+AT_CAPTURE_FILE([ielr.c])
+AT_CHECK([[diff lalr.c ielr.c]], [[0]])
+
+AT_CLEANUP
+
+
+
+## --------------------------------------- ##
+## %error-verbose and YYSTACK_USE_ALLOCA. ##
+## --------------------------------------- ##
+
+AT_SETUP([[%error-verbose and YYSTACK_USE_ALLOCA]])
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([input.y],
+[[%code {
+ #include <stdio.h>
+ ]AT_YYERROR_DECLARE[
+ ]AT_YYLEX_DECLARE[
+ #define YYSTACK_USE_ALLOCA 1
+}
+
+%error-verbose
+
+%%
+
+start: check syntax_error syntax_error ;
+
+check:
+{
+ if (128 < sizeof yymsgbuf)
+ {
+ fprintf (stderr,
+ "The initial size of yymsgbuf in yyparse has increased\n"
+ "since this test group was last updated. As a result,\n"
+ "this test group may no longer manage to induce a\n"
+ "reallocation of the syntax error message buffer.\n"
+ "This test group must be adjusted to produce a longer\n"
+ "error message.\n");
+ YYABORT;
+ }
+}
+;
+
+// Induce a syntax error message whose total length is more than
+// sizeof yymsgbuf in yyparse. Each token here is 64 bytes.
+syntax_error:
+ "123456789112345678921234567893123456789412345678951234567896123A"
+| "123456789112345678921234567893123456789412345678951234567896123B"
+| error 'a' 'b' 'c'
+;
+
+%%
+
+]AT_YYERROR_DEFINE[
+/* Induce two syntax error messages (which requires full error
+ recovery by shifting 3 tokens) in order to detect any loss of the
+ reallocated buffer. */
+]AT_YYLEX_DEFINE(["abc"])[
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+AT_BISON_CHECK([[-o input.c input.y]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]], [[1]], [],
+[[syntax error, unexpected 'a', expecting 123456789112345678921234567893123456789412345678951234567896123A or 123456789112345678921234567893123456789412345678951234567896123B
+syntax error, unexpected $end, expecting 123456789112345678921234567893123456789412345678951234567896123A or 123456789112345678921234567893123456789412345678951234567896123B
+]])
+
+AT_CLEANUP
+
+
+
+## ------------------------- ##
+## %error-verbose overflow. ##
+## ------------------------- ##
+
+# Imagine the case where YYSTACK_ALLOC_MAXIMUM = YYSIZE_MAXIMUM and an
+# invocation of yysyntax_error has caused yymsg_alloc to grow to exactly
+# YYSTACK_ALLOC_MAXIMUM (perhaps because the normal doubling of size had
+# to be clipped to YYSTACK_ALLOC_MAXIMUM). In an old version of yacc.c,
+# a subsequent invocation of yysyntax_error that overflows during its
+# size calculation would return YYSIZE_MAXIMUM to yyparse. Then,
+# yyparse would invoke yyerror using the old contents of yymsg.
+
+AT_SETUP([[%error-verbose overflow]])
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([input.y],
+[[%code {
+ #include <stdio.h>
+ ]AT_YYERROR_DECLARE[
+ ]AT_YYLEX_DECLARE[
+
+ /* This prevents this test case from having to induce error messages
+ large enough to overflow size_t. */
+ #define YYSIZE_T unsigned char
+
+ /* Bring in malloc and set EXIT_SUCCESS so yacc.c doesn't try to
+ provide a malloc prototype using our YYSIZE_T. */
+ #include <stdlib.h>
+ #ifndef EXIT_SUCCESS
+ # define EXIT_SUCCESS 0
+ #endif
+
+ /* Max depth is usually much smaller than YYSTACK_ALLOC_MAXIMUM, and
+ we don't want gcc to warn everywhere this constant would be too big
+ to make sense for our YYSIZE_T. */
+ #define YYMAXDEPTH 100
+}
+
+%error-verbose
+
+%%
+
+start: syntax_error1 check syntax_error2 ;
+
+// Induce a syntax error message whose total length causes yymsg in
+// yyparse to be reallocated to size YYSTACK_ALLOC_MAXIMUM, which
+// should be 255. Each token here is 64 bytes.
+syntax_error1:
+ "123456789112345678921234567893123456789412345678951234567896123A"
+| "123456789112345678921234567893123456789412345678951234567896123B"
+| "123456789112345678921234567893123456789412345678951234567896123C"
+| error 'a' 'b' 'c'
+;
+
+check:
+{
+ if (yymsg_alloc != YYSTACK_ALLOC_MAXIMUM
+ || YYSTACK_ALLOC_MAXIMUM != YYSIZE_MAXIMUM
+ || YYSIZE_MAXIMUM != 255)
+ {
+ fprintf (stderr,
+ "The assumptions of this test group are no longer\n"
+ "valid, so it may no longer catch the error it was\n"
+ "designed to catch. Specifically, the following\n"
+ "values should all be 255:\n\n");
+ fprintf (stderr, " yymsg_alloc = %d\n", yymsg_alloc);
+ fprintf (stderr, " YYSTACK_ALLOC_MAXIMUM = %d\n",
+ YYSTACK_ALLOC_MAXIMUM);
+ fprintf (stderr, " YYSIZE_MAXIMUM = %d\n", YYSIZE_MAXIMUM);
+ YYABORT;
+ }
+}
+;
+
+// Now overflow.
+syntax_error2:
+ "123456789112345678921234567893123456789412345678951234567896123A"
+| "123456789112345678921234567893123456789412345678951234567896123B"
+| "123456789112345678921234567893123456789412345678951234567896123C"
+| "123456789112345678921234567893123456789412345678951234567896123D"
+| "123456789112345678921234567893123456789412345678951234567896123E"
+;
+
+%%
+
+]AT_YYERROR_DEFINE[
+/* Induce two syntax error messages (which requires full error
+ recovery by shifting 3 tokens). */
+]AT_YYLEX_DEFINE(["abc"])[
+int
+main (void)
+{
+ /* Push parsers throw away the message buffer between tokens, so skip
+ this test under maintainer-push-check. */
+ if (YYPUSH)
+ return 77;
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o input.c input.y]])
+
+# gcc warns about tautologies and fallacies involving comparisons for
+# unsigned char. However, it doesn't produce these same warnings for
+# size_t and many other types when the warnings would seem to make just
+# as much sense. We ignore the warnings.
+[CFLAGS="$NO_WERROR_CFLAGS"]
+AT_COMPILE([[input]])
+
+AT_PARSER_CHECK([[./input]], [[2]], [],
+[[syntax error, unexpected 'a', expecting 123456789112345678921234567893123456789412345678951234567896123A or 123456789112345678921234567893123456789412345678951234567896123B or 123456789112345678921234567893123456789412345678951234567896123C
+syntax error
+memory exhausted
+]])
+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])