Dart: view the dill compiled code file

Write it at the front

Dart VM At run time .dart File compiled into .dill file , Sometimes we can check .dill File to understand the code from a deeper perspective . This article is mainly about .dill Compile and view files , Some practical examples will be added later .

Content

Get ready

Because in Dart Packed SDK and Flutter Under the SDK All have been screened , Like here we need to use one dump_kernel.dart file , This is packed SDK It's not in there .

So first we go GitHub On clone complete dart-sdk.

If we don't have Flutter, Let's just put clone Under the dart-sdk Configure to environment variables , Then you can use it directly .

If there is Flutter, So the dart The order should be Flutter Of , Then we need to make sure that at present Flutter Of dart-sdk With us clone Under the dart-sdk Consistent versions of .

for instance , adopt dart --version Command view Flutter Under the dart-sdk edition ：

* dart --version
Dart SDK version: 2.14.0-188.5.beta (beta) (Thu Jun 24 15:29:20 2021 +0200) on “macos_x64”

Here is 2.14.0-188.5.beta, Then we can put us clone Under the dart-sdk Switch to the corresponding tag, So both sides are consistent .

* git checkout 2.14.0-188.5.beta
Note: checking out ‘2.14.0-188.5.beta’.

compile

Let's say we've written a main.dart file , Want to view its compiled code file , Let's do it first dart compile kernel main.dart, And that creates main.dill file .
Then passed dart .../pkg/vm/bin/dump_kernel.dart main.dill main.txt The compiled code will be output to main.txt in , So we can check the compiled code .

dump_kernel.dart The document is in our clone Under the dart-sdk Of pkg Directory , The above path should be completed according to your own situation .

Because we will Flutter Of dart-sdk and clone Under the dart-sdk The version is consistent , So our orders can be carried out normally . Otherwise, errors like the following will occur ：

Unhandled exception:
Unexpected Kernel Format Version 60 (expected 65)
#0 BinaryBuilder.readComponent. (package:kernel/binary/ast_from_binary.dart:601:9)
#1 Timeline.timeSync (dart:developer/timeline.dart:163:22)
#2 BinaryBuilder.readComponent (package:kernel/binary/ast_from_binary.dart:588:21)
#3 main (file:///…/dart_sdk/sdk/pkg/vm/bin/dump_kernel.dart:54:40)
#4 _delayEntrypointInvocation. (dart:isolate-patch/isolate_patch.dart:281:32)
#5 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)

Reference resources

dart compile