;;;; This file contains load-time support for declaration processing.
;;;; In CMU CL it was split off from the compiler so that the compiler
;;;; doesn't have to be in the cold load, but in SBCL the compiler is
;;;; in the cold load again, so this might not be valuable.

;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; This software is derived from the CMU CL system, which was
;;;; written at Carnegie Mellon University and released into the
;;;; public domain. The software is in the public domain and is
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.

(in-package "SB!C")

;;; A list of UNDEFINED-WARNING structures representing references to unknown
;;; stuff which came up in a compilation unit.
(defvar *undefined-warnings*)
(declaim (list *undefined-warnings*))

;;; Look up some symbols in *FREE-VARS*, returning the var
;;; structures for any which exist. If any of the names aren't
;;; symbols, we complain.
(declaim (ftype (function (list) list) get-old-vars))
(defun get-old-vars (names)
  (collect ((vars))
    (dolist (name names (vars))
      (unless (symbolp name)
        (compiler-error "The name ~S is not a symbol." name))
      (let ((old (gethash name *free-vars*)))
        (when old (vars old))))))

;;; Return a new POLICY containing the policy information represented
;;; by the optimize declaration SPEC. Any parameters not specified are
;;; defaulted from the POLICY argument.
(declaim (ftype (function (list policy) (values policy list))
                process-optimize-decl))
(defun process-optimize-decl (spec policy)
  (let ((result nil)
        (specified-qualities))
    ;; Add new entries from SPEC.
    (dolist (q-and-v-or-just-q (cdr spec))
      (multiple-value-bind (quality raw-value)
          (if (atom q-and-v-or-just-q)
              (values q-and-v-or-just-q 3)
              (destructuring-bind (quality raw-value) q-and-v-or-just-q
                (values quality raw-value)))
        (cond ((not (policy-quality-name-p quality))
               (or (policy-quality-deprecation-warning quality)
                   (compiler-warn
                    "~@<Ignoring unknown optimization quality ~S in:~_ ~S~:>"
                    quality spec)))
              ((not (typep raw-value 'policy-quality))
               (compiler-warn "~@<Ignoring bad optimization value ~S in:~_ ~S~:>"
                              raw-value spec))
              (t
               ;; we can't do this yet, because CLOS macros expand
               ;; into code containing INHIBIT-WARNINGS.
               #+nil
               (when (eql quality 'inhibit-warnings)
                 (compiler-style-warn "~S is deprecated: use ~S instead"
                                      quality 'muffle-conditions))
               (let* ((pair (cons quality raw-value))
                      (found (member quality result :key #'car)))
                 (push pair specified-qualities)
                 (if found
                     (rplaca found pair)
                     (push pair result)))))))
    ;; Add any nonredundant entries from old POLICY.
    (dolist (old-entry policy)
      (unless (assq (car old-entry) result)
        (push old-entry result)))
    ;; Voila.
    (values (sort-policy result) specified-qualities)))

(declaim (ftype (function (list list) list)
                process-handle-conditions-decl))
(defun process-handle-conditions-decl (spec list)
  (let ((new (copy-alist list)))
    (dolist (clause (cdr spec))
      (destructuring-bind (typespec restart-name) clause
        (let ((ospec (rassoc restart-name new :test #'eq)))
          (if ospec
              (setf (car ospec)
                    (type-specifier
                     (type-union (specifier-type (car ospec))
                                 (specifier-type typespec))))
              (push (cons (type-specifier (specifier-type typespec))
                          restart-name)
                    new)))))
    new))

(declaim (ftype (function (list list) list)
                process-muffle-conditions-decl))
(defun process-muffle-conditions-decl (spec list)
  (process-handle-conditions-decl
   (cons 'handle-conditions
         (mapcar (lambda (x) (list x 'muffle-warning)) (cdr spec)))
   list))

(declaim (ftype (function (list list) list)
                process-unhandle-conditions-decl))
(defun process-unhandle-conditions-decl (spec list)
  (let ((new (copy-alist list)))
    (dolist (clause (cdr spec))
      (destructuring-bind (typespec restart-name) clause
        (let ((ospec (rassoc restart-name new :test #'eq)))
          (if ospec
              (let ((type-specifier
                     (type-specifier
                      (type-intersection
                       (specifier-type (car ospec))
                       (specifier-type `(not ,typespec))))))
                (if type-specifier
                    (setf (car ospec) type-specifier)
                    (setq new
                          (delete restart-name new :test #'eq :key #'cdr))))
              ;; do nothing?
              nil))))
    new))

(declaim (ftype (function (list list) list)
                process-unmuffle-conditions-decl))
(defun process-unmuffle-conditions-decl (spec list)
  (process-unhandle-conditions-decl
   (cons 'unhandle-conditions
         (mapcar (lambda (x) (list x 'muffle-warning)) (cdr spec)))
   list))

(declaim (ftype (function (list list) list)
                process-package-lock-decl))
(defun process-package-lock-decl (spec old)
  (destructuring-bind (decl &rest names) spec
    (ecase decl
      (disable-package-locks
       (union old names :test #'equal))
      (enable-package-locks
       (set-difference old names :test #'equal)))))

(!defvar *queued-proclaims* nil) ; should this be !*QUEUED-PROCLAIMS* ?

(defun process-variable-declaration (name kind info-value)
  (unless (symbolp name)
    (error "Cannot proclaim a non-symbol as ~A: ~S" kind name))

  (when (and (eq kind 'always-bound) (eq info-value :always-bound)
             (not (boundp name)))
    (error "Cannot proclaim an unbound symbol as ~A: ~S" kind name))

  (multiple-value-bind (allowed test)
      (ecase kind
        (special (values '(:special :unknown) #'eq))
        (global (values '(:global :unknown) #'eq))
        (always-bound (values '(:constant) #'neq)))
    (let ((old (info :variable :kind name)))
      (unless (member old allowed :test test)
        (error "Cannot proclaim a ~A variable ~A: ~S" old kind name))))

  (with-single-package-locked-error
      (:symbol name "globally declaring ~A ~A" kind)
    (if (eq kind 'always-bound)
        (setf (info :variable :always-bound name) info-value)
        (setf (info :variable :kind name) info-value))))

(defun proclaim-type (name type where-from)
  (unless (symbolp name)
    (error "Cannot proclaim TYPE of a non-symbol: ~S" name))

  (with-single-package-locked-error
      (:symbol name "globally declaring the TYPE of ~A")
    (when (eq (info :variable :where-from name) :declared)
      (let ((old-type (info :variable :type name)))
        (when (type/= type old-type)
          (type-proclamation-mismatch-warn
           name (type-specifier old-type) (type-specifier type)))))
    (setf (info :variable :type name) type
          (info :variable :where-from name) where-from)))

(defun proclaim-ftype (name type where-from)
  (unless (legal-fun-name-p name)
    (error "Cannot declare FTYPE of illegal function name ~S" name))
  (unless (csubtypep type (specifier-type 'function))
    (error "Not a function type: ~S" (type-specifier type)))

  (with-single-package-locked-error
      (:symbol name "globally declaring the FTYPE of ~A")
    (when (eq (info :function :where-from name) :declared)
      (let ((old-type (info :function :type name)))
        (cond
          ((not (type/= type old-type))) ; not changed
          ((not (info :function :info name)) ; not a known function
           (ftype-proclamation-mismatch-warn
            name (type-specifier old-type) (type-specifier type)))
          ((csubtypep type old-type)) ; tighten known function type
          (t
           (cerror "Continue"
                   'ftype-proclamation-mismatch-error
                   :name name
                   :old (type-specifier old-type)
                   :new (type-specifier type))))))
    ;; Now references to this function shouldn't be warned about as
    ;; undefined, since even if we haven't seen a definition yet, we
    ;; know one is planned.
    ;;
    ;; Other consequences of we-know-you're-a-function-now are
    ;; appropriate too, e.g. any MACRO-FUNCTION goes away.
    (proclaim-as-fun-name name)
    (note-name-defined name :function)

    ;; The actual type declaration.
    (setf (info :function :type name) type
          (info :function :where-from name) where-from)))

(defun seal-class (class)
  (declare (type classoid class))
  (setf (classoid-state class) :sealed)
  (let ((subclasses (classoid-subclasses class)))
    (when subclasses
      (dohash ((subclass layout) subclasses :locked t)
        (declare (ignore layout))
        (setf (classoid-state subclass) :sealed)))))

(defun process-freeze-type-declaration (type-specifier)
  (let ((class (specifier-type type-specifier)))
    (when (typep class 'classoid)
      (seal-class class))))

(defun process-inline-declaration (name kind)
  ;; since implicitly it is a function, also scrubs *FREE-FUNS*
  (proclaim-as-fun-name name)
  ;; Check for problems before touching globaldb,
  ;; so that the report function can see the old value.
  (let ((newval
         (ecase kind
          (inline :inline)
          (notinline :notinline)
          (maybe-inline :maybe-inline))))
    (warn-if-inline-failed/proclaim name newval)
    (setf (info :function :inlinep name) newval)))

(defun process-declaration-declaration (name form)
  (unless (symbolp name)
    (error "In~%  ~S~%the declaration to be recognized is not a ~
            symbol:~%  ~S"
           form name))
  (with-single-package-locked-error
      (:symbol name "globally declaring ~A as a declaration proclamation"))
  (setf (info :declaration :recognized name) t))

;;; ANSI defines the declaration (FOO X Y) to be equivalent to
;;; (TYPE FOO X Y) when FOO is a type specifier. This function
;;; implements that by converting (FOO X Y) to (TYPE FOO X Y).
(defun canonized-decl-spec (decl-spec)
  (let* ((id (first decl-spec))
         (id-is-type (if (symbolp id)
                         (info :type :kind id)
                         ;; A cons might not be a valid type specifier,
                         ;; but it can't be a declaration either.
                         (or (consp id)
                             (typep id 'class))))
         (id-is-declared-decl (info :declaration :recognized id)))
    ;; FIXME: Checking ID-IS-DECLARED is probably useless these days,
    ;; since we refuse to use the same symbol as both a type name and
    ;; recognized declaration name.
    (cond ((and id-is-type id-is-declared-decl)
           (compiler-error
            "ambiguous declaration ~S:~%  ~
             ~S was declared as a DECLARATION, but is also a type name."
            decl-spec id))
          (id-is-type
           (list* 'type decl-spec))
          (t
           decl-spec))))

(defun %proclaim (raw-form location)
  (destructuring-bind (&whole form &optional kind &rest args)
      (canonized-decl-spec raw-form)
    (labels ((store-location (name)
               (if location
                   (setf (getf (info :source-location :declaration name) kind)
                         location)
                   (remf (info :source-location :declaration name) kind)))
             (map-names (names function &rest extra-args)
               (mapc (lambda (name)
                       (store-location name)
                       (apply function name extra-args))
                     names))
             (map-args (function &rest extra-args)
               (apply #'map-names args function extra-args)))
      (case kind
        ((special global always-bound)
         (map-args #'process-variable-declaration kind
                   (case kind
                     (special :special)
                     (global :global)
                     (always-bound :always-bound))))
        ((type ftype)
         (if *type-system-initialized*
             (destructuring-bind (type &rest names) args
               (let ((ctype (specifier-type type)))
                 (map-names names (ecase kind
                                    (type #'proclaim-type)
                                    (ftype #'proclaim-ftype))
                            ctype :declared)))
             (push raw-form *queued-proclaims*)))
        (freeze-type
         (map-args #'process-freeze-type-declaration))
        (optimize
         (multiple-value-bind (new-policy specified-qualities)
             (process-optimize-decl form *policy*)
           (setq *policy* new-policy)
           (advise-if-repeated-optimize-qualities
            new-policy specified-qualities)))
        (muffle-conditions
         (setq *handled-conditions*
               (process-muffle-conditions-decl form *handled-conditions*)))
        (unmuffle-conditions
         (setq *handled-conditions*
               (process-unmuffle-conditions-decl form *handled-conditions*)))
        ((disable-package-locks enable-package-locks)
         (setq *disabled-package-locks*
               (process-package-lock-decl form *disabled-package-locks*)))
        ((inline notinline maybe-inline)
         (map-args #'process-inline-declaration kind))
        (declaration
         (map-args #'process-declaration-declaration form))
        (t
         (unless (info :declaration :recognized kind)
           (compiler-warn "unrecognized declaration ~S" raw-form)))))))

(defun sb!xc:proclaim (raw-form)
  #+sb-xc (/show0 "entering PROCLAIM, RAW-FORM=..")
  #+sb-xc (/hexstr raw-form)
  (%proclaim raw-form nil)
  #+sb-xc (/show0 "returning from PROCLAIM")
  (values))

(defun advise-if-repeated-optimize-qualities (new-policy specified-qualities)
  (let (dups)
    (dolist (quality-and-value specified-qualities)
      (let* ((quality (car quality-and-value))
             (current (assq quality new-policy)))
        (when (and (not (eql (cdr quality-and-value) (cdr current)))
                   (not (assq quality dups)))
          (push `(,quality ,(cdr current)) dups))))
    (when dups
      (compiler-style-warn
       "Repeated OPTIMIZE qualit~@P. Using ~{~S~^ and ~}"
       (length dups) dups))))
