src/code/early-fasl.lisp

   1 ;;;; needed-early, or at least meaningful-early, stuff for FASL files
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!FASL")
  13 \f
  14 ;;;; various constants and essentially-constants
  15
  16 ;;; a string which appears at the start of a fasl file header
  17 ;;;
  18 ;;; This value is used to identify fasl files. Even though this is not
  19 ;;; declared as a constant (because ANSI Common Lisp has no facility
  20 ;;; for declaring values which are constant under EQUAL but not EQL),
  21 ;;; obviously you shouldn't mess with it lightly. If you do set a new
  22 ;;; value for some reason, keep these things in mind:
  23 ;;; * To avoid confusion with the similar but incompatible CMU CL
  24 ;;;   fasl file format, the value should not be "FASL FILE", which
  25 ;;;   is what CMU CL used for the same purpose.
  26 ;;; * Since its presence at the head of a file is used by LOAD to
  27 ;;;   decide whether a file is to be fasloaded or just loaded
  28 ;;;   ordinarily (as source), the value should be something which
  29 ;;;   can't legally appear at the head of a Lisp source file.
  30 ;;; * The value should not contain any line-terminating characters,
  31 ;;;   because they're hard to express portably and because the LOAD
  32 ;;;   code might reasonably use READ-LINE to get the value to compare
  33 ;;;   against.
  34 (defparameter *fasl-header-string-start-string* "# FASL")
  35
  36 ;;; the code for a character which terminates a fasl file header
  37 (def!constant +fasl-header-string-stop-char-code+ 255)
  38
  39 ;;; This value should be incremented when the system changes in such a
  40 ;;; way that it will no longer work reliably with old fasl files. In
  41 ;;; practice, I (WHN) fairly often forget to increment it for CVS
  42 ;;; versions which break binary compatibility. But it certainly should
  43 ;;; be incremented for release versions which break binary
  44 ;;; compatibility.
  45 (def!constant +fasl-file-version+ 32)
  46 ;;; (record of versions before 0.7.0 deleted in 0.7.1.41)
  47 ;;; 23 = sbcl-0.7.0.1 deleted no-longer-used EVAL-STACK stuff,
  48 ;;;      causing changes in *STATIC-SYMBOLS*.
  49 ;;; 24 = sbcl-0.7.1.19 changed PCL service routines which might be
  50 ;;;      called from macroexpanded code
  51 ;;; 25 = sbcl-0.7.1.41 (and immediately preceding versions, actually)
  52 ;;;      introduced new functions to check for control stack exhaustion
  53 ;;; 26 = sbcl-0.7.2.4 or so added :VARIABLE :MACRO-EXPANSION to INFO codes
  54 ;;; 27: (2002-04-08) added MIGHT-CONTAIN-OTHER-TYPES? slot to CTYPE
  55 ;;; 28: (2002-05-08) new convention for foreign symbols to support
  56 ;;;     dynamic loading in OpenBSD
  57 ;;; 29: (2002-06-24) removed *!INITIAL-FDEFN-OBJECTS* from static symbols
  58 ;;; 30: (2002-07-26) deleted all references to %DETECT-STACK-EXHAUSTION,
  59 ;;;     which was introduced in version 25, since now control stack
  60 ;;;     is checked using mmap() page protection
  61 ;;; 31: (2002-08-14) changed encoding of PCL internal MAKE-INSTANCE
  62 ;;;     function names so they're insensitive to whether the class name
  63 ;;;     is currently external to its package
  64 ;;; 32: (2002-09-21) changes in implementation of sequence functions,
  65 ;;;     causing old utility functions like COERCE-TO-SIMPLE-VECTOR to go away
  66
  67 ;;; the conventional file extension for our fasl files
  68 (declaim (type simple-string *fasl-file-type*))
  69 (defvar *fasl-file-type* "fasl")
  70 \f
  71 ;;;; information about below-Lisp-level linkage
  72
  73 ;;; Note:
  74 ;;;   Assembler routines are named by full Lisp symbols: they
  75 ;;;     have packages and that sort of native Lisp stuff associated
  76 ;;;     with them. We can compare them with EQ.
  77 ;;;   Foreign symbols are named by Lisp STRINGs: the Lisp package
  78 ;;;     system doesn't extend out to symbols in languages like C.
  79 ;;;     We want to use EQUAL to compare them.
  80 ;;;   *STATIC-FOREIGN-SYMBOLS* are static as opposed to "dynamic" (not
  81 ;;;     as opposed to C's "extern"). The table contains symbols known at
  82 ;;;     the time that the program was built, but not symbols defined
  83 ;;;     in object files which have been loaded dynamically since then.
  84 (declaim (type hash-table *assembler-routines* *static-foreign-symbols*))
  85 (defvar *assembler-routines* (make-hash-table :test 'eq))
  86 (defvar *static-foreign-symbols* (make-hash-table :test 'equal))
  87 \f
  88 ;;;; the FOP database
  89
  90 (declaim (simple-vector *fop-names* *fop-funs*))
  91
  92 ;;; a vector indexed by a FaslOP that yields the FOP's name
  93 (defvar *fop-names* (make-array 256 :initial-element nil))
  94
  95 ;;; a vector indexed by a FaslOP that yields a function of 0 arguments
  96 ;;; which will perform the operation
  97 (defvar *fop-funs*
  98   (make-array 256
  99               :initial-element (lambda ()
 100                                  (error "corrupt fasl file: losing FOP"))))
 101 \f
 102 ;;;; other miscellaneous loading-related stuff
 103
 104 \f
 105 ;;;; variables
 106
 107 (defvar *load-depth* 0
 108   #!+sb-doc
 109   "the current number of recursive LOADs")
 110 (declaim (type index *load-depth*))
 111
 112 ;;; the FASL file we're reading from
 113 (defvar *fasl-input-stream*)
 114 (declaim (type ansi-stream *fasl-input-stream*))
 115
 116 (defvar *load-print* nil
 117   #!+sb-doc
 118   "the default for the :PRINT argument to LOAD")
 119 (defvar *load-verbose* nil
 120   ;; Note that CMU CL's default for this was T, and ANSI says it's
 121   ;; implementation-dependent. We choose NIL on the theory that it's
 122   ;; a nicer default behavior for Unix programs.
 123   #!+sb-doc
 124   "the default for the :VERBOSE argument to LOAD")
 125
 126 (defvar *load-code-verbose* nil)
 127