Re: overriding autoconf macros (was: autoconf 2.64 warning: AC_REQUIRE: `AC_PROG_CC' was expanded before it was required)

[Diego Saravia]

> If you override the definition of an autoconf macro, then the maintenance
> burden is shifted away from autoconf onto your shoulders.  If it works for
> you, great.  But if autoconf changes for the next release, and upgrading
> autoconf then breaks your override (and that has been known to happen), we
> don't have any sympathy, because it was not our fault that you did an
> override.
>

I agree

> Maybe the better thing to do is take a step back, and tell us what you are
> really trying to accomplish, and why you felt that your override was
> necessary.  If we agree, then we can fix it upstream, or perhaps we can
> suggest a better idiom that accomplishes your same goal without requiring
> you to do an override.

ok, thank you, for your atention

>
> That sentence was hard to parse.  If I understood correctly, you are
> trying to make it so that if a person lacks a compiler, but runs
> ./configure, that ./configure will attempt to install the compiler on the
> user's behalf, rather than flat out dying with an error.
>

yes, but these is not done by configure

configure only writes a file "./lacks"  telling another program what
projects my system is lacking

> Unfortunately, there is no way to portably install a compiler.  Having a
> configure script attempt to do a non-portable installation of a compiler
> goes against the philosophy of autoconf.

yes, is not a job for autoconf, I agree, but if configure writes a
lacks file it will not hurt anyone.

> Rather, it is a sane assumption,
> and documented in the default INSTALL file that many projects borrow from
> autoconf, that a user attempting to build a package from source can
> already be expected to have a working compiler.  It is not configure's job
> to make up for users that can't meet the prerequisites.

ok, but configure  could help us in that problem, cc is obvious, but
another projects no.


##################################################################3
>> I changed AC_MSG_FAILURE, --it is used by AC_PROG_CC*--, locating this:

> Changed it how?  The discussion would be a lot easier if you showed us
> your replacement, so we could see in code what you are trying to describe
> in English.

I added code to an m4 file in the m4 directory in the source code of
the project:

m4_define([AC_MSG_FAILURE],
[{ AS_MESSAGE([error: in `$ac_pwd': See `config.log' for more details: [$1]], 2)
AC_MSG_NOTICE([$1])
 #, [$2]);
}])

original code is located in general.m4 in autoconf distributed files
m4_define([AC_MSG_FAILURE],
[{ AS_MESSAGE([error: in `$ac_pwd':], 2)
AC_MSG_ERROR([$1
See `config.log' for more details.], [$2]); }])

So I am changing ERROR for NOTICE


What I think could be a better way is to put a YES|NO  variable in
each TEST provide by autoconf, for example
AC_PROG_CC

in one case configure will stop if it do not found a program it needs

in other case it will inform the fact and continue until it finish,
telling us at once all the programs its needs.

By now I am puting in my configure.ac a macro:



TEST_PACKS([subversion wget xz texinfo tar cc ranlib ar ld strip latex
 tgif latex2html emacs muse-el dvips ])




this macro is expanded to individual test of each program


AC_DEFUN([TEST_PACKS],[
 for dep in [$1]; do
   echo Package: ${dep}
   TEST_PACK([${dep}])
  done
  #echo NEEDS-LACKS: $FALTA - $NECESITA
###########################################$FALTA is  filled up in
individual tests (must put in english)
  echo $FALTA|tr ':' '\n' >lacks
  echo $NECESITA|tr ':' '\n' >needs
])



AC_DEFUN([PROG_DEP],[
   #depends
   if test "x${NECESITA}" = "x"; then
       NECESITA=[$1]
     else
       NECESITA=${NECESITA}:[$1]
   fi
   AC_MSG_NOTICE([Depends on:[$1]]);
])
####################################################################################################
AC_DEFUN([PROG_ALERT],[
   # ejecutable, paquete
   #lacks
   if test "x${FALTA}" = "x"; then
       FALTA=[$1]
     else
       FALTA=${FALTA}:[$1]
   fi
   AC_MSG_NOTICE([Needs:[$1]]);
])


# I dont figure out yet how to call macros using variables in the names.
AC_DEFUN([TEST_PACK],[
   case [$1] in
    cc)
       TEST_PROG_CC
       ;;
    lex)
       TEST_PROG_LEX
       ;;
    fortran)
       TEST_PROG_FORTRAN
       ;;
   ranlib)
       TEST_PROG_RANLIB
       ;;

etc


AC_DEFUN([PROG_FIND],[
# variable, archivo ejecutable, paquete generico
AC_PATH_PROGS([$1], [$2],no,[${PATH}:/usr/local/bin])
PROG_DEP([$3])
if test "x$[$1]" = "xno" -o ! -x "$[$1]"; then
    AC_MSG_WARN([No encuentro [$2] del paquete generico [$3]]);
    PROG_ALERT([$3])
fi
])

AC_DEFUN([TEST_PROG_WGET],[
        #PROG_WGET
        PROG_FIND([WGET],[wget],[wget])
])

AC_DEFUN([TEST_PROG_CC],[
       AC_PROG_CC
       PROG_DEP([cc])
       if test "x$CC" = "x"; then
          PROG_ALERT([cc])
       ])

> --
> Don't work too hard, make some time for fun as well!
>
> Eric Blake             address@hidden
>
>



-- 
Diego Saravia
address@hidden
NO FUNCIONA->address@hidden