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->thunkSym) 126 continue; 127 128 if (!file->thunkLive) 129 continue; 130 131 if (auto *thunkSym = dyn_cast<Defined>(file->thunkSym)) 132 syms.push_back(thunkSym); 133 134 if (auto *impSym = dyn_cast_or_null<Defined>(file->impSym)) 135 syms.push_back(impSym); 136 } 137 138 sortUniqueSymbols(syms, ctx.config.imageBase); 139 sortUniqueSymbols(staticSyms, ctx.config.imageBase); 140 } 141 142 // Construct a map from symbols to their stringified representations. 143 static DenseMap<Defined *, std::string> 144 getSymbolStrings(const COFFLinkerContext &ctx, ArrayRef<Defined *> syms) { 145 std::vector<std::string> str(syms.size()); 146 parallelFor((size_t)0, syms.size(), [&](size_t i) { 147 raw_string_ostream os(str[i]); 148 Defined *sym = syms[i]; 149 150 uint16_t sectionIdx = 0; 151 uint64_t address = 0; 152 SmallString<128> fileDescr; 153 154 if (auto *absSym = dyn_cast<DefinedAbsolute>(sym)) { 155 address = absSym->getVA(); 156 fileDescr = "<absolute>"; 157 } else if (isa<DefinedSynthetic>(sym)) { 158 fileDescr = "<linker-defined>"; 159 } else if (isa<DefinedCommon>(sym)) { 160 fileDescr = "<common>"; 161 } else if (Chunk *chunk = sym->getChunk()) { 162 address = sym->getRVA(); 163 if (OutputSection *sec = ctx.getOutputSection(chunk)) 164 address -= sec->header.VirtualAddress; 165 166 sectionIdx = chunk->getOutputSectionIdx(); 167 168 InputFile *file; 169 if (auto *impSym = dyn_cast<DefinedImportData>(sym)) 170 file = impSym->file; 171 else if (auto *thunkSym = dyn_cast<DefinedImportThunk>(sym)) 172 file = thunkSym->wrappedSym->file; 173 else 174 file = sym->getFile(); 175 176 if (file) { 177 if (!file->parentName.empty()) { 178 fileDescr = sys::path::filename(file->parentName); 179 sys::path::replace_extension(fileDescr, ""); 180 fileDescr += ":"; 181 } 182 fileDescr += sys::path::filename(file->getName()); 183 } 184 } 185 writeHeader(os, sectionIdx, address); 186 os << " "; 187 os << left_justify(sym->getName(), 26); 188 os << " "; 189 os << format_hex_no_prefix((ctx.config.imageBase + sym->getRVA()), 16); 190 if (!fileDescr.empty()) { 191 os << " "; // FIXME : Handle "f" and "i" flags sometimes generated 192 // by link.exe in those spaces 193 os << fileDescr; 194 } 195 }); 196 197 DenseMap<Defined *, std::string> ret; 198 for (size_t i = 0, e = syms.size(); i < e; ++i) 199 ret[syms[i]] = std::move(str[i]); 200 return ret; 201 } 202 203 void lld::coff::writeMapFile(COFFLinkerContext &ctx) { 204 if (ctx.config.mapFile.empty()) 205 return; 206 207 llvm::TimeTraceScope timeScope("Map file"); 208 std::error_code ec; 209 raw_fd_ostream os(ctx.config.mapFile, ec, sys::fs::OF_None); 210 if (ec) 211 fatal("cannot open " + ctx.config.mapFile + ": " + ec.message()); 212 213 ScopedTimer t1(ctx.totalMapTimer); 214 215 // Collect symbol info that we want to print out. 216 ScopedTimer t2(ctx.symbolGatherTimer); 217 std::vector<Defined *> syms; 218 std::vector<Defined *> staticSyms; 219 getSymbols(ctx, syms, staticSyms); 220 t2.stop(); 221 222 ScopedTimer t3(ctx.symbolStringsTimer); 223 DenseMap<Defined *, std::string> symStr = getSymbolStrings(ctx, syms); 224 DenseMap<Defined *, std::string> staticSymStr = 225 getSymbolStrings(ctx, staticSyms); 226 t3.stop(); 227 228 ScopedTimer t4(ctx.writeTimer); 229 SmallString<128> AppName = sys::path::filename(ctx.config.outputFile); 230 sys::path::replace_extension(AppName, ""); 231 232 // Print out the file header 233 os << " " << AppName << "\n"; 234 os << "\n"; 235 236 os << " Timestamp is " << format_hex_no_prefix(ctx.config.timestamp, 8) 237 << " ("; 238 if (ctx.config.repro) { 239 os << "Repro mode"; 240 } else { 241 writeFormattedTimestamp(os, ctx.config.timestamp); 242 } 243 os << ")\n"; 244 245 os << "\n"; 246 os << " Preferred load address is " 247 << format_hex_no_prefix(ctx.config.imageBase, 16) << "\n"; 248 os << "\n"; 249 250 // Print out section table. 251 os << " Start Length Name Class\n"; 252 253 for (OutputSection *sec : ctx.outputSections) { 254 // Merge display of chunks with same sectionName 255 std::vector<std::pair<SectionChunk *, SectionChunk *>> ChunkRanges; 256 for (Chunk *c : sec->chunks) { 257 auto *sc = dyn_cast<SectionChunk>(c); 258 if (!sc) 259 continue; 260 261 if (ChunkRanges.empty() || 262 c->getSectionName() != ChunkRanges.back().first->getSectionName()) { 263 ChunkRanges.emplace_back(sc, sc); 264 } else { 265 ChunkRanges.back().second = sc; 266 } 267 } 268 269 const bool isCodeSection = 270 (sec->header.Characteristics & COFF::IMAGE_SCN_CNT_CODE) && 271 (sec->header.Characteristics & COFF::IMAGE_SCN_MEM_READ) && 272 (sec->header.Characteristics & COFF::IMAGE_SCN_MEM_EXECUTE); 273 StringRef SectionClass = (isCodeSection ? "CODE" : "DATA"); 274 275 for (auto &cr : ChunkRanges) { 276 size_t size = 277 cr.second->getRVA() + cr.second->getSize() - cr.first->getRVA(); 278 279 auto address = cr.first->getRVA() - sec->header.VirtualAddress; 280 writeHeader(os, sec->sectionIndex, address); 281 os << " " << format_hex_no_prefix(size, 8) << "H"; 282 os << " " << left_justify(cr.first->getSectionName(), 23); 283 os << " " << SectionClass; 284 os << '\n'; 285 } 286 } 287 288 // Print out the symbols table (without static symbols) 289 os << "\n"; 290 os << " Address Publics by Value Rva+Base" 291 " Lib:Object\n"; 292 os << "\n"; 293 for (Defined *sym : syms) 294 os << symStr[sym] << '\n'; 295 296 // Print out the entry point. 297 os << "\n"; 298 299 uint16_t entrySecIndex = 0; 300 uint64_t entryAddress = 0; 301 302 if (!ctx.config.noEntry) { 303 Defined *entry = dyn_cast_or_null<Defined>(ctx.config.entry); 304 if (entry) { 305 Chunk *chunk = entry->getChunk(); 306 entrySecIndex = chunk->getOutputSectionIdx(); 307 entryAddress = 308 entry->getRVA() - ctx.getOutputSection(chunk)->header.VirtualAddress; 309 } 310 } 311 os << " entry point at "; 312 os << format("%04x:%08llx", entrySecIndex, entryAddress); 313 os << "\n"; 314 315 // Print out the static symbols 316 os << "\n"; 317 os << " Static symbols\n"; 318 os << "\n"; 319 for (Defined *sym : staticSyms) 320 os << staticSymStr[sym] << '\n'; 321 322 // Print out the exported functions 323 if (ctx.config.mapInfo) { 324 os << "\n"; 325 os << " Exports\n"; 326 os << "\n"; 327 os << " ordinal name\n\n"; 328 for (Export &e : ctx.config.exports) { 329 os << format(" %7d", e.ordinal) << " " << e.name << "\n"; 330 if (!e.extName.empty() && e.extName != e.name) 331 os << " exported name: " << e.extName << "\n"; 332 } 333 } 334 335 t4.stop(); 336 t1.stop(); 337 } 338