testcover.el 21.2 KB
Newer Older
1 2
;;;; testcover.el -- Visual code-coverage tool

3
;; Copyright (C) 2002-2013 Free Software Foundation, Inc.
4

Jonathan Yavner's avatar
Jonathan Yavner committed
5 6
;; Author: Jonathan Yavner <jyavner@member.fsf.org>
;; Maintainer: Jonathan Yavner <jyavner@member.fsf.org>
7 8 9 10
;; Keywords: lisp utility

;; This file is part of GNU Emacs.

11
;; GNU Emacs is free software: you can redistribute it and/or modify
12
;; it under the terms of the GNU General Public License as published by
13 14
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
15 16 17 18 19 20 21

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
22
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
23 24 25 26 27 28 29 30


;;; Commentary:

;; * Use `testcover-start' to instrument a Lisp file for coverage testing.
;; * Use `testcover-mark-all' to add overlay "splotches" to the Lisp file's
;;   buffer to show where coverage is lacking.  Normally, a red splotch
;;   indicates the form was never evaluated; a brown splotch means it always
Juanma Barranquero's avatar
Juanma Barranquero committed
31
;;   evaluated to the same value.
32 33 34 35 36 37 38
;; * Use `testcover-next-mark' (bind it to a key!) to jump to the next spot
;;   that has a splotch.

;; * Basic algorithm: use `edebug' to mark up the function text with
;;   instrumentation callbacks, then replace edebug's callbacks with ours.
;; * To show good coverage, we want to see two values for every form, except
;;   functions that always return the same value and `defconst' variables
39 40 41
;;   need show only one value for good coverage.  To avoid the brown
;;   splotch, the definitions for constants and 1-valued functions must
;;   precede the references.
42 43 44 45 46 47 48 49 50 51 52 53 54 55
;; * Use the macro `1value' in your Lisp code to mark spots where the local
;;   code environment causes a function or variable to always have the same
;;   value, but the function or variable is not intrinsically 1-valued.
;; * Use the macro `noreturn' in your Lisp code to mark function calls that
;;   never return, because of the local code environment, even though the
;;   function being called is capable of returning in other cases.

;; Problems:
;; * To detect different values, we store the form's result in a vector and
;;   compare the next result using `equal'.  We don't copy the form's
;;   result, so if caller alters it (`setcar', etc.) we'll think the next
;;   call has the same value!  Also, equal thinks two strings are the same
;;   if they differ only in properties.
;; * Because we have only a "1value" class and no "always nil" class, we have
56 57
;;   to treat as potentially 1-valued any `and' whose last term is 1-valued,
;;   in case the last term is always nil.  Example:
58
;;     (and (< (point) 1000) (forward-char 10))
59 60 61 62 63
;;   This form always returns nil.  Similarly, `or', `if', and `cond' are
;;   treated as potentially 1-valued if all clauses are, in case those
;;   values are always nil.  Unlike truly 1-valued functions, it is not an
;;   error if these "potentially" 1-valued forms actually return differing
;;   values.
64 65 66 67 68 69 70 71 72 73

(require 'edebug)
(provide 'testcover)


;;;==========================================================================
;;; User options
;;;==========================================================================

(defgroup testcover nil
74
  "Code-coverage tester."
75 76 77 78 79 80 81 82 83 84 85 86 87 88
  :group 'lisp
  :prefix "testcover-"
  :version "21.1")

(defcustom testcover-constants
  '(nil t emacs-build-time emacs-version emacs-major-version
    emacs-minor-version)
  "Variables whose values never change.  No brown splotch is shown for
these.  This list is quite incomplete!"
  :group 'testcover
  :type '(repeat variable))

(defcustom testcover-1value-functions
  '(backward-char barf-if-buffer-read-only beginning-of-line
89 90 91 92 93 94 95 96
    buffer-disable-undo buffer-enable-undo current-global-map
    deactivate-mark delete-backward-char delete-char delete-region ding
    forward-char function* insert insert-and-inherit kill-all-local-variables
    kill-line kill-paragraph kill-region kill-sexp lambda
    minibuffer-complete-and-exit narrow-to-region next-line push-mark
    put-text-property run-hooks set-match-data signal
    substitute-key-definition suppress-keymap undo use-local-map while widen
    yank)
97 98 99 100 101 102
  "Functions that always return the same value.  No brown splotch is shown
for these.  This list is quite incomplete!  Notes: Nobody ever changes the
current global map.  The macro `lambda' is self-evaluating, hence always
returns the same value (the function it defines may return varying values
when called)."
  :group 'testcover
103
  :type '(repeat symbol))
104 105 106 107 108 109

(defcustom testcover-noreturn-functions
  '(error noreturn throw signal)
  "Subset of `testcover-1value-functions' -- these never return.  We mark
them as having returned nil just before calling them."
  :group 'testcover
110
  :type '(repeat symbol))
111 112

(defcustom testcover-compose-functions
113 114 115
  '(+ - * / = append length list make-keymap make-sparse-keymap
    mapcar message propertize replace-regexp-in-string
    run-with-idle-timer set-buffer-modified-p)
116 117 118 119 120 121 122 123
  "Functions that are 1-valued if all their args are either constants or
calls to one of the `testcover-1value-functions', so if that's true then no
brown splotch is shown for these.  This list is quite incomplete!  Most
side-effect-free functions should be here."
  :group 'testcover
  :type 'hook)

(defcustom testcover-progn-functions
124 125 126 127 128 129
  '(define-key fset function goto-char mapc overlay-put progn
    save-current-buffer save-excursion save-match-data
    save-restriction save-selected-window save-window-excursion
    set set-default set-marker-insertion-type setq setq-default
    with-current-buffer with-output-to-temp-buffer with-syntax-table
    with-temp-buffer with-temp-file with-temp-message with-timeout)
130 131 132
  "Functions whose return value is the same as their last argument.  No
brown splotch is shown for these if the last argument is a constant or a
call to one of the `testcover-1value-functions'.  This list is probably
133
incomplete!"
134
  :group 'testcover
135
  :type '(repeat symbol))
136 137 138 139 140 141 142

(defcustom testcover-prog1-functions
  '(prog1 unwind-protect)
  "Functions whose return value is the same as their first argument.  No
brown splotch is shown for these if the first argument is a constant or a
call to one of the `testcover-1value-functions'."
  :group 'testcover
143
  :type '(repeat symbol))
144

145 146 147
(defcustom testcover-potentially-1value-functions
  '(add-hook and beep or remove-hook unless when)
  "Functions that are potentially 1-valued.  No brown splotch if actually
148 149
1-valued, no error if actually multi-valued."
  :group 'testcover)
150

151
(defface testcover-nohits
152 153 154 155
  '((t (:background "DeepPink2")))
  "Face for forms that had no hits during coverage test"
  :group 'testcover)

156
(defface testcover-1value
157 158 159 160 161 162 163 164 165 166 167 168 169 170 171
  '((t (:background "Wheat2")))
  "Face for forms that always produced the same value during coverage test"
  :group 'testcover)


;;;=========================================================================
;;; Other variables
;;;=========================================================================

(defvar testcover-module-constants nil
  "Symbols declared with defconst in the last file processed by
`testcover-start'.")

(defvar testcover-module-1value-functions nil
  "Symbols declared with defun in the last file processed by
172 173 174 175 176
`testcover-start', whose functions should always return the same value.")

(defvar testcover-module-potentially-1value-functions nil
  "Symbols declared with defun in the last file processed by
`testcover-start', whose functions might always return the same value.")
177 178 179 180 181 182 183 184 185 186 187 188 189 190

(defvar testcover-vector nil
  "Locally bound to coverage vector for function in progress.")


;;;=========================================================================
;;; Add instrumentation to your module
;;;=========================================================================

(defun testcover-start (filename &optional byte-compile)
  "Uses edebug to instrument all macros and functions in FILENAME, then
changes the instrumentation from edebug to testcover--much faster, no
problems with type-ahead or post-command-hook, etc.  If BYTE-COMPILE is
non-nil, byte-compiles each function after instrumenting."
191
  (interactive "fStart covering file: ")
192
  (let ((buf                (find-file filename))
193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220
	(load-read-function 'testcover-read)
	(edebug-all-defs t))
    (setq edebug-form-data                       nil
	  testcover-module-constants             nil
	  testcover-module-1value-functions nil)
    (eval-buffer buf))
  (when byte-compile
    (dolist (x (reverse edebug-form-data))
      (when (fboundp (car x))
	(message "Compiling %s..." (car x))
	(byte-compile (car x))))))

;;;###autoload
(defun testcover-this-defun ()
  "Start coverage on function under point."
  (interactive)
  (let* ((edebug-all-defs t)
	 (x (symbol-function (eval-defun nil))))
    (testcover-reinstrument x)
    x))

(defun testcover-read (&optional stream)
  "Read a form using edebug, changing edebug callbacks to testcover callbacks."
  (let ((x (edebug-read stream)))
    (testcover-reinstrument x)
    x))

(defun testcover-reinstrument (form)
221 222
  "Reinstruments FORM to use testcover instead of edebug.  This
function modifies the list that FORM points to.  Result is nil if
Paul Eggert's avatar
Paul Eggert committed
223
FORM should return multiple values, t if should always return same
224
value, 'maybe if either is acceptable."
225
  (let ((fun (car-safe form))
226
	id val)
227
    (cond
228 229 230 231 232 233
     ((not fun)				;Atom
      (when (or (not (symbolp form))
		(memq form testcover-constants)
		(memq form testcover-module-constants))
	t))
     ((consp fun)			;Embedded list
234 235 236 237 238
      (testcover-reinstrument fun)
      (testcover-reinstrument-list (cdr form))
      nil)
     ((or (memq fun testcover-1value-functions)
	  (memq fun testcover-module-1value-functions))
239
      ;;Should always return same value
240 241
      (testcover-reinstrument-list (cdr form))
      t)
242 243 244 245 246
     ((or (memq fun testcover-potentially-1value-functions)
	  (memq fun testcover-module-potentially-1value-functions))
      ;;Might always return same value
      (testcover-reinstrument-list (cdr form))
      'maybe)
247 248 249 250 251 252 253 254
     ((memq fun testcover-progn-functions)
      ;;1-valued if last argument is
      (testcover-reinstrument-list (cdr form)))
     ((memq fun testcover-prog1-functions)
      ;;1-valued if first argument is
      (testcover-reinstrument-list (cddr form))
      (testcover-reinstrument (cadr form)))
     ((memq fun testcover-compose-functions)
255 256 257
      ;;1-valued if all arguments are.  Potentially 1-valued if all
      ;;arguments are either definitely or potentially.
      (testcover-reinstrument-compose (cdr form) 'testcover-reinstrument))
258 259 260 261 262 263 264 265 266 267 268 269
     ((eq fun 'edebug-enter)
      ;;(edebug-enter 'SYM ARGS #'(lambda nil FORMS))
      ;;  => (testcover-enter 'SYM #'(lambda nil FORMS))
      (setcar form 'testcover-enter)
      (setcdr (nthcdr 1 form) (nthcdr 3 form))
      (let ((testcover-vector (get (cadr (cadr form)) 'edebug-coverage)))
	(testcover-reinstrument-list (nthcdr 2 (cadr (nth 2 form))))))
     ((eq fun 'edebug-after)
      ;;(edebug-after (edebug-before XXX) YYY FORM)
      ;; => (testcover-after YYY FORM), mark XXX as ok-coverage
      (unless (eq (cadr form) 0)
	(aset testcover-vector (cadr (cadr form)) 'ok-coverage))
270
      (setq id (nth 2 form))
271
      (setcdr form (nthcdr 2 form))
272
      (setq val (testcover-reinstrument (nth 2 form)))
273 274 275
      (setcar form (if (eq val t)
                       'testcover-1value
                     'testcover-after))
276 277 278
      (when val
	;;1-valued or potentially 1-valued
	(aset testcover-vector id '1value))
279 280
      (cond
       ((memq (car-safe (nth 2 form)) testcover-noreturn-functions)
281 282 283
	;;This function won't return, so set the value in advance
	;;(edebug-after (edebug-before XXX) YYY FORM)
	;;  => (progn (edebug-after YYY nil) FORM)
284
	(setcar (cdr form) `(,(car form) ,id nil))
285
	(setcar form 'progn)
286 287
	(aset testcover-vector id '1value)
	(setq val t))
288 289
       ((eq (car-safe (nth 2 form)) '1value)
	;;This function is always supposed to return the same value
290 291 292 293
	(setq val t)
	(aset testcover-vector id '1value)
	(setcar form 'testcover-1value)))
      val)
294
     ((eq fun 'defun)
295 296 297 298 299 300
      (setq val (testcover-reinstrument-list (nthcdr 3 form)))
      (when (eq val t)
	(push (cadr form) testcover-module-1value-functions))
      (when (eq val 'maybe)
	(push (cadr form) testcover-module-potentially-1value-functions)))
     ((memq fun '(defconst defcustom))
301 302 303 304 305 306
      ;;Define this symbol as 1-valued
      (push (cadr form) testcover-module-constants)
      (testcover-reinstrument-list (cddr form)))
     ((memq fun '(dotimes dolist))
      ;;Always returns third value from SPEC
      (testcover-reinstrument-list (cddr form))
307
      (setq val (testcover-reinstrument-list (cadr form)))
308
      (if (nth 2 (cadr form))
309
	  val
310 311 312 313 314 315 316
	;;No third value, always returns nil
	t))
     ((memq fun '(let let*))
      ;;Special parsing for second argument
      (mapc 'testcover-reinstrument-list (cadr form))
      (testcover-reinstrument-list (cddr form)))
     ((eq fun 'if)
317
      ;;Potentially 1-valued if both THEN and ELSE clauses are
318 319 320
      (testcover-reinstrument (cadr form))
      (let ((then (testcover-reinstrument (nth 2 form)))
	    (else (testcover-reinstrument-list (nthcdr 3 form))))
321
	(and then else 'maybe)))
322
     ((eq fun 'cond)
323 324 325 326
      ;;Potentially 1-valued if all clauses are
      (when (testcover-reinstrument-compose (cdr form)
					    'testcover-reinstrument-list)
	'maybe))
327
     ((eq fun 'condition-case)
328
      ;;Potentially 1-valued if BODYFORM is and all HANDLERS are
329
      (let ((body (testcover-reinstrument (nth 2 form)))
330 331 332 333
	    (errs (testcover-reinstrument-compose
		   (mapcar #'cdr (nthcdr 3 form))
		   'testcover-reinstrument-list)))
	(and body errs 'maybe)))
334 335 336 337 338 339 340 341 342 343 344 345 346 347
     ((eq fun 'quote)
      ;;Don't reinstrument what's inside!
      ;;This doesn't apply within a backquote
      t)
     ((eq fun '\`)
      ;;Quotes are not special within backquotes
      (let ((testcover-1value-functions
	     (cons 'quote testcover-1value-functions)))
	(testcover-reinstrument (cadr form))))
     ((eq fun '\,)
      ;;In commas inside backquotes, quotes are special again
      (let ((testcover-1value-functions
	     (remq 'quote testcover-1value-functions)))
	(testcover-reinstrument (cadr form))))
348
     ((eq fun '1value)
349
      ;;Hack - pretend the arg is 1-valued here
350 351 352 353 354 355 356 357 358 359 360 361
      (cond
       ((symbolp (cadr form))
	;;A pseudoconstant variable
	t)
       ((and (eq (car (cadr form)) 'edebug-after)
	     (symbolp (nth 3 (cadr form))))
	;;Reference to pseudoconstant
	(aset testcover-vector (nth 2 (cadr form)) '1value)
	(setcar (cdr form) `(testcover-1value ,(nth 2 (cadr form))
					      ,(nth 3 (cadr form))))
	t)
       (t
362 363 364
	(setq id (car (if (eq (car (cadr form)) 'edebug-after)
                          (nth 3 (cadr form))
                        (cadr form))))
365
	(let ((testcover-1value-functions
366
	       (cons id testcover-1value-functions)))
367 368 369 370 371 372 373 374 375 376 377 378 379 380 381
	  (testcover-reinstrument (cadr form))))))
     ((eq fun 'noreturn)
      ;;Hack - pretend the arg has no return
      (cond
       ((symbolp (cadr form))
	;;A pseudoconstant variable
	'maybe)
       ((and (eq (car (cadr form)) 'edebug-after)
	     (symbolp (nth 3 (cadr form))))
	;;Reference to pseudoconstant
	(aset testcover-vector (nth 2 (cadr form)) '1value)
	(setcar (cdr form) `(progn (testcover-after ,(nth 2 (cadr form)) nil)
				   ,(nth 3 (cadr form))))
	'maybe)
       (t
382 383 384
	(setq id (car (if (eq (car (cadr form)) 'edebug-after)
                          (nth 3 (cadr form))
                        (cadr form))))
385 386 387 388 389 390 391 392 393 394 395 396
	(let ((testcover-noreturn-functions
	       (cons id testcover-noreturn-functions)))
	  (testcover-reinstrument (cadr form))))))
     ((and (eq fun 'apply)
	   (eq (car-safe (cadr form)) 'quote)
	   (symbolp (cadr (cadr form))))
      ;;Apply of a constant symbol.  Process as 1value or noreturn
      ;;depending on symbol.
      (setq fun (cons (cadr (cadr form)) (cddr form))
	    val (testcover-reinstrument fun))
      (setcdr (cdr form) (cdr fun))
      val)
397 398 399 400 401 402 403 404 405 406 407 408 409 410
     (t ;Some other function or weird thing
      (testcover-reinstrument-list (cdr form))
      nil))))

(defun testcover-reinstrument-list (list)
  "Reinstruments each form in LIST to use testcover instead of edebug.
This function modifies the forms in LIST.  Result is `testcover-reinstrument's
value for the last form in LIST.  If the LIST is empty, its evaluation will
always be nil, so we return t for 1-valued."
  (let ((result t))
    (while (consp list)
      (setq result (testcover-reinstrument (pop list))))
    result))

411 412 413 414 415 416
(defun testcover-reinstrument-compose (list fun)
  "For a compositional function, the result is 1-valued if all
arguments are, potentially 1-valued if all arguments are either
definitely or potentially 1-valued, and multi-valued otherwise.
FUN should be `testcover-reinstrument' for compositional functions,
  `testcover-reinstrument-list' for clauses in a `cond'."
417 418
  (let ((result t))
    (mapc #'(lambda (x)
419 420 421 422 423 424 425 426
	      (setq x (funcall fun x))
	      (cond
	       ((eq result t)
		(setq result x))
	       ((eq result 'maybe)
		(when (not x)
		  (setq result nil)))))
	  list)
427 428
    result))

429
(defun testcover-end (filename)
430
  "Turn off instrumentation of all macros and functions in FILENAME."
431 432
  (interactive "fStop covering file: ")
  (let ((buf (find-file-noselect filename)))
Stefan Monnier's avatar
Stefan Monnier committed
433
    (eval-buffer buf)))
434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449


;;;=========================================================================
;;; Accumulate coverage data
;;;=========================================================================

(defun testcover-enter (testcover-sym testcover-fun)
  "Internal function for coverage testing.  Invokes TESTCOVER-FUN while
binding `testcover-vector' to the code-coverage vector for TESTCOVER-SYM
\(the name of the current function)."
  (let ((testcover-vector (get testcover-sym 'edebug-coverage)))
    (funcall testcover-fun)))

(defun testcover-after (idx val)
  "Internal function for coverage testing.  Returns VAL after installing it in
`testcover-vector' at offset IDX."
450 451 452 453 454 455
  (declare (gv-expander (lambda (do)
                          (gv-letplace (getter setter) val
                            (funcall do getter
                                     (lambda (store)
                                       `(progn (testcover-after ,idx ,getter)
                                               ,(funcall setter store))))))))
456 457 458 459 460 461 462
  (cond
   ((eq (aref testcover-vector idx) 'unknown)
    (aset testcover-vector idx val))
   ((not (equal (aref testcover-vector idx) val))
    (aset testcover-vector idx 'ok-coverage)))
  val)

463 464 465 466 467 468 469 470 471
(defun testcover-1value (idx val)
  "Internal function for coverage testing.  Returns VAL after installing it in
`testcover-vector' at offset IDX.  Error if FORM does not always return the
same value during coverage testing."
  (cond
   ((eq (aref testcover-vector idx) '1value)
    (aset testcover-vector idx (cons '1value val)))
   ((not (and (eq (car-safe (aref testcover-vector idx)) '1value)
	      (equal (cdr (aref testcover-vector idx)) val)))
472
    (error "Value of form marked with `1value' does vary: %s" val)))
473 474 475
  val)


476 477 478 479 480 481 482 483

;;;=========================================================================
;;; Display the coverage data as color splotches on your code.
;;;=========================================================================

(defun testcover-mark (def)
  "Marks one DEF (a function or macro symbol) to highlight its contained forms
that did not get completely tested during coverage tests.
484 485
  A marking with the face `testcover-nohits' (default = red) indicates that the
form was never evaluated.  A marking using the `testcover-1value' face
486 487 488 489 490 491 492 493 494 495 496 497 498 499
\(default = tan) indicates that the form always evaluated to the same value.
  The forms throw, error, and signal are not marked.  They do not return and
would always get a red mark.  Some forms that always return the same
value (e.g., setq of a constant), always get a tan mark that can't be
eliminated by adding more test cases."
  (let* ((data     (get def 'edebug))
	 (def-mark (car data))
	 (points   (nth 2 data))
	 (len      (length points))
	 (changed (buffer-modified-p))
	 (coverage (get def 'edebug-coverage))
	 ov j item)
    (or (and def-mark points coverage)
	(error "Missing edebug data for function %s" def))
500
    (when (> len 0)
501 502 503 504 505 506 507
      (set-buffer (marker-buffer def-mark))
      (mapc 'delete-overlay
	    (overlays-in def-mark (+ def-mark (aref points (1- len)) 1)))
      (while (> len 0)
	(setq len  (1- len)
	      data (aref coverage len))
	(when (and (not (eq data 'ok-coverage))
508
		   (not (eq (car-safe data) '1value))
509
		   (setq j (+ def-mark (aref points len))))
510 511 512
	  (setq ov (make-overlay (1- j) j))
	  (overlay-put ov 'face
		       (if (memq data '(unknown 1value))
513 514
			   'testcover-nohits
			 'testcover-1value))))
515
      (set-buffer-modified-p changed))))
516 517

(defun testcover-mark-all (&optional buffer)
Paul Eggert's avatar
Paul Eggert committed
518
  "Mark all forms in BUFFER that did not get completely tested during
519
coverage tests.  This function creates many overlays."
520
  (interactive "bMark forms in buffer: ")
521 522 523 524
  (if buffer
      (switch-to-buffer buffer))
  (goto-char 1)
  (dolist (x edebug-form-data)
525
    (if (get (car x) 'edebug)
526 527 528 529
	(testcover-mark (car x)))))

(defun testcover-unmark-all (buffer)
  "Remove all overlays from FILENAME."
530
  (interactive "bUnmark forms in buffer: ")
531 532 533 534 535 536 537 538 539 540 541 542 543
  (condition-case nil
      (progn
	(set-buffer buffer)
	(mapc 'delete-overlay (overlays-in 1 (buffer-size))))
    (error nil)))  ;Ignore "No such buffer" errors

(defun testcover-next-mark ()
  "Moves point to next line in current buffer that has a splotch."
  (interactive)
  (goto-char (next-overlay-change (point)))
  (end-of-line))

;; testcover.el ends here.