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- //===- Driver.cpp ---------------------------------------------------------===//
- //
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
- // See https://llvm.org/LICENSE.txt for license information.
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
- //
- //===----------------------------------------------------------------------===//
- #include "Driver.h"
- #include "Config.h"
- #include "DebugTypes.h"
- #include "ICF.h"
- #include "InputFiles.h"
- #include "MarkLive.h"
- #include "MinGW.h"
- #include "SymbolTable.h"
- #include "Symbols.h"
- #include "Writer.h"
- #include "lld/Common/Args.h"
- #include "lld/Common/Driver.h"
- #include "lld/Common/ErrorHandler.h"
- #include "lld/Common/Filesystem.h"
- #include "lld/Common/Memory.h"
- #include "lld/Common/Threads.h"
- #include "lld/Common/Timer.h"
- #include "lld/Common/Version.h"
- #include "llvm/ADT/Optional.h"
- #include "llvm/ADT/StringSwitch.h"
- #include "llvm/BinaryFormat/Magic.h"
- #include "llvm/LTO/LTO.h"
- #include "llvm/Object/ArchiveWriter.h"
- #include "llvm/Object/COFFImportFile.h"
- #include "llvm/Object/COFFModuleDefinition.h"
- #include "llvm/Object/WindowsMachineFlag.h"
- #include "llvm/Option/Arg.h"
- #include "llvm/Option/ArgList.h"
- #include "llvm/Option/Option.h"
- #include "llvm/Support/CommandLine.h"
- #include "llvm/Support/Debug.h"
- #include "llvm/Support/LEB128.h"
- #include "llvm/Support/MathExtras.h"
- #include "llvm/Support/Path.h"
- #include "llvm/Support/Process.h"
- #include "llvm/Support/TarWriter.h"
- #include "llvm/Support/TargetSelect.h"
- #include "llvm/Support/raw_ostream.h"
- #include "llvm/ToolDrivers/llvm-lib/LibDriver.h"
- #include <algorithm>
- #include <future>
- #include <memory>
- using namespace llvm;
- using namespace llvm::object;
- using namespace llvm::COFF;
- using llvm::sys::Process;
- namespace polly {
- void initializePollyPasses(llvm::PassRegistry &Registry);
- }
- namespace lld {
- namespace coff {
- static Timer inputFileTimer("Input File Reading", Timer::root());
- Configuration *config;
- LinkerDriver *driver;
- bool link(ArrayRef<const char *> args, bool canExitEarly, raw_ostream &stdoutOS,
- raw_ostream &stderrOS) {
- lld::stdoutOS = &stdoutOS;
- lld::stderrOS = &stderrOS;
- errorHandler().logName = args::getFilenameWithoutExe(args[0]);
- errorHandler().errorLimitExceededMsg =
- "too many errors emitted, stopping now"
- " (use /errorlimit:0 to see all errors)";
- errorHandler().exitEarly = canExitEarly;
- stderrOS.enable_colors(stderrOS.has_colors());
- config = make<Configuration>();
- symtab = make<SymbolTable>();
- driver = make<LinkerDriver>();
- driver->link(args);
- // Call exit() if we can to avoid calling destructors.
- if (canExitEarly)
- exitLld(errorCount() ? 1 : 0);
- freeArena();
- ObjFile::instances.clear();
- ImportFile::instances.clear();
- BitcodeFile::instances.clear();
- memset(MergeChunk::instances, 0, sizeof(MergeChunk::instances));
- return !errorCount();
- }
- // Parse options of the form "old;new".
- static std::pair<StringRef, StringRef> getOldNewOptions(opt::InputArgList &args,
- unsigned id) {
- auto *arg = args.getLastArg(id);
- if (!arg)
- return {"", ""};
- StringRef s = arg->getValue();
- std::pair<StringRef, StringRef> ret = s.split(';');
- if (ret.second.empty())
- error(arg->getSpelling() + " expects 'old;new' format, but got " + s);
- return ret;
- }
- // Drop directory components and replace extension with
- // ".exe", ".dll" or ".sys".
- static std::string getOutputPath(StringRef path) {
- StringRef ext = ".exe";
- if (config->dll)
- ext = ".dll";
- else if (config->driver)
- ext = ".sys";
- return (sys::path::stem(path) + ext).str();
- }
- // Returns true if S matches /crtend.?\.o$/.
- static bool isCrtend(StringRef s) {
- if (!s.endswith(".o"))
- return false;
- s = s.drop_back(2);
- if (s.endswith("crtend"))
- return true;
- return !s.empty() && s.drop_back().endswith("crtend");
- }
- // ErrorOr is not default constructible, so it cannot be used as the type
- // parameter of a future.
- // FIXME: We could open the file in createFutureForFile and avoid needing to
- // return an error here, but for the moment that would cost us a file descriptor
- // (a limited resource on Windows) for the duration that the future is pending.
- using MBErrPair = std::pair<std::unique_ptr<MemoryBuffer>, std::error_code>;
- // Create a std::future that opens and maps a file using the best strategy for
- // the host platform.
- static std::future<MBErrPair> createFutureForFile(std::string path) {
- #if _WIN32
- // On Windows, file I/O is relatively slow so it is best to do this
- // asynchronously.
- auto strategy = std::launch::async;
- #else
- auto strategy = std::launch::deferred;
- #endif
- return std::async(strategy, [=]() {
- auto mbOrErr = MemoryBuffer::getFile(path,
- /*FileSize*/ -1,
- /*RequiresNullTerminator*/ false);
- if (!mbOrErr)
- return MBErrPair{nullptr, mbOrErr.getError()};
- return MBErrPair{std::move(*mbOrErr), std::error_code()};
- });
- }
- // Symbol names are mangled by prepending "_" on x86.
- static StringRef mangle(StringRef sym) {
- assert(config->machine != IMAGE_FILE_MACHINE_UNKNOWN);
- if (config->machine == I386)
- return saver.save("_" + sym);
- return sym;
- }
- static bool findUnderscoreMangle(StringRef sym) {
- Symbol *s = symtab->findMangle(mangle(sym));
- return s && !isa<Undefined>(s);
- }
- MemoryBufferRef LinkerDriver::takeBuffer(std::unique_ptr<MemoryBuffer> mb) {
- MemoryBufferRef mbref = *mb;
- make<std::unique_ptr<MemoryBuffer>>(std::move(mb)); // take ownership
- if (driver->tar)
- driver->tar->append(relativeToRoot(mbref.getBufferIdentifier()),
- mbref.getBuffer());
- return mbref;
- }
- void LinkerDriver::addBuffer(std::unique_ptr<MemoryBuffer> mb,
- bool wholeArchive, bool lazy) {
- StringRef filename = mb->getBufferIdentifier();
- MemoryBufferRef mbref = takeBuffer(std::move(mb));
- filePaths.push_back(filename);
- // File type is detected by contents, not by file extension.
- switch (identify_magic(mbref.getBuffer())) {
- case file_magic::windows_resource:
- resources.push_back(mbref);
- break;
- case file_magic::archive:
- if (wholeArchive) {
- std::unique_ptr<Archive> file =
- CHECK(Archive::create(mbref), filename + ": failed to parse archive");
- Archive *archive = file.get();
- make<std::unique_ptr<Archive>>(std::move(file)); // take ownership
- int memberIndex = 0;
- for (MemoryBufferRef m : getArchiveMembers(archive))
- addArchiveBuffer(m, "<whole-archive>", filename, memberIndex++);
- return;
- }
- symtab->addFile(make<ArchiveFile>(mbref));
- break;
- case file_magic::bitcode:
- if (lazy)
- symtab->addFile(make<LazyObjFile>(mbref));
- else
- symtab->addFile(make<BitcodeFile>(mbref, "", 0));
- break;
- case file_magic::coff_object:
- case file_magic::coff_import_library:
- if (lazy)
- symtab->addFile(make<LazyObjFile>(mbref));
- else
- symtab->addFile(make<ObjFile>(mbref));
- break;
- case file_magic::pdb:
- loadTypeServerSource(mbref);
- break;
- case file_magic::coff_cl_gl_object:
- error(filename + ": is not a native COFF file. Recompile without /GL");
- break;
- case file_magic::pecoff_executable:
- if (filename.endswith_lower(".dll")) {
- error(filename + ": bad file type. Did you specify a DLL instead of an "
- "import library?");
- break;
- }
- LLVM_FALLTHROUGH;
- default:
- error(mbref.getBufferIdentifier() + ": unknown file type");
- break;
- }
- }
- void LinkerDriver::enqueuePath(StringRef path, bool wholeArchive, bool lazy) {
- auto future =
- std::make_shared<std::future<MBErrPair>>(createFutureForFile(path));
- std::string pathStr = path;
- enqueueTask([=]() {
- auto mbOrErr = future->get();
- if (mbOrErr.second) {
- std::string msg =
- "could not open '" + pathStr + "': " + mbOrErr.second.message();
- // Check if the filename is a typo for an option flag. OptTable thinks
- // that all args that are not known options and that start with / are
- // filenames, but e.g. `/nodefaultlibs` is more likely a typo for
- // the option `/nodefaultlib` than a reference to a file in the root
- // directory.
- std::string nearest;
- if (COFFOptTable().findNearest(pathStr, nearest) > 1)
- error(msg);
- else
- error(msg + "; did you mean '" + nearest + "'");
- } else
- driver->addBuffer(std::move(mbOrErr.first), wholeArchive, lazy);
- });
- }
- void LinkerDriver::addArchiveBuffer(MemoryBufferRef mb, StringRef symName,
- StringRef parentName,
- uint64_t offsetInArchive) {
- file_magic magic = identify_magic(mb.getBuffer());
- if (magic == file_magic::coff_import_library) {
- InputFile *imp = make<ImportFile>(mb);
- imp->parentName = parentName;
- symtab->addFile(imp);
- return;
- }
- InputFile *obj;
- if (magic == file_magic::coff_object) {
- obj = make<ObjFile>(mb);
- } else if (magic == file_magic::bitcode) {
- obj = make<BitcodeFile>(mb, parentName, offsetInArchive);
- } else {
- error("unknown file type: " + mb.getBufferIdentifier());
- return;
- }
- obj->parentName = parentName;
- symtab->addFile(obj);
- log("Loaded " + toString(obj) + " for " + symName);
- }
- void LinkerDriver::enqueueArchiveMember(const Archive::Child &c,
- const Archive::Symbol &sym,
- StringRef parentName) {
- auto reportBufferError = [=](Error &&e, StringRef childName) {
- fatal("could not get the buffer for the member defining symbol " +
- toCOFFString(sym) + ": " + parentName + "(" + childName + "): " +
- toString(std::move(e)));
- };
- if (!c.getParent()->isThin()) {
- uint64_t offsetInArchive = c.getChildOffset();
- Expected<MemoryBufferRef> mbOrErr = c.getMemoryBufferRef();
- if (!mbOrErr)
- reportBufferError(mbOrErr.takeError(), check(c.getFullName()));
- MemoryBufferRef mb = mbOrErr.get();
- enqueueTask([=]() {
- driver->addArchiveBuffer(mb, toCOFFString(sym), parentName,
- offsetInArchive);
- });
- return;
- }
- std::string childName = CHECK(
- c.getFullName(),
- "could not get the filename for the member defining symbol " +
- toCOFFString(sym));
- auto future = std::make_shared<std::future<MBErrPair>>(
- createFutureForFile(childName));
- enqueueTask([=]() {
- auto mbOrErr = future->get();
- if (mbOrErr.second)
- reportBufferError(errorCodeToError(mbOrErr.second), childName);
- // Pass empty string as archive name so that the original filename is
- // used as the buffer identifier.
- driver->addArchiveBuffer(takeBuffer(std::move(mbOrErr.first)),
- toCOFFString(sym), "", /*OffsetInArchive=*/0);
- });
- }
- static bool isDecorated(StringRef sym) {
- return sym.startswith("@") || sym.contains("@@") || sym.startswith("?") ||
- (!config->mingw && sym.contains('@'));
- }
- // Parses .drectve section contents and returns a list of files
- // specified by /defaultlib.
- void LinkerDriver::parseDirectives(InputFile *file) {
- StringRef s = file->getDirectives();
- if (s.empty())
- return;
- log("Directives: " + toString(file) + ": " + s);
- ArgParser parser;
- // .drectve is always tokenized using Windows shell rules.
- // /EXPORT: option can appear too many times, processing in fastpath.
- opt::InputArgList args;
- std::vector<StringRef> exports;
- std::tie(args, exports) = parser.parseDirectives(s);
- for (StringRef e : exports) {
- // If a common header file contains dllexported function
- // declarations, many object files may end up with having the
- // same /EXPORT options. In order to save cost of parsing them,
- // we dedup them first.
- if (!directivesExports.insert(e).second)
- continue;
- Export exp = parseExport(e);
- if (config->machine == I386 && config->mingw) {
- if (!isDecorated(exp.name))
- exp.name = saver.save("_" + exp.name);
- if (!exp.extName.empty() && !isDecorated(exp.extName))
- exp.extName = saver.save("_" + exp.extName);
- }
- exp.directives = true;
- config->exports.push_back(exp);
- }
- for (auto *arg : args) {
- switch (arg->getOption().getID()) {
- case OPT_aligncomm:
- parseAligncomm(arg->getValue());
- break;
- case OPT_alternatename:
- parseAlternateName(arg->getValue());
- break;
- case OPT_defaultlib:
- if (Optional<StringRef> path = findLib(arg->getValue()))
- enqueuePath(*path, false, false);
- break;
- case OPT_entry:
- config->entry = addUndefined(mangle(arg->getValue()));
- break;
- case OPT_failifmismatch:
- checkFailIfMismatch(arg->getValue(), file);
- break;
- case OPT_incl:
- addUndefined(arg->getValue());
- break;
- case OPT_merge:
- parseMerge(arg->getValue());
- break;
- case OPT_nodefaultlib:
- config->noDefaultLibs.insert(doFindLib(arg->getValue()).lower());
- break;
- case OPT_section:
- parseSection(arg->getValue());
- break;
- case OPT_subsystem:
- parseSubsystem(arg->getValue(), &config->subsystem,
- &config->majorOSVersion, &config->minorOSVersion);
- break;
- // Only add flags here that link.exe accepts in
- // `#pragma comment(linker, "/flag")`-generated sections.
- case OPT_editandcontinue:
- case OPT_guardsym:
- case OPT_throwingnew:
- break;
- default:
- error(arg->getSpelling() + " is not allowed in .drectve");
- }
- }
- }
- // Find file from search paths. You can omit ".obj", this function takes
- // care of that. Note that the returned path is not guaranteed to exist.
- StringRef LinkerDriver::doFindFile(StringRef filename) {
- bool hasPathSep = (filename.find_first_of("/\\") != StringRef::npos);
- if (hasPathSep)
- return filename;
- bool hasExt = filename.contains('.');
- for (StringRef dir : searchPaths) {
- SmallString<128> path = dir;
- sys::path::append(path, filename);
- if (sys::fs::exists(path.str()))
- return saver.save(path.str());
- if (!hasExt) {
- path.append(".obj");
- if (sys::fs::exists(path.str()))
- return saver.save(path.str());
- }
- }
- return filename;
- }
- static Optional<sys::fs::UniqueID> getUniqueID(StringRef path) {
- sys::fs::UniqueID ret;
- if (sys::fs::getUniqueID(path, ret))
- return None;
- return ret;
- }
- // Resolves a file path. This never returns the same path
- // (in that case, it returns None).
- Optional<StringRef> LinkerDriver::findFile(StringRef filename) {
- StringRef path = doFindFile(filename);
- if (Optional<sys::fs::UniqueID> id = getUniqueID(path)) {
- bool seen = !visitedFiles.insert(*id).second;
- if (seen)
- return None;
- }
- if (path.endswith_lower(".lib"))
- visitedLibs.insert(sys::path::filename(path));
- return path;
- }
- // MinGW specific. If an embedded directive specified to link to
- // foo.lib, but it isn't found, try libfoo.a instead.
- StringRef LinkerDriver::doFindLibMinGW(StringRef filename) {
- if (filename.contains('/') || filename.contains('\\'))
- return filename;
- SmallString<128> s = filename;
- sys::path::replace_extension(s, ".a");
- StringRef libName = saver.save("lib" + s.str());
- return doFindFile(libName);
- }
- // Find library file from search path.
- StringRef LinkerDriver::doFindLib(StringRef filename) {
- // Add ".lib" to Filename if that has no file extension.
- bool hasExt = filename.contains('.');
- if (!hasExt)
- filename = saver.save(filename + ".lib");
- StringRef ret = doFindFile(filename);
- // For MinGW, if the find above didn't turn up anything, try
- // looking for a MinGW formatted library name.
- if (config->mingw && ret == filename)
- return doFindLibMinGW(filename);
- return ret;
- }
- // Resolves a library path. /nodefaultlib options are taken into
- // consideration. This never returns the same path (in that case,
- // it returns None).
- Optional<StringRef> LinkerDriver::findLib(StringRef filename) {
- if (config->noDefaultLibAll)
- return None;
- if (!visitedLibs.insert(filename.lower()).second)
- return None;
- StringRef path = doFindLib(filename);
- if (config->noDefaultLibs.count(path.lower()))
- return None;
- if (Optional<sys::fs::UniqueID> id = getUniqueID(path))
- if (!visitedFiles.insert(*id).second)
- return None;
- return path;
- }
- // Parses LIB environment which contains a list of search paths.
- void LinkerDriver::addLibSearchPaths() {
- Optional<std::string> envOpt = Process::GetEnv("LIB");
- if (!envOpt.hasValue())
- return;
- StringRef env = saver.save(*envOpt);
- while (!env.empty()) {
- StringRef path;
- std::tie(path, env) = env.split(';');
- searchPaths.push_back(path);
- }
- }
- Symbol *LinkerDriver::addUndefined(StringRef name) {
- Symbol *b = symtab->addUndefined(name);
- if (!b->isGCRoot) {
- b->isGCRoot = true;
- config->gcroot.push_back(b);
- }
- return b;
- }
- StringRef LinkerDriver::mangleMaybe(Symbol *s) {
- // If the plain symbol name has already been resolved, do nothing.
- Undefined *unmangled = dyn_cast<Undefined>(s);
- if (!unmangled)
- return "";
- // Otherwise, see if a similar, mangled symbol exists in the symbol table.
- Symbol *mangled = symtab->findMangle(unmangled->getName());
- if (!mangled)
- return "";
- // If we find a similar mangled symbol, make this an alias to it and return
- // its name.
- log(unmangled->getName() + " aliased to " + mangled->getName());
- unmangled->weakAlias = symtab->addUndefined(mangled->getName());
- return mangled->getName();
- }
- // Windows specific -- find default entry point name.
- //
- // There are four different entry point functions for Windows executables,
- // each of which corresponds to a user-defined "main" function. This function
- // infers an entry point from a user-defined "main" function.
- StringRef LinkerDriver::findDefaultEntry() {
- assert(config->subsystem != IMAGE_SUBSYSTEM_UNKNOWN &&
- "must handle /subsystem before calling this");
- if (config->mingw)
- return mangle(config->subsystem == IMAGE_SUBSYSTEM_WINDOWS_GUI
- ? "WinMainCRTStartup"
- : "mainCRTStartup");
- if (config->subsystem == IMAGE_SUBSYSTEM_WINDOWS_GUI) {
- if (findUnderscoreMangle("wWinMain")) {
- if (!findUnderscoreMangle("WinMain"))
- return mangle("wWinMainCRTStartup");
- warn("found both wWinMain and WinMain; using latter");
- }
- return mangle("WinMainCRTStartup");
- }
- if (findUnderscoreMangle("wmain")) {
- if (!findUnderscoreMangle("main"))
- return mangle("wmainCRTStartup");
- warn("found both wmain and main; using latter");
- }
- return mangle("mainCRTStartup");
- }
- WindowsSubsystem LinkerDriver::inferSubsystem() {
- if (config->dll)
- return IMAGE_SUBSYSTEM_WINDOWS_GUI;
- if (config->mingw)
- return IMAGE_SUBSYSTEM_WINDOWS_CUI;
- // Note that link.exe infers the subsystem from the presence of these
- // functions even if /entry: or /nodefaultlib are passed which causes them
- // to not be called.
- bool haveMain = findUnderscoreMangle("main");
- bool haveWMain = findUnderscoreMangle("wmain");
- bool haveWinMain = findUnderscoreMangle("WinMain");
- bool haveWWinMain = findUnderscoreMangle("wWinMain");
- if (haveMain || haveWMain) {
- if (haveWinMain || haveWWinMain) {
- warn(std::string("found ") + (haveMain ? "main" : "wmain") + " and " +
- (haveWinMain ? "WinMain" : "wWinMain") +
- "; defaulting to /subsystem:console");
- }
- return IMAGE_SUBSYSTEM_WINDOWS_CUI;
- }
- if (haveWinMain || haveWWinMain)
- return IMAGE_SUBSYSTEM_WINDOWS_GUI;
- return IMAGE_SUBSYSTEM_UNKNOWN;
- }
- static uint64_t getDefaultImageBase() {
- if (config->is64())
- return config->dll ? 0x180000000 : 0x140000000;
- return config->dll ? 0x10000000 : 0x400000;
- }
- static std::string createResponseFile(const opt::InputArgList &args,
- ArrayRef<StringRef> filePaths,
- ArrayRef<StringRef> searchPaths) {
- SmallString<0> data;
- raw_svector_ostream os(data);
- for (auto *arg : args) {
- switch (arg->getOption().getID()) {
- case OPT_linkrepro:
- case OPT_reproduce:
- case OPT_INPUT:
- case OPT_defaultlib:
- case OPT_libpath:
- case OPT_manifest:
- case OPT_manifest_colon:
- case OPT_manifestdependency:
- case OPT_manifestfile:
- case OPT_manifestinput:
- case OPT_manifestuac:
- break;
- case OPT_implib:
- case OPT_pdb:
- case OPT_out:
- os << arg->getSpelling() << sys::path::filename(arg->getValue()) << "\n";
- break;
- default:
- os << toString(*arg) << "\n";
- }
- }
- for (StringRef path : searchPaths) {
- std::string relPath = relativeToRoot(path);
- os << "/libpath:" << quote(relPath) << "\n";
- }
- for (StringRef path : filePaths)
- os << quote(relativeToRoot(path)) << "\n";
- return data.str();
- }
- enum class DebugKind { Unknown, None, Full, FastLink, GHash, Dwarf, Symtab };
- static DebugKind parseDebugKind(const opt::InputArgList &args) {
- auto *a = args.getLastArg(OPT_debug, OPT_debug_opt);
- if (!a)
- return DebugKind::None;
- if (a->getNumValues() == 0)
- return DebugKind::Full;
- DebugKind debug = StringSwitch<DebugKind>(a->getValue())
- .CaseLower("none", DebugKind::None)
- .CaseLower("full", DebugKind::Full)
- .CaseLower("fastlink", DebugKind::FastLink)
- // LLD extensions
- .CaseLower("ghash", DebugKind::GHash)
- .CaseLower("dwarf", DebugKind::Dwarf)
- .CaseLower("symtab", DebugKind::Symtab)
- .Default(DebugKind::Unknown);
- if (debug == DebugKind::FastLink) {
- warn("/debug:fastlink unsupported; using /debug:full");
- return DebugKind::Full;
- }
- if (debug == DebugKind::Unknown) {
- error("/debug: unknown option: " + Twine(a->getValue()));
- return DebugKind::None;
- }
- return debug;
- }
- static unsigned parseDebugTypes(const opt::InputArgList &args) {
- unsigned debugTypes = static_cast<unsigned>(DebugType::None);
- if (auto *a = args.getLastArg(OPT_debugtype)) {
- SmallVector<StringRef, 3> types;
- StringRef(a->getValue())
- .split(types, ',', /*MaxSplit=*/-1, /*KeepEmpty=*/false);
- for (StringRef type : types) {
- unsigned v = StringSwitch<unsigned>(type.lower())
- .Case("cv", static_cast<unsigned>(DebugType::CV))
- .Case("pdata", static_cast<unsigned>(DebugType::PData))
- .Case("fixup", static_cast<unsigned>(DebugType::Fixup))
- .Default(0);
- if (v == 0) {
- warn("/debugtype: unknown option '" + type + "'");
- continue;
- }
- debugTypes |= v;
- }
- return debugTypes;
- }
- // Default debug types
- debugTypes = static_cast<unsigned>(DebugType::CV);
- if (args.hasArg(OPT_driver))
- debugTypes |= static_cast<unsigned>(DebugType::PData);
- if (args.hasArg(OPT_profile))
- debugTypes |= static_cast<unsigned>(DebugType::Fixup);
- return debugTypes;
- }
- static std::string getMapFile(const opt::InputArgList &args) {
- auto *arg = args.getLastArg(OPT_lldmap, OPT_lldmap_file);
- if (!arg)
- return "";
- if (arg->getOption().getID() == OPT_lldmap_file)
- return arg->getValue();
- assert(arg->getOption().getID() == OPT_lldmap);
- StringRef outFile = config->outputFile;
- return (outFile.substr(0, outFile.rfind('.')) + ".map").str();
- }
- static std::string getImplibPath() {
- if (!config->implib.empty())
- return config->implib;
- SmallString<128> out = StringRef(config->outputFile);
- sys::path::replace_extension(out, ".lib");
- return out.str();
- }
- // The import name is calculated as follows:
- //
- // | LIBRARY w/ ext | LIBRARY w/o ext | no LIBRARY
- // -----+----------------+---------------------+------------------
- // LINK | {value} | {value}.{.dll/.exe} | {output name}
- // LIB | {value} | {value}.dll | {output name}.dll
- //
- static std::string getImportName(bool asLib) {
- SmallString<128> out;
- if (config->importName.empty()) {
- out.assign(sys::path::filename(config->outputFile));
- if (asLib)
- sys::path::replace_extension(out, ".dll");
- } else {
- out.assign(config->importName);
- if (!sys::path::has_extension(out))
- sys::path::replace_extension(out,
- (config->dll || asLib) ? ".dll" : ".exe");
- }
- return out.str();
- }
- static void createImportLibrary(bool asLib) {
- std::vector<COFFShortExport> exports;
- for (Export &e1 : config->exports) {
- COFFShortExport e2;
- e2.Name = e1.name;
- e2.SymbolName = e1.symbolName;
- e2.ExtName = e1.extName;
- e2.Ordinal = e1.ordinal;
- e2.Noname = e1.noname;
- e2.Data = e1.data;
- e2.Private = e1.isPrivate;
- e2.Constant = e1.constant;
- exports.push_back(e2);
- }
- auto handleError = [](Error &&e) {
- handleAllErrors(std::move(e),
- [](ErrorInfoBase &eib) { error(eib.message()); });
- };
- std::string libName = getImportName(asLib);
- std::string path = getImplibPath();
- if (!config->incremental) {
- handleError(writeImportLibrary(libName, path, exports, config->machine,
- config->mingw));
- return;
- }
- // If the import library already exists, replace it only if the contents
- // have changed.
- ErrorOr<std::unique_ptr<MemoryBuffer>> oldBuf = MemoryBuffer::getFile(
- path, /*FileSize*/ -1, /*RequiresNullTerminator*/ false);
- if (!oldBuf) {
- handleError(writeImportLibrary(libName, path, exports, config->machine,
- config->mingw));
- return;
- }
- SmallString<128> tmpName;
- if (std::error_code ec =
- sys::fs::createUniqueFile(path + ".tmp-%%%%%%%%.lib", tmpName))
- fatal("cannot create temporary file for import library " + path + ": " +
- ec.message());
- if (Error e = writeImportLibrary(libName, tmpName, exports, config->machine,
- config->mingw)) {
- handleError(std::move(e));
- return;
- }
- std::unique_ptr<MemoryBuffer> newBuf = check(MemoryBuffer::getFile(
- tmpName, /*FileSize*/ -1, /*RequiresNullTerminator*/ false));
- if ((*oldBuf)->getBuffer() != newBuf->getBuffer()) {
- oldBuf->reset();
- handleError(errorCodeToError(sys::fs::rename(tmpName, path)));
- } else {
- sys::fs::remove(tmpName);
- }
- }
- static void parseModuleDefs(StringRef path) {
- std::unique_ptr<MemoryBuffer> mb = CHECK(
- MemoryBuffer::getFile(path, -1, false, true), "could not open " + path);
- COFFModuleDefinition m = check(parseCOFFModuleDefinition(
- mb->getMemBufferRef(), config->machine, config->mingw));
- if (config->outputFile.empty())
- config->outputFile = saver.save(m.OutputFile);
- config->importName = saver.save(m.ImportName);
- if (m.ImageBase)
- config->imageBase = m.ImageBase;
- if (m.StackReserve)
- config->stackReserve = m.StackReserve;
- if (m.StackCommit)
- config->stackCommit = m.StackCommit;
- if (m.HeapReserve)
- config->heapReserve = m.HeapReserve;
- if (m.HeapCommit)
- config->heapCommit = m.HeapCommit;
- if (m.MajorImageVersion)
- config->majorImageVersion = m.MajorImageVersion;
- if (m.MinorImageVersion)
- config->minorImageVersion = m.MinorImageVersion;
- if (m.MajorOSVersion)
- config->majorOSVersion = m.MajorOSVersion;
- if (m.MinorOSVersion)
- config->minorOSVersion = m.MinorOSVersion;
- for (COFFShortExport e1 : m.Exports) {
- Export e2;
- // In simple cases, only Name is set. Renamed exports are parsed
- // and set as "ExtName = Name". If Name has the form "OtherDll.Func",
- // it shouldn't be a normal exported function but a forward to another
- // DLL instead. This is supported by both MS and GNU linkers.
- if (e1.ExtName != e1.Name && StringRef(e1.Name).contains('.')) {
- e2.name = saver.save(e1.ExtName);
- e2.forwardTo = saver.save(e1.Name);
- config->exports.push_back(e2);
- continue;
- }
- e2.name = saver.save(e1.Name);
- e2.extName = saver.save(e1.ExtName);
- e2.ordinal = e1.Ordinal;
- e2.noname = e1.Noname;
- e2.data = e1.Data;
- e2.isPrivate = e1.Private;
- e2.constant = e1.Constant;
- config->exports.push_back(e2);
- }
- }
- void LinkerDriver::enqueueTask(std::function<void()> task) {
- taskQueue.push_back(std::move(task));
- }
- bool LinkerDriver::run() {
- ScopedTimer t(inputFileTimer);
- bool didWork = !taskQueue.empty();
- while (!taskQueue.empty()) {
- taskQueue.front()();
- taskQueue.pop_front();
- }
- return didWork;
- }
- // Parse an /order file. If an option is given, the linker places
- // COMDAT sections in the same order as their names appear in the
- // given file.
- static void parseOrderFile(StringRef arg) {
- // For some reason, the MSVC linker requires a filename to be
- // preceded by "@".
- if (!arg.startswith("@")) {
- error("malformed /order option: '@' missing");
- return;
- }
- // Get a list of all comdat sections for error checking.
- DenseSet<StringRef> set;
- for (Chunk *c : symtab->getChunks())
- if (auto *sec = dyn_cast<SectionChunk>(c))
- if (sec->sym)
- set.insert(sec->sym->getName());
- // Open a file.
- StringRef path = arg.substr(1);
- std::unique_ptr<MemoryBuffer> mb = CHECK(
- MemoryBuffer::getFile(path, -1, false, true), "could not open " + path);
- // Parse a file. An order file contains one symbol per line.
- // All symbols that were not present in a given order file are
- // considered to have the lowest priority 0 and are placed at
- // end of an output section.
- for (std::string s : args::getLines(mb->getMemBufferRef())) {
- if (config->machine == I386 && !isDecorated(s))
- s = "_" + s;
- if (set.count(s) == 0) {
- if (config->warnMissingOrderSymbol)
- warn("/order:" + arg + ": missing symbol: " + s + " [LNK4037]");
- }
- else
- config->order[s] = INT_MIN + config->order.size();
- }
- }
- static void markAddrsig(Symbol *s) {
- if (auto *d = dyn_cast_or_null<Defined>(s))
- if (SectionChunk *c = dyn_cast_or_null<SectionChunk>(d->getChunk()))
- c->keepUnique = true;
- }
- static void findKeepUniqueSections() {
- // Exported symbols could be address-significant in other executables or DSOs,
- // so we conservatively mark them as address-significant.
- for (Export &r : config->exports)
- markAddrsig(r.sym);
- // Visit the address-significance table in each object file and mark each
- // referenced symbol as address-significant.
- for (ObjFile *obj : ObjFile::instances) {
- ArrayRef<Symbol *> syms = obj->getSymbols();
- if (obj->addrsigSec) {
- ArrayRef<uint8_t> contents;
- cantFail(
- obj->getCOFFObj()->getSectionContents(obj->addrsigSec, contents));
- const uint8_t *cur = contents.begin();
- while (cur != contents.end()) {
- unsigned size;
- const char *err;
- uint64_t symIndex = decodeULEB128(cur, &size, contents.end(), &err);
- if (err)
- fatal(toString(obj) + ": could not decode addrsig section: " + err);
- if (symIndex >= syms.size())
- fatal(toString(obj) + ": invalid symbol index in addrsig section");
- markAddrsig(syms[symIndex]);
- cur += size;
- }
- } else {
- // If an object file does not have an address-significance table,
- // conservatively mark all of its symbols as address-significant.
- for (Symbol *s : syms)
- markAddrsig(s);
- }
- }
- }
- // link.exe replaces each %foo% in altPath with the contents of environment
- // variable foo, and adds the two magic env vars _PDB (expands to the basename
- // of pdb's output path) and _EXT (expands to the extension of the output
- // binary).
- // lld only supports %_PDB% and %_EXT% and warns on references to all other env
- // vars.
- static void parsePDBAltPath(StringRef altPath) {
- SmallString<128> buf;
- StringRef pdbBasename =
- sys::path::filename(config->pdbPath, sys::path::Style::windows);
- StringRef binaryExtension =
- sys::path::extension(config->outputFile, sys::path::Style::windows);
- if (!binaryExtension.empty())
- binaryExtension = binaryExtension.substr(1); // %_EXT% does not include '.'.
- // Invariant:
- // +--------- cursor ('a...' might be the empty string).
- // | +----- firstMark
- // | | +- secondMark
- // v v v
- // a...%...%...
- size_t cursor = 0;
- while (cursor < altPath.size()) {
- size_t firstMark, secondMark;
- if ((firstMark = altPath.find('%', cursor)) == StringRef::npos ||
- (secondMark = altPath.find('%', firstMark + 1)) == StringRef::npos) {
- // Didn't find another full fragment, treat rest of string as literal.
- buf.append(altPath.substr(cursor));
- break;
- }
- // Found a full fragment. Append text in front of first %, and interpret
- // text between first and second % as variable name.
- buf.append(altPath.substr(cursor, firstMark - cursor));
- StringRef var = altPath.substr(firstMark, secondMark - firstMark + 1);
- if (var.equals_lower("%_pdb%"))
- buf.append(pdbBasename);
- else if (var.equals_lower("%_ext%"))
- buf.append(binaryExtension);
- else {
- warn("only %_PDB% and %_EXT% supported in /pdbaltpath:, keeping " +
- var + " as literal");
- buf.append(var);
- }
- cursor = secondMark + 1;
- }
- config->pdbAltPath = buf;
- }
- /// Convert resource files and potentially merge input resource object
- /// trees into one resource tree.
- /// Call after ObjFile::Instances is complete.
- void LinkerDriver::convertResources() {
- std::vector<ObjFile *> resourceObjFiles;
- for (ObjFile *f : ObjFile::instances) {
- if (f->isResourceObjFile())
- resourceObjFiles.push_back(f);
- }
- if (!config->mingw &&
- (resourceObjFiles.size() > 1 ||
- (resourceObjFiles.size() == 1 && !resources.empty()))) {
- error((!resources.empty() ? "internal .obj file created from .res files"
- : toString(resourceObjFiles[1])) +
- ": more than one resource obj file not allowed, already got " +
- toString(resourceObjFiles.front()));
- return;
- }
- if (resources.empty() && resourceObjFiles.size() <= 1) {
- // No resources to convert, and max one resource object file in
- // the input. Keep that preconverted resource section as is.
- for (ObjFile *f : resourceObjFiles)
- f->includeResourceChunks();
- return;
- }
- ObjFile *f = make<ObjFile>(convertResToCOFF(resources, resourceObjFiles));
- symtab->addFile(f);
- f->includeResourceChunks();
- }
- // In MinGW, if no symbols are chosen to be exported, then all symbols are
- // automatically exported by default. This behavior can be forced by the
- // -export-all-symbols option, so that it happens even when exports are
- // explicitly specified. The automatic behavior can be disabled using the
- // -exclude-all-symbols option, so that lld-link behaves like link.exe rather
- // than MinGW in the case that nothing is explicitly exported.
- void LinkerDriver::maybeExportMinGWSymbols(const opt::InputArgList &args) {
- if (!config->dll)
- return;
- if (!args.hasArg(OPT_export_all_symbols)) {
- if (!config->exports.empty())
- return;
- if (args.hasArg(OPT_exclude_all_symbols))
- return;
- }
- AutoExporter exporter;
- for (auto *arg : args.filtered(OPT_wholearchive_file))
- if (Optional<StringRef> path = doFindFile(arg->getValue()))
- exporter.addWholeArchive(*path);
- symtab->forEachSymbol([&](Symbol *s) {
- auto *def = dyn_cast<Defined>(s);
- if (!exporter.shouldExport(def))
- return;
- Export e;
- e.name = def->getName();
- e.sym = def;
- if (Chunk *c = def->getChunk())
- if (!(c->getOutputCharacteristics() & IMAGE_SCN_MEM_EXECUTE))
- e.data = true;
- config->exports.push_back(e);
- });
- }
- // lld has a feature to create a tar file containing all input files as well as
- // all command line options, so that other people can run lld again with exactly
- // the same inputs. This feature is accessible via /linkrepro and /reproduce.
- //
- // /linkrepro and /reproduce are very similar, but /linkrepro takes a directory
- // name while /reproduce takes a full path. We have /linkrepro for compatibility
- // with Microsoft link.exe.
- Optional<std::string> getReproduceFile(const opt::InputArgList &args) {
- if (auto *arg = args.getLastArg(OPT_reproduce))
- return std::string(arg->getValue());
- if (auto *arg = args.getLastArg(OPT_linkrepro)) {
- SmallString<64> path = StringRef(arg->getValue());
- sys::path::append(path, "repro.tar");
- return path.str().str();
- }
- return None;
- }
- void LinkerDriver::link(ArrayRef<const char *> argsArr) {
- // Needed for LTO.
- InitializeAllTargetInfos();
- InitializeAllTargets();
- InitializeAllTargetMCs();
- InitializeAllAsmParsers();
- InitializeAllAsmPrinters();
- PassRegistry &Registry = *PassRegistry::getPassRegistry();
- polly::initializePollyPasses(Registry);
- // If the first command line argument is "/lib", link.exe acts like lib.exe.
- // We call our own implementation of lib.exe that understands bitcode files.
- if (argsArr.size() > 1 && StringRef(argsArr[1]).equals_lower("/lib")) {
- if (llvm::libDriverMain(argsArr.slice(1)) != 0)
- fatal("lib failed");
- return;
- }
- // Parse command line options.
- ArgParser parser;
- opt::InputArgList args = parser.parse(argsArr);
- // Parse and evaluate -mllvm options.
- std::vector<const char *> v;
- v.push_back("lld-link (LLVM option parsing)");
- for (auto *arg : args.filtered(OPT_mllvm))
- v.push_back(arg->getValue());
- cl::ParseCommandLineOptions(v.size(), v.data());
- // Handle /errorlimit early, because error() depends on it.
- if (auto *arg = args.getLastArg(OPT_errorlimit)) {
- int n = 20;
- StringRef s = arg->getValue();
- if (s.getAsInteger(10, n))
- error(arg->getSpelling() + " number expected, but got " + s);
- errorHandler().errorLimit = n;
- }
- // Handle /help
- if (args.hasArg(OPT_help)) {
- printHelp(argsArr[0]);
- return;
- }
- lld::threadsEnabled = args.hasFlag(OPT_threads, OPT_threads_no, true);
- if (args.hasArg(OPT_show_timing))
- config->showTiming = true;
- config->showSummary = args.hasArg(OPT_summary);
- ScopedTimer t(Timer::root());
- // Handle --version, which is an lld extension. This option is a bit odd
- // because it doesn't start with "/", but we deliberately chose "--" to
- // avoid conflict with /version and for compatibility with clang-cl.
- if (args.hasArg(OPT_dash_dash_version)) {
- lld::outs() << getLLDVersion() << "\n";
- return;
- }
- // Handle /lldmingw early, since it can potentially affect how other
- // options are handled.
- config->mingw = args.hasArg(OPT_lldmingw);
- // Handle /linkrepro and /reproduce.
- if (Optional<std::string> path = getReproduceFile(args)) {
- Expected<std::unique_ptr<TarWriter>> errOrWriter =
- TarWriter::create(*path, sys::path::stem(*path));
- if (errOrWriter) {
- tar = std::move(*errOrWriter);
- } else {
- error("/linkrepro: failed to open " + *path + ": " +
- toString(errOrWriter.takeError()));
- }
- }
- if (!args.hasArg(OPT_INPUT, OPT_wholearchive_file)) {
- if (args.hasArg(OPT_deffile))
- config->noEntry = true;
- else
- fatal("no input files");
- }
- // Construct search path list.
- searchPaths.push_back("");
- for (auto *arg : args.filtered(OPT_libpath))
- searchPaths.push_back(arg->getValue());
- if (!args.hasArg(OPT_lldignoreenv))
- addLibSearchPaths();
- // Handle /ignore
- for (auto *arg : args.filtered(OPT_ignore)) {
- SmallVector<StringRef, 8> vec;
- StringRef(arg->getValue()).split(vec, ',');
- for (StringRef s : vec) {
- if (s == "4037")
- config->warnMissingOrderSymbol = false;
- else if (s == "4099")
- config->warnDebugInfoUnusable = false;
- else if (s == "4217")
- config->warnLocallyDefinedImported = false;
- else if (s == "longsections")
- config->warnLongSectionNames = false;
- // Other warning numbers are ignored.
- }
- }
- // Handle /out
- if (auto *arg = args.getLastArg(OPT_out))
- config->outputFile = arg->getValue();
- // Handle /verbose
- if (args.hasArg(OPT_verbose))
- config->verbose = true;
- errorHandler().verbose = config->verbose;
- // Handle /force or /force:unresolved
- if (args.hasArg(OPT_force, OPT_force_unresolved))
- config->forceUnresolved = true;
- // Handle /force or /force:multiple
- if (args.hasArg(OPT_force, OPT_force_multiple))
- config->forceMultiple = true;
- // Handle /force or /force:multipleres
- if (args.hasArg(OPT_force, OPT_force_multipleres))
- config->forceMultipleRes = true;
- // Handle /debug
- DebugKind debug = parseDebugKind(args);
- if (debug == DebugKind::Full || debug == DebugKind::Dwarf ||
- debug == DebugKind::GHash) {
- config->debug = true;
- config->incremental = true;
- }
- // Handle /demangle
- config->demangle = args.hasFlag(OPT_demangle, OPT_demangle_no);
- // Handle /debugtype
- config->debugTypes = parseDebugTypes(args);
- // Handle /driver[:uponly|:wdm].
- config->driverUponly = args.hasArg(OPT_driver_uponly) ||
- args.hasArg(OPT_driver_uponly_wdm) ||
- args.hasArg(OPT_driver_wdm_uponly);
- config->driverWdm = args.hasArg(OPT_driver_wdm) ||
- args.hasArg(OPT_driver_uponly_wdm) ||
- args.hasArg(OPT_driver_wdm_uponly);
- config->driver =
- config->driverUponly || config->driverWdm || args.hasArg(OPT_driver);
- // Handle /pdb
- bool shouldCreatePDB =
- (debug == DebugKind::Full || debug == DebugKind::GHash);
- if (shouldCreatePDB) {
- if (auto *arg = args.getLastArg(OPT_pdb))
- config->pdbPath = arg->getValue();
- if (auto *arg = args.getLastArg(OPT_pdbaltpath))
- config->pdbAltPath = arg->getValue();
- if (args.hasArg(OPT_natvis))
- config->natvisFiles = args.getAllArgValues(OPT_natvis);
- if (auto *arg = args.getLastArg(OPT_pdb_source_path))
- config->pdbSourcePath = arg->getValue();
- }
- // Handle /noentry
- if (args.hasArg(OPT_noentry)) {
- if (args.hasArg(OPT_dll))
- config->noEntry = true;
- else
- error("/noentry must be specified with /dll");
- }
- // Handle /dll
- if (args.hasArg(OPT_dll)) {
- config->dll = true;
- config->manifestID = 2;
- }
- // Handle /dynamicbase and /fixed. We can't use hasFlag for /dynamicbase
- // because we need to explicitly check whether that option or its inverse was
- // present in the argument list in order to handle /fixed.
- auto *dynamicBaseArg = args.getLastArg(OPT_dynamicbase, OPT_dynamicbase_no);
- if (dynamicBaseArg &&
- dynamicBaseArg->getOption().getID() == OPT_dynamicbase_no)
- config->dynamicBase = false;
- // MSDN claims "/FIXED:NO is the default setting for a DLL, and /FIXED is the
- // default setting for any other project type.", but link.exe defaults to
- // /FIXED:NO for exe outputs as well. Match behavior, not docs.
- bool fixed = args.hasFlag(OPT_fixed, OPT_fixed_no, false);
- if (fixed) {
- if (dynamicBaseArg &&
- dynamicBaseArg->getOption().getID() == OPT_dynamicbase) {
- error("/fixed must not be specified with /dynamicbase");
- } else {
- config->relocatable = false;
- config->dynamicBase = false;
- }
- }
- // Handle /appcontainer
- config->appContainer =
- args.hasFlag(OPT_appcontainer, OPT_appcontainer_no, false);
- // Handle /machine
- if (auto *arg = args.getLastArg(OPT_machine)) {
- config->machine = getMachineType(arg->getValue());
- if (config->machine == IMAGE_FILE_MACHINE_UNKNOWN)
- fatal(Twine("unknown /machine argument: ") + arg->getValue());
- }
- // Handle /nodefaultlib:<filename>
- for (auto *arg : args.filtered(OPT_nodefaultlib))
- config->noDefaultLibs.insert(doFindLib(arg->getValue()).lower());
- // Handle /nodefaultlib
- if (args.hasArg(OPT_nodefaultlib_all))
- config->noDefaultLibAll = true;
- // Handle /base
- if (auto *arg = args.getLastArg(OPT_base))
- parseNumbers(arg->getValue(), &config->imageBase);
- // Handle /filealign
- if (auto *arg = args.getLastArg(OPT_filealign)) {
- parseNumbers(arg->getValue(), &config->fileAlign);
- if (!isPowerOf2_64(config->fileAlign))
- error("/filealign: not a power of two: " + Twine(config->fileAlign));
- }
- // Handle /stack
- if (auto *arg = args.getLastArg(OPT_stack))
- parseNumbers(arg->getValue(), &config->stackReserve, &config->stackCommit);
- // Handle /guard:cf
- if (auto *arg = args.getLastArg(OPT_guard))
- parseGuard(arg->getValue());
- // Handle /heap
- if (auto *arg = args.getLastArg(OPT_heap))
- parseNumbers(arg->getValue(), &config->heapReserve, &config->heapCommit);
- // Handle /version
- if (auto *arg = args.getLastArg(OPT_version))
- parseVersion(arg->getValue(), &config->majorImageVersion,
- &config->minorImageVersion);
- // Handle /subsystem
- if (auto *arg = args.getLastArg(OPT_subsystem))
- parseSubsystem(arg->getValue(), &config->subsystem, &config->majorOSVersion,
- &config->minorOSVersion);
- // Handle /timestamp
- if (llvm::opt::Arg *arg = args.getLastArg(OPT_timestamp, OPT_repro)) {
- if (arg->getOption().getID() == OPT_repro) {
- config->timestamp = 0;
- config->repro = true;
- } else {
- config->repro = false;
- StringRef value(arg->getValue());
- if (value.getAsInteger(0, config->timestamp))
- fatal(Twine("invalid timestamp: ") + value +
- ". Expected 32-bit integer");
- }
- } else {
- config->repro = false;
- config->timestamp = time(nullptr);
- }
- // Handle /alternatename
- for (auto *arg : args.filtered(OPT_alternatename))
- parseAlternateName(arg->getValue());
- // Handle /include
- for (auto *arg : args.filtered(OPT_incl))
- addUndefined(arg->getValue());
- // Handle /implib
- if (auto *arg = args.getLastArg(OPT_implib))
- config->implib = arg->getValue();
- // Handle /opt.
- bool doGC = debug == DebugKind::None || args.hasArg(OPT_profile);
- unsigned icfLevel =
- args.hasArg(OPT_profile) ? 0 : 1; // 0: off, 1: limited, 2: on
- unsigned tailMerge = 1;
- for (auto *arg : args.filtered(OPT_opt)) {
- std::string str = StringRef(arg->getValue()).lower();
- SmallVector<StringRef, 1> vec;
- StringRef(str).split(vec, ',');
- for (StringRef s : vec) {
- if (s == "ref") {
- doGC = true;
- } else if (s == "noref") {
- doGC = false;
- } else if (s == "icf" || s.startswith("icf=")) {
- icfLevel = 2;
- } else if (s == "noicf") {
- icfLevel = 0;
- } else if (s == "lldtailmerge") {
- tailMerge = 2;
- } else if (s == "nolldtailmerge") {
- tailMerge = 0;
- } else if (s.startswith("lldlto=")) {
- StringRef optLevel = s.substr(7);
- if (optLevel.getAsInteger(10, config->ltoo) || config->ltoo > 3)
- error("/opt:lldlto: invalid optimization level: " + optLevel);
- } else if (s.startswith("lldltojobs=")) {
- StringRef jobs = s.substr(11);
- if (jobs.getAsInteger(10, config->thinLTOJobs) ||
- config->thinLTOJobs == 0)
- error("/opt:lldltojobs: invalid job count: " + jobs);
- } else if (s.startswith("lldltopartitions=")) {
- StringRef n = s.substr(17);
- if (n.getAsInteger(10, config->ltoPartitions) ||
- config->ltoPartitions == 0)
- error("/opt:lldltopartitions: invalid partition count: " + n);
- } else if (s != "lbr" && s != "nolbr")
- error("/opt: unknown option: " + s);
- }
- }
- // Limited ICF is enabled if GC is enabled and ICF was never mentioned
- // explicitly.
- // FIXME: LLD only implements "limited" ICF, i.e. it only merges identical
- // code. If the user passes /OPT:ICF explicitly, LLD should merge identical
- // comdat readonly data.
- if (icfLevel == 1 && !doGC)
- icfLevel = 0;
- config->doGC = doGC;
- config->doICF = icfLevel > 0;
- config->tailMerge = (tailMerge == 1 && config->doICF) || tailMerge == 2;
- // Handle /lldsavetemps
- if (args.hasArg(OPT_lldsavetemps))
- config->saveTemps = true;
- // Handle /kill-at
- if (args.hasArg(OPT_kill_at))
- config->killAt = true;
- // Handle /lldltocache
- if (auto *arg = args.getLastArg(OPT_lldltocache))
- config->ltoCache = arg->getValue();
- // Handle /lldsavecachepolicy
- if (auto *arg = args.getLastArg(OPT_lldltocachepolicy))
- config->ltoCachePolicy = CHECK(
- parseCachePruningPolicy(arg->getValue()),
- Twine("/lldltocachepolicy: invalid cache policy: ") + arg->getValue());
- // Handle /failifmismatch
- for (auto *arg : args.filtered(OPT_failifmismatch))
- checkFailIfMismatch(arg->getValue(), nullptr);
- // Handle /merge
- for (auto *arg : args.filtered(OPT_merge))
- parseMerge(arg->getValue());
- // Add default section merging rules after user rules. User rules take
- // precedence, but we will emit a warning if there is a conflict.
- parseMerge(".idata=.rdata");
- parseMerge(".didat=.rdata");
- parseMerge(".edata=.rdata");
- parseMerge(".xdata=.rdata");
- parseMerge(".bss=.data");
- if (config->mingw) {
- parseMerge(".ctors=.rdata");
- parseMerge(".dtors=.rdata");
- parseMerge(".CRT=.rdata");
- }
- // Handle /section
- for (auto *arg : args.filtered(OPT_section))
- parseSection(arg->getValue());
- // Handle /align
- if (auto *arg = args.getLastArg(OPT_align)) {
- parseNumbers(arg->getValue(), &config->align);
- if (!isPowerOf2_64(config->align))
- error("/align: not a power of two: " + StringRef(arg->getValue()));
- if (!args.hasArg(OPT_driver))
- warn("/align specified without /driver; image may not run");
- }
- // Handle /aligncomm
- for (auto *arg : args.filtered(OPT_aligncomm))
- parseAligncomm(arg->getValue());
- // Handle /manifestdependency. This enables /manifest unless /manifest:no is
- // also passed.
- if (auto *arg = args.getLastArg(OPT_manifestdependency)) {
- config->manifestDependency = arg->getValue();
- config->manifest = Configuration::SideBySide;
- }
- // Handle /manifest and /manifest:
- if (auto *arg = args.getLastArg(OPT_manifest, OPT_manifest_colon)) {
- if (arg->getOption().getID() == OPT_manifest)
- config->manifest = Configuration::SideBySide;
- else
- parseManifest(arg->getValue());
- }
- // Handle /manifestuac
- if (auto *arg = args.getLastArg(OPT_manifestuac))
- parseManifestUAC(arg->getValue());
- // Handle /manifestfile
- if (auto *arg = args.getLastArg(OPT_manifestfile))
- config->manifestFile = arg->getValue();
- // Handle /manifestinput
- for (auto *arg : args.filtered(OPT_manifestinput))
- config->manifestInput.push_back(arg->getValue());
- if (!config->manifestInput.empty() &&
- config->manifest != Configuration::Embed) {
- fatal("/manifestinput: requires /manifest:embed");
- }
- config->thinLTOEmitImportsFiles = args.hasArg(OPT_thinlto_emit_imports_files);
- config->thinLTOIndexOnly = args.hasArg(OPT_thinlto_index_only) ||
- args.hasArg(OPT_thinlto_index_only_arg);
- config->thinLTOIndexOnlyArg =
- args.getLastArgValue(OPT_thinlto_index_only_arg);
- config->thinLTOPrefixReplace =
- getOldNewOptions(args, OPT_thinlto_prefix_replace);
- config->thinLTOObjectSuffixReplace =
- getOldNewOptions(args, OPT_thinlto_object_suffix_replace);
- config->ltoObjPath = args.getLastArgValue(OPT_lto_obj_path);
- // Handle miscellaneous boolean flags.
- config->allowBind = args.hasFlag(OPT_allowbind, OPT_allowbind_no, true);
- config->allowIsolation =
- args.hasFlag(OPT_allowisolation, OPT_allowisolation_no, true);
- config->incremental =
- args.hasFlag(OPT_incremental, OPT_incremental_no,
- !config->doGC && !config->doICF && !args.hasArg(OPT_order) &&
- !args.hasArg(OPT_profile));
- config->integrityCheck =
- args.hasFlag(OPT_integritycheck, OPT_integritycheck_no, false);
- config->nxCompat = args.hasFlag(OPT_nxcompat, OPT_nxcompat_no, true);
- for (auto *arg : args.filtered(OPT_swaprun))
- parseSwaprun(arg->getValue());
- config->terminalServerAware =
- !config->dll && args.hasFlag(OPT_tsaware, OPT_tsaware_no, true);
- config->debugDwarf = debug == DebugKind::Dwarf;
- config->debugGHashes = debug == DebugKind::GHash;
- config->debugSymtab = debug == DebugKind::Symtab;
- // Don't warn about long section names, such as .debug_info, for mingw or when
- // -debug:dwarf is requested.
- if (config->mingw || config->debugDwarf)
- config->warnLongSectionNames = false;
- config->mapFile = getMapFile(args);
- if (config->incremental && args.hasArg(OPT_profile)) {
- warn("ignoring '/incremental' due to '/profile' specification");
- config->incremental = false;
- }
- if (config->incremental && args.hasArg(OPT_order)) {
- warn("ignoring '/incremental' due to '/order' specification");
- config->incremental = false;
- }
- if (config->incremental && config->doGC) {
- warn("ignoring '/incremental' because REF is enabled; use '/opt:noref' to "
- "disable");
- config->incremental = false;
- }
- if (config->incremental && config->doICF) {
- warn("ignoring '/incremental' because ICF is enabled; use '/opt:noicf' to "
- "disable");
- config->incremental = false;
- }
- if (errorCount())
- return;
- std::set<sys::fs::UniqueID> wholeArchives;
- for (auto *arg : args.filtered(OPT_wholearchive_file))
- if (Optional<StringRef> path = doFindFile(arg->getValue()))
- if (Optional<sys::fs::UniqueID> id = getUniqueID(*path))
- wholeArchives.insert(*id);
- // A predicate returning true if a given path is an argument for
- // /wholearchive:, or /wholearchive is enabled globally.
- // This function is a bit tricky because "foo.obj /wholearchive:././foo.obj"
- // needs to be handled as "/wholearchive:foo.obj foo.obj".
- auto isWholeArchive = [&](StringRef path) -> bool {
- if (args.hasArg(OPT_wholearchive_flag))
- return true;
- if (Optional<sys::fs::UniqueID> id = getUniqueID(path))
- return wholeArchives.count(*id);
- return false;
- };
- // Create a list of input files. These can be given as OPT_INPUT options
- // and OPT_wholearchive_file options, and we also need to track OPT_start_lib
- // and OPT_end_lib.
- bool inLib = false;
- for (auto *arg : args) {
- switch (arg->getOption().getID()) {
- case OPT_end_lib:
- if (!inLib)
- error("stray " + arg->getSpelling());
- inLib = false;
- break;
- case OPT_start_lib:
- if (inLib)
- error("nested " + arg->getSpelling());
- inLib = true;
- break;
- case OPT_wholearchive_file:
- if (Optional<StringRef> path = findFile(arg->getValue()))
- enqueuePath(*path, true, inLib);
- break;
- case OPT_INPUT:
- if (Optional<StringRef> path = findFile(arg->getValue()))
- enqueuePath(*path, isWholeArchive(*path), inLib);
- break;
- default:
- // Ignore other options.
- break;
- }
- }
- // Process files specified as /defaultlib. These should be enequeued after
- // other files, which is why they are in a separate loop.
- for (auto *arg : args.filtered(OPT_defaultlib))
- if (Optional<StringRef> path = findLib(arg->getValue()))
- enqueuePath(*path, false, false);
- // Windows specific -- Create a resource file containing a manifest file.
- if (config->manifest == Configuration::Embed)
- addBuffer(createManifestRes(), false, false);
- // Read all input files given via the command line.
- run();
- if (errorCount())
- return;
- // We should have inferred a machine type by now from the input files, but if
- // not we assume x64.
- if (config->machine == IMAGE_FILE_MACHINE_UNKNOWN) {
- warn("/machine is not specified. x64 is assumed");
- config->machine = AMD64;
- }
- config->wordsize = config->is64() ? 8 : 4;
- // Handle /safeseh, x86 only, on by default, except for mingw.
- if (config->machine == I386 &&
- args.hasFlag(OPT_safeseh, OPT_safeseh_no, !config->mingw))
- config->safeSEH = true;
- // Handle /functionpadmin
- for (auto *arg : args.filtered(OPT_functionpadmin, OPT_functionpadmin_opt))
- parseFunctionPadMin(arg, config->machine);
- if (tar)
- tar->append("response.txt",
- createResponseFile(args, filePaths,
- ArrayRef<StringRef>(searchPaths).slice(1)));
- // Handle /largeaddressaware
- config->largeAddressAware = args.hasFlag(
- OPT_largeaddressaware, OPT_largeaddressaware_no, config->is64());
- // Handle /highentropyva
- config->highEntropyVA =
- config->is64() &&
- args.hasFlag(OPT_highentropyva, OPT_highentropyva_no, true);
- if (!config->dynamicBase &&
- (config->machine == ARMNT || config->machine == ARM64))
- error("/dynamicbase:no is not compatible with " +
- machineToStr(config->machine));
- // Handle /export
- for (auto *arg : args.filtered(OPT_export)) {
- Export e = parseExport(arg->getValue());
- if (config->machine == I386) {
- if (!isDecorated(e.name))
- e.name = saver.save("_" + e.name);
- if (!e.extName.empty() && !isDecorated(e.extName))
- e.extName = saver.save("_" + e.extName);
- }
- config->exports.push_back(e);
- }
- // Handle /def
- if (auto *arg = args.getLastArg(OPT_deffile)) {
- // parseModuleDefs mutates Config object.
- parseModuleDefs(arg->getValue());
- }
- // Handle generation of import library from a def file.
- if (!args.hasArg(OPT_INPUT, OPT_wholearchive_file)) {
- fixupExports();
- createImportLibrary(/*asLib=*/true);
- return;
- }
- // Windows specific -- if no /subsystem is given, we need to infer
- // that from entry point name. Must happen before /entry handling,
- // and after the early return when just writing an import library.
- if (config->subsystem == IMAGE_SUBSYSTEM_UNKNOWN) {
- config->subsystem = inferSubsystem();
- if (config->subsystem == IMAGE_SUBSYSTEM_UNKNOWN)
- fatal("subsystem must be defined");
- }
- // Handle /entry and /dll
- if (auto *arg = args.getLastArg(OPT_entry)) {
- config->entry = addUndefined(mangle(arg->getValue()));
- } else if (!config->entry && !config->noEntry) {
- if (args.hasArg(OPT_dll)) {
- StringRef s = (config->machine == I386) ? "__DllMainCRTStartup@12"
- : "_DllMainCRTStartup";
- config->entry = addUndefined(s);
- } else if (config->driverWdm) {
- // /driver:wdm implies /entry:_NtProcessStartup
- config->entry = addUndefined(mangle("_NtProcessStartup"));
- } else {
- // Windows specific -- If entry point name is not given, we need to
- // infer that from user-defined entry name.
- StringRef s = findDefaultEntry();
- if (s.empty())
- fatal("entry point must be defined");
- config->entry = addUndefined(s);
- log("Entry name inferred: " + s);
- }
- }
- // Handle /delayload
- for (auto *arg : args.filtered(OPT_delayload)) {
- config->delayLoads.insert(StringRef(arg->getValue()).lower());
- if (config->machine == I386) {
- config->delayLoadHelper = addUndefined("___delayLoadHelper2@8");
- } else {
- config->delayLoadHelper = addUndefined("__delayLoadHelper2");
- }
- }
- // Set default image name if neither /out or /def set it.
- if (config->outputFile.empty()) {
- config->outputFile = getOutputPath(
- (*args.filtered(OPT_INPUT, OPT_wholearchive_file).begin())->getValue());
- }
- // Fail early if an output file is not writable.
- if (auto e = tryCreateFile(config->outputFile)) {
- error("cannot open output file " + config->outputFile + ": " + e.message());
- return;
- }
- if (shouldCreatePDB) {
- // Put the PDB next to the image if no /pdb flag was passed.
- if (config->pdbPath.empty()) {
- config->pdbPath = config->outputFile;
- sys::path::replace_extension(config->pdbPath, ".pdb");
- }
- // The embedded PDB path should be the absolute path to the PDB if no
- // /pdbaltpath flag was passed.
- if (config->pdbAltPath.empty()) {
- config->pdbAltPath = config->pdbPath;
- // It's important to make the path absolute and remove dots. This path
- // will eventually be written into the PE header, and certain Microsoft
- // tools won't work correctly if these assumptions are not held.
- sys::fs::make_absolute(config->pdbAltPath);
- sys::path::remove_dots(config->pdbAltPath);
- } else {
- // Don't do this earlier, so that Config->OutputFile is ready.
- parsePDBAltPath(config->pdbAltPath);
- }
- }
- // Set default image base if /base is not given.
- if (config->imageBase == uint64_t(-1))
- config->imageBase = getDefaultImageBase();
- symtab->addSynthetic(mangle("__ImageBase"), nullptr);
- if (config->machine == I386) {
- symtab->addAbsolute("___safe_se_handler_table", 0);
- symtab->addAbsolute("___safe_se_handler_count", 0);
- }
- symtab->addAbsolute(mangle("__guard_fids_count"), 0);
- symtab->addAbsolute(mangle("__guard_fids_table"), 0);
- symtab->addAbsolute(mangle("__guard_flags"), 0);
- symtab->addAbsolute(mangle("__guard_iat_count"), 0);
- symtab->addAbsolute(mangle("__guard_iat_table"), 0);
- symtab->addAbsolute(mangle("__guard_longjmp_count"), 0);
- symtab->addAbsolute(mangle("__guard_longjmp_table"), 0);
- // Needed for MSVC 2017 15.5 CRT.
- symtab->addAbsolute(mangle("__enclave_config"), 0);
- if (config->mingw) {
- symtab->addAbsolute(mangle("__RUNTIME_PSEUDO_RELOC_LIST__"), 0);
- symtab->addAbsolute(mangle("__RUNTIME_PSEUDO_RELOC_LIST_END__"), 0);
- symtab->addAbsolute(mangle("__CTOR_LIST__"), 0);
- symtab->addAbsolute(mangle("__DTOR_LIST__"), 0);
- }
- // This code may add new undefined symbols to the link, which may enqueue more
- // symbol resolution tasks, so we need to continue executing tasks until we
- // converge.
- do {
- // Windows specific -- if entry point is not found,
- // search for its mangled names.
- if (config->entry)
- mangleMaybe(config->entry);
- // Windows specific -- Make sure we resolve all dllexported symbols.
- for (Export &e : config->exports) {
- if (!e.forwardTo.empty())
- continue;
- e.sym = addUndefined(e.name);
- if (!e.directives)
- e.symbolName = mangleMaybe(e.sym);
- }
- // Add weak aliases. Weak aliases is a mechanism to give remaining
- // undefined symbols final chance to be resolved successfully.
- for (auto pair : config->alternateNames) {
- StringRef from = pair.first;
- StringRef to = pair.second;
- Symbol *sym = symtab->find(from);
- if (!sym)
- continue;
- if (auto *u = dyn_cast<Undefined>(sym))
- if (!u->weakAlias)
- u->weakAlias = symtab->addUndefined(to);
- }
- // If any inputs are bitcode files, the LTO code generator may create
- // references to library functions that are not explicit in the bitcode
- // file's symbol table. If any of those library functions are defined in a
- // bitcode file in an archive member, we need to arrange to use LTO to
- // compile those archive members by adding them to the link beforehand.
- if (!BitcodeFile::instances.empty())
- for (auto *s : lto::LTO::getRuntimeLibcallSymbols())
- symtab->addLibcall(s);
- // Windows specific -- if __load_config_used can be resolved, resolve it.
- if (symtab->findUnderscore("_load_config_used"))
- addUndefined(mangle("_load_config_used"));
- } while (run());
- if (args.hasArg(OPT_include_optional)) {
- // Handle /includeoptional
- for (auto *arg : args.filtered(OPT_include_optional))
- if (dyn_cast_or_null<LazyArchive>(symtab->find(arg->getValue())))
- addUndefined(arg->getValue());
- while (run());
- }
- if (config->mingw) {
- // Load any further object files that might be needed for doing automatic
- // imports.
- //
- // For cases with no automatically imported symbols, this iterates once
- // over the symbol table and doesn't do anything.
- //
- // For the normal case with a few automatically imported symbols, this
- // should only need to be run once, since each new object file imported
- // is an import library and wouldn't add any new undefined references,
- // but there's nothing stopping the __imp_ symbols from coming from a
- // normal object file as well (although that won't be used for the
- // actual autoimport later on). If this pass adds new undefined references,
- // we won't iterate further to resolve them.
- symtab->loadMinGWAutomaticImports();
- run();
- }
- // At this point, we should not have any symbols that cannot be resolved.
- // If we are going to do codegen for link-time optimization, check for
- // unresolvable symbols first, so we don't spend time generating code that
- // will fail to link anyway.
- if (!BitcodeFile::instances.empty() && !config->forceUnresolved)
- symtab->reportUnresolvable();
- if (errorCount())
- return;
- // Do LTO by compiling bitcode input files to a set of native COFF files then
- // link those files (unless -thinlto-index-only was given, in which case we
- // resolve symbols and write indices, but don't generate native code or link).
- symtab->addCombinedLTOObjects();
- // If -thinlto-index-only is given, we should create only "index
- // files" and not object files. Index file creation is already done
- // in addCombinedLTOObject, so we are done if that's the case.
- if (config->thinLTOIndexOnly)
- return;
- // If we generated native object files from bitcode files, this resolves
- // references to the symbols we use from them.
- run();
- // Resolve remaining undefined symbols and warn about imported locals.
- symtab->resolveRemainingUndefines();
- if (errorCount())
- return;
- config->hadExplicitExports = !config->exports.empty();
- if (config->mingw) {
- // In MinGW, all symbols are automatically exported if no symbols
- // are chosen to be exported.
- maybeExportMinGWSymbols(args);
- // Make sure the crtend.o object is the last object file. This object
- // file can contain terminating section chunks that need to be placed
- // last. GNU ld processes files and static libraries explicitly in the
- // order provided on the command line, while lld will pull in needed
- // files from static libraries only after the last object file on the
- // command line.
- for (auto i = ObjFile::instances.begin(), e = ObjFile::instances.end();
- i != e; i++) {
- ObjFile *file = *i;
- if (isCrtend(file->getName())) {
- ObjFile::instances.erase(i);
- ObjFile::instances.push_back(file);
- break;
- }
- }
- }
- // Windows specific -- when we are creating a .dll file, we also
- // need to create a .lib file. In MinGW mode, we only do that when the
- // -implib option is given explicitly, for compatibility with GNU ld.
- if (!config->exports.empty() || config->dll) {
- fixupExports();
- if (!config->mingw || !config->implib.empty())
- createImportLibrary(/*asLib=*/false);
- assignExportOrdinals();
- }
- // Handle /output-def (MinGW specific).
- if (auto *arg = args.getLastArg(OPT_output_def))
- writeDefFile(arg->getValue());
- // Set extra alignment for .comm symbols
- for (auto pair : config->alignComm) {
- StringRef name = pair.first;
- uint32_t alignment = pair.second;
- Symbol *sym = symtab->find(name);
- if (!sym) {
- warn("/aligncomm symbol " + name + " not found");
- continue;
- }
- // If the symbol isn't common, it must have been replaced with a regular
- // symbol, which will carry its own alignment.
- auto *dc = dyn_cast<DefinedCommon>(sym);
- if (!dc)
- continue;
- CommonChunk *c = dc->getChunk();
- c->setAlignment(std::max(c->getAlignment(), alignment));
- }
- // Windows specific -- Create a side-by-side manifest file.
- if (config->manifest == Configuration::SideBySide)
- createSideBySideManifest();
- // Handle /order. We want to do this at this moment because we
- // need a complete list of comdat sections to warn on nonexistent
- // functions.
- if (auto *arg = args.getLastArg(OPT_order))
- parseOrderFile(arg->getValue());
- // Identify unreferenced COMDAT sections.
- if (config->doGC)
- markLive(symtab->getChunks());
- // Needs to happen after the last call to addFile().
- convertResources();
- // Identify identical COMDAT sections to merge them.
- if (config->doICF) {
- findKeepUniqueSections();
- doICF(symtab->getChunks());
- }
- // Write the result.
- writeResult();
- // Stop early so we can print the results.
- Timer::root().stop();
- if (config->showTiming)
- Timer::root().print();
- }
- } // namespace coff
- } // namespace lld
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