-AT_CHECK([[bison input.y]], 0, [],
-[[input.y contains 9 useless nonterminals and 9 useless rules
+AT_BISON_CHECK([[input.y]], 0, [],
+[[input.y: warning: 9 nonterminals useless in grammar
+input.y: warning: 9 rules useless in grammar
+input.y:6.1-8: warning: nonterminal useless in grammar: useless1
+input.y:7.1-8: warning: nonterminal useless in grammar: useless2
+input.y:8.1-8: warning: nonterminal useless in grammar: useless3
+input.y:9.1-8: warning: nonterminal useless in grammar: useless4
+input.y:10.1-8: warning: nonterminal useless in grammar: useless5
+input.y:11.1-8: warning: nonterminal useless in grammar: useless6
+input.y:12.1-8: warning: nonterminal useless in grammar: useless7
+input.y:13.1-8: warning: nonterminal useless in grammar: useless8
+input.y:14.1-8: warning: nonterminal useless in grammar: useless9
+input.y:6.11-13: warning: rule useless in grammar: useless1: '1'
+input.y:7.11-13: warning: rule useless in grammar: useless2: '2'
+input.y:8.11-13: warning: rule useless in grammar: useless3: '3'
+input.y:9.11-13: warning: rule useless in grammar: useless4: '4'
+input.y:10.11-13: warning: rule useless in grammar: useless5: '5'
+input.y:11.11-13: warning: rule useless in grammar: useless6: '6'
+input.y:12.11-13: warning: rule useless in grammar: useless7: '7'
+input.y:13.11-13: warning: rule useless in grammar: useless8: '8'
+input.y:14.11-13: warning: rule useless in grammar: useless9: '9'