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

368 lines
10 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/Driver/GnuLdInputGraph.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 GnuLdOptions.td
enum {
OPT_INVALID = 0,
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELP, META) \
OPT_##ID,
#include "GnuLdOptions.inc"
#undef OPTION
};
// Create prefix string literals used in GnuLdOptions.td
#define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
#include "GnuLdOptions.inc"
#undef PREFIX
// Create table mapping all options defined in GnuLdOptions.td
static const llvm::opt::OptTable::Info infoTable[] = {
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELPTEXT, METAVAR) \
{ PREFIX, NAME, HELPTEXT, METAVAR, OPT_##ID, llvm::opt::Option::KIND##Class, \
PARAM, FLAGS, OPT_##GROUP, OPT_##ALIAS, ALIASARGS },
#include "GnuLdOptions.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
llvm::ErrorOr<std::unique_ptr<lld::LinkerInput> >
ELFFileNode::createLinkerInput(const LinkingContext &ctx) {
auto inputFile(FileNode::createLinkerInput(ctx));
if (inputFile) {
(*inputFile)->setAsNeeded(_asNeeded);
(*inputFile)->setWholeArchive(_isWholeArchive);
}
return std::move(inputFile);
}
llvm::ErrorOr<StringRef> ELFFileNode::path(const LinkingContext &) const {
if (!_isDashlPrefix)
return _path;
return _elfLinkingContext.searchLibrary(_path, _libraryPaths);
}
std::string ELFFileNode::errStr(llvm::error_code errc) {
std::string errorMsg;
if (errc == llvm::errc::no_such_file_or_directory) {
if (_isDashlPrefix)
errorMsg = (Twine("Unable to find library -l") + _path).str();
else
errorMsg = (Twine("Unable to find file ") + _path).str();
}
else {
return "Unknown Error";
}
return std::move(errorMsg);
}
bool GnuLdDriver::linkELF(int argc, const char *argv[],
raw_ostream &diagnostics) {
std::unique_ptr<ELFLinkingContext> options;
bool error = parse(argc, argv, options, diagnostics);
if (error)
return true;
if (!options)
return false;
return link(*options, diagnostics);
}
bool GnuLdDriver::parse(int argc, const char *argv[],
std::unique_ptr<ELFLinkingContext> &context,
raw_ostream &diagnostics) {
// Parse command line options using GnuLdOptions.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 true;
}
// Handle --help
if (parsedArgs->getLastArg(OPT_help)) {
table.PrintHelp(llvm::outs(), argv[0], "LLVM Linker", false);
return false;
}
// Use -target or use default target triple to instantiate LinkingContext
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<ELFLinkingContext> ctx(ELFLinkingContext::create(triple));
if (!ctx) {
diagnostics << "unknown target triple\n";
return true;
}
std::unique_ptr<InputGraph> inputGraph(new InputGraph());
std::stack<InputElement *> controlNodeStack;
// Positional options for an Input File
std::vector<StringRef> searchPath;
bool isWholeArchive = false;
bool asNeeded = false;
bool _outputOptionSet = false;
// Create a dynamic executable by default
ctx->setOutputFileType(llvm::ELF::ET_EXEC);
ctx->setIsStaticExecutable(false);
ctx->setAllowShlibUndefines(false);
ctx->setUseShlibUndefines(true);
// Set the output file to be a.out
ctx->setOutputPath("a.out");
// Process all the arguments and create Input Elements
for (auto inputArg : *parsedArgs) {
switch (inputArg->getOption().getID()) {
case OPT_mllvm:
ctx->appendLLVMOption(inputArg->getValue());
break;
case OPT_relocatable:
ctx->setOutputFileType(llvm::ELF::ET_REL);
ctx->setPrintRemainingUndefines(false);
ctx->setAllowRemainingUndefines(true);
break;
case OPT_static:
ctx->setOutputFileType(llvm::ELF::ET_EXEC);
ctx->setIsStaticExecutable(true);
break;
case OPT_shared:
ctx->setOutputFileType(llvm::ELF::ET_DYN);
ctx->setAllowShlibUndefines(true);
ctx->setUseShlibUndefines(false);
break;
case OPT_e:
ctx->setEntrySymbolName(inputArg->getValue());
break;
case OPT_output:
_outputOptionSet = true;
ctx->setOutputPath(inputArg->getValue());
break;
case OPT_noinhibit_exec:
ctx->setAllowRemainingUndefines(true);
break;
case OPT_merge_strings:
ctx->setMergeCommonStrings(true);
break;
case OPT_t:
ctx->setLogInputFiles(true);
break;
case OPT_no_allow_shlib_undefs:
ctx->setAllowShlibUndefines(false);
break;
case OPT_allow_shlib_undefs:
ctx->setAllowShlibUndefines(true);
break;
case OPT_use_shlib_undefs:
ctx->setUseShlibUndefines(true);
break;
case OPT_dynamic_linker:
ctx->setInterpreter(inputArg->getValue());
break;
case OPT_nmagic:
ctx->setOutputMagic(ELFLinkingContext::OutputMagic::NMAGIC);
ctx->setIsStaticExecutable(true);
break;
case OPT_omagic:
ctx->setOutputMagic(ELFLinkingContext::OutputMagic::OMAGIC);
ctx->setIsStaticExecutable(true);
break;
case OPT_no_omagic:
ctx->setOutputMagic(ELFLinkingContext::OutputMagic::DEFAULT);
ctx->setNoAllowDynamicLibraries();
break;
case OPT_u:
ctx->addInitialUndefinedSymbol(inputArg->getValue());
break;
case OPT_init:
ctx->addInitFunction(inputArg->getValue());
break;
case OPT_fini:
ctx->addFiniFunction(inputArg->getValue());
break;
case OPT_emit_yaml:
if (!_outputOptionSet)
ctx->setOutputPath("-");
ctx->setOutputYAML(true);
break;
case OPT_no_whole_archive:
isWholeArchive = false;
break;
case OPT_whole_archive:
isWholeArchive = true;
break;
case OPT_as_needed:
asNeeded = true;
break;
case OPT_no_as_needed:
asNeeded = false;
break;
case OPT_L:
searchPath.push_back(inputArg->getValue());
break;
case OPT_start_group: {
std::unique_ptr<InputElement> controlStart(new ELFGroup(*ctx));
controlNodeStack.push(controlStart.get());
(llvm::dyn_cast<ControlNode>)(controlNodeStack.top())
->processControlEnter();
inputGraph->addInputElement(std::move(controlStart));
break;
}
case OPT_end_group:
(llvm::dyn_cast<ControlNode>)(controlNodeStack.top())
->processControlExit();
controlNodeStack.pop();
return false;
case OPT_INPUT:
case OPT_l: {
std::unique_ptr<InputElement> inputFile =
std::move(std::unique_ptr<InputElement>(new ELFFileNode(
*ctx, inputArg->getValue(), searchPath, isWholeArchive, asNeeded,
inputArg->getOption().getID() == OPT_l)));
if (controlNodeStack.empty())
inputGraph->addInputElement(std::move(inputFile));
else
(llvm::dyn_cast<ControlNode>)(controlNodeStack.top())
->processInputElement(std::move(inputFile));
break;
}
case OPT_rpath: {
SmallVector<StringRef, 2> rpaths;
StringRef(inputArg->getValue()).split(rpaths, ":");
for (auto path : rpaths)
ctx->addRpath(path);
break;
}
case OPT_rpath_link: {
SmallVector<StringRef, 2> rpaths;
StringRef(inputArg->getValue()).split(rpaths, ":");
for (auto path : rpaths)
ctx->addRpathLink(path);
break;
}
case OPT_sysroot:
ctx->setSysroot(inputArg->getValue());
break;
default:
break;
} // end switch on option ID
} // end for
if (!inputGraph->numFiles()) {
diagnostics << "No input files\n";
return true;
}
inputGraph->addInternalFile(ctx->createInternalFiles());
if (ctx->outputYAML())
inputGraph->dump(diagnostics);
// Validate the combination of options used.
if (ctx->validate(diagnostics))
return true;
ctx->setInputGraph(std::move(inputGraph));
context.swap(ctx);
return false;
}
/// 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());
}