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// This file contains utility functions for the driver. Because there
10// are so many small functions, we created this separate file to make
11// Driver.cpp less cluttered.
12//
13//===----------------------------------------------------------------------===//
14
15#include "COFFLinkerContext.h"
16#include "Driver.h"
17#include "Symbols.h"
18#include "lld/Common/ErrorHandler.h"
19#include "lld/Common/Memory.h"
20#include "llvm/ADT/STLExtras.h"
21#include "llvm/ADT/StringExtras.h"
22#include "llvm/ADT/StringSwitch.h"
23#include "llvm/BinaryFormat/COFF.h"
24#include "llvm/Object/COFF.h"
25#include "llvm/Object/WindowsResource.h"
26#include "llvm/Option/Arg.h"
27#include "llvm/Option/ArgList.h"
28#include "llvm/Option/Option.h"
29#include "llvm/Support/CommandLine.h"
30#include "llvm/Support/FileUtilities.h"
31#include "llvm/Support/MathExtras.h"
32#include "llvm/Support/Process.h"
33#include "llvm/Support/Program.h"
34#include "llvm/Support/TimeProfiler.h"
35#include "llvm/Support/raw_ostream.h"
36#include "llvm/WindowsManifest/WindowsManifestMerger.h"
37#include <limits>
38#include <memory>
39#include <optional>
40
41using namespace llvm::COFF;
42using namespace llvm::opt;
43using namespace llvm;
44using llvm::sys::Process;
45
46namespace lld {
47namespace coff {
48namespace {
49
50const uint16_t SUBLANG_ENGLISH_US = 0x0409;
51const uint16_t RT_MANIFEST = 24;
52
53class Executor {
54public:
55 explicit Executor(StringRef s) : prog(saver().save(S: s)) {}
56 void add(StringRef s) { args.push_back(x: saver().save(S: s)); }
57 void add(std::string &s) { args.push_back(x: saver().save(S: s)); }
58 void add(Twine s) { args.push_back(x: saver().save(S: s)); }
59 void add(const char *s) { args.push_back(x: saver().save(S: s)); }
60
61 void run() {
62 ErrorOr<std::string> exeOrErr = sys::findProgramByName(Name: prog);
63 if (auto ec = exeOrErr.getError())
64 fatal(msg: "unable to find " + prog + " in PATH: " + ec.message());
65 StringRef exe = saver().save(S: *exeOrErr);
66 args.insert(position: args.begin(), x: exe);
67
68 if (sys::ExecuteAndWait(Program: args[0], Args: args) != 0)
69 fatal(msg: "ExecuteAndWait failed: " +
70 llvm::join(Begin: args.begin(), End: args.end(), Separator: " "));
71 }
72
73private:
74 StringRef prog;
75 std::vector<StringRef> args;
76};
77
78} // anonymous namespace
79
80// Parses a string in the form of "<integer>[,<integer>]".
81void LinkerDriver::parseNumbers(StringRef arg, uint64_t *addr, uint64_t *size) {
82 auto [s1, s2] = arg.split(Separator: ',');
83 if (s1.getAsInteger(Radix: 0, Result&: *addr))
84 fatal(msg: "invalid number: " + s1);
85 if (size && !s2.empty() && s2.getAsInteger(Radix: 0, Result&: *size))
86 fatal(msg: "invalid number: " + s2);
87}
88
89// Parses a string in the form of "<integer>[.<integer>]".
90// If second number is not present, Minor is set to 0.
91void LinkerDriver::parseVersion(StringRef arg, uint32_t *major,
92 uint32_t *minor) {
93 auto [s1, s2] = arg.split(Separator: '.');
94 if (s1.getAsInteger(Radix: 10, Result&: *major))
95 fatal(msg: "invalid number: " + s1);
96 *minor = 0;
97 if (!s2.empty() && s2.getAsInteger(Radix: 10, Result&: *minor))
98 fatal(msg: "invalid number: " + s2);
99}
100
101void LinkerDriver::parseGuard(StringRef fullArg) {
102 SmallVector<StringRef, 1> splitArgs;
103 fullArg.split(A&: splitArgs, Separator: ",");
104 for (StringRef arg : splitArgs) {
105 if (arg.equals_insensitive(RHS: "no"))
106 ctx.config.guardCF = GuardCFLevel::Off;
107 else if (arg.equals_insensitive(RHS: "nolongjmp"))
108 ctx.config.guardCF &= ~GuardCFLevel::LongJmp;
109 else if (arg.equals_insensitive(RHS: "noehcont"))
110 ctx.config.guardCF &= ~GuardCFLevel::EHCont;
111 else if (arg.equals_insensitive(RHS: "cf") || arg.equals_insensitive(RHS: "longjmp"))
112 ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::LongJmp;
113 else if (arg.equals_insensitive(RHS: "ehcont"))
114 ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::EHCont;
115 else
116 fatal(msg: "invalid argument to /guard: " + arg);
117 }
118}
119
120// Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
121void LinkerDriver::parseSubsystem(StringRef arg, WindowsSubsystem *sys,
122 uint32_t *major, uint32_t *minor,
123 bool *gotVersion) {
124 auto [sysStr, ver] = arg.split(Separator: ',');
125 std::string sysStrLower = sysStr.lower();
126 *sys = StringSwitch<WindowsSubsystem>(sysStrLower)
127 .Case(S: "boot_application", Value: IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
128 .Case(S: "console", Value: IMAGE_SUBSYSTEM_WINDOWS_CUI)
129 .Case(S: "default", Value: IMAGE_SUBSYSTEM_UNKNOWN)
130 .Case(S: "efi_application", Value: IMAGE_SUBSYSTEM_EFI_APPLICATION)
131 .Case(S: "efi_boot_service_driver", Value: IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
132 .Case(S: "efi_rom", Value: IMAGE_SUBSYSTEM_EFI_ROM)
133 .Case(S: "efi_runtime_driver", Value: IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
134 .Case(S: "native", Value: IMAGE_SUBSYSTEM_NATIVE)
135 .Case(S: "posix", Value: IMAGE_SUBSYSTEM_POSIX_CUI)
136 .Case(S: "windows", Value: IMAGE_SUBSYSTEM_WINDOWS_GUI)
137 .Default(Value: IMAGE_SUBSYSTEM_UNKNOWN);
138 if (*sys == IMAGE_SUBSYSTEM_UNKNOWN && sysStrLower != "default")
139 fatal(msg: "unknown subsystem: " + sysStr);
140 if (!ver.empty())
141 parseVersion(arg: ver, major, minor);
142 if (gotVersion)
143 *gotVersion = !ver.empty();
144}
145
146// Parse a string of the form of "<from>=<to>".
147// Results are directly written to Config.
148void LinkerDriver::parseAlternateName(StringRef s) {
149 auto [from, to] = s.split(Separator: '=');
150 if (from.empty() || to.empty())
151 fatal(msg: "/alternatename: invalid argument: " + s);
152 auto it = ctx.config.alternateNames.find(x: from);
153 if (it != ctx.config.alternateNames.end() && it->second != to)
154 fatal(msg: "/alternatename: conflicts: " + s);
155 ctx.config.alternateNames.insert(position: it, x: std::make_pair(x&: from, y&: to));
156}
157
158// Parse a string of the form of "<from>=<to>".
159// Results are directly written to Config.
160void LinkerDriver::parseMerge(StringRef s) {
161 auto [from, to] = s.split(Separator: '=');
162 if (from.empty() || to.empty())
163 fatal(msg: "/merge: invalid argument: " + s);
164 if (from == ".rsrc" || to == ".rsrc")
165 fatal(msg: "/merge: cannot merge '.rsrc' with any section");
166 if (from == ".reloc" || to == ".reloc")
167 fatal(msg: "/merge: cannot merge '.reloc' with any section");
168 auto pair = ctx.config.merge.insert(x: std::make_pair(x&: from, y&: to));
169 bool inserted = pair.second;
170 if (!inserted) {
171 StringRef existing = pair.first->second;
172 if (existing != to)
173 warn(msg: s + ": already merged into " + existing);
174 }
175}
176
177void LinkerDriver::parsePDBPageSize(StringRef s) {
178 int v;
179 if (s.getAsInteger(Radix: 0, Result&: v)) {
180 error(msg: "/pdbpagesize: invalid argument: " + s);
181 return;
182 }
183 if (v != 4096 && v != 8192 && v != 16384 && v != 32768) {
184 error(msg: "/pdbpagesize: invalid argument: " + s);
185 return;
186 }
187
188 ctx.config.pdbPageSize = v;
189}
190
191static uint32_t parseSectionAttributes(StringRef s) {
192 uint32_t ret = 0;
193 for (char c : s.lower()) {
194 switch (c) {
195 case 'd':
196 ret |= IMAGE_SCN_MEM_DISCARDABLE;
197 break;
198 case 'e':
199 ret |= IMAGE_SCN_MEM_EXECUTE;
200 break;
201 case 'k':
202 ret |= IMAGE_SCN_MEM_NOT_CACHED;
203 break;
204 case 'p':
205 ret |= IMAGE_SCN_MEM_NOT_PAGED;
206 break;
207 case 'r':
208 ret |= IMAGE_SCN_MEM_READ;
209 break;
210 case 's':
211 ret |= IMAGE_SCN_MEM_SHARED;
212 break;
213 case 'w':
214 ret |= IMAGE_SCN_MEM_WRITE;
215 break;
216 default:
217 fatal(msg: "/section: invalid argument: " + s);
218 }
219 }
220 return ret;
221}
222
223// Parses /section option argument.
224void LinkerDriver::parseSection(StringRef s) {
225 auto [name, attrs] = s.split(Separator: ',');
226 if (name.empty() || attrs.empty())
227 fatal(msg: "/section: invalid argument: " + s);
228 ctx.config.section[name] = parseSectionAttributes(s: attrs);
229}
230
231// Parses /aligncomm option argument.
232void LinkerDriver::parseAligncomm(StringRef s) {
233 auto [name, align] = s.split(Separator: ',');
234 if (name.empty() || align.empty()) {
235 error(msg: "/aligncomm: invalid argument: " + s);
236 return;
237 }
238 int v;
239 if (align.getAsInteger(Radix: 0, Result&: v)) {
240 error(msg: "/aligncomm: invalid argument: " + s);
241 return;
242 }
243 ctx.config.alignComm[std::string(name)] =
244 std::max(a: ctx.config.alignComm[std::string(name)], b: 1 << v);
245}
246
247// Parses /functionpadmin option argument.
248void LinkerDriver::parseFunctionPadMin(llvm::opt::Arg *a) {
249 StringRef arg = a->getNumValues() ? a->getValue() : "";
250 if (!arg.empty()) {
251 // Optional padding in bytes is given.
252 if (arg.getAsInteger(Radix: 0, Result&: ctx.config.functionPadMin))
253 error(msg: "/functionpadmin: invalid argument: " + arg);
254 return;
255 }
256 // No optional argument given.
257 // Set default padding based on machine, similar to link.exe.
258 // There is no default padding for ARM platforms.
259 if (ctx.config.machine == I386) {
260 ctx.config.functionPadMin = 5;
261 } else if (ctx.config.machine == AMD64) {
262 ctx.config.functionPadMin = 6;
263 } else {
264 error(msg: "/functionpadmin: invalid argument for this machine: " + arg);
265 }
266}
267
268// Parses /dependentloadflag option argument.
269void LinkerDriver::parseDependentLoadFlags(llvm::opt::Arg *a) {
270 StringRef arg = a->getNumValues() ? a->getValue() : "";
271 if (!arg.empty()) {
272 if (arg.getAsInteger(Radix: 0, Result&: ctx.config.dependentLoadFlags))
273 error(msg: "/dependentloadflag: invalid argument: " + arg);
274 return;
275 }
276 // MSVC linker reports error "no argument specified", although MSDN describes
277 // argument as optional.
278 error(msg: "/dependentloadflag: no argument specified");
279}
280
281// Parses a string in the form of "EMBED[,=<integer>]|NO".
282// Results are directly written to
283// Config.
284void LinkerDriver::parseManifest(StringRef arg) {
285 if (arg.equals_insensitive(RHS: "no")) {
286 ctx.config.manifest = Configuration::No;
287 return;
288 }
289 if (!arg.starts_with_insensitive(Prefix: "embed"))
290 fatal(msg: "invalid option " + arg);
291 ctx.config.manifest = Configuration::Embed;
292 arg = arg.substr(Start: strlen(s: "embed"));
293 if (arg.empty())
294 return;
295 if (!arg.starts_with_insensitive(Prefix: ",id="))
296 fatal(msg: "invalid option " + arg);
297 arg = arg.substr(Start: strlen(s: ",id="));
298 if (arg.getAsInteger(Radix: 0, Result&: ctx.config.manifestID))
299 fatal(msg: "invalid option " + arg);
300}
301
302// Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
303// Results are directly written to Config.
304void LinkerDriver::parseManifestUAC(StringRef arg) {
305 if (arg.equals_insensitive(RHS: "no")) {
306 ctx.config.manifestUAC = false;
307 return;
308 }
309 for (;;) {
310 arg = arg.ltrim();
311 if (arg.empty())
312 return;
313 if (arg.consume_front_insensitive(Prefix: "level=")) {
314 std::tie(args&: ctx.config.manifestLevel, args&: arg) = arg.split(Separator: " ");
315 continue;
316 }
317 if (arg.consume_front_insensitive(Prefix: "uiaccess=")) {
318 std::tie(args&: ctx.config.manifestUIAccess, args&: arg) = arg.split(Separator: " ");
319 continue;
320 }
321 fatal(msg: "invalid option " + arg);
322 }
323}
324
325// Parses a string in the form of "cd|net[,(cd|net)]*"
326// Results are directly written to Config.
327void LinkerDriver::parseSwaprun(StringRef arg) {
328 do {
329 auto [swaprun, newArg] = arg.split(Separator: ',');
330 if (swaprun.equals_insensitive(RHS: "cd"))
331 ctx.config.swaprunCD = true;
332 else if (swaprun.equals_insensitive(RHS: "net"))
333 ctx.config.swaprunNet = true;
334 else if (swaprun.empty())
335 error(msg: "/swaprun: missing argument");
336 else
337 error(msg: "/swaprun: invalid argument: " + swaprun);
338 // To catch trailing commas, e.g. `/spawrun:cd,`
339 if (newArg.empty() && arg.ends_with(Suffix: ","))
340 error(msg: "/swaprun: missing argument");
341 arg = newArg;
342 } while (!arg.empty());
343}
344
345// An RAII temporary file class that automatically removes a temporary file.
346namespace {
347class TemporaryFile {
348public:
349 TemporaryFile(StringRef prefix, StringRef extn, StringRef contents = "") {
350 SmallString<128> s;
351 if (auto ec = sys::fs::createTemporaryFile(Prefix: "lld-" + prefix, Suffix: extn, ResultPath&: s))
352 fatal(msg: "cannot create a temporary file: " + ec.message());
353 path = std::string(s);
354
355 if (!contents.empty()) {
356 std::error_code ec;
357 raw_fd_ostream os(path, ec, sys::fs::OF_None);
358 if (ec)
359 fatal(msg: "failed to open " + path + ": " + ec.message());
360 os << contents;
361 }
362 }
363
364 TemporaryFile(TemporaryFile &&obj) noexcept { std::swap(lhs&: path, rhs&: obj.path); }
365
366 ~TemporaryFile() {
367 if (path.empty())
368 return;
369 if (sys::fs::remove(path))
370 fatal(msg: "failed to remove " + path);
371 }
372
373 // Returns a memory buffer of this temporary file.
374 // Note that this function does not leave the file open,
375 // so it is safe to remove the file immediately after this function
376 // is called (you cannot remove an opened file on Windows.)
377 std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
378 // IsVolatile=true forces MemoryBuffer to not use mmap().
379 return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
380 /*RequiresNullTerminator=*/false,
381 /*IsVolatile=*/true),
382 "could not open " + path);
383 }
384
385 std::string path;
386};
387}
388
389std::string LinkerDriver::createDefaultXml() {
390 std::string ret;
391 raw_string_ostream os(ret);
392
393 // Emit the XML. Note that we do *not* verify that the XML attributes are
394 // syntactically correct. This is intentional for link.exe compatibility.
395 os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
396 << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
397 << " manifestVersion=\"1.0\">\n";
398 if (ctx.config.manifestUAC) {
399 os << " <trustInfo>\n"
400 << " <security>\n"
401 << " <requestedPrivileges>\n"
402 << " <requestedExecutionLevel level=" << ctx.config.manifestLevel
403 << " uiAccess=" << ctx.config.manifestUIAccess << "/>\n"
404 << " </requestedPrivileges>\n"
405 << " </security>\n"
406 << " </trustInfo>\n";
407 }
408 for (auto manifestDependency : ctx.config.manifestDependencies) {
409 os << " <dependency>\n"
410 << " <dependentAssembly>\n"
411 << " <assemblyIdentity " << manifestDependency << " />\n"
412 << " </dependentAssembly>\n"
413 << " </dependency>\n";
414 }
415 os << "</assembly>\n";
416 return os.str();
417}
418
419std::string
420LinkerDriver::createManifestXmlWithInternalMt(StringRef defaultXml) {
421 std::unique_ptr<MemoryBuffer> defaultXmlCopy =
422 MemoryBuffer::getMemBufferCopy(InputData: defaultXml);
423
424 windows_manifest::WindowsManifestMerger merger;
425 if (auto e = merger.merge(Manifest: *defaultXmlCopy.get()))
426 fatal(msg: "internal manifest tool failed on default xml: " +
427 toString(E: std::move(e)));
428
429 for (StringRef filename : ctx.config.manifestInput) {
430 std::unique_ptr<MemoryBuffer> manifest =
431 check(e: MemoryBuffer::getFile(Filename: filename));
432 // Call takeBuffer to include in /reproduce: output if applicable.
433 if (auto e = merger.merge(Manifest: takeBuffer(mb: std::move(manifest))))
434 fatal(msg: "internal manifest tool failed on file " + filename + ": " +
435 toString(E: std::move(e)));
436 }
437
438 return std::string(merger.getMergedManifest().get()->getBuffer());
439}
440
441std::string
442LinkerDriver::createManifestXmlWithExternalMt(StringRef defaultXml) {
443 // Create the default manifest file as a temporary file.
444 TemporaryFile Default("defaultxml", "manifest");
445 std::error_code ec;
446 raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
447 if (ec)
448 fatal(msg: "failed to open " + Default.path + ": " + ec.message());
449 os << defaultXml;
450 os.close();
451
452 // Merge user-supplied manifests if they are given. Since libxml2 is not
453 // enabled, we must shell out to Microsoft's mt.exe tool.
454 TemporaryFile user("user", "manifest");
455
456 Executor e("mt.exe");
457 e.add(s: "/manifest");
458 e.add(s&: Default.path);
459 for (StringRef filename : ctx.config.manifestInput) {
460 e.add(s: "/manifest");
461 e.add(s: filename);
462
463 // Manually add the file to the /reproduce: tar if needed.
464 if (tar)
465 if (auto mbOrErr = MemoryBuffer::getFile(Filename: filename))
466 takeBuffer(mb: std::move(*mbOrErr));
467 }
468 e.add(s: "/nologo");
469 e.add(s: "/out:" + StringRef(user.path));
470 e.run();
471
472 return std::string(
473 CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
474 .get()
475 ->getBuffer());
476}
477
478std::string LinkerDriver::createManifestXml() {
479 std::string defaultXml = createDefaultXml();
480 if (ctx.config.manifestInput.empty())
481 return defaultXml;
482
483 if (windows_manifest::isAvailable())
484 return createManifestXmlWithInternalMt(defaultXml);
485
486 return createManifestXmlWithExternalMt(defaultXml);
487}
488
489std::unique_ptr<WritableMemoryBuffer>
490LinkerDriver::createMemoryBufferForManifestRes(size_t manifestSize) {
491 size_t resSize = alignTo(
492 Value: object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
493 sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
494 sizeof(object::WinResHeaderSuffix) + manifestSize,
495 Align: object::WIN_RES_DATA_ALIGNMENT);
496 return WritableMemoryBuffer::getNewMemBuffer(Size: resSize, BufferName: ctx.config.outputFile +
497 ".manifest.res");
498}
499
500static void writeResFileHeader(char *&buf) {
501 memcpy(dest: buf, src: COFF::WinResMagic, n: sizeof(COFF::WinResMagic));
502 buf += sizeof(COFF::WinResMagic);
503 memset(s: buf, c: 0, n: object::WIN_RES_NULL_ENTRY_SIZE);
504 buf += object::WIN_RES_NULL_ENTRY_SIZE;
505}
506
507static void writeResEntryHeader(char *&buf, size_t manifestSize,
508 int manifestID) {
509 // Write the prefix.
510 auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
511 prefix->DataSize = manifestSize;
512 prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
513 sizeof(object::WinResIDs) +
514 sizeof(object::WinResHeaderSuffix);
515 buf += sizeof(object::WinResHeaderPrefix);
516
517 // Write the Type/Name IDs.
518 auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
519 iDs->setType(RT_MANIFEST);
520 iDs->setName(manifestID);
521 buf += sizeof(object::WinResIDs);
522
523 // Write the suffix.
524 auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
525 suffix->DataVersion = 0;
526 suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
527 suffix->Language = SUBLANG_ENGLISH_US;
528 suffix->Version = 0;
529 suffix->Characteristics = 0;
530 buf += sizeof(object::WinResHeaderSuffix);
531}
532
533// Create a resource file containing a manifest XML.
534std::unique_ptr<MemoryBuffer> LinkerDriver::createManifestRes() {
535 std::string manifest = createManifestXml();
536
537 std::unique_ptr<WritableMemoryBuffer> res =
538 createMemoryBufferForManifestRes(manifestSize: manifest.size());
539
540 char *buf = res->getBufferStart();
541 writeResFileHeader(buf);
542 writeResEntryHeader(buf, manifestSize: manifest.size(), manifestID: ctx.config.manifestID);
543
544 // Copy the manifest data into the .res file.
545 std::copy(first: manifest.begin(), last: manifest.end(), result: buf);
546 return std::move(res);
547}
548
549void LinkerDriver::createSideBySideManifest() {
550 std::string path = std::string(ctx.config.manifestFile);
551 if (path == "")
552 path = ctx.config.outputFile + ".manifest";
553 std::error_code ec;
554 raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
555 if (ec)
556 fatal(msg: "failed to create manifest: " + ec.message());
557 out << createManifestXml();
558}
559
560// Parse a string in the form of
561// "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
562// or "<name>=<dllname>.<name>".
563// Used for parsing /export arguments.
564Export LinkerDriver::parseExport(StringRef arg) {
565 Export e;
566 e.source = ExportSource::Export;
567
568 StringRef rest;
569 std::tie(args&: e.name, args&: rest) = arg.split(Separator: ",");
570 if (e.name.empty())
571 goto err;
572
573 if (e.name.contains(C: '=')) {
574 auto [x, y] = e.name.split(Separator: "=");
575
576 // If "<name>=<dllname>.<name>".
577 if (y.contains(Other: ".")) {
578 e.name = x;
579 e.forwardTo = y;
580 } else {
581 e.extName = x;
582 e.name = y;
583 if (e.name.empty())
584 goto err;
585 }
586 }
587
588 // Optional parameters
589 // "[,@ordinal[,NONAME]][,DATA][,PRIVATE][,EXPORTAS,exportname]"
590 while (!rest.empty()) {
591 StringRef tok;
592 std::tie(args&: tok, args&: rest) = rest.split(Separator: ",");
593 if (tok.equals_insensitive(RHS: "noname")) {
594 if (e.ordinal == 0)
595 goto err;
596 e.noname = true;
597 continue;
598 }
599 if (tok.equals_insensitive(RHS: "data")) {
600 e.data = true;
601 continue;
602 }
603 if (tok.equals_insensitive(RHS: "constant")) {
604 e.constant = true;
605 continue;
606 }
607 if (tok.equals_insensitive(RHS: "private")) {
608 e.isPrivate = true;
609 continue;
610 }
611 if (tok.equals_insensitive(RHS: "exportas")) {
612 if (!rest.empty() && !rest.contains(C: ','))
613 e.exportAs = rest;
614 else
615 error(msg: "invalid EXPORTAS value: " + rest);
616 break;
617 }
618 if (tok.starts_with(Prefix: "@")) {
619 int32_t ord;
620 if (tok.substr(Start: 1).getAsInteger(Radix: 0, Result&: ord))
621 goto err;
622 if (ord <= 0 || 65535 < ord)
623 goto err;
624 e.ordinal = ord;
625 continue;
626 }
627 goto err;
628 }
629 return e;
630
631err:
632 fatal(msg: "invalid /export: " + arg);
633}
634
635static StringRef undecorate(COFFLinkerContext &ctx, StringRef sym) {
636 if (ctx.config.machine != I386)
637 return sym;
638 // In MSVC mode, a fully decorated stdcall function is exported
639 // as-is with the leading underscore (with type IMPORT_NAME).
640 // In MinGW mode, a decorated stdcall function gets the underscore
641 // removed, just like normal cdecl functions.
642 if (sym.starts_with(Prefix: "_") && sym.contains(C: '@') && !ctx.config.mingw)
643 return sym;
644 return sym.starts_with(Prefix: "_") ? sym.substr(Start: 1) : sym;
645}
646
647// Convert stdcall/fastcall style symbols into unsuffixed symbols,
648// with or without a leading underscore. (MinGW specific.)
649static StringRef killAt(StringRef sym, bool prefix) {
650 if (sym.empty())
651 return sym;
652 // Strip any trailing stdcall suffix
653 sym = sym.substr(Start: 0, N: sym.find(C: '@', From: 1));
654 if (!sym.starts_with(Prefix: "@")) {
655 if (prefix && !sym.starts_with(Prefix: "_"))
656 return saver().save(S: "_" + sym);
657 return sym;
658 }
659 // For fastcall, remove the leading @ and replace it with an
660 // underscore, if prefixes are used.
661 sym = sym.substr(Start: 1);
662 if (prefix)
663 sym = saver().save(S: "_" + sym);
664 return sym;
665}
666
667static StringRef exportSourceName(ExportSource s) {
668 switch (s) {
669 case ExportSource::Directives:
670 return "source file (directives)";
671 case ExportSource::Export:
672 return "/export";
673 case ExportSource::ModuleDefinition:
674 return "/def";
675 default:
676 llvm_unreachable("unknown ExportSource");
677 }
678}
679
680// Performs error checking on all /export arguments.
681// It also sets ordinals.
682void LinkerDriver::fixupExports() {
683 llvm::TimeTraceScope timeScope("Fixup exports");
684 // Symbol ordinals must be unique.
685 std::set<uint16_t> ords;
686 for (Export &e : ctx.config.exports) {
687 if (e.ordinal == 0)
688 continue;
689 if (!ords.insert(x: e.ordinal).second)
690 fatal(msg: "duplicate export ordinal: " + e.name);
691 }
692
693 for (Export &e : ctx.config.exports) {
694 if (!e.exportAs.empty()) {
695 e.exportName = e.exportAs;
696 } else if (!e.forwardTo.empty()) {
697 e.exportName = undecorate(ctx, sym: e.name);
698 } else {
699 e.exportName = undecorate(ctx, sym: e.extName.empty() ? e.name : e.extName);
700 }
701 }
702
703 if (ctx.config.killAt && ctx.config.machine == I386) {
704 for (Export &e : ctx.config.exports) {
705 e.name = killAt(sym: e.name, prefix: true);
706 e.exportName = killAt(sym: e.exportName, prefix: false);
707 e.extName = killAt(sym: e.extName, prefix: true);
708 e.symbolName = killAt(sym: e.symbolName, prefix: true);
709 }
710 }
711
712 // Uniquefy by name.
713 DenseMap<StringRef, std::pair<Export *, unsigned>> map(
714 ctx.config.exports.size());
715 std::vector<Export> v;
716 for (Export &e : ctx.config.exports) {
717 auto pair = map.insert(KV: std::make_pair(x&: e.exportName, y: std::make_pair(x: &e, y: 0)));
718 bool inserted = pair.second;
719 if (inserted) {
720 pair.first->second.second = v.size();
721 v.push_back(x: e);
722 continue;
723 }
724 Export *existing = pair.first->second.first;
725 if (e == *existing || e.name != existing->name)
726 continue;
727 // If the existing export comes from .OBJ directives, we are allowed to
728 // overwrite it with /DEF: or /EXPORT without any warning, as MSVC link.exe
729 // does.
730 if (existing->source == ExportSource::Directives) {
731 *existing = e;
732 v[pair.first->second.second] = e;
733 continue;
734 }
735 if (existing->source == e.source) {
736 warn(msg: Twine("duplicate ") + exportSourceName(s: existing->source) +
737 " option: " + e.name);
738 } else {
739 warn(msg: "duplicate export: " + e.name +
740 Twine(" first seen in " + exportSourceName(s: existing->source) +
741 Twine(", now in " + exportSourceName(s: e.source))));
742 }
743 }
744 ctx.config.exports = std::move(v);
745
746 // Sort by name.
747 llvm::sort(C&: ctx.config.exports, Comp: [](const Export &a, const Export &b) {
748 return a.exportName < b.exportName;
749 });
750}
751
752void LinkerDriver::assignExportOrdinals() {
753 // Assign unique ordinals if default (= 0).
754 uint32_t max = 0;
755 for (Export &e : ctx.config.exports)
756 max = std::max(a: max, b: (uint32_t)e.ordinal);
757 for (Export &e : ctx.config.exports)
758 if (e.ordinal == 0)
759 e.ordinal = ++max;
760 if (max > std::numeric_limits<uint16_t>::max())
761 fatal(msg: "too many exported symbols (got " + Twine(max) + ", max " +
762 Twine(std::numeric_limits<uint16_t>::max()) + ")");
763}
764
765// Parses a string in the form of "key=value" and check
766// if value matches previous values for the same key.
767void LinkerDriver::checkFailIfMismatch(StringRef arg, InputFile *source) {
768 auto [k, v] = arg.split(Separator: '=');
769 if (k.empty() || v.empty())
770 fatal(msg: "/failifmismatch: invalid argument: " + arg);
771 std::pair<StringRef, InputFile *> existing = ctx.config.mustMatch[k];
772 if (!existing.first.empty() && v != existing.first) {
773 std::string sourceStr = source ? toString(file: source) : "cmd-line";
774 std::string existingStr =
775 existing.second ? toString(file: existing.second) : "cmd-line";
776 fatal(msg: "/failifmismatch: mismatch detected for '" + k + "':\n>>> " +
777 existingStr + " has value " + existing.first + "\n>>> " + sourceStr +
778 " has value " + v);
779 }
780 ctx.config.mustMatch[k] = {v, source};
781}
782
783// Convert Windows resource files (.res files) to a .obj file.
784// Does what cvtres.exe does, but in-process and cross-platform.
785MemoryBufferRef LinkerDriver::convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
786 ArrayRef<ObjFile *> objs) {
787 object::WindowsResourceParser parser(/* MinGW */ ctx.config.mingw);
788
789 std::vector<std::string> duplicates;
790 for (MemoryBufferRef mb : mbs) {
791 std::unique_ptr<object::Binary> bin = check(e: object::createBinary(Source: mb));
792 object::WindowsResource *rf = dyn_cast<object::WindowsResource>(Val: bin.get());
793 if (!rf)
794 fatal(msg: "cannot compile non-resource file as resource");
795
796 if (auto ec = parser.parse(WR: rf, Duplicates&: duplicates))
797 fatal(msg: toString(E: std::move(ec)));
798 }
799
800 // Note: This processes all .res files before all objs. Ideally they'd be
801 // handled in the same order they were linked (to keep the right one, if
802 // there are duplicates that are tolerated due to forceMultipleRes).
803 for (ObjFile *f : objs) {
804 object::ResourceSectionRef rsf;
805 if (auto ec = rsf.load(O: f->getCOFFObj()))
806 fatal(msg: toString(file: f) + ": " + toString(E: std::move(ec)));
807
808 if (auto ec = parser.parse(RSR&: rsf, Filename: f->getName(), Duplicates&: duplicates))
809 fatal(msg: toString(E: std::move(ec)));
810 }
811
812 if (ctx.config.mingw)
813 parser.cleanUpManifests(Duplicates&: duplicates);
814
815 for (const auto &dupeDiag : duplicates)
816 if (ctx.config.forceMultipleRes)
817 warn(msg: dupeDiag);
818 else
819 error(msg: dupeDiag);
820
821 Expected<std::unique_ptr<MemoryBuffer>> e =
822 llvm::object::writeWindowsResourceCOFF(MachineType: ctx.config.machine, Parser: parser,
823 TimeDateStamp: ctx.config.timestamp);
824 if (!e)
825 fatal(msg: "failed to write .res to COFF: " + toString(E: e.takeError()));
826
827 MemoryBufferRef mbref = **e;
828 make<std::unique_ptr<MemoryBuffer>>(args: std::move(*e)); // take ownership
829 return mbref;
830}
831
832// Create OptTable
833
834// Create prefix string literals used in Options.td
835#define PREFIX(NAME, VALUE) \
836 static constexpr llvm::StringLiteral NAME##_init[] = VALUE; \
837 static constexpr llvm::ArrayRef<llvm::StringLiteral> NAME( \
838 NAME##_init, std::size(NAME##_init) - 1);
839#include "Options.inc"
840#undef PREFIX
841
842// Create table mapping all options defined in Options.td
843static constexpr llvm::opt::OptTable::Info infoTable[] = {
844#define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
845#include "Options.inc"
846#undef OPTION
847};
848
849COFFOptTable::COFFOptTable() : GenericOptTable(infoTable, true) {}
850
851// Set color diagnostics according to --color-diagnostics={auto,always,never}
852// or --no-color-diagnostics flags.
853static void handleColorDiagnostics(opt::InputArgList &args) {
854 auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
855 OPT_no_color_diagnostics);
856 if (!arg)
857 return;
858 if (arg->getOption().getID() == OPT_color_diagnostics) {
859 lld::errs().enable_colors(enable: true);
860 } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
861 lld::errs().enable_colors(enable: false);
862 } else {
863 StringRef s = arg->getValue();
864 if (s == "always")
865 lld::errs().enable_colors(enable: true);
866 else if (s == "never")
867 lld::errs().enable_colors(enable: false);
868 else if (s != "auto")
869 error(msg: "unknown option: --color-diagnostics=" + s);
870 }
871}
872
873static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
874 if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
875 StringRef s = arg->getValue();
876 if (s != "windows" && s != "posix")
877 error(msg: "invalid response file quoting: " + s);
878 if (s == "windows")
879 return cl::TokenizeWindowsCommandLine;
880 return cl::TokenizeGNUCommandLine;
881 }
882 // The COFF linker always defaults to Windows quoting.
883 return cl::TokenizeWindowsCommandLine;
884}
885
886ArgParser::ArgParser(COFFLinkerContext &c) : ctx(c) {}
887
888// Parses a given list of options.
889opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
890 // Make InputArgList from string vectors.
891 unsigned missingIndex;
892 unsigned missingCount;
893
894 // We need to get the quoting style for response files before parsing all
895 // options so we parse here before and ignore all the options but
896 // --rsp-quoting and /lldignoreenv.
897 // (This means --rsp-quoting can't be added through %LINK%.)
898 opt::InputArgList args =
899 ctx.optTable.ParseArgs(argv, missingIndex, missingCount);
900
901 // Expand response files (arguments in the form of @<filename>) and insert
902 // flags from %LINK% and %_LINK_%, and then parse the argument again.
903 SmallVector<const char *, 256> expandedArgv(argv.data(),
904 argv.data() + argv.size());
905 if (!args.hasArg(OPT_lldignoreenv))
906 addLINK(argv&: expandedArgv);
907 cl::ExpandResponseFiles(Saver&: saver(), Tokenizer: getQuotingStyle(args), Argv&: expandedArgv);
908 args = ctx.optTable.ParseArgs(ArrayRef(expandedArgv).drop_front(),
909 missingIndex, missingCount);
910
911 // Print the real command line if response files are expanded.
912 if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
913 std::string msg = "Command line:";
914 for (const char *s : expandedArgv)
915 msg += " " + std::string(s);
916 message(msg);
917 }
918
919 // Save the command line after response file expansion so we can write it to
920 // the PDB if necessary. Mimic MSVC, which skips input files.
921 ctx.config.argv = {argv[0]};
922 for (opt::Arg *arg : args) {
923 if (arg->getOption().getKind() != opt::Option::InputClass) {
924 ctx.config.argv.emplace_back(args.getArgString(arg->getIndex()));
925 }
926 }
927
928 // Handle /WX early since it converts missing argument warnings to errors.
929 errorHandler().fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
930
931 if (missingCount)
932 fatal(msg: Twine(args.getArgString(Index: missingIndex)) + ": missing argument");
933
934 handleColorDiagnostics(args);
935
936 for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
937 std::string nearest;
938 if (ctx.optTable.findNearest(arg->getAsString(args), nearest) > 1)
939 warn("ignoring unknown argument '" + arg->getAsString(args) + "'");
940 else
941 warn("ignoring unknown argument '" + arg->getAsString(args) +
942 "', did you mean '" + nearest + "'");
943 }
944
945 if (args.hasArg(OPT_lib))
946 warn(msg: "ignoring /lib since it's not the first argument");
947
948 return args;
949}
950
951// Tokenizes and parses a given string as command line in .drective section.
952ParsedDirectives ArgParser::parseDirectives(StringRef s) {
953 ParsedDirectives result;
954 SmallVector<const char *, 16> rest;
955
956 // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
957 // potentially every symbol in the object, so they must be handled quickly.
958 SmallVector<StringRef, 16> tokens;
959 cl::TokenizeWindowsCommandLineNoCopy(Source: s, Saver&: saver(), NewArgv&: tokens);
960 for (StringRef tok : tokens) {
961 if (tok.starts_with_insensitive("/export:") ||
962 tok.starts_with_insensitive("-export:"))
963 result.exports.push_back(tok.substr(strlen("/export:")));
964 else if (tok.starts_with_insensitive("/include:") ||
965 tok.starts_with_insensitive("-include:"))
966 result.includes.push_back(tok.substr(strlen("/include:")));
967 else if (tok.starts_with_insensitive("/exclude-symbols:") ||
968 tok.starts_with_insensitive("-exclude-symbols:"))
969 result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
970 else {
971 // Copy substrings that are not valid C strings. The tokenizer may have
972 // already copied quoted arguments for us, so those do not need to be
973 // copied again.
974 bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
975 rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
976 }
977 }
978
979 // Make InputArgList from unparsed string vectors.
980 unsigned missingIndex;
981 unsigned missingCount;
982
983 result.args = ctx.optTable.ParseArgs(rest, missingIndex, missingCount);
984
985 if (missingCount)
986 fatal(msg: Twine(result.args.getArgString(Index: missingIndex)) + ": missing argument");
987 for (auto *arg : result.args.filtered(OPT_UNKNOWN))
988 warn("ignoring unknown argument: " + arg->getAsString(result.args));
989 return result;
990}
991
992// link.exe has an interesting feature. If LINK or _LINK_ environment
993// variables exist, their contents are handled as command line strings.
994// So you can pass extra arguments using them.
995void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
996 // Concatenate LINK env and command line arguments, and then parse them.
997 if (std::optional<std::string> s = Process::GetEnv(name: "LINK")) {
998 std::vector<const char *> v = tokenize(*s);
999 argv.insert(std::next(argv.begin()), v.begin(), v.end());
1000 }
1001 if (std::optional<std::string> s = Process::GetEnv(name: "_LINK_")) {
1002 std::vector<const char *> v = tokenize(*s);
1003 argv.insert(std::next(argv.begin()), v.begin(), v.end());
1004 }
1005}
1006
1007std::vector<const char *> ArgParser::tokenize(StringRef s) {
1008 SmallVector<const char *, 16> tokens;
1009 cl::TokenizeWindowsCommandLine(Source: s, Saver&: saver(), NewArgv&: tokens);
1010 return std::vector<const char *>(tokens.begin(), tokens.end());
1011}
1012
1013void LinkerDriver::printHelp(const char *argv0) {
1014 ctx.optTable.printHelp(lld::outs(),
1015 (std::string(argv0) + " [options] file...").c_str(),
1016 "LLVM Linker", false);
1017}
1018
1019} // namespace coff
1020} // namespace lld
1021

source code of lld/COFF/DriverUtils.cpp