[patch bfd]: Fix PR ld/12742 for windows targets

[Kai Tietz <ktietz70 at googlemail dot com>]

Hi,

this patch adds compatible implementation of dlfcn API on Windows
targets, if this header/API isn't present.

ChangeLog

2012-03-09  Kai Tietz  <ktietz@redhat.com>

	PR ld/12742
	* configure.in (AC_CHECK_HEADERS): Test for windows.h and dlfcn.h.
	* plugin.c: Guard include of dlfcn.h if HAVE_DLFCN_H is defined.
	Add windows.h header include if HAVE_WINDOWS_H is defined.
	(dlerror): New static function if windows variant is used instead
	of dlfcn.h.
	(dlclose): Likewise.
	(dlopen): Likewise.
	(dlsym): Likewise.
	* configure: Regenerated.
	* config.in: Regenerated.

Tested for i686-w64-mingw32 and x86_64-w64-mingw32.  Ok for apply?

Regards,
Kai

Index: config.in
===================================================================
RCS file: /cvs/src/src/bfd/config.in,v
retrieving revision 1.49
diff -u -p -r1.49 config.in
--- config.in	12 May 2011 07:41:40 -0000	1.49
+++ config.in	9 Mar 2012 19:38:18 -0000
@@ -245,6 +245,9 @@
 /* Define if <sys/procfs.h> has win32_pstatus_t. */
 #undef HAVE_WIN32_PSTATUS_T

+/* Define to 1 if you have the <windows.h> header file. */
+#undef HAVE_WINDOWS_H
+
 /* Define to 1 if you have the <zlib.h> header file. */
 #undef HAVE_ZLIB_H

Index: configure
===================================================================
RCS file: /cvs/src/src/bfd/configure,v
retrieving revision 1.359
diff -u -p -r1.359 configure
--- configure	25 Feb 2012 19:51:31 -0000	1.359
+++ configure	9 Mar 2012 19:38:21 -0000
@@ -13508,6 +13508,22 @@ fi

 fi

+
+for ac_header in windows.h dlfcn.h
+do :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header"
"$ac_includes_default"
+eval as_val=\$$as_ac_Header
+   if test "x$as_val" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether string.h
and strings.h may both be included" >&5
 $as_echo_n "checking whether string.h and strings.h may both be
included... " >&6; }
 if test "${gcc_cv_header_string+set}" = set; then :
Index: configure.in
===================================================================
RCS file: /cvs/src/src/bfd/configure.in,v
retrieving revision 1.307
diff -u -p -r1.307 configure.in
--- configure.in	25 Feb 2012 19:51:32 -0000	1.307
+++ configure.in	9 Mar 2012 19:38:21 -0000
@@ -190,6 +190,9 @@ AC_CHECK_HEADERS(fcntl.h sys/file.h sys/
 GCC_HEADER_STDINT(bfd_stdint.h)
 AC_HEADER_TIME
 AC_HEADER_DIRENT
+
+AC_CHECK_HEADERS(windows.h dlfcn.h)
+
 ACX_HEADER_STRING
 AC_CHECK_FUNCS(fcntl getpagesize setitimer sysconf fdopen getuid getgid fileno)
 AC_CHECK_FUNCS(strtoull)
Index: plugin.c
===================================================================
RCS file: /cvs/src/src/bfd/plugin.c,v
retrieving revision 1.14
diff -u -p -r1.14 plugin.c
--- plugin.c	11 Jul 2011 15:03:07 -0000	1.14
+++ plugin.c	9 Mar 2012 19:38:22 -0000
@@ -25,7 +25,13 @@
 #if BFD_SUPPORTS_PLUGINS

 #include <assert.h>
+#ifdef HAVE_DLFCN_H
 #include <dlfcn.h>
+#elif defined (HAVE_WINDOWS_H)
+#include <windows.h>
+#else
+#error Unknown how to handle dynamic-load-libraries.
+#endif
 #include <stdarg.h>
 #include "plugin-api.h"
 #include "sysdep.h"
@@ -34,6 +40,37 @@
 #include "libiberty.h"
 #include <dirent.h>

+#if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
+
+#define RTLD_NOW 0      /* Dummy value.  */
+
+static void *
+dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
+{
+  return LoadLibrary (file);
+}
+
+static void *
+dlsym (void *handle, const char *name)
+{
+  return GetProcAddress (handle, name);
+}
+
+static int ATTRIBUTE_UNUSED
+dlclose (void *handle)
+{
+  FreeLibrary (handle);
+  return 0;
+}
+
+static const char *
+dlerror (void)
+{
+  return "Unable to load DLL.";
+}
+
+#endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */
+
 #define bfd_plugin_close_and_cleanup
_bfd_generic_close_and_cleanup
 #define bfd_plugin_bfd_free_cached_info
_bfd_generic_bfd_free_cached_info
 #define bfd_plugin_new_section_hook
_bfd_generic_new_section_hook