RE: [patch 1/28] top-level: Use automake-1.11.6

[Bernd Edlinger <bernd.edlinger@hotmail.de>]

Hi,

On Thu, 7 May 2015 15:25:14, Joseph S. Myers wrote:
>
> On Thu, 7 May 2015, Bernd Edlinger wrote:
>
>> But that is not the case for other tool scripts.  I think these should
>> be in-sync with the automake version that creates the configure scripts
>> that make use of them.
>
> At least some of these scripts are also usable other than from
> automake-generated code (I don't know if they're used like that in GCC,
> but some projects use them like that). New versions should be compatible
> with older automake, and I don't think we should be downgrading these
> scripts to older versions (which is what this patch would do).
>

Yes, but the world is not as perfect as it should be.

One example where there is an incompatibility is "missing":

Formerly it had code that emulated the missing "flex" by
creating a dummy lex.yy.c from the hopefully installed
pre-compiled flex output file.  But the version from the
trunk does nothing, which breaks all configure scripts
that used AM_PROG_LEX.  I do assume that the
automake scripts just use a different way to achieve
the same goal, if flex is not installed.

See https://gcc.gnu.org/ml/gcc-patches/2014-11/msg03007.html
for an example what can happen, if the tool scripts are
updated, but the automake is not updated.


Bernd.