ltdl.c

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 * 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;

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