Re: Broken example in autoconf manual

[Bert Wesarg]

On Thu, Mar 16, 2017 at 11:26 PM, Nick Bowler  wrote:
> Hello,
>
> On 2017-03-16, Max Horn  wrote:
>> on
>> https://www.gnu.org/software/autoconf/manual/autoconf.html#Using-System-Type
>>
>> this example is given:
>>
>>  case $host in
>>alpha*-*-*)   AC_CONFIG_LINKS([dither.c:alpha/dither.c]) ;;
>>powerpc*-*-*) AC_CONFIG_LINKS([dither.c:powerpc/dither.c]) ;;
>>*-*-*)AC_CONFIG_LINKS([dither.c:generic/dither.c]) ;;
>>  esac
>>
>> But that doesn't actually work; inserting it into configure.ac leads to this
>> error:
>>
>> configure.ac:396: error: `dither.c' is already registered with
>> AC_CONFIG_LINKS.
>
> Nice catch.
>
> [...]
>> Which leaves me wondering how to achieve equivalent behavior correctly?
>
> Probably the example could be written something like this (untested):
>
>case $host in
>  alpha*-*-*)   dither_src=alpha ;;
>  powerpc*-*-*) dither_src=powerpc ;;
>  *-*-*)dither_src=generic ;;
>esac
>AC_CONFIG_LINKS([dither.c:$dither_src/dither.c]) ;;
>

I think you also need to pass the value of 'dither_src' to
config.status (still untested):

AC_CONFIG_LINKS([dither.c:$dither_src/dither.c], [], [dither_src='$dither_src'])

Bert

> Cheers,
>   Nick
>

Re: Broken example in autoconf manual

[Nick Bowler]

Hello,

On 2017-03-16, Max Horn  wrote:
> on
> https://www.gnu.org/software/autoconf/manual/autoconf.html#Using-System-Type
>
> this example is given:
>
>  case $host in
>alpha*-*-*)   AC_CONFIG_LINKS([dither.c:alpha/dither.c]) ;;
>powerpc*-*-*) AC_CONFIG_LINKS([dither.c:powerpc/dither.c]) ;;
>*-*-*)AC_CONFIG_LINKS([dither.c:generic/dither.c]) ;;
>  esac
>
> But that doesn't actually work; inserting it into configure.ac leads to this
> error:
>
> configure.ac:396: error: `dither.c' is already registered with
> AC_CONFIG_LINKS.

Nice catch.

[...]
> Which leaves me wondering how to achieve equivalent behavior correctly?

Probably the example could be written something like this (untested):

   case $host in
 alpha*-*-*)   dither_src=alpha ;;
 powerpc*-*-*) dither_src=powerpc ;;
 *-*-*)dither_src=generic ;;
   esac
   AC_CONFIG_LINKS([dither.c:$dither_src/dither.c]) ;;

Cheers,
  Nick

Broken example in autoconf manual

[Max Horn]

Hi there,

on https://www.gnu.org/software/autoconf/manual/autoconf.html#Using-System-Type

this example is given:

 case $host in
   alpha*-*-*)   AC_CONFIG_LINKS([dither.c:alpha/dither.c]) ;;
   powerpc*-*-*) AC_CONFIG_LINKS([dither.c:powerpc/dither.c]) ;;
   *-*-*)AC_CONFIG_LINKS([dither.c:generic/dither.c]) ;;
 esac

But that doesn't actually work; inserting it into configure.ac leads to this 
error:

configure.ac:396: error: `dither.c' is already registered with AC_CONFIG_LINKS.
../../lib/autoconf/status.m4:921: AC_CONFIG_LINKS is expanded from...
configure.ac:396: the top level
autom4te-2.69: /usr/bin/m4 failed with exit status: 1


Which leaves me wondering how to achieve equivalent behavior correctly?


Cheers,
Max