+[[%define var "value1"
+%define var "value1"
+ %define var "value2"
+%define special1 "@:>@"
+%define special2 "@<:@"
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[input.y]], [0], [],
+[[input.y:2.9-11: warning: %define variable `var' redefined
+input.y:1.9-11: warning: previous definition
+input.y:3.10-12: warning: %define variable `var' redefined
+input.y:2.9-11: warning: previous definition
+input.y:1.9-11: warning: %define variable `var' is not used
+input.y:2.9-11: warning: %define variable `var' is not used
+input.y:3.10-12: warning: %define variable `var' is not used
+input.y:4.9-16: warning: %define variable `special1' is not used
+input.y:5.9-16: warning: %define variable `special2' is not used
+]])
+
+AT_CLEANUP
+
+
+## ------------------- ##
+## %define, --define. ##
+## ------------------- ##
+
+AT_SETUP([%define, --define])
+
+AT_DATA([input.y],
+[[%define var "value1"
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[input.y -DFOO -DFOO -Dvar=value]], [0], [],
+[[<command line>:4: warning: %define variable `FOO' redefined
+<command line>:3: warning: previous definition
+input.y:1.9-11: warning: %define variable `var' redefined
+<command line>:5: warning: previous definition
+<command line>:3: warning: %define variable `FOO' is not used
+<command line>:4: warning: %define variable `FOO' is not used
+<command line>:5: warning: %define variable `var' is not used
+input.y:1.9-11: warning: %define variable `var' is not used
+]])
+
+AT_CLEANUP
+
+## --------------------------- ##
+## %define Boolean variables. ##
+## --------------------------- ##
+
+AT_SETUP([[%define Boolean variables]])
+
+AT_DATA([Input.y],
+[[%language "Java"
+%define public "maybe"
+%define parser_class_name "Input"
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[Input.y]], [1], [],
+[[Input.y:2.9-14: invalid value for %define Boolean variable `public'
+]])
+
+AT_CLEANUP
+
+## ------------------------ ##
+## %define enum variables. ##
+## ------------------------ ##
+
+AT_SETUP([[%define enum variables]])
+
+AT_DATA([[input.y]],
+[[%define api.push_pull "neither"
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[input.y]], [1], [],
+[[input.y:1.9-21: invalid value for %define variable `api.push_pull': `neither'
+]])
+
+AT_CLEANUP
+
+## ------------------------- ##
+## Unused %define api.pure. ##
+## ------------------------- ##
+
+AT_SETUP([[Unused %define api.pure]])
+
+# AT_CHECK_API_PURE(DECLS, VALUE)
+# -------------------------------
+# Make sure Bison reports that `%define api.pure VALUE' is unused when DECLS
+# are specified.
+m4_define([AT_CHECK_API_PURE],
+[
+AT_DATA([[input.y]],
+[[%define api.pure ]$2[
+]$1[