Merge branch 'lisp-func-type-decls' into 'master'

doc/lispref/functions.texi

@@ -2709,6 +2709,58 @@ native code emitted for the function.  In particular, if @var{n} is
 @minus{}1, native compilation of the function will emit bytecode
 instead of native code for the function.
 
+@item (type @var{type})
+Declare @var{type} to be the type of this function.  This is used for
+documentation by @code{describe-function}.  Also it can be used by the
+native compiler (@pxref{Native Compilation}) for improving code
+generation and for deriving more precisely the type of other functions
+without type declaration.
+
+@var{type} is a type specifier in the form @w{@code{(function
+(ARG-1-TYPE ... ARG-N-TYPE) RETURN-TYPE)}}.  Argument types can be
+interleaved with symbols @code{&optional} and @code{&rest} to match the
+function's arguments (@pxref{Argument List}).
+
+Here's an example of using @code{type} inside @code{declare} to declare
+a function @code{positive-p} that takes an argument of type @var{number}
+and return a @var{boolean}:
+
+@group
+@lisp
+(defun positive-p (x)
+  (declare (type (function (number) boolean)))
+  (when (> x 0)
+    t))
+@end lisp
+@end group
+
+Similarly this declares a function @code{cons-or-number} that: expects a
+first argument being a @var{cons} or a @var{number}, a second optional
+argument of type @var{string} and return one of the symbols
+@code{is-cons} or @code{is-number}:
+
+@group
+@lisp
+(defun cons-or-number (x &optional err-msg)
+  (declare (type (function ((or cons number) &optional string)
+			   (member is-cons is-number))))
+  (if (consp x)
+      'is-cons
+    (if (numberp x)
+	'is-number
+      (error (or err-msg "Unexpected input")))))
+@end lisp
+@end group
+
+More types are described in the Lisp Data Types chapter (@ref{Lisp Data
+Types}).
+
+Declaring a function with an incorrect type produces undefined behavior
+and could lead to unexpected results or might even crash Emacs when code
+is native-compiled and loaded.  Note also that when redefining (or
+advising) a type declared function the replacement should respect the
+original signature to avoid undefined behavior.
+
 @item no-font-lock-keyword
 This is valid for macros only.  Macros with this declaration are
 highlighted by font-lock (@pxref{Font Lock Mode}) as normal functions,

etc/NEWS

@@ -1939,6 +1939,11 @@ unibyte string.
 
 * Lisp Changes in Emacs 30.1
 
++++
+** Function type declaration
+It is now possible, using the 'declare' macro, to declare expected types
+of function arguments and return type.
+
 ** New types 'closure' and 'interpreted-function'.
 'interpreted-function' is the new type used for interpreted functions,
 and 'closure' is the common parent type of 'interpreted-function'

lisp/custom.el

@@ -667,7 +667,8 @@ 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))
+  (declare (type (function (symbol) t))
+           (side-effect-free t))
   (when (symbolp variable)
     (setq variable (indirect-variable variable))
     (or (get variable 'standard-value)

lisp/emacs-lisp/byte-run.el

@@ -217,6 +217,11 @@ So far, FUNCTION can only be a symbol, not a lambda expression."
                  (cadr elem)))
               val)))))
 
+(defalias 'byte-run--set-function-type
+  #'(lambda (f _args &rest val)
+      (list 'function-put (list 'quote f)
+            ''function-type (list 'quote val))))
+
 ;; Add any new entries to info node `(elisp)Declare Form'.
 (defvar defun-declarations-alist
   (list
@@ -239,7 +244,8 @@ If `error-free', drop calls even if `byte-compile-delete-errors' is nil.")
    (list 'speed #'byte-run--set-speed)
    (list 'completion #'byte-run--set-completion)
    (list 'modes #'byte-run--set-modes)
-   (list 'interactive-args #'byte-run--set-interactive-args))
+   (list 'interactive-args #'byte-run--set-interactive-args)
+   (list 'type #'byte-run--set-function-type))
   "List associating function properties to their macro expansion.
 Each element of the list takes the form (PROP FUN) where FUN is
 a function.  For each (PROP . VALUES) in a function's declaration,

lisp/emacs-lisp/comp-common.el

@@ -68,7 +68,7 @@ Used to modify the compiler environment."
   :risky t
   :version "28.1")
 
-(defconst comp-known-type-specifiers
+(defconst comp-primitive-type-specifiers
   `(
     ;; Functions we can trust not to be redefined, or, if redefined,
     ;; to expose the same type.  The vast majority of these are
@@ -97,7 +97,6 @@ Used to modify the compiler environment."
     (assq (function (t list) list))
     (atan (function (number &optional number) float))
     (atom (function (t) boolean))
-    (bignump (function (t) boolean))
     (bobp (function () boolean))
     (bolp (function () boolean))
     (bool-vector-count-consecutive
@@ -107,7 +106,6 @@ Used to modify the compiler environment."
     (bool-vector-p (function (t) boolean))
     (bool-vector-subsetp (function (bool-vector bool-vector) boolean))
     (boundp (function (symbol) boolean))
-    (buffer-end (function ((or number marker)) integer))
     (buffer-file-name (function (&optional buffer) (or string null)))
     (buffer-list (function (&optional frame) list))
     (buffer-local-variables (function (&optional buffer) list))
@@ -157,8 +155,6 @@ Used to modify the compiler environment."
     (copy-sequence (function (sequence) sequence))
     (copysign (function (float float) float))
     (cos (function (number) float))
-    (count-lines
-     (function ((or integer marker) (or integer marker) &optional t) integer))
     (current-buffer (function () buffer))
     (current-global-map (function () cons))
     (current-indentation (function () integer))
@@ -171,7 +167,6 @@ Used to modify the compiler environment."
     (current-time-zone (function (&optional (or number list)
                                             (or symbol string cons integer))
                                  cons))
-    (custom-variable-p (function (symbol) t))
     (decode-char (function (cons t) (or fixnum null)))
     (decode-time (function (&optional (or number list)
                                       (or symbol string cons integer)
@@ -179,7 +174,6 @@ Used to modify the compiler environment."
                            cons))
     (default-boundp (function (symbol) boolean))
     (default-value (function (symbol) t))
-    (degrees-to-radians (function (number) float))
     (documentation
      (function ((or function symbol subr) &optional t) (or null string)))
     (downcase (function ((or fixnum string)) (or fixnum string)))
@@ -192,7 +186,6 @@ Used to modify the compiler environment."
     (eql (function (t t) boolean))
     (equal (function (t t) boolean))
     (error-message-string (function (list) string))
-    (eventp (function (t) boolean))
     (exp (function (number) float))
     (expt (function (number number) number))
     (fboundp (function (symbol) boolean))
@@ -207,7 +200,6 @@ Used to modify the compiler environment."
     (file-readable-p (function (string) boolean))
     (file-symlink-p (function (string) (or boolean string)))
     (file-writable-p (function (string) boolean))
-    (fixnump (function (t) boolean))
     (float (function (number) float))
     (float-time (function (&optional (or number list)) float))
     (floatp (function (t) boolean))
@@ -230,18 +222,12 @@ Used to modify the compiler environment."
      (function (&optional (or buffer string) (or symbol (integer 0 0)))
                (or null window)))
     (get-file-buffer (function (string) (or null buffer)))
-    (get-largest-window (function (&optional t t t) (or window null)))
-    (get-lru-window (function (&optional t t t) (or window null)))
-    (getenv (function (string &optional frame) (or null string)))
     (gethash (function (t hash-table &optional t) t))
     (hash-table-count (function (hash-table) integer))
     (hash-table-p (function (t) boolean))
     (identity (function (t) t))
-    (ignore (function (&rest t) null))
-    (int-to-string (function (number) string))
     (integer-or-marker-p (function (t) boolean))
     (integerp (function (t) boolean))
-    (interactive-p (function () boolean))
     (intern-soft (function ((or string symbol) &optional (or obarray vector))
                            symbol))
     (invocation-directory (function () string))
@@ -250,8 +236,6 @@ Used to modify the compiler environment."
     (keymap-parent (function (cons) (or cons null)))
     (keymapp (function (t) boolean))
     (keywordp (function (t) boolean))
-    (last (function (list &optional integer) list))
-    (lax-plist-get (function (list t) t))
     (ldexp (function (number integer) float))
     (length (function (t) (integer 0 *)))
     (length< (function (sequence fixnum) boolean))
@@ -265,7 +249,6 @@ Used to modify the compiler environment."
     (local-variable-p (function (symbol &optional buffer) boolean))
     (locale-info (function ((member codeset days months paper)) (or null string)))
     (log (function (number number) float))
-    (log10 (function (number) float))
     (logand (function (&rest (or integer marker)) integer))
     (logb (function (number) integer))
     (logcount (function (integer) integer))
@@ -273,7 +256,6 @@ Used to modify the compiler environment."
     (lognot (function (integer) integer))
     (logxor (function (&rest (or integer marker)) integer))
     ;; (lsh (function ((integer ,most-negative-fixnum *) integer) integer)) ?
-    (lsh (function (integer integer) integer))
     (make-byte-code
      (function ((or fixnum list) string vector integer &optional string t
                 &rest t)
@@ -282,14 +264,12 @@ Used to modify the compiler environment."
     (make-marker (function () marker))
     (make-string (function (integer fixnum &optional t) string))
     (make-symbol (function (string) symbol))
-    (mark (function (&optional t) (or integer null)))
     (mark-marker (function () marker))
     (marker-buffer (function (marker) (or buffer null)))
     (markerp (function (t) boolean))
     (max (function ((or number marker) &rest (or number marker)) number))
     (max-char (function (&optional t) fixnum))
     (member (function (t list) list))
-    (memory-limit (function () integer))
     (memq (function (t list) list))
     (memql (function (t list) list))
     (min (function ((or number marker) &rest (or number marker)) number))
@@ -298,7 +278,6 @@ Used to modify the compiler environment."
     (mod
      (function ((or number marker) (or number marker))
                (or (integer 0 *) (float 0 *))))
-    (mouse-movement-p (function (t) boolean))
     (multibyte-char-to-unibyte (function (fixnum) fixnum))
     (natnump (function (t) boolean))
     (next-window (function (&optional window t t) window))
@@ -310,9 +289,7 @@ Used to modify the compiler environment."
     (number-or-marker-p (function (t) boolean))
     (number-to-string (function (number) string))
     (numberp (function (t) boolean))
-    (one-window-p (function (&optional t t) boolean))
     (overlayp (function (t) boolean))
-    (parse-colon-path (function (string) list))
     (plist-get (function (list t &optional t) t))
     (plist-member (function (list t &optional t) list))
     (point (function () integer))
@@ -325,13 +302,11 @@ Used to modify the compiler environment."
     (processp (function (t) boolean))
     (proper-list-p (function (t) (or fixnum null)))
     (propertize (function (string &rest t) string))
-    (radians-to-degrees (function (number) float))
     (rassoc (function (t list) list))
     (rassq (function (t list) list))
     (read-from-string (function (string &optional integer integer) cons))
     (recent-keys (function (&optional (or cons null)) vector))
     (recursion-depth (function () integer))
-    (regexp-opt (function (list) string))
     (regexp-quote (function (string) string))
     (region-beginning (function () integer))
     (region-end (function () integer))
@@ -387,7 +362,6 @@ Used to modify the compiler environment."
     (upcase (function ((or fixnum string)) (or fixnum string)))
     (user-full-name (function (&optional integer) (or string null)))
     (user-login-name (function (&optional integer) (or string null)))
-    (user-original-login-name (function (&optional integer) (or string null)))
     (user-real-login-name (function () string))
     (user-real-uid (function () integer))
     (user-uid (function () integer))
@@ -400,13 +374,8 @@ Used to modify the compiler environment."
     (window-live-p (function (t) boolean))
     (window-valid-p (function (t) boolean))
     (windowp (function (t) boolean))
-    (zerop (function (number) boolean))
-    ;; Type hints
-    (comp-hint-fixnum (function (t) fixnum))
-    (comp-hint-cons (function (t) cons))
     ;; Non returning functions
     (throw (function (t t) nil))
-    (error (function (string &rest t) nil))
     (signal (function (symbol t) nil)))
   "Alist used for type propagation.")
 
@@ -532,22 +501,27 @@ Account for `native-comp-eln-load-path' and `comp-native-version-dir'."
 (defun comp-function-type-spec (function)
   "Return the type specifier of FUNCTION.
 
-This function returns a cons cell whose car is the function
+This function returns a cons cell whose car is the function specifier,
-specifier, and cdr is a symbol, either `inferred' or `know'.
+and cdr is a symbol, either `inferred' or `declared'.  If the symbol is
-If the symbol is `inferred', the type specifier is automatically
+`inferred', the type specifier is automatically inferred from the code
-inferred from the code itself by the native compiler; if it is
+itself by the native compiler; if it is `declared', the type specifier
-`know', the type specifier comes from `comp-known-type-specifiers'."
+comes from `comp-primitive-type-specifiers' or the function type declaration
-  (let ((kind 'know)
+itself."
-        type-spec )
+  (let ((kind 'declared)
-    (when-let ((res (assoc function comp-known-type-specifiers)))
+        type-spec)
+    (when-let ((res (assoc function comp-primitive-type-specifiers)))
+      ;; Declared primitive
       (setf type-spec (cadr res)))
     (let ((f (and (symbolp function)
                   (symbol-function function))))
-      (when (and f
+      (when (and f (null type-spec))
-                 (null type-spec)
+        (if-let ((delc-type (function-get function 'function-type)))
-                 (subr-native-elisp-p f))
+            ;; Declared Lisp function
-        (setf kind 'inferred
+            (setf type-spec (car delc-type))
-              type-spec (subr-type f))))
+          (when (subr-native-elisp-p f)
+            ;; Native compiled inferred
+            (setf kind 'inferred
+                  type-spec (subr-type f))))))
     (when type-spec
         (cons type-spec kind))))
 

lisp/emacs-lisp/comp.el

@@ -179,16 +179,24 @@ For internal use by the test suite only.")
 Each function in FUNCTIONS is run after PASS.
 Useful to hook into pass checkers.")
 
-(defconst comp-known-func-cstr-h
+(defconst comp-primitive-func-cstr-h
   (cl-loop
    with comp-ctxt = (make-comp-cstr-ctxt)
    with h = (make-hash-table :test #'eq)
-   for (f type-spec) in comp-known-type-specifiers
+   for (f type-spec) in comp-primitive-type-specifiers
    for cstr = (comp-type-spec-to-cstr type-spec)
    do (puthash f cstr h)
    finally return h)
   "Hash table function -> `comp-constraint'.")
 
+(defun comp--get-function-cstr (function)
+  "Given FUNCTION return the corresponding `comp-constraint'."
+  (when (symbolp function)
+    (let ((f (symbol-function function)))
+      (or (gethash f comp-primitive-func-cstr-h)
+          (when-let ((res (function-get function 'function-type)))
+            (comp-type-spec-to-cstr (car res)))))))
+
 ;; Keep it in sync with the `cl-deftype-satisfies' property set in
 ;; cl-macs.el. We can't use `cl-deftype-satisfies' directly as the
 ;; relation type <-> predicate is not bijective (bug#45576).
@@ -2102,10 +2110,10 @@ TARGET-BB-SYM is the symbol name of the target block."
      (when-let ((match
                  (pcase insn
                    (`(set ,lhs (,(pred comp--call-op-p) ,f . ,args))
-                    (when-let ((cstr-f (gethash f comp-known-func-cstr-h)))
+                    (when-let ((cstr-f (comp--get-function-cstr f)))
                       (cl-values f cstr-f lhs args)))
                    (`(,(pred comp--call-op-p) ,f . ,args)
-                    (when-let ((cstr-f (gethash f comp-known-func-cstr-h)))
+                    (when-let ((cstr-f (comp--get-function-cstr f)))
                       (cl-values f cstr-f nil args))))))
        (cl-multiple-value-bind (f cstr-f lhs args) match
          (cl-loop
@@ -2642,7 +2650,7 @@ Fold the call in case."
                (comp-cstr-imm-vld-p (car args)))
       (setf f (comp-cstr-imm (car args))
             args (cdr args)))
-    (when-let ((cstr-f (gethash f comp-known-func-cstr-h)))
+    (when-let ((cstr-f (comp--get-function-cstr f)))
       (let ((cstr (comp-cstr-f-ret cstr-f)))
         (when (comp-cstr-empty-p cstr)
           ;; Store it to be rewritten as non local exit.
@@ -3301,11 +3309,13 @@ Prepare every function for final compilation and drive the C back-end."
 ;; are assumed just to be true. Use with extreme caution...
 
 (defun comp-hint-fixnum (x)
-  (declare (gv-setter (lambda (val) `(setf ,x ,val))))
+  (declare (type (function (t) fixnum))
+           (gv-setter (lambda (val) `(setf ,x ,val))))
   x)
 
 (defun comp-hint-cons (x)
-  (declare (gv-setter (lambda (val) `(setf ,x ,val))))
+  (declare (type (function (t) cons))
+           (gv-setter (lambda (val) `(setf ,x ,val))))
   x)
 
 

lisp/emacs-lisp/lisp.el

@@ -534,7 +534,8 @@ 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))
+  (declare (type (function ((or number marker)) integer))
+           (side-effect-free error-free))
   (if (> arg 0) (point-max) (point-min)))
 
 (defun end-of-defun (&optional arg interactive)

lisp/emacs-lisp/regexp-opt.el

@@ -130,7 +130,8 @@ 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))
+  (declare (type (function (list &optional t) string))
+           (pure t) (side-effect-free t))
   (save-match-data
     ;; Recurse on the sorted list.
     (let* ((max-lisp-eval-depth 10000)

lisp/env.el

@@ -207,7 +207,8 @@ parameter.
 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."
-  (declare (side-effect-free t))
+  (declare (type (function (string &optional frame) (or null string)))
+           (side-effect-free t))
   (interactive (list (read-envvar-name "Get environment variable: " t)))
   (let ((value (getenv-internal (if (multibyte-string-p variable)
 				    (encode-coding-string

lisp/files.el

@@ -862,6 +862,7 @@ GNU and Unix systems).  Substitute environment variables into the
 resulting list of directory names.  For an empty path element (i.e.,
 a leading or trailing separator, or two adjacent separators), return
 nil (meaning `default-directory') as the associated list element."
+  (declare (type (function (string) list)))
   (when (stringp search-path)
     (let ((spath (substitute-env-vars search-path))
           (double-slash-special-p

lisp/help-fns.el

@@ -732,7 +732,7 @@ the C sources, too."
               (insert (format
                        (if (eq kind 'inferred)
                            "\nInferred type: %s\n"
-                         "\nType: %s\n")
+                         "\nDeclared type: %s\n")
                        type-spec))))
           (fill-region fill-begin (point))
           high-doc)))))

lisp/simple.el

@@ -1762,7 +1762,9 @@ 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))
+  (declare (type (function ((or integer marker) (or integer marker) &optional t)
+                           integer))
+           (side-effect-free t))
   (save-excursion
     (save-restriction
       (narrow-to-region start end)
@@ -6882,7 +6884,8 @@ 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))
+  (declare (type (function (&optional t) (or integer null)))
+           (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)))
@@ -11163,7 +11166,8 @@ killed."
 
 (defun lax-plist-get (plist prop)
   "Extract a value from a property list, comparing with `equal'."
-  (declare (pure t) (side-effect-free t) (obsolete plist-get "29.1"))
+  (declare (type (function (list t) t))
+           (pure t) (side-effect-free t) (obsolete plist-get "29.1"))
   (plist-get plist prop #'equal))
 
 (defun lax-plist-put (plist prop val)

lisp/subr.el

@@ -451,7 +451,8 @@ This function accepts any number of arguments in ARGUMENTS.
 Also see `always'."
   ;; Not declared `side-effect-free' because we don't want calls to it
   ;; elided; see `byte-compile-ignore'.
-  (declare (pure t) (completion ignore))
+  (declare (type (function (&rest t) null))
+           (pure t) (completion ignore))
   (interactive)
   nil)
 
@@ -480,7 +481,8 @@ for the sake of consistency.
 
 To alter the look of the displayed error messages, you can use
 the `command-error-function' variable."
-  (declare (advertised-calling-convention (string &rest args) "23.1"))
+  (declare (type (function (string &rest t) nil))
+           (advertised-calling-convention (string &rest args) "23.1"))
   (signal 'error (list (apply #'format-message args))))
 
 (defun user-error (format &rest args)
@@ -545,19 +547,22 @@ 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 (pure t) (side-effect-free t)
+  (declare (type (function (number) boolean))
+           (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))
+  (declare (type (function (t) boolean))
+           (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))
+  (declare (type (function (t) boolean))
+           (side-effect-free error-free))
   (and (integerp object) (not (fixnump object))))
 
 (defun lsh (value count)
@@ -570,7 +575,8 @@ Most uses of this function turn out to be mistakes.  We recommend
 to use `ash' instead, unless COUNT could ever be negative, and
 if, when COUNT is negative, your program really needs the special
 treatment of negative COUNT provided by this function."
-  (declare (compiler-macro
+  (declare (type (function (integer integer) integer))
+           (compiler-macro
             (lambda (form)
               (macroexp-warn-and-return
                (format-message "avoid `lsh'; use `ash' instead")
@@ -748,7 +754,8 @@ treatment of negative COUNT provided by this function."
 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 (pure t) (side-effect-free t))    ; pure up to mutation
+  (declare (type (function (list &optional integer) list))
+           (pure t) (side-effect-free t))    ; pure up to mutation
   (if n
       (and (>= n 0)
            (let ((m (safe-length list)))
@@ -1585,7 +1592,8 @@ 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))
+  (declare (type (function (t) boolean))
+           (pure t) (side-effect-free error-free))
   (or (integerp object)
       (and (if (consp object)
                (setq object (car object))
@@ -1652,7 +1660,8 @@ 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))
+  (declare (type (function (t) boolean))
+           (side-effect-free error-free))
   (eq (car-safe object) 'mouse-movement))
 
 (defun mouse-event-p (object)
@@ -1961,7 +1970,8 @@ 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 (side-effect-free t) (obsolete log "24.4"))
+  (declare (type (function (number) float))
+           (side-effect-free t) (obsolete log "24.4"))
   (log x 10))
 
 (set-advertised-calling-convention
@@ -3245,7 +3255,8 @@ 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))
+  (declare (type (function () integer))
+           (side-effect-free error-free))
   (let ((default-directory temporary-file-directory))
     (or (cdr (assq 'vsize (process-attributes (emacs-pid)))) 0)))
 
@@ -6467,7 +6478,8 @@ 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 (type (function () boolean))
+           (obsolete called-interactively-p "23.2")
            (side-effect-free error-free))
   (called-interactively-p 'interactive))
 

lisp/window.el

@@ -2515,7 +2515,8 @@ 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))
+  (declare (type (function (&optional t t t) (or window null)))
+           (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)
@@ -2594,7 +2595,8 @@ 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))
+  (declare (type (function (&optional t t t) (or window null)))
+           (side-effect-free error-free))
   (let ((best-size 0)
 	best-window size)
     (dolist (window (window-list-1 nil 'nomini all-frames))
@@ -4089,7 +4091,8 @@ with a special meaning are:
 
 Anything else means consider all windows on the selected frame
 and no others."
-  (declare (side-effect-free error-free))
+  (declare (type (function (&optional t t) boolean))
+           (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)))