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1//===-- llvm/CodeGen/DIEHash.h - Dwarf Hashing Framework -------*- C++ -*--===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file contains support for DWARF4 hashing of DIEs.10//11//===----------------------------------------------------------------------===//12 13#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DIEHASH_H14#define LLVM_LIB_CODEGEN_ASMPRINTER_DIEHASH_H15 16#include "llvm/ADT/DenseMap.h"17#include "llvm/CodeGen/DIE.h"18#include "llvm/Support/Compiler.h"19#include "llvm/Support/MD5.h"20 21namespace llvm {22 23class AsmPrinter;24 25/// An object containing the capability of hashing and adding hash26/// attributes onto a DIE.27class DIEHash {28 // Collection of all attributes used in hashing a particular DIE.29 struct DIEAttrs {30#define HANDLE_DIE_HASH_ATTR(NAME) DIEValue NAME;31#include "DIEHashAttributes.def"32 };33 34public:35 DIEHash(AsmPrinter *A = nullptr, DwarfCompileUnit *CU = nullptr)36 : AP(A), CU(CU) {}37 38 /// Computes the CU signature.39 uint64_t computeCUSignature(StringRef DWOName, const DIE &Die);40 41 /// Computes the type signature.42 LLVM_ABI_FOR_TEST uint64_t computeTypeSignature(const DIE &Die);43 44 // Helper routines to process parts of a DIE.45private: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.56public:57 /// Adds \param Value to the hash.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 void hashRawTypeReference(const DIE &Entry);67 68private:69 /// Adds \param Str to the hash and includes a NULL byte.70 void addString(StringRef Str);71 72 /// Collects the attributes of DIE \param Die into the \param Attrs73 /// structure.74 void collectAttributes(const DIE &Die, DIEAttrs &Attrs);75 76 /// Hashes the attributes in \param Attrs in order.77 void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag);78 79 /// Hashes the data in a block like DIEValue, e.g. DW_FORM_block or80 /// DW_FORM_exprloc.81 void hashBlockData(const DIE::const_value_range &Values);82 83 /// Hashes the contents pointed to in the .debug_loc section.84 void hashLocList(const DIELocList &LocList);85 86 /// Hashes an individual attribute.87 void hashAttribute(const DIEValue &Value, dwarf::Tag Tag);88 89 /// Hashes an attribute that refers to another DIE.90 void hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag,91 const DIE &Entry);92 93 /// Hashes a reference to a named type in such a way that is94 /// independent of whether that type is described by a declaration or a95 /// definition.96 void hashShallowTypeReference(dwarf::Attribute Attribute, const DIE &Entry,97 StringRef Name);98 99 /// Hashes a reference to a previously referenced type DIE.100 void hashRepeatedTypeReference(dwarf::Attribute Attribute,101 unsigned DieNumber);102 103 void hashNestedType(const DIE &Die, StringRef Name);104 105private:106 MD5 Hash;107 AsmPrinter *AP;108 DwarfCompileUnit *CU;109 DenseMap<const DIE *, unsigned> Numbering;110};111}112 113#endif114