/* ltdl.c -- system independent dlopen wrapper
   Copyright (C) 1998, 1999, 2000, 2004, 2005  Free Software Foundation, Inc.
   Originally by Thomas Tanner <tanner@ffii.org>
   This file is part of GNU Libtool.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

As a special exception to the GNU Lesser General Public License,
if you distribute this file as part of a program or library that
is built using GNU libtool, you may include it under the same
distribution terms that you use for the rest of that program.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301  USA

*/

#if HAVE_CONFIG_H
#  include <config.h>
#endif

#if HAVE_UNISTD_H
#  include <unistd.h>
#endif

#if HAVE_STDIO_H
#  include <stdio.h>
#endif

/* Include the header defining malloc.  On K&R C compilers,
   that's <malloc.h>, on ANSI C and ISO C compilers, that's <stdlib.h>.  */
#if HAVE_STDLIB_H
#  include <stdlib.h>
#else
#  if HAVE_MALLOC_H
#    include <malloc.h>
#  endif
#endif

#if HAVE_STRING_H
#  include <string.h>
#else
#  if HAVE_STRINGS_H
#    include <strings.h>
#  endif
#endif

#if HAVE_CTYPE_H
#  include <ctype.h>
#endif

#if HAVE_MEMORY_H
#  include <memory.h>
#endif

#if HAVE_ERRNO_H
#  include <errno.h>
#endif


#ifndef __WINDOWS__
#  ifdef __WIN32__
#    define __WINDOWS__
#  endif
#endif


#undef LT_USE_POSIX_DIRENT
#ifdef HAVE_CLOSEDIR
#  ifdef HAVE_OPENDIR
#    ifdef HAVE_READDIR
#      ifdef HAVE_DIRENT_H
#        define LT_USE_POSIX_DIRENT
#      endif /* HAVE_DIRENT_H */
#    endif /* HAVE_READDIR */
#  endif /* HAVE_OPENDIR */
#endif /* HAVE_CLOSEDIR */


#undef LT_USE_WINDOWS_DIRENT_EMULATION
#ifndef LT_USE_POSIX_DIRENT
#  ifdef __WINDOWS__
#    define LT_USE_WINDOWS_DIRENT_EMULATION
#  endif /* __WINDOWS__ */
#endif /* LT_USE_POSIX_DIRENT */


#ifdef LT_USE_POSIX_DIRENT
#  include <dirent.h>
#  define LT_D_NAMLEN(dirent) (strlen((dirent)->d_name))
#else
#  ifdef LT_USE_WINDOWS_DIRENT_EMULATION
#    define LT_D_NAMLEN(dirent) (strlen((dirent)->d_name))
#  else
#    define dirent direct
#    define LT_D_NAMLEN(dirent) ((dirent)->d_namlen)
#    if HAVE_SYS_NDIR_H
#      include <sys/ndir.h>
#    endif
#    if HAVE_SYS_DIR_H
#      include <sys/dir.h>
#    endif
#    if HAVE_NDIR_H
#      include <ndir.h>
#    endif
#  endif
#endif

#if HAVE_ARGZ_H
#  include <argz.h>
#endif

#if HAVE_ASSERT_H
#  include <assert.h>
#else
#  define assert(arg)	((void) 0)
#endif

#include "ltdl.h"

#if WITH_DMALLOC
#  include <dmalloc.h>
#endif




/* --- WINDOWS SUPPORT --- */


#ifdef DLL_EXPORT
#  define LT_GLOBAL_DATA	__declspec(dllexport)
#else
#  define LT_GLOBAL_DATA
#endif

/* fopen() mode flags for reading a text file */
#undef	LT_READTEXT_MODE
#ifdef __WINDOWS__
#  define LT_READTEXT_MODE "rt"
#else
#  define LT_READTEXT_MODE "r"
#endif

#ifdef LT_USE_WINDOWS_DIRENT_EMULATION

#include <windows.h>

#define dirent lt_dirent
#define DIR lt_DIR

struct dirent
{
  char d_name[2048];
  int  d_namlen;
};

typedef struct _DIR
{
  HANDLE hSearch;
  WIN32_FIND_DATA Win32FindData;
  BOOL firsttime;
  struct dirent file_info;
} DIR;

#endif /* LT_USE_WINDOWS_DIRENT_EMULATION */


/* --- MANIFEST CONSTANTS --- */


/* Standard libltdl search path environment variable name  */
#undef  LTDL_SEARCHPATH_VAR
#define LTDL_SEARCHPATH_VAR	"LTDL_LIBRARY_PATH"

/* Standard libtool archive file extension.  */
#undef  LTDL_ARCHIVE_EXT
#define LTDL_ARCHIVE_EXT	".la"

/* max. filename length */
#ifndef LT_FILENAME_MAX
#  define LT_FILENAME_MAX	1024
#endif

/* This is the maximum symbol size that won't require malloc/free */
#undef	LT_SYMBOL_LENGTH
#define LT_SYMBOL_LENGTH	128

/* This accounts for the _LTX_ separator */
#undef	LT_SYMBOL_OVERHEAD
#define LT_SYMBOL_OVERHEAD	5




/* --- MEMORY HANDLING --- */


/* These are the functions used internally.  In addition to making
   use of the associated function pointers above, they also perform
   error handling.  */
static char   *lt_estrdup	LT_PARAMS((const char *str));
static lt_ptr lt_emalloc	LT_PARAMS((size_t size));
static lt_ptr lt_erealloc	LT_PARAMS((lt_ptr addr, size_t size));

/* static lt_ptr rpl_realloc	LT_PARAMS((lt_ptr ptr, size_t size)); */
#define rpl_realloc realloc

/* These are the pointers that can be changed by the caller:  */
LT_GLOBAL_DATA lt_ptr (*lt_dlmalloc)	LT_PARAMS((size_t size))
 			= (lt_ptr (*) LT_PARAMS((size_t))) malloc;
LT_GLOBAL_DATA lt_ptr (*lt_dlrealloc)	LT_PARAMS((lt_ptr ptr, size_t size))
 			= (lt_ptr (*) LT_PARAMS((lt_ptr, size_t))) rpl_realloc;
LT_GLOBAL_DATA void   (*lt_dlfree)	LT_PARAMS((lt_ptr ptr))
 			= (void (*) LT_PARAMS((lt_ptr))) free;

/* The following macros reduce the amount of typing needed to cast
   assigned memory.  */
#if WITH_DMALLOC

#define LT_DLMALLOC(tp, n)	((tp *) xmalloc ((n) * sizeof(tp)))
#define LT_DLREALLOC(tp, p, n)	((tp *) xrealloc ((p), (n) * sizeof(tp)))
#define LT_DLFREE(p)						\
	LT_STMT_START { if (p) (p) = (xfree (p), (lt_ptr) 0); } LT_STMT_END

#define LT_EMALLOC(tp, n)	((tp *) xmalloc ((n) * sizeof(tp)))
#define LT_EREALLOC(tp, p, n)	((tp *) xrealloc ((p), (n) * sizeof(tp)))

#else

#define LT_DLMALLOC(tp, n)	((tp *) lt_dlmalloc ((n) * sizeof(tp)))
#define LT_DLREALLOC(tp, p, n)	((tp *) lt_dlrealloc ((p), (n) * sizeof(tp)))
#define LT_DLFREE(p)						\
	LT_STMT_START { if (p) (p) = (lt_dlfree (p), (lt_ptr) 0); } LT_STMT_END

#define LT_EMALLOC(tp, n)	((tp *) lt_emalloc ((n) * sizeof(tp)))
#define LT_EREALLOC(tp, p, n)	((tp *) lt_erealloc ((p), (n) * sizeof(tp)))

#endif

#define LT_DLMEM_REASSIGN(p, q)			LT_STMT_START {	\
	if ((p) != (q)) { if (p) lt_dlfree (p); (p) = (q); (q) = 0; }	\
						} LT_STMT_END


/* --- REPLACEMENT FUNCTIONS --- */


#undef strdup
#define strdup rpl_strdup

static char *strdup LT_PARAMS((const char *str));

static char *
strdup(str)
     const char *str;
{
  char *tmp = 0;

  if (str)
    {
      tmp = LT_DLMALLOC (char, 1+ strlen (str));
      if (tmp)
	{
	  strcpy(tmp, str);
	}
    }

  return tmp;
}


#if ! HAVE_STRCMP

#undef strcmp
#define strcmp rpl_strcmp

static int strcmp LT_PARAMS((const char *str1, const char *str2));

static int
strcmp (str1, str2)
     const char *str1;
     const char *str2;
{
  if (str1 == str2)
    return 0;
  if (str1 == 0)
    return -1;
  if (str2 == 0)
    return 1;

  for (;*str1 && *str2; ++str1, ++str2)
    {
      if (*str1 != *str2)
	break;
    }

  return (int)(*str1 - *str2);
}
#endif


#if ! HAVE_STRCHR

#  if HAVE_INDEX
#    define strchr index
#  else
#    define strchr rpl_strchr

static const char *strchr LT_PARAMS((const char *str, int ch));

static const char*
strchr(str, ch)
     const char *str;
     int ch;
{
  const char *p;

  for (p = str; *p != (char)ch && *p != LT_EOS_CHAR; ++p)
    /*NOWORK*/;

  return (*p == (char)ch) ? p : 0;
}

#  endif
#endif /* !HAVE_STRCHR */


#if ! HAVE_STRRCHR

#  if HAVE_RINDEX
#    define strrchr rindex
#  else
#    define strrchr rpl_strrchr

static const char *strrchr LT_PARAMS((const char *str, int ch));

static const char*
strrchr(str, ch)
     const char *str;
     int ch;
{
  const char *p, *q = 0;

  for (p = str; *p != LT_EOS_CHAR; ++p)
    {
      if (*p == (char) ch)
	{
	  q = p;
	}
    }

  return q;
}

# endif
#endif

/* NOTE:  Neither bcopy nor the memcpy implementation below can
          reliably handle copying in overlapping areas of memory.  Use
          memmove (for which there is a fallback implmentation below)
	  if you need that behaviour.  */
#if ! HAVE_MEMCPY

#  if HAVE_BCOPY
#    define memcpy(dest, src, size)	bcopy (src, dest, size)
#  else
#    define memcpy rpl_memcpy

static lt_ptr memcpy LT_PARAMS((lt_ptr dest, const lt_ptr src, size_t size));

static lt_ptr
memcpy (dest, src, size)
     lt_ptr dest;
     const lt_ptr src;
     size_t size;
{
  const char *	s = src;
  char *	d = dest;
  size_t	i = 0;

  for (i = 0; i < size; ++i)
    {
      d[i] = s[i];
    }

  return dest;
}

#  endif /* !HAVE_BCOPY */
#endif   /* !HAVE_MEMCPY */

#if ! HAVE_MEMMOVE
#  define memmove rpl_memmove

static lt_ptr memmove LT_PARAMS((lt_ptr dest, const lt_ptr src, size_t size));

static lt_ptr
memmove (dest, src, size)
     lt_ptr dest;
     const lt_ptr src;
     size_t size;
{
  const char *	s = src;
  char *	d = dest;
  size_t	i;

  if (d < s)
    for (i = 0; i < size; ++i)
      {
	d[i] = s[i];
      }
  else if (d > s && size > 0)
    for (i = size -1; ; --i)
      {
	d[i] = s[i];
	if (i == 0)
	  break;
      }

  return dest;
}

#endif /* !HAVE_MEMMOVE */

#ifdef LT_USE_WINDOWS_DIRENT_EMULATION

static void closedir LT_PARAMS((DIR *entry));

static void
closedir(entry)
  DIR *entry;
{
  assert(entry != (DIR *) NULL);
  FindClose(entry->hSearch);
  lt_dlfree((lt_ptr)entry);
}


static DIR * opendir LT_PARAMS((const char *path));

static DIR*
opendir (path)
  const char *path;
{
  char file_specification[LT_FILENAME_MAX];
  DIR *entry;

  assert(path != (char *) NULL);
  /* allow space for: path + '\\' '\\' '*' '.' '*' + '\0' */
  (void) strncpy (file_specification, path, LT_FILENAME_MAX-6);
  file_specification[LT_FILENAME_MAX-6] = LT_EOS_CHAR;
  (void) strcat(file_specification,"\\");
  entry = LT_DLMALLOC (DIR,sizeof(DIR));
  if (entry != (DIR *) 0)
    {
      entry->firsttime = TRUE;
      entry->hSearch = FindFirstFile(file_specification,&entry->Win32FindData);
    }
  if (entry->hSearch == INVALID_HANDLE_VALUE)
    {
      (void) strcat(file_specification,"\\*.*");
      entry->hSearch = FindFirstFile(file_specification,&entry->Win32FindData);
      if (entry->hSearch == INVALID_HANDLE_VALUE)
        {
          LT_DLFREE (entry);
          return (DIR *) 0;
        }
    }
  return(entry);
}


static struct dirent *readdir LT_PARAMS((DIR *entry));

static struct dirent *readdir(entry)
  DIR *entry;
{
  int
    status;

  if (entry == (DIR *) 0)
    return((struct dirent *) 0);
  if (!entry->firsttime)
    {
      status = FindNextFile(entry->hSearch,&entry->Win32FindData);
      if (status == 0)
        return((struct dirent *) 0);
    }
  entry->firsttime = FALSE;
  (void) strncpy(entry->file_info.d_name,entry->Win32FindData.cFileName,
    LT_FILENAME_MAX-1);
  entry->file_info.d_name[LT_FILENAME_MAX - 1] = LT_EOS_CHAR;
  entry->file_info.d_namlen = strlen(entry->file_info.d_name);
  return(&entry->file_info);
}

#endif /* LT_USE_WINDOWS_DIRENT_EMULATION */

/* According to Alexandre Oliva <oliva@lsd.ic.unicamp.br>,
    ``realloc is not entirely portable''
   In any case we want to use the allocator supplied by the user without
   burdening them with an lt_dlrealloc function pointer to maintain.
   Instead implement our own version (with known boundary conditions)
   using lt_dlmalloc and lt_dlfree. */

/* #undef realloc
   #define realloc rpl_realloc
*/
#if 0
  /* You can't (re)define realloc unless you also (re)define malloc.
     Right now, this code uses the size of the *destination* to decide
     how much to copy.  That's not right, but you can't know the size
     of the source unless you know enough about, or wrote malloc.  So
     this code is disabled... */

static lt_ptr
realloc (ptr, size)
     lt_ptr ptr;
     size_t size;
{
  if (size == 0)
    {
      /* For zero or less bytes, free the original memory */
      if (ptr != 0)
	{
	  lt_dlfree (ptr);
	}

      return (lt_ptr) 0;
    }
  else if (ptr == 0)
    {
      /* Allow reallocation of a NULL pointer.  */
      return lt_dlmalloc (size);
    }
  else
    {
      /* Allocate a new block, copy and free the old block.  */
      lt_ptr mem = lt_dlmalloc (size);

      if (mem)
	{
	  memcpy (mem, ptr, size);
	  lt_dlfree (ptr);
	}

      /* Note that the contents of PTR are not damaged if there is
	 insufficient memory to realloc.  */
      return mem;
    }
}
#endif


#if ! HAVE_ARGZ_APPEND
#  define argz_append rpl_argz_append

static error_t argz_append LT_PARAMS((char **pargz, size_t *pargz_len,
					const char *buf, size_t buf_len));

static error_t
argz_append (pargz, pargz_len, buf, buf_len)
     char **pargz;
     size_t *pargz_len;
     const char *buf;
     size_t buf_len;
{
  size_t argz_len;
  char  *argz;

  assert (pargz);
  assert (pargz_len);
  assert ((*pargz && *pargz_len) || (!*pargz && !*pargz_len));

  /* If nothing needs to be appended, no more work is required.  */
  if (buf_len == 0)
    return 0;

  /* Ensure there is enough room to append BUF_LEN.  */
  argz_len = *pargz_len + buf_len;
  argz = LT_DLREALLOC (char, *pargz, argz_len);
  if (!argz)
    return ENOMEM;

  /* Copy characters from BUF after terminating '\0' in ARGZ.  */
  memcpy (argz + *pargz_len, buf, buf_len);

  /* Assign new values.  */
  *pargz = argz;
  *pargz_len = argz_len;

  return 0;
}
#endif /* !HAVE_ARGZ_APPEND */


#if ! HAVE_ARGZ_CREATE_SEP
#  define argz_create_sep rpl_argz_create_sep

static error_t argz_create_sep LT_PARAMS((const char *str, int delim,
					    char **pargz, size_t *pargz_len));

static error_t
argz_create_sep (str, delim, pargz, pargz_len)
     const char *str;
     int delim;
     char **pargz;
     size_t *pargz_len;
{
  size_t argz_len;
  char *argz = 0;

  assert (str);
  assert (pargz);
  assert (pargz_len);

  /* Make a copy of STR, but replacing each occurrence of
     DELIM with '\0'.  */
  argz_len = 1+ LT_STRLEN (str);
  if (argz_len)
    {
      const char *p;
      char *q;

      argz = LT_DLMALLOC (char, argz_len);
      if (!argz)
	return ENOMEM;

      for (p = str, q = argz; *p != LT_EOS_CHAR; ++p)
	{
	  if (*p == delim)
	    {
	      /* Ignore leading delimiters, and fold consecutive
		 delimiters in STR into a single '\0' in ARGZ.  */
	      if ((q > argz) && (q[-1] != LT_EOS_CHAR))
		*q++ = LT_EOS_CHAR;
	      else
		--argz_len;
	    }
	  else
	    *q++ = *p;
	}
      /* Copy terminating LT_EOS_CHAR.  */
      *q = *p;
    }

  /* If ARGZ_LEN has shrunk to nothing, release ARGZ's memory.  */
  if (!argz_len)
    LT_DLFREE (argz);

  /* Assign new values.  */
  *pargz = argz;
  *pargz_len = argz_len;

  return 0;
}
#endif /* !HAVE_ARGZ_CREATE_SEP */


#if ! HAVE_ARGZ_INSERT
#  define argz_insert rpl_argz_insert

static error_t argz_insert LT_PARAMS((char **pargz, size_t *pargz_len,
					char *before, const char *entry));

static error_t
argz_insert (pargz, pargz_len, before, entry)
     char **pargz;
     size_t *pargz_len;
     char *before;
     const char *entry;
{
  assert (pargz);
  assert (pargz_len);
  assert (entry && *entry);

  /* No BEFORE address indicates ENTRY should be inserted after the
     current last element.  */
  if (!before)
    return argz_append (pargz, pargz_len, entry, 1+ LT_STRLEN (entry));

  /* This probably indicates a programmer error, but to preserve
     semantics, scan back to the start of an entry if BEFORE points
     into the middle of it.  */
  while ((before > *pargz) && (before[-1] != LT_EOS_CHAR))
    --before;

  {
    size_t entry_len	= 1+ LT_STRLEN (entry);
    size_t argz_len	= *pargz_len + entry_len;
    size_t offset	= before - *pargz;
    char   *argz	= LT_DLREALLOC (char, *pargz, argz_len);

    if (!argz)
      return ENOMEM;

    /* Make BEFORE point to the equivalent offset in ARGZ that it
       used to have in *PARGZ incase realloc() moved the block.  */
    before = argz + offset;

    /* Move the ARGZ entries starting at BEFORE up into the new
       space at the end -- making room to copy ENTRY into the
       resulting gap.  */
    memmove (before + entry_len, before, *pargz_len - offset);
    memcpy  (before, entry, entry_len);

    /* Assign new values.  */
    *pargz = argz;
    *pargz_len = argz_len;
  }

  return 0;
}
#endif /* !HAVE_ARGZ_INSERT */


#if ! HAVE_ARGZ_NEXT
#  define argz_next rpl_argz_next

static char *argz_next LT_PARAMS((char *argz, size_t argz_len,
				    const char *entry));

static char *
argz_next (argz, argz_len, entry)
     char *argz;
     size_t argz_len;
     const char *entry;
{
  assert ((argz && argz_len) || (!argz && !argz_len));

  if (entry)
    {
      /* Either ARGZ/ARGZ_LEN is empty, or ENTRY points into an address
	 within the ARGZ vector.  */
      assert ((!argz && !argz_len)
	      || ((argz <= entry) && (entry < (argz + argz_len))));

      /* Move to the char immediately after the terminating
	 '\0' of ENTRY.  */
      entry = 1+ strchr (entry, LT_EOS_CHAR);

      /* Return either the new ENTRY, or else NULL if ARGZ is
	 exhausted.  */
      return (entry >= argz + argz_len) ? 0 : (char *) entry;
    }
  else
    {
      /* This should probably be flagged as a programmer error,
	 since starting an argz_next loop with the iterator set
	 to ARGZ is safer.  To preserve semantics, handle the NULL
	 case by returning the start of ARGZ (if any).  */
      if (argz_len > 0)
	return argz;
      else
	return 0;
    }
}
#endif /* !HAVE_ARGZ_NEXT */



#if ! HAVE_ARGZ_STRINGIFY
#  define argz_stringify rpl_argz_stringify

static void argz_stringify LT_PARAMS((char *argz, size_t argz_len,
				       int sep));

static void
argz_stringify (argz, argz_len, sep)
     char *argz;
     size_t argz_len;
     int sep;
{
  assert ((argz && argz_len) || (!argz && !argz_len));

  if (sep)
    {
      --argz_len;		/* don't stringify the terminating EOS */
      while (--argz_len > 0)
	{
	  if (argz[argz_len] == LT_EOS_CHAR)
	    argz[argz_len] = sep;
	}
    }
}
#endif /* !HAVE_ARGZ_STRINGIFY */




/* --- TYPE DEFINITIONS -- */


/* This type is used for the array of caller data sets in each handler. */
typedef struct {
  lt_dlcaller_id	key;
  lt_ptr		data;
} lt_caller_data;




/* --- OPAQUE STRUCTURES DECLARED IN LTDL.H --- */


/* Extract the diagnostic strings from the error table macro in the same
   order as the enumerated indices in ltdl.h. */

static const char *lt_dlerror_strings[] =
  {
#define LT_ERROR(name, diagnostic)	(diagnostic),
    lt_dlerror_table
#undef LT_ERROR

    0
  };

/* This structure is used for the list of registered loaders. */
struct lt_dlloader {
  struct lt_dlloader   *next;
  const char	       *loader_name;	/* identifying name for each loader */
  const char	       *sym_prefix;	/* prefix for symbols */
  lt_module_open       *module_open;
  lt_module_close      *module_close;
  lt_find_sym	       *find_sym;
  lt_dlloader_exit     *dlloader_exit;
  lt_user_data		dlloader_data;
};

struct lt_dlhandle_struct {
  struct lt_dlhandle_struct   *next;
  lt_dlloader	       *loader;		/* dlopening interface */
  lt_dlinfo		info;
  int			depcount;	/* number of dependencies */
  lt_dlhandle	       *deplibs;	/* dependencies */
  lt_module		module;		/* system module handle */
  lt_ptr		system;		/* system specific data */
  lt_caller_data       *caller_data;	/* per caller associated data */
  int			flags;		/* various boolean stats */
};

/* Various boolean flags can be stored in the flags field of an
   lt_dlhandle_struct... */
#define LT_DLGET_FLAG(handle, flag) (((handle)->flags & (flag)) == (flag))
#define LT_DLSET_FLAG(handle, flag) ((handle)->flags |= (flag))

#define LT_DLRESIDENT_FLAG	    (0x01 << 0)
/* ...add more flags here... */

#define LT_DLIS_RESIDENT(handle)    LT_DLGET_FLAG(handle, LT_DLRESIDENT_FLAG)


#define LT_DLSTRERROR(name)	lt_dlerror_strings[LT_CONC(LT_ERROR_,name)]

static	const char	objdir[]		= LTDL_OBJDIR;
static	const char	archive_ext[]		= LTDL_ARCHIVE_EXT;
#ifdef	LTDL_SHLIB_EXT
static	const char	shlib_ext[]		= LTDL_SHLIB_EXT;
#endif
#ifdef	LTDL_SYSSEARCHPATH
static	const char	sys_search_path[]	= LTDL_SYSSEARCHPATH;
#endif




/* --- MUTEX LOCKING --- */


/* Macros to make it easier to run the lock functions only if they have
   been registered.  The reason for the complicated lock macro is to
   ensure that the stored error message from the last error is not
   accidentally erased if the current function doesn't generate an
   error of its own.  */
#define LT_DLMUTEX_LOCK()			LT_STMT_START {	\
	if (lt_dlmutex_lock_func) (*lt_dlmutex_lock_func)();	\
						} LT_STMT_END
#define LT_DLMUTEX_UNLOCK()			LT_STMT_START { \
	if (lt_dlmutex_unlock_func) (*lt_dlmutex_unlock_func)();\
						} LT_STMT_END
#define LT_DLMUTEX_SETERROR(errormsg)		LT_STMT_START {	\
	if (lt_dlmutex_seterror_func)				\
		(*lt_dlmutex_seterror_func) (errormsg);		\
	else 	lt_dllast_error = (errormsg);	} LT_STMT_END
#define LT_DLMUTEX_GETERROR(errormsg)		LT_STMT_START {	\
	if (lt_dlmutex_geterror_func)				\
		(errormsg) = (*lt_dlmutex_geterror_func) ();	\
	else	(errormsg) = lt_dllast_error;	} LT_STMT_END

/* The mutex functions stored here are global, and are necessarily the
   same for all threads that wish to share access to libltdl.  */
static	lt_dlmutex_lock	    *lt_dlmutex_lock_func     = 0;
static	lt_dlmutex_unlock   *lt_dlmutex_unlock_func   = 0;
static	lt_dlmutex_seterror *lt_dlmutex_seterror_func = 0;
static	lt_dlmutex_geterror *lt_dlmutex_geterror_func = 0;
static	const char	    *lt_dllast_error	      = 0;


/* Either set or reset the mutex functions.  Either all the arguments must
   be valid functions, or else all can be NULL to turn off locking entirely.
   The registered functions should be manipulating a static global lock
   from the lock() and unlock() callbacks, which needs to be reentrant.  */
int
lt_dlmutex_register (lock, unlock, seterror, geterror)
     lt_dlmutex_lock *lock;
     lt_dlmutex_unlock *unlock;
     lt_dlmutex_seterror *seterror;
     lt_dlmutex_geterror *geterror;
{
  lt_dlmutex_unlock *old_unlock = unlock;
  int		     errors	= 0;

  /* Lock using the old lock() callback, if any.  */
  LT_DLMUTEX_LOCK ();

  if ((lock && unlock && seterror && geterror)
      || !(lock || unlock || seterror || geterror))
    {
      lt_dlmutex_lock_func     = lock;
      lt_dlmutex_unlock_func   = unlock;
      lt_dlmutex_geterror_func = geterror;
    }
  else
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (INVALID_MUTEX_ARGS));
      ++errors;
    }

  /* Use the old unlock() callback we saved earlier, if any.  Otherwise
     record any errors using internal storage.  */
  if (old_unlock)
    (*old_unlock) ();

  /* Return the number of errors encountered during the execution of
     this function.  */
  return errors;
}




/* --- ERROR HANDLING --- */


static	const char    **user_error_strings	= 0;
static	int		errorcount		= LT_ERROR_MAX;

int
lt_dladderror (diagnostic)
     const char *diagnostic;
{
  int		errindex = 0;
  int		result	 = -1;
  const char  **temp     = (const char **) 0;

  assert (diagnostic);

  LT_DLMUTEX_LOCK ();

  errindex = errorcount - LT_ERROR_MAX;
  temp = LT_EREALLOC (const char *, user_error_strings, 1 + errindex);
  if (temp)
    {
      user_error_strings		= temp;
      user_error_strings[errindex]	= diagnostic;
      result				= errorcount++;
    }

  LT_DLMUTEX_UNLOCK ();

  return result;
}

int
lt_dlseterror (errindex)
     int errindex;
{
  int		errors	 = 0;

  LT_DLMUTEX_LOCK ();

  if (errindex >= errorcount || errindex < 0)
    {
      /* Ack!  Error setting the error message! */
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (INVALID_ERRORCODE));
      ++errors;
    }
  else if (errindex < LT_ERROR_MAX)
    {
      /* No error setting the error message! */
      LT_DLMUTEX_SETERROR (lt_dlerror_strings[errindex]);
    }
  else
    {
      /* No error setting the error message! */
      LT_DLMUTEX_SETERROR (user_error_strings[errindex - LT_ERROR_MAX]);
    }

  LT_DLMUTEX_UNLOCK ();

  return errors;
}

static lt_ptr
lt_emalloc (size)
     size_t size;
{
  lt_ptr mem = lt_dlmalloc (size);
  if (size && !mem)
    LT_DLMUTEX_SETERROR (LT_DLSTRERROR (NO_MEMORY));
  return mem;
}

static lt_ptr
lt_erealloc (addr, size)
     lt_ptr addr;
     size_t size;
{
  lt_ptr mem = lt_dlrealloc (addr, size);
  if (size && !mem)
    LT_DLMUTEX_SETERROR (LT_DLSTRERROR (NO_MEMORY));
  return mem;
}

static char *
lt_estrdup (str)
     const char *str;
{
  char *copy = strdup (str);
  if (LT_STRLEN (str) && !copy)
    LT_DLMUTEX_SETERROR (LT_DLSTRERROR (NO_MEMORY));
  return copy;
}




/* --- DLOPEN() INTERFACE LOADER --- */


#if HAVE_LIBDL

/* dynamic linking with dlopen/dlsym */

#if HAVE_DLFCN_H
#  include <dlfcn.h>
#endif

#if HAVE_SYS_DL_H
#  include <sys/dl.h>
#endif

#ifdef RTLD_GLOBAL
#  define LT_GLOBAL		RTLD_GLOBAL
#else
#  ifdef DL_GLOBAL
#    define LT_GLOBAL		DL_GLOBAL
#  endif
#endif /* !RTLD_GLOBAL */
#ifndef LT_GLOBAL
#  define LT_GLOBAL		0
#endif /* !LT_GLOBAL */

/* We may have to define LT_LAZY_OR_NOW in the command line if we
   find out it does not work in some platform. */
#ifndef LT_LAZY_OR_NOW
#  ifdef RTLD_LAZY
#    define LT_LAZY_OR_NOW	RTLD_LAZY
#  else
#    ifdef DL_LAZY
#      define LT_LAZY_OR_NOW	DL_LAZY
#    endif
#  endif /* !RTLD_LAZY */
#endif
#ifndef LT_LAZY_OR_NOW
#  ifdef RTLD_NOW
#    define LT_LAZY_OR_NOW	RTLD_NOW
#  else
#    ifdef DL_NOW
#      define LT_LAZY_OR_NOW	DL_NOW
#    endif
#  endif /* !RTLD_NOW */
#endif
#ifndef LT_LAZY_OR_NOW
#  define LT_LAZY_OR_NOW	0
#endif /* !LT_LAZY_OR_NOW */

#if HAVE_DLERROR
#  define DLERROR(arg)	dlerror ()
#else
#  define DLERROR(arg)	LT_DLSTRERROR (arg)
#endif

static lt_module
sys_dl_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
  lt_module   module   = dlopen (filename, LT_GLOBAL | LT_LAZY_OR_NOW);

  if (!module)
    {
      LT_DLMUTEX_SETERROR (DLERROR (CANNOT_OPEN));
    }

  return module;
}

static int
sys_dl_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
  int errors = 0;

  if (dlclose (module) != 0)
    {
      LT_DLMUTEX_SETERROR (DLERROR (CANNOT_CLOSE));
      ++errors;
    }

  return errors;
}

static lt_ptr
sys_dl_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
  lt_ptr address = dlsym (module, symbol);

  if (!address)
    {
      LT_DLMUTEX_SETERROR (DLERROR (SYMBOL_NOT_FOUND));
    }

  return address;
}

static struct lt_user_dlloader sys_dl =
  {
#  ifdef NEED_USCORE
    "_",
#  else
    0,
#  endif
    sys_dl_open, sys_dl_close, sys_dl_sym, 0, 0 };


#endif /* HAVE_LIBDL */



/* --- SHL_LOAD() INTERFACE LOADER --- */

#if HAVE_SHL_LOAD

/* dynamic linking with shl_load (HP-UX) (comments from gmodule) */

#ifdef HAVE_DL_H
#  include <dl.h>
#endif

/* some flags are missing on some systems, so we provide
 * harmless defaults.
 *
 * Mandatory:
 * BIND_IMMEDIATE  - Resolve symbol references when the library is loaded.
 * BIND_DEFERRED   - Delay code symbol resolution until actual reference.
 *
 * Optionally:
 * BIND_FIRST	   - Place the library at the head of the symbol search
 * 		     order.
 * BIND_NONFATAL   - The default BIND_IMMEDIATE behavior is to treat all
 * 		     unsatisfied symbols as fatal.  This flag allows
 * 		     binding of unsatisfied code symbols to be deferred
 * 		     until use.
 *		     [Perl: For certain libraries, like DCE, deferred
 *		     binding often causes run time problems. Adding
 *		     BIND_NONFATAL to BIND_IMMEDIATE still allows
 *		     unresolved references in situations like this.]
 * BIND_NOSTART	   - Do not call the initializer for the shared library
 *		     when the library is loaded, nor on a future call to
 *		     shl_unload().
 * BIND_VERBOSE	   - Print verbose messages concerning possible
 *		     unsatisfied symbols.
 *
 * hp9000s700/hp9000s800:
 * BIND_RESTRICTED - Restrict symbols visible by the library to those
 *		     present at library load time.
 * DYNAMIC_PATH	   - Allow the loader to dynamically search for the
 *		     library specified by the path argument.
 */

#ifndef	DYNAMIC_PATH
#  define DYNAMIC_PATH		0
#endif
#ifndef	BIND_RESTRICTED
#  define BIND_RESTRICTED	0
#endif

#define	LT_BIND_FLAGS	(BIND_IMMEDIATE | BIND_NONFATAL | DYNAMIC_PATH)

static lt_module
sys_shl_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
  static shl_t self = (shl_t) 0;
  lt_module module = shl_load (filename, LT_BIND_FLAGS, 0L);

  /* Since searching for a symbol against a NULL module handle will also
     look in everything else that was already loaded and exported with
     the -E compiler flag, we always cache a handle saved before any
     modules are loaded.  */
  if (!self)
    {
      lt_ptr address;
      shl_findsym (&self, "main", TYPE_UNDEFINED, &address);
    }

  if (!filename)
    {
      module = self;
    }
  else
    {
      module = shl_load (filename, LT_BIND_FLAGS, 0L);

      if (!module)
	{
	  LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_OPEN));
	}
    }

  return module;
}

static int
sys_shl_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
  int errors = 0;

  if (module && (shl_unload ((shl_t) (module)) != 0))
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_CLOSE));
      ++errors;
    }

  return errors;
}

static lt_ptr
sys_shl_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
  lt_ptr address = 0;

  /* sys_shl_open should never return a NULL module handle */
  if (module == (lt_module) 0)
  {
    LT_DLMUTEX_SETERROR (LT_DLSTRERROR (INVALID_HANDLE));
  }
  else if (!shl_findsym((shl_t*) &module, symbol, TYPE_UNDEFINED, &address))
    {
      if (!address)
	{
	  LT_DLMUTEX_SETERROR (LT_DLSTRERROR (SYMBOL_NOT_FOUND));
	}
    }

  return address;
}

static struct lt_user_dlloader sys_shl = {
  0, sys_shl_open, sys_shl_close, sys_shl_sym, 0, 0
};

#endif /* HAVE_SHL_LOAD */




/* --- LOADLIBRARY() INTERFACE LOADER --- */

#ifdef __WINDOWS__

/* dynamic linking for Win32 */

#include <windows.h>

/* Forward declaration; required to implement handle search below. */
static lt_dlhandle handles;

static lt_module
sys_wll_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
  lt_dlhandle	cur;
  lt_module	module	   = 0;
  const char   *errormsg   = 0;
  char	       *searchname = 0;
  char	       *ext;
  char		self_name_buf[MAX_PATH];

  if (!filename)
    {
      /* Get the name of main module */
      *self_name_buf = 0;
      GetModuleFileName (NULL, self_name_buf, sizeof (self_name_buf));
      filename = ext = self_name_buf;
    }
  else
    {
      ext = strrchr (filename, '.');
    }

  if (ext)
    {
      /* FILENAME already has an extension. */
      searchname = lt_estrdup (filename);
    }
  else
    {
      /* Append a `.' to stop Windows from adding an
	 implicit `.dll' extension. */
      searchname = LT_EMALLOC (char, 2+ LT_STRLEN (filename));
      if (searchname)
	sprintf (searchname, "%s.", filename);
    }
  if (!searchname)
    return 0;

  {
    /* Silence dialog from LoadLibrary on some failures.
       No way to get the error mode, but to set it,
       so set it twice to preserve any previous flags. */
    UINT errormode = SetErrorMode(SEM_FAILCRITICALERRORS);
    SetErrorMode(errormode | SEM_FAILCRITICALERRORS);

#if defined(__CYGWIN__)
    {
      char wpath[MAX_PATH];
      cygwin_conv_to_full_win32_path (searchname, wpath);
      module = LoadLibrary (wpath);
    }
#else
    module = LoadLibrary (searchname);
#endif

    /* Restore the error mode. */
    SetErrorMode(errormode);
  }

  LT_DLFREE (searchname);

  /* libltdl expects this function to fail if it is unable
     to physically load the library.  Sadly, LoadLibrary
     will search the loaded libraries for a match and return
     one of them if the path search load fails.

     We check whether LoadLibrary is returning a handle to
     an already loaded module, and simulate failure if we
     find one. */
  LT_DLMUTEX_LOCK ();
  cur = handles;
  while (cur)
    {
      if (!cur->module)
	{
	  cur = 0;
	  break;
	}

      if (cur->module == module)
	{
	  break;
	}

      cur = cur->next;
  }
  LT_DLMUTEX_UNLOCK ();

  if (cur || !module)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_OPEN));
      module = 0;
    }

  return module;
}

static int
sys_wll_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
  int	      errors   = 0;

  if (FreeLibrary(module) == 0)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_CLOSE));
      ++errors;
    }

  return errors;
}

static lt_ptr
sys_wll_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
  lt_ptr      address  = GetProcAddress (module, symbol);

  if (!address)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (SYMBOL_NOT_FOUND));
    }

  return address;
}

static struct lt_user_dlloader sys_wll = {
  0, sys_wll_open, sys_wll_close, sys_wll_sym, 0, 0
};

#endif /* __WINDOWS__ */




/* --- LOAD_ADD_ON() INTERFACE LOADER --- */


#ifdef __BEOS__

/* dynamic linking for BeOS */

#include <kernel/image.h>

static lt_module
sys_bedl_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
  image_id image = 0;

  if (filename)
    {
      image = load_add_on (filename);
    }
  else
    {
      image_info info;
      int32 cookie = 0;
      if (get_next_image_info (0, &cookie, &info) == B_OK)
	image = load_add_on (info.name);
    }

  if (image <= 0)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_OPEN));
      image = 0;
    }

  return (lt_module) image;
}

static int
sys_bedl_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
  int errors = 0;

  if (unload_add_on ((image_id) module) != B_OK)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_CLOSE));
      ++errors;
    }

  return errors;
}

static lt_ptr
sys_bedl_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
  lt_ptr address = 0;
  image_id image = (image_id) module;

  if (get_image_symbol (image, symbol, B_SYMBOL_TYPE_ANY, address) != B_OK)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (SYMBOL_NOT_FOUND));
      address = 0;
    }

  return address;
}

static struct lt_user_dlloader sys_bedl = {
  0, sys_bedl_open, sys_bedl_close, sys_bedl_sym, 0, 0
};

#endif /* __BEOS__ */




/* --- DLD_LINK() INTERFACE LOADER --- */


#if HAVE_DLD

/* dynamic linking with dld */

#if HAVE_DLD_H
#include <dld.h>
#endif

static lt_module
sys_dld_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
  lt_module module = strdup (filename);

  if (dld_link (filename) != 0)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_OPEN));
      LT_DLFREE (module);
      module = 0;
    }

  return module;
}

static int
sys_dld_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
  int errors = 0;

  if (dld_unlink_by_file ((char*)(module), 1) != 0)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (CANNOT_CLOSE));
      ++errors;
    }
  else
    {
      LT_DLFREE (module);
    }

  return errors;
}

static lt_ptr
sys_dld_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
  lt_ptr address = dld_get_func (symbol);

  if (!address)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (SYMBOL_NOT_FOUND));
    }

  return address;
}

static struct lt_user_dlloader sys_dld = {
  0, sys_dld_open, sys_dld_close, sys_dld_sym, 0, 0
};

#endif /* HAVE_DLD */

/* --- DYLD() MACOSX/DARWIN INTERFACE LOADER --- */
#if HAVE_DYLD


#if HAVE_MACH_O_DYLD_H
#if !defined(__APPLE_CC__) && !defined(__MWERKS__) && !defined(__private_extern__)
/* Is this correct? Does it still function properly? */
#define __private_extern__ extern
#endif
# include <mach-o/dyld.h>
#endif
#include <mach-o/getsect.h>

/* We have to put some stuff here that isn't in older dyld.h files */
#ifndef ENUM_DYLD_BOOL
# define ENUM_DYLD_BOOL
# undef FALSE
# undef TRUE
 enum DYLD_BOOL {
    FALSE,
    TRUE
 };
#endif
#ifndef LC_REQ_DYLD
# define LC_REQ_DYLD 0x80000000
#endif
#ifndef LC_LOAD_WEAK_DYLIB
# define LC_LOAD_WEAK_DYLIB (0x18 | LC_REQ_DYLD)
#endif
static const struct mach_header * (*ltdl_NSAddImage)(const char *image_name, unsigned long options) = 0;
static NSSymbol (*ltdl_NSLookupSymbolInImage)(const struct mach_header *image,const char *symbolName, unsigned long options) = 0;
static enum DYLD_BOOL (*ltdl_NSIsSymbolNameDefinedInImage)(const struct mach_header *image, const char *symbolName) = 0;
static enum DYLD_BOOL (*ltdl_NSMakePrivateModulePublic)(NSModule module) = 0;

#ifndef NSADDIMAGE_OPTION_NONE
#define NSADDIMAGE_OPTION_NONE                          0x0
#endif
#ifndef NSADDIMAGE_OPTION_RETURN_ON_ERROR
#define NSADDIMAGE_OPTION_RETURN_ON_ERROR               0x1
#endif
#ifndef NSADDIMAGE_OPTION_WITH_SEARCHING
#define NSADDIMAGE_OPTION_WITH_SEARCHING                0x2
#endif
#ifndef NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED
#define NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED         0x4
#endif
#ifndef NSADDIMAGE_OPTION_MATCH_FILENAME_BY_INSTALLNAME
#define NSADDIMAGE_OPTION_MATCH_FILENAME_BY_INSTALLNAME 0x8
#endif
#ifndef NSLOOKUPSYMBOLINIMAGE_OPTION_BIND
#define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND            0x0
#endif
#ifndef NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW
#define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW        0x1
#endif
#ifndef NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_FULLY
#define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_FULLY      0x2
#endif
#ifndef NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR
#define NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR 0x4
#endif


static const char *
lt_int_dyld_error(othererror)
	char* othererror;
{
/* return the dyld error string, or the passed in error string if none */
	NSLinkEditErrors ler;
	int lerno;
	const char *errstr;
	const char *file;
	NSLinkEditError(&ler,&lerno,&file,&errstr);
	if (!errstr || !strlen(errstr)) errstr = othererror;
	return errstr;
}

static const struct mach_header *
lt_int_dyld_get_mach_header_from_nsmodule(module)
	NSModule module;
{
/* There should probably be an apple dyld api for this */
	int i=_dyld_image_count();
	int j;
	const char *modname=NSNameOfModule(module);
	const struct mach_header *mh=NULL;
	if (!modname) return NULL;
	for (j = 0; j < i; j++)
	{
		if (!strcmp(_dyld_get_image_name(j),modname))
		{
			mh=_dyld_get_image_header(j);
			break;
		}
	}
	return mh;
}

static const char* lt_int_dyld_lib_install_name(mh)
	const struct mach_header *mh;
{
/* NSAddImage is also used to get the loaded image, but it only works if the lib
   is installed, for uninstalled libs we need to check the install_names against
   each other. Note that this is still broken if DYLD_IMAGE_SUFFIX is set and a
   different lib was loaded as a result
*/
	int j;
	struct load_command *lc;
	unsigned long offset = sizeof(struct mach_header);
	const char* retStr=NULL;
	for (j = 0; j < mh->ncmds; j++)
	{
		lc = (struct load_command*)(((unsigned long)mh) + offset);
		if (LC_ID_DYLIB == lc->cmd)
		{
			retStr=(char*)(((struct dylib_command*)lc)->dylib.name.offset +
									(unsigned long)lc);
		}
		offset += lc->cmdsize;
	}
	return retStr;
}

static const struct mach_header *
lt_int_dyld_match_loaded_lib_by_install_name(const char *name)
{
	int i=_dyld_image_count();
	int j;
	const struct mach_header *mh=NULL;
	const char *id=NULL;
	for (j = 0; j < i; j++)
	{
		id=lt_int_dyld_lib_install_name(_dyld_get_image_header(j));
		if ((id) && (!strcmp(id,name)))
		{
			mh=_dyld_get_image_header(j);
			break;
		}
	}
	return mh;
}

static NSSymbol
lt_int_dyld_NSlookupSymbolInLinkedLibs(symbol,mh)
	const char *symbol;
	const struct mach_header *mh;
{
	/* Safe to assume our mh is good */
	int j;
	struct load_command *lc;
	unsigned long offset = sizeof(struct mach_header);
	NSSymbol retSym = 0;
	const struct mach_header *mh1;
	if ((ltdl_NSLookupSymbolInImage) && NSIsSymbolNameDefined(symbol) )
	{
		for (j = 0; j < mh->ncmds; j++)
		{
			lc = (struct load_command*)(((unsigned long)mh) + offset);
			if ((LC_LOAD_DYLIB == lc->cmd) || (LC_LOAD_WEAK_DYLIB == lc->cmd))
			{
				mh1=lt_int_dyld_match_loaded_lib_by_install_name((char*)(((struct dylib_command*)lc)->dylib.name.offset +
										(unsigned long)lc));
				if (!mh1)
				{
					/* Maybe NSAddImage can find it */
					mh1=ltdl_NSAddImage((char*)(((struct dylib_command*)lc)->dylib.name.offset +
										(unsigned long)lc),
										NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED +
										NSADDIMAGE_OPTION_WITH_SEARCHING +
										NSADDIMAGE_OPTION_RETURN_ON_ERROR );
				}
				if (mh1)
				{
					retSym = ltdl_NSLookupSymbolInImage(mh1,
											symbol,
											NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW
											| NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR
											);
					if (retSym) break;
				}
			}
			offset += lc->cmdsize;
		}
	}
	return retSym;
}

static int
sys_dyld_init()
{
	int retCode = 0;
	int err = 0;
	if (!_dyld_present()) {
		retCode=1;
	}
	else {
      err = _dyld_func_lookup("__dyld_NSAddImage",(unsigned long*)&ltdl_NSAddImage);
      err = _dyld_func_lookup("__dyld_NSLookupSymbolInImage",(unsigned long*)&ltdl_NSLookupSymbolInImage);
      err = _dyld_func_lookup("__dyld_NSIsSymbolNameDefinedInImage",(unsigned long*)&ltdl_NSIsSymbolNameDefinedInImage);
      err = _dyld_func_lookup("__dyld_NSMakePrivateModulePublic",(unsigned long*)&ltdl_NSMakePrivateModulePublic);
    }
 return retCode;
}

static lt_module
sys_dyld_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
	lt_module   module   = 0;
	NSObjectFileImage ofi = 0;
	NSObjectFileImageReturnCode ofirc;

  	if (!filename)
  		return (lt_module)-1;
	ofirc = NSCreateObjectFileImageFromFile(filename, &ofi);
	switch (ofirc)
	{
		case NSObjectFileImageSuccess:
			module = NSLinkModule(ofi, filename,
						NSLINKMODULE_OPTION_RETURN_ON_ERROR
						 | NSLINKMODULE_OPTION_PRIVATE
						 | NSLINKMODULE_OPTION_BINDNOW);
			NSDestroyObjectFileImage(ofi);
			if (module)
				ltdl_NSMakePrivateModulePublic(module);
			break;
		case NSObjectFileImageInappropriateFile:
		    if (ltdl_NSIsSymbolNameDefinedInImage && ltdl_NSLookupSymbolInImage)
		    {
				module = (lt_module)ltdl_NSAddImage(filename, NSADDIMAGE_OPTION_RETURN_ON_ERROR);
				break;
			}
		default:
			LT_DLMUTEX_SETERROR (lt_int_dyld_error(LT_DLSTRERROR(CANNOT_OPEN)));
			return 0;
	}
	if (!module) LT_DLMUTEX_SETERROR (lt_int_dyld_error(LT_DLSTRERROR(CANNOT_OPEN)));
  return module;
}

static int
sys_dyld_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
	int retCode = 0;
	int flags = 0;
	if (module == (lt_module)-1) return 0;
#ifdef __BIG_ENDIAN__
  	if (((struct mach_header *)module)->magic == MH_MAGIC)
#else
    if (((struct mach_header *)module)->magic == MH_CIGAM)
#endif
	{
	  LT_DLMUTEX_SETERROR("Can not close a dylib");
	  retCode = 1;
	}
	else
	{
#if 1
/* Currently, if a module contains c++ static destructors and it is unloaded, we
   get a segfault in atexit(), due to compiler and dynamic loader differences of
   opinion, this works around that.
*/
		if ((const struct section *)NULL !=
		   getsectbynamefromheader(lt_int_dyld_get_mach_header_from_nsmodule(module),
		   "__DATA","__mod_term_func"))
		{
			flags += NSUNLINKMODULE_OPTION_KEEP_MEMORY_MAPPED;
		}
#endif
#ifdef __ppc__
			flags += NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES;
#endif
		if (!NSUnLinkModule(module,flags))
		{
			retCode=1;
			LT_DLMUTEX_SETERROR (lt_int_dyld_error(LT_DLSTRERROR(CANNOT_CLOSE)));
		}
	}

 return retCode;
}

static lt_ptr
sys_dyld_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
	lt_ptr address = 0;
  	NSSymbol *nssym = 0;
  	void *unused;
  	const struct mach_header *mh=NULL;
  	char saveError[256] = "Symbol not found";
  	if (module == (lt_module)-1)
  	{
  		_dyld_lookup_and_bind(symbol,(unsigned long*)&address,&unused);
  		return address;
  	}
#ifdef __BIG_ENDIAN__
  	if (((struct mach_header *)module)->magic == MH_MAGIC)
#else
    if (((struct mach_header *)module)->magic == MH_CIGAM)
#endif
  	{
  	    if (ltdl_NSIsSymbolNameDefinedInImage && ltdl_NSLookupSymbolInImage)
  	    {
  	    	mh=module;
			if (ltdl_NSIsSymbolNameDefinedInImage((struct mach_header*)module,symbol))
			{
				nssym = ltdl_NSLookupSymbolInImage((struct mach_header*)module,
											symbol,
											NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW
											| NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR
											);
			}
	    }

  	}
  else {
	nssym = NSLookupSymbolInModule(module, symbol);
	}
	if (!nssym)
	{
		strncpy(saveError, lt_int_dyld_error(LT_DLSTRERROR(SYMBOL_NOT_FOUND)), 255);
		saveError[255] = 0;
		if (!mh) mh=lt_int_dyld_get_mach_header_from_nsmodule(module);
		nssym = lt_int_dyld_NSlookupSymbolInLinkedLibs(symbol,mh);
	}
	if (!nssym)
	{
		LT_DLMUTEX_SETERROR (saveError);
		return NULL;
	}
	return NSAddressOfSymbol(nssym);
}

static struct lt_user_dlloader sys_dyld =
  { "_", sys_dyld_open, sys_dyld_close, sys_dyld_sym, 0, 0 };


#endif /* HAVE_DYLD */


/* --- DLPREOPEN() INTERFACE LOADER --- */


/* emulate dynamic linking using preloaded_symbols */

typedef struct lt_dlsymlists_t
{
  struct lt_dlsymlists_t       *next;
  const lt_dlsymlist	       *syms;
} lt_dlsymlists_t;

static	const lt_dlsymlist     *default_preloaded_symbols	= 0;
static	lt_dlsymlists_t	       *preloaded_symbols		= 0;

static int
presym_init (loader_data)
     lt_user_data loader_data;
{
  int errors = 0;

  LT_DLMUTEX_LOCK ();

  preloaded_symbols = 0;
  if (default_preloaded_symbols)
    {
      errors = lt_dlpreload (default_preloaded_symbols);
    }

  LT_DLMUTEX_UNLOCK ();

  return errors;
}

static int
presym_free_symlists ()
{
  lt_dlsymlists_t *lists;

  LT_DLMUTEX_LOCK ();

  lists = preloaded_symbols;
  while (lists)
    {
      lt_dlsymlists_t	*tmp = lists;

      lists = lists->next;
      LT_DLFREE (tmp);
    }
  preloaded_symbols = 0;

  LT_DLMUTEX_UNLOCK ();

  return 0;
}

static int
presym_exit (loader_data)
     lt_user_data loader_data;
{
  presym_free_symlists ();
  return 0;
}

static int
presym_add_symlist (preloaded)
     const lt_dlsymlist *preloaded;
{
  lt_dlsymlists_t *tmp;
  lt_dlsymlists_t *lists;
  int		   errors   = 0;

  LT_DLMUTEX_LOCK ();

  lists = preloaded_symbols;
  while (lists)
    {
      if (lists->syms == preloaded)
	{
	  goto done;
	}
      lists = lists->next;
    }

  tmp = LT_EMALLOC (lt_dlsymlists_t, 1);
  if (tmp)
    {
      memset (tmp, 0, sizeof(lt_dlsymlists_t));
      tmp->syms = preloaded;
      tmp->next = preloaded_symbols;
      preloaded_symbols = tmp;
    }
  else
    {
      ++errors;
    }

 done:
  LT_DLMUTEX_UNLOCK ();
  return errors;
}

static lt_module
presym_open (loader_data, filename)
     lt_user_data loader_data;
     const char *filename;
{
  lt_dlsymlists_t *lists;
  lt_module	   module = (lt_module) 0;

  LT_DLMUTEX_LOCK ();
  lists = preloaded_symbols;

  if (!lists)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (NO_SYMBOLS));
      goto done;
    }

  /* Can't use NULL as the reflective symbol header, as NULL is
     used to mark the end of the entire symbol list.  Self-dlpreopened
     symbols follow this magic number, chosen to be an unlikely
     clash with a real module name.  */
  if (!filename)
    {
      filename = "@PROGRAM@";
    }

  while (lists)
    {
      const lt_dlsymlist *syms = lists->syms;

      while (syms->name)
	{
	  if (!syms->address && strcmp(syms->name, filename) == 0)
	    {
	      module = (lt_module) syms;
	      goto done;
	    }
	  ++syms;
	}

      lists = lists->next;
    }

  LT_DLMUTEX_SETERROR (LT_DLSTRERROR (FILE_NOT_FOUND));

 done:
  LT_DLMUTEX_UNLOCK ();
  return module;
}

static int
presym_close (loader_data, module)
     lt_user_data loader_data;
     lt_module module;
{
  /* Just to silence gcc -Wall */
  module = 0;
  return 0;
}

static lt_ptr
presym_sym (loader_data, module, symbol)
     lt_user_data loader_data;
     lt_module module;
     const char *symbol;
{
  lt_dlsymlist *syms = (lt_dlsymlist*) module;

  ++syms;
  while (syms->address)
    {
      if (strcmp(syms->name, symbol) == 0)
	{
	  return syms->address;
	}

    ++syms;
  }

  LT_DLMUTEX_SETERROR (LT_DLSTRERROR (SYMBOL_NOT_FOUND));

  return 0;
}

static struct lt_user_dlloader presym = {
  0, presym_open, presym_close, presym_sym, presym_exit, 0
};





/* --- DYNAMIC MODULE LOADING --- */


/* The type of a function used at each iteration of  foreach_dirinpath().  */
typedef int	foreach_callback_func LT_PARAMS((char *filename, lt_ptr data1,
						 lt_ptr data2));

static	int	foreach_dirinpath     LT_PARAMS((const char *search_path,
						 const char *base_name,
						 foreach_callback_func *func,
						 lt_ptr data1, lt_ptr data2));

static	int	find_file_callback    LT_PARAMS((char *filename, lt_ptr data,
						 lt_ptr ignored));
static	int	find_handle_callback  LT_PARAMS((char *filename, lt_ptr data,
						 lt_ptr ignored));
static	int	foreachfile_callback  LT_PARAMS((char *filename, lt_ptr data1,
						 lt_ptr data2));


static	int     canonicalize_path     LT_PARAMS((const char *path,
						 char **pcanonical));
static	int	argzize_path 	      LT_PARAMS((const char *path,
						 char **pargz,
						 size_t *pargz_len));
static	FILE   *find_file	      LT_PARAMS((const char *search_path,
						 const char *base_name,
						 char **pdir));
static	lt_dlhandle *find_handle      LT_PARAMS((const char *search_path,
						 const char *base_name,
						 lt_dlhandle *handle));
static	int	find_module	      LT_PARAMS((lt_dlhandle *handle,
						 const char *dir,
						 const char *libdir,
						 const char *dlname,
						 const char *old_name,
						 int installed));
static	int	free_vars	      LT_PARAMS((char *dlname, char *oldname,
						 char *libdir, char *deplibs));
static	int	load_deplibs	      LT_PARAMS((lt_dlhandle handle,
						 char *deplibs));
s…