+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]])
+
+# Front-end.
+AT_DATA([[input.y]],
+[[%define lr.default-reductions "bogus"
+%%
+start: ;
+]])
+AT_BISON_CHECK([[input.y]], [[1]], [[]],
+[[input.y:1.9-29: invalid value for %define variable `lr.default-reductions': `bogus'
+input.y:1.9-29: accepted value: `all'
+input.y:1.9-29: accepted value: `consistent'
+input.y:1.9-29: accepted value: `accepting'
+]])
+
+# Back-end.
+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'
+input.y:1.9-21: accepted value: `pull'
+input.y:1.9-21: accepted value: `push'
+input.y:1.9-21: accepted value: `both'
+]])
+
+AT_CLEANUP
+
+## -------------------------------- ##
+## %define backward compatibility. ##
+## -------------------------------- ##
+
+AT_SETUP([[%define backward compatibility]])
+
+# The error messages tell us whether underscores in these variables are
+# being converted to dashes.
+
+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'
+input.y:1.9-21: accepted value: `pull'
+input.y:1.9-21: accepted value: `push'
+input.y:1.9-21: accepted value: `both'
+]])
+
+AT_DATA([[input.y]],
+[[%define lr.keep_unreachable_states "maybe"
+%%
+start: ;
+]])
+AT_BISON_CHECK([[input.y]], [1], [],
+[[input.y:1.9-34: invalid value for %define Boolean variable `lr.keep-unreachable-states'
+]])
+
+AT_DATA([[input.y]],
+[[%define foo_bar "baz"
+%%
+start: ;
+]])
+AT_BISON_CHECK([[input.y]], [0], [],
+[[input.y:1.9-15: warning: %define variable `foo_bar' is not used
+]])
+
+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[
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[input.y]], [0], [],
+[[input.y:1.9-16: warning: %define variable `api.pure' is not used
+]])
+])
+
+AT_CHECK_API_PURE([[%language "c++" %defines]], [[]])
+AT_CHECK_API_PURE([[%language "c++" %defines]], [["false"]])
+AT_CHECK_API_PURE([[%language "c++" %defines %glr-parser]], [[""]])
+AT_CHECK_API_PURE([[%language "c++" %defines %glr-parser]], [["false"]])
+AT_CHECK_API_PURE([[%language "java"]], [["true"]])
+AT_CHECK_API_PURE([[%language "java"]], [["false"]])
+
+AT_CLEANUP
+
+## -------------------------------- ##
+## C++ namespace reference errors. ##
+## -------------------------------- ##
+
+AT_SETUP([[C++ namespace reference errors]])
+
+# AT_CHECK_NAMESPACE_ERROR(NAMESPACE-DECL, ERROR, [ERROR], ...)
+# -------------------------------------------------------------
+# Make sure Bison reports all ERROR's for %define namespace "NAMESPACE-DECL".
+m4_define([AT_CHECK_NAMESPACE_ERROR],
+[
+AT_DATA([[input.y]],
+[[%language "C++"
+%defines
+%define api.namespace "]$1["
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[input.y]], [1], [],
+[m4_foreach([b4_arg], m4_dquote(m4_shift($@)),
+[[input.y:3.9-21: ]b4_arg[
+]])])
+])
+
+AT_CHECK_NAMESPACE_ERROR([[]],
+ [[namespace reference is empty]])
+AT_CHECK_NAMESPACE_ERROR([[ ]],
+ [[namespace reference is empty]])
+AT_CHECK_NAMESPACE_ERROR([[foo::::bar]],
+ [[namespace reference has consecutive "::"]])
+AT_CHECK_NAMESPACE_ERROR([[foo:: ::bar]],
+ [[namespace reference has consecutive "::"]])
+AT_CHECK_NAMESPACE_ERROR([[::::bar]],
+ [[namespace reference has consecutive "::"]])
+AT_CHECK_NAMESPACE_ERROR([[:: ::bar]],
+ [[namespace reference has consecutive "::"]])
+AT_CHECK_NAMESPACE_ERROR([[foo::bar:: ::]],
+ [[namespace reference has consecutive "::"]],
+ [[namespace reference has a trailing "::"]])
+AT_CHECK_NAMESPACE_ERROR([[foo::bar::]],
+ [[namespace reference has a trailing "::"]])
+AT_CHECK_NAMESPACE_ERROR([[foo::bar:: ]],
+ [[namespace reference has a trailing "::"]])
+AT_CHECK_NAMESPACE_ERROR([[::]],
+ [[namespace reference has a trailing "::"]])
+
+AT_CLEANUP
+
+## ------------------------ ##
+## Bad character literals. ##
+## ------------------------ ##
+
+# Bison used to accept character literals that were empty or contained
+# too many characters.
+
+# FIXME: $ECHO_N and $ECHO_C are not very portable according to the
+# Autoconf manual. Switch to AS_ECHO_N when Autoconf 2.64 is released?
+# Even better, AT_DATA or some variant of AT_DATA may eventually permit
+# a trailing newline. See the threads starting at
+# <http://lists.gnu.org/archive/html/bison-patches/2009-07/msg00019.html>.
+
+AT_SETUP([[Bad character literals]])
+
+AT_DATA([empty.y],
+[[%%
+start: '';
+start: '
+]])
+echo $ECHO_N "start: '$ECHO_C" >> empty.y
+
+AT_BISON_CHECK([empty.y], [1], [],
+[[empty.y:2.8-9: warning: empty character literal
+empty.y:3.8-4.0: warning: empty character literal
+empty.y:3.8-4.0: missing `'' at end of line
+empty.y:4.8: warning: empty character literal
+empty.y:4.8: missing `'' at end of file
+]])
+
+AT_DATA([two.y],
+[[%%
+start: 'ab';
+start: 'ab
+]])
+echo $ECHO_N "start: 'ab$ECHO_C" >> two.y
+
+AT_BISON_CHECK([two.y], [1], [],
+[[two.y:2.8-11: warning: extra characters in character literal
+two.y:3.8-4.0: warning: extra characters in character literal
+two.y:3.8-4.0: missing `'' at end of line
+two.y:4.8-10: warning: extra characters in character literal
+two.y:4.8-10: missing `'' at end of file
+]])
+
+AT_DATA([three.y],
+[[%%
+start: 'abc';
+start: 'abc
+]])
+echo $ECHO_N "start: 'abc$ECHO_C" >> three.y
+
+AT_BISON_CHECK([three.y], [1], [],
+[[three.y:2.8-12: warning: extra characters in character literal
+three.y:3.8-4.0: warning: extra characters in character literal
+three.y:3.8-4.0: missing `'' at end of line
+three.y:4.8-11: warning: extra characters in character literal
+three.y:4.8-11: missing `'' at end of file