gimp/plug-ins/script-fu/tinyscheme/dynload.c

138 lines
3.1 KiB
C

/* dynload.c Dynamic Loader for TinyScheme */
/* Original Copyright (c) 1999 Alexander Shendi */
/* Modifications for NT and dl_* interface, scm_load_ext: D. Souflis */
/* Refurbished by Stephen Gildea */
#define _SCHEME_SOURCE
#include "dynload.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#ifndef MAXPATHLEN
# define MAXPATHLEN 1024
#endif
static void make_filename(const char *name, char *filename);
static void make_init_fn(const char *name, char *init_fn);
#ifdef _WIN32
# include <windows.h>
#else
typedef void *HMODULE;
typedef void (*FARPROC)();
#endif
#ifdef _WIN32
#define PREFIX ""
#define SUFFIX ".dll"
static void display_w32_error_msg(const char *additional_message)
{
LPVOID msg_buf;
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,
NULL, GetLastError(), 0,
(LPTSTR)&msg_buf, 0, NULL);
fprintf(stderr, "scheme load-extension: %s: %s", additional_message, msg_buf);
LocalFree(msg_buf);
}
static HMODULE dl_attach(const char *module) {
HMODULE dll = LoadLibrary(module);
if (!dll) display_w32_error_msg(module);
return dll;
}
static FARPROC dl_proc(HMODULE mo, const char *proc) {
FARPROC procedure = GetProcAddress(mo,proc);
if (!procedure) display_w32_error_msg(proc);
return procedure;
}
static void dl_detach(HMODULE mo) {
(void)FreeLibrary(mo);
}
#elif defined(SUN_DL)
#include <dlfcn.h>
#define PREFIX "lib"
#define SUFFIX ".so"
static HMODULE dl_attach(const char *module) {
HMODULE so=dlopen(module,RTLD_LAZY);
if(!so) {
fprintf(stderr, "Error loading scheme extension \"%s\": %s\n", module, dlerror());
}
return so;
}
static FARPROC dl_proc(HMODULE mo, const char *proc) {
const char *errmsg;
FARPROC fp=(FARPROC)dlsym(mo,proc);
if ((errmsg = dlerror()) == 0) {
return fp;
}
fprintf(stderr, "Error initializing scheme module \"%s\": %s\n", proc, errmsg);
return 0;
}
static void dl_detach(HMODULE mo) {
(void)dlclose(mo);
}
#endif
pointer scm_load_ext(scheme *sc, pointer args)
{
pointer first_arg;
pointer retval;
char filename[MAXPATHLEN], init_fn[MAXPATHLEN+6];
char *name;
HMODULE dll_handle;
void (*module_init)(scheme *sc);
if ((args != sc->NIL) && is_string((first_arg = pair_car(args)))) {
name = string_value(first_arg);
make_filename(name,filename);
make_init_fn(name,init_fn);
dll_handle = dl_attach(filename);
if (dll_handle == 0) {
retval = sc -> F;
}
else {
module_init = (void(*)(scheme *))dl_proc(dll_handle, init_fn);
if (module_init != 0) {
(*module_init)(sc);
retval = sc -> T;
}
else {
retval = sc->F;
}
}
}
else {
retval = sc -> F;
}
return(retval);
}
static void make_filename(const char *name, char *filename) {
strcpy(filename,name);
strcat(filename,SUFFIX);
}
static void make_init_fn(const char *name, char *init_fn) {
const char *p=strrchr(name,'/');
if(p==0) {
p=name;
} else {
p++;
}
strcpy(init_fn,"init_");
strcat(init_fn,p);
}