On 2013-01-08 13:17 +0100, Stefano Lattarini wrote: > Actually, the warning about a missing AM_PROG_CC_C_O will be automatically > given once the user has added 'subdir-objects' to the AUTOMAKE_OPTIONS. > > - the user sees the warning about missing 'subdir-objects' option; > - he adds it to AM_INIT_AUTOMAKE, and calls "autoreconf"; > - he now sees the warning about AM_PROG_CC_C_O that is now triggered > by the presence of 'subdir-objects'; > - he add AM_PROG_CC_C_O to configure.ac, and calls autoreconf. > > However, I see that it would be nice to try to be smarter and give > the warning right away, to save the user that potentially annoy > second bootstrap. So I still think your suggestion is a good idea.
I don't think AM_PROG_CC_C_O is optional at all when subdir-objects is enabled. Even with a single source file in a the same directory as the Makefile, Automake is generating a suffix rule that looks like this: .c.o: [...] @am__fastdepCC_FALSE@ $(COMPILE) -c -o $@ $< which looks like it's using -c and -o together to me. So if subdir-objects is made mandatory, AM_PROG_CC_C_O will become mandatory as well, so AM_INIT_AUTOMAKE may as well just call it automatically. Cheers, -- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
