1 //===- DriverUtils.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 #include "Config.h"
10 #include "Driver.h"
11 #include "InputFiles.h"
12 #include "ObjC.h"
13 #include "Target.h"
14
15 #include "lld/Common/Args.h"
16 #include "lld/Common/CommonLinkerContext.h"
17 #include "lld/Common/Reproduce.h"
18 #include "llvm/ADT/CachedHashString.h"
19 #include "llvm/ADT/DenseMap.h"
20 #include "llvm/LTO/LTO.h"
21 #include "llvm/Option/Arg.h"
22 #include "llvm/Option/ArgList.h"
23 #include "llvm/Option/Option.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/Path.h"
27 #include "llvm/TextAPI/InterfaceFile.h"
28 #include "llvm/TextAPI/TextAPIReader.h"
29
30 using namespace llvm;
31 using namespace llvm::MachO;
32 using namespace llvm::opt;
33 using namespace llvm::sys;
34 using namespace lld;
35 using namespace lld::macho;
36
37 // Create prefix string literals used in Options.td
38 #define PREFIX(NAME, VALUE) \
39 static constexpr StringLiteral NAME##_init[] = VALUE; \
40 static constexpr ArrayRef<StringLiteral> NAME(NAME##_init, \
41 std::size(NAME##_init) - 1);
42 #include "Options.inc"
43 #undef PREFIX
44
45 // Create table mapping all options defined in Options.td
46 static constexpr OptTable::Info optInfo[] = {
47 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12) \
48 {X1, X2, X10, X11, OPT_##ID, Option::KIND##Class, \
49 X9, X8, OPT_##GROUP, OPT_##ALIAS, X7, X12},
50 #include "Options.inc"
51 #undef OPTION
52 };
53
MachOOptTable()54 MachOOptTable::MachOOptTable() : GenericOptTable(optInfo) {}
55
56 // Set color diagnostics according to --color-diagnostics={auto,always,never}
57 // or --no-color-diagnostics flags.
handleColorDiagnostics(InputArgList & args)58 static void handleColorDiagnostics(InputArgList &args) {
59 const Arg *arg =
60 args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
61 OPT_no_color_diagnostics);
62 if (!arg)
63 return;
64 if (arg->getOption().getID() == OPT_color_diagnostics) {
65 lld::errs().enable_colors(true);
66 } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
67 lld::errs().enable_colors(false);
68 } else {
69 StringRef s = arg->getValue();
70 if (s == "always")
71 lld::errs().enable_colors(true);
72 else if (s == "never")
73 lld::errs().enable_colors(false);
74 else if (s != "auto")
75 error("unknown option: --color-diagnostics=" + s);
76 }
77 }
78
parse(ArrayRef<const char * > argv)79 InputArgList MachOOptTable::parse(ArrayRef<const char *> argv) {
80 // Make InputArgList from string vectors.
81 unsigned missingIndex;
82 unsigned missingCount;
83 SmallVector<const char *, 256> vec(argv.data(), argv.data() + argv.size());
84
85 // Expand response files (arguments in the form of @<filename>)
86 // and then parse the argument again.
87 cl::ExpandResponseFiles(saver(), cl::TokenizeGNUCommandLine, vec);
88 InputArgList args = ParseArgs(vec, missingIndex, missingCount);
89
90 // Handle -fatal_warnings early since it converts missing argument warnings
91 // to errors.
92 errorHandler().fatalWarnings = args.hasArg(OPT_fatal_warnings);
93 errorHandler().suppressWarnings = args.hasArg(OPT_w);
94
95 if (missingCount)
96 error(Twine(args.getArgString(missingIndex)) + ": missing argument");
97
98 handleColorDiagnostics(args);
99
100 for (const Arg *arg : args.filtered(OPT_UNKNOWN)) {
101 std::string nearest;
102 if (findNearest(arg->getAsString(args), nearest) > 1)
103 error("unknown argument '" + arg->getAsString(args) + "'");
104 else
105 error("unknown argument '" + arg->getAsString(args) +
106 "', did you mean '" + nearest + "'");
107 }
108 return args;
109 }
110
printHelp(const char * argv0,bool showHidden) const111 void MachOOptTable::printHelp(const char *argv0, bool showHidden) const {
112 OptTable::printHelp(lld::outs(),
113 (std::string(argv0) + " [options] file...").c_str(),
114 "LLVM Linker", showHidden);
115 lld::outs() << "\n";
116 }
117
rewritePath(StringRef s)118 static std::string rewritePath(StringRef s) {
119 if (fs::exists(s))
120 return relativeToRoot(s);
121 return std::string(s);
122 }
123
rewriteInputPath(StringRef s)124 static std::string rewriteInputPath(StringRef s) {
125 // Don't bother rewriting "absolute" paths that are actually under the
126 // syslibroot; simply rewriting the syslibroot is sufficient.
127 if (rerootPath(s) == s && fs::exists(s))
128 return relativeToRoot(s);
129 return std::string(s);
130 }
131
132 // Reconstructs command line arguments so that so that you can re-run
133 // the same command with the same inputs. This is for --reproduce.
createResponseFile(const InputArgList & args)134 std::string macho::createResponseFile(const InputArgList &args) {
135 SmallString<0> data;
136 raw_svector_ostream os(data);
137
138 // Copy the command line to the output while rewriting paths.
139 for (const Arg *arg : args) {
140 switch (arg->getOption().getID()) {
141 case OPT_reproduce:
142 break;
143 case OPT_INPUT:
144 os << quote(rewriteInputPath(arg->getValue())) << "\n";
145 break;
146 case OPT_o:
147 os << "-o " << quote(path::filename(arg->getValue())) << "\n";
148 break;
149 case OPT_filelist:
150 if (std::optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
151 for (StringRef path : args::getLines(*buffer))
152 os << quote(rewriteInputPath(path)) << "\n";
153 break;
154 case OPT_force_load:
155 case OPT_weak_library:
156 case OPT_load_hidden:
157 os << arg->getSpelling() << " "
158 << quote(rewriteInputPath(arg->getValue())) << "\n";
159 break;
160 case OPT_F:
161 case OPT_L:
162 case OPT_bundle_loader:
163 case OPT_exported_symbols_list:
164 case OPT_order_file:
165 case OPT_syslibroot:
166 case OPT_unexported_symbols_list:
167 os << arg->getSpelling() << " " << quote(rewritePath(arg->getValue()))
168 << "\n";
169 break;
170 case OPT_sectcreate:
171 os << arg->getSpelling() << " " << quote(arg->getValue(0)) << " "
172 << quote(arg->getValue(1)) << " "
173 << quote(rewritePath(arg->getValue(2))) << "\n";
174 break;
175 default:
176 os << toString(*arg) << "\n";
177 }
178 }
179 return std::string(data.str());
180 }
181
searchedDylib(const Twine & path,bool found)182 static void searchedDylib(const Twine &path, bool found) {
183 if (config->printDylibSearch)
184 message("searched " + path + (found ? ", found " : ", not found"));
185 if (!found)
186 depTracker->logFileNotFound(path);
187 }
188
resolveDylibPath(StringRef dylibPath)189 std::optional<StringRef> macho::resolveDylibPath(StringRef dylibPath) {
190 // TODO: if a tbd and dylib are both present, we should check to make sure
191 // they are consistent.
192 SmallString<261> tbdPath = dylibPath;
193 path::replace_extension(tbdPath, ".tbd");
194 bool tbdExists = fs::exists(tbdPath);
195 searchedDylib(tbdPath, tbdExists);
196 if (tbdExists)
197 return saver().save(tbdPath.str());
198
199 bool dylibExists = fs::exists(dylibPath);
200 searchedDylib(dylibPath, dylibExists);
201 if (dylibExists)
202 return saver().save(dylibPath);
203 return {};
204 }
205
206 // It's not uncommon to have multiple attempts to load a single dylib,
207 // especially if it's a commonly re-exported core library.
208 static DenseMap<CachedHashStringRef, DylibFile *> loadedDylibs;
209
loadDylib(MemoryBufferRef mbref,DylibFile * umbrella,bool isBundleLoader,bool explicitlyLinked)210 DylibFile *macho::loadDylib(MemoryBufferRef mbref, DylibFile *umbrella,
211 bool isBundleLoader, bool explicitlyLinked) {
212 CachedHashStringRef path(mbref.getBufferIdentifier());
213 DylibFile *&file = loadedDylibs[path];
214 if (file) {
215 if (explicitlyLinked)
216 file->setExplicitlyLinked();
217 return file;
218 }
219
220 DylibFile *newFile;
221 file_magic magic = identify_magic(mbref.getBuffer());
222 if (magic == file_magic::tapi_file) {
223 Expected<std::unique_ptr<InterfaceFile>> result = TextAPIReader::get(mbref);
224 if (!result) {
225 error("could not load TAPI file at " + mbref.getBufferIdentifier() +
226 ": " + toString(result.takeError()));
227 return nullptr;
228 }
229 file =
230 make<DylibFile>(**result, umbrella, isBundleLoader, explicitlyLinked);
231
232 // parseReexports() can recursively call loadDylib(). That's fine since
233 // we wrote the DylibFile we just loaded to the loadDylib cache via the
234 // `file` reference. But the recursive load can grow loadDylibs, so the
235 // `file` reference might become invalid after parseReexports() -- so copy
236 // the pointer it refers to before continuing.
237 newFile = file;
238 if (newFile->exportingFile)
239 newFile->parseReexports(**result);
240 } else {
241 assert(magic == file_magic::macho_dynamically_linked_shared_lib ||
242 magic == file_magic::macho_dynamically_linked_shared_lib_stub ||
243 magic == file_magic::macho_executable ||
244 magic == file_magic::macho_bundle);
245 file = make<DylibFile>(mbref, umbrella, isBundleLoader, explicitlyLinked);
246
247 // parseLoadCommands() can also recursively call loadDylib(). See comment
248 // in previous block for why this means we must copy `file` here.
249 newFile = file;
250 if (newFile->exportingFile)
251 newFile->parseLoadCommands(mbref);
252 }
253 return newFile;
254 }
255
resetLoadedDylibs()256 void macho::resetLoadedDylibs() { loadedDylibs.clear(); }
257
258 std::optional<StringRef>
findPathCombination(const Twine & name,const std::vector<StringRef> & roots,ArrayRef<StringRef> extensions)259 macho::findPathCombination(const Twine &name,
260 const std::vector<StringRef> &roots,
261 ArrayRef<StringRef> extensions) {
262 SmallString<261> base;
263 for (StringRef dir : roots) {
264 base = dir;
265 path::append(base, name);
266 for (StringRef ext : extensions) {
267 Twine location = base + ext;
268 bool exists = fs::exists(location);
269 searchedDylib(location, exists);
270 if (exists)
271 return saver().save(location.str());
272 }
273 }
274 return {};
275 }
276
rerootPath(StringRef path)277 StringRef macho::rerootPath(StringRef path) {
278 if (!path::is_absolute(path, path::Style::posix) || path.endswith(".o"))
279 return path;
280
281 if (std::optional<StringRef> rerootedPath =
282 findPathCombination(path, config->systemLibraryRoots))
283 return *rerootedPath;
284
285 return path;
286 }
287
getModTime(StringRef path)288 uint32_t macho::getModTime(StringRef path) {
289 if (config->zeroModTime)
290 return 0;
291
292 fs::file_status stat;
293 if (!fs::status(path, stat))
294 if (fs::exists(stat))
295 return toTimeT(stat.getLastModificationTime());
296
297 warn("failed to get modification time of " + path);
298 return 0;
299 }
300
printArchiveMemberLoad(StringRef reason,const InputFile * f)301 void macho::printArchiveMemberLoad(StringRef reason, const InputFile *f) {
302 if (config->printEachFile)
303 message(toString(f));
304 if (config->printWhyLoad)
305 message(reason + " forced load of " + toString(f));
306 }
307
DependencyTracker(StringRef path)308 macho::DependencyTracker::DependencyTracker(StringRef path)
309 : path(path), active(!path.empty()) {
310 if (active && fs::exists(path) && !fs::can_write(path)) {
311 warn("Ignoring dependency_info option since specified path is not "
312 "writeable.");
313 active = false;
314 }
315 }
316
write(StringRef version,const SetVector<InputFile * > & inputs,StringRef output)317 void macho::DependencyTracker::write(StringRef version,
318 const SetVector<InputFile *> &inputs,
319 StringRef output) {
320 if (!active)
321 return;
322
323 std::error_code ec;
324 raw_fd_ostream os(path, ec, fs::OF_None);
325 if (ec) {
326 warn("Error writing dependency info to file");
327 return;
328 }
329
330 auto addDep = [&os](DepOpCode opcode, const StringRef &path) {
331 // XXX: Even though DepOpCode's underlying type is uint8_t,
332 // this cast is still needed because Clang older than 10.x has a bug,
333 // where it doesn't know to cast the enum to its underlying type.
334 // Hence `<< DepOpCode` is ambiguous to it.
335 os << static_cast<uint8_t>(opcode);
336 os << path;
337 os << '\0';
338 };
339
340 addDep(DepOpCode::Version, version);
341
342 // Sort the input by its names.
343 std::vector<StringRef> inputNames;
344 inputNames.reserve(inputs.size());
345 for (InputFile *f : inputs)
346 inputNames.push_back(f->getName());
347 llvm::sort(inputNames);
348
349 for (const StringRef &in : inputNames)
350 addDep(DepOpCode::Input, in);
351
352 for (const std::string &f : notFounds)
353 addDep(DepOpCode::NotFound, f);
354
355 addDep(DepOpCode::Output, output);
356 }
357