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 CODEGEN_ASMPRINTER_DIEHASH_H__ 15 #define CODEGEN_ASMPRINTER_DIEHASH_H__ 16 17 #include "DIE.h" 18 #include "llvm/ADT/DenseMap.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 30 // The entry for a particular attribute. 31 struct AttrEntry { 32 const DIEValue *Val; 33 const DIEAbbrevData *Desc; 34 }; 35 36 // Collection of all attributes used in hashing a particular DIE. 37 struct DIEAttrs { 38 AttrEntry DW_AT_name; 39 AttrEntry DW_AT_accessibility; 40 AttrEntry DW_AT_address_class; 41 AttrEntry DW_AT_allocated; 42 AttrEntry DW_AT_artificial; 43 AttrEntry DW_AT_associated; 44 AttrEntry DW_AT_binary_scale; 45 AttrEntry DW_AT_bit_offset; 46 AttrEntry DW_AT_bit_size; 47 AttrEntry DW_AT_bit_stride; 48 AttrEntry DW_AT_byte_size; 49 AttrEntry DW_AT_byte_stride; 50 AttrEntry DW_AT_const_expr; 51 AttrEntry DW_AT_const_value; 52 AttrEntry DW_AT_containing_type; 53 AttrEntry DW_AT_count; 54 AttrEntry DW_AT_data_bit_offset; 55 AttrEntry DW_AT_data_location; 56 AttrEntry DW_AT_data_member_location; 57 AttrEntry DW_AT_decimal_scale; 58 AttrEntry DW_AT_decimal_sign; 59 AttrEntry DW_AT_default_value; 60 AttrEntry DW_AT_digit_count; 61 AttrEntry DW_AT_discr; 62 AttrEntry DW_AT_discr_list; 63 AttrEntry DW_AT_discr_value; 64 AttrEntry DW_AT_encoding; 65 AttrEntry DW_AT_enum_class; 66 AttrEntry DW_AT_endianity; 67 AttrEntry DW_AT_explicit; 68 AttrEntry DW_AT_is_optional; 69 AttrEntry DW_AT_location; 70 AttrEntry DW_AT_lower_bound; 71 AttrEntry DW_AT_mutable; 72 AttrEntry DW_AT_ordering; 73 AttrEntry DW_AT_picture_string; 74 AttrEntry DW_AT_prototyped; 75 AttrEntry DW_AT_small; 76 AttrEntry DW_AT_segment; 77 AttrEntry DW_AT_string_length; 78 AttrEntry DW_AT_threads_scaled; 79 AttrEntry DW_AT_upper_bound; 80 AttrEntry DW_AT_use_location; 81 AttrEntry DW_AT_use_UTF8; 82 AttrEntry DW_AT_variable_parameter; 83 AttrEntry DW_AT_virtuality; 84 AttrEntry DW_AT_visibility; 85 AttrEntry DW_AT_vtable_elem_location; 86 AttrEntry DW_AT_type; 87 88 // Insert any additional ones here... 89 }; 90 91 public: 92 DIEHash(AsmPrinter *A = nullptr) : AP(A) {} 93 94 /// \brief Computes the ODR signature. 95 uint64_t computeDIEODRSignature(const DIE &Die); 96 97 /// \brief Computes the CU signature. 98 uint64_t computeCUSignature(const DIE &Die); 99 100 /// \brief Computes the type signature. 101 uint64_t computeTypeSignature(const DIE &Die); 102 103 // Helper routines to process parts of a DIE. 104 private: 105 /// \brief Adds the parent context of \param Die to the hash. 106 void addParentContext(const DIE &Die); 107 108 /// \brief Adds the attributes of \param Die to the hash. 109 void addAttributes(const DIE &Die); 110 111 /// \brief Computes the full DWARF4 7.27 hash of the DIE. 112 void computeHash(const DIE &Die); 113 114 // Routines that add DIEValues to the hash. 115 public: 116 /// \brief Adds \param Value to the hash. 117 void update(uint8_t Value) { Hash.update(Value); } 118 119 /// \brief Encodes and adds \param Value to the hash as a ULEB128. 120 void addULEB128(uint64_t Value); 121 122 /// \brief Encodes and adds \param Value to the hash as a SLEB128. 123 void addSLEB128(int64_t Value); 124 125 private: 126 /// \brief Adds \param Str to the hash and includes a NULL byte. 127 void addString(StringRef Str); 128 129 /// \brief Collects the attributes of DIE \param Die into the \param Attrs 130 /// structure. 131 void collectAttributes(const DIE &Die, DIEAttrs &Attrs); 132 133 /// \brief Hashes the attributes in \param Attrs in order. 134 void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag); 135 136 /// \brief Hashes the data in a block like DIEValue, e.g. DW_FORM_block or 137 /// DW_FORM_exprloc. 138 void hashBlockData(const SmallVectorImpl<DIEValue *> &Values); 139 140 /// \brief Hashes the contents pointed to in the .debug_loc section. 141 void hashLocList(const DIELocList &LocList); 142 143 /// \brief Hashes an individual attribute. 144 void hashAttribute(AttrEntry Attr, dwarf::Tag Tag); 145 146 /// \brief Hashes an attribute that refers to another DIE. 147 void hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag, 148 const DIE &Entry); 149 150 /// \brief Hashes a reference to a named type in such a way that is 151 /// independent of whether that type is described by a declaration or a 152 /// definition. 153 void hashShallowTypeReference(dwarf::Attribute Attribute, const DIE &Entry, 154 StringRef Name); 155 156 /// \brief Hashes a reference to a previously referenced type DIE. 157 void hashRepeatedTypeReference(dwarf::Attribute Attribute, 158 unsigned DieNumber); 159 160 void hashNestedType(const DIE &Die, StringRef Name); 161 162 private: 163 MD5 Hash; 164 AsmPrinter *AP; 165 DenseMap<const DIE *, unsigned> Numbering; 166 }; 167 } 168 169 #endif 170
