1 //===---------- IssueHash.cpp - Generate identification hashes --*- 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "clang/Analysis/IssueHash.h" 10 #include "clang/AST/ASTContext.h" 11 #include "clang/AST/Decl.h" 12 #include "clang/AST/DeclCXX.h" 13 #include "clang/Basic/SourceManager.h" 14 #include "clang/Basic/Specifiers.h" 15 #include "clang/Lex/Lexer.h" 16 #include "llvm/ADT/StringExtras.h" 17 #include "llvm/ADT/StringRef.h" 18 #include "llvm/ADT/Twine.h" 19 #include "llvm/Support/LineIterator.h" 20 #include "llvm/Support/MD5.h" 21 #include "llvm/Support/Path.h" 22 23 #include <functional> 24 #include <sstream> 25 #include <string> 26 27 using namespace clang; 28 29 // Get a string representation of the parts of the signature that can be 30 // overloaded on. 31 static std::string GetSignature(const FunctionDecl *Target) { 32 if (!Target) 33 return ""; 34 std::string Signature; 35 36 // When a flow sensitive bug happens in templated code we should not generate 37 // distinct hash value for every instantiation. Use the signature from the 38 // primary template. 39 if (const FunctionDecl *InstantiatedFrom = 40 Target->getTemplateInstantiationPattern()) 41 Target = InstantiatedFrom; 42 43 if (!isa<CXXConstructorDecl>(Target) && !isa<CXXDestructorDecl>(Target) && 44 !isa<CXXConversionDecl>(Target)) 45 Signature.append(Target->getReturnType().getAsString()).append(" "); 46 Signature.append(Target->getQualifiedNameAsString()).append("("); 47 48 for (int i = 0, paramsCount = Target->getNumParams(); i < paramsCount; ++i) { 49 if (i) 50 Signature.append(", "); 51 Signature.append(Target->getParamDecl(i)->getType().getAsString()); 52 } 53 54 if (Target->isVariadic()) 55 Signature.append(", ..."); 56 Signature.append(")"); 57 58 const auto *TargetT = 59 llvm::dyn_cast_or_null<FunctionType>(Target->getType().getTypePtr()); 60 61 if (!TargetT || !isa<CXXMethodDecl>(Target)) 62 return Signature; 63 64 if (TargetT->isConst()) 65 Signature.append(" const"); 66 if (TargetT->isVolatile()) 67 Signature.append(" volatile"); 68 if (TargetT->isRestrict()) 69 Signature.append(" restrict"); 70 71 if (const auto *TargetPT = 72 dyn_cast_or_null<FunctionProtoType>(Target->getType().getTypePtr())) { 73 switch (TargetPT->getRefQualifier()) { 74 case RQ_LValue: 75 Signature.append(" &"); 76 break; 77 case RQ_RValue: 78 Signature.append(" &&"); 79 break; 80 default: 81 break; 82 } 83 } 84 85 return Signature; 86 } 87 88 static std::string GetEnclosingDeclContextSignature(const Decl *D) { 89 if (!D) 90 return ""; 91 92 if (const auto *ND = dyn_cast<NamedDecl>(D)) { 93 std::string DeclName; 94 95 switch (ND->getKind()) { 96 case Decl::Namespace: 97 case Decl::Record: 98 case Decl::CXXRecord: 99 case Decl::Enum: 100 DeclName = ND->getQualifiedNameAsString(); 101 break; 102 case Decl::CXXConstructor: 103 case Decl::CXXDestructor: 104 case Decl::CXXConversion: 105 case Decl::CXXMethod: 106 case Decl::Function: 107 DeclName = GetSignature(dyn_cast_or_null<FunctionDecl>(ND)); 108 break; 109 case Decl::ObjCMethod: 110 // ObjC Methods can not be overloaded, qualified name uniquely identifies 111 // the method. 112 DeclName = ND->getQualifiedNameAsString(); 113 break; 114 default: 115 break; 116 } 117 118 return DeclName; 119 } 120 121 return ""; 122 } 123 124 static StringRef GetNthLineOfFile(const llvm::MemoryBuffer *Buffer, int Line) { 125 if (!Buffer) 126 return ""; 127 128 llvm::line_iterator LI(*Buffer, false); 129 for (; !LI.is_at_eof() && LI.line_number() != Line; ++LI) 130 ; 131 132 return *LI; 133 } 134 135 static std::string NormalizeLine(const SourceManager &SM, const FullSourceLoc &L, 136 const LangOptions &LangOpts) { 137 static StringRef Whitespaces = " \t\n"; 138 139 StringRef Str = GetNthLineOfFile(SM.getBuffer(L.getFileID(), L), 140 L.getExpansionLineNumber()); 141 StringRef::size_type col = Str.find_first_not_of(Whitespaces); 142 if (col == StringRef::npos) 143 col = 1; // The line only contains whitespace. 144 else 145 col++; 146 SourceLocation StartOfLine = 147 SM.translateLineCol(SM.getFileID(L), L.getExpansionLineNumber(), col); 148 const llvm::MemoryBuffer *Buffer = 149 SM.getBuffer(SM.getFileID(StartOfLine), StartOfLine); 150 if (!Buffer) 151 return {}; 152 153 const char *BufferPos = SM.getCharacterData(StartOfLine); 154 155 Token Token; 156 Lexer Lexer(SM.getLocForStartOfFile(SM.getFileID(StartOfLine)), LangOpts, 157 Buffer->getBufferStart(), BufferPos, Buffer->getBufferEnd()); 158 159 size_t NextStart = 0; 160 std::ostringstream LineBuff; 161 while (!Lexer.LexFromRawLexer(Token) && NextStart < 2) { 162 if (Token.isAtStartOfLine() && NextStart++ > 0) 163 continue; 164 LineBuff << std::string(SM.getCharacterData(Token.getLocation()), 165 Token.getLength()); 166 } 167 168 return LineBuff.str(); 169 } 170 171 static llvm::SmallString<32> GetMD5HashOfContent(StringRef Content) { 172 llvm::MD5 Hash; 173 llvm::MD5::MD5Result MD5Res; 174 SmallString<32> Res; 175 176 Hash.update(Content); 177 Hash.final(MD5Res); 178 llvm::MD5::stringifyResult(MD5Res, Res); 179 180 return Res; 181 } 182 183 std::string clang::getIssueString(const FullSourceLoc &IssueLoc, 184 StringRef CheckerName, 185 StringRef WarningMessage, 186 const Decl *IssueDecl, 187 const LangOptions &LangOpts) { 188 static StringRef Delimiter = "$"; 189 190 return (llvm::Twine(CheckerName) + Delimiter + 191 GetEnclosingDeclContextSignature(IssueDecl) + Delimiter + 192 Twine(IssueLoc.getExpansionColumnNumber()) + Delimiter + 193 NormalizeLine(IssueLoc.getManager(), IssueLoc, LangOpts) + 194 Delimiter + WarningMessage) 195 .str(); 196 } 197 198 SmallString<32> clang::getIssueHash(const FullSourceLoc &IssueLoc, 199 StringRef CheckerName, 200 StringRef WarningMessage, 201 const Decl *IssueDecl, 202 const LangOptions &LangOpts) { 203 204 return GetMD5HashOfContent(getIssueString( 205 IssueLoc, CheckerName, WarningMessage, IssueDecl, LangOpts)); 206 } 207