;;; project.el --- Operations on the current project -*- lexical-binding: t; -*-
-;; Copyright (C) 2015 Free Software Foundation, Inc.
+;; Copyright (C) 2015-2016 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;;; Commentary:
;; This file contains generic infrastructure for dealing with
-;; projects, and a number of public functions: finding the current
-;; root, related project directories, search path, etc.
+;; projects, some utility functions, and commands using that
+;; infrastructure.
+;;
+;; The goal is to make it easier for Lisp programs to operate on the
+;; current project, without having to know which package handles
+;; detection of that project type, parsing its config files, etc.
+;;
+;; Infrastructure:
+;;
+;; Function `project-current', to determine the current project
+;; instance, and 3 (at the moment) generic functions that act on it.
+;; This list is to be extended in future versions.
+;;
+;; Utils:
+;;
+;; `project-combine-directories' and `project-subtract-directories',
+;; mainly for use in the abovementioned generics' implementations.
+;;
+;; Commands:
+;;
+;; `project-find-regexp' and `project-or-external-find-regexp' use the
+;; current API, and thus will work in any project that has an adapter.
+
+;;; TODO:
+
+;; * Reliably cache the list of files in the project, probably using
+;; filenotify.el (if supported) to invalidate. And avoiding caching
+;; if it's not available (manual cache invalidation is not nice).
+;;
+;; * Allow the backend to override the file-listing logic? Maybe also
+;; to delegate file name completion to an external tool.
+;;
+;; * Build tool related functionality. Start with a `project-build'
+;; command, which should provide completions on tasks to run, and
+;; maybe allow entering some additional arguments. This might
+;; be handled better with a separate API, though. Then we won't
+;; force every project backend to be aware of the build tool(s) the
+;; project is using.
+;;
+;; * Command to (re)build the tag files in all project roots. To that
+;; end, we might need to add a way to provide file whitelist
+;; wildcards for each root to limit etags to certain files (in
+;; addition to the blacklist provided by ignores), and/or allow
+;; specifying additional tag regexps.
+;;
+;; * UI for the user to be able to pick the current project for the
+;; whole Emacs session, independent of the current directory. Or,
+;; in the more advanced case, open a set of projects, and have some
+;; project-related commands to use them all. E.g., have a command
+;; to search for a regexp across all open projects. Provide a
+;; history of projects that were opened in the past (storing it as a
+;; list of directories should suffice).
+;;
+;; * Support for project-local variables: a UI to edit them, and a
+;; utility function to retrieve a value. Probably useless without
+;; support in various built-in commands. In the API, we might get
+;; away with only adding a `project-configuration-directory' method,
+;; defaulting to the project root the current file/buffer is in.
+;; And prompting otherwise. How to best mix that with backends that
+;; want to set/provide certain variables themselves, is up for
+;; discussion.
;;; Code:
(require 'cl-generic)
-(defvar project-find-functions (list #'project-try-vc
- #'project-ask-user)
+(defvar project-find-functions (list #'project-try-vc)
"Special hook to find the project containing a given directory.
Each functions on this hook is called in turn with one
argument (the directory) and should return either nil to mean
that it is not applicable, or a project instance.")
-(declare-function etags-search-path "etags" ())
+;;;###autoload
+(defun project-current (&optional maybe-prompt dir)
+ "Return the project instance in DIR or `default-directory'.
+When no project found in DIR, and MAYBE-PROMPT is non-nil, ask
+the user for a different directory to look in."
+ (unless dir (setq dir default-directory))
+ (let ((pr (project--find-in-directory dir)))
+ (cond
+ (pr)
+ (maybe-prompt
+ (setq dir (read-directory-name "Choose the project directory: " dir nil t)
+ pr (project--find-in-directory dir))
+ (unless pr
+ (user-error "No project found in `%s'" dir))))
+ pr))
-(defvar project-search-path-function #'etags-search-path
- "Function that returns a list of source root directories.
+(defun project--find-in-directory (dir)
+ (run-hook-with-args-until-success 'project-find-functions dir))
-The directories in which we can recursively look for the
-declarations or other references to the symbols used in the
-current buffer. Depending on the language, it should include the
-headers search path, load path, class path, or so on.
+(cl-defgeneric project-roots (project)
+ "Return the list of directory roots of the current project.
-The directory names should be absolute. This variable is
-normally set by the major mode. Used in the default
-implementation of `project-search-path'.")
+Most often it's just one directory which contains the project
+build file and everything else in the project. But in more
+advanced configurations, a project can span multiple directories.
-;;;###autoload
-(defun project-current (&optional dir)
- "Return the project instance in DIR or `default-directory'."
- (unless dir (setq dir default-directory))
- (run-hook-with-args-until-success 'project-find-functions dir))
+The directory names should be absolute.")
;; FIXME: Add MODE argument, like in `ede-source-paths'?
-(cl-defgeneric project-search-path (project)
- "Return the list of source root directories.
-Any directory roots where source (or header, etc) files used by
-the current project may be found, inside or outside of the
-current project tree(s). The directory names should be absolute.
-
-Unless it really knows better, a specialized implementation
-should take into account the value returned by
-`project-search-path-function' and call
-`project-prune-directories' on the result."
- (project-prune-directories
- (append
- ;; We don't know the project layout, like where the sources are,
- ;; so we simply include the roots.
- (project-roots project)
- (funcall project-search-path-function))))
+(cl-defgeneric project-external-roots (_project)
+ "Return the list of external roots for PROJECT.
-(cl-defgeneric project-roots (project)
- "Return the list of directory roots related to the current project.
-It should include the current project root, as well as the roots
-of any other currently open projects, if they're meant to be
-edited together. The directory names should be absolute.")
+It's the list of directories outside of the project that are
+still related to it. If the project deals with source code then,
+depending on the languages used, this list should include the
+headers search path, load path, class path, and so on.
+
+The rule of thumb for whether to include a directory here, and
+not in `project-roots', is whether its contents are meant to be
+edited together with the rest of the project."
+ nil)
(cl-defgeneric project-ignores (_project _dir)
"Return the list of glob patterns to ignore inside DIR.
Patterns can match both regular files and directories.
To root an entry, start it with `./'. To match directories only,
-end it with `/'. DIR must be either one of `project-roots', or
-an element of `project-search-path'."
+end it with `/'. DIR must be one of `project-roots' or
+`project-external-roots'."
(require 'grep)
(defvar grep-find-ignored-files)
(nconc
vc-directory-exclusion-list)
grep-find-ignored-files))
+(defgroup project-vc nil
+ "Project implementation using the VC package."
+ :group 'tools)
+
+(defcustom project-vc-ignores nil
+ "List ot patterns to include in `project-ignores'."
+ :type '(repeat string)
+ :safe 'listp)
+
+;; FIXME: Using the current approach, major modes are supposed to set
+;; this variable to a buffer-local value. So we don't have access to
+;; the "external roots" of language A from buffers of language B, which
+;; seems desirable in multi-language projects, at least for some
+;; potential uses, like "jump to a file in project or external dirs".
+;;
+;; We could add a second argument to this function: a file extension,
+;; or a language name. Some projects will know the set of languages
+;; used in them; for others, like VC-based projects, we'll need
+;; auto-detection. I see two options:
+;;
+;; - That could be implemented as a separate second hook, with a
+;; list of functions that return file extensions.
+;;
+;; - This variable will be turned into a hook with "append" semantics,
+;; and each function in it will perform auto-detection when passed
+;; nil instead of an actual file extension. Then this hook will, in
+;; general, be modified globally, and not from major mode functions.
+;;
+;; The second option seems simpler, but the first one has the
+;; advantage that the user could override the list of languages used
+;; in a project via a directory-local variable, thus skipping
+;; languages they're not working on personally (in a big project), or
+;; working around problems in language detection (the detection logic
+;; might be imperfect for the project in question, or it might work
+;; too slowly for the user's taste).
+(defvar project-vc-external-roots-function (lambda () tags-table-list)
+ "Function that returns a list of external roots.
+
+It should return a list of directory roots that contain source
+files related to the current buffer.
+
+The directory names should be absolute. Used in the VC project
+backend implementation of `project-external-roots'.")
+
(defun project-try-vc (dir)
(let* ((backend (ignore-errors (vc-responsible-backend dir)))
(root (and backend (ignore-errors
(cl-defmethod project-roots ((project (head vc)))
(list (cdr project)))
+(cl-defmethod project-external-roots ((project (head vc)))
+ (project-subtract-directories
+ (project-combine-directories
+ (mapcar
+ #'file-name-as-directory
+ (funcall project-vc-external-roots-function)))
+ (project-roots project)))
+
(cl-defmethod project-ignores ((project (head vc)) dir)
- (nconc
- (let* ((root (cdr project))
+ (let* ((root (cdr project))
backend)
+ (append
(when (file-equal-p dir root)
(setq backend (vc-responsible-backend root))
(mapcar
(if (string-match "\\`/" entry)
(replace-match "./" t t entry)
entry))
- (vc-call-backend backend 'ignore-completion-table root))))
- (cl-call-next-method)))
+ (vc-call-backend backend 'ignore-completion-table root)))
+ (project--value-in-dir 'project-vc-ignores root)
+ (cl-call-next-method))))
-(defun project-ask-user (dir)
- (cons 'user (read-directory-name "Project root: " dir nil t)))
-
-(cl-defmethod project-roots ((project (head user)))
- (list (cdr project)))
-
-(defun project-prune-directories (dirs)
- "Returns a copy of DIRS sorted, without subdirectories or non-existing ones."
+(defun project-combine-directories (&rest lists-of-dirs)
+ "Return a sorted and culled list of directory names.
+Appends the elements of LISTS-OF-DIRS together, removes
+non-existing directories, as well as directories a parent of
+whose is already in the list."
(let* ((dirs (sort
(mapcar
(lambda (dir)
(file-name-as-directory (expand-file-name dir)))
- dirs)
+ (apply #'append lists-of-dirs))
#'string<))
(ref dirs))
;; Delete subdirectories from the list.
(setq ref (cdr ref))))
(cl-delete-if-not #'file-exists-p dirs)))
+(defun project-subtract-directories (files dirs)
+ "Return a list of elements from FILES that are outside of DIRS.
+DIRS must contain directory names."
+ ;; Sidestep the issue of expanded/abbreviated file names here.
+ (cl-set-difference files dirs :test #'file-in-directory-p))
+
+(defun project--value-in-dir (var dir)
+ (with-temp-buffer
+ (setq default-directory dir)
+ (hack-dir-local-variables-non-file-buffer)
+ (symbol-value var)))
+
+(declare-function grep-read-files "grep")
+(declare-function xref-collect-matches "xref")
+(declare-function xref--show-xrefs "xref")
+(declare-function xref-backend-identifier-at-point "xref")
+(declare-function xref--find-ignores-arguments "xref")
+
+;;;###autoload
+(defun project-find-regexp (regexp)
+ "Find all matches for REGEXP in the current project's roots.
+With \\[universal-argument] prefix, you can specify the directory
+to search in, and the file name pattern to search for."
+ (interactive (list (project--read-regexp)))
+ (let* ((pr (project-current t))
+ (dirs (if current-prefix-arg
+ (list (read-directory-name "Base directory: "
+ nil default-directory t))
+ (project-roots pr))))
+ (project--find-regexp-in dirs regexp pr)))
+
+;;;###autoload
+(defun project-or-external-find-regexp (regexp)
+ "Find all matches for REGEXP in the project roots or external roots.
+With \\[universal-argument] prefix, you can specify the file name
+pattern to search for."
+ (interactive (list (project--read-regexp)))
+ (let* ((pr (project-current t))
+ (dirs (append
+ (project-roots pr)
+ (project-external-roots pr))))
+ (project--find-regexp-in dirs regexp pr)))
+
+(defun project--read-regexp ()
+ (read-regexp "Find regexp"
+ (xref-backend-identifier-at-point (xref-find-backend))))
+
+(defun project--find-regexp-in (dirs regexp project)
+ (require 'grep)
+ (let* ((files (if current-prefix-arg
+ (grep-read-files regexp)
+ "*"))
+ (xrefs (cl-mapcan
+ (lambda (dir)
+ (xref-collect-matches regexp files dir
+ (project-ignores project dir)))
+ dirs)))
+ (unless xrefs
+ (user-error "No matches for: %s" regexp))
+ (xref--show-xrefs xrefs nil)))
+
+(defun project-find-file ()
+ (interactive)
+ (let* ((pr (project-current t))
+ (dirs (project-roots pr)))
+ (project--find-file-in dirs pr)))
+
+(defun project-or-external-find-file ()
+ (interactive)
+ (let* ((pr (project-current t))
+ (dirs (append
+ (project-roots pr)
+ (project-external-roots pr))))
+ (project--find-file-in dirs pr)))
+
+;; FIXME: Uniquely abbreviate the roots?
+(defun project--find-file-in (dirs project)
+ (let* ((all-files
+ (cl-mapcan
+ (lambda (dir)
+ (let ((command
+ (format "%s %s %s -type f -print0"
+ find-program
+ dir
+ (xref--find-ignores-arguments
+ (project-ignores project dir)
+ (expand-file-name dir)))))
+ (split-string (shell-command-to-string command) "\0" t)))
+ dirs))
+ (table (lambda (string pred action)
+ (cond
+ ((eq action 'metadata)
+ '(metadata . ((category . project-file))))
+ (t
+ (complete-with-action action all-files string pred))))))
+ (find-file
+ (completing-read "Find file: " table nil t))))
+
(provide 'project)
;;; project.el ends here