Factor out snapshot helpers from main.cc.

runtime/bin/snapshot_utils.cc

+// 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 "bin/snapshot_utils.h"
+
+#include "bin/dartutils.h"
+#include "bin/error_exit.h"
+#include "bin/extensions.h"
+#include "bin/file.h"
+#include "bin/platform.h"
+#include "include/dart_api.h"
+#include "platform/utils.h"
+
+namespace dart {
+namespace bin {
+
+extern const char* kVmSnapshotDataSymbolName;
+extern const char* kVmSnapshotInstructionsSymbolName;
+extern const char* kIsolateSnapshotDataSymbolName;
+extern const char* kIsolateSnapshotInstructionsSymbolName;
+
+static const int64_t kAppSnapshotHeaderSize = 5 * kInt64Size;
+static const int64_t kAppSnapshotMagicNumber = 0xf6f6dcdc;
+static const int64_t kAppSnapshotPageSize = 4 * KB;
+
+static bool ReadAppSnapshotBlobs(const char* script_name,
+                                 const uint8_t** vm_data_buffer,
+                                 const uint8_t** vm_instructions_buffer,
+                                 const uint8_t** isolate_data_buffer,
+                                 const uint8_t** isolate_instructions_buffer) {
+  File* file = File::Open(script_name, File::kRead);
+  if (file == NULL) {
+    return false;
+  }
+  if (file->Length() < kAppSnapshotHeaderSize) {
+    file->Release();
+    return false;
+  }
+  int64_t header[5];
+  ASSERT(sizeof(header) == kAppSnapshotHeaderSize);
+  if (!file->ReadFully(&header, kAppSnapshotHeaderSize)) {
+    file->Release();
+    return false;
+  }
+  if (header[0] != kAppSnapshotMagicNumber) {
+    file->Release();
+    return false;
+  }
+
+  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);
+  }
+
+  if (vm_data_size != 0) {
+    *vm_data_buffer = reinterpret_cast<const uint8_t*>(
+        file->Map(File::kReadOnly, vm_data_position, vm_data_size));
+    if (vm_data_buffer == NULL) {
+      Log::PrintErr("Failed to memory map snapshot\n");
+      Platform::Exit(kErrorExitCode);
+    }
+  }
+
+  if (vm_instructions_size != 0) {
+    *vm_instructions_buffer = reinterpret_cast<const uint8_t*>(file->Map(
+        File::kReadExecute, vm_instructions_position, vm_instructions_size));
+    if (*vm_instructions_buffer == NULL) {
+      Log::PrintErr("Failed to memory map snapshot\n");
+      Platform::Exit(kErrorExitCode);
+    }
+  }
+
+  *isolate_data_buffer = reinterpret_cast<const uint8_t*>(
+      file->Map(File::kReadOnly, isolate_data_position, isolate_data_size));
+  if (isolate_data_buffer == NULL) {
+    Log::PrintErr("Failed to memory map snapshot\n");
+    Platform::Exit(kErrorExitCode);
+  }
+
+  if (isolate_instructions_size == 0) {
+    *isolate_instructions_buffer = NULL;
+  } else {
+    *isolate_instructions_buffer = reinterpret_cast<const uint8_t*>(
+        file->Map(File::kReadExecute, isolate_instructions_position,
+                  isolate_instructions_size));
+    if (*isolate_instructions_buffer == NULL) {
+      Log::PrintErr("Failed to memory map snapshot\n");
+      Platform::Exit(kErrorExitCode);
+    }
+  }
+
+  file->Release();
+  return true;
+}
+
+
+#if defined(DART_PRECOMPILED_RUNTIME)
+static bool ReadAppSnapshotDynamicLibrary(
+    const char* script_name,
+    const uint8_t** vm_data_buffer,
+    const uint8_t** vm_instructions_buffer,
+    const uint8_t** isolate_data_buffer,
+    const uint8_t** isolate_instructions_buffer) {
+  void* library = Extensions::LoadExtensionLibrary(script_name);
+  if (library == NULL) {
+    return false;
+  }
+
+  *vm_data_buffer = reinterpret_cast<const uint8_t*>(
+      Extensions::ResolveSymbol(library, kVmSnapshotDataSymbolName));
+  if (*vm_data_buffer == NULL) {
+    Log::PrintErr("Failed to resolve symbol '%s'\n", kVmSnapshotDataSymbolName);
+    Platform::Exit(kErrorExitCode);
+  }
+
+  *vm_instructions_buffer = reinterpret_cast<const uint8_t*>(
+      Extensions::ResolveSymbol(library, kVmSnapshotInstructionsSymbolName));
+  if (*vm_instructions_buffer == NULL) {
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kVmSnapshotInstructionsSymbolName);
+    Platform::Exit(kErrorExitCode);
+  }
+
+  *isolate_data_buffer = reinterpret_cast<const uint8_t*>(
+      Extensions::ResolveSymbol(library, kIsolateSnapshotDataSymbolName));
+  if (*isolate_data_buffer == NULL) {
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kIsolateSnapshotDataSymbolName);
+    Platform::Exit(kErrorExitCode);
+  }
+
+  *isolate_instructions_buffer =
+      reinterpret_cast<const uint8_t*>(Extensions::ResolveSymbol(
+          library, kIsolateSnapshotInstructionsSymbolName));
+  if (*isolate_instructions_buffer == NULL) {
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kIsolateSnapshotInstructionsSymbolName);
+    Platform::Exit(kErrorExitCode);
+  }
+
+  return true;
+}
+#endif  // defined(DART_PRECOMPILED_RUNTIME)
+
+
+bool Snapshot::ReadAppSnapshot(const char* script_name,
+                               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 (File::GetType(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 false;
+  }
+  if (ReadAppSnapshotBlobs(script_name, vm_data_buffer, vm_instructions_buffer,
+                           isolate_data_buffer, isolate_instructions_buffer)) {
+    return true;
+  }
+#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.
+  return ReadAppSnapshotDynamicLibrary(
+      script_name, vm_data_buffer, vm_instructions_buffer, isolate_data_buffer,
+      isolate_instructions_buffer);
+#else
+  return false;
+#endif  //  defined(DART_PRECOMPILED_RUNTIME)
+}
+
+
+static void WriteSnapshotFile(const char* filename,
+                              bool write_magic_number,
+                              const uint8_t* buffer,
+                              const intptr_t size) {
+  File* file = File::Open(filename, File::kWriteTruncate);
+  if (file == NULL) {
+    ErrorExit(kErrorExitCode, "Unable to open file %s for writing snapshot\n",
+              filename);
+  }
+
+  if (write_magic_number) {
+    // Write the magic number to indicate file is a script snapshot.
+    DartUtils::WriteMagicNumber(file);
+  }
+
+  if (!file->WriteFully(buffer, size)) {
+    ErrorExit(kErrorExitCode, "Unable to write file %s for writing snapshot\n",
+              filename);
+  }
+  file->Release();
+}
+
+
+static bool WriteInt64(File* file, int64_t size) {
+  return file->WriteFully(&size, sizeof(size));
+}
+
+
+static void 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(filename, File::kWriteTruncate);
+  if (file == NULL) {
+    ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n", filename);
+  }
+
+  file->WriteFully(&kAppSnapshotMagicNumber, sizeof(kAppSnapshotMagicNumber));
+  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 (!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 (!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 (!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 (!file->WriteFully(isolate_instructions_buffer,
+                          isolate_instructions_size)) {
+      ErrorExit(kErrorExitCode, "Unable to write snapshot file '%s'\n",
+                filename);
+    }
+  }
+
+  file->Flush();
+  file->Release();
+}
+
+
+void Snapshot::GenerateScript(const char* snapshot_filename) {
+  // First create a snapshot.
+  uint8_t* buffer = NULL;
+  intptr_t size = 0;
+  Dart_Handle result = Dart_CreateScriptSnapshot(&buffer, &size);
+  if (Dart_IsError(result)) {
+    ErrorExit(kErrorExitCode, "%s\n", Dart_GetError(result));
+  }
+
+  WriteSnapshotFile(snapshot_filename, true, buffer, size);
+}
+
+
+void Snapshot::GenerateAppJIT(const char* snapshot_filename) {
+#if defined(TARGET_ARCH_X64)
+  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);
+#else
+  uint8_t* isolate_buffer = NULL;
+  intptr_t isolate_size = 0;
+
+  Dart_Handle result =
+      Dart_CreateSnapshot(NULL, NULL, &isolate_buffer, &isolate_size);
+  if (Dart_IsError(result)) {
+    ErrorExit(kErrorExitCode, "%s\n", Dart_GetError(result));
+  }
+
+  WriteAppSnapshot(snapshot_filename, NULL, 0, NULL, 0, isolate_buffer,
+                   isolate_size, NULL, 0);
+#endif  // defined(TARGET_ARCH_X64)
+}
+
+
+void Snapshot::GenerateAppAOTAsBlobs(const char* snapshot_filename) {
+  uint8_t* vm_data_buffer = NULL;
+  intptr_t vm_data_size = 0;
+  uint8_t* vm_instructions_buffer = NULL;
+  intptr_t vm_instructions_size = 0;
+  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_CreateAppAOTSnapshotAsBlobs(
+      &vm_data_buffer, &vm_data_size, &vm_instructions_buffer,
+      &vm_instructions_size, &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, vm_data_buffer, vm_data_size,
+                   vm_instructions_buffer, vm_instructions_size,
+                   isolate_data_buffer, isolate_data_size,
+                   isolate_instructions_buffer, isolate_instructions_size);
+}
+
+
+void Snapshot::GenerateAppAOTAsAssembly(const char* snapshot_filename) {
+  uint8_t* assembly_buffer = NULL;
+  intptr_t assembly_size = 0;
+  Dart_Handle result =
+      Dart_CreateAppAOTSnapshotAsAssembly(&assembly_buffer, &assembly_size);
+  if (Dart_IsError(result)) {
+    ErrorExit(kErrorExitCode, "%s\n", Dart_GetError(result));
+  }
+  WriteSnapshotFile(snapshot_filename, false, assembly_buffer, assembly_size);
+}
+
+}  // namespace bin
+}  // namespace dart