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 /// 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: AP(A)36 DIEHash(AsmPrinter *A = nullptr) : AP(A) {} 37 38 /// Computes the CU signature. 39 uint64_t computeCUSignature(StringRef DWOName, const DIE &Die); 40 41 /// Computes the type signature. 42 uint64_t computeTypeSignature(const DIE &Die); 43 44 // Helper routines to process parts of a DIE. 45 private: 46 /// Adds the parent context of \param Parent to the hash. 47 void addParentContext(const DIE &Parent); 48 49 /// Adds the attributes of \param Die to the hash. 50 void addAttributes(const DIE &Die); 51 52 /// 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 /// Adds \param Value to the hash. update(uint8_t Value)58 void update(uint8_t Value) { Hash.update(Value); } 59 60 /// Encodes and adds \param Value to the hash as a ULEB128. 61 void addULEB128(uint64_t Value); 62 63 /// Encodes and adds \param Value to the hash as a SLEB128. 64 void addSLEB128(int64_t Value); 65 66 private: 67 /// Adds \param Str to the hash and includes a NULL byte. 68 void addString(StringRef Str); 69 70 /// Collects the attributes of DIE \param Die into the \param Attrs 71 /// structure. 72 void collectAttributes(const DIE &Die, DIEAttrs &Attrs); 73 74 /// Hashes the attributes in \param Attrs in order. 75 void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag); 76 77 /// 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 /// Hashes the contents pointed to in the .debug_loc section. 82 void hashLocList(const DIELocList &LocList); 83 84 /// Hashes an individual attribute. 85 void hashAttribute(const DIEValue &Value, dwarf::Tag Tag); 86 87 /// Hashes an attribute that refers to another DIE. 88 void hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag, 89 const DIE &Entry); 90 91 /// 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 /// 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; 106 DenseMap<const DIE *, unsigned> Numbering; 107 }; 108 } 109 110 #endif 111