LLVM  13.0.0git
DWARFAbbreviationDeclaration.h
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1 //===- DWARFAbbreviationDeclaration.h ---------------------------*- 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_DEBUGINFO_DWARF_DWARFABBREVIATIONDECLARATION_H
10 #define LLVM_DEBUGINFO_DWARF_DWARFABBREVIATIONDECLARATION_H
11 
12 #include "llvm/ADT/Optional.h"
13 #include "llvm/ADT/SmallVector.h"
17 #include <cassert>
18 #include <cstddef>
19 #include <cstdint>
20 
21 namespace llvm {
22 
23 class DWARFFormValue;
24 class DWARFUnit;
25 class raw_ostream;
26 
28 public:
29  struct AttributeSpec {
31  : Attr(A), Form(F), Value(Value) {
33  }
35  : Attr(A), Form(F) {
37  this->ByteSize.HasByteSize = ByteSize.hasValue();
38  if (this->ByteSize.HasByteSize)
39  this->ByteSize.ByteSize = *ByteSize;
40  }
41 
44 
45  private:
46  /// The following field is used for ByteSize for non-implicit_const
47  /// attributes and as value for implicit_const ones, indicated by
48  /// Form == DW_FORM_implicit_const.
49  /// The following cases are distinguished:
50  /// * Form != DW_FORM_implicit_const and HasByteSize is true:
51  /// ByteSize contains the fixed size in bytes for the Form in this
52  /// object.
53  /// * Form != DW_FORM_implicit_const and HasByteSize is false:
54  /// byte size of Form either varies according to the DWARFUnit
55  /// that it is contained in or the value size varies and must be
56  /// decoded from the debug information in order to determine its size.
57  /// * Form == DW_FORM_implicit_const:
58  /// Value contains value for the implicit_const attribute.
59  struct ByteSizeStorage {
60  bool HasByteSize;
61  uint8_t ByteSize;
62  };
63  union {
64  ByteSizeStorage ByteSize;
65  int64_t Value;
66  };
67 
68  public:
69  bool isImplicitConst() const {
70  return Form == dwarf::DW_FORM_implicit_const;
71  }
72 
73  int64_t getImplicitConstValue() const {
75  return Value;
76  }
77 
78  /// Get the fixed byte size of this Form if possible. This function might
79  /// use the DWARFUnit to calculate the size of the Form, like for
80  /// DW_AT_address and DW_AT_ref_addr, so this isn't just an accessor for
81  /// the ByteSize member.
82  Optional<int64_t> getByteSize(const DWARFUnit &U) const;
83  };
85 
87 
88  uint32_t getCode() const { return Code; }
89  uint8_t getCodeByteSize() const { return CodeByteSize; }
90  dwarf::Tag getTag() const { return Tag; }
91  bool hasChildren() const { return HasChildren; }
92 
93  using attr_iterator_range =
95 
97  return attr_iterator_range(AttributeSpecs.begin(), AttributeSpecs.end());
98  }
99 
101  assert(idx < AttributeSpecs.size());
102  return AttributeSpecs[idx].Form;
103  }
104 
105  size_t getNumAttributes() const {
106  return AttributeSpecs.size();
107  }
108 
110  assert(idx < AttributeSpecs.size());
111  return AttributeSpecs[idx].Attr;
112  }
113 
115  assert(idx < AttributeSpecs.size());
116  return AttributeSpecs[idx].isImplicitConst();
117  }
118 
120  assert(idx < AttributeSpecs.size());
121  return AttributeSpecs[idx].getImplicitConstValue();
122  }
123 
124  /// Get the index of the specified attribute.
125  ///
126  /// Searches the this abbreviation declaration for the index of the specified
127  /// attribute.
128  ///
129  /// \param attr DWARF attribute to search for.
130  /// \returns Optional index of the attribute if found, None otherwise.
132 
133  /// Extract a DWARF form value from a DIE specified by DIE offset.
134  ///
135  /// Extract an attribute value for a DWARFUnit given the DIE offset and the
136  /// attribute.
137  ///
138  /// \param DIEOffset the DIE offset that points to the ULEB128 abbreviation
139  /// code in the .debug_info data.
140  /// \param Attr DWARF attribute to search for.
141  /// \param U the DWARFUnit the contains the DIE.
142  /// \returns Optional DWARF form value if the attribute was extracted.
143  Optional<DWARFFormValue> getAttributeValue(const uint64_t DIEOffset,
144  const dwarf::Attribute Attr,
145  const DWARFUnit &U) const;
146 
147  bool extract(DataExtractor Data, uint64_t* OffsetPtr);
148  void dump(raw_ostream &OS) const;
149 
150  // Return an optional byte size of all attribute data in this abbreviation
151  // if a constant byte size can be calculated given a DWARFUnit. This allows
152  // DWARF parsing to be faster as many DWARF DIEs have a fixed byte size.
154 
155 private:
156  void clear();
157 
158  /// A helper structure that can quickly determine the size in bytes of an
159  /// abbreviation declaration.
160  struct FixedSizeInfo {
161  /// The fixed byte size for fixed size forms.
162  uint16_t NumBytes = 0;
163  /// Number of DW_FORM_address forms in this abbrevation declaration.
164  uint8_t NumAddrs = 0;
165  /// Number of DW_FORM_ref_addr forms in this abbrevation declaration.
166  uint8_t NumRefAddrs = 0;
167  /// Number of 4 byte in DWARF32 and 8 byte in DWARF64 forms.
168  uint8_t NumDwarfOffsets = 0;
169 
170  FixedSizeInfo() = default;
171 
172  /// Calculate the fixed size in bytes given a DWARFUnit.
173  ///
174  /// \param U the DWARFUnit to use when determing the byte size.
175  /// \returns the size in bytes for all attribute data in this abbreviation.
176  /// The returned size does not include bytes for the ULEB128 abbreviation
177  /// code
178  size_t getByteSize(const DWARFUnit &U) const;
179  };
180 
181  uint32_t Code;
182  dwarf::Tag Tag;
183  uint8_t CodeByteSize;
184  bool HasChildren;
185  AttributeSpecVector AttributeSpecs;
186  /// If this abbreviation has a fixed byte size then FixedAttributeSize member
187  /// variable below will have a value.
188  Optional<FixedSizeInfo> FixedAttributeSize;
189 };
190 
191 } // end namespace llvm
192 
193 #endif // LLVM_DEBUGINFO_DWARF_DWARFABBREVIATIONDECLARATION_H
llvm::DWARFAbbreviationDeclaration::getTag
dwarf::Tag getTag() const
Definition: DWARFAbbreviationDeclaration.h:90
llvm::DWARFAbbreviationDeclaration::getFixedAttributesByteSize
Optional< size_t > getFixedAttributesByteSize(const DWARFUnit &U) const
Definition: DWARFAbbreviationDeclaration.cpp:210
llvm
Definition: AllocatorList.h:23
Optional.h
llvm::DWARFAbbreviationDeclaration::dump
void dump(raw_ostream &OS) const
Definition: DWARFAbbreviationDeclaration.cpp:128
llvm::DWARFAbbreviationDeclaration::getFormByIndex
dwarf::Form getFormByIndex(uint32_t idx) const
Definition: DWARFAbbreviationDeclaration.h:100
llvm::DWARFAbbreviationDeclaration::AttributeSpec
Definition: DWARFAbbreviationDeclaration.h:29
llvm::SmallVector< AttributeSpec, 8 >
llvm::DWARFAbbreviationDeclaration::getCodeByteSize
uint8_t getCodeByteSize() const
Definition: DWARFAbbreviationDeclaration.h:89
llvm::dwarf::Form
Form
Definition: Dwarf.h:131
llvm::DWARFAbbreviationDeclaration::getAttrByIndex
dwarf::Attribute getAttrByIndex(uint32_t idx) const
Definition: DWARFAbbreviationDeclaration.h:109
llvm::DWARFAbbreviationDeclaration::AttributeSpec::getByteSize
Optional< int64_t > getByteSize(const DWARFUnit &U) const
Get the fixed byte size of this Form if possible.
Definition: DWARFAbbreviationDeclaration.cpp:197
llvm::Optional< uint8_t >
llvm::DWARFAbbreviationDeclaration::hasChildren
bool hasChildren() const
Definition: DWARFAbbreviationDeclaration.h:91
llvm::dwarf::Tag
Tag
Definition: Dwarf.h:104
llvm::Data
@ Data
Definition: SIMachineScheduler.h:56
llvm::dwarf::Attribute
Attribute
Attributes.
Definition: Dwarf.h:124
F
#define F(x, y, z)
Definition: MD5.cpp:56
llvm::DWARFAbbreviationDeclaration::getAttributeValue
Optional< DWARFFormValue > getAttributeValue(const uint64_t DIEOffset, const dwarf::Attribute Attr, const DWARFUnit &U) const
Extract a DWARF form value from a DIE specified by DIE offset.
Definition: DWARFAbbreviationDeclaration.cpp:150
llvm::DWARFAbbreviationDeclaration::AttributeSpec::AttributeSpec
AttributeSpec(dwarf::Attribute A, dwarf::Form F, int64_t Value)
Definition: DWARFAbbreviationDeclaration.h:30
llvm::DWARFAbbreviationDeclaration::AttributeSpec::Value
int64_t Value
Definition: DWARFAbbreviationDeclaration.h:65
llvm::DWARFAbbreviationDeclaration::AttributeSpec::Attr
dwarf::Attribute Attr
Definition: DWARFAbbreviationDeclaration.h:42
llvm::raw_ostream
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:50
llvm::DWARFAbbreviationDeclaration::extract
bool extract(DataExtractor Data, uint64_t *OffsetPtr)
Definition: DWARFAbbreviationDeclaration.cpp:40
llvm::DWARFAbbreviationDeclaration::AttributeSpecVector
SmallVector< AttributeSpec, 8 > AttributeSpecVector
Definition: DWARFAbbreviationDeclaration.h:84
llvm::DWARFAbbreviationDeclaration::AttributeSpec::Form
dwarf::Form Form
Definition: DWARFAbbreviationDeclaration.h:43
llvm::DWARFAbbreviationDeclaration::findAttributeIndex
Optional< uint32_t > findAttributeIndex(dwarf::Attribute attr) const
Get the index of the specified attribute.
Definition: DWARFAbbreviationDeclaration.cpp:142
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
iterator_range.h
llvm::DWARFAbbreviationDeclaration::AttributeSpec::getImplicitConstValue
int64_t getImplicitConstValue() const
Definition: DWARFAbbreviationDeclaration.h:73
llvm::DWARFAbbreviationDeclaration::attr_iterator_range
iterator_range< AttributeSpecVector::const_iterator > attr_iterator_range
Definition: DWARFAbbreviationDeclaration.h:94
llvm::DWARFAbbreviationDeclaration::getNumAttributes
size_t getNumAttributes() const
Definition: DWARFAbbreviationDeclaration.h:105
llvm::DWARFAbbreviationDeclaration::getAttrIsImplicitConstByIndex
bool getAttrIsImplicitConstByIndex(uint32_t idx) const
Definition: DWARFAbbreviationDeclaration.h:114
Dwarf.h
llvm::DWARFAbbreviationDeclaration::AttributeSpec::ByteSize
ByteSizeStorage ByteSize
Definition: DWARFAbbreviationDeclaration.h:64
uint32_t
llvm::DWARFAbbreviationDeclaration::AttributeSpec::isImplicitConst
bool isImplicitConst() const
Definition: DWARFAbbreviationDeclaration.h:69
uint16_t
llvm::DWARFAbbreviationDeclaration
Definition: DWARFAbbreviationDeclaration.h:27
llvm::DWARFUnit
Definition: DWARFUnit.h:203
DataExtractor.h
llvm::DWARFAbbreviationDeclaration::AttributeSpec::AttributeSpec
AttributeSpec(dwarf::Attribute A, dwarf::Form F, Optional< uint8_t > ByteSize)
Definition: DWARFAbbreviationDeclaration.h:34
llvm::DWARFAbbreviationDeclaration::getCode
uint32_t getCode() const
Definition: DWARFAbbreviationDeclaration.h:88
llvm::DWARFAbbreviationDeclaration::getAttrImplicitConstValueByIndex
int64_t getAttrImplicitConstValueByIndex(uint32_t idx) const
Definition: DWARFAbbreviationDeclaration.h:119
llvm::DataExtractor
Definition: DataExtractor.h:41
llvm::DWARFAbbreviationDeclaration::DWARFAbbreviationDeclaration
DWARFAbbreviationDeclaration()
Definition: DWARFAbbreviationDeclaration.cpp:35
SmallVector.h
llvm::iterator_range
A range adaptor for a pair of iterators.
Definition: iterator_range.h:30
llvm::Value
LLVM Value Representation.
Definition: Value.h:75
llvm::DWARFAbbreviationDeclaration::attributes
attr_iterator_range attributes() const
Definition: DWARFAbbreviationDeclaration.h:96