autoconf: Warn a user if no asciidoc/xmlto found

It's been noticed on nasm forum that we don't complain
if no asciidoc/xmlto package installed on a system while
they are required for man pages generation.

So warn a user then, but still allow to build nasm.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

diff --git a/configure.in b/configure.in
index da2154d..8571973 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -74,6 +74,14 @@ AC_CHECK_PROGS(ACRODIST, acrodist, false)
 AC_CHECK_PROGS(PS2PDF,   ps2pdf,   false)
 AC_CHECK_PROGS(PSTOPDF,  pstopdf,  false)
 
+dnl Check for progs needed for manpage generation
+if test $ASCIIDOC = false; then
+  AC_MSG_WARN([No acsciidoc package found])
+fi
+if test $XMLTO = false; then
+  AC_MSG_WARN([No xmlto package found])
+fi
+
 dnl Checks for header files.
 AC_HEADER_STDC
 if test $ac_cv_header_stdc = no; then