master d5bf26f488b: Move side-effect-free and pure declarations to function definitions

[Mattias Engdegård]

branch: master
commit d5bf26f488b7968feed9f43e612a90da2aab15a8
Author: Mattias Engdegård <mattiase@acm.org>
Commit: Mattias Engdegård <mattiase@acm.org>

    Move side-effect-free and pure declarations to function definitions
    
    Some Lisp functions still had their `side-effect-free` and `pure`
    properties declared in byte-opt.el; do it at their definition instead.
    The lists in byte-opt.el now only contain functions implemented in C
    and function aliases.
    
    * lisp/emacs-lisp/byte-opt.el (side-effect-free-fns)
    (side-effect-and-error-free-fns, pure-fns):
    Remove functions whose properties are now declared elsewhere
    and some obsolete entries.
    * lisp/custom.el (custom-variable-p):
    * lisp/emacs-lisp/lisp.el (buffer-end):
    * lisp/emacs-lisp/regexp-opt.el (regexp-opt):
    * lisp/env.el (getenv):
    * lisp/simple.el (count-lines, mark, string-empty-p, lax-plist-get):
    * lisp/subr.el (ignore, always, zerop, fixnump, bignump, lsh, last)
    (eventp, mouse-movement-p, log10, memory-limit, string-greaterp)
    (interactive-p):
    * lisp/window.el (get-lru-window, get-largest-window, (window-edges)
    (window-body-edges, window-pixel-edges, window-body-pixel-edges)
    (window-absolute-pixel-edges, window-absolute-body-pixel-edges)
    (one-window-p):
    Declare functions `side-effect-free` and/or `pure` as appropriate.
---
 lisp/custom.el                |  1 +
 lisp/emacs-lisp/byte-opt.el   | 57 ++++++++++++++++++-------------------------
 lisp/emacs-lisp/lisp.el       |  1 +
 lisp/emacs-lisp/regexp-opt.el |  1 +
 lisp/env.el                   |  1 +
 lisp/simple.el                |  5 +++-
 lisp/subr.el                  | 24 +++++++++++++-----
 lisp/window.el                |  9 +++++++
 8 files changed, 59 insertions(+), 40 deletions(-)

diff --git a/lisp/custom.el b/lisp/custom.el
index 0522bdd447b..fa77e5c2c56 100644
--- a/lisp/custom.el
+++ b/lisp/custom.el
@@ -665,6 +665,7 @@ If NOSET is non-nil, don't bother autoloading LOAD when 
setting the variable."
 A customizable variable is either (i) a variable whose property
 list contains a non-nil `standard-value' or `custom-autoload'
 property, or (ii) an alias for another customizable variable."
+  (declare (side-effect-free t))
   (when (symbolp variable)
     (setq variable (indirect-variable variable))
     (or (get variable 'standard-value)
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index b578b99954c..a9630b6f7c2 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -1647,7 +1647,7 @@ See Info node `(elisp) Integer Basics'."
         capitalize car-less-than-car car cdr ceiling char-after char-before
         char-equal char-to-string char-width compare-strings
         window-configuration-equal-p concat coordinates-in-window-p
-        copy-alist copy-sequence copy-marker copysign cos count-lines
+        copy-alist copy-sequence copy-marker copysign cos
         current-time-string current-time-zone
         decode-char
         decode-time default-boundp default-value documentation downcase
@@ -1659,26 +1659,24 @@ See Info node `(elisp) Integer Basics'."
         float float-time floor format format-time-string frame-first-window
         frame-root-window frame-selected-window
         frame-visible-p fround ftruncate
-        get gethash get-buffer get-buffer-window getenv get-file-buffer
+        get gethash get-buffer get-buffer-window get-file-buffer
         hash-table-count
         int-to-string intern-soft isnan
         keymap-parent
-         lax-plist-get ldexp
+         ldexp
          length length< length> length=
          line-beginning-position line-end-position pos-bol pos-eol
         local-variable-if-set-p local-variable-p locale-info
-        log log10 logand logb logcount logior lognot logxor lsh
-        make-byte-code make-list make-string make-symbol mark marker-buffer max
+        log logand logb logcount logior lognot logxor
+        make-byte-code make-list make-string make-symbol marker-buffer max
          match-beginning match-end
         member memq memql min minibuffer-selected-window minibuffer-window
         mod multibyte-char-to-unibyte next-window nth nthcdr number-to-string
-        parse-colon-path
         prefix-numeric-value previous-window prin1-to-string propertize
-        degrees-to-radians
-        radians-to-degrees rassq rassoc read-from-string regexp-opt
+        rassq rassoc read-from-string
          regexp-quote region-beginning region-end reverse round
         sin sqrt string string< string= string-equal string-lessp
-         string> string-greaterp string-empty-p string-blank-p
+         string>
          string-search string-to-char
         string-to-number string-to-syntax substring
         sxhash sxhash-equal sxhash-eq sxhash-eql
@@ -1687,45 +1685,40 @@ See Info node `(elisp) Integer Basics'."
         string-to-multibyte
         take tan time-convert truncate
         unibyte-char-to-multibyte upcase user-full-name
-        user-login-name user-original-login-name custom-variable-p
+        user-login-name user-original-login-name
         vconcat
-        window-absolute-pixel-edges window-at window-body-height
+        window-at window-body-height
         window-body-width window-buffer window-dedicated-p window-display-table
-        window-combination-limit window-edges window-frame window-fringes
+        window-combination-limit window-frame window-fringes
         window-height window-hscroll window-inside-edges
         window-inside-absolute-pixel-edges window-inside-pixel-edges
         window-left-child window-left-column window-margins window-minibuffer-p
         window-next-buffers window-next-sibling window-new-normal
         window-new-total window-normal-size window-parameter window-parameters
-        window-parent window-pixel-edges window-point window-prev-buffers
+        window-parent window-point window-prev-buffers
          window-prev-sibling window-scroll-bars
         window-start window-text-height window-top-child window-top-line
         window-total-height window-total-width window-use-time window-vscroll
-        window-width zerop))
+        window-width))
       (side-effect-and-error-free-fns
-       '(always arrayp atom
-        bignump bobp bolp bool-vector-p
-        buffer-end buffer-list buffer-size buffer-string bufferp
+       '(arrayp atom
+        bobp bolp bool-vector-p
+        buffer-list buffer-size buffer-string bufferp
         car-safe case-table-p cdr-safe char-or-string-p characterp
         charsetp commandp cons consp
         current-buffer current-global-map current-indentation
         current-local-map current-minor-mode-maps current-time
-        eobp eolp eq equal eventp
-        fixnump floatp following-char framep
-        get-largest-window get-lru-window
+        eobp eolp eq equal
+        floatp following-char framep
         hash-table-p
-         ;; `ignore' isn't here because we don't want calls to it elided;
-         ;; see `byte-compile-ignore'.
-        identity integerp integer-or-marker-p interactive-p
+        identity integerp integer-or-marker-p
         invocation-directory invocation-name
         keymapp keywordp
         list listp
         make-marker mark-marker markerp max-char
-        memory-limit
-        mouse-movement-p
         natnump nlistp not null number-or-marker-p numberp
-        one-window-p overlayp
-        point point-marker point-min point-max preceding-char primary-charset
+        overlayp
+        point point-marker point-min point-max preceding-char
         processp proper-list-p
         recent-keys recursion-depth
         safe-length selected-frame selected-window sequencep
@@ -1761,7 +1754,7 @@ See Info node `(elisp) Integer Basics'."
 ;; values if a marker is moved.
 
 (let ((pure-fns
-       '(concat regexp-opt regexp-quote
+       '(concat regexp-quote
         string-to-char string-to-syntax symbol-name
          eq eql
          = /= < <= >= > min max
@@ -1770,8 +1763,7 @@ See Info node `(elisp) Integer Basics'."
          copysign isnan ldexp float logb
          floor ceiling round truncate
          ffloor fceiling fround ftruncate
-         string= string-equal string< string-lessp string> string-greaterp
-         string-empty-p string-blank-p
+         string= string-equal string< string-lessp string>
          string-search
          consp atom listp nlistp proper-list-p
          sequencep arrayp vectorp stringp bool-vector-p hash-table-p
@@ -1780,20 +1772,19 @@ See Info node `(elisp) Integer Basics'."
          integer-or-marker-p number-or-marker-p char-or-string-p
          symbolp keywordp
          type-of
-         identity ignore
+         identity
 
          ;; The following functions are pure up to mutation of their
          ;; arguments.  This is pure enough for the purposes of
          ;; constant folding, but not necessarily for all kinds of
          ;; code motion.
-         car cdr car-safe cdr-safe nth nthcdr last take
+         car cdr car-safe cdr-safe nth nthcdr take
          equal
          length safe-length
          memq memql member
          ;; `assoc' and `assoc-default' are excluded since they are
          ;; impure if the test function is (consider `string-match').
          assq rassq rassoc
-         lax-plist-get
          aref elt
          base64-decode-string base64-encode-string base64url-encode-string
          bool-vector-subsetp
diff --git a/lisp/emacs-lisp/lisp.el b/lisp/emacs-lisp/lisp.el
index e3ed28f097a..417c218c6d7 100644
--- a/lisp/emacs-lisp/lisp.el
+++ b/lisp/emacs-lisp/lisp.el
@@ -519,6 +519,7 @@ major mode's decisions about context.")
   "Return the \"far end\" position of the buffer, in direction ARG.
 If ARG is positive, that's the end of the buffer.
 Otherwise, that's the beginning of the buffer."
+  (declare (side-effect-free error-free))
   (if (> arg 0) (point-max) (point-min)))
 
 (defun end-of-defun (&optional arg interactive)
diff --git a/lisp/emacs-lisp/regexp-opt.el b/lisp/emacs-lisp/regexp-opt.el
index e64a3dcea1e..fd9fbbe25a4 100644
--- a/lisp/emacs-lisp/regexp-opt.el
+++ b/lisp/emacs-lisp/regexp-opt.el
@@ -130,6 +130,7 @@ usually more efficient than that of a simplified version:
      (concat (car parens)
              (mapconcat \\='regexp-quote strings \"\\\\|\")
              (cdr parens))))"
+  (declare (pure t) (side-effect-free t))
   (save-match-data
     ;; Recurse on the sorted list.
     (let* ((max-lisp-eval-depth 10000)
diff --git a/lisp/env.el b/lisp/env.el
index 33c02f6f920..a9d1d27e1ee 100644
--- a/lisp/env.el
+++ b/lisp/env.el
@@ -205,6 +205,7 @@ Otherwise, this function searches `process-environment' for
 VARIABLE.  If it is not found there, then it continues the search
 in the environment list of the selected frame."
   (interactive (list (read-envvar-name "Get environment variable: " t)))
+  (declare (side-effect-free t))
   (let ((value (getenv-internal (if (multibyte-string-p variable)
                                    (encode-coding-string
                                     variable locale-coding-system)
diff --git a/lisp/simple.el b/lisp/simple.el
index bed6dfb8292..f141b8f1734 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1755,6 +1755,7 @@ not at the start of a line.
 
 When IGNORE-INVISIBLE-LINES is non-nil, invisible lines are not
 included in the count."
+  (declare (side-effect-free t))
   (save-excursion
     (save-restriction
       (narrow-to-region start end)
@@ -6830,6 +6831,7 @@ is active, and returns an integer or nil in the usual way.
 
 If you are using this in an editing command, you are most likely making
 a mistake; see the documentation of `set-mark'."
+  (declare (side-effect-free t))
   (if (or force (not transient-mark-mode) mark-active mark-even-if-inactive)
       (marker-position (mark-marker))
     (signal 'mark-inactive nil)))
@@ -10840,6 +10842,7 @@ If the buffer doesn't exist, create it first."
 
 (defsubst string-empty-p (string)
   "Check whether STRING is empty."
+  (declare (pure t) (side-effect-free t))
   (string= string ""))
 
 (defun read-signal-name ()
@@ -10857,7 +10860,7 @@ If the buffer doesn't exist, create it first."
 
 (defun lax-plist-get (plist prop)
   "Extract a value from a property list, comparing with `equal'."
-  (declare (obsolete plist-get "29.1"))
+  (declare (pure t) (side-effect-free t) (obsolete plist-get "29.1"))
   (plist-get plist prop #'equal))
 
 (defun lax-plist-put (plist prop val)
diff --git a/lisp/subr.el b/lisp/subr.el
index a1397fa6781..819d2a51101 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -422,7 +422,9 @@ PREFIX is a string, and defaults to \"g\"."
   "Do nothing and return nil.
 This function accepts any number of ARGUMENTS, but ignores them.
 Also see `always'."
-  (declare (completion ignore))
+  ;; Not declared `side-effect-free' because we don't want calls to it
+  ;; elided; see `byte-compile-ignore'.
+  (declare (pure t) (completion ignore))
   (interactive)
   nil)
 
@@ -430,6 +432,7 @@ Also see `always'."
   "Do nothing and return t.
 This function accepts any number of ARGUMENTS, but ignores them.
 Also see `ignore'."
+  (declare (pure t) (side-effect-free error-free))
   t)
 
 ;; Signal a compile-error if the first arg is missing.
@@ -509,16 +512,19 @@ was called."
   "Return t if NUMBER is zero."
   ;; Used to be in C, but it's pointless since (= 0 n) is faster anyway because
   ;; = has a byte-code.
-  (declare (compiler-macro (lambda (_) `(= 0 ,number))))
+  (declare (pure t) (side-effect-free t)
+           (compiler-macro (lambda (_) `(= 0 ,number))))
   (= 0 number))
 
 (defun fixnump (object)
   "Return t if OBJECT is a fixnum."
+  (declare (side-effect-free error-free))
   (and (integerp object)
        (<= most-negative-fixnum object most-positive-fixnum)))
 
 (defun bignump (object)
   "Return t if OBJECT is a bignum."
+  (declare (side-effect-free error-free))
   (and (integerp object) (not (fixnump object))))
 
 (defun lsh (value count)
@@ -533,7 +539,8 @@ instead."
             (lambda (form)
               (macroexp-warn-and-return
                (format-message "avoid `lsh'; use `ash' instead")
-               form '(suspicious lsh) t form))))
+               form '(suspicious lsh) t form)))
+           (side-effect-free t))
   (when (and (< value 0) (< count 0))
     (when (< value most-negative-fixnum)
       (signal 'args-out-of-range (list value count)))
@@ -706,7 +713,7 @@ instead."
 If LIST is nil, return nil.
 If N is non-nil, return the Nth-to-last link of LIST.
 If N is bigger than the length of LIST, return LIST."
-  (declare (side-effect-free t))
+  (declare (pure t) (side-effect-free t))    ; pure up to mutation
   (if n
       (and (>= n 0)
            (let ((m (safe-length list)))
@@ -1525,6 +1532,7 @@ See also `current-global-map'.")
 
 (defun eventp (object)
   "Return non-nil if OBJECT is an input event or event object."
+  (declare (pure t) (side-effect-free error-free))
   (or (integerp object)
       (and (if (consp object)
                (setq object (car object))
@@ -1587,6 +1595,7 @@ in the current Emacs session, then this function may 
return nil."
 
 (defsubst mouse-movement-p (object)
   "Return non-nil if OBJECT is a mouse movement event."
+  (declare (side-effect-free error-free))
   (eq (car-safe object) 'mouse-movement))
 
 (defun mouse-event-p (object)
@@ -1859,7 +1868,7 @@ be a list of the form returned by `event-start' and 
`event-end'."
 
 (defun log10 (x)
   "Return (log X 10), the log base 10 of X."
-  (declare (obsolete log "24.4"))
+  (declare (side-effect-free t) (obsolete log "24.4"))
   (log x 10))
 
 (set-advertised-calling-convention
@@ -2983,6 +2992,7 @@ It can be retrieved with `(process-get PROCESS 
PROPNAME)'."
 
 (defun memory-limit ()
   "Return an estimate of Emacs virtual memory usage, divided by 1024."
+  (declare (side-effect-free error-free))
   (let ((default-directory temporary-file-directory))
     (or (cdr (assq 'vsize (process-attributes (emacs-pid)))) 0)))
 
@@ -5544,6 +5554,7 @@ consisting of STR followed by an invisible left-to-right 
mark
   "Return non-nil if STRING1 is greater than STRING2 in lexicographic order.
 Case is significant.
 Symbols are also allowed; their print names are used instead."
+  (declare (pure t) (side-effect-free t))
   (string-lessp string2 string1))
 
 
@@ -6187,7 +6198,8 @@ To test whether a function can be called interactively, 
use
 `commandp'."
   ;; Kept around for now.  See discussion at:
   ;; https://lists.gnu.org/r/emacs-devel/2020-08/msg00564.html
-  (declare (obsolete called-interactively-p "23.2"))
+  (declare (obsolete called-interactively-p "23.2")
+           (side-effect-free error-free))
   (called-interactively-p 'interactive))
 
 (defun internal-push-keymap (keymap symbol)
diff --git a/lisp/window.el b/lisp/window.el
index 2d9f746d8fb..6f9cd9fc3bf 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -2522,6 +2522,7 @@ selected frame and no others.
 `display-buffer-avoid-small-windows', if non-nil, is also taken into
 consideration.  Windows whose height is smaller that the value of that
 variable will be avoided if larger windows are available."
+  (declare (side-effect-free error-free))
   (let ((windows (window-list-1 nil 'nomini all-frames))
         best-window best-time second-best-window second-best-time time)
     (dolist (window windows)
@@ -2603,6 +2604,7 @@ have special meanings:
 
 Any other value of ALL-FRAMES means consider all windows on the
 selected frame and no others."
+  (declare (side-effect-free error-free))
   (let ((best-size 0)
        best-window size)
     (dolist (window (window-list-1 nil 'nomini all-frames))
@@ -3801,6 +3803,7 @@ frame, rounded if necessary.  PIXELWISE non-nil means to 
return
 the coordinates in pixels where the values for RIGHT and BOTTOM
 are one more than the actual value of these edges.  Note that if
 ABSOLUTE is non-nil, PIXELWISE is implicitly non-nil too."
+  (declare (side-effect-free t))
   (let* ((window (window-normalize-window window body))
         (frame (window-frame window))
         (border-width (frame-internal-border-width frame))
@@ -3856,6 +3859,7 @@ ABSOLUTE is non-nil, PIXELWISE is implicitly non-nil too."
   "Return a list of the edge coordinates of WINDOW's body.
 The return value is that of `window-edges' called with argument
 BODY non-nil."
+  (declare (side-effect-free t))
   (window-edges window t))
 (defalias 'window-inside-edges 'window-body-edges)
 
@@ -3863,12 +3867,14 @@ BODY non-nil."
   "Return a list of the edge pixel coordinates of WINDOW.
 The return value is that of `window-edges' called with argument
 PIXELWISE non-nil."
+  (declare (side-effect-free t))
   (window-edges window nil nil t))
 
 (defun window-body-pixel-edges (&optional window)
   "Return a list of the edge pixel coordinates of WINDOW's body.
 The return value is that of `window-edges' called with arguments
 BODY and PIXELWISE non-nil."
+  (declare (side-effect-free t))
   (window-edges window t nil t))
 (defalias 'window-inside-pixel-edges 'window-body-pixel-edges)
 
@@ -3876,12 +3882,14 @@ BODY and PIXELWISE non-nil."
   "Return a list of the edge pixel coordinates of WINDOW.
 The return value is that of `window-edges' called with argument
 ABSOLUTE non-nil."
+  (declare (side-effect-free t))
   (window-edges window nil t t))
 
 (defun window-absolute-body-pixel-edges (&optional window)
   "Return a list of the edge pixel coordinates of WINDOW's text area.
 The return value is that of `window-edges' called with arguments
 BODY and ABSOLUTE non-nil."
+  (declare (side-effect-free t))
   (window-edges window t t t))
 (defalias 'window-inside-absolute-pixel-edges 
'window-absolute-body-pixel-edges)
 
@@ -4091,6 +4099,7 @@ with a special meaning are:
 
 Anything else means consider all windows on the selected frame
 and no others."
+  (declare (side-effect-free error-free))
   (let ((base-window (selected-window)))
     (if (and nomini (eq base-window (minibuffer-window)))
        (setq base-window (next-window base-window)))