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 "SymbolTable.h"
32 #include "Symbols.h"
33 #include "Writer.h"
34 #include "lld/Common/ErrorHandler.h"
35 #include "lld/Common/Timer.h"
36 #include "llvm/Support/Parallel.h"
37 #include "llvm/Support/Path.h"
38 #include "llvm/Support/raw_ostream.h"
39
40 using namespace llvm;
41 using namespace llvm::object;
42 using namespace lld;
43 using namespace lld::coff;
44
45 static Timer totalMapTimer("MAP emission (Cumulative)", Timer::root());
46 static Timer symbolGatherTimer("Gather symbols", totalMapTimer);
47 static Timer symbolStringsTimer("Build symbol strings", totalMapTimer);
48 static Timer writeTimer("Write to file", totalMapTimer);
49
50 // Print out the first two columns of a line.
writeHeader(raw_ostream & os,uint32_t sec,uint64_t addr)51 static void writeHeader(raw_ostream &os, uint32_t sec, uint64_t addr) {
52 os << format(" %04x:%08llx", sec, addr);
53 }
54
55 // Write the time stamp with the format used by link.exe
56 // It seems identical to strftime with "%c" on msvc build, but we need a
57 // locale-agnostic version.
writeFormattedTimestamp(raw_ostream & os,time_t tds)58 static void writeFormattedTimestamp(raw_ostream &os, time_t tds) {
59 constexpr const char *const days[7] = {"Sun", "Mon", "Tue", "Wed",
60 "Thu", "Fri", "Sat"};
61 constexpr const char *const months[12] = {"Jan", "Feb", "Mar", "Apr",
62 "May", "Jun", "Jul", "Aug",
63 "Sep", "Oct", "Nov", "Dec"};
64 tm *time = localtime(&tds);
65 os << format("%s %s %2d %02d:%02d:%02d %d", days[time->tm_wday],
66 months[time->tm_mon], time->tm_mday, time->tm_hour, time->tm_min,
67 time->tm_sec, time->tm_year + 1900);
68 }
69
sortUniqueSymbols(std::vector<Defined * > & syms)70 static void sortUniqueSymbols(std::vector<Defined *> &syms) {
71 // Build helper vector
72 using SortEntry = std::pair<Defined *, size_t>;
73 std::vector<SortEntry> v;
74 v.resize(syms.size());
75 for (size_t i = 0, e = syms.size(); i < e; ++i)
76 v[i] = SortEntry(syms[i], i);
77
78 // Remove duplicate symbol pointers
79 parallelSort(v, std::less<SortEntry>());
80 auto end = std::unique(v.begin(), v.end(),
81 [](const SortEntry &a, const SortEntry &b) {
82 return a.first == b.first;
83 });
84 v.erase(end, v.end());
85
86 // Sort by RVA then original order
87 parallelSort(v, [](const SortEntry &a, const SortEntry &b) {
88 // Add config->imageBase to avoid comparing "negative" RVAs.
89 // This can happen with symbols of Absolute kind
90 uint64_t rvaa = config->imageBase + a.first->getRVA();
91 uint64_t rvab = config->imageBase + b.first->getRVA();
92 return rvaa < rvab || (rvaa == rvab && a.second < b.second);
93 });
94
95 syms.resize(v.size());
96 for (size_t i = 0, e = v.size(); i < e; ++i)
97 syms[i] = v[i].first;
98 }
99
100 // Returns the lists of all symbols that we want to print out.
getSymbols(std::vector<Defined * > & syms,std::vector<Defined * > & staticSyms)101 static void getSymbols(std::vector<Defined *> &syms,
102 std::vector<Defined *> &staticSyms) {
103
104 for (ObjFile *file : ObjFile::instances)
105 for (Symbol *b : file->getSymbols()) {
106 if (!b || !b->isLive())
107 continue;
108 if (auto *sym = dyn_cast<DefinedCOFF>(b)) {
109 COFFSymbolRef symRef = sym->getCOFFSymbol();
110 if (!symRef.isSectionDefinition() &&
111 symRef.getStorageClass() != COFF::IMAGE_SYM_CLASS_LABEL) {
112 if (symRef.getStorageClass() == COFF::IMAGE_SYM_CLASS_STATIC)
113 staticSyms.push_back(sym);
114 else
115 syms.push_back(sym);
116 }
117 } else if (auto *sym = dyn_cast<Defined>(b)) {
118 syms.push_back(sym);
119 }
120 }
121
122 for (ImportFile *file : ImportFile::instances) {
123 if (!file->live)
124 continue;
125
126 if (!file->thunkSym)
127 continue;
128
129 if (!file->thunkLive)
130 continue;
131
132 if (auto *thunkSym = dyn_cast<Defined>(file->thunkSym))
133 syms.push_back(thunkSym);
134
135 if (auto *impSym = dyn_cast_or_null<Defined>(file->impSym))
136 syms.push_back(impSym);
137 }
138
139 sortUniqueSymbols(syms);
140 sortUniqueSymbols(staticSyms);
141 }
142
143 // Construct a map from symbols to their stringified representations.
144 static DenseMap<Defined *, std::string>
getSymbolStrings(ArrayRef<Defined * > syms)145 getSymbolStrings(ArrayRef<Defined *> syms) {
146 std::vector<std::string> str(syms.size());
147 parallelForEachN((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 = chunk->getOutputSection())
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((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
writeMapFile(ArrayRef<OutputSection * > outputSections)204 void lld::coff::writeMapFile(ArrayRef<OutputSection *> outputSections) {
205 if (config->mapFile.empty())
206 return;
207
208 std::error_code ec;
209 raw_fd_ostream os(config->mapFile, ec, sys::fs::OF_None);
210 if (ec)
211 fatal("cannot open " + config->mapFile + ": " + ec.message());
212
213 ScopedTimer t1(totalMapTimer);
214
215 // Collect symbol info that we want to print out.
216 ScopedTimer t2(symbolGatherTimer);
217 std::vector<Defined *> syms;
218 std::vector<Defined *> staticSyms;
219 getSymbols(syms, staticSyms);
220 t2.stop();
221
222 ScopedTimer t3(symbolStringsTimer);
223 DenseMap<Defined *, std::string> symStr = getSymbolStrings(syms);
224 DenseMap<Defined *, std::string> staticSymStr = getSymbolStrings(staticSyms);
225 t3.stop();
226
227 ScopedTimer t4(writeTimer);
228 SmallString<128> AppName = sys::path::filename(config->outputFile);
229 sys::path::replace_extension(AppName, "");
230
231 // Print out the file header
232 os << " " << AppName << "\n";
233 os << "\n";
234
235 os << " Timestamp is " << format_hex_no_prefix(config->timestamp, 8) << " (";
236 if (config->repro) {
237 os << "Repro mode";
238 } else {
239 writeFormattedTimestamp(os, config->timestamp);
240 }
241 os << ")\n";
242
243 os << "\n";
244 os << " Preferred load address is "
245 << format_hex_no_prefix(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 : 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 (!config->noEntry) {
301 Defined *entry = dyn_cast_or_null<Defined>(config->entry);
302 if (entry) {
303 Chunk *chunk = entry->getChunk();
304 entrySecIndex = chunk->getOutputSectionIdx();
305 entryAddress =
306 entry->getRVA() - chunk->getOutputSection()->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 t4.stop();
321 t1.stop();
322 }
323