Re: auto* overhead

[Bruce Korb <bkorb at pacbell dot net>]

> One question is: how does this scale?  Maybe there is a high fixed
> overhead and then a low cost for additional changes.

autoconf macros have a high multiplier, and that will
depend on the particular macro.  From my favorite example:

$ find ag -type f -name 'Make*.in' | xargs fileinfo -s -N32
ag/xml2ag/Makefile.in                 13906
ag/agen5/test/Makefile.in              9275
ag/agen5/Makefile.in                  23887
ag/getdefs/test/Makefile.in            8342
ag/getdefs/Makefile.in                17153
ag/compat/Makefile.in                  6948
ag/pkg/Makefile.in                     6799
ag/columns/Makefile.in                13259
ag/snprintfv/config/Makefile.in        6138
ag/snprintfv/tests/Makefile.in        14041
ag/snprintfv/snprintfv/Makefile.in    17499
ag/snprintfv/doc/Makefile.in          11424
ag/snprintfv/Makefile.in              13912
ag/autoopts/test/Makefile.in           8760
ag/autoopts/Makefile.in               26063
ag/doc/Makefile.in                    12739
ag/Makefile.in                        15936
$ find ag -type f -name 'configure*' | xargs fileinfo -s -N32
ag/configure                         400696
ag/snprintfv/configure               346527
ag/snprintfv/configure.in             13391
ag/configure.in                        7538

$ find bs -type f -name 'configure*' | xargs fileinfo -s -N32
bs/configure.ac                        2623
bs/configure                         330745
/home/bkorb/ag
$ find bs -type f -name 'Make*.in' | xargs fileinfo -s -N32
bs/libopts/Makefile.in                11651
bs/Makefile.in                        24515

Looks like configure is a much bigger problem, unless
you have an awful lot of buildable subdirectories.

> Another question is: how much of the overhead is `foo = @foo@' lines
> in Makefile.in?  There's a way we could eliminate this overhead.

Nice, but I think there is bigger, lower hanging fruit.