Files
clang-p2996/lld/lib/Driver/GnuLdDriver.cpp
Rui Ueyama 14133d5551 Replace nested switch statements.
Differential Revision: http://llvm-reviews.chandlerc.com/D2501

llvm-svn: 198535
2014-01-05 02:41:07 +00:00

518 lines
15 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/Optional.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)){}
};
// Get the Input file magic for creating appropriate InputGraph nodes.
error_code getFileMagic(ELFLinkingContext &ctx, StringRef path,
llvm::sys::fs::file_magic &magic) {
error_code ec = llvm::sys::fs::identify_magic(path, magic);
if (ec)
return ec;
switch (magic) {
case llvm::sys::fs::file_magic::archive:
case llvm::sys::fs::file_magic::elf_relocatable:
case llvm::sys::fs::file_magic::elf_shared_object:
case llvm::sys::fs::file_magic::unknown:
return error_code::success();
default:
break;
}
return make_error_code(ReaderError::unknown_file_format);
}
} // namespace
llvm::ErrorOr<StringRef> ELFFileNode::getPath(const LinkingContext &) const {
if (!_isDashlPrefix)
return _path;
return _elfLinkingContext.searchLibrary(_path);
}
std::string ELFFileNode::errStr(error_code errc) {
if (errc == llvm::errc::no_such_file_or_directory) {
if (_isDashlPrefix)
return (Twine("Unable to find library -l") + _path).str();
return (Twine("Unable to find file ") + _path).str();
}
return FileNode::errStr(errc);
}
bool GnuLdDriver::linkELF(int argc, const char *argv[],
raw_ostream &diagnostics) {
std::unique_ptr<ELFLinkingContext> options;
if (!parse(argc, argv, options, diagnostics))
return false;
if (!options)
return true;
// Register possible input file parsers.
options->registry().addSupportELFObjects(options->mergeCommonStrings(),
options->targetHandler());
options->registry().addSupportArchives(options->logInputFiles());
options->registry().addSupportYamlFiles();
options->registry().addSupportNativeObjects();
if (options->allowLinkWithDynamicLibraries())
options->registry().addSupportELFDynamicSharedObjects(
options->useShlibUndefines());
return link(*options, diagnostics);
}
static llvm::Optional<llvm::Triple::ArchType>
getArchType(const llvm::Triple &triple, StringRef value) {
if (triple.getOS() != llvm::Triple::NetBSD)
return llvm::None;
switch (triple.getArch()) {
case llvm::Triple::x86:
case llvm::Triple::x86_64:
if (value == "elf_i386")
return llvm::Triple::x86;
if (value == "elf_x86_64")
return llvm::Triple::x86_64;
return llvm::None;
default:
return llvm::None;
}
}
bool GnuLdDriver::applyEmulation(llvm::Triple &triple,
llvm::opt::InputArgList &args,
raw_ostream &diagnostics) {
llvm::opt::Arg *arg = args.getLastArg(OPT_m);
if (!arg)
return true;
llvm::Optional<llvm::Triple::ArchType> arch =
getArchType(triple, arg->getValue());
if (!arch) {
diagnostics << "error: unsupported emulation '" << arg->getValue()
<< "'.\n";
return false;
}
triple.setArch(*arch);
return true;
}
void GnuLdDriver::addPlatformSearchDirs(ELFLinkingContext &ctx,
llvm::Triple &triple,
llvm::Triple &baseTriple) {
switch (triple.getOS()) {
case llvm::Triple::NetBSD:
switch (triple.getArch()) {
case llvm::Triple::x86:
if (baseTriple.getArch() == llvm::Triple::x86_64) {
ctx.addSearchPath("=/usr/lib/i386");
return;
}
break;
default:
break;
}
break;
default:
break;
}
ctx.addSearchPath("=/usr/lib");
}
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 false;
}
// Handle --help
if (parsedArgs->getLastArg(OPT_help)) {
table.PrintHelp(llvm::outs(), argv[0], "LLVM Linker", false);
return true;
}
// Use -target or use default target triple to instantiate LinkingContext
llvm::Triple baseTriple;
if (llvm::opt::Arg *trip = parsedArgs->getLastArg(OPT_target))
baseTriple = llvm::Triple(trip->getValue());
else
baseTriple = getDefaultTarget(argv[0]);
llvm::Triple triple(baseTriple);
if (!applyEmulation(triple, *parsedArgs, diagnostics))
return false;
std::unique_ptr<ELFLinkingContext> ctx(ELFLinkingContext::create(triple));
if (!ctx) {
diagnostics << "unknown target triple\n";
return false;
}
std::unique_ptr<InputGraph> inputGraph(new InputGraph());
std::stack<InputElement *> controlNodeStack;
// Positional options for an Input File
bool isWholeArchive = false;
bool asNeeded = false;
bool _outputOptionSet = false;
int index = 0;
// Ignore unknown arguments.
for (auto it = parsedArgs->filtered_begin(OPT_UNKNOWN),
ie = parsedArgs->filtered_end();
it != ie; ++it)
diagnostics << "warning: ignoring unknown argument: " << (*it)->getValue()
<< "\n";
// Set sys root path.
if (llvm::opt::Arg *sysRootPath = parsedArgs->getLastArg(OPT_sysroot))
ctx->setSysroot(sysRootPath->getValue());
// Add all search paths.
for (auto it = parsedArgs->filtered_begin(OPT_L),
ie = parsedArgs->filtered_end();
it != ie; ++it)
ctx->addSearchPath((*it)->getValue());
if (!parsedArgs->hasArg(OPT_nostdlib))
addPlatformSearchDirs(*ctx, triple, baseTriple);
// Figure out output kind ( -r, -static, -shared)
if ( llvm::opt::Arg *kind = parsedArgs->getLastArg(OPT_relocatable, OPT_static,
OPT_shared, OPT_nmagic,
OPT_omagic, OPT_no_omagic)) {
switch (kind->getOption().getID()) {
case OPT_relocatable:
ctx->setOutputELFType(llvm::ELF::ET_REL);
ctx->setPrintRemainingUndefines(false);
ctx->setAllowRemainingUndefines(true);
break;
case OPT_static:
ctx->setOutputELFType(llvm::ELF::ET_EXEC);
ctx->setIsStaticExecutable(true);
break;
case OPT_shared:
ctx->setOutputELFType(llvm::ELF::ET_DYN);
ctx->setAllowShlibUndefines(true);
ctx->setUseShlibUndefines(false);
break;
}
}
// Figure out if the output type is nmagic/omagic
if ( llvm::opt::Arg *kind = parsedArgs->getLastArg(OPT_nmagic, OPT_omagic,
OPT_no_omagic)) {
switch (kind->getOption().getID()) {
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;
}
}
// 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_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_u:
ctx->addInitialUndefinedSymbol(inputArg->getValue());
break;
case OPT_init:
ctx->addInitFunction(inputArg->getValue());
break;
case OPT_fini:
ctx->addFiniFunction(inputArg->getValue());
break;
case OPT_output_filetype:
ctx->setOutputFileType(inputArg->getValue());
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_start_group: {
std::unique_ptr<InputElement> controlStart(new ELFGroup(*ctx, index++));
controlNodeStack.push(controlStart.get());
dyn_cast<ControlNode>(controlNodeStack.top())->processControlEnter();
inputGraph->addInputElement(std::move(controlStart));
break;
}
case OPT_end_group:
dyn_cast<ControlNode>(controlNodeStack.top())->processControlExit();
controlNodeStack.pop();
break;
case OPT_INPUT:
case OPT_l: {
bool isDashlPrefix = (inputArg->getOption().getID() == OPT_l);
bool isELFFileNode = true;
StringRef userPath = inputArg->getValue();
std::string resolvedInputPath = userPath;
// If the path was referred to by using a -l argument, let's search
// for the file in the search path.
if (isDashlPrefix) {
ErrorOr<StringRef> resolvedPath = ctx->searchLibrary(userPath);
if (!resolvedPath) {
diagnostics << " Unable to find library -l" << userPath << "\n";
return false;
}
resolvedInputPath = resolvedPath->str();
}
// FIXME: Calling getFileMagic() is expensive. It would be better to
// wire up the LdScript parser into the registry.
llvm::sys::fs::file_magic magic = llvm::sys::fs::file_magic::unknown;
error_code ec = getFileMagic(*ctx, resolvedInputPath, magic);
if (ec) {
diagnostics << "lld: unknown input file format for file " << userPath
<< "\n";
return false;
}
if ((!userPath.endswith(".objtxt")) &&
(magic == llvm::sys::fs::file_magic::unknown))
isELFFileNode = false;
FileNode *inputNode = nullptr;
if (isELFFileNode)
inputNode = new ELFFileNode(*ctx, userPath, index++, isWholeArchive,
asNeeded, isDashlPrefix);
else {
inputNode = new ELFGNULdScript(*ctx, resolvedInputPath, index++);
ec = inputNode->parse(*ctx, diagnostics);
if (ec) {
diagnostics << userPath << ": Error parsing linker script"
<< "\n";
return false;
}
}
std::unique_ptr<InputElement> inputFile(inputNode);
if (controlNodeStack.empty())
inputGraph->addInputElement(std::move(inputFile));
else
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_soname:
ctx->setSharedObjectName(inputArg->getValue());
break;
default:
break;
} // end switch on option ID
} // end for
if (!inputGraph->size()) {
diagnostics << "No input files\n";
return false;
}
// Set default output file name if the output file was not
// specified.
if (!_outputOptionSet) {
switch (ctx->outputFileType()) {
case LinkingContext::OutputFileType::YAML:
ctx->setOutputPath("-");
break;
case LinkingContext::OutputFileType::Native:
ctx->setOutputPath("a.native");
break;
default:
ctx->setOutputPath("a.out");
break;
}
}
if (ctx->outputFileType() == LinkingContext::OutputFileType::YAML)
inputGraph->dump(diagnostics);
// Validate the combination of options used.
if (!ctx->validate(diagnostics))
return false;
// Normalize the InputGraph.
inputGraph->normalize();
ctx->setInputGraph(std::move(inputGraph));
context.swap(ctx);
return true;
}
/// 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());
}