dart::bin::elf::LoadedElf Class Reference

Public Member Functions
	LoadedElf (std::unique_ptr< Mappable > mappable, uint64_t elf_data_offset)
	~LoadedElf ()
bool	Load ()
bool	ResolveSymbols (const uint8_t **vm_data, const uint8_t **vm_instrs, const uint8_t **isolate_data, const uint8_t **isolate_instrs)
const char *	error ()

Detailed Description

A loader for a subset of ELF which may be used to load objects produced by Dart_CreateAppAOTSnapshotAsElf.

Definition at line 167 of file elf_loader.cc.

Constructor & Destructor Documentation

LoadedElf()

dart::bin::elf::LoadedElf::LoadedElf ( std::unique_ptr< Mappable >  mappable, uint64_t  elf_data_offset  )

inlineexplicit

Definition at line 169 of file elf_loader.cc.

      : mappable_(std::move(mappable)), elf_data_offset_(elf_data_offset) {}

~LoadedElf()

dart::bin::elf::LoadedElf::~LoadedElf

(

)

Definition at line 297 of file elf_loader.cc.

                      {
#if defined(DART_HOST_OS_WINDOWS) &&                                           \
    (defined(HOST_ARCH_X64) || defined(HOST_ARCH_ARM64))
  for (intptr_t i = 0; i < dynamic_runtime_function_tables_.length(); i++) {
    UnwindingRecordsPlatform::UnregisterDynamicTable(
        dynamic_runtime_function_tables_[i]);
  }
#endif
 
  // Unmap the image.
  base_.reset();
 
  // Explicitly destroy all the mappings before closing the file.
  program_table_mapping_.reset();
  section_table_mapping_.reset();
  section_string_table_mapping_.reset();
}

Member Function Documentation

error()

const char * dart::bin::elf::LoadedElf::error ( )

inline

Definition at line 197 of file elf_loader.cc.

{ return error_; }

Load()

bool dart::bin::elf::LoadedElf::Load

(

)

Loads the ELF object into memory. Returns whether the load was successful. On failure, the error may be retrieved by 'error()'.

Definition at line 272 of file elf_loader.cc.

                     {
  VirtualMemory::Init();
 
  if (error_ != nullptr) {
    return false;
  }
 
  CHECK_ERROR(Utils::IsAligned(elf_data_offset_, PageSize()),
              "File offset must be page-aligned.");
 
  ASSERT(mappable_ != nullptr);
  CHECK_ERROR(mappable_->SetPosition(elf_data_offset_), "Invalid file offset.");
 
  CHECK(ReadHeader());
  CHECK(ReadProgramTable());
  CHECK(LoadSegments());
  CHECK(ReadSectionTable());
  CHECK(ReadSectionStringTable());
  CHECK(ReadSections());
 
  mappable_.reset();
 
  return true;
}

ResolveSymbols()

bool dart::bin::elf::LoadedElf::ResolveSymbols	(	const uint8_t **	vm_data,
		const uint8_t **	vm_instrs,
		const uint8_t **	isolate_data,
		const uint8_t **	isolate_instrs
	)

Reads Dart-specific symbols from the loaded ELF.

Stores the address of the corresponding symbol in each non-null output parameter.

Fails if any output parameter is non-null but points to null and the corresponding symbol was not found, or if the dynamic symbol table could not be decoded.

Has the side effect of initializing the relocated addresses for the text sections corresponding to non-null output parameters in the BSS segment.

On failure, the error may be retrieved by 'error()'.

Definition at line 505 of file elf_loader.cc.

                                                               {
  if (error_ != nullptr) {
    return false;
  }
 
  // The first entry of the symbol table is reserved.
  for (uword i = 1; i < dynamic_symbol_count_; ++i) {
    const dart::elf::Symbol sym = dynamic_symbol_table_[i];
    const char* name = dynamic_string_table_ + sym.name;
    const uint8_t** output = nullptr;
 
    if (strcmp(name, kVmSnapshotDataAsmSymbol) == 0) {
      output = vm_data;
    } else if (strcmp(name, kVmSnapshotInstructionsAsmSymbol) == 0) {
      output = vm_instrs;
    } else if (strcmp(name, kIsolateSnapshotDataAsmSymbol) == 0) {
      output = isolate_data;
    } else if (strcmp(name, kIsolateSnapshotInstructionsAsmSymbol) == 0) {
      output = isolate_instrs;
    }
 
    if (output != nullptr) {
      *output = reinterpret_cast<const uint8_t*>(base_->start() + sym.value);
    }
  }
 
  CHECK_ERROR(isolate_data == nullptr || *isolate_data != nullptr,
              "Could not find isolate snapshot data.");
  CHECK_ERROR(isolate_instrs == nullptr || *isolate_instrs != nullptr,
              "Could not find isolate instructions.");
  return true;
}

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The documentation for this class was generated from the following file:

• third_party/dart-lang/sdk/runtime/bin/elf_loader.cc