configure.ac - allow user to switch off/on documentation generation

Andrian Nord <NightNord@gmail.com>:
>> > > As documentation requires docbook2man to be installed, which is not,
>> > > otherwise, required for proper LXC work or compilation process, it
>> > > might be usefull to be able to switch it off.

Michel Normand <normand@fr.ibm.com>:
> > For me, it is Ok to add a --enable/disable/-doc,
> > but not make configure to fail if no option specified
> > and no docbook2man package.
> >
> > For me it should be optionnal.
> > I like the current behaviour where configure is running without option
> > and is enabling/disabling by itself the doc building.
> > Could you send a new patch with this idea ?

Andrian Nord <NightNord@gmail.com>:
Of course. You mean, that you what default behaviour to remain
auto-detection? That is:
--enable-doc: require docbook2man or fail, generate mans
--enable-doc=auto, or not specified (default): check for docbook2man,
generate mans if found, silently ignore if not found (I suppose
diagnostic message is redundant, as information already contains into
./configure --help)
--disable-doc: never check for docbook2man and don't gen mans

Here comes a patch what do this, as far as I see
(I'm sorry for violating post-rules in previous mail, now I'll do all
right, I hope. Should I attach patch anyway, as it might be usefull
for applying?)

Signed-off-by: Andrian Nord <NightNord@gmail.com>
Acked-by: Michel Normand <normand@fr.ibm.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

diff --git a/configure.ac b/configure.ac
index db348767003151e1d2ac8775cf775d004479d922..e44d40a7933fe0d7b46cce287fa899fe292226f4 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -11,8 +11,20 @@ AC_CANONICAL_HOST
 AM_PROG_CC_C_O
 AC_GNU_SOURCE
 AC_CHECK_PROG(SETCAP, setcap, yes, no, $PATH$PATH_SEPARATOR/sbin)
-AC_CHECK_PROG(DOCBOOK, docbook2man, yes, no)
-AM_CONDITIONAL(ENABLE_DOCBOOK, test x$DOCBOOK = xyes)
+
+AC_ARG_ENABLE([doc],
+       [AC_HELP_STRING([--enable-doc], [make mans (require docbook2man installed) [default=auto]])],
+       [], [enable_doc=auto])
+
+if test "x$enable_doc" = "xyes" -o "x$enable_doc" = "xauto"; then
+       AC_CHECK_PROG(have_docbook, [docbook2man], [yes], [no])
+
+       test "x$have_docbook" = "xno" -a "x$enable_doc" = "xyes" && \
+               AC_MSG_ERROR([docbook2man required by man request, but not found])
+fi
+
+AM_CONDITIONAL([ENABLE_DOCBOOK], [test "x$have_docbook" = "xyes"])
+
 AS_AC_EXPAND(PREFIX, $prefix)
 AS_AC_EXPAND(LIBDIR, $libdir)
 AS_AC_EXPAND(BINDIR, $bindir)
@@ -108,18 +120,6 @@ AC_CONFIG_FILES([
 AC_CONFIG_COMMANDS([default],[[]],[[]])
 AC_OUTPUT
 
-if test "x$DOCBOOK" = "xno"; then
-   AC_MSG_NOTICE([
-
-Warning:
---------
-The docbook tool is not installed, the man pages won't be regenerated.
-If you need to update the manpages, install docbook and rerun 'configure'.
-
-])
-
-fi
-
 if test "x$SETCAP" = "xno"; then
    AC_MSG_NOTICE([