* automake.in (am_macro_for_var, ac_macro_for_var, required_variables): New variables. (am_c_prototypes, seen_prog_lex, am_lispdir_location, pythondir_location): Remove. (initialize_per_input): Clear %required_variables. (require_variables, require_variables_for_macro): New functions. (handle_languages): Call &require_variables for $lang->config_vars. (handle_compile): Call &require_variables_for_macro for the ANSI2KNR and U variables. (handle_emacs_lisp): Call &require_variables for EMACS and libdir. (handle_python): Call &require_variables for PYTHON. Don't explicitly allow `python' as a prefix for PYTHON. (scan_autoconf_traces): Don't scan AC_PROG_LEX, AM_C_PROTOTYPES, AM_PATH_LISPDIR, and AM_PATH_PYTHON. (scan_autoconf_traces) <AC_SUBST>: Don't filter out ANSI2KNR and AMDEPBACKSLASH here... (define_configure_variable): ... do this here. (am_primary_prefixes): Probe the existence of ${X}dir using &require_variables_for_macro. If a standard prefix is not legitimate, say so. Ignore all configure variables. * tests/ansi8.test, tests/cxx2.test, tests/gcj5.test, tests/lisp2.test, tests/python2.test: New files * tests/Makefile.am (TESTS): Add them. * tests/asm.test: Grep stderr. * tests/lex2.test: Rewrite to test that Automake suggests AM_PROG_LEX. * tests/python.test: Make sure py-compile is installed.