+# 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: invalid number after \-escape: 777
+input.y:2.8-13: warning: empty character literal
+input.y:2.16-17: invalid number after \-escape: 0
+input.y:2.15-18: warning: empty character literal
+input.y:2.21-25: invalid number after \-escape: xfff
+input.y:2.20-26: warning: empty character literal
+input.y:2.29-31: invalid number after \-escape: x0
+input.y:2.28-32: warning: empty character literal
+input.y:3.9-14: invalid number after \-escape: uffff
+input.y:3.8-15: warning: empty character literal
+input.y:3.18-23: invalid number after \-escape: u0000
+input.y:3.17-24: warning: empty character literal
+input.y:3.27-36: invalid number after \-escape: Uffffffff
+input.y:3.26-37: warning: empty character literal
+input.y:3.40-49: invalid number after \-escape: U00000000
+input.y:3.39-50: warning: empty character literal
+input.y:4.9-10: invalid character after \-escape: ' '
+input.y:4.8-11: warning: empty character literal
+input.y:4.14-15: invalid character after \-escape: A
+input.y:4.13-16: warning: empty character literal
+input.y:5.9-16: invalid character after \-escape: \t
+input.y:5.17: invalid character after \-escape: \f
+input.y:5.18: invalid character after \-escape: \0
+input.y:5.19: invalid character after \-escape: \001
+]])
+
+AT_CLEANUP
+
+## ------------------------- ##
+## LAC: Errors for %define. ##
+## ------------------------- ##
+
+AT_SETUP([[LAC: Errors for %define]])
+
+AT_DATA([[input.y]],
+[[%%
+start: ;
+]])
+
+# 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: %define variable 'parse.lac.es-capacity-initial' is not used
+]])
+AT_BISON_CHECK([[-Dparse.lac.memory-trace=full input.y]],
+ [[1]], [],
+[[<command line>:2: %define variable 'parse.lac.memory-trace' is not used
+]])
+
+AT_CLEANUP
+
+## --------------------------------------------- ##
+## -Werror is not affected by -Wnone and -Wall. ##
+## --------------------------------------------- ##
+
+AT_SETUP([[-Werror is not affected by -Wnone and -Wall]])
+
+AT_DATA([[input.y]],
+[[%%
+foo-bar: ;
+]])
+
+# -Werror is not enabled by -Wall or equivalent.
+AT_BISON_CHECK([[-Wall input.y]], [[0]], [[]],
+[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+AT_BISON_CHECK([[-W input.y]], [[0]], [[]],
+[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+AT_BISON_CHECK([[-Wno-none input.y]], [[0]], [[]],
+[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+
+# -Werror is not disabled by -Wnone or equivalent.
+AT_BISON_CHECK([[-Werror,none,yacc input.y]], [[1]], [[]], [[stderr]])
+AT_CHECK([[sed 's/^.*bison:/bison:/' stderr]], [[0]],
+[[bison: warnings being treated as errors
+input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+[mv stderr experr]
+AT_BISON_CHECK([[-Werror,no-all,yacc input.y]], [[1]], [[]], [[experr]])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------ ##
+## %name-prefix and %define api.prefix are incompatible. ##
+## ------------------------------------------------------ ##
+
+AT_SETUP([[%name-prefix and %define api.prefix are incompatible]])
+
+# AT_TEST(DIRECTIVES, OPTIONS, ERROR-LOCATION)
+# --------------------------------------------
+m4_pushdef([AT_TEST],
+[AT_DATA([[input.y]],
+[[$1
+%%
+exp:;
+]])
+AT_BISON_CHECK([[$2 input.y]], [[1]], [[]],
+[[$3: '%name-prefix' and '%define api.prefix' cannot be used together
+]])
+])
+
+AT_TEST([%define api.prefix foo %name-prefix "bar"], [], [input.y:1.9-18])
+AT_TEST([], [-Dapi.prefix=foo -p bar], [<command line>:2])
+AT_TEST([%name-prefix "bar"], [-Dapi.prefix=foo], [<command line>:2])
+AT_TEST([%define api.prefix foo], [-p bar], [input.y:1.9-18])
+
+m4_popdef([AT_TEST])
+