A toy example of embedding C code in lisp and vice versa
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From: nanothermite911fbibustards on 13 Jun 2010 17:40 On Jun 12, 12:08 pm, bolega <gnuist...(a)gmail.com> wrote: > Here is a link to a thread that discusses this topic but there is no > complete example. > > http://objectmix.com/lisp/362409-howto-use-lisp-scripting-language-wi... > > Lars Lune has a good section on code by searching this string > > "On Tue, 18 Mar 2008 01:16:00 -0700, Blackguester wrote:" > > but his code is replaced with smileys and even source shows it. I > could not muster the confidence as a newbie to go into it by myself. > Unless a guru can guide and explain. > > http://common-lisp.net/project/cffi/http://common-lisp.net/project/cffi/manual/html_node/Tutorial.htmlhttp://www.sbcl.org/manual/Foreign-Function-Interface.html > > Should I pick SBCL or ECL ? I have a long term view. 8.8 Step-By-Step Example of the Foreign Function Interface This section presents a complete example of an interface to a somewhat complicated C function. Suppose you have the following C function which you want to be able to call from Lisp in the file test.c struct c_struct { int x; char *s; }; struct c_struct *c_function (i, s, r, a) int i; char *s; struct c_struct *r; int a[10]; { int j; struct c_struct *r2; printf("i = %d\n", i); printf("s = %s\n", s); printf("r->x = %d\n", r->x); printf("r->s = %s\n", r->s); for (j = 0; j < 10; j++) printf("a[%d] = %d.\n", j, a[j]); r2 = (struct c_struct *) malloc (sizeof(struct c_struct)); r2->x = i + 5; r2->s = "a C string"; return(r2); }; It is possible to call this C function from Lisp using the file test.lisp containing (cl:defpackage "TEST-C-CALL" (:use "CL" "SB-ALIEN" "SB-C-CALL")) (cl:in-package "TEST-C-CALL") ;;; Define the record C-STRUCT in Lisp. (define-alien-type nil (struct c-struct (x int) (s c-string))) ;;; Define the Lisp function interface to the C routine. It returns a ;;; pointer to a record of type C-STRUCT. It accepts four parameters: ;;; I, an int; S, a pointer to a string; R, a pointer to a C- STRUCT ;;; record; and A, a pointer to the array of 10 ints. ;;; ;;; The INLINE declaration eliminates some efficiency notes about heap ;;; allocation of alien values. (declaim (inline c-function)) (define-alien-routine c-function (* (struct c-struct)) (i int) (s c-string) (r (* (struct c-struct))) (a (array int 10))) ;;; a function which sets up the parameters to the C function and ;;; actually calls it (defun call-cfun () (with-alien ((ar (array int 10)) (c-struct (struct c-struct))) (dotimes (i 10) ; Fill array. (setf (deref ar i) i)) (setf (slot c-struct 'x) 20) (setf (slot c-struct 's) "a Lisp string") (with-alien ((res (* (struct c-struct)) (c-function 5 "another Lisp string" (addr c- struct) ar))) (format t "~&back from C function~%") (multiple-value-prog1 (values (slot res 'x) (slot res 's)) ;; Deallocate result. (after we are done referring to it: ;; "Pillage, *then* burn.") (free-alien res))))) To execute the above example, it is necessary to compile the C routine, e.g.: `cc -c test.c && ld -shared -o test.so test.o' (In order to enable incremental loading with some linkers, you may need to say `cc -G 0 -c test.c') Once the C code has been compiled, you can start up Lisp and load it in: `sbcl'. Lisp should start up with its normal prompt. Within Lisp, compile the Lisp file. (This step can be done separately. You don't have to recompile every time.) `(compile-file "test.lisp")' Within Lisp, load the foreign object file to define the necessary symbols: `(load-shared-object "test.so")'. Now you can load the compiled Lisp (fasl) file into Lisp: `(load "test.fasl")' And once the Lisp file is loaded, you can call the Lisp routine that sets up the parameters and calls the C function: `(test-c- call::call-cfun)' The C routine should print the following information to standard output: i = 5 s = another Lisp string r->x = 20 r->s = a Lisp string a[0] = 0. a[1] = 1. a[2] = 2. a[3] = 3. a[4] = 4. a[5] = 5. a[6] = 6. a[7] = 7. a[8] = 8. a[9] = 9. After return from the C function, the Lisp wrapper function should print the following output: back from C function And upon return from the Lisp wrapper function, before the next prompt is printed, the Lisp read-eval-print loop should print the following return values: 10 "a C string"
From: nanothermite911fbibustards on 13 Jun 2010 17:42
On Jun 13, 2:40 pm, nanothermite911fbibustards <nanothermite911fbibusta...(a)gmail.com> wrote: > On Jun 12, 12:08 pm, bolega <gnuist...(a)gmail.com> wrote: > > > > > Here is a link to a thread that discusses this topic but there is no > > complete example. > > >http://objectmix.com/lisp/362409-howto-use-lisp-scripting-language-wi... > > > Lars Lune has a good section on code by searching this string > > > "On Tue, 18 Mar 2008 01:16:00 -0700, Blackguester wrote:" > > > but his code is replaced with smileys and even source shows it. I > > could not muster the confidence as a newbie to go into it by myself. > > Unless a guru can guide and explain. > > >http://common-lisp.net/project/cffi/http://common-lisp.net/project/cf... > > > Should I pick SBCL or ECL ? I have a long term view. > > 8.8 Step-By-Step Example of the Foreign Function Interface > > This section presents a complete example of an interface to a somewhat > complicated C function. > > Suppose you have the following C function which you want to be able to > call from Lisp in the file test.c > > struct c_struct > { > int x; > char *s; > }; > > struct c_struct *c_function (i, s, r, a) > int i; > char *s; > struct c_struct *r; > int a[10]; > { > int j; > struct c_struct *r2; > > printf("i = %d\n", i); > printf("s = %s\n", s); > printf("r->x = %d\n", r->x); > printf("r->s = %s\n", r->s); > for (j = 0; j < 10; j++) printf("a[%d] = %d.\n", j, a[j]); > r2 = (struct c_struct *) malloc (sizeof(struct c_struct)); > r2->x = i + 5; > r2->s = "a C string"; > return(r2); > }; > > It is possible to call this C function from Lisp using the file > test.lisp containing > > (cl:defpackage "TEST-C-CALL" (:use "CL" "SB-ALIEN" "SB-C-CALL")) > (cl:in-package "TEST-C-CALL") > > ;;; Define the record C-STRUCT in Lisp. > (define-alien-type nil > (struct c-struct > (x int) > (s c-string))) > > ;;; Define the Lisp function interface to the C routine. It > returns a > ;;; pointer to a record of type C-STRUCT. It accepts four > parameters: > ;;; I, an int; S, a pointer to a string; R, a pointer to a C- > STRUCT > ;;; record; and A, a pointer to the array of 10 ints. > ;;; > ;;; The INLINE declaration eliminates some efficiency notes about > heap > ;;; allocation of alien values. > (declaim (inline c-function)) > (define-alien-routine c-function > (* (struct c-struct)) > (i int) > (s c-string) > (r (* (struct c-struct))) > (a (array int 10))) > > ;;; a function which sets up the parameters to the C function and > ;;; actually calls it > (defun call-cfun () > (with-alien ((ar (array int 10)) > (c-struct (struct c-struct))) > (dotimes (i 10) ; Fill array. > (setf (deref ar i) i)) > (setf (slot c-struct 'x) 20) > (setf (slot c-struct 's) "a Lisp string") > > (with-alien ((res (* (struct c-struct)) > (c-function 5 "another Lisp string" (addr c- > struct) ar))) > (format t "~&back from C function~%") > (multiple-value-prog1 > (values (slot res 'x) > (slot res 's)) > > ;; Deallocate result. (after we are done referring to it: > ;; "Pillage, *then* burn.") > (free-alien res))))) > > To execute the above example, it is necessary to compile the C > routine, e.g.: `cc -c test.c && ld -shared -o test.so test.o' (In > order to enable incremental loading with some linkers, you may need to > say `cc -G 0 -c test.c') > > Once the C code has been compiled, you can start up Lisp and load it > in: `sbcl'. Lisp should start up with its normal prompt. > > Within Lisp, compile the Lisp file. (This step can be done separately. > You don't have to recompile every time.) `(compile-file "test.lisp")' > > Within Lisp, load the foreign object file to define the necessary > symbols: `(load-shared-object "test.so")'. > > Now you can load the compiled Lisp (fasl) file into Lisp: `(load > "test.fasl")' And once the Lisp file is loaded, you can call the Lisp > routine that sets up the parameters and calls the C function: `(test-c- > call::call-cfun)' > > The C routine should print the following information to standard > output: > > i = 5 > s = another Lisp string > r->x = 20 > r->s = a Lisp string > a[0] = 0. > a[1] = 1. > a[2] = 2. > a[3] = 3. > a[4] = 4. > a[5] = 5. > a[6] = 6. > a[7] = 7. > a[8] = 8. > a[9] = 9. > > After return from the C function, the Lisp wrapper function should > print the following output: > > back from C function > > And upon return from the Lisp wrapper function, before the next prompt > is printed, the Lisp read-eval-print loop should print the following > return values: > > 10 > "a C string" My Sig was missed http://www.youtube.com/watch?v=lX18zUp6WPY http://www.youtube.com/watch?v=XQapkVCx1HI http://www.youtube.com/watch?v=tXJ-k-iOg0M Hey Racist and INcompetent FBI Bustards, where is the ANTHRAX Mailer ? Where are the 4 blackboxes ? Where are the Pentagon Videos ? Why did you release the 5 dancing Israelis compromising the whole 911 investigation ? If the Dubai Police can catch Mossad Murderers and put the videos and Iranian Police can why cant you put the Pentagon Videos ? If Iran police can put the AMERICAN TERRORIST, Riggi and puting on INTERNATIONAL MEDIA a day after catching him without TORTURE, why cant you put the INNOCENT patsies on the MEDIA. Why did you have to LIE about Dr Afiya Siddiqui and torture that Innocent little mother of 3 and smashing the skull of her one child ? http://www.youtube.com/watch?v=DhMcii8smxk http://www.youtube.com/watch?v=0SZ2lxDJmdg There are CRIMINAL cases against CIA CRIMINAL Bustards in Italian courts. FBI bustards paid a penalty of $5.8 million to Steven Hatfill, but only because he was a white. They got away with MURDER of thousands of Non-whites in all parts of the world. Daily 911 news : http://911blogger.com http://www.youtube.com/watch?v=tRfhUezbKLw http://www.youtube.com/watch?v=x7kGZ3XPEm4 http://www.youtube.com/watch?v=lX18zUp6WPY |