Teach gen_snapshot how to create script snapshots if given a core snapshot to create them against.

runtime/bin/gen_snapshot.cc

Index: runtime/bin/gen_snapshot.cc
diff --git a/runtime/bin/gen_snapshot.cc b/runtime/bin/gen_snapshot.cc
index 3f2940dc74b91486fbfbe31f3883063498e5a768..36c521a771147f98edc1a7c359cc81f2429f3513 100644
--- a/runtime/bin/gen_snapshot.cc
+++ b/runtime/bin/gen_snapshot.cc
@@ -42,7 +42,7 @@ static const int kRestartRequestExitCode = 1000;
 #define CHECK_RESULT(result)                                                   \
   if (Dart_IsError(result)) {                                                  \
     intptr_t exit_code = 0;                                                    \
-    Log::PrintErr("Error: %s", Dart_GetError(result));                         \
+    Log::PrintErr("Error: %s\n", Dart_GetError(result));                       \
     if (Dart_IsCompilationError(result)) {                                     \
       exit_code = kCompilationErrorExitCode;                                   \
     } else if (Dart_IsApiError(result)) {                                      \
@@ -58,13 +58,26 @@ static const int kRestartRequestExitCode = 1000;
   }
 
 
+// The core snapshot to use when creating isolates. Normally NULL, but loaded
+// from a file when creating script snapshots.
+const uint8_t* isolate_snapshot_data = NULL;
+
+
 // Global state that indicates whether a snapshot is to be created and
 // if so which file to write the snapshot into.
+enum SnapshotKind {
+  kCore,
+  kScript,
+  kAppAOTBlobs,
+  kAppAOTAssembly,
+};
+static SnapshotKind snapshot_kind = kCore;
 static const char* vm_snapshot_data_filename = NULL;
 static const char* vm_snapshot_instructions_filename = NULL;
 static const char* isolate_snapshot_data_filename = NULL;
 static const char* isolate_snapshot_instructions_filename = NULL;
 static const char* assembly_filename = NULL;
+static const char* script_snapshot_filename = NULL;
 
 
 // Value of the --package-root flag.
@@ -189,6 +202,32 @@ static const char* ProcessOption(const char* option, const char* name) {
 }
 
 
+static bool ProcessSnapshotKindOption(const char* option) {
+  const char* kind = ProcessOption(option, "--snapshot_kind=");
+  if (kind == NULL) {
+    return false;
+  }
+  if (strcmp(kind, "core") == 0) {
+    snapshot_kind = kCore;
+    return true;
+  } else if (strcmp(kind, "script") == 0) {
+    snapshot_kind = kScript;
+    return true;
+  } else if (strcmp(kind, "app-aot-blobs") == 0) {
+    snapshot_kind = kAppAOTBlobs;
+    return true;
+  } else if (strcmp(kind, "app-aot-assembly") == 0) {
+    snapshot_kind = kAppAOTAssembly;
+    return true;
+  }
+  Log::PrintErr(
+      "Unrecognized snapshot kind: '%s'\nValid kinds are: "
+      "core, script, app-aot-blobs, app-aot-assembly\n",
+      kind);
+  return false;
+}
+
+
 static bool ProcessVmSnapshotDataOption(const char* option) {
   const char* name = ProcessOption(option, "--vm_snapshot_data=");
   if (name != NULL) {
@@ -239,6 +278,16 @@ static bool ProcessAssemblyOption(const char* option) {
 }
 
 
+static bool ProcessScriptSnapshotOption(const char* option) {
+  const char* name = ProcessOption(option, "--script_snapshot=");
+  if (name != NULL) {
+    script_snapshot_filename = name;
+    return true;
+  }
+  return false;
+}
+
+
 static bool ProcessEmbedderEntryPointsManifestOption(const char* option) {
   const char* name = ProcessOption(option, "--embedder_entry_points_manifest=");
   if (name != NULL) {
@@ -286,8 +335,7 @@ static bool ProcessURLmappingOption(const char* option) {
 
 
 static bool IsSnapshottingForPrecompilation() {
-  return (assembly_filename != NULL) ||
-         (vm_snapshot_instructions_filename != NULL);
+  return (snapshot_kind == kAppAOTBlobs) || (snapshot_kind == kAppAOTAssembly);
 }
 
 
@@ -305,11 +353,13 @@ static int ParseArguments(int argc,
 
   // Parse out the vm options.
   while ((i < argc) && IsValidFlag(argv[i], kPrefix, kPrefixLen)) {
-    if (ProcessVmSnapshotDataOption(argv[i]) ||
+    if (ProcessSnapshotKindOption(argv[i]) ||
+        ProcessVmSnapshotDataOption(argv[i]) ||
         ProcessVmSnapshotInstructionsOption(argv[i]) ||
         ProcessIsolateSnapshotDataOption(argv[i]) ||
         ProcessIsolateSnapshotInstructionsOption(argv[i]) ||
         ProcessAssemblyOption(argv[i]) ||
+        ProcessScriptSnapshotOption(argv[i]) ||
         ProcessEmbedderEntryPointsManifestOption(argv[i]) ||
         ProcessURLmappingOption(argv[i]) || ProcessPackageRootOption(argv[i]) ||
         ProcessPackagesOption(argv[i]) || ProcessEnvironmentOption(argv[i])) {
@@ -333,43 +383,63 @@ static int ParseArguments(int argc,
       (commandline_packages_file != NULL)) {
     Log::PrintErr(
         "Specifying both a packages directory and a packages "
-        "file is invalid.\n");
-    return -1;
-  }
-
-  if (vm_snapshot_data_filename == NULL) {
-    Log::PrintErr("No vm snapshot output file specified.\n\n");
+        "file is invalid.\n\n");
     return -1;
   }
 
-  if (isolate_snapshot_data_filename == NULL) {
-    Log::PrintErr("No isolate snapshot output file specified.\n\n");
-    return -1;
+  switch (snapshot_kind) {
+    case kCore: {
+      if ((vm_snapshot_data_filename == NULL) ||
+          (isolate_snapshot_data_filename == NULL)) {
+        Log::PrintErr(
+            "Building a core snapshot requires specifying output files for "
+            "--vm_snapshot_data and --isolate_snapshot_data.\n\n");
+        return -1;
+      }
+      break;
+    }
+    case kScript: {
+      if ((vm_snapshot_data_filename == NULL) ||
+          (isolate_snapshot_data_filename == NULL) ||
+          (script_snapshot_filename == NULL) || (script_name == NULL)) {
+        Log::PrintErr(
+            "Building a script snapshot requires specifying input files for "
+            "--vm_snapshot_data and --isolate_snapshot_data, an output file "
+            "for --script-snapshot, and a Dart script.\n\n");
+        return -1;
+      }
+      break;
+    }
+    case kAppAOTBlobs: {
+      if ((vm_snapshot_data_filename == NULL) ||
+          (vm_snapshot_instructions_filename == NULL) ||
+          (isolate_snapshot_data_filename == NULL) ||
+          (isolate_snapshot_instructions_filename == NULL) ||
+          (script_name == NULL)) {
+        Log::PrintErr(
+            "Building an AOT snapshot as blobs requires specifying output "
+            "files for --vm_snapshot_data, --vm_snapshot_instructions, "
+            "--isolate_snapshot_data and --isolate_snapshot_instructions and a "
+            "Dart script.\n\n");
+        return -1;
+      }
+      break;
+    }
+    case kAppAOTAssembly: {
+      if ((assembly_filename == NULL) || (script_name == NULL)) {
+        Log::PrintErr(
+            "Building an AOT snapshot as assembly requires specifying "
+            "an output file for --assembly and a Dart script.\n\n");
+        return -1;
+      }
+      break;
+    }
   }
 
-  bool precompiled_as_assembly = assembly_filename != NULL;
-  bool precompiled_as_blobs = (vm_snapshot_instructions_filename != NULL) ||
-                              (isolate_snapshot_instructions_filename != NULL);
-  if (precompiled_as_assembly && precompiled_as_blobs) {
-    Log::PrintErr(
-        "Cannot request a precompiled snapshot simultaneously as "
-        "assembly (--assembly=<output.file>) and as blobs "
-        "(--instructions-blob=<output.file> and "
-        "--rodata-blob=<output.file>)\n\n");
-    return -1;
-  }
-  if ((vm_snapshot_instructions_filename != NULL) !=
-      (isolate_snapshot_instructions_filename != NULL)) {
-    Log::PrintErr(
-        "Requesting a precompiled snapshot as blobs requires both "
-        "(--vm_snapshot_instructions=<output.file> and "
-        "--isolate_snapshot_instructions=<output.file>)\n\n");
-    return -1;
-  }
   if (IsSnapshottingForPrecompilation() && (entry_points_files->count() == 0)) {
     Log::PrintErr(
-        "Specifying an instructions snapshot filename indicates precompilation"
-        ". But no embedder entry points manifest was specified.\n\n");
+        "Building an AOT snapshot requires at least one embedder "
+        "entry points manifest.\n\n");
     return -1;
   }
 
@@ -379,17 +449,24 @@ static int ParseArguments(int argc,
 
 static void WriteSnapshotFile(const char* filename,
                               const uint8_t* buffer,
-                              const intptr_t size) {
+                              const intptr_t size,
+                              bool write_magic_number = false) {
   File* file = File::Open(filename, File::kWriteTruncate);
   if (file == NULL) {
     Log::PrintErr("Error: Unable to write snapshot file: %s\n\n", filename);
     Dart_ExitScope();
     Dart_ShutdownIsolate();
-    Dart_Cleanup();
     exit(kErrorExitCode);
   }
+  if (write_magic_number) {
+    // Write the magic number to indicate file is a script snapshot.
+    DartUtils::WriteMagicNumber(file);
+  }
   if (!file->WriteFully(buffer, size)) {
-    Log::PrintErr("Error: Failed to write snapshot file.\n\n");
+    Log::PrintErr("Error: Unable to write snapshot file: %s\n\n", filename);
+    Dart_ExitScope();
+    Dart_ShutdownIsolate();
+    exit(kErrorExitCode);
   }
   file->Release();
 }
@@ -495,10 +572,10 @@ static Dart_Handle LoadSnapshotCreationScript(const char* script_name) {
   if (Dart_IsError(source)) {
     return source;
   }
-  if (IsSnapshottingForPrecompilation()) {
-    return Dart_LoadScript(resolved_uri, Dart_Null(), source, 0, 0);
-  } else {
+  if (snapshot_kind == kCore) {
     return Dart_LoadLibrary(resolved_uri, Dart_Null(), source, 0, 0);
+  } else {
+    return Dart_LoadScript(resolved_uri, Dart_Null(), source, 0, 0);
   }
 }
 
@@ -614,61 +691,65 @@ static void PrintUsage() {
 "Usage:                                                                      \n"
 " gen_snapshot [<vm-flags>] [<options>] [<dart-script-file>]                 \n"
 "                                                                            \n"
-"  Writes a snapshot of <dart-script-file> to the specified snapshot files.  \n"
-"  If no <dart-script-file> is passed, a generic snapshot of all the corelibs\n"
-"  is created. It is required to specify the VM isolate snapshot and the     \n"
-"  isolate snapshot. The other flags are related to precompilation and are   \n"
-"  optional.                                                                 \n"
+" Global options:                                                            \n"
+"   --package_root=<path>             Where to find packages, that is,       \n"
+"                                     package:...  imports.                  \n"
+"                                                                            \n"
+"   --packages=<packages_file>        Where to find a package spec file      \n"
 "                                                                            \n"
-"  Precompilation:                                                           \n"
-"  In order to configure the snapshotter for precompilation, either          \n"
-"  --assembly=outputfile or --instructions_blob=outputfile1 and              \n"
-"  --rodata_blob=outputfile2 must be specified. If the former is choosen,    \n"
-"  assembly for the target architecture will be output into the given file,  \n"
-"  which must be compiled separately and either statically linked or         \n"
-"  dynamically loaded in the target executable. The symbols                  \n"
-"  kInstructionsSnapshot and kDataSnapshot must be passed to Dart_Initialize.\n"
-"  If the latter is choosen, binary data is output into the given files,     \n"
-"  which should be mmapped and passed to Dart_Initialize, with the           \n"
-"  instruction blob being mapped as executable.                              \n"
-"  In both cases, a entry points manifest must be given to list the places   \n"
-"  in the Dart program the embedder calls from the C API (Dart_Invoke, etc). \n"
-"  Not specifying these may cause the tree shaker to remove them from the    \n"
-"  program. The format of this manifest is as follows. Each line in the      \n"
-"  manifest is a comma separated list of three elements. The first entry is  \n"
-"  the library URI, the second entry is the class name and the final entry   \n"
-"  the function name. The file must be terminated with a newline charater.   \n"
+"   --url_mapping=<mapping>           Uses the URL mapping(s) specified on   \n"
+"                                     the command line to load the           \n"
+"                                     libraries.                             \n"
 "                                                                            \n"
-"    Example:                                                                \n"
-"      dart:something,SomeClass,doSomething                                  \n"
+" To create a core snapshot:                                                 \n"
+"   --snapshot-kind=core                                                     \n"
+"   --vm_snapshot_data=<output-file>                                         \n"
+"   --isolate_snapshot_data=<output-file>                                    \n"
+"   [<dart-script-file>]                                                     \n"
 "                                                                            \n"
-"  Supported options:                                                        \n"
-"    --vm_snapshot_data=<file>         A full snapshot is a compact          \n"
-"    --isolate_snapshot_data=<file>    representation of the dart vm isolate \n"
-"                                      heap and dart isolate heap states.    \n"
-"                                      Both these options are required       \n"
+" Writes a snapshot of <dart-script-file> to the specified snapshot files.   \n"
+" If no <dart-script-file> is passed, a generic snapshot of all the corelibs \n"
+" is created.                                                                \n"
 "                                                                            \n"
-"    --package_root=<path>             Where to find packages, that is,      \n"
-"                                      package:...  imports.                 \n"
+" To create a script snapshot with respect to a given core snapshot:         \n"
+"   --snapshot-kind=script                                                   \n"
+"   --vm_snapshot_data=<intput-file>                                         \n"
+"   --isolate_snapshot_data=<intput-file>                                    \n"
+"   --script_snapshot=<output-file>                                          \n"
+"   <dart-script-file>                                                       \n"
 "                                                                            \n"
-"    --packages=<packages_file>        Where to find a package spec file     \n"
+"  Writes a snapshot of <dart-script-file> to the specified snapshot files.  \n"
+"  If no <dart-script-file> is passed, a generic snapshot of all the corelibs\n"
+"  is created.                                                               \n"
 "                                                                            \n"
-"    --url_mapping=<mapping>           Uses the URL mapping(s) specified on  \n"
-"                                      the command line to load the          \n"
-"                                      libraries.                            \n"
+" To create an AOT application snapshot as blobs suitable for loading with   \n"
+" mmap:                                                                      \n"
+"   --snapshot-kind=app-aot-blobs                                            \n"
+"   --vm_snapshot_data=<output-file>                                         \n"
+"   --vm_snapshot_instructions=<output-file>                                 \n"
+"   --isolate_snapshot_data=<output-file>                                    \n"
+"   --isolate_snapshot_instructions=<output-file>                            \n"
+"   {--embedder_entry_points_manifest=<input-file>}                          \n"
+"   <dart-script-file>                                                       \n"
 "                                                                            \n"
-"    --assembly=<file>                 (Precompilation only) Contains the    \n"
-"                                      assembly that must be linked into     \n"
-"                                      the target binary                     \n"
+" To create an AOT application snapshot as assembly suitable for compilation \n"
+" as a static or dynamic library:                                            \n"
+" mmap:                                                                      \n"
+"   --snapshot-kind=app-aot-blobs                                            \n"
+"   --assembly=<output-file>                                                 \n"
+"   {--embedder_entry_points_manifest=<input-file>}                          \n"
+"   <dart-script-file>                                                       \n"
 "                                                                            \n"
-"    --vm_snapshot_instructions=<file> (Precompilation only) Contains the    \n"
-"    --isolate_snapshot_instructions=<file> instructions and read-only data  \n"
-"                                      that must be mapped into the target   \n"
-"                                      binary                                \n"
+" AOT snapshots require entry points manifest files, which list the places   \n"
+" in the Dart program the embedder calls from the C API (Dart_Invoke, etc).  \n"
+" Not specifying these may cause the tree shaker to remove them from the     \n"
+" program. The format of this manifest is as follows. Each line in the       \n"
+" manifest is a comma separated list of three elements. The first entry is   \n"
+" the library URI, the second entry is the class name and the final entry    \n"
+" the function name. The file must be terminated with a newline charater.    \n"
 "                                                                            \n"
-"    --embedder_entry_points_manifest=<file> (Precompilation or app          \n"
-"                                      snapshots) Contains embedder's entry  \n"
-"                                      points into Dart code from the C API. \n"
+"   Example:                                                                 \n"
+"     dart:something,SomeClass,doSomething                                   \n"
 "\n");
 }
 // clang-format on
@@ -1018,8 +1099,11 @@ static Dart_QualifiedFunctionName* ParseEntryPointsManifestIfPresent() {
 }
 
 
-static void CreateAndWriteSnapshot() {
-  ASSERT(!IsSnapshottingForPrecompilation());
+static void CreateAndWriteCoreSnapshot() {
+  ASSERT(snapshot_kind == kCore);
+  ASSERT(vm_snapshot_data_filename != NULL);
+  ASSERT(isolate_snapshot_data_filename != NULL);
+
   Dart_Handle result;
   uint8_t* vm_snapshot_data_buffer = NULL;
   intptr_t vm_snapshot_data_size = 0;
@@ -1038,10 +1122,21 @@ static void CreateAndWriteSnapshot() {
                     vm_snapshot_data_size);
   WriteSnapshotFile(isolate_snapshot_data_filename,
                     isolate_snapshot_data_buffer, isolate_snapshot_data_size);
-  Dart_ExitScope();
+}
+
 
-  // Shutdown the isolate.
-  Dart_ShutdownIsolate();
+static void CreateAndWriteScriptSnapshot() {
+  ASSERT(snapshot_kind == kScript);
+  ASSERT(script_snapshot_filename != NULL);
+
+  // First create a snapshot.
+  uint8_t* buffer = NULL;
+  intptr_t size = 0;
+  Dart_Handle result = Dart_CreateScriptSnapshot(&buffer, &size);
+  CHECK_RESULT(result);
+
+  // Now write it out to the specified file.
+  WriteSnapshotFile(script_snapshot_filename, buffer, size, true);
 }
 
 
@@ -1057,13 +1152,18 @@ static void CreateAndWritePrecompiledSnapshot(
   // Create a precompiled snapshot.
   bool as_assembly = assembly_filename != NULL;
   if (as_assembly) {
+    ASSERT(snapshot_kind == kAppAOTAssembly);
+
     uint8_t* assembly_buffer = NULL;
     intptr_t assembly_size = 0;
     result =
         Dart_CreateAppAOTSnapshotAsAssembly(&assembly_buffer, &assembly_size);
     CHECK_RESULT(result);
+
     WriteSnapshotFile(assembly_filename, assembly_buffer, assembly_size);
   } else {
+    ASSERT(snapshot_kind == kAppAOTBlobs);
+
     uint8_t* vm_snapshot_data_buffer = NULL;
     intptr_t vm_snapshot_data_size = 0;
     uint8_t* vm_snapshot_instructions_buffer = NULL;
@@ -1079,6 +1179,7 @@ static void CreateAndWritePrecompiledSnapshot(
         &isolate_snapshot_instructions_buffer,
         &isolate_snapshot_instructions_size);
     CHECK_RESULT(result);
+
     WriteSnapshotFile(vm_snapshot_data_filename, vm_snapshot_data_buffer,
                       vm_snapshot_data_size);
     WriteSnapshotFile(vm_snapshot_instructions_filename,
@@ -1090,11 +1191,6 @@ static void CreateAndWritePrecompiledSnapshot(
                       isolate_snapshot_instructions_buffer,
                       isolate_snapshot_instructions_size);
   }
-
-  Dart_ExitScope();
-
-  // Shutdown the isolate.
-  Dart_ShutdownIsolate();
 }
 
 
@@ -1102,7 +1198,7 @@ static void SetupForUriResolution() {
   // Set up the library tag handler for this isolate.
   Dart_Handle result = Dart_SetLibraryTagHandler(Loader::LibraryTagHandler);
   if (Dart_IsError(result)) {
-    Log::PrintErr("%s", Dart_GetError(result));
+    Log::PrintErr("%s\n", Dart_GetError(result));
     Dart_ExitScope();
     Dart_ShutdownIsolate();
     exit(kErrorExitCode);
@@ -1140,28 +1236,28 @@ static Dart_Isolate CreateServiceIsolate(const char* script_uri,
   IsolateData* isolate_data =
       new IsolateData(script_uri, package_root, package_config);
   Dart_Isolate isolate = NULL;
-  isolate = Dart_CreateIsolate(script_uri, main, NULL, NULL, NULL, isolate_data,
-                               error);
+  isolate = Dart_CreateIsolate(script_uri, main, isolate_snapshot_data, NULL,
+                               NULL, isolate_data, error);
 
   if (isolate == NULL) {
-    Log::PrintErr("Error: Could not create service isolate");
+    Log::PrintErr("Error: Could not create service isolate\n");
     return NULL;
   }
 
   Dart_EnterScope();
   if (!Dart_IsServiceIsolate(isolate)) {
-    Log::PrintErr("Error: We only expect to create the service isolate");
+    Log::PrintErr("Error: We only expect to create the service isolate\n");
     return NULL;
   }
   Dart_Handle result = Dart_SetLibraryTagHandler(Loader::LibraryTagHandler);
-  // Setup the native resolver.
-  Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
-  Builtin::LoadAndCheckLibrary(Builtin::kIOLibrary);
   if (Dart_IsError(result)) {
-    Log::PrintErr("Error: Could not set tag handler for service isolate");
+    Log::PrintErr("Error: Could not set tag handler for service isolate\n");
     return NULL;
   }
-  CHECK_RESULT(result);
+  // Setup the native resolver.
+  Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
+  Builtin::LoadAndCheckLibrary(Builtin::kIOLibrary);
+
   ASSERT(Dart_IsServiceIsolate(isolate));
   // Load embedder specific bits and return. Will not start http server.
   if (!VmService::Setup("127.0.0.1", -1, false /* running_precompiled */,
@@ -1234,6 +1330,34 @@ int main(int argc, char** argv) {
   init_params.file_close = DartUtils::CloseFile;
   init_params.entropy_source = DartUtils::EntropySource;
 
+  if (snapshot_kind == kScript) {
+    File* file = File::Open(vm_snapshot_data_filename, File::kRead);
+    if (file == NULL) {
+      Log::PrintErr("Failed to open: %s\n", vm_snapshot_data_filename);
+      return kErrorExitCode;
+    }
+    void* buffer = file->Map(File::kReadOnly, 0, file->Length());
+    if (buffer == NULL) {
+      Log::PrintErr("Failed to read: %s\n", vm_snapshot_data_filename);
+      return kErrorExitCode;
+    }
+    file->Close();
+    init_params.vm_snapshot_data = reinterpret_cast<const uint8_t*>(buffer);
+
+    file = File::Open(isolate_snapshot_data_filename, File::kRead);
+    if (file == NULL) {
+      Log::PrintErr("Failed to open: %s\n", isolate_snapshot_data_filename);
+      return kErrorExitCode;
+    }
+    buffer = file->Map(File::kReadOnly, 0, file->Length());
+    if (buffer == NULL) {
+      Log::PrintErr("Failed to read: %s\n", isolate_snapshot_data_filename);
+      return kErrorExitCode;
+    }
+    file->Close();
+    isolate_snapshot_data = reinterpret_cast<const uint8_t*>(buffer);
+  }
+
   char* error = Dart_Initialize(&init_params);
   if (error != NULL) {
     Log::PrintErr("VM initialization failed: %s\n", error);
@@ -1243,10 +1367,10 @@ int main(int argc, char** argv) {
 
   IsolateData* isolate_data = new IsolateData(NULL, commandline_package_root,
                                               commandline_packages_file);
-  Dart_Isolate isolate =
-      Dart_CreateIsolate(NULL, NULL, NULL, NULL, NULL, isolate_data, &error);
+  Dart_Isolate isolate = Dart_CreateIsolate(NULL, NULL, isolate_snapshot_data,
+                                            NULL, NULL, isolate_data, &error);
   if (isolate == NULL) {
-    Log::PrintErr("Error: %s", error);
+    Log::PrintErr("Error: %s\n", error);
     free(error);
     exit(kErrorExitCode);
   }
@@ -1306,10 +1430,10 @@ int main(int argc, char** argv) {
         is_kernel_file
             ? Dart_CreateIsolateFromKernel(NULL, NULL, kernel_program, NULL,
                                            isolate_data, &error)
-            : Dart_CreateIsolate(NULL, NULL, NULL, NULL, NULL, isolate_data,
-                                 &error);
+            : Dart_CreateIsolate(NULL, NULL, isolate_snapshot_data, NULL, NULL,
+                                 isolate_data, &error);
     if (isolate == NULL) {
-      Log::PrintErr("%s", error);
+      Log::PrintErr("%s\n", error);
       free(error);
       exit(kErrorExitCode);
     }
@@ -1351,19 +1475,34 @@ int main(int argc, char** argv) {
     result = Dart_FinalizeLoading(false);
     CHECK_RESULT(result);
 
-    if (!IsSnapshottingForPrecompilation()) {
-      CreateAndWriteSnapshot();
-    } else {
-      CreateAndWritePrecompiledSnapshot(entry_points);
+    switch (snapshot_kind) {
+      case kCore:
+        CreateAndWriteCoreSnapshot();
+        break;
+      case kScript:
+        CreateAndWriteScriptSnapshot();
+        break;
+      case kAppAOTBlobs:
+      case kAppAOTAssembly:
+        CreateAndWritePrecompiledSnapshot(entry_points);
+        break;
+      default:
+        UNREACHABLE();
     }
 
+    Dart_ExitScope();
+    Dart_ShutdownIsolate();
+
     CleanupEntryPointsCollection(entry_points);
 
     Dart_EnterIsolate(UriResolverIsolateScope::isolate);
     Dart_ShutdownIsolate();
   } else {
     SetupForGenericSnapshotCreation();
-    CreateAndWriteSnapshot();
+    CreateAndWriteCoreSnapshot();
+
+    Dart_ExitScope();
+    Dart_ShutdownIsolate();
   }
   error = Dart_Cleanup();
   if (error != NULL) {