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.
writeHeader(raw_ostream & os,uint32_t sec,uint64_t addr)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.
writeFormattedTimestamp(raw_ostream & os,time_t tds)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
sortUniqueSymbols(std::vector<Defined * > & syms,uint64_t imageBase)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.
getSymbols(const COFFLinkerContext & ctx,std::vector<Defined * > & syms,std::vector<Defined * > & staticSyms)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>
getSymbolStrings(const COFFLinkerContext & ctx,ArrayRef<Defined * > syms)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
writeMapFile(COFFLinkerContext & ctx)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