-;;;; support for dynamically loading foreign object files
+;;;; support for dynamically loading foreign object files and
+;;;; resolving symbols therein
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.
-(in-package "SB-SYS")
-
-(file-comment
- "$Header$")
-
-;;; not needed until we implement full-blown LOAD-FOREIGN
-#|
-(defun pick-temporary-file-name (&optional
- ;; KLUDGE: There are various security
- ;; nastyisms associated with easily
- ;; guessable temporary file names,
- ;; and we haven't done anything to
- ;; work around them here. -- pointed
- ;; out by Dan Barlow on sbcl-devel
- ;; 20000702
- (base "/tmp/sbcl-tmp-~D~C"))
- (let ((code (char-code #\A)))
- (loop
- (let ((name (format nil base (sb-unix:unix-getpid) (code-char code))))
- (multiple-value-bind (fd errno)
- (sb-unix:unix-open name
- (logior sb-unix:o_wronly
- sb-unix:o_creat
- sb-unix:o_excl)
- #o666)
- (cond ((not (null fd))
- (sb-unix:unix-close fd)
- (return name))
- ((not (= errno sb-unix:eexist))
- (error "could not create temporary file ~S: ~A"
- name
- (sb-unix:get-unix-error-msg errno)))
- ;; KLUDGE: depends on ASCII character ordering -- WHN 20000128
- ((= code (char-code #\Z))
- (setf code (char-code #\a)))
- ((= code (char-code #\z))
- (return nil))
- (t
- (incf code))))))))
-|#
+(in-package "SB-ALIEN") ; (SB-ALIEN, not SB!ALIEN, since we're in warm load.)
;;; On any OS where we don't support foreign object file loading, any
;;; query of a foreign symbol value is answered with "no definition
;;; known", i.e. NIL.
-;;;
-;;; (On any OS which *does* support foreign object file loading, this
-;;; placeholder implementation is overwritten by a subsequent real
-;;; implementation.)
+#-(or linux sunos FreeBSD OpenBSD NetBSD darwin)
(defun get-dynamic-foreign-symbol-address (symbol)
(declare (type simple-string symbol) (ignore symbol))
nil)
-;;; Linux implementation of GET-DYNAMIC-FOREIGN-SYMBOL-ADDRESS
-;;; and functions (e.g. LOAD-FOREIGN) which affect it
-#+(or linux FreeBSD)
-(progn
-
-;;; flags for dlopen()
-(defconstant rtld-lazy 1) ; lazy function call binding?
-(defconstant rtld-now 2) ; immediate function call binding?
-(defconstant rtld-global #x100) ; symbols of loaded obj file
- ; (and its dependencies) made
- ; visible (as though the
- ; obj file were linked directly
- ; into the program)?
-
-;;; a list of tables returned from dlopen(3) (or possibly some
+;;; dlsym()-based implementation of GET-DYNAMIC-FOREIGN-SYMBOL-ADDRESS
+;;; and functions (e.g. LOAD-FOREIGN) which affect it. This should
+;;; work on any ELF system with dlopen(3) and dlsym(3)
+;;; It also works on OpenBSD, which isn't ELF, but is otherwise modern
+;;; enough to have a fairly well working dlopen/dlsym implementation.
+(macrolet ((define-unsupported-fun (fun-name &optional (error-message "unsupported on this system"))
+ `(defun ,fun-name (&rest rest)
+ ,error-message
+ (declare (ignore rest))
+ (error 'unsupported-operator :name ',fun-name))))
+ #-(or linux sunos FreeBSD OpenBSD NetBSD darwin)
+ (define-unsupported-fun load-shared-object)
+ #+(or linux sunos FreeBSD OpenBSD NetBSD darwin)
+ (progn
+
+ (define-unsupported-fun load-foreign "Unsupported as of SBCL 0.8.13.")
+ (define-unsupported-fun load-1-foreign "Unsupported as of SBCL 0.8.13. Please use LOAD-SHARED-OBJECT.")
+
+;;; a list of handles returned from dlopen(3) (or possibly some
;;; bogus value temporarily during initialization)
-(defvar *tables-from-dlopen* nil)
+ (defvar *handles-from-dlopen* nil)
+
;;; Dynamically loaded stuff isn't there upon restoring from a save.
;;; Clearing the variable this way was originally done primarily for
;;; Irix, which resolves tzname at runtime, resulting in
-;;; *TABLES-FROM-DLOPEN* being set in the saved core image, resulting
-;;; in havoc upon restart; but it seems harmless and tidy for other
-;;; OSes too.
+;;; *HANDLES-FROM-DLOPEN* (which was then called *TABLES-FROM-DLOPEN*)
+;;; being set in the saved core image, resulting in havoc upon
+;;; restart; but it seems harmless and tidy for other OSes too.
;;;
;;; Of course, it can be inconvenient that dynamically loaded stuff
;;; goes away when we save and restore. However,
;;; dynamic loading of foreign files and saving/restoring cores,
;;; he probably has the sophistication to write his own after-save
;;; code to reload the libraries without much difficulty.
-(push (lambda () (setq *tables-from-dlopen* nil))
- sb-int:*after-save-initializations*)
-
-;;; not needed until we implement full-blown LOAD-FOREIGN
-#|
-(defvar *dso-linker* "/usr/bin/ld")
-(defvar *dso-linker-options* '("-G" "-o"))
-|#
-
-(sb-alien:def-alien-routine dlopen system-area-pointer
- (file sb-c-call:c-string) (mode sb-c-call:int))
-(sb-alien:def-alien-routine dlsym system-area-pointer
- (lib system-area-pointer)
- (name sb-c-call:c-string))
-(sb-alien:def-alien-routine dlerror sb-c-call:c-string)
-
-;;; Ensure that we've opened our own binary so we can resolve global
-;;; variables in the Lisp image that come from libraries. This used to
-;;; happen only in GET-DYNAMIC-FOREIGN-SYMBOL-ADDRESS, and only if no
-;;; libraries were dlopen()ed already, but that didn't work if
-;;; something was dlopen()ed before any problem global vars were used.
-;;; So now we do this in any function that can add to the
-;;; *TABLES-FROM-DLOPEN*, as well as in
-;;; GET-DYNAMIC-FOREIGN-SYMBOL-ADDRESS.
-(defun ensure-lisp-table-opened ()
- (unless *tables-from-dlopen*
- ;; Prevent recursive call if dlopen() isn't defined.
- (setf *tables-from-dlopen* (int-sap 0))
- (setf *tables-from-dlopen* (list (dlopen nil rtld-lazy)))
- (when (zerop (sb-sys:sap-int (first *tables-from-dlopen*)))
- (error "can't open global symbol table: ~S" (dlerror)))))
-(defun load-1-foreign (file)
- "a primitive way to load a foreign object file. (LOAD-FOREIGN is
- probably preferred, but as of SBCL 0.6.7 is not implemented..)
-
- To use LOAD-1-FOREIGN, at the Unix command line do this:
+;;; dan 2001.05.10 suspects that objection (1) is bogus for
+;;; dlsym()-enabled systems
+
+ (push (lambda () (setq *handles-from-dlopen* nil))
+ *after-save-initializations*)
+
+ (define-alien-routine dlopen system-area-pointer
+ (file c-string) (mode int))
+
+ (define-alien-routine dlsym system-area-pointer
+ (lib system-area-pointer) (name c-string))
+
+ (define-alien-routine dlerror c-string)
+
+;;; Ensure that we've opened our own binary so we can dynamically resolve
+;;; symbols in the C runtime.
+;;;
+;;; Old comment: This used to happen only in
+;;; GET-DYNAMIC-FOREIGN-SYMBOL-ADDRESS, and only if no libraries were
+;;; dlopen()ed already, but that didn't work if something was
+;;; dlopen()ed before any problem global vars were used. So now we do
+;;; this in any function that can add to the *HANDLES-FROM-DLOPEN*, as
+;;; well as in GET-DYNAMIC-FOREIGN-SYMBOL-ADDRESS.
+;;;
+;;; FIXME: It would work just as well to do it once at startup, actually.
+;;; Then at least we know it's done. -dan 2001.05.10
+ (defun ensure-runtime-symbol-table-opened ()
+ (unless *handles-from-dlopen*
+ ;; Prevent recursive call if dlopen() isn't defined.
+ (setf *handles-from-dlopen* (int-sap 0))
+ (setf *handles-from-dlopen* (list (dlopen nil rtld-lazy)))
+ (when (zerop (sb-sys:sap-int (first *handles-from-dlopen*)))
+ (error "can't open our own binary's symbol table: ~S" (dlerror)))))
+
+ (defun load-shared-object (file)
+ "Load a shared library/dynamic shared object file/general
+ dlopenable alien container.
+
+ To use LOAD-SHARED-OBJECT, at the Unix command line do this:
echo 'int summish(int x, int y) { return 1 + x + y; }' > /tmp/ffi-test.c
make /tmp/ffi-test.o # i.e. cc -c -o /tmp/ffi-test.o /tmp/ffi-test.c
ld -shared -o /tmp/ffi-test.so /tmp/ffi-test.o
then in SBCL do this:
- (LOAD-1-FOREIGN \"/tmp/ffi-test.so\")
- (DEF-ALIEN-ROUTINE SUMMISH INT (X INT) (Y INT))
+ (LOAD-SHARED-OBJECT \"/tmp/ffi-test.so\")
+ (DEFINE-ALIEN-ROUTINE SUMMISH INT (X INT) (Y INT))
Now running (SUMMISH 10 20) should return 31.
"
- (ensure-lisp-table-opened)
- ;; Note: We use RTLD-GLOBAL so that it can find all the symbols
- ;; previously loaded. We use RTLD-NOW so that dlopen() will fail if
- ;; not all symbols are defined.
- (let ((sap (dlopen file (logior rtld-now rtld-global))))
- (if (zerop (sap-int sap))
- (error "can't open object ~S: ~S" file (dlerror))
- (pushnew sap *tables-from-dlopen* :test #'sap=)))
- (values))
-
-(defun get-dynamic-foreign-symbol-address (symbol)
- (ensure-lisp-table-opened)
- ;; Find the symbol in any of the loaded object files. Search in
- ;; reverse order of loading, so that later loadings take precedence.
- ;;
- ;; FIXME: The way that we use PUSHNEW SAP in LOAD-1-FOREIGN means
- ;; that the list isn't guaranteed to be in reverse order of loading,
- ;; at least not if a file is loaded more than once. Is this the
- ;; right thing? (In what cases does it matter?)
- (dolist (table *tables-from-dlopen*)
- ;; KLUDGE: We implicitly exclude the possibility that the variable
- ;; could actually be NULL, but the man page for dlsym(3)
- ;; recommends doing a more careful test. -- WHN 20000825
- (let ((possible-result (sap-int (dlsym table symbol))))
- (unless (zerop possible-result)
- (return possible-result)))))
-
-;;; code partially ported from CMU CL to SBCL, but needs RUN-PROGRAM
-#|
-(defun load-foreign (files &key
- (libraries '("-lc"))
- (base-file nil)
- ;; Note: Since SBCL has no *ENVIRONMENT-LIST*
- ;; variable, if this code is ever restored,
- ;; the default should be taken from the alien
- ;; "environ" variable.
- ,, ; do it!
- (env sb-ext:*environment-list*))
- #+sb-doc
- "LOAD-FOREIGN loads a list of C object files into a running Lisp. The FILES
- argument should be a single file or a list of files. The files may be
- specified as namestrings or as pathnames. The libraries argument should be a
- list of library files as would be specified to ld. They will be searched in
- the order given. The default is just \"-lc\", i.e., the C library. The
- base-file argument is used to specify a file to use as the starting place for
- defined symbols. The default is the C start up code for Lisp. The ENV
- argument is the Unix environment variable definitions for the invocation of
- the linker. The default is the environment passed to Lisp."
- ;; Note: dlopen() remembers the name of an object, when dlopen()ing
- ;; the same name twice, the old object is reused.
- (declare (ignore base-file))
- (let ((output-file (pick-temporary-file-name
- (concatenate 'string "/tmp/~D~C" (string (gensym)))))
- (error-output (make-string-output-stream)))
-
- (/show "running" *dso-linker*)
- (force-output)
- (unwind-protect
- (let ((proc (sb-ext:run-program
- *dso-linker*
- (append *dso-linker-options*
- (list output-file)
- (append (mapcar #'(lambda (name)
- (unix-namestring name nil))
- (if (atom files)
- (list files)
- files))
- libraries))
- :env env
- :input nil
- :output error-output
- :error :output)))
- (unless proc
- (error "could not run ~A" *dso-linker*))
- (unless (zerop (sb-ext:process-exit-code proc))
- (sb-sys:serve-all-events 0)
- (error "~A failed:~%~A" *dso-linker*
- (get-output-stream-string error-output)))
- (load-1-foreign output-file))
- #-sb-show (sb-unix:unix-unlink output-file)
- #+sb-show (/show "not unlinking" output-file)))) ; so we can look at it
-|#
-
-) ; PROGN
+ (ensure-runtime-symbol-table-opened)
+ ;; Note: We use RTLD-GLOBAL so that it can find all the symbols
+ ;; previously loaded. We use RTLD-NOW so that dlopen() will fail if
+ ;; not all symbols are defined.
+ (let* ((real-file (or (unix-namestring file) file))
+ (sap (dlopen real-file (logior rtld-now rtld-global))))
+ (if (zerop (sap-int sap))
+ (error "can't open object ~S: ~S" real-file (dlerror))
+ (pushnew sap *handles-from-dlopen* :test #'sap=)))
+ (values))
+
+ (defun get-dynamic-foreign-symbol-address (symbol)
+ (ensure-runtime-symbol-table-opened)
+ ;; Find the symbol in any of the loaded object files. Search in
+ ;; reverse order of loading, so that later loadings take precedence.
+ ;;
+ ;; FIXME: The way that we use PUSHNEW SAP in LOAD-SHARED-OBJECT means
+ ;; that the list isn't guaranteed to be in reverse order of loading,
+ ;; at least not if a file is loaded more than once. Is this the
+ ;; right thing? (In what cases does it matter?)
+ (dolist (handle (reverse *handles-from-dlopen*))
+ ;; KLUDGE: We implicitly exclude the possibility that the variable
+ ;; could actually be NULL, but the man page for dlsym(3)
+ ;; recommends doing a more careful test. -- WHN 20000825
+ (let ((possible-result (sap-int (dlsym handle symbol))))
+ (unless (zerop possible-result)
+ (return possible-result)))))
+
+ (defun foreign-symbol-in-address (sap)
+ (declare (ignore sap)))
+
+ (when (ignore-errors (foreign-symbol-address "dladdr"))
+ (setf (symbol-function 'foreign-symbol-in-address)
+ ;; KLUDGE: This COMPILE trick is to avoid trying to
+ ;; compile a reference to dladdr on platforms without it.
+ (compile nil
+ '(lambda (sap)
+ (let ((addr (sap-int sap)))
+ (with-alien ((info
+ (struct dl-info
+ (filename c-string)
+ (base unsigned)
+ (symbol c-string)
+ (symbol-address unsigned)))
+ (dladdr
+ (function unsigned
+ unsigned (* (struct dl-info)))
+ :extern "dladdr"))
+ (let ((err (alien-funcall dladdr addr (addr info))))
+ (if (zerop err)
+ nil
+ (values (slot info 'symbol)
+ (slot info 'filename)
+ addr
+ (- addr (slot info 'symbol-address)))))))))))
+
+ )) ; PROGN, MACROLET