https://bugs.gentoo.org/show_bug.cgi?id=347931

Fix mingw gold build with plugins enabled
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;h=0bf402d505d293fd9ceaa6bf7ca7bd4d910fd545


diff --git a/gold/Makefile.in b/gold/Makefile.in
index 216532a..f12832b 100644
--- a/gold/Makefile.in
+++ b/gold/Makefile.in
@@ -272,6 +273,7 @@ CYGPATH_W = @CYGPATH_W@
 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 @@ AM_CPPFLAGS = \
 	-DTOOLLIBDIR="\"$(tooldir)/lib\"" @INCINTL@
 
 LIBIBERTY = ../libiberty/libiberty.a
-@PLUGINS_TRUE@LIBDL = -ldl
+@PLUGINS_TRUE@LIBDL = @DLOPEN_LIBS@
 @THREADS_TRUE@THREADSLIB = -lpthread
 AM_YFLAGS = -d
 
diff --git a/gold/config.in b/gold/config.in
index 42252bf..d46fd75 100644
--- a/gold/config.in
+++ b/gold/config.in
@@ -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
 
diff --git a/gold/configure b/gold/configure
index 9e1ee27..7e58cdf 100755
--- a/gold/configure
+++ b/gold/configure
@@ -596,6 +596,7 @@ MAINTAINER_MODE_FALSE
 MAINTAINER_MODE_TRUE
 HAVE_PUBNAMES_FALSE
 HAVE_PUBNAMES_TRUE
+DLOPEN_LIBS
 CXXCPP
 HAVE_ZLIB_FALSE
 HAVE_ZLIB_TRUE
@@ -7139,6 +7140,35 @@ fi
 
 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`
diff --git a/gold/plugin.cc b/gold/plugin.cc
index c39e11e..9176e06 100644
--- a/gold/plugin.cc
+++ b/gold/plugin.cc
@@ -1,6 +1,6 @@
 // plugin.cc -- plugin manager for gold      -*- C++ -*-
 
-// Copyright 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
 // Written by Cary Coutant <ccoutant@google.com>.
 
 // This file is part of gold.
@@ -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"
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 6e22934..b2eb352 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -1878,6 +1878,7 @@ CYGPATH_W = @CYGPATH_W@
 DATADIRNAME = @DATADIRNAME@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
+DLOPEN_LIBS = @DLOPEN_LIBS@
 ECHO_C = @ECHO_C@
 ECHO_N = @ECHO_N@
 ECHO_T = @ECHO_T@