lua help build, autotools update (was: Re: build error with current CVS)

[Hans-Bernhard B. <HBB...@t-...>]

Am 15.11.2014 um 08:12 schrieb sfeam:

> Now if lua is not present or if you ./configure --without-lua then it
> will not include the help section for tikz in the docs.

> This is imperfect, because if you change your mind later and do
> ./configure --with-lua it won't go back and rebuild the help file.

I've looked at this a bit.  I don't think there really is a need to 
build a dummy version because it is used is only by term.h, and then 
only #ifdef HAVE_LUA.

I think that for this to work correctly, the "build gnuplot-tikz.help" 
section is in the wrong Makefile.  As-is, if the file isn't there, 
docs/Makefile fails to build it before trying to use it, and therefore 
fails to build docs/allterm.h.  And we cannot safely assume that 
docs/Makefile will always be run before term/Makefile.

So docs/Makefile has to handle the creation of that file itself, and 
while at it, the file should actually be moved to the docs directory, 
since its only purpose is to be included in allterm.h:

if BUILD_LUA
LUA_HELP = gnuplot-tikz.help
$(LUA_HELP): $(top_srcdir)/term/lua/gnuplot-tikz.lua
	lua $< termhelp > $@
else
LUA_HELP =
endif

allterm.h: $(CORETERM) $(LUA_HELP)

I'll check this (and the removal of corresponding code in 
term/Makefile.am.in) in soon, unless there are objections.

As an aside, I propose to upgrade the entire auto-tools configuration to 
current versions (autoconf 2.69, automake 1.14).  Some of our automake 
support scripts are almost a decade out of date...  This I will only 
check in after some discussion.