flutter_flutter/mojo/devtools/common

Devtools

Unopinionated tools for running, debugging and testing Mojo apps.

Install

git clone https://github.com/domokit/devtools.git

Contents

Devtools offers the following tools:

• mojo_shell - universal shell runner
• debugger - supports interactive tracing and debugging of a running mojo shell
• remote_adb_setup - configures adb on a remote machine to communicate with a device attached to the local machine

and a Python scripting library designed for being embedded (devtoolslib).

debugger

The debugger script allows you to interactively inspect a running shell, collect performance traces and attach a gdb debugger.

Tracing

To collect performance traces and retrieve the result:

debugger tracing start
debugger tracing stop [result.json]

The trace file can be then loaded using the trace viewer in Chrome available at about://tracing.

GDB

It is possible to inspect a Mojo Shell process using GDB. The debugger script can be used to launch GDB and attach it to a running shell process (android only):

debugger gdb attach

Android crash stacks

When Mojo shell crashes on Android ("Unfortunately, Mojo shell has stopped.") due to a crash in native code, debugger can be used to find and symbolize the stack trace present in the device log:

debugger device stack

devtoolslib

devtoolslib is a Python module containing the core scripting functionality for running Mojo apps: shell abstraction with implementations for Android and Linux and support for apptest frameworks. The executable scripts in devtools are based on this module. One can also choose to embed the functionality provided by devtoolslib in their own wrapper.

Development

The library is canonically developed in the mojo repository, https://github.com/domokit/devtools is a mirror allowing to consume it separately.