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