Add function declarations

* lisp/emacs-lisp/byte-opt.el (side-effect-free-fns):
Add get-byte, string-width, unibyte-string, special-variable-p, frexp,
buffer-hash, buffer-line-statistics, load-average, md5, secure-hash,
string-collate-equalp, string-collate-lessp, string-to-unibyte,
string-version-lessp, current-cpu-time.
(side-effect-and-error-free-fns): Add equal-including-properties.
(pure-fns): Add equal-including-properties, string-version-lessp.
* lisp/emacs-lisp/bytecomp.el (important-return-value-fns):
Add match-data.
* lisp/subr.el (buffer-local-boundp, subr-primitive-p, gensym)
(frame-configuration-p, apply-partially, make-composed-keymap)
(keymap-canonicalize, listify-key-sequence, event-modifiers)
(event-basic-type, mouse-event-p, event-start, event-end)
(event-click-count, event-line-count, posnp, posn-window, posn-area)
(posn-point, posn-x-y, posn-col-row, posn-actual-col-row)
(posn-timestamp, posn-string, posn-image, posn-object)
(posn-object-x-y, posn-object-width-height, provided-mode-derived-p)
(derived-mode-p, autoloadp, locate-eln-file, symbol-file)
(process-lines-handling-status, process-lines)
(process-lines-ignore-status, process-get)
(copy-overlay, shell-quote-argument, field-at-pos):
Add appropriate function declarations.

lisp/emacs-lisp/byte-opt.el

@@ -1685,7 +1685,8 @@ See Info node `(elisp) Integer Basics'."
          category-docstring category-set-mnemonics char-category-set
          copy-category-table get-unused-category make-category-set
          ;; character.c
-         char-width multibyte-char-to-unibyte string unibyte-char-to-multibyte
+         char-width get-byte multibyte-char-to-unibyte string string-width
+         unibyte-char-to-multibyte unibyte-string
          ;; charset.c
          decode-char encode-char
          ;; chartab.c
@@ -1715,6 +1716,8 @@ See Info node `(elisp) Integer Basics'."
          line-beginning-position line-end-position ngettext pos-bol pos-eol
          propertize region-beginning region-end string-to-char
          user-full-name user-login-name
+         ;; eval.c
+         special-variable-p
          ;; fileio.c
          car-less-than-car directory-name-p file-directory-p file-exists-p
          file-name-absolute-p file-name-concat file-newer-than-file-p
@@ -1723,23 +1726,28 @@ See Info node `(elisp) Integer Basics'."
          file-locked-p
          ;; floatfns.c
          abs acos asin atan ceiling copysign cos exp expt fceiling ffloor
-         float floor fround ftruncate isnan ldexp log logb round sin sqrt tan
+         float floor frexp fround ftruncate isnan ldexp log logb round
+         sin sqrt tan
          truncate
          ;; fns.c
          append assq
          base64-decode-string base64-encode-string base64url-encode-string
+         buffer-hash buffer-line-statistics
          compare-strings concat copy-alist copy-hash-table copy-sequence elt
          featurep get
          gethash hash-table-count hash-table-rehash-size
          hash-table-rehash-threshold hash-table-size hash-table-test
          hash-table-weakness
          length length< length= length>
-         line-number-at-pos locale-info make-hash-table
+         line-number-at-pos load-average locale-info make-hash-table md5
          member memq memql nth nthcdr
-         object-intervals rassoc rassq reverse
-         string-as-multibyte string-as-unibyte string-bytes string-distance
+         object-intervals rassoc rassq reverse secure-hash
+         string-as-multibyte string-as-unibyte string-bytes
+         string-collate-equalp string-collate-lessp string-distance
          string-equal string-lessp string-make-multibyte string-make-unibyte
-         string-search string-to-multibyte substring substring-no-properties
+         string-search string-to-multibyte string-to-unibyte
+         string-version-lessp
+         substring substring-no-properties
          sxhash-eq sxhash-eql sxhash-equal sxhash-equal-including-properties
          take vconcat
          ;; frame.c
@@ -1799,6 +1807,7 @@ See Info node `(elisp) Integer Basics'."
          all-threads condition-mutex condition-name mutex-name thread-live-p
          thread-name
          ;; timefns.c
+         current-cpu-time
          current-time-string current-time-zone decode-time encode-time
          float-time format-time-string time-add time-convert time-equal-p
          time-less-p time-subtract
@@ -1858,7 +1867,8 @@ See Info node `(elisp) Integer Basics'."
          ;; fileio.c
          default-file-modes
          ;; fns.c
-         eql equal hash-table-p identity proper-list-p safe-length
+         eql equal equal-including-properties
+         hash-table-p identity proper-list-p safe-length
          secure-hash-algorithms
          ;; frame.c
          frame-list frame-live-p framep last-nonminibuffer-frame
@@ -1936,10 +1946,11 @@ See Info node `(elisp) Integer Basics'."
          isnan ldexp logb round sqrt truncate
          ;; fns.c
          assq base64-decode-string base64-encode-string base64url-encode-string
-         concat elt eql equal hash-table-p identity length length< length=
+         concat elt eql equal equal-including-properties
+         hash-table-p identity length length< length=
          length> member memq memql nth nthcdr proper-list-p rassoc rassq
          safe-length string-bytes string-distance string-equal string-lessp
-         string-search take
+         string-search string-version-lessp take
          ;; search.c
          regexp-quote
          ;; syntax.c

lisp/emacs-lisp/bytecomp.el

@@ -3566,6 +3566,8 @@ lambda-expression."
          ;; when used on arrays, but most calls pass lists.
          nreverse sort
 
+         match-data
+
          ;; Adding these functions causes many warnings;
          ;; evaluate how many of them are false first.
          delq delete

lisp/subr.el

@@ -205,6 +205,7 @@ buffer-local wherever it is set."
 (defun buffer-local-boundp (symbol buffer)
   "Return non-nil if SYMBOL is bound in BUFFER.
 Also see `local-variable-p'."
+  (declare (side-effect-free t))
   (condition-case nil
       (buffer-local-value symbol buffer)
     (:success t)
@@ -298,6 +299,7 @@ value of last one, or nil if there are none."
 
 (defsubst subr-primitive-p (object)
   "Return t if OBJECT is a built-in primitive function."
+  (declare (side-effect-free error-free))
   (and (subrp object)
        (not (subr-native-elisp-p object))))
 
@@ -415,6 +417,7 @@ The CONDITION argument is not evaluated.  Do not quote it."
   "Return a new uninterned symbol.
 The name is made by appending `gensym-counter' to PREFIX.
 PREFIX is a string, and defaults to \"g\"."
+  (declare (important-return-value t))
   (let ((num (prog1 gensym-counter
                (setq gensym-counter (1+ gensym-counter)))))
     (make-symbol (format "%s%d" (or prefix "g") num))))
@@ -497,6 +500,7 @@ Defaults to `error'."
   "Return non-nil if OBJECT seems to be a frame configuration.
 Any list whose car is `frame-configuration' is assumed to be a frame
 configuration."
+  (declare (pure t) (side-effect-free error-free))
   (and (consp object)
        (eq (car object) 'frame-configuration)))
 
@@ -506,6 +510,7 @@ ARGS is a list of the first N arguments to pass to FUN.
 The result is a new function which does the same as FUN, except that
 the first N arguments are fixed at the values with which this function
 was called."
+  (declare (side-effect-free error-free))
   (lambda (&rest args2)
     (apply fun (append args args2))))
 
@@ -1076,6 +1081,7 @@ any corresponding binding in PARENT, but it does not override corresponding
 bindings in other keymaps of MAPS.
 MAPS can be a list of keymaps or a single keymap.
 PARENT if non-nil should be a keymap."
+  (declare (side-effect-free t))
   `(keymap
     ,@(if (keymapp maps) (list maps) maps)
     ,@parent))
@@ -1216,6 +1222,7 @@ This resolves inheritance and redefinitions.  The returned keymap
 should behave identically to a copy of KEYMAP w.r.t `lookup-key'
 and use in active keymaps and menus.
 Subkeymaps may be modified but are not canonicalized."
+  (declare (important-return-value t))
   ;; FIXME: Problem with the difference between a nil binding
   ;; that hides a binding in an inherited map and a nil binding that's ignored
   ;; to let some further binding visible.  Currently a nil binding hides all.
@@ -1538,6 +1545,7 @@ See also `current-global-map'.")
 
 (defun listify-key-sequence (key)
   "Convert a key sequence to a list of events."
+  (declare (side-effect-free t))
   (if (vectorp key)
       (append key nil)
     (mapcar (lambda (c)
@@ -1565,6 +1573,7 @@ EVENT may be an event or an event type.  If EVENT is a symbol
 that has never been used in an event that has been read as input
 in the current Emacs session, then this function may fail to include
 the `click' modifier."
+  (declare (side-effect-free t))
   (unless (stringp event)
     (let ((type event))
       (if (listp type)
@@ -1598,6 +1607,7 @@ The value is a printing character (not upper case) or a symbol.
 EVENT may be an event or an event type.  If EVENT is a symbol
 that has never been used in an event that has been read as input
 in the current Emacs session, then this function may return nil."
+  (declare (side-effect-free t))
   (unless (stringp event)
     (if (consp event)
         (setq event (car event)))
@@ -1618,6 +1628,7 @@ in the current Emacs session, then this function may return nil."
 
 (defun mouse-event-p (object)
   "Return non-nil if OBJECT is a mouse click event."
+  (declare (side-effect-free t))
   ;; is this really correct? maybe remove mouse-movement?
   (memq (event-basic-type object) '(mouse-1 mouse-2 mouse-3 mouse-movement)))
 
@@ -1663,6 +1674,7 @@ nil or (STRING . POSITION)'.
 `posn-timestamp': The time the event occurred, in milliseconds.
 
 For more information, see Info node `(elisp)Click Events'."
+  (declare (side-effect-free t))
   (or (and (consp event) (nth 1 event))
       (event--posn-at-point)))
 
@@ -1671,17 +1683,20 @@ For more information, see Info node `(elisp)Click Events'."
 EVENT should be a click, drag, or key press event.
 
 See `event-start' for a description of the value returned."
+  (declare (side-effect-free t))
   (or (and (consp event) (nth (if (consp (nth 2 event)) 2 1) event))
       (event--posn-at-point)))
 
 (defsubst event-click-count (event)
   "Return the multi-click count of EVENT, a click or drag event.
 The return value is a positive integer."
+  (declare (side-effect-free t))
   (if (and (consp event) (integerp (nth 2 event))) (nth 2 event) 1))
 
 (defsubst event-line-count (event)
   "Return the line count of EVENT, a mousewheel event.
 The return value is a positive integer."
+  (declare (side-effect-free t))
   (if (and (consp event) (integerp (nth 3 event))) (nth 3 event) 1))
 
 ;;;; Extracting fields of the positions in an event.
@@ -1691,6 +1706,7 @@ The return value is a positive integer."
 A `posn' object is returned from functions such as `event-start'.
 If OBJ is a valid `posn' object, but specifies a frame rather
 than a window, return nil."
+  (declare (side-effect-free error-free))
   ;; FIXME: Correct the behavior of this function so that all valid
   ;; `posn' objects are recognized, after updating other code that
   ;; depends on its present behavior.
@@ -1704,12 +1720,14 @@ than a window, return nil."
 If POSITION is outside the frame where the event was initiated,
 return that frame instead.  POSITION should be a list of the form
 returned by the `event-start' and `event-end' functions."
+  (declare (side-effect-free t))
   (nth 0 position))
 
 (defsubst posn-area (position)
   "Return the window area recorded in POSITION, or nil for the text area.
 POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions."
+  (declare (side-effect-free t))
   (let ((area (if (consp (nth 1 position))
 		  (car (nth 1 position))
 		(nth 1 position))))
@@ -1721,6 +1739,7 @@ POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions.
 Returns nil if POSITION does not correspond to any buffer location (e.g.
 a click on a scroll bar)."
+  (declare (side-effect-free t))
   (or (nth 5 position)
       (let ((pt (nth 1 position)))
         (or (car-safe pt)
@@ -1746,6 +1765,7 @@ Select the corresponding window as well."
 The return value has the form (X . Y), where X and Y are given in
 pixels.  POSITION should be a list of the form returned by
 `event-start' and `event-end'."
+  (declare (side-effect-free t))
   (nth 2 position))
 
 (declare-function scroll-bar-scale "scroll-bar" (num-denom whole))
@@ -1765,6 +1785,7 @@ corresponds to the vertical position of the click in the scroll bar.
 
 POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions."
+  (declare (side-effect-free t))
   (let* ((pair            (posn-x-y position))
          (frame-or-window (posn-window position))
          (frame           (if (framep frame-or-window)
@@ -1810,12 +1831,14 @@ This function does not account for the width on display, like the
 number of visual columns taken by a TAB or image.  If you need
 the coordinates of POSITION in character units, you should use
 `posn-col-row', not this function."
+  (declare (side-effect-free t))
   (nth 6 position))
 
 (defsubst posn-timestamp (position)
   "Return the timestamp of POSITION.
 POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions."
+  (declare (side-effect-free t))
   (nth 3 position))
 
 (defun posn-string (position)
@@ -1823,6 +1846,7 @@ and `event-end' functions."
 Value is a cons (STRING . STRING-POS), or nil if not a string.
 POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions."
+  (declare (side-effect-free t))
   (let ((x (nth 4 position)))
     ;; Apparently this can also be `handle' or `below-handle' (bug#13979).
     (when (consp x) x)))
@@ -1832,6 +1856,7 @@ and `event-end' functions."
 Value is a list (image ...), or nil if not an image.
 POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions."
+  (declare (side-effect-free t))
   (nth 7 position))
 
 (defsubst posn-object (position)
@@ -1840,6 +1865,7 @@ Value is a list (image ...) for an image object, a cons cell
 \(STRING . STRING-POS) for a string object, and nil for a buffer position.
 POSITION should be a list of the form returned by the `event-start'
 and `event-end' functions."
+  (declare (side-effect-free t))
   (or (posn-image position) (posn-string position)))
 
 (defsubst posn-object-x-y (position)
@@ -1848,12 +1874,14 @@ The return value has the form (DX . DY), where DX and DY are
 given in pixels, and they are relative to the top-left corner of
 the clicked glyph of object at POSITION.  POSITION should be a
 list of the form returned by `event-start' and `event-end'."
+  (declare (side-effect-free t))
   (nth 8 position))
 
 (defsubst posn-object-width-height (position)
   "Return the pixel width and height of the object of POSITION.
 The return value has the form (WIDTH . HEIGHT).  POSITION should
 be a list of the form returned by `event-start' and `event-end'."
+  (declare (side-effect-free t))
   (nth 9 position))
 
 (defun values--store-value (value)
@@ -2614,6 +2642,7 @@ The variable list SPEC is the same as in `if-let*'."
 Uses the `derived-mode-parent' property of the symbol to trace backwards.
 If you just want to check `major-mode', use `derived-mode-p'."
   ;; If MODE is an alias, then look up the real mode function first.
+  (declare (side-effect-free t))
   (when-let ((alias (symbol-function mode)))
     (when (symbolp alias)
       (setq mode alias)))
@@ -2628,6 +2657,7 @@ If you just want to check `major-mode', use `derived-mode-p'."
 (defun derived-mode-p (&rest modes)
   "Non-nil if the current major mode is derived from one of MODES.
 Uses the `derived-mode-parent' property of the symbol to trace backwards."
+  (declare (side-effect-free t))
   (apply #'provided-mode-derived-p major-mode modes))
 
 (defvar-local major-mode--suspended nil)
@@ -2751,6 +2781,7 @@ If TOGGLE has a `:menu-tag', that is used for the menu item's label."
 
 (defsubst autoloadp (object)
   "Non-nil if OBJECT is an autoload."
+  (declare (side-effect-free error-free))
   (eq 'autoload (car-safe object)))
 
 ;; (defun autoload-type (object)
@@ -2795,6 +2826,7 @@ This is to `put' what `defalias' is to `fset'."
 (defun locate-eln-file (eln-file)
   "Locate a natively-compiled ELN-FILE by searching its load path.
 This function looks in directories named by `native-comp-eln-load-path'."
+  (declare (important-return-value t))
   (or (locate-file-internal (concat comp-native-version-dir "/" eln-file)
 		   native-comp-eln-load-path)
       (locate-file-internal
@@ -2826,6 +2858,7 @@ instead.
 This function only works for symbols defined in Lisp files.  For
 symbols that are defined in C files, use `help-C-file-name'
 instead."
+  (declare (important-return-value t))
   (if (and (or (null type) (eq type 'defun))
 	   (symbolp symbol)
 	   (autoloadp (symbol-function symbol)))
@@ -2952,6 +2985,7 @@ argument, which will be called with the exit status of the
 program before the output is collected.  If STATUS-HANDLER is
 nil, an error is signaled if the program returns with a non-zero
 exit status."
+  (declare (important-return-value t))
   (with-temp-buffer
     (let ((status (apply #'call-process program nil (current-buffer) nil args)))
       (if status-handler
@@ -2972,12 +3006,14 @@ exit status."
   "Execute PROGRAM with ARGS, returning its output as a list of lines.
 Signal an error if the program returns with a non-zero exit status.
 Also see `process-lines-ignore-status'."
+  (declare (important-return-value t))
   (apply #'process-lines-handling-status program nil args))
 
 (defun process-lines-ignore-status (program &rest args)
   "Execute PROGRAM with ARGS, returning its output as a list of lines.
 The exit status of the program is ignored.
 Also see `process-lines'."
+  (declare (important-return-value t))
   (apply #'process-lines-handling-status program #'ignore args))
 
 (defun process-live-p (process)
@@ -3006,6 +3042,7 @@ process."
 (defun process-get (process propname)
   "Return the value of PROCESS' PROPNAME property.
 This is the last value stored with `(process-put PROCESS PROPNAME VALUE)'."
+  (declare (side-effect-free t))
   (plist-get (process-plist process) propname))
 
 (defun process-put (process propname value)
@@ -3924,6 +3961,7 @@ If MESSAGE is nil, instructions to type EXIT-CHAR are displayed there."
 
 (defun copy-overlay (o)
   "Return a copy of overlay O."
+  (declare (important-return-value t))
   (let ((o1 (if (overlay-buffer o)
                 (make-overlay (overlay-start o) (overlay-end o)
                               ;; FIXME: there's no easy way to find the
@@ -4133,6 +4171,7 @@ See Info node `(elisp)Security Considerations'.
 If the optional POSIX argument is non-nil, ARGUMENT is quoted
 according to POSIX shell quoting rules, regardless of the
 system's shell."
+  (declare (important-return-value t))
   (cond
    ((and (not posix) (eq system-type 'ms-dos))
     ;; Quote using double quotes, but escape any existing quotes in
@@ -4250,6 +4289,7 @@ or byte-code."
 
 (defun field-at-pos (pos)
   "Return the field at position POS, taking stickiness etc into account."
+  (declare (important-return-value t))
   (let ((raw-field (get-char-property (field-beginning pos) 'field)))
     (if (eq raw-field 'boundary)
 	(get-char-property (1- (field-end pos)) 'field)