autotools: force make not to rebuild configure/Makefile

Question

I have a project with autotools: automake, autoconf.

I want to prohibit make from remaking files configure, Makefile.in, etc;

Answer 1

Try to explicitly tell make those files should not be remade, via command-line

$ make -o configure -o Makefile.in

or by using MAKEFLAGS

$ MAKEFLAGS="-o configure -o Makefile.in" make

The excerpt from GNU make's manual

‘-o file’
‘--old-file=file’
‘--assume-old=file’
Do not remake the file file even if it is older than its prerequisites, and do not remake
anything on account of changes in file. Essentially the file is treated as very old and
its rules are ignored. See Avoiding Recompilation of Some Files.

If yours autotools template correctly uses $(MAKE) for subdirs, there should be no problems.

Answer 2

touch confdb/*.m4
touch configure.in
touch *.m4
touch *.am
touch Makefile.in */Makefile.in
touch *config.h.in */*config.h.in
touch configure
touch config.status
touch config.h
touch Makefile

Problems with automake & cvs are described here http://www.gnu.org/s/hello/manual/automake/CVS.html

Answer 3

First of all, if you edit a generated file directly, it wouldn't be rebuilt anyway, because it is then newer then its prerequisites.

Then, there are two separate things going on here: config.status and Makefile are created during the build. It's hard to prevent these from being remade during the build unless you make their timestamps newer.

The other files are generated by the various autotools. Recent versions of Automake do not create rules by default that remake them automatically. Depending on your package, you might want to use the configure option --disable-maintainer-mode. The Automake documentation contains some more interesting information about that option.

One trick I sometimes use with a package that I don't know much about or that has a pretty messed up build system is to run something like

make all AUTOCONF=: AUTOHEADER=: AUTOMAKE=: ACLOCAL=:

so that if these programs happen to be called, a noop would be substituted.