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1//===- MCAsmLayout.h - Assembly Layout Object -------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLVM_MC_MCASMLAYOUT_H
10#define LLVM_MC_MCASMLAYOUT_H
11
12#include "llvm/ADT/DenseMap.h"
14
15namespace llvm {
16class MCAssembler;
17class MCFragment;
18class MCSection;
19class MCSymbol;
20
21/// Encapsulates the layout of an assembly file at a particular point in time.
22///
23/// Assembly may require computing 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 address of any symbol in the assembly file,
27/// even during the relaxation process.
29 MCAssembler &Assembler;
30
31 /// List of sections in layout order.
33
34 /// The last fragment which was laid out, or 0 if nothing has been laid
35 /// out. Fragments are always laid out in order, so all fragments with a
36 /// lower ordinal will be valid.
37 mutable DenseMap<const MCSection *, MCFragment *> LastValidFragment;
38
39 /// Make sure that the layout for the given fragment is valid, lazily
40 /// computing it if necessary.
41 void ensureValid(const MCFragment *F) const;
42
43 /// Is the layout for this fragment valid?
44 bool isFragmentValid(const MCFragment *F) const;
45
46public:
47 MCAsmLayout(MCAssembler &Assembler);
48
49 /// Get the assembler object this is a layout for.
50 MCAssembler &getAssembler() const { return Assembler; }
51
52 /// \returns whether the offset of fragment \p F can be obtained via
53 /// getFragmentOffset.
54 bool canGetFragmentOffset(const MCFragment *F) const;
55
56 /// Invalidate the fragments starting with F because it has been
57 /// resized. The fragment's size should have already been updated, but
58 /// its bundle padding will be recomputed.
60
61 /// Perform layout for a single fragment, assuming that the previous
62 /// fragment has already been laid out correctly, and the parent section has
63 /// been initialized.
64 void layoutFragment(MCFragment *Fragment);
65
66 /// \name Section Access (in layout order)
67 /// @{
68
71 return SectionOrder;
72 }
73
74 /// @}
75 /// \name Fragment Layout Data
76 /// @{
77
78 /// Get the offset of the given fragment inside its containing section.
80
81 /// @}
82 /// \name Utility Functions
83 /// @{
84
85 /// Get the address space size of the given section, as it effects
86 /// layout. This may differ from the size reported by \see
87 /// getSectionFileSize() by not including section tail padding.
89
90 /// Get the data size of the given section, as emitted to the object
91 /// file. This may include additional padding, or be 0 for virtual sections.
92 uint64_t getSectionFileSize(const MCSection *Sec) const;
93
94 /// Get the offset of the given symbol, as computed in the current
95 /// layout.
96 /// \return True on success.
97 bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const;
98
99 /// Variant that reports a fatal error if the offset is not computable.
100 uint64_t getSymbolOffset(const MCSymbol &S) const;
101
102 /// If this symbol is equivalent to A + Constant, return A.
103 const MCSymbol *getBaseSymbol(const MCSymbol &Symbol) const;
104
105 /// @}
106};
107
108} // end namespace llvm
109
110#endif
This file defines the DenseMap class.
#define F(x, y, z)
Definition: MD5.cpp:55
This file defines the SmallVector class.
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:28
void invalidateFragmentsFrom(MCFragment *F)
Invalidate the fragments starting with F because it has been resized.
Definition: MCFragment.cpp:70
const MCSymbol * getBaseSymbol(const MCSymbol &Symbol) const
If this symbol is equivalent to A + Constant, return A.
Definition: MCFragment.cpp:162
uint64_t getSectionAddressSize(const MCSection *Sec) const
Get the address space size of the given section, as it effects layout.
Definition: MCFragment.cpp:198
llvm::SmallVectorImpl< MCSection * > & getSectionOrder()
Definition: MCAsmLayout.h:69
uint64_t getSectionFileSize(const MCSection *Sec) const
Get the data size of the given section, as emitted to the object file.
Definition: MCFragment.cpp:204
bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const
Get the offset of the given symbol, as computed in the current layout.
Definition: MCFragment.cpp:152
void layoutFragment(MCFragment *Fragment)
Perform layout for a single fragment, assuming that the previous fragment has already been laid out c...
uint64_t getFragmentOffset(const MCFragment *F) const
Get the offset of the given fragment inside its containing section.
Definition: MCFragment.cpp:96
const llvm::SmallVectorImpl< MCSection * > & getSectionOrder() const
Definition: MCAsmLayout.h:70
bool canGetFragmentOffset(const MCFragment *F) const
Definition: MCFragment.cpp:51
MCAssembler & getAssembler() const
Get the assembler object this is a layout for.
Definition: MCAsmLayout.h:50
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:39
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1209
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18