1 files changed, 392 insertions, 1583 deletions

diff --git a/dln.c b/dln.c
index f3d6bf936f..d3b03e3e87 100644
--- a/dln.c
+++ b/dln.c
@@ -9,23 +9,29 @@
 
 **********************************************************************/
 
+#ifdef RUBY_EXPORT
 #include "ruby/ruby.h"
+#define dln_notimplement rb_notimplement
+#define dln_memerror rb_memerror
+#define dln_exit rb_exit
+#define dln_loaderror rb_loaderror
+#define dln_fatalerror rb_fatal
+#else
+#define dln_notimplement --->>> dln not implemented <<<---
+#define dln_memerror abort
+#define dln_exit exit
+static void dln_loaderror(const char *format, ...);
+#define dln_fatalerror dln_loaderror
+#endif
 #include "dln.h"
+#include "internal.h"
+#include "internal/box.h"
+#include "internal/compilers.h"
 
 #ifdef HAVE_STDLIB_H
 # include <stdlib.h>
 #endif
 
-#ifdef __CHECKER__
-#undef HAVE_DLOPEN
-#undef USE_DLN_A_OUT
-#undef USE_DLN_DLOPEN
-#endif
-
-#ifdef USE_DLN_A_OUT
-char *dln_argv0;
-#endif
-
 #if defined(HAVE_ALLOCA_H)
 #include <alloca.h>
 #endif
@@ -36,21 +42,28 @@ char *dln_argv0;
 # include <strings.h>
 #endif
 
+#if defined __APPLE__
+# include <AvailabilityMacros.h>
+#endif
+
 #ifndef xmalloc
 void *xmalloc();
 void *xcalloc();
 void *xrealloc();
 #endif
 
+#undef free
+#define free(x) xfree(x)
+
 #include <stdio.h>
-#if defined(_WIN32) || defined(__VMS)
+#if defined(_WIN32)
 #include "missing/file.h"
 #endif
 #include <sys/types.h>
 #include <sys/stat.h>
 
 #ifndef S_ISDIR
-#   define S_ISDIR(m) ((m & S_IFMT) == S_IFDIR)
+# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
 #endif
 
 #ifdef HAVE_SYS_PARAM_H
@@ -64,1031 +77,86 @@ void *xrealloc();
 # include <unistd.h>
 #endif
 
-#ifndef _WIN32
-char *getenv();
-#endif
-
-#if defined(__VMS)
-#pragma builtins
-#include <dlfcn.h>
-#endif
-
-#ifdef __MACOS__
-# include <TextUtils.h>
-# include <CodeFragments.h>
-# include <Aliases.h>
-# include "macruby_private.h"
-#endif
-
-#if defined(__APPLE__) && defined(__MACH__)   /* Mac OS X */
-# if defined(HAVE_DLOPEN)
-   /* Mac OS X with dlopen (10.3 or later) */
-#  define MACOSX_DLOPEN
-# else
-#  define MACOSX_DYLD
-# endif
-#endif
-
-#ifdef __BEOS__
-# include <image.h>
-#endif
-
-#ifndef NO_DLN_LOAD
-
-#if defined(HAVE_DLOPEN) && !defined(USE_DLN_A_OUT) && !defined(_AIX) && !defined(MACOSX_DYLD) && !defined(_UNICOSMP)
-/* dynamic load with dlopen() */
-# define USE_DLN_DLOPEN
-#endif
-
-#ifndef FUNCNAME_PATTERN
-# if defined(__hp9000s300) ||  (defined(__NetBSD__) && !defined(__ELF__)) || defined(__BORLANDC__) || (defined(__FreeBSD__) && !defined(__ELF__)) || (defined(__OpenBSD__) && !defined(__ELF__)) || defined(NeXT) || defined(__WATCOMC__) || defined(MACOSX_DYLD)
-#  define FUNCNAME_PATTERN "_Init_%s"
-# else
-#  define FUNCNAME_PATTERN "Init_%s"
-# endif
-#endif
-
-static int
-init_funcname_len(char **buf, const char *file)
-{
-    char *p;
-    const char *slash;
-    int len;
-
-    /* Load the file as an object one */
-    for (slash = file-1; *file; file++) /* Find position of last '/' */
-#ifdef __MACOS__
-	if (*file == ':') slash = file;
-#else
-	if (*file == '/') slash = file;
-#endif
-
-    len = strlen(FUNCNAME_PATTERN) + strlen(slash + 1);
-    *buf = xmalloc(len);
-    snprintf(*buf, len, FUNCNAME_PATTERN, slash + 1);
-    for (p = *buf; *p; p++) {         /* Delete suffix if it exists */
-	if (*p == '.') {
-	    *p = '\0'; break;
-	}
-    }
-    return p - *buf;
-}
-
-#define init_funcname(buf, file) do {\
-    int len = init_funcname_len(buf, file);\
-    char *tmp = ALLOCA_N(char, len+1);\
-    if (!tmp) {\
-	free(*buf);\
-	rb_memerror();\
-    }\
-    strcpy(tmp, *buf);\
-    free(*buf);\
-    *buf = tmp;\
-} while (0)
-
-#ifdef USE_DLN_A_OUT
-
-#ifndef LIBC_NAME
-# define LIBC_NAME "libc.a"
-#endif
-
-#ifndef DLN_DEFAULT_LIB_PATH
-#  define DLN_DEFAULT_LIB_PATH "/lib:/usr/lib:/usr/local/lib:."
-#endif
-
-#include <errno.h>
-
-static int dln_errno;
-
-#define DLN_ENOEXEC	ENOEXEC	/* Exec format error */
-#define DLN_ECONFL	1201	/* Symbol name conflict */
-#define DLN_ENOINIT	1202	/* No initializer given */
-#define DLN_EUNDEF	1203	/* Undefine symbol remains */
-#define DLN_ENOTLIB	1204	/* Not a library file */
-#define DLN_EBADLIB	1205	/* Malformed library file */
-#define DLN_EINIT	1206	/* Not initialized */
-
-static int dln_init_p = 0;
-
-#include <ar.h>
-#include <a.out.h>
-#ifndef N_COMM
-# define N_COMM 0x12
-#endif
-#ifndef N_MAGIC
-# define N_MAGIC(x) (x).a_magic
-#endif
-
-#define INVALID_OBJECT(h) (N_MAGIC(h) != OMAGIC)
-
-#include "ruby/util.h"
-#include "ruby/st.h"
-
-static st_table *sym_tbl;
-static st_table *undef_tbl;
-
-static int load_lib();
-
-static int
-load_header(int fd, struct exec *hdrp, long disp)
-{
-    int size;
-
-    lseek(fd, disp, 0);
-    size = read(fd, hdrp, sizeof(struct exec));
-    if (size == -1) {
-	dln_errno = errno;
-	return -1;
-    }
-    if (size != sizeof(struct exec) || N_BADMAG(*hdrp)) {
-	dln_errno = DLN_ENOEXEC;
-	return -1;
-    }
-    return 0;
-}
-
-#if defined(sequent)
-#define RELOC_SYMBOL(r)			((r)->r_symbolnum)
-#define RELOC_MEMORY_SUB_P(r)		((r)->r_bsr)
-#define RELOC_PCREL_P(r)		((r)->r_pcrel || (r)->r_bsr)
-#define RELOC_TARGET_SIZE(r)		((r)->r_length)
+#ifndef UNREACHABLE_RETURN
+# define UNREACHABLE_RETURN(x) return (x)
 #endif
 
-/* Default macros */
-#ifndef RELOC_ADDRESS
-#define RELOC_ADDRESS(r)		((r)->r_address)
-#define RELOC_EXTERN_P(r)		((r)->r_extern)
-#define RELOC_SYMBOL(r)			((r)->r_symbolnum)
-#define RELOC_MEMORY_SUB_P(r)		0
-#define RELOC_PCREL_P(r)		((r)->r_pcrel)
-#define RELOC_TARGET_SIZE(r)		((r)->r_length)
-#endif
-
-#if defined(sun) && defined(sparc)
-/* Sparc (Sun 4) macros */
-#  undef relocation_info
-#  define relocation_info reloc_info_sparc
-#  define R_RIGHTSHIFT(r)	(reloc_r_rightshift[(r)->r_type])
-#  define R_BITSIZE(r) 		(reloc_r_bitsize[(r)->r_type])
-#  define R_LENGTH(r)		(reloc_r_length[(r)->r_type])
-static int reloc_r_rightshift[] = {
-  0, 0, 0, 0, 0, 0, 2, 2, 10, 0, 0, 0, 0, 0, 0,
-};
-static int reloc_r_bitsize[] = {
-  8, 16, 32, 8, 16, 32, 30, 22, 22, 22, 13, 10, 32, 32, 16,
-};
-static int reloc_r_length[] = {
-  0, 1, 2, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-};
-#  define R_PCREL(r) \
-    ((r)->r_type >= RELOC_DISP8 && (r)->r_type <= RELOC_WDISP22)
-#  define R_SYMBOL(r) ((r)->r_index)
-#endif
-
-#if defined(sequent)
-#define R_SYMBOL(r)		((r)->r_symbolnum)
-#define R_MEMORY_SUB(r)		((r)->r_bsr)
-#define R_PCREL(r)		((r)->r_pcrel || (r)->r_bsr)
-#define R_LENGTH(r)		((r)->r_length)
-#endif
-
-#ifndef R_SYMBOL
-#  define R_SYMBOL(r) 		((r)->r_symbolnum)
-#  define R_MEMORY_SUB(r)	0
-#  define R_PCREL(r)  		((r)->r_pcrel)
-#  define R_LENGTH(r) 		((r)->r_length)
-#endif
-
-static struct relocation_info *
-load_reloc(int fd, struct exec *hdrp, long disp)
-{
-    struct relocation_info *reloc;
-    int size;
-
-    lseek(fd, disp + N_TXTOFF(*hdrp) + hdrp->a_text + hdrp->a_data, 0);
-    size = hdrp->a_trsize + hdrp->a_drsize;
-    reloc = (struct relocation_info*)xmalloc(size);
-    if (reloc == NULL) {
-	dln_errno = errno;
-	return NULL;
-    }
-
-    if (read(fd, reloc, size) !=  size) {
-	dln_errno = errno;
-	free(reloc);
-	return NULL;
-    }
-
-    return reloc;
-}
-
-static struct nlist *
-load_sym(int fd, struct exec *hdrp, long disp)
-{
-    struct nlist * buffer;
-    struct nlist * sym;
-    struct nlist * end;
-    long displ;
-    int size;
-
-    lseek(fd, N_SYMOFF(*hdrp) + hdrp->a_syms + disp, 0);
-    if (read(fd, &size, sizeof(int)) != sizeof(int)) {
-	goto err_noexec;
-    }
-
-    buffer = (struct nlist*)xmalloc(hdrp->a_syms + size);
-    if (buffer == NULL) {
-	dln_errno = errno;
-	return NULL;
-    }
-
-    lseek(fd, disp + N_SYMOFF(*hdrp), 0);
-    if (read(fd, buffer, hdrp->a_syms + size) != hdrp->a_syms + size) {
-	free(buffer);
-	goto err_noexec;
-    }
-
-    sym = buffer;
-    end = sym + hdrp->a_syms / sizeof(struct nlist);
-    displ = (long)buffer + (long)(hdrp->a_syms);
-
-    while (sym < end) {
-	sym->n_un.n_name = (char*)sym->n_un.n_strx + displ;
-	sym++;
-    }
-    return buffer;
-
-  err_noexec:
-    dln_errno = DLN_ENOEXEC;
-    return NULL;
-}
-
-static st_table *
-sym_hash(struct exec *hdrp, struct nlist *syms)
-{
-    st_table *tbl;
-    struct nlist *sym = syms;
-    struct nlist *end = syms + (hdrp->a_syms / sizeof(struct nlist));
-
-    tbl = st_init_strtable();
-    if (tbl == NULL) {
-	dln_errno = errno;
-	return NULL;
-    }
-
-    while (sym < end) {
-	st_insert(tbl, sym->n_un.n_name, sym);
-	sym++;
-    }
-    return tbl;
-}
-
-static int
-dln_init(const char *prog)
-{
-    char *file;
-    int fd;
-    struct exec hdr;
-    struct nlist *syms;
-
-    if (dln_init_p == 1) return 0;
-
-    file = dln_find_exe(prog, NULL);
-    if (file == NULL || (fd = open(file, O_RDONLY)) < 0) {
-	dln_errno = errno;
-	return -1;
-    }
-
-    if (load_header(fd, &hdr, 0) == -1) return -1;
-    syms = load_sym(fd, &hdr, 0);
-    if (syms == NULL) {
-	close(fd);
-	return -1;
-    }
-    sym_tbl = sym_hash(&hdr, syms);
-    if (sym_tbl == NULL) {	/* file may be start with #! */
-	char c = '\0';
-	char buf[MAXPATHLEN];
-	char *p;
-
-	free(syms);
-	lseek(fd, 0L, 0);
-	if (read(fd, &c, 1) == -1) {
-	    dln_errno = errno;
-	    return -1;
-	}
-	if (c != '#') goto err_noexec;
-	if (read(fd, &c, 1) == -1) {
-	    dln_errno = errno;
-	    return -1;
-	}
-	if (c != '!') goto err_noexec;
-
-	p = buf;
-	/* skip forwarding spaces */
-	while (read(fd, &c, 1) == 1) {
-	    if (c == '\n') goto err_noexec;
-	    if (c != '\t' && c != ' ') {
-		*p++ = c;
-		break;
-	    }
-	}
-	/* read in command name */
-	while (read(fd, p, 1) == 1) {
-	    if (*p == '\n' || *p == '\t' || *p == ' ') break;
-	    p++;
-	    if (p-buf >= MAXPATHLEN) {
-		dln_errno = ENAMETOOLONG;
-		return -1;
-	    }
-	}
-	*p = '\0';
-
-	return dln_init(buf);
-    }
-    dln_init_p = 1;
-    undef_tbl = st_init_strtable();
-    close(fd);
-    return 0;
-
-  err_noexec:
-    close(fd);
-    dln_errno = DLN_ENOEXEC;
-    return -1;
-}
-
-static long
-load_text_data(int fd, struct exec *hdrp, int bss, long disp)
-{
-    int size;
-    unsigned char* addr;
-
-    lseek(fd, disp + N_TXTOFF(*hdrp), 0);
-    size = hdrp->a_text + hdrp->a_data;
-
-    if (bss == -1) size += hdrp->a_bss;
-    else if (bss > 1) size += bss;
-
-    addr = (unsigned char*)xmalloc(size);
-    if (addr == NULL) {
-	dln_errno = errno;
-	return 0;
-    }
-
-    if (read(fd, addr, size) !=  size) {
-	dln_errno = errno;
-	free(addr);
-	return 0;
-    }
-
-    if (bss == -1) {
-	memset(addr +  hdrp->a_text + hdrp->a_data, 0, hdrp->a_bss);
-    }
-    else if (bss > 0) {
-	memset(addr +  hdrp->a_text + hdrp->a_data, 0, bss);
-    }
-
-    return (long)addr;
-}
-
-static int
-undef_print(char *key, char *value)
-{
-    fprintf(stderr, "  %s\n", key);
-    return ST_CONTINUE;
-}
-
+#ifndef dln_loaderror
 static void
-dln_print_undef()
+dln_loaderror(const char *format, ...)
 {
-    fprintf(stderr, " Undefined symbols:\n");
-    st_foreach(undef_tbl, undef_print, NULL);
+    va_list ap;
+    va_start(ap, format);
+    vfprintf(stderr, format, ap);
+    va_end(ap);
+    abort();
 }
-
-static void
-dln_undefined()
-{
-    if (undef_tbl->num_entries > 0) {
-	fprintf(stderr, "dln: Calling undefined function\n");
-	dln_print_undef();
-	rb_exit(1);
-    }
-}
-
-struct undef {
-    char *name;
-    struct relocation_info reloc;
-    long base;
-    char *addr;
-    union {
-	char c;
-	short s;
-	long l;
-    } u;
-};
-
-static st_table *reloc_tbl = NULL;
-static void
-link_undef(const char *name, long base, struct relocation_info *reloc)
-{
-    static int u_no = 0;
-    struct undef *obj;
-    char *addr = (char*)(reloc->r_address + base);
-
-    obj = (struct undef*)xmalloc(sizeof(struct undef));
-    obj->name = strdup(name);
-    obj->reloc = *reloc;
-    obj->base = base;
-    switch (R_LENGTH(reloc)) {
-      case 0:		/* byte */
-	obj->u.c = *addr;
-	break;
-      case 1:		/* word */
-	obj->u.s = *(short*)addr;
-	break;
-      case 2:		/* long */
-	obj->u.l = *(long*)addr;
-	break;
-    }
-    if (reloc_tbl == NULL) {
-	reloc_tbl = st_init_numtable();
-    }
-    st_insert(reloc_tbl, u_no++, obj);
-}
-
-struct reloc_arg {
-    const char *name;
-    long value;
-};
-
-static int
-reloc_undef(int no, struct undef *undef, struct reloc_arg *arg)
-{
-    int datum;
-    char *address;
-#if defined(sun) && defined(sparc)
-    unsigned int mask = 0;
-#endif
-
-    if (strcmp(arg->name, undef->name) != 0) return ST_CONTINUE;
-    address = (char*)(undef->base + undef->reloc.r_address);
-    datum = arg->value;
-
-    if (R_PCREL(&(undef->reloc))) datum -= undef->base;
-#if defined(sun) && defined(sparc)
-    datum += undef->reloc.r_addend;
-    datum >>= R_RIGHTSHIFT(&(undef->reloc));
-    mask = (1 << R_BITSIZE(&(undef->reloc))) - 1;
-    mask |= mask -1;
-    datum &= mask;
-    switch (R_LENGTH(&(undef->reloc))) {
-      case 0:
-	*address = undef->u.c;
-	*address &= ~mask;
-	*address |= datum;
-	break;
-      case 1:
-	*(short *)address = undef->u.s;
-	*(short *)address &= ~mask;
-	*(short *)address |= datum;
-	break;
-      case 2:
-	*(long *)address = undef->u.l;
-	*(long *)address &= ~mask;
-	*(long *)address |= datum;
-	break;
-    }
-#else
-    switch (R_LENGTH(&(undef->reloc))) {
-      case 0:		/* byte */
-	if (R_MEMORY_SUB(&(undef->reloc)))
-	    *address = datum - *address;
-	else *address = undef->u.c + datum;
-	break;
-      case 1:		/* word */
-	if (R_MEMORY_SUB(&(undef->reloc)))
-	    *(short*)address = datum - *(short*)address;
-	else *(short*)address = undef->u.s + datum;
-	break;
-      case 2:		/* long */
-	if (R_MEMORY_SUB(&(undef->reloc)))
-	    *(long*)address = datum - *(long*)address;
-	else *(long*)address = undef->u.l + datum;
-	break;
-    }
 #endif
-    free(undef->name);
-    free(undef);
-    return ST_DELETE;
-}
-
-static void
-unlink_undef(const char *name, long value)
-{
-    struct reloc_arg arg;
 
-    arg.name = name;
-    arg.value = value;
-    st_foreach(reloc_tbl, reloc_undef, &arg);
-}
-
-#ifdef N_INDR
-struct indr_data {
-    char *name0, *name1;
-};
-
-static int
-reloc_repl(int no, struct undef *undef, struct indr_data *data)
-{
-    if (strcmp(data->name0, undef->name) == 0) {
-	free(undef->name);
-	undef->name = strdup(data->name1);
-    }
-    return ST_CONTINUE;
-}
-#endif
-
-static int
-load_1(int fd, long disp, const char *need_init)
-{
-    static const char *libc = LIBC_NAME;
-    struct exec hdr;
-    struct relocation_info *reloc = NULL;
-    long block = 0;
-    long new_common = 0; /* Length of new common */
-    struct nlist *syms = NULL;
-    struct nlist *sym;
-    struct nlist *end;
-    int init_p = 0;
-
-    if (load_header(fd, &hdr, disp) == -1) return -1;
-    if (INVALID_OBJECT(hdr)) {
-	dln_errno = DLN_ENOEXEC;
-	return -1;
-    }
-    reloc = load_reloc(fd, &hdr, disp);
-    if (reloc == NULL) return -1;
-
-    syms = load_sym(fd, &hdr, disp);
-    if (syms == NULL) {
-	free(reloc);
-	return -1;
-    }
-
-    sym = syms;
-    end = syms + (hdr.a_syms / sizeof(struct nlist));
-    while (sym < end) {
-	struct nlist *old_sym;
-	int value = sym->n_value;
-
-#ifdef N_INDR
-	if (sym->n_type == (N_INDR | N_EXT)) {
-	    char *key = sym->n_un.n_name;
-
-	    if (st_lookup(sym_tbl, sym[1].n_un.n_name, &old_sym)) {
-		if (st_delete(undef_tbl, (st_data_t*)&key, NULL)) {
-		    unlink_undef(key, old_sym->n_value);
-		    free(key);
-		}
-	    }
-	    else {
-		struct indr_data data;
-
-		data.name0 = sym->n_un.n_name;
-		data.name1 = sym[1].n_un.n_name;
-		st_foreach(reloc_tbl, reloc_repl, &data);
-
-		st_insert(undef_tbl, strdup(sym[1].n_un.n_name), NULL);
-		if (st_delete(undef_tbl, (st_data_t*)&key, NULL)) {
-		    free(key);
-		}
-	    }
-	    sym += 2;
-	    continue;
-	}
+#if defined(HAVE_DLOPEN) && !defined(_AIX) && !defined(_UNICOSMP)
+/* dynamic load with dlopen() */
+# define USE_DLN_DLOPEN
 #endif
-	if (sym->n_type == (N_UNDF | N_EXT)) {
-	    if (st_lookup(sym_tbl, sym->n_un.n_name, &old_sym) == 0) {
-		old_sym = NULL;
-	    }
-
-	    if (value) {
-		if (old_sym) {
-		    sym->n_type = N_EXT | N_COMM;
-		    sym->n_value = old_sym->n_value;
-		}
-		else {
-		    int rnd =
-			value >= sizeof(double) ? sizeof(double) - 1
-			    : value >= sizeof(long) ? sizeof(long) - 1
-				: sizeof(short) - 1;
-
-		    sym->n_type = N_COMM;
-		    new_common += rnd;
-		    new_common &= ~(long)rnd;
-		    sym->n_value = new_common;
-		    new_common += value;
-		}
-	    }
-	    else {
-		if (old_sym) {
-		    sym->n_type = N_EXT | N_COMM;
-		    sym->n_value = old_sym->n_value;
-		}
-		else {
-		    sym->n_value = (long)dln_undefined;
-		    st_insert(undef_tbl, strdup(sym->n_un.n_name), NULL);
-		}
-	    }
-	}
-	sym++;
-    }
-
-    block = load_text_data(fd, &hdr, hdr.a_bss + new_common, disp);
-    if (block == 0) goto err_exit;
-
-    sym = syms;
-    while (sym < end) {
-	struct nlist *new_sym;
-	char *key;
-
-	switch (sym->n_type) {
-	  case N_COMM:
-	    sym->n_value += hdr.a_text + hdr.a_data;
-	  case N_TEXT|N_EXT:
-	  case N_DATA|N_EXT:
-
-	    sym->n_value += block;
-
-	    if (st_lookup(sym_tbl, sym->n_un.n_name, &new_sym) != 0
-		&& new_sym->n_value != (long)dln_undefined) {
-		dln_errno = DLN_ECONFL;
-		goto err_exit;
-	    }
-
-	    key = sym->n_un.n_name;
-	    if (st_delete(undef_tbl, (st_data_t*)&key, NULL) != 0) {
-		unlink_undef(key, sym->n_value);
-		free(key);
-	    }
-
-	    new_sym = (struct nlist*)xmalloc(sizeof(struct nlist));
-	    *new_sym = *sym;
-	    new_sym->n_un.n_name = strdup(sym->n_un.n_name);
-	    st_insert(sym_tbl, new_sym->n_un.n_name, new_sym);
-	    break;
-
-	  case N_TEXT:
-	  case N_DATA:
-	    sym->n_value += block;
-	    break;
-	}
-	sym++;
-    }
 
-    /*
-     * First comes the text-relocation
-     */
-    {
-	struct relocation_info * rel = reloc;
-	struct relocation_info * rel_beg = reloc +
-	    (hdr.a_trsize/sizeof(struct relocation_info));
-	struct relocation_info * rel_end = reloc +
-	    (hdr.a_trsize+hdr.a_drsize)/sizeof(struct relocation_info);
-
-	while (rel < rel_end) {
-	    char *address = (char*)(rel->r_address + block);
-	    long datum = 0;
-#if defined(sun) && defined(sparc)
-	    unsigned int mask = 0;
+#if defined(__hp9000s300) || ((defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)) && !defined(__ELF__)) || defined(NeXT)
+# define EXTERNAL_PREFIX "_"
+#else
+# define EXTERNAL_PREFIX ""
 #endif
+#define FUNCNAME_PREFIX EXTERNAL_PREFIX"Init_"
 
-	    if(rel >= rel_beg)
-		address += hdr.a_text;
-
-	    if (rel->r_extern) { /* Look it up in symbol-table */
-		sym = &(syms[R_SYMBOL(rel)]);
-		switch (sym->n_type) {
-		  case N_EXT|N_UNDF:
-		    link_undef(sym->n_un.n_name, block, rel);
-		  case N_EXT|N_COMM:
-		  case N_COMM:
-		    datum = sym->n_value;
-		    break;
-		  default:
-		    goto err_exit;
-		}
-	    } /* end.. look it up */
-	    else { /* is static */
-		switch (R_SYMBOL(rel)) { 
-		  case N_TEXT:
-		  case N_DATA:
-		    datum = block;
-		    break;
-		  case N_BSS:
-		    datum = block +  new_common;
-		    break;
-		  case N_ABS:
-		    break;
-		}
-	    } /* end .. is static */
-	    if (R_PCREL(rel)) datum -= block;
-
-#if defined(sun) && defined(sparc)
-	    datum += rel->r_addend;
-	    datum >>= R_RIGHTSHIFT(rel);
-	    mask = (1 << R_BITSIZE(rel)) - 1;
-	    mask |= mask -1;
-	    datum &= mask;
-
-	    switch (R_LENGTH(rel)) {
-	      case 0:
-		*address &= ~mask;
-		*address |= datum;
-		break;
-	      case 1:
-		*(short *)address &= ~mask;
-		*(short *)address |= datum;
-		break;
-	      case 2:
-		*(long *)address &= ~mask;
-		*(long *)address |= datum;
-		break;
-	    }
+#if defined __CYGWIN__ || defined DOSISH
+#define isdirsep(x) ((x) == '/' || (x) == '\\')
 #else
-	    switch (R_LENGTH(rel)) {
-	      case 0:		/* byte */
-		if (datum < -128 || datum > 127) goto err_exit;
-		*address += datum;
-		break;
-	      case 1:		/* word */
-		*(short *)address += datum;
-		break;
-	      case 2:		/* long */
-		*(long *)address += datum;
-		break;
-	    }
+#define isdirsep(x) ((x) == '/')
 #endif
-	    rel++;
-	}
-    }
-
-    if (need_init) {
-	int len;
-	char **libs_to_be_linked = 0;
-	char *buf;
-
-	if (undef_tbl->num_entries > 0) {
-	    if (load_lib(libc) == -1) goto err_exit;
-	}
-
-	init_funcname(&buf, need_init);
-	len = strlen(buf);
-
-	for (sym = syms; sym<end; sym++) {
-	    char *name = sym->n_un.n_name;
-	    if (name[0] == '_' && sym->n_value >= block) {
-		if (strcmp(name+1, "dln_libs_to_be_linked") == 0) {
-		    libs_to_be_linked = (char**)sym->n_value;
-		}
-		else if (strcmp(name+1, buf) == 0) {
-		    init_p = 1;
-		    ((int (*)())sym->n_value)();
-		}
-	    }
-	}
-	if (libs_to_be_linked && undef_tbl->num_entries > 0) {
-	    while (*libs_to_be_linked) {
-		load_lib(*libs_to_be_linked);
-		libs_to_be_linked++;
-	    }
-	}
-    }
-    free(reloc);
-    free(syms);
-    if (need_init) {
-	if (init_p == 0) {
-	    dln_errno = DLN_ENOINIT;
-	    return -1;
-	}
-	if (undef_tbl->num_entries > 0) {
-	    if (load_lib(libc) == -1) goto err_exit;
-	    if (undef_tbl->num_entries > 0) {
-		dln_errno = DLN_EUNDEF;
-		return -1;
-	    }
-	}
-    }
-    return 0;
-
-  err_exit:
-    if (syms) free(syms);
-    if (reloc) free(reloc);
-    if (block) free((char*)block);
-    return -1;
-}
-
-static int target_offset;
-static int
-search_undef(const char *key, int value, st_table *lib_tbl)
-{
-    long offset;
 
-    if (st_lookup(lib_tbl, key, &offset) == 0) return ST_CONTINUE;
-    target_offset = offset;
-    return ST_STOP;
-}
-
-struct symdef {
-    int rb_str_index;
-    int lib_offset;
+#if defined(_WIN32) || defined(USE_DLN_DLOPEN)
+struct string_part {
+    const char *ptr;
+    size_t len;
 };
 
-char *dln_librrb_ary_path = DLN_DEFAULT_LIB_PATH;
-
-static int
-load_lib(const char *lib)
+static struct string_part
+init_funcname_len(const char *file)
 {
-    char *path, *file;
-    char armagic[SARMAG];
-    int fd, size;
-    struct ar_hdr ahdr;
-    st_table *lib_tbl = NULL;
-    int *data, nsym;
-    struct symdef *base;
-    char *name_base;
-
-    if (dln_init_p == 0) {
-	dln_errno = DLN_ENOINIT;
-	return -1;
-    }
+    const char *p = file, *base, *dot = NULL;
 
-    if (undef_tbl->num_entries == 0) return 0;
-    dln_errno = DLN_EBADLIB;
-
-    if (lib[0] == '-' && lib[1] == 'l') {
-	long len = strlen(lib) + 4;
-	char *p = alloca(len);
-	snprintf(p, len, "lib%s.a", lib+2);
-	lib = p;
-    }
-
-    /* library search path: */
-    /* look for environment variable DLN_LIBRARY_PATH first. */
-    /* then variable dln_librrb_ary_path. */
-    /* if path is still NULL, use "." for path. */
-    path = getenv("DLN_LIBRARY_PATH");
-    if (path == NULL) path = dln_librrb_ary_path;
-
-    file = dln_find_file(lib, path);
-    fd = open(file, O_RDONLY);
-    if (fd == -1) goto syserr;
-    size = read(fd, armagic, SARMAG);
-    if (size == -1) goto syserr;
-
-    if (size != SARMAG) {
-	dln_errno = DLN_ENOTLIB;
-	goto badlib;
-    }
-    size = read(fd, &ahdr, sizeof(ahdr));
-    if (size == -1) goto syserr;
-    if (size != sizeof(ahdr) || sscanf(ahdr.ar_size, "%d", &size) != 1) {
-	goto badlib;
-    }
-
-    if (strncmp(ahdr.ar_name, "__.SYMDEF", 9) == 0) {
-	/* make hash table from __.SYMDEF */
-
-	lib_tbl = st_init_strtable();
-	data = (int*)xmalloc(size);
-	if (data == NULL) goto syserr;
-	size = read(fd, data, size);
-	nsym = *data / sizeof(struct symdef);
-	base = (struct symdef*)(data + 1);
-	name_base = (char*)(base + nsym) + sizeof(int);
-	while (nsym > 0) {
-	    char *name = name_base + base->rb_str_index;
-
-	    st_insert(lib_tbl, name, base->lib_offset + sizeof(ahdr));
-	    nsym--;
-	    base++;
-	}
-	for (;;) {
-	    target_offset = -1;
-	    st_foreach(undef_tbl, search_undef, lib_tbl);
-	    if (target_offset == -1) break;
-	    if (load_1(fd, target_offset, 0) == -1) {
-		st_free_table(lib_tbl);
-		free(data);
-		goto badlib;
-	    }
-	    if (undef_tbl->num_entries == 0) break;
-	}
-	free(data);
-	st_free_table(lib_tbl);
-    }
-    else {
-	/* linear library, need to scan (FUTURE) */
-
-	for (;;) {
-	    int offset = SARMAG;
-	    int found = 0;
-	    struct exec hdr;
-	    struct nlist *syms, *sym, *end;
-
-	    while (undef_tbl->num_entries > 0) {
-		found = 0;
-		lseek(fd, offset, 0);
-		size = read(fd, &ahdr, sizeof(ahdr));
-		if (size == -1) goto syserr;
-		if (size == 0) break;
-		if (size != sizeof(ahdr)
-		    || sscanf(ahdr.ar_size, "%d", &size) != 1) {
-		    goto badlib;
-		}
-		offset += sizeof(ahdr);
-		if (load_header(fd, &hdr, offset) == -1)
-		    goto badlib;
-		syms = load_sym(fd, &hdr, offset);
-		if (syms == NULL) goto badlib;
-		sym = syms;
-		end = syms + (hdr.a_syms / sizeof(struct nlist));
-		while (sym < end) {
-		    if (sym->n_type == N_EXT|N_TEXT
-			&& st_lookup(undef_tbl, sym->n_un.n_name, NULL)) {
-			break;
-		    }
-		    sym++;
-		}
-		if (sym < end) {
-		    found++;
-		    free(syms);
-		    if (load_1(fd, offset, 0) == -1) {
-			goto badlib;
-		    }
-		}
-		offset += size;
-		if (offset & 1) offset++;
-	    }
-	    if (found) break;
-	}
+    /* Load the file as an object one */
+    for (base = p; *p; p++) { /* Find position of last '/' */
+        if (*p == '.' && !dot) dot = p;
+        if (isdirsep(*p)) base = p+1, dot = NULL;
     }
-    close(fd);
-    return 0;
-
-  syserr:
-    dln_errno = errno;
-  badlib:
-    if (fd >= 0) close(fd);
-    return -1;
+    /* Delete suffix if it exists */
+    const size_t len = (dot ? dot : p) - base;
+    return (struct string_part){base, len};
 }
 
-static int
-load(const char *file)
+static inline char *
+concat_funcname(char *buf, const char *prefix, size_t plen, const struct string_part base)
 {
-    int fd;
-    int result;
-
-    if (dln_init_p == 0) {
-	if (dln_init(dln_argv0) == -1) return -1;
+    if (!buf) {
+        dln_memerror();
     }
-    result = strlen(file);
-    if (file[result-1] == 'a') {
-	return load_lib(file);
-    }
-
-    fd = open(file, O_RDONLY);
-    if (fd == -1) {
-	dln_errno = errno;
-	return -1;
-    }
-    result = load_1(fd, 0, file);
-    close(fd);
-
-    return result;
+    memcpy(buf, prefix, plen);
+    memcpy(buf + plen, base.ptr, base.len);
+    buf[plen + base.len] = '\0';
+    return buf;
 }
 
-void*
-dln_sym(const char *name)
-{
-    struct nlist *sym;
-
-    if (st_lookup(sym_tbl, name, &sym))
-	return (void*)sym->n_value;
-    return NULL;
-}
+#define build_funcname(prefix, buf, file) do {\
+    const struct string_part f = init_funcname_len(file);\
+    const size_t plen = sizeof(prefix "") - 1;\
+    *(buf) = concat_funcname(ALLOCA_N(char, plen+f.len+1), prefix, plen, f);\
+} while (0)
 
-#endif /* USE_DLN_A_OUT */
+#define init_funcname(buf, file) build_funcname(FUNCNAME_PREFIX, buf, file)
+#endif
 
 #ifdef USE_DLN_DLOPEN
 # include <dlfcn.h>
 #endif
 
-#ifdef __hpux
-#include <errno.h>
-#include "dl.h"
-#endif
-
 #if defined(_AIX)
 #include <ctype.h>	/* for isdigit()	*/
 #include <errno.h>	/* for global errno	*/
@@ -1104,658 +172,399 @@ dln_sym(const char *name)
 #define NSLINKMODULE_OPTION_BINDNOW 1
 #endif
 #endif
-#else
-#ifdef MACOSX_DYLD
-#include <mach-o/dyld.h>
-#endif
 #endif
 
-#if defined _WIN32 && !defined __CYGWIN__
+#ifdef _WIN32
 #include <windows.h>
+#include <imagehlp.h>
 #endif
 
-#ifdef _WIN32_WCE
-#undef FormatMessage
-#define FormatMessage FormatMessageA
-#undef LoadLibrary
-#define LoadLibrary LoadLibraryA
-#undef GetProcAddress
-#define GetProcAddress GetProcAddressA
-#endif
-
+#ifdef _WIN32
 static const char *
-dln_strerror(void)
+dln_strerror(char *message, size_t size)
 {
-#ifdef USE_DLN_A_OUT
-    char *strerror();
-
-    switch (dln_errno) {
-      case DLN_ECONFL:
-	return "Symbol name conflict";
-      case DLN_ENOINIT:
-	return "No initializer given";
-      case DLN_EUNDEF:
-	return "Unresolved symbols";
-      case DLN_ENOTLIB:
-	return "Not a library file";
-      case DLN_EBADLIB:
-	return "Malformed library file";
-      case DLN_EINIT:
-	return "Not initialized";
-      default:
-	return strerror(dln_errno);
-    }
-#endif
-
-#ifdef USE_DLN_DLOPEN
-    return (char*)dlerror();
-#endif
-
-#if defined _WIN32 && !defined __CYGWIN__
-    static char message[1024];
     int error = GetLastError();
     char *p = message;
-    p += sprintf(message, "%d: ", error);
-    FormatMessage(
-	FORMAT_MESSAGE_FROM_SYSTEM	 | FORMAT_MESSAGE_IGNORE_INSERTS,
-	NULL,
-	error,
-	MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-	p,
-	sizeof message - strlen(message),
-	NULL);
-
-    for (p = message; *p; p++) {
-	if (*p == '\n' || *p == '\r')
-	    *p = ' ';
+    size_t len = snprintf(message, size, "%d: ", error);
+
+#define format_message(sublang) FormatMessage(\
+        FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,	\
+        NULL, error, MAKELANGID(LANG_NEUTRAL, (sublang)),		\
+        message + len, size - len, NULL)
+    if (format_message(SUBLANG_ENGLISH_US) == 0)
+        format_message(SUBLANG_DEFAULT);
+    for (p = message + len; *p; p++) {
+        if (*p == '\n' || *p == '\r')
+            *p = ' ';
     }
     return message;
-#endif
 }
+#define dln_strerror() dln_strerror(message, sizeof message)
+#elif defined USE_DLN_DLOPEN
+static const char *
+dln_strerror(void)
+{
+    return (char*)dlerror();
+}
+#endif
 
-
-#if defined(_AIX) && ! defined(_IA64)
+#if defined(_AIX)
 static void
 aix_loaderror(const char *pathname)
 {
-    char *message[8], errbuf[1024];
-    int i,j;
-
-    struct errtab { 
-	int errnum;
-	char *errstr;
-    } load_errtab[] = {
-	{L_ERROR_TOOMANY,	"too many errors, rest skipped."},
-	{L_ERROR_NOLIB,		"can't load library:"},
-	{L_ERROR_UNDEF,		"can't find symbol in library:"},
-	{L_ERROR_RLDBAD,
-	     "RLD index out of range or bad relocation type:"},
-	{L_ERROR_FORMAT,	"not a valid, executable xcoff file:"},
-	{L_ERROR_MEMBER,
-	     "file not an archive or does not contain requested member:"},
-	{L_ERROR_TYPE,		"symbol table mismatch:"},
-	{L_ERROR_ALIGN,		"text alignment in file is wrong."},
-	{L_ERROR_SYSTEM,	"System error:"},
-	{L_ERROR_ERRNO,		NULL}
-    };
-
-#define LOAD_ERRTAB_LEN	(sizeof(load_errtab)/sizeof(load_errtab[0]))
-#define ERRBUF_APPEND(s) strncat(errbuf, s, sizeof(errbuf)-strlen(errbuf)-1)
-
-    snprintf(errbuf, 1024, "load failed - %s ", pathname);
-
-    if (!loadquery(1, &message[0], sizeof(message))) 
-	ERRBUF_APPEND(strerror(errno));
-    for(i = 0; message[i] && *message[i]; i++) {
-	int nerr = atoi(message[i]);
-	for (j=0; j<LOAD_ERRTAB_LEN; j++) {
-           if (nerr == load_errtab[i].errnum && load_errtab[i].errstr)
-		ERRBUF_APPEND(load_errtab[i].errstr);
-	}
-	while (isdigit(*message[i])) message[i]++; 
-	ERRBUF_APPEND(message[i]);
-	ERRBUF_APPEND("\n");
+    char *message[1024], errbuf[1024];
+    int i;
+#define ERRBUF_APPEND(s) strlcat(errbuf, (s), sizeof(errbuf))
+    snprintf(errbuf, sizeof(errbuf), "load failed - %s. ", pathname);
+
+    if (loadquery(L_GETMESSAGES, &message[0], sizeof(message)) != -1) {
+        ERRBUF_APPEND("Please issue below command for detailed reasons:\n\t");
+        ERRBUF_APPEND("/usr/sbin/execerror ruby ");
+        for (i=0; message[i]; i++) {
+            ERRBUF_APPEND("\"");
+            ERRBUF_APPEND(message[i]);
+            ERRBUF_APPEND("\" ");
+        }
+        ERRBUF_APPEND("\n");
     }
-    errbuf[strlen(errbuf)-1] = '\0';	/* trim off last newline */
-    rb_loaderror(errbuf);
-    return;
+    else {
+        ERRBUF_APPEND(strerror(errno));
+        ERRBUF_APPEND("[loadquery failed]");
+    }
+    dln_loaderror("%s", errbuf);
 }
 #endif
 
-#endif /* NO_DLN_LOAD */
+#if defined _WIN32 && defined RUBY_EXPORT
+HANDLE rb_libruby_handle(void);
 
-void*
-dln_load(const char *file)
+static int
+rb_w32_check_imported(HMODULE ext, HMODULE mine)
 {
-#ifdef NO_DLN_LOAD
-    rb_raise(rb_eLoadError, "this executable file can't load extension libraries");
-#else
-
-#if !defined(_AIX) && !defined(NeXT)
-    const char *error = 0;
-#define DLN_ERROR() (error = dln_strerror(), strcpy(ALLOCA_N(char, strlen(error) + 1), error))
+    ULONG size;
+    const IMAGE_IMPORT_DESCRIPTOR *desc;
+
+    desc = ImageDirectoryEntryToData(ext, TRUE, IMAGE_DIRECTORY_ENTRY_IMPORT, &size);
+    if (!desc) return 0;
+    while (desc->Name) {
+        PIMAGE_THUNK_DATA pint = (PIMAGE_THUNK_DATA)((char *)ext + desc->Characteristics);
+        PIMAGE_THUNK_DATA piat = (PIMAGE_THUNK_DATA)((char *)ext + desc->FirstThunk);
+        for (; piat->u1.Function; piat++, pint++) {
+            static const char prefix[] = "rb_";
+            PIMAGE_IMPORT_BY_NAME pii;
+            const char *name;
+
+            if (IMAGE_SNAP_BY_ORDINAL(pint->u1.Ordinal)) continue;
+            pii = (PIMAGE_IMPORT_BY_NAME)((char *)ext + (size_t)pint->u1.AddressOfData);
+            name = (const char *)pii->Name;
+            if (strncmp(name, prefix, sizeof(prefix) - 1) == 0) {
+                FARPROC addr = GetProcAddress(mine, name);
+                if (addr) return (FARPROC)piat->u1.Function == addr;
+            }
+        }
+        desc++;
+    }
+    return 1;
+}
 #endif
 
-#if defined _WIN32 && !defined __CYGWIN__
-    HINSTANCE handle;
-    char winfile[MAXPATHLEN];
-    void (*init_fct)();
-    char *buf;
-
-    if (strlen(file) >= MAXPATHLEN) rb_loaderror("filename too long");
-
-    /* Load the file as an object one */
-    init_funcname(&buf, file);
-
-    strcpy(winfile, file);
-
-    /* Load file */
-    if ((handle = LoadLibrary(winfile)) == NULL) {
-	error = dln_strerror();
-	goto failed;
-    }
-
-    if ((init_fct = (void(*)())GetProcAddress(handle, buf)) == NULL) {
-	rb_loaderror("%s - %s\n%s", dln_strerror(), buf, file);
-    }
-
-    /* Call the init code */
-    (*init_fct)();
-    return handle;
-#else
-#ifdef USE_DLN_A_OUT
-    if (load(file) == -1) {
-	error = dln_strerror();
-	goto failed;
-    }
-    return 0;
+#if defined(DLN_NEEDS_ALT_SEPARATOR) && DLN_NEEDS_ALT_SEPARATOR
+#define translit_separator(src) do { \
+        char *tmp = ALLOCA_N(char, strlen(src) + 1), *p = tmp, c; \
+        do { \
+            *p++ = ((c = *file++) == '/') ? DLN_NEEDS_ALT_SEPARATOR : c; \
+        } while (c); \
+        (src) = tmp; \
+    } while (0)
 #else
-
-    char *buf;
-    /* Load the file as an object one */
-    init_funcname(&buf, file);
+#define translit_separator(str) (void)(str)
+#endif
 
 #ifdef USE_DLN_DLOPEN
-#define DLN_DEFINED
-    {
-	void *handle;
-	void (*init_fct)();
+# include "ruby/internal/stdbool.h"
+# include "internal/warnings.h"
+static bool
+dln_incompatible_func(void *handle, const char *funcname, void *const fp, const char **libname)
+{
+    void *ex = dlsym(handle, funcname);
+    if (!ex) return false;
+    if (ex == fp) return false;
+#  if defined(HAVE_DLADDR) && !defined(__CYGWIN__)
+    Dl_info dli;
+    if (dladdr(ex, &dli)) {
+        *libname = dli.dli_fname;
+    }
+#  endif
+    return true;
+}
 
-#ifndef RTLD_LAZY
-# define RTLD_LAZY 1
+COMPILER_WARNING_PUSH
+#if defined(__clang__) || GCC_VERSION_SINCE(4, 2, 0)
+COMPILER_WARNING_IGNORED(-Wpedantic)
 #endif
-#ifdef __INTERIX
-# undef RTLD_GLOBAL
-#endif
-#ifndef RTLD_GLOBAL
-# define RTLD_GLOBAL 0
+static bool
+dln_incompatible_library_p(void *handle, const char **libname)
+{
+#define check_func(func) \
+    if (dln_incompatible_func(handle, EXTERNAL_PREFIX #func, (void *)&func, libname)) \
+        return true
+    check_func(ruby_xmalloc);
+    return false;
+}
+COMPILER_WARNING_POP
 #endif
 
-	/* Load file */
-	if ((handle = (void*)dlopen(file, RTLD_LAZY|RTLD_GLOBAL)) == NULL) {
-	    error = dln_strerror();
-	    goto failed;
-	}
-
-	init_fct = (void(*)())dlsym(handle, buf);
-	if (init_fct == NULL) {
-	    error = DLN_ERROR();
-	    dlclose(handle);
-	    goto failed;
-	}
-	/* Call the init code */
-	(*init_fct)();
-
-	return handle;
-    }
-#endif /* USE_DLN_DLOPEN */
+#if !defined(MAC_OS_X_VERSION_MIN_REQUIRED)
+/* assume others than old Mac OS X have no problem */
+# define dln_disable_dlclose() false
 
-#ifdef __hpux
-#define DLN_DEFINED
-    {
-	shl_t lib = NULL;
-	int flags;
-	void (*init_fct)();
-
-	flags = BIND_DEFERRED;
-	lib = shl_load(file, flags, 0);
-	if (lib == NULL) {
-	    extern int errno;
-	    rb_loaderror("%s - %s", strerror(errno), file);
-	}
-	shl_findsym(&lib, buf, TYPE_PROCEDURE, (void*)&init_fct);
-	if (init_fct == NULL) {
-	    shl_findsym(&lib, buf, TYPE_UNDEFINED, (void*)&init_fct);
-	    if (init_fct == NULL) {
-		errno = ENOSYM;
-		rb_loaderror("%s - %s", strerror(ENOSYM), file);
-	    }
-	}
-	(*init_fct)();
-	return (void*)lib;
-    }
-#endif /* hpux */
+#elif !defined(MAC_OS_X_VERSION_10_11) || \
+    (MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_11)
+/* targeting older versions only */
+# define dln_disable_dlclose() true
 
-#if defined(_AIX) && ! defined(_IA64)
-#define DLN_DEFINED
-    {
-	void (*init_fct)();
-
-	init_fct = (void(*)())load((char*)file, 1, 0);
-	if (init_fct == NULL) {
-	    aix_loaderror(file);
-	}
-	if (loadbind(0, (void*)dln_load, (void*)init_fct) == -1) {
-	    aix_loaderror(file);
-	}
-	(*init_fct)();
-	return (void*)init_fct;
-    }
-#endif /* _AIX */
-
-#if defined(NeXT) || defined(MACOSX_DYLD)
-#define DLN_DEFINED
-/*----------------------------------------------------
-   By SHIROYAMA Takayuki Psi@fortune.nest.or.jp
- 
-   Special Thanks...
-    Yu tomoak-i@is.aist-nara.ac.jp,
-    Mi hisho@tasihara.nest.or.jp,
-    sunshine@sunshineco.com,
-    and... Miss ARAI Akino(^^;)
- ----------------------------------------------------*/
-#if defined(NeXT) && (NS_TARGET_MAJOR < 4)/* NeXTSTEP rld functions */
+#elif MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_11
+/* targeting newer versions only */
+# define dln_disable_dlclose() false
 
-    {
-        NXStream* s;
-	unsigned long init_address;
-	char *object_files[2] = {NULL, NULL};
-
-	void (*init_fct)();
-	
-	object_files[0] = (char*)file;
-	
-	s = NXOpenFile(2,NX_WRITEONLY);
-
-	/* Load object file, if return value ==0 ,  load failed*/
-	if(rld_load(s, NULL, object_files, NULL) == 0) {
-	    NXFlush(s);
-	    NXClose(s);
-	    rb_loaderror("Failed to load %.200s", file);
-	}
-
-	/* lookup the initial function */
-	if(rld_lookup(s, buf, &init_address) == 0) {
-	    NXFlush(s);
-	    NXClose(s);
-	    rb_loaderror("Failed to lookup Init function %.200s", file);
-	}
-
-	NXFlush(s);
-	NXClose(s);
-
-	/* Cannot call *init_address directory, so copy this value to
-	   funtion pointer */
-	init_fct = (void(*)())init_address;
-	(*init_fct)();
-	return (void*)init_address;
-    }
-#else/* OPENSTEP dyld functions */
-    {
-	int dyld_result;
-	NSObjectFileImage obj_file; /* handle, but not use it */
-	/* "file" is module file name .
-	   "buf" is pointer to initial function name with "_" . */
-
-	void (*init_fct)();
+#else
+/* support both versions, and check at runtime */
+# include <sys/sysctl.h>
 
+static bool
+dln_disable_dlclose(void)
+{
+    int mib[] = {CTL_KERN, KERN_OSREV};
+    int32_t rev;
+    size_t size = sizeof(rev);
+    if (sysctl(mib, numberof(mib), &rev, &size, NULL, 0)) return true;
+    if (rev < MAC_OS_X_VERSION_10_11) return true;
+    return false;
+}
+#endif
 
-	dyld_result = NSCreateObjectFileImageFromFile(file, &obj_file);
+#if defined(_WIN32) || defined(USE_DLN_DLOPEN)
+static void *
+dln_open(const char *file)
+{
+    static const char incompatible[] = "incompatible library version";
+    const char *error = NULL;
+    void *handle;
 
-	if (dyld_result != NSObjectFileImageSuccess) {
-	    rb_loaderror("Failed to load %.200s", file);
-	}
+#if defined(_WIN32)
+# define DLN_DEFINED
+    char message[1024];
 
-	NSLinkModule(obj_file, file, NSLINKMODULE_OPTION_BINDNOW);
+    /* Convert the file path to wide char */
+    WCHAR *winfile = rb_w32_mbstr_to_wstr(CP_UTF8, file, -1, NULL);
+    if (!winfile) {
+        dln_memerror();
+    }
 
-	/* lookup the initial function */
-	if(!NSIsSymbolNameDefined(buf)) {
-	    rb_loaderror("Failed to lookup Init function %.200s",file);
-	}	
-	init_fct = NSAddressOfSymbol(NSLookupAndBindSymbol(buf));
-	(*init_fct)();
+    /* Load file */
+    handle = LoadLibraryW(winfile);
+    free(winfile);
 
-	return (void*)init_fct;
+    if (!handle) {
+        error = dln_strerror();
+        goto failed;
     }
-#endif /* rld or dyld */
-#endif
 
-#ifdef __BEOS__
-# define DLN_DEFINED
-    {
-      status_t err_stat;  /* BeOS error status code */
-      image_id img_id;    /* extention module unique id */
-      void (*init_fct)(); /* initialize function for extention module */
-
-      /* load extention module */
-      img_id = load_add_on(file);
-      if (img_id <= 0) {
-	rb_loaderror("Failed to load %.200s", file);
-      }
-      
-      /* find symbol for module initialize function. */
-      /* The Be Book KernelKit Images section described to use
-	 B_SYMBOL_TYPE_TEXT for symbol of function, not
-	 B_SYMBOL_TYPE_CODE. Why ? */
-      /* strcat(init_fct_symname, "__Fv"); */  /* parameter nothing. */
-      /* "__Fv" dont need! The Be Book Bug ? */
-      err_stat = get_image_symbol(img_id, buf,
-				  B_SYMBOL_TYPE_TEXT, (void **)&init_fct);
-
-      if (err_stat != B_NO_ERROR) {
-	char real_name[MAXPATHLEN];
-
-	strcpy(real_name, buf);
-	strcat(real_name, "__Fv");
-        err_stat = get_image_symbol(img_id, real_name,
-				    B_SYMBOL_TYPE_TEXT, (void **)&init_fct);
-      }
-
-      if ((B_BAD_IMAGE_ID == err_stat) || (B_BAD_INDEX == err_stat)) {
-	unload_add_on(img_id);
-	rb_loaderror("Failed to lookup Init function %.200s", file);
-      }
-      else if (B_NO_ERROR != err_stat) {
-	char errmsg[] = "Internal of BeOS version. %.200s (symbol_name = %s)";
-	unload_add_on(img_id);
-	rb_loaderror(errmsg, strerror(err_stat), buf);
-      }
-
-      /* call module initialize function. */
-      (*init_fct)();
-      return (void*)img_id;
+# if defined(RUBY_EXPORT)
+    if (!rb_w32_check_imported(handle, rb_libruby_handle())) {
+        FreeLibrary(handle);
+        error = incompatible;
+        goto failed;
     }
-#endif /* __BEOS__*/
+# endif
 
-#ifdef __MACOS__   /* Mac OS 9 or before */
+#elif defined(USE_DLN_DLOPEN)
 # define DLN_DEFINED
-    {
-      OSErr err;
-      FSSpec libspec;
-      CFragConnectionID connID;
-      Ptr mainAddr;
-      char errMessage[1024];
-      Boolean isfolder, didsomething;
-      Str63 fragname;
-      Ptr symAddr;
-      CFragSymbolClass class;
-      void (*init_fct)();
-      char fullpath[MAXPATHLEN];
-
-      strcpy(fullpath, file);
-
-      /* resolve any aliases to find the real file */
-      c2pstr(fullpath);
-      (void)FSMakeFSSpec(0, 0, fullpath, &libspec);
-      err = ResolveAliasFile(&libspec, 1, &isfolder, &didsomething);
-      if (err) {
-	  rb_loaderror("Unresolved Alias - %s", file);
-      }
-
-      /* Load the fragment (or return the connID if it is already loaded */
-      fragname[0] = 0;
-      err = GetDiskFragment(&libspec, 0, 0, fragname, 
-			    kLoadCFrag, &connID, &mainAddr,
-			    errMessage);
-      if (err) {
-	  p2cstr(errMessage);
-	  rb_loaderror("%s - %s",errMessage , file);
-      }
-
-      /* Locate the address of the correct init function */
-      c2pstr(buf);
-      err = FindSymbol(connID, buf, &symAddr, &class);
-      if (err) {
-	  rb_loaderror("Unresolved symbols - %s" , file);
-      }
-      init_fct = (void (*)())symAddr;
-      (*init_fct)();
-      return (void*)init_fct;
+
+# ifndef RTLD_LAZY
+#  define RTLD_LAZY 1
+# endif
+# ifdef __INTERIX
+#  undef RTLD_GLOBAL
+# endif
+# ifndef RTLD_GLOBAL
+#  define RTLD_GLOBAL 0
+# endif
+# ifndef RTLD_LOCAL
+#  define RTLD_LOCAL 0 /* TODO: 0??? some systems (including libc) use 0x00100 for RTLD_GLOBAL, 0x00000 for RTLD_LOCAL */
+# endif
+
+    /* Load file */
+    int mode = rb_box_available() ? RTLD_LAZY|RTLD_LOCAL : RTLD_LAZY|RTLD_GLOBAL;
+    handle = dlopen(file, mode);
+    if (handle == NULL) {
+        error = dln_strerror();
+        goto failed;
     }
-#endif /* __MACOS__ */
 
-#if defined(__VMS)
-#define DLN_DEFINED
+# if defined(RUBY_EXPORT)
     {
-	void *handle, (*init_fct)();
-	char *fname, *p1, *p2;
-
-	fname = (char *)__alloca(strlen(file)+1);
-	strcpy(fname,file);
-	if (p1 = strrchr(fname,'/'))
-	    fname = p1 + 1;
-	if (p2 = strrchr(fname,'.'))
-	    *p2 = '\0';
-
-	if ((handle = (void*)dlopen(fname, 0)) == NULL) {
-	    error = dln_strerror();
-	    goto failed;
-	}
-
-	if ((init_fct = (void (*)())dlsym(handle, buf)) == NULL) {
-	    error = DLN_ERROR();
-	    dlclose(handle);
-	    goto failed;
-	}
-	/* Call the init code */
-	(*init_fct)();
-	return handle;
+        const char *libruby_name = NULL;
+        if (dln_incompatible_library_p(handle, &libruby_name)) {
+            if (dln_disable_dlclose()) {
+                /* dlclose() segfaults */
+                if (libruby_name) {
+                    dln_fatalerror("linked to incompatible %s - %s", libruby_name, file);
+                }
+                dln_fatalerror("%s - %s", incompatible, file);
+            }
+            else {
+                if (libruby_name) {
+                    const size_t len = strlen(libruby_name);
+                    char *const tmp = ALLOCA_N(char, len + 1);
+                    if (tmp) memcpy(tmp, libruby_name, len + 1);
+                    libruby_name = tmp;
+                }
+                dlclose(handle);
+                if (libruby_name) {
+                    dln_loaderror("linked to incompatible %s - %s", libruby_name, file);
+                }
+                error = incompatible;
+                goto failed;
+            }
+        }
     }
-#endif /* __VMS */
-
-#ifndef DLN_DEFINED
-    rb_notimplement();
+# endif
 #endif
 
-#endif /* USE_DLN_A_OUT */
-#endif
-#if !defined(_AIX) && !defined(NeXT)
-  failed:
-    rb_loaderror("%s - %s", error, file);
-#endif
+    return handle;
 
-#endif /* NO_DLN_LOAD */
-    return 0;			/* dummy return */
+  failed:
+    dln_loaderror("%s - %s", error, file);
 }
 
-static char *dln_find_1(const char *fname, const char *path, int exe_flag);
+static void *
+dln_sym(void *handle, const char *symbol)
+{
+#if defined(_WIN32)
+    return GetProcAddress(handle, symbol);
+#elif defined(USE_DLN_DLOPEN)
+    return dlsym(handle, symbol);
+#endif
+}
 
-char *
-dln_find_exe(const char *fname, const char *path)
+static uintptr_t
+dln_sym_func(void *handle, const char *symbol)
 {
-    if (!path) {
-	path = getenv(PATH_ENV);
-    }
+    void *func = dln_sym(handle, symbol);
 
-    if (!path) {
-#if defined(MSDOS) || defined(_WIN32) || defined(__human68k__) || defined(__MACOS__)
-	path = "/usr/local/bin;/usr/ucb;/usr/bin;/bin;.";
-#else
-	path = "/usr/local/bin:/usr/ucb:/usr/bin:/bin:.";
+    if (func == NULL) {
+        const char *error;
+#if defined(_WIN32)
+        char message[1024];
+        error = dln_strerror();
+#elif defined(USE_DLN_DLOPEN)
+        const size_t errlen = strlen(error = dln_strerror()) + 1;
+        error = memcpy(ALLOCA_N(char, errlen), error, errlen);
 #endif
+        dln_loaderror("%s - %s", error, symbol);
     }
-    return dln_find_1(fname, path, 1);
+    return (uintptr_t)func;
 }
 
-char *
-dln_find_file(const char *fname, const char *path)
+#define dln_sym_callable(rettype, argtype, handle, symbol) \
+    (*(rettype (*)argtype)dln_sym_func(handle, symbol))
+#endif
+
+void *
+dln_symbol(void *handle, const char *symbol)
 {
-#ifndef __MACOS__
-    if (!path) path = ".";
-    return dln_find_1(fname, path, 0);
+#if defined(_WIN32) || defined(USE_DLN_DLOPEN)
+    if (EXTERNAL_PREFIX[0]) {
+        const size_t symlen = strlen(symbol);
+        char *const tmp = ALLOCA_N(char, symlen + sizeof(EXTERNAL_PREFIX));
+        if (!tmp) dln_memerror();
+        memcpy(tmp, EXTERNAL_PREFIX, sizeof(EXTERNAL_PREFIX) - 1);
+        memcpy(tmp + sizeof(EXTERNAL_PREFIX) - 1, symbol, symlen + 1);
+        symbol = tmp;
+    }
+    if (handle == NULL) {
+# if defined(USE_DLN_DLOPEN)
+        handle = dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL);
+# elif defined(_WIN32)
+        handle = rb_libruby_handle();
+# else
+        return NULL;
+# endif
+    }
+    return dln_sym(handle, symbol);
 #else
-    if (!path) path = ".";
-    return _macruby_path_conv_posix_to_macos(dln_find_1(fname, path, 0));
+    return NULL;
 #endif
 }
 
-static char fbuf[MAXPATHLEN];
 
-static char *
-dln_find_1(const char *fname, const char *path, int exe_flag /* non 0 if looking for executable. */)
+#if defined(RUBY_DLN_CHECK_ABI) && defined(USE_DLN_DLOPEN)
+static bool
+abi_check_enabled_p(void)
 {
-    register const char *dp;
-    register const char *ep;
-    register char *bp;
-    struct stat st;
-#ifdef __MACOS__
-    const char* mac_fullpath;
+    const char *val = getenv("RUBY_ABI_CHECK");
+    return val == NULL || !(val[0] == '0' && val[1] == '\0');
+}
 #endif
 
-#define RETURN_IF(expr) if (expr) return (char *)fname;
+static void *
+dln_load_and_init(const char *file, const char *init_fct_name)
+{
+#if defined(DLN_DEFINED)
+    void *handle = dln_open(file);
 
-    RETURN_IF(!fname);
-    RETURN_IF(fname[0] == '/');
-    RETURN_IF(strncmp("./", fname, 2) == 0 || strncmp("../", fname, 3) == 0);
-    RETURN_IF(exe_flag && strchr(fname, '/'));
-#ifdef DOSISH
-    RETURN_IF(fname[0] == '\\');
-# ifdef DOSISH_DRIVE_LETTER
-    RETURN_IF(strlen(fname) > 2 && fname[1] == ':');
-# endif
-    RETURN_IF(strncmp(".\\", fname, 2) == 0 || strncmp("..\\", fname, 3) == 0);
-    RETURN_IF(exe_flag && strchr(fname, '\\'));
+#ifdef RUBY_DLN_CHECK_ABI
+    typedef unsigned long long abi_version_number;
+    abi_version_number binary_abi_version =
+        dln_sym_callable(abi_version_number, (void), handle, EXTERNAL_PREFIX "ruby_abi_version")();
+    if (binary_abi_version != RUBY_ABI_VERSION && abi_check_enabled_p()) {
+        dln_loaderror("incompatible ABI version of binary - %s", file);
+    }
 #endif
 
-#undef RETURN_IF
-
-    for (dp = path;; dp = ++ep) {
-	register int l;
-	int i;
-	int fspace;
-
-	/* extract a component */
-	ep = strchr(dp, PATH_SEP[0]);
-	if (ep == NULL)
-	    ep = dp+strlen(dp);
-
-	/* find the length of that component */
-	l = ep - dp;
-	bp = fbuf;
-	fspace = sizeof fbuf - 2;
-	if (l > 0) {
-	    /*
-	    **	If the length of the component is zero length,
-	    **	start from the current directory.  If the
-	    **	component begins with "~", start from the
-	    **	user's $HOME environment variable.  Otherwise
-	    **	take the path literally.
-	    */
-
-	    if (*dp == '~' && (l == 1 ||
-#if defined(DOSISH)
-			       dp[1] == '\\' || 
-#endif
-			       dp[1] == '/')) {
-		char *home;
-
-		home = getenv("HOME");
-		if (home != NULL) {
-		    i = strlen(home);
-		    if ((fspace -= i) < 0)
-			goto toolong;
-		    memcpy(bp, home, i);
-		    bp += i;
-		}
-		dp++;
-		l--;
-	    }
-	    if (l > 0) {
-		if ((fspace -= l) < 0)
-		    goto toolong;
-		memcpy(bp, dp, l);
-		bp += l;
-	    }
-
-	    /* add a "/" between directory and filename */
-	    if (ep[-1] != '/')
-		*bp++ = '/';
-	}
-
-	/* now append the file name */
-	i = strlen(fname);
-	if ((fspace -= i) < 0) {
-	  toolong:
-	    fprintf(stderr, "openpath: pathname too long (ignored)\n");
-	    *bp = '\0';
-	    fprintf(stderr, "\tDirectory \"%s\"\n", fbuf);
-	    fprintf(stderr, "\tFile \"%s\"\n", fname);
-	    goto next;
-	}
-	memcpy(bp, fname, i + 1);
-
-#ifndef __MACOS__
-	if (stat(fbuf, &st) == 0) {
-	    if (exe_flag == 0) return fbuf;
-	    /* looking for executable */
-	    if (!S_ISDIR(st.st_mode) && eaccess(fbuf, X_OK) == 0)
-		return fbuf;
-	}
-#else
-	if (mac_fullpath = _macruby_exist_file_in_libdir_as_posix_name(fbuf)) {
-	    if (exe_flag == 0) return mac_fullpath;
-	    /* looking for executable */
-	    if (stat(mac_fullpath, &st) == 0) {
-		if (!S_ISDIR(st.st_mode) && eaccess(mac_fullpath, X_OK) == 0)
-		    return mac_fullpath;
-	    }
-	}
-#endif
-#if defined(DOSISH)
-	if (exe_flag) {
-	    static const char *const extension[] = {
-#if defined(MSDOS)
-		".com", ".exe", ".bat",
-#if defined(DJGPP)
-		".btm", ".sh", ".ksh", ".pl", ".sed",
-#endif
-#elif defined(__EMX__) || defined(_WIN32)
-		".exe", ".com", ".cmd", ".bat",
-/* end of __EMX__ or _WIN32 */
-#else
-		".r", ".R", ".x", ".X", ".bat", ".BAT",
-/* __human68k__ */
-#endif
-		(char *) NULL
-	    };
-	    int j;
-
-	    for (j = 0; extension[j]; j++) {
-		if (fspace < strlen(extension[j])) {
-		    fprintf(stderr, "openpath: pathname too long (ignored)\n");
-		    fprintf(stderr, "\tDirectory \"%.*s\"\n", (int) (bp - fbuf), fbuf);
-		    fprintf(stderr, "\tFile \"%s%s\"\n", fname, extension[j]);
-		    continue;
-		}
-		strcpy(bp + i, extension[j]);
-#ifndef __MACOS__
-		if (stat(fbuf, &st) == 0)
-		    return fbuf;
-#else
-		if (mac_fullpath = _macruby_exist_file_in_libdir_as_posix_name(fbuf))
-		    return mac_fullpath;
+    /* Call the init code */
+    dln_sym_callable(void, (void), handle, init_fct_name)();
+
+    return handle;
 
+#elif defined(_AIX)
+# define DLN_DEFINED
+    {
+        void (*init_fct)(void);
+
+        /* TODO: check - AIX's load system call will return the first/last symbol/function? */
+        init_fct = (void(*)(void))load((char*)file, 1, 0);
+        if (init_fct == NULL) {
+            aix_loaderror(file);
+        }
+        if (loadbind(0, (void*)dln_load, (void*)init_fct) == -1) {
+            aix_loaderror(file);
+        }
+        (*init_fct)();
+        return (void*)init_fct;
+    }
+#else
+    dln_notimplement();
+    UNREACHABLE_RETURN(0);
 #endif
-	    }
-	}
-#endif /* MSDOS or _WIN32 or __human68k__ or __EMX__ */
+}
 
-      next:
-	/* if not, and no other alternatives, life is bleak */
-	if (*ep == '\0') {
-	    return NULL;
-	}
+void *
+dln_load(const char *file)
+{
+    return dln_load_feature(file, file);
+}
 
-	/* otherwise try the next component in the search path */
-    }
+void *
+dln_load_feature(const char *file, const char *fname)
+{
+#if defined(DLN_DEFINED)
+    char *init_fct_name;
+    init_funcname(&init_fct_name, fname);
+    return dln_load_and_init(file, init_fct_name);
+#else
+    dln_notimplement();
+    UNREACHABLE_RETURN(0);
+#endif
 }