\f
;;;; LOAD-AS-SOURCE
-;;; Load a text file.
+;;; Load a text file. (Note that load-as-fasl is in another file.)
(defun load-as-source (stream verbose print)
(maybe-announce-load stream verbose)
(do ((sexpr (read stream nil *eof-object*)
(invalid-fasl-expected condition)
(invalid-fasl-fhsss condition)))))
-;;; a helper function for LOAD: Load the stuff in a file when we have
-;;; the name.
-;;;
-;;; FIXME: with the addition of the EXTERNAL-FORMAT argument, this
-;;; interface has become truly sucky.
-(defun internal-load (pathname truename if-does-not-exist verbose print
- &optional contents external-format)
- (declare (type (member nil :error) if-does-not-exist))
- (unless truename
- (if if-does-not-exist
- (error 'simple-file-error
- :pathname pathname
- :format-control "~S does not exist."
- :format-arguments (list (namestring pathname)))
- (return-from internal-load nil)))
+;; Pretty well any way of doing LOAD will expose race conditions: for
+;; example, a file might get deleted or renamed after we open it but
+;; before we find its truename. It seems useful to say that
+;; detectible ways the file system can fail to be static are good
+;; enough reason to stop loading, but to stop in a way that
+;; distinguishes errors that occur mid-way through LOAD from the
+;; initial failure to OPEN the file, so that handlers can try do
+;; defaulting only when the file didn't exist at the start of LOAD,
+;; while allowing race conditions to get through.
+(define-condition load-race-condition (error)
+ ((pathname :reader load-race-condition-pathname :initarg :pathname))
+ (:report (lambda (condition stream)
+ (format stream "~@<File~S was deleted or renamed during LOAD.~:>"
+ (load-race-condition-pathname condition)))))
- (let ((*load-truename* truename)
- (*load-pathname* (merge-pathnames pathname)))
- (case contents
- (:source
- (with-open-file (stream truename
- :direction :input
- :if-does-not-exist if-does-not-exist
- :external-format external-format)
- (load-as-source stream verbose print)))
- (:binary
- (with-open-file (stream truename
- :direction :input
- :if-does-not-exist if-does-not-exist
- :element-type '(unsigned-byte 8))
- (load-as-fasl stream verbose print)))
- (t
- (let* ((fhsss *fasl-header-string-start-string*)
- (first-line (make-array (length fhsss)
- :element-type '(unsigned-byte 8)))
- (read-length
- (with-open-file (stream truename
- :direction :input
- :element-type '(unsigned-byte 8))
- (read-sequence first-line stream))))
- (cond
- ((and (= read-length (length fhsss))
- (do ((i 0 (1+ i)))
- ((= i read-length) t)
- (when (/= (char-code (aref fhsss i)) (aref first-line i))
- (return))))
- (internal-load pathname truename if-does-not-exist verbose print
- :binary))
- (t
- (when (string= (pathname-type truename) *fasl-file-type*)
- (error 'fasl-header-missing
- :stream (namestring truename)
- :fhsss first-line
- :expected fhsss))
- (internal-load pathname truename if-does-not-exist verbose print
- :source external-format))))))))
+(defmacro resignal-race-condition (&body body)
+ `(handler-case (progn ,@body)
+ (file-error (error)
+ (error 'load-race-condition :pathname (file-error-pathname error)))))
-;;; a helper function for INTERNAL-LOAD-DEFAULT-TYPE: Try the default
-;;; file type TYPE and return (VALUES PATHNAME TRUENAME) for a match,
-;;; or (VALUES PATHNAME NIL) if the file doesn't exist.
-;;;
-;;; This is analogous to CMU CL's TRY-DEFAULT-TYPES, but we only try a
-;;; single type. By avoiding CMU CL's generality here, we avoid having
-;;; to worry about some annoying ambiguities. (E.g. what if the
-;;; possible types are ".lisp" and ".cl", and both "foo.lisp" and
-;;; "foo.cl" exist?)
-(defun try-default-type (pathname type)
- (let ((pn (translate-logical-pathname (make-pathname :type type :defaults pathname))))
- (values pn (probe-file pn))))
+;;; The following comment preceded the pre 1.0.12.36 definition of
+;;; LOAD; it may no longer be accurate:
-;;; a helper function for LOAD: Handle the case of INTERNAL-LOAD where
-;;; the file does not exist.
-(defun internal-load-default-type
- (pathname if-does-not-exist verbose print external-format)
- (declare (type (member nil :error) if-does-not-exist))
- (multiple-value-bind (src-pn src-tn)
- (try-default-type pathname *load-source-default-type*)
- (multiple-value-bind (obj-pn obj-tn)
- (try-default-type pathname *fasl-file-type*)
- (cond
- ((and obj-tn
- src-tn
- (> (file-write-date src-tn) (file-write-date obj-tn)))
- (restart-case
- (error "The object file ~A is~@
- older than the presumed source:~% ~A."
- (namestring obj-tn)
- (namestring src-tn))
- (source () :report "load source file"
- (internal-load src-pn src-tn if-does-not-exist verbose print
- :source external-format))
- (object () :report "load object file"
- (internal-load src-pn obj-tn if-does-not-exist verbose print
- :binary))))
- (obj-tn
- (internal-load obj-pn obj-tn if-does-not-exist verbose print :binary))
- (src-pn
- (internal-load src-pn src-tn if-does-not-exist
- verbose print :source external-format))
- (t
- (internal-load pathname nil if-does-not-exist
- verbose print nil external-format))))))
+;; FIXME: Daniel Barlow's ilsb.tar ILISP-for-SBCL patches contain an
+;; implementation of "DEFUN SOURCE-FILE" which claims, in a comment,
+;; that CMU CL does not correctly record source file information when
+;; LOADing a non-compiled file. Check whether this bug exists in SBCL
+;; and fix it if so.
-;;; This function mainly sets up special bindings and then calls
-;;; sub-functions. We conditionally bind the switches with PROGV so
-;;; that people can set them in their init files and have the values
-;;; take effect. If the compiler is loaded, we make the
-;;; compiler-policy local to LOAD by binding it to itself.
-;;;
-;;; FIXME: Daniel Barlow's ilsb.tar ILISP-for-SBCL patches contain an
-;;; implementation of "DEFUN SOURCE-FILE" which claims, in a comment, that CMU
-;;; CL does not correctly record source file information when LOADing a
-;;; non-compiled file. Check whether this bug exists in SBCL and fix it if so.
-(defun load (filespec
- &key
- (verbose *load-verbose*)
- (print *load-print*)
- (if-does-not-exist t)
- (external-format :default))
+;;; This is our real LOAD. The LOAD below is just a wrapper that does
+;;; some defaulting in case the user asks us to load a file that
+;;; doesn't exist at the time we start.
+(defun %load (pathspec &key (verbose *load-verbose*) (print *load-print*)
+ (if-does-not-exist t) (external-format :default))
+ (when (streamp pathspec)
+ (let* (;; Bindings required by ANSI.
+ (*readtable* *readtable*)
+ (*package* (sane-package))
+ ;; FIXME: we should probably document the circumstances
+ ;; where *LOAD-PATHNAME* and *LOAD-TRUENAME* aren't
+ ;; pathnames during LOAD. ANSI makes no exceptions here.
+ (*load-pathname* (handler-case (pathname pathspec)
+ ;; FIXME: it should probably be a type
+ ;; error to try to get a pathname for a
+ ;; stream that doesn't have one, but I
+ ;; don't know if we guarantee that.
+ (error () nil)))
+ (*load-truename* (when *load-pathname*
+ (handler-case (truename *load-pathname*)
+ (file-error () nil))))
+ ;; Bindings used internally.
+ (*load-depth* (1+ *load-depth*))
+ ;; KLUDGE: I can't find in the ANSI spec where it says
+ ;; that DECLAIM/PROCLAIM of optimization policy should
+ ;; have file scope. CMU CL did this, and it seems
+ ;; reasonable, but it might not be right; after all,
+ ;; things like (PROCLAIM '(TYPE ..)) don't have file
+ ;; scope, and I can't find anything under PROCLAIM or
+ ;; COMPILE-FILE or LOAD or OPTIMIZE which justifies this
+ ;; behavior. Hmm. -- WHN 2001-04-06
+ (sb!c::*policy* sb!c::*policy*))
+ (return-from %load
+ (if (equal (stream-element-type pathspec) '(unsigned-byte 8))
+ (load-as-fasl pathspec verbose print)
+ (load-as-source pathspec verbose print)))))
+ ;; If we're here, PATHSPEC isn't a stream, so must be some other
+ ;; kind of pathname designator.
+ (with-open-file (stream pathspec
+ :element-type '(unsigned-byte 8)
+ :if-does-not-exist
+ (if if-does-not-exist :error nil))
+ (unless stream
+ (return-from %load nil))
+ (let* ((header-line (make-array
+ (length *fasl-header-string-start-string*)
+ :element-type '(unsigned-byte 8))))
+ (read-sequence header-line stream)
+ (if (mismatch header-line *fasl-header-string-start-string*
+ :test #'(lambda (code char) (= code (char-code char))))
+ (let ((truename (resignal-race-condition (probe-file stream))))
+ (when (and truename
+ (string= (pathname-type truename) *fasl-file-type*))
+ (error 'fasl-header-missing
+ :stream (namestring truename)
+ :fhsss header-line
+ :expected *fasl-header-string-start-string*)))
+ (progn
+ (file-position stream :start)
+ (return-from %load
+ (%load stream :verbose verbose :print print))))))
+ (resignal-race-condition
+ (with-open-file (stream pathspec
+ :external-format
+ external-format)
+ (%load stream :verbose verbose :print print))))
+
+;; Given a simple %LOAD like the above, one can implement any
+;; particular defaulting strategy with a wrapper like this one:
+(defun load (pathspec &key (verbose *load-verbose*) (print *load-print*)
+ (if-does-not-exist :error) (external-format :default))
#!+sb-doc
"Load the file given by FILESPEC into the Lisp environment, returning
T on success."
- (let ((*load-depth* (1+ *load-depth*))
- ;; KLUDGE: I can't find in the ANSI spec where it says that
- ;; DECLAIM/PROCLAIM of optimization policy should have file
- ;; scope. CMU CL did this, and it seems reasonable, but it
- ;; might not be right; after all, things like (PROCLAIM '(TYPE
- ;; ..)) don't have file scope, and I can't find anything under
- ;; PROCLAIM or COMPILE-FILE or LOAD or OPTIMIZE which
- ;; justifies this behavior. Hmm. -- WHN 2001-04-06
- (sb!c::*policy* sb!c::*policy*)
- ;; The ANSI spec for LOAD says "LOAD binds *READTABLE* and
- ;; *PACKAGE* to the values they held before loading the file."
- (*package* (sane-package))
- (*readtable* *readtable*)
- ;; The old CMU CL LOAD function used an IF-DOES-NOT-EXIST
- ;; argument of (MEMBER :ERROR NIL) type. ANSI constrains us to
- ;; accept a generalized boolean argument value for this
- ;; externally-visible function, but the internal functions
- ;; still use the old convention.
- (internal-if-does-not-exist (if if-does-not-exist :error nil)))
- ;; FIXME: This VALUES wrapper is inherited from CMU CL. Once SBCL
- ;; gets function return type checking right, we can achieve a
- ;; similar effect better by adding FTYPE declarations.
- (values
- (if (streamp filespec)
- (if (or (equal (stream-element-type filespec)
- '(unsigned-byte 8)))
- (load-as-fasl filespec verbose print)
- (load-as-source filespec verbose print))
- (let* ((pathname (pathname filespec))
- (physical-pathname (translate-logical-pathname pathname))
- (probed-file (probe-file physical-pathname)))
- (if (or probed-file
- (pathname-type physical-pathname))
- (internal-load
- physical-pathname probed-file internal-if-does-not-exist
- verbose print nil external-format)
- (internal-load-default-type
- pathname internal-if-does-not-exist
- verbose print external-format)))))))
+ (handler-bind ((file-error
+ #'(lambda (error)
+ ;; This handler will run if %LOAD failed to OPEN
+ ;; the file to look for a fasl header.
+ (let ((pathname (file-error-pathname error)))
+ ;; As PROBE-FILE returned NIL, the file
+ ;; doesn't exist. If the filename we tried to
+ ;; open lacked a type, try loading a filename
+ ;; determined by our defaulting.
+ (when (null (handler-case (probe-file pathname)
+ (file-error (error) error)))
+ (when (null (pathname-type pathname))
+ (let ((default (probe-load-defaults pathname)))
+ (when default
+ (return-from load
+ (resignal-race-condition
+ (%load default
+ :verbose verbose
+ :print print
+ :external-format
+ external-format
+ :if-does-not-exist
+ if-does-not-exist))))))))
+ ;; If we're here, one of three things happened:
+ ;; (1) %LOAD errored and PROBE-FILE succeeded,
+ ;; in which case the file must be a bad symlink,
+ ;; unreadable, or it was created between %LOAD
+ ;; and PROBE-FILE; (2) %LOAD errored and
+ ;; PROBE-FILE errored, and so things are amiss
+ ;; in the file system (albeit possibly
+ ;; differently now than when OPEN errored); (3)
+ ;; our defaulting did not find a file. In any
+ ;; of these cases, decline to handle the
+ ;; original error or return NIL, depending on
+ ;; IF-DOES-NOT-EXIST.
+ (if if-does-not-exist
+ nil
+ (return-from load nil)))))
+ (%load pathspec :verbose verbose :print print
+ :external-format external-format)))
+
+;; This implements the defaulting SBCL seems to have inherited from
+;; CMU. This routine does not try to perform any loading; all it does
+;; is return the pathname (not the truename) of a file to be loaded,
+;; or NIL if no such file can be found. This routine is supposed to
+;; signal an error if a fasl's timestamp is older than its source
+;; file, but we protect against errors in PROBE-FILE, because any of
+;; the ways that we might fail to find a defaulted file are reasons
+;; not to load it, but not worth exposing to the user who didn't
+;; expicitly ask us to load a file with a made-up name (e.g., the
+;; defaulted filename might exceed filename length limits).
+(defun probe-load-defaults (pathname)
+ (destructuring-bind (defaulted-source-pathname
+ defaulted-source-truename
+ defaulted-fasl-pathname
+ defaulted-fasl-truename)
+ (loop for type in (list *load-source-default-type*
+ *fasl-file-type*)
+ as probe-pathname = (make-pathname :type type
+ :defaults pathname)
+ collect probe-pathname
+ collect (handler-case (probe-file probe-pathname)
+ (file-error () nil)))
+ (cond ((and defaulted-fasl-truename
+ defaulted-source-truename
+ (> (resignal-race-condition
+ (file-write-date defaulted-source-truename))
+ (resignal-race-condition
+ (file-write-date defaulted-fasl-truename))))
+ (restart-case
+ (error "The object file ~A is~@
+ older than the presumed source:~% ~A."
+ defaulted-fasl-truename
+ defaulted-source-truename)
+ (source () :report "load source file"
+ defaulted-source-pathname)
+ (object () :report "load object file"
+ defaulted-fasl-pathname)))
+ (defaulted-fasl-truename defaulted-fasl-pathname)
+ (defaulted-source-truename defaulted-source-pathname))))
\f
;;; Load a code object. BOX-NUM objects are popped off the stack for
;;; the boxed storage section, then SIZE bytes of code are read in.
(load *tmp-filename*)
(assert (equal (merge-pathnames *tmp-filename*) *saved-load-pathname*)))
(delete-file *tmp-filename*))))
+\f
+;;; Test many, many variations on LOAD.
+(defparameter *counter* 0)
+(defparameter *loaded-pathname* nil)
+(defparameter *loaded-truename* nil)
+(defparameter *test-program-string* (format nil "~
+ (incf *counter*)
+ (setf *loaded-pathname* *load-pathname*)
+ (setf *loaded-truename* *load-truename*)"))
+
+(defmacro load-and-assert (load-argument pathname truename)
+ (let ((before (gensym)))
+ `(let ((,before *counter*)
+ *loaded-pathname* *loaded-truename*)
+ (load ,load-argument :print t :verbose t)
+ (assert (and (= (1+ ,before) *counter*)
+ (equal ,(if pathname `(merge-pathnames ,pathname))
+ *loaded-pathname*)
+ (equal ,(if pathname `(merge-pathnames ,truename))
+ *loaded-truename*))))))
+
+(defmacro with-test-program (source fasl &body body)
+ (let ((src (gensym))
+ (fsl (gensym)))
+ `(let ((,src ,source)
+ (,fsl ,fasl))
+ (with-open-file (*standard-output* ,src :direction :output
+ :if-exists :supersede)
+ (princ *test-program-string*))
+ (when ,fsl
+ (compile-file ,src :output-file ,fsl))
+ (unwind-protect
+ (progn
+ ,@body)
+ (when (probe-file ,src)
+ (delete-file ,src))
+ (when (and ,fsl (probe-file ,fsl))
+ (delete-file ,fsl))))))
+
+;;; Loading from streams.
+
+;; string-stream
+(with-input-from-string (s *test-program-string*)
+ (load-and-assert s nil nil))
+
+;; file-stream associated with a source file
+(let ((source (pathname "load-impure-test.lisp")))
+ (with-test-program source nil
+ (with-open-file (stream source)
+ (load-and-assert stream source source))))
+
+;; file-stream associated with a fasl file
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source)))
+ (with-test-program source fasl
+ (with-open-file (stream fasl :element-type 'unsigned-byte)
+ (load-and-assert fasl fasl fasl))))
+
+;; Develop a simple Gray stream to test loading from.
+(defclass load-impure-gray-stream (fundamental-character-input-stream)
+ ((pointer :initform 0 :accessor load-impure-gray-stream-pointer)))
+
+(defmethod stream-read-char ((stream load-impure-gray-stream))
+ (with-accessors ((pointer load-impure-gray-stream-pointer)) stream
+ (prog1
+ (if (>= pointer (length *test-program-string*))
+ :eof
+ (char *test-program-string* pointer))
+ (incf pointer))))
+
+(defmethod stream-unread-char ((stream load-impure-gray-stream) char)
+ (with-accessors ((pointer load-impure-gray-stream-pointer)) stream
+ (if (<= pointer 0)
+ (error "fibber! you never read from this stream ~S" stream)
+ (decf pointer)))
+ nil)
+
+(with-open-stream (stream (make-instance 'load-impure-gray-stream))
+ (load-and-assert stream nil nil))
+
+;;; Loading from things named by pathname designators.
+
+;; Test loading a source file by supplying a complete pathname.
+(let ((source (pathname "load-impure-test.lisp")))
+ (with-test-program source nil
+ (load-and-assert source source source)))
+
+;; Test loading a source file when supplying a partial pathname.
+(let ((source (pathname "load-impure-test.lisp"))
+ (partial (pathname "load-impure-test")))
+ (with-test-program source nil
+ (load-and-assert partial source source)))
+
+;; Test loading a source file whose name lacks a type when supplying a
+;; partial pathname.
+(let ((source (make-pathname :type :unspecific
+ :defaults (pathname "load-impure-test")))
+ (partial (pathname "load-impure-test")))
+ (with-test-program source nil
+ (load-and-assert partial partial partial)))
+
+;; Test loading a fasl
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source)))
+ (with-test-program source fasl
+ (load-and-assert fasl fasl fasl)))
+
+;; Test loading a fasl when supplying a partial pathname.
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source))
+ (partial (pathname "load-impure-test")))
+ (with-test-program source fasl
+ (load-and-assert partial fasl fasl)))
+
+;; Test loading a fasl whose name lacks a type when supplying a
+;; partial pathname.
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (make-pathname :type :unspecific
+ :defaults (compile-file-pathname source)))
+ (partial (pathname "load-impure-test")))
+ (with-test-program source fasl
+ (load-and-assert partial partial partial)))
+
+;; Test loading a fasl with a strange type
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (make-pathname :defaults (compile-file-pathname source)
+ :type "compiled-lisp")))
+ (with-test-program source fasl
+ (load-and-assert fasl fasl fasl)))
+
+;;; Errors
+
+;; Ensure that loading a fasl specified with a type checks for the
+;; header.
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source)))
+ (with-test-program source fasl
+ (with-open-file (f fasl :direction :io :if-exists :overwrite
+ :element-type '(unsigned-byte 8))
+ (write-byte 0 f))
+ (handler-case (load fasl)
+ (sb-fasl::fasl-header-missing () :ok))))
+
+;; Ensure that loading a fasl specified without a type checks for the
+;; header. Note: this wasn't the behavior in
+;; src/code/target-load.lisp v1.40 and earlier (SBCL version 1.0.12.35
+;; or so). If target-load.lisp is reverted to that state eventually,
+;; this test should be removed (or that definition of LOAD altered).
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source))
+ (fasl-spec (make-pathname :type nil
+ :defaults (compile-file-pathname source))))
+ (with-test-program source fasl
+ (with-open-file (f fasl :direction :io :if-exists :overwrite
+ :element-type '(unsigned-byte 8))
+ (write-byte 0 f))
+ (handler-case (load fasl-spec)
+ (sb-fasl::fasl-header-missing () :ok))))
+
+;; Ensure that we get an error when the source file is newer than the
+;; fasl and the supplied argument is an incomplete pathname.
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source))
+ (spec (make-pathname :type nil :defaults source)))
+ (with-test-program source fasl
+ (sleep 1)
+ (with-open-file (*standard-output* source :direction :output
+ :if-exists :append)
+ (write-line ";;comment"))
+ (handler-case (load spec)
+ ;; IWBNI the error signalled here were more specific than
+ ;; SIMPLE-ERROR.
+ (error () :|well, we got an error!|))))
+
+;; Ensure that we can invoke the restart SOURCE in the above case.
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source))
+ (spec (make-pathname :type nil :defaults source)))
+ (with-test-program source fasl
+ (sleep 1)
+ (with-open-file (*standard-output* source :direction :output
+ :if-exists :append)
+ (write-line ";;comment"))
+ (handler-bind ((error (lambda (error)
+ (declare (ignore error))
+ (when (find-restart 'sb-fasl::source)
+ (invoke-restart 'sb-fasl::source)))))
+ (load-and-assert spec source source))))
+
+;; Ensure that we can invoke the restart OBJECT in the above case.
+(let* ((source (pathname "load-impure-test.lisp"))
+ (fasl (compile-file-pathname source))
+ (spec (make-pathname :type nil :defaults source)))
+ (with-test-program source fasl
+ (sleep 1)
+ (with-open-file (*standard-output* source :direction :output
+ :if-exists :append)
+ (write-line ";;comment"))
+ (handler-bind ((error (lambda (error)
+ (declare (ignore error))
+ (when (find-restart 'sb-fasl::object)
+ (invoke-restart 'sb-fasl::object)))))
+ (load-and-assert spec fasl fasl))))
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