LLVM  6.0.0svn
DIEHash.h
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1 //===-- llvm/CodeGen/DIEHash.h - Dwarf Hashing Framework -------*- 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 // This file contains support for DWARF4 hashing of DIEs.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DIEHASH_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_DIEHASH_H
16 
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/CodeGen/DIE.h"
19 #include "llvm/Support/MD5.h"
20 
21 namespace llvm {
22 
23 class AsmPrinter;
24 class CompileUnit;
25 
26 /// \brief An object containing the capability of hashing and adding hash
27 /// attributes onto a DIE.
28 class DIEHash {
29  // Collection of all attributes used in hashing a particular DIE.
30  struct DIEAttrs {
31 #define HANDLE_DIE_HASH_ATTR(NAME) DIEValue NAME;
32 #include "DIEHashAttributes.def"
33  };
34 
35 public:
36  DIEHash(AsmPrinter *A = nullptr) : AP(A) {}
37 
38  /// \brief Computes the CU signature.
39  uint64_t computeCUSignature(StringRef DWOName, const DIE &Die);
40 
41  /// \brief Computes the type signature.
42  uint64_t computeTypeSignature(const DIE &Die);
43 
44  // Helper routines to process parts of a DIE.
45 private:
46  /// \brief Adds the parent context of \param Die to the hash.
47  void addParentContext(const DIE &Die);
48 
49  /// \brief Adds the attributes of \param Die to the hash.
50  void addAttributes(const DIE &Die);
51 
52  /// \brief Computes the full DWARF4 7.27 hash of the DIE.
53  void computeHash(const DIE &Die);
54 
55  // Routines that add DIEValues to the hash.
56 public:
57  /// \brief Adds \param Value to the hash.
58  void update(uint8_t Value) { Hash.update(Value); }
59 
60  /// \brief Encodes and adds \param Value to the hash as a ULEB128.
61  void addULEB128(uint64_t Value);
62 
63  /// \brief Encodes and adds \param Value to the hash as a SLEB128.
64  void addSLEB128(int64_t Value);
65 
66 private:
67  /// \brief Adds \param Str to the hash and includes a NULL byte.
68  void addString(StringRef Str);
69 
70  /// \brief Collects the attributes of DIE \param Die into the \param Attrs
71  /// structure.
72  void collectAttributes(const DIE &Die, DIEAttrs &Attrs);
73 
74  /// \brief Hashes the attributes in \param Attrs in order.
75  void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag);
76 
77  /// \brief Hashes the data in a block like DIEValue, e.g. DW_FORM_block or
78  /// DW_FORM_exprloc.
79  void hashBlockData(const DIE::const_value_range &Values);
80 
81  /// \brief Hashes the contents pointed to in the .debug_loc section.
82  void hashLocList(const DIELocList &LocList);
83 
84  /// \brief Hashes an individual attribute.
85  void hashAttribute(const DIEValue &Value, dwarf::Tag Tag);
86 
87  /// \brief Hashes an attribute that refers to another DIE.
88  void hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag,
89  const DIE &Entry);
90 
91  /// \brief Hashes a reference to a named type in such a way that is
92  /// independent of whether that type is described by a declaration or a
93  /// definition.
94  void hashShallowTypeReference(dwarf::Attribute Attribute, const DIE &Entry,
95  StringRef Name);
96 
97  /// \brief Hashes a reference to a previously referenced type DIE.
98  void hashRepeatedTypeReference(dwarf::Attribute Attribute,
99  unsigned DieNumber);
100 
101  void hashNestedType(const DIE &Die, StringRef Name);
102 
103 private:
104  MD5 Hash;
105  AsmPrinter *AP;
107 };
108 }
109 
110 #endif
Global Value Numbering
Definition: NewGVN.cpp:4228
An object containing the capability of hashing and adding hash attributes onto a DIE.
Definition: DIEHash.h:28
DIEHash(AsmPrinter *A=nullptr)
Definition: DIEHash.h:36
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
Attribute
Attributes.
Definition: Dwarf.h:107
void addULEB128(uint64_t Value)
Encodes and adds.
Definition: DIEHash.cpp:55
Represents a pointer to a location list in the debug_loc section.
Definition: DIE.h:312
uint64_t computeCUSignature(StringRef DWOName, const DIE &Die)
Computes the CU signature.
Definition: DIEHash.cpp:383
uint64_t computeTypeSignature(const DIE &Die)
Computes the type signature.
Definition: DIEHash.cpp:406
constexpr char Attrs[]
Key for Kernel::Metadata::mAttrs.
A structured debug information entry.
Definition: DIE.h:662
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:77
A range adaptor for a pair of iterators.
void update(uint8_t Value)
Adds.
Definition: DIEHash.h:58
void addSLEB128(int64_t Value)
Encodes and adds.
Definition: DIEHash.cpp:66
Definition: MD5.h:41
LLVM Value Representation.
Definition: Value.h:73
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49