(Illustration by Gaich Muramatsu)
Jan Harkes <jaharkes_at_cs.cmu.edu> writes: > The test for success was added to avoid build problems later on when > people didn't have bison or yacc installed. The warnings were pretty > obscure. In fact I think the missing script basically creates an empty > rp2gen_parser.c, which then results in a lot of obscure warnings during > the link phase that don't really indicate that the 'generated' parser > code is really an empty file. > > So if AC_PROG_YACC does the right thing already, but only fails to set > the ac_cv_prog_YACC variable when /usr/bin/yacc is installed, then I'm > just testing the wrong variable. It doesn't do the right thing. It looks for bison and byacc, and if found sets YACC to those and ac_cv_prog_YACC. If not found, it sets YACC to yacc - without checking that a yacc is there - and doesn't set ac_cv_prog_YACC. This is clearly from the days when of course all computers had yacc, since it was in Sixth Edition or some such, so how could you have a machine without it. My AC_CHECK_PROGS looks for yacc explicitly, so it will behave differently in 'use yacc by default' and 'found yacc' cases.Received on 2007-08-07 13:18:30