msimtf: Add a mostly wrapper stub for IActiveIMMApp.
[wine/multimedia.git] / libs / wine / loader.c
blobdde5a70d04e9dae2c1dff7a16877d933048f7152
1 /*
2 * Win32 builtin dlls support
4 * Copyright 2000 Alexandre Julliard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
21 #include "config.h"
22 #include "wine/port.h"
24 #include <assert.h>
25 #include <ctype.h>
26 #include <fcntl.h>
27 #include <limits.h>
28 #include <stdarg.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sys/types.h>
32 #ifdef HAVE_SYS_MMAN_H
33 #include <sys/mman.h>
34 #endif
35 #ifdef HAVE_SYS_RESOURCE_H
36 # include <sys/resource.h>
37 #endif
38 #ifdef HAVE_UNISTD_H
39 # include <unistd.h>
40 #endif
42 #define NONAMELESSUNION
43 #define NONAMELESSSTRUCT
44 #include "windef.h"
45 #include "winbase.h"
46 #include "wine/library.h"
48 #ifdef __APPLE__
49 #include <crt_externs.h>
50 #define environ (*_NSGetEnviron())
51 #else
52 extern char **environ;
53 #endif
55 /* argc/argv for the Windows application */
56 int __wine_main_argc = 0;
57 char **__wine_main_argv = NULL;
58 WCHAR **__wine_main_wargv = NULL;
59 char **__wine_main_environ = NULL;
61 struct dll_path_context
63 unsigned int index; /* current index in the dll path list */
64 char *buffer; /* buffer used for storing path names */
65 char *name; /* start of file name part in buffer (including leading slash) */
66 int namelen; /* length of file name without .so extension */
67 int win16; /* 16-bit dll search */
70 #define MAX_DLLS 100
72 static struct
74 const IMAGE_NT_HEADERS *nt; /* NT header */
75 const char *filename; /* DLL file name */
76 } builtin_dlls[MAX_DLLS];
78 static int nb_dlls;
80 static const IMAGE_NT_HEADERS *main_exe;
82 static load_dll_callback_t load_dll_callback;
84 static const char *build_dir;
85 static const char *default_dlldir;
86 static const char **dll_paths;
87 static unsigned int nb_dll_paths;
88 static int dll_path_maxlen;
90 extern void mmap_init(void);
91 extern const char *get_dlldir( const char **default_dlldir );
93 /* build the dll load path from the WINEDLLPATH variable */
94 static void build_dll_path(void)
96 int len, count = 0;
97 char *p, *path = getenv( "WINEDLLPATH" );
98 const char *dlldir = get_dlldir( &default_dlldir );
100 if (path)
102 /* count how many path elements we need */
103 path = strdup(path);
104 p = path;
105 while (*p)
107 while (*p == ':') p++;
108 if (!*p) break;
109 count++;
110 while (*p && *p != ':') p++;
114 dll_paths = malloc( (count+2) * sizeof(*dll_paths) );
115 nb_dll_paths = 0;
117 if (dlldir)
119 dll_path_maxlen = strlen(dlldir);
120 dll_paths[nb_dll_paths++] = dlldir;
122 else if ((build_dir = wine_get_build_dir()))
124 dll_path_maxlen = strlen(build_dir) + sizeof("/programs");
127 if (count)
129 p = path;
130 while (*p)
132 while (*p == ':') *p++ = 0;
133 if (!*p) break;
134 dll_paths[nb_dll_paths] = p;
135 while (*p && *p != ':') p++;
136 if (p - dll_paths[nb_dll_paths] > dll_path_maxlen)
137 dll_path_maxlen = p - dll_paths[nb_dll_paths];
138 nb_dll_paths++;
142 /* append default dll dir (if not empty) to path */
143 if ((len = strlen(default_dlldir)) > 0)
145 if (len > dll_path_maxlen) dll_path_maxlen = len;
146 dll_paths[nb_dll_paths++] = default_dlldir;
150 /* check if a given file can be opened */
151 static inline int file_exists( const char *name )
153 int fd = open( name, O_RDONLY );
154 if (fd != -1) close( fd );
155 return (fd != -1);
158 static inline char *prepend( char *buffer, const char *str, size_t len )
160 return memcpy( buffer - len, str, len );
163 /* get a filename from the next entry in the dll path */
164 static char *next_dll_path( struct dll_path_context *context )
166 unsigned int index = context->index++;
167 int namelen = context->namelen;
168 char *path = context->name;
170 switch(index)
172 case 0: /* try programs dir for .exe files */
173 if (!context->win16 && namelen > 4 && !memcmp( context->name + namelen - 4, ".exe", 4 ))
175 path = prepend( path, context->name, namelen - 4 );
176 path = prepend( path, "/programs", sizeof("/programs") - 1 );
177 path = prepend( path, build_dir, strlen(build_dir) );
178 return path;
180 context->index++;
181 /* fall through */
182 case 1: /* try dlls dir with subdir prefix */
183 if (namelen > 4 && !memcmp( context->name + namelen - 4, ".dll", 4 )) namelen -= 4;
184 if (!context->win16) path = prepend( path, context->name, namelen );
185 path = prepend( path, "/dlls", sizeof("/dlls") - 1 );
186 path = prepend( path, build_dir, strlen(build_dir) );
187 return path;
188 default:
189 index -= 2;
190 if (index < nb_dll_paths)
191 return prepend( context->name, dll_paths[index], strlen( dll_paths[index] ));
192 break;
194 return NULL;
198 /* get a filename from the first entry in the dll path */
199 static char *first_dll_path( const char *name, int win16, struct dll_path_context *context )
201 char *p;
202 int namelen = strlen( name );
203 const char *ext = win16 ? "16" : ".so";
205 context->buffer = malloc( dll_path_maxlen + 2 * namelen + strlen(ext) + 3 );
206 context->index = build_dir ? 0 : 2; /* if no build dir skip all the build dir magic cases */
207 context->name = context->buffer + dll_path_maxlen + namelen + 1;
208 context->namelen = namelen + 1;
209 context->win16 = win16;
211 /* store the name at the end of the buffer, followed by extension */
212 p = context->name;
213 *p++ = '/';
214 memcpy( p, name, namelen );
215 strcpy( p + namelen, ext );
216 return next_dll_path( context );
220 /* free the dll path context created by first_dll_path */
221 static inline void free_dll_path( struct dll_path_context *context )
223 free( context->buffer );
227 /* open a library for a given dll, searching in the dll path
228 * 'name' must be the Windows dll name (e.g. "kernel32.dll") */
229 static void *dlopen_dll( const char *name, char *error, int errorsize,
230 int test_only, int *exists )
232 struct dll_path_context context;
233 char *path;
234 void *ret = NULL;
236 *exists = 0;
237 for (path = first_dll_path( name, 0, &context ); path; path = next_dll_path( &context ))
239 if (!test_only && (ret = wine_dlopen( path, RTLD_NOW, error, errorsize ))) break;
240 if ((*exists = file_exists( path ))) break; /* exists but cannot be loaded, return the error */
242 free_dll_path( &context );
243 return ret;
247 /* adjust an array of pointers to make them into RVAs */
248 static inline void fixup_rva_ptrs( void *array, BYTE *base, unsigned int count )
250 void **src = (void **)array;
251 DWORD *dst = (DWORD *)array;
252 while (count--)
254 *dst++ = *src ? (BYTE *)*src - base : 0;
255 src++;
259 /* fixup an array of RVAs by adding the specified delta */
260 static inline void fixup_rva_dwords( DWORD *ptr, int delta, unsigned int count )
262 while (count--)
264 if (*ptr) *ptr += delta;
265 ptr++;
270 /* fixup RVAs in the import directory */
271 static void fixup_imports( IMAGE_IMPORT_DESCRIPTOR *dir, BYTE *base, int delta )
273 UINT_PTR *ptr;
275 while (dir->Name)
277 fixup_rva_dwords( &dir->u.OriginalFirstThunk, delta, 1 );
278 fixup_rva_dwords( &dir->Name, delta, 1 );
279 fixup_rva_dwords( &dir->FirstThunk, delta, 1 );
280 ptr = (UINT_PTR *)(base + (dir->u.OriginalFirstThunk ? dir->u.OriginalFirstThunk : dir->FirstThunk));
281 while (*ptr)
283 if (!(*ptr & IMAGE_ORDINAL_FLAG)) *ptr += delta;
284 ptr++;
286 dir++;
291 /* fixup RVAs in the export directory */
292 static void fixup_exports( IMAGE_EXPORT_DIRECTORY *dir, BYTE *base, int delta )
294 fixup_rva_dwords( &dir->Name, delta, 1 );
295 fixup_rva_dwords( &dir->AddressOfFunctions, delta, 1 );
296 fixup_rva_dwords( &dir->AddressOfNames, delta, 1 );
297 fixup_rva_dwords( &dir->AddressOfNameOrdinals, delta, 1 );
298 fixup_rva_dwords( (DWORD *)(base + dir->AddressOfNames), delta, dir->NumberOfNames );
299 fixup_rva_ptrs( (base + dir->AddressOfFunctions), base, dir->NumberOfFunctions );
303 /* fixup RVAs in the resource directory */
304 static void fixup_resources( IMAGE_RESOURCE_DIRECTORY *dir, BYTE *root, int delta )
306 IMAGE_RESOURCE_DIRECTORY_ENTRY *entry;
307 int i;
309 entry = (IMAGE_RESOURCE_DIRECTORY_ENTRY *)(dir + 1);
310 for (i = 0; i < dir->NumberOfNamedEntries + dir->NumberOfIdEntries; i++, entry++)
312 void *ptr = root + entry->u2.s3.OffsetToDirectory;
313 if (entry->u2.s3.DataIsDirectory) fixup_resources( ptr, root, delta );
314 else
316 IMAGE_RESOURCE_DATA_ENTRY *data = ptr;
317 fixup_rva_dwords( &data->OffsetToData, delta, 1 );
323 /* map a builtin dll in memory and fixup RVAs */
324 static void *map_dll( const IMAGE_NT_HEADERS *nt_descr )
326 #ifdef HAVE_MMAP
327 IMAGE_DATA_DIRECTORY *dir;
328 IMAGE_DOS_HEADER *dos;
329 IMAGE_NT_HEADERS *nt;
330 IMAGE_SECTION_HEADER *sec;
331 BYTE *addr;
332 DWORD code_start, data_start, data_end;
333 const size_t page_size = getpagesize();
334 const size_t page_mask = page_size - 1;
335 int delta, nb_sections = 2; /* code + data */
336 unsigned int i;
338 size_t size = (sizeof(IMAGE_DOS_HEADER)
339 + sizeof(IMAGE_NT_HEADERS)
340 + nb_sections * sizeof(IMAGE_SECTION_HEADER));
342 assert( size <= page_size );
344 /* module address must be aligned on 64K boundary */
345 addr = (BYTE *)((nt_descr->OptionalHeader.ImageBase + 0xffff) & ~0xffff);
346 if (wine_anon_mmap( addr, page_size, PROT_READ|PROT_WRITE, MAP_FIXED ) != addr) return NULL;
348 dos = (IMAGE_DOS_HEADER *)addr;
349 nt = (IMAGE_NT_HEADERS *)(dos + 1);
350 sec = (IMAGE_SECTION_HEADER *)(nt + 1);
352 /* Build the DOS and NT headers */
354 dos->e_magic = IMAGE_DOS_SIGNATURE;
355 dos->e_cblp = 0x90;
356 dos->e_cp = 3;
357 dos->e_cparhdr = (sizeof(*dos)+0xf)/0x10;
358 dos->e_minalloc = 0;
359 dos->e_maxalloc = 0xffff;
360 dos->e_ss = 0x0000;
361 dos->e_sp = 0x00b8;
362 dos->e_lfarlc = sizeof(*dos);
363 dos->e_lfanew = sizeof(*dos);
365 *nt = *nt_descr;
367 delta = (const BYTE *)nt_descr - addr;
368 code_start = page_size;
369 data_start = delta & ~page_mask;
370 data_end = (nt->OptionalHeader.SizeOfImage + delta + page_mask) & ~page_mask;
372 fixup_rva_ptrs( &nt->OptionalHeader.AddressOfEntryPoint, addr, 1 );
374 nt->FileHeader.NumberOfSections = nb_sections;
375 nt->OptionalHeader.BaseOfCode = code_start;
376 #ifndef _WIN64
377 nt->OptionalHeader.BaseOfData = data_start;
378 #endif
379 nt->OptionalHeader.SizeOfCode = data_start - code_start;
380 nt->OptionalHeader.SizeOfInitializedData = data_end - data_start;
381 nt->OptionalHeader.SizeOfUninitializedData = 0;
382 nt->OptionalHeader.SizeOfImage = data_end;
383 nt->OptionalHeader.ImageBase = (ULONG_PTR)addr;
385 /* Build the code section */
387 memcpy( sec->Name, ".text", sizeof(".text") );
388 sec->SizeOfRawData = data_start - code_start;
389 sec->Misc.VirtualSize = sec->SizeOfRawData;
390 sec->VirtualAddress = code_start;
391 sec->PointerToRawData = code_start;
392 sec->Characteristics = (IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ);
393 sec++;
395 /* Build the data section */
397 memcpy( sec->Name, ".data", sizeof(".data") );
398 sec->SizeOfRawData = data_end - data_start;
399 sec->Misc.VirtualSize = sec->SizeOfRawData;
400 sec->VirtualAddress = data_start;
401 sec->PointerToRawData = data_start;
402 sec->Characteristics = (IMAGE_SCN_CNT_INITIALIZED_DATA |
403 IMAGE_SCN_MEM_WRITE | IMAGE_SCN_MEM_READ);
404 sec++;
406 for (i = 0; i < nt->OptionalHeader.NumberOfRvaAndSizes; i++)
407 fixup_rva_dwords( &nt->OptionalHeader.DataDirectory[i].VirtualAddress, delta, 1 );
409 /* Build the import directory */
411 dir = &nt->OptionalHeader.DataDirectory[IMAGE_FILE_IMPORT_DIRECTORY];
412 if (dir->Size)
414 IMAGE_IMPORT_DESCRIPTOR *imports = (void *)(addr + dir->VirtualAddress);
415 fixup_imports( imports, addr, delta );
418 /* Build the resource directory */
420 dir = &nt->OptionalHeader.DataDirectory[IMAGE_FILE_RESOURCE_DIRECTORY];
421 if (dir->Size)
423 void *ptr = (void *)(addr + dir->VirtualAddress);
424 fixup_resources( ptr, ptr, delta );
427 /* Build the export directory */
429 dir = &nt->OptionalHeader.DataDirectory[IMAGE_FILE_EXPORT_DIRECTORY];
430 if (dir->Size)
432 IMAGE_EXPORT_DIRECTORY *exports = (void *)(addr + dir->VirtualAddress);
433 fixup_exports( exports, addr, delta );
435 return addr;
436 #else /* HAVE_MMAP */
437 return NULL;
438 #endif /* HAVE_MMAP */
442 /***********************************************************************
443 * __wine_dll_register
445 * Register a built-in DLL descriptor.
447 void __wine_dll_register( const IMAGE_NT_HEADERS *header, const char *filename )
449 if (load_dll_callback) load_dll_callback( map_dll(header), filename );
450 else
452 if (!(header->FileHeader.Characteristics & IMAGE_FILE_DLL))
453 main_exe = header;
454 else
456 assert( nb_dlls < MAX_DLLS );
457 builtin_dlls[nb_dlls].nt = header;
458 builtin_dlls[nb_dlls].filename = filename;
459 nb_dlls++;
465 /***********************************************************************
466 * wine_dll_set_callback
468 * Set the callback function for dll loading, and call it
469 * for all dlls that were implicitly loaded already.
471 void wine_dll_set_callback( load_dll_callback_t load )
473 int i;
474 load_dll_callback = load;
475 for (i = 0; i < nb_dlls; i++)
477 const IMAGE_NT_HEADERS *nt = builtin_dlls[i].nt;
478 if (!nt) continue;
479 builtin_dlls[i].nt = NULL;
480 load_dll_callback( map_dll(nt), builtin_dlls[i].filename );
482 nb_dlls = 0;
483 if (main_exe) load_dll_callback( map_dll(main_exe), "" );
487 /***********************************************************************
488 * wine_dll_load
490 * Load a builtin dll.
492 void *wine_dll_load( const char *filename, char *error, int errorsize, int *file_exists )
494 int i;
496 /* callback must have been set already */
497 assert( load_dll_callback );
499 /* check if we have it in the list */
500 /* this can happen when initializing pre-loaded dlls in wine_dll_set_callback */
501 for (i = 0; i < nb_dlls; i++)
503 if (!builtin_dlls[i].nt) continue;
504 if (!strcmp( builtin_dlls[i].filename, filename ))
506 const IMAGE_NT_HEADERS *nt = builtin_dlls[i].nt;
507 builtin_dlls[i].nt = NULL;
508 load_dll_callback( map_dll(nt), builtin_dlls[i].filename );
509 *file_exists = 1;
510 return (void *)1;
513 return dlopen_dll( filename, error, errorsize, 0, file_exists );
517 /***********************************************************************
518 * wine_dll_unload
520 * Unload a builtin dll.
522 void wine_dll_unload( void *handle )
524 if (handle != (void *)1)
525 wine_dlclose( handle, NULL, 0 );
529 /***********************************************************************
530 * wine_dll_load_main_exe
532 * Try to load the .so for the main exe.
534 void *wine_dll_load_main_exe( const char *name, char *error, int errorsize,
535 int test_only, int *file_exists )
537 return dlopen_dll( name, error, errorsize, test_only, file_exists );
541 /***********************************************************************
542 * wine_dll_enum_load_path
544 * Enumerate the dll load path.
546 const char *wine_dll_enum_load_path( unsigned int index )
548 if (index >= nb_dll_paths) return NULL;
549 return dll_paths[index];
553 /***********************************************************************
554 * wine_dll_get_owner
556 * Retrieve the name of the 32-bit owner dll for a 16-bit dll.
557 * Return 0 if OK, -1 on error.
559 int wine_dll_get_owner( const char *name, char *buffer, int size, int *exists )
561 int ret = -1;
562 char *path;
563 struct dll_path_context context;
565 *exists = 0;
567 for (path = first_dll_path( name, 1, &context ); path; path = next_dll_path( &context ))
569 int fd = open( path, O_RDONLY );
570 if (fd != -1)
572 int res = read( fd, buffer, size - 1 );
573 while (res > 0 && (buffer[res-1] == '\n' || buffer[res-1] == '\r')) res--;
574 buffer[res] = 0;
575 close( fd );
576 *exists = 1;
577 ret = 0;
578 break;
581 free_dll_path( &context );
582 return ret;
586 /***********************************************************************
587 * set_max_limit
589 * Set a user limit to the maximum allowed value.
591 static void set_max_limit( int limit )
593 #ifdef HAVE_SETRLIMIT
594 struct rlimit rlimit;
596 if (!getrlimit( limit, &rlimit ))
598 rlimit.rlim_cur = rlimit.rlim_max;
599 if (setrlimit( limit, &rlimit ) != 0)
601 #if defined(__APPLE__) && defined(RLIMIT_NOFILE) && defined(OPEN_MAX)
602 /* On Leopard, setrlimit(RLIMIT_NOFILE, ...) fails on attempts to set
603 * rlim_cur above OPEN_MAX (even if rlim_max > OPEN_MAX). */
604 if (limit == RLIMIT_NOFILE && rlimit.rlim_cur > OPEN_MAX)
606 rlimit.rlim_cur = OPEN_MAX;
607 setrlimit( limit, &rlimit );
609 #endif
612 #endif
616 /***********************************************************************
617 * wine_init
619 * Main Wine initialisation.
621 void wine_init( int argc, char *argv[], char *error, int error_size )
623 struct dll_path_context context;
624 char *path;
625 void *ntdll = NULL;
626 void (*init_func)(void);
628 /* force a few limits that are set too low on some platforms */
629 #ifdef RLIMIT_NOFILE
630 set_max_limit( RLIMIT_NOFILE );
631 #endif
632 #ifdef RLIMIT_AS
633 set_max_limit( RLIMIT_AS );
634 #endif
636 wine_init_argv0_path( argv[0] );
637 build_dll_path();
638 __wine_main_argc = argc;
639 __wine_main_argv = argv;
640 __wine_main_environ = environ;
641 mmap_init();
643 for (path = first_dll_path( "ntdll.dll", 0, &context ); path; path = next_dll_path( &context ))
645 if ((ntdll = wine_dlopen( path, RTLD_NOW, error, error_size )))
647 /* if we didn't use the default dll dir, remove it from the search path */
648 if (default_dlldir[0] && context.index < nb_dll_paths + 2) nb_dll_paths--;
649 break;
652 free_dll_path( &context );
654 if (!ntdll) return;
655 if (!(init_func = wine_dlsym( ntdll, "__wine_process_init", error, error_size ))) return;
656 init_func();
661 * These functions provide wrappers around dlopen() and associated
662 * functions. They work around a bug in glibc 2.1.x where calling
663 * a dl*() function after a previous dl*() function has failed
664 * without a dlerror() call between the two will cause a crash.
665 * They all take a pointer to a buffer that
666 * will receive the error description (from dlerror()). This
667 * parameter may be NULL if the error description is not required.
670 #ifndef RTLD_FIRST
671 #define RTLD_FIRST 0
672 #endif
674 /***********************************************************************
675 * wine_dlopen
677 void *wine_dlopen( const char *filename, int flag, char *error, size_t errorsize )
679 #ifdef HAVE_DLOPEN
680 void *ret;
681 const char *s;
683 #ifdef __APPLE__
684 /* the Mac OS loader pretends to be able to load PE files, so avoid them here */
685 unsigned char magic[2];
686 int fd = open( filename, O_RDONLY );
687 if (fd != -1)
689 if (pread( fd, magic, 2, 0 ) == 2 && magic[0] == 'M' && magic[1] == 'Z')
691 static const char msg[] = "MZ format";
692 size_t len = min( errorsize, sizeof(msg) );
693 memcpy( error, msg, len );
694 error[len - 1] = 0;
695 close( fd );
696 return NULL;
698 close( fd );
700 #endif
701 dlerror(); dlerror();
702 #ifdef __sun
703 if (strchr( filename, ':' ))
705 char path[PATH_MAX];
706 /* Solaris' brain damaged dlopen() treats ':' as a path separator */
707 realpath( filename, path );
708 ret = dlopen( path, flag | RTLD_FIRST );
710 else
711 #endif
712 ret = dlopen( filename, flag | RTLD_FIRST );
713 s = dlerror();
714 if (error && errorsize)
716 if (s)
718 size_t len = strlen(s);
719 if (len >= errorsize) len = errorsize - 1;
720 memcpy( error, s, len );
721 error[len] = 0;
723 else error[0] = 0;
725 dlerror();
726 return ret;
727 #else
728 if (error)
730 static const char msg[] = "dlopen interface not detected by configure";
731 size_t len = min( errorsize, sizeof(msg) );
732 memcpy( error, msg, len );
733 error[len - 1] = 0;
735 return NULL;
736 #endif
739 /***********************************************************************
740 * wine_dlsym
742 void *wine_dlsym( void *handle, const char *symbol, char *error, size_t errorsize )
744 #ifdef HAVE_DLOPEN
745 void *ret;
746 const char *s;
747 dlerror(); dlerror();
748 ret = dlsym( handle, symbol );
749 s = dlerror();
750 if (error && errorsize)
752 if (s)
754 size_t len = strlen(s);
755 if (len >= errorsize) len = errorsize - 1;
756 memcpy( error, s, len );
757 error[len] = 0;
759 else error[0] = 0;
761 dlerror();
762 return ret;
763 #else
764 if (error)
766 static const char msg[] = "dlopen interface not detected by configure";
767 size_t len = min( errorsize, sizeof(msg) );
768 memcpy( error, msg, len );
769 error[len - 1] = 0;
771 return NULL;
772 #endif
775 /***********************************************************************
776 * wine_dlclose
778 int wine_dlclose( void *handle, char *error, size_t errorsize )
780 #ifdef HAVE_DLOPEN
781 int ret;
782 const char *s;
783 dlerror(); dlerror();
784 ret = dlclose( handle );
785 s = dlerror();
786 if (error && errorsize)
788 if (s)
790 size_t len = strlen(s);
791 if (len >= errorsize) len = errorsize - 1;
792 memcpy( error, s, len );
793 error[len] = 0;
795 else error[0] = 0;
797 dlerror();
798 return ret;
799 #else
800 if (error)
802 static const char msg[] = "dlopen interface not detected by configure";
803 size_t len = min( errorsize, sizeof(msg) );
804 memcpy( error, msg, len );
805 error[len - 1] = 0;
807 return 1;
808 #endif