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diff --git a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
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index 000000000000..8bf7e0f88010
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+++ b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
@@ -0,0 +1,815 @@
+//===- ELFObjcopy.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
+//
+//===----------------------------------------------------------------------===//
+
+#include "ELFObjcopy.h"
+#include "Buffer.h"
+#include "CopyConfig.h"
+#include "Object.h"
+#include "llvm-objcopy.h"
+
+#include "llvm/ADT/BitmaskEnum.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/MC/MCTargetOptions.h"
+#include "llvm/Object/Binary.h"
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/ELFTypes.h"
+#include "llvm/Object/Error.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Compression.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/Memory.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>
+
+namespace llvm {
+namespace objcopy {
+namespace elf {
+
+using namespace object;
+using namespace ELF;
+using SectionPred = std::function<bool(const SectionBase &Sec)>;
+
+static bool isDebugSection(const SectionBase &Sec) {
+ return StringRef(Sec.Name).startswith(".debug") ||
+ StringRef(Sec.Name).startswith(".zdebug") || Sec.Name == ".gdb_index";
+}
+
+static bool isDWOSection(const SectionBase &Sec) {
+ return StringRef(Sec.Name).endswith(".dwo");
+}
+
+static 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);
+}
+
+uint64_t getNewShfFlags(SectionFlag AllFlags) {
+ uint64_t NewFlags = 0;
+ if (AllFlags & SectionFlag::SecAlloc)
+ NewFlags |= ELF::SHF_ALLOC;
+ if (!(AllFlags & SectionFlag::SecReadonly))
+ NewFlags |= ELF::SHF_WRITE;
+ if (AllFlags & SectionFlag::SecCode)
+ NewFlags |= ELF::SHF_EXECINSTR;
+ if (AllFlags & SectionFlag::SecMerge)
+ NewFlags |= ELF::SHF_MERGE;
+ if (AllFlags & SectionFlag::SecStrings)
+ NewFlags |= ELF::SHF_STRINGS;
+ return NewFlags;
+}
+
+static uint64_t getSectionFlagsPreserveMask(uint64_t OldFlags,
+ uint64_t NewFlags) {
+ // Preserve some flags which should not be dropped when setting flags.
+ // Also, preserve anything OS/processor dependant.
+ const uint64_t PreserveMask = ELF::SHF_COMPRESSED | ELF::SHF_EXCLUDE |
+ ELF::SHF_GROUP | ELF::SHF_LINK_ORDER |
+ ELF::SHF_MASKOS | ELF::SHF_MASKPROC |
+ ELF::SHF_TLS | ELF::SHF_INFO_LINK;
+ return (OldFlags & PreserveMask) | (NewFlags & ~PreserveMask);
+}
+
+static void setSectionFlagsAndType(SectionBase &Sec, SectionFlag Flags) {
+ Sec.Flags = getSectionFlagsPreserveMask(Sec.Flags, getNewShfFlags(Flags));
+
+ // In GNU objcopy, certain flags promote SHT_NOBITS to SHT_PROGBITS. This rule
+ // may promote more non-ALLOC sections than GNU objcopy, but it is fine as
+ // non-ALLOC SHT_NOBITS sections do not make much sense.
+ if (Sec.Type == SHT_NOBITS &&
+ (!(Sec.Flags & ELF::SHF_ALLOC) ||
+ Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)))
+ Sec.Type = SHT_PROGBITS;
+}
+
+static ElfType getOutputElfType(const Binary &Bin) {
+ // Infer output ELF type from the input ELF object
+ if (isa<ELFObjectFile<ELF32LE>>(Bin))
+ return ELFT_ELF32LE;
+ if (isa<ELFObjectFile<ELF64LE>>(Bin))
+ return ELFT_ELF64LE;
+ if (isa<ELFObjectFile<ELF32BE>>(Bin))
+ return ELFT_ELF32BE;
+ if (isa<ELFObjectFile<ELF64BE>>(Bin))
+ return ELFT_ELF64BE;
+ llvm_unreachable("Invalid ELFType");
+}
+
+static ElfType getOutputElfType(const MachineInfo &MI) {
+ // Infer output ELF type from the binary arch specified
+ if (MI.Is64Bit)
+ return MI.IsLittleEndian ? ELFT_ELF64LE : ELFT_ELF64BE;
+ else
+ return MI.IsLittleEndian ? ELFT_ELF32LE : ELFT_ELF32BE;
+}
+
+static std::unique_ptr<Writer> createELFWriter(const CopyConfig &Config,
+ Object &Obj, Buffer &Buf,
+ ElfType OutputElfType) {
+ // Depending on the initial ELFT and OutputFormat we need a different Writer.
+ switch (OutputElfType) {
+ case ELFT_ELF32LE:
+ return std::make_unique<ELFWriter<ELF32LE>>(Obj, Buf,
+ !Config.StripSections);
+ case ELFT_ELF64LE:
+ return std::make_unique<ELFWriter<ELF64LE>>(Obj, Buf,
+ !Config.StripSections);
+ case ELFT_ELF32BE:
+ return std::make_unique<ELFWriter<ELF32BE>>(Obj, Buf,
+ !Config.StripSections);
+ case ELFT_ELF64BE:
+ return std::make_unique<ELFWriter<ELF64BE>>(Obj, Buf,
+ !Config.StripSections);
+ }
+ llvm_unreachable("Invalid output format");
+}
+
+static std::unique_ptr<Writer> createWriter(const CopyConfig &Config,
+ Object &Obj, Buffer &Buf,
+ ElfType OutputElfType) {
+ switch (Config.OutputFormat) {
+ case FileFormat::Binary:
+ return std::make_unique<BinaryWriter>(Obj, Buf);
+ case FileFormat::IHex:
+ return std::make_unique<IHexWriter>(Obj, Buf);
+ default:
+ return createELFWriter(Config, Obj, Buf, OutputElfType);
+ }
+}
+
+template <class ELFT>
+static Expected<ArrayRef<uint8_t>>
+findBuildID(const CopyConfig &Config, const object::ELFFile<ELFT> &In) {
+ auto PhdrsOrErr = In.program_headers();
+ if (auto Err = PhdrsOrErr.takeError())
+ return createFileError(Config.InputFilename, std::move(Err));
+
+ for (const auto &Phdr : *PhdrsOrErr) {
+ if (Phdr.p_type != PT_NOTE)
+ continue;
+ Error Err = Error::success();
+ for (const auto &Note : In.notes(Phdr, Err))
+ if (Note.getType() == NT_GNU_BUILD_ID && Note.getName() == ELF_NOTE_GNU)
+ return Note.getDesc();
+ if (Err)
+ return createFileError(Config.InputFilename, std::move(Err));
+ }
+
+ return createFileError(
+ Config.InputFilename,
+ createStringError(llvm::errc::invalid_argument,
+ "could not find build ID"));
+}
+
+static Expected<ArrayRef<uint8_t>>
+findBuildID(const CopyConfig &Config, const object::ELFObjectFileBase &In) {
+ if (auto *O = dyn_cast<ELFObjectFile<ELF32LE>>(&In))
+ return findBuildID(Config, *O->getELFFile());
+ else if (auto *O = dyn_cast<ELFObjectFile<ELF64LE>>(&In))
+ return findBuildID(Config, *O->getELFFile());
+ else if (auto *O = dyn_cast<ELFObjectFile<ELF32BE>>(&In))
+ return findBuildID(Config, *O->getELFFile());
+ else if (auto *O = dyn_cast<ELFObjectFile<ELF64BE>>(&In))
+ return findBuildID(Config, *O->getELFFile());
+
+ llvm_unreachable("Bad file format");
+}
+
+template <class... Ts>
+static Error makeStringError(std::error_code EC, const Twine &Msg, Ts &&... Args) {
+ std::string FullMsg = (EC.message() + ": " + Msg).str();
+ return createStringError(EC, FullMsg.c_str(), std::forward<Ts>(Args)...);
+}
+
+#define MODEL_8 "%%%%%%%%"
+#define MODEL_16 MODEL_8 MODEL_8
+#define MODEL_32 (MODEL_16 MODEL_16)
+
+static Error linkToBuildIdDir(const CopyConfig &Config, StringRef ToLink,
+ StringRef Suffix,
+ ArrayRef<uint8_t> BuildIdBytes) {
+ SmallString<128> Path = Config.BuildIdLinkDir;
+ sys::path::append(Path, llvm::toHex(BuildIdBytes[0], /*LowerCase*/ true));
+ if (auto EC = sys::fs::create_directories(Path))
+ return createFileError(
+ Path.str(),
+ makeStringError(EC, "cannot create build ID link directory"));
+
+ sys::path::append(Path,
+ llvm::toHex(BuildIdBytes.slice(1), /*LowerCase*/ true));
+ Path += Suffix;
+ SmallString<128> TmpPath;
+ // create_hard_link races so we need to link to a temporary path but
+ // we want to make sure that we choose a filename that does not exist.
+ // By using 32 model characters we get 128-bits of entropy. It is
+ // unlikely that this string has ever existed before much less exists
+ // on this disk or in the current working directory.
+ // Additionally we prepend the original Path for debugging but also
+ // because it ensures that we're linking within a directory on the same
+ // partition on the same device which is critical. It has the added
+ // win of yet further decreasing the odds of a conflict.
+ sys::fs::createUniquePath(Twine(Path) + "-" + MODEL_32 + ".tmp", TmpPath,
+ /*MakeAbsolute*/ false);
+ if (auto EC = sys::fs::create_hard_link(ToLink, TmpPath)) {
+ Path.push_back('\0');
+ return makeStringError(EC, "cannot link '%s' to '%s'", ToLink.data(),
+ Path.data());
+ }
+ // We then atomically rename the link into place which will just move the
+ // link. If rename fails something is more seriously wrong so just return
+ // an error.
+ if (auto EC = sys::fs::rename(TmpPath, Path)) {
+ Path.push_back('\0');
+ return makeStringError(EC, "cannot link '%s' to '%s'", ToLink.data(),
+ Path.data());
+ }
+ // If `Path` was already a hard-link to the same underlying file then the
+ // temp file will be left so we need to remove it. Remove will not cause
+ // an error by default if the file is already gone so just blindly remove
+ // it rather than checking.
+ if (auto EC = sys::fs::remove(TmpPath)) {
+ TmpPath.push_back('\0');
+ return makeStringError(EC, "could not remove '%s'", TmpPath.data());
+ }
+ return Error::success();
+}
+
+static Error splitDWOToFile(const CopyConfig &Config, const Reader &Reader,
+ StringRef File, ElfType OutputElfType) {
+ auto DWOFile = Reader.create(false);
+ auto OnlyKeepDWOPred = [&DWOFile](const SectionBase &Sec) {
+ return onlyKeepDWOPred(*DWOFile, Sec);
+ };
+ if (Error E = DWOFile->removeSections(Config.AllowBrokenLinks,
+ OnlyKeepDWOPred))
+ return E;
+ if (Config.OutputArch) {
+ DWOFile->Machine = Config.OutputArch.getValue().EMachine;
+ DWOFile->OSABI = Config.OutputArch.getValue().OSABI;
+ }
+ FileBuffer FB(File);
+ auto Writer = createWriter(Config, *DWOFile, FB, OutputElfType);
+ if (Error E = Writer->finalize())
+ return E;
+ return Writer->write();
+}
+
+static Error dumpSectionToFile(StringRef SecName, StringRef Filename,
+ Object &Obj) {
+ for (auto &Sec : Obj.sections()) {
+ if (Sec.Name == SecName) {
+ if (Sec.OriginalData.empty())
+ return createStringError(object_error::parse_failed,
+ "cannot dump section '%s': it has no contents",
+ SecName.str().c_str());
+ Expected<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
+ FileOutputBuffer::create(Filename, Sec.OriginalData.size());
+ if (!BufferOrErr)
+ return BufferOrErr.takeError();
+ std::unique_ptr<FileOutputBuffer> Buf = std::move(*BufferOrErr);
+ std::copy(Sec.OriginalData.begin(), Sec.OriginalData.end(),
+ Buf->getBufferStart());
+ if (Error E = Buf->commit())
+ return E;
+ return Error::success();
+ }
+ }
+ return createStringError(object_error::parse_failed, "section '%s' not found",
+ SecName.str().c_str());
+}
+
+static bool isCompressable(const SectionBase &Sec) {
+ return !(Sec.Flags & ELF::SHF_COMPRESSED) &&
+ StringRef(Sec.Name).startswith(".debug");
+}
+
+static void replaceDebugSections(
+ Object &Obj, SectionPred &RemovePred,
+ function_ref<bool(const SectionBase &)> shouldReplace,
+ function_ref<SectionBase *(const SectionBase *)> addSection) {
+ // Build a list of the debug sections we are going to replace.
+ // We can't call `addSection` while iterating over sections,
+ // because it would mutate the sections array.
+ SmallVector<SectionBase *, 13> ToReplace;
+ for (auto &Sec : Obj.sections())
+ if (shouldReplace(Sec))
+ ToReplace.push_back(&Sec);
+
+ // Build a mapping from original section to a new one.
+ DenseMap<SectionBase *, SectionBase *> FromTo;
+ for (SectionBase *S : ToReplace)
+ FromTo[S] = addSection(S);
+
+ // Now we want to update the target sections of relocation
+ // sections. Also we will update the relocations themselves
+ // to update the symbol references.
+ for (auto &Sec : Obj.sections())
+ Sec.replaceSectionReferences(FromTo);
+
+ RemovePred = [shouldReplace, RemovePred](const SectionBase &Sec) {
+ return shouldReplace(Sec) || RemovePred(Sec);
+ };
+}
+
+static bool isUnneededSymbol(const Symbol &Sym) {
+ return !Sym.Referenced &&
+ (Sym.Binding == STB_LOCAL || Sym.getShndx() == SHN_UNDEF) &&
+ Sym.Type != STT_SECTION;
+}
+
+static Error updateAndRemoveSymbols(const CopyConfig &Config, Object &Obj) {
+ // TODO: update or remove symbols only if there is an option that affects
+ // them.
+ if (!Obj.SymbolTable)
+ return Error::success();
+
+ Obj.SymbolTable->updateSymbols([&](Symbol &Sym) {
+ // Common and undefined symbols don't make sense as local symbols, and can
+ // even cause crashes if we localize those, so skip them.
+ if (!Sym.isCommon() && Sym.getShndx() != SHN_UNDEF &&
+ ((Config.LocalizeHidden &&
+ (Sym.Visibility == STV_HIDDEN || Sym.Visibility == STV_INTERNAL)) ||
+ Config.SymbolsToLocalize.matches(Sym.Name)))
+ Sym.Binding = STB_LOCAL;
+
+ // Note: these two globalize flags have very similar names but different
+ // meanings:
+ //
+ // --globalize-symbol: promote a symbol to global
+ // --keep-global-symbol: all symbols except for these should be made local
+ //
+ // If --globalize-symbol is specified for a given symbol, it will be
+ // global in the output file even if it is not included via
+ // --keep-global-symbol. Because of that, make sure to check
+ // --globalize-symbol second.
+ if (!Config.SymbolsToKeepGlobal.empty() &&
+ !Config.SymbolsToKeepGlobal.matches(Sym.Name) &&
+ Sym.getShndx() != SHN_UNDEF)
+ Sym.Binding = STB_LOCAL;
+
+ if (Config.SymbolsToGlobalize.matches(Sym.Name) &&
+ Sym.getShndx() != SHN_UNDEF)
+ Sym.Binding = STB_GLOBAL;
+
+ if (Config.SymbolsToWeaken.matches(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();
+
+ if (!Config.SymbolsPrefix.empty() && Sym.Type != STT_SECTION)
+ Sym.Name = (Config.SymbolsPrefix + Sym.Name).str();
+ });
+
+ // The purpose of this loop is to mark symbols referenced by sections
+ // (like GroupSection or RelocationSection). This way, we know which
+ // symbols are still 'needed' and which are not.
+ if (Config.StripUnneeded || !Config.UnneededSymbolsToRemove.empty() ||
+ !Config.OnlySection.empty()) {
+ for (SectionBase &Sec : Obj.sections())
+ Sec.markSymbols();
+ }
+
+ auto RemoveSymbolsPred = [&](const Symbol &Sym) {
+ if (Config.SymbolsToKeep.matches(Sym.Name) ||
+ (Config.KeepFileSymbols && Sym.Type == STT_FILE))
+ return false;
+
+ if ((Config.DiscardMode == DiscardType::All ||
+ (Config.DiscardMode == DiscardType::Locals &&
+ StringRef(Sym.Name).startswith(".L"))) &&
+ Sym.Binding == STB_LOCAL && Sym.getShndx() != SHN_UNDEF &&
+ Sym.Type != STT_FILE && Sym.Type != STT_SECTION)
+ return true;
+
+ if (Config.StripAll || Config.StripAllGNU)
+ return true;
+
+ if (Config.SymbolsToRemove.matches(Sym.Name))
+ return true;
+
+ if ((Config.StripUnneeded ||
+ Config.UnneededSymbolsToRemove.matches(Sym.Name)) &&
+ (!Obj.isRelocatable() || isUnneededSymbol(Sym)))
+ return true;
+
+ // We want to remove undefined symbols if all references have been stripped.
+ if (!Config.OnlySection.empty() && !Sym.Referenced &&
+ Sym.getShndx() == SHN_UNDEF)
+ return true;
+
+ return false;
+ };
+
+ return Obj.removeSymbols(RemoveSymbolsPred);
+}
+
+static Error replaceAndRemoveSections(const CopyConfig &Config, Object &Obj) {
+ SectionPred RemovePred = [](const SectionBase &) { return false; };
+
+ // Removes:
+ if (!Config.ToRemove.empty()) {
+ RemovePred = [&Config](const SectionBase &Sec) {
+ return Config.ToRemove.matches(Sec.Name);
+ };
+ }
+
+ 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 isDebugSection(Sec);
+ };
+
+ if (Config.StripSections) {
+ RemovePred = [RemovePred](const SectionBase &Sec) {
+ return RemovePred(Sec) || Sec.ParentSegment == nullptr;
+ };
+ }
+
+ if (Config.StripDebug || Config.StripUnneeded) {
+ RemovePred = [RemovePred](const SectionBase &Sec) {
+ return RemovePred(Sec) || isDebugSection(Sec);
+ };
+ }
+
+ 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 && Sec.ParentSegment == nullptr;
+ };
+
+ if (Config.StripAll)
+ RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
+ if (RemovePred(Sec))
+ return true;
+ if (&Sec == Obj.SectionNames)
+ return false;
+ if (StringRef(Sec.Name).startswith(".gnu.warning"))
+ return false;
+ if (Sec.ParentSegment != nullptr)
+ return false;
+ return (Sec.Flags & SHF_ALLOC) == 0;
+ };
+
+ if (Config.ExtractPartition || Config.ExtractMainPartition) {
+ RemovePred = [RemovePred](const SectionBase &Sec) {
+ if (RemovePred(Sec))
+ return true;
+ if (Sec.Type == SHT_LLVM_PART_EHDR || Sec.Type == SHT_LLVM_PART_PHDR)
+ return true;
+ return (Sec.Flags & SHF_ALLOC) != 0 && !Sec.ParentSegment;
+ };
+ }
+
+ // Explicit copies:
+ if (!Config.OnlySection.empty()) {
+ RemovePred = [&Config, RemovePred, &Obj](const SectionBase &Sec) {
+ // Explicitly keep these sections regardless of previous removes.
+ if (Config.OnlySection.matches(Sec.Name))
+ 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 && Obj.SymbolTable->getStrTab() == &Sec))
+ return false;
+
+ // Remove everything else.
+ return true;
+ };
+ }
+
+ if (!Config.KeepSection.empty()) {
+ RemovePred = [&Config, RemovePred](const SectionBase &Sec) {
+ // Explicitly keep these sections regardless of previous removes.
+ if (Config.KeepSection.matches(Sec.Name))
+ return false;
+ // Otherwise defer to RemovePred.
+ return RemovePred(Sec);
+ };
+ }
+
+ // This has to be the last predicate assignment.
+ // If the option --keep-symbol has been specified
+ // and at least one of those symbols is present
+ // (equivalently, the updated symbol table is not empty)
+ // the symbol table and the string table should not be removed.
+ if ((!Config.SymbolsToKeep.empty() || Config.KeepFileSymbols) &&
+ Obj.SymbolTable && !Obj.SymbolTable->empty()) {
+ RemovePred = [&Obj, RemovePred](const SectionBase &Sec) {
+ if (&Sec == Obj.SymbolTable || &Sec == Obj.SymbolTable->getStrTab())
+ return false;
+ return RemovePred(Sec);
+ };
+ }
+
+ if (Config.CompressionType != DebugCompressionType::None)
+ replaceDebugSections(Obj, RemovePred, isCompressable,
+ [&Config, &Obj](const SectionBase *S) {
+ return &Obj.addSection<CompressedSection>(
+ *S, Config.CompressionType);
+ });
+ else if (Config.DecompressDebugSections)
+ replaceDebugSections(
+ Obj, RemovePred,
+ [](const SectionBase &S) { return isa<CompressedSection>(&S); },
+ [&Obj](const SectionBase *S) {
+ auto CS = cast<CompressedSection>(S);
+ return &Obj.addSection<DecompressedSection>(*CS);
+ });
+
+ return Obj.removeSections(Config.AllowBrokenLinks, RemovePred);
+}
+
+// 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.
+static Error handleArgs(const CopyConfig &Config, Object &Obj,
+ const Reader &Reader, ElfType OutputElfType) {
+
+ if (!Config.SplitDWO.empty())
+ if (Error E =
+ splitDWOToFile(Config, Reader, Config.SplitDWO, OutputElfType))
+ return E;
+
+ if (Config.OutputArch) {
+ Obj.Machine = Config.OutputArch.getValue().EMachine;
+ Obj.OSABI = Config.OutputArch.getValue().OSABI;
+ }
+
+ // It is important to remove the sections first. For example, we want to
+ // remove the relocation sections before removing the symbols. That allows
+ // us to avoid reporting the inappropriate errors about removing symbols
+ // named in relocations.
+ if (Error E = replaceAndRemoveSections(Config, Obj))
+ return E;
+
+ if (Error E = updateAndRemoveSymbols(Config, Obj))
+ return E;
+
+ if (!Config.SectionsToRename.empty()) {
+ for (SectionBase &Sec : Obj.sections()) {
+ const auto Iter = Config.SectionsToRename.find(Sec.Name);
+ if (Iter != Config.SectionsToRename.end()) {
+ const SectionRename &SR = Iter->second;
+ Sec.Name = SR.NewName;
+ if (SR.NewFlags.hasValue())
+ setSectionFlagsAndType(Sec, SR.NewFlags.getValue());
+ }
+ }
+ }
+
+ // Add a prefix to allocated sections and their relocation sections. This
+ // should be done after renaming the section by Config.SectionToRename to
+ // imitate the GNU objcopy behavior.
+ if (!Config.AllocSectionsPrefix.empty()) {
+ DenseSet<SectionBase *> PrefixedSections;
+ for (SectionBase &Sec : Obj.sections()) {
+ if (Sec.Flags & SHF_ALLOC) {
+ Sec.Name = (Config.AllocSectionsPrefix + Sec.Name).str();
+ PrefixedSections.insert(&Sec);
+ } else if (auto *RelocSec = dyn_cast<RelocationSectionBase>(&Sec)) {
+ // Rename relocation sections associated to the allocated sections.
+ // For example, if we rename .text to .prefix.text, we also rename
+ // .rel.text to .rel.prefix.text.
+ //
+ // Dynamic relocation sections (SHT_REL[A] with SHF_ALLOC) are handled
+ // above, e.g., .rela.plt is renamed to .prefix.rela.plt, not
+ // .rela.prefix.plt since GNU objcopy does so.
+ const SectionBase *TargetSec = RelocSec->getSection();
+ if (TargetSec && (TargetSec->Flags & SHF_ALLOC)) {
+ StringRef prefix;
+ switch (Sec.Type) {
+ case SHT_REL:
+ prefix = ".rel";
+ break;
+ case SHT_RELA:
+ prefix = ".rela";
+ break;
+ default:
+ llvm_unreachable("not a relocation section");
+ }
+
+ // If the relocation section comes *after* the target section, we
+ // don't add Config.AllocSectionsPrefix because we've already added
+ // the prefix to TargetSec->Name. Otherwise, if the relocation
+ // section comes *before* the target section, we add the prefix.
+ if (PrefixedSections.count(TargetSec))
+ Sec.Name = (prefix + TargetSec->Name).str();
+ else
+ Sec.Name =
+ (prefix + Config.AllocSectionsPrefix + TargetSec->Name).str();
+ }
+ }
+ }
+ }
+
+ if (!Config.SetSectionAlignment.empty()) {
+ for (SectionBase &Sec : Obj.sections()) {
+ auto I = Config.SetSectionAlignment.find(Sec.Name);
+ if (I != Config.SetSectionAlignment.end())
+ Sec.Align = I->second;
+ }
+ }
+
+ if (!Config.SetSectionFlags.empty()) {
+ for (auto &Sec : Obj.sections()) {
+ const auto Iter = Config.SetSectionFlags.find(Sec.Name);
+ if (Iter != Config.SetSectionFlags.end()) {
+ const SectionFlagsUpdate &SFU = Iter->second;
+ setSectionFlagsAndType(Sec, SFU.NewFlags);
+ }
+ }
+ }
+
+ for (const auto &Flag : Config.AddSection) {
+ std::pair<StringRef, StringRef> SecPair = Flag.split("=");
+ StringRef SecName = SecPair.first;
+ StringRef File = SecPair.second;
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrErr =
+ MemoryBuffer::getFile(File);
+ if (!BufOrErr)
+ return createFileError(File, errorCodeToError(BufOrErr.getError()));
+ std::unique_ptr<MemoryBuffer> Buf = std::move(*BufOrErr);
+ ArrayRef<uint8_t> Data(
+ reinterpret_cast<const uint8_t *>(Buf->getBufferStart()),
+ Buf->getBufferSize());
+ OwnedDataSection &NewSection =
+ Obj.addSection<OwnedDataSection>(SecName, Data);
+ if (SecName.startswith(".note") && SecName != ".note.GNU-stack")
+ NewSection.Type = SHT_NOTE;
+ }
+
+ for (const auto &Flag : Config.DumpSection) {
+ std::pair<StringRef, StringRef> SecPair = Flag.split("=");
+ StringRef SecName = SecPair.first;
+ StringRef File = SecPair.second;
+ if (Error E = dumpSectionToFile(SecName, File, Obj))
+ return E;
+ }
+
+ if (!Config.AddGnuDebugLink.empty())
+ Obj.addSection<GnuDebugLinkSection>(Config.AddGnuDebugLink,
+ Config.GnuDebugLinkCRC32);
+
+ for (const NewSymbolInfo &SI : Config.ELF->SymbolsToAdd) {
+ SectionBase *Sec = Obj.findSection(SI.SectionName);
+ uint64_t Value = Sec ? Sec->Addr + SI.Value : SI.Value;
+ Obj.SymbolTable->addSymbol(
+ SI.SymbolName, SI.Bind, SI.Type, Sec, Value, SI.Visibility,
+ Sec ? (uint16_t)SYMBOL_SIMPLE_INDEX : (uint16_t)SHN_ABS, 0);
+ }
+
+ if (Config.EntryExpr)
+ Obj.Entry = Config.EntryExpr(Obj.Entry);
+ return Error::success();
+}
+
+static Error writeOutput(const CopyConfig &Config, Object &Obj, Buffer &Out,
+ ElfType OutputElfType) {
+ std::unique_ptr<Writer> Writer =
+ createWriter(Config, Obj, Out, OutputElfType);
+ if (Error E = Writer->finalize())
+ return E;
+ return Writer->write();
+}
+
+Error executeObjcopyOnIHex(const CopyConfig &Config, MemoryBuffer &In,
+ Buffer &Out) {
+ IHexReader Reader(&In);
+ std::unique_ptr<Object> Obj = Reader.create(true);
+ const ElfType OutputElfType =
+ getOutputElfType(Config.OutputArch.getValueOr(MachineInfo()));
+ if (Error E = handleArgs(Config, *Obj, Reader, OutputElfType))
+ return E;
+ return writeOutput(Config, *Obj, Out, OutputElfType);
+}
+
+Error executeObjcopyOnRawBinary(const CopyConfig &Config, MemoryBuffer &In,
+ Buffer &Out) {
+ uint8_t NewSymbolVisibility =
+ Config.ELF->NewSymbolVisibility.getValueOr((uint8_t)ELF::STV_DEFAULT);
+ BinaryReader Reader(&In, NewSymbolVisibility);
+ std::unique_ptr<Object> Obj = Reader.create(true);
+
+ // Prefer OutputArch (-O<format>) if set, otherwise fallback to BinaryArch
+ // (-B<arch>).
+ const ElfType OutputElfType =
+ getOutputElfType(Config.OutputArch.getValueOr(MachineInfo()));
+ if (Error E = handleArgs(Config, *Obj, Reader, OutputElfType))
+ return E;
+ return writeOutput(Config, *Obj, Out, OutputElfType);
+}
+
+Error executeObjcopyOnBinary(const CopyConfig &Config,
+ object::ELFObjectFileBase &In, Buffer &Out) {
+ ELFReader Reader(&In, Config.ExtractPartition);
+ std::unique_ptr<Object> Obj = Reader.create(!Config.SymbolsToAdd.empty());
+ // Prefer OutputArch (-O<format>) if set, otherwise infer it from the input.
+ const ElfType OutputElfType =
+ Config.OutputArch ? getOutputElfType(Config.OutputArch.getValue())
+ : getOutputElfType(In);
+ ArrayRef<uint8_t> BuildIdBytes;
+
+ if (!Config.BuildIdLinkDir.empty()) {
+ auto BuildIdBytesOrErr = findBuildID(Config, In);
+ if (auto E = BuildIdBytesOrErr.takeError())
+ return E;
+ BuildIdBytes = *BuildIdBytesOrErr;
+
+ if (BuildIdBytes.size() < 2)
+ return createFileError(
+ Config.InputFilename,
+ createStringError(object_error::parse_failed,
+ "build ID is smaller than two bytes"));
+ }
+
+ if (!Config.BuildIdLinkDir.empty() && Config.BuildIdLinkInput)
+ if (Error E =
+ linkToBuildIdDir(Config, Config.InputFilename,
+ Config.BuildIdLinkInput.getValue(), BuildIdBytes))
+ return E;
+
+ if (Error E = handleArgs(Config, *Obj, Reader, OutputElfType))
+ return createFileError(Config.InputFilename, std::move(E));
+
+ if (Error E = writeOutput(Config, *Obj, Out, OutputElfType))
+ return createFileError(Config.InputFilename, std::move(E));
+ if (!Config.BuildIdLinkDir.empty() && Config.BuildIdLinkOutput)
+ if (Error E =
+ linkToBuildIdDir(Config, Config.OutputFilename,
+ Config.BuildIdLinkOutput.getValue(), BuildIdBytes))
+ return createFileError(Config.OutputFilename, std::move(E));
+
+ return Error::success();
+}
+
+} // end namespace elf
+} // end namespace objcopy
+} // end namespace llvm
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 02:28:59 +0000