August 2010 - cffi-devel - mailman3.common-lisp.net

Re: [cffi-devel] uffi compatible library
by Gustavo 06 Sep '10

06 Sep '10

Those don't fail, but: UFFI-TESTS> (let ((native-string "test string")) (uffi:with-foreign-string (fs native-string) (ensure-char-character (deref-pointer fs :char)))) #\t UFFI-TESTS> (let ((native-string "test string")) (uffi:with-foreign-string (fs native-string) (deref-pointer fs :char))) 116 The latter would return #\t in uffi-compat. Em 22 de agosto de 2010 18:25, Luís Oliveira <luismbo(a)gmail.com> escreveu: 2010/8/10 Gustavo <gugamilare(a)gmail.com>: > > I found one inconsistency in uffi's documentation. Uffi's doc says that > > dereferencing types :char and :unsigned-char return characters where > > actually it returns integers (at least here). > > Does that mean these tests fail for you? > <http://git.b9.com/?p=uffi.git;a=blob;f=tests/objects.lisp> > > -- > Luís Oliveira > http://r42.eu/~luis/ <http://r42.eu/%7Eluis/> >

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[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] Cffi-uffi-compat and clsql-mysql on SBCL
by Alexandre Paes 22 Aug '10

22 Aug '10

Hi everyone, I'm having some trouble running with the latest clsql-mysql package because the systems complains about a couple of undefined functions. I'm running the latest cffi (i believe it's still 0.10.5). Here's where my compilation fails: The function CFFI-UFFI-COMPAT::FOREIGN-ENCODED-OCTET-COUNT is undefined. [Condition of type UNDEFINED-FUNCTION] My first attempt was to copy that function definition along with some required global variable uffi:*default-foreign-encoding* but then i get a new failure with a different function: The function CFFI-UFFI-COMPAT::STRING-TO-OCTETS is undefined. [Condition of type UNDEFINED-FUNCTION] I guess i can copy the uffi definition for this function as well, but that feels like getting too hackish for my taste. Is this something i'm doing wrong or the cffi-uffi-compat package is not fully uffi-2.0.0 compatible? Any ideas of how i should tackle this issue? Cheers, Alex Paes

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[cffi-devel] Foreign string arguments
by Michael Raskin 22 Aug '10

22 Aug '10

Hello. I use callback feature of CFFI. I want to use an encoding as a default and if I get an invalid string (non-UTF-8 in my case), I'd just reject it by returning an error. Unfortunately, if I declare string arguments with encoding, attempts by CFFI to decode the string raise an error which prevents me from returning protocol-compliant error to the caller. The context: I currently work on FUSE bindings for Common Lisp (or at least SBCL for now). In case of error occurring in my code, I return EIO. Of course, for invalid file names I want to return either EIO or ENOENT. Currently, request just hangs. This can be mitigated by patching CFFI. If I just wrap the conversion in ignore-errors, I lose the distinction between an invalid string and null pointer, but I get a chance to process the request (both cases are wrong in my case). Specifying a designated "wrong string object" and letting user change it seems to be the nicest way: the user gets an error on trying to use the object as a string, but user code can handle it nicely. I changed the following in string conversion code: (defmethod translate-from-foreign (ptr (type foreign-string-type)) (unwind-protect (block nil (handler-case (values (foreign-string-to-lisp ptr :encoding (fst-encoding type))) (error (x) (return t)) )) (when (fst-free-from-foreign-p type) (foreign-free ptr)))) That allowed me to handle invalid requests to the FS by returning ENOENT (just as originally intended). Would you please consider adding some similar modification in official CFFI repository? Michael Raskin

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[cffi-devel] Various CFFI news
by Luís Oliveira 22 Aug '10

22 Aug '10

Hello, A couple of announcements: 1. We have moved to Git. See <http://common-lisp.net/gitweb?p=projects/cffi/cffi.git>. Thanks to Stelian Ionescu for doing the repository conversion. Let us know if there are still any references to the darcs repository somewhere. 2. There is a new bug tracker at <http://bugs.launchpad.net/cffi>. I have populated it with the contents of my TODO list. Please let me know if you have any pending issues not listed there. I hope this will help providing better feedback to people reporting bugs and sending patches who might otherwise think their contributions have been lost or ignored. Still have to figure out the proper dynamics between these mailing list and launchpad, though. Thoughts on that are most welcome. 3. CFFI 0.10.6 has been released. (I hope to add a NEWS file for future releases.) Cheers, -- Luís Oliveira http://r42.eu/~luis/

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[cffi-devel] uffi compatible library
by Gustavo 22 Aug '10

22 Aug '10

Hello, As I've noticed, the compatibility layer of cffi to uffi has a couple of problems. For that reason it does not work with elephant out of the box. I intend trying to address these problems and send patches afterwards. I'm using SBCL. It seems to me that one of the problems it that functions defined with (original) uffi accepts aliens and saps as pointer arguments, while cffi (and uffi-compat) only work with saps, right? Another problems seems to be that uffi's def-function accepts :out arguments, unlike cffi's defcfun. Such arguments are not passed when you call the wrapper function, the wrapper automatically pass foreign-allocated pointers to the C function which is supposed to put some value in that pointer. Then the wrapper function returns the values inserted by the C function as multiple values (starting from the second value). I intend to adapt uffi-compat's functions to unwrap aliens into saps. That is implementation dependent, so I was thinking about putting one function named unwrap-typed-pointer in cffi-sys and also put an entry in the documentation for other implementations (that have typed pointers like SBCL's aliens) to possibly implement this function as well. That function would only be used in uffi-compat, not in cffi. Now, about :out arguments, wouldn't it be nice if cffi supports this as well? Currently many projects have to do this by hand, why not abstract it away? That would also make elephant portable to cffi more easily. The list of arguments of defcfun<http://common-lisp.net/project/cffi/manual/html_node/defcfun.html#defcfun>would become arguments ::= { (arg-name arg-type [direction]) }* where direction could be :in (the default) or :out. In case it's :out, the argument should not be passed to the function, like in uffi. Other possible options are :copy and :in-out like sbcl's define-alien-routine<http://www.sbcl.org/manual/#The-define_002dalien_002droutine-Macro> . Any thoughts are appreciated. Regards, Gustavo.

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[cffi-devel] Memory fault using CFFI
by Andrew Kirkpatrick 22 Aug '10

22 Aug '10

Hi, It seems that in many cases when I call code in a library that results in a loaded foreign library function being called, I get a memory fault. Typically this error appears in my slime REPL: Help! 11 nested errors. SB-KERNEL:*MAXIMUM-ERROR-DEPTH* exceeded. 0: ; Evaluation aborted. The 11 errors appear in my *inferior-lisp* buffer, each one similar to: CORRUPTION WARNING in SBCL pid 3239(tid 3039865744): Memory fault at 100020 (pc=0x9c77963, sp=0xb52f6110) The integrity of this image is possibly compromised. Continuing with fingers crossed. Crossed fingers or not, from that point on the lisp image is unstable. It happens when I try to use Elephant to open a BDB store, or when I use CL-SQLITE directly to open a database. However I just discovered that I can successfully run the hello-world.lisp example in CLG. I'm using clbuild on 32bit x86 Ubuntu 9.10, that I used to install SBCL 1.0.35.1 and the latest (according to clbuild) CFFI. Looking closer at CFFI, it fails one test unexpectedly. I'm quite baffled and googling and asking on #lisp draws a blank. The failed test is below. Any ideas? Test DEFCFUN.BFF.2 failed Form: (SUM-127 (MAKE-POINTER 2746181372) (MAKE-POINTER 177623060) -32334.0 3158055028 (MAKE-POINTER 242315091) 4288001754991016425 -21047.0d0 287.0d0 18722 243379286 -8677366518541007140 581399424 -13872 4240394881 1353358999 226 969197676 -26207.0d0 6484 11150 1241680089902988480 106068320 61865 2253 (MAKE-POINTER 866809333) -31613 35616 11715 1393601698 8940888681199591845 (MAKE-POINTER 1524606024) 805638893 3315410736 3432596795 (MAKE-POINTER 1490355706) 696175657106383698 -25438.0 1294381547 26724 (MAKE-POINTER 3196569545) 2506913373410783697 -4405955718732597856 4075932032 3224670123 2183829215657835866 1318320964 -22 -3786.0d0 -2017024146 1579225515 -626617701 -1456 (MAKE-POINTER 3561444187) 395687791 1968033632506257320 -1847773261 48853 142937735275669133 -17974.0 (MAKE-POINTER 2791749948) -14140.0 2707 3691328585 3306.0 1132012981 303633191773289330 (MAKE-POINTER 981183954) 9114.0d0 8664374572369470 -19013.0d0 -10288.0d0 -3679345119891954339 (MAKE-POINTER 3538786709) 23761 -154264605 (MAKE-POINTER 2694396308) 7023 997.0d0 1009561368 241 (MAKE-POINTER 2612292671) 48 1431872408 -32675.0d0 (MAKE-POINTER 1587599336) 958916472 -9857.0d0 111 -14370.0d0 -7308 -967514912 488790941 2146978095 -24111.0d0 13711 86681861 717987770 111 1013402998690933877 17234.0d0 -8772.0 3959216275 -8711 (MAKE-POINTER 3142780851) 9480.0 -3820453146461186120 1616574376 -3336232268263990050 -1906114671562979758 -27925.0d0 9695970875869913114 27033.0d0 1096518219 -12 104 3392025403 -27911 60 89 509297051 -533066551 29158.0 110 54 -9802.0d0 593950442165910888 -79) Expected value: 7758614658402721936 Actual value: 7758614624042983568. Thanks! -- Andrew Kirkpatrick "The first rule of Perl Club... has subscript 0. Unless you changed $[. But don't!" -- blazar on perlmonks.org

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[cffi-devel] Elephant is working with cffi
by Gustavo 11 Aug '10

11 Aug '10

Hello, everyone, I've got elephant working along with cffi. Both cffi and elephant need to be patched for this to work, the patches for cffi were already made in the cffi mailing list. The patch was made against elephant-unstable. There were some incompatible changes in elephant, but I've separated those using #-elephant-cffi, what makes elephant also work with uffi. The file elephant.asd detects whether the asdf component :uffi is actually :cffi-uffi-compat, in which case the key :elephant-cffi is pushed into *features*, so everything is done automatically. I compiled elephant with :elephant-without-optimize and tested the tutorial (with a :bdb 4.7 database). I'll test without the key :elephant-without-optimize later. I believe this port helps with elephant optimization. For instance, cffi mem-ref is already optimized using implementation specific details (using compiler macros) so I think implementation specific optimizations are not needed anymore. Otherwise it should be possible to do the optimizations in cffi itself. Also cffi does not allocate aliens (my sbcl emits style-warnings complaining about that when using uffi). Gustavo.

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[cffi-devel] Problem with cffi-grovel on windows/cygwin(mingw mode)
by Heka Treep 08 Aug '10

08 Aug '10

Hi, some problem I have with this: (defsystem ... (cffi-grovel:wrapper-file "...") ... generates a call: gcc -m32 -fPIC -o *.dll *.c -shared but cygwin want at least flag `-mno-cygwin'. It would be possible to define this flag in some variable, but the flag is added to the end of the list of arguments - and it just not work. I try this format: gcc cpu-flags cc-flags platform-library-flags* -o output-file input-file by reimplement `cc-compile-and-link' function: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; (in-package :cffi-grovel) (defun cc-compile-and-link (input-file output-file &key library) (apply #'invoke (or (getenv "CC") *cc*) *cpu-word-size-flags* `(,@*cc-flags* ,@(when library *platform-library-flags*) "-o" ,(native-namestring output-file) ,(native-namestring input-file)))) (setf *cc* "C:/dev/cygwin/bin/gcc-3.exe") ;; its my (setf *cc-flags* '()) ;; remove -fPIC (setf *cpu-word-size-flags* "") ;; and this too (setf *platform-library-flags* '("-mno-cygwin" "-shared")) ;; added -mno-cygwin in begin ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; It is normal, or I don't understand something?

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[cffi-devel] CFFI (SBCL) bug with dynamic definition of the foreign function
by Serhiy Yakovyn 06 Aug '10

06 Aug '10

Hello all, I have the following snippet of code that doesn't work as expected under SBCL 1.0.29, CFFI 0.10.5 and Windows 7. (let ((library (cffi:load-foreign-library "user32.dll"))) (cffi:foreign-funcall "GetDesktopWindow" :int) (cffi:close-foreign-library library))) I have also tested it under LispWorks and CCL - no issues. Could anybody suggest the workaround? Thanks, Serhiy Y

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