1 //===-- SpecialCaseList.cpp - special case list for sanitizers ------------===// 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 // This is a utility class for instrumentation passes (like AddressSanitizer 10 // or ThreadSanitizer) to avoid instrumenting some functions or global 11 // variables, or to instrument some functions or global variables in a specific 12 // way, based on a user-supplied list. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #include "llvm/Support/SpecialCaseList.h" 17 #include "llvm/ADT/SmallVector.h" 18 #include "llvm/ADT/StringExtras.h" 19 #include "llvm/Support/MemoryBuffer.h" 20 #include "llvm/Support/Regex.h" 21 #include <string> 22 #include <system_error> 23 #include <utility> 24 25 #include <stdio.h> 26 namespace llvm { 27 28 bool SpecialCaseList::Matcher::insert(std::string Regexp, 29 unsigned LineNumber, 30 std::string &REError) { 31 if (Regexp.empty()) { 32 REError = "Supplied regexp was blank"; 33 return false; 34 } 35 36 if (Regex::isLiteralERE(Regexp)) { 37 Strings[Regexp] = LineNumber; 38 return true; 39 } 40 Trigrams.insert(Regexp); 41 42 // Replace * with .* 43 for (size_t pos = 0; (pos = Regexp.find('*', pos)) != std::string::npos; 44 pos += strlen(".*")) { 45 Regexp.replace(pos, strlen("*"), ".*"); 46 } 47 48 Regexp = (Twine("^(") + StringRef(Regexp) + ")$").str(); 49 50 // Check that the regexp is valid. 51 Regex CheckRE(Regexp); 52 if (!CheckRE.isValid(REError)) 53 return false; 54 55 RegExes.emplace_back( 56 std::make_pair(std::make_unique<Regex>(std::move(CheckRE)), LineNumber)); 57 return true; 58 } 59 60 unsigned SpecialCaseList::Matcher::match(StringRef Query) const { 61 auto It = Strings.find(Query); 62 if (It != Strings.end()) 63 return It->second; 64 if (Trigrams.isDefinitelyOut(Query)) 65 return false; 66 for (auto& RegExKV : RegExes) 67 if (RegExKV.first->match(Query)) 68 return RegExKV.second; 69 return 0; 70 } 71 72 std::unique_ptr<SpecialCaseList> 73 SpecialCaseList::create(const std::vector<std::string> &Paths, 74 std::string &Error) { 75 std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList()); 76 if (SCL->createInternal(Paths, Error)) 77 return SCL; 78 return nullptr; 79 } 80 81 std::unique_ptr<SpecialCaseList> SpecialCaseList::create(const MemoryBuffer *MB, 82 std::string &Error) { 83 std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList()); 84 if (SCL->createInternal(MB, Error)) 85 return SCL; 86 return nullptr; 87 } 88 89 std::unique_ptr<SpecialCaseList> 90 SpecialCaseList::createOrDie(const std::vector<std::string> &Paths) { 91 std::string Error; 92 if (auto SCL = create(Paths, Error)) 93 return SCL; 94 report_fatal_error(Error); 95 } 96 97 bool SpecialCaseList::createInternal(const std::vector<std::string> &Paths, 98 std::string &Error) { 99 StringMap<size_t> Sections; 100 for (const auto &Path : Paths) { 101 ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr = 102 MemoryBuffer::getFile(Path); 103 if (std::error_code EC = FileOrErr.getError()) { 104 Error = (Twine("can't open file '") + Path + "': " + EC.message()).str(); 105 return false; 106 } 107 std::string ParseError; 108 if (!parse(FileOrErr.get().get(), Sections, ParseError)) { 109 Error = (Twine("error parsing file '") + Path + "': " + ParseError).str(); 110 return false; 111 } 112 } 113 return true; 114 } 115 116 bool SpecialCaseList::createInternal(const MemoryBuffer *MB, 117 std::string &Error) { 118 StringMap<size_t> Sections; 119 if (!parse(MB, Sections, Error)) 120 return false; 121 return true; 122 } 123 124 bool SpecialCaseList::parse(const MemoryBuffer *MB, 125 StringMap<size_t> &SectionsMap, 126 std::string &Error) { 127 // Iterate through each line in the blacklist file. 128 SmallVector<StringRef, 16> Lines; 129 MB->getBuffer().split(Lines, '\n'); 130 131 unsigned LineNo = 1; 132 StringRef Section = "*"; 133 134 for (auto I = Lines.begin(), E = Lines.end(); I != E; ++I, ++LineNo) { 135 *I = I->trim(); 136 // Ignore empty lines and lines starting with "#" 137 if (I->empty() || I->startswith("#")) 138 continue; 139 140 // Save section names 141 if (I->startswith("[")) { 142 if (!I->endswith("]")) { 143 Error = (Twine("malformed section header on line ") + Twine(LineNo) + 144 ": " + *I).str(); 145 return false; 146 } 147 148 Section = I->slice(1, I->size() - 1); 149 150 std::string REError; 151 Regex CheckRE(Section); 152 if (!CheckRE.isValid(REError)) { 153 Error = 154 (Twine("malformed regex for section ") + Section + ": '" + REError) 155 .str(); 156 return false; 157 } 158 159 continue; 160 } 161 162 // Get our prefix and unparsed regexp. 163 std::pair<StringRef, StringRef> SplitLine = I->split(":"); 164 StringRef Prefix = SplitLine.first; 165 if (SplitLine.second.empty()) { 166 // Missing ':' in the line. 167 Error = (Twine("malformed line ") + Twine(LineNo) + ": '" + 168 SplitLine.first + "'").str(); 169 return false; 170 } 171 172 std::pair<StringRef, StringRef> SplitRegexp = SplitLine.second.split("="); 173 std::string Regexp = SplitRegexp.first; 174 StringRef Category = SplitRegexp.second; 175 176 // Create this section if it has not been seen before. 177 if (SectionsMap.find(Section) == SectionsMap.end()) { 178 std::unique_ptr<Matcher> M = std::make_unique<Matcher>(); 179 std::string REError; 180 if (!M->insert(Section, LineNo, REError)) { 181 Error = (Twine("malformed section ") + Section + ": '" + REError).str(); 182 return false; 183 } 184 185 SectionsMap[Section] = Sections.size(); 186 Sections.emplace_back(std::move(M)); 187 } 188 189 auto &Entry = Sections[SectionsMap[Section]].Entries[Prefix][Category]; 190 std::string REError; 191 if (!Entry.insert(std::move(Regexp), LineNo, REError)) { 192 Error = (Twine("malformed regex in line ") + Twine(LineNo) + ": '" + 193 SplitLine.second + "': " + REError).str(); 194 return false; 195 } 196 } 197 return true; 198 } 199 200 SpecialCaseList::~SpecialCaseList() {} 201 202 bool SpecialCaseList::inSection(StringRef Section, StringRef Prefix, 203 StringRef Query, StringRef Category) const { 204 return inSectionBlame(Section, Prefix, Query, Category); 205 } 206 207 unsigned SpecialCaseList::inSectionBlame(StringRef Section, StringRef Prefix, 208 StringRef Query, 209 StringRef Category) const { 210 for (auto &SectionIter : Sections) 211 if (SectionIter.SectionMatcher->match(Section)) { 212 unsigned Blame = 213 inSectionBlame(SectionIter.Entries, Prefix, Query, Category); 214 if (Blame) 215 return Blame; 216 } 217 return 0; 218 } 219 220 unsigned SpecialCaseList::inSectionBlame(const SectionEntries &Entries, 221 StringRef Prefix, StringRef Query, 222 StringRef Category) const { 223 SectionEntries::const_iterator I = Entries.find(Prefix); 224 if (I == Entries.end()) return 0; 225 StringMap<Matcher>::const_iterator II = I->second.find(Category); 226 if (II == I->second.end()) return 0; 227 228 return II->getValue().match(Query); 229 } 230 231 } // namespace llvm 232