+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+
+
+
+## ------------------------ ##
+## LAC: Exploratory stack. ##
+## ------------------------ ##
+
+AT_SETUP([[LAC: Exploratory stack]])
+
+m4_pushdef([AT_LAC_CHECK], [
+
+AT_BISON_OPTION_PUSHDEFS([$1])
+
+AT_DATA_GRAMMAR([input.y],
+[[%code {
+ #include <stdio.h>
+ ]AT_YYERROR_DECLARE[
+ int yylex (]AT_PURE_IF([[YYSTYPE *]], [[void]])[);
+}
+
+]$1[
+%error-verbose
+%token 'c'
+
+%%
+
+// default reductions in inconsistent states
+// v v v v v v v v v v v v v v
+S: A B A A B A A A A B A A A A A A A B C C A A A A A A A A A A A A B ;
+// ^ ^ ^
+// LAC reallocs
+
+A: 'a' | /*empty*/ { printf ("inconsistent default reduction\n"); } ;
+B: 'b' ;
+C: /*empty*/ { printf ("consistent default reduction\n"); } ;
+
+%%
+]AT_YYERROR_DEFINE[
+int
+yylex (]AT_PURE_IF([[YYSTYPE *v]], [[void]])[)
+{
+ static char const *input = "bbbbc";]AT_PURE_IF([[
+ *v = 0;]])[
+ return *input++;
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-Dparse.lac=full -Dparse.lac.es-capacity-initial=1 \
+ -Dparse.lac.memory-trace=full \
+ -t -o input.c input.y]], [[0]], [],
+[[input.y: conflicts: 21 shift/reduce
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input > stdout.txt 2> stderr.txt]], [[1]])
+
+# Make sure syntax error doesn't forget that 'a' is expected. It would
+# be forgotten without lookahead correction.
+AT_CHECK([[grep 'syntax error,' stderr.txt]], [[0]],
+[[syntax error, unexpected 'c', expecting 'a' or 'b'
+]])
+
+# Check number of default reductions in inconsistent states to be sure
+# syntax error is detected before unnecessary reductions are performed.
+AT_CHECK([[perl -0777 -ne 'print s/inconsistent default reduction//g;' \
+ < stdout.txt || exit 77]], [[0]], [[14]])
+
+# Check number of default reductions in consistent states to be sure
+# it is performed before the syntax error is detected.
+AT_CHECK([[perl -0777 -ne 'print s/\bconsistent default reduction//g;' \
+ < stdout.txt || exit 77]], [[0]], [[2]])
+
+# Check number of reallocs to be sure reallocated memory isn't somehow
+# lost between LAC invocations.
+AT_CHECK([[perl -0777 -ne 'print s/\(realloc//g;' < stderr.txt \
+ || exit 77]], [[0]], [[3]])
+
+AT_BISON_OPTION_POPDEFS
+])
+
+AT_LAC_CHECK([[%define api.push-pull pull]])
+AT_LAC_CHECK([[%define api.push-pull pull %define api.pure]])
+AT_LAC_CHECK([[%define api.push-pull both]])
+AT_LAC_CHECK([[%define api.push-pull both %define api.pure]])
+
+m4_popdef([AT_LAC_CHECK])
+
+AT_CLEANUP
+
+
+
+## ------------------------ ##
+## LAC: Memory exhaustion. ##
+## ------------------------ ##
+
+AT_SETUP([[LAC: Memory exhaustion]])
+
+m4_pushdef([AT_LAC_CHECK],
+[AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([input.y],
+[[%code {
+ #include <stdio.h>
+ ]AT_YYERROR_DECLARE[
+ ]AT_YYLEX_DECLARE[
+ #define YYMAXDEPTH 8
+}
+
+%error-verbose
+
+%%
+
+S: A A A A A A A A A ;
+A: /*empty*/ | 'a' ;
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(["$1"])[
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-Dparse.lac=full -Dparse.lac.es-capacity-initial=1 \
+ -t -o input.c input.y]], [[0]], [],
+[[input.y: conflicts: 8 shift/reduce
+]])
+AT_COMPILE([[input]])
+AT_BISON_OPTION_POPDEFS
+])
+
+# Check for memory exhaustion during parsing.
+AT_LAC_CHECK([])
+AT_PARSER_CHECK([[./input]], [[2]], [],
+[[Starting parse
+Entering state 0
+Reading a token: Now at end of input.
+LAC: initial context established for $end
+LAC: checking lookahead $end: R2 G3 R2 G5 R2 G6 R2 G7 R2 G8 R2 G9 R2 G10 R2 G11 R2 (max size exceeded)
+memory exhausted
+Cleanup: discarding lookahead token $end ()
+Stack now 0
+]])
+
+# Induce an immediate syntax error with an undefined token, and check
+# for memory exhaustion while building syntax error message.
+AT_LAC_CHECK([z], [[0]])
+AT_PARSER_CHECK([[./input]], [[2]], [],
+[[Starting parse
+Entering state 0
+Reading a token: Next token is token $undefined ()
+LAC: initial context established for $undefined
+LAC: checking lookahead $undefined: Always Err
+Constructing syntax error message
+LAC: checking lookahead $end: R2 G3 R2 G5 R2 G6 R2 G7 R2 G8 R2 G9 R2 G10 R2 G11 R2 (max size exceeded)
+syntax error
+memory exhausted
+Cleanup: discarding lookahead token $undefined ()
+Stack now 0
+]])
+
+m4_popdef([AT_LAC_CHECK])