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 just loaded
38 ;;; ordinarily (as source), the value should be something which
39 ;;; can't legally appear at the head of a Lisp source file.
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)))))
147 ;;; FIXME: This deserves a more descriptive name, and should probably
148 ;;; be implemented as an ordinary function, not a macro.
150 ;;; (for the names: There seem to be only two cases, so it could be
151 ;;; named READ-U-INTEGER-8 and READ-U-INTEGER-32 or something.)
155 ;;; The table is implemented as a simple-vector indexed by the table
156 ;;; offset. We may need to have several, since LOAD can be called
159 ;;; a list of free fop tables for the fasloader
161 ;;; FIXME: Is it really a win to have this permanently bound?
162 ;;; Couldn't we just bind it on entry to LOAD-AS-FASL?
163 (defvar *free-fop-tables* (list (make-array 1000)))
165 ;;; the current fop table
166 (defvar *current-fop-table*)
167 (declaim (simple-vector *current-fop-table*))
169 ;;; the length of the current fop table
170 (defvar *current-fop-table-size*)
171 (declaim (type index *current-fop-table-size*))
173 ;;; the index in the fop-table of the next entry to be used
174 (defvar *current-fop-table-index*)
175 (declaim (type index *current-fop-table-index*))
177 (defun grow-fop-table ()
178 (let* ((new-size (* *current-fop-table-size* 2))
179 (new-table (make-array new-size)))
180 (declare (fixnum new-size) (simple-vector new-table))
181 (replace new-table (the simple-vector *current-fop-table*))
182 (setq *current-fop-table* new-table)
183 (setq *current-fop-table-size* new-size)))
185 (defmacro push-fop-table (thing)
186 (let ((n-index (gensym)))
187 `(let ((,n-index *current-fop-table-index*))
188 (declare (fixnum ,n-index))
189 (when (= ,n-index (the fixnum *current-fop-table-size*))
191 (setq *current-fop-table-index* (1+ ,n-index))
192 (setf (svref *current-fop-table* ,n-index) ,thing))))
196 ;;; (This is in a SIMPLE-VECTOR, but it grows down, since it is
197 ;;; somewhat cheaper to test for overflow that way.)
198 (defvar *fop-stack* (make-array 100))
199 (declaim (simple-vector *fop-stack*))
201 ;;; the index of the most recently pushed item on the fop stack
202 (defvar *fop-stack-pointer* 100)
204 ;;; the current index into the fop stack when we last recursively
206 (defvar *fop-stack-pointer-on-entry*)
207 (declaim (type index *fop-stack-pointer* *fop-stack-pointer-on-entry*))
209 (defun grow-fop-stack ()
210 (let* ((size (length (the simple-vector *fop-stack*)))
211 (new-size (* size 2))
212 (new-stack (make-array new-size)))
213 (declare (fixnum size new-size) (simple-vector new-stack))
214 (replace new-stack (the simple-vector *fop-stack*) :start1 size)
215 (incf *fop-stack-pointer-on-entry* size)
216 (setq *fop-stack-pointer* size)
217 (setq *fop-stack* new-stack)))
219 ;;; Cache information about the fop stack in local variables. Define a
220 ;;; local macro to pop from the stack. Push the result of evaluation
222 (defmacro with-fop-stack (pushp &body forms)
223 (aver (member pushp '(nil t :nope)))
224 (let ((n-stack (gensym))
227 `(let ((,n-stack *fop-stack*)
228 (,n-index *fop-stack-pointer*))
229 (declare (simple-vector ,n-stack) (type index ,n-index))
230 (macrolet ((pop-stack ()
232 (svref ,',n-stack ,',n-index)
234 (call-with-popped-things (fun n)
235 (let ((n-start (gensym)))
236 `(let ((,n-start (+ ,',n-index ,n)))
237 (declare (type index ,n-start))
238 (setq ,',n-index ,n-start)
239 (,fun ,@(make-list n :initial-element
241 (decf ,n-start))))))))
243 `(let ((,n-res (progn ,@forms)))
244 (when (zerop ,n-index)
246 (setq ,n-index *fop-stack-pointer*
247 ,n-stack *fop-stack*))
249 (setq *fop-stack-pointer* ,n-index)
250 (setf (svref ,n-stack ,n-index) ,n-res))
253 (setq *fop-stack-pointer* ,n-index)))))))
257 ;;;; Note: LOAD-AS-FASL is used not only by LOAD, but also (with
258 ;;;; suitable modification of the fop table) in GENESIS. Therefore,
259 ;;;; it's needed not only in the target Lisp, but also in the
260 ;;;; cross-compilation host.
262 ;;; a helper function for LOAD-FASL-GROUP
264 ;;; Return true if we successfully read a FASL header from the stream,
265 ;;; or NIL if EOF was hit before anything was read. Signal an error if
266 ;;; we encounter garbage.
267 (defun check-fasl-header (stream)
269 (let ((byte (read-byte stream nil)))
272 ;; Read the string part of the fasl header, or die.
273 (let* ((fhsss sb!c:*fasl-header-string-start-string*)
274 (fhsss-length (length fhsss)))
275 (unless (= byte (char-code (schar fhsss 0)))
276 (error "illegal first byte in fasl file header"))
277 (do ((byte (read-byte stream) (read-byte stream))
278 (count 1 (1+ count)))
279 ((= byte sb!c:*fasl-header-string-stop-char-code*)
281 (declare (fixnum byte count))
282 (when (and (< count fhsss-length)
283 (not (eql byte (char-code (schar fhsss count)))))
285 "illegal subsequent (not first) byte in fasl file header"))))
287 ;; Read and validate implementation and version, or die.
288 (let* ((implementation-length (read-arg 4))
289 (implementation-string (make-string implementation-length))
290 (ignore (read-string-as-bytes stream implementation-string))
291 (implementation (keywordicate implementation-string))
292 ;; FIXME: The logic above to read a keyword from the fasl file
293 ;; could probably be shared with the read-a-keyword fop.
294 (version (read-arg 4)))
295 (declare (ignore ignore))
296 (flet ((check-version (variant possible-implementation needed-version)
297 (when (string= possible-implementation implementation)
298 (unless (= version needed-version)
299 (error "~@<~S is in ~A fasl file format version ~D, ~
300 but this version of SBCL uses ~
301 format version ~D.~:@>"
307 (or (check-version "native code"
308 #.sb!c:*backend-fasl-file-implementation*
309 #.sb!c:*backend-fasl-file-version*)
310 (check-version "byte code"
311 #.(sb!c:backend-byte-fasl-file-implementation)
312 sb!c:byte-fasl-file-version)
313 (error "~S was compiled for implementation ~A, but this is a ~A."
316 sb!c:*backend-fasl-file-implementation*)))))))
318 ;; Setting this variable gives you a trace of fops as they are loaded and
321 (defvar *show-fops-p* nil)
323 ;;; a helper function for LOAD-AS-FASL
325 ;;; Return true if we successfully load a group from the stream, or
326 ;;; NIL if EOF was encountered while trying to read from the stream.
327 ;;; Dispatch to the right function for each fop. Special-case
328 ;;; FOP-BYTE-PUSH since it is real common.
329 (defun load-fasl-group (stream)
330 (when (check-fasl-header stream)
331 (catch 'fasl-group-end
332 (let ((*current-fop-table-index* 0))
334 (let ((byte (read-byte stream)))
336 ;; Do some debugging output.
339 (let ((ptr *fop-stack-pointer*)
341 (fresh-line *trace-output*)
342 ;; The FOP operations are stack based, so it's sorta
343 ;; logical to display the operand before the operator.
344 ;; ("reverse Polish notation")
345 (unless (= ptr (length stack))
346 (write-char #\space *trace-output*)
347 (prin1 (svref stack ptr) *trace-output*)
348 (terpri *trace-output*))
349 ;; Display the operator.
350 (format *trace-output*
351 "~&~S (#X~X at ~D) (~S)~%"
352 (svref *fop-names* byte)
354 (1- (file-position stream))
355 (svref *fop-functions* byte))))
357 ;; Actually execute the fop.
359 ;; FIXME: This is the special case for FOP-BYTE-PUSH.
360 ;; Benchmark to see whether it's really worth special
361 ;; casing it. If it is, at least express the test in
362 ;; terms of a symbolic name for the FOP-BYTE-PUSH code,
363 ;; not a bare '3' (!). Failing that, remove the special
364 ;; case (and the comment at the head of this function
365 ;; which mentions it).
366 (let ((index *fop-stack-pointer*))
367 (declare (type index index))
370 (setq index *fop-stack-pointer*))
372 (setq *fop-stack-pointer* index)
373 (setf (svref *fop-stack* index)
374 (svref *current-fop-table* (read-byte stream))))
375 (funcall (the function (svref *fop-functions* byte))))))))))
377 (defun load-as-fasl (stream verbose print)
378 ;; KLUDGE: ANSI says it's good to do something with the :PRINT
379 ;; argument to LOAD when we're fasloading a file, but currently we
380 ;; don't. (CMU CL did, but implemented it in a non-ANSI way, and I
381 ;; just disabled that instead of rewriting it.) -- WHN 20000131
382 (declare (ignore print))
384 ;; FIXME: In sbcl-0.6.12.8 the OpenBSD implementation of FILE-LENGTH
385 ;; broke because changed handling of Unix stat(2) stuff couldn't
386 ;; deal with OpenBSD's 64-bit size slot. Once that's fixed, this
387 ;; code can be restored.
389 (when (zerop (file-length stream))
390 (error "attempt to load an empty FASL file:~% ~S" (namestring stream)))
392 (do-load-verbose stream verbose)
393 (let* ((*fasl-file* stream)
394 (*current-fop-table* (or (pop *free-fop-tables*) (make-array 1000)))
395 (*current-fop-table-size* (length *current-fop-table*))
396 (*fop-stack-pointer-on-entry* *fop-stack-pointer*))
398 ;; FIXME: This should probably become
399 ;; (LOOP WHILE (LOAD-FASL-GROUP-STREAM))
400 ;; but as a LOOP newbie I don't want to do that until I can
402 (do ((loaded-group (load-fasl-group stream) (load-fasl-group stream)))
403 ((not loaded-group)))
404 (setq *fop-stack-pointer* *fop-stack-pointer-on-entry*)
405 (push *current-fop-table* *free-fop-tables*)
406 ;; NIL out the stack and table, so that we don't hold onto garbage.
408 ;; FIXME: Couldn't we just get rid of the free fop table pool so
409 ;; that some of this NILing out would go away?
410 (fill *fop-stack* nil :end *fop-stack-pointer-on-entry*)
411 (fill *current-fop-table* nil)))
414 ;;;; stuff for debugging/tuning by collecting statistics on FOPs (?)
417 (defvar *fop-counts* (make-array 256 :initial-element 0))
418 (defvar *fop-times* (make-array 256 :initial-element 0))
419 (defvar *print-fops* nil)
421 (defun clear-counts ()
422 (fill (the simple-vector *fop-counts*) 0)
423 (fill (the simple-vector *fop-times*) 0)
426 (defun analyze-counts ()
431 (macrolet ((breakdown (lvar tvar vec)
435 (let ((n (svref ,vec i)))
436 (push (cons (svref *fop-names* i) n) ,lvar)
438 (setq ,lvar (subseq (sort ,lvar #'(lambda (x y)
439 (> (cdr x) (cdr y))))
442 (breakdown counts total-count *fop-counts*)
443 (breakdown times total-time *fop-times*)
444 (format t "Total fop count is ~D~%" total-count)
446 (format t "~30S: ~4D~%" (car c) (cdr c)))
447 (format t "~%Total fop time is ~D~%" (/ (float total-time) 60.0))
449 (format t "~30S: ~6,2F~%" (car m) (/ (float (cdr m)) 60.0))))))