vimspector

A multi language graphical debugger for Vim.

Features and Usage

The plugin is a capable Vim graphical debugger for multiple languages.
It's mostly tested for c++ and python, but in theory supports any
language that Visual Studio Code supports (but see caveats).

The [Vimspector website][website] has an overview of the UI, along with basic
instructions for configuration and setup.

But for now, here's a (rather old) screenshot of Vimsepctor debugging Vim:

vimspector-vim-screenshot

Supported debugging features

  • breakpoints (function, line and exception breakpoints)
  • step in/out/over/up, stop, restart
  • launch and attach
  • remote launch, remote attach
  • locals and globals display
  • watch expressions
  • call stack and navigation
  • variable value display hover
  • interactive debug console
  • launch debugee within Vim's embedded terminal
  • logging/stdout display

Supported languages:

The following languages are used frequently by the author and are known to work
with little effort, and are supported as first-class languages.

  • C, C++, etc. (languages supported by gdb or lldb)
  • Python 2 and Python 3
  • TCL
  • Bash scripts

Languages known to work

The following languages are used frequently by the author, but require some sort
of hackery that makes it challenging to support generally. These languages are
on a best-efforts basis:

  • Java (see caveats)
  • C# (c-sharp) using dotnet core
  • Go (requires separate installation of [Delve][])
  • Node.js (requires node <12 for installation)
  • Anything running in chrome (i.e. javascript).

Languages known not to work

  • C# (c-sharp) using mono debug adapter (vimspector unable to set breakpoints)

Other languages

Vimspector should work for any debug adapter that works in Visual Studio Code,
but there are certain limitations (see FAQ). If you're trying to get vimspector
to work with a language that's not "supported", head over to Gitter and contact
the author. It should be possible to get it going.

Installation

There are 2 installation methods:

  • Using a release tarball, or
  • Manually

Release tarballs come with debug adapters for the default languages
pre-packaged. To use a release tarball:

  1. Check the dependencies
  2. Untar the release tarball for your OS into $HOME/.vim/pack:
$ mkdir -p $HOME/.vim/pack
$ curl -L <url> | tar -C $HOME/.vim/pack zxvf -
  1. Configure your project's debug profiles (create .vimspector.json)

Alternatively, you can clone the repo and select which gadgets are installed:

  1. Check the dependencies
  2. Install the plugin as a Vim package. See :help packages.
  3. Install some 'gadgets' (debug adapters)
  4. Configure your project's debug profiles (create .vimspector.json)

Dependencies

Vimspector requires:

  • Vim version 8.1 with at least patch 1264, or Neovim 0.4.3
  • One of the following operating systems:
    • Linux
    • macOS Mojave or pater

Why such a new vim ? Well 2 reasons:

  1. Because vimspector uses a lot of new Vim features
  2. Because there are Vim bugs that vimspector triggers that will frustrate you
    if you hit them.

Why no Windows support? Because it's effort and it's not a priority for the
author. PRs are welcome.

Which Linux versions? I only test on Ubuntu 18.04 and later and RHEL 7.

Neovim differences

neovim doesn't implement some features Vimspector relies on:

  • WinBar - used for the buttons at the top of the code window and for changing
    the output window's current output.
  • Prompt Buffers - used to send commands in the Console and add Watches
  • Balloons - used to display the values of variables when debugging.

Workarounds are in place as follows:

There is no workaroud for the lack of balloons; you'll just have to use
:VimspectorEval or :VimspectorWatch, or switch to Vim.

Language dependencies

The debug adapters themselves have certain runtime dependencies:

Language Status Switch Adapter Dependencies
C, C++, etc. Supported --all or --enable-c vscode-cpptools mono-core
Python Supported --all or --enable-python vscode-python Python 2.7 or Python 3
TCL Experimental --all or --enable-tcl tclpro TCL 8.5
Bourne Shell Experimental --all or --enable-bash vscode-bash-debug Bash v??
C# (dotnet core) Experimental --force-enable-csharp netcoredbg DotNet core
C# (mono) Experimental --force-enable-csharp vscode-mono-debug Mono
Go Experimental --enable-go vscode-go Go, [Delve][]
Node.js Experimental --force-enable-node vscode-node-debug2 6 < Node < 12, Npm
Javascript Experimental --force-enable-chrome debugger-for-chrome Chrome

For other languages, you'll need some other way to install the gadget.

Clone the plugin

There are many Vim plugin managers, and I'm not going to state a particular
preference, so if you choose to use one, you're on your own with installation
issues.

Install vimspector as a Vim package, either by cloning this repository into your
package path, like this:

$ git clone https://github.com/puremourning/vimspector ~/.vim/pack/vimspector/opt/vimspector
  1. Configure vimspector in your .vimrc:
let g:vimspector_enable_mappings = 'HUMAN'
  1. Load vimspector at runtime. This can also be added to your .vimrc after
    configuring vimspector:
packadd! vimspector

See support/doc/example_vimrc.vim.

Also, if you want to try out vimspector without changing your vim config, run:

vim -Nu /path/to/vimspector/tests/vimrc --cmd "let g:vimspector_enable_mappings='HUMAN'"

Install some gadgets

There are a couple of ways of doing this, but using install_gadget.py is
highly recommended where that's an option.

For supported languages, install_gadget.py will:

  • Download the relevant debug adapter at a version that's been tested from the
    internet, either as a 'vsix' (Visusal Studio plugin), or clone from GitHub. If
    you're in a corporate environment and this is a problem, you may need to
    install the gadgets manually.
  • Perform any necessary post-installation actions, such as:
    • Building any binary components
    • Ensuring scripts are executable, because the VSIX pacakges are usually
      broken in this regard.
    • Set up the gadgetDir symlinks for the platform.

To install the tested debug adapter for a language, run:

./install_gadget.py --enable-<language>

Or to install all supported gagtets:

./install_gadget.py --all

To install everything other than TCL (because TCL is sadly not as popular as it
should be):

./install_gadget.py --all --disable-tcl

See --help for more info.

Manual gadget installation

You essentially need to get a working installation of the debug adapter, find
out how to start it, and configure that in an adapters entry in either your
.vimspector.json or in .gadgets.json.

The simplest way in practice is to install or start Visusal Studio Code and use
its extension manager to install the relevant extension. You can then configure
the adapter manually in the adapters section of your .vimspector.json or in
a gadgets.json.

PRs are always welcome to add configuration to do this to install_gadget.py.

The gadget directory

Vimspector uses the following directory by default to look for a file named
.gadgets.json: </path/to/vimspector>/gadgets/<os>.

This path is exposed as the vimspector variable ${gadgetDir}. This is useful
for configuring gadget command lines.

Where os is one of:

  • macos
  • linux
  • windows (though note: Windows is not supported)

The format is the same as .vimspector.json, but only the adapters key is
used:

Example:

{
  "adapters": {
    "lldb-vscode": {
      "variables": {
        "LLVM": {
          "shell": "brew --prefix llvm"
        }
      },
      "attach": {
        "pidProperty": "pid",
        "pidSelect": "ask"
      },
      "command": [
        "${LLVM}/bin/lldb-vscode"
      ],
      "env": {
        "LLDB_LAUNCH_FLAG_LAUNCH_IN_TTY": "YES"
      },
      "name": "lldb"
    },
    "vscode-cpptools": {
      "attach": {
        "pidProperty": "processId", 
        "pidSelect": "ask"
      }, 
      "command": [
        "${gadgetDir}/vscode-cpptools/debugAdapters/OpenDebugAD7"
      ], 
      "name": "cppdbg"
    }, 
    "vscode-python": {
      "command": [
        "node", 
        "${gadgetDir}/vscode-python/out/client/debugger/debugAdapter/main.js"
      ], 
      "name": "vscode-python"
    }
  }
}

The gadget file is automatically written by install_gadget.py.

Vimspector will also load any fies matching:
</path/to/vimspector>/gadgets/<os>/.gadgets.d/*.json. These have the same
format as .gadgets.json but are not overwritten when running
install_gadget.py.

About

Background

The motivation is that debugging in Vim is a pretty horrible experience,
particularly if you use multiple languages. With pyclewn no more and the
built-in termdebug plugin limited to gdb, I wanted to explore options.

While Language Server Protocol is well known, the Debug Adapter Protocol is less
well known, but achieves a similar goal: language agnostic API abstracting
debuggers from clients.

The aim of this project is to provide a simple but effective debugging
experience in Vim for multiple languages, by leveraging the debug adapters that
are being built for Visual Studio Code.

The ability to do remote debugging is a must. This is key to my workflow, so
baking it in to the debugging experience is a top bill goal for the project. So
vimspector has first-class support for executing programs remotely and attaching
to them. This support is unique to vimspector and on top of (complementary to)
any such support in actual debug adapters.

Status

Vimspector is a work in progress, and any feedback/contributions are more
than welcome.

The backlog can be viewed on Trello.

In order to use it you have to currently:

  • Write a mostly undocumented configuration file that contains essentially
    undocumented parameters.
  • Accept that it isn't complete yet
  • Work around some frustrating bugs in Vim
  • Ignore probably many bugs in vimspector!

Experimental

The plugin is currently experimental. That means that any part of it
can (and probably will) change, including things like:

  • breaking changes to the configuration
  • keys, layout, functionatlity of the UI

If a large number of people start using it then I will do my best to
minimise this, or at least announce on Gitter.

Mappings

By default, vimspector does not change any of your mappings. Mappings are very
personal and so you should work out what you like and use vim's powerful mapping
features to set your own mappings. To that end, Vimspector defines the following
<Plug> mappings:

  • <Plug>VimspectorContinue
  • <Plug>VimspectorStop
  • <Plug>VimspectorRestart
  • <Plug>VimspectorPause
  • <Plug>VimspectorToggleBreakpoint
  • <Plug>VimspectorAddFunctionBreakpoint
  • <Plug>VimspectorStepOver
  • <Plug>VimspectorStepInto
  • <Plug>VimspectorStepOut

These map 1-1 with the API functions below.

For example, if you want <F5> to start/continue debugging, add this to some
appropriate place, such as your vimrc (hint: run :e $MYVIMRC).

nmap <F5> <Plug>VimspectorContinue

That said, many people are familiar with particular debuggers, so the following
mappings can be enabled by setting g:vimspector_enable_mappings to the
specified value.

Please note: Currently there are no <plug> mappings. These will be added in
future to make custom mappings much easier.

Visual Studio / VSCode

To use Visual Studio-like mappings, add the following to your vimrc before
loading vimspector:

let g:vimspector_enable_mappings = 'VISUAL_STUDIO'
Key Function API
F5 When debugging, continue. Otherwise start debugging. vimspector#Continue()
Shift F5 Stop debugging. vimspector#Stop()
Ctrl Shift F5 Restart debugging with the same configuration. vimspector#Restart()
F6 Pause debugee. vimspector#Pause()
F9 Toggle line breakpoint on the current line. vimspector#ToggleBreakpoint()
Shift F9 Add a function breakpoint for the expression under cursor vimspector#AddFunctionBreakpoint( '<cexpr>' )
F10 Step Over vimspector#StepOver()
F11 Step Into vimspector#StepInto()
Shift F11 Step out of current function scope vimspector#StepOut()

Human Mode

If, like me, you only have 2 hands and 10 fingers, you probably don't like
Ctrl-Shift-F keys. Also, if you're running in a terminal, there's a real
possibility of terminfo being wrong for shifted-F-keys, particularly if your
TERM is screen-256color. If these issues (number of hands, TERM variables)
are unfixable, try the following mappings, by adding the following before
loading vimspector:

let g:vimspector_enable_mappings = 'HUMAN'
Key Function API
F5 When debugging, continue. Otherwise start debugging. vimspector#Continue()
F3 Stop debugging. vimspector#Stop()
F4 Restart debugging with the same configuration. vimspector#Restart()
F6 Pause debugee. vimspector#Pause()
F9 Toggle line breakpoint on the current line. vimspector#ToggleBreakpoint()
F8 Add a function breakpoint for the expression under cursor vimspector#AddFunctionBreakpoint( '<cexpr>' )
F10 Step Over vimspector#StepOver()
F11 Step Into vimspector#StepInto()
F12 Step out of current function scope vimspector#StepOut()

Usage

Launch and attach by PID:

  • Create vimspector.json. See below.
  • :call vimspector#Launch() and select a configuration.

Breakpoints

  • Use vimspector#ToggleBreakpoint() to set/disable/delete a line breakpoint.
  • Use vimspector#AddFunctionBreakpoint( '<name>' ) to add a function
    breakpoint.

Stepping

  • Step in/out, finish, continue, pause etc. using the WinBar.
  • If you really want to, the API is vimspector#StepInto() etc.

Variables and scopes

  • Current scope shows values of locals.
  • Use <CR> to expand/collapse (+, -).
  • When changing the stack frame the locals window updates.
  • While paused, hover to see values

Watches

The watches window is a prompt buffer, where that's available. Enter insert mode
to add a new watch expression.

  • Add watches to the variables window by entering insert mode and
    typing the expression. Commit with <CR>.
  • Alternatively, use :VimspectorWatch <expression>. Tab-completion for
    expression is available in some debug adapters.
  • Expand result with <CR>.
  • Delete with <DEL>.

Stack Traces

  • In the threads window, use <CR> to expand/collapse.
  • Use <CR> on a stack frame to jump to it.

Program Output

  • In the outputs window use the WinBar to select the output channel.
  • Alternatively, use :VimspectorShowOutput <category>. Use command-line
    completion to see the categories.
  • The debugee prints to the stdout channel.
  • Other channels may be useful for debugging.

Console

The console window is a prompt buffer, where that's available, and can be used
as an interactive CLI for the debug adapter. Support for this varies amongt
adapters.

  • Enter insert mode to enter a command to evaluate.
  • Alternatively, :VimspectorEval <expression>. Completion is available with
    some debug adapters.
  • Commit the request with <CR>
  • The request and subsequent result are printed.

NOTE: See also Watches above.

Closing debugger

To close the debugger, use:

  • Reset WinBar button (set mouse=a)
  • :VimspectorReset when the WinBar is not available.
  • call vimspector#Reset()

Debug adapter configuration

For more information on the configuration of .vimspector.json, take a look at
the Getting Started section of the [Vimspector website][website].

Current tested with the following debug adapters.

C, C++, Rust, etc.

NOTE FOR macOS USERS: Currently VSCode cpptools does not work on macOS
out of the box.
See this issue
for the full details.

To resolve it:

  • Install my build of
    lldb-mi. Instructions
    here.
  • Add the following to the configuration section of your .vimspector.json
    (below):
{
  "configurations": {
    "<name>: Launch": {
      "adapter": "vscode-cpptools",
      "configuration": {
        "miDebuggerPath": "/path/to/my/build/of/lldb-mi",
        ...

An alternative is to to use lldb-vscode, which comes with llvm. Here's how:

  • Install llvm with HomeBrew: brew install llvm
  • Create a file named
    /path/to/vimspector/gadgets/macos/.gadgets.d/lldb-vscode.json:

{
  "adapters": {
    "lldb-vscode": {
      "variables": {
        "LLVM": {
          "shell": "brew --prefix llvm"
        }
      },
      "attach": {
        "pidProperty": "pid",
        "pidSelect": "ask"
      },
      "command": [
        "${LLVM}/bin/lldb-vscode"
      ],
      "env": {
        "LLDB_LAUNCH_FLAG_LAUNCH_IN_TTY": "YES"
      },
      "name": "lldb"
    }
  }
}

Example .vimspector.json (works with both vscode-cpptools and lldb-vscode.
For lldb-vscode replace the name of the adapter with lldb-vscode:

{
  "configurations": {
    "<name>: Launch": {
      "adapter": "vscode-cpptools",
      "configuration": {
        "name": "<name>",
        "type": "cppdbg",
        "request": "launch",
        "program": "<path to binary>",
        "args": [ ... ],
        "cwd": "<working directory>",
        "environment": [ ... ],
        "externalConsole": true,
        "MIMode": "lldb"
      }
    },
    "<name>: Attach": {
      "adapter": "vscode-cpptools",
      "configuration": {
        "name": "<name>: Attach",
        "type": "cppdbg",
        "request": "attach",
        "program": "<path to binary>",
        "MIMode": "lldb"
      }
    }
    ...
  }
}

Python

{
  "configurations": {
    "<name>: Launch": {
      "adapter": "vscode-python",
      "configuration": {
        "name": "<name>: Launch",
        "type": "python",
        "request": "launch",
        "cwd": "<working directory>",
        "stopOnEntry": true,
        "console": "externalTerminal",
        "debugOptions": [],
        "program": "<path to main python file>"
      }
    }
    ...
  }
}

TCL

  • TCL (TclProDebug)

See my fork of TclProDebug for instructions.

C♯

  • C# - dotnet core

Requires install_gadget.py --force-enable-c-sharp

{
  "configurations": {
    "launch - netcoredbg": {
      "adapter": "netcoredbg",
      "configuration": {
        "request": "launch",
        "program": "${workspaceRoot}/bin/Debug/netcoreapp2.2/csharp.dll",
        "args": [],
        "stopAtEntry": true
      }
    }
  }
}
  • C# - mono

Requires install_gadget.py --force-enable-c-sharp.

Known not to work.*

{
  "configurations": {
    "launch - mono": {
      "adapter": "vscode-mono-debug",
      "configuration": {
        "request": "launch",
        "program": "${workspaceRoot}/bin/Debug/netcoreapp2.2/csharp.dll",
        "args": [],
        "cwd": "${workspaceRoot}",
        "runtimeExecutable": "mono",
        "runtimeArgs": [],
        "env": [],
        "externalConsole": false,
        "console": "integratedTerminal"
      }
    }
  }
}

Go

  • Go

Requires:

  • install_gadget.py --enable-go
  • [Delve][delve-install] installed, e.g. go get -u github.com/go-delve/delve/cmd/dlv
  • Delve to be in your PATH, or specify the dlvToolPath launch option
{
  "configurations": {
    "run": {
      "adapter": "vscode-go",
      "configuration": {
        "request": "launch",
        "program": "${fileDirname}",
        "mode": "debug",
        "dlvToolPath": "$HOME/go/bin/dlv"
      }
    }
  }
}

PHP

This uses the php-debug, see
https://marketplace.visualstudio.com/items?itemName=felixfbecker.php-debug

Requires:

zend_extension=xdebug.so
xdebug.remote_enable=on
xdebug.remote_handler=dbgp
xdebug.remote_host=localhost
xdebug.remote_port=9000

replace localhost with the ip of your workstation.

lazy alternative

zend_extension=xdebug.so
xdebug.remote_enable=on
xdebug.remote_handler=dbgp
xdebug.remote_connect_back=true
xdebug.remote_port=9000
  • .vimspectory.json
{
  "configurations": {
    "Listen for XDebug": {
      "adapter": "vscode-php-debug",
      "configuration": {
        "name": "Listen for XDebug",
        "type": "php",
        "request": "launch",
        "port": 9000,
        "stopOnEntry": false,
        "pathMappings": {
          "/var/www/html": "${workspaceRoot}"
        }
      }
    },
    "Launch currently open script": {
      "adapter": "vscode-php-debug",
      "configuration": {
        "name": "Launch currently open script",
        "type": "php",
        "request": "launch",
        "program": "${file}",
        "cwd": "${fileDirname}",
        "port": 9000
      }
    }
  }
}

Debug web application

append XDEBUG_SESSION_START=xdebug to your query string

curl "http://localhost?XDEBUG_SESSION_START=xdebug"

or use the previously mentioned Xdebug Helper extension (which sets a XDEBUG_SESSION cookie)

Debug cli application

export XDEBUG_CONFIG="idekey=xdebug"
php <path to script>

JavaScript, TypeScript, etc.

  • Node.js

Requires:

  • install_gadget.py --force-enable-node
  • For installation, a Node.js environemt that is < node 12. I believe this is an
    incompatibility with gulp. Advice, use [nvm][] with nvm install --lts 10; nvm use --lts 10; ./install_gadget.py --force-enable-node ...
  • Options described here:
    https://code.visualstudio.com/docs/nodejs/nodejs-debugging
  • Example: support/test/node/simple
{
  "configurations": {
    "run": {
      "adapter": "vscode-node",
      "configuration": {
        "request": "launch",
        "protocol": "auto",
        "stopOnEntry": true,
        "console": "integratedTerminal",
        "program": "${workspaceRoot}/simple.js",
        "cwd": "${workspaceRoot}"
      }
    }
  }
}
  • Chrome

This uses the chrome debugger, see
https://marketplace.visualstudio.com/items?itemName=msjsdiag.debugger-for-chrome.

It allows you to debug scripts running inside chrome from within Vim.

  • ./install_gadget.py --force-enable-chrome
  • Example: support/test/chrome
{
  "configurations": {
    "launch": {
      "adapter": "chrome",
      "configuration": {
        "request": "launch",
        "url": "http://localhost:1234/",
        "webRoot": "${workspaceRoot}/www"
      }
    }
  }
}

Java - partially supported

  • Java Debug Server. The [java debug server][java-debug-server] runs as a
    jdt.ls plugin, rather than a standalone debug adapter. This makes a lot
    of sense if you already happen to be running the language server.
    Vimspector is not in the business of running language servers. So, rather
    than doing so, vimspector simply allows you to start the java debug server
    manually (however you might do so) and you can tell vimspector the port
    on which it is listening. See this issue
    for more background.

  • Java - vscode-javac. This works, but is not as functional as Java Debug
    Server. Take a look at this
    comment
    for instructions.

Customisation

There is very limited support for customistaion of the UI.

Changing the default signs

Vimsector uses the following signs internally. If they are defined before
Vimsector uses them, they will not be replaced. So to customise the signs,
define them in your vimrc.

  • vimspectorBP: A breakpoint.
  • vimspectorBPDisabled: A disabled breakpoint
  • vimspectorPC The program counter, i.e. current line.

For example, to use some unicode symbols, you could put this in your vimrc:

sign define vimspectorBP text=? texthl=Normal
sign define vimspectorBPDisabled text=? texthl=Normal
sign define vimspectorPC text=? texthl=SpellBad

GitHub