doomemacs/modules/tools/debugger/README.org

#+title:    :tools debugger
#+subtitle: Step through code to help you add bugs
#+created:  February 20, 2020
#+since:    2.0.0

* Description :unfold:
Introduces a code debugger to Emacs, powered by [[doom-package:realgud]] or [[doom-package:dap-mode]] (LSP).

This document will help you to configure [[doom-package:dap-mode]] [[https://emacs-lsp.github.io/dap-mode/page/configuration/#native-debug-gdblldb][Native Debug(GDB/LLDB)]] as
there is still not *enough* documentation for it.

** Maintainers
/This module has no dedicated maintainers./ [[doom-contrib-maintainer:][Become a maintainer?]]

** Module flags
- +lsp ::
  Enable support for [[https://microsoft.github.io/debug-adapter-protocol/][Debug Adapter Protocol]] (DAP) debuggers.

** Packages
- [[doom-package:realgud]]
- [[doom-package:realgud-trepan-ni]] if [[doom-module::lang javascript]]
- if [[doom-module:+lsp]]
  - [[doom-package:dap-mode]] 
  - [[doom-package:posframe]] 

** TODO Hacks
#+begin_quote
 🔨 This module's hacks haven't been documented yet. [[doom-contrib-module:][Document them?]]
#+end_quote

** TODO Changelog
# This section will be machine generated. Don't edit it by hand.
/This module does not have a changelog yet./

* TODO Installation
#+begin_quote
 🔨 /This module's prerequisites documentation is incomplete./ [[doom-contrib-module:][Complete it?]]
#+end_quote

[[id:01cffea4-3329-45e2-a892-95a384ab2338][Enable this module in your ~doom!~ block.]]

Make sure all of these pre-requirements is in your ~$PATH~:
- =nodejs=
- =lldb= and =lldb-mi= (optional)
- =gdb= (optional), requires =unzip=

If you are getting an error like ~Searching for program no such file or
directory "node"~, then you need [[github:nodejs/node][nodejs]] ([[github:emacs-lsp/dap-mode/issues/79][emacs-lsp/dap-mode#79]]).

** Realgud debuggers
*** lldb and lldb-mi
This is optional if you want to debug with [[https:lldb.llvm.org][LLDB]]. Install lldb and [[github:lldb-tools/lldb-mi][lldb-mi]].

*** gdb
This is optional if you want to debug with [[https:www.gnu.org/software/gdb/][GDB]]. Install gdb.

You will need ~unzip~ for ~dap-gdb-lldb-setup~. It downloads a VS-Code extension
and it needs to extract compressed downloaded file.

You need this if you are having ~"wrong-type-argument stringp nil"~ error when
calling ~dap-gdb-lldb-setup~. [[github:emacs-lsp/dap-mode/issues/313][See emacs-lsp/dap-mode#313]]

** DAP debuggers
*** Python
DAP expects [[https://github.com/Microsoft/ptvsd][ptvsd]] by default as the Python debugger, but [[https://github.com/microsoft/debugpy][debugpy]] is recommended.
See [[*Configuration][Configuration]].

*installing ptvsd:*
#+begin_src sh
pip3 install ptvsd --user
#+end_src

*install debugpy:*
#+begin_src sh
pip3 install debugpy --user
#+end_src

#+begin_src emacs-lisp
;; in $DOOMDIR/config.el
(after! dap-mode
  (setq dap-python-debugger 'debugpy))
#+end_src

*** C, C++, Rust, Golang
Needs [[https://github.com/llvm/llvm-project/tree/main/lldb/tools/lldb-vscode][lldb-vscode]]. Install LLDB from your package manager.

*Fedora:*
#+begin_src sh
dnf install lldb
#+end_src

* TODO Usage
#+begin_quote
 🔨 /This module's usage documentation is incomplete./ [[doom-contrib-module:][Complete it?]]
#+end_quote

- ~M-x +debugger/start~
- ~M-x +debugger/start-last~
- ~M-x +debugger/quit~
  
** Realgud
1. Call ~dap-gdb-lldb-setup~ function.
2. Use ~dap-debug-edit-template~ to configure debugging settings for your
   project. [[github:WebFreak001/code-debug/blob/master/package.json#L72][Available settings can be inspected here.]] Call ~eval-buffer~ to save
   your settings. *Don't save the file!*
3. Call ~dap-debug~, select a configuration and start debugging.

** dap-mode with ~+lsp~
Intuitive and powerful debugging.

- Breakpoints
- REPL
- *local variable view:* Allows you to browse variables in the current stack
  frame.
- *expressions:* Add expressions to either watch variables or generic
  expressions.
  
** Keybindings
#+begin_src emacs-lisp
(map! :map dap-mode-map
      :leader
      :prefix ("d" . "dap")
      ;; basics
      :desc "dap next"          "n" #'dap-next
      :desc "dap step in"       "i" #'dap-step-in
      :desc "dap step out"      "o" #'dap-step-out
      :desc "dap continue"      "c" #'dap-continue
      :desc "dap hydra"         "h" #'dap-hydra
      :desc "dap debug restart" "r" #'dap-debug-restart
      :desc "dap debug"         "s" #'dap-debug

      ;; debug
      :prefix ("dd" . "Debug")
      :desc "dap debug recent"  "r" #'dap-debug-recent
      :desc "dap debug last"    "l" #'dap-debug-last

      ;; eval
      :prefix ("de" . "Eval")
      :desc "eval"                "e" #'dap-eval
      :desc "eval region"         "r" #'dap-eval-region
      :desc "eval thing at point" "s" #'dap-eval-thing-at-point
      :desc "add expression"      "a" #'dap-ui-expressions-add
      :desc "remove expression"   "d" #'dap-ui-expressions-remove

      :prefix ("db" . "Breakpoint")
      :desc "dap breakpoint toggle"      "b" #'dap-breakpoint-toggle
      :desc "dap breakpoint condition"   "c" #'dap-breakpoint-condition
      :desc "dap breakpoint hit count"   "h" #'dap-breakpoint-hit-condition
      :desc "dap breakpoint log message" "l" #'dap-breakpoint-log-message)
#+end_src

* TODO Configuration
#+begin_quote
 🔨 This module has no configuration documentation yet. [[doom-contrib-module:][Write some?]]
#+end_quote

* Troubleshooting
- There is a known issue with the ~+debugger/start~ command, which is bound to
  [[kbd:][SPC o d]] right now. It prints "No debugging session to quit" no matter what.

* Frequently asked questions
/This module has no FAQs yet./ [[doom-suggest-faq:][Ask one?]]

* TODO Appendix
#+begin_quote
 🔨 This module has no appendix yet. [[doom-contrib-module:][Write one?]]
#+end_quote