DIEHash.h revision 15f387c93ef8d5c23f110143996c8b9b4a089864 
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#include "llvm/Support/MD5.h"
15
16namespace llvm {
17
18class CompileUnit;
19
20/// \brief An object containing the capability of hashing and adding hash
21/// attributes onto a DIE.
22class LLVM_LIBRARY_VISIBILITY DIEHash {
23  // The entry for a particular attribute.
24  struct AttrEntry {
25    const DIEValue *Val;
26    const DIEAbbrevData *Desc;
27  };
28
29  // Collection of all attributes used in hashing a particular DIE.
30  struct DIEAttrs {
31    AttrEntry DW_AT_name;
32    AttrEntry DW_AT_accessibility;
33    AttrEntry DW_AT_address_class;
34    AttrEntry DW_AT_allocated;
35    AttrEntry DW_AT_artificial;
36    AttrEntry DW_AT_associated;
37    AttrEntry DW_AT_binary_scale;
38    AttrEntry DW_AT_bit_offset;
39    AttrEntry DW_AT_bit_size;
40    AttrEntry DW_AT_bit_stride;
41    AttrEntry DW_AT_byte_size;
42    AttrEntry DW_AT_byte_stride;
43    AttrEntry DW_AT_const_expr;
44    AttrEntry DW_AT_const_value;
45    AttrEntry DW_AT_containing_type;
46    AttrEntry DW_AT_count;
47    AttrEntry DW_AT_data_bit_offset;
48    AttrEntry DW_AT_data_location;
49    AttrEntry DW_AT_data_member_location;
50    AttrEntry DW_AT_decimal_scale;
51    AttrEntry DW_AT_decimal_sign;
52    AttrEntry DW_AT_default_value;
53    AttrEntry DW_AT_digit_count;
54    AttrEntry DW_AT_discr;
55    AttrEntry DW_AT_discr_list;
56    AttrEntry DW_AT_discr_value;
57    AttrEntry DW_AT_encoding;
58    AttrEntry DW_AT_enum_class;
59    AttrEntry DW_AT_endianity;
60    AttrEntry DW_AT_explicit;
61    AttrEntry DW_AT_is_optional;
62    AttrEntry DW_AT_location;
63    AttrEntry DW_AT_lower_bound;
64    AttrEntry DW_AT_mutable;
65    AttrEntry DW_AT_ordering;
66    AttrEntry DW_AT_picture_string;
67    AttrEntry DW_AT_prototyped;
68    AttrEntry DW_AT_small;
69    AttrEntry DW_AT_segment;
70    AttrEntry DW_AT_string_length;
71    AttrEntry DW_AT_threads_scaled;
72    AttrEntry DW_AT_upper_bound;
73    AttrEntry DW_AT_use_location;
74    AttrEntry DW_AT_use_UTF8;
75    AttrEntry DW_AT_variable_parameter;
76    AttrEntry DW_AT_virtuality;
77    AttrEntry DW_AT_visibility;
78    AttrEntry DW_AT_vtable_elem_location;
79
80    // Insert any additional ones here...
81  };
82
83public:
84  /// \brief Computes the ODR signature.
85  uint64_t computeDIEODRSignature(DIE *Die);
86
87  /// \brief Computes the CU signature.
88  uint64_t computeCUSignature(DIE *Die);
89
90  /// \brief Computes the type signature.
91  uint64_t computeTypeSignature(DIE *Die);
92
93  // Helper routines to process parts of a DIE.
94private:
95  /// \brief Adds the parent context of \param Die to the hash.
96  void addParentContext(DIE *Die);
97
98  /// \brief Adds the attributes of \param Die to the hash.
99  void addAttributes(DIE *Die);
100
101  /// \brief Computes the full DWARF4 7.27 hash of the DIE.
102  void computeHash(DIE *Die);
103
104  // Routines that add DIEValues to the hash.
105private:
106  /// \brief Encodes and adds \param Value to the hash as a ULEB128.
107  void addULEB128(uint64_t Value);
108
109  /// \brief Adds \param Str to the hash and includes a NULL byte.
110  void addString(StringRef Str);
111
112  /// \brief Collects the attributes of DIE \param Die into the \param Attrs
113  /// structure.
114  void collectAttributes(DIE *Die, DIEAttrs &Attrs);
115
116  /// \brief Hashes the attributes in \param Attrs in order.
117  void hashAttributes(const DIEAttrs &Attrs);
118
119  /// \brief Hashes an individual attribute.
120  void hashAttribute(AttrEntry Attr);
121
122private:
123  MD5 Hash;
124};
125}
126