ELFEmitter.cpp | Explore in Territory

//===- yaml2elf - Convert YAML to a ELF object file -----------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// The ELF component of yaml2obj.
///
//===----------------------------------------------------------------------===//

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/StringTableBuilder.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/ELFTypes.h"
#include "llvm/ObjectYAML/DWARFEmitter.h"
#include "llvm/ObjectYAML/DWARFYAML.h"
#include "llvm/ObjectYAML/ELFYAML.h"
#include "llvm/ObjectYAML/yaml2obj.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"
#include <optional>
#include <variant>

usingnamespacellvm;

// This class is used to build up a contiguous binary blob while keeping
// track of an offset in the output (which notionally begins at
// `InitialOffset`).
// The blob might be limited to an arbitrary size. All attempts to write data
// are ignored and the error condition is remembered once the limit is reached.
// Such an approach allows us to simplify the code by delaying error reporting
// and doing it at a convenient time.
namespace {
class ContiguousBlobAccumulator { … };

// Used to keep track of section and symbol names, so that in the YAML file
// sections and symbols can be referenced by name instead of by index.
class NameToIdxMap { … };

namespace {
struct Fragment { … };
} // namespace

/// "Single point of truth" for the ELF file construction.
/// TODO: This class still has a ways to go before it is truly a "single
/// point of truth".
template <class ELFT> class ELFState { … };
} // end anonymous namespace

template <class T> static size_t arrayDataSize(ArrayRef<T> A) { … }

template <class T> static void writeArrayData(raw_ostream &OS, ArrayRef<T> A) { … }

template <class T> static void zero(T &Obj) { … }

template <class ELFT>
ELFState<ELFT>::ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH)
    : … { … }

template <class ELFT>
void ELFState<ELFT>::writeELFHeader(raw_ostream &OS) { … }

template <class ELFT>
void ELFState<ELFT>::initProgramHeaders(std::vector<Elf_Phdr> &PHeaders) { … }

template <class ELFT>
unsigned ELFState<ELFT>::toSectionIndex(StringRef S, StringRef LocSec,
                                        StringRef LocSym) { … }

template <class ELFT>
unsigned ELFState<ELFT>::toSymbolIndex(StringRef S, StringRef LocSec,
                                       bool IsDynamic) { … }

template <class ELFT>
static void overrideFields(ELFYAML::Section *From, typename ELFT::Shdr &To) { … }

template <class ELFT>
bool ELFState<ELFT>::initImplicitHeader(ContiguousBlobAccumulator &CBA,
                                        Elf_Shdr &Header, StringRef SecName,
                                        ELFYAML::Section *YAMLSec) { … }

constexpr char SuffixStart = …;
constexpr char SuffixEnd = …;

std::string llvm::ELFYAML::appendUniqueSuffix(StringRef Name,
                                              const Twine &Msg) { … }

StringRef llvm::ELFYAML::dropUniqueSuffix(StringRef S) { … }

template <class ELFT>
uint64_t ELFState<ELFT>::getSectionNameOffset(StringRef Name) { … }

static uint64_t writeContent(ContiguousBlobAccumulator &CBA,
                             const std::optional<yaml::BinaryRef> &Content,
                             const std::optional<llvm::yaml::Hex64> &Size) { … }

static StringRef getDefaultLinkSec(unsigned SecType) { … }

template <class ELFT>
void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
                                        ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::assignSectionAddress(Elf_Shdr &SHeader,
                                          ELFYAML::Section *YAMLSec) { … }

static size_t findFirstNonGlobal(ArrayRef<ELFYAML::Symbol> Symbols) { … }

template <class ELFT>
std::vector<typename ELFT::Sym>
ELFState<ELFT>::toELFSymbols(ArrayRef<ELFYAML::Symbol> Symbols,
                             const StringTableBuilder &Strtab) { … }

template <class ELFT>
void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
                                             SymtabType STType,
                                             ContiguousBlobAccumulator &CBA,
                                             ELFYAML::Section *YAMLSec) { … }

template <class ELFT>
void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
                                             StringTableBuilder &STB,
                                             ContiguousBlobAccumulator &CBA,
                                             ELFYAML::Section *YAMLSec) { … }

static bool shouldEmitDWARF(DWARFYAML::Data &DWARF, StringRef Name) { … }

template <class ELFT>
Expected<uint64_t> emitDWARF(typename ELFT::Shdr &SHeader, StringRef Name,
                             const DWARFYAML::Data &DWARF,
                             ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::initDWARFSectionHeader(Elf_Shdr &SHeader, StringRef Name,
                                            ContiguousBlobAccumulator &CBA,
                                            ELFYAML::Section *YAMLSec) { … }

template <class ELFT> void ELFState<ELFT>::reportError(const Twine &Msg) { … }

template <class ELFT> void ELFState<ELFT>::reportError(Error Err) { … }

template <class ELFT>
std::vector<Fragment>
ELFState<ELFT>::getPhdrFragments(const ELFYAML::ProgramHeader &Phdr,
                                 ArrayRef<Elf_Shdr> SHeaders) { … }

template <class ELFT>
void ELFState<ELFT>::setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
                                            std::vector<Elf_Shdr> &SHeaders) { … }

bool llvm::ELFYAML::shouldAllocateFileSpace(
    ArrayRef<ELFYAML::ProgramHeader> Phdrs, const ELFYAML::NoBitsSection &S) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::NoBitsSection &S,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::RawContentSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

static bool isMips64EL(const ELFYAML::Object &Obj) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::RelocationSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::RelrSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::SymtabShndxSection &Shndx,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::GroupSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::SymverSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::StackSizesSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::BBAddrMapSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::LinkerOptionsSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::DependentLibrariesSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
uint64_t
ELFState<ELFT>::alignToOffset(ContiguousBlobAccumulator &CBA, uint64_t Align,
                              std::optional<llvm::yaml::Hex64> Offset) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::CallGraphProfileSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::HashSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::VerdefSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::VerneedSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(
    Elf_Shdr &SHeader, const ELFYAML::ARMIndexTableSection &Section,
    ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::MipsABIFlags &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::DynamicSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::AddrsigSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::NoteSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                         const ELFYAML::GnuHashSection &Section,
                                         ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
void ELFState<ELFT>::writeFill(ELFYAML::Fill &Fill,
                               ContiguousBlobAccumulator &CBA) { … }

template <class ELFT>
DenseMap<StringRef, size_t> ELFState<ELFT>::buildSectionHeaderReorderMap() { … }

template <class ELFT> void ELFState<ELFT>::buildSectionIndex() { … }

template <class ELFT> void ELFState<ELFT>::buildSymbolIndexes() { … }

template <class ELFT> void ELFState<ELFT>::finalizeStrings() { … }

template <class ELFT>
bool ELFState<ELFT>::writeELF(raw_ostream &OS, ELFYAML::Object &Doc,
                              yaml::ErrorHandler EH, uint64_t MaxSize) { … }

namespace llvm {
namespace yaml {

bool yaml2elf(llvm::ELFYAML::Object &Doc, raw_ostream &Out, ErrorHandler EH,
              uint64_t MaxSize) { … }

} // namespace yaml
} // namespace llvm
llvm/llvm/lib/ObjectYAML/ELFEmitter.cpp
