Features#

Launch/Attach
Breakpoints
Exceptions
Pause & Continue
Step In/Out/Over
Callstacks
Threads
Multiple simultaneous debug sessions
Evaluating statements
Debug/Run configurations (also with launch.json files)
Expressions

Debugger commands#

Command	Description
`dap-breakpoint-toggle`	Toggle breakpoint at line
`dap-breakpoint-delete`	Delete breakpoint at line
`dap-breakpoint-add`	Add breakpoint at line
`dap-breakpoint-condition`	Set/unset breakpoint condition
`dap-breakpoint-hit-condition`	Set/unset breakpoint hit condition
`dap-breakpoint-log-message`	Set/unset breakpoint log message
`dap-eval`	Eval string
`dap-eval-region`	Eval region string
`dap-eval-thing-at-point`	Eval symbol at point
`dap-step-in`	Debug step in
`dap-next`	Debug next
`dap-step-out`	Debug step out
`dap-stop-thread`	Stop thread
`dap-restart-frame`	Restart frame
`dap-continue`	Debug continue
`dap-disconnect`	Cancel current debug session
`dap-switch-stack-frame`	Switch active stack frame
`dap-switch-thread`	Switch active thread
`dap-switch-session`	Switch active session
`dap-debug-edit-template`	Generate run command
`dap-debug`	Create and run new configuration using the available templates
`dap-debug-last`	Debug previous configuration
`dap-debug-recent`	Select configuration to run from the previously started command
`dap-go-to-output-buffer`	Go output buffer

Windows#

Command	Description
`dap-ui-sessions`	Show active/terminated sessions view
`dap-ui-locals`	Show locals view
`dap-ui-expressions`	Show expressions view
`dap-ui-breakpoints`	Show breakpoints view
`dap-ui-repl`	DAP UI REPL

Sessions#

The session view is shown after invoking dap-ui-sessions . It represents the list of the active sessions.

Locals#

Locals can be viewed after invoking dap-ui-locals.

Expressions#

Watch expressions can be viewed after invoking dap-ui-expressions. You could add remove watch expressions via dap-ui-expressions-add and dap-ui-expressions-remove.

Breakpoints#

Breakpoints can be viewed after invoking dap-ui-breakpoints.

Keybindings

Command	Description	Keybindings
`dap-ui-breakpoints-goto`	Go to breakpoint under cursor	\<return>
`dap-ui-breakpoints-delete`	Delete breakpoint under cursor	d
`dap-ui-breakpoints-delete-selected`	Delete selected breakpoints	D
`bui-list-mark`	Mark breakpoint under point	m
`bui-list-unmark`	Unmark breakpoint under point	u
`bui-list-unmark-all`	Unmark breakpoint under point	U

Loaded sources#

Loaded sources can be viewed by invoking dap-tm-loaded-sources.

DAP debug REPL#

DAP provides a debug shell to execute commands when the program has hit breakpoints. The REPL has the same features as regular emacs shells (e.g. command history, C-p/n navigation through history, etc.) in addition to optional company-mode autocompletion.

launch.json support#

DAP supports launch.json files out of the box, and there is nothing that needs to be enabled. All that needs to be done is to add a launch.json file at the project root or the .vscode directory within the project root and to run dap-debug. All configurations stored in the launch.json will automatically show up in the selection. launch.json files in DAP are just like in VSCode and even support variables. See:

Compiling the project before debugging#

Many modern IDEs, for example Eclipse and VSCode (preLaunchTask), provide functionality to compile the project before starting the debug session.

dap-mode also has such a feature: the :dap-compilation property of launch configurations ("dap-compilation" in launch.json) specifies a shell command that needs to execute successfully before the debug session is started. :dap-compilation-dir can be used to control where the compilation is started.

In the future, we want to support VSCode's preLaunchTask instead, but currently there is no tasks.json-compatible task runner for Emacs.

Last update: November 1, 2024