Replace -ldl with @lt_cv_dlopen_libs@

https://sourceware.org/cgi-bin/cvsweb.cgi/src/bfd/Makefile.am.diff?r1=1.265&r2=1.266&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/bfd/configure.in.diff?r1=1.319&r2=1.320&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/bfd/Makefile.in.diff?r1=1.294&r2=1.295&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/bfd/configure.diff?r1=1.373&r2=1.374&cvsroot=src

Fix mingw gold build with plugins enabled
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/Makefile.am.diff?r1=1.69&r2=1.70&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/configure.ac.diff?r1=1.83&r2=1.84&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/plugin.cc.diff?r1=1.55&r2=1.56&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/Makefile.in.diff?r1=1.97&r2=1.98&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/config.in.diff?r1=1.36&r2=1.37&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/configure.diff?r1=1.85&r2=1.86&cvsroot=src
https://sourceware.org/cgi-bin/cvsweb.cgi/src/gold/testsuite/Makefile.in.diff?r1=1.215&r2=1.216&cvsroot=src


===================================================================
RCS file: /cvs/src/src/bfd/Makefile.am,v
retrieving revision 1.265
retrieving revision 1.266
diff -u -r1.265 -r1.266
--- src/bfd/Makefile.am	2012/08/13 14:52:33	1.265
+++ src/bfd/Makefile.am	2012/10/13 14:17:10	1.266
@@ -35,7 +35,7 @@
 AM_CPPFLAGS = -DBINDIR='"$(bindir)"'
 if PLUGINS
 bfdinclude_HEADERS += $(INCDIR)/plugin-api.h
-LIBDL = -ldl
+LIBDL = @lt_cv_dlopen_libs@
 endif
 
 # bfd.h goes here, for now
===================================================================
RCS file: /cvs/src/src/bfd/configure.in,v
retrieving revision 1.319
retrieving revision 1.320
diff -u -r1.319 -r1.320
--- src/bfd/configure.in	2012/09/13 22:24:49	1.319
+++ src/bfd/configure.in	2012/10/13 14:17:14	1.320
@@ -1100,6 +1100,7 @@
   supports_plugins=0
 fi
 AC_SUBST(supports_plugins)
+AC_SUBST(lt_cv_dlopen_libs)
 
 # Determine the host dependant file_ptr a.k.a. off_t type.  In order
 # prefer: off64_t - if ftello64 and fseeko64, off_t - if ftello and
===================================================================
RCS file: /cvs/src/src/bfd/Makefile.in,v
retrieving revision 1.294
retrieving revision 1.295
diff -u -r1.294 -r1.295
--- src/bfd/Makefile.in	2012/08/13 14:52:34	1.294
+++ src/bfd/Makefile.in	2012/10/13 14:17:10	1.295
@@ -293,6 +293,7 @@
 libexecdir = @libexecdir@
 localedir = @localedir@
 localstatedir = @localstatedir@
+lt_cv_dlopen_libs = @lt_cv_dlopen_libs@
 mandir = @mandir@
 mkdir_p = @mkdir_p@
 oldincludedir = @oldincludedir@
@@ -336,7 +337,7 @@
 @INSTALL_LIBBFD_FALSE@noinst_LTLIBRARIES = libbfd.la
 AM_CFLAGS = $(WARN_CFLAGS)
 AM_CPPFLAGS = -DBINDIR='"$(bindir)"'
-@PLUGINS_TRUE@LIBDL = -ldl
+@PLUGINS_TRUE@LIBDL = @lt_cv_dlopen_libs@
 
 # bfd.h goes here, for now
 BFD_H = bfd.h
===================================================================
RCS file: /cvs/src/src/bfd/configure,v
retrieving revision 1.373
retrieving revision 1.374
diff -u -r1.373 -r1.374
--- src/bfd/configure	2012/09/14 23:56:47	1.373
+++ src/bfd/configure	2012/10/13 14:17:11	1.374
@@ -606,6 +606,7 @@
 tdefaults
 bfd_ufile_ptr
 bfd_file_ptr
+lt_cv_dlopen_libs
 supports_plugins
 bfd_default_target_size
 bfd_machines
@@ -15633,6 +15634,7 @@
 fi
 
 
+
 # Determine the host dependant file_ptr a.k.a. off_t type.  In order
 # prefer: off64_t - if ftello64 and fseeko64, off_t - if ftello and
 # fseeko, long.  This assumes that sizeof off_t is .ge. sizeof long.
===================================================================
RCS file: /cvs/src/src/gold/Makefile.am,v
retrieving revision 1.69
retrieving revision 1.70
diff -u -r1.69 -r1.70
--- src/gold/Makefile.am	2012/12/17 16:56:02	1.69
+++ src/gold/Makefile.am	2013/01/11 14:36:36	1.70
@@ -37,7 +38,7 @@
 LIBIBERTY = ../libiberty/libiberty.a
 
 if PLUGINS
-LIBDL = -ldl
+LIBDL = @DLOPEN_LIBS@
 endif
 
 if THREADS
===================================================================
RCS file: /cvs/src/src/gold/configure.ac,v
retrieving revision 1.83
retrieving revision 1.84
diff -u -r1.83 -r1.84
--- src/gold/configure.ac	2013/01/07 19:55:41	1.83
+++ src/gold/configure.ac	2013/01/11 14:36:36	1.84
@@ -505,6 +506,13 @@
 AC_CHECK_HEADERS(tr1/unordered_set tr1/unordered_map)
 AC_CHECK_HEADERS(ext/hash_map ext/hash_set)
 AC_CHECK_HEADERS(byteswap.h)
+
+dnl When plugins enabled dynamic loader interface is required. Check headers
+dnl which may provide this interface. In case of dlfcn.h add libdl to link.
+AC_CHECK_HEADERS(windows.h)
+AC_CHECK_HEADERS(dlfcn.h, [DLOPEN_LIBS="-ldl"], [DLOPEN_LIBS=""])
+AC_SUBST(DLOPEN_LIBS)
+
 AC_CHECK_FUNCS(mallinfo posix_fallocate fallocate readv sysconf times)
 AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf, snprintf, vsnprintf, strverscmp, strndup, memmem])
 
===================================================================
RCS file: /cvs/src/src/gold/plugin.cc,v
retrieving revision 1.55
retrieving revision 1.56
diff -u -r1.55 -r1.56
--- src/gold/plugin.cc	2012/08/24 18:35:34	1.55
+++ src/gold/plugin.cc	2013/01/11 14:36:36	1.56
@@ -29,9 +29,39 @@
 #include <vector>
 
 #ifdef ENABLE_PLUGINS
+#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
 
+#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 reinterpret_cast<void *>(
+     GetProcAddress(static_cast<HMODULE>(handle),name));
+}
+
+static const char *
+dlerror(void)
+{
+  return "unable to load dll";
+}
+
+#endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */
+#endif /* ENABLE_PLUGINS */
+
 #include "parameters.h"
 #include "errors.h"
 #include "fileread.h"
===================================================================
RCS file: /cvs/src/src/gold/Makefile.in,v
retrieving revision 1.97
retrieving revision 1.98
diff -u -r1.97 -r1.98
--- src/gold/Makefile.in	2012/12/17 16:56:02	1.97
+++ src/gold/Makefile.in	2013/01/11 14:36:36	1.98
@@ -272,6 +273,7 @@
 DATADIRNAME = @DATADIRNAME@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
+DLOPEN_LIBS = @DLOPEN_LIBS@
 ECHO_C = @ECHO_C@
 ECHO_N = @ECHO_N@
 ECHO_T = @ECHO_T@
@@ -398,7 +400,7 @@
 	-DTOOLLIBDIR="\"$(tooldir)/lib\"" @INCINTL@
 
 LIBIBERTY = ../libiberty/libiberty.a
-@PLUGINS_TRUE@LIBDL = -ldl
+@PLUGINS_TRUE@LIBDL = @DLOPEN_LIBS@
 @THREADS_TRUE@THREADSLIB = -lpthread
 AM_YFLAGS = -d
===================================================================
RCS file: /cvs/src/src/gold/config.in,v
retrieving revision 1.36
retrieving revision 1.37
diff -u -r1.36 -r1.37
--- src/gold/config.in	2012/09/10 22:30:56	1.36
+++ src/gold/config.in	2013/01/11 14:36:36	1.37
@@ -73,6 +73,9 @@
    don't. */
 #undef HAVE_DECL_VSNPRINTF
 
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#undef HAVE_DLFCN_H
+
 /* Define to 1 if you have the <ext/hash_map> header file. */
 #undef HAVE_EXT_HASH_MAP
 
@@ -184,6 +187,9 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
+/* 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
 
===================================================================
RCS file: /cvs/src/src/gold/configure,v
retrieving revision 1.85
retrieving revision 1.86
diff -u -r1.85 -r1.86
--- src/gold/configure	2013/01/07 19:55:41	1.85
+++ src/gold/configure	2013/01/11 14:36:36	1.86
@@ -596,6 +596,7 @@
 MAINTAINER_MODE_TRUE
 HAVE_PUBNAMES_FALSE
 HAVE_PUBNAMES_TRUE
+DLOPEN_LIBS
 CXXCPP
 HAVE_ZLIB_FALSE
 HAVE_ZLIB_TRUE
@@ -7139,6 +7140,35 @@
 
 done
 
+
+for ac_header in windows.h
+do :
+  ac_fn_cxx_check_header_mongrel "$LINENO" "windows.h" "ac_cv_header_windows_h" "$ac_includes_default"
+if test "x$ac_cv_header_windows_h" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_WINDOWS_H 1
+_ACEOF
+
+fi
+
+done
+
+for ac_header in dlfcn.h
+do :
+  ac_fn_cxx_check_header_mongrel "$LINENO" "dlfcn.h" "ac_cv_header_dlfcn_h" "$ac_includes_default"
+if test "x$ac_cv_header_dlfcn_h" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_DLFCN_H 1
+_ACEOF
+ DLOPEN_LIBS="-ldl"
+else
+  DLOPEN_LIBS=""
+fi
+
+done
+
+
+
 for ac_func in mallinfo posix_fallocate fallocate readv sysconf times
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
===================================================================
RCS file: /cvs/src/src/gold/testsuite/Makefile.in,v
retrieving revision 1.215
retrieving revision 1.216
diff -u -r1.215 -r1.216
--- src/gold/testsuite/Makefile.in	2013/01/10 00:18:15	1.215
+++ src/gold/testsuite/Makefile.in	2013/01/11 14:36:36	1.216
@@ -1878,6 +1878,7 @@
 DATADIRNAME = @DATADIRNAME@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
+DLOPEN_LIBS = @DLOPEN_LIBS@
 ECHO_C = @ECHO_C@
 ECHO_N = @ECHO_N@
 ECHO_T = @ECHO_T@