Improve the checks for where to find ndbm (dbm_open etc); should now

[mmh] / aclocal.m4

diff --git a/aclocal.m4 b/aclocal.m4
index 7dd6110..c9362ec 100644 (file)
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -19,3 +19,68 @@ AC_DEFUN(AC_CHECK_NETLIBS,
 AC_CHECK_FUNC(socket, ,
   AC_CHECK_LIB(socket, socket))
 ])
+
+dnl --------------
+dnl CHECK FOR NDBM
+dnl --------------
+dnl
+dnl NMH_CHECK_DBM(libname,action-if-true,action-if-false,other-libraries)
+dnl Check for presence of dbm_open() in the specified library
+dnl (if libname is the empty string then don't try to link against
+dnl any particular library). If action-if-true is unspecified it
+dnl defaults to adding "-llibname" to the beginning of LIBS.
+dnl If other-libraries is specified then these are prepended to
+dnl LIBS for the duration of the check.
+dnl NB that the checks for the right dbm header files must
+dnl be done before using this macro!
+dnl
+dnl We try to link our own code fragment (which includes the
+dnl headers in the same way slocal.c does) rather than
+dnl using AC_CHECK_LIB because on later versions of libdb
+dnl the dbm_open() function is provided via a #define and
+dnl we don't want to hardcode searching for the internal
+dnl function that lies behind it. (AC_CHECK_LIB works by
+dnl defining its own bogus prototype rather than pulling in
+dnl the right header files.)
+AC_DEFUN(NMH_CHECK_DBM,
+[
+if test "x$1" == "x"; then
+   nmh_libs=
+   dnl this is just for the benefit of AC_CACHE_CHECK's message
+   nmh_testname=libc
+else
+   nmh_libs="-l$1 "
+   nmh_testname="$1"
+fi
+AC_CACHE_CHECK([for dbm in $nmh_testname], [nmh_cv_check_dbm_$1],[
+nmh_saved_libs="$LIBS"
+LIBS="$nmh_libs $4 $LIBS"
+AC_LINK_IFELSE(AC_LANG_PROGRAM([[
+#ifdef HAVE_DB1_NDBM_H
+#include <db1/ndbm.h>
+#else
+#ifdef HAVE_GDBM_NDBM_H
+#include <gdbm/ndbm.h>
+#else
+#if defined(HAVE_DB_H)
+#define DB_DBM_HSEARCH 1
+#include <db.h>
+#else
+#include <ndbm.h>
+#endif
+#endif
+#endif
+]],
+[[dbm_open("",0,0);]]),[nmh_cv_check_dbm_$1=yes],[
+nmh_cv_check_dbm_$1=no])
+LIBS="$nmh_saved_libs"
+])
+if eval "test \"`echo '$nmh_cv_check_dbm_'$1`\" = yes"; then
+  nmh_tr_macro=HAVE_LIB`echo $1 | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
+  AC_DEFINE_UNQUOTED($nmh_tr_macro)
+  m4_if([$2],,[LIBS="$nmh_libs$LIBS"],[$2])
+else
+  $3
+  :
+fi
+])dnl