Reapply "Use a single file for app snapshots."

runtime/bin/gen_snapshot.cc

 // Copyright (c) 2013, 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.
 
 // Generate a snapshot file after loading all the scripts specified on the
 // command line.
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 1018 matching lines @@
 
   // Shutdown the isolate.
   Dart_ShutdownIsolate();
 }
 
 
 static void CreateAndWritePrecompiledSnapshot(
     Dart_QualifiedFunctionName* standalone_entry_points) {
   ASSERT(IsSnapshottingForPrecompilation());
   Dart_Handle result;
-  uint8_t* vm_isolate_buffer = NULL;
-  intptr_t vm_isolate_size = 0;
-  uint8_t* isolate_buffer = NULL;
-  intptr_t isolate_size = 0;
-  uint8_t* assembly_buffer = NULL;
-  intptr_t assembly_size = 0;
-  uint8_t* instructions_blob_buffer = NULL;
-  intptr_t instructions_blob_size = 0;
-  uint8_t* rodata_blob_buffer = NULL;
-  intptr_t rodata_blob_size = 0;
 
   // Precompile with specified embedder entry points
   result = Dart_Precompile(standalone_entry_points, true);
   CHECK_RESULT(result);
 
   // Create a precompiled snapshot.
   bool as_assembly = assembly_filename != NULL;
   if (as_assembly) {
-    result = Dart_CreatePrecompiledSnapshotAssembly(&vm_isolate_buffer,
-                                                    &vm_isolate_size,
-                                                    &isolate_buffer,
-                                                    &isolate_size,
-                                                    &assembly_buffer,
+    uint8_t* assembly_buffer = NULL;
+    intptr_t assembly_size = 0;
+    result = Dart_CreatePrecompiledSnapshotAssembly(&assembly_buffer,
                                                     &assembly_size);
     CHECK_RESULT(result);
+    WriteSnapshotFile(assembly_filename,
+                      assembly_buffer,
+                      assembly_size);
   } else {
+    uint8_t* vm_isolate_buffer = NULL;
+    intptr_t vm_isolate_size = 0;
+    uint8_t* isolate_buffer = NULL;
+    intptr_t isolate_size = 0;
+    uint8_t* instructions_blob_buffer = NULL;
+    intptr_t instructions_blob_size = 0;
+    uint8_t* rodata_blob_buffer = NULL;
+    intptr_t rodata_blob_size = 0;
     result = Dart_CreatePrecompiledSnapshotBlob(&vm_isolate_buffer,
                                                 &vm_isolate_size,
                                                 &isolate_buffer,
                                                 &isolate_size,
                                                 &instructions_blob_buffer,
                                                 &instructions_blob_size,
                                                 &rodata_blob_buffer,
                                                 &rodata_blob_size);
     CHECK_RESULT(result);
-  }
-
-  // Now write the snapshot pieces out to the specified files and exit.
-  WriteSnapshotFile(vm_isolate_snapshot_filename,
-                    vm_isolate_buffer,
-                    vm_isolate_size);
-  WriteSnapshotFile(isolate_snapshot_filename,
-                    isolate_buffer,
-                    isolate_size);
-  if (as_assembly) {
-    WriteSnapshotFile(assembly_filename,
-                      assembly_buffer,
-                      assembly_size);
-  } else {
+    WriteSnapshotFile(vm_isolate_snapshot_filename,
+                      vm_isolate_buffer,
+                      vm_isolate_size);
+    WriteSnapshotFile(isolate_snapshot_filename,
+                      isolate_buffer,
+                      isolate_size);
     WriteSnapshotFile(instructions_blob_filename,
                       instructions_blob_buffer,
                       instructions_blob_size);
     WriteSnapshotFile(rodata_blob_filename,
                       rodata_blob_buffer,
                       rodata_blob_size);
   }
+
   Dart_ExitScope();
 
   // Shutdown the isolate.
   Dart_ShutdownIsolate();
 }
 
 
 static void SetupForUriResolution() {
   // Set up the library tag handler for this isolate.
   Dart_Handle result = Dart_SetLibraryTagHandler(Loader::LibraryTagHandler);
@@ skipping 249 matching lines @@
   EventHandler::Stop();
   return 0;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   return dart::bin::main(argc, argv);
 }