| // Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include <memory> |
| |
| #include "bin/snapshot_utils.h" |
| |
| #include "bin/dartutils.h" |
| #include "bin/dfe.h" |
| #include "bin/elf_loader.h" |
| #include "bin/error_exit.h" |
| #include "bin/file.h" |
| #include "bin/platform.h" |
| #include "include/dart_api.h" |
| #include "platform/utils.h" |
| |
| #define LOG_SECTION_BOUNDARIES false |
| |
| namespace dart { |
| namespace bin { |
| |
| static const int64_t kAppSnapshotHeaderSize = 5 * kInt64Size; |
| static const int64_t kAppSnapshotPageSize = 16 * KB; |
| |
| class MappedAppSnapshot : public AppSnapshot { |
| public: |
| MappedAppSnapshot(MappedMemory* vm_snapshot_data, |
| MappedMemory* vm_snapshot_instructions, |
| MappedMemory* isolate_snapshot_data, |
| MappedMemory* isolate_snapshot_instructions) |
| : vm_data_mapping_(vm_snapshot_data), |
| vm_instructions_mapping_(vm_snapshot_instructions), |
| isolate_data_mapping_(isolate_snapshot_data), |
| isolate_instructions_mapping_(isolate_snapshot_instructions) {} |
| |
| ~MappedAppSnapshot() { |
| delete vm_data_mapping_; |
| delete vm_instructions_mapping_; |
| delete isolate_data_mapping_; |
| delete isolate_instructions_mapping_; |
| } |
| |
| void SetBuffers(const uint8_t** vm_data_buffer, |
| const uint8_t** vm_instructions_buffer, |
| const uint8_t** isolate_data_buffer, |
| const uint8_t** isolate_instructions_buffer) { |
| if (vm_data_mapping_ != NULL) { |
| *vm_data_buffer = |
| reinterpret_cast<const uint8_t*>(vm_data_mapping_->address()); |
| } |
| if (vm_instructions_mapping_ != NULL) { |
| *vm_instructions_buffer = |
| reinterpret_cast<const uint8_t*>(vm_instructions_mapping_->address()); |
| } |
| if (isolate_data_mapping_ != NULL) { |
| *isolate_data_buffer = |
| reinterpret_cast<const uint8_t*>(isolate_data_mapping_->address()); |
| } |
| if (isolate_instructions_mapping_ != NULL) { |
| *isolate_instructions_buffer = reinterpret_cast<const uint8_t*>( |
| isolate_instructions_mapping_->address()); |
| } |
| } |
| |
| private: |
| MappedMemory* vm_data_mapping_; |
| MappedMemory* vm_instructions_mapping_; |
| MappedMemory* isolate_data_mapping_; |
| MappedMemory* isolate_instructions_mapping_; |
| }; |
| |
| static AppSnapshot* TryReadAppSnapshotBlobs(const char* script_name, |
| File* file) { |
| if ((file->Length() - file->Position()) < kAppSnapshotHeaderSize) { |
| return nullptr; |
| } |
| |
| int64_t header[5]; |
| ASSERT(sizeof(header) == kAppSnapshotHeaderSize); |
| if (!file->ReadFully(&header, kAppSnapshotHeaderSize)) { |
| return nullptr; |
| } |
| ASSERT(sizeof(header[0]) == appjit_magic_number.length); |
| if (memcmp(&header[0], appjit_magic_number.bytes, |
| appjit_magic_number.length) != 0) { |
| return nullptr; |
| } |
| |
| int64_t vm_data_size = header[1]; |
| int64_t vm_data_position = |
| Utils::RoundUp(file->Position(), kAppSnapshotPageSize); |
| int64_t vm_instructions_size = header[2]; |
| int64_t vm_instructions_position = vm_data_position + vm_data_size; |
| if (vm_instructions_size != 0) { |
| vm_instructions_position = |
| Utils::RoundUp(vm_instructions_position, kAppSnapshotPageSize); |
| } |
| int64_t isolate_data_size = header[3]; |
| int64_t isolate_data_position = Utils::RoundUp( |
| vm_instructions_position + vm_instructions_size, kAppSnapshotPageSize); |
| int64_t isolate_instructions_size = header[4]; |
| int64_t isolate_instructions_position = |
| isolate_data_position + isolate_data_size; |
| if (isolate_instructions_size != 0) { |
| isolate_instructions_position = |
| Utils::RoundUp(isolate_instructions_position, kAppSnapshotPageSize); |
| } |
| |
| MappedMemory* vm_data_mapping = nullptr; |
| if (vm_data_size != 0) { |
| vm_data_mapping = |
| file->Map(File::kReadOnly, vm_data_position, vm_data_size); |
| if (vm_data_mapping == nullptr) { |
| FATAL1("Failed to memory map snapshot: %s\n", script_name); |
| } |
| } |
| |
| MappedMemory* vm_instr_mapping = nullptr; |
| if (vm_instructions_size != 0) { |
| vm_instr_mapping = file->Map(File::kReadExecute, vm_instructions_position, |
| vm_instructions_size); |
| if (vm_instr_mapping == nullptr) { |
| FATAL1("Failed to memory map snapshot: %s\n", script_name); |
| } |
| } |
| |
| MappedMemory* isolate_data_mapping = nullptr; |
| if (isolate_data_size != 0) { |
| isolate_data_mapping = |
| file->Map(File::kReadOnly, isolate_data_position, isolate_data_size); |
| if (isolate_data_mapping == nullptr) { |
| FATAL1("Failed to memory map snapshot: %s\n", script_name); |
| } |
| } |
| |
| MappedMemory* isolate_instr_mapping = nullptr; |
| if (isolate_instructions_size != 0) { |
| isolate_instr_mapping = |
| file->Map(File::kReadExecute, isolate_instructions_position, |
| isolate_instructions_size); |
| if (isolate_instr_mapping == nullptr) { |
| FATAL1("Failed to memory map snapshot: %s\n", script_name); |
| } |
| } |
| |
| return new MappedAppSnapshot(vm_data_mapping, vm_instr_mapping, |
| isolate_data_mapping, isolate_instr_mapping); |
| } |
| |
| static AppSnapshot* TryReadAppSnapshotBlobs(const char* script_name) { |
| File* file = File::Open(NULL, script_name, File::kRead); |
| if (file == nullptr) { |
| return nullptr; |
| } |
| RefCntReleaseScope<File> rs(file); |
| return TryReadAppSnapshotBlobs(script_name, file); |
| } |
| |
| #if defined(DART_PRECOMPILED_RUNTIME) |
| class ElfAppSnapshot : public AppSnapshot { |
| public: |
| ElfAppSnapshot(Dart_LoadedElf* elf, |
| const uint8_t* vm_snapshot_data, |
| const uint8_t* vm_snapshot_instructions, |
| const uint8_t* isolate_snapshot_data, |
| const uint8_t* isolate_snapshot_instructions) |
| : elf_(elf), |
| vm_snapshot_data_(vm_snapshot_data), |
| vm_snapshot_instructions_(vm_snapshot_instructions), |
| isolate_snapshot_data_(isolate_snapshot_data), |
| isolate_snapshot_instructions_(isolate_snapshot_instructions) {} |
| |
| virtual ~ElfAppSnapshot() { Dart_UnloadELF(elf_); } |
| |
| void SetBuffers(const uint8_t** vm_data_buffer, |
| const uint8_t** vm_instructions_buffer, |
| const uint8_t** isolate_data_buffer, |
| const uint8_t** isolate_instructions_buffer) { |
| *vm_data_buffer = vm_snapshot_data_; |
| *vm_instructions_buffer = vm_snapshot_instructions_; |
| *isolate_data_buffer = isolate_snapshot_data_; |
| *isolate_instructions_buffer = isolate_snapshot_instructions_; |
| } |
| |
| private: |
| Dart_LoadedElf* elf_; |
| const uint8_t* vm_snapshot_data_; |
| const uint8_t* vm_snapshot_instructions_; |
| const uint8_t* isolate_snapshot_data_; |
| const uint8_t* isolate_snapshot_instructions_; |
| }; |
| |
| static AppSnapshot* TryReadAppSnapshotElf( |
| const char* script_name, |
| uint64_t file_offset, |
| bool force_load_elf_from_memory = false) { |
| const char* error = nullptr; |
| const uint8_t *vm_data_buffer = nullptr, *vm_instructions_buffer = nullptr, |
| *isolate_data_buffer = nullptr, |
| *isolate_instructions_buffer = nullptr; |
| Dart_LoadedElf* handle = nullptr; |
| #if !defined(DART_HOST_OS_FUCHSIA) |
| if (force_load_elf_from_memory) { |
| #endif |
| File* const file = |
| File::Open(/*namespc=*/nullptr, script_name, File::kRead); |
| if (file == nullptr) return nullptr; |
| MappedMemory* memory = file->Map(File::kReadOnly, /*position=*/0, |
| /*length=*/file->Length()); |
| if (memory == nullptr) return nullptr; |
| const uint8_t* address = |
| reinterpret_cast<const uint8_t*>(memory->address()); |
| handle = |
| Dart_LoadELF_Memory(address + file_offset, file->Length(), &error, |
| &vm_data_buffer, &vm_instructions_buffer, |
| &isolate_data_buffer, &isolate_instructions_buffer); |
| delete memory; |
| file->Release(); |
| #if !defined(DART_HOST_OS_FUCHSIA) |
| } else { |
| handle = Dart_LoadELF(script_name, file_offset, &error, &vm_data_buffer, |
| &vm_instructions_buffer, &isolate_data_buffer, |
| &isolate_instructions_buffer); |
| } |
| #endif |
| if (handle == nullptr) { |
| Syslog::PrintErr("Loading failed: %s\n", error); |
| return nullptr; |
| } |
| return new ElfAppSnapshot(handle, vm_data_buffer, vm_instructions_buffer, |
| isolate_data_buffer, isolate_instructions_buffer); |
| return nullptr; |
| } |
| |
| AppSnapshot* Snapshot::TryReadAppendedAppSnapshotElf( |
| const char* container_path) { |
| File* file = File::Open(NULL, container_path, File::kRead); |
| if (file == nullptr) { |
| return nullptr; |
| } |
| RefCntReleaseScope<File> rs(file); |
| |
| // Check for payload appended at the end of the container file. |
| // If header is found, jump to payload offset. |
| int64_t appended_header[2]; |
| if (!file->SetPosition(file->Length() - sizeof(appended_header))) { |
| return nullptr; |
| } |
| if (!file->ReadFully(&appended_header, sizeof(appended_header))) { |
| return nullptr; |
| } |
| // Length is always encoded as Little Endian. |
| const uint64_t appended_offset = |
| Utils::LittleEndianToHost64(appended_header[0]); |
| if (memcmp(&appended_header[1], appjit_magic_number.bytes, |
| appjit_magic_number.length) != 0 || |
| appended_offset <= 0) { |
| return nullptr; |
| } |
| |
| return TryReadAppSnapshotElf(container_path, appended_offset); |
| } |
| |
| class DylibAppSnapshot : public AppSnapshot { |
| public: |
| DylibAppSnapshot(void* library, |
| const uint8_t* vm_snapshot_data, |
| const uint8_t* vm_snapshot_instructions, |
| const uint8_t* isolate_snapshot_data, |
| const uint8_t* isolate_snapshot_instructions) |
| : library_(library), |
| vm_snapshot_data_(vm_snapshot_data), |
| vm_snapshot_instructions_(vm_snapshot_instructions), |
| isolate_snapshot_data_(isolate_snapshot_data), |
| isolate_snapshot_instructions_(isolate_snapshot_instructions) {} |
| |
| ~DylibAppSnapshot() { Utils::UnloadDynamicLibrary(library_); } |
| |
| void SetBuffers(const uint8_t** vm_data_buffer, |
| const uint8_t** vm_instructions_buffer, |
| const uint8_t** isolate_data_buffer, |
| const uint8_t** isolate_instructions_buffer) { |
| *vm_data_buffer = vm_snapshot_data_; |
| *vm_instructions_buffer = vm_snapshot_instructions_; |
| *isolate_data_buffer = isolate_snapshot_data_; |
| *isolate_instructions_buffer = isolate_snapshot_instructions_; |
| } |
| |
| private: |
| void* library_; |
| const uint8_t* vm_snapshot_data_; |
| const uint8_t* vm_snapshot_instructions_; |
| const uint8_t* isolate_snapshot_data_; |
| const uint8_t* isolate_snapshot_instructions_; |
| }; |
| |
| static AppSnapshot* TryReadAppSnapshotDynamicLibrary(const char* script_name) { |
| void* library = Utils::LoadDynamicLibrary(script_name); |
| if (library == nullptr) { |
| return nullptr; |
| } |
| |
| const uint8_t* vm_data_buffer = reinterpret_cast<const uint8_t*>( |
| Utils::ResolveSymbolInDynamicLibrary(library, kVmSnapshotDataCSymbol)); |
| |
| const uint8_t* vm_instructions_buffer = |
| reinterpret_cast<const uint8_t*>(Utils::ResolveSymbolInDynamicLibrary( |
| library, kVmSnapshotInstructionsCSymbol)); |
| |
| const uint8_t* isolate_data_buffer = |
| reinterpret_cast<const uint8_t*>(Utils::ResolveSymbolInDynamicLibrary( |
| library, kIsolateSnapshotDataCSymbol)); |
| if (isolate_data_buffer == nullptr) { |
| FATAL1("Failed to resolve symbol '%s'\n", kIsolateSnapshotDataCSymbol); |
| } |
| |
| const uint8_t* isolate_instructions_buffer = |
| reinterpret_cast<const uint8_t*>(Utils::ResolveSymbolInDynamicLibrary( |
| library, kIsolateSnapshotInstructionsCSymbol)); |
| if (isolate_instructions_buffer == nullptr) { |
| FATAL1("Failed to resolve symbol '%s'\n", |
| kIsolateSnapshotInstructionsCSymbol); |
| } |
| |
| return new DylibAppSnapshot(library, vm_data_buffer, vm_instructions_buffer, |
| isolate_data_buffer, isolate_instructions_buffer); |
| } |
| |
| #endif // defined(DART_PRECOMPILED_RUNTIME) |
| |
| AppSnapshot* Snapshot::TryReadAppSnapshot(const char* script_uri, |
| bool force_load_elf_from_memory, |
| bool decode_uri) { |
| Utils::CStringUniquePtr decoded_path(nullptr, std::free); |
| const char* script_name = nullptr; |
| if (decode_uri) { |
| decoded_path = File::UriToPath(script_uri); |
| if (decoded_path == nullptr) { |
| return nullptr; |
| } |
| script_name = decoded_path.get(); |
| } else { |
| script_name = script_uri; |
| } |
| if (File::GetType(nullptr, script_name, true) != File::kIsFile) { |
| // If 'script_name' refers to a pipe, don't read to check for an app |
| // snapshot since we cannot rewind if it isn't (and couldn't mmap it in |
| // anyway if it was). |
| return nullptr; |
| } |
| AppSnapshot* snapshot = TryReadAppSnapshotBlobs(script_name); |
| if (snapshot != nullptr) { |
| return snapshot; |
| } |
| #if defined(DART_PRECOMPILED_RUNTIME) |
| // For testing AOT with the standalone embedder, we also support loading |
| // from a dynamic library to simulate what happens on iOS. |
| |
| #if defined(DART_TARGET_OS_LINUX) || defined(DART_TARGET_OS_MACOS) |
| // On Linux and OSX, resolve the script path before passing into dlopen() |
| // since dlopen will not search the filesystem for paths like 'libtest.so'. |
| std::unique_ptr<char, decltype(std::free)*> absolute_path{ |
| realpath(script_name, nullptr), std::free}; |
| script_name = absolute_path.get(); |
| #endif |
| |
| if (!force_load_elf_from_memory) { |
| snapshot = TryReadAppSnapshotDynamicLibrary(script_name); |
| if (snapshot != nullptr) { |
| return snapshot; |
| } |
| } |
| |
| snapshot = TryReadAppSnapshotElf(script_name, /*file_offset=*/0, |
| force_load_elf_from_memory); |
| if (snapshot != nullptr) { |
| return snapshot; |
| } |
| #endif // defined(DART_PRECOMPILED_RUNTIME) |
| return nullptr; |
| } |
| |
| #if !defined(EXCLUDE_CFE_AND_KERNEL_PLATFORM) && !defined(TESTING) |
| static void WriteSnapshotFile(const char* filename, |
| const uint8_t* buffer, |
| const intptr_t size) { |
| File* file = File::Open(NULL, filename, File::kWriteTruncate); |
| if (file == NULL) { |
| ErrorExit(kErrorExitCode, "Unable to open file %s for writing snapshot\n", |
| filename); |
| } |
| |
| if (!file->WriteFully(buffer, size)) { |
| ErrorExit(kErrorExitCode, "Unable to write file %s for writing snapshot\n", |
| filename); |
| } |
| file->Release(); |
| } |
| #endif |
| |
| static bool WriteInt64(File* file, int64_t size) { |
| return file->WriteFully(&size, sizeof(size)); |
| } |
| |
| void Snapshot::WriteAppSnapshot(const char* filename, |
| uint8_t* vm_data_buffer, |
| intptr_t vm_data_size, |
| uint8_t* vm_instructions_buffer, |
| intptr_t vm_instructions_size, |
| uint8_t* isolate_data_buffer, |
| intptr_t isolate_data_size, |
| uint8_t* isolate_instructions_buffer, |
| intptr_t isolate_instructions_size) { |
| File* file = File::Open(NULL, filename, File::kWriteTruncate); |
| if (file == NULL) { |
| ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n", filename); |
| } |
| |
| file->WriteFully(appjit_magic_number.bytes, appjit_magic_number.length); |
| WriteInt64(file, vm_data_size); |
| WriteInt64(file, vm_instructions_size); |
| WriteInt64(file, isolate_data_size); |
| WriteInt64(file, isolate_instructions_size); |
| ASSERT(file->Position() == kAppSnapshotHeaderSize); |
| |
| file->SetPosition(Utils::RoundUp(file->Position(), kAppSnapshotPageSize)); |
| if (LOG_SECTION_BOUNDARIES) { |
| Syslog::PrintErr("%" Px64 ": VM Data\n", file->Position()); |
| } |
| if (!file->WriteFully(vm_data_buffer, vm_data_size)) { |
| ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n", filename); |
| } |
| |
| if (vm_instructions_size != 0) { |
| file->SetPosition(Utils::RoundUp(file->Position(), kAppSnapshotPageSize)); |
| if (LOG_SECTION_BOUNDARIES) { |
| Syslog::PrintErr("%" Px64 ": VM Instructions\n", file->Position()); |
| } |
| if (!file->WriteFully(vm_instructions_buffer, vm_instructions_size)) { |
| ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n", |
| filename); |
| } |
| } |
| |
| file->SetPosition(Utils::RoundUp(file->Position(), kAppSnapshotPageSize)); |
| if (LOG_SECTION_BOUNDARIES) { |
| Syslog::PrintErr("%" Px64 ": Isolate Data\n", file->Position()); |
| } |
| if (!file->WriteFully(isolate_data_buffer, isolate_data_size)) { |
| ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n", filename); |
| } |
| |
| if (isolate_instructions_size != 0) { |
| file->SetPosition(Utils::RoundUp(file->Position(), kAppSnapshotPageSize)); |
| if (LOG_SECTION_BOUNDARIES) { |
| Syslog::PrintErr("%" Px64 ": Isolate Instructions\n", file->Position()); |
| } |
| if (!file->WriteFully(isolate_instructions_buffer, |
| isolate_instructions_size)) { |
| ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n", |
| filename); |
| } |
| } |
| |
| file->Flush(); |
| file->Release(); |
| } |
| |
| void Snapshot::GenerateKernel(const char* snapshot_filename, |
| const char* script_name, |
| const char* package_config) { |
| #if !defined(EXCLUDE_CFE_AND_KERNEL_PLATFORM) && !defined(TESTING) |
| ASSERT(Dart_CurrentIsolate() == nullptr); |
| |
| uint8_t* kernel_buffer = NULL; |
| intptr_t kernel_buffer_size = 0; |
| dfe.ReadScript(script_name, &kernel_buffer, &kernel_buffer_size); |
| if (kernel_buffer != NULL) { |
| WriteSnapshotFile(snapshot_filename, kernel_buffer, kernel_buffer_size); |
| free(kernel_buffer); |
| } else { |
| PathSanitizer script_uri_sanitizer(script_name); |
| PathSanitizer packages_config_sanitizer(package_config); |
| |
| bool null_safety = |
| Dart_DetectNullSafety(script_uri_sanitizer.sanitized_uri(), |
| packages_config_sanitizer.sanitized_uri(), |
| DartUtils::original_working_directory, |
| /*isolate_snapshot_data=*/nullptr, |
| /*isolate_snapshot_instructions=*/nullptr, |
| /*kernel_buffer=*/nullptr, |
| /*kernel_buffer_size=*/0); |
| |
| Dart_KernelCompilationResult result = dfe.CompileScriptWithGivenNullsafety( |
| script_name, package_config, /*snapshot=*/true, null_safety); |
| if (result.status != Dart_KernelCompilationStatus_Ok) { |
| Syslog::PrintErr("%s\n", result.error); |
| Platform::Exit(kCompilationErrorExitCode); |
| } |
| WriteSnapshotFile(snapshot_filename, result.kernel, result.kernel_size); |
| free(result.kernel); |
| } |
| #else |
| UNREACHABLE(); |
| #endif // !defined(EXCLUDE_CFE_AND_KERNEL_PLATFORM) && !defined(TESTING) |
| } |
| |
| void Snapshot::GenerateAppJIT(const char* snapshot_filename) { |
| #if defined(TARGET_ARCH_IA32) |
| // Snapshots with code are not supported on IA32. |
| uint8_t* isolate_buffer = NULL; |
| intptr_t isolate_size = 0; |
| |
| Dart_Handle result = Dart_CreateSnapshot(NULL, NULL, &isolate_buffer, |
| &isolate_size, /*is_core=*/false); |
| if (Dart_IsError(result)) { |
| ErrorExit(kErrorExitCode, "%s\n", Dart_GetError(result)); |
| } |
| |
| WriteAppSnapshot(snapshot_filename, NULL, 0, NULL, 0, isolate_buffer, |
| isolate_size, NULL, 0); |
| #else |
| uint8_t* isolate_data_buffer = NULL; |
| intptr_t isolate_data_size = 0; |
| uint8_t* isolate_instructions_buffer = NULL; |
| intptr_t isolate_instructions_size = 0; |
| Dart_Handle result = Dart_CreateAppJITSnapshotAsBlobs( |
| &isolate_data_buffer, &isolate_data_size, &isolate_instructions_buffer, |
| &isolate_instructions_size); |
| if (Dart_IsError(result)) { |
| ErrorExit(kErrorExitCode, "%s\n", Dart_GetError(result)); |
| } |
| WriteAppSnapshot(snapshot_filename, NULL, 0, NULL, 0, isolate_data_buffer, |
| isolate_data_size, isolate_instructions_buffer, |
| isolate_instructions_size); |
| #endif |
| } |
| |
| static void StreamingWriteCallback(void* callback_data, |
| const uint8_t* buffer, |
| intptr_t size) { |
| File* file = reinterpret_cast<File*>(callback_data); |
| if (!file->WriteFully(buffer, size)) { |
| ErrorExit(kErrorExitCode, "Unable to write snapshot file\n"); |
| } |
| } |
| |
| void Snapshot::GenerateAppAOTAsAssembly(const char* snapshot_filename) { |
| File* file = File::Open(NULL, snapshot_filename, File::kWriteTruncate); |
| RefCntReleaseScope<File> rs(file); |
| if (file == NULL) { |
| ErrorExit(kErrorExitCode, "Unable to open file %s for writing snapshot\n", |
| snapshot_filename); |
| } |
| Dart_Handle result = Dart_CreateAppAOTSnapshotAsAssembly( |
| StreamingWriteCallback, file, /*strip=*/false, |
| /*debug_callback_data=*/nullptr); |
| if (Dart_IsError(result)) { |
| ErrorExit(kErrorExitCode, "%s\n", Dart_GetError(result)); |
| } |
| } |
| |
| bool Snapshot::IsAOTSnapshot(const char* snapshot_filename) { |
| // Header is simply "ELF" prefixed with the DEL character. |
| const char elf_header[] = {0x7F, 0x45, 0x4C, 0x46, 0x0}; |
| const int64_t elf_header_len = strlen(elf_header); |
| File* file = File::Open(NULL, snapshot_filename, File::kRead); |
| if (file == nullptr) { |
| return false; |
| } |
| if (file->Length() < elf_header_len) { |
| file->Release(); |
| return false; |
| } |
| auto buf = std::unique_ptr<char[]>(new char[elf_header_len]); |
| bool success = file->ReadFully(buf.get(), elf_header_len); |
| file->Release(); |
| ASSERT(success); |
| return (strncmp(elf_header, buf.get(), elf_header_len) == 0); |
| } |
| |
| } // namespace bin |
| } // namespace dart |