Re: Fix chdir-long.m4 caching

[Ralf Wildenhues]

* Eric Blake wrote on Fri, Sep 28, 2007 at 06:33:45AM CEST:
> >> 2006-09-26  Eric Blake  <address@hidden>
> >>    and Ralf Wildenhues  <address@hidden>
> > 
> >>    * lib/autoconf/general.m4 (AC_CACHE_VAL): Warn if cache-id is not
> >>    cached.
> >>    * tests/base.at (AC_CACHE_CHECK): Adjust test to expect this,
> >>    also test that macro names and correct literals are not checked.
> > 
> > Applied as follows:
[...]

Ahh, now I remember why I postponed that.  With a package using CVS HEAD
Libtool:

| configure.ac:1001: warning: 
AC_CACHE_VAL(_LT_TAGVAR(lt_prog_compiler_pic_works, ), ...): suspicious 
cache-id, must contain _cv_ to be cached
| ../../../autoconf/lib/autoconf/general.m4:1952: AC_CACHE_VAL is expanded 
from...
| ../../../autoconf/lib/autoconf/general.m4:1972: AC_CACHE_CHECK is expanded 
from...
| aclocal.m4:1282: _LT_COMPILER_OPTION is expanded from...
| aclocal.m4:3415: _LT_COMPILER_PIC is expanded from...
| aclocal.m4:5148: _LT_LANG_C_CONFIG is expanded from...
| aclocal.m4:142: _LT_SETUP is expanded from...
| aclocal.m4:75: LT_INIT is expanded from...
| configure.ac:1001: the top level
| configure.ac:1001: warning: AC_CACHE_VAL(lt_prog_compiler_static_works, ...): 
suspicious cache-id, must contain _cv_ to be cached
| aclocal.m4:1334: _LT_LINKER_OPTION is expanded from...
| configure.ac:1001: warning: 
AC_CACHE_VAL(_LT_TAGVAR(lt_prog_compiler_pic_works, CXX), ...): suspicious 
cache-id, must contain _cv_ to be cached
| aclocal.m4:5251: _LT_LANG_CXX_CONFIG is expanded from...
| aclocal.m4:785: _LT_LANG is expanded from...
| aclocal.m4:768: LT_LANG is expanded from...
| aclocal.m4:796: _LT_LANG_DEFAULT_CONFIG is expanded from...
| configure.ac:1001: warning: AC_CACHE_VAL(lt_prog_compiler_static_works_CXX, 
...): suspicious cache-id, must contain _cv_ to be cached
| configure.ac:1001: warning: 
AC_CACHE_VAL(_LT_TAGVAR(lt_prog_compiler_pic_works, F77), ...): suspicious 
cache-id, must contain _cv_ to be cached
| aclocal.m4:6559: _LT_LANG_F77_CONFIG is expanded from...
| configure.ac:1001: warning: AC_CACHE_VAL(lt_prog_compiler_static_works_F77, 
...): suspicious cache-id, must contain _cv_ to be cached
| configure.ac:1001: warning: 
AC_CACHE_VAL(_LT_TAGVAR(lt_prog_compiler_pic_works, FC), ...): suspicious 
cache-id, must contain _cv_ to be cached
| aclocal.m4:6700: _LT_LANG_FC_CONFIG is expanded from...
| configure.ac:1001: warning: AC_CACHE_VAL(lt_prog_compiler_static_works_FC, 
...): suspicious cache-id, must contain _cv_ to be cached

Bugs in both Autoconf and Libtool (the error messages seem a bit
inconsistent)?

I guess branch-1-5 Libtool is affected just as well, and I wonder
whether, if we rename variables in Libtool, we need to provide the old
names for compatibility as well.

FWIW, HEAD autoconf is about 8 sec, i.e., 25% faster on this package
(Open MPI) now.  Nice work, Eric!

Cheers,
Ralf