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