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llvm-project/lld/lib/Driver/DarwinLdDriver.cpp

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//===- lib/Driver/DarwinLdDriver.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
//
//===----------------------------------------------------------------------===//
///
/// \file
///
/// Concrete instance of the Driver for darwin's ld.
///
//===----------------------------------------------------------------------===//
#include "lld/Common/Args.h"
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/LLVM.h"
#include "lld/Core/ArchiveLibraryFile.h"
#include "lld/Core/Error.h"
#include "lld/Core/File.h"
#include "lld/Core/Instrumentation.h"
#include "lld/Core/LinkingContext.h"
#include "lld/Core/Node.h"
#include "lld/Core/PassManager.h"
#include "lld/Core/Resolver.h"
#include "lld/Core/SharedLibraryFile.h"
#include "lld/Core/Simple.h"
#include "lld/ReaderWriter/MachOLinkingContext.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Option/OptTable.h"
#include "llvm/Option/Option.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstdint>
#include <memory>
#include <string>
#include <system_error>
#include <utility>
#include <vector>
using namespace lld;
namespace {
// Create enum with OPT_xxx values for each option in DarwinLdOptions.td
enum {
OPT_INVALID = 0,
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELP, META, VALUES) \
OPT_##ID,
#include "DarwinLdOptions.inc"
#undef OPTION
};
// Create prefix string literals used in DarwinLdOptions.td
#define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
#include "DarwinLdOptions.inc"
#undef PREFIX
// Create table mapping all options defined in DarwinLdOptions.td
static const llvm::opt::OptTable::Info InfoTable[] = {
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELPTEXT, METAVAR, VALUES) \
{PREFIX, NAME, HELPTEXT, \
METAVAR, OPT_##ID, llvm::opt::Option::KIND##Class, \
PARAM, FLAGS, OPT_##GROUP, \
OPT_##ALIAS, ALIASARGS, VALUES},
#include "DarwinLdOptions.inc"
#undef OPTION
};
// Create OptTable class for parsing actual command line arguments
class DarwinLdOptTable : public llvm::opt::OptTable {
public:
DarwinLdOptTable() : OptTable(InfoTable) {}
};
static std::vector<std::unique_ptr<File>>
makeErrorFile(StringRef path, std::error_code ec) {
std::vector<std::unique_ptr<File>> result;
result.push_back(std::make_unique<ErrorFile>(path, ec));
return result;
}
static std::vector<std::unique_ptr<File>>
parseMemberFiles(std::unique_ptr<File> file) {
std::vector<std::unique_ptr<File>> members;
if (auto *archive = dyn_cast<ArchiveLibraryFile>(file.get())) {
if (std::error_code ec = archive->parseAllMembers(members))
return makeErrorFile(file->path(), ec);
} else {
members.push_back(std::move(file));
}
return members;
}
std::vector<std::unique_ptr<File>> loadFile(MachOLinkingContext &ctx,
StringRef path, bool wholeArchive,
bool upwardDylib) {
if (ctx.logInputFiles())
message(path);
ErrorOr<std::unique_ptr<MemoryBuffer>> mbOrErr = ctx.getMemoryBuffer(path);
if (std::error_code ec = mbOrErr.getError())
return makeErrorFile(path, ec);
ErrorOr<std::unique_ptr<File>> fileOrErr =
ctx.registry().loadFile(std::move(mbOrErr.get()));
if (std::error_code ec = fileOrErr.getError())
return makeErrorFile(path, ec);
std::unique_ptr<File> &file = fileOrErr.get();
// If file is a dylib, inform LinkingContext about it.
if (SharedLibraryFile *shl = dyn_cast<SharedLibraryFile>(file.get())) {
if (std::error_code ec = shl->parse())
return makeErrorFile(path, ec);
ctx.registerDylib(reinterpret_cast<mach_o::MachODylibFile *>(shl),
upwardDylib);
}
if (wholeArchive)
return parseMemberFiles(std::move(file));
std::vector<std::unique_ptr<File>> files;
files.push_back(std::move(file));
return files;
}
} // end anonymous namespace
// Test may be running on Windows. Canonicalize the path
// separator to '/' to get consistent outputs for tests.
static std::string canonicalizePath(StringRef path) {
char sep = llvm::sys::path::get_separator().front();
if (sep != '/') {
std::string fixedPath = std::string(path);
std::replace(fixedPath.begin(), fixedPath.end(), sep, '/');
return fixedPath;
} else {
return std::string(path);
}
}
static void addFile(StringRef path, MachOLinkingContext &ctx,
bool loadWholeArchive, bool upwardDylib) {
std::vector<std::unique_ptr<File>> files =
loadFile(ctx, path, loadWholeArchive, upwardDylib);
for (std::unique_ptr<File> &file : files)
ctx.getNodes().push_back(std::make_unique<FileNode>(std::move(file)));
}
// Export lists are one symbol per line. Blank lines are ignored.
// Trailing comments start with #.
static std::error_code parseExportsList(StringRef exportFilePath,
MachOLinkingContext &ctx) {
// Map in export list file.
ErrorOr<std::unique_ptr<MemoryBuffer>> mb =
MemoryBuffer::getFileOrSTDIN(exportFilePath);
if (std::error_code ec = mb.getError())
return ec;
ctx.addInputFileDependency(exportFilePath);
StringRef buffer = mb->get()->getBuffer();
while (!buffer.empty()) {
// Split off each line in the file.
std::pair<StringRef, StringRef> lineAndRest = buffer.split('\n');
StringRef line = lineAndRest.first;
// Ignore trailing # comments.
std::pair<StringRef, StringRef> symAndComment = line.split('#');
StringRef sym = symAndComment.first.trim();
if (!sym.empty())
ctx.addExportSymbol(sym);
buffer = lineAndRest.second;
}
return std::error_code();
}
/// Order files are one symbol per line. Blank lines are ignored.
/// Trailing comments start with #. Symbol names can be prefixed with an
/// architecture name and/or .o leaf name. Examples:
/// _foo
/// bar.o:_bar
/// libfrob.a(bar.o):_bar
/// x86_64:_foo64
static std::error_code parseOrderFile(StringRef orderFilePath,
MachOLinkingContext &ctx) {
// Map in order file.
ErrorOr<std::unique_ptr<MemoryBuffer>> mb =
MemoryBuffer::getFileOrSTDIN(orderFilePath);
if (std::error_code ec = mb.getError())
return ec;
ctx.addInputFileDependency(orderFilePath);
StringRef buffer = mb->get()->getBuffer();
while (!buffer.empty()) {
// Split off each line in the file.
std::pair<StringRef, StringRef> lineAndRest = buffer.split('\n');
StringRef line = lineAndRest.first;
buffer = lineAndRest.second;
// Ignore trailing # comments.
std::pair<StringRef, StringRef> symAndComment = line.split('#');
if (symAndComment.first.empty())
continue;
StringRef sym = symAndComment.first.trim();
if (sym.empty())
continue;
// Check for prefix.
StringRef prefix;
std::pair<StringRef, StringRef> prefixAndSym = sym.split(':');
if (!prefixAndSym.second.empty()) {
sym = prefixAndSym.second;
prefix = prefixAndSym.first;
if (!prefix.endswith(".o") && !prefix.endswith(".o)")) {
// If arch name prefix does not match arch being linked, ignore symbol.
if (!ctx.archName().equals(prefix))
continue;
prefix = "";
}
} else
sym = prefixAndSym.first;
if (!sym.empty()) {
ctx.appendOrderedSymbol(sym, prefix);
// llvm::errs() << sym << ", prefix=" << prefix << "\n";
}
}
return std::error_code();
}
//
// There are two variants of the -filelist option:
//
// -filelist <path>
// In this variant, the path is to a text file which contains one file path
// per line. There are no comments or trimming of whitespace.
//
// -fileList <path>,<dir>
// In this variant, the path is to a text file which contains a partial path
// per line. The <dir> prefix is prepended to each partial path.
//
static llvm::Error loadFileList(StringRef fileListPath,
MachOLinkingContext &ctx, bool forceLoad) {
// If there is a comma, split off <dir>.
std::pair<StringRef, StringRef> opt = fileListPath.split(',');
StringRef filePath = opt.first;
StringRef dirName = opt.second;
ctx.addInputFileDependency(filePath);
// Map in file list file.
ErrorOr<std::unique_ptr<MemoryBuffer>> mb =
MemoryBuffer::getFileOrSTDIN(filePath);
if (std::error_code ec = mb.getError())
return llvm::errorCodeToError(ec);
StringRef buffer = mb->get()->getBuffer();
while (!buffer.empty()) {
// Split off each line in the file.
std::pair<StringRef, StringRef> lineAndRest = buffer.split('\n');
StringRef line = lineAndRest.first;
StringRef path;
if (!dirName.empty()) {
// If there is a <dir> then prepend dir to each line.
SmallString<256> fullPath;
fullPath.assign(dirName);
llvm::sys::path::append(fullPath, Twine(line));
path = ctx.copy(fullPath.str());
} else {
// No <dir> use whole line as input file path.
path = ctx.copy(line);
}
if (!ctx.pathExists(path)) {
return llvm::make_error<GenericError>(Twine("File not found '")
+ path
+ "'");
}
if (ctx.testingFileUsage()) {
message("Found filelist entry " + canonicalizePath(path));
}
addFile(path, ctx, forceLoad, false);
buffer = lineAndRest.second;
}
return llvm::Error::success();
}
/// Parse number assuming it is base 16, but allow 0x prefix.
static bool parseNumberBase16(StringRef numStr, uint64_t &baseAddress) {
if (numStr.startswith_lower("0x"))
numStr = numStr.drop_front(2);
return numStr.getAsInteger(16, baseAddress);
}
static void parseLLVMOptions(const LinkingContext &ctx) {
// Honor -mllvm
if (!ctx.llvmOptions().empty()) {
unsigned numArgs = ctx.llvmOptions().size();
auto **args = new const char *[numArgs + 2];
args[0] = "lld (LLVM option parsing)";
for (unsigned i = 0; i != numArgs; ++i)
args[i + 1] = ctx.llvmOptions()[i];
args[numArgs + 1] = nullptr;
llvm::cl::ParseCommandLineOptions(numArgs + 1, args);
}
}
namespace lld {
namespace mach_o {
bool parse(llvm::ArrayRef<const char *> args, MachOLinkingContext &ctx) {
// Parse command line options using DarwinLdOptions.td
DarwinLdOptTable table;
unsigned missingIndex;
unsigned missingCount;
llvm::opt::InputArgList parsedArgs =
table.ParseArgs(args.slice(1), missingIndex, missingCount);
if (missingCount) {
error("missing arg value for '" +
Twine(parsedArgs.getArgString(missingIndex)) + "' expected " +
Twine(missingCount) + " argument(s).");
return false;
}
for (auto unknownArg : parsedArgs.filtered(OPT_UNKNOWN)) {
warn("ignoring unknown argument: " +
Twine(unknownArg->getAsString(parsedArgs)));
}
errorHandler().verbose = parsedArgs.hasArg(OPT_v);
errorHandler().errorLimit = args::getInteger(parsedArgs, OPT_error_limit, 20);
// Figure out output kind ( -dylib, -r, -bundle, -preload, or -static )
llvm::MachO::HeaderFileType fileType = llvm::MachO::MH_EXECUTE;
bool isStaticExecutable = false;
if (llvm::opt::Arg *kind = parsedArgs.getLastArg(
OPT_dylib, OPT_relocatable, OPT_bundle, OPT_static, OPT_preload)) {
switch (kind->getOption().getID()) {
case OPT_dylib:
fileType = llvm::MachO::MH_DYLIB;
break;
case OPT_relocatable:
fileType = llvm::MachO::MH_OBJECT;
break;
case OPT_bundle:
fileType = llvm::MachO::MH_BUNDLE;
break;
case OPT_static:
fileType = llvm::MachO::MH_EXECUTE;
isStaticExecutable = true;
break;
case OPT_preload:
fileType = llvm::MachO::MH_PRELOAD;
break;
}
}
// Handle -arch xxx
MachOLinkingContext::Arch arch = MachOLinkingContext::arch_unknown;
if (llvm::opt::Arg *archStr = parsedArgs.getLastArg(OPT_arch)) {
arch = MachOLinkingContext::archFromName(archStr->getValue());
if (arch == MachOLinkingContext::arch_unknown) {
error("unknown arch named '" + Twine(archStr->getValue()) + "'");
return false;
}
}
// If no -arch specified, scan input files to find first non-fat .o file.
if (arch == MachOLinkingContext::arch_unknown) {
for (auto &inFile : parsedArgs.filtered(OPT_INPUT)) {
// This is expensive because it opens and maps the file. But that is
// ok because no -arch is rare.
if (MachOLinkingContext::isThinObjectFile(inFile->getValue(), arch))
break;
}
if (arch == MachOLinkingContext::arch_unknown &&
!parsedArgs.getLastArg(OPT_test_file_usage)) {
// If no -arch and no options at all, print usage message.
if (parsedArgs.size() == 0) {
table.PrintHelp(llvm::outs(),
(std::string(args[0]) + " [options] file...").c_str(),
"LLVM Linker", false);
} else {
error("-arch not specified and could not be inferred");
}
return false;
}
}
// Handle -macosx_version_min or -ios_version_min
MachOLinkingContext::OS os = MachOLinkingContext::OS::unknown;
uint32_t minOSVersion = 0;
if (llvm::opt::Arg *minOS =
parsedArgs.getLastArg(OPT_macosx_version_min, OPT_ios_version_min,
OPT_ios_simulator_version_min)) {
switch (minOS->getOption().getID()) {
case OPT_macosx_version_min:
os = MachOLinkingContext::OS::macOSX;
if (MachOLinkingContext::parsePackedVersion(minOS->getValue(),
minOSVersion)) {
error("malformed macosx_version_min value");
return false;
}
break;
case OPT_ios_version_min:
os = MachOLinkingContext::OS::iOS;
if (MachOLinkingContext::parsePackedVersion(minOS->getValue(),
minOSVersion)) {
error("malformed ios_version_min value");
return false;
}
break;
case OPT_ios_simulator_version_min:
os = MachOLinkingContext::OS::iOS_simulator;
if (MachOLinkingContext::parsePackedVersion(minOS->getValue(),
minOSVersion)) {
error("malformed ios_simulator_version_min value");
return false;
}
break;
}
} else {
// No min-os version on command line, check environment variables
}
// Handle export_dynamic
// FIXME: Should we warn when this applies to something other than a static
// executable or dylib? Those are the only cases where this has an effect.
// Note, this has to come before ctx.configure() so that we get the correct
// value for _globalsAreDeadStripRoots.
bool exportDynamicSymbols = parsedArgs.hasArg(OPT_export_dynamic);
// Now that there's enough information parsed in, let the linking context
// set up default values.
ctx.configure(fileType, arch, os, minOSVersion, exportDynamicSymbols);
// Handle -e xxx
if (llvm::opt::Arg *entry = parsedArgs.getLastArg(OPT_entry))
ctx.setEntrySymbolName(entry->getValue());
// Handle -o xxx
if (llvm::opt::Arg *outpath = parsedArgs.getLastArg(OPT_output))
ctx.setOutputPath(outpath->getValue());
else
ctx.setOutputPath("a.out");
// Handle -image_base XXX and -seg1addr XXXX
if (llvm::opt::Arg *imageBase = parsedArgs.getLastArg(OPT_image_base)) {
uint64_t baseAddress;
if (parseNumberBase16(imageBase->getValue(), baseAddress)) {
error("image_base expects a hex number");
return false;
} else if (baseAddress < ctx.pageZeroSize()) {
error("image_base overlaps with __PAGEZERO");
return false;
} else if (baseAddress % ctx.pageSize()) {
error("image_base must be a multiple of page size (0x" +
llvm::utohexstr(ctx.pageSize()) + ")");
return false;
}
ctx.setBaseAddress(baseAddress);
}
// Handle -dead_strip
if (parsedArgs.getLastArg(OPT_dead_strip))
ctx.setDeadStripping(true);
bool globalWholeArchive = false;
// Handle -all_load
if (parsedArgs.getLastArg(OPT_all_load))
globalWholeArchive = true;
// Handle -install_name
if (llvm::opt::Arg *installName = parsedArgs.getLastArg(OPT_install_name))
ctx.setInstallName(installName->getValue());
else
ctx.setInstallName(ctx.outputPath());
// Handle -mark_dead_strippable_dylib
if (parsedArgs.getLastArg(OPT_mark_dead_strippable_dylib))
ctx.setDeadStrippableDylib(true);
// Handle -compatibility_version and -current_version
if (llvm::opt::Arg *vers = parsedArgs.getLastArg(OPT_compatibility_version)) {
if (ctx.outputMachOType() != llvm::MachO::MH_DYLIB) {
error("-compatibility_version can only be used with -dylib");
return false;
}
uint32_t parsedVers;
if (MachOLinkingContext::parsePackedVersion(vers->getValue(), parsedVers)) {
error("-compatibility_version value is malformed");
return false;
}
ctx.setCompatibilityVersion(parsedVers);
}
if (llvm::opt::Arg *vers = parsedArgs.getLastArg(OPT_current_version)) {
if (ctx.outputMachOType() != llvm::MachO::MH_DYLIB) {
error("-current_version can only be used with -dylib");
return false;
}
uint32_t parsedVers;
if (MachOLinkingContext::parsePackedVersion(vers->getValue(), parsedVers)) {
error("-current_version value is malformed");
return false;
}
ctx.setCurrentVersion(parsedVers);
}
// Handle -bundle_loader
if (llvm::opt::Arg *loader = parsedArgs.getLastArg(OPT_bundle_loader))
ctx.setBundleLoader(loader->getValue());
// Handle -sectalign segname sectname align
for (auto &alignArg : parsedArgs.filtered(OPT_sectalign)) {
const char* segName = alignArg->getValue(0);
const char* sectName = alignArg->getValue(1);
const char* alignStr = alignArg->getValue(2);
if ((alignStr[0] == '0') && (alignStr[1] == 'x'))
alignStr += 2;
unsigned long long alignValue;
if (llvm::getAsUnsignedInteger(alignStr, 16, alignValue)) {
error("-sectalign alignment value '" + Twine(alignStr) +
"' not a valid number");
return false;
}
uint16_t align = 1 << llvm::countTrailingZeros(alignValue);
if (!llvm::isPowerOf2_64(alignValue)) {
std::string Msg;
llvm::raw_string_ostream OS(Msg);
OS << "alignment for '-sectalign " << segName << " " << sectName
<< llvm::format(" 0x%llX", alignValue)
<< "' is not a power of two, using " << llvm::format("0x%08X", align);
OS.flush();
warn(Msg);
}
ctx.addSectionAlignment(segName, sectName, align);
}
// Handle -mllvm
for (auto &llvmArg : parsedArgs.filtered(OPT_mllvm)) {
ctx.appendLLVMOption(llvmArg->getValue());
}
// Handle -print_atoms
if (parsedArgs.getLastArg(OPT_print_atoms))
ctx.setPrintAtoms();
// Handle -t (trace) option.
if (parsedArgs.getLastArg(OPT_t))
ctx.setLogInputFiles(true);
// Handle -demangle option.
if (parsedArgs.getLastArg(OPT_demangle))
ctx.setDemangleSymbols(true);
// Handle -keep_private_externs
if (parsedArgs.getLastArg(OPT_keep_private_externs)) {
ctx.setKeepPrivateExterns(true);
if (ctx.outputMachOType() != llvm::MachO::MH_OBJECT)
warn("-keep_private_externs only used in -r mode");
}
// Handle -dependency_info <path> used by Xcode.
if (llvm::opt::Arg *depInfo = parsedArgs.getLastArg(OPT_dependency_info))
if (std::error_code ec = ctx.createDependencyFile(depInfo->getValue()))
warn(ec.message() + ", processing '-dependency_info " +
depInfo->getValue());
// In -test_file_usage mode, we'll be given an explicit list of paths that
// exist. We'll also be expected to print out information about how we located
// libraries and so on that the user specified, but not to actually do any
// linking.
if (parsedArgs.getLastArg(OPT_test_file_usage)) {
ctx.setTestingFileUsage();
// With paths existing by fiat, linking is not going to end well.
ctx.setDoNothing(true);
// Only bother looking for an existence override if we're going to use it.
for (auto existingPath : parsedArgs.filtered(OPT_path_exists)) {
ctx.addExistingPathForDebug(existingPath->getValue());
}
}
// Register possible input file parsers.
if (!ctx.doNothing()) {
ctx.registry().addSupportMachOObjects(ctx);
ctx.registry().addSupportArchives(ctx.logInputFiles());
ctx.registry().addSupportYamlFiles();
}
// Now construct the set of library search directories, following ld64's
// baroque set of accumulated hacks. Mostly, the algorithm constructs
// { syslibroots } x { libpaths }
//
// Unfortunately, there are numerous exceptions:
// 1. Only absolute paths get modified by syslibroot options.
// 2. If there is just 1 -syslibroot, system paths not found in it are
// skipped.
// 3. If the last -syslibroot is "/", all of them are ignored entirely.
// 4. If { syslibroots } x path == {}, the original path is kept.
std::vector<StringRef> sysLibRoots;
for (auto syslibRoot : parsedArgs.filtered(OPT_syslibroot)) {
sysLibRoots.push_back(syslibRoot->getValue());
}
if (!sysLibRoots.empty()) {
// Ignore all if last -syslibroot is "/".
if (sysLibRoots.back() != "/")
ctx.setSysLibRoots(sysLibRoots);
}
// Paths specified with -L come first, and are not considered system paths for
// the case where there is precisely 1 -syslibroot.
for (auto libPath : parsedArgs.filtered(OPT_L)) {
ctx.addModifiedSearchDir(libPath->getValue());
}
// Process -F directories (where to look for frameworks).
for (auto fwPath : parsedArgs.filtered(OPT_F)) {
ctx.addFrameworkSearchDir(fwPath->getValue());
}
// -Z suppresses the standard search paths.
if (!parsedArgs.hasArg(OPT_Z)) {
ctx.addModifiedSearchDir("/usr/lib", true);
ctx.addModifiedSearchDir("/usr/local/lib", true);
ctx.addFrameworkSearchDir("/Library/Frameworks", true);
ctx.addFrameworkSearchDir("/System/Library/Frameworks", true);
}
// Now that we've constructed the final set of search paths, print out those
// search paths in verbose mode.
if (errorHandler().verbose) {
message("Library search paths:");
for (auto path : ctx.searchDirs()) {
message(" " + path);
}
message("Framework search paths:");
for (auto path : ctx.frameworkDirs()) {
message(" " + path);
}
}
// Handle -exported_symbols_list <file>
for (auto expFile : parsedArgs.filtered(OPT_exported_symbols_list)) {
if (ctx.exportMode() == MachOLinkingContext::ExportMode::blackList) {
error("-exported_symbols_list cannot be combined with "
"-unexported_symbol[s_list]");
return false;
}
ctx.setExportMode(MachOLinkingContext::ExportMode::whiteList);
if (std::error_code ec = parseExportsList(expFile->getValue(), ctx)) {
error(ec.message() + ", processing '-exported_symbols_list " +
expFile->getValue());
return false;
}
}
// Handle -exported_symbol <symbol>
for (auto symbol : parsedArgs.filtered(OPT_exported_symbol)) {
if (ctx.exportMode() == MachOLinkingContext::ExportMode::blackList) {
error("-exported_symbol cannot be combined with "
"-unexported_symbol[s_list]");
return false;
}
ctx.setExportMode(MachOLinkingContext::ExportMode::whiteList);
ctx.addExportSymbol(symbol->getValue());
}
// Handle -unexported_symbols_list <file>
for (auto expFile : parsedArgs.filtered(OPT_unexported_symbols_list)) {
if (ctx.exportMode() == MachOLinkingContext::ExportMode::whiteList) {
error("-unexported_symbols_list cannot be combined with "
"-exported_symbol[s_list]");
return false;
}
ctx.setExportMode(MachOLinkingContext::ExportMode::blackList);
if (std::error_code ec = parseExportsList(expFile->getValue(), ctx)) {
error(ec.message() + ", processing '-unexported_symbols_list " +
expFile->getValue());
return false;
}
}
// Handle -unexported_symbol <symbol>
for (auto symbol : parsedArgs.filtered(OPT_unexported_symbol)) {
if (ctx.exportMode() == MachOLinkingContext::ExportMode::whiteList) {
error("-unexported_symbol cannot be combined with "
"-exported_symbol[s_list]");
return false;
}
ctx.setExportMode(MachOLinkingContext::ExportMode::blackList);
ctx.addExportSymbol(symbol->getValue());
}
// Handle obosolete -multi_module and -single_module
if (llvm::opt::Arg *mod =
parsedArgs.getLastArg(OPT_multi_module, OPT_single_module)) {
if (mod->getOption().getID() == OPT_multi_module)
warn("-multi_module is obsolete and being ignored");
else if (ctx.outputMachOType() != llvm::MachO::MH_DYLIB)
warn("-single_module being ignored. It is only for use when producing a "
"dylib");
}
// Handle obsolete ObjC options: -objc_gc_compaction, -objc_gc, -objc_gc_only
if (parsedArgs.getLastArg(OPT_objc_gc_compaction)) {
error("-objc_gc_compaction is not supported");
return false;
}
if (parsedArgs.getLastArg(OPT_objc_gc)) {
error("-objc_gc is not supported");
return false;
}
if (parsedArgs.getLastArg(OPT_objc_gc_only)) {
error("-objc_gc_only is not supported");
return false;
}
// Handle -pie or -no_pie
if (llvm::opt::Arg *pie = parsedArgs.getLastArg(OPT_pie, OPT_no_pie)) {
switch (ctx.outputMachOType()) {
case llvm::MachO::MH_EXECUTE:
switch (ctx.os()) {
case MachOLinkingContext::OS::macOSX:
if ((minOSVersion < 0x000A0500) &&
(pie->getOption().getID() == OPT_pie)) {
error("-pie can only be used when targeting Mac OS X 10.5 or later");
return false;
}
break;
case MachOLinkingContext::OS::iOS:
if ((minOSVersion < 0x00040200) &&
(pie->getOption().getID() == OPT_pie)) {
error("-pie can only be used when targeting iOS 4.2 or later");
return false;
}
break;
case MachOLinkingContext::OS::iOS_simulator:
if (pie->getOption().getID() == OPT_no_pie) {
error("iOS simulator programs must be built PIE");
return false;
}
break;
case MachOLinkingContext::OS::unknown:
break;
}
ctx.setPIE(pie->getOption().getID() == OPT_pie);
break;
case llvm::MachO::MH_PRELOAD:
break;
case llvm::MachO::MH_DYLIB:
case llvm::MachO::MH_BUNDLE:
warn(pie->getSpelling() +
" being ignored. It is only used when linking main executables");
break;
default:
error(pie->getSpelling() +
" can only used when linking main executables");
return false;
}
}
// Handle -version_load_command or -no_version_load_command
{
bool flagOn = false;
bool flagOff = false;
if (auto *arg = parsedArgs.getLastArg(OPT_version_load_command,
OPT_no_version_load_command)) {
flagOn = arg->getOption().getID() == OPT_version_load_command;
flagOff = arg->getOption().getID() == OPT_no_version_load_command;
}
// default to adding version load command for dynamic code,
// static code must opt-in
switch (ctx.outputMachOType()) {
case llvm::MachO::MH_OBJECT:
ctx.setGenerateVersionLoadCommand(false);
break;
case llvm::MachO::MH_EXECUTE:
// dynamic executables default to generating a version load command,
// while static executables only generate it if required.
if (isStaticExecutable) {
if (flagOn)
ctx.setGenerateVersionLoadCommand(true);
} else {
if (!flagOff)
ctx.setGenerateVersionLoadCommand(true);
}
break;
case llvm::MachO::MH_PRELOAD:
case llvm::MachO::MH_KEXT_BUNDLE:
if (flagOn)
ctx.setGenerateVersionLoadCommand(true);
break;
case llvm::MachO::MH_DYLINKER:
case llvm::MachO::MH_DYLIB:
case llvm::MachO::MH_BUNDLE:
if (!flagOff)
ctx.setGenerateVersionLoadCommand(true);
break;
case llvm::MachO::MH_FVMLIB:
case llvm::MachO::MH_DYLDLINK:
case llvm::MachO::MH_DYLIB_STUB:
case llvm::MachO::MH_DSYM:
// We don't generate load commands for these file types, even if
// forced on.
break;
}
}
// Handle -function_starts or -no_function_starts
{
bool flagOn = false;
bool flagOff = false;
if (auto *arg = parsedArgs.getLastArg(OPT_function_starts,
OPT_no_function_starts)) {
flagOn = arg->getOption().getID() == OPT_function_starts;
flagOff = arg->getOption().getID() == OPT_no_function_starts;
}
// default to adding functions start for dynamic code, static code must
// opt-in
switch (ctx.outputMachOType()) {
case llvm::MachO::MH_OBJECT:
ctx.setGenerateFunctionStartsLoadCommand(false);
break;
case llvm::MachO::MH_EXECUTE:
// dynamic executables default to generating a version load command,
// while static executables only generate it if required.
if (isStaticExecutable) {
if (flagOn)
ctx.setGenerateFunctionStartsLoadCommand(true);
} else {
if (!flagOff)
ctx.setGenerateFunctionStartsLoadCommand(true);
}
break;
case llvm::MachO::MH_PRELOAD:
case llvm::MachO::MH_KEXT_BUNDLE:
if (flagOn)
ctx.setGenerateFunctionStartsLoadCommand(true);
break;
case llvm::MachO::MH_DYLINKER:
case llvm::MachO::MH_DYLIB:
case llvm::MachO::MH_BUNDLE:
if (!flagOff)
ctx.setGenerateFunctionStartsLoadCommand(true);
break;
case llvm::MachO::MH_FVMLIB:
case llvm::MachO::MH_DYLDLINK:
case llvm::MachO::MH_DYLIB_STUB:
case llvm::MachO::MH_DSYM:
// We don't generate load commands for these file types, even if
// forced on.
break;
}
}
// Handle -data_in_code_info or -no_data_in_code_info
{
bool flagOn = false;
bool flagOff = false;
if (auto *arg = parsedArgs.getLastArg(OPT_data_in_code_info,
OPT_no_data_in_code_info)) {
flagOn = arg->getOption().getID() == OPT_data_in_code_info;
flagOff = arg->getOption().getID() == OPT_no_data_in_code_info;
}
// default to adding data in code for dynamic code, static code must
// opt-in
switch (ctx.outputMachOType()) {
case llvm::MachO::MH_OBJECT:
if (!flagOff)
ctx.setGenerateDataInCodeLoadCommand(true);
break;
case llvm::MachO::MH_EXECUTE:
// dynamic executables default to generating a version load command,
// while static executables only generate it if required.
if (isStaticExecutable) {
if (flagOn)
ctx.setGenerateDataInCodeLoadCommand(true);
} else {
if (!flagOff)
ctx.setGenerateDataInCodeLoadCommand(true);
}
break;
case llvm::MachO::MH_PRELOAD:
case llvm::MachO::MH_KEXT_BUNDLE:
if (flagOn)
ctx.setGenerateDataInCodeLoadCommand(true);
break;
case llvm::MachO::MH_DYLINKER:
case llvm::MachO::MH_DYLIB:
case llvm::MachO::MH_BUNDLE:
if (!flagOff)
ctx.setGenerateDataInCodeLoadCommand(true);
break;
case llvm::MachO::MH_FVMLIB:
case llvm::MachO::MH_DYLDLINK:
case llvm::MachO::MH_DYLIB_STUB:
case llvm::MachO::MH_DSYM:
// We don't generate load commands for these file types, even if
// forced on.
break;
}
}
// Handle sdk_version
if (llvm::opt::Arg *arg = parsedArgs.getLastArg(OPT_sdk_version)) {
uint32_t sdkVersion = 0;
if (MachOLinkingContext::parsePackedVersion(arg->getValue(),
sdkVersion)) {
error("malformed sdkVersion value");
return false;
}
ctx.setSdkVersion(sdkVersion);
} else if (ctx.generateVersionLoadCommand()) {
// If we don't have an sdk version, but were going to emit a load command
// with min_version, then we need to give a warning as we have no sdk
// version to put in that command.
// FIXME: We need to decide whether to make this an error.
warn("-sdk_version is required when emitting min version load command. "
"Setting sdk version to match provided min version");
ctx.setSdkVersion(ctx.osMinVersion());
}
// Handle source_version
if (llvm::opt::Arg *arg = parsedArgs.getLastArg(OPT_source_version)) {
uint64_t version = 0;
if (MachOLinkingContext::parsePackedVersion(arg->getValue(),
version)) {
error("malformed source_version value");
return false;
}
ctx.setSourceVersion(version);
}
// Handle stack_size
if (llvm::opt::Arg *stackSize = parsedArgs.getLastArg(OPT_stack_size)) {
uint64_t stackSizeVal;
if (parseNumberBase16(stackSize->getValue(), stackSizeVal)) {
error("stack_size expects a hex number");
return false;
}
if ((stackSizeVal % ctx.pageSize()) != 0) {
error("stack_size must be a multiple of page size (0x" +
llvm::utohexstr(ctx.pageSize()) + ")");
return false;
}
ctx.setStackSize(stackSizeVal);
}
// Handle debug info handling options: -S
if (parsedArgs.hasArg(OPT_S))
ctx.setDebugInfoMode(MachOLinkingContext::DebugInfoMode::noDebugMap);
// Handle -order_file <file>
for (auto orderFile : parsedArgs.filtered(OPT_order_file)) {
if (std::error_code ec = parseOrderFile(orderFile->getValue(), ctx)) {
error(ec.message() + ", processing '-order_file " + orderFile->getValue()
+ "'");
return false;
}
}
// Handle -flat_namespace.
if (llvm::opt::Arg *ns =
parsedArgs.getLastArg(OPT_flat_namespace, OPT_twolevel_namespace)) {
if (ns->getOption().getID() == OPT_flat_namespace)
ctx.setUseFlatNamespace(true);
}
// Handle -undefined
if (llvm::opt::Arg *undef = parsedArgs.getLastArg(OPT_undefined)) {
MachOLinkingContext::UndefinedMode UndefMode;
if (StringRef(undef->getValue()).equals("error"))
UndefMode = MachOLinkingContext::UndefinedMode::error;
else if (StringRef(undef->getValue()).equals("warning"))
UndefMode = MachOLinkingContext::UndefinedMode::warning;
else if (StringRef(undef->getValue()).equals("suppress"))
UndefMode = MachOLinkingContext::UndefinedMode::suppress;
else if (StringRef(undef->getValue()).equals("dynamic_lookup"))
UndefMode = MachOLinkingContext::UndefinedMode::dynamicLookup;
else {
error("invalid option to -undefined [ warning | error | suppress | "
"dynamic_lookup ]");
return false;
}
if (ctx.useFlatNamespace()) {
// If we're using -flat_namespace then 'warning', 'suppress' and
// 'dynamic_lookup' are all equivalent, so map them to 'suppress'.
if (UndefMode != MachOLinkingContext::UndefinedMode::error)
UndefMode = MachOLinkingContext::UndefinedMode::suppress;
} else {
// If we're using -twolevel_namespace then 'warning' and 'suppress' are
// illegal. Emit a diagnostic if they've been (mis)used.
if (UndefMode == MachOLinkingContext::UndefinedMode::warning ||
UndefMode == MachOLinkingContext::UndefinedMode::suppress) {
error("can't use -undefined warning or suppress with "
"-twolevel_namespace");
return false;
}
}
ctx.setUndefinedMode(UndefMode);
}
// Handle -no_objc_category_merging.
if (parsedArgs.getLastArg(OPT_no_objc_category_merging))
ctx.setMergeObjCCategories(false);
// Handle -rpath <path>
if (parsedArgs.hasArg(OPT_rpath)) {
switch (ctx.outputMachOType()) {
case llvm::MachO::MH_EXECUTE:
case llvm::MachO::MH_DYLIB:
case llvm::MachO::MH_BUNDLE:
if (!ctx.minOS("10.5", "2.0")) {
if (ctx.os() == MachOLinkingContext::OS::macOSX)
error("-rpath can only be used when targeting OS X 10.5 or later");
else
error("-rpath can only be used when targeting iOS 2.0 or later");
return false;
}
break;
default:
error("-rpath can only be used when creating a dynamic final linked "
"image");
return false;
}
for (auto rPath : parsedArgs.filtered(OPT_rpath)) {
ctx.addRpath(rPath->getValue());
}
}
// Parse the LLVM options before we process files in case the file handling
// makes use of things like LLVM_DEBUG().
parseLLVMOptions(ctx);
// Handle input files and sectcreate.
for (auto &arg : parsedArgs) {
bool upward;
llvm::Optional<StringRef> resolvedPath;
switch (arg->getOption().getID()) {
default:
continue;
case OPT_INPUT:
addFile(arg->getValue(), ctx, globalWholeArchive, false);
break;
case OPT_upward_library:
addFile(arg->getValue(), ctx, false, true);
break;
case OPT_force_load:
addFile(arg->getValue(), ctx, true, false);
break;
case OPT_l:
case OPT_upward_l:
upward = (arg->getOption().getID() == OPT_upward_l);
resolvedPath = ctx.searchLibrary(arg->getValue());
if (!resolvedPath) {
error("Unable to find library for " + arg->getSpelling() +
arg->getValue());
return false;
} else if (ctx.testingFileUsage()) {
message(Twine("Found ") + (upward ? "upward " : " ") + "library " +
canonicalizePath(resolvedPath.getValue()));
}
addFile(resolvedPath.getValue(), ctx, globalWholeArchive, upward);
break;
case OPT_framework:
case OPT_upward_framework:
upward = (arg->getOption().getID() == OPT_upward_framework);
resolvedPath = ctx.findPathForFramework(arg->getValue());
if (!resolvedPath) {
error("Unable to find framework for " + arg->getSpelling() + " " +
arg->getValue());
return false;
} else if (ctx.testingFileUsage()) {
message(Twine("Found ") + (upward ? "upward " : " ") + "framework " +
canonicalizePath(resolvedPath.getValue()));
}
addFile(resolvedPath.getValue(), ctx, globalWholeArchive, upward);
break;
case OPT_filelist:
if (auto ec = loadFileList(arg->getValue(), ctx, globalWholeArchive)) {
handleAllErrors(std::move(ec), [&](const llvm::ErrorInfoBase &EI) {
error(EI.message() + ", processing '-filelist " + arg->getValue());
});
return false;
}
break;
case OPT_sectcreate: {
const char* seg = arg->getValue(0);
const char* sect = arg->getValue(1);
const char* fileName = arg->getValue(2);
ErrorOr<std::unique_ptr<MemoryBuffer>> contentOrErr =
MemoryBuffer::getFile(fileName);
if (!contentOrErr) {
error("can't open -sectcreate file " + Twine(fileName));
return false;
}
ctx.addSectCreateSection(seg, sect, std::move(*contentOrErr));
}
break;
}
}
if (ctx.getNodes().empty()) {
error("No input files");
return false;
}
// Validate the combination of options used.
return ctx.validate();
}
static void createFiles(MachOLinkingContext &ctx, bool Implicit) {
std::vector<std::unique_ptr<File>> Files;
if (Implicit)
ctx.createImplicitFiles(Files);
else
ctx.createInternalFiles(Files);
for (auto i = Files.rbegin(), e = Files.rend(); i != e; ++i) {
auto &members = ctx.getNodes();
members.insert(members.begin(), std::make_unique<FileNode>(std::move(*i)));
}
}
/// This is where the link is actually performed.
bool link(llvm::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());
MachOLinkingContext ctx;
if (!parse(args, ctx))
return false;
if (ctx.doNothing())
return true;
if (ctx.getNodes().empty())
return false;
for (std::unique_ptr<Node> &ie : ctx.getNodes())
if (FileNode *node = dyn_cast<FileNode>(ie.get()))
node->getFile()->parse();
createFiles(ctx, false /* Implicit */);
// Give target a chance to add files
createFiles(ctx, true /* Implicit */);
// Give target a chance to postprocess input files.
// Mach-O uses this chance to move all object files before library files.
ctx.finalizeInputFiles();
// Do core linking.
ScopedTask resolveTask(getDefaultDomain(), "Resolve");
Resolver resolver(ctx);
if (!resolver.resolve())
return false;
SimpleFile *merged = nullptr;
{
std::unique_ptr<SimpleFile> mergedFile = resolver.resultFile();
merged = mergedFile.get();
auto &members = ctx.getNodes();
members.insert(members.begin(),
std::make_unique<FileNode>(std::move(mergedFile)));
}
resolveTask.end();
// Run passes on linked atoms.
ScopedTask passTask(getDefaultDomain(), "Passes");
PassManager pm;
ctx.addPasses(pm);
if (auto ec = pm.runOnFile(*merged)) {
// FIXME: This should be passed to logAllUnhandledErrors but it needs
// to be passed a Twine instead of a string.
lld::errs() << "Failed to run passes on file '" << ctx.outputPath()
<< "': ";
logAllUnhandledErrors(std::move(ec), lld::errs(), std::string());
return false;
}
passTask.end();
// Give linked atoms to Writer to generate output file.
ScopedTask writeTask(getDefaultDomain(), "Write");
if (auto ec = ctx.writeFile(*merged)) {
// FIXME: This should be passed to logAllUnhandledErrors but it needs
// to be passed a Twine instead of a string.
lld::errs() << "Failed to write file '" << ctx.outputPath() << "': ";
logAllUnhandledErrors(std::move(ec), lld::errs(), std::string());
return false;
}
// Call exit() if we can to avoid calling destructors.
if (CanExitEarly)
exitLld(errorCount() ? 1 : 0);
return true;
}
} // end namespace mach_o
} // end namespace lld
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