forked from llvm/llvm-project
/
Driver.cpp
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/
Driver.cpp
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//===- Driver.cpp ---------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// The driver drives the entire linking process. It is responsible for
// parsing command line options and doing whatever it is instructed to do.
//
// One notable thing in the LLD's driver when compared to other linkers is
// that the LLD's driver is agnostic on the host operating system.
// Other linkers usually have implicit default values (such as a dynamic
// linker path or library paths) for each host OS.
//
// I don't think implicit default values are useful because they are
// usually explicitly specified by the compiler ctx.driver. They can even
// be harmful when you are doing cross-linking. Therefore, in LLD, we
// simply trust the compiler driver to pass all required options and
// don't try to make effort on our side.
//
//===----------------------------------------------------------------------===//
#include "Driver.h"
#include "Config.h"
#include "ICF.h"
#include "InputFiles.h"
#include "InputSection.h"
#include "LTO.h"
#include "LinkerScript.h"
#include "MarkLive.h"
#include "OutputSections.h"
#include "ScriptParser.h"
#include "SymbolTable.h"
#include "Symbols.h"
#include "SyntheticSections.h"
#include "Target.h"
#include "Writer.h"
#include "lld/Common/Args.h"
#include "lld/Common/CommonLinkerContext.h"
#include "lld/Common/Driver.h"
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/Filesystem.h"
#include "lld/Common/Memory.h"
#include "lld/Common/Strings.h"
#include "lld/Common/TargetOptionsCommandFlags.h"
#include "lld/Common/Version.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/IRObjectFile.h"
#include "llvm/Remarks/HotnessThresholdParser.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/GlobPattern.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/Parallel.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/TarWriter.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
#include <tuple>
#include <utility>
using namespace llvm;
using namespace llvm::ELF;
using namespace llvm::object;
using namespace llvm::sys;
using namespace llvm::support;
using namespace lld;
using namespace lld::elf;
ConfigWrapper elf::config;
Ctx elf::ctx;
static void setConfigs(opt::InputArgList &args);
static void readConfigs(opt::InputArgList &args);
void elf::errorOrWarn(const Twine &msg) {
if (config->noinhibitExec)
warn(msg);
else
error(msg);
}
void Ctx::reset() {
driver = LinkerDriver();
memoryBuffers.clear();
objectFiles.clear();
sharedFiles.clear();
binaryFiles.clear();
bitcodeFiles.clear();
lazyBitcodeFiles.clear();
inputSections.clear();
ehInputSections.clear();
duplicates.clear();
nonPrevailingSyms.clear();
whyExtractRecords.clear();
backwardReferences.clear();
auxiliaryFiles.clear();
hasSympart.store(false, std::memory_order_relaxed);
hasTlsIe.store(false, std::memory_order_relaxed);
needsTlsLd.store(false, std::memory_order_relaxed);
scriptSymOrderCounter = 1;
scriptSymOrder.clear();
}
llvm::raw_fd_ostream Ctx::openAuxiliaryFile(llvm::StringRef filename,
std::error_code &ec) {
using namespace llvm::sys::fs;
OpenFlags flags =
auxiliaryFiles.insert(filename).second ? OF_None : OF_Append;
return {filename, ec, flags};
}
namespace lld {
namespace elf {
bool link(ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput) {
// This driver-specific context will be freed later by unsafeLldMain().
auto *ctx = new CommonLinkerContext;
ctx->e.initialize(stdoutOS, stderrOS, exitEarly, disableOutput);
ctx->e.cleanupCallback = []() {
elf::ctx.reset();
symtab = SymbolTable();
outputSections.clear();
symAux.clear();
tar = nullptr;
in.reset();
partitions.clear();
partitions.emplace_back();
SharedFile::vernauxNum = 0;
};
ctx->e.logName = args::getFilenameWithoutExe(args[0]);
ctx->e.errorLimitExceededMsg = "too many errors emitted, stopping now (use "
"--error-limit=0 to see all errors)";
config = ConfigWrapper();
script = std::make_unique<LinkerScript>();
symAux.emplace_back();
partitions.clear();
partitions.emplace_back();
config->progName = args[0];
elf::ctx.driver.linkerMain(args);
return errorCount() == 0;
}
} // namespace elf
} // namespace lld
// Parses a linker -m option.
static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(StringRef emul) {
uint8_t osabi = 0;
StringRef s = emul;
if (s.ends_with("_fbsd")) {
s = s.drop_back(5);
osabi = ELFOSABI_FREEBSD;
}
std::pair<ELFKind, uint16_t> ret =
StringSwitch<std::pair<ELFKind, uint16_t>>(s)
.Cases("aarch64elf", "aarch64linux", {ELF64LEKind, EM_AARCH64})
.Cases("aarch64elfb", "aarch64linuxb", {ELF64BEKind, EM_AARCH64})
.Cases("armelf", "armelf_linux_eabi", {ELF32LEKind, EM_ARM})
.Cases("armelfb", "armelfb_linux_eabi", {ELF32BEKind, EM_ARM})
.Case("elf32_x86_64", {ELF32LEKind, EM_X86_64})
.Cases("elf32btsmip", "elf32btsmipn32", {ELF32BEKind, EM_MIPS})
.Cases("elf32ltsmip", "elf32ltsmipn32", {ELF32LEKind, EM_MIPS})
.Case("elf32lriscv", {ELF32LEKind, EM_RISCV})
.Cases("elf32ppc", "elf32ppclinux", {ELF32BEKind, EM_PPC})
.Cases("elf32lppc", "elf32lppclinux", {ELF32LEKind, EM_PPC})
.Case("elf32loongarch", {ELF32LEKind, EM_LOONGARCH})
.Case("elf64btsmip", {ELF64BEKind, EM_MIPS})
.Case("elf64ltsmip", {ELF64LEKind, EM_MIPS})
.Case("elf64lriscv", {ELF64LEKind, EM_RISCV})
.Case("elf64ppc", {ELF64BEKind, EM_PPC64})
.Case("elf64lppc", {ELF64LEKind, EM_PPC64})
.Cases("elf_amd64", "elf_x86_64", {ELF64LEKind, EM_X86_64})
.Case("elf_i386", {ELF32LEKind, EM_386})
.Case("elf_iamcu", {ELF32LEKind, EM_IAMCU})
.Case("elf64_sparc", {ELF64BEKind, EM_SPARCV9})
.Case("msp430elf", {ELF32LEKind, EM_MSP430})
.Case("elf64_amdgpu", {ELF64LEKind, EM_AMDGPU})
.Case("elf64loongarch", {ELF64LEKind, EM_LOONGARCH})
.Default({ELFNoneKind, EM_NONE});
if (ret.first == ELFNoneKind)
error("unknown emulation: " + emul);
if (ret.second == EM_MSP430)
osabi = ELFOSABI_STANDALONE;
else if (ret.second == EM_AMDGPU)
osabi = ELFOSABI_AMDGPU_HSA;
return std::make_tuple(ret.first, ret.second, osabi);
}
// Returns slices of MB by parsing MB as an archive file.
// Each slice consists of a member file in the archive.
std::vector<std::pair<MemoryBufferRef, uint64_t>> static getArchiveMembers(
MemoryBufferRef mb) {
std::unique_ptr<Archive> file =
CHECK(Archive::create(mb),
mb.getBufferIdentifier() + ": failed to parse archive");
std::vector<std::pair<MemoryBufferRef, uint64_t>> v;
Error err = Error::success();
bool addToTar = file->isThin() && tar;
for (const Archive::Child &c : file->children(err)) {
MemoryBufferRef mbref =
CHECK(c.getMemoryBufferRef(),
mb.getBufferIdentifier() +
": could not get the buffer for a child of the archive");
if (addToTar)
tar->append(relativeToRoot(check(c.getFullName())), mbref.getBuffer());
v.push_back(std::make_pair(mbref, c.getChildOffset()));
}
if (err)
fatal(mb.getBufferIdentifier() + ": Archive::children failed: " +
toString(std::move(err)));
// Take ownership of memory buffers created for members of thin archives.
std::vector<std::unique_ptr<MemoryBuffer>> mbs = file->takeThinBuffers();
std::move(mbs.begin(), mbs.end(), std::back_inserter(ctx.memoryBuffers));
return v;
}
static bool isBitcode(MemoryBufferRef mb) {
return identify_magic(mb.getBuffer()) == llvm::file_magic::bitcode;
}
bool LinkerDriver::tryAddFatLTOFile(MemoryBufferRef mb, StringRef archiveName,
uint64_t offsetInArchive, bool lazy) {
if (!config->fatLTOObjects)
return false;
Expected<MemoryBufferRef> fatLTOData =
IRObjectFile::findBitcodeInMemBuffer(mb);
if (errorToBool(fatLTOData.takeError()))
return false;
files.push_back(
make<BitcodeFile>(*fatLTOData, archiveName, offsetInArchive, lazy));
return true;
}
// Opens a file and create a file object. Path has to be resolved already.
void LinkerDriver::addFile(StringRef path, bool withLOption) {
using namespace sys::fs;
std::optional<MemoryBufferRef> buffer = readFile(path);
if (!buffer)
return;
MemoryBufferRef mbref = *buffer;
if (config->formatBinary) {
files.push_back(make<BinaryFile>(mbref));
return;
}
switch (identify_magic(mbref.getBuffer())) {
case file_magic::unknown:
readLinkerScript(mbref);
return;
case file_magic::archive: {
auto members = getArchiveMembers(mbref);
if (inWholeArchive) {
for (const std::pair<MemoryBufferRef, uint64_t> &p : members) {
if (isBitcode(p.first))
files.push_back(make<BitcodeFile>(p.first, path, p.second, false));
else if (!tryAddFatLTOFile(p.first, path, p.second, false))
files.push_back(createObjFile(p.first, path));
}
return;
}
archiveFiles.emplace_back(path, members.size());
// Handle archives and --start-lib/--end-lib using the same code path. This
// scans all the ELF relocatable object files and bitcode files in the
// archive rather than just the index file, with the benefit that the
// symbols are only loaded once. For many projects archives see high
// utilization rates and it is a net performance win. --start-lib scans
// symbols in the same order that llvm-ar adds them to the index, so in the
// common case the semantics are identical. If the archive symbol table was
// created in a different order, or is incomplete, this strategy has
// different semantics. Such output differences are considered user error.
//
// All files within the archive get the same group ID to allow mutual
// references for --warn-backrefs.
bool saved = InputFile::isInGroup;
InputFile::isInGroup = true;
for (const std::pair<MemoryBufferRef, uint64_t> &p : members) {
auto magic = identify_magic(p.first.getBuffer());
if (magic == file_magic::elf_relocatable) {
if (!tryAddFatLTOFile(p.first, path, p.second, true))
files.push_back(createObjFile(p.first, path, true));
} else if (magic == file_magic::bitcode)
files.push_back(make<BitcodeFile>(p.first, path, p.second, true));
else
warn(path + ": archive member '" + p.first.getBufferIdentifier() +
"' is neither ET_REL nor LLVM bitcode");
}
InputFile::isInGroup = saved;
if (!saved)
++InputFile::nextGroupId;
return;
}
case file_magic::elf_shared_object: {
if (config->isStatic || config->relocatable) {
error("attempted static link of dynamic object " + path);
return;
}
// Shared objects are identified by soname. soname is (if specified)
// DT_SONAME and falls back to filename. If a file was specified by -lfoo,
// the directory part is ignored. Note that path may be a temporary and
// cannot be stored into SharedFile::soName.
path = mbref.getBufferIdentifier();
auto *f =
make<SharedFile>(mbref, withLOption ? path::filename(path) : path);
f->init();
files.push_back(f);
return;
}
case file_magic::bitcode:
files.push_back(make<BitcodeFile>(mbref, "", 0, inLib));
break;
case file_magic::elf_relocatable:
if (!tryAddFatLTOFile(mbref, "", 0, inLib))
files.push_back(createObjFile(mbref, "", inLib));
break;
default:
error(path + ": unknown file type");
}
}
// Add a given library by searching it from input search paths.
void LinkerDriver::addLibrary(StringRef name) {
if (std::optional<std::string> path = searchLibrary(name))
addFile(saver().save(*path), /*withLOption=*/true);
else
error("unable to find library -l" + name, ErrorTag::LibNotFound, {name});
}
// This function is called on startup. We need this for LTO since
// LTO calls LLVM functions to compile bitcode files to native code.
// Technically this can be delayed until we read bitcode files, but
// we don't bother to do lazily because the initialization is fast.
static void initLLVM() {
InitializeAllTargets();
InitializeAllTargetMCs();
InitializeAllAsmPrinters();
InitializeAllAsmParsers();
}
// Some command line options or some combinations of them are not allowed.
// This function checks for such errors.
static void checkOptions() {
// The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
// table which is a relatively new feature.
if (config->emachine == EM_MIPS && config->gnuHash)
error("the .gnu.hash section is not compatible with the MIPS target");
if (config->emachine == EM_ARM) {
if (!config->cmseImplib) {
if (!config->cmseInputLib.empty())
error("--in-implib may not be used without --cmse-implib");
if (!config->cmseOutputLib.empty())
error("--out-implib may not be used without --cmse-implib");
}
} else {
if (config->cmseImplib)
error("--cmse-implib is only supported on ARM targets");
if (!config->cmseInputLib.empty())
error("--in-implib is only supported on ARM targets");
if (!config->cmseOutputLib.empty())
error("--out-implib is only supported on ARM targets");
}
if (config->fixCortexA53Errata843419 && config->emachine != EM_AARCH64)
error("--fix-cortex-a53-843419 is only supported on AArch64 targets");
if (config->fixCortexA8 && config->emachine != EM_ARM)
error("--fix-cortex-a8 is only supported on ARM targets");
if (config->armBe8 && config->emachine != EM_ARM)
error("--be8 is only supported on ARM targets");
if (config->fixCortexA8 && !config->isLE)
error("--fix-cortex-a8 is not supported on big endian targets");
if (config->tocOptimize && config->emachine != EM_PPC64)
error("--toc-optimize is only supported on PowerPC64 targets");
if (config->pcRelOptimize && config->emachine != EM_PPC64)
error("--pcrel-optimize is only supported on PowerPC64 targets");
if (config->relaxGP && config->emachine != EM_RISCV)
error("--relax-gp is only supported on RISC-V targets");
if (config->pie && config->shared)
error("-shared and -pie may not be used together");
if (!config->shared && !config->filterList.empty())
error("-F may not be used without -shared");
if (!config->shared && !config->auxiliaryList.empty())
error("-f may not be used without -shared");
if (config->strip == StripPolicy::All && config->emitRelocs)
error("--strip-all and --emit-relocs may not be used together");
if (config->zText && config->zIfuncNoplt)
error("-z text and -z ifunc-noplt may not be used together");
if (config->relocatable) {
if (config->shared)
error("-r and -shared may not be used together");
if (config->gdbIndex)
error("-r and --gdb-index may not be used together");
if (config->icf != ICFLevel::None)
error("-r and --icf may not be used together");
if (config->pie)
error("-r and -pie may not be used together");
if (config->exportDynamic)
error("-r and --export-dynamic may not be used together");
}
if (config->executeOnly) {
if (config->emachine != EM_AARCH64)
error("--execute-only is only supported on AArch64 targets");
if (config->singleRoRx && !script->hasSectionsCommand)
error("--execute-only and --no-rosegment cannot be used together");
}
if (config->zRetpolineplt && config->zForceIbt)
error("-z force-ibt may not be used with -z retpolineplt");
if (config->emachine != EM_AARCH64) {
if (config->zPacPlt)
error("-z pac-plt only supported on AArch64");
if (config->zForceBti)
error("-z force-bti only supported on AArch64");
if (config->zBtiReport != "none")
error("-z bti-report only supported on AArch64");
}
if (config->emachine != EM_386 && config->emachine != EM_X86_64 &&
config->zCetReport != "none")
error("-z cet-report only supported on X86 and X86_64");
}
static const char *getReproduceOption(opt::InputArgList &args) {
if (auto *arg = args.getLastArg(OPT_reproduce))
return arg->getValue();
return getenv("LLD_REPRODUCE");
}
static bool hasZOption(opt::InputArgList &args, StringRef key) {
for (auto *arg : args.filtered(OPT_z))
if (key == arg->getValue())
return true;
return false;
}
static bool getZFlag(opt::InputArgList &args, StringRef k1, StringRef k2,
bool Default) {
for (auto *arg : args.filtered_reverse(OPT_z)) {
if (k1 == arg->getValue())
return true;
if (k2 == arg->getValue())
return false;
}
return Default;
}
static SeparateSegmentKind getZSeparate(opt::InputArgList &args) {
for (auto *arg : args.filtered_reverse(OPT_z)) {
StringRef v = arg->getValue();
if (v == "noseparate-code")
return SeparateSegmentKind::None;
if (v == "separate-code")
return SeparateSegmentKind::Code;
if (v == "separate-loadable-segments")
return SeparateSegmentKind::Loadable;
}
return SeparateSegmentKind::None;
}
static GnuStackKind getZGnuStack(opt::InputArgList &args) {
for (auto *arg : args.filtered_reverse(OPT_z)) {
if (StringRef("execstack") == arg->getValue())
return GnuStackKind::Exec;
if (StringRef("noexecstack") == arg->getValue())
return GnuStackKind::NoExec;
if (StringRef("nognustack") == arg->getValue())
return GnuStackKind::None;
}
return GnuStackKind::NoExec;
}
static uint8_t getZStartStopVisibility(opt::InputArgList &args) {
for (auto *arg : args.filtered_reverse(OPT_z)) {
std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split('=');
if (kv.first == "start-stop-visibility") {
if (kv.second == "default")
return STV_DEFAULT;
else if (kv.second == "internal")
return STV_INTERNAL;
else if (kv.second == "hidden")
return STV_HIDDEN;
else if (kv.second == "protected")
return STV_PROTECTED;
error("unknown -z start-stop-visibility= value: " + StringRef(kv.second));
}
}
return STV_PROTECTED;
}
constexpr const char *knownZFlags[] = {
"combreloc",
"copyreloc",
"defs",
"execstack",
"force-bti",
"force-ibt",
"global",
"hazardplt",
"ifunc-noplt",
"initfirst",
"interpose",
"keep-text-section-prefix",
"lazy",
"muldefs",
"nocombreloc",
"nocopyreloc",
"nodefaultlib",
"nodelete",
"nodlopen",
"noexecstack",
"nognustack",
"nokeep-text-section-prefix",
"nopack-relative-relocs",
"norelro",
"noseparate-code",
"nostart-stop-gc",
"notext",
"now",
"origin",
"pac-plt",
"pack-relative-relocs",
"rel",
"rela",
"relro",
"retpolineplt",
"rodynamic",
"separate-code",
"separate-loadable-segments",
"shstk",
"start-stop-gc",
"text",
"undefs",
"wxneeded",
};
static bool isKnownZFlag(StringRef s) {
return llvm::is_contained(knownZFlags, s) ||
s.starts_with("common-page-size=") || s.starts_with("bti-report=") ||
s.starts_with("cet-report=") ||
s.starts_with("dead-reloc-in-nonalloc=") ||
s.starts_with("max-page-size=") || s.starts_with("stack-size=") ||
s.starts_with("start-stop-visibility=");
}
// Report a warning for an unknown -z option.
static void checkZOptions(opt::InputArgList &args) {
for (auto *arg : args.filtered(OPT_z))
if (!isKnownZFlag(arg->getValue()))
warn("unknown -z value: " + StringRef(arg->getValue()));
}
constexpr const char *saveTempsValues[] = {
"resolution", "preopt", "promote", "internalize", "import",
"opt", "precodegen", "prelink", "combinedindex"};
void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
ELFOptTable parser;
opt::InputArgList args = parser.parse(argsArr.slice(1));
// Interpret these flags early because error()/warn() depend on them.
errorHandler().errorLimit = args::getInteger(args, OPT_error_limit, 20);
errorHandler().fatalWarnings =
args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false) &&
!args.hasArg(OPT_no_warnings);
errorHandler().suppressWarnings = args.hasArg(OPT_no_warnings);
checkZOptions(args);
// Handle -help
if (args.hasArg(OPT_help)) {
printHelp();
return;
}
// Handle -v or -version.
//
// A note about "compatible with GNU linkers" message: this is a hack for
// scripts generated by GNU Libtool up to 2021-10 to recognize LLD as
// a GNU compatible linker. See
// <https://lists.gnu.org/archive/html/libtool/2017-01/msg00007.html>.
//
// This is somewhat ugly hack, but in reality, we had no choice other
// than doing this. Considering the very long release cycle of Libtool,
// it is not easy to improve it to recognize LLD as a GNU compatible
// linker in a timely manner. Even if we can make it, there are still a
// lot of "configure" scripts out there that are generated by old version
// of Libtool. We cannot convince every software developer to migrate to
// the latest version and re-generate scripts. So we have this hack.
if (args.hasArg(OPT_v) || args.hasArg(OPT_version))
message(getLLDVersion() + " (compatible with GNU linkers)");
if (const char *path = getReproduceOption(args)) {
// Note that --reproduce is a debug option so you can ignore it
// if you are trying to understand the whole picture of the code.
Expected<std::unique_ptr<TarWriter>> errOrWriter =
TarWriter::create(path, path::stem(path));
if (errOrWriter) {
tar = std::move(*errOrWriter);
tar->append("response.txt", createResponseFile(args));
tar->append("version.txt", getLLDVersion() + "\n");
StringRef ltoSampleProfile = args.getLastArgValue(OPT_lto_sample_profile);
if (!ltoSampleProfile.empty())
readFile(ltoSampleProfile);
} else {
error("--reproduce: " + toString(errOrWriter.takeError()));
}
}
readConfigs(args);
// The behavior of -v or --version is a bit strange, but this is
// needed for compatibility with GNU linkers.
if (args.hasArg(OPT_v) && !args.hasArg(OPT_INPUT))
return;
if (args.hasArg(OPT_version))
return;
// Initialize time trace profiler.
if (config->timeTraceEnabled)
timeTraceProfilerInitialize(config->timeTraceGranularity, config->progName);
{
llvm::TimeTraceScope timeScope("ExecuteLinker");
initLLVM();
createFiles(args);
if (errorCount())
return;
inferMachineType();
setConfigs(args);
checkOptions();
if (errorCount())
return;
link(args);
}
if (config->timeTraceEnabled) {
checkError(timeTraceProfilerWrite(
args.getLastArgValue(OPT_time_trace_eq).str(), config->outputFile));
timeTraceProfilerCleanup();
}
}
static std::string getRpath(opt::InputArgList &args) {
SmallVector<StringRef, 0> v = args::getStrings(args, OPT_rpath);
return llvm::join(v.begin(), v.end(), ":");
}
// Determines what we should do if there are remaining unresolved
// symbols after the name resolution.
static void setUnresolvedSymbolPolicy(opt::InputArgList &args) {
UnresolvedPolicy errorOrWarn = args.hasFlag(OPT_error_unresolved_symbols,
OPT_warn_unresolved_symbols, true)
? UnresolvedPolicy::ReportError
: UnresolvedPolicy::Warn;
// -shared implies --unresolved-symbols=ignore-all because missing
// symbols are likely to be resolved at runtime.
bool diagRegular = !config->shared, diagShlib = !config->shared;
for (const opt::Arg *arg : args) {
switch (arg->getOption().getID()) {
case OPT_unresolved_symbols: {
StringRef s = arg->getValue();
if (s == "ignore-all") {
diagRegular = false;
diagShlib = false;
} else if (s == "ignore-in-object-files") {
diagRegular = false;
diagShlib = true;
} else if (s == "ignore-in-shared-libs") {
diagRegular = true;
diagShlib = false;
} else if (s == "report-all") {
diagRegular = true;
diagShlib = true;
} else {
error("unknown --unresolved-symbols value: " + s);
}
break;
}
case OPT_no_undefined:
diagRegular = true;
break;
case OPT_z:
if (StringRef(arg->getValue()) == "defs")
diagRegular = true;
else if (StringRef(arg->getValue()) == "undefs")
diagRegular = false;
break;
case OPT_allow_shlib_undefined:
diagShlib = false;
break;
case OPT_no_allow_shlib_undefined:
diagShlib = true;
break;
}
}
config->unresolvedSymbols =
diagRegular ? errorOrWarn : UnresolvedPolicy::Ignore;
config->unresolvedSymbolsInShlib =
diagShlib ? errorOrWarn : UnresolvedPolicy::Ignore;
}
static Target2Policy getTarget2(opt::InputArgList &args) {
StringRef s = args.getLastArgValue(OPT_target2, "got-rel");
if (s == "rel")
return Target2Policy::Rel;
if (s == "abs")
return Target2Policy::Abs;
if (s == "got-rel")
return Target2Policy::GotRel;
error("unknown --target2 option: " + s);
return Target2Policy::GotRel;
}
static bool isOutputFormatBinary(opt::InputArgList &args) {
StringRef s = args.getLastArgValue(OPT_oformat, "elf");
if (s == "binary")
return true;
if (!s.starts_with("elf"))
error("unknown --oformat value: " + s);
return false;
}
static DiscardPolicy getDiscard(opt::InputArgList &args) {
auto *arg =
args.getLastArg(OPT_discard_all, OPT_discard_locals, OPT_discard_none);
if (!arg)
return DiscardPolicy::Default;
if (arg->getOption().getID() == OPT_discard_all)
return DiscardPolicy::All;
if (arg->getOption().getID() == OPT_discard_locals)
return DiscardPolicy::Locals;
return DiscardPolicy::None;
}
static StringRef getDynamicLinker(opt::InputArgList &args) {
auto *arg = args.getLastArg(OPT_dynamic_linker, OPT_no_dynamic_linker);
if (!arg)
return "";
if (arg->getOption().getID() == OPT_no_dynamic_linker) {
// --no-dynamic-linker suppresses undefined weak symbols in .dynsym
config->noDynamicLinker = true;
return "";
}
return arg->getValue();
}
static int getMemtagMode(opt::InputArgList &args) {
StringRef memtagModeArg = args.getLastArgValue(OPT_android_memtag_mode);
if (memtagModeArg.empty()) {
if (config->androidMemtagStack)
warn("--android-memtag-mode is unspecified, leaving "
"--android-memtag-stack a no-op");
else if (config->androidMemtagHeap)
warn("--android-memtag-mode is unspecified, leaving "
"--android-memtag-heap a no-op");
return ELF::NT_MEMTAG_LEVEL_NONE;
}
if (memtagModeArg == "sync")
return ELF::NT_MEMTAG_LEVEL_SYNC;
if (memtagModeArg == "async")
return ELF::NT_MEMTAG_LEVEL_ASYNC;
if (memtagModeArg == "none")
return ELF::NT_MEMTAG_LEVEL_NONE;
error("unknown --android-memtag-mode value: \"" + memtagModeArg +
"\", should be one of {async, sync, none}");
return ELF::NT_MEMTAG_LEVEL_NONE;
}
static ICFLevel getICF(opt::InputArgList &args) {
auto *arg = args.getLastArg(OPT_icf_none, OPT_icf_safe, OPT_icf_all);
if (!arg || arg->getOption().getID() == OPT_icf_none)
return ICFLevel::None;
if (arg->getOption().getID() == OPT_icf_safe)
return ICFLevel::Safe;
return ICFLevel::All;
}
static StripPolicy getStrip(opt::InputArgList &args) {
if (args.hasArg(OPT_relocatable))
return StripPolicy::None;
auto *arg = args.getLastArg(OPT_strip_all, OPT_strip_debug);
if (!arg)
return StripPolicy::None;
if (arg->getOption().getID() == OPT_strip_all)
return StripPolicy::All;
return StripPolicy::Debug;
}
static uint64_t parseSectionAddress(StringRef s, opt::InputArgList &args,
const opt::Arg &arg) {
uint64_t va = 0;
if (s.starts_with("0x"))
s = s.drop_front(2);
if (!to_integer(s, va, 16))
error("invalid argument: " + arg.getAsString(args));
return va;
}
static StringMap<uint64_t> getSectionStartMap(opt::InputArgList &args) {
StringMap<uint64_t> ret;
for (auto *arg : args.filtered(OPT_section_start)) {
StringRef name;
StringRef addr;
std::tie(name, addr) = StringRef(arg->getValue()).split('=');
ret[name] = parseSectionAddress(addr, args, *arg);
}
if (auto *arg = args.getLastArg(OPT_Ttext))
ret[".text"] = parseSectionAddress(arg->getValue(), args, *arg);
if (auto *arg = args.getLastArg(OPT_Tdata))
ret[".data"] = parseSectionAddress(arg->getValue(), args, *arg);
if (auto *arg = args.getLastArg(OPT_Tbss))
ret[".bss"] = parseSectionAddress(arg->getValue(), args, *arg);
return ret;
}
static SortSectionPolicy getSortSection(opt::InputArgList &args) {
StringRef s = args.getLastArgValue(OPT_sort_section);
if (s == "alignment")
return SortSectionPolicy::Alignment;
if (s == "name")
return SortSectionPolicy::Name;
if (!s.empty())
error("unknown --sort-section rule: " + s);
return SortSectionPolicy::Default;
}
static OrphanHandlingPolicy getOrphanHandling(opt::InputArgList &args) {
StringRef s = args.getLastArgValue(OPT_orphan_handling, "place");
if (s == "warn")
return OrphanHandlingPolicy::Warn;
if (s == "error")
return OrphanHandlingPolicy::Error;
if (s != "place")
error("unknown --orphan-handling mode: " + s);
return OrphanHandlingPolicy::Place;
}
// Parse --build-id or --build-id=<style>. We handle "tree" as a
// synonym for "sha1" because all our hash functions including
// --build-id=sha1 are actually tree hashes for performance reasons.
static std::pair<BuildIdKind, SmallVector<uint8_t, 0>>
getBuildId(opt::InputArgList &args) {
auto *arg = args.getLastArg(OPT_build_id);
if (!arg)
return {BuildIdKind::None, {}};
StringRef s = arg->getValue();
if (s == "fast")
return {BuildIdKind::Fast, {}};
if (s == "md5")
return {BuildIdKind::Md5, {}};
if (s == "sha1" || s == "tree")
return {BuildIdKind::Sha1, {}};
if (s == "uuid")
return {BuildIdKind::Uuid, {}};
if (s.starts_with("0x"))
return {BuildIdKind::Hexstring, parseHex(s.substr(2))};
if (s != "none")
error("unknown --build-id style: " + s);
return {BuildIdKind::None, {}};
}
static std::pair<bool, bool> getPackDynRelocs(opt::InputArgList &args) {
StringRef s = args.getLastArgValue(OPT_pack_dyn_relocs, "none");
if (s == "android")
return {true, false};
if (s == "relr")
return {false, true};
if (s == "android+relr")
return {true, true};
if (s != "none")
error("unknown --pack-dyn-relocs format: " + s);
return {false, false};
}
static void readCallGraph(MemoryBufferRef mb) {
// Build a map from symbol name to section
DenseMap<StringRef, Symbol *> map;
for (ELFFileBase *file : ctx.objectFiles)
for (Symbol *sym : file->getSymbols())
map[sym->getName()] = sym;
auto findSection = [&](StringRef name) -> InputSectionBase * {
Symbol *sym = map.lookup(name);
if (!sym) {
if (config->warnSymbolOrdering)
warn(mb.getBufferIdentifier() + ": no such symbol: " + name);
return nullptr;
}
maybeWarnUnorderableSymbol(sym);
if (Defined *dr = dyn_cast_or_null<Defined>(sym))
return dyn_cast_or_null<InputSectionBase>(dr->section);
return nullptr;
};
for (StringRef line : args::getLines(mb)) {
SmallVector<StringRef, 3> fields;
line.split(fields, ' ');
uint64_t count;
if (fields.size() != 3 || !to_integer(fields[2], count)) {
error(mb.getBufferIdentifier() + ": parse error");
return;
}
if (InputSectionBase *from = findSection(fields[0]))
if (InputSectionBase *to = findSection(fields[1]))
config->callGraphProfile[std::make_pair(from, to)] += count;
}
}
// If SHT_LLVM_CALL_GRAPH_PROFILE and its relocation section exist, returns
// true and populates cgProfile and symbolIndices.
template <class ELFT>
static bool
processCallGraphRelocations(SmallVector<uint32_t, 32> &symbolIndices,
ArrayRef<typename ELFT::CGProfile> &cgProfile,
ObjFile<ELFT> *inputObj) {
if (inputObj->cgProfileSectionIndex == SHN_UNDEF)
return false;
ArrayRef<Elf_Shdr_Impl<ELFT>> objSections =
inputObj->template getELFShdrs<ELFT>();
symbolIndices.clear();
const ELFFile<ELFT> &obj = inputObj->getObj();
cgProfile =
check(obj.template getSectionContentsAsArray<typename ELFT::CGProfile>(
objSections[inputObj->cgProfileSectionIndex]));
for (size_t i = 0, e = objSections.size(); i < e; ++i) {
const Elf_Shdr_Impl<ELFT> &sec = objSections[i];
if (sec.sh_info == inputObj->cgProfileSectionIndex) {
if (sec.sh_type == SHT_RELA) {
ArrayRef<typename ELFT::Rela> relas =
CHECK(obj.relas(sec), "could not retrieve cg profile rela section");
for (const typename ELFT::Rela &rel : relas)
symbolIndices.push_back(rel.getSymbol(config->isMips64EL));
break;
}
if (sec.sh_type == SHT_REL) {
ArrayRef<typename ELFT::Rel> rels =
CHECK(obj.rels(sec), "could not retrieve cg profile rel section");
for (const typename ELFT::Rel &rel : rels)