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