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/Support/MemoryBuffer.h" 19 #include "llvm/Support/Regex.h" 20 #include "llvm/Support/VirtualFileSystem.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 (const 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 llvm::vfs::FileSystem &FS, std::string &Error) { 75 std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList()); 76 if (SCL->createInternal(Paths, FS, 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 llvm::vfs::FileSystem &FS) { 92 std::string Error; 93 if (auto SCL = create(Paths, FS, Error)) 94 return SCL; 95 report_fatal_error(Twine(Error)); 96 } 97 98 bool SpecialCaseList::createInternal(const std::vector<std::string> &Paths, 99 vfs::FileSystem &VFS, std::string &Error) { 100 StringMap<size_t> Sections; 101 for (const auto &Path : Paths) { 102 ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr = 103 VFS.getBufferForFile(Path); 104 if (std::error_code EC = FileOrErr.getError()) { 105 Error = (Twine("can't open file '") + Path + "': " + EC.message()).str(); 106 return false; 107 } 108 std::string ParseError; 109 if (!parse(FileOrErr.get().get(), Sections, ParseError)) { 110 Error = (Twine("error parsing file '") + Path + "': " + ParseError).str(); 111 return false; 112 } 113 } 114 return true; 115 } 116 117 bool SpecialCaseList::createInternal(const MemoryBuffer *MB, 118 std::string &Error) { 119 StringMap<size_t> Sections; 120 if (!parse(MB, Sections, Error)) 121 return false; 122 return true; 123 } 124 125 bool SpecialCaseList::parse(const MemoryBuffer *MB, 126 StringMap<size_t> &SectionsMap, 127 std::string &Error) { 128 // Iterate through each line in the exclusion list file. 129 SmallVector<StringRef, 16> Lines; 130 MB->getBuffer().split(Lines, '\n'); 131 132 unsigned LineNo = 1; 133 StringRef Section = "*"; 134 135 for (auto I = Lines.begin(), E = Lines.end(); I != E; ++I, ++LineNo) { 136 *I = I->trim(); 137 // Ignore empty lines and lines starting with "#" 138 if (I->empty() || I->startswith("#")) 139 continue; 140 141 // Save section names 142 if (I->startswith("[")) { 143 if (!I->endswith("]")) { 144 Error = (Twine("malformed section header on line ") + Twine(LineNo) + 145 ": " + *I).str(); 146 return false; 147 } 148 149 Section = I->slice(1, I->size() - 1); 150 151 std::string REError; 152 Regex CheckRE(Section); 153 if (!CheckRE.isValid(REError)) { 154 Error = 155 (Twine("malformed regex for section ") + Section + ": '" + REError) 156 .str(); 157 return false; 158 } 159 160 continue; 161 } 162 163 // Get our prefix and unparsed regexp. 164 std::pair<StringRef, StringRef> SplitLine = I->split(":"); 165 StringRef Prefix = SplitLine.first; 166 if (SplitLine.second.empty()) { 167 // Missing ':' in the line. 168 Error = (Twine("malformed line ") + Twine(LineNo) + ": '" + 169 SplitLine.first + "'").str(); 170 return false; 171 } 172 173 std::pair<StringRef, StringRef> SplitRegexp = SplitLine.second.split("="); 174 std::string Regexp = std::string(SplitRegexp.first); 175 StringRef Category = SplitRegexp.second; 176 177 // Create this section if it has not been seen before. 178 if (SectionsMap.find(Section) == SectionsMap.end()) { 179 std::unique_ptr<Matcher> M = std::make_unique<Matcher>(); 180 std::string REError; 181 if (!M->insert(std::string(Section), LineNo, REError)) { 182 Error = (Twine("malformed section ") + Section + ": '" + REError).str(); 183 return false; 184 } 185 186 SectionsMap[Section] = Sections.size(); 187 Sections.emplace_back(std::move(M)); 188 } 189 190 auto &Entry = Sections[SectionsMap[Section]].Entries[Prefix][Category]; 191 std::string REError; 192 if (!Entry.insert(std::move(Regexp), LineNo, REError)) { 193 Error = (Twine("malformed regex in line ") + Twine(LineNo) + ": '" + 194 SplitLine.second + "': " + REError).str(); 195 return false; 196 } 197 } 198 return true; 199 } 200 201 SpecialCaseList::~SpecialCaseList() {} 202 203 bool SpecialCaseList::inSection(StringRef Section, StringRef Prefix, 204 StringRef Query, StringRef Category) const { 205 return inSectionBlame(Section, Prefix, Query, Category); 206 } 207 208 unsigned SpecialCaseList::inSectionBlame(StringRef Section, StringRef Prefix, 209 StringRef Query, 210 StringRef Category) const { 211 for (const auto &SectionIter : Sections) 212 if (SectionIter.SectionMatcher->match(Section)) { 213 unsigned Blame = 214 inSectionBlame(SectionIter.Entries, Prefix, Query, Category); 215 if (Blame) 216 return Blame; 217 } 218 return 0; 219 } 220 221 unsigned SpecialCaseList::inSectionBlame(const SectionEntries &Entries, 222 StringRef Prefix, StringRef Query, 223 StringRef Category) const { 224 SectionEntries::const_iterator I = Entries.find(Prefix); 225 if (I == Entries.end()) return 0; 226 StringMap<Matcher>::const_iterator II = I->second.find(Category); 227 if (II == I->second.end()) return 0; 228 229 return II->getValue().match(Query); 230 } 231 232 } // namespace llvm 233