src/compiler/early-c.lisp

   1 ;;;; This file contains compiler code and compiler-related stuff which
   2 ;;;; can be built early on. Some of the stuff may be here because it's
   3 ;;;; needed early on, some other stuff (e.g. constants) just because
   4 ;;;; it might as well be done early so we don't have to think about
   5 ;;;; whether it's done early enough.
   6
   7 ;;;; This software is part of the SBCL system. See the README file for
   8 ;;;; more information.
   9 ;;;;
  10 ;;;; This software is derived from the CMU CL system, which was
  11 ;;;; written at Carnegie Mellon University and released into the
  12 ;;;; public domain. The software is in the public domain and is
  13 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  14 ;;;; files for more information.
  15
  16 (in-package "SB!C")
  17
  18 ;;; ANSI limits on compilation
  19 (def!constant sb!xc:call-arguments-limit sb!xc:most-positive-fixnum
  20   #!+sb-doc
  21   "The exclusive upper bound on the number of arguments which may be passed
  22   to a function, including &REST args.")
  23 (def!constant sb!xc:lambda-parameters-limit sb!xc:most-positive-fixnum
  24   #!+sb-doc
  25   "The exclusive upper bound on the number of parameters which may be specified
  26   in a given lambda list. This is actually the limit on required and &OPTIONAL
  27   parameters. With &KEY and &AUX you can get more.")
  28 (def!constant sb!xc:multiple-values-limit sb!xc:most-positive-fixnum
  29   #!+sb-doc
  30   "The exclusive upper bound on the number of multiple VALUES that you can
  31   return.")
  32 \f
  33 ;;;; cross-compiler-only versions of CL special variables, so that we
  34 ;;;; don't have weird interactions with the host compiler
  35
  36 (defvar sb!xc:*compile-file-pathname*)
  37 (defvar sb!xc:*compile-file-truename*)
  38 (defvar sb!xc:*compile-print*)
  39 (defvar sb!xc:*compile-verbose*)
  40 \f
  41 ;;;; miscellaneous types used both in the cross-compiler and on the target
  42
  43 ;;;; FIXME: The INDEX and LAYOUT-DEPTHOID definitions probably belong
  44 ;;;; somewhere else, not "early-c", since they're after all not part
  45 ;;;; of the compiler.
  46
  47 ;;; the type of LAYOUT-DEPTHOID slot values
  48 (def!type layout-depthoid () '(or index (integer -1 -1)))
  49 (def!type layout-bitmap ()
  50   ;; FIXME: Probably should exclude negative bignum
  51   #!+compact-instance-header 'integer
  52   #!-compact-instance-header '(and integer (not (eql 0))))
  53 \f
  54 ;;; An INLINEP value describes how a function is called. The values
  55 ;;; have these meanings:
  56 ;;;     NIL     No declaration seen: do whatever you feel like, but don't
  57 ;;;             dump an inline expansion.
  58 ;;; :NOTINLINE  NOTINLINE declaration seen: always do full function call.
  59 ;;;    :INLINE  INLINE declaration seen: save expansion, expanding to it
  60 ;;;             if policy favors.
  61 ;;; :MAYBE-INLINE
  62 ;;;             Retain expansion, but only use it opportunistically.
  63 ;;;             :MAYBE-INLINE is quite different from :INLINE. As explained
  64 ;;;             by APD on #lisp 2005-11-26: "MAYBE-INLINE lambda is
  65 ;;;             instantiated once per component, INLINE - for all
  66 ;;;             references (even under #'without FUNCALL)."
  67 (deftype inlinep ()
  68   '(member :inline :maybe-inline :notinline nil))
  69 (defparameter *inlinep-translations*
  70   '((inline . :inline)
  71     (notinline . :notinline)
  72     (maybe-inline . :maybe-inline)))
  73
  74 ;;; *FREE-VARS* translates from the names of variables referenced
  75 ;;; globally to the LEAF structures for them. *FREE-FUNS* is like
  76 ;;; *FREE-VARS*, only it deals with function names.
  77 (defvar *free-vars*)
  78 (defvar *free-funs*)
  79 (declaim (type hash-table *free-vars* *free-funs*))
  80
  81 ;;; We use the same CONSTANT structure to represent all equal anonymous
  82 ;;; constants. This hashtable translates from constants to the LEAFs that
  83 ;;; represent them.
  84 (defvar *constants*)
  85 (declaim (type hash-table *constants*))
  86
  87 ;;; *ALLOW-INSTRUMENTING* controls whether we should allow the
  88 ;;; insertion of instrumenting code (like a (CATCH ...)) around code
  89 ;;; to allow the debugger RETURN and STEP commands to function (we
  90 ;;; disallow it for internal stuff).
  91 (defvar *allow-instrumenting*)
  92
  93 ;;; miscellaneous forward declarations
  94 (defvar *code-segment*)
  95 #!+sb-dyncount (defvar *collect-dynamic-statistics*)
  96 (defvar *component-being-compiled*)
  97 (defvar *compiler-error-context*)
  98 (defvar *compiler-error-count*)
  99 (defvar *compiler-warning-count*)
 100 (defvar *compiler-style-warning-count*)
 101 (defvar *compiler-note-count*)
 102 (defvar *compiler-trace-output*)
 103 (defvar *constraint-universe*)
 104 (defvar *current-path*)
 105 (defvar *current-component*)
 106 (defvar *delayed-ir1-transforms*)
 107 (defvar *eval-tlf-index*)
 108 (defvar *dynamic-counts-tn*)
 109 (defvar *elsewhere*)
 110 (defvar *event-info*)
 111 (defvar *event-note-threshold*)
 112 (defvar *failure-p*)
 113 (defvar *fixup-notes*)
 114 #!+inline-constants
 115 (progn
 116   (defvar *unboxed-constants*)
 117   (defstruct (unboxed-constants (:conc-name constant-)
 118                                 (:predicate nil) (:copier nil))
 119     (table (make-hash-table :test #'equal) :read-only t)
 120     (segment
 121      (sb!assem:make-segment :type :elsewhere
 122                             :run-scheduler nil
 123                             :inst-hook (default-segment-inst-hook)
 124                             :alignment 0) :read-only t)
 125     (vector (make-array 16 :adjustable t :fill-pointer 0) :read-only t))
 126   (declaim (freeze-type unboxed-constants)))
 127 (defvar *source-info*)
 128 (defvar *source-plist*)
 129 (defvar *source-namestring*)
 130 (defvar *undefined-warnings*)
 131 (defvar *warnings-p*)
 132 (defvar *lambda-conversions*)
 133
 134 (defvar *stack-allocate-dynamic-extent* t
 135   #!+sb-doc
 136   "If true (the default), the compiler respects DYNAMIC-EXTENT declarations
 137 and stack allocates otherwise inaccessible parts of the object whenever
 138 possible. Potentially long (over one page in size) vectors are, however, not
 139 stack allocated except in zero SAFETY code, as such a vector could overflow
 140 the stack without triggering overflow protection.")
 141
 142 (!begin-collecting-cold-init-forms)
 143 ;;; This lock is seized in the compiler, and related areas -- like the
 144 ;;; classoid/layout/class system.
 145 (defglobal **world-lock** nil)
 146 (!cold-init-forms
 147  (setf **world-lock** (sb!thread:make-mutex :name "World Lock")))
 148 (!defun-from-collected-cold-init-forms !world-lock-cold-init)
 149
 150 (defmacro with-world-lock (() &body body)
 151   `(sb!thread:with-recursive-lock (**world-lock**)
 152      ,@body))
 153
 154 (declaim (type fixnum *compiler-sset-counter*))
 155 (defvar *compiler-sset-counter* 0)
 156
 157 ;;; unique ID for the next object created (to let us track object
 158 ;;; identity even across GC, useful for understanding weird compiler
 159 ;;; bugs where something is supposed to be unique but is instead
 160 ;;; exists as duplicate objects)
 161 #!+sb-show
 162 (progn
 163   (defvar *object-id-counter* 0)
 164   (defun new-object-id ()
 165     (prog1
 166         *object-id-counter*
 167       (incf *object-id-counter*))))
 168 \f
 169 ;;;; miscellaneous utilities
 170
 171 ;;; This is for "observers" who want to know if type names have been added.
 172 ;;; Rather than registering listeners, they can detect changes by comparing
 173 ;;; their stored nonce to the current nonce. Additionally the observers
 174 ;;; can detect whether function definitions have occurred.
 175 (declaim (fixnum *type-cache-nonce*))
 176 (!defglobal *type-cache-nonce* 0)
 177
 178 (def!struct (undefined-warning
 179             #-no-ansi-print-object
 180             (:print-object (lambda (x s)
 181                              (print-unreadable-object (x s :type t)
 182                                (prin1 (undefined-warning-name x) s))))
 183             (:copier nil))
 184   ;; the name of the unknown thing
 185   (name nil :type (or symbol list))
 186   ;; the kind of reference to NAME
 187   (kind (missing-arg) :type (member :function :type :variable))
 188   ;; the number of times this thing was used
 189   (count 0 :type unsigned-byte)
 190   ;; a list of COMPILER-ERROR-CONTEXT structures describing places
 191   ;; where this thing was used. Note that we only record the first
 192   ;; *UNDEFINED-WARNING-LIMIT* calls.
 193   (warnings () :type list))
 194
 195 ;;; Delete any undefined warnings for NAME and KIND. This is for the
 196 ;;; benefit of the compiler, but it's sometimes called from stuff like
 197 ;;; type-defining code which isn't logically part of the compiler.
 198 (declaim (ftype (function ((or symbol cons) keyword) (values))
 199                 note-name-defined))
 200 (defun note-name-defined (name kind)
 201   #-sb-xc-host (atomic-incf *type-cache-nonce*)
 202   ;; We do this BOUNDP check because this function can be called when
 203   ;; not in a compilation unit (as when loading top level forms).
 204   (when (boundp '*undefined-warnings*)
 205     (let ((name (uncross name)))
 206       (setq *undefined-warnings*
 207             (delete-if (lambda (x)
 208                          (and (equal (undefined-warning-name x) name)
 209                               (eq (undefined-warning-kind x) kind)))
 210                        *undefined-warnings*))))
 211   (values))
 212
 213 ;;; to be called when a variable is lexically bound
 214 (declaim (ftype (function (symbol) (values)) note-lexical-binding))
 215 (defun note-lexical-binding (symbol)
 216     ;; This check is intended to protect us from getting silently
 217     ;; burned when we define
 218     ;;   foo.lisp:
 219     ;;     (DEFVAR *FOO* -3)
 220     ;;     (DEFUN FOO (X) (+ X *FOO*))
 221     ;;   bar.lisp:
 222     ;;     (DEFUN BAR (X)
 223     ;;       (LET ((*FOO* X))
 224     ;;         (FOO 14)))
 225     ;; and then we happen to compile bar.lisp before foo.lisp.
 226   (when (looks-like-name-of-special-var-p symbol)
 227     ;; FIXME: should be COMPILER-STYLE-WARNING?
 228     (style-warn 'asterisks-around-lexical-variable-name
 229                 :format-control
 230                 "using the lexical binding of the symbol ~
 231                  ~/sb-impl::print-symbol-with-prefix/, not the~@
 232                  dynamic binding"
 233                 :format-arguments (list symbol)))
 234   (values))
 235
 236 (def!struct (debug-name-marker (:print-function print-debug-name-marker)))
 237
 238 (defvar *debug-name-level* 4)
 239 (defvar *debug-name-length* 12)
 240 (defvar *debug-name-punt*)
 241 (defvar *debug-name-sharp*)
 242 (defvar *debug-name-ellipsis*)
 243
 244 (defmethod make-load-form ((marker debug-name-marker) &optional env)
 245   (declare (ignore env))
 246   (cond ((eq marker *debug-name-sharp*)
 247          `(if (boundp '*debug-name-sharp*)
 248               *debug-name-sharp*
 249               (make-debug-name-marker)))
 250         ((eq marker *debug-name-ellipsis*)
 251          `(if (boundp '*debug-name-ellipsis*)
 252               *debug-name-ellipsis*
 253               (make-debug-name-marker)))
 254         (t
 255          (warn "Dumping unknown debug-name marker.")
 256          '(make-debug-name-marker))))
 257
 258 (defun print-debug-name-marker (marker stream level)
 259   (declare (ignore level))
 260   (cond ((eq marker *debug-name-sharp*)
 261          (write-char #\# stream))
 262         ((eq marker *debug-name-ellipsis*)
 263          (write-string "..." stream))
 264         (t
 265          (write-string "???" stream))))
 266
 267 (setf *debug-name-sharp* (make-debug-name-marker)
 268       *debug-name-ellipsis* (make-debug-name-marker))
 269
 270 (declaim (ftype (sfunction () list) name-context))
 271 (defun debug-name (type thing &optional context)
 272   (let ((*debug-name-punt* nil))
 273     (labels ((walk (x)
 274                (typecase x
 275                  (cons
 276                   (if (plusp *debug-name-level*)
 277                       (let ((*debug-name-level* (1- *debug-name-level*)))
 278                         (do ((tail (cdr x) (cdr tail))
 279                              (name (cons (walk (car x)) nil)
 280                                    (cons (walk (car tail)) name))
 281                              (n (1- *debug-name-length*) (1- n)))
 282                             ((or (not (consp tail))
 283                                  (not (plusp n))
 284                                  *debug-name-punt*)
 285                              (cond (*debug-name-punt*
 286                                     (setf *debug-name-punt* nil)
 287                                     (nreverse name))
 288                                    ((atom tail)
 289                                     (nconc (nreverse name) (walk tail)))
 290                                    (t
 291                                     (setf *debug-name-punt* t)
 292                                     (nconc (nreverse name) (list *debug-name-ellipsis*)))))))
 293                       *debug-name-sharp*))
 294                  ((or symbol number string)
 295                   x)
 296                  (t
 297                   (type-of x)))))
 298       (let ((name (list* type (walk thing) (when context (name-context)))))
 299         (when (legal-fun-name-p name)
 300           (bug "~S is a legal function name, and cannot be used as a ~
 301                 debug name." name))
 302         name))))
 303
 304 ;;; Set this to NIL to inhibit assembly-level optimization. (For
 305 ;;; compiler debugging, rather than policy control.)
 306 (defvar *assembly-optimize* t)
 307
 308 (in-package "SB!ALIEN")
 309
 310 ;;; Information describing a heap-allocated alien.
 311 (def!struct (heap-alien-info)
 312   ;; The type of this alien.
 313   (type (missing-arg) :type alien-type)
 314   ;; Its name.
 315   (alien-name (missing-arg) :type simple-string)
 316   ;; Data or code?
 317   (datap (missing-arg) :type boolean))
 318 (!set-load-form-method heap-alien-info (:xc :target))