DIEHash.h revision 261991
168349Sobrien//===-- llvm/CodeGen/DIEHash.h - Dwarf Hashing Framework -------*- C++ -*--===// 268349Sobrien// 368349Sobrien// The LLVM Compiler Infrastructure 468349Sobrien// 568349Sobrien// This file is distributed under the University of Illinois Open Source 668349Sobrien// License. See LICENSE.TXT for details. 768349Sobrien// 868349Sobrien//===----------------------------------------------------------------------===// 968349Sobrien// 1068349Sobrien// This file contains support for DWARF4 hashing of DIEs. 11103373Sobrien// 12103373Sobrien//===----------------------------------------------------------------------===// 13103373Sobrien 14103373Sobrien#include "DIE.h" 15103373Sobrien#include "llvm/ADT/DenseMap.h" 16103373Sobrien#include "llvm/Support/MD5.h" 17103373Sobrien 18103373Sobriennamespace llvm { 19103373Sobrien 20class CompileUnit; 21 22/// \brief An object containing the capability of hashing and adding hash 23/// attributes onto a DIE. 24class DIEHash { 25 // The entry for a particular attribute. 26 struct AttrEntry { 27 const DIEValue *Val; 28 const DIEAbbrevData *Desc; 29 }; 30 31 // Collection of all attributes used in hashing a particular DIE. 32 struct DIEAttrs { 33 AttrEntry DW_AT_name; 34 AttrEntry DW_AT_accessibility; 35 AttrEntry DW_AT_address_class; 36 AttrEntry DW_AT_allocated; 37 AttrEntry DW_AT_artificial; 38 AttrEntry DW_AT_associated; 39 AttrEntry DW_AT_binary_scale; 40 AttrEntry DW_AT_bit_offset; 41 AttrEntry DW_AT_bit_size; 42 AttrEntry DW_AT_bit_stride; 43 AttrEntry DW_AT_byte_size; 44 AttrEntry DW_AT_byte_stride; 45 AttrEntry DW_AT_const_expr; 46 AttrEntry DW_AT_const_value; 47 AttrEntry DW_AT_containing_type; 48 AttrEntry DW_AT_count; 49 AttrEntry DW_AT_data_bit_offset; 50 AttrEntry DW_AT_data_location; 51 AttrEntry DW_AT_data_member_location; 52 AttrEntry DW_AT_decimal_scale; 53 AttrEntry DW_AT_decimal_sign; 54 AttrEntry DW_AT_default_value; 55 AttrEntry DW_AT_digit_count; 56 AttrEntry DW_AT_discr; 57 AttrEntry DW_AT_discr_list; 58 AttrEntry DW_AT_discr_value; 59 AttrEntry DW_AT_encoding; 60 AttrEntry DW_AT_enum_class; 61 AttrEntry DW_AT_endianity; 62 AttrEntry DW_AT_explicit; 63 AttrEntry DW_AT_is_optional; 64 AttrEntry DW_AT_location; 65 AttrEntry DW_AT_lower_bound; 66 AttrEntry DW_AT_mutable; 67 AttrEntry DW_AT_ordering; 68 AttrEntry DW_AT_picture_string; 69 AttrEntry DW_AT_prototyped; 70 AttrEntry DW_AT_small; 71 AttrEntry DW_AT_segment; 72 AttrEntry DW_AT_string_length; 73 AttrEntry DW_AT_threads_scaled; 74 AttrEntry DW_AT_upper_bound; 75 AttrEntry DW_AT_use_location; 76 AttrEntry DW_AT_use_UTF8; 77 AttrEntry DW_AT_variable_parameter; 78 AttrEntry DW_AT_virtuality; 79 AttrEntry DW_AT_visibility; 80 AttrEntry DW_AT_vtable_elem_location; 81 AttrEntry DW_AT_type; 82 83 // Insert any additional ones here... 84 }; 85 86public: 87 /// \brief Computes the ODR signature. 88 uint64_t computeDIEODRSignature(const DIE &Die); 89 90 /// \brief Computes the CU signature. 91 uint64_t computeCUSignature(const DIE &Die); 92 93 /// \brief Computes the type signature. 94 uint64_t computeTypeSignature(const DIE &Die); 95 96 // Helper routines to process parts of a DIE. 97private: 98 /// \brief Adds the parent context of \param Die to the hash. 99 void addParentContext(const DIE &Die); 100 101 /// \brief Adds the attributes of \param Die to the hash. 102 void addAttributes(const DIE &Die); 103 104 /// \brief Computes the full DWARF4 7.27 hash of the DIE. 105 void computeHash(const DIE &Die); 106 107 // Routines that add DIEValues to the hash. 108private: 109 /// \brief Encodes and adds \param Value to the hash as a ULEB128. 110 void addULEB128(uint64_t Value); 111 112 /// \brief Encodes and adds \param Value to the hash as a SLEB128. 113 void addSLEB128(int64_t Value); 114 115 /// \brief Adds \param Str to the hash and includes a NULL byte. 116 void addString(StringRef Str); 117 118 /// \brief Collects the attributes of DIE \param Die into the \param Attrs 119 /// structure. 120 void collectAttributes(const DIE &Die, DIEAttrs &Attrs); 121 122 /// \brief Hashes the attributes in \param Attrs in order. 123 void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag); 124 125 /// \brief Hashes an individual attribute. 126 void hashAttribute(AttrEntry Attr, dwarf::Tag Tag); 127 128 /// \brief Hashes an attribute that refers to another DIE. 129 void hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag, 130 const DIE &Entry); 131 132 /// \brief Hashes a reference to a named type in such a way that is 133 /// independent of whether that type is described by a declaration or a 134 /// definition. 135 void hashShallowTypeReference(dwarf::Attribute Attribute, const DIE &Entry, 136 StringRef Name); 137 138 /// \brief Hashes a reference to a previously referenced type DIE. 139 void hashRepeatedTypeReference(dwarf::Attribute Attribute, unsigned DieNumber); 140 141 void hashNestedType(const DIE &Die, StringRef Name); 142 143private: 144 MD5 Hash; 145 DenseMap<const DIE *, unsigned> Numbering; 146}; 147} 148