X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-load.lisp;h=ed607ff6c99947a8ef92e7e06a3c16633b223d98;hb=a01e7ac2e8a9f3afae8f759381a0829fceb5bfde;hp=9ae8a460cd22349209aa02d5869d1620d2f970da;hpb=4898ef32c639b1c7f4ee13a5ba566ce6debd03e6;p=sbcl.git diff --git a/src/code/target-load.lisp b/src/code/target-load.lisp index 9ae8a46..ed607ff 100644 --- a/src/code/target-load.lisp +++ b/src/code/target-load.lisp @@ -27,7 +27,7 @@ ;;;; 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*) @@ -52,167 +52,192 @@ (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 "~@" + (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)))))) + ;; Because we're just opening for input, we don't need + ;; WITH-OPEN-FILE's abort handling semantics, and we want to say + ;; it's an error for PATHSPEC to have existed before but not now, so + ;; WITH-OPEN-STREAM it is. + (with-open-stream (stream (resignal-race-condition + (open 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)))) ;;; 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.