Re: [Bug-gnubg] New feature: direction arrow

[Joern Thyssen]

On Mon, May 26, 2003 at 12:45:17PM +0200, Holger wrote
> At 07:53 25.05.2003 +0000, Joern Thyssen wrote:
> 
> I've just tried to do it on Solaris. But it fails. It doesn't find 
> AM_PATH_LIBART. Do I have to copy the contents of libart.m4 or should it 
> find it by itself?

You may have to run

aclocal -I m4

first.

> >Which variables are you particular interested in?
> 
> None really. Just trying to understand how it works and where they come 
> from.
> 
> >Some of them are standard autoconf variables. Others are generated from
> >our macros (or macros used by our macros) in configure.in, e.g.,
> >ARTSC_CFLAGS og PKG_CONFIG etc.
> 
> Does any particular line in Makefile.am generate this list? Or is it some 
> automatism that always produces this depending on what macros are found?
> I relate e.g. to these lines in Makefile.in:
> GNUPLOT = @GNUPLOT@
> GTK_LIBS = @GTK_LIBS@

An AC_SUBST will create a variable in Makefile.in. For example,

AC_SUBST(GTK_LIBS)    (found in m4/gtk-2.0.m4)

Other macro like AC_CHECK_PROG will also create variables, e.g.,

AC_CHECK_PROG(GNUPLOT, gnuplot, gnuplot)    (found in configure.in)

>From the manual:

AC_CHECK_PROG (variable, prog-to-check-for, value-if-found,
[value-if-not-found], [path], [reject])
Check whether program prog-to-check-for exists in PATH. If it is found,
set variable to value-if-found, otherwise to value-if-not-found, if
given. Always pass over reject (an absolute file name) even if it is the
first found in the search path; in that case, set variable using the
absolute file name of the prog-to-check-for found that is not reject. If
variable was already set, do nothing. Calls AC_SUBST for variable. 


CHeck

http://www.gnu.org/manual/autoconf/html_chapter/autoconf_toc.html


Jørn