clang-format.el source code [clang_source_code/tools/clang-format/clang-format.el]

1	;;; clang-format.el --- Format code using clang-format -- lexical-binding: t; --
2
3	;; Keywords: tools, c
4	;; Package-Requires: ((cl-lib "0.3"))
5
6	;;; Commentary:
7
8	;; This package allows to filter code through clang-format to fix its formatting.
9	;; clang-format is a tool that formats C/C++/Obj-C code according to a set of
10	;; style options, see <http://clang.llvm.org/docs/ClangFormatStyleOptions.html>.
11	;; Note that clang-format 3.4 or newer is required.
12
13	;; clang-format.el is available via MELPA and can be installed via
14	;;
15	;; M-x package-install clang-format
16	;;
17	;; when ("melpa" . "http://melpa.org/packages/") is included in
18	;; `package-archives'. Alternatively, ensure the directory of this
19	;; file is in your `load-path' and add
20	;;
21	;; (require 'clang-format)
22	;;
23	;; to your .emacs configuration.
24
25	;; You may also want to bind `clang-format-region' to a key:
26	;;
27	;; (global-set-key [C-M-tab] 'clang-format-region)
28
29	;;; Code:
30
31	(require 'cl-lib)
32	(require 'xml)
33
34	(defgroup clang-format nil
35	"Format code using clang-format."
36	:group 'tools)
37
38	(defcustom clang-format-executable
39	(or (executable-find "clang-format")
40	"clang-format")
41	"Location of the clang-format executable.
42
43	A string containing the name or the full path of the executable."
44	:group 'clang-format
45	:type '(file :must-match t)
46	:risky t)
47
48	(defcustom clang-format-style "file"
49	"Style argument to pass to clang-format.
50
51	By default clang-format will load the style configuration from
52	a file named .clang-format located in one of the parent directories
53	of the buffer."
54	:group 'clang-format
55	:type 'string
56	:safe #'stringp)
57	(make-variable-buffer-local 'clang-format-style)
58
59	(defun clang-format--extract (xml-node)
60	"Extract replacements and cursor information from XML-NODE."
61	(unless (and (listp xml-node) (eq (xml-node-name xml-node) 'replacements))
62	(error "Expected <replacements> node"))
63	(let ((nodes (xml-node-children xml-node))
64	(incomplete-format (xml-get-attribute xml-node 'incomplete_format))
65	replacements
66	cursor)
67	(dolist (node nodes)
68	(when (listp node)
69	(let* ((children (xml-node-children node))
70	(text (car children)))
71	(cl-case (xml-node-name node)
72	('replacement
73	(let* ((offset (xml-get-attribute-or-nil node 'offset))
74	(length (xml-get-attribute-or-nil node 'length)))
75	(when (or (null offset) (null length))
76	(error "<replacement> node does not have offset and length attributes"))
77	(when (cdr children)
78	(error "More than one child node in <replacement> node"))
79
80	(setq offset (string-to-number offset))
81	(setq length (string-to-number length))
82	(push (list offset length text) replacements)))
83	('cursor
84	(setq cursor (string-to-number text)))))))
85
86	;; Sort by decreasing offset, length.
87	(setq replacements (sort (delq nil replacements)
88	(lambda (a b)
89	(or (> (car a) (car b))
90	(and (= (car a) (car b))
91	(> (cadr a) (cadr b)))))))
92
93	(list replacements cursor (string= incomplete-format "true"))))
94
95	(defun clang-format--replace (offset length &optional text)
96	"Replace the region defined by OFFSET and LENGTH with TEXT.
97	OFFSET and LENGTH are measured in bytes, not characters. OFFSET
98	is a zero-based file offset, assuming ‘utf-8-unix’ coding."
99	(let ((start (clang-format--filepos-to-bufferpos offset 'exact 'utf-8-unix))
100	(end (clang-format--filepos-to-bufferpos (+ offset length) 'exact
101	'utf-8-unix)))
102	(goto-char start)
103	(delete-region start end)
104	(when text
105	(insert text))))
106
107	;; ‘bufferpos-to-filepos’ and ‘filepos-to-bufferpos’ are new in Emacs 25.1.
108	;; Provide fallbacks for older versions.
109	(defalias 'clang-format--bufferpos-to-filepos
110	(if (fboundp 'bufferpos-to-filepos)
111	'bufferpos-to-filepos
112	(lambda (position &optional _quality _coding-system)
113	(1- (position-bytes position)))))
114
115	(defalias 'clang-format--filepos-to-bufferpos
116	(if (fboundp 'filepos-to-bufferpos)
117	'filepos-to-bufferpos
118	(lambda (byte &optional _quality _coding-system)
119	(byte-to-position (1+ byte)))))
120
121	;;;###autoload
122	(defun clang-format-region (start end &optional style assume-file-name)
123	"Use clang-format to format the code between START and END according to STYLE.
124	If called interactively uses the region or the current statement if there is no
125	no active region. If no STYLE is given uses `clang-format-style'. Use
126	ASSUME-FILE-NAME to locate a style config file, if no ASSUME-FILE-NAME is given
127	uses the function `buffer-file-name'."
128	(interactive
129	(if (use-region-p)
130	(list (region-beginning) (region-end))
131	(list (point) (point))))
132
133	(unless style
134	(setq style clang-format-style))
135
136	(unless assume-file-name
137	(setq assume-file-name buffer-file-name))
138
139	(let ((file-start (clang-format--bufferpos-to-filepos start 'approximate
140	'utf-8-unix))
141	(file-end (clang-format--bufferpos-to-filepos end 'approximate
142	'utf-8-unix))
143	(cursor (clang-format--bufferpos-to-filepos (point) 'exact 'utf-8-unix))
144	(temp-buffer (generate-new-buffer " clang-format-temp"))
145	(temp-file (make-temp-file "clang-format"))
146	;; Output is XML, which is always UTF-8. Input encoding should match
147	;; the encoding used to convert between buffer and file positions,
148	;; otherwise the offsets calculated above are off. For simplicity, we
149	;; always use ‘utf-8-unix’ and ignore the buffer coding system.
150	(default-process-coding-system '(utf-8-unix . utf-8-unix)))
151	(unwind-protect
152	(let ((status (apply #'call-process-region
153	nil nil clang-format-executable
154	nil `(,temp-buffer ,temp-file) nil
155	`("-output-replacements-xml"
156	;; Guard against a nil assume-file-name.
157	;; If the clang-format option -assume-filename
158	;; is given a blank string it will crash as per
159	;; the following bug report
160	;; https://bugs.llvm.org/show_bug.cgi?id=34667
161	,@(and assume-file-name
162	(list "-assume-filename" assume-file-name))
163	"-style" ,style
164	"-offset" ,(number-to-string file-start)
165	"-length" ,(number-to-string (- file-end file-start))
166	"-cursor" ,(number-to-string cursor))))
167	(stderr (with-temp-buffer
168	(unless (zerop (cadr (insert-file-contents temp-file)))
169	(insert ": "))
170	(buffer-substring-no-properties
171	(point-min) (line-end-position)))))
172	(cond
173	((stringp status)
174	(error "(clang-format killed by signal %s%s)" status stderr))
175	((not (zerop status))
176	(error "(clang-format failed with code %d%s)" status stderr)))
177
178	(cl-destructuring-bind (replacements cursor incomplete-format)
179	(with-current-buffer temp-buffer
180	(clang-format--extract (car (xml-parse-region))))
181	(save-excursion
182	(dolist (rpl replacements)
183	(apply #'clang-format--replace rpl)))
184	(when cursor
185	(goto-char (clang-format--filepos-to-bufferpos cursor 'exact
186	'utf-8-unix)))
187	(if incomplete-format
188	(message "(clang-format: incomplete (syntax errors)%s)" stderr)
189	(message "(clang-format: success%s)" stderr))))
190	(delete-file temp-file)
191	(when (buffer-name temp-buffer) (kill-buffer temp-buffer)))))
192
193	;;;###autoload
194	(defun clang-format-buffer (&optional style assume-file-name)
195	"Use clang-format to format the current buffer according to STYLE.
196	If no STYLE is given uses `clang-format-style'. Use ASSUME-FILE-NAME
197	to locate a style config file. If no ASSUME-FILE-NAME is given uses
198	the function `buffer-file-name'."
199	(interactive)
200	(clang-format-region (point-min) (point-max) style assume-file-name))
201
202	;;;###autoload
203	(defalias 'clang-format 'clang-format-region)
204
205	(provide 'clang-format)
206	;;; clang-format.el ends here
207

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