helm-gtags.el

Introduction

helm-gtags.el is GNU GLOBAL helm interface.

Screenshot

Requirements

• Emacs 24 or higher.
• helm 1.7.7 or higher
• GNU Global 6.2.3 or higher

helm-gtags.el does not require gtags.el.

Ubuntu/Debian users

Please do not use Ubuntu/Debian GNU gtags package. It's too old.

Installation

helm-gtags is available on MELPA and MELPA stable

You can install helm-gtags with the following command.

M-x package-install [RET] helm-gtags [RET]

Use Ctags with helm-gtags

You can use helm-gtags for languages which are supported by ctags(Both exuberant ctags and universal ctags) with ctags backend feature of GNU global. You can generate ctags backend tags by following command.

# exuberant ctags
% gtags --gtagslabel=ctags

# universal ctags
% gtags --gtagslabel=new-ctags

Basic Usage

helm-gtags-mode

Enable helm-gtags-mode.

helm-gtags-find-tag

Input tag name and move to the definition.

helm-gtags-find-tag-from-here

Find tag from here and move to its definition.

helm-gtags-find-rtag

Input tag name and move to the referenced point.

helm-gtags-find-symbol

Input symbol and move to the locations.

helm-gtags-find-files

Input file name and open it.

You can use those searching commands with prefix key.

Prefix Key	Description
C-u	Searches from specified directory
C-u C-u	Searches under current directory
C--	Jump to symbol with other window

helm-gtags-select

Tag jump using gtags and helm

helm-gtags-dwim

Find name by context.

• Jump to header file if cursor is on include statement
• Jump to tag definition if cursor is on tag reference
• Jump to tag reference if cursor is on tag definition

helm-gtags-tags-in-this-function

Show tagnames which are referenced in this function and jump to them.

helm-gtags-update-tags

Update TAG file. Default is update only current file, You can update all files with C-u prefix.

helm-gtags-create-tags

Create TAG file. Please choose default as GTAGSLABEL if you don't enable --with-ctags and plugin parser options. If you use homebrew on MacOSX, you can enable those features by following command.

# You should uninstall global at first if you already install global
% brew install global --with-ctags --with-pygments

helm-gtags-parse-file

Show symbols in current file like gtags-parse-file. You can choose any files with C-u prefix.

helm-gtags-pop-stack

Move to previous point on the stack. helm-gtags pushes current point to stack before executing each jump functions.

helm-gtags-next-history

Move to next history on context stack.

helm-gtags-previous-history

Move to previous history on context stack.

helm-gtags-show-stack

Show context stack with helm interface. You can jump to the context.

helm-gtags-clear-stack

Clear current context stack.

helm-gtags-clear-all-stacks

Clear all context stacks.

helm-gtags-clear-cache

Clear current project cache for helm-gtags-select and helm-gtags-select-path

helm-gtags-clear-all-cache

Clear all result cache for helm-gtags-select and helm-gtags-select-path

helm-gtags-resume

Resurrect previously invoked helm-gtags command. This is similar to helm-resume however this command resurrects helm gtags buffer if other helm commands are called.

Using Suggested Key Mapping

helm-gtags.el provides suggested key maps like gtags.el by setting helm-gtags-suggested-key-mapping to non-nil. Its prefix key is C-c as default. You can change prefix by setting helm-gtags-prefix-key.

You have to set them before loading helm-gtags.el. I recommend you to use custom-set-variables for setting this value.

(custom-set-variables
 '(helm-gtags-prefix-key "\C-t")
 '(helm-gtags-suggested-key-mapping t))

If you use invalid modifier string(like C-,) as prefix key, please don't escape Control prefix.(OK: C-,, NG: \C-,).

Default Key Mapping

Key	Command
Prefix h	helm-gtags-display-browser
Prefix C-]	helm-gtags-find-tag-from-here
Prefix C-t	helm-gtags-pop-stack
Prefix P	helm-gtags-find-files
Prefix f	helm-gtags-parse-file
Prefix g	helm-gtags-find-pattern
Prefix s	helm-gtags-find-symbol
Prefix r	helm-gtags-find-rtag
Prefix t	helm-gtags-find-tag
Prefix d	helm-gtags-find-tag
M-*	helm-gtags-pop-stack
M-.	helm-gtags-find-tag
C-x 4 .	helm-gtags-find-tag-other-window

Customize Variables

helm-gtags-path-style(Default 'root)

File path style, 'root or 'relative or 'absolute. You can only use 'absolute if you use Windows and set GTAGSLIBPATH environment variable. helm-gtags.el forces to use absolute style in such case.

helm-gtags-ignore-case(Default nil)

Ignore case for searching flag

helm-gtags-read-only(Default nil)

Open file as readonly, if this value is non-nil

helm-gtags-use-input-at-cursor(Default nil)

Use word at cursor as input if this value is non-nil

helm-gtags-highlight-candidate(Default t)

Highlighting candidates if this value is non-nil

helm-gtags-display-style(Default nil)

Show detail information if this value is 'detail, show reference point of function etc.

helm-gtags-auto-update(Default nil)

If this variable is non-nil, TAG file is updated after saving buffer

helm-gtags-update-interval-second(Default 60)

Tags are updated in `after-save-hook' if this seconds is passed from last update Always update if value of this variable is nil.

helm-gtags-cache-select-result(Default nil)

If this variable is non-nil, use cache for helm-gtags-select and helm-gtags-select-path

helm-gtags-cache-max-result-size(Default 10MB)

Max size(bytes) to cache for each select result

helm-gtags-pulse-at-cursor(Default nil)

If this variable is non-nil, pulse at point after jumping

helm-gtags-fuzzy-match(Default nil)

Enable fuzzy match. You should set this value before loading helm-gtags.el.

helm-gtags-direct-helm-completing(Default nil)

Use helm completion instead of normal Emacs completion if this value is non-nil.

helm-gtags-maximum-candidates

Maximum number of helm candidates in helm-gtags.el. Please set small number if you feel slow for large source tree such as Linux kernel.

Default value is

• 9999(Disable fuzzy match)
• 100(Enable fuzzy match)

helm-gtags-preselect

If this variable is non-nil, preselect current file and line.

helm-gtags-cygwin-use-global-w32-port

This variable is only for Cygwin users. If you use both Cygwin version Emacs and GNU global, please set nil to this variable.

Faces

helm-gtags-file

Face of file name of candidates

helm-gtags-lineno

Face of line number of candidates

anything-gtags.el

helm-gtags.el is not compatible anything-gtags.el. But helm-gtags.el is designed for faster search than anything-gtags.el.

anything-gtags.el is slow in large source tree such as Linux kernel, FreeBSD, Android etc. Because anything-gtags.el creates candidates by processing output of gtags.el. helm-gtags.el creates candidates by itself, so helm-gtags.el is faster than anything-gtags.el.

Sample Configuration

;;; Enable helm-gtags-mode
(add-hook 'c-mode-hook 'helm-gtags-mode)
(add-hook 'c++-mode-hook 'helm-gtags-mode)
(add-hook 'asm-mode-hook 'helm-gtags-mode)

;; customize
(custom-set-variables
 '(helm-gtags-path-style 'relative)
 '(helm-gtags-ignore-case t)
 '(helm-gtags-auto-update t))

;; key bindings
(with-eval-after-load 'helm-gtags
  (define-key helm-gtags-mode-map (kbd "M-t") 'helm-gtags-find-tag)
  (define-key helm-gtags-mode-map (kbd "M-r") 'helm-gtags-find-rtag)
  (define-key helm-gtags-mode-map (kbd "M-s") 'helm-gtags-find-symbol)
  (define-key helm-gtags-mode-map (kbd "M-g M-p") 'helm-gtags-parse-file)
  (define-key helm-gtags-mode-map (kbd "C-c <") 'helm-gtags-previous-history)
  (define-key helm-gtags-mode-map (kbd "C-c >") 'helm-gtags-next-history)
  (define-key helm-gtags-mode-map (kbd "M-,") 'helm-gtags-pop-stack))