RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-19 11:02:59 +02:00
Code Issues Projects Releases Wiki Activity
58ef761cf2
llvm-mirror/tools/llvm-objcopy/llvm-objcopy.cpp
Jake Ehrlich b63074777b [llvm-objcopy] Add --only-keep-debug as a noop 
This option just keeps being a problem and really needs to be implemented
in some fashion. Implementing it properly requires some kind of
"replaceSectionReference" method because all the existing links need to be
maintained. The desired behavior is just for allocated sections to become
NOBITS but actually implementing that is rather tricky due to the current
design of llvm-objcopy. However converting allocated sections to NOBITS is
just an optimization and not something debuggers need. Debuggers can debug
a stripped executable and take an unstripped executable for that stripped
executable as input. Additionally allocated sections account for a very
small part of debug binaries so this optimization is quite small. I propose
that for the time being we implement this as a NOP so that people can use
llvm-objcopy where they need to, just in a sub-optimal way.

This option has already blocked a lot of people and its currently blocking me.

llvm-svn: 332396
2018-05-15 20:53:53 +00:00

557 lines
19 KiB
C++
Raw Blame History

//===- llvm-objcopy.cpp ---------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm-objcopy.h"
#include "Object.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/ELFTypes.h"
#include "llvm/Object/Error.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Option/Option.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileOutputBuffer.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstdlib>
#include <functional>
#include <iterator>
#include <memory>
#include <string>
#include <system_error>
#include <utility>
using namespace llvm;
using namespace object;
using namespace ELF;
namespace {
enum ObjcopyID {
OBJCOPY_INVALID = 0, // This is not an option ID.
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELPTEXT, METAVAR, VALUES) \
OBJCOPY_##ID,
#include "ObjcopyOpts.inc"
#undef OPTION
};
#define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
#include "ObjcopyOpts.inc"
#undef PREFIX
static const opt::OptTable::Info ObjcopyInfoTable[] = {
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELPTEXT, METAVAR, VALUES) \
{PREFIX, NAME, HELPTEXT, \
METAVAR, OBJCOPY_##ID, opt::Option::KIND##Class, \
PARAM, FLAGS, OBJCOPY_##GROUP, \
OBJCOPY_##ALIAS, ALIASARGS, VALUES},
#include "ObjcopyOpts.inc"
#undef OPTION
};
class ObjcopyOptTable : public opt::OptTable {
public:
ObjcopyOptTable() : OptTable(ObjcopyInfoTable, true) {}
};
enum StripID {
STRIP_INVALID = 0, // This is not an option ID.
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELPTEXT, METAVAR, VALUES) \
STRIP_##ID,
#include "StripOpts.inc"
#undef OPTION
};
static const opt::OptTable::Info StripInfoTable[] = {
#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
HELPTEXT, METAVAR, VALUES) \
{PREFIX, NAME, HELPTEXT, \
METAVAR, STRIP_##ID, opt::Option::KIND##Class, \
PARAM, FLAGS, STRIP_##GROUP, \
STRIP_##ALIAS, ALIASARGS, VALUES},
#include "StripOpts.inc"
#undef OPTION
};
class StripOptTable : public opt::OptTable {
public:
StripOptTable() : OptTable(StripInfoTable, true) {}
};
} // namespace
// The name this program was invoked as.
static StringRef ToolName;
namespace llvm {
LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
errs() << ToolName << ": " << Message << ".\n";
errs().flush();
exit(1);
}
LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
assert(EC);
errs() << ToolName << ": '" << File << "': " << EC.message() << ".\n";
exit(1);
}
LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, Error E) {
assert(E);
std::string Buf;
raw_string_ostream OS(Buf);
logAllUnhandledErrors(std::move(E), OS, "");
OS.flush();
errs() << ToolName << ": '" << File << "': " << Buf;
exit(1);
}
} // end namespace llvm
struct CopyConfig {
StringRef OutputFilename;
StringRef InputFilename;
StringRef OutputFormat;
StringRef InputFormat;
StringRef BinaryArch;
StringRef SplitDWO;
StringRef AddGnuDebugLink;
std::vector<StringRef> ToRemove;
std::vector<StringRef> Keep;
std::vector<StringRef> OnlyKeep;
std::vector<StringRef> AddSection;
std::vector<StringRef> SymbolsToLocalize;
std::vector<StringRef> SymbolsToGlobalize;
std::vector<StringRef> SymbolsToWeaken;
std::vector<StringRef> SymbolsToRemove;
std::vector<StringRef> SymbolsToKeep;
StringMap<StringRef> SymbolsToRename;
bool StripAll = false;
bool StripAllGNU = false;
bool StripDebug = false;
bool StripSections = false;
bool StripNonAlloc = false;
bool StripDWO = false;
bool ExtractDWO = false;
bool LocalizeHidden = false;
bool Weaken = false;
bool DiscardAll = false;
bool OnlyKeepDebug = false;
};
using SectionPred = std::function<bool(const SectionBase &Sec)>;
bool IsDWOSection(const SectionBase &Sec) { return Sec.Name.endswith(".dwo"); }
bool OnlyKeepDWOPred(const Object &Obj, const SectionBase &Sec) {
// We can't remove the section header string table.
if (&Sec == Obj.SectionNames)
return false;
// Short of keeping the string table we want to keep everything that is a DWO
// section and remove everything else.
return !IsDWOSection(Sec);
}
std::unique_ptr<Writer> CreateWriter(const CopyConfig &Config, Object &Obj,
StringRef File, ElfType OutputElfType) {
if (Config.OutputFormat == "binary") {
return llvm::make_unique<BinaryWriter>(File, Obj);
}
// Depending on the initial ELFT and OutputFormat we need a different Writer.
switch (OutputElfType) {
case ELFT_ELF32LE:
return llvm::make_unique<ELFWriter<ELF32LE>>(File, Obj,
!Config.StripSections);
case ELFT_ELF64LE:
return llvm::make_unique<ELFWriter<ELF64LE>>(File, Obj,
!Config.StripSections);
case ELFT_ELF32BE:
return llvm::make_unique<ELFWriter<ELF32BE>>(File, Obj,
!Config.StripSections);
case ELFT_ELF64BE:
return llvm::make_unique<ELFWriter<ELF64BE>>(File, Obj,
!Config.StripSections);
}
llvm_unreachable("Invalid output format");
}
void SplitDWOToFile(const CopyConfig &Config, const Reader &Reader,
StringRef File, ElfType OutputElfType) {
auto DWOFile = Reader.create();
DWOFile->removeSections(
[&](const SectionBase &Sec) { return OnlyKeepDWOPred(*DWOFile, Sec); });
auto Writer = CreateWriter(Config, *DWOFile, File, OutputElfType);
Writer->finalize();
Writer->write();
}
// This function handles the high level operations of GNU objcopy including
// handling command line options. It's important to outline certain properties
// we expect to hold of the command line operations. Any operation that "keeps"
// should keep regardless of a remove. Additionally any removal should respect
// any previous removals. Lastly whether or not something is removed shouldn't
// depend a) on the order the options occur in or b) on some opaque priority
// system. The only priority is that keeps/copies overrule removes.
void HandleArgs(const CopyConfig &Config, Object &Obj, const Reader &Reader,
ElfType OutputElfType) {
if (!Config.SplitDWO.empty()) {
SplitDWOToFile(Config, Reader, Config.SplitDWO, OutputElfType);
}
SectionPred RemovePred = [](const SectionBase &) { return false; };
// Removes:
if (!Config.ToRemove.empty()) {
RemovePred = [&Config](const SectionBase &Sec) {
return std::find(std::begin(Config.ToRemove), std::end(Config.ToRemove),
Sec.Name) != std::end(Config.ToRemove);
};
}
if (Config.StripDWO || !Config.SplitDWO.empty())
RemovePred = [RemovePred](const SectionBase &Sec) {
return IsDWOSection(Sec) || RemovePred(Sec);
};
if (Config.ExtractDWO)
RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
return OnlyKeepDWOPred(Obj, Sec) || RemovePred(Sec);
};
if (Config.StripAllGNU)
RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
if (RemovePred(Sec))
return true;
if ((Sec.Flags & SHF_ALLOC) != 0)
return false;
if (&Sec == Obj.SectionNames)
return false;
switch (Sec.Type) {
case SHT_SYMTAB:
case SHT_REL:
case SHT_RELA:
case SHT_STRTAB:
return true;
}
return Sec.Name.startswith(".debug");
};
if (Config.StripSections) {
RemovePred = [RemovePred](const SectionBase &Sec) {
return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
};
}
if (Config.StripDebug) {
RemovePred = [RemovePred](const SectionBase &Sec) {
return RemovePred(Sec) || Sec.Name.startswith(".debug");
};
}
if (Config.StripNonAlloc)
RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
if (RemovePred(Sec))
return true;
if (&Sec == Obj.SectionNames)
return false;
return (Sec.Flags & SHF_ALLOC) == 0;
};
if (Config.StripAll)
RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
if (RemovePred(Sec))
return true;
if (&Sec == Obj.SectionNames)
return false;
if (Sec.Name.startswith(".gnu.warning"))
return false;
return (Sec.Flags & SHF_ALLOC) == 0;
};
// Explicit copies:
if (!Config.OnlyKeep.empty()) {
RemovePred = [&Config, RemovePred, &Obj](const SectionBase &Sec) {
// Explicitly keep these sections regardless of previous removes.
if (std::find(std::begin(Config.OnlyKeep), std::end(Config.OnlyKeep),
Sec.Name) != std::end(Config.OnlyKeep))
return false;
// Allow all implicit removes.
if (RemovePred(Sec))
return true;
// Keep special sections.
if (Obj.SectionNames == &Sec)
return false;
if (Obj.SymbolTable == &Sec || Obj.SymbolTable->getStrTab() == &Sec)
return false;
// Remove everything else.
return true;
};
}
if (!Config.Keep.empty()) {
RemovePred = [Config, RemovePred](const SectionBase &Sec) {
// Explicitly keep these sections regardless of previous removes.
if (std::find(std::begin(Config.Keep), std::end(Config.Keep), Sec.Name) !=
std::end(Config.Keep))
return false;
// Otherwise defer to RemovePred.
return RemovePred(Sec);
};
}
Obj.removeSections(RemovePred);
if (!Config.AddSection.empty()) {
for (const auto &Flag : Config.AddSection) {
auto SecPair = Flag.split("=");
auto SecName = SecPair.first;
auto File = SecPair.second;
auto BufOrErr = MemoryBuffer::getFile(File);
if (!BufOrErr)
reportError(File, BufOrErr.getError());
auto Buf = std::move(*BufOrErr);
auto BufPtr = reinterpret_cast<const uint8_t *>(Buf->getBufferStart());
auto BufSize = Buf->getBufferSize();
Obj.addSection<OwnedDataSection>(SecName,
ArrayRef<uint8_t>(BufPtr, BufSize));
}
}
if (!Config.AddGnuDebugLink.empty())
Obj.addSection<GnuDebugLinkSection>(Config.AddGnuDebugLink);
if (Obj.SymbolTable) {
Obj.SymbolTable->updateSymbols([&](Symbol &Sym) {
if ((Config.LocalizeHidden &&
(Sym.Visibility == STV_HIDDEN || Sym.Visibility == STV_INTERNAL)) ||
(!Config.SymbolsToLocalize.empty() &&
is_contained(Config.SymbolsToLocalize, Sym.Name)))
Sym.Binding = STB_LOCAL;
if (!Config.SymbolsToGlobalize.empty() &&
is_contained(Config.SymbolsToGlobalize, Sym.Name))
Sym.Binding = STB_GLOBAL;
if (!Config.SymbolsToWeaken.empty() &&
is_contained(Config.SymbolsToWeaken, Sym.Name) &&
Sym.Binding == STB_GLOBAL)
Sym.Binding = STB_WEAK;
if (Config.Weaken && Sym.Binding == STB_GLOBAL &&
Sym.getShndx() != SHN_UNDEF)
Sym.Binding = STB_WEAK;
const auto I = Config.SymbolsToRename.find(Sym.Name);
if (I != Config.SymbolsToRename.end())
Sym.Name = I->getValue();
});
Obj.removeSymbols([&](const Symbol &Sym) {
if (!Config.SymbolsToKeep.empty() &&
is_contained(Config.SymbolsToKeep, Sym.Name))
return false;
if (Config.DiscardAll && Sym.Binding == STB_LOCAL &&
Sym.getShndx() != SHN_UNDEF && Sym.Type != STT_FILE &&
Sym.Type != STT_SECTION)
return true;
if (!Config.SymbolsToRemove.empty() &&
is_contained(Config.SymbolsToRemove, Sym.Name)) {
return true;
}
return false;
});
}
}
std::unique_ptr<Reader> CreateReader(StringRef InputFilename,
ElfType &OutputElfType) {
// Right now we can only read ELF files so there's only one reader;
auto Out = llvm::make_unique<ELFReader>(InputFilename);
// We need to set the default ElfType for output.
OutputElfType = Out->getElfType();
return std::move(Out);
}
void ExecuteElfObjcopy(const CopyConfig &Config) {
ElfType OutputElfType;
auto Reader = CreateReader(Config.InputFilename, OutputElfType);
auto Obj = Reader->create();
auto Writer =
CreateWriter(Config, *Obj, Config.OutputFilename, OutputElfType);
HandleArgs(Config, *Obj, *Reader, OutputElfType);
Writer->finalize();
Writer->write();
}
// ParseObjcopyOptions returns the config and sets the input arguments. If a
// help flag is set then ParseObjcopyOptions will print the help messege and
// exit.
CopyConfig ParseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
ObjcopyOptTable T;
unsigned MissingArgumentIndex, MissingArgumentCount;
llvm::opt::InputArgList InputArgs =
T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
if (InputArgs.size() == 0) {
T.PrintHelp(errs(), "llvm-objcopy <input> [ <output> ]", "objcopy tool");
exit(1);
}
if (InputArgs.hasArg(OBJCOPY_help)) {
T.PrintHelp(outs(), "llvm-objcopy <input> [ <output> ]", "objcopy tool");
exit(0);
}
SmallVector<const char *, 2> Positional;
for (auto Arg : InputArgs.filtered(OBJCOPY_UNKNOWN))
error("unknown argument '" + Arg->getAsString(InputArgs) + "'");
for (auto Arg : InputArgs.filtered(OBJCOPY_INPUT))
Positional.push_back(Arg->getValue());
if (Positional.empty())
error("No input file specified");
if (Positional.size() > 2)
error("Too many positional arguments");
CopyConfig Config;
Config.InputFilename = Positional[0];
Config.OutputFilename = Positional[Positional.size() == 1 ? 0 : 1];
Config.InputFormat = InputArgs.getLastArgValue(OBJCOPY_input_target);
Config.OutputFormat = InputArgs.getLastArgValue(OBJCOPY_output_target);
Config.BinaryArch = InputArgs.getLastArgValue(OBJCOPY_binary_architecture);
Config.SplitDWO = InputArgs.getLastArgValue(OBJCOPY_split_dwo);
Config.AddGnuDebugLink = InputArgs.getLastArgValue(OBJCOPY_add_gnu_debuglink);
for (auto Arg : InputArgs.filtered(OBJCOPY_redefine_symbol)) {
if (!StringRef(Arg->getValue()).contains('='))
error("Bad format for --redefine-sym");
auto Old2New = StringRef(Arg->getValue()).split('=');
if (!Config.SymbolsToRename.insert(Old2New).second)
error("Multiple redefinition of symbol " + Old2New.first);
}
for (auto Arg : InputArgs.filtered(OBJCOPY_remove_section))
Config.ToRemove.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_keep))
Config.Keep.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_only_keep))
Config.OnlyKeep.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_add_section))
Config.AddSection.push_back(Arg->getValue());
Config.StripAll = InputArgs.hasArg(OBJCOPY_strip_all);
Config.StripAllGNU = InputArgs.hasArg(OBJCOPY_strip_all_gnu);
Config.StripDebug = InputArgs.hasArg(OBJCOPY_strip_debug);
Config.StripDWO = InputArgs.hasArg(OBJCOPY_strip_dwo);
Config.StripSections = InputArgs.hasArg(OBJCOPY_strip_sections);
Config.StripNonAlloc = InputArgs.hasArg(OBJCOPY_strip_non_alloc);
Config.ExtractDWO = InputArgs.hasArg(OBJCOPY_extract_dwo);
Config.LocalizeHidden = InputArgs.hasArg(OBJCOPY_localize_hidden);
Config.Weaken = InputArgs.hasArg(OBJCOPY_weaken);
Config.DiscardAll = InputArgs.hasArg(OBJCOPY_discard_all);
Config.OnlyKeepDebug = InputArgs.hasArg(OBJCOPY_only_keep_debug);
for (auto Arg : InputArgs.filtered(OBJCOPY_localize_symbol))
Config.SymbolsToLocalize.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_globalize_symbol))
Config.SymbolsToGlobalize.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_weaken_symbol))
Config.SymbolsToWeaken.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_strip_symbol))
Config.SymbolsToRemove.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_keep_symbol))
Config.SymbolsToKeep.push_back(Arg->getValue());
return Config;
}
// ParseStripOptions returns the config and sets the input arguments. If a
// help flag is set then ParseStripOptions will print the help messege and
// exit.
CopyConfig ParseStripOptions(ArrayRef<const char *> ArgsArr) {
StripOptTable T;
unsigned MissingArgumentIndex, MissingArgumentCount;
llvm::opt::InputArgList InputArgs =
T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
if (InputArgs.size() == 0) {
T.PrintHelp(errs(), "llvm-strip <input> [ <output> ]", "strip tool");
exit(1);
}
if (InputArgs.hasArg(STRIP_help)) {
T.PrintHelp(outs(), "llvm-strip <input> [ <output> ]", "strip tool");
exit(0);
}
SmallVector<const char *, 2> Positional;
for (auto Arg : InputArgs.filtered(STRIP_UNKNOWN))
error("unknown argument '" + Arg->getAsString(InputArgs) + "'");
for (auto Arg : InputArgs.filtered(STRIP_INPUT))
Positional.push_back(Arg->getValue());
if (Positional.empty())
error("No input file specified");
if (Positional.size() > 2)
error("Support for multiple input files is not implemented yet");
CopyConfig Config;
Config.InputFilename = Positional[0];
Config.OutputFilename = Positional[0];
// Strip debug info only.
Config.StripDebug = InputArgs.hasArg(STRIP_strip_debug);
if (!Config.StripDebug)
Config.StripAll = true;
for (auto Arg : InputArgs.filtered(STRIP_remove_section))
Config.ToRemove.push_back(Arg->getValue());
return Config;
}
int main(int argc, char **argv) {
InitLLVM X(argc, argv);
ToolName = argv[0];
CopyConfig Config;
if (sys::path::stem(ToolName).endswith_lower("strip"))
Config = ParseStripOptions(makeArrayRef(argv + 1, argc));
else
Config = ParseObjcopyOptions(makeArrayRef(argv + 1, argc));
ExecuteElfObjcopy(Config);
}
Reference in New Issue View Git Blame Copy Permalink