+%define public maybe
+%define parser_class_name {Input}
+%%
+start: %empty;
+]])
+
+AT_BISON_CHECK([[Input.y]], [1], [],
+[[Input.y:2.9-14: error: invalid value for %define Boolean variable 'public'
+]])
+
+AT_CLEANUP
+
+## ------------------------ ##
+## %define code variables. ##
+## ------------------------ ##
+
+AT_SETUP([["%define" code variables]])
+
+m4_pushdef([AT_TEST],
+[AT_DATA([input.yy],
+[[%skeleton "lalr1.cc" %locations
+%define api.location.type ]$1[quux]$2[
+%define api.namespace ]$1[quux]$2[
+%define api.prefix ]$1[quux]$2[
+%define api.token.prefix ]$1[quux]$2[
+%token TOK // Otherwise api.token.prefix is unused.
+%%
+start: TOK;
+]])
+
+AT_BISON_CHECK([[input.yy]], [0], [],
+[[input.yy:2.9-25: warning: %define variable 'api.location.type' requires '{...}' values [-Wdeprecated]
+input.yy:4.9-18: warning: %define variable 'api.prefix' requires '{...}' values [-Wdeprecated]
+input.yy:5.9-24: warning: %define variable 'api.token.prefix' requires '{...}' values [-Wdeprecated]
+input.yy:3.9-21: warning: %define variable 'api.namespace' requires '{...}' values [-Wdeprecated]
+]])
+])
+
+AT_TEST([], [])
+AT_TEST(["], ["])
+m4_popdef([AT_TEST])
+
+AT_CLEANUP
+
+
+## --------------------------- ##
+## %define keyword variables. ##
+## --------------------------- ##
+
+AT_SETUP([["%define" keyword variables]])
+
+m4_pushdef([AT_TEST],
+[AT_DATA([input.y],
+[[%define api.pure ]$1[true]$2[
+%define api.push-pull ]$1[both]$2[
+%define lr.default-reduction ]$1[most]$2[
+%define lr.keep-unreachable-state ]$1[true]$2[
+%define lr.type ]$1[lalr]$2[
+%%
+exp: %empty
+]])
+
+AT_BISON_CHECK([[input.y]], [0], [],
+[[input.y:5.9-15: warning: %define variable 'lr.type' requires keyword values [-Wdeprecated]
+input.y:3.9-28: warning: %define variable 'lr.default-reduction' requires keyword values [-Wdeprecated]
+input.y:4.9-33: warning: %define variable 'lr.keep-unreachable-state' requires keyword values [-Wdeprecated]
+input.y:2.9-21: warning: %define variable 'api.push-pull' requires keyword values [-Wdeprecated]
+input.y:1.9-16: warning: %define variable 'api.pure' requires keyword values [-Wdeprecated]
+]])
+])
+
+AT_TEST(["], ["])
+AT_TEST([{], [}])
+m4_popdef([AT_TEST])
+
+AT_CLEANUP
+
+
+## ------------------------ ##
+## %define enum variables. ##
+## ------------------------ ##
+
+AT_SETUP([["%define" enum variables]])
+
+# Check errors from the front-end, and the back-end. Since the
+# front-end quits before calling the back-end, these tests cannot be
+# fused.
+
+# Front-end.
+AT_DATA([[input.y]],
+[[%define lr.default-reduction bogus
+%%
+start: %empty;
+]])
+AT_BISON_CHECK([[-fcaret input.y]], [[1]], [[]],
+[[input.y:1.9-28: error: invalid value for %define variable 'lr.default-reduction': 'bogus'
+ %define lr.default-reduction bogus
+ ^^^^^^^^^^^^^^^^^^^^
+input.y:1.9-28: accepted value: 'most'
+input.y:1.9-28: accepted value: 'consistent'
+input.y:1.9-28: accepted value: 'accepting'
+]])
+
+# Back-end.
+AT_DATA([[input.y]],
+[[%define api.push-pull neither
+%%
+start: %empty;
+]])
+AT_BISON_CHECK([[-fcaret input.y]], [[1]], [[]],
+[[input.y:1.9-21: error: invalid value for %define variable 'api.push-pull': 'neither'
+ %define 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 the variables are properly updated.
+AT_DATA([[input.y]],
+[[%define api.push_pull both
+%define lr.keep_unreachable_states maybe
+%define namespace "foo"
+%define api.namespace {foo}
+%define variant
+%%
+start: %empty;
+]])
+AT_BISON_CHECK([[-fcaret input.y]], [1], [],
+[[input.y:1.9-21: warning: deprecated directive, use '%define api.push-pull both' [-Wdeprecated]
+ %define api.push_pull both
+ ^^^^^^^^^^^^^
+input.y:2.9-34: warning: deprecated directive, use '%define lr.keep-unreachable-state maybe' [-Wdeprecated]
+ %define lr.keep_unreachable_states maybe
+ ^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:3.9-17: warning: deprecated directive, use '%define api.namespace foo' [-Wdeprecated]
+ %define namespace "foo"
+ ^^^^^^^^^
+input.y:4.9-21: error: %define variable 'api.namespace' redefined
+ %define api.namespace {foo}
+ ^^^^^^^^^^^^^
+input.y:3.9-17: previous definition
+ %define namespace "foo"
+ ^^^^^^^^^
+input.y:5.9-15: warning: deprecated directive, use '%define api.value.type variant' [-Wdeprecated]
+ %define variant
+ ^^^^^^^
+]])
+
+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: %empty;
+]])
+
+AT_BISON_CHECK([[input.y]], [[1]], [],
+[[input.y:1.9-16: error: %define variable 'api.pure' is not used
+]])
+])
+
+AT_CHECK_API_PURE([[%language "c++"]], [[]])
+AT_CHECK_API_PURE([[%language "c++"]], [[false]])
+AT_CHECK_API_PURE([[%language "c++" %glr-parser]], [[""]])
+AT_CHECK_API_PURE([[%language "c++" %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 {]$1[}
+%%
+start: %empty;
+]])
+
+AT_BISON_CHECK([[input.y]], [1], [],
+[m4_foreach([b4_arg], m4_dquote(m4_shift($@)),
+[[input.y:3.9-21: error: ]b4_arg[
+]])])
+])
+
+AT_CHECK_NAMESPACE_ERROR([[]],
+ [[namespace reference is empty]])
+AT_CHECK_NAMESPACE_ERROR([[ @tb@@tb@ @tb@ @tb@]],
+ [[namespace reference is empty]])
+AT_CHECK_NAMESPACE_ERROR([[foo::::bar]],
+ [[namespace reference has consecutive "::"]])
+AT_CHECK_NAMESPACE_ERROR([[foo:: @tb@::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::@tb@::]],
+ [[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:: @tb@]],
+ [[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: AT_DATA or some variant of AT_DATA may eventually permit
+# the final newline to be omitted. 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: '
+]])
+AT_CHECK([[$PERL -e "print 'start: \'';" >> empty.y || exit 77]])
+
+AT_BISON_CHECK([-fcaret empty.y], [1], [],
+[[empty.y:2.8-9: warning: empty character literal [-Wother]
+ start: '';
+ ^^
+empty.y:3.8-4.0: error: missing "'" at end of line
+ start: '
+ ^
+empty.y:3.8-4.0: warning: empty character literal [-Wother]
+ start: '
+ ^
+empty.y:4.8: error: missing "'" at end of file
+ start: '
+ ^
+empty.y:4.8: warning: empty character literal [-Wother]
+ start: '
+ ^
+]])
+
+AT_DATA([two.y],
+[[%%
+start: 'ab';
+start: 'ab
+]])
+AT_CHECK([[$PERL -e "print 'start: \'ab';" >> two.y || exit 77]])
+
+AT_BISON_CHECK([two.y], [1], [],
+[[two.y:2.8-11: warning: extra characters in character literal [-Wother]
+two.y:3.8-4.0: error: missing "'" at end of line
+two.y:3.8-4.0: warning: extra characters in character literal [-Wother]
+two.y:4.8-10: error: missing "'" at end of file
+two.y:4.8-10: warning: extra characters in character literal [-Wother]
+]])
+
+AT_DATA([three.y],
+[[%%
+start: 'abc';
+start: 'abc
+]])
+AT_CHECK([[$PERL -e "print 'start: \'abc';" >> three.y || exit 77]])
+
+AT_BISON_CHECK([three.y], [1], [],
+[[three.y:2.8-12: warning: extra characters in character literal [-Wother]
+three.y:3.8-4.0: error: missing "'" at end of line
+three.y:3.8-4.0: warning: extra characters in character literal [-Wother]
+three.y:4.8-11: error: missing "'" at end of file
+three.y:4.8-11: warning: extra characters in character literal [-Wother]
+]])
+
+AT_CLEANUP
+
+## ------------------------- ##
+## Bad escapes in literals. ##
+## ------------------------- ##
+
+AT_SETUP([[Bad escapes in literals]])
+
+AT_DATA([input.y],
+[[%%
+start: '\777' '\0' '\xfff' '\x0'
+ '\uffff' '\u0000' '\Uffffffff' '\U00000000'
+ '\ ' '\A';
+]])
+
+# It is not easy to create special characters, we cannot even trust tr.
+# Beside we cannot even expect "echo '\0'" to output two characters
+# (well three with \n): at least Bash 3.2 converts the two-character
+# sequence "\0" into a single NUL character.
+AT_CHECK([[$PERL -e 'print "start: \"\\\t\\\f\\\0\\\1\" ;";' >> input.y \
+ || exit 77]])
+
+AT_BISON_CHECK([input.y], [1], [],
+[[input.y:2.9-12: error: invalid number after \-escape: 777
+input.y:2.8-13: warning: empty character literal [-Wother]
+input.y:2.16-17: error: invalid number after \-escape: 0
+input.y:2.15-18: warning: empty character literal [-Wother]
+input.y:2.21-25: error: invalid number after \-escape: xfff
+input.y:2.20-26: warning: empty character literal [-Wother]
+input.y:2.29-31: error: invalid number after \-escape: x0
+input.y:2.28-32: warning: empty character literal [-Wother]
+input.y:3.9-14: error: invalid number after \-escape: uffff
+input.y:3.8-15: warning: empty character literal [-Wother]
+input.y:3.18-23: error: invalid number after \-escape: u0000
+input.y:3.17-24: warning: empty character literal [-Wother]
+input.y:3.27-36: error: invalid number after \-escape: Uffffffff
+input.y:3.26-37: warning: empty character literal [-Wother]
+input.y:3.40-49: error: invalid number after \-escape: U00000000
+input.y:3.39-50: warning: empty character literal [-Wother]
+input.y:4.9-10: error: invalid character after \-escape: ' '
+input.y:4.8-11: warning: empty character literal [-Wother]
+input.y:4.14-15: error: invalid character after \-escape: A
+input.y:4.13-16: warning: empty character literal [-Wother]
+input.y:5.9-16: error: invalid character after \-escape: \t
+input.y:5.17: error: invalid character after \-escape: \f
+input.y:5.18: error: invalid character after \-escape: \0
+input.y:5.19: error: invalid character after \-escape: \001
+]])
+
+AT_CLEANUP
+
+## ------------------------- ##
+## LAC: Errors for %define. ##
+## ------------------------- ##
+
+AT_SETUP([[LAC: Errors for %define]])
+
+AT_DATA([[input.y]],
+[[%%
+start: %empty;
+]])
+
+# parse.lac.* options are useless if LAC isn't actually activated.
+AT_BISON_CHECK([[-Dparse.lac.es-capacity-initial=1 input.y]],
+ [[1]], [],
+[[<command line>:2: error: %define variable 'parse.lac.es-capacity-initial' is not used
+]])
+AT_BISON_CHECK([[-Dparse.lac.memory-trace=full input.y]],
+ [[1]], [],
+[[<command line>:2: error: %define variable 'parse.lac.memory-trace' is not used
+]])
+
+AT_CLEANUP
+
+## ---------------------- ##
+## -Werror combinations. ##
+## ---------------------- ##
+
+AT_SETUP([[-Werror combinations]])
+
+AT_DATA([[input.y]],
+[[%%
+a: '0' { $$ = $; };
+]])
+
+# -Werror is not enabled by -Wall or equivalent.
+AT_BISON_CHECK([[-Wall input.y]], [[0]], [[]],
+[[input.y:2.15: warning: stray '$' [-Wother]
+]])
+AT_BISON_CHECK([[-W input.y]], [[0]], [[]],
+[[input.y:2.15: warning: stray '$' [-Wother]
+]])
+AT_BISON_CHECK([[-Wno-none input.y]], [[0]], [[]],
+[[input.y:2.15: warning: stray '$' [-Wother]
+]])
+
+# -Werror is not disabled by -Wnone or equivalent.
+AT_BISON_CHECK([[-Werror,none,other input.y]], [[1]], [[]],
+[[input.y:2.15: error: stray '$' [-Werror=other]
+]])
+AT_BISON_CHECK([[-Werror,no-all,other input.y]], [[1]], [[]],
+[[input.y:2.15: error: stray '$' [-Werror=other]
+]])
+
+# Check that -Wno-error keeps warnings enabled, but non fatal.
+AT_BISON_CHECK([[-Werror -Wno-error=other input.y]], [[0]], [[]],
+[[input.y:2.15: warning: stray '$' [-Wother]
+]])
+
+AT_BISON_CHECK([[-Wno-error=other -Werror input.y]], [[0]], [[]],
+[[input.y:2.15: warning: stray '$' [-Wother]
+]])
+
+AT_BISON_CHECK([[-Werror=other -Wno-other input.y]], [[0]], [[]],
+[[]])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------ ##
+## %name-prefix and %define api.prefix are incompatible. ##
+## ------------------------------------------------------ ##
+
+AT_SETUP([[%name-prefix and api.prefix are incompatible]])
+
+# AT_TEST(DIRECTIVES, OPTIONS, ERROR-LOCATION)
+# --------------------------------------------
+m4_pushdef([AT_TEST],
+[AT_DATA([[input.y]],
+[[$1