blob: fc8eb327be49bdd9739d884f8ad5b3b5136a01fa [file] [log] [blame]
//===- DriverUtils.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
//
//===----------------------------------------------------------------------===//
//
// This file contains utility functions for the driver. Because there
// are so many small functions, we created this separate file to make
// Driver.cpp less cluttered.
//
//===----------------------------------------------------------------------===//
#include "COFFLinkerContext.h"
#include "Driver.h"
#include "Symbols.h"
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/Memory.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/Object/COFF.h"
#include "llvm/Object/WindowsResource.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Option/Option.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/WindowsManifest/WindowsManifestMerger.h"
#include <limits>
#include <memory>
#include <optional>
using namespace llvm::COFF;
using namespace llvm::opt;
using namespace llvm;
using llvm::sys::Process;
namespace lld {
namespace coff {
namespace {
const uint16_t SUBLANG_ENGLISH_US = 0x0409;
const uint16_t RT_MANIFEST = 24;
class Executor {
public:
explicit Executor(StringRef s) : prog(saver().save(s)) {}
void add(StringRef s) { args.push_back(saver().save(s)); }
void add(std::string &s) { args.push_back(saver().save(s)); }
void add(Twine s) { args.push_back(saver().save(s)); }
void add(const char *s) { args.push_back(saver().save(s)); }
void run() {
ErrorOr<std::string> exeOrErr = sys::findProgramByName(prog);
if (auto ec = exeOrErr.getError())
fatal("unable to find " + prog + " in PATH: " + ec.message());
StringRef exe = saver().save(*exeOrErr);
args.insert(args.begin(), exe);
if (sys::ExecuteAndWait(args[0], args) != 0)
fatal("ExecuteAndWait failed: " +
llvm::join(args.begin(), args.end(), " "));
}
private:
StringRef prog;
std::vector<StringRef> args;
};
} // anonymous namespace
// Parses a string in the form of "<integer>[,<integer>]".
void LinkerDriver::parseNumbers(StringRef arg, uint64_t *addr, uint64_t *size) {
auto [s1, s2] = arg.split(',');
if (s1.getAsInteger(0, *addr))
fatal("invalid number: " + s1);
if (size && !s2.empty() && s2.getAsInteger(0, *size))
fatal("invalid number: " + s2);
}
// Parses a string in the form of "<integer>[.<integer>]".
// If second number is not present, Minor is set to 0.
void LinkerDriver::parseVersion(StringRef arg, uint32_t *major,
uint32_t *minor) {
auto [s1, s2] = arg.split('.');
if (s1.getAsInteger(10, *major))
fatal("invalid number: " + s1);
*minor = 0;
if (!s2.empty() && s2.getAsInteger(10, *minor))
fatal("invalid number: " + s2);
}
void LinkerDriver::parseGuard(StringRef fullArg) {
SmallVector<StringRef, 1> splitArgs;
fullArg.split(splitArgs, ",");
for (StringRef arg : splitArgs) {
if (arg.equals_insensitive("no"))
ctx.config.guardCF = GuardCFLevel::Off;
else if (arg.equals_insensitive("nolongjmp"))
ctx.config.guardCF &= ~GuardCFLevel::LongJmp;
else if (arg.equals_insensitive("noehcont"))
ctx.config.guardCF &= ~GuardCFLevel::EHCont;
else if (arg.equals_insensitive("cf") || arg.equals_insensitive("longjmp"))
ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::LongJmp;
else if (arg.equals_insensitive("ehcont"))
ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::EHCont;
else
fatal("invalid argument to /guard: " + arg);
}
}
// Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
void LinkerDriver::parseSubsystem(StringRef arg, WindowsSubsystem *sys,
uint32_t *major, uint32_t *minor,
bool *gotVersion) {
auto [sysStr, ver] = arg.split(',');
std::string sysStrLower = sysStr.lower();
*sys = StringSwitch<WindowsSubsystem>(sysStrLower)
.Case("boot_application", IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
.Case("console", IMAGE_SUBSYSTEM_WINDOWS_CUI)
.Case("default", IMAGE_SUBSYSTEM_UNKNOWN)
.Case("efi_application", IMAGE_SUBSYSTEM_EFI_APPLICATION)
.Case("efi_boot_service_driver", IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
.Case("efi_rom", IMAGE_SUBSYSTEM_EFI_ROM)
.Case("efi_runtime_driver", IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
.Case("native", IMAGE_SUBSYSTEM_NATIVE)
.Case("posix", IMAGE_SUBSYSTEM_POSIX_CUI)
.Case("windows", IMAGE_SUBSYSTEM_WINDOWS_GUI)
.Default(IMAGE_SUBSYSTEM_UNKNOWN);
if (*sys == IMAGE_SUBSYSTEM_UNKNOWN && sysStrLower != "default")
fatal("unknown subsystem: " + sysStr);
if (!ver.empty())
parseVersion(ver, major, minor);
if (gotVersion)
*gotVersion = !ver.empty();
}
// Parse a string of the form of "<from>=<to>".
// Results are directly written to Config.
void LinkerDriver::parseAlternateName(StringRef s) {
auto [from, to] = s.split('=');
if (from.empty() || to.empty())
fatal("/alternatename: invalid argument: " + s);
auto it = ctx.config.alternateNames.find(from);
if (it != ctx.config.alternateNames.end() && it->second != to)
fatal("/alternatename: conflicts: " + s);
ctx.config.alternateNames.insert(it, std::make_pair(from, to));
}
// Parse a string of the form of "<from>=<to>".
// Results are directly written to Config.
void LinkerDriver::parseMerge(StringRef s) {
auto [from, to] = s.split('=');
if (from.empty() || to.empty())
fatal("/merge: invalid argument: " + s);
if (from == ".rsrc" || to == ".rsrc")
fatal("/merge: cannot merge '.rsrc' with any section");
if (from == ".reloc" || to == ".reloc")
fatal("/merge: cannot merge '.reloc' with any section");
auto pair = ctx.config.merge.insert(std::make_pair(from, to));
bool inserted = pair.second;
if (!inserted) {
StringRef existing = pair.first->second;
if (existing != to)
warn(s + ": already merged into " + existing);
}
}
void LinkerDriver::parsePDBPageSize(StringRef s) {
int v;
if (s.getAsInteger(0, v)) {
error("/pdbpagesize: invalid argument: " + s);
return;
}
if (v != 4096 && v != 8192 && v != 16384 && v != 32768) {
error("/pdbpagesize: invalid argument: " + s);
return;
}
ctx.config.pdbPageSize = v;
}
static uint32_t parseSectionAttributes(StringRef s) {
uint32_t ret = 0;
for (char c : s.lower()) {
switch (c) {
case 'd':
ret |= IMAGE_SCN_MEM_DISCARDABLE;
break;
case 'e':
ret |= IMAGE_SCN_MEM_EXECUTE;
break;
case 'k':
ret |= IMAGE_SCN_MEM_NOT_CACHED;
break;
case 'p':
ret |= IMAGE_SCN_MEM_NOT_PAGED;
break;
case 'r':
ret |= IMAGE_SCN_MEM_READ;
break;
case 's':
ret |= IMAGE_SCN_MEM_SHARED;
break;
case 'w':
ret |= IMAGE_SCN_MEM_WRITE;
break;
default:
fatal("/section: invalid argument: " + s);
}
}
return ret;
}
// Parses /section option argument.
void LinkerDriver::parseSection(StringRef s) {
auto [name, attrs] = s.split(',');
if (name.empty() || attrs.empty())
fatal("/section: invalid argument: " + s);
ctx.config.section[name] = parseSectionAttributes(attrs);
}
// Parses /aligncomm option argument.
void LinkerDriver::parseAligncomm(StringRef s) {
auto [name, align] = s.split(',');
if (name.empty() || align.empty()) {
error("/aligncomm: invalid argument: " + s);
return;
}
int v;
if (align.getAsInteger(0, v)) {
error("/aligncomm: invalid argument: " + s);
return;
}
ctx.config.alignComm[std::string(name)] =
std::max(ctx.config.alignComm[std::string(name)], 1 << v);
}
// Parses /functionpadmin option argument.
void LinkerDriver::parseFunctionPadMin(llvm::opt::Arg *a) {
StringRef arg = a->getNumValues() ? a->getValue() : "";
if (!arg.empty()) {
// Optional padding in bytes is given.
if (arg.getAsInteger(0, ctx.config.functionPadMin))
error("/functionpadmin: invalid argument: " + arg);
return;
}
// No optional argument given.
// Set default padding based on machine, similar to link.exe.
// There is no default padding for ARM platforms.
if (ctx.config.machine == I386) {
ctx.config.functionPadMin = 5;
} else if (ctx.config.machine == AMD64) {
ctx.config.functionPadMin = 6;
} else {
error("/functionpadmin: invalid argument for this machine: " + arg);
}
}
// Parses /dependentloadflag option argument.
void LinkerDriver::parseDependentLoadFlags(llvm::opt::Arg *a) {
StringRef arg = a->getNumValues() ? a->getValue() : "";
if (!arg.empty()) {
if (arg.getAsInteger(0, ctx.config.dependentLoadFlags))
error("/dependentloadflag: invalid argument: " + arg);
return;
}
// MSVC linker reports error "no argument specified", although MSDN describes
// argument as optional.
error("/dependentloadflag: no argument specified");
}
// Parses a string in the form of "EMBED[,=<integer>]|NO".
// Results are directly written to
// Config.
void LinkerDriver::parseManifest(StringRef arg) {
if (arg.equals_insensitive("no")) {
ctx.config.manifest = Configuration::No;
return;
}
if (!arg.starts_with_insensitive("embed"))
fatal("invalid option " + arg);
ctx.config.manifest = Configuration::Embed;
arg = arg.substr(strlen("embed"));
if (arg.empty())
return;
if (!arg.starts_with_insensitive(",id="))
fatal("invalid option " + arg);
arg = arg.substr(strlen(",id="));
if (arg.getAsInteger(0, ctx.config.manifestID))
fatal("invalid option " + arg);
}
// Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
// Results are directly written to Config.
void LinkerDriver::parseManifestUAC(StringRef arg) {
if (arg.equals_insensitive("no")) {
ctx.config.manifestUAC = false;
return;
}
for (;;) {
arg = arg.ltrim();
if (arg.empty())
return;
if (arg.consume_front_insensitive("level=")) {
std::tie(ctx.config.manifestLevel, arg) = arg.split(" ");
continue;
}
if (arg.consume_front_insensitive("uiaccess=")) {
std::tie(ctx.config.manifestUIAccess, arg) = arg.split(" ");
continue;
}
fatal("invalid option " + arg);
}
}
// Parses a string in the form of "cd|net[,(cd|net)]*"
// Results are directly written to Config.
void LinkerDriver::parseSwaprun(StringRef arg) {
do {
auto [swaprun, newArg] = arg.split(',');
if (swaprun.equals_insensitive("cd"))
ctx.config.swaprunCD = true;
else if (swaprun.equals_insensitive("net"))
ctx.config.swaprunNet = true;
else if (swaprun.empty())
error("/swaprun: missing argument");
else
error("/swaprun: invalid argument: " + swaprun);
// To catch trailing commas, e.g. `/spawrun:cd,`
if (newArg.empty() && arg.ends_with(","))
error("/swaprun: missing argument");
arg = newArg;
} while (!arg.empty());
}
// An RAII temporary file class that automatically removes a temporary file.
namespace {
class TemporaryFile {
public:
TemporaryFile(StringRef prefix, StringRef extn, StringRef contents = "") {
SmallString<128> s;
if (auto ec = sys::fs::createTemporaryFile("lld-" + prefix, extn, s))
fatal("cannot create a temporary file: " + ec.message());
path = std::string(s);
if (!contents.empty()) {
std::error_code ec;
raw_fd_ostream os(path, ec, sys::fs::OF_None);
if (ec)
fatal("failed to open " + path + ": " + ec.message());
os << contents;
}
}
TemporaryFile(TemporaryFile &&obj) noexcept { std::swap(path, obj.path); }
~TemporaryFile() {
if (path.empty())
return;
if (sys::fs::remove(path))
fatal("failed to remove " + path);
}
// Returns a memory buffer of this temporary file.
// Note that this function does not leave the file open,
// so it is safe to remove the file immediately after this function
// is called (you cannot remove an opened file on Windows.)
std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
// IsVolatile=true forces MemoryBuffer to not use mmap().
return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
/*RequiresNullTerminator=*/false,
/*IsVolatile=*/true),
"could not open " + path);
}
std::string path;
};
}
std::string LinkerDriver::createDefaultXml() {
std::string ret;
raw_string_ostream os(ret);
// Emit the XML. Note that we do *not* verify that the XML attributes are
// syntactically correct. This is intentional for link.exe compatibility.
os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
<< "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
<< " manifestVersion=\"1.0\">\n";
if (ctx.config.manifestUAC) {
os << " <trustInfo>\n"
<< " <security>\n"
<< " <requestedPrivileges>\n"
<< " <requestedExecutionLevel level=" << ctx.config.manifestLevel
<< " uiAccess=" << ctx.config.manifestUIAccess << "/>\n"
<< " </requestedPrivileges>\n"
<< " </security>\n"
<< " </trustInfo>\n";
}
for (auto manifestDependency : ctx.config.manifestDependencies) {
os << " <dependency>\n"
<< " <dependentAssembly>\n"
<< " <assemblyIdentity " << manifestDependency << " />\n"
<< " </dependentAssembly>\n"
<< " </dependency>\n";
}
os << "</assembly>\n";
return os.str();
}
std::string
LinkerDriver::createManifestXmlWithInternalMt(StringRef defaultXml) {
std::unique_ptr<MemoryBuffer> defaultXmlCopy =
MemoryBuffer::getMemBufferCopy(defaultXml);
windows_manifest::WindowsManifestMerger merger;
if (auto e = merger.merge(*defaultXmlCopy.get()))
fatal("internal manifest tool failed on default xml: " +
toString(std::move(e)));
for (StringRef filename : ctx.config.manifestInput) {
std::unique_ptr<MemoryBuffer> manifest =
check(MemoryBuffer::getFile(filename));
// Call takeBuffer to include in /reproduce: output if applicable.
if (auto e = merger.merge(takeBuffer(std::move(manifest))))
fatal("internal manifest tool failed on file " + filename + ": " +
toString(std::move(e)));
}
return std::string(merger.getMergedManifest().get()->getBuffer());
}
std::string
LinkerDriver::createManifestXmlWithExternalMt(StringRef defaultXml) {
// Create the default manifest file as a temporary file.
TemporaryFile Default("defaultxml", "manifest");
std::error_code ec;
raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
if (ec)
fatal("failed to open " + Default.path + ": " + ec.message());
os << defaultXml;
os.close();
// Merge user-supplied manifests if they are given. Since libxml2 is not
// enabled, we must shell out to Microsoft's mt.exe tool.
TemporaryFile user("user", "manifest");
Executor e("mt.exe");
e.add("/manifest");
e.add(Default.path);
for (StringRef filename : ctx.config.manifestInput) {
e.add("/manifest");
e.add(filename);
// Manually add the file to the /reproduce: tar if needed.
if (tar)
if (auto mbOrErr = MemoryBuffer::getFile(filename))
takeBuffer(std::move(*mbOrErr));
}
e.add("/nologo");
e.add("/out:" + StringRef(user.path));
e.run();
return std::string(
CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
.get()
->getBuffer());
}
std::string LinkerDriver::createManifestXml() {
std::string defaultXml = createDefaultXml();
if (ctx.config.manifestInput.empty())
return defaultXml;
if (windows_manifest::isAvailable())
return createManifestXmlWithInternalMt(defaultXml);
return createManifestXmlWithExternalMt(defaultXml);
}
std::unique_ptr<WritableMemoryBuffer>
LinkerDriver::createMemoryBufferForManifestRes(size_t manifestSize) {
size_t resSize = alignTo(
object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
sizeof(object::WinResHeaderSuffix) + manifestSize,
object::WIN_RES_DATA_ALIGNMENT);
return WritableMemoryBuffer::getNewMemBuffer(resSize, ctx.config.outputFile +
".manifest.res");
}
static void writeResFileHeader(char *&buf) {
memcpy(buf, COFF::WinResMagic, sizeof(COFF::WinResMagic));
buf += sizeof(COFF::WinResMagic);
memset(buf, 0, object::WIN_RES_NULL_ENTRY_SIZE);
buf += object::WIN_RES_NULL_ENTRY_SIZE;
}
static void writeResEntryHeader(char *&buf, size_t manifestSize,
int manifestID) {
// Write the prefix.
auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
prefix->DataSize = manifestSize;
prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
sizeof(object::WinResIDs) +
sizeof(object::WinResHeaderSuffix);
buf += sizeof(object::WinResHeaderPrefix);
// Write the Type/Name IDs.
auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
iDs->setType(RT_MANIFEST);
iDs->setName(manifestID);
buf += sizeof(object::WinResIDs);
// Write the suffix.
auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
suffix->DataVersion = 0;
suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
suffix->Language = SUBLANG_ENGLISH_US;
suffix->Version = 0;
suffix->Characteristics = 0;
buf += sizeof(object::WinResHeaderSuffix);
}
// Create a resource file containing a manifest XML.
std::unique_ptr<MemoryBuffer> LinkerDriver::createManifestRes() {
std::string manifest = createManifestXml();
std::unique_ptr<WritableMemoryBuffer> res =
createMemoryBufferForManifestRes(manifest.size());
char *buf = res->getBufferStart();
writeResFileHeader(buf);
writeResEntryHeader(buf, manifest.size(), ctx.config.manifestID);
// Copy the manifest data into the .res file.
std::copy(manifest.begin(), manifest.end(), buf);
return std::move(res);
}
void LinkerDriver::createSideBySideManifest() {
std::string path = std::string(ctx.config.manifestFile);
if (path == "")
path = ctx.config.outputFile + ".manifest";
std::error_code ec;
raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
if (ec)
fatal("failed to create manifest: " + ec.message());
out << createManifestXml();
}
// Parse a string in the form of
// "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
// or "<name>=<dllname>.<name>".
// Used for parsing /export arguments.
Export LinkerDriver::parseExport(StringRef arg) {
Export e;
e.source = ExportSource::Export;
StringRef rest;
std::tie(e.name, rest) = arg.split(",");
if (e.name.empty())
goto err;
if (e.name.contains('=')) {
auto [x, y] = e.name.split("=");
// If "<name>=<dllname>.<name>".
if (y.contains(".")) {
e.name = x;
e.forwardTo = y;
return e;
}
e.extName = x;
e.name = y;
if (e.name.empty())
goto err;
}
// If "<name>=<internalname>[,@ordinal[,NONAME]][,DATA][,PRIVATE]"
while (!rest.empty()) {
StringRef tok;
std::tie(tok, rest) = rest.split(",");
if (tok.equals_insensitive("noname")) {
if (e.ordinal == 0)
goto err;
e.noname = true;
continue;
}
if (tok.equals_insensitive("data")) {
e.data = true;
continue;
}
if (tok.equals_insensitive("constant")) {
e.constant = true;
continue;
}
if (tok.equals_insensitive("private")) {
e.isPrivate = true;
continue;
}
if (tok.starts_with("@")) {
int32_t ord;
if (tok.substr(1).getAsInteger(0, ord))
goto err;
if (ord <= 0 || 65535 < ord)
goto err;
e.ordinal = ord;
continue;
}
goto err;
}
return e;
err:
fatal("invalid /export: " + arg);
}
static StringRef undecorate(COFFLinkerContext &ctx, StringRef sym) {
if (ctx.config.machine != I386)
return sym;
// In MSVC mode, a fully decorated stdcall function is exported
// as-is with the leading underscore (with type IMPORT_NAME).
// In MinGW mode, a decorated stdcall function gets the underscore
// removed, just like normal cdecl functions.
if (sym.starts_with("_") && sym.contains('@') && !ctx.config.mingw)
return sym;
return sym.starts_with("_") ? sym.substr(1) : sym;
}
// Convert stdcall/fastcall style symbols into unsuffixed symbols,
// with or without a leading underscore. (MinGW specific.)
static StringRef killAt(StringRef sym, bool prefix) {
if (sym.empty())
return sym;
// Strip any trailing stdcall suffix
sym = sym.substr(0, sym.find('@', 1));
if (!sym.starts_with("@")) {
if (prefix && !sym.starts_with("_"))
return saver().save("_" + sym);
return sym;
}
// For fastcall, remove the leading @ and replace it with an
// underscore, if prefixes are used.
sym = sym.substr(1);
if (prefix)
sym = saver().save("_" + sym);
return sym;
}
static StringRef exportSourceName(ExportSource s) {
switch (s) {
case ExportSource::Directives:
return "source file (directives)";
case ExportSource::Export:
return "/export";
case ExportSource::ModuleDefinition:
return "/def";
default:
llvm_unreachable("unknown ExportSource");
}
}
// Performs error checking on all /export arguments.
// It also sets ordinals.
void LinkerDriver::fixupExports() {
llvm::TimeTraceScope timeScope("Fixup exports");
// Symbol ordinals must be unique.
std::set<uint16_t> ords;
for (Export &e : ctx.config.exports) {
if (e.ordinal == 0)
continue;
if (!ords.insert(e.ordinal).second)
fatal("duplicate export ordinal: " + e.name);
}
for (Export &e : ctx.config.exports) {
if (!e.forwardTo.empty()) {
e.exportName = undecorate(ctx, e.name);
} else {
e.exportName = undecorate(ctx, e.extName.empty() ? e.name : e.extName);
}
}
if (ctx.config.killAt && ctx.config.machine == I386) {
for (Export &e : ctx.config.exports) {
e.name = killAt(e.name, true);
e.exportName = killAt(e.exportName, false);
e.extName = killAt(e.extName, true);
e.symbolName = killAt(e.symbolName, true);
}
}
// Uniquefy by name.
DenseMap<StringRef, std::pair<Export *, unsigned>> map(
ctx.config.exports.size());
std::vector<Export> v;
for (Export &e : ctx.config.exports) {
auto pair = map.insert(std::make_pair(e.exportName, std::make_pair(&e, 0)));
bool inserted = pair.second;
if (inserted) {
pair.first->second.second = v.size();
v.push_back(e);
continue;
}
Export *existing = pair.first->second.first;
if (e == *existing || e.name != existing->name)
continue;
// If the existing export comes from .OBJ directives, we are allowed to
// overwrite it with /DEF: or /EXPORT without any warning, as MSVC link.exe
// does.
if (existing->source == ExportSource::Directives) {
*existing = e;
v[pair.first->second.second] = e;
continue;
}
if (existing->source == e.source) {
warn(Twine("duplicate ") + exportSourceName(existing->source) +
" option: " + e.name);
} else {
warn("duplicate export: " + e.name +
Twine(" first seen in " + exportSourceName(existing->source) +
Twine(", now in " + exportSourceName(e.source))));
}
}
ctx.config.exports = std::move(v);
// Sort by name.
llvm::sort(ctx.config.exports, [](const Export &a, const Export &b) {
return a.exportName < b.exportName;
});
}
void LinkerDriver::assignExportOrdinals() {
// Assign unique ordinals if default (= 0).
uint32_t max = 0;
for (Export &e : ctx.config.exports)
max = std::max(max, (uint32_t)e.ordinal);
for (Export &e : ctx.config.exports)
if (e.ordinal == 0)
e.ordinal = ++max;
if (max > std::numeric_limits<uint16_t>::max())
fatal("too many exported symbols (got " + Twine(max) + ", max " +
Twine(std::numeric_limits<uint16_t>::max()) + ")");
}
// Parses a string in the form of "key=value" and check
// if value matches previous values for the same key.
void LinkerDriver::checkFailIfMismatch(StringRef arg, InputFile *source) {
auto [k, v] = arg.split('=');
if (k.empty() || v.empty())
fatal("/failifmismatch: invalid argument: " + arg);
std::pair<StringRef, InputFile *> existing = ctx.config.mustMatch[k];
if (!existing.first.empty() && v != existing.first) {
std::string sourceStr = source ? toString(source) : "cmd-line";
std::string existingStr =
existing.second ? toString(existing.second) : "cmd-line";
fatal("/failifmismatch: mismatch detected for '" + k + "':\n>>> " +
existingStr + " has value " + existing.first + "\n>>> " + sourceStr +
" has value " + v);
}
ctx.config.mustMatch[k] = {v, source};
}
// Convert Windows resource files (.res files) to a .obj file.
// Does what cvtres.exe does, but in-process and cross-platform.
MemoryBufferRef LinkerDriver::convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
ArrayRef<ObjFile *> objs) {
object::WindowsResourceParser parser(/* MinGW */ ctx.config.mingw);
std::vector<std::string> duplicates;
for (MemoryBufferRef mb : mbs) {
std::unique_ptr<object::Binary> bin = check(object::createBinary(mb));
object::WindowsResource *rf = dyn_cast<object::WindowsResource>(bin.get());
if (!rf)
fatal("cannot compile non-resource file as resource");
if (auto ec = parser.parse(rf, duplicates))
fatal(toString(std::move(ec)));
}
// Note: This processes all .res files before all objs. Ideally they'd be
// handled in the same order they were linked (to keep the right one, if
// there are duplicates that are tolerated due to forceMultipleRes).
for (ObjFile *f : objs) {
object::ResourceSectionRef rsf;
if (auto ec = rsf.load(f->getCOFFObj()))
fatal(toString(f) + ": " + toString(std::move(ec)));
if (auto ec = parser.parse(rsf, f->getName(), duplicates))
fatal(toString(std::move(ec)));
}
if (ctx.config.mingw)
parser.cleanUpManifests(duplicates);
for (const auto &dupeDiag : duplicates)
if (ctx.config.forceMultipleRes)
warn(dupeDiag);
else
error(dupeDiag);
Expected<std::unique_ptr<MemoryBuffer>> e =
llvm::object::writeWindowsResourceCOFF(ctx.config.machine, parser,
ctx.config.timestamp);
if (!e)
fatal("failed to write .res to COFF: " + toString(e.takeError()));
MemoryBufferRef mbref = **e;
make<std::unique_ptr<MemoryBuffer>>(std::move(*e)); // take ownership
return mbref;
}
// Create OptTable
// Create prefix string literals used in Options.td
#define PREFIX(NAME, VALUE) \
static constexpr llvm::StringLiteral NAME##_init[] = VALUE; \
static constexpr llvm::ArrayRef<llvm::StringLiteral> NAME( \
NAME##_init, std::size(NAME##_init) - 1);
#include "Options.inc"
#undef PREFIX
// Create table mapping all options defined in Options.td
static constexpr llvm::opt::OptTable::Info infoTable[] = {
#define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
#include "Options.inc"
#undef OPTION
};
COFFOptTable::COFFOptTable() : GenericOptTable(infoTable, true) {}
// Set color diagnostics according to --color-diagnostics={auto,always,never}
// or --no-color-diagnostics flags.
static void handleColorDiagnostics(opt::InputArgList &args) {
auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
OPT_no_color_diagnostics);
if (!arg)
return;
if (arg->getOption().getID() == OPT_color_diagnostics) {
lld::errs().enable_colors(true);
} else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
lld::errs().enable_colors(false);
} else {
StringRef s = arg->getValue();
if (s == "always")
lld::errs().enable_colors(true);
else if (s == "never")
lld::errs().enable_colors(false);
else if (s != "auto")
error("unknown option: --color-diagnostics=" + s);
}
}
static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
StringRef s = arg->getValue();
if (s != "windows" && s != "posix")
error("invalid response file quoting: " + s);
if (s == "windows")
return cl::TokenizeWindowsCommandLine;
return cl::TokenizeGNUCommandLine;
}
// The COFF linker always defaults to Windows quoting.
return cl::TokenizeWindowsCommandLine;
}
ArgParser::ArgParser(COFFLinkerContext &c) : ctx(c) {}
// Parses a given list of options.
opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
// Make InputArgList from string vectors.
unsigned missingIndex;
unsigned missingCount;
// We need to get the quoting style for response files before parsing all
// options so we parse here before and ignore all the options but
// --rsp-quoting and /lldignoreenv.
// (This means --rsp-quoting can't be added through %LINK%.)
opt::InputArgList args =
ctx.optTable.ParseArgs(argv, missingIndex, missingCount);
// Expand response files (arguments in the form of @<filename>) and insert
// flags from %LINK% and %_LINK_%, and then parse the argument again.
SmallVector<const char *, 256> expandedArgv(argv.data(),
argv.data() + argv.size());
if (!args.hasArg(OPT_lldignoreenv))
addLINK(expandedArgv);
cl::ExpandResponseFiles(saver(), getQuotingStyle(args), expandedArgv);
args = ctx.optTable.ParseArgs(ArrayRef(expandedArgv).drop_front(),
missingIndex, missingCount);
// Print the real command line if response files are expanded.
if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
std::string msg = "Command line:";
for (const char *s : expandedArgv)
msg += " " + std::string(s);
message(msg);
}
// Save the command line after response file expansion so we can write it to
// the PDB if necessary. Mimic MSVC, which skips input files.
ctx.config.argv = {argv[0]};
for (opt::Arg *arg : args) {
if (arg->getOption().getKind() != opt::Option::InputClass) {
ctx.config.argv.emplace_back(args.getArgString(arg->getIndex()));
}
}
// Handle /WX early since it converts missing argument warnings to errors.
errorHandler().fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
if (missingCount)
fatal(Twine(args.getArgString(missingIndex)) + ": missing argument");
handleColorDiagnostics(args);
for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
std::string nearest;
if (ctx.optTable.findNearest(arg->getAsString(args), nearest) > 1)
warn("ignoring unknown argument '" + arg->getAsString(args) + "'");
else
warn("ignoring unknown argument '" + arg->getAsString(args) +
"', did you mean '" + nearest + "'");
}
if (args.hasArg(OPT_lib))
warn("ignoring /lib since it's not the first argument");
return args;
}
// Tokenizes and parses a given string as command line in .drective section.
ParsedDirectives ArgParser::parseDirectives(StringRef s) {
ParsedDirectives result;
SmallVector<const char *, 16> rest;
// Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
// potentially every symbol in the object, so they must be handled quickly.
SmallVector<StringRef, 16> tokens;
cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
for (StringRef tok : tokens) {
if (tok.starts_with_insensitive("/export:") ||
tok.starts_with_insensitive("-export:"))
result.exports.push_back(tok.substr(strlen("/export:")));
else if (tok.starts_with_insensitive("/include:") ||
tok.starts_with_insensitive("-include:"))
result.includes.push_back(tok.substr(strlen("/include:")));
else if (tok.starts_with_insensitive("/exclude-symbols:") ||
tok.starts_with_insensitive("-exclude-symbols:"))
result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
else {
// Copy substrings that are not valid C strings. The tokenizer may have
// already copied quoted arguments for us, so those do not need to be
// copied again.
bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
}
}
// Make InputArgList from unparsed string vectors.
unsigned missingIndex;
unsigned missingCount;
result.args = ctx.optTable.ParseArgs(rest, missingIndex, missingCount);
if (missingCount)
fatal(Twine(result.args.getArgString(missingIndex)) + ": missing argument");
for (auto *arg : result.args.filtered(OPT_UNKNOWN))
warn("ignoring unknown argument: " + arg->getAsString(result.args));
return result;
}
// link.exe has an interesting feature. If LINK or _LINK_ environment
// variables exist, their contents are handled as command line strings.
// So you can pass extra arguments using them.
void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
// Concatenate LINK env and command line arguments, and then parse them.
if (std::optional<std::string> s = Process::GetEnv("LINK")) {
std::vector<const char *> v = tokenize(*s);
argv.insert(std::next(argv.begin()), v.begin(), v.end());
}
if (std::optional<std::string> s = Process::GetEnv("_LINK_")) {
std::vector<const char *> v = tokenize(*s);
argv.insert(std::next(argv.begin()), v.begin(), v.end());
}
}
std::vector<const char *> ArgParser::tokenize(StringRef s) {
SmallVector<const char *, 16> tokens;
cl::TokenizeWindowsCommandLine(s, saver(), tokens);
return std::vector<const char *>(tokens.begin(), tokens.end());
}
void LinkerDriver::printHelp(const char *argv0) {
ctx.optTable.printHelp(lld::outs(),
(std::string(argv0) + " [options] file...").c_str(),
"LLVM Linker", false);
}
} // namespace coff
} // namespace lld