src/compiler/ir1tran-lambda.lisp

   1 ;;;; This file contains code which does the translation of lambda
   2 ;;;; forms from Lisp code to the first intermediate representation
   3 ;;;; (IR1).
   4
   5 ;;;; This software is part of the SBCL system. See the README file for
   6 ;;;; more information.
   7 ;;;;
   8 ;;;; This software is derived from the CMU CL system, which was
   9 ;;;; written at Carnegie Mellon University and released into the
  10 ;;;; public domain. The software is in the public domain and is
  11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  12 ;;;; files for more information.
  13
  14 (in-package "SB!C")
  15
  16 ;;;; LAMBDA hackery
  17
  18 ;;;; Note: Take a look at the compiler-overview.tex section on "Hairy
  19 ;;;; function representation" before you seriously mess with this
  20 ;;;; stuff.
  21
  22 ;;; Verify that the NAME is a legal name for a variable and return a
  23 ;;; VAR structure for it, filling in info if it is globally special.
  24 ;;; If it is losing, we punt with a COMPILER-ERROR. NAMES-SO-FAR is a
  25 ;;; list of names which have previously been bound. If the NAME is in
  26 ;;; this list, then we error out.
  27 (declaim (ftype (sfunction (t list) lambda-var) varify-lambda-arg))
  28 (defun varify-lambda-arg (name names-so-far)
  29   (declare (inline member))
  30   (unless (symbolp name)
  31     (compiler-error "The lambda variable ~S is not a symbol." name))
  32   (when (member name names-so-far :test #'eq)
  33     (compiler-error "The variable ~S occurs more than once in the lambda list."
  34                     name))
  35   (let ((kind (info :variable :kind name)))
  36     (when (or (keywordp name) (eq kind :constant))
  37       (compiler-error "The name of the lambda variable ~S is already in use to name a constant."
  38                       name))
  39     (cond ((eq kind :special)
  40            (let ((specvar (find-free-var name)))
  41              (make-lambda-var :%source-name name
  42                               :type (leaf-type specvar)
  43                               :where-from (leaf-where-from specvar)
  44                               :specvar specvar)))
  45           (t
  46            (make-lambda-var :%source-name name)))))
  47
  48 ;;; Make the default keyword for a &KEY arg, checking that the keyword
  49 ;;; isn't already used by one of the VARS.
  50 (declaim (ftype (sfunction (symbol list t) symbol) make-keyword-for-arg))
  51 (defun make-keyword-for-arg (symbol vars keywordify)
  52   (let ((key (if (and keywordify (not (keywordp symbol)))
  53                  (keywordicate symbol)
  54                  symbol)))
  55     (dolist (var vars)
  56       (let ((info (lambda-var-arg-info var)))
  57         (when (and info
  58                    (eq (arg-info-kind info) :keyword)
  59                    (eq (arg-info-key info) key))
  60           (compiler-error
  61            "The keyword ~S appears more than once in the lambda list."
  62            key))))
  63     key))
  64
  65 ;;; Parse a lambda list into a list of VAR structures, stripping off
  66 ;;; any &AUX bindings. Each arg name is checked for legality, and
  67 ;;; duplicate names are checked for. If an arg is globally special,
  68 ;;; the var is marked as :SPECIAL instead of :LEXICAL. &KEY,
  69 ;;; &OPTIONAL and &REST args are annotated with an ARG-INFO structure
  70 ;;; which contains the extra information. If we hit something losing,
  71 ;;; we bug out with COMPILER-ERROR. These values are returned:
  72 ;;;  1. a list of the var structures for each top level argument;
  73 ;;;  2. a flag indicating whether &KEY was specified;
  74 ;;;  3. a flag indicating whether other &KEY args are allowed;
  75 ;;;  4. a list of the &AUX variables; and
  76 ;;;  5. a list of the &AUX values.
  77 (declaim (ftype (sfunction (list) (values list boolean boolean list list))
  78                 make-lambda-vars))
  79 (defun make-lambda-vars (list)
  80   (multiple-value-bind (required optional restp rest keyp keys allowp auxp aux
  81                         morep more-context more-count)
  82       (parse-lambda-list list)
  83     (declare (ignore auxp)) ; since we just iterate over AUX regardless
  84     (collect ((vars)
  85               (names-so-far)
  86               (aux-vars)
  87               (aux-vals))
  88       (flet (;; PARSE-DEFAULT deals with defaults and supplied-p args
  89              ;; for optionals and keywords args.
  90              (parse-default (spec info)
  91                (when (consp (cdr spec))
  92                  (setf (arg-info-default info) (second spec))
  93                  (when (consp (cddr spec))
  94                    (let* ((supplied-p (third spec))
  95                           (supplied-var (varify-lambda-arg supplied-p
  96                                                            (names-so-far))))
  97                      (setf (arg-info-supplied-p info) supplied-var)
  98                      (names-so-far supplied-p)
  99                      (when (> (length (the list spec)) 3)
 100                        (compiler-error
 101                         "The list ~S is too long to be an arg specifier."
 102                         spec)))))))
 103
 104         (dolist (name required)
 105           (let ((var (varify-lambda-arg name (names-so-far))))
 106             (vars var)
 107             (names-so-far name)))
 108
 109         (dolist (spec optional)
 110           (if (atom spec)
 111               (let ((var (varify-lambda-arg spec (names-so-far))))
 112                 (setf (lambda-var-arg-info var)
 113                       (make-arg-info :kind :optional))
 114                 (vars var)
 115                 (names-so-far spec))
 116               (let* ((name (first spec))
 117                      (var (varify-lambda-arg name (names-so-far)))
 118                      (info (make-arg-info :kind :optional)))
 119                 (setf (lambda-var-arg-info var) info)
 120                 (vars var)
 121                 (names-so-far name)
 122                 (parse-default spec info))))
 123
 124         (when restp
 125           (let ((var (varify-lambda-arg rest (names-so-far))))
 126             (setf (lambda-var-arg-info var) (make-arg-info :kind :rest))
 127             (vars var)
 128             (names-so-far rest)))
 129
 130         (when morep
 131           (let ((var (varify-lambda-arg more-context (names-so-far))))
 132             (setf (lambda-var-arg-info var)
 133                   (make-arg-info :kind :more-context))
 134             (vars var)
 135             (names-so-far more-context))
 136           (let ((var (varify-lambda-arg more-count (names-so-far))))
 137             (setf (lambda-var-arg-info var)
 138                   (make-arg-info :kind :more-count))
 139             (vars var)
 140             (names-so-far more-count)))
 141
 142         (dolist (spec keys)
 143           (cond
 144            ((atom spec)
 145             (let ((var (varify-lambda-arg spec (names-so-far))))
 146               (setf (lambda-var-arg-info var)
 147                     (make-arg-info :kind :keyword
 148                                    :key (make-keyword-for-arg spec
 149                                                               (vars)
 150                                                               t)))
 151               (vars var)
 152               (names-so-far spec)))
 153            ((atom (first spec))
 154             (let* ((name (first spec))
 155                    (var (varify-lambda-arg name (names-so-far)))
 156                    (info (make-arg-info
 157                           :kind :keyword
 158                           :key (make-keyword-for-arg name (vars) t))))
 159               (setf (lambda-var-arg-info var) info)
 160               (vars var)
 161               (names-so-far name)
 162               (parse-default spec info)))
 163            (t
 164             (let ((head (first spec)))
 165               (unless (proper-list-of-length-p head 2)
 166                 (error "malformed &KEY argument specifier: ~S" spec))
 167               (let* ((name (second head))
 168                      (var (varify-lambda-arg name (names-so-far)))
 169                      (info (make-arg-info
 170                             :kind :keyword
 171                             :key (make-keyword-for-arg (first head)
 172                                                        (vars)
 173                                                        nil))))
 174                 (setf (lambda-var-arg-info var) info)
 175                 (vars var)
 176                 (names-so-far name)
 177                 (parse-default spec info))))))
 178
 179         (dolist (spec aux)
 180           (cond ((atom spec)
 181                  (let ((var (varify-lambda-arg spec nil)))
 182                    (aux-vars var)
 183                    (aux-vals nil)
 184                    (names-so-far spec)))
 185                 (t
 186                  (unless (proper-list-of-length-p spec 1 2)
 187                    (compiler-error "malformed &AUX binding specifier: ~S"
 188                                    spec))
 189                  (let* ((name (first spec))
 190                         (var (varify-lambda-arg name nil)))
 191                    (aux-vars var)
 192                    (aux-vals (second spec))
 193                    (names-so-far name)))))
 194
 195         (values (vars) keyp allowp (aux-vars) (aux-vals))))))
 196
 197 ;;; This is similar to IR1-CONVERT-PROGN-BODY except that we
 198 ;;; sequentially bind each AUX-VAR to the corresponding AUX-VAL before
 199 ;;; converting the body. If there are no bindings, just convert the
 200 ;;; body, otherwise do one binding and recurse on the rest.
 201 ;;;
 202 ;;; FIXME: This could and probably should be converted to use
 203 ;;; SOURCE-NAME and DEBUG-NAME. But I (WHN) don't use &AUX bindings,
 204 ;;; so I'm not motivated. Patches will be accepted...
 205 (defun ir1-convert-aux-bindings (start next result body aux-vars aux-vals
 206                                  post-binding-lexenv)
 207   (declare (type ctran start next) (type (or lvar null) result)
 208            (list body aux-vars aux-vals))
 209   (if (null aux-vars)
 210       (let ((*lexenv* (make-lexenv :vars (copy-list post-binding-lexenv))))
 211         (ir1-convert-progn-body start next result body))
 212       (let ((ctran (make-ctran))
 213             (fun-lvar (make-lvar))
 214             (fun (ir1-convert-lambda-body body
 215                                           (list (first aux-vars))
 216                                           :aux-vars (rest aux-vars)
 217                                           :aux-vals (rest aux-vals)
 218                                           :post-binding-lexenv post-binding-lexenv
 219                                           :debug-name (debug-name
 220                                                        '&aux-bindings
 221                                                        aux-vars))))
 222         (reference-leaf start ctran fun-lvar fun)
 223         (ir1-convert-combination-args fun-lvar ctran next result
 224                                       (list (first aux-vals)))))
 225   (values))
 226
 227 ;;; This is similar to IR1-CONVERT-PROGN-BODY except that code to bind
 228 ;;; the SPECVAR for each SVAR to the value of the variable is wrapped
 229 ;;; around the body. If there are no special bindings, we just convert
 230 ;;; the body, otherwise we do one special binding and recurse on the
 231 ;;; rest.
 232 ;;;
 233 ;;; We make a cleanup and introduce it into the lexical
 234 ;;; environment. If there are multiple special bindings, the cleanup
 235 ;;; for the blocks will end up being the innermost one. We force NEXT
 236 ;;; to start a block outside of this cleanup, causing cleanup code to
 237 ;;; be emitted when the scope is exited.
 238 (defun ir1-convert-special-bindings
 239     (start next result body aux-vars aux-vals svars post-binding-lexenv)
 240   (declare (type ctran start next) (type (or lvar null) result)
 241            (list body aux-vars aux-vals svars))
 242   (cond
 243    ((null svars)
 244     (ir1-convert-aux-bindings start next result body aux-vars aux-vals
 245                               post-binding-lexenv))
 246    (t
 247     (ctran-starts-block next)
 248     (let ((cleanup (make-cleanup :kind :special-bind))
 249           (var (first svars))
 250           (bind-ctran (make-ctran))
 251           (cleanup-ctran (make-ctran)))
 252       (ir1-convert start bind-ctran nil
 253                    `(%special-bind ',(lambda-var-specvar var) ,var))
 254       (setf (cleanup-mess-up cleanup) (ctran-use bind-ctran))
 255       (let ((*lexenv* (make-lexenv :cleanup cleanup)))
 256         (ir1-convert bind-ctran cleanup-ctran nil '(%cleanup-point))
 257         (ir1-convert-special-bindings cleanup-ctran next result
 258                                       body aux-vars aux-vals
 259                                       (rest svars)
 260                                       post-binding-lexenv)))))
 261   (values))
 262
 263 ;;; Create a lambda node out of some code, returning the result. The
 264 ;;; bindings are specified by the list of VAR structures VARS. We deal
 265 ;;; with adding the names to the LEXENV-VARS for the conversion. The
 266 ;;; result is added to the NEW-FUNCTIONALS in the *CURRENT-COMPONENT*
 267 ;;; and linked to the component head and tail.
 268 ;;;
 269 ;;; We detect special bindings here, replacing the original VAR in the
 270 ;;; lambda list with a temporary variable. We then pass a list of the
 271 ;;; special vars to IR1-CONVERT-SPECIAL-BINDINGS, which actually emits
 272 ;;; the special binding code.
 273 ;;;
 274 ;;; We ignore any ARG-INFO in the VARS, trusting that someone else is
 275 ;;; dealing with &NONSENSE, except for &REST vars with DYNAMIC-EXTENT.
 276 ;;;
 277 ;;; AUX-VARS is a list of VAR structures for variables that are to be
 278 ;;; sequentially bound. Each AUX-VAL is a form that is to be evaluated
 279 ;;; to get the initial value for the corresponding AUX-VAR.
 280 (defun ir1-convert-lambda-body (body
 281                                 vars
 282                                 &key
 283                                 aux-vars
 284                                 aux-vals
 285                                 (source-name '.anonymous.)
 286                                 debug-name
 287                                 (note-lexical-bindings t)
 288                                 post-binding-lexenv
 289                                 system-lambda)
 290   (declare (list body vars aux-vars aux-vals))
 291
 292   ;; We're about to try to put new blocks into *CURRENT-COMPONENT*.
 293   (aver-live-component *current-component*)
 294
 295   (let* ((bind (make-bind))
 296          (lambda (make-lambda :vars vars
 297                   :bind bind
 298                   :%source-name source-name
 299                   :%debug-name debug-name
 300                   :system-lambda-p system-lambda))
 301          (result-ctran (make-ctran))
 302          (result-lvar (make-lvar)))
 303
 304     (awhen (lexenv-lambda *lexenv*)
 305       (push lambda (lambda-children it))
 306       (setf (lambda-parent lambda) it))
 307
 308     ;; just to check: This function should fail internal assertions if
 309     ;; we didn't set up a valid debug name above.
 310     ;;
 311     ;; (In SBCL we try to make everything have a debug name, since we
 312     ;; lack the omniscient perspective the original implementors used
 313     ;; to decide which things didn't need one.)
 314     (functional-debug-name lambda)
 315
 316     (setf (lambda-home lambda) lambda)
 317     (collect ((svars)
 318               (new-venv nil cons))
 319
 320       (dolist (var vars)
 321         ;; As far as I can see, LAMBDA-VAR-HOME should never have
 322         ;; been set before. Let's make sure. -- WHN 2001-09-29
 323         (aver (not (lambda-var-home var)))
 324         (setf (lambda-var-home var) lambda)
 325         (let ((specvar (lambda-var-specvar var)))
 326           (cond (specvar
 327                  (svars var)
 328                  (new-venv (cons (leaf-source-name specvar) specvar)))
 329                 (t
 330                  (when note-lexical-bindings
 331                    (note-lexical-binding (leaf-source-name var)))
 332                  (new-venv (cons (leaf-source-name var) var))))))
 333
 334       (let ((*lexenv* (make-lexenv :vars (new-venv)
 335                                    :lambda lambda
 336                                    :cleanup nil)))
 337         (setf (bind-lambda bind) lambda)
 338         (setf (node-lexenv bind) *lexenv*)
 339
 340         (let ((block (ctran-starts-block result-ctran)))
 341           (let ((return (make-return :result result-lvar :lambda lambda))
 342                 (tail-set (make-tail-set :funs (list lambda))))
 343             (setf (lambda-tail-set lambda) tail-set)
 344             (setf (lambda-return lambda) return)
 345             (setf (lvar-dest result-lvar) return)
 346             (link-node-to-previous-ctran return result-ctran)
 347             (setf (block-last block) return))
 348           (link-blocks block (component-tail *current-component*)))
 349
 350         (with-component-last-block (*current-component*
 351                                     (ctran-block result-ctran))
 352           (let ((prebind-ctran (make-ctran))
 353                 (postbind-ctran (make-ctran)))
 354             (ctran-starts-block prebind-ctran)
 355             (link-node-to-previous-ctran bind prebind-ctran)
 356             (use-ctran bind postbind-ctran)
 357             (ir1-convert-special-bindings postbind-ctran result-ctran
 358                                           result-lvar body
 359                                           aux-vars aux-vals (svars)
 360                                           post-binding-lexenv)))))
 361
 362     (link-blocks (component-head *current-component*) (node-block bind))
 363     (push lambda (component-new-functionals *current-component*))
 364
 365     lambda))
 366
 367 ;;; Entry point CLAMBDAs have a special kind
 368 (defun register-entry-point (entry dispatcher)
 369   (declare (type clambda entry)
 370            (type optional-dispatch dispatcher))
 371   (setf (functional-kind entry) :optional)
 372   (setf (leaf-ever-used entry) t)
 373   (setf (lambda-optional-dispatch entry) dispatcher)
 374   entry)
 375
 376 ;;; Create the actual entry-point function for an optional entry
 377 ;;; point. The lambda binds copies of each of the VARS, then calls FUN
 378 ;;; with the argument VALS and the DEFAULTS. Presumably the VALS refer
 379 ;;; to the VARS by name. The VALS are passed in the reverse order.
 380 ;;;
 381 ;;; If any of the copies of the vars are referenced more than once,
 382 ;;; then we mark the corresponding var as EVER-USED to inhibit
 383 ;;; "defined but not read" warnings for arguments that are only used
 384 ;;; by default forms.
 385 (defun convert-optional-entry (fun vars vals defaults name)
 386   (declare (type clambda fun) (list vars vals defaults))
 387   (let* ((fvars (reverse vars))
 388          (arg-vars (mapcar (lambda (var)
 389                              (make-lambda-var
 390                               :%source-name (leaf-source-name var)
 391                               :type (leaf-type var)
 392                               :where-from (leaf-where-from var)
 393                               :specvar (lambda-var-specvar var)))
 394                            fvars))
 395          (fun (collect ((default-bindings)
 396                         (default-vals))
 397                 (dolist (default defaults)
 398                   (if (sb!xc:constantp default)
 399                       (default-vals default)
 400                       (let ((var (gensym)))
 401                         (default-bindings `(,var ,default))
 402                         (default-vals var))))
 403                 (let ((bindings (default-bindings))
 404                       (call `(%funcall ,fun ,@(reverse vals) ,@(default-vals))))
 405                   (ir1-convert-lambda-body (if bindings
 406                                                `((let (,@bindings) ,call))
 407                                                `(,call))
 408                                           arg-vars
 409                                           ;; FIXME: Would be nice to
 410                                           ;; share these names instead
 411                                           ;; of consing up several
 412                                           ;; identical ones. Oh well.
 413                                           :debug-name (debug-name
 414                                                        '&optional-processor
 415                                                        name)
 416                                           :note-lexical-bindings nil
 417                                           :system-lambda t)))))
 418     (mapc (lambda (var arg-var)
 419             (when (cdr (leaf-refs arg-var))
 420               (setf (leaf-ever-used var) t)))
 421           fvars arg-vars)
 422     fun))
 423
 424 ;;; This function deals with supplied-p vars in optional arguments. If
 425 ;;; the there is no supplied-p arg, then we just call
 426 ;;; IR1-CONVERT-HAIRY-ARGS on the remaining arguments, and generate a
 427 ;;; optional entry that calls the result. If there is a supplied-p
 428 ;;; var, then we add it into the default vars and throw a T into the
 429 ;;; entry values. The resulting entry point function is returned.
 430 (defun generate-optional-default-entry (res default-vars default-vals
 431                                         entry-vars entry-vals
 432                                         vars supplied-p-p body
 433                                         aux-vars aux-vals
 434                                         source-name debug-name
 435                                         force post-binding-lexenv
 436                                         system-lambda)
 437   (declare (type optional-dispatch res)
 438            (list default-vars default-vals entry-vars entry-vals vars body
 439                  aux-vars aux-vals))
 440   (let* ((arg (first vars))
 441          (arg-name (leaf-source-name arg))
 442          (info (lambda-var-arg-info arg))
 443          (default (arg-info-default info))
 444          (supplied-p (arg-info-supplied-p info))
 445          (force (or force
 446                     (not (sb!xc:constantp (arg-info-default info)))))
 447          (ep (if supplied-p
 448                  (ir1-convert-hairy-args
 449                   res
 450                   (list* supplied-p arg default-vars)
 451                   (list* (leaf-source-name supplied-p) arg-name default-vals)
 452                   (cons arg entry-vars)
 453                   (list* t arg-name entry-vals)
 454                   (rest vars) t body aux-vars aux-vals
 455                   source-name debug-name
 456                   force post-binding-lexenv system-lambda)
 457                  (ir1-convert-hairy-args
 458                   res
 459                   (cons arg default-vars)
 460                   (cons arg-name default-vals)
 461                   (cons arg entry-vars)
 462                   (cons arg-name entry-vals)
 463                   (rest vars) supplied-p-p body aux-vars aux-vals
 464                   source-name debug-name
 465                   force post-binding-lexenv system-lambda))))
 466
 467     ;; We want to delay converting the entry, but there exist
 468     ;; problems: hidden references should not be established to
 469     ;; lambdas of kind NIL should not have (otherwise the compiler
 470     ;; might let-convert or delete them) and to variables.
 471     (let ((name (or debug-name source-name)))
 472       (if (or force
 473               supplied-p-p ; this entry will be of kind NIL
 474               (and (lambda-p ep) (eq (lambda-kind ep) nil)))
 475           (convert-optional-entry ep
 476                                   default-vars default-vals
 477                                   (if supplied-p (list default nil) (list default))
 478                                   name)
 479           (let* ((default `',(constant-form-value default))
 480                  (defaults (if supplied-p (list default nil) (list default))))
 481             ;; DEFAULT can contain a reference to a
 482             ;; to-be-optimized-away function/block/tag, so better to
 483             ;; reduce code now (but we possibly lose syntax checking
 484             ;; in an unreachable code).
 485             (delay
 486              (register-entry-point
 487               (convert-optional-entry (force ep)
 488                                       default-vars default-vals
 489                                       defaults
 490                                       name)
 491               res)))))))
 492
 493 ;;; Create the MORE-ENTRY function for the OPTIONAL-DISPATCH RES.
 494 ;;; ENTRY-VARS and ENTRY-VALS describe the fixed arguments. REST is
 495 ;;; the var for any &REST arg. KEYS is a list of the &KEY arg vars.
 496 ;;;
 497 ;;; The most interesting thing that we do is parse keywords. We create
 498 ;;; a bunch of temporary variables to hold the result of the parse,
 499 ;;; and then loop over the supplied arguments, setting the appropriate
 500 ;;; temps for the supplied keyword. Note that it is significant that
 501 ;;; we iterate over the keywords in reverse order --- this implements
 502 ;;; the CL requirement that (when a keyword appears more than once)
 503 ;;; the first value is used.
 504 ;;;
 505 ;;; If there is no supplied-p var, then we initialize the temp to the
 506 ;;; default and just pass the temp into the main entry. Since
 507 ;;; non-constant &KEY args are forcibly given a supplied-p var, we
 508 ;;; know that the default is constant, and thus safe to evaluate out
 509 ;;; of order.
 510 ;;;
 511 ;;; If there is a supplied-p var, then we create temps for both the
 512 ;;; value and the supplied-p, and pass them into the main entry,
 513 ;;; letting it worry about defaulting.
 514 ;;;
 515 ;;; We deal with :ALLOW-OTHER-KEYS by delaying unknown keyword errors
 516 ;;; until we have scanned all the keywords.
 517 (defun convert-more-entry (res entry-vars entry-vals rest morep keys name)
 518   (declare (type optional-dispatch res) (list entry-vars entry-vals keys))
 519   (collect ((arg-vars)
 520             (arg-vals (reverse entry-vals))
 521             (temps)
 522             (body))
 523
 524     (dolist (var (reverse entry-vars))
 525       (arg-vars (make-lambda-var :%source-name (leaf-source-name var)
 526                                  :type (leaf-type var)
 527                                  :where-from (leaf-where-from var))))
 528
 529     (let* ((n-context (gensym "N-CONTEXT-"))
 530            (context-temp (make-lambda-var :%source-name n-context))
 531            (n-count (gensym "N-COUNT-"))
 532            (count-temp (make-lambda-var :%source-name n-count
 533                                         :type (specifier-type 'index))))
 534
 535       (arg-vars context-temp count-temp)
 536
 537       (when rest
 538         (arg-vals `(%listify-rest-args
 539                     ,n-context ,n-count)))
 540       (when morep
 541         (arg-vals n-context)
 542         (arg-vals n-count))
 543
 544       ;; The reason for all the noise with
 545       ;; STACK-GROWS-DOWNWARD-NOT-UPWARD is to enable generation of
 546       ;; slightly more efficient code on x86oid processors.  (We can
 547       ;; hoist the negation of the index outside the main parsing loop
 548       ;; and take advantage of the base+index+displacement addressing
 549       ;; mode on x86oids.)
 550       (when (optional-dispatch-keyp res)
 551         (let ((n-index (gensym "N-INDEX-"))
 552               (n-key (gensym "N-KEY-"))
 553               (n-value-temp (gensym "N-VALUE-TEMP-"))
 554               (n-allowp (gensym "N-ALLOWP-"))
 555               (n-losep (gensym "N-LOSEP-"))
 556               (allowp (or (optional-dispatch-allowp res)
 557                           (policy *lexenv* (zerop safety))))
 558               (found-allow-p nil))
 559
 560           (temps #!-stack-grows-downward-not-upward
 561                  `(,n-index (1- ,n-count))
 562                  #!+stack-grows-downward-not-upward
 563                  `(,n-index (- (1- ,n-count)))
 564                  #!-stack-grows-downward-not-upward n-value-temp
 565                  #!-stack-grows-downward-not-upward n-key)
 566           (body `(declare (fixnum ,n-index)
 567                           #!-stack-grows-downward-not-upward
 568                           (ignorable ,n-value-temp ,n-key)))
 569
 570           (collect ((tests))
 571             (dolist (key keys)
 572               (let* ((info (lambda-var-arg-info key))
 573                      (default (arg-info-default info))
 574                      (keyword (arg-info-key info))
 575                      (supplied-p (arg-info-supplied-p info))
 576                      (n-value (gensym "N-VALUE-"))
 577                      (clause (cond (supplied-p
 578                                     (let ((n-supplied (gensym "N-SUPPLIED-")))
 579                                       (temps n-supplied)
 580                                       (arg-vals n-value n-supplied)
 581                                       `((eq ,n-key ',keyword)
 582                                         (setq ,n-supplied t)
 583                                         (setq ,n-value ,n-value-temp))))
 584                                    (t
 585                                     (arg-vals n-value)
 586                                     `((eq ,n-key ',keyword)
 587                                       (setq ,n-value ,n-value-temp))))))
 588                 (when (and (not allowp) (eq keyword :allow-other-keys))
 589                   (setq found-allow-p t)
 590                   (setq clause
 591                         (append clause `((setq ,n-allowp ,n-value-temp)))))
 592
 593                 (temps `(,n-value ,default))
 594                 (tests clause)))
 595
 596             (unless allowp
 597               (temps n-allowp n-losep)
 598               (unless found-allow-p
 599                 (tests `((eq ,n-key :allow-other-keys)
 600                          (setq ,n-allowp ,n-value-temp))))
 601               (tests `(t
 602                        (setq ,n-losep (list ,n-key)))))
 603
 604             (body
 605              `(when (oddp ,n-count)
 606                 (%odd-key-args-error)))
 607
 608             (body
 609              #!-stack-grows-downward-not-upward
 610              `(locally
 611                 (declare (optimize (safety 0)))
 612                 (loop
 613                   (when (minusp ,n-index) (return))
 614                   (setf ,n-value-temp (%more-arg ,n-context ,n-index))
 615                   (decf ,n-index)
 616                   (setq ,n-key (%more-arg ,n-context ,n-index))
 617                   (decf ,n-index)
 618                   (cond ,@(tests))))
 619              #!+stack-grows-downward-not-upward
 620              `(locally (declare (optimize (safety 0)))
 621                 (loop
 622                   (when (plusp ,n-index) (return))
 623                   (multiple-value-bind (,n-value-temp ,n-key)
 624                       (%more-kw-arg ,n-context ,n-index)
 625                     (declare (ignorable ,n-value-temp ,n-key))
 626                     (incf ,n-index 2)
 627                     (cond ,@(tests))))))
 628
 629             (unless allowp
 630               (body `(when (and ,n-losep (not ,n-allowp))
 631                        (%unknown-key-arg-error (car ,n-losep))))))))
 632
 633       (let ((ep (ir1-convert-lambda-body
 634                  `((let ,(temps)
 635                      ,@(body)
 636                      (%funcall ,(optional-dispatch-main-entry res)
 637                                ,@(arg-vals))))
 638                  (arg-vars)
 639                  :debug-name (debug-name '&more-processor name)
 640                  :note-lexical-bindings nil
 641                  :system-lambda t)))
 642         (setf (optional-dispatch-more-entry res)
 643               (register-entry-point ep res)))))
 644
 645   (values))
 646
 647 ;;; This is called by IR1-CONVERT-HAIRY-ARGS when we run into a &REST
 648 ;;; or &KEY arg. The arguments are similar to that function, but we
 649 ;;; split off any &REST arg and pass it in separately. REST is the
 650 ;;; &REST arg var, or NIL if there is no &REST arg. KEYS is a list of
 651 ;;; the &KEY argument vars.
 652 ;;;
 653 ;;; When there are &KEY arguments, we introduce temporary gensym
 654 ;;; variables to hold the values while keyword defaulting is in
 655 ;;; progress to get the required sequential binding semantics.
 656 ;;;
 657 ;;; This gets interesting mainly when there are &KEY arguments with
 658 ;;; supplied-p vars or non-constant defaults. In either case, pass in
 659 ;;; a supplied-p var. If the default is non-constant, we introduce an
 660 ;;; IF in the main entry that tests the supplied-p var and decides
 661 ;;; whether to evaluate the default or not. In this case, the real
 662 ;;; incoming value is NIL, so we must union NULL with the declared
 663 ;;; type when computing the type for the main entry's argument.
 664 (defun ir1-convert-more (res default-vars default-vals entry-vars entry-vals
 665                          rest more-context more-count keys supplied-p-p
 666                          body aux-vars aux-vals source-name debug-name
 667                          post-binding-lexenv system-lambda)
 668   (declare (type optional-dispatch res)
 669            (list default-vars default-vals entry-vars entry-vals keys body
 670                  aux-vars aux-vals))
 671   (collect ((main-vars (reverse default-vars))
 672             (main-vals default-vals cons)
 673             (bind-vars)
 674             (bind-vals))
 675     (when rest
 676       (main-vars rest)
 677       (main-vals '()))
 678     (when more-context
 679       (main-vars more-context)
 680       (main-vals nil)
 681       (main-vars more-count)
 682       (main-vals 0))
 683
 684     (dolist (key keys)
 685       (let* ((info (lambda-var-arg-info key))
 686              (default (arg-info-default info))
 687              (hairy-default (not (sb!xc:constantp default)))
 688              (supplied-p (arg-info-supplied-p info))
 689              (n-val (make-symbol (format nil
 690                                          "~A-DEFAULTING-TEMP"
 691                                          (leaf-source-name key))))
 692              (val-temp (make-lambda-var :%source-name n-val)))
 693         (main-vars val-temp)
 694         (bind-vars key)
 695         (cond ((or hairy-default supplied-p)
 696                (let* ((n-supplied (gensym "N-SUPPLIED-"))
 697                       (supplied-temp (make-lambda-var
 698                                       :%source-name n-supplied)))
 699                  (unless supplied-p
 700                    (setf (arg-info-supplied-p info) supplied-temp))
 701                  (when hairy-default
 702                    (setf (arg-info-default info) nil))
 703                  (main-vars supplied-temp)
 704                  (cond (hairy-default
 705                         (main-vals nil nil)
 706                         (bind-vals `(if ,n-supplied ,n-val ,default)))
 707                        (t
 708                         (main-vals default nil)
 709                         (bind-vals n-val)))
 710                  (when supplied-p
 711                    (bind-vars supplied-p)
 712                    (bind-vals n-supplied))))
 713               (t
 714                (main-vals (arg-info-default info))
 715                (bind-vals n-val)))))
 716
 717     (let* ((name (or debug-name source-name))
 718            (main-entry (ir1-convert-lambda-body
 719                         body (main-vars)
 720                         :aux-vars (append (bind-vars) aux-vars)
 721                         :aux-vals (append (bind-vals) aux-vals)
 722                         :post-binding-lexenv post-binding-lexenv
 723                         :debug-name (debug-name 'varargs-entry name)
 724                         :system-lambda system-lambda))
 725            (last-entry (convert-optional-entry main-entry default-vars
 726                                                (main-vals) () name)))
 727       (setf (optional-dispatch-main-entry res)
 728             (register-entry-point main-entry res))
 729       (convert-more-entry res entry-vars entry-vals rest more-context keys
 730                           name)
 731
 732       (push (register-entry-point
 733              (if supplied-p-p
 734                 (convert-optional-entry last-entry entry-vars entry-vals
 735                                         () name)
 736                 last-entry)
 737              res)
 738             (optional-dispatch-entry-points res))
 739       last-entry)))
 740
 741 ;;; This function generates the entry point functions for the
 742 ;;; OPTIONAL-DISPATCH RES. We accomplish this by recursion on the list
 743 ;;; of arguments, analyzing the arglist on the way down and generating
 744 ;;; entry points on the way up.
 745 ;;;
 746 ;;; DEFAULT-VARS is a reversed list of all the argument vars processed
 747 ;;; so far, including supplied-p vars. DEFAULT-VALS is a list of the
 748 ;;; names of the DEFAULT-VARS.
 749 ;;;
 750 ;;; ENTRY-VARS is a reversed list of processed argument vars,
 751 ;;; excluding supplied-p vars. ENTRY-VALS is a list things that can be
 752 ;;; evaluated to get the values for all the vars from the ENTRY-VARS.
 753 ;;; It has the var name for each required or optional arg, and has T
 754 ;;; for each supplied-p arg.
 755 ;;;
 756 ;;; VARS is a list of the LAMBDA-VAR structures for arguments that
 757 ;;; haven't been processed yet. SUPPLIED-P-P is true if a supplied-p
 758 ;;; argument has already been processed; only in this case are the
 759 ;;; DEFAULT-XXX and ENTRY-XXX different.
 760 ;;;
 761 ;;; The result at each point is a lambda which should be called by the
 762 ;;; above level to default the remaining arguments and evaluate the
 763 ;;; body. We cause the body to be evaluated by converting it and
 764 ;;; returning it as the result when the recursion bottoms out.
 765 ;;;
 766 ;;; Each level in the recursion also adds its entry point function to
 767 ;;; the result OPTIONAL-DISPATCH. For most arguments, the defaulting
 768 ;;; function and the entry point function will be the same, but when
 769 ;;; SUPPLIED-P args are present they may be different.
 770 ;;;
 771 ;;; When we run into a &REST or &KEY arg, we punt out to
 772 ;;; IR1-CONVERT-MORE, which finishes for us in this case.
 773 (defun ir1-convert-hairy-args (res default-vars default-vals
 774                                entry-vars entry-vals
 775                                vars supplied-p-p body aux-vars
 776                                aux-vals
 777                                source-name debug-name
 778                                force post-binding-lexenv
 779                                system-lambda)
 780   (declare (type optional-dispatch res)
 781            (list default-vars default-vals entry-vars entry-vals vars body
 782                  aux-vars aux-vals))
 783   (aver (or debug-name (neq '.anonymous. source-name)))
 784   (cond ((not vars)
 785          (if (optional-dispatch-keyp res)
 786              ;; Handle &KEY with no keys...
 787              (ir1-convert-more res default-vars default-vals
 788                                entry-vars entry-vals
 789                                nil nil nil vars supplied-p-p body aux-vars
 790                                aux-vals source-name debug-name
 791                                post-binding-lexenv system-lambda)
 792              (let* ((name (or debug-name source-name))
 793                     (fun (ir1-convert-lambda-body
 794                          body (reverse default-vars)
 795                          :aux-vars aux-vars
 796                          :aux-vals aux-vals
 797                          :post-binding-lexenv post-binding-lexenv
 798                          :debug-name (debug-name 'hairy-arg-processor name)
 799                          :system-lambda system-lambda)))
 800
 801                (setf (optional-dispatch-main-entry res) fun)
 802                (register-entry-point fun res)
 803                (push (if supplied-p-p
 804                          (register-entry-point
 805                           (convert-optional-entry fun entry-vars entry-vals ()
 806                                                   name)
 807                           res)
 808                           fun)
 809                      (optional-dispatch-entry-points res))
 810                fun)))
 811         ((not (lambda-var-arg-info (first vars)))
 812          (let* ((arg (first vars))
 813                 (nvars (cons arg default-vars))
 814                 (nvals (cons (leaf-source-name arg) default-vals)))
 815            (ir1-convert-hairy-args res nvars nvals nvars nvals
 816                                    (rest vars) nil body aux-vars aux-vals
 817                                    source-name debug-name
 818                                    nil post-binding-lexenv system-lambda)))
 819         (t
 820          (let* ((arg (first vars))
 821                 (info (lambda-var-arg-info arg))
 822                 (kind (arg-info-kind info)))
 823            (ecase kind
 824              (:optional
 825               (let ((ep (generate-optional-default-entry
 826                          res default-vars default-vals
 827                          entry-vars entry-vals vars supplied-p-p body
 828                          aux-vars aux-vals
 829                          source-name debug-name
 830                          force post-binding-lexenv
 831                          system-lambda)))
 832                 ;; See GENERATE-OPTIONAL-DEFAULT-ENTRY.
 833                 (push (if (lambda-p ep)
 834                           (register-entry-point
 835                            (if supplied-p-p
 836                                (convert-optional-entry
 837                                 ep entry-vars entry-vals nil
 838                                 (or debug-name source-name))
 839                                ep)
 840                            res)
 841                           (progn (aver (not supplied-p-p))
 842                                  ep))
 843                       (optional-dispatch-entry-points res))
 844                 ep))
 845              (:rest
 846               (ir1-convert-more res default-vars default-vals
 847                                 entry-vars entry-vals
 848                                 arg nil nil (rest vars) supplied-p-p body
 849                                 aux-vars aux-vals
 850                                 source-name debug-name
 851                                 post-binding-lexenv system-lambda))
 852              (:more-context
 853               (ir1-convert-more res default-vars default-vals
 854                                 entry-vars entry-vals
 855                                 nil arg (second vars) (cddr vars) supplied-p-p
 856                                 body aux-vars aux-vals
 857                                 source-name debug-name
 858                                 post-binding-lexenv system-lambda))
 859              (:keyword
 860               (ir1-convert-more res default-vars default-vals
 861                                 entry-vars entry-vals
 862                                 nil nil nil vars supplied-p-p body aux-vars
 863                                 aux-vals source-name debug-name
 864                                 post-binding-lexenv system-lambda)))))))
 865
 866 ;;; This function deals with the case where we have to make an
 867 ;;; OPTIONAL-DISPATCH to represent a LAMBDA. We cons up the result and
 868 ;;; call IR1-CONVERT-HAIRY-ARGS to do the work. When it is done, we
 869 ;;; figure out the MIN-ARGS and MAX-ARGS.
 870 (defun ir1-convert-hairy-lambda (body vars keyp allowp aux-vars aux-vals
 871                                  &key post-binding-lexenv
 872                                  (source-name '.anonymous.)
 873                                  debug-name system-lambda)
 874   (declare (list body vars aux-vars aux-vals))
 875   (aver (or debug-name (neq '.anonymous. source-name)))
 876   (let ((res (make-optional-dispatch :arglist vars
 877                                      :allowp allowp
 878                                      :keyp keyp
 879                                      :%source-name source-name
 880                                      :%debug-name debug-name
 881                                      :plist `(:ir1-environment
 882                                               (,*lexenv*
 883                                                ,*current-path*))))
 884         (min (or (position-if #'lambda-var-arg-info vars) (length vars))))
 885     (aver-live-component *current-component*)
 886     (push res (component-new-functionals *current-component*))
 887     (ir1-convert-hairy-args res () () () () vars nil body aux-vars aux-vals
 888                             source-name debug-name nil post-binding-lexenv
 889                             system-lambda)
 890     (setf (optional-dispatch-min-args res) min)
 891     (setf (optional-dispatch-max-args res)
 892           (+ (1- (length (optional-dispatch-entry-points res))) min))
 893
 894     res))
 895
 896 ;;; Convert a LAMBDA form into a LAMBDA leaf or an OPTIONAL-DISPATCH leaf.
 897 (defun ir1-convert-lambda (form &key (source-name '.anonymous.)
 898                            debug-name maybe-add-debug-catch
 899                            system-lambda)
 900   (unless (consp form)
 901     (compiler-error "A ~S was found when expecting a lambda expression:~%  ~S"
 902                     (type-of form)
 903                     form))
 904   (unless (eq (car form) 'lambda)
 905     (compiler-error "~S was expected but ~S was found:~%  ~S"
 906                     'lambda
 907                     (car form)
 908                     form))
 909   (unless (and (consp (cdr form)) (listp (cadr form)))
 910     (compiler-error
 911      "The lambda expression has a missing or non-list lambda list:~%  ~S"
 912      form))
 913   (when (and system-lambda maybe-add-debug-catch)
 914     (bug "Both SYSTEM-LAMBDA and MAYBE-ADD-DEBUG-CATCH specified"))
 915   (unless (or debug-name (neq '.anonymous. source-name))
 916     (setf debug-name (name-lambdalike form)))
 917   (multiple-value-bind (vars keyp allow-other-keys aux-vars aux-vals)
 918       (make-lambda-vars (cadr form))
 919     (multiple-value-bind (forms decls) (parse-body (cddr form))
 920       (binding* (((*lexenv* result-type post-binding-lexenv)
 921                   (process-decls decls (append aux-vars vars) nil
 922                                  :binding-form-p t))
 923                  (debug-catch-p (and maybe-add-debug-catch
 924                                      *allow-instrumenting*
 925                                      (policy *lexenv*
 926                                              (>= insert-debug-catch 2))))
 927                  (forms (if debug-catch-p
 928                             (wrap-forms-in-debug-catch forms)
 929                             forms))
 930                  (forms (if (eq result-type *wild-type*)
 931                             forms
 932                             `((the ,result-type (progn ,@forms)))))
 933                  (*allow-instrumenting* (and (not system-lambda) *allow-instrumenting*))
 934                  (res (cond ((or (find-if #'lambda-var-arg-info vars) keyp)
 935                              (ir1-convert-hairy-lambda forms vars keyp
 936                                                        allow-other-keys
 937                                                        aux-vars aux-vals
 938                                                        :post-binding-lexenv post-binding-lexenv
 939                                                        :source-name source-name
 940                                                        :debug-name debug-name
 941                                                        :system-lambda system-lambda))
 942                             (t
 943                              (ir1-convert-lambda-body forms vars
 944                                                       :aux-vars aux-vars
 945                                                       :aux-vals aux-vals
 946                                                       :post-binding-lexenv post-binding-lexenv
 947                                                       :source-name source-name
 948                                                       :debug-name debug-name
 949                                                       :system-lambda system-lambda)))))
 950         (setf (functional-inline-expansion res) form)
 951         (setf (functional-arg-documentation res) (cadr form))
 952         (when (boundp '*lambda-conversions*)
 953           ;; KLUDGE: Not counting TL-XEPs is a lie, of course, but
 954           ;; keeps things less confusing to users of TIME, where this
 955           ;; count gets used.
 956           (unless (and (consp debug-name) (eq 'tl-xep (car debug-name)))
 957             (incf *lambda-conversions*)))
 958         res))))
 959
 960 (defun wrap-forms-in-debug-catch (forms)
 961   #!+unwind-to-frame-and-call-vop
 962   `((multiple-value-prog1
 963       (progn
 964         ,@forms)
 965       ;; Just ensure that there won't be any tail-calls, IR2 magic will
 966       ;; handle the rest.
 967       (values)))
 968   #!-unwind-to-frame-and-call-vop
 969   `( ;; Normally, we'll return from this block with the below RETURN-FROM.
 970     (block
 971         return-value-tag
 972       ;; If DEBUG-CATCH-TAG is thrown (with a thunk as the value) the
 973       ;; RETURN-FROM is elided and we funcall the thunk instead. That
 974       ;; thunk might either return a value (for a RETURN-FROM-FRAME)
 975       ;; or call this same function again (for a RESTART-FRAME).
 976       ;; -- JES, 2007-01-09
 977       (funcall
 978        (the function
 979          ;; Use a constant catch tag instead of consing a new one for every
 980          ;; entry to this block. The uniquencess of the catch tags is
 981          ;; ensured when the tag is throw by the debugger. It'll allocate a
 982          ;; new tag, and modify the reference this tag in the proper
 983          ;; catch-block structure to refer to that new tag. This
 984          ;; significantly decreases the runtime cost of high debug levels.
 985          ;;  -- JES, 2007-01-09
 986          (catch 'debug-catch-tag
 987            (return-from return-value-tag
 988              (progn
 989                ,@forms))))))))
 990
 991 ;;; helper for LAMBDA-like things, to massage them into a form
 992 ;;; suitable for IR1-CONVERT-LAMBDA.
 993 (defun ir1-convert-lambdalike (thing
 994                                &key
 995                                (source-name '.anonymous.)
 996                                debug-name)
 997   (when (and (not debug-name) (eq '.anonymous. source-name))
 998     (setf debug-name (name-lambdalike thing)))
 999   (ecase (car thing)
1000     ((lambda)
1001      (ir1-convert-lambda thing
1002                          :maybe-add-debug-catch t
1003                          :source-name source-name
1004                          :debug-name debug-name))
1005     ((instance-lambda)
1006      (deprecation-warning 'instance-lambda 'lambda)
1007      (ir1-convert-lambda `(lambda ,@(cdr thing))
1008                          :source-name source-name
1009                          :debug-name debug-name))
1010     ((named-lambda)
1011      (let ((name (cadr thing))
1012            (lambda-expression `(lambda ,@(cddr thing))))
1013        (if (and name (legal-fun-name-p name))
1014            (let ((defined-fun-res (get-defined-fun name))
1015                  (res (ir1-convert-lambda lambda-expression
1016                                           :maybe-add-debug-catch t
1017                                           :source-name name)))
1018              (assert-global-function-definition-type name res)
1019              (setf (defined-fun-functional defined-fun-res) res)
1020              (unless (eq (defined-fun-inlinep defined-fun-res) :notinline)
1021                (substitute-leaf-if
1022                 (lambda (ref)
1023                   (policy ref (> recognize-self-calls 0)))
1024                 res defined-fun-res))
1025              res)
1026            (ir1-convert-lambda lambda-expression
1027                                :maybe-add-debug-catch t
1028                                :debug-name
1029                                (or name (name-lambdalike thing))))))
1030     ((lambda-with-lexenv)
1031      (ir1-convert-inline-lambda thing
1032                                 :source-name source-name
1033                                 :debug-name debug-name))))
1034 \f
1035 ;;;; defining global functions
1036
1037 ;;; Convert FUN as a lambda in the null environment, but use the
1038 ;;; current compilation policy. Note that FUN may be a
1039 ;;; LAMBDA-WITH-LEXENV, so we may have to augment the environment to
1040 ;;; reflect the state at the definition site.
1041 (defun ir1-convert-inline-lambda (fun
1042                                   &key
1043                                   (source-name '.anonymous.)
1044                                   debug-name
1045                                   system-lambda)
1046   (when (and (not debug-name) (eq '.anonymous. source-name))
1047     (setf debug-name (name-lambdalike fun)))
1048   (destructuring-bind (decls macros symbol-macros &rest body)
1049       (if (eq (car fun) 'lambda-with-lexenv)
1050           (cdr fun)
1051           `(() () () . ,(cdr fun)))
1052     (let* ((*lexenv* (make-lexenv
1053                       :default (process-decls decls nil nil
1054                                               :lexenv (make-null-lexenv))
1055                       :vars (copy-list symbol-macros)
1056                       :funs (mapcar (lambda (x)
1057                                       `(,(car x) .
1058                                          (macro . ,(coerce (cdr x) 'function))))
1059                                     macros)
1060                       ;; Inherit MUFFLE-CONDITIONS from the call-site lexenv
1061                       ;; rather than the definition-site lexenv, since it seems
1062                       ;; like a much more common case.
1063                       :handled-conditions (lexenv-handled-conditions *lexenv*)
1064                       :policy (lexenv-policy *lexenv*)))
1065            (clambda (ir1-convert-lambda `(lambda ,@body)
1066                                         :source-name source-name
1067                                         :debug-name debug-name
1068                                         :system-lambda system-lambda)))
1069       (setf (functional-inline-expanded clambda) t)
1070       clambda)))
1071
1072 ;;; Get a DEFINED-FUN object for a function we are about to define. If
1073 ;;; the function has been forward referenced, then substitute for the
1074 ;;; previous references.
1075 (defun get-defined-fun (name)
1076   (proclaim-as-fun-name name)
1077   (let ((found (find-free-fun name "shouldn't happen! (defined-fun)")))
1078     (note-name-defined name :function)
1079     (cond ((not (defined-fun-p found))
1080            (aver (not (info :function :inlinep name)))
1081            (let* ((where-from (leaf-where-from found))
1082                   (res (make-defined-fun
1083                         :%source-name name
1084                         :where-from (if (eq where-from :declared)
1085                                         :declared :defined)
1086                         :type (leaf-type found))))
1087              (substitute-leaf res found)
1088              (setf (gethash name *free-funs*) res)))
1089           ;; If *FREE-FUNS* has a previously converted definition
1090           ;; for this name, then blow it away and try again.
1091           ((defined-fun-functional found)
1092            (remhash name *free-funs*)
1093            (get-defined-fun name))
1094           (t found))))
1095
1096 ;;; Check a new global function definition for consistency with
1097 ;;; previous declaration or definition, and assert argument/result
1098 ;;; types if appropriate. This assertion is suppressed by the
1099 ;;; EXPLICIT-CHECK attribute, which is specified on functions that
1100 ;;; check their argument types as a consequence of type dispatching.
1101 ;;; This avoids redundant checks such as NUMBERP on the args to +, etc.
1102 (defun assert-new-definition (var fun)
1103   (let ((type (leaf-type var))
1104         (for-real (eq (leaf-where-from var) :declared))
1105         (info (info :function :info (leaf-source-name var))))
1106     (assert-definition-type
1107      fun type
1108      ;; KLUDGE: Common Lisp is such a dynamic language that in general
1109      ;; all we can do here in general is issue a STYLE-WARNING. It
1110      ;; would be nice to issue a full WARNING in the special case of
1111      ;; of type mismatches within a compilation unit (as in section
1112      ;; 3.2.2.3 of the spec) but at least as of sbcl-0.6.11, we don't
1113      ;; keep track of whether the mismatched data came from the same
1114      ;; compilation unit, so we can't do that. -- WHN 2001-02-11
1115      :lossage-fun #'compiler-style-warn
1116      :unwinnage-fun (cond (info #'compiler-style-warn)
1117                           (for-real #'compiler-notify)
1118                           (t nil))
1119      :really-assert
1120      (and for-real
1121           (not (and info
1122                     (ir1-attributep (fun-info-attributes info)
1123                                     explicit-check))))
1124      :where (if for-real
1125                 "previous declaration"
1126                 "previous definition"))))
1127
1128 ;;; Used for global inline expansion. Earlier something like this was
1129 ;;; used by %DEFUN too. FIXME: And now it's probably worth rethinking
1130 ;;; whether this function is a good idea at all.
1131 (defun ir1-convert-inline-expansion (name expansion var inlinep info)
1132   ;; Unless a :INLINE function, we temporarily clobber the inline
1133   ;; expansion. This prevents recursive inline expansion of
1134   ;; opportunistic pseudo-inlines.
1135   (unless (eq inlinep :inline)
1136     (setf (defined-fun-inline-expansion var) nil))
1137   (let ((fun (ir1-convert-inline-lambda expansion
1138                                         :source-name name
1139                                         ;; prevent instrumentation of
1140                                         ;; known function expansions
1141                                         :system-lambda (and info t))))
1142     (setf (functional-inlinep fun) inlinep)
1143     (assert-new-definition var fun)
1144     (setf (defined-fun-inline-expansion var) expansion)
1145     ;; substitute for any old references
1146     (unless (or (not *block-compile*)
1147                 (and info
1148                      (or (fun-info-transforms info)
1149                          (fun-info-templates info)
1150                          (fun-info-ir2-convert info))))
1151       (substitute-leaf fun var))
1152     fun))
1153
1154 ;;; the even-at-compile-time part of DEFUN
1155 ;;;
1156 ;;; The INLINE-EXPANSION is a LAMBDA-WITH-LEXENV, or NIL if there is
1157 ;;; no inline expansion.
1158 (defun %compiler-defun (name lambda-with-lexenv compile-toplevel)
1159   (let ((defined-fun nil)) ; will be set below if we're in the compiler
1160     (when compile-toplevel
1161       ;; better be in the compiler
1162       (aver (boundp '*lexenv*))
1163       (remhash name *free-funs*)
1164       (setf defined-fun (get-defined-fun name))
1165       (aver (fasl-output-p *compile-object*))
1166       (if (member name *fun-names-in-this-file* :test #'equal)
1167           (warn 'duplicate-definition :name name)
1168           (push name *fun-names-in-this-file*)))
1169
1170     (become-defined-fun-name name)
1171
1172     (cond (lambda-with-lexenv
1173            (setf (info :function :inline-expansion-designator name)
1174                  lambda-with-lexenv)
1175            (when defined-fun
1176              (setf (defined-fun-inline-expansion defined-fun)
1177                    lambda-with-lexenv)))
1178           (t
1179            (clear-info :function :inline-expansion-designator name)))
1180
1181     ;; old CMU CL comment:
1182     ;;   If there is a type from a previous definition, blast it,
1183     ;;   since it is obsolete.
1184     (when (and defined-fun
1185                (eq (leaf-where-from defined-fun) :defined))
1186       (setf (leaf-type defined-fun)
1187             ;; FIXME: If this is a block compilation thing, shouldn't
1188             ;; we be setting the type to the full derived type for the
1189             ;; definition, instead of this most general function type?
1190             (specifier-type 'function))))
1191
1192   (values))
1193
1194 \f
1195 ;;; Entry point utilities
1196
1197 ;;; Return a function for the Nth entry point.
1198 (defun optional-dispatch-entry-point-fun (dispatcher n)
1199   (declare (type optional-dispatch dispatcher)
1200            (type unsigned-byte n))
1201   (let* ((env (getf (optional-dispatch-plist dispatcher) :ir1-environment))
1202          (*lexenv* (first env))
1203          (*current-path* (second env)))
1204     (force (nth n (optional-dispatch-entry-points dispatcher)))))