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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 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 "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/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/Threads.h"
#include "lld/Common/Version.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/GlobPattern.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/TarWriter.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
#include <utility>
using namespace llvm;
using namespace llvm::ELF;
using namespace llvm::object;
using namespace llvm::sys;
using namespace llvm::support;
namespace lld {
namespace elf {
Configuration *config;
LinkerDriver *driver;
static void setConfigs(opt::InputArgList &args);
static void readConfigs(opt::InputArgList &args);
bool link(ArrayRef<const char *> args, bool canExitEarly, raw_ostream &stdoutOS,
raw_ostream &stderrOS) {
lld::stdoutOS = &stdoutOS;
lld::stderrOS = &stderrOS;
errorHandler().logName = args::getFilenameWithoutExe(args[0]);
errorHandler().errorLimitExceededMsg =
"too many errors emitted, stopping now (use "
"-error-limit=0 to see all errors)";
errorHandler().exitEarly = canExitEarly;
stderrOS.enable_colors(stderrOS.has_colors());
inputSections.clear();
outputSections.clear();
binaryFiles.clear();
bitcodeFiles.clear();
objectFiles.clear();
sharedFiles.clear();
config = make<Configuration>();
driver = make<LinkerDriver>();
script = make<LinkerScript>();
symtab = make<SymbolTable>();
tar = nullptr;
memset(&in, 0, sizeof(in));
partitions = {Partition()};
SharedFile::vernauxNum = 0;
config->progName = args[0];
driver->main(args);
// Exit immediately if we don't need to return to the caller.
// This saves time because the overhead of calling destructors
// for all globally-allocated objects is not negligible.
if (canExitEarly)
exitLld(errorCount() ? 1 : 0);
freeArena();
return !errorCount();
}
// 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.endswith("_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", "aarch64_elf64_le_vec",
{ELF64LEKind, EM_AARCH64})
.Cases("armelf", "armelf_linux_eabi", {ELF32LEKind, 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})
.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})
.Default({ELFNoneKind, EM_NONE});
if (ret.first == ELFNoneKind)
error("unknown emulation: " + emul);
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.
for (std::unique_ptr<MemoryBuffer> &mb : file->takeThinBuffers())
make<std::unique_ptr<MemoryBuffer>>(std::move(mb));
return v;
}
// 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;
Optional<MemoryBufferRef> buffer = readFile(path);
if (!buffer.hasValue())
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: {
// Handle -whole-archive.
if (inWholeArchive) {
for (const auto &p : getArchiveMembers(mbref))
files.push_back(createObjectFile(p.first, path, p.second));
return;
}
std::unique_ptr<Archive> file =
CHECK(Archive::create(mbref), path + ": failed to parse archive");
// If an archive file has no symbol table, it is likely that a user
// is attempting LTO and using a default ar command that doesn't
// understand the LLVM bitcode file. It is a pretty common error, so
// we'll handle it as if it had a symbol table.
if (!file->isEmpty() && !file->hasSymbolTable()) {
// Check if all members are bitcode files. If not, ignore, which is the
// default action without the LTO hack described above.
for (const std::pair<MemoryBufferRef, uint64_t> &p :
getArchiveMembers(mbref))
if (identify_magic(p.first.getBuffer()) != file_magic::bitcode) {
error(path + ": archive has no index; run ranlib to add one");
return;
}
for (const std::pair<MemoryBufferRef, uint64_t> &p :
getArchiveMembers(mbref))
files.push_back(make<LazyObjFile>(p.first, path, p.second));
return;
}
// Handle the regular case.
files.push_back(make<ArchiveFile>(std::move(file)));
return;
}
case file_magic::elf_shared_object:
if (config->isStatic || config->relocatable) {
error("attempted static link of dynamic object " + path);
return;
}
// DSOs usually have DT_SONAME tags in their ELF headers, and the
// sonames are used to identify DSOs. But if they are missing,
// they are identified by filenames. We don't know whether the new
// file has a DT_SONAME or not because we haven't parsed it yet.
// Here, we set the default soname for the file because we might
// need it later.
//
// If a file was specified by -lfoo, the directory part is not
// significant, as a user did not specify it. This behavior is
// compatible with GNU.
files.push_back(
make<SharedFile>(mbref, withLOption ? path::filename(path) : path));
return;
case file_magic::bitcode:
case file_magic::elf_relocatable:
if (inLib)
files.push_back(make<LazyObjFile>(mbref, "", 0));
else
files.push_back(createObjectFile(mbref));
break;
default:
error(path + ": unknown file type");
}
}
// Add a given library by searching it from input search paths.
void LinkerDriver::addLibrary(StringRef name) {
if (Optional<std::string> path = searchLibrary(name))
addFile(*path, /*withLOption=*/true);
else
error("unable to find library -l" + 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->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->tocOptimize && config->emachine != EM_PPC64)
error("--toc-optimize is only supported on the PowerPC64 target");
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->relocatable && !config->defineCommon)
error("-no-define-common not supported in non relocatable output");
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->gcSections)
error("-r and --gc-sections 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->requireCET)
error("--require-cet may not be used with -z retpolineplt");
if (config->emachine != EM_AARCH64) {
if (config->pacPlt)
error("-z pac-plt only supported on AArch64");
if (config->forceBTI)
error("-z force-bti only supported on AArch64");
}
}
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 bool isKnownZFlag(StringRef s) {
return s == "combreloc" || s == "copyreloc" || s == "defs" ||
s == "execstack" || s == "force-bti" || s == "global" ||
s == "hazardplt" || s == "ifunc-noplt" || s == "initfirst" ||
s == "interpose" || s == "keep-text-section-prefix" || s == "lazy" ||
s == "muldefs" || s == "separate-code" ||
s == "separate-loadable-segments" || s == "nocombreloc" ||
s == "nocopyreloc" || s == "nodefaultlib" || s == "nodelete" ||
s == "nodlopen" || s == "noexecstack" || s == "nognustack" ||
s == "nokeep-text-section-prefix" || s == "norelro" ||
s == "noseparate-code" || s == "notext" || s == "now" ||
s == "origin" || s == "pac-plt" || s == "relro" ||
s == "retpolineplt" || s == "rodynamic" || s == "text" ||
s == "undefs" || s == "wxneeded" ||
s.startswith("common-page-size=") || s.startswith("max-page-size=") ||
s.startswith("stack-size=");
}
// Report an error for an unknown -z option.
static void checkZOptions(opt::InputArgList &args) {
for (auto *arg : args.filtered(OPT_z))
if (!isKnownZFlag(arg->getValue()))
error("unknown -z value: " + StringRef(arg->getValue()));
}
void LinkerDriver::main(ArrayRef<const char *> argsArr) {
ELFOptTable parser;
opt::InputArgList args = parser.parse(argsArr.slice(1));
// Interpret this flag early because error() depends on them.
errorHandler().errorLimit = args::getInteger(args, OPT_error_limit, 20);
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 2.4.6 (released in February 2014 and
// still the newest version in March 2017) or earlier to recognize LLD as
// a GNU compatible linker. As long as an output for the -v option
// contains "GNU" or "with BFD", they recognize us as GNU-compatible.
//
// 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");
} 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;
initLLVM();
createFiles(args);
if (errorCount())
return;
inferMachineType();
setConfigs(args);
checkOptions();
if (errorCount())
return;
// The Target instance handles target-specific stuff, such as applying
// relocations or writing a PLT section. It also contains target-dependent
// values such as a default image base address.
target = getTarget();
switch (config->ekind) {
case ELF32LEKind:
link<ELF32LE>(args);
return;
case ELF32BEKind:
link<ELF32BE>(args);
return;
case ELF64LEKind:
link<ELF64LE>(args);
return;
case ELF64BEKind:
link<ELF64BE>(args);
return;
default:
llvm_unreachable("unknown Config->EKind");
}
}
static std::string getRpath(opt::InputArgList &args) {
std::vector<StringRef> 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 UnresolvedPolicy getUnresolvedSymbolPolicy(opt::InputArgList &args) {
UnresolvedPolicy errorOrWarn = args.hasFlag(OPT_error_unresolved_symbols,
OPT_warn_unresolved_symbols, true)
? UnresolvedPolicy::ReportError
: UnresolvedPolicy::Warn;
// Process the last of -unresolved-symbols, -no-undefined or -z defs.
for (auto *arg : llvm::reverse(args)) {
switch (arg->getOption().getID()) {
case OPT_unresolved_symbols: {
StringRef s = arg->getValue();
if (s == "ignore-all" || s == "ignore-in-object-files")
return UnresolvedPolicy::Ignore;
if (s == "ignore-in-shared-libs" || s == "report-all")
return errorOrWarn;
error("unknown --unresolved-symbols value: " + s);
continue;
}
case OPT_no_undefined:
return errorOrWarn;
case OPT_z:
if (StringRef(arg->getValue()) == "defs")
return errorOrWarn;
if (StringRef(arg->getValue()) == "undefs")
return UnresolvedPolicy::Ignore;
continue;
}
}
// -shared implies -unresolved-symbols=ignore-all because missing
// symbols are likely to be resolved at runtime using other DSOs.
if (config->shared)
return UnresolvedPolicy::Ignore;
return errorOrWarn;
}
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.startswith("elf"))
error("unknown --oformat value: " + s);
return false;
}
static DiscardPolicy getDiscard(opt::InputArgList &args) {
if (args.hasArg(OPT_relocatable))
return DiscardPolicy::None;
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 || arg->getOption().getID() == OPT_no_dynamic_linker)
return "";
return arg->getValue();
}
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.startswith("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, std::vector<uint8_t>>
getBuildId(opt::InputArgList &args) {
auto *arg = args.getLastArg(OPT_build_id, OPT_build_id_eq);
if (!arg)
return {BuildIdKind::None, {}};
if (arg->getOption().getID() == OPT_build_id)
return {BuildIdKind::Fast, {}};
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.startswith("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 (InputFile *file : 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;
}
}
template <class ELFT> static void readCallGraphsFromObjectFiles() {
for (auto file : objectFiles) {
auto *obj = cast<ObjFile<ELFT>>(file);
for (const Elf_CGProfile_Impl<ELFT> &cgpe : obj->cgProfile) {
auto *fromSym = dyn_cast<Defined>(&obj->getSymbol(cgpe.cgp_from));
auto *toSym = dyn_cast<Defined>(&obj->getSymbol(cgpe.cgp_to));
if (!fromSym || !toSym)
continue;
auto *from = dyn_cast_or_null<InputSectionBase>(fromSym->section);
auto *to = dyn_cast_or_null<InputSectionBase>(toSym->section);
if (from && to)
config->callGraphProfile[{from, to}] += cgpe.cgp_weight;
}
}
}
static bool getCompressDebugSections(opt::InputArgList &args) {
StringRef s = args.getLastArgValue(OPT_compress_debug_sections, "none");
if (s == "none")
return false;
if (s != "zlib")
error("unknown --compress-debug-sections value: " + s);
if (!zlib::isAvailable())
error("--compress-debug-sections: zlib is not available");
return true;
}
static StringRef getAliasSpelling(opt::Arg *arg) {
if (const opt::Arg *alias = arg->getAlias())
return alias->getSpelling();
return arg->getSpelling();
}
static std::pair<StringRef, StringRef> getOldNewOptions(opt::InputArgList &args,
unsigned id) {
auto *arg = args.getLastArg(id);
if (!arg)
return {"", ""};
StringRef s = arg->getValue();
std::pair<StringRef, StringRef> ret = s.split(';');
if (ret.second.empty())
error(getAliasSpelling(arg) + " expects 'old;new' format, but got " + s);
return ret;
}
// Parse the symbol ordering file and warn for any duplicate entries.
static std::vector<StringRef> getSymbolOrderingFile(MemoryBufferRef mb) {
SetVector<StringRef> names;
for (StringRef s : args::getLines(mb))
if (!names.insert(s) && config->warnSymbolOrdering)
warn(mb.getBufferIdentifier() + ": duplicate ordered symbol: " + s);
return names.takeVector();
}
static void parseClangOption(StringRef opt, const Twine &msg) {
std::string err;
raw_string_ostream os(err);
const char *argv[] = {config->progName.data(), opt.data()};
if (cl::ParseCommandLineOptions(2, argv, "", &os))
return;
os.flush();
error(msg + ": " + StringRef(err).trim());
}
// Initializes Config members by the command line options.
static void readConfigs(opt::InputArgList &args) {
errorHandler().verbose = args.hasArg(OPT_verbose);
errorHandler().fatalWarnings =
args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false);
errorHandler().vsDiagnostics =
args.hasArg(OPT_visual_studio_diagnostics_format, false);
threadsEnabled = args.hasFlag(OPT_threads, OPT_no_threads, true);
config->allowMultipleDefinition =
args.hasFlag(OPT_allow_multiple_definition,
OPT_no_allow_multiple_definition, false) ||
hasZOption(args, "muldefs");
config->allowShlibUndefined =
args.hasFlag(OPT_allow_shlib_undefined, OPT_no_allow_shlib_undefined,
args.hasArg(OPT_shared));
config->auxiliaryList = args::getStrings(args, OPT_auxiliary);
config->bsymbolic = args.hasArg(OPT_Bsymbolic);
config->bsymbolicFunctions = args.hasArg(OPT_Bsymbolic_functions);
config->checkSections =
args.hasFlag(OPT_check_sections, OPT_no_check_sections, true);
config->chroot = args.getLastArgValue(OPT_chroot);
config->compressDebugSections = getCompressDebugSections(args);
config->cref = args.hasFlag(OPT_cref, OPT_no_cref, false);
config->defineCommon = args.hasFlag(OPT_define_common, OPT_no_define_common,
!args.hasArg(OPT_relocatable));
config->demangle = args.hasFlag(OPT_demangle, OPT_no_demangle, true);
config->dependentLibraries = args.hasFlag(OPT_dependent_libraries, OPT_no_dependent_libraries, true);
config->disableVerify = args.hasArg(OPT_disable_verify);
config->discard = getDiscard(args);
config->dwoDir = args.getLastArgValue(OPT_plugin_opt_dwo_dir_eq);
config->dynamicLinker = getDynamicLinker(args);
config->ehFrameHdr =
args.hasFlag(OPT_eh_frame_hdr, OPT_no_eh_frame_hdr, false);
config->emitLLVM = args.hasArg(OPT_plugin_opt_emit_llvm, false);
config->emitRelocs = args.hasArg(OPT_emit_relocs);
config->callGraphProfileSort = args.hasFlag(
OPT_call_graph_profile_sort, OPT_no_call_graph_profile_sort, true);
config->enableNewDtags =
args.hasFlag(OPT_enable_new_dtags, OPT_disable_new_dtags, true);
config->entry = args.getLastArgValue(OPT_entry);
config->executeOnly =
args.hasFlag(OPT_execute_only, OPT_no_execute_only, false);
config->exportDynamic =
args.hasFlag(OPT_export_dynamic, OPT_no_export_dynamic, false);
config->filterList = args::getStrings(args, OPT_filter);
config->fini = args.getLastArgValue(OPT_fini, "_fini");
config->fixCortexA53Errata843419 = args.hasArg(OPT_fix_cortex_a53_843419);
config->fixCortexA8 = args.hasArg(OPT_fix_cortex_a8);
config->forceBTI = hasZOption(args, "force-bti");
config->requireCET = args.hasArg(OPT_require_cet);
config->gcSections = args.hasFlag(OPT_gc_sections, OPT_no_gc_sections, false);
config->gnuUnique = args.hasFlag(OPT_gnu_unique, OPT_no_gnu_unique, true);
config->gdbIndex = args.hasFlag(OPT_gdb_index, OPT_no_gdb_index, false);
config->icf = getICF(args);
config->ignoreDataAddressEquality =
args.hasArg(OPT_ignore_data_address_equality);
config->ignoreFunctionAddressEquality =
args.hasArg(OPT_ignore_function_address_equality);
config->init = args.getLastArgValue(OPT_init, "_init");
config->ltoAAPipeline = args.getLastArgValue(OPT_lto_aa_pipeline);
config->ltoCSProfileGenerate = args.hasArg(OPT_lto_cs_profile_generate);
config->ltoCSProfileFile = args.getLastArgValue(OPT_lto_cs_profile_file);
config->ltoDebugPassManager = args.hasArg(OPT_lto_debug_pass_manager);
config->ltoNewPassManager = args.hasArg(OPT_lto_new_pass_manager);
config->ltoNewPmPasses = args.getLastArgValue(OPT_lto_newpm_passes);
config->ltoo = args::getInteger(args, OPT_lto_O, 2);
config->ltoObjPath = args.getLastArgValue(OPT_lto_obj_path_eq);
config->ltoPartitions = args::getInteger(args, OPT_lto_partitions, 1);
config->ltoSampleProfile = args.getLastArgValue(OPT_lto_sample_profile);
config->mapFile = args.getLastArgValue(OPT_Map);
config->mipsGotSize = args::getInteger(args, OPT_mips_got_size, 0xfff0);
config->mergeArmExidx =
args.hasFlag(OPT_merge_exidx_entries, OPT_no_merge_exidx_entries, true);
config->mmapOutputFile =
args.hasFlag(OPT_mmap_output_file, OPT_no_mmap_output_file, true);
config->nmagic = args.hasFlag(OPT_nmagic, OPT_no_nmagic, false);
config->noinhibitExec = args.hasArg(OPT_noinhibit_exec);
config->nostdlib = args.hasArg(OPT_nostdlib);
config->oFormatBinary = isOutputFormatBinary(args);
config->omagic = args.hasFlag(OPT_omagic, OPT_no_omagic, false);
config->optRemarksFilename = args.getLastArgValue(OPT_opt_remarks_filename);
config->optRemarksPasses = args.getLastArgValue(OPT_opt_remarks_passes);
config->optRemarksWithHotness = args.hasArg(OPT_opt_remarks_with_hotness);
config->optRemarksFormat = args.getLastArgValue(OPT_opt_remarks_format);
config->optimize = args::getInteger(args, OPT_O, 1);
config->orphanHandling = getOrphanHandling(args);
config->outputFile = args.getLastArgValue(OPT_o);
config->pacPlt = hasZOption(args, "pac-plt");
config->pie = args.hasFlag(OPT_pie, OPT_no_pie, false);
config->printIcfSections =
args.hasFlag(OPT_print_icf_sections, OPT_no_print_icf_sections, false);
config->printGcSections =
args.hasFlag(OPT_print_gc_sections, OPT_no_print_gc_sections, false);
config->printSymbolOrder =
args.getLastArgValue(OPT_print_symbol_order);
config->rpath = getRpath(args);
config->relocatable = args.hasArg(OPT_relocatable);
config->saveTemps = args.hasArg(OPT_save_temps);
config->searchPaths = args::getStrings(args, OPT_library_path);
config->sectionStartMap = getSectionStartMap(args);
config->shared = args.hasArg(OPT_shared);
config->singleRoRx = args.hasArg(OPT_no_rosegment);
config->soName = args.getLastArgValue(OPT_soname);
config->sortSection = getSortSection(args);
config->splitStackAdjustSize = args::getInteger(args, OPT_split_stack_adjust_size, 16384);
config->strip = getStrip(args);
config->sysroot = args.getLastArgValue(OPT_sysroot);
config->target1Rel = args.hasFlag(OPT_target1_rel, OPT_target1_abs, false);
config->target2 = getTarget2(args);
config->thinLTOCacheDir = args.getLastArgValue(OPT_thinlto_cache_dir);
config->thinLTOCachePolicy = CHECK(
parseCachePruningPolicy(args.getLastArgValue(OPT_thinlto_cache_policy)),
"--thinlto-cache-policy: invalid cache policy");
config->thinLTOEmitImportsFiles = args.hasArg(OPT_thinlto_emit_imports_files);
config->thinLTOIndexOnly = args.hasArg(OPT_thinlto_index_only) ||
args.hasArg(OPT_thinlto_index_only_eq);
config->thinLTOIndexOnlyArg = args.getLastArgValue(OPT_thinlto_index_only_eq);
config->thinLTOJobs = args::getInteger(args, OPT_thinlto_jobs, -1u);
config->thinLTOObjectSuffixReplace =
getOldNewOptions(args, OPT_thinlto_object_suffix_replace_eq);
config->thinLTOPrefixReplace =
getOldNewOptions(args, OPT_thinlto_prefix_replace_eq);
config->trace = args.hasArg(OPT_trace);
config->undefined = args::getStrings(args, OPT_undefined);
config->undefinedVersion =
args.hasFlag(OPT_undefined_version, OPT_no_undefined_version, true);
config->useAndroidRelrTags = args.hasFlag(
OPT_use_android_relr_tags, OPT_no_use_android_relr_tags, false);
config->unresolvedSymbols = getUnresolvedSymbolPolicy(args);
config->warnBackrefs =
args.hasFlag(OPT_warn_backrefs, OPT_no_warn_backrefs, false);
config->warnCommon = args.hasFlag(OPT_warn_common, OPT_no_warn_common, false);
config->warnIfuncTextrel =
args.hasFlag(OPT_warn_ifunc_textrel, OPT_no_warn_ifunc_textrel, false);
config->warnSymbolOrdering =
args.hasFlag(OPT_warn_symbol_ordering, OPT_no_warn_symbol_ordering, true);
config->zCombreloc = getZFlag(args, "combreloc", "nocombreloc", true);
config->zCopyreloc = getZFlag(args, "copyreloc", "nocopyreloc", true);
config->zGlobal = hasZOption(args, "global");
config->zGnustack = getZGnuStack(args);
config->zHazardplt = hasZOption(args, "hazardplt");
config->zIfuncNoplt = hasZOption(args, "ifunc-noplt");
config->zInitfirst = hasZOption(args, "initfirst");
config->zInterpose = hasZOption(args, "interpose");
config->zKeepTextSectionPrefix = getZFlag(
args, "keep-text-section-prefix", "nokeep-text-section-prefix", false);
config->zNodefaultlib = hasZOption(args, "nodefaultlib");
config->zNodelete = hasZOption(args, "nodelete");
config->zNodlopen = hasZOption(args, "nodlopen");
config->zNow = getZFlag(args, "now", "lazy", false);
config->zOrigin = hasZOption(args, "origin");
config->zRelro = getZFlag(args, "relro", "norelro", true);
config->zRetpolineplt = hasZOption(args, "retpolineplt");
config->zRodynamic = hasZOption(args, "rodynamic");
config->zSeparate = getZSeparate(args);
config->zStackSize = args::getZOptionValue(args, OPT_z, "stack-size", 0);
config->zText = getZFlag(args, "text", "notext", true);
config->zWxneeded = hasZOption(args, "wxneeded");
// Parse LTO options.
if (auto *arg = args.getLastArg(OPT_plugin_opt_mcpu_eq))
parseClangOption(saver.save("-mcpu=" + StringRef(arg->getValue())),
arg->getSpelling());
for (auto *arg : args.filtered(OPT_plugin_opt))
parseClangOption(arg->getValue(), arg->getSpelling());
// Parse -mllvm options.
for (auto *arg : args.filtered(OPT_mllvm))
parseClangOption(arg->getValue(), arg->getSpelling());