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

255 lines
8.0 KiB
C++

//===- lib/Driver/GnuLdDriver.cpp -----------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
///
/// Concrete instance of the Driver for GNU's ld.
///
//===----------------------------------------------------------------------===//
#include "lld/Driver/Driver.h"
#include "lld/ReaderWriter/ELFTargetInfo.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/Option.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Signals.h"
using namespace lld;
namespace {
// Create enum with OPT_xxx values for each option in LDOptions.td
enum LDOpt {
OPT_INVALID = 0,
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, FLAGS, PARAM, HELP, META) \
OPT_##ID,
#include "LDOptions.inc"
LastOption
#undef OPTION
};
// Create prefix string literals used in LDOptions.td
#define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
#include "LDOptions.inc"
#undef PREFIX
// Create table mapping all options defined in LDOptions.td
static const llvm::opt::OptTable::Info infoTable[] = {
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, FLAGS, PARAM, \
HELPTEXT, METAVAR) \
{ PREFIX, NAME, HELPTEXT, METAVAR, OPT_##ID, llvm::opt::Option::KIND##Class, \
PARAM, FLAGS, OPT_##GROUP, OPT_##ALIAS },
#include "LDOptions.inc"
#undef OPTION
};
// Create OptTable class for parsing actual command line arguments
class GnuLdOptTable : public llvm::opt::OptTable {
public:
GnuLdOptTable() : OptTable(infoTable, llvm::array_lengthof(infoTable)){}
};
} // namespace
bool GnuLdDriver::linkELF(int argc, const char *argv[],
raw_ostream &diagnostics) {
std::unique_ptr<ELFTargetInfo> options(parse(argc, argv, diagnostics));
if (!options)
return true;
return link(*options, diagnostics);
}
std::unique_ptr<ELFTargetInfo>
GnuLdDriver::parse(int argc, const char *argv[], raw_ostream &diagnostics) {
// Parse command line options using LDOptions.td
std::unique_ptr<llvm::opt::InputArgList> parsedArgs;
GnuLdOptTable table;
unsigned missingIndex;
unsigned missingCount;
parsedArgs.reset(
table.ParseArgs(&argv[1], &argv[argc], missingIndex, missingCount));
if (missingCount) {
diagnostics << "error: missing arg value for '"
<< parsedArgs->getArgString(missingIndex) << "' expected "
<< missingCount << " argument(s).\n";
return nullptr;
}
for (auto it = parsedArgs->filtered_begin(OPT_UNKNOWN),
ie = parsedArgs->filtered_end(); it != ie; ++it) {
diagnostics << "warning: ignoring unknown argument: " << (*it)->getAsString(
*parsedArgs)
<< "\n";
}
// Handle --help
if (parsedArgs->getLastArg(OPT_help)) {
table.PrintHelp(llvm::outs(), argv[0], "LLVM Linker", false);
return nullptr;
}
// Use -target or use default target triple to instantiate TargetInfo
llvm::Triple triple;
if (llvm::opt::Arg *trip = parsedArgs->getLastArg(OPT_target))
triple = llvm::Triple(trip->getValue());
else
triple = getDefaultTarget(argv[0]);
std::unique_ptr<ELFTargetInfo> options(ELFTargetInfo::create(triple));
if (!options) {
diagnostics << "unknown target triple\n";
return nullptr;
}
// Handle -e xxx
if (llvm::opt::Arg *entry = parsedArgs->getLastArg(OPT_entry))
options->setEntrySymbolName(entry->getValue());
// Handle -emit-yaml
if (parsedArgs->getLastArg(OPT_emit_yaml))
options->setOutputYAML(true);
// Handle -o xxx
if (llvm::opt::Arg *output = parsedArgs->getLastArg(OPT_output))
options->setOutputPath(output->getValue());
else if (options->outputYAML())
options->setOutputPath("-"); // yaml writes to stdout by default
else
options->setOutputPath("a.out");
// Handle -r, -shared, or -static
if (llvm::opt::Arg *kind =
parsedArgs->getLastArg(OPT_relocatable, OPT_shared, OPT_static)) {
switch (kind->getOption().getID()) {
case OPT_relocatable:
options->setOutputFileType(llvm::ELF::ET_REL);
options->setPrintRemainingUndefines(false);
options->setAllowRemainingUndefines(true);
break;
case OPT_shared:
options->setOutputFileType(llvm::ELF::ET_DYN);
options->setAllowShlibUndefines(true);
options->setUseShlibUndefines(false);
break;
case OPT_static:
options->setOutputFileType(llvm::ELF::ET_EXEC);
options->setIsStaticExecutable(true);
break;
}
} else {
options->setOutputFileType(llvm::ELF::ET_EXEC);
options->setIsStaticExecutable(false);
options->setAllowShlibUndefines(false);
options->setUseShlibUndefines(true);
}
// Handle --noinhibit-exec
if (parsedArgs->getLastArg(OPT_noinhibit_exec))
options->setAllowRemainingUndefines(true);
// Handle --force-load
if (parsedArgs->getLastArg(OPT_force_load))
options->setForceLoadAllArchives(true);
// Handle --merge-strings
if (parsedArgs->getLastArg(OPT_merge_strings))
options->setMergeCommonStrings(true);
// Handle -t
if (parsedArgs->getLastArg(OPT_t))
options->setLogInputFiles(true);
// Handle --no-allow-shlib-undefined
if (parsedArgs->getLastArg(OPT_no_allow_shlib_undefs))
options->setAllowShlibUndefines(false);
// Handle --allow-shlib-undefined
if (parsedArgs->getLastArg(OPT_allow_shlib_undefs))
options->setAllowShlibUndefines(true);
// Handle --use-shlib-undefs
if (parsedArgs->getLastArg(OPT_use_shlib_undefs))
options->setUseShlibUndefines(true);
// Handle -Lxxx
for (llvm::opt::arg_iterator it = parsedArgs->filtered_begin(OPT_L),
ie = parsedArgs->filtered_end();
it != ie; ++it) {
options->appendSearchPath((*it)->getValue());
}
// Copy mllvm
for (llvm::opt::arg_iterator it = parsedArgs->filtered_begin(OPT_mllvm),
ie = parsedArgs->filtered_end();
it != ie; ++it) {
options->appendLLVMOption((*it)->getValue());
}
// Handle input files (full paths and -lxxx)
for (llvm::opt::arg_iterator
it = parsedArgs->filtered_begin(OPT_INPUT, OPT_l),
ie = parsedArgs->filtered_end();
it != ie; ++it) {
switch ((*it)->getOption().getID()) {
case OPT_INPUT:
options->appendInputFile((*it)->getValue());
break;
case OPT_l:
if (options->appendLibrary((*it)->getValue())) {
diagnostics << "Failed to find library for " << (*it)->getValue()
<< "\n";
return nullptr;
}
break;
default:
llvm_unreachable("input option type not handled");
}
}
// Validate the combination of options used.
if (options->validate(diagnostics))
return nullptr;
return options;
}
/// Get the default target triple based on either the program name
/// (e.g. "x86-ibm-linux-lld") or the primary target llvm was configured for.
llvm::Triple GnuLdDriver::getDefaultTarget(const char *progName) {
SmallVector<StringRef, 4> components;
llvm::SplitString(llvm::sys::path::stem(progName), components, "-");
// If has enough parts to be start with a triple.
if (components.size() >= 4) {
llvm::Triple triple(components[0], components[1], components[2],
components[3]);
// If first component looks like an arch.
if (triple.getArch() != llvm::Triple::UnknownArch)
return triple;
}
// Fallback to use whatever default triple llvm was configured for.
return llvm::Triple(llvm::sys::getDefaultTargetTriple());
}