On Mac OS X try .dylib as well as .so with lt_dlopenext

* libltdl/m4/ltdl.m4: Define extra extension if module extension
differs from shared lib extension.
* libltdl/ltdl.c: Use it.
* tests/darwin.at: Test it.
* NEWS: Announce it.
Reported by Hans Aberg, Michael Ellis, and others.

ChangeLog

@@ -1,3 +1,13 @@
+2011-03-04  Peter O'Gorman  <peter@pogma.com>
+
+	On Mac OS X try .dylib as well as .so with lt_dlopenext
+	* libltdl/m4/ltdl.m4: Define extra extension if module extension
+	differs from shared lib extension.
+	* libltdl/ltdl.c: Use it.
+	* tests/darwin.at: Test it.
+	* NEWS: Announce it.
+	Reported by Hans Aberg, Michael Ellis, and others.
+
 2011-02-12  Peter O'Gorman  <peter@pogma.com>
 
 	Install ltmain.sh without execute bit set.

NEWS

@@ -10,6 +10,9 @@ New in 2.4.2 2011-??-??: git version 2.4.1a, Libtool team:
 
   - Initial support for Go, using the gccgo compiler.
 
+  - On Mac OS X .dylib is now tried as well as .so with
+    lt_dlopenext().
+
 * Bug fixes:
 
   - The generic approximation of the command line length limit (when getconf is

libltdl/ltdl.c

@@ -1,7 +1,7 @@
 /* ltdl.c -- system independent dlopen wrapper
 
    Copyright (C) 1998, 1999, 2000, 2004, 2005, 2006,
-		 2007, 2008 Free Software Foundation, Inc.
+		 2007, 2008, 2011 Free Software Foundation, Inc.
    Written by Thomas Tanner, 1998
 
    NOTE: The canonical source of this file is maintained with the
@@ -80,6 +80,11 @@ static  const char	libprefix[]		= LT_LIBPREFIX;
 #if defined(LT_MODULE_EXT)
 static	const char	shlib_ext[]		= LT_MODULE_EXT;
 #endif
+/* If the loadable module suffix is not the same as the linkable
+ * shared library suffix, this will be defined. */
+#if defined(LT_SHARED_EXT)
+static	const char	shared_ext[]		= LT_SHARED_EXT;
+#endif
 #if defined(LT_DLSEARCH_PATH)
 static	const char	sys_dlsearch_path[]	= LT_DLSEARCH_PATH;
 #endif
@@ -1536,6 +1541,9 @@ has_library_ext (const char *filename)
   if (ext && ((streq (ext, archive_ext))
 #if defined(LT_MODULE_EXT)
 	     || (streq (ext, shlib_ext))
+#endif
+#if defined(LT_SHARED_EXT)
+	     || (streq (ext, shared_ext))
 #endif
     ))
     {
@@ -1682,6 +1690,17 @@ lt_dlopenadvise (const char *filename, lt_dladvise advise)
       if (handle || ((errors > 0) && !file_not_found ()))
 	return handle;
 #endif
+
+#if defined(LT_SHARED_EXT)
+      /* Try appending SHARED_EXT.   */
+      LT__SETERRORSTR (saved_error);
+      errors = try_dlopen (&handle, filename, shared_ext, advise);
+
+      /* As before, if the file was found but loading failed, return now
+	 with the current error message.  */
+      if (handle || ((errors > 0) && !file_not_found ()))
+	return handle;
+#endif
     }
 
   /* Still here?  Then we really did fail to locate any of the file

libltdl/m4/ltdl.m4

@@ -1,6 +1,6 @@
 # ltdl.m4 - Configure ltdl for the target system. -*-Autoconf-*-
 #
-#   Copyright (C) 1999-2006, 2007, 2008 Free Software Foundation, Inc.
+#   Copyright (C) 1999-2006, 2007, 2008, 2011 Free Software Foundation, Inc.
 #   Written by Thomas Tanner, 1999
 #
 # This file is free software; the Free Software Foundation gives
@@ -553,12 +553,19 @@ AC_CACHE_CHECK([which extension is used for runtime loadable modules],
 [
 module=yes
 eval libltdl_cv_shlibext=$shrext_cmds
+module=no
+eval libltdl_cv_shrext=$shrext_cmds
   ])
 if test -n "$libltdl_cv_shlibext"; then
   m4_pattern_allow([LT_MODULE_EXT])dnl
   AC_DEFINE_UNQUOTED([LT_MODULE_EXT], ["$libltdl_cv_shlibext"],
     [Define to the extension used for runtime loadable modules, say, ".so".])
 fi
+if test "$libltdl_cv_shrext" != "$libltdl_cv_shlibext"; then
+  m4_pattern_allow([LT_SHARED_EXT])dnl
+  AC_DEFINE_UNQUOTED([LT_SHARED_EXT], ["$libltdl_cv_shrext"],
+    [Define to the shared library suffix, say, ".dylib".])
+fi
 ])# LT_SYS_MODULE_EXT
 
 # Old name:

tests/darwin.at

@@ -228,3 +228,219 @@ mv stdout expout
 LT_AT_CONFIGURE([LDFLAGS=-L/there/is/no/dir/here])
 AT_CHECK([./libtool --config],[ignore],[expout],[ignore])
 AT_CLEANUP
+
+AT_SETUP([darwin can lt_dlopen .dylib and .so files])
+
+AT_KEYWORDS([libltdl dylib])
+
+# This test requires shared library support.
+AT_CHECK([$LIBTOOL --features | grep 'enable shared libraries' || exit 77],
+	 [], [ignore])
+
+eval `$LIBTOOL --config | $EGREP '^shrext_cmds='`
+
+module=no
+eval shared_ext=\"$shrext_cmds\"
+module=yes
+eval module_ext=\"$shrext_cmds\"
+
+# Only bother with this test if module extension is different from
+# shared extension
+AT_CHECK([test "$shared_ext" != "$module_ext" || exit 77])
+
+# Skip this test when called from:
+#    make distcheck DISTCHECK_CONFIGURE_FLAGS=--disable-ltdl-install
+AT_CHECK([case $LIBLTDL in #(
+ */_inst/lib/*) test -f $LIBLTDL || (exit 77) ;;
+esac], [], [ignore])
+
+prefix=`pwd`/inst
+libdir=$prefix/lib
+bindir=$prefix/bin
+mkdir $prefix $libdir $bindir
+
+# This code is copied from the Autobook:
+# <http://sources.redhat.com/autobook/autobook/autobook_169.html>
+# so if it needs changes, be sure to notify the Autobook authors
+# about them.
+
+AT_DATA([simple-module.c],
+[[
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C"
+#endif
+int
+run (const char *argument)
+{
+  printf ("Hello, %s!\n", argument);
+  return 0;
+}
+]])
+
+AT_DATA([ltdl-loader.c],
+[[
+#include <stdio.h>
+#include <stdlib.h>
+#ifndef EXIT_FAILURE
+#  define EXIT_FAILURE        1
+#  define EXIT_SUCCESS        0
+#endif
+
+#include <limits.h>
+#ifndef PATH_MAX
+#  define PATH_MAX 255
+#endif
+
+#include <string.h>
+#include <ltdl.h>
+
+#ifndef MODULE_PATH_ENV
+#  define MODULE_PATH_ENV        "MODULE_PATH"
+#endif
+
+typedef int entrypoint (const char *argument);
+
+/* Save and return a copy of the dlerror() error  message,
+   since the next API call may overwrite the original. */
+static char *dlerrordup (char *errormsg);
+
+int
+main (int argc, const char *argv[])
+{
+  char *errormsg = NULL;
+  lt_dlhandle module = NULL;
+  entrypoint *run = NULL;
+  int errors = 0;
+
+  if (argc != 3)
+    {
+      fprintf (stderr, "USAGE: main MODULENAME ARGUMENT\n");
+      exit (EXIT_FAILURE);
+    }
+
+  /* Initialise libltdl. */
+  errors = lt_dlinit ();
+
+  /* Set the module search path. */
+  if (!errors)
+    {
+      const char *path = getenv (MODULE_PATH_ENV);
+
+      if (path != NULL)
+        errors = lt_dlsetsearchpath (path);
+    }
+
+  /* Load the module. */
+  if (!errors)
+    module = lt_dlopenext (argv[1]);
+
+  /* Find the entry point. */
+  if (module)
+    {
+      run = (entrypoint *) lt_dlsym (module, "run");
+
+      /* In principle, run might legitimately be NULL, so
+         I don't use run == NULL as an error indicator
+         in general. */
+      errormsg = dlerrordup (errormsg);
+      if (errormsg != NULL)
+        {
+          errors = lt_dlclose (module);
+          module = NULL;
+        }
+    }
+  else
+    errors = 1;
+
+  /* Call the entry point function. */
+  if (!errors)
+    {
+      int result = (*run) (argv[2]);
+      if (result < 0)
+        errormsg = strdup ("module entry point execution failed");
+      else
+        printf ("\t=> %d\n", result);
+    }
+
+  /* Unload the module, now that we are done with it. */
+  if (!errors)
+    errors = lt_dlclose (module);
+
+  if (errors)
+    {
+      /* Diagnose the encountered error. */
+      errormsg = dlerrordup (errormsg);
+
+      if (!errormsg)
+        {
+          fprintf (stderr, "%s: dlerror() failed.\n", argv[0]);
+          return EXIT_FAILURE;
+        }
+    }
+
+  /* Finished with ltdl now. */
+  if (!errors)
+    if (lt_dlexit () != 0)
+      errormsg = dlerrordup (errormsg);
+
+  if (errormsg)
+    {
+      fprintf (stderr, "%s: %s.\n", argv[0], errormsg);
+      free (errormsg);
+      exit (EXIT_FAILURE);
+    }
+
+  return EXIT_SUCCESS;
+}
+
+/* Be careful to save a copy of the error message,
+   since the  next API call may overwrite the original. */
+static char *
+dlerrordup (char *errormsg)
+{
+  char *error = (char *) lt_dlerror ();
+  if (error && !errormsg)
+    errormsg = strdup (error);
+  return errormsg;
+}
+]])
+
+: ${LTDLINCL="-I$abs_top_srcdir/libltdl"}
+: ${LIBLTDL="$abs_builddir/../libltdl/libltdlc.la"}
+
+CPPFLAGS="$LTDLINCL $CPPFLAGS"
+LDFLAGS="$LDFLAGS -no-undefined"
+
+AT_CHECK([$LIBTOOL --mode=compile $CC $CPPFLAGS $CFLAGS -c simple-module.c],
+	 [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=link $CC $CFLAGS $LDFLAGS -o simple-module.la ]dnl
+	 [simple-module.lo -rpath $libdir -module -avoid-version],
+	 [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=link $CC $CFLAGS $LDFLAGS -o libsimple-dylib.la ]dnl
+	 [simple-module.lo -rpath $libdir -avoid-version],
+	 [], [ignore], [ignore])
+AT_CHECK([$CC $CPPFLAGS $CFLAGS -c ltdl-loader.c],
+	 [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=link $CC $CFLAGS $LDFLAGS -o ltdl-loader$EXEEXT ]dnl
+	 [ltdl-loader.$OBJEXT -dlopen self $LIBLTDL],
+	 [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=install cp simple-module.la $libdir/simple-module.la], [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=install cp libsimple-dylib.la $libdir/libsimple-dylib.la], [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=clean rm -f simple-module.la], [], [ignore], [ignore])
+AT_CHECK([$LIBTOOL --mode=clean rm -f libsimple-dylib.la], [], [ignore], [ignore])
+
+rm $libdir/simple-module.la
+rm $libdir/libsimple-dylib.la
+
+for dir in inst/lib "$libdir"; do
+  LT_AT_EXEC_CHECK([./ltdl-loader], [], [stdout], [ignore],
+	    [$dir/simple-module World])
+  AT_CHECK([grep "Hello, World" stdout], [], [ignore])
+  LT_AT_EXEC_CHECK([./ltdl-loader], [], [stdout], [ignore],
+	    [$dir/libsimple-dylib World])
+  AT_CHECK([grep "Hello, World" stdout], [], [ignore])
+done
+
+AT_CLEANUP