-[AT_CHECK([echo "$1" | calc], 0, [$2], [$3])])
+[ifelse(regexp([$1], [--debug]),
+ [-1],
+ [AT_CHECK([echo "$2" | calc],
+ [0], [], [])],
+ [AT_CHECK([echo "$2" | calc 2>&1 >/dev/null | grep 'parse error' >&2],
+ [1], [], [])])])
+
+
+# _AT_CHECK_CALC_ERROR(BISON-OPTIONS, INPUT, [IF-YYERROR-VERBOSE])
+# ----------------------------------------------------------------
+# Run `calc' on INPUT, and expect STDERR.
+AT_DEFINE([_AT_CHECK_CALC_ERROR],
+[AT_CHECK([echo "$2" | calc 2>&1 >/dev/null | grep 'parse error' >&2], 0,
+ [],
+ [parse error[]ifelse(regexp([$1], [--yyerror-verbose]),
+ [-1], [], [$3])
+])])