xref: /freebsd/contrib/llvm-project/lld/ELF/Driver.cpp (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
10b57cec5SDimitry Andric //===- Driver.cpp ---------------------------------------------------------===//
20b57cec5SDimitry Andric //
30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
60b57cec5SDimitry Andric //
70b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
80b57cec5SDimitry Andric //
90b57cec5SDimitry Andric // The driver drives the entire linking process. It is responsible for
100b57cec5SDimitry Andric // parsing command line options and doing whatever it is instructed to do.
110b57cec5SDimitry Andric //
120b57cec5SDimitry Andric // One notable thing in the LLD's driver when compared to other linkers is
130b57cec5SDimitry Andric // that the LLD's driver is agnostic on the host operating system.
140b57cec5SDimitry Andric // Other linkers usually have implicit default values (such as a dynamic
150b57cec5SDimitry Andric // linker path or library paths) for each host OS.
160b57cec5SDimitry Andric //
170b57cec5SDimitry Andric // I don't think implicit default values are useful because they are
180b57cec5SDimitry Andric // usually explicitly specified by the compiler driver. They can even
190b57cec5SDimitry Andric // be harmful when you are doing cross-linking. Therefore, in LLD, we
200b57cec5SDimitry Andric // simply trust the compiler driver to pass all required options and
210b57cec5SDimitry Andric // don't try to make effort on our side.
220b57cec5SDimitry Andric //
230b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
240b57cec5SDimitry Andric 
250b57cec5SDimitry Andric #include "Driver.h"
260b57cec5SDimitry Andric #include "Config.h"
270b57cec5SDimitry Andric #include "ICF.h"
280b57cec5SDimitry Andric #include "InputFiles.h"
290b57cec5SDimitry Andric #include "InputSection.h"
300b57cec5SDimitry Andric #include "LinkerScript.h"
310b57cec5SDimitry Andric #include "MarkLive.h"
320b57cec5SDimitry Andric #include "OutputSections.h"
330b57cec5SDimitry Andric #include "ScriptParser.h"
340b57cec5SDimitry Andric #include "SymbolTable.h"
350b57cec5SDimitry Andric #include "Symbols.h"
360b57cec5SDimitry Andric #include "SyntheticSections.h"
370b57cec5SDimitry Andric #include "Target.h"
380b57cec5SDimitry Andric #include "Writer.h"
390b57cec5SDimitry Andric #include "lld/Common/Args.h"
400b57cec5SDimitry Andric #include "lld/Common/Driver.h"
410b57cec5SDimitry Andric #include "lld/Common/ErrorHandler.h"
420b57cec5SDimitry Andric #include "lld/Common/Filesystem.h"
430b57cec5SDimitry Andric #include "lld/Common/Memory.h"
440b57cec5SDimitry Andric #include "lld/Common/Strings.h"
450b57cec5SDimitry Andric #include "lld/Common/TargetOptionsCommandFlags.h"
460b57cec5SDimitry Andric #include "lld/Common/Version.h"
470b57cec5SDimitry Andric #include "llvm/ADT/SetVector.h"
480b57cec5SDimitry Andric #include "llvm/ADT/StringExtras.h"
490b57cec5SDimitry Andric #include "llvm/ADT/StringSwitch.h"
5085868e8aSDimitry Andric #include "llvm/LTO/LTO.h"
510b57cec5SDimitry Andric #include "llvm/Support/CommandLine.h"
520b57cec5SDimitry Andric #include "llvm/Support/Compression.h"
530b57cec5SDimitry Andric #include "llvm/Support/GlobPattern.h"
540b57cec5SDimitry Andric #include "llvm/Support/LEB128.h"
55*5ffd83dbSDimitry Andric #include "llvm/Support/Parallel.h"
560b57cec5SDimitry Andric #include "llvm/Support/Path.h"
570b57cec5SDimitry Andric #include "llvm/Support/TarWriter.h"
580b57cec5SDimitry Andric #include "llvm/Support/TargetSelect.h"
59*5ffd83dbSDimitry Andric #include "llvm/Support/TimeProfiler.h"
600b57cec5SDimitry Andric #include "llvm/Support/raw_ostream.h"
610b57cec5SDimitry Andric #include <cstdlib>
620b57cec5SDimitry Andric #include <utility>
630b57cec5SDimitry Andric 
640b57cec5SDimitry Andric using namespace llvm;
650b57cec5SDimitry Andric using namespace llvm::ELF;
660b57cec5SDimitry Andric using namespace llvm::object;
670b57cec5SDimitry Andric using namespace llvm::sys;
680b57cec5SDimitry Andric using namespace llvm::support;
69*5ffd83dbSDimitry Andric using namespace lld;
70*5ffd83dbSDimitry Andric using namespace lld::elf;
710b57cec5SDimitry Andric 
72*5ffd83dbSDimitry Andric Configuration *elf::config;
73*5ffd83dbSDimitry Andric LinkerDriver *elf::driver;
740b57cec5SDimitry Andric 
750b57cec5SDimitry Andric static void setConfigs(opt::InputArgList &args);
760b57cec5SDimitry Andric static void readConfigs(opt::InputArgList &args);
770b57cec5SDimitry Andric 
78*5ffd83dbSDimitry Andric bool elf::link(ArrayRef<const char *> args, bool canExitEarly,
79*5ffd83dbSDimitry Andric                raw_ostream &stdoutOS, raw_ostream &stderrOS) {
80480093f4SDimitry Andric   lld::stdoutOS = &stdoutOS;
81480093f4SDimitry Andric   lld::stderrOS = &stderrOS;
82480093f4SDimitry Andric 
830b57cec5SDimitry Andric   errorHandler().logName = args::getFilenameWithoutExe(args[0]);
840b57cec5SDimitry Andric   errorHandler().errorLimitExceededMsg =
850b57cec5SDimitry Andric       "too many errors emitted, stopping now (use "
860b57cec5SDimitry Andric       "-error-limit=0 to see all errors)";
870b57cec5SDimitry Andric   errorHandler().exitEarly = canExitEarly;
88480093f4SDimitry Andric   stderrOS.enable_colors(stderrOS.has_colors());
890b57cec5SDimitry Andric 
900b57cec5SDimitry Andric   inputSections.clear();
910b57cec5SDimitry Andric   outputSections.clear();
92*5ffd83dbSDimitry Andric   archiveFiles.clear();
930b57cec5SDimitry Andric   binaryFiles.clear();
940b57cec5SDimitry Andric   bitcodeFiles.clear();
95*5ffd83dbSDimitry Andric   lazyObjFiles.clear();
960b57cec5SDimitry Andric   objectFiles.clear();
970b57cec5SDimitry Andric   sharedFiles.clear();
98*5ffd83dbSDimitry Andric   backwardReferences.clear();
990b57cec5SDimitry Andric 
1000b57cec5SDimitry Andric   config = make<Configuration>();
1010b57cec5SDimitry Andric   driver = make<LinkerDriver>();
1020b57cec5SDimitry Andric   script = make<LinkerScript>();
1030b57cec5SDimitry Andric   symtab = make<SymbolTable>();
1040b57cec5SDimitry Andric 
1050b57cec5SDimitry Andric   tar = nullptr;
1060b57cec5SDimitry Andric   memset(&in, 0, sizeof(in));
1070b57cec5SDimitry Andric 
1080b57cec5SDimitry Andric   partitions = {Partition()};
1090b57cec5SDimitry Andric 
1100b57cec5SDimitry Andric   SharedFile::vernauxNum = 0;
1110b57cec5SDimitry Andric 
1120b57cec5SDimitry Andric   config->progName = args[0];
1130b57cec5SDimitry Andric 
1140b57cec5SDimitry Andric   driver->main(args);
1150b57cec5SDimitry Andric 
1160b57cec5SDimitry Andric   // Exit immediately if we don't need to return to the caller.
1170b57cec5SDimitry Andric   // This saves time because the overhead of calling destructors
1180b57cec5SDimitry Andric   // for all globally-allocated objects is not negligible.
1190b57cec5SDimitry Andric   if (canExitEarly)
1200b57cec5SDimitry Andric     exitLld(errorCount() ? 1 : 0);
1210b57cec5SDimitry Andric 
1220b57cec5SDimitry Andric   freeArena();
1230b57cec5SDimitry Andric   return !errorCount();
1240b57cec5SDimitry Andric }
1250b57cec5SDimitry Andric 
1260b57cec5SDimitry Andric // Parses a linker -m option.
1270b57cec5SDimitry Andric static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(StringRef emul) {
1280b57cec5SDimitry Andric   uint8_t osabi = 0;
1290b57cec5SDimitry Andric   StringRef s = emul;
1300b57cec5SDimitry Andric   if (s.endswith("_fbsd")) {
1310b57cec5SDimitry Andric     s = s.drop_back(5);
1320b57cec5SDimitry Andric     osabi = ELFOSABI_FREEBSD;
1330b57cec5SDimitry Andric   }
1340b57cec5SDimitry Andric 
1350b57cec5SDimitry Andric   std::pair<ELFKind, uint16_t> ret =
1360b57cec5SDimitry Andric       StringSwitch<std::pair<ELFKind, uint16_t>>(s)
1370b57cec5SDimitry Andric           .Cases("aarch64elf", "aarch64linux", "aarch64_elf64_le_vec",
1380b57cec5SDimitry Andric                  {ELF64LEKind, EM_AARCH64})
1390b57cec5SDimitry Andric           .Cases("armelf", "armelf_linux_eabi", {ELF32LEKind, EM_ARM})
1400b57cec5SDimitry Andric           .Case("elf32_x86_64", {ELF32LEKind, EM_X86_64})
1410b57cec5SDimitry Andric           .Cases("elf32btsmip", "elf32btsmipn32", {ELF32BEKind, EM_MIPS})
1420b57cec5SDimitry Andric           .Cases("elf32ltsmip", "elf32ltsmipn32", {ELF32LEKind, EM_MIPS})
1430b57cec5SDimitry Andric           .Case("elf32lriscv", {ELF32LEKind, EM_RISCV})
1440b57cec5SDimitry Andric           .Cases("elf32ppc", "elf32ppclinux", {ELF32BEKind, EM_PPC})
1450b57cec5SDimitry Andric           .Case("elf64btsmip", {ELF64BEKind, EM_MIPS})
1460b57cec5SDimitry Andric           .Case("elf64ltsmip", {ELF64LEKind, EM_MIPS})
1470b57cec5SDimitry Andric           .Case("elf64lriscv", {ELF64LEKind, EM_RISCV})
1480b57cec5SDimitry Andric           .Case("elf64ppc", {ELF64BEKind, EM_PPC64})
1490b57cec5SDimitry Andric           .Case("elf64lppc", {ELF64LEKind, EM_PPC64})
1500b57cec5SDimitry Andric           .Cases("elf_amd64", "elf_x86_64", {ELF64LEKind, EM_X86_64})
1510b57cec5SDimitry Andric           .Case("elf_i386", {ELF32LEKind, EM_386})
1520b57cec5SDimitry Andric           .Case("elf_iamcu", {ELF32LEKind, EM_IAMCU})
153*5ffd83dbSDimitry Andric           .Case("elf64_sparc", {ELF64BEKind, EM_SPARCV9})
1540b57cec5SDimitry Andric           .Default({ELFNoneKind, EM_NONE});
1550b57cec5SDimitry Andric 
1560b57cec5SDimitry Andric   if (ret.first == ELFNoneKind)
1570b57cec5SDimitry Andric     error("unknown emulation: " + emul);
1580b57cec5SDimitry Andric   return std::make_tuple(ret.first, ret.second, osabi);
1590b57cec5SDimitry Andric }
1600b57cec5SDimitry Andric 
1610b57cec5SDimitry Andric // Returns slices of MB by parsing MB as an archive file.
1620b57cec5SDimitry Andric // Each slice consists of a member file in the archive.
1630b57cec5SDimitry Andric std::vector<std::pair<MemoryBufferRef, uint64_t>> static getArchiveMembers(
1640b57cec5SDimitry Andric     MemoryBufferRef mb) {
1650b57cec5SDimitry Andric   std::unique_ptr<Archive> file =
1660b57cec5SDimitry Andric       CHECK(Archive::create(mb),
1670b57cec5SDimitry Andric             mb.getBufferIdentifier() + ": failed to parse archive");
1680b57cec5SDimitry Andric 
1690b57cec5SDimitry Andric   std::vector<std::pair<MemoryBufferRef, uint64_t>> v;
1700b57cec5SDimitry Andric   Error err = Error::success();
1710b57cec5SDimitry Andric   bool addToTar = file->isThin() && tar;
172480093f4SDimitry Andric   for (const Archive::Child &c : file->children(err)) {
1730b57cec5SDimitry Andric     MemoryBufferRef mbref =
1740b57cec5SDimitry Andric         CHECK(c.getMemoryBufferRef(),
1750b57cec5SDimitry Andric               mb.getBufferIdentifier() +
1760b57cec5SDimitry Andric                   ": could not get the buffer for a child of the archive");
1770b57cec5SDimitry Andric     if (addToTar)
1780b57cec5SDimitry Andric       tar->append(relativeToRoot(check(c.getFullName())), mbref.getBuffer());
1790b57cec5SDimitry Andric     v.push_back(std::make_pair(mbref, c.getChildOffset()));
1800b57cec5SDimitry Andric   }
1810b57cec5SDimitry Andric   if (err)
1820b57cec5SDimitry Andric     fatal(mb.getBufferIdentifier() + ": Archive::children failed: " +
1830b57cec5SDimitry Andric           toString(std::move(err)));
1840b57cec5SDimitry Andric 
1850b57cec5SDimitry Andric   // Take ownership of memory buffers created for members of thin archives.
1860b57cec5SDimitry Andric   for (std::unique_ptr<MemoryBuffer> &mb : file->takeThinBuffers())
1870b57cec5SDimitry Andric     make<std::unique_ptr<MemoryBuffer>>(std::move(mb));
1880b57cec5SDimitry Andric 
1890b57cec5SDimitry Andric   return v;
1900b57cec5SDimitry Andric }
1910b57cec5SDimitry Andric 
1920b57cec5SDimitry Andric // Opens a file and create a file object. Path has to be resolved already.
1930b57cec5SDimitry Andric void LinkerDriver::addFile(StringRef path, bool withLOption) {
1940b57cec5SDimitry Andric   using namespace sys::fs;
1950b57cec5SDimitry Andric 
1960b57cec5SDimitry Andric   Optional<MemoryBufferRef> buffer = readFile(path);
1970b57cec5SDimitry Andric   if (!buffer.hasValue())
1980b57cec5SDimitry Andric     return;
1990b57cec5SDimitry Andric   MemoryBufferRef mbref = *buffer;
2000b57cec5SDimitry Andric 
2010b57cec5SDimitry Andric   if (config->formatBinary) {
2020b57cec5SDimitry Andric     files.push_back(make<BinaryFile>(mbref));
2030b57cec5SDimitry Andric     return;
2040b57cec5SDimitry Andric   }
2050b57cec5SDimitry Andric 
2060b57cec5SDimitry Andric   switch (identify_magic(mbref.getBuffer())) {
2070b57cec5SDimitry Andric   case file_magic::unknown:
2080b57cec5SDimitry Andric     readLinkerScript(mbref);
2090b57cec5SDimitry Andric     return;
2100b57cec5SDimitry Andric   case file_magic::archive: {
2110b57cec5SDimitry Andric     // Handle -whole-archive.
2120b57cec5SDimitry Andric     if (inWholeArchive) {
2130b57cec5SDimitry Andric       for (const auto &p : getArchiveMembers(mbref))
2140b57cec5SDimitry Andric         files.push_back(createObjectFile(p.first, path, p.second));
2150b57cec5SDimitry Andric       return;
2160b57cec5SDimitry Andric     }
2170b57cec5SDimitry Andric 
2180b57cec5SDimitry Andric     std::unique_ptr<Archive> file =
2190b57cec5SDimitry Andric         CHECK(Archive::create(mbref), path + ": failed to parse archive");
2200b57cec5SDimitry Andric 
2210b57cec5SDimitry Andric     // If an archive file has no symbol table, it is likely that a user
2220b57cec5SDimitry Andric     // is attempting LTO and using a default ar command that doesn't
2230b57cec5SDimitry Andric     // understand the LLVM bitcode file. It is a pretty common error, so
2240b57cec5SDimitry Andric     // we'll handle it as if it had a symbol table.
2250b57cec5SDimitry Andric     if (!file->isEmpty() && !file->hasSymbolTable()) {
2260b57cec5SDimitry Andric       // Check if all members are bitcode files. If not, ignore, which is the
2270b57cec5SDimitry Andric       // default action without the LTO hack described above.
2280b57cec5SDimitry Andric       for (const std::pair<MemoryBufferRef, uint64_t> &p :
2290b57cec5SDimitry Andric            getArchiveMembers(mbref))
2300b57cec5SDimitry Andric         if (identify_magic(p.first.getBuffer()) != file_magic::bitcode) {
2310b57cec5SDimitry Andric           error(path + ": archive has no index; run ranlib to add one");
2320b57cec5SDimitry Andric           return;
2330b57cec5SDimitry Andric         }
2340b57cec5SDimitry Andric 
2350b57cec5SDimitry Andric       for (const std::pair<MemoryBufferRef, uint64_t> &p :
2360b57cec5SDimitry Andric            getArchiveMembers(mbref))
2370b57cec5SDimitry Andric         files.push_back(make<LazyObjFile>(p.first, path, p.second));
2380b57cec5SDimitry Andric       return;
2390b57cec5SDimitry Andric     }
2400b57cec5SDimitry Andric 
2410b57cec5SDimitry Andric     // Handle the regular case.
2420b57cec5SDimitry Andric     files.push_back(make<ArchiveFile>(std::move(file)));
2430b57cec5SDimitry Andric     return;
2440b57cec5SDimitry Andric   }
2450b57cec5SDimitry Andric   case file_magic::elf_shared_object:
2460b57cec5SDimitry Andric     if (config->isStatic || config->relocatable) {
2470b57cec5SDimitry Andric       error("attempted static link of dynamic object " + path);
2480b57cec5SDimitry Andric       return;
2490b57cec5SDimitry Andric     }
2500b57cec5SDimitry Andric 
2510b57cec5SDimitry Andric     // DSOs usually have DT_SONAME tags in their ELF headers, and the
2520b57cec5SDimitry Andric     // sonames are used to identify DSOs. But if they are missing,
2530b57cec5SDimitry Andric     // they are identified by filenames. We don't know whether the new
2540b57cec5SDimitry Andric     // file has a DT_SONAME or not because we haven't parsed it yet.
2550b57cec5SDimitry Andric     // Here, we set the default soname for the file because we might
2560b57cec5SDimitry Andric     // need it later.
2570b57cec5SDimitry Andric     //
2580b57cec5SDimitry Andric     // If a file was specified by -lfoo, the directory part is not
2590b57cec5SDimitry Andric     // significant, as a user did not specify it. This behavior is
2600b57cec5SDimitry Andric     // compatible with GNU.
2610b57cec5SDimitry Andric     files.push_back(
2620b57cec5SDimitry Andric         make<SharedFile>(mbref, withLOption ? path::filename(path) : path));
2630b57cec5SDimitry Andric     return;
2640b57cec5SDimitry Andric   case file_magic::bitcode:
2650b57cec5SDimitry Andric   case file_magic::elf_relocatable:
2660b57cec5SDimitry Andric     if (inLib)
2670b57cec5SDimitry Andric       files.push_back(make<LazyObjFile>(mbref, "", 0));
2680b57cec5SDimitry Andric     else
2690b57cec5SDimitry Andric       files.push_back(createObjectFile(mbref));
2700b57cec5SDimitry Andric     break;
2710b57cec5SDimitry Andric   default:
2720b57cec5SDimitry Andric     error(path + ": unknown file type");
2730b57cec5SDimitry Andric   }
2740b57cec5SDimitry Andric }
2750b57cec5SDimitry Andric 
2760b57cec5SDimitry Andric // Add a given library by searching it from input search paths.
2770b57cec5SDimitry Andric void LinkerDriver::addLibrary(StringRef name) {
2780b57cec5SDimitry Andric   if (Optional<std::string> path = searchLibrary(name))
2790b57cec5SDimitry Andric     addFile(*path, /*withLOption=*/true);
2800b57cec5SDimitry Andric   else
2810b57cec5SDimitry Andric     error("unable to find library -l" + name);
2820b57cec5SDimitry Andric }
2830b57cec5SDimitry Andric 
2840b57cec5SDimitry Andric // This function is called on startup. We need this for LTO since
2850b57cec5SDimitry Andric // LTO calls LLVM functions to compile bitcode files to native code.
2860b57cec5SDimitry Andric // Technically this can be delayed until we read bitcode files, but
2870b57cec5SDimitry Andric // we don't bother to do lazily because the initialization is fast.
2880b57cec5SDimitry Andric static void initLLVM() {
2890b57cec5SDimitry Andric   InitializeAllTargets();
2900b57cec5SDimitry Andric   InitializeAllTargetMCs();
2910b57cec5SDimitry Andric   InitializeAllAsmPrinters();
2920b57cec5SDimitry Andric   InitializeAllAsmParsers();
2930b57cec5SDimitry Andric }
2940b57cec5SDimitry Andric 
2950b57cec5SDimitry Andric // Some command line options or some combinations of them are not allowed.
2960b57cec5SDimitry Andric // This function checks for such errors.
2970b57cec5SDimitry Andric static void checkOptions() {
2980b57cec5SDimitry Andric   // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
2990b57cec5SDimitry Andric   // table which is a relatively new feature.
3000b57cec5SDimitry Andric   if (config->emachine == EM_MIPS && config->gnuHash)
3010b57cec5SDimitry Andric     error("the .gnu.hash section is not compatible with the MIPS target");
3020b57cec5SDimitry Andric 
3030b57cec5SDimitry Andric   if (config->fixCortexA53Errata843419 && config->emachine != EM_AARCH64)
3040b57cec5SDimitry Andric     error("--fix-cortex-a53-843419 is only supported on AArch64 targets");
3050b57cec5SDimitry Andric 
30685868e8aSDimitry Andric   if (config->fixCortexA8 && config->emachine != EM_ARM)
30785868e8aSDimitry Andric     error("--fix-cortex-a8 is only supported on ARM targets");
30885868e8aSDimitry Andric 
3090b57cec5SDimitry Andric   if (config->tocOptimize && config->emachine != EM_PPC64)
3100b57cec5SDimitry Andric     error("--toc-optimize is only supported on the PowerPC64 target");
3110b57cec5SDimitry Andric 
3120b57cec5SDimitry Andric   if (config->pie && config->shared)
3130b57cec5SDimitry Andric     error("-shared and -pie may not be used together");
3140b57cec5SDimitry Andric 
3150b57cec5SDimitry Andric   if (!config->shared && !config->filterList.empty())
3160b57cec5SDimitry Andric     error("-F may not be used without -shared");
3170b57cec5SDimitry Andric 
3180b57cec5SDimitry Andric   if (!config->shared && !config->auxiliaryList.empty())
3190b57cec5SDimitry Andric     error("-f may not be used without -shared");
3200b57cec5SDimitry Andric 
3210b57cec5SDimitry Andric   if (!config->relocatable && !config->defineCommon)
3220b57cec5SDimitry Andric     error("-no-define-common not supported in non relocatable output");
3230b57cec5SDimitry Andric 
32485868e8aSDimitry Andric   if (config->strip == StripPolicy::All && config->emitRelocs)
32585868e8aSDimitry Andric     error("--strip-all and --emit-relocs may not be used together");
32685868e8aSDimitry Andric 
3270b57cec5SDimitry Andric   if (config->zText && config->zIfuncNoplt)
3280b57cec5SDimitry Andric     error("-z text and -z ifunc-noplt may not be used together");
3290b57cec5SDimitry Andric 
3300b57cec5SDimitry Andric   if (config->relocatable) {
3310b57cec5SDimitry Andric     if (config->shared)
3320b57cec5SDimitry Andric       error("-r and -shared may not be used together");
3330b57cec5SDimitry Andric     if (config->gcSections)
3340b57cec5SDimitry Andric       error("-r and --gc-sections may not be used together");
3350b57cec5SDimitry Andric     if (config->gdbIndex)
3360b57cec5SDimitry Andric       error("-r and --gdb-index may not be used together");
3370b57cec5SDimitry Andric     if (config->icf != ICFLevel::None)
3380b57cec5SDimitry Andric       error("-r and --icf may not be used together");
3390b57cec5SDimitry Andric     if (config->pie)
3400b57cec5SDimitry Andric       error("-r and -pie may not be used together");
34185868e8aSDimitry Andric     if (config->exportDynamic)
34285868e8aSDimitry Andric       error("-r and --export-dynamic may not be used together");
3430b57cec5SDimitry Andric   }
3440b57cec5SDimitry Andric 
3450b57cec5SDimitry Andric   if (config->executeOnly) {
3460b57cec5SDimitry Andric     if (config->emachine != EM_AARCH64)
3470b57cec5SDimitry Andric       error("-execute-only is only supported on AArch64 targets");
3480b57cec5SDimitry Andric 
3490b57cec5SDimitry Andric     if (config->singleRoRx && !script->hasSectionsCommand)
3500b57cec5SDimitry Andric       error("-execute-only and -no-rosegment cannot be used together");
3510b57cec5SDimitry Andric   }
3520b57cec5SDimitry Andric 
353480093f4SDimitry Andric   if (config->zRetpolineplt && config->zForceIbt)
354480093f4SDimitry Andric     error("-z force-ibt may not be used with -z retpolineplt");
3550b57cec5SDimitry Andric 
3560b57cec5SDimitry Andric   if (config->emachine != EM_AARCH64) {
357*5ffd83dbSDimitry Andric     if (config->zPacPlt)
358480093f4SDimitry Andric       error("-z pac-plt only supported on AArch64");
359*5ffd83dbSDimitry Andric     if (config->zForceBti)
360480093f4SDimitry Andric       error("-z force-bti only supported on AArch64");
3610b57cec5SDimitry Andric   }
3620b57cec5SDimitry Andric }
3630b57cec5SDimitry Andric 
3640b57cec5SDimitry Andric static const char *getReproduceOption(opt::InputArgList &args) {
3650b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_reproduce))
3660b57cec5SDimitry Andric     return arg->getValue();
3670b57cec5SDimitry Andric   return getenv("LLD_REPRODUCE");
3680b57cec5SDimitry Andric }
3690b57cec5SDimitry Andric 
3700b57cec5SDimitry Andric static bool hasZOption(opt::InputArgList &args, StringRef key) {
3710b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_z))
3720b57cec5SDimitry Andric     if (key == arg->getValue())
3730b57cec5SDimitry Andric       return true;
3740b57cec5SDimitry Andric   return false;
3750b57cec5SDimitry Andric }
3760b57cec5SDimitry Andric 
3770b57cec5SDimitry Andric static bool getZFlag(opt::InputArgList &args, StringRef k1, StringRef k2,
3780b57cec5SDimitry Andric                      bool Default) {
3790b57cec5SDimitry Andric   for (auto *arg : args.filtered_reverse(OPT_z)) {
3800b57cec5SDimitry Andric     if (k1 == arg->getValue())
3810b57cec5SDimitry Andric       return true;
3820b57cec5SDimitry Andric     if (k2 == arg->getValue())
3830b57cec5SDimitry Andric       return false;
3840b57cec5SDimitry Andric   }
3850b57cec5SDimitry Andric   return Default;
3860b57cec5SDimitry Andric }
3870b57cec5SDimitry Andric 
38885868e8aSDimitry Andric static SeparateSegmentKind getZSeparate(opt::InputArgList &args) {
38985868e8aSDimitry Andric   for (auto *arg : args.filtered_reverse(OPT_z)) {
39085868e8aSDimitry Andric     StringRef v = arg->getValue();
39185868e8aSDimitry Andric     if (v == "noseparate-code")
39285868e8aSDimitry Andric       return SeparateSegmentKind::None;
39385868e8aSDimitry Andric     if (v == "separate-code")
39485868e8aSDimitry Andric       return SeparateSegmentKind::Code;
39585868e8aSDimitry Andric     if (v == "separate-loadable-segments")
39685868e8aSDimitry Andric       return SeparateSegmentKind::Loadable;
39785868e8aSDimitry Andric   }
39885868e8aSDimitry Andric   return SeparateSegmentKind::None;
39985868e8aSDimitry Andric }
40085868e8aSDimitry Andric 
401480093f4SDimitry Andric static GnuStackKind getZGnuStack(opt::InputArgList &args) {
402480093f4SDimitry Andric   for (auto *arg : args.filtered_reverse(OPT_z)) {
403480093f4SDimitry Andric     if (StringRef("execstack") == arg->getValue())
404480093f4SDimitry Andric       return GnuStackKind::Exec;
405480093f4SDimitry Andric     if (StringRef("noexecstack") == arg->getValue())
406480093f4SDimitry Andric       return GnuStackKind::NoExec;
407480093f4SDimitry Andric     if (StringRef("nognustack") == arg->getValue())
408480093f4SDimitry Andric       return GnuStackKind::None;
409480093f4SDimitry Andric   }
410480093f4SDimitry Andric 
411480093f4SDimitry Andric   return GnuStackKind::NoExec;
412480093f4SDimitry Andric }
413480093f4SDimitry Andric 
414*5ffd83dbSDimitry Andric static uint8_t getZStartStopVisibility(opt::InputArgList &args) {
415*5ffd83dbSDimitry Andric   for (auto *arg : args.filtered_reverse(OPT_z)) {
416*5ffd83dbSDimitry Andric     std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split('=');
417*5ffd83dbSDimitry Andric     if (kv.first == "start-stop-visibility") {
418*5ffd83dbSDimitry Andric       if (kv.second == "default")
419*5ffd83dbSDimitry Andric         return STV_DEFAULT;
420*5ffd83dbSDimitry Andric       else if (kv.second == "internal")
421*5ffd83dbSDimitry Andric         return STV_INTERNAL;
422*5ffd83dbSDimitry Andric       else if (kv.second == "hidden")
423*5ffd83dbSDimitry Andric         return STV_HIDDEN;
424*5ffd83dbSDimitry Andric       else if (kv.second == "protected")
425*5ffd83dbSDimitry Andric         return STV_PROTECTED;
426*5ffd83dbSDimitry Andric       error("unknown -z start-stop-visibility= value: " + StringRef(kv.second));
427*5ffd83dbSDimitry Andric     }
428*5ffd83dbSDimitry Andric   }
429*5ffd83dbSDimitry Andric   return STV_PROTECTED;
430*5ffd83dbSDimitry Andric }
431*5ffd83dbSDimitry Andric 
4320b57cec5SDimitry Andric static bool isKnownZFlag(StringRef s) {
4330b57cec5SDimitry Andric   return s == "combreloc" || s == "copyreloc" || s == "defs" ||
434480093f4SDimitry Andric          s == "execstack" || s == "force-bti" || s == "force-ibt" ||
435480093f4SDimitry Andric          s == "global" || s == "hazardplt" || s == "ifunc-noplt" ||
436480093f4SDimitry Andric          s == "initfirst" || s == "interpose" ||
4370b57cec5SDimitry Andric          s == "keep-text-section-prefix" || s == "lazy" || s == "muldefs" ||
43885868e8aSDimitry Andric          s == "separate-code" || s == "separate-loadable-segments" ||
4390b57cec5SDimitry Andric          s == "nocombreloc" || s == "nocopyreloc" || s == "nodefaultlib" ||
4400b57cec5SDimitry Andric          s == "nodelete" || s == "nodlopen" || s == "noexecstack" ||
441480093f4SDimitry Andric          s == "nognustack" || s == "nokeep-text-section-prefix" ||
442480093f4SDimitry Andric          s == "norelro" || s == "noseparate-code" || s == "notext" ||
443*5ffd83dbSDimitry Andric          s == "now" || s == "origin" || s == "pac-plt" || s == "rel" ||
444*5ffd83dbSDimitry Andric          s == "rela" || s == "relro" || s == "retpolineplt" ||
445*5ffd83dbSDimitry Andric          s == "rodynamic" || s == "shstk" || s == "text" || s == "undefs" ||
446*5ffd83dbSDimitry Andric          s == "wxneeded" || s.startswith("common-page-size=") ||
447*5ffd83dbSDimitry Andric          s.startswith("dead-reloc-in-nonalloc=") ||
448*5ffd83dbSDimitry Andric          s.startswith("max-page-size=") || s.startswith("stack-size=") ||
449*5ffd83dbSDimitry Andric          s.startswith("start-stop-visibility=");
4500b57cec5SDimitry Andric }
4510b57cec5SDimitry Andric 
4520b57cec5SDimitry Andric // Report an error for an unknown -z option.
4530b57cec5SDimitry Andric static void checkZOptions(opt::InputArgList &args) {
4540b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_z))
4550b57cec5SDimitry Andric     if (!isKnownZFlag(arg->getValue()))
4560b57cec5SDimitry Andric       error("unknown -z value: " + StringRef(arg->getValue()));
4570b57cec5SDimitry Andric }
4580b57cec5SDimitry Andric 
4590b57cec5SDimitry Andric void LinkerDriver::main(ArrayRef<const char *> argsArr) {
4600b57cec5SDimitry Andric   ELFOptTable parser;
4610b57cec5SDimitry Andric   opt::InputArgList args = parser.parse(argsArr.slice(1));
4620b57cec5SDimitry Andric 
4630b57cec5SDimitry Andric   // Interpret this flag early because error() depends on them.
4640b57cec5SDimitry Andric   errorHandler().errorLimit = args::getInteger(args, OPT_error_limit, 20);
4650b57cec5SDimitry Andric   checkZOptions(args);
4660b57cec5SDimitry Andric 
4670b57cec5SDimitry Andric   // Handle -help
4680b57cec5SDimitry Andric   if (args.hasArg(OPT_help)) {
4690b57cec5SDimitry Andric     printHelp();
4700b57cec5SDimitry Andric     return;
4710b57cec5SDimitry Andric   }
4720b57cec5SDimitry Andric 
4730b57cec5SDimitry Andric   // Handle -v or -version.
4740b57cec5SDimitry Andric   //
4750b57cec5SDimitry Andric   // A note about "compatible with GNU linkers" message: this is a hack for
4760b57cec5SDimitry Andric   // scripts generated by GNU Libtool 2.4.6 (released in February 2014 and
4770b57cec5SDimitry Andric   // still the newest version in March 2017) or earlier to recognize LLD as
4780b57cec5SDimitry Andric   // a GNU compatible linker. As long as an output for the -v option
4790b57cec5SDimitry Andric   // contains "GNU" or "with BFD", they recognize us as GNU-compatible.
4800b57cec5SDimitry Andric   //
4810b57cec5SDimitry Andric   // This is somewhat ugly hack, but in reality, we had no choice other
4820b57cec5SDimitry Andric   // than doing this. Considering the very long release cycle of Libtool,
4830b57cec5SDimitry Andric   // it is not easy to improve it to recognize LLD as a GNU compatible
4840b57cec5SDimitry Andric   // linker in a timely manner. Even if we can make it, there are still a
4850b57cec5SDimitry Andric   // lot of "configure" scripts out there that are generated by old version
4860b57cec5SDimitry Andric   // of Libtool. We cannot convince every software developer to migrate to
4870b57cec5SDimitry Andric   // the latest version and re-generate scripts. So we have this hack.
4880b57cec5SDimitry Andric   if (args.hasArg(OPT_v) || args.hasArg(OPT_version))
4890b57cec5SDimitry Andric     message(getLLDVersion() + " (compatible with GNU linkers)");
4900b57cec5SDimitry Andric 
4910b57cec5SDimitry Andric   if (const char *path = getReproduceOption(args)) {
4920b57cec5SDimitry Andric     // Note that --reproduce is a debug option so you can ignore it
4930b57cec5SDimitry Andric     // if you are trying to understand the whole picture of the code.
4940b57cec5SDimitry Andric     Expected<std::unique_ptr<TarWriter>> errOrWriter =
4950b57cec5SDimitry Andric         TarWriter::create(path, path::stem(path));
4960b57cec5SDimitry Andric     if (errOrWriter) {
4970b57cec5SDimitry Andric       tar = std::move(*errOrWriter);
4980b57cec5SDimitry Andric       tar->append("response.txt", createResponseFile(args));
4990b57cec5SDimitry Andric       tar->append("version.txt", getLLDVersion() + "\n");
5000b57cec5SDimitry Andric     } else {
5010b57cec5SDimitry Andric       error("--reproduce: " + toString(errOrWriter.takeError()));
5020b57cec5SDimitry Andric     }
5030b57cec5SDimitry Andric   }
5040b57cec5SDimitry Andric 
5050b57cec5SDimitry Andric   readConfigs(args);
5060b57cec5SDimitry Andric 
5070b57cec5SDimitry Andric   // The behavior of -v or --version is a bit strange, but this is
5080b57cec5SDimitry Andric   // needed for compatibility with GNU linkers.
5090b57cec5SDimitry Andric   if (args.hasArg(OPT_v) && !args.hasArg(OPT_INPUT))
5100b57cec5SDimitry Andric     return;
5110b57cec5SDimitry Andric   if (args.hasArg(OPT_version))
5120b57cec5SDimitry Andric     return;
5130b57cec5SDimitry Andric 
514*5ffd83dbSDimitry Andric   // Initialize time trace profiler.
515*5ffd83dbSDimitry Andric   if (config->timeTraceEnabled)
516*5ffd83dbSDimitry Andric     timeTraceProfilerInitialize(config->timeTraceGranularity, config->progName);
517*5ffd83dbSDimitry Andric 
518*5ffd83dbSDimitry Andric   {
519*5ffd83dbSDimitry Andric     llvm::TimeTraceScope timeScope("ExecuteLinker");
520*5ffd83dbSDimitry Andric 
5210b57cec5SDimitry Andric     initLLVM();
5220b57cec5SDimitry Andric     createFiles(args);
5230b57cec5SDimitry Andric     if (errorCount())
5240b57cec5SDimitry Andric       return;
5250b57cec5SDimitry Andric 
5260b57cec5SDimitry Andric     inferMachineType();
5270b57cec5SDimitry Andric     setConfigs(args);
5280b57cec5SDimitry Andric     checkOptions();
5290b57cec5SDimitry Andric     if (errorCount())
5300b57cec5SDimitry Andric       return;
5310b57cec5SDimitry Andric 
5320b57cec5SDimitry Andric     // The Target instance handles target-specific stuff, such as applying
5330b57cec5SDimitry Andric     // relocations or writing a PLT section. It also contains target-dependent
5340b57cec5SDimitry Andric     // values such as a default image base address.
5350b57cec5SDimitry Andric     target = getTarget();
5360b57cec5SDimitry Andric 
5370b57cec5SDimitry Andric     switch (config->ekind) {
5380b57cec5SDimitry Andric     case ELF32LEKind:
5390b57cec5SDimitry Andric       link<ELF32LE>(args);
540*5ffd83dbSDimitry Andric       break;
5410b57cec5SDimitry Andric     case ELF32BEKind:
5420b57cec5SDimitry Andric       link<ELF32BE>(args);
543*5ffd83dbSDimitry Andric       break;
5440b57cec5SDimitry Andric     case ELF64LEKind:
5450b57cec5SDimitry Andric       link<ELF64LE>(args);
546*5ffd83dbSDimitry Andric       break;
5470b57cec5SDimitry Andric     case ELF64BEKind:
5480b57cec5SDimitry Andric       link<ELF64BE>(args);
549*5ffd83dbSDimitry Andric       break;
5500b57cec5SDimitry Andric     default:
5510b57cec5SDimitry Andric       llvm_unreachable("unknown Config->EKind");
5520b57cec5SDimitry Andric     }
5530b57cec5SDimitry Andric   }
5540b57cec5SDimitry Andric 
555*5ffd83dbSDimitry Andric   if (config->timeTraceEnabled) {
556*5ffd83dbSDimitry Andric     if (auto E = timeTraceProfilerWrite(args.getLastArgValue(OPT_time_trace_file_eq).str(),
557*5ffd83dbSDimitry Andric                                         config->outputFile)) {
558*5ffd83dbSDimitry Andric       handleAllErrors(std::move(E), [&](const StringError &SE) {
559*5ffd83dbSDimitry Andric         error(SE.getMessage());
560*5ffd83dbSDimitry Andric       });
561*5ffd83dbSDimitry Andric       return;
562*5ffd83dbSDimitry Andric     }
563*5ffd83dbSDimitry Andric 
564*5ffd83dbSDimitry Andric     timeTraceProfilerCleanup();
565*5ffd83dbSDimitry Andric   }
566*5ffd83dbSDimitry Andric }
567*5ffd83dbSDimitry Andric 
5680b57cec5SDimitry Andric static std::string getRpath(opt::InputArgList &args) {
5690b57cec5SDimitry Andric   std::vector<StringRef> v = args::getStrings(args, OPT_rpath);
5700b57cec5SDimitry Andric   return llvm::join(v.begin(), v.end(), ":");
5710b57cec5SDimitry Andric }
5720b57cec5SDimitry Andric 
5730b57cec5SDimitry Andric // Determines what we should do if there are remaining unresolved
5740b57cec5SDimitry Andric // symbols after the name resolution.
5750b57cec5SDimitry Andric static UnresolvedPolicy getUnresolvedSymbolPolicy(opt::InputArgList &args) {
5760b57cec5SDimitry Andric   UnresolvedPolicy errorOrWarn = args.hasFlag(OPT_error_unresolved_symbols,
5770b57cec5SDimitry Andric                                               OPT_warn_unresolved_symbols, true)
5780b57cec5SDimitry Andric                                      ? UnresolvedPolicy::ReportError
5790b57cec5SDimitry Andric                                      : UnresolvedPolicy::Warn;
5800b57cec5SDimitry Andric 
5810b57cec5SDimitry Andric   // Process the last of -unresolved-symbols, -no-undefined or -z defs.
5820b57cec5SDimitry Andric   for (auto *arg : llvm::reverse(args)) {
5830b57cec5SDimitry Andric     switch (arg->getOption().getID()) {
5840b57cec5SDimitry Andric     case OPT_unresolved_symbols: {
5850b57cec5SDimitry Andric       StringRef s = arg->getValue();
5860b57cec5SDimitry Andric       if (s == "ignore-all" || s == "ignore-in-object-files")
5870b57cec5SDimitry Andric         return UnresolvedPolicy::Ignore;
5880b57cec5SDimitry Andric       if (s == "ignore-in-shared-libs" || s == "report-all")
5890b57cec5SDimitry Andric         return errorOrWarn;
5900b57cec5SDimitry Andric       error("unknown --unresolved-symbols value: " + s);
5910b57cec5SDimitry Andric       continue;
5920b57cec5SDimitry Andric     }
5930b57cec5SDimitry Andric     case OPT_no_undefined:
5940b57cec5SDimitry Andric       return errorOrWarn;
5950b57cec5SDimitry Andric     case OPT_z:
5960b57cec5SDimitry Andric       if (StringRef(arg->getValue()) == "defs")
5970b57cec5SDimitry Andric         return errorOrWarn;
59885868e8aSDimitry Andric       if (StringRef(arg->getValue()) == "undefs")
59985868e8aSDimitry Andric         return UnresolvedPolicy::Ignore;
6000b57cec5SDimitry Andric       continue;
6010b57cec5SDimitry Andric     }
6020b57cec5SDimitry Andric   }
6030b57cec5SDimitry Andric 
6040b57cec5SDimitry Andric   // -shared implies -unresolved-symbols=ignore-all because missing
6050b57cec5SDimitry Andric   // symbols are likely to be resolved at runtime using other DSOs.
6060b57cec5SDimitry Andric   if (config->shared)
6070b57cec5SDimitry Andric     return UnresolvedPolicy::Ignore;
6080b57cec5SDimitry Andric   return errorOrWarn;
6090b57cec5SDimitry Andric }
6100b57cec5SDimitry Andric 
6110b57cec5SDimitry Andric static Target2Policy getTarget2(opt::InputArgList &args) {
6120b57cec5SDimitry Andric   StringRef s = args.getLastArgValue(OPT_target2, "got-rel");
6130b57cec5SDimitry Andric   if (s == "rel")
6140b57cec5SDimitry Andric     return Target2Policy::Rel;
6150b57cec5SDimitry Andric   if (s == "abs")
6160b57cec5SDimitry Andric     return Target2Policy::Abs;
6170b57cec5SDimitry Andric   if (s == "got-rel")
6180b57cec5SDimitry Andric     return Target2Policy::GotRel;
6190b57cec5SDimitry Andric   error("unknown --target2 option: " + s);
6200b57cec5SDimitry Andric   return Target2Policy::GotRel;
6210b57cec5SDimitry Andric }
6220b57cec5SDimitry Andric 
6230b57cec5SDimitry Andric static bool isOutputFormatBinary(opt::InputArgList &args) {
6240b57cec5SDimitry Andric   StringRef s = args.getLastArgValue(OPT_oformat, "elf");
6250b57cec5SDimitry Andric   if (s == "binary")
6260b57cec5SDimitry Andric     return true;
6270b57cec5SDimitry Andric   if (!s.startswith("elf"))
6280b57cec5SDimitry Andric     error("unknown --oformat value: " + s);
6290b57cec5SDimitry Andric   return false;
6300b57cec5SDimitry Andric }
6310b57cec5SDimitry Andric 
6320b57cec5SDimitry Andric static DiscardPolicy getDiscard(opt::InputArgList &args) {
6330b57cec5SDimitry Andric   auto *arg =
6340b57cec5SDimitry Andric       args.getLastArg(OPT_discard_all, OPT_discard_locals, OPT_discard_none);
6350b57cec5SDimitry Andric   if (!arg)
6360b57cec5SDimitry Andric     return DiscardPolicy::Default;
6370b57cec5SDimitry Andric   if (arg->getOption().getID() == OPT_discard_all)
6380b57cec5SDimitry Andric     return DiscardPolicy::All;
6390b57cec5SDimitry Andric   if (arg->getOption().getID() == OPT_discard_locals)
6400b57cec5SDimitry Andric     return DiscardPolicy::Locals;
6410b57cec5SDimitry Andric   return DiscardPolicy::None;
6420b57cec5SDimitry Andric }
6430b57cec5SDimitry Andric 
6440b57cec5SDimitry Andric static StringRef getDynamicLinker(opt::InputArgList &args) {
6450b57cec5SDimitry Andric   auto *arg = args.getLastArg(OPT_dynamic_linker, OPT_no_dynamic_linker);
64655e4f9d5SDimitry Andric   if (!arg)
6470b57cec5SDimitry Andric     return "";
64855e4f9d5SDimitry Andric   if (arg->getOption().getID() == OPT_no_dynamic_linker) {
64955e4f9d5SDimitry Andric     // --no-dynamic-linker suppresses undefined weak symbols in .dynsym
65055e4f9d5SDimitry Andric     config->noDynamicLinker = true;
65155e4f9d5SDimitry Andric     return "";
65255e4f9d5SDimitry Andric   }
6530b57cec5SDimitry Andric   return arg->getValue();
6540b57cec5SDimitry Andric }
6550b57cec5SDimitry Andric 
6560b57cec5SDimitry Andric static ICFLevel getICF(opt::InputArgList &args) {
6570b57cec5SDimitry Andric   auto *arg = args.getLastArg(OPT_icf_none, OPT_icf_safe, OPT_icf_all);
6580b57cec5SDimitry Andric   if (!arg || arg->getOption().getID() == OPT_icf_none)
6590b57cec5SDimitry Andric     return ICFLevel::None;
6600b57cec5SDimitry Andric   if (arg->getOption().getID() == OPT_icf_safe)
6610b57cec5SDimitry Andric     return ICFLevel::Safe;
6620b57cec5SDimitry Andric   return ICFLevel::All;
6630b57cec5SDimitry Andric }
6640b57cec5SDimitry Andric 
6650b57cec5SDimitry Andric static StripPolicy getStrip(opt::InputArgList &args) {
6660b57cec5SDimitry Andric   if (args.hasArg(OPT_relocatable))
6670b57cec5SDimitry Andric     return StripPolicy::None;
6680b57cec5SDimitry Andric 
6690b57cec5SDimitry Andric   auto *arg = args.getLastArg(OPT_strip_all, OPT_strip_debug);
6700b57cec5SDimitry Andric   if (!arg)
6710b57cec5SDimitry Andric     return StripPolicy::None;
6720b57cec5SDimitry Andric   if (arg->getOption().getID() == OPT_strip_all)
6730b57cec5SDimitry Andric     return StripPolicy::All;
6740b57cec5SDimitry Andric   return StripPolicy::Debug;
6750b57cec5SDimitry Andric }
6760b57cec5SDimitry Andric 
6770b57cec5SDimitry Andric static uint64_t parseSectionAddress(StringRef s, opt::InputArgList &args,
6780b57cec5SDimitry Andric                                     const opt::Arg &arg) {
6790b57cec5SDimitry Andric   uint64_t va = 0;
6800b57cec5SDimitry Andric   if (s.startswith("0x"))
6810b57cec5SDimitry Andric     s = s.drop_front(2);
6820b57cec5SDimitry Andric   if (!to_integer(s, va, 16))
6830b57cec5SDimitry Andric     error("invalid argument: " + arg.getAsString(args));
6840b57cec5SDimitry Andric   return va;
6850b57cec5SDimitry Andric }
6860b57cec5SDimitry Andric 
6870b57cec5SDimitry Andric static StringMap<uint64_t> getSectionStartMap(opt::InputArgList &args) {
6880b57cec5SDimitry Andric   StringMap<uint64_t> ret;
6890b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_section_start)) {
6900b57cec5SDimitry Andric     StringRef name;
6910b57cec5SDimitry Andric     StringRef addr;
6920b57cec5SDimitry Andric     std::tie(name, addr) = StringRef(arg->getValue()).split('=');
6930b57cec5SDimitry Andric     ret[name] = parseSectionAddress(addr, args, *arg);
6940b57cec5SDimitry Andric   }
6950b57cec5SDimitry Andric 
6960b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_Ttext))
6970b57cec5SDimitry Andric     ret[".text"] = parseSectionAddress(arg->getValue(), args, *arg);
6980b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_Tdata))
6990b57cec5SDimitry Andric     ret[".data"] = parseSectionAddress(arg->getValue(), args, *arg);
7000b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_Tbss))
7010b57cec5SDimitry Andric     ret[".bss"] = parseSectionAddress(arg->getValue(), args, *arg);
7020b57cec5SDimitry Andric   return ret;
7030b57cec5SDimitry Andric }
7040b57cec5SDimitry Andric 
7050b57cec5SDimitry Andric static SortSectionPolicy getSortSection(opt::InputArgList &args) {
7060b57cec5SDimitry Andric   StringRef s = args.getLastArgValue(OPT_sort_section);
7070b57cec5SDimitry Andric   if (s == "alignment")
7080b57cec5SDimitry Andric     return SortSectionPolicy::Alignment;
7090b57cec5SDimitry Andric   if (s == "name")
7100b57cec5SDimitry Andric     return SortSectionPolicy::Name;
7110b57cec5SDimitry Andric   if (!s.empty())
7120b57cec5SDimitry Andric     error("unknown --sort-section rule: " + s);
7130b57cec5SDimitry Andric   return SortSectionPolicy::Default;
7140b57cec5SDimitry Andric }
7150b57cec5SDimitry Andric 
7160b57cec5SDimitry Andric static OrphanHandlingPolicy getOrphanHandling(opt::InputArgList &args) {
7170b57cec5SDimitry Andric   StringRef s = args.getLastArgValue(OPT_orphan_handling, "place");
7180b57cec5SDimitry Andric   if (s == "warn")
7190b57cec5SDimitry Andric     return OrphanHandlingPolicy::Warn;
7200b57cec5SDimitry Andric   if (s == "error")
7210b57cec5SDimitry Andric     return OrphanHandlingPolicy::Error;
7220b57cec5SDimitry Andric   if (s != "place")
7230b57cec5SDimitry Andric     error("unknown --orphan-handling mode: " + s);
7240b57cec5SDimitry Andric   return OrphanHandlingPolicy::Place;
7250b57cec5SDimitry Andric }
7260b57cec5SDimitry Andric 
7270b57cec5SDimitry Andric // Parse --build-id or --build-id=<style>. We handle "tree" as a
7280b57cec5SDimitry Andric // synonym for "sha1" because all our hash functions including
7290b57cec5SDimitry Andric // -build-id=sha1 are actually tree hashes for performance reasons.
7300b57cec5SDimitry Andric static std::pair<BuildIdKind, std::vector<uint8_t>>
7310b57cec5SDimitry Andric getBuildId(opt::InputArgList &args) {
7320b57cec5SDimitry Andric   auto *arg = args.getLastArg(OPT_build_id, OPT_build_id_eq);
7330b57cec5SDimitry Andric   if (!arg)
7340b57cec5SDimitry Andric     return {BuildIdKind::None, {}};
7350b57cec5SDimitry Andric 
7360b57cec5SDimitry Andric   if (arg->getOption().getID() == OPT_build_id)
7370b57cec5SDimitry Andric     return {BuildIdKind::Fast, {}};
7380b57cec5SDimitry Andric 
7390b57cec5SDimitry Andric   StringRef s = arg->getValue();
7400b57cec5SDimitry Andric   if (s == "fast")
7410b57cec5SDimitry Andric     return {BuildIdKind::Fast, {}};
7420b57cec5SDimitry Andric   if (s == "md5")
7430b57cec5SDimitry Andric     return {BuildIdKind::Md5, {}};
7440b57cec5SDimitry Andric   if (s == "sha1" || s == "tree")
7450b57cec5SDimitry Andric     return {BuildIdKind::Sha1, {}};
7460b57cec5SDimitry Andric   if (s == "uuid")
7470b57cec5SDimitry Andric     return {BuildIdKind::Uuid, {}};
7480b57cec5SDimitry Andric   if (s.startswith("0x"))
7490b57cec5SDimitry Andric     return {BuildIdKind::Hexstring, parseHex(s.substr(2))};
7500b57cec5SDimitry Andric 
7510b57cec5SDimitry Andric   if (s != "none")
7520b57cec5SDimitry Andric     error("unknown --build-id style: " + s);
7530b57cec5SDimitry Andric   return {BuildIdKind::None, {}};
7540b57cec5SDimitry Andric }
7550b57cec5SDimitry Andric 
7560b57cec5SDimitry Andric static std::pair<bool, bool> getPackDynRelocs(opt::InputArgList &args) {
7570b57cec5SDimitry Andric   StringRef s = args.getLastArgValue(OPT_pack_dyn_relocs, "none");
7580b57cec5SDimitry Andric   if (s == "android")
7590b57cec5SDimitry Andric     return {true, false};
7600b57cec5SDimitry Andric   if (s == "relr")
7610b57cec5SDimitry Andric     return {false, true};
7620b57cec5SDimitry Andric   if (s == "android+relr")
7630b57cec5SDimitry Andric     return {true, true};
7640b57cec5SDimitry Andric 
7650b57cec5SDimitry Andric   if (s != "none")
7660b57cec5SDimitry Andric     error("unknown -pack-dyn-relocs format: " + s);
7670b57cec5SDimitry Andric   return {false, false};
7680b57cec5SDimitry Andric }
7690b57cec5SDimitry Andric 
7700b57cec5SDimitry Andric static void readCallGraph(MemoryBufferRef mb) {
7710b57cec5SDimitry Andric   // Build a map from symbol name to section
7720b57cec5SDimitry Andric   DenseMap<StringRef, Symbol *> map;
7730b57cec5SDimitry Andric   for (InputFile *file : objectFiles)
7740b57cec5SDimitry Andric     for (Symbol *sym : file->getSymbols())
7750b57cec5SDimitry Andric       map[sym->getName()] = sym;
7760b57cec5SDimitry Andric 
7770b57cec5SDimitry Andric   auto findSection = [&](StringRef name) -> InputSectionBase * {
7780b57cec5SDimitry Andric     Symbol *sym = map.lookup(name);
7790b57cec5SDimitry Andric     if (!sym) {
7800b57cec5SDimitry Andric       if (config->warnSymbolOrdering)
7810b57cec5SDimitry Andric         warn(mb.getBufferIdentifier() + ": no such symbol: " + name);
7820b57cec5SDimitry Andric       return nullptr;
7830b57cec5SDimitry Andric     }
7840b57cec5SDimitry Andric     maybeWarnUnorderableSymbol(sym);
7850b57cec5SDimitry Andric 
7860b57cec5SDimitry Andric     if (Defined *dr = dyn_cast_or_null<Defined>(sym))
7870b57cec5SDimitry Andric       return dyn_cast_or_null<InputSectionBase>(dr->section);
7880b57cec5SDimitry Andric     return nullptr;
7890b57cec5SDimitry Andric   };
7900b57cec5SDimitry Andric 
7910b57cec5SDimitry Andric   for (StringRef line : args::getLines(mb)) {
7920b57cec5SDimitry Andric     SmallVector<StringRef, 3> fields;
7930b57cec5SDimitry Andric     line.split(fields, ' ');
7940b57cec5SDimitry Andric     uint64_t count;
7950b57cec5SDimitry Andric 
7960b57cec5SDimitry Andric     if (fields.size() != 3 || !to_integer(fields[2], count)) {
7970b57cec5SDimitry Andric       error(mb.getBufferIdentifier() + ": parse error");
7980b57cec5SDimitry Andric       return;
7990b57cec5SDimitry Andric     }
8000b57cec5SDimitry Andric 
8010b57cec5SDimitry Andric     if (InputSectionBase *from = findSection(fields[0]))
8020b57cec5SDimitry Andric       if (InputSectionBase *to = findSection(fields[1]))
8030b57cec5SDimitry Andric         config->callGraphProfile[std::make_pair(from, to)] += count;
8040b57cec5SDimitry Andric   }
8050b57cec5SDimitry Andric }
8060b57cec5SDimitry Andric 
8070b57cec5SDimitry Andric template <class ELFT> static void readCallGraphsFromObjectFiles() {
8080b57cec5SDimitry Andric   for (auto file : objectFiles) {
8090b57cec5SDimitry Andric     auto *obj = cast<ObjFile<ELFT>>(file);
8100b57cec5SDimitry Andric 
8110b57cec5SDimitry Andric     for (const Elf_CGProfile_Impl<ELFT> &cgpe : obj->cgProfile) {
8120b57cec5SDimitry Andric       auto *fromSym = dyn_cast<Defined>(&obj->getSymbol(cgpe.cgp_from));
8130b57cec5SDimitry Andric       auto *toSym = dyn_cast<Defined>(&obj->getSymbol(cgpe.cgp_to));
8140b57cec5SDimitry Andric       if (!fromSym || !toSym)
8150b57cec5SDimitry Andric         continue;
8160b57cec5SDimitry Andric 
8170b57cec5SDimitry Andric       auto *from = dyn_cast_or_null<InputSectionBase>(fromSym->section);
8180b57cec5SDimitry Andric       auto *to = dyn_cast_or_null<InputSectionBase>(toSym->section);
8190b57cec5SDimitry Andric       if (from && to)
8200b57cec5SDimitry Andric         config->callGraphProfile[{from, to}] += cgpe.cgp_weight;
8210b57cec5SDimitry Andric     }
8220b57cec5SDimitry Andric   }
8230b57cec5SDimitry Andric }
8240b57cec5SDimitry Andric 
8250b57cec5SDimitry Andric static bool getCompressDebugSections(opt::InputArgList &args) {
8260b57cec5SDimitry Andric   StringRef s = args.getLastArgValue(OPT_compress_debug_sections, "none");
8270b57cec5SDimitry Andric   if (s == "none")
8280b57cec5SDimitry Andric     return false;
8290b57cec5SDimitry Andric   if (s != "zlib")
8300b57cec5SDimitry Andric     error("unknown --compress-debug-sections value: " + s);
8310b57cec5SDimitry Andric   if (!zlib::isAvailable())
8320b57cec5SDimitry Andric     error("--compress-debug-sections: zlib is not available");
8330b57cec5SDimitry Andric   return true;
8340b57cec5SDimitry Andric }
8350b57cec5SDimitry Andric 
83685868e8aSDimitry Andric static StringRef getAliasSpelling(opt::Arg *arg) {
83785868e8aSDimitry Andric   if (const opt::Arg *alias = arg->getAlias())
83885868e8aSDimitry Andric     return alias->getSpelling();
83985868e8aSDimitry Andric   return arg->getSpelling();
84085868e8aSDimitry Andric }
84185868e8aSDimitry Andric 
8420b57cec5SDimitry Andric static std::pair<StringRef, StringRef> getOldNewOptions(opt::InputArgList &args,
8430b57cec5SDimitry Andric                                                         unsigned id) {
8440b57cec5SDimitry Andric   auto *arg = args.getLastArg(id);
8450b57cec5SDimitry Andric   if (!arg)
8460b57cec5SDimitry Andric     return {"", ""};
8470b57cec5SDimitry Andric 
8480b57cec5SDimitry Andric   StringRef s = arg->getValue();
8490b57cec5SDimitry Andric   std::pair<StringRef, StringRef> ret = s.split(';');
8500b57cec5SDimitry Andric   if (ret.second.empty())
85185868e8aSDimitry Andric     error(getAliasSpelling(arg) + " expects 'old;new' format, but got " + s);
8520b57cec5SDimitry Andric   return ret;
8530b57cec5SDimitry Andric }
8540b57cec5SDimitry Andric 
8550b57cec5SDimitry Andric // Parse the symbol ordering file and warn for any duplicate entries.
8560b57cec5SDimitry Andric static std::vector<StringRef> getSymbolOrderingFile(MemoryBufferRef mb) {
8570b57cec5SDimitry Andric   SetVector<StringRef> names;
8580b57cec5SDimitry Andric   for (StringRef s : args::getLines(mb))
8590b57cec5SDimitry Andric     if (!names.insert(s) && config->warnSymbolOrdering)
8600b57cec5SDimitry Andric       warn(mb.getBufferIdentifier() + ": duplicate ordered symbol: " + s);
8610b57cec5SDimitry Andric 
8620b57cec5SDimitry Andric   return names.takeVector();
8630b57cec5SDimitry Andric }
8640b57cec5SDimitry Andric 
865*5ffd83dbSDimitry Andric static bool getIsRela(opt::InputArgList &args) {
866*5ffd83dbSDimitry Andric   // If -z rel or -z rela is specified, use the last option.
867*5ffd83dbSDimitry Andric   for (auto *arg : args.filtered_reverse(OPT_z)) {
868*5ffd83dbSDimitry Andric     StringRef s(arg->getValue());
869*5ffd83dbSDimitry Andric     if (s == "rel")
870*5ffd83dbSDimitry Andric       return false;
871*5ffd83dbSDimitry Andric     if (s == "rela")
872*5ffd83dbSDimitry Andric       return true;
873*5ffd83dbSDimitry Andric   }
874*5ffd83dbSDimitry Andric 
875*5ffd83dbSDimitry Andric   // Otherwise use the psABI defined relocation entry format.
876*5ffd83dbSDimitry Andric   uint16_t m = config->emachine;
877*5ffd83dbSDimitry Andric   return m == EM_AARCH64 || m == EM_AMDGPU || m == EM_HEXAGON || m == EM_PPC ||
878*5ffd83dbSDimitry Andric          m == EM_PPC64 || m == EM_RISCV || m == EM_X86_64;
879*5ffd83dbSDimitry Andric }
880*5ffd83dbSDimitry Andric 
8810b57cec5SDimitry Andric static void parseClangOption(StringRef opt, const Twine &msg) {
8820b57cec5SDimitry Andric   std::string err;
8830b57cec5SDimitry Andric   raw_string_ostream os(err);
8840b57cec5SDimitry Andric 
8850b57cec5SDimitry Andric   const char *argv[] = {config->progName.data(), opt.data()};
8860b57cec5SDimitry Andric   if (cl::ParseCommandLineOptions(2, argv, "", &os))
8870b57cec5SDimitry Andric     return;
8880b57cec5SDimitry Andric   os.flush();
8890b57cec5SDimitry Andric   error(msg + ": " + StringRef(err).trim());
8900b57cec5SDimitry Andric }
8910b57cec5SDimitry Andric 
8920b57cec5SDimitry Andric // Initializes Config members by the command line options.
8930b57cec5SDimitry Andric static void readConfigs(opt::InputArgList &args) {
8940b57cec5SDimitry Andric   errorHandler().verbose = args.hasArg(OPT_verbose);
8950b57cec5SDimitry Andric   errorHandler().fatalWarnings =
8960b57cec5SDimitry Andric       args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false);
8970b57cec5SDimitry Andric   errorHandler().vsDiagnostics =
8980b57cec5SDimitry Andric       args.hasArg(OPT_visual_studio_diagnostics_format, false);
8990b57cec5SDimitry Andric 
9000b57cec5SDimitry Andric   config->allowMultipleDefinition =
9010b57cec5SDimitry Andric       args.hasFlag(OPT_allow_multiple_definition,
9020b57cec5SDimitry Andric                    OPT_no_allow_multiple_definition, false) ||
9030b57cec5SDimitry Andric       hasZOption(args, "muldefs");
9040b57cec5SDimitry Andric   config->allowShlibUndefined =
9050b57cec5SDimitry Andric       args.hasFlag(OPT_allow_shlib_undefined, OPT_no_allow_shlib_undefined,
9060b57cec5SDimitry Andric                    args.hasArg(OPT_shared));
9070b57cec5SDimitry Andric   config->auxiliaryList = args::getStrings(args, OPT_auxiliary);
9080b57cec5SDimitry Andric   config->bsymbolic = args.hasArg(OPT_Bsymbolic);
9090b57cec5SDimitry Andric   config->bsymbolicFunctions = args.hasArg(OPT_Bsymbolic_functions);
9100b57cec5SDimitry Andric   config->checkSections =
9110b57cec5SDimitry Andric       args.hasFlag(OPT_check_sections, OPT_no_check_sections, true);
9120b57cec5SDimitry Andric   config->chroot = args.getLastArgValue(OPT_chroot);
9130b57cec5SDimitry Andric   config->compressDebugSections = getCompressDebugSections(args);
9140b57cec5SDimitry Andric   config->cref = args.hasFlag(OPT_cref, OPT_no_cref, false);
9150b57cec5SDimitry Andric   config->defineCommon = args.hasFlag(OPT_define_common, OPT_no_define_common,
9160b57cec5SDimitry Andric                                       !args.hasArg(OPT_relocatable));
917*5ffd83dbSDimitry Andric   config->optimizeBBJumps =
918*5ffd83dbSDimitry Andric       args.hasFlag(OPT_optimize_bb_jumps, OPT_no_optimize_bb_jumps, false);
9190b57cec5SDimitry Andric   config->demangle = args.hasFlag(OPT_demangle, OPT_no_demangle, true);
9200b57cec5SDimitry Andric   config->dependentLibraries = args.hasFlag(OPT_dependent_libraries, OPT_no_dependent_libraries, true);
9210b57cec5SDimitry Andric   config->disableVerify = args.hasArg(OPT_disable_verify);
9220b57cec5SDimitry Andric   config->discard = getDiscard(args);
9230b57cec5SDimitry Andric   config->dwoDir = args.getLastArgValue(OPT_plugin_opt_dwo_dir_eq);
9240b57cec5SDimitry Andric   config->dynamicLinker = getDynamicLinker(args);
9250b57cec5SDimitry Andric   config->ehFrameHdr =
9260b57cec5SDimitry Andric       args.hasFlag(OPT_eh_frame_hdr, OPT_no_eh_frame_hdr, false);
9270b57cec5SDimitry Andric   config->emitLLVM = args.hasArg(OPT_plugin_opt_emit_llvm, false);
9280b57cec5SDimitry Andric   config->emitRelocs = args.hasArg(OPT_emit_relocs);
9290b57cec5SDimitry Andric   config->callGraphProfileSort = args.hasFlag(
9300b57cec5SDimitry Andric       OPT_call_graph_profile_sort, OPT_no_call_graph_profile_sort, true);
9310b57cec5SDimitry Andric   config->enableNewDtags =
9320b57cec5SDimitry Andric       args.hasFlag(OPT_enable_new_dtags, OPT_disable_new_dtags, true);
9330b57cec5SDimitry Andric   config->entry = args.getLastArgValue(OPT_entry);
9340b57cec5SDimitry Andric   config->executeOnly =
9350b57cec5SDimitry Andric       args.hasFlag(OPT_execute_only, OPT_no_execute_only, false);
9360b57cec5SDimitry Andric   config->exportDynamic =
9370b57cec5SDimitry Andric       args.hasFlag(OPT_export_dynamic, OPT_no_export_dynamic, false);
9380b57cec5SDimitry Andric   config->filterList = args::getStrings(args, OPT_filter);
9390b57cec5SDimitry Andric   config->fini = args.getLastArgValue(OPT_fini, "_fini");
940*5ffd83dbSDimitry Andric   config->fixCortexA53Errata843419 = args.hasArg(OPT_fix_cortex_a53_843419) &&
941*5ffd83dbSDimitry Andric                                      !args.hasArg(OPT_relocatable);
942*5ffd83dbSDimitry Andric   config->fixCortexA8 =
943*5ffd83dbSDimitry Andric       args.hasArg(OPT_fix_cortex_a8) && !args.hasArg(OPT_relocatable);
9440b57cec5SDimitry Andric   config->gcSections = args.hasFlag(OPT_gc_sections, OPT_no_gc_sections, false);
9450b57cec5SDimitry Andric   config->gnuUnique = args.hasFlag(OPT_gnu_unique, OPT_no_gnu_unique, true);
9460b57cec5SDimitry Andric   config->gdbIndex = args.hasFlag(OPT_gdb_index, OPT_no_gdb_index, false);
9470b57cec5SDimitry Andric   config->icf = getICF(args);
9480b57cec5SDimitry Andric   config->ignoreDataAddressEquality =
9490b57cec5SDimitry Andric       args.hasArg(OPT_ignore_data_address_equality);
9500b57cec5SDimitry Andric   config->ignoreFunctionAddressEquality =
9510b57cec5SDimitry Andric       args.hasArg(OPT_ignore_function_address_equality);
9520b57cec5SDimitry Andric   config->init = args.getLastArgValue(OPT_init, "_init");
9530b57cec5SDimitry Andric   config->ltoAAPipeline = args.getLastArgValue(OPT_lto_aa_pipeline);
9540b57cec5SDimitry Andric   config->ltoCSProfileGenerate = args.hasArg(OPT_lto_cs_profile_generate);
9550b57cec5SDimitry Andric   config->ltoCSProfileFile = args.getLastArgValue(OPT_lto_cs_profile_file);
9560b57cec5SDimitry Andric   config->ltoDebugPassManager = args.hasArg(OPT_lto_debug_pass_manager);
957*5ffd83dbSDimitry Andric   config->ltoEmitAsm = args.hasArg(OPT_lto_emit_asm);
9580b57cec5SDimitry Andric   config->ltoNewPassManager = args.hasArg(OPT_lto_new_pass_manager);
9590b57cec5SDimitry Andric   config->ltoNewPmPasses = args.getLastArgValue(OPT_lto_newpm_passes);
960*5ffd83dbSDimitry Andric   config->ltoWholeProgramVisibility =
961*5ffd83dbSDimitry Andric       args.hasArg(OPT_lto_whole_program_visibility);
9620b57cec5SDimitry Andric   config->ltoo = args::getInteger(args, OPT_lto_O, 2);
96385868e8aSDimitry Andric   config->ltoObjPath = args.getLastArgValue(OPT_lto_obj_path_eq);
9640b57cec5SDimitry Andric   config->ltoPartitions = args::getInteger(args, OPT_lto_partitions, 1);
9650b57cec5SDimitry Andric   config->ltoSampleProfile = args.getLastArgValue(OPT_lto_sample_profile);
966*5ffd83dbSDimitry Andric   config->ltoBasicBlockSections =
967*5ffd83dbSDimitry Andric       args.getLastArgValue(OPT_lto_basicblock_sections);
968*5ffd83dbSDimitry Andric   config->ltoUniqueBasicBlockSectionNames =
969*5ffd83dbSDimitry Andric       args.hasFlag(OPT_lto_unique_bb_section_names,
970*5ffd83dbSDimitry Andric                    OPT_no_lto_unique_bb_section_names, false);
9710b57cec5SDimitry Andric   config->mapFile = args.getLastArgValue(OPT_Map);
9720b57cec5SDimitry Andric   config->mipsGotSize = args::getInteger(args, OPT_mips_got_size, 0xfff0);
9730b57cec5SDimitry Andric   config->mergeArmExidx =
9740b57cec5SDimitry Andric       args.hasFlag(OPT_merge_exidx_entries, OPT_no_merge_exidx_entries, true);
975480093f4SDimitry Andric   config->mmapOutputFile =
976480093f4SDimitry Andric       args.hasFlag(OPT_mmap_output_file, OPT_no_mmap_output_file, true);
9770b57cec5SDimitry Andric   config->nmagic = args.hasFlag(OPT_nmagic, OPT_no_nmagic, false);
9780b57cec5SDimitry Andric   config->noinhibitExec = args.hasArg(OPT_noinhibit_exec);
9790b57cec5SDimitry Andric   config->nostdlib = args.hasArg(OPT_nostdlib);
9800b57cec5SDimitry Andric   config->oFormatBinary = isOutputFormatBinary(args);
9810b57cec5SDimitry Andric   config->omagic = args.hasFlag(OPT_omagic, OPT_no_omagic, false);
9820b57cec5SDimitry Andric   config->optRemarksFilename = args.getLastArgValue(OPT_opt_remarks_filename);
9830b57cec5SDimitry Andric   config->optRemarksPasses = args.getLastArgValue(OPT_opt_remarks_passes);
9840b57cec5SDimitry Andric   config->optRemarksWithHotness = args.hasArg(OPT_opt_remarks_with_hotness);
9850b57cec5SDimitry Andric   config->optRemarksFormat = args.getLastArgValue(OPT_opt_remarks_format);
9860b57cec5SDimitry Andric   config->optimize = args::getInteger(args, OPT_O, 1);
9870b57cec5SDimitry Andric   config->orphanHandling = getOrphanHandling(args);
9880b57cec5SDimitry Andric   config->outputFile = args.getLastArgValue(OPT_o);
9890b57cec5SDimitry Andric   config->pie = args.hasFlag(OPT_pie, OPT_no_pie, false);
9900b57cec5SDimitry Andric   config->printIcfSections =
9910b57cec5SDimitry Andric       args.hasFlag(OPT_print_icf_sections, OPT_no_print_icf_sections, false);
9920b57cec5SDimitry Andric   config->printGcSections =
9930b57cec5SDimitry Andric       args.hasFlag(OPT_print_gc_sections, OPT_no_print_gc_sections, false);
994*5ffd83dbSDimitry Andric   config->printArchiveStats = args.getLastArgValue(OPT_print_archive_stats);
9950b57cec5SDimitry Andric   config->printSymbolOrder =
9960b57cec5SDimitry Andric       args.getLastArgValue(OPT_print_symbol_order);
9970b57cec5SDimitry Andric   config->rpath = getRpath(args);
9980b57cec5SDimitry Andric   config->relocatable = args.hasArg(OPT_relocatable);
9990b57cec5SDimitry Andric   config->saveTemps = args.hasArg(OPT_save_temps);
1000*5ffd83dbSDimitry Andric   if (args.hasArg(OPT_shuffle_sections))
1001*5ffd83dbSDimitry Andric     config->shuffleSectionSeed = args::getInteger(args, OPT_shuffle_sections, 0);
10020b57cec5SDimitry Andric   config->searchPaths = args::getStrings(args, OPT_library_path);
10030b57cec5SDimitry Andric   config->sectionStartMap = getSectionStartMap(args);
10040b57cec5SDimitry Andric   config->shared = args.hasArg(OPT_shared);
1005*5ffd83dbSDimitry Andric   config->singleRoRx = !args.hasFlag(OPT_rosegment, OPT_no_rosegment, true);
10060b57cec5SDimitry Andric   config->soName = args.getLastArgValue(OPT_soname);
10070b57cec5SDimitry Andric   config->sortSection = getSortSection(args);
10080b57cec5SDimitry Andric   config->splitStackAdjustSize = args::getInteger(args, OPT_split_stack_adjust_size, 16384);
10090b57cec5SDimitry Andric   config->strip = getStrip(args);
10100b57cec5SDimitry Andric   config->sysroot = args.getLastArgValue(OPT_sysroot);
10110b57cec5SDimitry Andric   config->target1Rel = args.hasFlag(OPT_target1_rel, OPT_target1_abs, false);
10120b57cec5SDimitry Andric   config->target2 = getTarget2(args);
10130b57cec5SDimitry Andric   config->thinLTOCacheDir = args.getLastArgValue(OPT_thinlto_cache_dir);
10140b57cec5SDimitry Andric   config->thinLTOCachePolicy = CHECK(
10150b57cec5SDimitry Andric       parseCachePruningPolicy(args.getLastArgValue(OPT_thinlto_cache_policy)),
10160b57cec5SDimitry Andric       "--thinlto-cache-policy: invalid cache policy");
101785868e8aSDimitry Andric   config->thinLTOEmitImportsFiles = args.hasArg(OPT_thinlto_emit_imports_files);
101885868e8aSDimitry Andric   config->thinLTOIndexOnly = args.hasArg(OPT_thinlto_index_only) ||
101985868e8aSDimitry Andric                              args.hasArg(OPT_thinlto_index_only_eq);
102085868e8aSDimitry Andric   config->thinLTOIndexOnlyArg = args.getLastArgValue(OPT_thinlto_index_only_eq);
10210b57cec5SDimitry Andric   config->thinLTOObjectSuffixReplace =
102285868e8aSDimitry Andric       getOldNewOptions(args, OPT_thinlto_object_suffix_replace_eq);
10230b57cec5SDimitry Andric   config->thinLTOPrefixReplace =
102485868e8aSDimitry Andric       getOldNewOptions(args, OPT_thinlto_prefix_replace_eq);
1025*5ffd83dbSDimitry Andric   config->thinLTOModulesToCompile =
1026*5ffd83dbSDimitry Andric       args::getStrings(args, OPT_thinlto_single_module_eq);
1027*5ffd83dbSDimitry Andric   config->timeTraceEnabled = args.hasArg(OPT_time_trace);
1028*5ffd83dbSDimitry Andric   config->timeTraceGranularity =
1029*5ffd83dbSDimitry Andric       args::getInteger(args, OPT_time_trace_granularity, 500);
10300b57cec5SDimitry Andric   config->trace = args.hasArg(OPT_trace);
10310b57cec5SDimitry Andric   config->undefined = args::getStrings(args, OPT_undefined);
10320b57cec5SDimitry Andric   config->undefinedVersion =
10330b57cec5SDimitry Andric       args.hasFlag(OPT_undefined_version, OPT_no_undefined_version, true);
1034*5ffd83dbSDimitry Andric   config->unique = args.hasArg(OPT_unique);
10350b57cec5SDimitry Andric   config->useAndroidRelrTags = args.hasFlag(
10360b57cec5SDimitry Andric       OPT_use_android_relr_tags, OPT_no_use_android_relr_tags, false);
10370b57cec5SDimitry Andric   config->unresolvedSymbols = getUnresolvedSymbolPolicy(args);
10380b57cec5SDimitry Andric   config->warnBackrefs =
10390b57cec5SDimitry Andric       args.hasFlag(OPT_warn_backrefs, OPT_no_warn_backrefs, false);
10400b57cec5SDimitry Andric   config->warnCommon = args.hasFlag(OPT_warn_common, OPT_no_warn_common, false);
10410b57cec5SDimitry Andric   config->warnIfuncTextrel =
10420b57cec5SDimitry Andric       args.hasFlag(OPT_warn_ifunc_textrel, OPT_no_warn_ifunc_textrel, false);
10430b57cec5SDimitry Andric   config->warnSymbolOrdering =
10440b57cec5SDimitry Andric       args.hasFlag(OPT_warn_symbol_ordering, OPT_no_warn_symbol_ordering, true);
10450b57cec5SDimitry Andric   config->zCombreloc = getZFlag(args, "combreloc", "nocombreloc", true);
10460b57cec5SDimitry Andric   config->zCopyreloc = getZFlag(args, "copyreloc", "nocopyreloc", true);
1047*5ffd83dbSDimitry Andric   config->zForceBti = hasZOption(args, "force-bti");
1048480093f4SDimitry Andric   config->zForceIbt = hasZOption(args, "force-ibt");
10490b57cec5SDimitry Andric   config->zGlobal = hasZOption(args, "global");
1050480093f4SDimitry Andric   config->zGnustack = getZGnuStack(args);
10510b57cec5SDimitry Andric   config->zHazardplt = hasZOption(args, "hazardplt");
10520b57cec5SDimitry Andric   config->zIfuncNoplt = hasZOption(args, "ifunc-noplt");
10530b57cec5SDimitry Andric   config->zInitfirst = hasZOption(args, "initfirst");
10540b57cec5SDimitry Andric   config->zInterpose = hasZOption(args, "interpose");
10550b57cec5SDimitry Andric   config->zKeepTextSectionPrefix = getZFlag(
10560b57cec5SDimitry Andric       args, "keep-text-section-prefix", "nokeep-text-section-prefix", false);
10570b57cec5SDimitry Andric   config->zNodefaultlib = hasZOption(args, "nodefaultlib");
10580b57cec5SDimitry Andric   config->zNodelete = hasZOption(args, "nodelete");
10590b57cec5SDimitry Andric   config->zNodlopen = hasZOption(args, "nodlopen");
10600b57cec5SDimitry Andric   config->zNow = getZFlag(args, "now", "lazy", false);
10610b57cec5SDimitry Andric   config->zOrigin = hasZOption(args, "origin");
1062*5ffd83dbSDimitry Andric   config->zPacPlt = hasZOption(args, "pac-plt");
10630b57cec5SDimitry Andric   config->zRelro = getZFlag(args, "relro", "norelro", true);
10640b57cec5SDimitry Andric   config->zRetpolineplt = hasZOption(args, "retpolineplt");
10650b57cec5SDimitry Andric   config->zRodynamic = hasZOption(args, "rodynamic");
106685868e8aSDimitry Andric   config->zSeparate = getZSeparate(args);
1067480093f4SDimitry Andric   config->zShstk = hasZOption(args, "shstk");
10680b57cec5SDimitry Andric   config->zStackSize = args::getZOptionValue(args, OPT_z, "stack-size", 0);
1069*5ffd83dbSDimitry Andric   config->zStartStopVisibility = getZStartStopVisibility(args);
10700b57cec5SDimitry Andric   config->zText = getZFlag(args, "text", "notext", true);
10710b57cec5SDimitry Andric   config->zWxneeded = hasZOption(args, "wxneeded");
10720b57cec5SDimitry Andric 
1073*5ffd83dbSDimitry Andric   for (opt::Arg *arg : args.filtered(OPT_z)) {
1074*5ffd83dbSDimitry Andric     std::pair<StringRef, StringRef> option =
1075*5ffd83dbSDimitry Andric         StringRef(arg->getValue()).split('=');
1076*5ffd83dbSDimitry Andric     if (option.first != "dead-reloc-in-nonalloc")
1077*5ffd83dbSDimitry Andric       continue;
1078*5ffd83dbSDimitry Andric     constexpr StringRef errPrefix = "-z dead-reloc-in-nonalloc=: ";
1079*5ffd83dbSDimitry Andric     std::pair<StringRef, StringRef> kv = option.second.split('=');
1080*5ffd83dbSDimitry Andric     if (kv.first.empty() || kv.second.empty()) {
1081*5ffd83dbSDimitry Andric       error(errPrefix + "expected <section_glob>=<value>");
1082*5ffd83dbSDimitry Andric       continue;
1083*5ffd83dbSDimitry Andric     }
1084*5ffd83dbSDimitry Andric     uint64_t v;
1085*5ffd83dbSDimitry Andric     if (!to_integer(kv.second, v))
1086*5ffd83dbSDimitry Andric       error(errPrefix + "expected a non-negative integer, but got '" +
1087*5ffd83dbSDimitry Andric             kv.second + "'");
1088*5ffd83dbSDimitry Andric     else if (Expected<GlobPattern> pat = GlobPattern::create(kv.first))
1089*5ffd83dbSDimitry Andric       config->deadRelocInNonAlloc.emplace_back(std::move(*pat), v);
1090*5ffd83dbSDimitry Andric     else
1091*5ffd83dbSDimitry Andric       error(errPrefix + toString(pat.takeError()));
1092*5ffd83dbSDimitry Andric   }
1093*5ffd83dbSDimitry Andric 
10940b57cec5SDimitry Andric   // Parse LTO options.
10950b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_plugin_opt_mcpu_eq))
10960b57cec5SDimitry Andric     parseClangOption(saver.save("-mcpu=" + StringRef(arg->getValue())),
10970b57cec5SDimitry Andric                      arg->getSpelling());
10980b57cec5SDimitry Andric 
1099*5ffd83dbSDimitry Andric   for (opt::Arg *arg : args.filtered(OPT_plugin_opt_eq_minus))
1100*5ffd83dbSDimitry Andric     parseClangOption(std::string("-") + arg->getValue(), arg->getSpelling());
1101*5ffd83dbSDimitry Andric 
1102*5ffd83dbSDimitry Andric   // GCC collect2 passes -plugin-opt=path/to/lto-wrapper with an absolute or
1103*5ffd83dbSDimitry Andric   // relative path. Just ignore. If not ended with "lto-wrapper", consider it an
1104*5ffd83dbSDimitry Andric   // unsupported LLVMgold.so option and error.
1105*5ffd83dbSDimitry Andric   for (opt::Arg *arg : args.filtered(OPT_plugin_opt_eq))
1106*5ffd83dbSDimitry Andric     if (!StringRef(arg->getValue()).endswith("lto-wrapper"))
1107*5ffd83dbSDimitry Andric       error(arg->getSpelling() + ": unknown plugin option '" + arg->getValue() +
1108*5ffd83dbSDimitry Andric             "'");
11090b57cec5SDimitry Andric 
11100b57cec5SDimitry Andric   // Parse -mllvm options.
11110b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_mllvm))
11120b57cec5SDimitry Andric     parseClangOption(arg->getValue(), arg->getSpelling());
11130b57cec5SDimitry Andric 
1114*5ffd83dbSDimitry Andric   // --threads= takes a positive integer and provides the default value for
1115*5ffd83dbSDimitry Andric   // --thinlto-jobs=.
1116*5ffd83dbSDimitry Andric   if (auto *arg = args.getLastArg(OPT_threads)) {
1117*5ffd83dbSDimitry Andric     StringRef v(arg->getValue());
1118*5ffd83dbSDimitry Andric     unsigned threads = 0;
1119*5ffd83dbSDimitry Andric     if (!llvm::to_integer(v, threads, 0) || threads == 0)
1120*5ffd83dbSDimitry Andric       error(arg->getSpelling() + ": expected a positive integer, but got '" +
1121*5ffd83dbSDimitry Andric             arg->getValue() + "'");
1122*5ffd83dbSDimitry Andric     parallel::strategy = hardware_concurrency(threads);
1123*5ffd83dbSDimitry Andric     config->thinLTOJobs = v;
1124*5ffd83dbSDimitry Andric   }
1125*5ffd83dbSDimitry Andric   if (auto *arg = args.getLastArg(OPT_thinlto_jobs))
1126*5ffd83dbSDimitry Andric     config->thinLTOJobs = arg->getValue();
1127*5ffd83dbSDimitry Andric 
11280b57cec5SDimitry Andric   if (config->ltoo > 3)
11290b57cec5SDimitry Andric     error("invalid optimization level for LTO: " + Twine(config->ltoo));
11300b57cec5SDimitry Andric   if (config->ltoPartitions == 0)
11310b57cec5SDimitry Andric     error("--lto-partitions: number of threads must be > 0");
1132*5ffd83dbSDimitry Andric   if (!get_threadpool_strategy(config->thinLTOJobs))
1133*5ffd83dbSDimitry Andric     error("--thinlto-jobs: invalid job count: " + config->thinLTOJobs);
11340b57cec5SDimitry Andric 
11350b57cec5SDimitry Andric   if (config->splitStackAdjustSize < 0)
11360b57cec5SDimitry Andric     error("--split-stack-adjust-size: size must be >= 0");
11370b57cec5SDimitry Andric 
1138480093f4SDimitry Andric   // The text segment is traditionally the first segment, whose address equals
1139480093f4SDimitry Andric   // the base address. However, lld places the R PT_LOAD first. -Ttext-segment
1140480093f4SDimitry Andric   // is an old-fashioned option that does not play well with lld's layout.
1141480093f4SDimitry Andric   // Suggest --image-base as a likely alternative.
1142480093f4SDimitry Andric   if (args.hasArg(OPT_Ttext_segment))
1143480093f4SDimitry Andric     error("-Ttext-segment is not supported. Use --image-base if you "
1144480093f4SDimitry Andric           "intend to set the base address");
1145480093f4SDimitry Andric 
11460b57cec5SDimitry Andric   // Parse ELF{32,64}{LE,BE} and CPU type.
11470b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_m)) {
11480b57cec5SDimitry Andric     StringRef s = arg->getValue();
11490b57cec5SDimitry Andric     std::tie(config->ekind, config->emachine, config->osabi) =
11500b57cec5SDimitry Andric         parseEmulation(s);
11510b57cec5SDimitry Andric     config->mipsN32Abi =
11520b57cec5SDimitry Andric         (s.startswith("elf32btsmipn32") || s.startswith("elf32ltsmipn32"));
11530b57cec5SDimitry Andric     config->emulation = s;
11540b57cec5SDimitry Andric   }
11550b57cec5SDimitry Andric 
11560b57cec5SDimitry Andric   // Parse -hash-style={sysv,gnu,both}.
11570b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_hash_style)) {
11580b57cec5SDimitry Andric     StringRef s = arg->getValue();
11590b57cec5SDimitry Andric     if (s == "sysv")
11600b57cec5SDimitry Andric       config->sysvHash = true;
11610b57cec5SDimitry Andric     else if (s == "gnu")
11620b57cec5SDimitry Andric       config->gnuHash = true;
11630b57cec5SDimitry Andric     else if (s == "both")
11640b57cec5SDimitry Andric       config->sysvHash = config->gnuHash = true;
11650b57cec5SDimitry Andric     else
11660b57cec5SDimitry Andric       error("unknown -hash-style: " + s);
11670b57cec5SDimitry Andric   }
11680b57cec5SDimitry Andric 
11690b57cec5SDimitry Andric   if (args.hasArg(OPT_print_map))
11700b57cec5SDimitry Andric     config->mapFile = "-";
11710b57cec5SDimitry Andric 
11720b57cec5SDimitry Andric   // Page alignment can be disabled by the -n (--nmagic) and -N (--omagic).
11730b57cec5SDimitry Andric   // As PT_GNU_RELRO relies on Paging, do not create it when we have disabled
11740b57cec5SDimitry Andric   // it.
11750b57cec5SDimitry Andric   if (config->nmagic || config->omagic)
11760b57cec5SDimitry Andric     config->zRelro = false;
11770b57cec5SDimitry Andric 
11780b57cec5SDimitry Andric   std::tie(config->buildId, config->buildIdVector) = getBuildId(args);
11790b57cec5SDimitry Andric 
11800b57cec5SDimitry Andric   std::tie(config->androidPackDynRelocs, config->relrPackDynRelocs) =
11810b57cec5SDimitry Andric       getPackDynRelocs(args);
11820b57cec5SDimitry Andric 
11830b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_symbol_ordering_file)){
11840b57cec5SDimitry Andric     if (args.hasArg(OPT_call_graph_ordering_file))
11850b57cec5SDimitry Andric       error("--symbol-ordering-file and --call-graph-order-file "
11860b57cec5SDimitry Andric             "may not be used together");
11870b57cec5SDimitry Andric     if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue())){
11880b57cec5SDimitry Andric       config->symbolOrderingFile = getSymbolOrderingFile(*buffer);
11890b57cec5SDimitry Andric       // Also need to disable CallGraphProfileSort to prevent
11900b57cec5SDimitry Andric       // LLD order symbols with CGProfile
11910b57cec5SDimitry Andric       config->callGraphProfileSort = false;
11920b57cec5SDimitry Andric     }
11930b57cec5SDimitry Andric   }
11940b57cec5SDimitry Andric 
119585868e8aSDimitry Andric   assert(config->versionDefinitions.empty());
119685868e8aSDimitry Andric   config->versionDefinitions.push_back({"local", (uint16_t)VER_NDX_LOCAL, {}});
119785868e8aSDimitry Andric   config->versionDefinitions.push_back(
119885868e8aSDimitry Andric       {"global", (uint16_t)VER_NDX_GLOBAL, {}});
119985868e8aSDimitry Andric 
12000b57cec5SDimitry Andric   // If --retain-symbol-file is used, we'll keep only the symbols listed in
12010b57cec5SDimitry Andric   // the file and discard all others.
12020b57cec5SDimitry Andric   if (auto *arg = args.getLastArg(OPT_retain_symbols_file)) {
120385868e8aSDimitry Andric     config->versionDefinitions[VER_NDX_LOCAL].patterns.push_back(
120485868e8aSDimitry Andric         {"*", /*isExternCpp=*/false, /*hasWildcard=*/true});
12050b57cec5SDimitry Andric     if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
12060b57cec5SDimitry Andric       for (StringRef s : args::getLines(*buffer))
120785868e8aSDimitry Andric         config->versionDefinitions[VER_NDX_GLOBAL].patterns.push_back(
120885868e8aSDimitry Andric             {s, /*isExternCpp=*/false, /*hasWildcard=*/false});
12090b57cec5SDimitry Andric   }
12100b57cec5SDimitry Andric 
1211*5ffd83dbSDimitry Andric   for (opt::Arg *arg : args.filtered(OPT_warn_backrefs_exclude)) {
1212*5ffd83dbSDimitry Andric     StringRef pattern(arg->getValue());
1213*5ffd83dbSDimitry Andric     if (Expected<GlobPattern> pat = GlobPattern::create(pattern))
1214*5ffd83dbSDimitry Andric       config->warnBackrefsExclude.push_back(std::move(*pat));
1215*5ffd83dbSDimitry Andric     else
1216*5ffd83dbSDimitry Andric       error(arg->getSpelling() + ": " + toString(pat.takeError()));
1217*5ffd83dbSDimitry Andric   }
1218*5ffd83dbSDimitry Andric 
1219*5ffd83dbSDimitry Andric   // When producing an executable, --dynamic-list specifies non-local defined
1220*5ffd83dbSDimitry Andric   // symbols whith are required to be exported. When producing a shared object,
1221*5ffd83dbSDimitry Andric   // symbols not specified by --dynamic-list are non-preemptible.
1222*5ffd83dbSDimitry Andric   config->symbolic =
1223*5ffd83dbSDimitry Andric       args.hasArg(OPT_Bsymbolic) || args.hasArg(OPT_dynamic_list);
12240b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_dynamic_list))
12250b57cec5SDimitry Andric     if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
12260b57cec5SDimitry Andric       readDynamicList(*buffer);
12270b57cec5SDimitry Andric 
1228*5ffd83dbSDimitry Andric   // --export-dynamic-symbol specifies additional --dynamic-list symbols if any
1229*5ffd83dbSDimitry Andric   // other option expresses a symbolic intention: -no-pie, -pie, -Bsymbolic,
1230*5ffd83dbSDimitry Andric   // -Bsymbolic-functions (if STT_FUNC), --dynamic-list.
12310b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_export_dynamic_symbol))
12320b57cec5SDimitry Andric     config->dynamicList.push_back(
1233*5ffd83dbSDimitry Andric         {arg->getValue(), /*isExternCpp=*/false,
1234*5ffd83dbSDimitry Andric          /*hasWildcard=*/hasWildcard(arg->getValue())});
12350b57cec5SDimitry Andric 
12360b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_version_script))
12370b57cec5SDimitry Andric     if (Optional<std::string> path = searchScript(arg->getValue())) {
12380b57cec5SDimitry Andric       if (Optional<MemoryBufferRef> buffer = readFile(*path))
12390b57cec5SDimitry Andric         readVersionScript(*buffer);
12400b57cec5SDimitry Andric     } else {
12410b57cec5SDimitry Andric       error(Twine("cannot find version script ") + arg->getValue());
12420b57cec5SDimitry Andric     }
12430b57cec5SDimitry Andric }
12440b57cec5SDimitry Andric 
12450b57cec5SDimitry Andric // Some Config members do not directly correspond to any particular
12460b57cec5SDimitry Andric // command line options, but computed based on other Config values.
12470b57cec5SDimitry Andric // This function initialize such members. See Config.h for the details
12480b57cec5SDimitry Andric // of these values.
12490b57cec5SDimitry Andric static void setConfigs(opt::InputArgList &args) {
12500b57cec5SDimitry Andric   ELFKind k = config->ekind;
12510b57cec5SDimitry Andric   uint16_t m = config->emachine;
12520b57cec5SDimitry Andric 
12530b57cec5SDimitry Andric   config->copyRelocs = (config->relocatable || config->emitRelocs);
12540b57cec5SDimitry Andric   config->is64 = (k == ELF64LEKind || k == ELF64BEKind);
12550b57cec5SDimitry Andric   config->isLE = (k == ELF32LEKind || k == ELF64LEKind);
12560b57cec5SDimitry Andric   config->endianness = config->isLE ? endianness::little : endianness::big;
12570b57cec5SDimitry Andric   config->isMips64EL = (k == ELF64LEKind && m == EM_MIPS);
12580b57cec5SDimitry Andric   config->isPic = config->pie || config->shared;
12590b57cec5SDimitry Andric   config->picThunk = args.hasArg(OPT_pic_veneer, config->isPic);
12600b57cec5SDimitry Andric   config->wordsize = config->is64 ? 8 : 4;
12610b57cec5SDimitry Andric 
12620b57cec5SDimitry Andric   // ELF defines two different ways to store relocation addends as shown below:
12630b57cec5SDimitry Andric   //
1264*5ffd83dbSDimitry Andric   //  Rel: Addends are stored to the location where relocations are applied. It
1265*5ffd83dbSDimitry Andric   //  cannot pack the full range of addend values for all relocation types, but
1266*5ffd83dbSDimitry Andric   //  this only affects relocation types that we don't support emitting as
1267*5ffd83dbSDimitry Andric   //  dynamic relocations (see getDynRel).
12680b57cec5SDimitry Andric   //  Rela: Addends are stored as part of relocation entry.
12690b57cec5SDimitry Andric   //
12700b57cec5SDimitry Andric   // In other words, Rela makes it easy to read addends at the price of extra
1271*5ffd83dbSDimitry Andric   // 4 or 8 byte for each relocation entry.
12720b57cec5SDimitry Andric   //
1273*5ffd83dbSDimitry Andric   // We pick the format for dynamic relocations according to the psABI for each
1274*5ffd83dbSDimitry Andric   // processor, but a contrary choice can be made if the dynamic loader
1275*5ffd83dbSDimitry Andric   // supports.
1276*5ffd83dbSDimitry Andric   config->isRela = getIsRela(args);
12770b57cec5SDimitry Andric 
12780b57cec5SDimitry Andric   // If the output uses REL relocations we must store the dynamic relocation
12790b57cec5SDimitry Andric   // addends to the output sections. We also store addends for RELA relocations
12800b57cec5SDimitry Andric   // if --apply-dynamic-relocs is used.
12810b57cec5SDimitry Andric   // We default to not writing the addends when using RELA relocations since
12820b57cec5SDimitry Andric   // any standard conforming tool can find it in r_addend.
12830b57cec5SDimitry Andric   config->writeAddends = args.hasFlag(OPT_apply_dynamic_relocs,
12840b57cec5SDimitry Andric                                       OPT_no_apply_dynamic_relocs, false) ||
12850b57cec5SDimitry Andric                          !config->isRela;
12860b57cec5SDimitry Andric 
12870b57cec5SDimitry Andric   config->tocOptimize =
12880b57cec5SDimitry Andric       args.hasFlag(OPT_toc_optimize, OPT_no_toc_optimize, m == EM_PPC64);
12890b57cec5SDimitry Andric }
12900b57cec5SDimitry Andric 
12910b57cec5SDimitry Andric // Returns a value of "-format" option.
12920b57cec5SDimitry Andric static bool isFormatBinary(StringRef s) {
12930b57cec5SDimitry Andric   if (s == "binary")
12940b57cec5SDimitry Andric     return true;
12950b57cec5SDimitry Andric   if (s == "elf" || s == "default")
12960b57cec5SDimitry Andric     return false;
12970b57cec5SDimitry Andric   error("unknown -format value: " + s +
12980b57cec5SDimitry Andric         " (supported formats: elf, default, binary)");
12990b57cec5SDimitry Andric   return false;
13000b57cec5SDimitry Andric }
13010b57cec5SDimitry Andric 
13020b57cec5SDimitry Andric void LinkerDriver::createFiles(opt::InputArgList &args) {
13030b57cec5SDimitry Andric   // For --{push,pop}-state.
13040b57cec5SDimitry Andric   std::vector<std::tuple<bool, bool, bool>> stack;
13050b57cec5SDimitry Andric 
13060b57cec5SDimitry Andric   // Iterate over argv to process input files and positional arguments.
13070b57cec5SDimitry Andric   for (auto *arg : args) {
13080b57cec5SDimitry Andric     switch (arg->getOption().getID()) {
13090b57cec5SDimitry Andric     case OPT_library:
13100b57cec5SDimitry Andric       addLibrary(arg->getValue());
13110b57cec5SDimitry Andric       break;
13120b57cec5SDimitry Andric     case OPT_INPUT:
13130b57cec5SDimitry Andric       addFile(arg->getValue(), /*withLOption=*/false);
13140b57cec5SDimitry Andric       break;
13150b57cec5SDimitry Andric     case OPT_defsym: {
13160b57cec5SDimitry Andric       StringRef from;
13170b57cec5SDimitry Andric       StringRef to;
13180b57cec5SDimitry Andric       std::tie(from, to) = StringRef(arg->getValue()).split('=');
13190b57cec5SDimitry Andric       if (from.empty() || to.empty())
13200b57cec5SDimitry Andric         error("-defsym: syntax error: " + StringRef(arg->getValue()));
13210b57cec5SDimitry Andric       else
13220b57cec5SDimitry Andric         readDefsym(from, MemoryBufferRef(to, "-defsym"));
13230b57cec5SDimitry Andric       break;
13240b57cec5SDimitry Andric     }
13250b57cec5SDimitry Andric     case OPT_script:
13260b57cec5SDimitry Andric       if (Optional<std::string> path = searchScript(arg->getValue())) {
13270b57cec5SDimitry Andric         if (Optional<MemoryBufferRef> mb = readFile(*path))
13280b57cec5SDimitry Andric           readLinkerScript(*mb);
13290b57cec5SDimitry Andric         break;
13300b57cec5SDimitry Andric       }
13310b57cec5SDimitry Andric       error(Twine("cannot find linker script ") + arg->getValue());
13320b57cec5SDimitry Andric       break;
13330b57cec5SDimitry Andric     case OPT_as_needed:
13340b57cec5SDimitry Andric       config->asNeeded = true;
13350b57cec5SDimitry Andric       break;
13360b57cec5SDimitry Andric     case OPT_format:
13370b57cec5SDimitry Andric       config->formatBinary = isFormatBinary(arg->getValue());
13380b57cec5SDimitry Andric       break;
13390b57cec5SDimitry Andric     case OPT_no_as_needed:
13400b57cec5SDimitry Andric       config->asNeeded = false;
13410b57cec5SDimitry Andric       break;
13420b57cec5SDimitry Andric     case OPT_Bstatic:
13430b57cec5SDimitry Andric     case OPT_omagic:
13440b57cec5SDimitry Andric     case OPT_nmagic:
13450b57cec5SDimitry Andric       config->isStatic = true;
13460b57cec5SDimitry Andric       break;
13470b57cec5SDimitry Andric     case OPT_Bdynamic:
13480b57cec5SDimitry Andric       config->isStatic = false;
13490b57cec5SDimitry Andric       break;
13500b57cec5SDimitry Andric     case OPT_whole_archive:
13510b57cec5SDimitry Andric       inWholeArchive = true;
13520b57cec5SDimitry Andric       break;
13530b57cec5SDimitry Andric     case OPT_no_whole_archive:
13540b57cec5SDimitry Andric       inWholeArchive = false;
13550b57cec5SDimitry Andric       break;
13560b57cec5SDimitry Andric     case OPT_just_symbols:
13570b57cec5SDimitry Andric       if (Optional<MemoryBufferRef> mb = readFile(arg->getValue())) {
13580b57cec5SDimitry Andric         files.push_back(createObjectFile(*mb));
13590b57cec5SDimitry Andric         files.back()->justSymbols = true;
13600b57cec5SDimitry Andric       }
13610b57cec5SDimitry Andric       break;
13620b57cec5SDimitry Andric     case OPT_start_group:
13630b57cec5SDimitry Andric       if (InputFile::isInGroup)
13640b57cec5SDimitry Andric         error("nested --start-group");
13650b57cec5SDimitry Andric       InputFile::isInGroup = true;
13660b57cec5SDimitry Andric       break;
13670b57cec5SDimitry Andric     case OPT_end_group:
13680b57cec5SDimitry Andric       if (!InputFile::isInGroup)
13690b57cec5SDimitry Andric         error("stray --end-group");
13700b57cec5SDimitry Andric       InputFile::isInGroup = false;
13710b57cec5SDimitry Andric       ++InputFile::nextGroupId;
13720b57cec5SDimitry Andric       break;
13730b57cec5SDimitry Andric     case OPT_start_lib:
13740b57cec5SDimitry Andric       if (inLib)
13750b57cec5SDimitry Andric         error("nested --start-lib");
13760b57cec5SDimitry Andric       if (InputFile::isInGroup)
13770b57cec5SDimitry Andric         error("may not nest --start-lib in --start-group");
13780b57cec5SDimitry Andric       inLib = true;
13790b57cec5SDimitry Andric       InputFile::isInGroup = true;
13800b57cec5SDimitry Andric       break;
13810b57cec5SDimitry Andric     case OPT_end_lib:
13820b57cec5SDimitry Andric       if (!inLib)
13830b57cec5SDimitry Andric         error("stray --end-lib");
13840b57cec5SDimitry Andric       inLib = false;
13850b57cec5SDimitry Andric       InputFile::isInGroup = false;
13860b57cec5SDimitry Andric       ++InputFile::nextGroupId;
13870b57cec5SDimitry Andric       break;
13880b57cec5SDimitry Andric     case OPT_push_state:
13890b57cec5SDimitry Andric       stack.emplace_back(config->asNeeded, config->isStatic, inWholeArchive);
13900b57cec5SDimitry Andric       break;
13910b57cec5SDimitry Andric     case OPT_pop_state:
13920b57cec5SDimitry Andric       if (stack.empty()) {
13930b57cec5SDimitry Andric         error("unbalanced --push-state/--pop-state");
13940b57cec5SDimitry Andric         break;
13950b57cec5SDimitry Andric       }
13960b57cec5SDimitry Andric       std::tie(config->asNeeded, config->isStatic, inWholeArchive) = stack.back();
13970b57cec5SDimitry Andric       stack.pop_back();
13980b57cec5SDimitry Andric       break;
13990b57cec5SDimitry Andric     }
14000b57cec5SDimitry Andric   }
14010b57cec5SDimitry Andric 
14020b57cec5SDimitry Andric   if (files.empty() && errorCount() == 0)
14030b57cec5SDimitry Andric     error("no input files");
14040b57cec5SDimitry Andric }
14050b57cec5SDimitry Andric 
14060b57cec5SDimitry Andric // If -m <machine_type> was not given, infer it from object files.
14070b57cec5SDimitry Andric void LinkerDriver::inferMachineType() {
14080b57cec5SDimitry Andric   if (config->ekind != ELFNoneKind)
14090b57cec5SDimitry Andric     return;
14100b57cec5SDimitry Andric 
14110b57cec5SDimitry Andric   for (InputFile *f : files) {
14120b57cec5SDimitry Andric     if (f->ekind == ELFNoneKind)
14130b57cec5SDimitry Andric       continue;
14140b57cec5SDimitry Andric     config->ekind = f->ekind;
14150b57cec5SDimitry Andric     config->emachine = f->emachine;
14160b57cec5SDimitry Andric     config->osabi = f->osabi;
14170b57cec5SDimitry Andric     config->mipsN32Abi = config->emachine == EM_MIPS && isMipsN32Abi(f);
14180b57cec5SDimitry Andric     return;
14190b57cec5SDimitry Andric   }
14200b57cec5SDimitry Andric   error("target emulation unknown: -m or at least one .o file required");
14210b57cec5SDimitry Andric }
14220b57cec5SDimitry Andric 
14230b57cec5SDimitry Andric // Parse -z max-page-size=<value>. The default value is defined by
14240b57cec5SDimitry Andric // each target.
14250b57cec5SDimitry Andric static uint64_t getMaxPageSize(opt::InputArgList &args) {
14260b57cec5SDimitry Andric   uint64_t val = args::getZOptionValue(args, OPT_z, "max-page-size",
14270b57cec5SDimitry Andric                                        target->defaultMaxPageSize);
14280b57cec5SDimitry Andric   if (!isPowerOf2_64(val))
14290b57cec5SDimitry Andric     error("max-page-size: value isn't a power of 2");
14300b57cec5SDimitry Andric   if (config->nmagic || config->omagic) {
14310b57cec5SDimitry Andric     if (val != target->defaultMaxPageSize)
14320b57cec5SDimitry Andric       warn("-z max-page-size set, but paging disabled by omagic or nmagic");
14330b57cec5SDimitry Andric     return 1;
14340b57cec5SDimitry Andric   }
14350b57cec5SDimitry Andric   return val;
14360b57cec5SDimitry Andric }
14370b57cec5SDimitry Andric 
14380b57cec5SDimitry Andric // Parse -z common-page-size=<value>. The default value is defined by
14390b57cec5SDimitry Andric // each target.
14400b57cec5SDimitry Andric static uint64_t getCommonPageSize(opt::InputArgList &args) {
14410b57cec5SDimitry Andric   uint64_t val = args::getZOptionValue(args, OPT_z, "common-page-size",
14420b57cec5SDimitry Andric                                        target->defaultCommonPageSize);
14430b57cec5SDimitry Andric   if (!isPowerOf2_64(val))
14440b57cec5SDimitry Andric     error("common-page-size: value isn't a power of 2");
14450b57cec5SDimitry Andric   if (config->nmagic || config->omagic) {
14460b57cec5SDimitry Andric     if (val != target->defaultCommonPageSize)
14470b57cec5SDimitry Andric       warn("-z common-page-size set, but paging disabled by omagic or nmagic");
14480b57cec5SDimitry Andric     return 1;
14490b57cec5SDimitry Andric   }
14500b57cec5SDimitry Andric   // commonPageSize can't be larger than maxPageSize.
14510b57cec5SDimitry Andric   if (val > config->maxPageSize)
14520b57cec5SDimitry Andric     val = config->maxPageSize;
14530b57cec5SDimitry Andric   return val;
14540b57cec5SDimitry Andric }
14550b57cec5SDimitry Andric 
14560b57cec5SDimitry Andric // Parses -image-base option.
14570b57cec5SDimitry Andric static Optional<uint64_t> getImageBase(opt::InputArgList &args) {
14580b57cec5SDimitry Andric   // Because we are using "Config->maxPageSize" here, this function has to be
14590b57cec5SDimitry Andric   // called after the variable is initialized.
14600b57cec5SDimitry Andric   auto *arg = args.getLastArg(OPT_image_base);
14610b57cec5SDimitry Andric   if (!arg)
14620b57cec5SDimitry Andric     return None;
14630b57cec5SDimitry Andric 
14640b57cec5SDimitry Andric   StringRef s = arg->getValue();
14650b57cec5SDimitry Andric   uint64_t v;
14660b57cec5SDimitry Andric   if (!to_integer(s, v)) {
14670b57cec5SDimitry Andric     error("-image-base: number expected, but got " + s);
14680b57cec5SDimitry Andric     return 0;
14690b57cec5SDimitry Andric   }
14700b57cec5SDimitry Andric   if ((v % config->maxPageSize) != 0)
14710b57cec5SDimitry Andric     warn("-image-base: address isn't multiple of page size: " + s);
14720b57cec5SDimitry Andric   return v;
14730b57cec5SDimitry Andric }
14740b57cec5SDimitry Andric 
14750b57cec5SDimitry Andric // Parses `--exclude-libs=lib,lib,...`.
14760b57cec5SDimitry Andric // The library names may be delimited by commas or colons.
14770b57cec5SDimitry Andric static DenseSet<StringRef> getExcludeLibs(opt::InputArgList &args) {
14780b57cec5SDimitry Andric   DenseSet<StringRef> ret;
14790b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_exclude_libs)) {
14800b57cec5SDimitry Andric     StringRef s = arg->getValue();
14810b57cec5SDimitry Andric     for (;;) {
14820b57cec5SDimitry Andric       size_t pos = s.find_first_of(",:");
14830b57cec5SDimitry Andric       if (pos == StringRef::npos)
14840b57cec5SDimitry Andric         break;
14850b57cec5SDimitry Andric       ret.insert(s.substr(0, pos));
14860b57cec5SDimitry Andric       s = s.substr(pos + 1);
14870b57cec5SDimitry Andric     }
14880b57cec5SDimitry Andric     ret.insert(s);
14890b57cec5SDimitry Andric   }
14900b57cec5SDimitry Andric   return ret;
14910b57cec5SDimitry Andric }
14920b57cec5SDimitry Andric 
14930b57cec5SDimitry Andric // Handles the -exclude-libs option. If a static library file is specified
14940b57cec5SDimitry Andric // by the -exclude-libs option, all public symbols from the archive become
14950b57cec5SDimitry Andric // private unless otherwise specified by version scripts or something.
14960b57cec5SDimitry Andric // A special library name "ALL" means all archive files.
14970b57cec5SDimitry Andric //
14980b57cec5SDimitry Andric // This is not a popular option, but some programs such as bionic libc use it.
14990b57cec5SDimitry Andric static void excludeLibs(opt::InputArgList &args) {
15000b57cec5SDimitry Andric   DenseSet<StringRef> libs = getExcludeLibs(args);
15010b57cec5SDimitry Andric   bool all = libs.count("ALL");
15020b57cec5SDimitry Andric 
15030b57cec5SDimitry Andric   auto visit = [&](InputFile *file) {
15040b57cec5SDimitry Andric     if (!file->archiveName.empty())
15050b57cec5SDimitry Andric       if (all || libs.count(path::filename(file->archiveName)))
15060b57cec5SDimitry Andric         for (Symbol *sym : file->getSymbols())
1507480093f4SDimitry Andric           if (!sym->isUndefined() && !sym->isLocal() && sym->file == file)
15080b57cec5SDimitry Andric             sym->versionId = VER_NDX_LOCAL;
15090b57cec5SDimitry Andric   };
15100b57cec5SDimitry Andric 
15110b57cec5SDimitry Andric   for (InputFile *file : objectFiles)
15120b57cec5SDimitry Andric     visit(file);
15130b57cec5SDimitry Andric 
15140b57cec5SDimitry Andric   for (BitcodeFile *file : bitcodeFiles)
15150b57cec5SDimitry Andric     visit(file);
15160b57cec5SDimitry Andric }
15170b57cec5SDimitry Andric 
1518*5ffd83dbSDimitry Andric // Force Sym to be entered in the output.
15190b57cec5SDimitry Andric static void handleUndefined(Symbol *sym) {
15200b57cec5SDimitry Andric   // Since a symbol may not be used inside the program, LTO may
15210b57cec5SDimitry Andric   // eliminate it. Mark the symbol as "used" to prevent it.
15220b57cec5SDimitry Andric   sym->isUsedInRegularObj = true;
15230b57cec5SDimitry Andric 
15240b57cec5SDimitry Andric   if (sym->isLazy())
15250b57cec5SDimitry Andric     sym->fetch();
15260b57cec5SDimitry Andric }
15270b57cec5SDimitry Andric 
1528480093f4SDimitry Andric // As an extension to GNU linkers, lld supports a variant of `-u`
15290b57cec5SDimitry Andric // which accepts wildcard patterns. All symbols that match a given
15300b57cec5SDimitry Andric // pattern are handled as if they were given by `-u`.
15310b57cec5SDimitry Andric static void handleUndefinedGlob(StringRef arg) {
15320b57cec5SDimitry Andric   Expected<GlobPattern> pat = GlobPattern::create(arg);
15330b57cec5SDimitry Andric   if (!pat) {
15340b57cec5SDimitry Andric     error("--undefined-glob: " + toString(pat.takeError()));
15350b57cec5SDimitry Andric     return;
15360b57cec5SDimitry Andric   }
15370b57cec5SDimitry Andric 
15380b57cec5SDimitry Andric   std::vector<Symbol *> syms;
1539480093f4SDimitry Andric   for (Symbol *sym : symtab->symbols()) {
15400b57cec5SDimitry Andric     // Calling Sym->fetch() from here is not safe because it may
15410b57cec5SDimitry Andric     // add new symbols to the symbol table, invalidating the
15420b57cec5SDimitry Andric     // current iterator. So we just keep a note.
15430b57cec5SDimitry Andric     if (pat->match(sym->getName()))
15440b57cec5SDimitry Andric       syms.push_back(sym);
1545480093f4SDimitry Andric   }
15460b57cec5SDimitry Andric 
15470b57cec5SDimitry Andric   for (Symbol *sym : syms)
15480b57cec5SDimitry Andric     handleUndefined(sym);
15490b57cec5SDimitry Andric }
15500b57cec5SDimitry Andric 
15510b57cec5SDimitry Andric static void handleLibcall(StringRef name) {
15520b57cec5SDimitry Andric   Symbol *sym = symtab->find(name);
15530b57cec5SDimitry Andric   if (!sym || !sym->isLazy())
15540b57cec5SDimitry Andric     return;
15550b57cec5SDimitry Andric 
15560b57cec5SDimitry Andric   MemoryBufferRef mb;
15570b57cec5SDimitry Andric   if (auto *lo = dyn_cast<LazyObject>(sym))
15580b57cec5SDimitry Andric     mb = lo->file->mb;
15590b57cec5SDimitry Andric   else
15600b57cec5SDimitry Andric     mb = cast<LazyArchive>(sym)->getMemberBuffer();
15610b57cec5SDimitry Andric 
15620b57cec5SDimitry Andric   if (isBitcode(mb))
15630b57cec5SDimitry Andric     sym->fetch();
15640b57cec5SDimitry Andric }
15650b57cec5SDimitry Andric 
15660b57cec5SDimitry Andric // Replaces common symbols with defined symbols reside in .bss sections.
15670b57cec5SDimitry Andric // This function is called after all symbol names are resolved. As a
15680b57cec5SDimitry Andric // result, the passes after the symbol resolution won't see any
15690b57cec5SDimitry Andric // symbols of type CommonSymbol.
15700b57cec5SDimitry Andric static void replaceCommonSymbols() {
1571480093f4SDimitry Andric   for (Symbol *sym : symtab->symbols()) {
15720b57cec5SDimitry Andric     auto *s = dyn_cast<CommonSymbol>(sym);
15730b57cec5SDimitry Andric     if (!s)
1574480093f4SDimitry Andric       continue;
15750b57cec5SDimitry Andric 
15760b57cec5SDimitry Andric     auto *bss = make<BssSection>("COMMON", s->size, s->alignment);
15770b57cec5SDimitry Andric     bss->file = s->file;
15780b57cec5SDimitry Andric     bss->markDead();
15790b57cec5SDimitry Andric     inputSections.push_back(bss);
15800b57cec5SDimitry Andric     s->replace(Defined{s->file, s->getName(), s->binding, s->stOther, s->type,
15810b57cec5SDimitry Andric                        /*value=*/0, s->size, bss});
1582480093f4SDimitry Andric   }
15830b57cec5SDimitry Andric }
15840b57cec5SDimitry Andric 
15850b57cec5SDimitry Andric // If all references to a DSO happen to be weak, the DSO is not added
15860b57cec5SDimitry Andric // to DT_NEEDED. If that happens, we need to eliminate shared symbols
15870b57cec5SDimitry Andric // created from the DSO. Otherwise, they become dangling references
15880b57cec5SDimitry Andric // that point to a non-existent DSO.
15890b57cec5SDimitry Andric static void demoteSharedSymbols() {
1590480093f4SDimitry Andric   for (Symbol *sym : symtab->symbols()) {
15910b57cec5SDimitry Andric     auto *s = dyn_cast<SharedSymbol>(sym);
15920b57cec5SDimitry Andric     if (!s || s->getFile().isNeeded)
1593480093f4SDimitry Andric       continue;
15940b57cec5SDimitry Andric 
15950b57cec5SDimitry Andric     bool used = s->used;
15960b57cec5SDimitry Andric     s->replace(Undefined{nullptr, s->getName(), STB_WEAK, s->stOther, s->type});
15970b57cec5SDimitry Andric     s->used = used;
1598480093f4SDimitry Andric   }
15990b57cec5SDimitry Andric }
16000b57cec5SDimitry Andric 
16010b57cec5SDimitry Andric // The section referred to by `s` is considered address-significant. Set the
16020b57cec5SDimitry Andric // keepUnique flag on the section if appropriate.
16030b57cec5SDimitry Andric static void markAddrsig(Symbol *s) {
16040b57cec5SDimitry Andric   if (auto *d = dyn_cast_or_null<Defined>(s))
16050b57cec5SDimitry Andric     if (d->section)
16060b57cec5SDimitry Andric       // We don't need to keep text sections unique under --icf=all even if they
16070b57cec5SDimitry Andric       // are address-significant.
16080b57cec5SDimitry Andric       if (config->icf == ICFLevel::Safe || !(d->section->flags & SHF_EXECINSTR))
16090b57cec5SDimitry Andric         d->section->keepUnique = true;
16100b57cec5SDimitry Andric }
16110b57cec5SDimitry Andric 
16120b57cec5SDimitry Andric // Record sections that define symbols mentioned in --keep-unique <symbol>
16130b57cec5SDimitry Andric // and symbols referred to by address-significance tables. These sections are
16140b57cec5SDimitry Andric // ineligible for ICF.
16150b57cec5SDimitry Andric template <class ELFT>
16160b57cec5SDimitry Andric static void findKeepUniqueSections(opt::InputArgList &args) {
16170b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_keep_unique)) {
16180b57cec5SDimitry Andric     StringRef name = arg->getValue();
16190b57cec5SDimitry Andric     auto *d = dyn_cast_or_null<Defined>(symtab->find(name));
16200b57cec5SDimitry Andric     if (!d || !d->section) {
16210b57cec5SDimitry Andric       warn("could not find symbol " + name + " to keep unique");
16220b57cec5SDimitry Andric       continue;
16230b57cec5SDimitry Andric     }
16240b57cec5SDimitry Andric     d->section->keepUnique = true;
16250b57cec5SDimitry Andric   }
16260b57cec5SDimitry Andric 
16270b57cec5SDimitry Andric   // --icf=all --ignore-data-address-equality means that we can ignore
16280b57cec5SDimitry Andric   // the dynsym and address-significance tables entirely.
16290b57cec5SDimitry Andric   if (config->icf == ICFLevel::All && config->ignoreDataAddressEquality)
16300b57cec5SDimitry Andric     return;
16310b57cec5SDimitry Andric 
16320b57cec5SDimitry Andric   // Symbols in the dynsym could be address-significant in other executables
16330b57cec5SDimitry Andric   // or DSOs, so we conservatively mark them as address-significant.
1634480093f4SDimitry Andric   for (Symbol *sym : symtab->symbols())
16350b57cec5SDimitry Andric     if (sym->includeInDynsym())
16360b57cec5SDimitry Andric       markAddrsig(sym);
16370b57cec5SDimitry Andric 
16380b57cec5SDimitry Andric   // Visit the address-significance table in each object file and mark each
16390b57cec5SDimitry Andric   // referenced symbol as address-significant.
16400b57cec5SDimitry Andric   for (InputFile *f : objectFiles) {
16410b57cec5SDimitry Andric     auto *obj = cast<ObjFile<ELFT>>(f);
16420b57cec5SDimitry Andric     ArrayRef<Symbol *> syms = obj->getSymbols();
16430b57cec5SDimitry Andric     if (obj->addrsigSec) {
16440b57cec5SDimitry Andric       ArrayRef<uint8_t> contents =
16450b57cec5SDimitry Andric           check(obj->getObj().getSectionContents(obj->addrsigSec));
16460b57cec5SDimitry Andric       const uint8_t *cur = contents.begin();
16470b57cec5SDimitry Andric       while (cur != contents.end()) {
16480b57cec5SDimitry Andric         unsigned size;
16490b57cec5SDimitry Andric         const char *err;
16500b57cec5SDimitry Andric         uint64_t symIndex = decodeULEB128(cur, &size, contents.end(), &err);
16510b57cec5SDimitry Andric         if (err)
16520b57cec5SDimitry Andric           fatal(toString(f) + ": could not decode addrsig section: " + err);
16530b57cec5SDimitry Andric         markAddrsig(syms[symIndex]);
16540b57cec5SDimitry Andric         cur += size;
16550b57cec5SDimitry Andric       }
16560b57cec5SDimitry Andric     } else {
16570b57cec5SDimitry Andric       // If an object file does not have an address-significance table,
16580b57cec5SDimitry Andric       // conservatively mark all of its symbols as address-significant.
16590b57cec5SDimitry Andric       for (Symbol *s : syms)
16600b57cec5SDimitry Andric         markAddrsig(s);
16610b57cec5SDimitry Andric     }
16620b57cec5SDimitry Andric   }
16630b57cec5SDimitry Andric }
16640b57cec5SDimitry Andric 
16650b57cec5SDimitry Andric // This function reads a symbol partition specification section. These sections
16660b57cec5SDimitry Andric // are used to control which partition a symbol is allocated to. See
16670b57cec5SDimitry Andric // https://lld.llvm.org/Partitions.html for more details on partitions.
16680b57cec5SDimitry Andric template <typename ELFT>
16690b57cec5SDimitry Andric static void readSymbolPartitionSection(InputSectionBase *s) {
16700b57cec5SDimitry Andric   // Read the relocation that refers to the partition's entry point symbol.
16710b57cec5SDimitry Andric   Symbol *sym;
16720b57cec5SDimitry Andric   if (s->areRelocsRela)
16730b57cec5SDimitry Andric     sym = &s->getFile<ELFT>()->getRelocTargetSym(s->template relas<ELFT>()[0]);
16740b57cec5SDimitry Andric   else
16750b57cec5SDimitry Andric     sym = &s->getFile<ELFT>()->getRelocTargetSym(s->template rels<ELFT>()[0]);
16760b57cec5SDimitry Andric   if (!isa<Defined>(sym) || !sym->includeInDynsym())
16770b57cec5SDimitry Andric     return;
16780b57cec5SDimitry Andric 
16790b57cec5SDimitry Andric   StringRef partName = reinterpret_cast<const char *>(s->data().data());
16800b57cec5SDimitry Andric   for (Partition &part : partitions) {
16810b57cec5SDimitry Andric     if (part.name == partName) {
16820b57cec5SDimitry Andric       sym->partition = part.getNumber();
16830b57cec5SDimitry Andric       return;
16840b57cec5SDimitry Andric     }
16850b57cec5SDimitry Andric   }
16860b57cec5SDimitry Andric 
16870b57cec5SDimitry Andric   // Forbid partitions from being used on incompatible targets, and forbid them
16880b57cec5SDimitry Andric   // from being used together with various linker features that assume a single
16890b57cec5SDimitry Andric   // set of output sections.
16900b57cec5SDimitry Andric   if (script->hasSectionsCommand)
16910b57cec5SDimitry Andric     error(toString(s->file) +
16920b57cec5SDimitry Andric           ": partitions cannot be used with the SECTIONS command");
16930b57cec5SDimitry Andric   if (script->hasPhdrsCommands())
16940b57cec5SDimitry Andric     error(toString(s->file) +
16950b57cec5SDimitry Andric           ": partitions cannot be used with the PHDRS command");
16960b57cec5SDimitry Andric   if (!config->sectionStartMap.empty())
16970b57cec5SDimitry Andric     error(toString(s->file) + ": partitions cannot be used with "
16980b57cec5SDimitry Andric                               "--section-start, -Ttext, -Tdata or -Tbss");
16990b57cec5SDimitry Andric   if (config->emachine == EM_MIPS)
17000b57cec5SDimitry Andric     error(toString(s->file) + ": partitions cannot be used on this target");
17010b57cec5SDimitry Andric 
17020b57cec5SDimitry Andric   // Impose a limit of no more than 254 partitions. This limit comes from the
17030b57cec5SDimitry Andric   // sizes of the Partition fields in InputSectionBase and Symbol, as well as
17040b57cec5SDimitry Andric   // the amount of space devoted to the partition number in RankFlags.
17050b57cec5SDimitry Andric   if (partitions.size() == 254)
17060b57cec5SDimitry Andric     fatal("may not have more than 254 partitions");
17070b57cec5SDimitry Andric 
17080b57cec5SDimitry Andric   partitions.emplace_back();
17090b57cec5SDimitry Andric   Partition &newPart = partitions.back();
17100b57cec5SDimitry Andric   newPart.name = partName;
17110b57cec5SDimitry Andric   sym->partition = newPart.getNumber();
17120b57cec5SDimitry Andric }
17130b57cec5SDimitry Andric 
17140b57cec5SDimitry Andric static Symbol *addUndefined(StringRef name) {
17150b57cec5SDimitry Andric   return symtab->addSymbol(
17160b57cec5SDimitry Andric       Undefined{nullptr, name, STB_GLOBAL, STV_DEFAULT, 0});
17170b57cec5SDimitry Andric }
17180b57cec5SDimitry Andric 
1719*5ffd83dbSDimitry Andric static Symbol *addUnusedUndefined(StringRef name) {
1720*5ffd83dbSDimitry Andric   Undefined sym{nullptr, name, STB_GLOBAL, STV_DEFAULT, 0};
1721*5ffd83dbSDimitry Andric   sym.isUsedInRegularObj = false;
1722*5ffd83dbSDimitry Andric   return symtab->addSymbol(sym);
1723*5ffd83dbSDimitry Andric }
1724*5ffd83dbSDimitry Andric 
17250b57cec5SDimitry Andric // This function is where all the optimizations of link-time
17260b57cec5SDimitry Andric // optimization takes place. When LTO is in use, some input files are
17270b57cec5SDimitry Andric // not in native object file format but in the LLVM bitcode format.
17280b57cec5SDimitry Andric // This function compiles bitcode files into a few big native files
17290b57cec5SDimitry Andric // using LLVM functions and replaces bitcode symbols with the results.
17300b57cec5SDimitry Andric // Because all bitcode files that the program consists of are passed to
17310b57cec5SDimitry Andric // the compiler at once, it can do a whole-program optimization.
17320b57cec5SDimitry Andric template <class ELFT> void LinkerDriver::compileBitcodeFiles() {
1733*5ffd83dbSDimitry Andric   llvm::TimeTraceScope timeScope("LTO");
17340b57cec5SDimitry Andric   // Compile bitcode files and replace bitcode symbols.
17350b57cec5SDimitry Andric   lto.reset(new BitcodeCompiler);
17360b57cec5SDimitry Andric   for (BitcodeFile *file : bitcodeFiles)
17370b57cec5SDimitry Andric     lto->add(*file);
17380b57cec5SDimitry Andric 
17390b57cec5SDimitry Andric   for (InputFile *file : lto->compile()) {
17400b57cec5SDimitry Andric     auto *obj = cast<ObjFile<ELFT>>(file);
17410b57cec5SDimitry Andric     obj->parse(/*ignoreComdats=*/true);
1742*5ffd83dbSDimitry Andric 
1743*5ffd83dbSDimitry Andric     // Parse '@' in symbol names for non-relocatable output.
1744*5ffd83dbSDimitry Andric     if (!config->relocatable)
17450b57cec5SDimitry Andric       for (Symbol *sym : obj->getGlobalSymbols())
17460b57cec5SDimitry Andric         sym->parseSymbolVersion();
17470b57cec5SDimitry Andric     objectFiles.push_back(file);
17480b57cec5SDimitry Andric   }
17490b57cec5SDimitry Andric }
17500b57cec5SDimitry Andric 
17510b57cec5SDimitry Andric // The --wrap option is a feature to rename symbols so that you can write
17520b57cec5SDimitry Andric // wrappers for existing functions. If you pass `-wrap=foo`, all
17530b57cec5SDimitry Andric // occurrences of symbol `foo` are resolved to `wrap_foo` (so, you are
17540b57cec5SDimitry Andric // expected to write `wrap_foo` function as a wrapper). The original
17550b57cec5SDimitry Andric // symbol becomes accessible as `real_foo`, so you can call that from your
17560b57cec5SDimitry Andric // wrapper.
17570b57cec5SDimitry Andric //
17580b57cec5SDimitry Andric // This data structure is instantiated for each -wrap option.
17590b57cec5SDimitry Andric struct WrappedSymbol {
17600b57cec5SDimitry Andric   Symbol *sym;
17610b57cec5SDimitry Andric   Symbol *real;
17620b57cec5SDimitry Andric   Symbol *wrap;
17630b57cec5SDimitry Andric };
17640b57cec5SDimitry Andric 
17650b57cec5SDimitry Andric // Handles -wrap option.
17660b57cec5SDimitry Andric //
17670b57cec5SDimitry Andric // This function instantiates wrapper symbols. At this point, they seem
17680b57cec5SDimitry Andric // like they are not being used at all, so we explicitly set some flags so
17690b57cec5SDimitry Andric // that LTO won't eliminate them.
17700b57cec5SDimitry Andric static std::vector<WrappedSymbol> addWrappedSymbols(opt::InputArgList &args) {
17710b57cec5SDimitry Andric   std::vector<WrappedSymbol> v;
17720b57cec5SDimitry Andric   DenseSet<StringRef> seen;
17730b57cec5SDimitry Andric 
17740b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_wrap)) {
17750b57cec5SDimitry Andric     StringRef name = arg->getValue();
17760b57cec5SDimitry Andric     if (!seen.insert(name).second)
17770b57cec5SDimitry Andric       continue;
17780b57cec5SDimitry Andric 
17790b57cec5SDimitry Andric     Symbol *sym = symtab->find(name);
17800b57cec5SDimitry Andric     if (!sym)
17810b57cec5SDimitry Andric       continue;
17820b57cec5SDimitry Andric 
17830b57cec5SDimitry Andric     Symbol *real = addUndefined(saver.save("__real_" + name));
17840b57cec5SDimitry Andric     Symbol *wrap = addUndefined(saver.save("__wrap_" + name));
17850b57cec5SDimitry Andric     v.push_back({sym, real, wrap});
17860b57cec5SDimitry Andric 
17870b57cec5SDimitry Andric     // We want to tell LTO not to inline symbols to be overwritten
17880b57cec5SDimitry Andric     // because LTO doesn't know the final symbol contents after renaming.
17890b57cec5SDimitry Andric     real->canInline = false;
17900b57cec5SDimitry Andric     sym->canInline = false;
17910b57cec5SDimitry Andric 
17920b57cec5SDimitry Andric     // Tell LTO not to eliminate these symbols.
17930b57cec5SDimitry Andric     sym->isUsedInRegularObj = true;
17940b57cec5SDimitry Andric     wrap->isUsedInRegularObj = true;
17950b57cec5SDimitry Andric   }
17960b57cec5SDimitry Andric   return v;
17970b57cec5SDimitry Andric }
17980b57cec5SDimitry Andric 
17990b57cec5SDimitry Andric // Do renaming for -wrap by updating pointers to symbols.
18000b57cec5SDimitry Andric //
18010b57cec5SDimitry Andric // When this function is executed, only InputFiles and symbol table
18020b57cec5SDimitry Andric // contain pointers to symbol objects. We visit them to replace pointers,
18030b57cec5SDimitry Andric // so that wrapped symbols are swapped as instructed by the command line.
18040b57cec5SDimitry Andric static void wrapSymbols(ArrayRef<WrappedSymbol> wrapped) {
18050b57cec5SDimitry Andric   DenseMap<Symbol *, Symbol *> map;
18060b57cec5SDimitry Andric   for (const WrappedSymbol &w : wrapped) {
18070b57cec5SDimitry Andric     map[w.sym] = w.wrap;
18080b57cec5SDimitry Andric     map[w.real] = w.sym;
18090b57cec5SDimitry Andric   }
18100b57cec5SDimitry Andric 
18110b57cec5SDimitry Andric   // Update pointers in input files.
18120b57cec5SDimitry Andric   parallelForEach(objectFiles, [&](InputFile *file) {
18130b57cec5SDimitry Andric     MutableArrayRef<Symbol *> syms = file->getMutableSymbols();
18140b57cec5SDimitry Andric     for (size_t i = 0, e = syms.size(); i != e; ++i)
18150b57cec5SDimitry Andric       if (Symbol *s = map.lookup(syms[i]))
18160b57cec5SDimitry Andric         syms[i] = s;
18170b57cec5SDimitry Andric   });
18180b57cec5SDimitry Andric 
18190b57cec5SDimitry Andric   // Update pointers in the symbol table.
18200b57cec5SDimitry Andric   for (const WrappedSymbol &w : wrapped)
18210b57cec5SDimitry Andric     symtab->wrap(w.sym, w.real, w.wrap);
18220b57cec5SDimitry Andric }
18230b57cec5SDimitry Andric 
18240b57cec5SDimitry Andric // To enable CET (x86's hardware-assited control flow enforcement), each
18250b57cec5SDimitry Andric // source file must be compiled with -fcf-protection. Object files compiled
18260b57cec5SDimitry Andric // with the flag contain feature flags indicating that they are compatible
18270b57cec5SDimitry Andric // with CET. We enable the feature only when all object files are compatible
18280b57cec5SDimitry Andric // with CET.
18290b57cec5SDimitry Andric //
18300b57cec5SDimitry Andric // This is also the case with AARCH64's BTI and PAC which use the similar
18310b57cec5SDimitry Andric // GNU_PROPERTY_AARCH64_FEATURE_1_AND mechanism.
18320b57cec5SDimitry Andric template <class ELFT> static uint32_t getAndFeatures() {
18330b57cec5SDimitry Andric   if (config->emachine != EM_386 && config->emachine != EM_X86_64 &&
18340b57cec5SDimitry Andric       config->emachine != EM_AARCH64)
18350b57cec5SDimitry Andric     return 0;
18360b57cec5SDimitry Andric 
18370b57cec5SDimitry Andric   uint32_t ret = -1;
18380b57cec5SDimitry Andric   for (InputFile *f : objectFiles) {
18390b57cec5SDimitry Andric     uint32_t features = cast<ObjFile<ELFT>>(f)->andFeatures;
1840*5ffd83dbSDimitry Andric     if (config->zForceBti && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)) {
1841*5ffd83dbSDimitry Andric       warn(toString(f) + ": -z force-bti: file does not have "
1842*5ffd83dbSDimitry Andric                          "GNU_PROPERTY_AARCH64_FEATURE_1_BTI property");
18430b57cec5SDimitry Andric       features |= GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
1844480093f4SDimitry Andric     } else if (config->zForceIbt &&
1845480093f4SDimitry Andric                !(features & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
1846480093f4SDimitry Andric       warn(toString(f) + ": -z force-ibt: file does not have "
1847480093f4SDimitry Andric                          "GNU_PROPERTY_X86_FEATURE_1_IBT property");
1848480093f4SDimitry Andric       features |= GNU_PROPERTY_X86_FEATURE_1_IBT;
1849480093f4SDimitry Andric     }
1850*5ffd83dbSDimitry Andric     if (config->zPacPlt && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_PAC)) {
1851*5ffd83dbSDimitry Andric       warn(toString(f) + ": -z pac-plt: file does not have "
1852*5ffd83dbSDimitry Andric                          "GNU_PROPERTY_AARCH64_FEATURE_1_PAC property");
1853*5ffd83dbSDimitry Andric       features |= GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
1854*5ffd83dbSDimitry Andric     }
18550b57cec5SDimitry Andric     ret &= features;
18560b57cec5SDimitry Andric   }
18570b57cec5SDimitry Andric 
1858480093f4SDimitry Andric   // Force enable Shadow Stack.
1859480093f4SDimitry Andric   if (config->zShstk)
1860480093f4SDimitry Andric     ret |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
18610b57cec5SDimitry Andric 
18620b57cec5SDimitry Andric   return ret;
18630b57cec5SDimitry Andric }
18640b57cec5SDimitry Andric 
18650b57cec5SDimitry Andric // Do actual linking. Note that when this function is called,
18660b57cec5SDimitry Andric // all linker scripts have already been parsed.
18670b57cec5SDimitry Andric template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
1868*5ffd83dbSDimitry Andric   llvm::TimeTraceScope timeScope("Link", StringRef("LinkerDriver::Link"));
18690b57cec5SDimitry Andric   // If a -hash-style option was not given, set to a default value,
18700b57cec5SDimitry Andric   // which varies depending on the target.
18710b57cec5SDimitry Andric   if (!args.hasArg(OPT_hash_style)) {
18720b57cec5SDimitry Andric     if (config->emachine == EM_MIPS)
18730b57cec5SDimitry Andric       config->sysvHash = true;
18740b57cec5SDimitry Andric     else
18750b57cec5SDimitry Andric       config->sysvHash = config->gnuHash = true;
18760b57cec5SDimitry Andric   }
18770b57cec5SDimitry Andric 
18780b57cec5SDimitry Andric   // Default output filename is "a.out" by the Unix tradition.
18790b57cec5SDimitry Andric   if (config->outputFile.empty())
18800b57cec5SDimitry Andric     config->outputFile = "a.out";
18810b57cec5SDimitry Andric 
18820b57cec5SDimitry Andric   // Fail early if the output file or map file is not writable. If a user has a
18830b57cec5SDimitry Andric   // long link, e.g. due to a large LTO link, they do not wish to run it and
18840b57cec5SDimitry Andric   // find that it failed because there was a mistake in their command-line.
18850b57cec5SDimitry Andric   if (auto e = tryCreateFile(config->outputFile))
18860b57cec5SDimitry Andric     error("cannot open output file " + config->outputFile + ": " + e.message());
18870b57cec5SDimitry Andric   if (auto e = tryCreateFile(config->mapFile))
18880b57cec5SDimitry Andric     error("cannot open map file " + config->mapFile + ": " + e.message());
18890b57cec5SDimitry Andric   if (errorCount())
18900b57cec5SDimitry Andric     return;
18910b57cec5SDimitry Andric 
18920b57cec5SDimitry Andric   // Use default entry point name if no name was given via the command
18930b57cec5SDimitry Andric   // line nor linker scripts. For some reason, MIPS entry point name is
18940b57cec5SDimitry Andric   // different from others.
18950b57cec5SDimitry Andric   config->warnMissingEntry =
18960b57cec5SDimitry Andric       (!config->entry.empty() || (!config->shared && !config->relocatable));
18970b57cec5SDimitry Andric   if (config->entry.empty() && !config->relocatable)
18980b57cec5SDimitry Andric     config->entry = (config->emachine == EM_MIPS) ? "__start" : "_start";
18990b57cec5SDimitry Andric 
19000b57cec5SDimitry Andric   // Handle --trace-symbol.
19010b57cec5SDimitry Andric   for (auto *arg : args.filtered(OPT_trace_symbol))
19020b57cec5SDimitry Andric     symtab->insert(arg->getValue())->traced = true;
19030b57cec5SDimitry Andric 
1904*5ffd83dbSDimitry Andric   // Handle -u/--undefined before input files. If both a.a and b.so define foo,
1905*5ffd83dbSDimitry Andric   // -u foo a.a b.so will fetch a.a.
1906*5ffd83dbSDimitry Andric   for (StringRef name : config->undefined)
1907*5ffd83dbSDimitry Andric     addUnusedUndefined(name);
1908*5ffd83dbSDimitry Andric 
19090b57cec5SDimitry Andric   // Add all files to the symbol table. This will add almost all
19100b57cec5SDimitry Andric   // symbols that we need to the symbol table. This process might
19110b57cec5SDimitry Andric   // add files to the link, via autolinking, these files are always
19120b57cec5SDimitry Andric   // appended to the Files vector.
1913*5ffd83dbSDimitry Andric   {
1914*5ffd83dbSDimitry Andric     llvm::TimeTraceScope timeScope("Parse input files");
19150b57cec5SDimitry Andric     for (size_t i = 0; i < files.size(); ++i)
19160b57cec5SDimitry Andric       parseFile(files[i]);
1917*5ffd83dbSDimitry Andric   }
19180b57cec5SDimitry Andric 
19190b57cec5SDimitry Andric   // Now that we have every file, we can decide if we will need a
19200b57cec5SDimitry Andric   // dynamic symbol table.
19210b57cec5SDimitry Andric   // We need one if we were asked to export dynamic symbols or if we are
19220b57cec5SDimitry Andric   // producing a shared library.
19230b57cec5SDimitry Andric   // We also need one if any shared libraries are used and for pie executables
19240b57cec5SDimitry Andric   // (probably because the dynamic linker needs it).
19250b57cec5SDimitry Andric   config->hasDynSymTab =
19260b57cec5SDimitry Andric       !sharedFiles.empty() || config->isPic || config->exportDynamic;
19270b57cec5SDimitry Andric 
19280b57cec5SDimitry Andric   // Some symbols (such as __ehdr_start) are defined lazily only when there
19290b57cec5SDimitry Andric   // are undefined symbols for them, so we add these to trigger that logic.
19300b57cec5SDimitry Andric   for (StringRef name : script->referencedSymbols)
19310b57cec5SDimitry Andric     addUndefined(name);
19320b57cec5SDimitry Andric 
1933*5ffd83dbSDimitry Andric   // Prevent LTO from removing any definition referenced by -u.
1934*5ffd83dbSDimitry Andric   for (StringRef name : config->undefined)
1935*5ffd83dbSDimitry Andric     if (Defined *sym = dyn_cast_or_null<Defined>(symtab->find(name)))
1936*5ffd83dbSDimitry Andric       sym->isUsedInRegularObj = true;
19370b57cec5SDimitry Andric 
19380b57cec5SDimitry Andric   // If an entry symbol is in a static archive, pull out that file now.
19390b57cec5SDimitry Andric   if (Symbol *sym = symtab->find(config->entry))
19400b57cec5SDimitry Andric     handleUndefined(sym);
19410b57cec5SDimitry Andric 
19420b57cec5SDimitry Andric   // Handle the `--undefined-glob <pattern>` options.
19430b57cec5SDimitry Andric   for (StringRef pat : args::getStrings(args, OPT_undefined_glob))
19440b57cec5SDimitry Andric     handleUndefinedGlob(pat);
19450b57cec5SDimitry Andric 
1946480093f4SDimitry Andric   // Mark -init and -fini symbols so that the LTO doesn't eliminate them.
1947*5ffd83dbSDimitry Andric   if (Symbol *sym = dyn_cast_or_null<Defined>(symtab->find(config->init)))
1948480093f4SDimitry Andric     sym->isUsedInRegularObj = true;
1949*5ffd83dbSDimitry Andric   if (Symbol *sym = dyn_cast_or_null<Defined>(symtab->find(config->fini)))
1950480093f4SDimitry Andric     sym->isUsedInRegularObj = true;
1951480093f4SDimitry Andric 
19520b57cec5SDimitry Andric   // If any of our inputs are bitcode files, the LTO code generator may create
19530b57cec5SDimitry Andric   // references to certain library functions that might not be explicit in the
19540b57cec5SDimitry Andric   // bitcode file's symbol table. If any of those library functions are defined
19550b57cec5SDimitry Andric   // in a bitcode file in an archive member, we need to arrange to use LTO to
19560b57cec5SDimitry Andric   // compile those archive members by adding them to the link beforehand.
19570b57cec5SDimitry Andric   //
19580b57cec5SDimitry Andric   // However, adding all libcall symbols to the link can have undesired
19590b57cec5SDimitry Andric   // consequences. For example, the libgcc implementation of
19600b57cec5SDimitry Andric   // __sync_val_compare_and_swap_8 on 32-bit ARM pulls in an .init_array entry
19610b57cec5SDimitry Andric   // that aborts the program if the Linux kernel does not support 64-bit
19620b57cec5SDimitry Andric   // atomics, which would prevent the program from running even if it does not
19630b57cec5SDimitry Andric   // use 64-bit atomics.
19640b57cec5SDimitry Andric   //
19650b57cec5SDimitry Andric   // Therefore, we only add libcall symbols to the link before LTO if we have
19660b57cec5SDimitry Andric   // to, i.e. if the symbol's definition is in bitcode. Any other required
19670b57cec5SDimitry Andric   // libcall symbols will be added to the link after LTO when we add the LTO
19680b57cec5SDimitry Andric   // object file to the link.
19690b57cec5SDimitry Andric   if (!bitcodeFiles.empty())
197085868e8aSDimitry Andric     for (auto *s : lto::LTO::getRuntimeLibcallSymbols())
19710b57cec5SDimitry Andric       handleLibcall(s);
19720b57cec5SDimitry Andric 
19730b57cec5SDimitry Andric   // Return if there were name resolution errors.
19740b57cec5SDimitry Andric   if (errorCount())
19750b57cec5SDimitry Andric     return;
19760b57cec5SDimitry Andric 
19770b57cec5SDimitry Andric   // We want to declare linker script's symbols early,
19780b57cec5SDimitry Andric   // so that we can version them.
19790b57cec5SDimitry Andric   // They also might be exported if referenced by DSOs.
19800b57cec5SDimitry Andric   script->declareSymbols();
19810b57cec5SDimitry Andric 
19820b57cec5SDimitry Andric   // Handle the -exclude-libs option.
19830b57cec5SDimitry Andric   if (args.hasArg(OPT_exclude_libs))
19840b57cec5SDimitry Andric     excludeLibs(args);
19850b57cec5SDimitry Andric 
19860b57cec5SDimitry Andric   // Create elfHeader early. We need a dummy section in
19870b57cec5SDimitry Andric   // addReservedSymbols to mark the created symbols as not absolute.
19880b57cec5SDimitry Andric   Out::elfHeader = make<OutputSection>("", 0, SHF_ALLOC);
19890b57cec5SDimitry Andric   Out::elfHeader->size = sizeof(typename ELFT::Ehdr);
19900b57cec5SDimitry Andric 
19910b57cec5SDimitry Andric   // Create wrapped symbols for -wrap option.
19920b57cec5SDimitry Andric   std::vector<WrappedSymbol> wrapped = addWrappedSymbols(args);
19930b57cec5SDimitry Andric 
19940b57cec5SDimitry Andric   // We need to create some reserved symbols such as _end. Create them.
19950b57cec5SDimitry Andric   if (!config->relocatable)
19960b57cec5SDimitry Andric     addReservedSymbols();
19970b57cec5SDimitry Andric 
19980b57cec5SDimitry Andric   // Apply version scripts.
19990b57cec5SDimitry Andric   //
20000b57cec5SDimitry Andric   // For a relocatable output, version scripts don't make sense, and
20010b57cec5SDimitry Andric   // parsing a symbol version string (e.g. dropping "@ver1" from a symbol
20020b57cec5SDimitry Andric   // name "foo@ver1") rather do harm, so we don't call this if -r is given.
20030b57cec5SDimitry Andric   if (!config->relocatable)
20040b57cec5SDimitry Andric     symtab->scanVersionScript();
20050b57cec5SDimitry Andric 
20060b57cec5SDimitry Andric   // Do link-time optimization if given files are LLVM bitcode files.
20070b57cec5SDimitry Andric   // This compiles bitcode files into real object files.
20080b57cec5SDimitry Andric   //
20090b57cec5SDimitry Andric   // With this the symbol table should be complete. After this, no new names
20100b57cec5SDimitry Andric   // except a few linker-synthesized ones will be added to the symbol table.
20110b57cec5SDimitry Andric   compileBitcodeFiles<ELFT>();
2012*5ffd83dbSDimitry Andric 
2013*5ffd83dbSDimitry Andric   // Symbol resolution finished. Report backward reference problems.
2014*5ffd83dbSDimitry Andric   reportBackrefs();
20150b57cec5SDimitry Andric   if (errorCount())
20160b57cec5SDimitry Andric     return;
20170b57cec5SDimitry Andric 
20180b57cec5SDimitry Andric   // If -thinlto-index-only is given, we should create only "index
20190b57cec5SDimitry Andric   // files" and not object files. Index file creation is already done
20200b57cec5SDimitry Andric   // in addCombinedLTOObject, so we are done if that's the case.
2021*5ffd83dbSDimitry Andric   // Likewise, --plugin-opt=emit-llvm and --plugin-opt=emit-asm are the
2022*5ffd83dbSDimitry Andric   // options to create output files in bitcode or assembly code
2023*5ffd83dbSDimitry Andric   // repsectively. No object files are generated.
2024*5ffd83dbSDimitry Andric   // Also bail out here when only certain thinLTO modules are specified for
2025*5ffd83dbSDimitry Andric   // compilation. The intermediate object file are the expected output.
2026*5ffd83dbSDimitry Andric   if (config->thinLTOIndexOnly || config->emitLLVM || config->ltoEmitAsm ||
2027*5ffd83dbSDimitry Andric       !config->thinLTOModulesToCompile.empty())
20280b57cec5SDimitry Andric     return;
20290b57cec5SDimitry Andric 
20300b57cec5SDimitry Andric   // Apply symbol renames for -wrap.
20310b57cec5SDimitry Andric   if (!wrapped.empty())
20320b57cec5SDimitry Andric     wrapSymbols(wrapped);
20330b57cec5SDimitry Andric 
20340b57cec5SDimitry Andric   // Now that we have a complete list of input files.
20350b57cec5SDimitry Andric   // Beyond this point, no new files are added.
20360b57cec5SDimitry Andric   // Aggregate all input sections into one place.
20370b57cec5SDimitry Andric   for (InputFile *f : objectFiles)
20380b57cec5SDimitry Andric     for (InputSectionBase *s : f->getSections())
20390b57cec5SDimitry Andric       if (s && s != &InputSection::discarded)
20400b57cec5SDimitry Andric         inputSections.push_back(s);
20410b57cec5SDimitry Andric   for (BinaryFile *f : binaryFiles)
20420b57cec5SDimitry Andric     for (InputSectionBase *s : f->getSections())
20430b57cec5SDimitry Andric       inputSections.push_back(cast<InputSection>(s));
20440b57cec5SDimitry Andric 
20450b57cec5SDimitry Andric   llvm::erase_if(inputSections, [](InputSectionBase *s) {
20460b57cec5SDimitry Andric     if (s->type == SHT_LLVM_SYMPART) {
20470b57cec5SDimitry Andric       readSymbolPartitionSection<ELFT>(s);
20480b57cec5SDimitry Andric       return true;
20490b57cec5SDimitry Andric     }
20500b57cec5SDimitry Andric 
20510b57cec5SDimitry Andric     // We do not want to emit debug sections if --strip-all
20520b57cec5SDimitry Andric     // or -strip-debug are given.
2053d65cd7a5SDimitry Andric     if (config->strip == StripPolicy::None)
2054d65cd7a5SDimitry Andric       return false;
2055d65cd7a5SDimitry Andric 
2056d65cd7a5SDimitry Andric     if (isDebugSection(*s))
2057d65cd7a5SDimitry Andric       return true;
2058d65cd7a5SDimitry Andric     if (auto *isec = dyn_cast<InputSection>(s))
2059d65cd7a5SDimitry Andric       if (InputSectionBase *rel = isec->getRelocatedSection())
2060d65cd7a5SDimitry Andric         if (isDebugSection(*rel))
2061d65cd7a5SDimitry Andric           return true;
2062d65cd7a5SDimitry Andric 
2063d65cd7a5SDimitry Andric     return false;
20640b57cec5SDimitry Andric   });
20650b57cec5SDimitry Andric 
20660b57cec5SDimitry Andric   // Now that the number of partitions is fixed, save a pointer to the main
20670b57cec5SDimitry Andric   // partition.
20680b57cec5SDimitry Andric   mainPart = &partitions[0];
20690b57cec5SDimitry Andric 
20700b57cec5SDimitry Andric   // Read .note.gnu.property sections from input object files which
20710b57cec5SDimitry Andric   // contain a hint to tweak linker's and loader's behaviors.
20720b57cec5SDimitry Andric   config->andFeatures = getAndFeatures<ELFT>();
20730b57cec5SDimitry Andric 
20740b57cec5SDimitry Andric   // The Target instance handles target-specific stuff, such as applying
20750b57cec5SDimitry Andric   // relocations or writing a PLT section. It also contains target-dependent
20760b57cec5SDimitry Andric   // values such as a default image base address.
20770b57cec5SDimitry Andric   target = getTarget();
20780b57cec5SDimitry Andric 
20790b57cec5SDimitry Andric   config->eflags = target->calcEFlags();
20800b57cec5SDimitry Andric   // maxPageSize (sometimes called abi page size) is the maximum page size that
20810b57cec5SDimitry Andric   // the output can be run on. For example if the OS can use 4k or 64k page
20820b57cec5SDimitry Andric   // sizes then maxPageSize must be 64k for the output to be useable on both.
20830b57cec5SDimitry Andric   // All important alignment decisions must use this value.
20840b57cec5SDimitry Andric   config->maxPageSize = getMaxPageSize(args);
20850b57cec5SDimitry Andric   // commonPageSize is the most common page size that the output will be run on.
20860b57cec5SDimitry Andric   // For example if an OS can use 4k or 64k page sizes and 4k is more common
20870b57cec5SDimitry Andric   // than 64k then commonPageSize is set to 4k. commonPageSize can be used for
20880b57cec5SDimitry Andric   // optimizations such as DATA_SEGMENT_ALIGN in linker scripts. LLD's use of it
20890b57cec5SDimitry Andric   // is limited to writing trap instructions on the last executable segment.
20900b57cec5SDimitry Andric   config->commonPageSize = getCommonPageSize(args);
20910b57cec5SDimitry Andric 
20920b57cec5SDimitry Andric   config->imageBase = getImageBase(args);
20930b57cec5SDimitry Andric 
20940b57cec5SDimitry Andric   if (config->emachine == EM_ARM) {
20950b57cec5SDimitry Andric     // FIXME: These warnings can be removed when lld only uses these features
20960b57cec5SDimitry Andric     // when the input objects have been compiled with an architecture that
20970b57cec5SDimitry Andric     // supports them.
20980b57cec5SDimitry Andric     if (config->armHasBlx == false)
20990b57cec5SDimitry Andric       warn("lld uses blx instruction, no object with architecture supporting "
21000b57cec5SDimitry Andric            "feature detected");
21010b57cec5SDimitry Andric   }
21020b57cec5SDimitry Andric 
210385868e8aSDimitry Andric   // This adds a .comment section containing a version string.
21040b57cec5SDimitry Andric   if (!config->relocatable)
21050b57cec5SDimitry Andric     inputSections.push_back(createCommentSection());
21060b57cec5SDimitry Andric 
21070b57cec5SDimitry Andric   // Replace common symbols with regular symbols.
21080b57cec5SDimitry Andric   replaceCommonSymbols();
21090b57cec5SDimitry Andric 
211085868e8aSDimitry Andric   // Split SHF_MERGE and .eh_frame sections into pieces in preparation for garbage collection.
21110b57cec5SDimitry Andric   splitSections<ELFT>();
211285868e8aSDimitry Andric 
211385868e8aSDimitry Andric   // Garbage collection and removal of shared symbols from unused shared objects.
21140b57cec5SDimitry Andric   markLive<ELFT>();
21150b57cec5SDimitry Andric   demoteSharedSymbols();
211685868e8aSDimitry Andric 
211785868e8aSDimitry Andric   // Make copies of any input sections that need to be copied into each
211885868e8aSDimitry Andric   // partition.
211985868e8aSDimitry Andric   copySectionsIntoPartitions();
212085868e8aSDimitry Andric 
212185868e8aSDimitry Andric   // Create synthesized sections such as .got and .plt. This is called before
212285868e8aSDimitry Andric   // processSectionCommands() so that they can be placed by SECTIONS commands.
212385868e8aSDimitry Andric   createSyntheticSections<ELFT>();
212485868e8aSDimitry Andric 
212585868e8aSDimitry Andric   // Some input sections that are used for exception handling need to be moved
212685868e8aSDimitry Andric   // into synthetic sections. Do that now so that they aren't assigned to
212785868e8aSDimitry Andric   // output sections in the usual way.
212885868e8aSDimitry Andric   if (!config->relocatable)
212985868e8aSDimitry Andric     combineEhSections();
213085868e8aSDimitry Andric 
213185868e8aSDimitry Andric   // Create output sections described by SECTIONS commands.
213285868e8aSDimitry Andric   script->processSectionCommands();
213385868e8aSDimitry Andric 
213485868e8aSDimitry Andric   // Linker scripts control how input sections are assigned to output sections.
213585868e8aSDimitry Andric   // Input sections that were not handled by scripts are called "orphans", and
213685868e8aSDimitry Andric   // they are assigned to output sections by the default rule. Process that.
213785868e8aSDimitry Andric   script->addOrphanSections();
213885868e8aSDimitry Andric 
213985868e8aSDimitry Andric   // Migrate InputSectionDescription::sectionBases to sections. This includes
214085868e8aSDimitry Andric   // merging MergeInputSections into a single MergeSyntheticSection. From this
214185868e8aSDimitry Andric   // point onwards InputSectionDescription::sections should be used instead of
214285868e8aSDimitry Andric   // sectionBases.
214385868e8aSDimitry Andric   for (BaseCommand *base : script->sectionCommands)
214485868e8aSDimitry Andric     if (auto *sec = dyn_cast<OutputSection>(base))
214585868e8aSDimitry Andric       sec->finalizeInputSections();
214685868e8aSDimitry Andric   llvm::erase_if(inputSections,
214785868e8aSDimitry Andric                  [](InputSectionBase *s) { return isa<MergeInputSection>(s); });
214885868e8aSDimitry Andric 
214985868e8aSDimitry Andric   // Two input sections with different output sections should not be folded.
215085868e8aSDimitry Andric   // ICF runs after processSectionCommands() so that we know the output sections.
21510b57cec5SDimitry Andric   if (config->icf != ICFLevel::None) {
21520b57cec5SDimitry Andric     findKeepUniqueSections<ELFT>(args);
21530b57cec5SDimitry Andric     doIcf<ELFT>();
21540b57cec5SDimitry Andric   }
21550b57cec5SDimitry Andric 
21560b57cec5SDimitry Andric   // Read the callgraph now that we know what was gced or icfed
21570b57cec5SDimitry Andric   if (config->callGraphProfileSort) {
21580b57cec5SDimitry Andric     if (auto *arg = args.getLastArg(OPT_call_graph_ordering_file))
21590b57cec5SDimitry Andric       if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
21600b57cec5SDimitry Andric         readCallGraph(*buffer);
21610b57cec5SDimitry Andric     readCallGraphsFromObjectFiles<ELFT>();
21620b57cec5SDimitry Andric   }
21630b57cec5SDimitry Andric 
21640b57cec5SDimitry Andric   // Write the result to the file.
21650b57cec5SDimitry Andric   writeResult<ELFT>();
21660b57cec5SDimitry Andric }
2167