1 files changed, 54 insertions, 0 deletions
diff --git a/m4/dl.m4 b/m4/dl.m4
new file mode 100644
index 000000000..ff3fc71d5
--- /dev/null
+++ b/m4/dl.m4
@@ -0,0 +1,54 @@
+dnl
+dnl Check for dlopen symbol and set DYNAMIC_LD_LIBS.
+dnl
+dnl AM_DL()
+dnl
+
+AC_DEFUN([AM_DL], [
+  AC_CHECK_LIB(c, dlopen,
+   [DYNAMIC_LD_LIBS=""
+    have_dl=yes])
+
+  if test x$have_dl != "xyes"; then
+    AC_CHECK_LIB(dl, dlopen,
+     [DYNAMIC_LD_LIBS="-ldl"
+      have_dl=yes])
+  fi
+
+  if test x$have_dl != "xyes"; then
+    AC_MSG_CHECKING(for dlopen under win32)
+    AC_LANG_SAVE()
+    AC_LANG_C()
+
+    ac_save_CPPFLAGS="$CPPFLAGS"
+    ac_save_LIBS="$LIBS"
+    CPPFLAGS="-I${srcdir}/win32/include $CPPFLAGS"
+    LIBS="$LIBS -lkernel32"
+    AC_COMPILE_IFELSE([
+#include <stddef.h>
+#include <dlfcn.h>
+
+int main() {
+  dlopen(NULL, 0);
+  return 0;
+}
+], 
+      [DYNAMIC_LD_LIBS=-lkernel32
+       have_dl=yes
+       AC_MSG_RESULT(yes)],
+       AC_MSG_RESULT(no)
+    )
+
+    CPPFLAGS=$ac_save_CPPFLAGS
+    LIBS=$ac_save_LIBS
+
+    AC_LANG_RESTORE()
+  fi
+
+  if test x$have_dl != "xyes"; then
+    AC_MSG_ERROR(dynamic linker needed)
+  fi
+
+  AC_SUBST(DYNAMIC_LD_LIBS)
+
+])