1 ;;;; parts of the loader which make sense in the cross-compilation
2 ;;;; host (and which are useful in the host, because they're used by
5 ;;;; based on the CMU CL load.lisp code, written by Skef Wholey and
8 ;;;; This software is part of the SBCL system. See the README file for
11 ;;;; This software is derived from the CMU CL system, which was
12 ;;;; written at Carnegie Mellon University and released into the
13 ;;;; public domain. The software is in the public domain and is
14 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
15 ;;;; files for more information.
17 (in-package "SB!IMPL")
21 ;;; FIXME: It's awkward having LOAD stuff in SB!IMPL and dump stuff in
22 ;;; SB!C. Among other things, it makes it hard to figure out where
23 ;;; *FASL-HEADER-STRING-START-STRING* and
24 ;;; *FASL-HEADER-STRING-STOP-CHAR-CODE* should go. Perhaps we should
25 ;;; make a package called SB-DUMP or SB-LD which includes all
26 ;;; knowledge of both loading and dumping.
28 ;;; This value is used to identify fasl files. Even though this is not
29 ;;; declared as a constant (because ANSI Common Lisp has no facility
30 ;;; for declaring values which are constant under EQUAL but not EQL),
31 ;;; obviously you shouldn't mess with it lightly. If you do set a new
32 ;;; value for some reason, keep these things in mind:
33 ;;; * To avoid confusion with the similar but incompatible CMU CL
34 ;;; fasl file format, the value should not be "FASL FILE", which
35 ;;; is what CMU CL used for the same purpose.
36 ;;; * Since its presence at the head of a file is used by LOAD to
37 ;;; decide whether a file is to be fasloaded or sloloaded, the value
38 ;;; should be something which can't legally appear at the head of a
40 ;;; * The value should not contain any line-terminating characters,
41 ;;; because they're hard to express portably and because the LOAD
42 ;;; code might reasonably use READ-LINE to get the value to compare
44 (defparameter sb!c:*fasl-header-string-start-string* "# FASL"
46 "a string which appears at the start of a fasl file header")
48 (defparameter sb!c:*fasl-header-string-stop-char-code* 255
50 "the code for a character which terminates a fasl file header")
52 (defvar *load-depth* 0
54 "the current number of recursive loads")
55 (declaim (type index *load-depth*))
57 ;;; the FASL file we're reading from
59 (declaim (type lisp-stream fasl-file))
61 (defvar *load-print* nil
63 "the default for the :PRINT argument to LOAD")
64 (defvar *load-verbose* nil
65 ;; Note that CMU CL's default for this was T, and ANSI says it's
66 ;; implementation-dependent. We choose NIL on the theory that it's
67 ;; a nicer default behavior for Unix programs.
69 "the default for the :VERBOSE argument to LOAD")
71 ;;;; miscellaneous load utilities
73 ;;; Output the current number of semicolons after a fresh-line.
74 ;;; FIXME: non-mnemonic name
75 (defun load-fresh-line ()
77 (let ((semicolons ";;;;;;;;;;;;;;;;"))
78 (do ((count *load-depth* (- count (length semicolons))))
79 ((< count (length semicolons))
80 (write-string semicolons *standard-output* :end count))
81 (declare (fixnum count))
82 (write-string semicolons))
83 (write-char #\space)))
85 ;;; If VERBOSE, output (to *STANDARD-OUTPUT*) a message about how we're
86 ;;; loading from STREAM-WE-ARE-LOADING-FROM.
87 ;;; FIXME: non-mnemonic name
88 (defun do-load-verbose (stream-we-are-loading-from verbose)
91 (let ((name #-sb-xc-host (file-name stream-we-are-loading-from)
94 (format t "loading ~S~%" name)
95 (format t "loading stuff from ~S~%" stream-we-are-loading-from)))))
97 ;;;; utilities for reading from fasl files
99 #!-sb-fluid (declaim (inline read-byte))
101 ;;; Expands into code to read an N-byte unsigned integer using
103 (defmacro fast-read-u-integer (n)
104 (declare (optimize (speed 0)))
105 (do ((res '(fast-read-byte)
106 `(logior (fast-read-byte)
111 ;;; Like Fast-Read-U-Integer, but the size may be determined at run time.
112 (defmacro fast-read-variable-u-integer (n)
113 (let ((n-pos (gensym))
116 `(do ((,n-pos 8 (+ ,n-pos 8))
117 (,n-cnt (1- ,n) (1- ,n-cnt))
120 (dpb (fast-read-byte) (byte 8 ,n-pos) ,n-res)))
121 ((zerop ,n-cnt) ,n-res)
122 (declare (type index ,n-pos ,n-cnt)))))
124 ;;; Read a signed integer.
125 (defmacro fast-read-s-integer (n)
126 (declare (optimize (speed 0)))
127 (let ((n-last (gensym)))
128 (do ((res `(let ((,n-last (fast-read-byte)))
129 (if (zerop (logand ,n-last #x80))
131 (logior ,n-last #x-100)))
132 `(logior (fast-read-byte)
133 (ash (the (signed-byte ,(* cnt 8)) ,res) 8)))
137 ;;; Read an N-byte unsigned integer from the *FASL-FILE*
138 (defmacro read-arg (n)
139 (declare (optimize (speed 0)))
141 `(the (unsigned-byte 8) (read-byte *fasl-file*))
142 `(prepare-for-fast-read-byte *fasl-file*
144 (fast-read-u-integer ,n)
145 (done-with-fast-read-byte)))))
146 ;;; FIXME: This deserves a more descriptive name, and should probably
147 ;;; be implemented as an ordinary function, not a macro.
149 ;;; (for the names: There seem to be only two cases, so it could be
150 ;;; named READ-U-INTEGER-8 and READ-U-INTEGER-32 or something.)
154 ;;; The table is implemented as a simple-vector indexed by the table
155 ;;; offset. We may need to have several, since LOAD can be called
158 (defvar *free-fop-tables* (list (make-array 1000))
160 "List of free fop tables for the fasloader.")
162 ;;; the current fop table
163 (defvar *current-fop-table*)
164 (declaim (simple-vector *current-fop-table*))
166 ;;; the length of the current fop table
167 (defvar *current-fop-table-size*)
168 (declaim (type index *current-fop-table-size*))
170 ;;; the index in the fop-table of the next entry to be used
171 (defvar *current-fop-table-index*)
172 (declaim (type index *current-fop-table-index*))
174 (defun grow-fop-table ()
175 (let* ((new-size (* *current-fop-table-size* 2))
176 (new-table (make-array new-size)))
177 (declare (fixnum new-size) (simple-vector new-table))
178 (replace new-table (the simple-vector *current-fop-table*))
179 (setq *current-fop-table* new-table)
180 (setq *current-fop-table-size* new-size)))
182 (defmacro push-fop-table (thing)
183 (let ((n-index (gensym)))
184 `(let ((,n-index *current-fop-table-index*))
185 (declare (fixnum ,n-index))
186 (when (= ,n-index (the fixnum *current-fop-table-size*))
188 (setq *current-fop-table-index* (1+ ,n-index))
189 (setf (svref *current-fop-table* ,n-index) ,thing))))
193 ;;; (This is in a simple-vector, but it grows down, since it is
194 ;;; somewhat cheaper to test for overflow that way.)
195 (defvar *fop-stack* (make-array 100)
197 "The fop stack (we only need one!).")
198 (declaim (simple-vector *fop-stack*))
200 ;;; the index of the most recently pushed item on the fop-stack
201 (defvar *fop-stack-pointer* 100)
203 ;;; the current index into the fop stack when we last recursively
205 (defvar *fop-stack-pointer-on-entry*)
206 (declaim (type index *fop-stack-pointer* *fop-stack-pointer-on-entry*))
208 (defun grow-fop-stack ()
209 (let* ((size (length (the simple-vector *fop-stack*)))
210 (new-size (* size 2))
211 (new-stack (make-array new-size)))
212 (declare (fixnum size new-size) (simple-vector new-stack))
213 (replace new-stack (the simple-vector *fop-stack*) :start1 size)
214 (incf *fop-stack-pointer-on-entry* size)
215 (setq *fop-stack-pointer* size)
216 (setq *fop-stack* new-stack)))
218 ;;; Cache information about the fop-stack in local variables. Define a
219 ;;; local macro to pop from the stack. Push the result of evaluation
221 (defmacro with-fop-stack (pushp &body forms)
222 (check-type pushp (member nil t :nope))
223 (let ((n-stack (gensym))
226 `(let ((,n-stack *fop-stack*)
227 (,n-index *fop-stack-pointer*))
228 (declare (simple-vector ,n-stack) (type index ,n-index))
229 (macrolet ((pop-stack ()
231 (svref ,',n-stack ,',n-index)
233 (call-with-popped-things (fun n)
234 (let ((n-start (gensym)))
235 `(let ((,n-start (+ ,',n-index ,n)))
236 (declare (type index ,n-start))
237 (setq ,',n-index ,n-start)
238 (,fun ,@(make-list n :initial-element
240 (decf ,n-start))))))))
242 `(let ((,n-res (progn ,@forms)))
243 (when (zerop ,n-index)
245 (setq ,n-index *fop-stack-pointer*
246 ,n-stack *fop-stack*))
248 (setq *fop-stack-pointer* ,n-index)
249 (setf (svref ,n-stack ,n-index) ,n-res))
252 (setq *fop-stack-pointer* ,n-index)))))))
256 ;;;; Note: FASLOAD is used not only by LOAD, but also (after suitable
257 ;;;; modification of the fop table) in genesis. Therefore, it's needed
258 ;;;; not only in the target Lisp, but also in the cross-compilation
261 ;;; a helper function for LOAD-FASL-GROUP
263 ;;; Return true if we successfully read a FASL header from the stream,
264 ;;; or NIL if EOF was hit before anything was read. Signal an error if
265 ;;; we encounter garbage.
266 (defun check-fasl-header (stream)
268 (let ((byte (read-byte stream nil)))
271 ;; Read the string part of the fasl header, or die.
272 (let* ((fhsss sb!c:*fasl-header-string-start-string*)
273 (fhsss-length (length fhsss)))
274 (unless (= byte (char-code (schar fhsss 0)))
275 (error "illegal fasl file header"))
276 (do ((byte (read-byte stream) (read-byte stream))
277 (count 1 (1+ count)))
278 ((= byte sb!c:*fasl-header-string-stop-char-code*)
280 (declare (fixnum byte count))
281 (when (and (< count fhsss-length)
282 (not (eql byte (char-code (schar fhsss count)))))
283 (error "illegal fasl file header"))))
285 ;; Read and validate implementation and version, or die.
286 (let* ((implementation-length (read-arg 4))
287 (implementation-string (make-string implementation-length))
288 (ignore (read-string-as-bytes stream implementation-string))
289 (implementation (keywordicate implementation-string))
290 ;; FIXME: The logic above to read a keyword from the fasl file
291 ;; could probably be shared with the read-a-keyword fop.
292 (version (read-arg 4)))
293 (declare (ignore ignore))
294 (flet ((check-version (variant possible-implementation needed-version)
295 (when (string= possible-implementation implementation)
296 (unless (= version needed-version)
297 (error "~S was compiled for ~A fasl file format version ~
298 ~S, but we need version ~S."
304 (or (check-version "native code"
305 #.sb!c:*backend-fasl-file-implementation*
306 #.sb!c:*backend-fasl-file-version*)
307 (check-version "byte code"
308 #.(sb!c:backend-byte-fasl-file-implementation)
309 sb!c:byte-fasl-file-version)
310 (error "~S was compiled for implementation ~A, but this is a ~A."
313 sb!c:*backend-fasl-file-implementation*)))))))
315 ;; Setting this variable gives you a trace of fops as they are loaded and
318 (defvar *show-fops-p* nil)
320 ;;; a helper function for FASLOAD
322 ;;; Return true if we successfully load a group from the stream, or NIL if EOF
323 ;;; was encountered while trying to read from the stream. Dispatch to the right
324 ;;; function for each fop. Special-case FOP-BYTE-PUSH since it is real common.
325 (defun load-fasl-group (stream)
326 (when (check-fasl-header stream)
327 (catch 'fasl-group-end
328 (let ((*current-fop-table-index* 0))
330 (let ((byte (read-byte stream)))
332 ;; Do some debugging output.
335 (let ((ptr *fop-stack-pointer*)
337 (fresh-line *trace-output*)
338 ;; The FOP operations are stack based, so it's sorta
339 ;; logical to display the operand before the operator.
340 ;; ("reverse Polish notation")
341 (unless (= ptr (length stack))
342 (write-char #\space *trace-output*)
343 (prin1 (svref stack ptr) *trace-output*)
344 (terpri *trace-output*))
345 ;; Display the operator.
346 (format *trace-output*
347 "~&~S (#X~X at ~D) (~S)~%"
348 (svref *fop-names* byte)
350 (1- (file-position stream))
351 (svref *fop-functions* byte))))
353 ;; Actually execute the fop.
355 ;; FIXME: This is the special case for FOP-BYTE-PUSH.
356 ;; Benchmark to see whether it's really worth special
357 ;; casing it. If it is, at least express the test in
358 ;; terms of a symbolic name for the FOP-BYTE-PUSH code,
359 ;; not a bare '3' (!). Failing that, remove the special
360 ;; case (and the comment at the head of this function
361 ;; which mentions it).
362 (let ((index *fop-stack-pointer*))
363 (declare (type index index))
366 (setq index *fop-stack-pointer*))
368 (setq *fop-stack-pointer* index)
369 (setf (svref *fop-stack* index)
370 (svref *current-fop-table* (read-byte stream))))
371 (funcall (the function (svref *fop-functions* byte))))))))))
373 (defun fasload (stream verbose print)
374 ;; KLUDGE: ANSI says it's good to do something with the :PRINT
375 ;; argument to LOAD when we're fasloading a file, but currently we
376 ;; don't. (CMU CL did, but implemented it in a non-ANSI way, and I
377 ;; just disabled that instead of rewriting it.) -- WHN 20000131
378 (declare (ignore print))
379 (when (zerop (file-length stream))
380 (error "attempt to load an empty FASL file:~% ~S" (namestring stream)))
381 (do-load-verbose stream verbose)
382 (let* ((*fasl-file* stream)
383 (*current-fop-table* (or (pop *free-fop-tables*) (make-array 1000)))
384 (*current-fop-table-size* (length *current-fop-table*))
385 (*fop-stack-pointer-on-entry* *fop-stack-pointer*))
387 ;; FIXME: This should probably become
388 ;; (LOOP WHILE (LOAD-FASL-GROUP-STREAM))
389 ;; but as a LOOP newbie I don't want to do that until I can
391 (do ((loaded-group (load-fasl-group stream) (load-fasl-group stream)))
392 ((not loaded-group)))
393 (setq *fop-stack-pointer* *fop-stack-pointer-on-entry*)
394 (push *current-fop-table* *free-fop-tables*)
395 ;; NIL out the stack and table, so that we don't hold onto garbage.
397 ;; FIXME: Couldn't we just get rid of the free fop table pool so
398 ;; that some of this NILing out would go away?
399 (fill *fop-stack* nil :end *fop-stack-pointer-on-entry*)
400 (fill *current-fop-table* nil)))
403 ;;;; stuff for debugging/tuning by collecting statistics on FOPs (?)
406 (defvar *fop-counts* (make-array 256 :initial-element 0))
407 (defvar *fop-times* (make-array 256 :initial-element 0))
408 (defvar *print-fops* nil)
410 (defun clear-counts ()
411 (fill (the simple-vector *fop-counts*) 0)
412 (fill (the simple-vector *fop-times*) 0)
415 (defun analyze-counts ()
420 (macrolet ((breakdown (lvar tvar vec)
424 (let ((n (svref ,vec i)))
425 (push (cons (svref *fop-names* i) n) ,lvar)
427 (setq ,lvar (subseq (sort ,lvar #'(lambda (x y)
428 (> (cdr x) (cdr y))))
431 (breakdown counts total-count *fop-counts*)
432 (breakdown times total-time *fop-times*)
433 (format t "Total fop count is ~D~%" total-count)
435 (format t "~30S: ~4D~%" (car c) (cdr c)))
436 (format t "~%Total fop time is ~D~%" (/ (float total-time) 60.0))
438 (format t "~30S: ~6,2F~%" (car m) (/ (float (cdr m)) 60.0))))))