LLVM  16.0.0git
MCSection.h
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1 //===- MCSection.h - Machine Code Sections ----------------------*- 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 // This file declares the MCSection class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_MC_MCSECTION_H
14 #define LLVM_MC_MCSECTION_H
15 
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/ADT/ilist.h"
18 #include "llvm/MC/MCFragment.h"
19 #include "llvm/MC/SectionKind.h"
20 #include "llvm/Support/Alignment.h"
21 #include <cassert>
22 #include <utility>
23 
24 namespace llvm {
25 
26 class MCAsmInfo;
27 class MCContext;
28 class MCExpr;
29 class MCSymbol;
30 class raw_ostream;
31 class Triple;
32 
33 template <> struct ilist_alloc_traits<MCFragment> {
34  static void deleteNode(MCFragment *V);
35 };
36 
37 /// Instances of this class represent a uniqued identifier for a section in the
38 /// current translation unit. The MCContext class uniques and creates these.
39 class MCSection {
40 public:
41  static constexpr unsigned NonUniqueID = ~0U;
42 
44  SV_COFF = 0,
52  };
53 
54  /// Express the state of bundle locked groups while emitting code.
59  };
60 
62 
65 
68 
69 private:
70  MCSymbol *Begin;
71  MCSymbol *End = nullptr;
72  /// The alignment requirement of this section.
73  Align Alignment;
74  /// The section index in the assemblers section list.
75  unsigned Ordinal = 0;
76  /// The index of this section in the layout order.
77  unsigned LayoutOrder;
78 
79  /// Keeping track of bundle-locked state.
80  BundleLockStateType BundleLockState = NotBundleLocked;
81 
82  /// Current nesting depth of bundle_lock directives.
83  unsigned BundleLockNestingDepth = 0;
84 
85  /// We've seen a bundle_lock directive but not its first instruction
86  /// yet.
87  bool BundleGroupBeforeFirstInst : 1;
88 
89  /// Whether this section has had instructions emitted into it.
90  bool HasInstructions : 1;
91 
92  bool IsRegistered : 1;
93 
94  MCDummyFragment DummyFragment;
95 
96  FragmentListType Fragments;
97 
98  /// Mapping from subsection number to insertion point for subsection numbers
99  /// below that number.
100  SmallVector<std::pair<unsigned, MCFragment *>, 1> SubsectionFragmentMap;
101 
102  /// State for tracking labels that don't yet have Fragments
103  struct PendingLabel {
104  MCSymbol* Sym;
105  unsigned Subsection;
106  PendingLabel(MCSymbol* Sym, unsigned Subsection = 0)
107  : Sym(Sym), Subsection(Subsection) {}
108  };
109  SmallVector<PendingLabel, 2> PendingLabels;
110 
111 protected:
112  // TODO Make Name private when possible.
116 
118  ~MCSection();
119 
120 public:
121  MCSection(const MCSection &) = delete;
122  MCSection &operator=(const MCSection &) = delete;
123 
124  StringRef getName() const { return Name; }
125  SectionKind getKind() const { return Kind; }
126 
127  SectionVariant getVariant() const { return Variant; }
128 
129  MCSymbol *getBeginSymbol() { return Begin; }
130  const MCSymbol *getBeginSymbol() const {
131  return const_cast<MCSection *>(this)->getBeginSymbol();
132  }
134  assert(!Begin);
135  Begin = Sym;
136  }
138  bool hasEnded() const;
139 
140  unsigned getAlignment() const { return Alignment.value(); }
141  void setAlignment(Align Value) { Alignment = Value; }
142 
143  unsigned getOrdinal() const { return Ordinal; }
144  void setOrdinal(unsigned Value) { Ordinal = Value; }
145 
146  unsigned getLayoutOrder() const { return LayoutOrder; }
147  void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }
148 
149  BundleLockStateType getBundleLockState() const { return BundleLockState; }
151  bool isBundleLocked() const { return BundleLockState != NotBundleLocked; }
152 
154  return BundleGroupBeforeFirstInst;
155  }
156  void setBundleGroupBeforeFirstInst(bool IsFirst) {
157  BundleGroupBeforeFirstInst = IsFirst;
158  }
159 
160  bool hasInstructions() const { return HasInstructions; }
161  void setHasInstructions(bool Value) { HasInstructions = Value; }
162 
163  bool isRegistered() const { return IsRegistered; }
164  void setIsRegistered(bool Value) { IsRegistered = Value; }
165 
168  return const_cast<MCSection *>(this)->getFragmentList();
169  }
170 
171  /// Support for MCFragment::getNextNode().
173  return &MCSection::Fragments;
174  }
175 
176  const MCDummyFragment &getDummyFragment() const { return DummyFragment; }
177  MCDummyFragment &getDummyFragment() { return DummyFragment; }
178 
179  iterator begin() { return Fragments.begin(); }
180  const_iterator begin() const { return Fragments.begin(); }
181 
182  iterator end() { return Fragments.end(); }
183  const_iterator end() const { return Fragments.end(); }
184 
186 
187  void dump() const;
188 
189  virtual void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
190  raw_ostream &OS,
191  const MCExpr *Subsection) const = 0;
192 
193  /// Return true if a .align directive should use "optimized nops" to fill
194  /// instead of 0s.
195  virtual bool useCodeAlign() const = 0;
196 
197  /// Check whether this section is "virtual", that is has no actual object
198  /// file contents.
199  virtual bool isVirtualSection() const = 0;
200 
201  virtual StringRef getVirtualSectionKind() const;
202 
203  /// Add a pending label for the requested subsection. This label will be
204  /// associated with a fragment in flushPendingLabels()
205  void addPendingLabel(MCSymbol* label, unsigned Subsection = 0);
206 
207  /// Associate all pending labels in a subsection with a fragment.
208  void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0,
209  unsigned Subsection = 0);
210 
211  /// Associate all pending labels with empty data fragments. One fragment
212  /// will be created for each subsection as necessary.
213  void flushPendingLabels();
214 };
215 
216 } // end namespace llvm
217 
218 #endif // LLVM_MC_MCSECTION_H
llvm::MCSection::isBundleLocked
bool isBundleLocked() const
Definition: MCSection.h:151
llvm::MCSection::Name
StringRef Name
Definition: MCSection.h:113
llvm::MCSection::setIsRegistered
void setIsRegistered(bool Value)
Definition: MCSection.h:164
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::MCSection::SV_COFF
@ SV_COFF
Definition: MCSection.h:44
llvm::MCSymbol
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
llvm::MCSection::printSwitchToSection
virtual void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T, raw_ostream &OS, const MCExpr *Subsection) const =0
llvm::MCSection::setBundleLockState
void setBundleLockState(BundleLockStateType NewState)
Definition: MCSection.cpp:39
llvm::MCContext
Context object for machine code objects.
Definition: MCContext.h:76
llvm::MCSection::addPendingLabel
void addPendingLabel(MCSymbol *label, unsigned Subsection=0)
Add a pending label for the requested subsection.
Definition: MCSection.cpp:91
llvm::MCSection::SV_XCOFF
@ SV_XCOFF
Definition: MCSection.h:49
llvm::MCAsmInfo
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:56
llvm::MCSection::getDummyFragment
MCDummyFragment & getDummyFragment()
Definition: MCSection.h:177
llvm::MCSection::getBeginSymbol
MCSymbol * getBeginSymbol()
Definition: MCSection.h:129
llvm::SmallVector
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1182
ilist.h
llvm::MCSection::SV_MachO
@ SV_MachO
Definition: MCSection.h:47
llvm::MCSection::dump
void dump() const
Definition: MCSection.cpp:127
llvm::MCSection::getLayoutOrder
unsigned getLayoutOrder() const
Definition: MCSection.h:146
llvm::MCSection::getSublistAccess
static FragmentListType MCSection::* getSublistAccess(MCFragment *)
Support for MCFragment::getNextNode().
Definition: MCSection.h:172
MCFragment.h
llvm::Triple
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
llvm::iplist_impl< simple_ilist< MCFragment, Options... >, ilist_traits< MCFragment > >::const_reverse_iterator
base_list_type::const_reverse_iterator const_reverse_iterator
Definition: ilist.h:182
llvm::MCSection::getBundleLockState
BundleLockStateType getBundleLockState() const
Definition: MCSection.h:149
llvm::MCSection::getSubsectionInsertionPoint
MCSection::iterator getSubsectionInsertionPoint(unsigned Subsection)
Definition: MCSection.cpp:59
llvm::MCSection::MCSection
MCSection(SectionVariant V, StringRef Name, SectionKind K, MCSymbol *Begin)
Definition: MCSection.cpp:23
llvm::MCSection::setBundleGroupBeforeFirstInst
void setBundleGroupBeforeFirstInst(bool IsFirst)
Definition: MCSection.h:156
llvm::iplist< MCFragment >
llvm::MCSection::getFragmentList
MCSection::FragmentListType & getFragmentList()
Definition: MCSection.h:166
F
#define F(x, y, z)
Definition: MD5.cpp:55
llvm::MCSection::end
iterator end()
Definition: MCSection.h:182
llvm::MCFragment
Definition: MCFragment.h:30
llvm::MCDummyFragment
Definition: MCFragment.h:114
llvm::MCSection::setLayoutOrder
void setLayoutOrder(unsigned Value)
Definition: MCSection.h:147
llvm::MCSection::hasEnded
bool hasEnded() const
Definition: MCSection.cpp:35
llvm::MCSection::Variant
SectionVariant Variant
Definition: MCSection.h:114
llvm::raw_ostream
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
llvm::MCSection::end
const_iterator end() const
Definition: MCSection.h:183
llvm::MCSection::getFragmentList
const MCSection::FragmentListType & getFragmentList() const
Definition: MCSection.h:167
llvm::Align
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
llvm::MCSection::getVariant
SectionVariant getVariant() const
Definition: MCSection.h:127
llvm::MCSection::getEndSymbol
MCSymbol * getEndSymbol(MCContext &Ctx)
Definition: MCSection.cpp:29
llvm::iplist_impl< simple_ilist< MCFragment, Options... >, ilist_traits< MCFragment > >::reverse_iterator
base_list_type::reverse_iterator reverse_iterator
Definition: ilist.h:180
llvm::MCSection::BundleLockedAlignToEnd
@ BundleLockedAlignToEnd
Definition: MCSection.h:58
llvm::MCSection::~MCSection
~MCSection()
uint64_t
llvm::iplist_impl< simple_ilist< MCFragment, Options... >, ilist_traits< MCFragment > >::iterator
base_list_type::iterator iterator
Definition: ilist.h:178
llvm::MCSection::operator=
MCSection & operator=(const MCSection &)=delete
llvm::ilist_alloc_traits
Use delete by default for iplist and ilist.
Definition: ilist.h:41
llvm::MCSection::NonUniqueID
static constexpr unsigned NonUniqueID
Definition: MCSection.h:41
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::MCSection::getVirtualSectionKind
virtual StringRef getVirtualSectionKind() const
Definition: MCSection.cpp:89
llvm::MCSection::BundleLockStateType
BundleLockStateType
Express the state of bundle locked groups while emitting code.
Definition: MCSection.h:55
llvm::MCSection::setHasInstructions
void setHasInstructions(bool Value)
Definition: MCSection.h:161
llvm::MCSection::getAlignment
unsigned getAlignment() const
Definition: MCSection.h:140
llvm::MCSection::getDummyFragment
const MCDummyFragment & getDummyFragment() const
Definition: MCSection.h:176
llvm::StringRef
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
llvm::MCSection::isVirtualSection
virtual bool isVirtualSection() const =0
Check whether this section is "virtual", that is has no actual object file contents.
llvm::MCSection
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:39
llvm::MCSection::SV_GOFF
@ SV_GOFF
Definition: MCSection.h:46
llvm::MCSection::SV_ELF
@ SV_ELF
Definition: MCSection.h:45
llvm::MCSection::getName
StringRef getName() const
Definition: MCSection.h:124
llvm::MCSection::BundleLocked
@ BundleLocked
Definition: MCSection.h:57
llvm::MCSection::setAlignment
void setAlignment(Align Value)
Definition: MCSection.h:141
llvm::MCSection::isBundleGroupBeforeFirstInst
bool isBundleGroupBeforeFirstInst() const
Definition: MCSection.h:153
Alignment.h
llvm::MCSection::SectionVariant
SectionVariant
Definition: MCSection.h:43
llvm::SectionKind
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:22
llvm::MCSection::useCodeAlign
virtual bool useCodeAlign() const =0
Return true if a .align directive should use "optimized nops" to fill instead of 0s.
llvm::MCSection::hasInstructions
bool hasInstructions() const
Definition: MCSection.h:160
llvm::ilist_iterator
Iterator for intrusive lists based on ilist_node.
Definition: ilist_iterator.h:57
llvm::Align::value
uint64_t value() const
This is a hole in the type system and should not be abused.
Definition: Alignment.h:85
llvm::MCSection::flushPendingLabels
void flushPendingLabels()
Associate all pending labels with empty data fragments.
Definition: MCSection.cpp:112
llvm::MCSection::getBeginSymbol
const MCSymbol * getBeginSymbol() const
Definition: MCSection.h:130
llvm::TargetStackID::Value
Value
Definition: TargetFrameLowering.h:27
llvm::MCSection::setBeginSymbol
void setBeginSymbol(MCSymbol *Sym)
Definition: MCSection.h:133
llvm::MCSection::NotBundleLocked
@ NotBundleLocked
Definition: MCSection.h:56
llvm::MCSection::isRegistered
bool isRegistered() const
Definition: MCSection.h:163
SectionKind.h
llvm::MCSection::SV_DXContainer
@ SV_DXContainer
Definition: MCSection.h:51
llvm::MCSection::getKind
SectionKind getKind() const
Definition: MCSection.h:125
llvm::MCSection::begin
iterator begin()
Definition: MCSection.h:179
llvm::MCSection::SV_SPIRV
@ SV_SPIRV
Definition: MCSection.h:50
llvm::MCSection::begin
const_iterator begin() const
Definition: MCSection.h:180
SmallVector.h
llvm::MCSection::Kind
SectionKind Kind
Definition: MCSection.h:115
llvm::ilist_alloc_traits::deleteNode
static void deleteNode(NodeTy *V)
Definition: ilist.h:42
llvm::iplist_impl< simple_ilist< MCFragment, Options... >, ilist_traits< MCFragment > >::const_iterator
base_list_type::const_iterator const_iterator
Definition: ilist.h:179
llvm::MCSection::SV_Wasm
@ SV_Wasm
Definition: MCSection.h:48
llvm::MCSection::getOrdinal
unsigned getOrdinal() const
Definition: MCSection.h:143
llvm::Value
LLVM Value Representation.
Definition: Value.h:74
llvm::MCExpr
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
llvm::ISD::MCSymbol
@ MCSymbol
Definition: ISDOpcodes.h:172
llvm::MCSection::setOrdinal
void setOrdinal(unsigned Value)
Definition: MCSection.h:144