#include <ruby.h>
#include <errno.h>
#include "dl.h"
VALUE rb_cDLSymbol;
static const char *
char2type(int ch)
{
switch (ch) {
case '0':
return "void";
case 'P':
return "void *";
case 'p':
return "void *";
case 'C':
return "char";
case 'c':
return "char *";
case 'H':
return "short";
case 'h':
return "short *";
case 'I':
return "int";
case 'i':
return "int *";
case 'L':
return "long";
case 'l':
return "long *";
case 'F':
return "double";
case 'f':
return "double *";
case 'D':
return "double";
case 'd':
return "double *";
case 'S':
return "const char *";
case 's':
return "char *";
case 'A':
return "[]";
case 'a':
return "[]";
}
return NULL;
}
void
dlsym_free(struct sym_data *data)
{
if( data->name ){
DEBUG_CODE({
printf("dlsym_free(): free(data->name:%s)\n",data->name);
});
free(data->name);
}
if( data->type ){
DEBUG_CODE({
printf("dlsym_free(): free(data->type:%s)\n",data->type);
});
free(data->type);
}
}
VALUE
rb_dlsym_new(void (*func)(), const char *name, const char *type)
{
VALUE val;
struct sym_data *data;
const char *ptype;
rb_secure(4);
if( !type || !type[0] ){
return rb_dlptr_new((void*)func, 0, 0);
}
for( ptype = type; *ptype; ptype ++ ){
if( ! char2type(*ptype) ){
rb_raise(rb_eDLTypeError, "unknown type specifier '%c'", *ptype);
}
}
if( func ){
val = Data_Make_Struct(rb_cDLSymbol, struct sym_data, 0, dlsym_free, data);
data->func = func;
data->name = name ? strdup(name) : NULL;
data->type = type ? strdup(type) : NULL;
data->len = type ? strlen(type) : 0;
#if !(defined(DLSTACK))
if( data->len - 1 > MAX_ARG ){
rb_raise(rb_eDLError, "maximum number of arguments is %d.", MAX_ARG);
}
#endif
}
else{
val = Qnil;
}
return val;
}
freefunc_t
rb_dlsym2csym(VALUE val)
{
struct sym_data *data;
freefunc_t func;
if( rb_obj_is_kind_of(val, rb_cDLSymbol) ){
Data_Get_Struct(val, struct sym_data, data);
func = data->func;
}
else if( val == Qnil ){
func = NULL;
}
else{
rb_raise(rb_eTypeError, "DL::Symbol was expected");
}
return func;
}
VALUE
rb_dlsym_s_allocate(VALUE klass)
{
VALUE obj;
struct sym_data *data;
obj = Data_Make_Struct(klass, struct sym_data, 0, dlsym_free, data);
data->func = 0;
data->name = 0;
data->type = 0;
data->len = 0;
return obj;
}
VALUE
rb_dlsym_initialize(int argc, VALUE argv[], VALUE self)
{
VALUE addr, name, type;
struct sym_data *data;
void *saddr;
const char *sname, *stype;
rb_scan_args(argc, argv, "12", &addr, &name, &type);
saddr = (void*)(DLNUM2LONG(rb_Integer(addr)));
if (!NIL_P(name)) StringValue(name);
stype = NIL_P(type) ? NULL : StringValuePtr(type);
sname = NIL_P(name) ? NULL : RSTRING(name)->ptr;
if( saddr ){
Data_Get_Struct(self, struct sym_data, data);
if( data->name ) free(data->name);
if( data->type ) free(data->type);
data->func = saddr;
data->name = sname ? strdup(sname) : 0;
data->type = stype ? strdup(stype) : 0;
data->len = stype ? strlen(stype) : 0;
}
return Qnil;
}
VALUE
rb_s_dlsym_char2type(VALUE self, VALUE ch)
{
const char *type;
type = char2type(StringValuePtr(ch)[0]);
if (type == NULL)
return Qnil;
else
return rb_str_new2(type);
}
VALUE
rb_dlsym_name(VALUE self)
{
struct sym_data *sym;
Data_Get_Struct(self, struct sym_data, sym);
return sym->name ? rb_tainted_str_new2(sym->name) : Qnil;
}
VALUE
rb_dlsym_proto(VALUE self)
{
struct sym_data *sym;
Data_Get_Struct(self, struct sym_data, sym);
return sym->type ? rb_tainted_str_new2(sym->type) : Qnil;
}
VALUE
rb_dlsym_cproto(VALUE self)
{
struct sym_data *sym;
const char *ptype, *typestr;
size_t len;
VALUE val;
Data_Get_Struct(self, struct sym_data, sym);
ptype = sym->type;
if( ptype ){
typestr = char2type(*ptype++);
len = strlen(typestr);
val = rb_tainted_str_new(typestr, len);
if (typestr[len - 1] != '*')
rb_str_cat(val, " ", 1);
if( sym->name ){
rb_str_cat2(val, sym->name);
}
else{
rb_str_cat2(val, "(null)");
}
rb_str_cat(val, "(", 1);
while (*ptype) {
const char *ty = char2type(*ptype++);
rb_str_cat2(val, ty);
if (*ptype)
rb_str_cat(val, ", ", 2);
}
rb_str_cat(val, ");", 2);
}
else{
val = rb_tainted_str_new2("void (");
if( sym->name ){
rb_str_cat2(val, sym->name);
}
else{
rb_str_cat2(val, "(null)");
}
rb_str_cat2(val, ")()");
}
return val;
}
VALUE
rb_dlsym_inspect(VALUE self)
{
VALUE proto;
VALUE val;
char *str;
int str_size;
struct sym_data *sym;
Data_Get_Struct(self, struct sym_data, sym);
proto = rb_dlsym_cproto(self);
str_size = RSTRING(proto)->len + 100;
str = dlmalloc(str_size);
snprintf(str, str_size - 1,
"#<DL::Symbol:0x%lx func=0x%lx '%s'>",
sym, sym->func, RSTRING(proto)->ptr);
val = rb_tainted_str_new2(str);
dlfree(str);
return val;
}
static int
stack_size(struct sym_data *sym)
{
int i;
int size;
size = 0;
for( i=1; i < sym->len; i++ ){
switch(sym->type[i]){
case 'C':
case 'H':
case 'I':
case 'L':
size += sizeof(long);
break;
case 'F':
size += sizeof(float);
break;
case 'D':
size += sizeof(double);
break;
case 'c':
case 'h':
case 'i':
case 'l':
case 'f':
case 'd':
case 'p':
case 'P':
case 's':
case 'S':
case 'a':
case 'A':
size += sizeof(void*);
break;
default:
return -(sym->type[i]);
}
}
return size;
}
static ID rb_dl_id_DLErrno;
static VALUE
rb_dl_get_last_error(VALUE self)
{
return rb_thread_local_aref(rb_thread_current(), rb_dl_id_DLErrno);
}
static VALUE
rb_dl_set_last_error(VALUE self, VALUE val)
{
errno = NUM2INT(val);
rb_thread_local_aset(rb_thread_current(), rb_dl_id_DLErrno, val);
return Qnil;
}
#ifdef HAVE_WINDOWS_H
#include <windows.h>
static ID rb_dl_id_DLW32Error;
static VALUE
rb_dl_win32_get_last_error(VALUE self)
{
return rb_thread_local_aref(rb_thread_current(), rb_dl_id_DLW32Error);
}
static VALUE
rb_dl_win32_set_last_error(VALUE self, VALUE val)
{
SetLastError(NUM2INT(val));
rb_thread_local_aset(rb_thread_current(), rb_dl_id_DLW32Error, val);
return Qnil;
}
#endif
#ifdef DLSTACK_GUARD
# ifdef __MSVC_RUNTIME_CHECKS
# pragma runtime_checks("s", off)
# endif
# if _MSC_VER >= 1300
__declspec(noinline)
# endif
static int
rb_dlsym_guardcall(char type, ANY_TYPE *ret, long *stack, void *func)
{
char *volatile guard = ALLOCA_N(char, 1);
switch(type){
case '0':
{
void (*f)(DLSTACK_PROTO) = func;
f(DLSTACK_ARGS);
}
break;
case 'P':
case 'p':
{
void * (*f)(DLSTACK_PROTO) = func;
ret->p = f(DLSTACK_ARGS);
}
break;
case 'C':
case 'c':
{
char (*f)(DLSTACK_PROTO) = func;
ret->c = f(DLSTACK_ARGS);
}
break;
case 'H':
case 'h':
{
short (*f)(DLSTACK_PROTO) = func;
ret->h = f(DLSTACK_ARGS);
}
break;
case 'I':
case 'i':
{
int (*f)(DLSTACK_PROTO) = func;
ret->i = f(DLSTACK_ARGS);
}
break;
case 'L':
case 'l':
{
long (*f)(DLSTACK_PROTO) = func;
ret->l = f(DLSTACK_ARGS);
}
break;
case 'F':
case 'f':
{
float (*f)(DLSTACK_PROTO) = func;
ret->f = f(DLSTACK_ARGS);
}
break;
case 'D':
case 'd':
{
double (*f)(DLSTACK_PROTO) = func;
ret->d = f(DLSTACK_ARGS);
}
break;
case 'S':
case 's':
{
char * (*f)(DLSTACK_PROTO) = func;
ret->s = f(DLSTACK_ARGS);
}
break;
default:
return 0;
}
return 1;
}
# ifdef __MSVC_RUNTIME_CHECKS
# pragma runtime_checks("s", restore)
# endif
#endif
VALUE
rb_dlsym_call(int argc, VALUE argv[], VALUE self)
{
struct sym_data *sym;
ANY_TYPE *args;
ANY_TYPE *dargs;
ANY_TYPE ret;
int *dtypes;
VALUE val;
VALUE dvals;
int i;
long ftype;
void *func;
rb_secure_update(self);
Data_Get_Struct(self, struct sym_data, sym);
DEBUG_CODE({
printf("rb_dlsym_call(): type = '%s', func = 0x%x\n", sym->type, sym->func);
});
if( (sym->len - 1) != argc ){
rb_raise(rb_eArgError, "%d arguments are needed", sym->len - 1);
}
ftype = 0;
dvals = Qnil;
args = ALLOC_N(ANY_TYPE, sym->len - 1);
dargs = ALLOC_N(ANY_TYPE, sym->len - 1);
dtypes = ALLOC_N(int, sym->len - 1);
#define FREE_ARGS {xfree(args); xfree(dargs); xfree(dtypes);}
for( i = sym->len - 2; i >= 0; i-- ){
dtypes[i] = 0;
switch( sym->type[i+1] ){
case 'p':
dtypes[i] = 'p';
case 'P':
{
struct ptr_data *data;
VALUE pval;
if( argv[i] == Qnil ){
ANY2P(args[i]) = DLVOIDP(0);
}
else{
if( rb_obj_is_kind_of(argv[i], rb_cDLPtrData) ){
pval = argv[i];
}
else{
pval = rb_funcall(argv[i], rb_intern("to_ptr"), 0);
if( !rb_obj_is_kind_of(pval, rb_cDLPtrData) ){
rb_raise(rb_eDLTypeError, "unexpected type of argument #%d", i);
}
}
Data_Get_Struct(pval, struct ptr_data, data);
ANY2P(args[i]) = DLVOIDP(data->ptr);
}
}
PUSH_P(ftype);
break;
case 'a':
dtypes[i] = 'a';
case 'A':
if( argv[i] == Qnil ){
ANY2P(args[i]) = DLVOIDP(0);
}
else{
ANY2P(args[i]) = DLVOIDP(rb_ary2cary(0, argv[i], NULL));
}
PUSH_P(ftype);
break;
case 'C':
ANY2C(args[i]) = DLCHAR(NUM2CHR(argv[i]));
PUSH_C(ftype);
break;
case 'c':
ANY2C(dargs[i]) = DLCHAR(NUM2CHR(argv[i]));
ANY2P(args[i]) = DLVOIDP(&(ANY2C(dargs[i])));
dtypes[i] = 'c';
PUSH_P(ftype);
break;
case 'H':
ANY2H(args[i]) = DLSHORT(NUM2INT(argv[i]));
PUSH_C(ftype);
break;
case 'h':
ANY2H(dargs[i]) = DLSHORT(NUM2INT(argv[i]));
ANY2P(args[i]) = DLVOIDP(&(ANY2H(dargs[i])));
dtypes[i] = 'h';
PUSH_P(ftype);
break;
case 'I':
ANY2I(args[i]) = DLINT(NUM2INT(argv[i]));
PUSH_I(ftype);
break;
case 'i':
ANY2I(dargs[i]) = DLINT(NUM2INT(argv[i]));
ANY2P(args[i]) = DLVOIDP(&(ANY2I(dargs[i])));
dtypes[i] = 'i';
PUSH_P(ftype);
break;
case 'L':
ANY2L(args[i]) = DLNUM2LONG(argv[i]);
PUSH_L(ftype);
break;
case 'l':
ANY2L(dargs[i]) = DLNUM2LONG(argv[i]);
ANY2P(args[i]) = DLVOIDP(&(ANY2L(dargs[i])));
dtypes[i] = 'l';
PUSH_P(ftype);
break;
case 'F':
Check_Type(argv[i], T_FLOAT);
ANY2F(args[i]) = DLFLOAT(RFLOAT(argv[i])->value);
PUSH_F(ftype);
break;
case 'f':
Check_Type(argv[i], T_FLOAT);
ANY2F(dargs[i]) = DLFLOAT(RFLOAT(argv[i])->value);
ANY2P(args[i]) = DLVOIDP(&(ANY2F(dargs[i])));
dtypes[i] = 'f';
PUSH_P(ftype);
break;
case 'D':
Check_Type(argv[i], T_FLOAT);
ANY2D(args[i]) = RFLOAT(argv[i])->value;
PUSH_D(ftype);
break;
case 'd':
Check_Type(argv[i], T_FLOAT);
ANY2D(dargs[i]) = RFLOAT(argv[i])->value;
ANY2P(args[i]) = DLVOIDP(&(ANY2D(dargs[i])));
dtypes[i] = 'd';
PUSH_P(ftype);
break;
case 'S':
if( argv[i] == Qnil ){
ANY2S(args[i]) = DLSTR(0);
}
else{
VALUE str = argv[i];
SafeStringValue(str);
ANY2S(args[i]) = DLSTR(RSTRING(str)->ptr);
}
PUSH_P(ftype);
break;
case 's':
{
VALUE str = argv[i];
SafeStringValue(str);
ANY2S(args[i]) = DLSTR(dlmalloc(RSTRING(str)->len + 1));
memcpy((char*)(ANY2S(args[i])), RSTRING(str)->ptr, RSTRING(str)->len + 1);
dtypes[i] = 's';
}
PUSH_P(ftype);
break;
default:
FREE_ARGS;
rb_raise(rb_eDLTypeError,
"unknown type '%c' of the return value.",
sym->type[i+1]);
}
}
switch( sym->type[0] ){
case '0':
PUSH_0(ftype);
break;
case 'P':
case 'p':
case 'S':
case 's':
case 'A':
case 'a':
PUSH_P(ftype);
break;
case 'C':
case 'c':
PUSH_C(ftype);
break;
case 'H':
case 'h':
PUSH_H(ftype);
break;
case 'I':
case 'i':
PUSH_I(ftype);
break;
case 'L':
case 'l':
PUSH_L(ftype);
break;
case 'F':
case 'f':
PUSH_F(ftype);
break;
case 'D':
case 'd':
PUSH_D(ftype);
break;
default:
FREE_ARGS;
rb_raise(rb_eDLTypeError,
"unknown type `%c' of the return value.",
sym->type[0]);
}
func = sym->func;
#if defined(DLSTACK)
{
#if defined(DLSTACK_SIZE)
int stk_size;
long stack[DLSTACK_SIZE];
long *sp;
sp = stack;
stk_size = stack_size(sym);
if( stk_size < 0 ){
FREE_ARGS;
rb_raise(rb_eDLTypeError, "unknown type '%c'.", -stk_size);
}
else if( stk_size > (int)(DLSTACK_SIZE) ){
FREE_ARGS;
rb_raise(rb_eArgError, "too many arguments.");
}
#endif
DLSTACK_START(sym);
#if defined(DLSTACK_REVERSE)
for( i = sym->len - 2; i >= 0; i-- )
#else
for( i = 0; i <= sym->len -2; i++ )
#endif
{
switch( sym->type[i+1] ){
case 'p':
case 'P':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'a':
case 'A':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'C':
DLSTACK_PUSH_C(ANY2C(args[i]));
break;
case 'c':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'H':
DLSTACK_PUSH_H(ANY2H(args[i]));
break;
case 'h':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'I':
DLSTACK_PUSH_I(ANY2I(args[i]));
break;
case 'i':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'L':
DLSTACK_PUSH_L(ANY2L(args[i]));
break;
case 'l':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'F':
DLSTACK_PUSH_F(ANY2F(args[i]));
break;
case 'f':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'D':
DLSTACK_PUSH_D(ANY2D(args[i]));
break;
case 'd':
DLSTACK_PUSH_P(ANY2P(args[i]));
break;
case 'S':
case 's':
DLSTACK_PUSH_P(ANY2S(args[i]));
break;
}
}
DLSTACK_END(sym->type);
#ifdef DLSTACK_GUARD
if(!rb_dlsym_guardcall(sym->type[0], &ret, stack, func)) {
FREE_ARGS;
rb_raise(rb_eDLTypeError, "unknown type `%c'", sym->type[0]);
}
#else
{
switch( sym->type[0] ){
case '0':
{
void (*f)(DLSTACK_PROTO) = func;
f(DLSTACK_ARGS);
}
break;
case 'P':
case 'p':
{
void * (*f)(DLSTACK_PROTO) = func;
ret.p = f(DLSTACK_ARGS);
}
break;
case 'C':
case 'c':
{
char (*f)(DLSTACK_PROTO) = func;
ret.c = f(DLSTACK_ARGS);
}
break;
case 'H':
case 'h':
{
short (*f)(DLSTACK_PROTO) = func;
ret.h = f(DLSTACK_ARGS);
}
break;
case 'I':
case 'i':
{
int (*f)(DLSTACK_PROTO) = func;
ret.i = f(DLSTACK_ARGS);
}
break;
case 'L':
case 'l':
{
long (*f)(DLSTACK_PROTO) = func;
ret.l = f(DLSTACK_ARGS);
}
break;
case 'F':
case 'f':
{
float (*f)(DLSTACK_PROTO) = func;
ret.f = f(DLSTACK_ARGS);
}
break;
case 'D':
case 'd':
{
double (*f)(DLSTACK_PROTO) = func;
ret.d = f(DLSTACK_ARGS);
}
break;
case 'S':
case 's':
{
char * (*f)(DLSTACK_PROTO) = func;
ret.s = f(DLSTACK_ARGS);
}
break;
default:
FREE_ARGS;
rb_raise(rb_eDLTypeError, "unknown type `%c'", sym->type[0]);
}
}
#endif
{
int last_errno = errno;
#ifdef _WIN32
DWORD win32_last_err = GetLastError();
#endif
rb_thread_local_aset(rb_thread_current(), rb_dl_id_DLErrno, INT2NUM(last_errno));
#ifdef _WIN32
rb_thread_local_aset(rb_thread_current(), rb_dl_id_DLW32Error, INT2NUM(win32_last_err));
#endif
}
}
#else
switch(ftype){
#include "call.func"
default:
FREE_ARGS;
rb_raise(rb_eDLTypeError, "unsupported function type `%s'", sym->type);
}
#endif
switch( sym->type[0] ){
case '0':
val = Qnil;
break;
case 'P':
val = rb_dlptr_new((void*)(ANY2P(ret)), 0, 0);
break;
case 'p':
val = rb_dlptr_new((void*)(ANY2P(ret)), 0, dlfree);
break;
case 'C':
case 'c':
val = CHR2FIX((char)(ANY2C(ret)));
break;
case 'H':
case 'h':
val = INT2NUM((short)(ANY2H(ret)));
break;
case 'I':
case 'i':
val = INT2NUM((int)(ANY2I(ret)));
break;
case 'L':
case 'l':
val = DLLONG2NUM((long)(ANY2L(ret)));
break;
case 'F':
case 'f':
val = rb_float_new((double)(ANY2F(ret)));
break;
case 'D':
case 'd':
val = rb_float_new((double)(ANY2D(ret)));
break;
case 'S':
if( ANY2S(ret) ){
val = rb_tainted_str_new2((char*)(ANY2S(ret)));
}
else{
val = Qnil;
}
break;
case 's':
if( ANY2S(ret) ){
val = rb_tainted_str_new2((char*)(ANY2S(ret)));
DEBUG_CODE({
printf("dlfree(%s)\n",(char*)(ANY2S(ret)));
});
dlfree((void*)(ANY2S(ret)));
}
else{
val = Qnil;
}
break;
default:
FREE_ARGS;
rb_raise(rb_eDLTypeError, "unknown type `%c'", sym->type[0]);
}
dvals = rb_ary_new();
for( i = 0; i <= sym->len - 2; i++ ){
if( dtypes[i] ){
switch( dtypes[i] ){
case 'c':
rb_ary_push(dvals, CHR2FIX(*((char*)(ANY2P(args[i])))));
break;
case 'h':
rb_ary_push(dvals, INT2NUM(*((short*)(ANY2P(args[i])))));
break;
case 'i':
rb_ary_push(dvals, INT2NUM(*((int*)(ANY2P(args[i])))));
break;
case 'l':
rb_ary_push(dvals, DLLONG2NUM(*((long*)(ANY2P(args[i])))));
break;
case 'f':
rb_ary_push(dvals, rb_float_new(*((float*)(ANY2P(args[i])))));
break;
case 'd':
rb_ary_push(dvals, rb_float_new(*((double*)(ANY2P(args[i])))));
break;
case 'p':
rb_ary_push(dvals, rb_dlptr_new((void*)(ANY2P(args[i])), 0, 0));
break;
case 'a':
rb_ary_push(dvals, rb_dlptr_new((void*)ANY2P(args[i]), 0, 0));
break;
case 's':
rb_ary_push(dvals, rb_tainted_str_new2((char*)ANY2S(args[i])));
DEBUG_CODE({
printf("dlfree(%s)\n",(char*)ANY2S(args[i]));
});
dlfree((void*)ANY2S(args[i]));
break;
default:
{
char c = dtypes[i];
FREE_ARGS;
rb_raise(rb_eRuntimeError, "unknown argument type '%c'", i, c);
}
}
}
else{
switch( sym->type[i+1] ){
case 'A':
dlfree((void*)ANY2P(args[i]));
break;
}
rb_ary_push(dvals, argv[i]);
}
}
FREE_ARGS;
#undef FREE_ARGS
return rb_assoc_new(val,dvals);
}
VALUE
rb_dlsym_to_i(VALUE self)
{
struct sym_data *sym;
Data_Get_Struct(self, struct sym_data, sym);
return DLLONG2NUM(sym);
}
VALUE
rb_dlsym_to_ptr(VALUE self)
{
struct sym_data *sym;
Data_Get_Struct(self, struct sym_data, sym);
return rb_dlptr_new(sym->func, sizeof(freefunc_t), 0);
}
void
Init_dlsym()
{
rb_cDLSymbol = rb_define_class_under(rb_mDL, "Symbol", rb_cObject);
rb_define_alloc_func(rb_cDLSymbol, rb_dlsym_s_allocate);
rb_define_singleton_method(rb_cDLSymbol, "char2type", rb_s_dlsym_char2type, 1);
rb_define_method(rb_cDLSymbol, "initialize", rb_dlsym_initialize, -1);
rb_define_method(rb_cDLSymbol, "call", rb_dlsym_call, -1);
rb_define_method(rb_cDLSymbol, "[]", rb_dlsym_call, -1);
rb_define_method(rb_cDLSymbol, "name", rb_dlsym_name, 0);
rb_define_method(rb_cDLSymbol, "proto", rb_dlsym_proto, 0);
rb_define_method(rb_cDLSymbol, "cproto", rb_dlsym_cproto, 0);
rb_define_method(rb_cDLSymbol, "inspect", rb_dlsym_inspect, 0);
rb_define_method(rb_cDLSymbol, "to_s", rb_dlsym_cproto, 0);
rb_define_method(rb_cDLSymbol, "to_ptr", rb_dlsym_to_ptr, 0);
rb_define_method(rb_cDLSymbol, "to_i", rb_dlsym_to_i, 0);
rb_dl_id_DLErrno = rb_intern("DLErrno");
rb_define_singleton_method(rb_mDL, "last_error", rb_dl_get_last_error, 0);
rb_define_singleton_method(rb_mDL, "last_error=", rb_dl_set_last_error, 1);
#ifdef _WIN32
rb_dl_id_DLW32Error = rb_intern("DLW32Error");
rb_define_singleton_method(rb_mDL, "win32_last_error", rb_dl_win32_get_last_error, 0);
rb_define_singleton_method(rb_mDL, "win32_last_error=", rb_dl_win32_set_last_error, 1);
#endif
}