src/code/late-format.lisp

   1 ;;;; This software is part of the SBCL system. See the README file for
   2 ;;;; more information.
   3 ;;;;
   4 ;;;; This software is derived from the CMU CL system, which was
   5 ;;;; written at Carnegie Mellon University and released into the
   6 ;;;; public domain. The software is in the public domain and is
   7 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
   8 ;;;; files for more information.
   9
  10 (in-package "SB!FORMAT")
  11 \f
  12 (define-condition format-error (error reference-condition)
  13   ((complaint :reader format-error-complaint :initarg :complaint)
  14    (args :reader format-error-args :initarg :args :initform nil)
  15    (control-string :reader format-error-control-string
  16                    :initarg :control-string
  17                    :initform *default-format-error-control-string*)
  18    (offset :reader format-error-offset :initarg :offset
  19            :initform *default-format-error-offset*)
  20    (second-relative :reader format-error-second-relative
  21                     :initarg :second-relative :initform nil)
  22    (print-banner :reader format-error-print-banner :initarg :print-banner
  23                  :initform t))
  24   (:report %print-format-error)
  25   (:default-initargs :references nil))
  26
  27 (defun %print-format-error (condition stream)
  28   (format stream
  29           "~:[~*~;error in ~S: ~]~?~@[~%  ~A~%  ~V@T^~@[~V@T^~]~]"
  30           (format-error-print-banner condition)
  31           'format
  32           (format-error-complaint condition)
  33           (format-error-args condition)
  34           (format-error-control-string condition)
  35           (format-error-offset condition)
  36           (format-error-second-relative condition)))
  37 \f
  38 (def!struct format-directive
  39   (string (missing-arg) :type simple-string)
  40   (start (missing-arg) :type (and unsigned-byte fixnum))
  41   (end (missing-arg) :type (and unsigned-byte fixnum))
  42   (character (missing-arg) :type character)
  43   (colonp nil :type (member t nil))
  44   (atsignp nil :type (member t nil))
  45   (params nil :type list))
  46 (def!method print-object ((x format-directive) stream)
  47   (print-unreadable-object (x stream)
  48     (write-string (format-directive-string x)
  49                   stream
  50                   :start (format-directive-start x)
  51                   :end (format-directive-end x))))
  52 \f
  53 ;;;; TOKENIZE-CONTROL-STRING
  54
  55 (defun tokenize-control-string (string)
  56   (declare (simple-string string))
  57   (let ((index 0)
  58         (end (length string))
  59         (result nil)
  60         ;; FIXME: consider rewriting this 22.3.5.2-related processing
  61         ;; using specials to maintain state and doing the logic inside
  62         ;; the directive expanders themselves.
  63         (block)
  64         (pprint)
  65         (semicolon)
  66         (justification-semicolon))
  67     (loop
  68       (let ((next-directive (or (position #\~ string :start index) end)))
  69         (when (> next-directive index)
  70           (push (subseq string index next-directive) result))
  71         (when (= next-directive end)
  72           (return))
  73         (let* ((directive (parse-directive string next-directive))
  74                (char (format-directive-character directive)))
  75           ;; this processing is required by CLHS 22.3.5.2
  76           (cond
  77             ((char= char #\<) (push directive block))
  78             ((and block (char= char #\;) (format-directive-colonp directive))
  79              (setf semicolon directive))
  80             ((char= char #\>)
  81              (unless block
  82                (error 'format-error
  83                       :complaint "~~> without a matching ~~<"
  84                       :control-string string
  85                       :offset next-directive))
  86              (cond
  87                ((format-directive-colonp directive)
  88                 (unless pprint
  89                   (setf pprint (car block)))
  90                 (setf semicolon nil))
  91                (semicolon
  92                 (unless justification-semicolon
  93                   (setf justification-semicolon semicolon))))
  94              (pop block))
  95             ;; block cases are handled by the #\< expander/interpreter
  96             ((not block)
  97              (case char
  98                ((#\W #\I #\_) (unless pprint (setf pprint directive)))
  99                (#\T (when (and (format-directive-colonp directive)
 100                                (not pprint))
 101                       (setf pprint directive))))))
 102           (push directive result)
 103           (setf index (format-directive-end directive)))))
 104     (when (and pprint justification-semicolon)
 105       (let ((pprint-offset (1- (format-directive-end pprint)))
 106             (justification-offset
 107              (1- (format-directive-end justification-semicolon))))
 108         (error 'format-error
 109                :complaint "misuse of justification and pprint directives"
 110                :control-string string
 111                :offset (min pprint-offset justification-offset)
 112                :second-relative (- (max pprint-offset justification-offset)
 113                                    (min pprint-offset justification-offset)
 114                                    1)
 115                :references (list '(:ansi-cl :section (22 3 5 2))))))
 116     (nreverse result)))
 117
 118 (defun parse-directive (string start)
 119   (let ((posn (1+ start)) (params nil) (colonp nil) (atsignp nil)
 120         (end (length string)))
 121     (flet ((get-char ()
 122              (if (= posn end)
 123                  (error 'format-error
 124                         :complaint "string ended before directive was found"
 125                         :control-string string
 126                         :offset start)
 127                  (schar string posn)))
 128            (check-ordering ()
 129              (when (or colonp atsignp)
 130                (error 'format-error
 131                       :complaint "parameters found after #\\: or #\\@ modifier"
 132                       :control-string string
 133                       :offset posn
 134                       :references (list '(:ansi-cl :section (22 3)))))))
 135       (loop
 136         (let ((char (get-char)))
 137           (cond ((or (char<= #\0 char #\9) (char= char #\+) (char= char #\-))
 138                  (check-ordering)
 139                  (multiple-value-bind (param new-posn)
 140                      (parse-integer string :start posn :junk-allowed t)
 141                    (push (cons posn param) params)
 142                    (setf posn new-posn)
 143                    (case (get-char)
 144                      (#\,)
 145                      ((#\: #\@)
 146                       (decf posn))
 147                      (t
 148                       (return)))))
 149                 ((or (char= char #\v)
 150                      (char= char #\V))
 151                  (check-ordering)
 152                  (push (cons posn :arg) params)
 153                  (incf posn)
 154                  (case (get-char)
 155                    (#\,)
 156                    ((#\: #\@)
 157                     (decf posn))
 158                    (t
 159                     (return))))
 160                 ((char= char #\#)
 161                  (check-ordering)
 162                  (push (cons posn :remaining) params)
 163                  (incf posn)
 164                  (case (get-char)
 165                    (#\,)
 166                    ((#\: #\@)
 167                     (decf posn))
 168                    (t
 169                     (return))))
 170                 ((char= char #\')
 171                  (check-ordering)
 172                  (incf posn)
 173                  (push (cons posn (get-char)) params)
 174                  (incf posn)
 175                  (unless (char= (get-char) #\,)
 176                    (decf posn)))
 177                 ((char= char #\,)
 178                  (check-ordering)
 179                  (push (cons posn nil) params))
 180                 ((char= char #\:)
 181                  (if colonp
 182                      (error 'format-error
 183                             :complaint "too many colons supplied"
 184                             :control-string string
 185                             :offset posn
 186                             :references (list '(:ansi-cl :section (22 3))))
 187                      (setf colonp t)))
 188                 ((char= char #\@)
 189                  (if atsignp
 190                      (error 'format-error
 191                             :complaint "too many #\\@ characters supplied"
 192                             :control-string string
 193                             :offset posn
 194                             :references (list '(:ansi-cl :section (22 3))))
 195                      (setf atsignp t)))
 196                 (t
 197                  (when (and (char= (schar string (1- posn)) #\,)
 198                             (or (< posn 2)
 199                                 (char/= (schar string (- posn 2)) #\')))
 200                    (check-ordering)
 201                    (push (cons (1- posn) nil) params))
 202                  (return))))
 203         (incf posn))
 204       (let ((char (get-char)))
 205         (when (char= char #\/)
 206           (let ((closing-slash (position #\/ string :start (1+ posn))))
 207             (if closing-slash
 208                 (setf posn closing-slash)
 209                 (error 'format-error
 210                        :complaint "no matching closing slash"
 211                        :control-string string
 212                        :offset posn))))
 213         (make-format-directive
 214          :string string :start start :end (1+ posn)
 215          :character (char-upcase char)
 216          :colonp colonp :atsignp atsignp
 217          :params (nreverse params))))))
 218 \f
 219 ;;;; FORMATTER stuff
 220
 221 (sb!xc:defmacro formatter (control-string)
 222   `#',(%formatter control-string))
 223
 224 (defun %formatter (control-string)
 225   (block nil
 226     (catch 'need-orig-args
 227       (let* ((*simple-args* nil)
 228              (*only-simple-args* t)
 229              (guts (expand-control-string control-string))
 230              (args nil))
 231         (dolist (arg *simple-args*)
 232           (push `(,(car arg)
 233                   (error
 234                    'format-error
 235                    :complaint "required argument missing"
 236                    :control-string ,control-string
 237                    :offset ,(cdr arg)))
 238                 args))
 239         (return `(lambda (stream &optional ,@args &rest args)
 240                    (declare (ignorable stream))
 241                    ,guts
 242                    args))))
 243     (let ((*orig-args-available* t)
 244           (*only-simple-args* nil))
 245       `(lambda (stream &rest orig-args)
 246          (declare (ignorable stream))
 247          (let ((args orig-args))
 248            ,(expand-control-string control-string)
 249            args)))))
 250
 251 (defun expand-control-string (string)
 252   (let* ((string (etypecase string
 253                    (simple-string
 254                     string)
 255                    (string
 256                     (coerce string 'simple-string))))
 257          (*default-format-error-control-string* string)
 258          (directives (tokenize-control-string string)))
 259     `(block nil
 260        ,@(expand-directive-list directives))))
 261
 262 (defun expand-directive-list (directives)
 263   (let ((results nil)
 264         (remaining-directives directives))
 265     (loop
 266       (unless remaining-directives
 267         (return))
 268       (multiple-value-bind (form new-directives)
 269           (expand-directive (car remaining-directives)
 270                             (cdr remaining-directives))
 271         (push form results)
 272         (setf remaining-directives new-directives)))
 273     (reverse results)))
 274
 275 (defun expand-directive (directive more-directives)
 276   (etypecase directive
 277     (format-directive
 278      (let ((expander
 279             (let ((char (format-directive-character directive)))
 280               (typecase char
 281                 (base-char
 282                  (aref *format-directive-expanders* (sb!xc:char-code char))))))
 283            (*default-format-error-offset*
 284             (1- (format-directive-end directive))))
 285        (declare (type (or null function) expander))
 286        (if expander
 287            (funcall expander directive more-directives)
 288            (error 'format-error
 289                   :complaint "unknown directive ~@[(character: ~A)~]"
 290                   :args (list (char-name (format-directive-character directive)))))))
 291     (simple-string
 292      (values `(write-string ,directive stream)
 293              more-directives))))
 294
 295 (defmacro-mundanely expander-next-arg (string offset)
 296   `(if args
 297        (pop args)
 298        (error 'format-error
 299               :complaint "no more arguments"
 300               :control-string ,string
 301               :offset ,offset)))
 302
 303 (defun expand-next-arg (&optional offset)
 304   (if (or *orig-args-available* (not *only-simple-args*))
 305       `(,*expander-next-arg-macro*
 306         ,*default-format-error-control-string*
 307         ,(or offset *default-format-error-offset*))
 308       (let ((symbol (sb!xc:gensym "FORMAT-ARG")))
 309         (push (cons symbol (or offset *default-format-error-offset*))
 310               *simple-args*)
 311         symbol)))
 312
 313 (defmacro expand-bind-defaults (specs params &body body)
 314   (once-only ((params params))
 315     (if specs
 316         (collect ((expander-bindings) (runtime-bindings))
 317           (dolist (spec specs)
 318             (destructuring-bind (var default) spec
 319               (let ((symbol (sb!xc:gensym "FVAR")))
 320                 (expander-bindings
 321                  `(,var ',symbol))
 322                 (runtime-bindings
 323                  `(list ',symbol
 324                    (let* ((param-and-offset (pop ,params))
 325                           (offset (car param-and-offset))
 326                           (param (cdr param-and-offset)))
 327                      (case param
 328                        (:arg `(or ,(expand-next-arg offset) ,,default))
 329                        (:remaining
 330                         (setf *only-simple-args* nil)
 331                         '(length args))
 332                        ((nil) ,default)
 333                        (t param))))))))
 334           `(let ,(expander-bindings)
 335             `(let ,(list ,@(runtime-bindings))
 336               ,@(if ,params
 337                     (error
 338                      'format-error
 339                      :complaint "too many parameters, expected no more than ~W"
 340                      :args (list ,(length specs))
 341                      :offset (caar ,params)))
 342               ,,@body)))
 343         `(progn
 344            (when ,params
 345              (error 'format-error
 346                     :complaint "too many parameters, expected none"
 347                     :offset (caar ,params)))
 348            ,@body))))
 349 \f
 350 ;;;; format directive machinery
 351
 352 (eval-when (:compile-toplevel :execute)
 353 (#+sb-xc-host defmacro #-sb-xc-host sb!xc:defmacro def-complex-format-directive (char lambda-list &body body)
 354   (let ((defun-name (intern (format nil
 355                                     "~:@(~:C~)-FORMAT-DIRECTIVE-EXPANDER"
 356                                     char)))
 357         (directive (sb!xc:gensym "DIRECTIVE"))
 358         (directives (if lambda-list (car (last lambda-list)) (sb!xc:gensym "DIRECTIVES"))))
 359     `(progn
 360        (defun ,defun-name (,directive ,directives)
 361          ,@(if lambda-list
 362                `((let ,(mapcar (lambda (var)
 363                                  `(,var
 364                                    (,(symbolicate "FORMAT-DIRECTIVE-" var)
 365                                     ,directive)))
 366                                (butlast lambda-list))
 367                    ,@body))
 368                `((declare (ignore ,directive ,directives))
 369                  ,@body)))
 370        (%set-format-directive-expander ,char #',defun-name))))
 371
 372 (#+sb-xc-host defmacro #-sb-xc-host sb!xc:defmacro def-format-directive (char lambda-list &body body)
 373   (let ((directives (sb!xc:gensym "DIRECTIVES"))
 374         (declarations nil)
 375         (body-without-decls body))
 376     (loop
 377       (let ((form (car body-without-decls)))
 378         (unless (and (consp form) (eq (car form) 'declare))
 379           (return))
 380         (push (pop body-without-decls) declarations)))
 381     (setf declarations (reverse declarations))
 382     `(def-complex-format-directive ,char (,@lambda-list ,directives)
 383        ,@declarations
 384        (values (progn ,@body-without-decls)
 385                ,directives))))
 386 ) ; EVAL-WHEN
 387
 388 (eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
 389
 390 (defun %set-format-directive-expander (char fn)
 391   (let ((code (sb!xc:char-code (char-upcase char))))
 392     (setf (aref *format-directive-expanders* code) fn))
 393   char)
 394
 395 (defun %set-format-directive-interpreter (char fn)
 396   (let ((code (sb!xc:char-code (char-upcase char))))
 397     (setf (aref *format-directive-interpreters* code) fn))
 398   char)
 399
 400 (defun find-directive (directives kind stop-at-semi)
 401   (if directives
 402       (let ((next (car directives)))
 403         (if (format-directive-p next)
 404             (let ((char (format-directive-character next)))
 405               (if (or (char= kind char)
 406                       (and stop-at-semi (char= char #\;)))
 407                   (car directives)
 408                   (find-directive
 409                    (cdr (flet ((after (char)
 410                                  (member (find-directive (cdr directives)
 411                                                          char
 412                                                          nil)
 413                                          directives)))
 414                           (case char
 415                             (#\( (after #\)))
 416                             (#\< (after #\>))
 417                             (#\[ (after #\]))
 418                             (#\{ (after #\}))
 419                             (t directives))))
 420                    kind stop-at-semi)))
 421             (find-directive (cdr directives) kind stop-at-semi)))))
 422
 423 ) ; EVAL-WHEN
 424 \f
 425 ;;;; format directives for simple output
 426
 427 (def-format-directive #\A (colonp atsignp params)
 428   (if params
 429       (expand-bind-defaults ((mincol 0) (colinc 1) (minpad 0)
 430                              (padchar #\space))
 431                      params
 432         `(format-princ stream ,(expand-next-arg) ',colonp ',atsignp
 433                        ,mincol ,colinc ,minpad ,padchar))
 434       `(princ ,(if colonp
 435                    `(or ,(expand-next-arg) "()")
 436                    (expand-next-arg))
 437               stream)))
 438
 439 (def-format-directive #\S (colonp atsignp params)
 440   (cond (params
 441          (expand-bind-defaults ((mincol 0) (colinc 1) (minpad 0)
 442                                 (padchar #\space))
 443                         params
 444            `(format-prin1 stream ,(expand-next-arg) ,colonp ,atsignp
 445                           ,mincol ,colinc ,minpad ,padchar)))
 446         (colonp
 447          `(let ((arg ,(expand-next-arg)))
 448             (if arg
 449                 (prin1 arg stream)
 450                 (princ "()" stream))))
 451         (t
 452          `(prin1 ,(expand-next-arg) stream))))
 453
 454 (def-format-directive #\C (colonp atsignp params)
 455   (expand-bind-defaults () params
 456     (if colonp
 457         `(format-print-named-character ,(expand-next-arg) stream)
 458         (if atsignp
 459             `(prin1 ,(expand-next-arg) stream)
 460             `(write-char ,(expand-next-arg) stream)))))
 461
 462 (def-format-directive #\W (colonp atsignp params)
 463   (expand-bind-defaults () params
 464     (if (or colonp atsignp)
 465         `(let (,@(when colonp
 466                    '((*print-pretty* t)))
 467                ,@(when atsignp
 468                    '((*print-level* nil)
 469                      (*print-length* nil))))
 470            (output-object ,(expand-next-arg) stream))
 471         `(output-object ,(expand-next-arg) stream))))
 472 \f
 473 ;;;; format directives for integer output
 474
 475 (defun expand-format-integer (base colonp atsignp params)
 476   (if (or colonp atsignp params)
 477       (expand-bind-defaults
 478           ((mincol 0) (padchar #\space) (commachar #\,) (commainterval 3))
 479           params
 480         `(format-print-integer stream ,(expand-next-arg) ,colonp ,atsignp
 481                                ,base ,mincol ,padchar ,commachar
 482                                ,commainterval))
 483       `(let ((*print-base* ,base)
 484              (*print-radix* nil)
 485              (*print-escape* nil))
 486          (output-object ,(expand-next-arg) stream))))
 487
 488 (def-format-directive #\D (colonp atsignp params)
 489   (expand-format-integer 10 colonp atsignp params))
 490
 491 (def-format-directive #\B (colonp atsignp params)
 492   (expand-format-integer 2 colonp atsignp params))
 493
 494 (def-format-directive #\O (colonp atsignp params)
 495   (expand-format-integer 8 colonp atsignp params))
 496
 497 (def-format-directive #\X (colonp atsignp params)
 498   (expand-format-integer 16 colonp atsignp params))
 499
 500 (def-format-directive #\R (colonp atsignp params)
 501   (expand-bind-defaults
 502       ((base nil) (mincol 0) (padchar #\space) (commachar #\,)
 503        (commainterval 3))
 504       params
 505     (let ((n-arg (sb!xc:gensym "ARG")))
 506       `(let ((,n-arg ,(expand-next-arg)))
 507          (if ,base
 508              (format-print-integer stream ,n-arg ,colonp ,atsignp
 509                                    ,base ,mincol
 510                                    ,padchar ,commachar ,commainterval)
 511              ,(if atsignp
 512                   (if colonp
 513                       `(format-print-old-roman stream ,n-arg)
 514                       `(format-print-roman stream ,n-arg))
 515                   (if colonp
 516                       `(format-print-ordinal stream ,n-arg)
 517                       `(format-print-cardinal stream ,n-arg))))))))
 518 \f
 519 ;;;; format directive for pluralization
 520
 521 (def-format-directive #\P (colonp atsignp params end)
 522   (expand-bind-defaults () params
 523     (let ((arg (cond
 524                 ((not colonp)
 525                  (expand-next-arg))
 526                 (*orig-args-available*
 527                  `(if (eq orig-args args)
 528                       (error 'format-error
 529                              :complaint "no previous argument"
 530                              :offset ,(1- end))
 531                       (do ((arg-ptr orig-args (cdr arg-ptr)))
 532                           ((eq (cdr arg-ptr) args)
 533                            (car arg-ptr)))))
 534                 (*only-simple-args*
 535                  (unless *simple-args*
 536                    (error 'format-error
 537                           :complaint "no previous argument"))
 538                  (caar *simple-args*))
 539                 (t
 540                  (/show0 "THROWing NEED-ORIG-ARGS from tilde-P")
 541                  (throw 'need-orig-args nil)))))
 542       (if atsignp
 543           `(write-string (if (eql ,arg 1) "y" "ies") stream)
 544           `(unless (eql ,arg 1) (write-char #\s stream))))))
 545 \f
 546 ;;;; format directives for floating point output
 547
 548 (def-format-directive #\F (colonp atsignp params)
 549   (when colonp
 550     (error 'format-error
 551            :complaint
 552            "The colon modifier cannot be used with this directive."))
 553   (expand-bind-defaults ((w nil) (d nil) (k nil) (ovf nil) (pad #\space)) params
 554     `(format-fixed stream ,(expand-next-arg) ,w ,d ,k ,ovf ,pad ,atsignp)))
 555
 556 (def-format-directive #\E (colonp atsignp params)
 557   (when colonp
 558     (error 'format-error
 559            :complaint
 560            "The colon modifier cannot be used with this directive."))
 561   (expand-bind-defaults
 562       ((w nil) (d nil) (e nil) (k 1) (ovf nil) (pad #\space) (mark nil))
 563       params
 564     `(format-exponential stream ,(expand-next-arg) ,w ,d ,e ,k ,ovf ,pad ,mark
 565                          ,atsignp)))
 566
 567 (def-format-directive #\G (colonp atsignp params)
 568   (when colonp
 569     (error 'format-error
 570            :complaint
 571            "The colon modifier cannot be used with this directive."))
 572   (expand-bind-defaults
 573       ((w nil) (d nil) (e nil) (k nil) (ovf nil) (pad #\space) (mark nil))
 574       params
 575     `(format-general stream ,(expand-next-arg) ,w ,d ,e ,k ,ovf ,pad ,mark ,atsignp)))
 576
 577 (def-format-directive #\$ (colonp atsignp params)
 578   (expand-bind-defaults ((d 2) (n 1) (w 0) (pad #\space)) params
 579     `(format-dollars stream ,(expand-next-arg) ,d ,n ,w ,pad ,colonp
 580                      ,atsignp)))
 581 \f
 582 ;;;; format directives for line/page breaks etc.
 583
 584 (def-format-directive #\% (colonp atsignp params)
 585   (when (or colonp atsignp)
 586     (error 'format-error
 587            :complaint
 588            "The colon and atsign modifiers cannot be used with this directive."
 589            ))
 590   (if params
 591       (expand-bind-defaults ((count 1)) params
 592         `(dotimes (i ,count)
 593            (terpri stream)))
 594       '(terpri stream)))
 595
 596 (def-format-directive #\& (colonp atsignp params)
 597   (when (or colonp atsignp)
 598     (error 'format-error
 599            :complaint
 600            "The colon and atsign modifiers cannot be used with this directive."
 601            ))
 602   (if params
 603       (expand-bind-defaults ((count 1)) params
 604         `(progn
 605            (fresh-line stream)
 606            (dotimes (i (1- ,count))
 607              (terpri stream))))
 608       '(fresh-line stream)))
 609
 610 (def-format-directive #\| (colonp atsignp params)
 611   (when (or colonp atsignp)
 612     (error 'format-error
 613            :complaint
 614            "The colon and atsign modifiers cannot be used with this directive."
 615            ))
 616   (if params
 617       (expand-bind-defaults ((count 1)) params
 618         `(dotimes (i ,count)
 619            (write-char (code-char form-feed-char-code) stream)))
 620       '(write-char (code-char form-feed-char-code) stream)))
 621
 622 (def-format-directive #\~ (colonp atsignp params)
 623   (when (or colonp atsignp)
 624     (error 'format-error
 625            :complaint
 626            "The colon and atsign modifiers cannot be used with this directive."
 627            ))
 628   (if params
 629       (expand-bind-defaults ((count 1)) params
 630         `(dotimes (i ,count)
 631            (write-char #\~ stream)))
 632       '(write-char #\~ stream)))
 633
 634 (def-complex-format-directive #\newline (colonp atsignp params directives)
 635   (when (and colonp atsignp)
 636     (error 'format-error
 637            :complaint "both colon and atsign modifiers used simultaneously"))
 638   (values (expand-bind-defaults () params
 639             (if atsignp
 640                 '(write-char #\newline stream)
 641                 nil))
 642           (if (and (not colonp)
 643                    directives
 644                    (simple-string-p (car directives)))
 645               (cons (string-left-trim *format-whitespace-chars*
 646                                       (car directives))
 647                     (cdr directives))
 648               directives)))
 649 \f
 650 ;;;; format directives for tabs and simple pretty printing
 651
 652 (def-format-directive #\T (colonp atsignp params)
 653   (if colonp
 654       (expand-bind-defaults ((n 1) (m 1)) params
 655         `(pprint-tab ,(if atsignp :section-relative :section)
 656                      ,n ,m stream))
 657       (if atsignp
 658           (expand-bind-defaults ((colrel 1) (colinc 1)) params
 659             `(format-relative-tab stream ,colrel ,colinc))
 660           (expand-bind-defaults ((colnum 1) (colinc 1)) params
 661             `(format-absolute-tab stream ,colnum ,colinc)))))
 662
 663 (def-format-directive #\_ (colonp atsignp params)
 664   (expand-bind-defaults () params
 665     `(pprint-newline ,(if colonp
 666                           (if atsignp
 667                               :mandatory
 668                               :fill)
 669                           (if atsignp
 670                               :miser
 671                               :linear))
 672                      stream)))
 673
 674 (def-format-directive #\I (colonp atsignp params)
 675   (when atsignp
 676     (error 'format-error
 677            :complaint
 678            "cannot use the at-sign modifier with this directive"))
 679   (expand-bind-defaults ((n 0)) params
 680     `(pprint-indent ,(if colonp :current :block) ,n stream)))
 681 \f
 682 ;;;; format directive for ~*
 683
 684 (def-format-directive #\* (colonp atsignp params end)
 685   (if atsignp
 686       (if colonp
 687           (error 'format-error
 688                  :complaint
 689                  "both colon and atsign modifiers used simultaneously")
 690           (expand-bind-defaults ((posn 0)) params
 691             (unless *orig-args-available*
 692               (/show0 "THROWing NEED-ORIG-ARGS from tilde-@*")
 693               (throw 'need-orig-args nil))
 694             `(if (<= 0 ,posn (length orig-args))
 695                  (setf args (nthcdr ,posn orig-args))
 696                  (error 'format-error
 697                         :complaint "Index ~W out of bounds. Should have been ~
 698                                     between 0 and ~W."
 699                         :args (list ,posn (length orig-args))
 700                         :offset ,(1- end)))))
 701       (if colonp
 702           (expand-bind-defaults ((n 1)) params
 703             (unless *orig-args-available*
 704               (/show0 "THROWing NEED-ORIG-ARGS from tilde-:*")
 705               (throw 'need-orig-args nil))
 706             `(do ((cur-posn 0 (1+ cur-posn))
 707                   (arg-ptr orig-args (cdr arg-ptr)))
 708                  ((eq arg-ptr args)
 709                   (let ((new-posn (- cur-posn ,n)))
 710                     (if (<= 0 new-posn (length orig-args))
 711                         (setf args (nthcdr new-posn orig-args))
 712                         (error 'format-error
 713                                :complaint
 714                                "Index ~W is out of bounds; should have been ~
 715                                 between 0 and ~W."
 716                                :args (list new-posn (length orig-args))
 717                                :offset ,(1- end)))))))
 718           (if params
 719               (expand-bind-defaults ((n 1)) params
 720                 (setf *only-simple-args* nil)
 721                 `(dotimes (i ,n)
 722                    ,(expand-next-arg)))
 723               (expand-next-arg)))))
 724 \f
 725 ;;;; format directive for indirection
 726
 727 (def-format-directive #\? (colonp atsignp params string end)
 728   (when colonp
 729     (error 'format-error
 730            :complaint "cannot use the colon modifier with this directive"))
 731   (expand-bind-defaults () params
 732     `(handler-bind
 733          ((format-error
 734            (lambda (condition)
 735              (error 'format-error
 736                     :complaint
 737                     "~A~%while processing indirect format string:"
 738                     :args (list condition)
 739                     :print-banner nil
 740                     :control-string ,string
 741                     :offset ,(1- end)))))
 742        ,(if atsignp
 743             (if *orig-args-available*
 744                 `(setf args (%format stream ,(expand-next-arg) orig-args args))
 745                 (throw 'need-orig-args nil))
 746             `(%format stream ,(expand-next-arg) ,(expand-next-arg))))))
 747 \f
 748 ;;;; format directives for capitalization
 749
 750 (def-complex-format-directive #\( (colonp atsignp params directives)
 751   (let ((close (find-directive directives #\) nil)))
 752     (unless close
 753       (error 'format-error
 754              :complaint "no corresponding close parenthesis"))
 755     (let* ((posn (position close directives))
 756            (before (subseq directives 0 posn))
 757            (after (nthcdr (1+ posn) directives)))
 758       (values
 759        (expand-bind-defaults () params
 760          `(let ((stream (make-case-frob-stream stream
 761                                                ,(if colonp
 762                                                     (if atsignp
 763                                                         :upcase
 764                                                         :capitalize)
 765                                                     (if atsignp
 766                                                         :capitalize-first
 767                                                         :downcase)))))
 768             ,@(expand-directive-list before)))
 769        after))))
 770
 771 (def-complex-format-directive #\) ()
 772   (error 'format-error
 773          :complaint "no corresponding open parenthesis"))
 774 \f
 775 ;;;; format directives and support functions for conditionalization
 776
 777 (def-complex-format-directive #\[ (colonp atsignp params directives)
 778   (multiple-value-bind (sublists last-semi-with-colon-p remaining)
 779       (parse-conditional-directive directives)
 780     (values
 781      (if atsignp
 782          (if colonp
 783              (error 'format-error
 784                     :complaint
 785                     "both colon and atsign modifiers used simultaneously")
 786              (if (cdr sublists)
 787                  (error 'format-error
 788                         :complaint
 789                         "Can only specify one section")
 790                  (expand-bind-defaults () params
 791                    (expand-maybe-conditional (car sublists)))))
 792          (if colonp
 793              (if (= (length sublists) 2)
 794                  (expand-bind-defaults () params
 795                    (expand-true-false-conditional (car sublists)
 796                                                   (cadr sublists)))
 797                  (error 'format-error
 798                         :complaint
 799                         "must specify exactly two sections"))
 800              (expand-bind-defaults ((index nil)) params
 801                (setf *only-simple-args* nil)
 802                (let ((clauses nil)
 803                      (case `(or ,index ,(expand-next-arg))))
 804                  (when last-semi-with-colon-p
 805                    (push `(t ,@(expand-directive-list (pop sublists)))
 806                          clauses))
 807                  (let ((count (length sublists)))
 808                    (dolist (sublist sublists)
 809                      (push `(,(decf count)
 810                              ,@(expand-directive-list sublist))
 811                            clauses)))
 812                  `(case ,case ,@clauses)))))
 813      remaining)))
 814
 815 (defun parse-conditional-directive (directives)
 816   (let ((sublists nil)
 817         (last-semi-with-colon-p nil)
 818         (remaining directives))
 819     (loop
 820       (let ((close-or-semi (find-directive remaining #\] t)))
 821         (unless close-or-semi
 822           (error 'format-error
 823                  :complaint "no corresponding close bracket"))
 824         (let ((posn (position close-or-semi remaining)))
 825           (push (subseq remaining 0 posn) sublists)
 826           (setf remaining (nthcdr (1+ posn) remaining))
 827           (when (char= (format-directive-character close-or-semi) #\])
 828             (return))
 829           (setf last-semi-with-colon-p
 830                 (format-directive-colonp close-or-semi)))))
 831     (values sublists last-semi-with-colon-p remaining)))
 832
 833 (defun expand-maybe-conditional (sublist)
 834   (flet ((hairy ()
 835            `(let ((prev-args args)
 836                   (arg ,(expand-next-arg)))
 837               (when arg
 838                 (setf args prev-args)
 839                 ,@(expand-directive-list sublist)))))
 840     (if *only-simple-args*
 841         (multiple-value-bind (guts new-args)
 842             (let ((*simple-args* *simple-args*))
 843               (values (expand-directive-list sublist)
 844                       *simple-args*))
 845           (cond ((and new-args (eq *simple-args* (cdr new-args)))
 846                  (setf *simple-args* new-args)
 847                  `(when ,(caar new-args)
 848                     ,@guts))
 849                 (t
 850                  (setf *only-simple-args* nil)
 851                  (hairy))))
 852         (hairy))))
 853
 854 (defun expand-true-false-conditional (true false)
 855   (let ((arg (expand-next-arg)))
 856     (flet ((hairy ()
 857              `(if ,arg
 858                   (progn
 859                     ,@(expand-directive-list true))
 860                   (progn
 861                     ,@(expand-directive-list false)))))
 862       (if *only-simple-args*
 863           (multiple-value-bind (true-guts true-args true-simple)
 864               (let ((*simple-args* *simple-args*)
 865                     (*only-simple-args* t))
 866                 (values (expand-directive-list true)
 867                         *simple-args*
 868                         *only-simple-args*))
 869             (multiple-value-bind (false-guts false-args false-simple)
 870                 (let ((*simple-args* *simple-args*)
 871                       (*only-simple-args* t))
 872                   (values (expand-directive-list false)
 873                           *simple-args*
 874                           *only-simple-args*))
 875               (if (= (length true-args) (length false-args))
 876                   `(if ,arg
 877                        (progn
 878                          ,@true-guts)
 879                        ,(do ((false false-args (cdr false))
 880                              (true true-args (cdr true))
 881                              (bindings nil (cons `(,(caar false) ,(caar true))
 882                                                  bindings)))
 883                             ((eq true *simple-args*)
 884                              (setf *simple-args* true-args)
 885                              (setf *only-simple-args*
 886                                    (and true-simple false-simple))
 887                              (if bindings
 888                                  `(let ,bindings
 889                                     ,@false-guts)
 890                                  `(progn
 891                                     ,@false-guts)))))
 892                   (progn
 893                     (setf *only-simple-args* nil)
 894                     (hairy)))))
 895           (hairy)))))
 896
 897 (def-complex-format-directive #\; ()
 898   (error 'format-error
 899          :complaint
 900          "~~; directive not contained within either ~~[...~~] or ~~<...~~>"))
 901
 902 (def-complex-format-directive #\] ()
 903   (error 'format-error
 904          :complaint
 905          "no corresponding open bracket"))
 906 \f
 907 ;;;; format directive for up-and-out
 908
 909 (def-format-directive #\^ (colonp atsignp params)
 910   (when atsignp
 911     (error 'format-error
 912            :complaint "cannot use the at-sign modifier with this directive"))
 913   (when (and colonp (not *up-up-and-out-allowed*))
 914     (error 'format-error
 915            :complaint "attempt to use ~~:^ outside a ~~:{...~~} construct"))
 916   `(when ,(expand-bind-defaults ((arg1 nil) (arg2 nil) (arg3 nil)) params
 917             `(cond (,arg3 (<= ,arg1 ,arg2 ,arg3))
 918                    (,arg2 (eql ,arg1 ,arg2))
 919                    (,arg1 (eql ,arg1 0))
 920                    (t ,(if colonp
 921                            '(null outside-args)
 922                            (progn
 923                              (setf *only-simple-args* nil)
 924                              '(null args))))))
 925      ,(if colonp
 926           '(return-from outside-loop nil)
 927           '(return))))
 928 \f
 929 ;;;; format directives for iteration
 930
 931 (def-complex-format-directive #\{ (colonp atsignp params string end directives)
 932   (let ((close (find-directive directives #\} nil)))
 933     (unless close
 934       (error 'format-error
 935              :complaint "no corresponding close brace"))
 936     (let* ((closed-with-colon (format-directive-colonp close))
 937            (posn (position close directives)))
 938       (labels
 939           ((compute-insides ()
 940              (if (zerop posn)
 941                  (if *orig-args-available*
 942                      `((handler-bind
 943                            ((format-error
 944                              (lambda (condition)
 945                                (error 'format-error
 946                                       :complaint
 947                               "~A~%while processing indirect format string:"
 948                                       :args (list condition)
 949                                       :print-banner nil
 950                                       :control-string ,string
 951                                       :offset ,(1- end)))))
 952                          (setf args
 953                                (%format stream inside-string orig-args args))))
 954                      (throw 'need-orig-args nil))
 955                  (let ((*up-up-and-out-allowed* colonp))
 956                    (expand-directive-list (subseq directives 0 posn)))))
 957            (compute-loop (count)
 958              (when atsignp
 959                (setf *only-simple-args* nil))
 960              `(loop
 961                 ,@(unless closed-with-colon
 962                     '((when (null args)
 963                         (return))))
 964                 ,@(when count
 965                     `((when (and ,count (minusp (decf ,count)))
 966                         (return))))
 967                 ,@(if colonp
 968                       (let ((*expander-next-arg-macro* 'expander-next-arg)
 969                             (*only-simple-args* nil)
 970                             (*orig-args-available* t))
 971                         `((let* ((orig-args ,(expand-next-arg))
 972                                  (outside-args args)
 973                                  (args orig-args))
 974                             (declare (ignorable orig-args outside-args args))
 975                             (block nil
 976                               ,@(compute-insides)))))
 977                       (compute-insides))
 978                 ,@(when closed-with-colon
 979                     '((when (null args)
 980                         (return))))))
 981            (compute-block (count)
 982              (if colonp
 983                  `(block outside-loop
 984                     ,(compute-loop count))
 985                  (compute-loop count)))
 986            (compute-bindings (count)
 987              (if atsignp
 988                  (compute-block count)
 989                  `(let* ((orig-args ,(expand-next-arg))
 990                          (args orig-args))
 991                    (declare (ignorable orig-args args))
 992                    ,(let ((*expander-next-arg-macro* 'expander-next-arg)
 993                           (*only-simple-args* nil)
 994                           (*orig-args-available* t))
 995                       (compute-block count))))))
 996         (values (if params
 997                     (expand-bind-defaults ((count nil)) params
 998                       (if (zerop posn)
 999                           `(let ((inside-string ,(expand-next-arg)))
1000                             ,(compute-bindings count))
1001                           (compute-bindings count)))
1002                     (if (zerop posn)
1003                         `(let ((inside-string ,(expand-next-arg)))
1004                           ,(compute-bindings nil))
1005                         (compute-bindings nil)))
1006                 (nthcdr (1+ posn) directives))))))
1007
1008 (def-complex-format-directive #\} ()
1009   (error 'format-error
1010          :complaint "no corresponding open brace"))
1011 \f
1012 ;;;; format directives and support functions for justification
1013
1014 (defparameter *illegal-inside-justification*
1015   (mapcar (lambda (x) (parse-directive x 0))
1016           '("~W" "~:W" "~@W" "~:@W"
1017             "~_" "~:_" "~@_" "~:@_"
1018             "~:>" "~:@>"
1019             "~I" "~:I" "~@I" "~:@I"
1020             "~:T" "~:@T")))
1021
1022 (defun illegal-inside-justification-p (directive)
1023   (member directive *illegal-inside-justification*
1024           :test (lambda (x y)
1025                   (and (format-directive-p x)
1026                        (format-directive-p y)
1027                        (eql (format-directive-character x) (format-directive-character y))
1028                        (eql (format-directive-colonp x) (format-directive-colonp y))
1029                        (eql (format-directive-atsignp x) (format-directive-atsignp y))))))
1030
1031 (def-complex-format-directive #\< (colonp atsignp params string end directives)
1032   (multiple-value-bind (segments first-semi close remaining)
1033       (parse-format-justification directives)
1034     (values
1035      (if (format-directive-colonp close)
1036          (multiple-value-bind (prefix per-line-p insides suffix)
1037              (parse-format-logical-block segments colonp first-semi
1038                                          close params string end)
1039            (expand-format-logical-block prefix per-line-p insides
1040                                         suffix atsignp))
1041          (let ((count (reduce #'+ (mapcar (lambda (x) (count-if #'illegal-inside-justification-p x)) segments))))
1042            (when (> count 0)
1043              ;; ANSI specifies that "an error is signalled" in this
1044              ;; situation.
1045              (error 'format-error
1046                     :complaint "~D illegal directive~:P found inside justification block"
1047                     :args (list count)
1048                     :references (list '(:ansi-cl :section (22 3 5 2)))))
1049            (expand-format-justification segments colonp atsignp
1050                                         first-semi params)))
1051      remaining)))
1052
1053 (def-complex-format-directive #\> ()
1054   (error 'format-error
1055          :complaint "no corresponding open bracket"))
1056
1057 (defun parse-format-logical-block
1058        (segments colonp first-semi close params string end)
1059   (when params
1060     (error 'format-error
1061            :complaint "No parameters can be supplied with ~~<...~~:>."
1062            :offset (caar params)))
1063   (multiple-value-bind (prefix insides suffix)
1064       (multiple-value-bind (prefix-default suffix-default)
1065           (if colonp (values "(" ")") (values "" ""))
1066         (flet ((extract-string (list prefix-p)
1067                  (let ((directive (find-if #'format-directive-p list)))
1068                    (if directive
1069                        (error 'format-error
1070                               :complaint
1071                               "cannot include format directives inside the ~
1072                                ~:[suffix~;prefix~] segment of ~~<...~~:>"
1073                               :args (list prefix-p)
1074                               :offset (1- (format-directive-end directive))
1075                               :references
1076                               (list '(:ansi-cl :section (22 3 5 2))))
1077                        (apply #'concatenate 'string list)))))
1078         (case (length segments)
1079           (0 (values prefix-default nil suffix-default))
1080           (1 (values prefix-default (car segments) suffix-default))
1081           (2 (values (extract-string (car segments) t)
1082                      (cadr segments) suffix-default))
1083           (3 (values (extract-string (car segments) t)
1084                      (cadr segments)
1085                      (extract-string (caddr segments) nil)))
1086           (t
1087            (error 'format-error
1088                   :complaint "too many segments for ~~<...~~:>")))))
1089     (when (format-directive-atsignp close)
1090       (setf insides
1091             (add-fill-style-newlines insides
1092                                      string
1093                                      (if first-semi
1094                                          (format-directive-end first-semi)
1095                                          end))))
1096     (values prefix
1097             (and first-semi (format-directive-atsignp first-semi))
1098             insides
1099             suffix)))
1100
1101 (defun add-fill-style-newlines (list string offset &optional last-directive)
1102   (cond
1103     (list
1104      (let ((directive (car list)))
1105        (cond
1106          ((simple-string-p directive)
1107           (let* ((non-space (position #\Space directive :test #'char/=))
1108                  (newlinep (and last-directive
1109                                 (char=
1110                                  (format-directive-character last-directive)
1111                                  #\Newline))))
1112             (cond
1113               ((and newlinep non-space)
1114                (nconc
1115                 (list (subseq directive 0 non-space))
1116                 (add-fill-style-newlines-aux
1117                  (subseq directive non-space) string (+ offset non-space))
1118                 (add-fill-style-newlines
1119                  (cdr list) string (+ offset (length directive)))))
1120               (newlinep
1121                (cons directive
1122                      (add-fill-style-newlines
1123                       (cdr list) string (+ offset (length directive)))))
1124               (t
1125                (nconc (add-fill-style-newlines-aux directive string offset)
1126                       (add-fill-style-newlines
1127                        (cdr list) string (+ offset (length directive))))))))
1128          (t
1129           (cons directive
1130                 (add-fill-style-newlines
1131                  (cdr list) string
1132                  (format-directive-end directive) directive))))))
1133     (t nil)))
1134
1135 (defun add-fill-style-newlines-aux (literal string offset)
1136   (let ((end (length literal))
1137         (posn 0))
1138     (collect ((results))
1139       (loop
1140         (let ((blank (position #\space literal :start posn)))
1141           (when (null blank)
1142             (results (subseq literal posn))
1143             (return))
1144           (let ((non-blank (or (position #\space literal :start blank
1145                                          :test #'char/=)
1146                                end)))
1147             (results (subseq literal posn non-blank))
1148             (results (make-format-directive
1149                       :string string :character #\_
1150                       :start (+ offset non-blank) :end (+ offset non-blank)
1151                       :colonp t :atsignp nil :params nil))
1152             (setf posn non-blank))
1153           (when (= posn end)
1154             (return))))
1155       (results))))
1156
1157 (defun parse-format-justification (directives)
1158   (let ((first-semi nil)
1159         (close nil)
1160         (remaining directives))
1161     (collect ((segments))
1162       (loop
1163         (let ((close-or-semi (find-directive remaining #\> t)))
1164           (unless close-or-semi
1165             (error 'format-error
1166                    :complaint "no corresponding close bracket"))
1167           (let ((posn (position close-or-semi remaining)))
1168             (segments (subseq remaining 0 posn))
1169             (setf remaining (nthcdr (1+ posn) remaining)))
1170           (when (char= (format-directive-character close-or-semi)
1171                        #\>)
1172             (setf close close-or-semi)
1173             (return))
1174           (unless first-semi
1175             (setf first-semi close-or-semi))))
1176       (values (segments) first-semi close remaining))))
1177
1178 (sb!xc:defmacro expander-pprint-next-arg (string offset)
1179   `(progn
1180      (when (null args)
1181        (error 'format-error
1182               :complaint "no more arguments"
1183               :control-string ,string
1184               :offset ,offset))
1185      (pprint-pop)
1186      (pop args)))
1187
1188 (defun expand-format-logical-block (prefix per-line-p insides suffix atsignp)
1189   `(let ((arg ,(if atsignp 'args (expand-next-arg))))
1190      ,@(when atsignp
1191          (setf *only-simple-args* nil)
1192          '((setf args nil)))
1193      (pprint-logical-block
1194          (stream arg
1195                  ,(if per-line-p :per-line-prefix :prefix) ,prefix
1196                  :suffix ,suffix)
1197        (let ((args arg)
1198              ,@(unless atsignp
1199                  `((orig-args arg))))
1200          (declare (ignorable args ,@(unless atsignp '(orig-args))))
1201          (block nil
1202            ,@(let ((*expander-next-arg-macro* 'expander-pprint-next-arg)
1203                    (*only-simple-args* nil)
1204                    (*orig-args-available*
1205                     (if atsignp *orig-args-available* t)))
1206                (expand-directive-list insides)))))))
1207
1208 (defun expand-format-justification (segments colonp atsignp first-semi params)
1209   (let ((newline-segment-p
1210          (and first-semi
1211               (format-directive-colonp first-semi))))
1212     (expand-bind-defaults
1213         ((mincol 0) (colinc 1) (minpad 0) (padchar #\space))
1214         params
1215       `(let ((segments nil)
1216              ,@(when newline-segment-p
1217                  '((newline-segment nil)
1218                    (extra-space 0)
1219                    (line-len 72))))
1220          (block nil
1221            ,@(when newline-segment-p
1222                `((setf newline-segment
1223                        (with-output-to-string (stream)
1224                          ,@(expand-directive-list (pop segments))))
1225                  ,(expand-bind-defaults
1226                       ((extra 0)
1227                        (line-len '(or (sb!impl::line-length stream) 72)))
1228                       (format-directive-params first-semi)
1229                     `(setf extra-space ,extra line-len ,line-len))))
1230            ,@(mapcar (lambda (segment)
1231                        `(push (with-output-to-string (stream)
1232                                 ,@(expand-directive-list segment))
1233                               segments))
1234                      segments))
1235          (format-justification stream
1236                                ,@(if newline-segment-p
1237                                      '(newline-segment extra-space line-len)
1238                                      '(nil 0 0))
1239                                segments ,colonp ,atsignp
1240                                ,mincol ,colinc ,minpad ,padchar)))))
1241 \f
1242 ;;;; format directive and support function for user-defined method
1243
1244 (def-format-directive #\/ (string start end colonp atsignp params)
1245   (let ((symbol (extract-user-fun-name string start end)))
1246     (collect ((param-names) (bindings))
1247       (dolist (param-and-offset params)
1248         (let ((param (cdr param-and-offset)))
1249           (let ((param-name (sb!xc:gensym "PARAM")))
1250             (param-names param-name)
1251             (bindings `(,param-name
1252                         ,(case param
1253                            (:arg (expand-next-arg))
1254                            (:remaining '(length args))
1255                            (t param)))))))
1256       `(let ,(bindings)
1257          (,symbol stream ,(expand-next-arg) ,colonp ,atsignp
1258                   ,@(param-names))))))
1259
1260 (defun extract-user-fun-name (string start end)
1261   (let ((slash (position #\/ string :start start :end (1- end)
1262                          :from-end t)))
1263     (unless slash
1264       (error 'format-error
1265              :complaint "malformed ~~/ directive"))
1266     (let* ((name (string-upcase (let ((foo string))
1267                                   ;; Hack alert: This is to keep the compiler
1268                                   ;; quiet about deleting code inside the
1269                                   ;; subseq expansion.
1270                                   (subseq foo (1+ slash) (1- end)))))
1271            (first-colon (position #\: name))
1272            (second-colon (if first-colon (position #\: name :start (1+ first-colon))))
1273            (package-name (if first-colon
1274                              (subseq name 0 first-colon)
1275                              "COMMON-LISP-USER"))
1276            (package (find-package package-name)))
1277       (unless package
1278         ;; FIXME: should be PACKAGE-ERROR? Could we just use
1279         ;; FIND-UNDELETED-PACKAGE-OR-LOSE?
1280         (error 'format-error
1281                :complaint "no package named ~S"
1282                :args (list package-name)))
1283       (intern (cond
1284                 ((and second-colon (= second-colon (1+ first-colon)))
1285                  (subseq name (1+ second-colon)))
1286                 (first-colon
1287                  (subseq name (1+ first-colon)))
1288                 (t name))
1289               package))))
1290
1291 ;;; compile-time checking for argument mismatch.  This code is
1292 ;;; inspired by that of Gerd Moellmann, and comes decorated with
1293 ;;; FIXMEs:
1294 (defun %compiler-walk-format-string (string args)
1295   (declare (type simple-string string))
1296   (let ((*default-format-error-control-string* string))
1297     (macrolet ((incf-both (&optional (increment 1))
1298                  `(progn
1299                    (incf min ,increment)
1300                    (incf max ,increment)))
1301                (walk-complex-directive (function)
1302                  `(multiple-value-bind (min-inc max-inc remaining)
1303                    (,function directive directives args)
1304                    (incf min min-inc)
1305                    (incf max max-inc)
1306                    (setq directives remaining))))
1307       ;; FIXME: these functions take a list of arguments as well as
1308       ;; the directive stream.  This is to enable possibly some
1309       ;; limited type checking on FORMAT's arguments, as well as
1310       ;; simple argument count mismatch checking: when the minimum and
1311       ;; maximum argument counts are the same at a given point, we
1312       ;; know which argument is going to be used for a given
1313       ;; directive, and some (annotated below) require arguments of
1314       ;; particular types.
1315       (labels
1316           ((walk-justification (justification directives args)
1317              (declare (ignore args))
1318              (let ((*default-format-error-offset*
1319                     (1- (format-directive-end justification))))
1320                (multiple-value-bind (segments first-semi close remaining)
1321                    (parse-format-justification directives)
1322                  (declare (ignore segments first-semi))
1323                  (cond
1324                    ((not (format-directive-colonp close))
1325                     (values 0 0 directives))
1326                    ((format-directive-atsignp justification)
1327                     (values 0 sb!xc:call-arguments-limit directives))
1328                    ;; FIXME: here we could assert that the
1329                    ;; corresponding argument was a list.
1330                    (t (values 1 1 remaining))))))
1331            (walk-conditional (conditional directives args)
1332              (let ((*default-format-error-offset*
1333                     (1- (format-directive-end conditional))))
1334                (multiple-value-bind (sublists last-semi-with-colon-p remaining)
1335                    (parse-conditional-directive directives)
1336                  (declare (ignore last-semi-with-colon-p))
1337                  (let ((sub-max
1338                         (loop for s in sublists
1339                               maximize (nth-value
1340                                         1 (walk-directive-list s args)))))
1341                    (cond
1342                      ((format-directive-atsignp conditional)
1343                       (values 1 (max 1 sub-max) remaining))
1344                      ((loop for p in (format-directive-params conditional)
1345                             thereis (or (integerp (cdr p))
1346                                         (memq (cdr p) '(:remaining :arg))))
1347                       (values 0 sub-max remaining))
1348                      ;; FIXME: if not COLONP, then the next argument
1349                      ;; must be a number.
1350                      (t (values 1 (1+ sub-max) remaining)))))))
1351            (walk-iteration (iteration directives args)
1352              (declare (ignore args))
1353              (let ((*default-format-error-offset*
1354                     (1- (format-directive-end iteration))))
1355                (let* ((close (find-directive directives #\} nil))
1356                       (posn (or (position close directives)
1357                                 (error 'format-error
1358                                        :complaint "no corresponding close brace")))
1359                       (remaining (nthcdr (1+ posn) directives)))
1360                  ;; FIXME: if POSN is zero, the next argument must be
1361                  ;; a format control (either a function or a string).
1362                  (if (format-directive-atsignp iteration)
1363                      (values (if (zerop posn) 1 0)
1364                              sb!xc:call-arguments-limit
1365                              remaining)
1366                      ;; FIXME: the argument corresponding to this
1367                      ;; directive must be a list.
1368                      (let ((nreq (if (zerop posn) 2 1)))
1369                        (values nreq nreq remaining))))))
1370            (walk-directive-list (directives args)
1371              (let ((min 0) (max 0))
1372                (loop
1373                 (let ((directive (pop directives)))
1374                   (when (null directive)
1375                     (return (values min (min max sb!xc:call-arguments-limit))))
1376                   (when (format-directive-p directive)
1377                     (incf-both (count :arg (format-directive-params directive)
1378                                       :key #'cdr))
1379                     (let ((c (format-directive-character directive)))
1380                       (cond
1381                         ((find c "ABCDEFGORSWX$/")
1382                          (incf-both))
1383                         ((char= c #\P)
1384                          (unless (format-directive-colonp directive)
1385                            (incf-both)))
1386                         ((or (find c "IT%&|_();>~") (char= c #\Newline)))
1387                         ;; FIXME: check correspondence of ~( and ~)
1388                         ((char= c #\<)
1389                          (walk-complex-directive walk-justification))
1390                         ((char= c #\[)
1391                          (walk-complex-directive walk-conditional))
1392                         ((char= c #\{)
1393                          (walk-complex-directive walk-iteration))
1394                         ((char= c #\?)
1395                          ;; FIXME: the argument corresponding to this
1396                          ;; directive must be a format control.
1397                          (cond
1398                            ((format-directive-atsignp directive)
1399                             (incf min)
1400                             (setq max sb!xc:call-arguments-limit))
1401                            (t (incf-both 2))))
1402                         (t (throw 'give-up-format-string-walk nil))))))))))
1403         (catch 'give-up-format-string-walk
1404           (let ((directives (tokenize-control-string string)))
1405             (walk-directive-list directives args)))))))