September 2009 - cffi-devel - mailman3.common-lisp.net

[cffi-devel] Foreign structures by value
by Liam Healy 26 Aug '10

26 Aug '10

I have written Foreign Structures By Value (FSBV) to allow calling foreign functions while passing or returning structures by value. It uses CFFI and libffi. It currently provides two macros for users, fsbv:defcstruct and fsbv:foreign-funcall, which are used exactly like their CFFI counterparts. It works for small test cases I've tried, but probably could use some improvement. If the keepers of CFFI are interested, I would be happy for it to be included in CFFI. In the meantime, it can be found here: http://repo.or.cz/w/fsbv.git Thank you. Liam

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[cffi-devel] %load-foreign-library on SBCL
by Elliott Slaughter 27 Jan '10

27 Jan '10

Hi, I have a question about the implementation of %load-foreign-library on SBCL. It seems that the call to load-shared-object remembers the absolute pathname to the library that is loaded unless :dont-save t is used. This causes portability issues for my application, which can't load from the same path when used on different systems. Is there any reason to choose this behavior? Of course, with :dont-save t, the user then has to call use-foreign-library again when starting up from the saved image, but I find this preferable to the crash I receive otherwise. An example patch is included below. Thanks. --- src/cffi-sbcl.lisp~ 2009-04-14 19:33:40.000000000 -0700 +++ src/cffi-sbcl.lisp 2009-04-03 15:28:37.000000000 -0700 @@ -324,7 +324,7 @@ (defun %load-foreign-library (name path) "Load a foreign library." (declare (ignore name)) - (load-shared-object path)) + (load-shared-object path :dont-save t)) ;;; SBCL 1.0.21.15 renamed SB-ALIEN::SHARED-OBJECT-FILE but introduced ;;; SB-ALIEN:UNLOAD-SHARED-OBJECT which we can use instead. -- Elliott Slaughter "Don't worry about what anybody else is going to do. The best way to predict the future is to invent it." - Alan Kay

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[cffi-devel] automatic conversion of array of (unsigned-byte 8) to c-string
by Johan Ur Riise 27 Sep '09

27 Sep '09

this is exactly the example from the manual: (let ((str (make-array 4 :element-type '(unsigned-byte 8) :initial-element 65))) (foreign-funcall "strlen" :string str :int)) but my lisp says: #(65 65 65 65) is not a Lisp string or pointer. [Condition of type SIMPLE-ERROR] What is going on? This works as expected: (let ((str (make-array 4 :element-type 'character :initial-element (code-char 65)))) (foreign-funcall "strlen" :string str :int)) => 4 I run clozure cl on windows 32

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[cffi-devel] [johan@riise-data.no: Re: using defcenum keywords in function call]
by Johan Ur Riise 26 Sep '09

26 Sep '09

----- Forwarded message from Johan Ur Riise <johan(a)riise-data.no> ----- Subject: Re: [cffi-devel] using defcenum keywords in function call Date: Sat, 26 Sep 2009 07:09:49 +0200 From: Johan Ur Riise <johan(a)riise-data.no> To: Stelian Ionescu <sionescu(a)cddr.org> On Sat, Sep 26, 2009 at 05:19:15AM +0200, Stelian Ionescu wrote: > > DEFCENUM doesn't define constants(as in C), but a type which gets > translated to integers if you specify it as argument type. In other > words, this is correct: > > (defcfun ("socket" win-socket) socket > "Creates a socket with the overlapped mode as default" > (af af) > (type sock-type) > (protocol pf)) > Thanks, that worked, and I can see now that the curl example shows how to do it. For the record, this definition has a better chance of actually returning a socket: (defcenum af :af-unspec :af-unix :af-inet) (defcenum sock-type (:sock-stream 1) :sock-dgram :sock-raw) (defcenum proto (:tcp 6) (:udp 17)) (defun make-socket () (foreign-funcall "socket" af :af-inet sock-type :sock-stream proto :tcp socket)) ----- End forwarded message -----

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[cffi-devel] using defcenum keywords in function call
by Johan Ur Riise 26 Sep '09

26 Sep '09

I have some enums defined, a defcfun and I use the keywords of the enum when I call the function. The documentation says: Keywords will be automatically converted to values and vice-versa when being passed as arguments to or returned from foreign functions, respectively. But this does not seem to be the case, I get a type error. The following should be a minimalistic runnable example. What am I doing wrong? CL-USER> (require 'cffi) ; loading system definition from C:/prg/libcl/babel/babel.asd into #<Package "ASDF0"> ; registering #<SYSTEM BABEL #x14DE5106> as BABEL ; loading system definition from C:/prg/libcl/alexandria/alexandria.asd into #<Package "ASDF0"> ; registering #<SYSTEM :ALEXANDRIA #x14E038B6> as ALEXANDRIA ; loading system definition from C:/prg/libcl/trivial-features/trivial-features.asd into #<Package "ASDF0"> ; registering #<SYSTEM TRIVIAL-FEATURES #x14E5DAE6> as TRIVIAL-FEATURES CFFI NIL CL-USER> (in-package :cffi) #<Package "CFFI"> CFFI> (defctype SOCKET :uint) SOCKET CFFI> (defcenum af :af-unspec :af-unix :af-inet) AF CFFI> (defcenum sock-type (:sock-stream 1) :sock-dgram :sock-raw) SOCK-TYPE CFFI> (defcenum pf :pf-unspec :pf-unix :pf-inet) PF CFFI> (defcfun ("socket" win-socket) socket "Creates a socket with the overlapped mode as default" (af :int32) (type :int) (protocol :int)) WIN-SOCKET CFFI> (defun make-socket () (win-socket :af-inet :sock-stream :pf-inet)) MAKE-SOCKET CFFI> (make-socket) ; Evaluation aborted. CFFI> ;->value :AF-INET is not of the expected type (SIGNED-BYTE 32). ;[Condition of type TYPE-ERROR] ; No value CFFI>

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[cffi-devel] EPoll Bindings for CCL
by Volkan YAZICI 18 Sep '09

18 Sep '09

Hi, I've released the first draft of my EPoll package[1][2]. While everything works for SBCL, `EPFD-WAIT' returns weird file descriptors (e.g. -65536) on CCL. Consider example below. CL-USER> (loop for pkg in '(cffi alexandria usocket epoll) do (asdf:oos 'asdf:load-op pkg)) ... NIL CL-USER> (usocket:with-socket-listener (server-socket "0.0.0.0" 4040 :reuse-address t) (alexandria:when-let (client-socket (usocket:socket-accept server-socket)) (unwind-protect (progn (epoll:with-epfd (epfd) (epoll:epfd-control epfd :add (epoll:socket-fd (usocket:socket client-socket)) :in :pri :err) (epoll:epfd-wait epfd 5000))) (usocket:socket-close client-socket)))) ((-65536 :IN)) Any ideas about what might I be missing? Regards. [1] http://github.com/vy/epoll [2] http://cliki.net/epoll

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[cffi-devel] sizeof() Operator
by Volkan YAZICI 13 Sep '09

13 Sep '09

Hi, Is there anything available in CFFI similar to sizeof() operator in C? I want to get the size of the structs/types defined via DEFCSTURCT/DEFCTYPE. Regards.

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[cffi-devel] Grovel fails parsing file
by Reinout Stevens 12 Sep '09

12 Sep '09

Hi, I'm trying to use sysctl.h under FreeBSD (should also exists under OSX) , but grovel can't parse that file. /usr/include/sys/sysctl.h:699: error: expected declaration specifiers or '...' before 'size_t' grovel.c: In function 'print_double_for_lisp': grovel.c:64: warning: incompatible implicit declaration of built-in function 'memset' The offending line is: int sysctlnametomib(const char *, int *, size_t *); Any clues how to fix this or is it a known feature?

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[cffi-devel] EPoll Interface
by Volkan YAZICI 11 Sep '09

11 Sep '09

Hi, I'm working on an epoll interface, but having trouble with nested structs. Below code snippet is just a minor example where things explode. Does anybody have an idea about what I might be missing? Regards. (defmacro prog1-let ((var val) &body body) `(let ((,var ,val)) ,@body ,var)) (defmacro maybe-error (test) (let ((errno (gensym))) `(when ,test (let ((,errno *errno*)) (error (foreign-funcall "strerror" :int ,errno :string)))))) (defcvar "errno" :int) ; typedef union epoll_data { ; void *ptr; ; int fd; ; __uint32_t u32; ; __uint64_t u64; ; } epoll_data_t; (defcstruct data (ptr :pointer) (fd :int) (u32 :uint32) (u64 :uint64)) ; struct epoll_event { ; __uint32_t events; /* Epoll events */ ; epoll_data_t data; /* User data variable */ ; }; (defcstruct event (events :uint32) (data data)) ; int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event); (defcfun "epoll_ctl" :int (epfd :int) (op :int) (fd :int) (event (:pointer event))) (defun control (epfd op fd events) (with-foreign-object (event-ptr 'event) ;; Set `EVENTS' slot of the `EVENTS'. (setf (foreign-slot-value event-ptr 'event 'events) events) ;; Empty `DATA' slot of the `EVENTS', and set `FD' slot of the `DATA'. (let ((data-ptr (foreign-slot-pointer event-ptr 'event 'data))) (setf (foreign-slot-value data-ptr 'data 'ptr) 0 (foreign-slot-value data-ptr 'data 'u32) 0 (foreign-slot-value data-ptr 'data 'u64) 0 (foreign-slot-value data-ptr 'data 'fd) fd)) (prog1-let (res (foreign-funcall "epoll_ctl" :int epfd :int op :int fd :pointer event-ptr :int)) (maybe-error (minusp res))))) ; in: DEFUN CONTROL ; (SETF (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::PTR) ; 0 ; (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::U32) ; 0 ; (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::U64) ; 0 ; (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::FD) ; EPOLL::FD) ; --> PROGN SETF LET* MULTIPLE-VALUE-BIND LET PROGN CFFI::FOREIGN-SLOT-SET ; --> SETF LET* MULTIPLE-VALUE-BIND LET PROGN CFFI::MEM-SET ; --> CFFI-SYS:%MEM-SET LET SETF SB-KERNEL:%SET-SAP-REF-32 ; ==> ; EPOLL::DATA-PTR ; ; note: deleting unreachable code ; (EPOLL::PROG1-LET ; (EPOLL::RES ; (CFFI:FOREIGN-FUNCALL "epoll_ctl" :INT EPOLL::EPFD :INT EPOLL::OP :INT ; EPOLL::FD :POINTER EPOLL::EVENT-PTR :INT)) ; (EPOLL::MAYBE-ERROR (< EPOLL::RES 0))) ; --> LET ; ==> ; EPOLL::RES ; ; note: deleting unreachable code ; (SETF (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::PTR) ; 0 ; (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::U32) ; 0 ; (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::U64) ; 0 ; (CFFI:FOREIGN-SLOT-VALUE EPOLL::DATA-PTR 'EPOLL::DATA 'EPOLL::FD) ; EPOLL::FD) ; --> PROGN SETF LET* MULTIPLE-VALUE-BIND LET PROGN CFFI::FOREIGN-SLOT-SET ; --> SETF LET* MULTIPLE-VALUE-BIND LET PROGN CFFI::MEM-SET ; --> CFFI-SYS:%MEM-SET LET SETF ; ==> ; (SB-KERNEL:%SET-SAP-REF-SAP EPOLL::DATA-PTR 0 #:VALUE174) ; ; caught WARNING: ; Asserted type SB-SYS:SYSTEM-AREA-POINTER conflicts with derived type ; (VALUES (INTEGER 0 0) &OPTIONAL). ; See also: ; The SBCL Manual, Node "Handling of Types" ; ; compilation unit finished ; caught 1 WARNING condition ; printed 2 notes

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[cffi-devel] groveller doesn't grovel for functions?
by Andy Chambers 10 Sep '09

10 Sep '09

Hi, Am I correct in thinking that the groveller doesn't grovel for functions and automatically create the correct defcfun forms for a given library? -- ---- Andy Chambers Formedix Ltd

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