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//===-- ObjectFileELF.h --------------------------------------- -*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_SOURCE_PLUGINS_OBJECTFILE_ELF_OBJECTFILEELF_H
#define LLDB_SOURCE_PLUGINS_OBJECTFILE_ELF_OBJECTFILEELF_H
#include <stdint.h>
#include <vector>
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Utility/ArchSpec.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/UUID.h"
#include "lldb/lldb-private.h"
#include "ELFHeader.h"
struct ELFNote {
elf::elf_word n_namesz;
elf::elf_word n_descsz;
elf::elf_word n_type;
std::string n_name;
ELFNote() : n_namesz(0), n_descsz(0), n_type(0) {}
/// Parse an ELFNote entry from the given DataExtractor starting at position
/// \p offset.
///
/// \param[in] data
/// The DataExtractor to read from.
///
/// \param[in,out] offset
/// Pointer to an offset in the data. On return the offset will be
/// advanced by the number of bytes read.
///
/// \return
/// True if the ELFRel entry was successfully read and false otherwise.
bool Parse(const lldb_private::DataExtractor &data, lldb::offset_t *offset);
size_t GetByteSize() const {
return 12 + llvm::alignTo(n_namesz, 4) + llvm::alignTo(n_descsz, 4);
}
};
/// \class ObjectFileELF
/// Generic ELF object file reader.
///
/// This class provides a generic ELF (32/64 bit) reader plugin implementing
/// the ObjectFile protocol.
class ObjectFileELF : public lldb_private::ObjectFile {
public:
// Static Functions
static void Initialize();
static void Terminate();
static lldb_private::ConstString GetPluginNameStatic();
static const char *GetPluginDescriptionStatic();
static lldb_private::ObjectFile *
CreateInstance(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp,
lldb::offset_t data_offset, const lldb_private::FileSpec *file,
lldb::offset_t file_offset, lldb::offset_t length);
static lldb_private::ObjectFile *CreateMemoryInstance(
const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp,
const lldb::ProcessSP &process_sp, lldb::addr_t header_addr);
static size_t GetModuleSpecifications(const lldb_private::FileSpec &file,
lldb::DataBufferSP &data_sp,
lldb::offset_t data_offset,
lldb::offset_t file_offset,
lldb::offset_t length,
lldb_private::ModuleSpecList &specs);
static bool MagicBytesMatch(lldb::DataBufferSP &data_sp, lldb::addr_t offset,
lldb::addr_t length);
// PluginInterface protocol
lldb_private::ConstString GetPluginName() override;
uint32_t GetPluginVersion() override;
// LLVM RTTI support
static char ID;
bool isA(const void *ClassID) const override {
return ClassID == &ID || ObjectFile::isA(ClassID);
}
static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
// ObjectFile Protocol.
bool ParseHeader() override;
bool SetLoadAddress(lldb_private::Target &target, lldb::addr_t value,
bool value_is_offset) override;
lldb::ByteOrder GetByteOrder() const override;
bool IsExecutable() const override;
uint32_t GetAddressByteSize() const override;
lldb_private::AddressClass GetAddressClass(lldb::addr_t file_addr) override;
lldb_private::Symtab *GetSymtab() override;
bool IsStripped() override;
void CreateSections(lldb_private::SectionList &unified_section_list) override;
void Dump(lldb_private::Stream *s) override;
lldb_private::ArchSpec GetArchitecture() override;
lldb_private::UUID GetUUID() override;
/// Return the contents of the .gnu_debuglink section, if the object file
/// contains it.
llvm::Optional<lldb_private::FileSpec> GetDebugLink();
uint32_t GetDependentModules(lldb_private::FileSpecList &files) override;
lldb_private::Address
GetImageInfoAddress(lldb_private::Target *target) override;
lldb_private::Address GetEntryPointAddress() override;
lldb_private::Address GetBaseAddress() override;
ObjectFile::Type CalculateType() override;
ObjectFile::Strata CalculateStrata() override;
size_t ReadSectionData(lldb_private::Section *section,
lldb::offset_t section_offset, void *dst,
size_t dst_len) override;
size_t ReadSectionData(lldb_private::Section *section,
lldb_private::DataExtractor &section_data) override;
llvm::ArrayRef<elf::ELFProgramHeader> ProgramHeaders();
lldb_private::DataExtractor GetSegmentData(const elf::ELFProgramHeader &H);
llvm::StringRef
StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const override;
void RelocateSection(lldb_private::Section *section) override;
protected:
std::vector<LoadableData>
GetLoadableData(lldb_private::Target &target) override;
private:
ObjectFileELF(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp,
lldb::offset_t data_offset, const lldb_private::FileSpec *file,
lldb::offset_t offset, lldb::offset_t length);
ObjectFileELF(const lldb::ModuleSP &module_sp,
lldb::DataBufferSP &header_data_sp,
const lldb::ProcessSP &process_sp, lldb::addr_t header_addr);
typedef std::vector<elf::ELFProgramHeader> ProgramHeaderColl;
struct ELFSectionHeaderInfo : public elf::ELFSectionHeader {
lldb_private::ConstString section_name;
};
typedef std::vector<ELFSectionHeaderInfo> SectionHeaderColl;
typedef SectionHeaderColl::iterator SectionHeaderCollIter;
typedef SectionHeaderColl::const_iterator SectionHeaderCollConstIter;
typedef std::vector<elf::ELFDynamic> DynamicSymbolColl;
typedef DynamicSymbolColl::iterator DynamicSymbolCollIter;
typedef DynamicSymbolColl::const_iterator DynamicSymbolCollConstIter;
typedef std::map<lldb::addr_t, lldb_private::AddressClass>
FileAddressToAddressClassMap;
/// Version of this reader common to all plugins based on this class.
static const uint32_t m_plugin_version = 1;
static const uint32_t g_core_uuid_magic;
/// ELF file header.
elf::ELFHeader m_header;
/// ELF build ID.
lldb_private::UUID m_uuid;
/// ELF .gnu_debuglink file and crc data if available.
std::string m_gnu_debuglink_file;
uint32_t m_gnu_debuglink_crc = 0;
/// Collection of program headers.
ProgramHeaderColl m_program_headers;
/// Collection of section headers.
SectionHeaderColl m_section_headers;
/// Collection of symbols from the dynamic table.
DynamicSymbolColl m_dynamic_symbols;
/// Object file parsed from .gnu_debugdata section (\sa
/// GetGnuDebugDataObjectFile())
std::shared_ptr<ObjectFileELF> m_gnu_debug_data_object_file;
/// List of file specifications corresponding to the modules (shared
/// libraries) on which this object file depends.
mutable std::unique_ptr<lldb_private::FileSpecList> m_filespec_up;
/// Cached value of the entry point for this module.
lldb_private::Address m_entry_point_address;
/// The architecture detected from parsing elf file contents.
lldb_private::ArchSpec m_arch_spec;
/// The address class for each symbol in the elf file
FileAddressToAddressClassMap m_address_class_map;
/// Returns the index of the given section header.
size_t SectionIndex(const SectionHeaderCollIter &I);
/// Returns the index of the given section header.
size_t SectionIndex(const SectionHeaderCollConstIter &I) const;
// Parses the ELF program headers.
static size_t GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
lldb_private::DataExtractor &object_data,
const elf::ELFHeader &header);
// Finds PT_NOTE segments and calculates their crc sum.
static uint32_t
CalculateELFNotesSegmentsCRC32(const ProgramHeaderColl &program_headers,
lldb_private::DataExtractor &data);
/// Parses all section headers present in this object file and populates
/// m_program_headers. This method will compute the header list only once.
/// Returns true iff the headers have been successfully parsed.
bool ParseProgramHeaders();
/// Parses all section headers present in this object file and populates
/// m_section_headers. This method will compute the header list only once.
/// Returns the number of headers parsed.
size_t ParseSectionHeaders();
lldb::SectionType GetSectionType(const ELFSectionHeaderInfo &H) const;
static void ParseARMAttributes(lldb_private::DataExtractor &data,
uint64_t length,
lldb_private::ArchSpec &arch_spec);
/// Parses the elf section headers and returns the uuid, debug link name,
/// crc, archspec.
static size_t GetSectionHeaderInfo(SectionHeaderColl &section_headers,
lldb_private::DataExtractor &object_data,
const elf::ELFHeader &header,
lldb_private::UUID &uuid,
std::string &gnu_debuglink_file,
uint32_t &gnu_debuglink_crc,
lldb_private::ArchSpec &arch_spec);
/// Scans the dynamic section and locates all dependent modules (shared
/// libraries) populating m_filespec_up. This method will compute the
/// dependent module list only once. Returns the number of dependent
/// modules parsed.
size_t ParseDependentModules();
/// Parses the dynamic symbol table and populates m_dynamic_symbols. The
/// vector retains the order as found in the object file. Returns the
/// number of dynamic symbols parsed.
size_t ParseDynamicSymbols();
/// Populates m_symtab_up will all non-dynamic linker symbols. This method
/// will parse the symbols only once. Returns the number of symbols parsed.
unsigned ParseSymbolTable(lldb_private::Symtab *symbol_table,
lldb::user_id_t start_id,
lldb_private::Section *symtab);
/// Helper routine for ParseSymbolTable().
unsigned ParseSymbols(lldb_private::Symtab *symbol_table,
lldb::user_id_t start_id,
lldb_private::SectionList *section_list,
const size_t num_symbols,
const lldb_private::DataExtractor &symtab_data,
const lldb_private::DataExtractor &strtab_data);
/// Scans the relocation entries and adds a set of artificial symbols to the
/// given symbol table for each PLT slot. Returns the number of symbols
/// added.
unsigned ParseTrampolineSymbols(lldb_private::Symtab *symbol_table,
lldb::user_id_t start_id,
const ELFSectionHeaderInfo *rela_hdr,
lldb::user_id_t section_id);
void ParseUnwindSymbols(lldb_private::Symtab *symbol_table,
lldb_private::DWARFCallFrameInfo *eh_frame);
/// Relocates debug sections
unsigned RelocateDebugSections(const elf::ELFSectionHeader *rel_hdr,
lldb::user_id_t rel_id,
lldb_private::Symtab *thetab);
unsigned ApplyRelocations(lldb_private::Symtab *symtab,
const elf::ELFHeader *hdr,
const elf::ELFSectionHeader *rel_hdr,
const elf::ELFSectionHeader *symtab_hdr,
const elf::ELFSectionHeader *debug_hdr,
lldb_private::DataExtractor &rel_data,
lldb_private::DataExtractor &symtab_data,
lldb_private::DataExtractor &debug_data,
lldb_private::Section *rel_section);
/// Loads the section name string table into m_shstr_data. Returns the
/// number of bytes constituting the table.
size_t GetSectionHeaderStringTable();
/// Utility method for looking up a section given its name. Returns the
/// index of the corresponding section or zero if no section with the given
/// name can be found (note that section indices are always 1 based, and so
/// section index 0 is never valid).
lldb::user_id_t GetSectionIndexByName(const char *name);
/// Returns the section header with the given id or NULL.
const ELFSectionHeaderInfo *GetSectionHeaderByIndex(lldb::user_id_t id);
/// \name ELF header dump routines
//@{
static void DumpELFHeader(lldb_private::Stream *s,
const elf::ELFHeader &header);
static void DumpELFHeader_e_ident_EI_DATA(lldb_private::Stream *s,
unsigned char ei_data);
static void DumpELFHeader_e_type(lldb_private::Stream *s,
elf::elf_half e_type);
//@}
/// \name ELF program header dump routines
//@{
void DumpELFProgramHeaders(lldb_private::Stream *s);
static void DumpELFProgramHeader(lldb_private::Stream *s,
const elf::ELFProgramHeader &ph);
static void DumpELFProgramHeader_p_type(lldb_private::Stream *s,
elf::elf_word p_type);
static void DumpELFProgramHeader_p_flags(lldb_private::Stream *s,
elf::elf_word p_flags);
//@}
/// \name ELF section header dump routines
//@{
void DumpELFSectionHeaders(lldb_private::Stream *s);
static void DumpELFSectionHeader(lldb_private::Stream *s,
const ELFSectionHeaderInfo &sh);
static void DumpELFSectionHeader_sh_type(lldb_private::Stream *s,
elf::elf_word sh_type);
static void DumpELFSectionHeader_sh_flags(lldb_private::Stream *s,
elf::elf_xword sh_flags);
//@}
/// ELF dependent module dump routine.
void DumpDependentModules(lldb_private::Stream *s);
const elf::ELFDynamic *FindDynamicSymbol(unsigned tag);
unsigned PLTRelocationType();
static lldb_private::Status
RefineModuleDetailsFromNote(lldb_private::DataExtractor &data,
lldb_private::ArchSpec &arch_spec,
lldb_private::UUID &uuid);
bool AnySegmentHasPhysicalAddress();
/// Takes the .gnu_debugdata and returns the decompressed object file that is
/// stored within that section.
///
/// \returns either the decompressed object file stored within the
/// .gnu_debugdata section or \c nullptr if an error occured or if there's no
/// section with that name.
std::shared_ptr<ObjectFileELF> GetGnuDebugDataObjectFile();
};
#endif // LLDB_SOURCE_PLUGINS_OBJECTFILE_ELF_OBJECTFILEELF_H