1 //===- MapFile.cpp --------------------------------------------------------===// 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 file implements the /map option in the same format as link.exe 10 // (based on observations) 11 // 12 // Header (program name, timestamp info, preferred load address) 13 // 14 // Section list (Start = Section index:Base address): 15 // Start Length Name Class 16 // 0001:00001000 00000015H .text CODE 17 // 18 // Symbols list: 19 // Address Publics by Value Rva + Base Lib:Object 20 // 0001:00001000 main 0000000140001000 main.obj 21 // 0001:00001300 ?__scrt_common_main@@YAHXZ 0000000140001300 libcmt:exe_main.obj 22 // 23 // entry point at 0001:00000360 24 // 25 // Static symbols 26 // 27 // 0000:00000000 __guard_fids__ 0000000140000000 libcmt : exe_main.obj 28 //===----------------------------------------------------------------------===// 29 30 #include "MapFile.h" 31 #include "COFFLinkerContext.h" 32 #include "SymbolTable.h" 33 #include "Symbols.h" 34 #include "Writer.h" 35 #include "lld/Common/ErrorHandler.h" 36 #include "lld/Common/Timer.h" 37 #include "llvm/Support/Parallel.h" 38 #include "llvm/Support/Path.h" 39 #include "llvm/Support/TimeProfiler.h" 40 #include "llvm/Support/raw_ostream.h" 41 42 using namespace llvm; 43 using namespace llvm::object; 44 using namespace lld; 45 using namespace lld::coff; 46 47 // Print out the first two columns of a line. 48 static void writeHeader(raw_ostream &os, uint32_t sec, uint64_t addr) { 49 os << format(" %04x:%08llx", sec, addr); 50 } 51 52 // Write the time stamp with the format used by link.exe 53 // It seems identical to strftime with "%c" on msvc build, but we need a 54 // locale-agnostic version. 55 static void writeFormattedTimestamp(raw_ostream &os, time_t tds) { 56 constexpr const char *const days[7] = {"Sun", "Mon", "Tue", "Wed", 57 "Thu", "Fri", "Sat"}; 58 constexpr const char *const months[12] = {"Jan", "Feb", "Mar", "Apr", 59 "May", "Jun", "Jul", "Aug", 60 "Sep", "Oct", "Nov", "Dec"}; 61 tm *time = localtime(&tds); 62 os << format("%s %s %2d %02d:%02d:%02d %d", days[time->tm_wday], 63 months[time->tm_mon], time->tm_mday, time->tm_hour, time->tm_min, 64 time->tm_sec, time->tm_year + 1900); 65 } 66 67 static void sortUniqueSymbols(std::vector<Defined *> &syms, 68 uint64_t imageBase) { 69 // Build helper vector 70 using SortEntry = std::pair<Defined *, size_t>; 71 std::vector<SortEntry> v; 72 v.resize(syms.size()); 73 for (size_t i = 0, e = syms.size(); i < e; ++i) 74 v[i] = SortEntry(syms[i], i); 75 76 // Remove duplicate symbol pointers 77 parallelSort(v, std::less<SortEntry>()); 78 auto end = std::unique(v.begin(), v.end(), 79 [](const SortEntry &a, const SortEntry &b) { 80 return a.first == b.first; 81 }); 82 v.erase(end, v.end()); 83 84 // Sort by RVA then original order 85 parallelSort(v, [imageBase](const SortEntry &a, const SortEntry &b) { 86 // Add config.imageBase to avoid comparing "negative" RVAs. 87 // This can happen with symbols of Absolute kind 88 uint64_t rvaa = imageBase + a.first->getRVA(); 89 uint64_t rvab = imageBase + b.first->getRVA(); 90 return rvaa < rvab || (rvaa == rvab && a.second < b.second); 91 }); 92 93 syms.resize(v.size()); 94 for (size_t i = 0, e = v.size(); i < e; ++i) 95 syms[i] = v[i].first; 96 } 97 98 // Returns the lists of all symbols that we want to print out. 99 static void getSymbols(const COFFLinkerContext &ctx, 100 std::vector<Defined *> &syms, 101 std::vector<Defined *> &staticSyms) { 102 103 for (ObjFile *file : ctx.objFileInstances) 104 for (Symbol *b : file->getSymbols()) { 105 if (!b || !b->isLive()) 106 continue; 107 if (auto *sym = dyn_cast<DefinedCOFF>(b)) { 108 COFFSymbolRef symRef = sym->getCOFFSymbol(); 109 if (!symRef.isSectionDefinition() && 110 symRef.getStorageClass() != COFF::IMAGE_SYM_CLASS_LABEL) { 111 if (symRef.getStorageClass() == COFF::IMAGE_SYM_CLASS_STATIC) 112 staticSyms.push_back(sym); 113 else 114 syms.push_back(sym); 115 } 116 } else if (auto *sym = dyn_cast<Defined>(b)) { 117 syms.push_back(sym); 118 } 119 } 120 121 for (ImportFile *file : ctx.importFileInstances) { 122 if (!file->live) 123 continue; 124 125 if (file->impSym) 126 syms.push_back(file->impSym); 127 if (file->thunkSym && file->thunkSym->isLive()) 128 syms.push_back(file->thunkSym); 129 if (file->auxThunkSym && file->auxThunkSym->isLive()) 130 syms.push_back(file->auxThunkSym); 131 if (file->impchkThunk) 132 syms.push_back(file->impchkThunk->sym); 133 if (file->impECSym) 134 syms.push_back(file->impECSym); 135 if (file->auxImpCopySym) 136 syms.push_back(file->auxImpCopySym); 137 } 138 139 sortUniqueSymbols(syms, ctx.config.imageBase); 140 sortUniqueSymbols(staticSyms, ctx.config.imageBase); 141 } 142 143 // Construct a map from symbols to their stringified representations. 144 static DenseMap<Defined *, std::string> 145 getSymbolStrings(const COFFLinkerContext &ctx, ArrayRef<Defined *> syms) { 146 std::vector<std::string> str(syms.size()); 147 parallelFor((size_t)0, syms.size(), [&](size_t i) { 148 raw_string_ostream os(str[i]); 149 Defined *sym = syms[i]; 150 151 uint16_t sectionIdx = 0; 152 uint64_t address = 0; 153 SmallString<128> fileDescr; 154 155 if (auto *absSym = dyn_cast<DefinedAbsolute>(sym)) { 156 address = absSym->getVA(); 157 fileDescr = "<absolute>"; 158 } else if (isa<DefinedSynthetic>(sym)) { 159 fileDescr = "<linker-defined>"; 160 } else if (isa<DefinedCommon>(sym)) { 161 fileDescr = "<common>"; 162 } else if (Chunk *chunk = sym->getChunk()) { 163 address = sym->getRVA(); 164 if (OutputSection *sec = ctx.getOutputSection(chunk)) 165 address -= sec->header.VirtualAddress; 166 167 sectionIdx = chunk->getOutputSectionIdx(); 168 169 InputFile *file; 170 if (auto *impSym = dyn_cast<DefinedImportData>(sym)) 171 file = impSym->file; 172 else if (auto *thunkSym = dyn_cast<DefinedImportThunk>(sym)) 173 file = thunkSym->wrappedSym->file; 174 else 175 file = sym->getFile(); 176 177 if (file) { 178 if (!file->parentName.empty()) { 179 fileDescr = sys::path::filename(file->parentName); 180 sys::path::replace_extension(fileDescr, ""); 181 fileDescr += ":"; 182 } 183 fileDescr += sys::path::filename(file->getName()); 184 } 185 } 186 writeHeader(os, sectionIdx, address); 187 os << " "; 188 os << left_justify(sym->getName(), 26); 189 os << " "; 190 os << format_hex_no_prefix((ctx.config.imageBase + sym->getRVA()), 16); 191 if (!fileDescr.empty()) { 192 os << " "; // FIXME : Handle "f" and "i" flags sometimes generated 193 // by link.exe in those spaces 194 os << fileDescr; 195 } 196 }); 197 198 DenseMap<Defined *, std::string> ret; 199 for (size_t i = 0, e = syms.size(); i < e; ++i) 200 ret[syms[i]] = std::move(str[i]); 201 return ret; 202 } 203 204 void lld::coff::writeMapFile(COFFLinkerContext &ctx) { 205 if (ctx.config.mapFile.empty()) 206 return; 207 208 llvm::TimeTraceScope timeScope("Map file"); 209 std::error_code ec; 210 raw_fd_ostream os(ctx.config.mapFile, ec, sys::fs::OF_None); 211 if (ec) 212 Fatal(ctx) << "cannot open " << ctx.config.mapFile << ": " << ec.message(); 213 214 ScopedTimer t1(ctx.totalMapTimer); 215 216 // Collect symbol info that we want to print out. 217 ScopedTimer t2(ctx.symbolGatherTimer); 218 std::vector<Defined *> syms; 219 std::vector<Defined *> staticSyms; 220 getSymbols(ctx, syms, staticSyms); 221 t2.stop(); 222 223 ScopedTimer t3(ctx.symbolStringsTimer); 224 DenseMap<Defined *, std::string> symStr = getSymbolStrings(ctx, syms); 225 DenseMap<Defined *, std::string> staticSymStr = 226 getSymbolStrings(ctx, staticSyms); 227 t3.stop(); 228 229 ScopedTimer t4(ctx.writeTimer); 230 SmallString<128> AppName = sys::path::filename(ctx.config.outputFile); 231 sys::path::replace_extension(AppName, ""); 232 233 // Print out the file header 234 os << " " << AppName << "\n"; 235 os << "\n"; 236 237 os << " Timestamp is " << format_hex_no_prefix(ctx.config.timestamp, 8) 238 << " ("; 239 if (ctx.config.repro) { 240 os << "Repro mode"; 241 } else { 242 writeFormattedTimestamp(os, ctx.config.timestamp); 243 } 244 os << ")\n"; 245 246 os << "\n"; 247 os << " Preferred load address is " 248 << format_hex_no_prefix(ctx.config.imageBase, 16) << "\n"; 249 os << "\n"; 250 251 // Print out section table. 252 os << " Start Length Name Class\n"; 253 254 for (OutputSection *sec : ctx.outputSections) { 255 // Merge display of chunks with same sectionName 256 std::vector<std::pair<SectionChunk *, SectionChunk *>> ChunkRanges; 257 for (Chunk *c : sec->chunks) { 258 auto *sc = dyn_cast<SectionChunk>(c); 259 if (!sc) 260 continue; 261 262 if (ChunkRanges.empty() || 263 c->getSectionName() != ChunkRanges.back().first->getSectionName()) { 264 ChunkRanges.emplace_back(sc, sc); 265 } else { 266 ChunkRanges.back().second = sc; 267 } 268 } 269 270 const bool isCodeSection = 271 (sec->header.Characteristics & COFF::IMAGE_SCN_CNT_CODE) && 272 (sec->header.Characteristics & COFF::IMAGE_SCN_MEM_READ) && 273 (sec->header.Characteristics & COFF::IMAGE_SCN_MEM_EXECUTE); 274 StringRef SectionClass = (isCodeSection ? "CODE" : "DATA"); 275 276 for (auto &cr : ChunkRanges) { 277 size_t size = 278 cr.second->getRVA() + cr.second->getSize() - cr.first->getRVA(); 279 280 auto address = cr.first->getRVA() - sec->header.VirtualAddress; 281 writeHeader(os, sec->sectionIndex, address); 282 os << " " << format_hex_no_prefix(size, 8) << "H"; 283 os << " " << left_justify(cr.first->getSectionName(), 23); 284 os << " " << SectionClass; 285 os << '\n'; 286 } 287 } 288 289 // Print out the symbols table (without static symbols) 290 os << "\n"; 291 os << " Address Publics by Value Rva+Base" 292 " Lib:Object\n"; 293 os << "\n"; 294 for (Defined *sym : syms) 295 os << symStr[sym] << '\n'; 296 297 // Print out the entry point. 298 os << "\n"; 299 300 uint16_t entrySecIndex = 0; 301 uint64_t entryAddress = 0; 302 303 if (!ctx.config.noEntry) { 304 Defined *entry = dyn_cast_or_null<Defined>(ctx.symtab.entry); 305 if (entry) { 306 Chunk *chunk = entry->getChunk(); 307 entrySecIndex = chunk->getOutputSectionIdx(); 308 entryAddress = 309 entry->getRVA() - ctx.getOutputSection(chunk)->header.VirtualAddress; 310 } 311 } 312 os << " entry point at "; 313 os << format("%04x:%08llx", entrySecIndex, entryAddress); 314 os << "\n"; 315 316 // Print out the static symbols 317 os << "\n"; 318 os << " Static symbols\n"; 319 os << "\n"; 320 for (Defined *sym : staticSyms) 321 os << staticSymStr[sym] << '\n'; 322 323 // Print out the exported functions 324 if (ctx.config.mapInfo) { 325 os << "\n"; 326 os << " Exports\n"; 327 os << "\n"; 328 os << " ordinal name\n\n"; 329 for (Export &e : ctx.symtab.exports) { 330 os << format(" %7d", e.ordinal) << " " << e.name << "\n"; 331 if (!e.extName.empty() && e.extName != e.name) 332 os << " exported name: " << e.extName << "\n"; 333 } 334 } 335 336 t4.stop(); 337 t1.stop(); 338 } 339