/* dynl.c - dynamic linking * * Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001 Free Software Foundation, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this software; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA * * As a special exception, the Free Software Foundation gives permission * for additional uses of the text contained in its release of GUILE. * * The exception is that, if you link the GUILE library with other files * to produce an executable, this does not by itself cause the * resulting executable to be covered by the GNU General Public License. * Your use of that executable is in no way restricted on account of * linking the GUILE library code into it. * * This exception does not however invalidate any other reasons why * the executable file might be covered by the GNU General Public License. * * This exception applies only to the code released by the * Free Software Foundation under the name GUILE. If you copy * code from other Free Software Foundation releases into a copy of * GUILE, as the General Public License permits, the exception does * not apply to the code that you add in this way. To avoid misleading * anyone as to the status of such modified files, you must delete * this exception notice from them. * * If you write modifications of your own for GUILE, it is your choice * whether to permit this exception to apply to your modifications. * If you do not wish that, delete this exception notice. */ /* "dynl.c" dynamically link&load object files. Author: Aubrey Jaffer Modified for libguile by Marius Vollmer */ #if 0 /* Disabled until we know for sure that it isn't needed */ /* XXX - This is only here to drag in a definition of __eprintf. This is needed for proper operation of dynamic linking. The real solution would probably be a shared libgcc. */ #undef NDEBUG #include static void maybe_drag_in_eprintf () { assert (!maybe_drag_in_eprintf); } #endif #include #include #include "libguile/_scm.h" #include "libguile/dynl.h" #include "libguile/smob.h" #include "libguile/keywords.h" #include "libguile/ports.h" #include "libguile/strings.h" #include "libguile/deprecation.h" #include "libguile/lang.h" #include "libguile/validate.h" /* Create a new C argv array from a scheme list of strings. */ /* Dirk:FIXME:: A quite similar function is implemented in posix.c */ /* Dirk:FIXME:: In case of assertion errors, we get memory leaks */ /* Converting a list of SCM strings into a argv-style array. You must have ints disabled for the whole lifetime of the created argv (from before MAKE_ARGV_FROM_STRINGLIST until after MUST_FREE_ARGV). Atleast this is was the documentation for MAKARGVFROMSTRS says, it isn't really used that way. This code probably belongs into strings.c (Dirk: IMO strings.c is not the right place.) */ static char ** scm_make_argv_from_stringlist (SCM args, int *argcp, const char *subr, int argn) { char **argv; int argc; int i; argc = scm_ilength (args); SCM_ASSERT (argc >= 0, args, argn, subr); argv = (char **) scm_malloc ((argc + 1) * sizeof (char *)); for (i = 0; !SCM_NULL_OR_NIL_P (args); args = SCM_CDR (args), ++i) { SCM arg = SCM_CAR (args); size_t len; char *dst; char *src; SCM_ASSERT (SCM_STRINGP (arg), args, argn, subr); len = SCM_STRING_LENGTH (arg); src = SCM_STRING_CHARS (arg); dst = (char *) scm_malloc (len + 1); memcpy (dst, src, len); dst[len] = 0; argv[i] = dst; } if (argcp) *argcp = argc; argv[argc] = 0; return argv; } static void scm_free_argv (char **argv) { char **av = argv; while (*av) free (*(av++)); free (argv); } /* Dispatch to the system dependent files * * They define some static functions. These functions are called with * deferred interrupts. When they want to throw errors, they are * expected to insert a SCM_ALLOW_INTS before doing the throw. It * might work to throw an error while interrupts are deferred (because * they will be unconditionally allowed the next time a SCM_ALLOW_INTS * is executed, SCM_DEFER_INTS and SCM_ALLOW_INTS do not nest). */ #ifdef DYNAMIC_LINKING #include "libltdl/ltdl.h" static void * sysdep_dynl_link (const char *fname, const char *subr) { lt_dlhandle handle; handle = lt_dlopenext (fname); if (NULL == handle) { SCM fn; SCM msg; SCM_ALLOW_INTS; fn = scm_makfrom0str (fname); msg = scm_makfrom0str (lt_dlerror ()); scm_misc_error (subr, "file: ~S, message: ~S", scm_list_2 (fn, msg)); } return (void *) handle; } static void sysdep_dynl_unlink (void *handle, const char *subr) { if (lt_dlclose ((lt_dlhandle) handle)) { SCM_ALLOW_INTS; scm_misc_error (subr, (char *) lt_dlerror (), SCM_EOL); } } static void * sysdep_dynl_func (const char *symb, void *handle, const char *subr) { void *fptr; fptr = lt_dlsym ((lt_dlhandle) handle, symb); if (!fptr) { SCM_ALLOW_INTS; scm_misc_error (subr, (char *) lt_dlerror (), SCM_EOL); } return fptr; } static void sysdep_dynl_init () { lt_dlinit (); } #else /* no dynamic linking available, throw errors. */ static void sysdep_dynl_init (void) { } static void no_dynl_error (const char *subr) { SCM_ALLOW_INTS; scm_misc_error (subr, "dynamic linking not available", SCM_EOL); } static void * sysdep_dynl_link (const char *filename, const char *subr) { no_dynl_error (subr); return NULL; } static void sysdep_dynl_unlink (void *handle, const char *subr) { no_dynl_error (subr); } static void * sysdep_dynl_func (const char *symbol, void *handle, const char *subr) { no_dynl_error (subr); return NULL; } #endif scm_t_bits scm_tc16_dynamic_obj; #define DYNL_FILENAME(x) (SCM_CELL_OBJECT_1 (x)) #define DYNL_HANDLE(x) ((void *) SCM_CELL_WORD_2 (x)) #define SET_DYNL_HANDLE(x, v) (SCM_SET_CELL_WORD_2 ((x), (v))) static SCM dynl_obj_mark (SCM ptr) { return DYNL_FILENAME (ptr); } static int dynl_obj_print (SCM exp, SCM port, scm_print_state *pstate) { scm_puts ("#', port); return 1; } SCM_DEFINE (scm_dynamic_link, "dynamic-link", 1, 0, 0, (SCM filename), "Open the dynamic library called @var{filename}. A library\n" "handle representing the opened library is returned; this handle\n" "should be used as the @var{dobj} argument to the following\n" "functions.") #define FUNC_NAME s_scm_dynamic_link { void *handle; SCM_VALIDATE_STRING (1, filename); handle = sysdep_dynl_link (SCM_STRING_CHARS (filename), FUNC_NAME); SCM_RETURN_NEWSMOB2 (scm_tc16_dynamic_obj, SCM_UNPACK (filename), handle); } #undef FUNC_NAME SCM_DEFINE (scm_dynamic_object_p, "dynamic-object?", 1, 0, 0, (SCM obj), "Return @code{#t} if @var{obj} is a dynamic library handle, or @code{#f}\n" "otherwise.") #define FUNC_NAME s_scm_dynamic_object_p { return SCM_BOOL (SCM_TYP16_PREDICATE (scm_tc16_dynamic_obj, obj)); } #undef FUNC_NAME SCM_DEFINE (scm_dynamic_unlink, "dynamic-unlink", 1, 0, 0, (SCM dobj), "Unlink the indicated object file from the application. The\n" "argument @var{dobj} must have been obtained by a call to\n" "@code{dynamic-link}. After @code{dynamic-unlink} has been\n" "called on @var{dobj}, its content is no longer accessible.") #define FUNC_NAME s_scm_dynamic_unlink { /*fixme* GC-problem */ SCM_VALIDATE_SMOB (SCM_ARG1, dobj, dynamic_obj); if (DYNL_HANDLE (dobj) == NULL) { SCM_MISC_ERROR ("Already unlinked: ~S", dobj); } else { SCM_DEFER_INTS; sysdep_dynl_unlink (DYNL_HANDLE (dobj), FUNC_NAME); SET_DYNL_HANDLE (dobj, NULL); SCM_ALLOW_INTS; return SCM_UNSPECIFIED; } } #undef FUNC_NAME SCM_DEFINE (scm_dynamic_func, "dynamic-func", 2, 0, 0, (SCM name, SCM dobj), "Search the dynamic object @var{dobj} for the C function\n" "indicated by the string @var{name} and return some Scheme\n" "handle that can later be used with @code{dynamic-call} to\n" "actually call the function.\n\n" "Regardless whether your C compiler prepends an underscore @samp{_} to\n" "the global names in a program, you should @strong{not} include this\n" "underscore in @var{function}. Guile knows whether the underscore is\n" "needed or not and will add it when necessary.") #define FUNC_NAME s_scm_dynamic_func { /* The returned handle is formed by casting the address of the function to a * long value and converting this to a scheme number */ void (*func) (); SCM_VALIDATE_STRING (1, name); /*fixme* GC-problem */ SCM_VALIDATE_SMOB (SCM_ARG2, dobj, dynamic_obj); if (DYNL_HANDLE (dobj) == NULL) { SCM_MISC_ERROR ("Already unlinked: ~S", dobj); } else { char *chars; SCM_DEFER_INTS; chars = SCM_STRING_CHARS (name); func = (void (*) ()) sysdep_dynl_func (chars, DYNL_HANDLE (dobj), FUNC_NAME); SCM_ALLOW_INTS; return scm_ulong2num ((unsigned long) func); } } #undef FUNC_NAME SCM_DEFINE (scm_dynamic_call, "dynamic-call", 2, 0, 0, (SCM func, SCM dobj), "Call the C function indicated by @var{func} and @var{dobj}.\n" "The function is passed no arguments and its return value is\n" "ignored. When @var{function} is something returned by\n" "@code{dynamic-func}, call that function and ignore @var{dobj}.\n" "When @var{func} is a string , look it up in @var{dynobj}; this\n" "is equivalent to\n" "@smallexample\n" "(dynamic-call (dynamic-func @var{func} @var{dobj} #f))\n" "@end smallexample\n\n" "Interrupts are deferred while the C function is executing (with\n" "@code{SCM_DEFER_INTS}/@code{SCM_ALLOW_INTS}).") #define FUNC_NAME s_scm_dynamic_call { void (*fptr) (); if (SCM_STRINGP (func)) func = scm_dynamic_func (func, dobj); fptr = (void (*) ()) SCM_NUM2ULONG (1, func); SCM_DEFER_INTS; fptr (); SCM_ALLOW_INTS; return SCM_UNSPECIFIED; } #undef FUNC_NAME SCM_DEFINE (scm_dynamic_args_call, "dynamic-args-call", 3, 0, 0, (SCM func, SCM dobj, SCM args), "Call the C function indicated by @var{func} and @var{dobj},\n" "just like @code{dynamic-call}, but pass it some arguments and\n" "return its return value. The C function is expected to take\n" "two arguments and return an @code{int}, just like @code{main}:\n" "@smallexample\n" "int c_func (int argc, char **argv);\n" "@end smallexample\n\n" "The parameter @var{args} must be a list of strings and is\n" "converted into an array of @code{char *}. The array is passed\n" "in @var{argv} and its size in @var{argc}. The return value is\n" "converted to a Scheme number and returned from the call to\n" "@code{dynamic-args-call}.") #define FUNC_NAME s_scm_dynamic_args_call { int (*fptr) (int argc, char **argv); int result, argc; char **argv; if (SCM_STRINGP (func)) func = scm_dynamic_func (func, dobj); fptr = (int (*) (int, char **)) SCM_NUM2ULONG (1, func); SCM_DEFER_INTS; argv = scm_make_argv_from_stringlist (args, &argc, FUNC_NAME, SCM_ARG3); result = (*fptr) (argc, argv); scm_free_argv (argv); SCM_ALLOW_INTS; return SCM_MAKINUM (0L + result); } #undef FUNC_NAME void scm_init_dynamic_linking () { scm_tc16_dynamic_obj = scm_make_smob_type ("dynamic-object", 0); scm_set_smob_mark (scm_tc16_dynamic_obj, dynl_obj_mark); scm_set_smob_print (scm_tc16_dynamic_obj, dynl_obj_print); sysdep_dynl_init (); #ifndef SCM_MAGIC_SNARFER #include "libguile/dynl.x" #endif } /* Local Variables: c-file-style: "gnu" End: */