X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/965537bc543191a048b6afb2404c878f06ab877f..abd189e8dc6ca848f038da12e4110d6192374b82:/tests/regression.at

diff --git a/tests/regression.at b/tests/regression.at
index 1c5ccbbf..c07b7442 100644
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -1,22 +1,19 @@
 # Bison Regressions.                               -*- Autotest -*-
 
-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software
-# Foundation, Inc.
+# Copyright (C) 2001-2011 Free Software Foundation, Inc.
 
-# This program is free software; you can redistribute it and/or modify
+# This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
-
+#
 # You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-# 02110-1301, USA.
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 AT_BANNER([[Regression tests.]])
 
@@ -41,7 +38,7 @@ int yylex (void);
 program: 'x';
 ]])
 
-AT_CHECK([bison -o input.c input.y])
+AT_BISON_CHECK([-o input.c input.y])
 AT_COMPILE([input.o], [-c input.c])
 AT_COMPILE([input.o], [-DYYDEBUG -c input.c])
 
@@ -69,7 +66,7 @@ typedef union { char const *val; } YYSTYPE;
 program: { $$ = ""; };
 ]])
 
-AT_CHECK([bison -o input.c input.y])
+AT_BISON_CHECK([-o input.c input.y])
 AT_COMPILE([input.o], [-c input.c])
 
 AT_CLEANUP
@@ -107,7 +104,7 @@ exp: MY_TOKEN;
 %%
 ]])
 
-AT_CHECK([bison -y -o input.c input.y])
+AT_BISON_CHECK([-y -o input.c input.y])
 AT_COMPILE([input.o], [-c input.c])
 
 AT_CLEANUP
@@ -150,7 +147,7 @@ exp: MY_TOKEN;
 %%
 ]])
 
-AT_CHECK([bison -o input.c input.y])
+AT_BISON_CHECK([-o input.c input.y])
 AT_COMPILE([input.o], [-c input.c])
 
 AT_CLEANUP
@@ -172,7 +169,7 @@ exp: { tests = {{{{{{{{{{}}}}}}}}}}; };
 %%
 ]])
 
-AT_CHECK([bison -v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y])
 
 AT_CHECK([grep 'tests = {{{{{{{{{{}}}}}}}}}};' input.c], 0, [ignore])
 
@@ -199,7 +196,7 @@ exp: '(' exp ')' | NUM ;
 %%
 ]])
 
-AT_CHECK([bison -v -o input.c input.y], 0, [],
+AT_BISON_CHECK([-v -o input.c input.y], 0, [],
 [[input.y:6.8-14: warning: symbol `"<="' used more than once as a literal string
 ]])
 
@@ -244,7 +241,7 @@ expr:
 };
 ]])
 
-AT_CHECK([bison -o input.c -v input.y])
+AT_BISON_CHECK([-o input.c -v input.y])
 
 # Check the contents of the report.
 AT_CHECK([cat input.output], [],
@@ -252,13 +249,13 @@ AT_CHECK([cat input.output], [],
 
     0 $accept: expr $end
 
-    1 @1: /* empty */
+    1 $@1: /* empty */
 
-    2 expr: 'a' @1 'b'
+    2 expr: 'a' $@1 'b'
 
-    3 @2: /* empty */
+    3 $@2: /* empty */
 
-    4 expr: @2 'c'
+    4 expr: $@2 'c'
 
 
 Terminals, with rules where they appear
@@ -276,9 +273,9 @@ $accept (6)
     on left: 0
 expr (7)
     on left: 2 4, on right: 0
-@1 (8)
+$@1 (8)
     on left: 1, on right: 2
-@2 (9)
+$@2 (9)
     on left: 3, on right: 4
 
 
@@ -288,19 +285,19 @@ state 0
 
     'a'  shift, and go to state 1
 
-    $default  reduce using rule 3 (@2)
+    $default  reduce using rule 3 ($@2)
 
     expr  go to state 2
-    @2    go to state 3
+    $@2   go to state 3
 
 
 state 1
 
-    2 expr: 'a' . @1 'b'
+    2 expr: 'a' . $@1 'b'
 
-    $default  reduce using rule 1 (@1)
+    $default  reduce using rule 1 ($@1)
 
-    @1  go to state 4
+    $@1  go to state 4
 
 
 state 2
@@ -312,14 +309,14 @@ state 2
 
 state 3
 
-    4 expr: @2 . 'c'
+    4 expr: $@2 . 'c'
 
     'c'  shift, and go to state 6
 
 
 state 4
 
-    2 expr: 'a' @1 . 'b'
+    2 expr: 'a' $@1 . 'b'
 
     'b'  shift, and go to state 7
 
@@ -333,14 +330,14 @@ state 5
 
 state 6
 
-    4 expr: @2 'c' .
+    4 expr: $@2 'c' .
 
     $default  reduce using rule 4 (expr)
 
 
 state 7
 
-    2 expr: 'a' @1 'b' .
+    2 expr: 'a' $@1 'b' .
 
     $default  reduce using rule 2 (expr)
 ]])
@@ -366,7 +363,7 @@ exp: ;
 %%
 ]])
 
-AT_CHECK([bison -v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y])
 
 AT_CLEANUP
 
@@ -389,7 +386,7 @@ default: 'a' }
 %{
 ]])
 
-AT_CHECK([bison input.y], [1], [],
+AT_BISON_CHECK([input.y], [1], [],
 [[input.y:2.1: invalid character: `?'
 input.y:3.14: invalid character: `}'
 input.y:4.1: invalid character: `%'
@@ -416,7 +413,7 @@ AT_DATA([input.y],
 %union
 ]])
 
-AT_CHECK([bison input.y], [1], [],
+AT_BISON_CHECK([input.y], [1], [],
 [[input.y:3.1-15: syntax error, unexpected %initial-action, expecting {...}
 ]])
 
@@ -434,6 +431,7 @@ AT_SETUP([Token definitions])
 # Bison managed, when fed with `%token 'f' "f"' to #define 'f'!
 AT_DATA_GRAMMAR([input.y],
 [%{
+#include <stdlib.h>
 #include <stdio.h>
 void yyerror (const char *s);
 int yylex (void);
@@ -445,6 +443,7 @@ int yylex (void);
 %token C_TOKEN 'c'
 %token 'd' D_TOKEN
 %token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
+%token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
 %%
 exp: "a" "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!";
 %%
@@ -457,6 +456,9 @@ yyerror (char const *s)
 int
 yylex (void)
 {
+  static int called;
+  if (called++)
+    abort ();
   return SPECIAL;
 }
 
@@ -467,10 +469,22 @@ main (void)
 }
 ]])
 
-AT_CHECK([bison -o input.c input.y])
+# Checking the warning message guarantees that the trigraph "??!" isn't
+# unnecessarily escaped here even though it would need to be if encoded in a
+# C-string literal.  Also notice that unnecessary escaping, such as "\?", from
+# the user specification is eliminated.
+AT_BISON_CHECK([-o input.c input.y], [[0]], [[]],
+[[input.y:22.8-14: warning: symbol SPECIAL redeclared
+input.y:22.8-63: warning: symbol `"\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!"' used more than once as a literal string
+]])
 AT_COMPILE([input])
+
+# Checking the error message here guarantees that yytname, which does contain
+# C-string literals, does have the trigraph escaped correctly.  Thus, the
+# symbol name reported by the parser is exactly the same as that reported by
+# Bison itself.
 AT_DATA([experr],
-[[syntax error, unexpected "\\'?\"\a\b\f\n\r\t\v\001\201\001\201?\?!", expecting a
+[[syntax error, unexpected "\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!", expecting a
 ]])
 AT_PARSER_CHECK([./input], 1, [], [experr])
 AT_CLEANUP
@@ -489,9 +503,7 @@ AT_DATA_GRAMMAR([input.y],
 void yyerror (const char *s);
 int yylex (void);
 %}
-[%token QUOTES "\""
-%token TICK "'"
-%%
+[%%
 exp:
   '\'' "\'"
 | '\"' "\""
@@ -500,7 +512,7 @@ exp:
 ]])
 # Pacify font-lock-mode: "
 
-AT_CHECK([bison -o input.c input.y])
+AT_BISON_CHECK([-o input.c input.y])
 AT_COMPILE([input.o], [-c input.c])
 AT_CLEANUP
 
@@ -540,7 +552,7 @@ CONST_DEC:
 %%
 ]])
 
-AT_CHECK([bison -v input.y])
+AT_BISON_CHECK([-v input.y])
 AT_CHECK([cat input.output], 0,
 [[Grammar
 
@@ -551,9 +563,9 @@ AT_CHECK([cat input.output], 0,
     2 CONST_DEC_LIST: CONST_DEC
     3               | CONST_DEC_LIST CONST_DEC
 
-    4 @1: /* empty */
+    4 $@1: /* empty */
 
-    5 CONST_DEC: @1 undef_id_tok '=' const_id_tok ';'
+    5 CONST_DEC: $@1 undef_id_tok '=' const_id_tok ';'
 
 
 Terminals, with rules where they appear
@@ -576,7 +588,7 @@ CONST_DEC_LIST (9)
     on left: 2 3, on right: 1 3
 CONST_DEC (10)
     on left: 5, on right: 2 3
-@1 (11)
+$@1 (11)
     on left: 4, on right: 5
 
 
@@ -584,12 +596,12 @@ state 0
 
     0 $accept: . CONST_DEC_PART $end
 
-    $default  reduce using rule 4 (@1)
+    $default  reduce using rule 4 ($@1)
 
     CONST_DEC_PART  go to state 1
     CONST_DEC_LIST  go to state 2
     CONST_DEC       go to state 3
-    @1              go to state 4
+    $@1             go to state 4
 
 
 state 1
@@ -604,11 +616,11 @@ state 2
     1 CONST_DEC_PART: CONST_DEC_LIST .
     3 CONST_DEC_LIST: CONST_DEC_LIST . CONST_DEC
 
-    undef_id_tok  reduce using rule 4 (@1)
+    undef_id_tok  reduce using rule 4 ($@1)
     $default      reduce using rule 1 (CONST_DEC_PART)
 
     CONST_DEC  go to state 6
-    @1         go to state 4
+    $@1        go to state 4
 
 
 state 3
@@ -620,7 +632,7 @@ state 3
 
 state 4
 
-    5 CONST_DEC: @1 . undef_id_tok '=' const_id_tok ';'
+    5 CONST_DEC: $@1 . undef_id_tok '=' const_id_tok ';'
 
     undef_id_tok  shift, and go to state 7
 
@@ -641,28 +653,28 @@ state 6
 
 state 7
 
-    5 CONST_DEC: @1 undef_id_tok . '=' const_id_tok ';'
+    5 CONST_DEC: $@1 undef_id_tok . '=' const_id_tok ';'
 
     '='  shift, and go to state 8
 
 
 state 8
 
-    5 CONST_DEC: @1 undef_id_tok '=' . const_id_tok ';'
+    5 CONST_DEC: $@1 undef_id_tok '=' . const_id_tok ';'
 
     const_id_tok  shift, and go to state 9
 
 
 state 9
 
-    5 CONST_DEC: @1 undef_id_tok '=' const_id_tok . ';'
+    5 CONST_DEC: $@1 undef_id_tok '=' const_id_tok . ';'
 
     ';'  shift, and go to state 10
 
 
 state 10
 
-    5 CONST_DEC: @1 undef_id_tok '=' const_id_tok ';' .
+    5 CONST_DEC: $@1 undef_id_tok '=' const_id_tok ';' .
 
     $default  reduce using rule 5 (CONST_DEC)
 ]])
@@ -702,17 +714,12 @@ statement:  struct_stat;
 struct_stat:  /* empty. */ | if else;
 if: "if" "const" "then" statement;
 else: "else" statement;
-%token IF "if";
-%token CONST "const";
-%token THEN "then";
-%token ELSE "else";
 %%
 ]])
 
-AT_CHECK([bison -v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y])
 
-# Check only the tables.  We don't use --no-parser, because it is
-# still to be implemented in the experimental branch of Bison.
+# Check only the tables.
 [sed -n 's/  *$//;/^static const.*\[\] =/,/^}/p' input.c >tables.c]
 
 AT_CHECK([[cat tables.c]], 0,
@@ -828,7 +835,8 @@ m4_define([_AT_DATA_DANCER_Y],
 [%{
 static int yylex (AT_LALR1_CC_IF([int *], [void]));
 AT_LALR1_CC_IF([],
-[#include <stdio.h>
+[#include <stdlib.h>
+#include <stdio.h>
 static void yyerror (const char *);])
 %}
 $1
@@ -887,7 +895,9 @@ int
 yyparse ()
 {
   yy::parser parser;
-  parser.set_debug_level (!!YYDEBUG);
+#if YYDEBUG
+  parser.set_debug_level (YYDEBUG);
+#endif
   return parser.parse ();
 }
 ],
@@ -900,12 +910,14 @@ yyerror (const char *s)
 static int
 yylex (AT_LALR1_CC_IF([int *lval], [void]))
 [{
-  static int toknum = 0;
-  static int tokens[] =
+  static int const tokens[] =
     {
       ':', -1
     };
+  static size_t toknum;
   ]AT_LALR1_CC_IF([*lval = 0; /* Pacify GCC.  */])[
+  if (! (toknum < sizeof tokens / sizeof *tokens))
+    abort ();
   return tokens[toknum++];
 }]
 
@@ -925,12 +937,8 @@ m4_define([AT_CHECK_DANCER],
 [AT_SETUP([Dancer $1])
 AT_BISON_OPTION_PUSHDEFS([$1])
 _AT_DATA_DANCER_Y([$1])
-AT_CHECK([bison -o dancer.c dancer.y])
-AT_LALR1_CC_IF(
-  [AT_CHECK([bison -o dancer.cc dancer.y])
-   AT_COMPILE_CXX([dancer])],
-  [AT_CHECK([bison -o dancer.c dancer.y])
-   AT_COMPILE([dancer])])
+AT_BISON_CHECK([-o dancer.c dancer.y])
+AT_FULL_COMPILE([dancer])
 AT_PARSER_CHECK([./dancer], 1, [],
 [syntax error, unexpected ':'
 ])
@@ -956,6 +964,7 @@ m4_define([_AT_DATA_EXPECT2_Y],
 static int yylex (AT_LALR1_CC_IF([int *], [void]));
 AT_LALR1_CC_IF([],
 [#include <stdio.h>
+#include <stdlib.h>
 static void yyerror (const char *);])
 %}
 $1
@@ -997,12 +1006,14 @@ yyerror (const char *s)
 static int
 yylex (AT_LALR1_CC_IF([int *lval], [void]))
 [{
-  static int toknum = 0;
-  static int tokens[] =
+  static int const tokens[] =
     {
       1000, '+', '+', -1
     };
+  static size_t toknum;
   ]AT_LALR1_CC_IF([*lval = 0; /* Pacify GCC.  */])[
+  if (! (toknum < sizeof tokens / sizeof *tokens))
+    abort ();
   return tokens[toknum++];
 }]
 
@@ -1022,12 +1033,8 @@ m4_define([AT_CHECK_EXPECT2],
 [AT_SETUP([Expecting two tokens $1])
 AT_BISON_OPTION_PUSHDEFS([$1])
 _AT_DATA_EXPECT2_Y([$1])
-AT_CHECK([bison -o expect2.c expect2.y])
-AT_LALR1_CC_IF(
-  [AT_CHECK([bison -o expect2.cc expect2.y])
-   AT_COMPILE_CXX([expect2])],
-  [AT_CHECK([bison -o expect2.c expect2.y])
-   AT_COMPILE([expect2])])
+AT_BISON_CHECK([-o expect2.c expect2.y])
+AT_FULL_COMPILE([expect2])
 AT_PARSER_CHECK([./expect2], 1, [],
 [syntax error, unexpected '+', expecting A or B
 ])
@@ -1093,14 +1100,14 @@ main (void)
 }
 ]])
 
-AT_CHECK([bison -t -o input.c input.y])
+AT_BISON_CHECK([-t -o input.c input.y])
 AT_COMPILE([input])
 AT_PARSER_CHECK([./input], 0,
 [[Bison would once convert this action to a midrule because of the subsequent braced code.
 ]],
 [[Starting parse
 Entering state 0
-Reducing stack by rule 1 (line 22):
+Reducing stack by rule 1 (line 20):
 -> $$ = nterm start ()
 Stack now 0
 Entering state 1
@@ -1126,7 +1133,7 @@ AT_SETUP([String alias declared after use])
 # Bison once incorrectly asserted that the symbol number for either a token or
 # its alias was the highest symbol number so far at the point of the alias
 # declaration.  That was true unless the declaration appeared after their first
-# uses.
+# uses and other tokens appeared in between.
 
 AT_DATA([input.y],
 [[%%
@@ -1134,28 +1141,533 @@ start: 'a' "A" 'b';
 %token 'a' "A";
 ]])
 
-AT_CHECK([bison -t -o input.c input.y])
+AT_BISON_CHECK([-t -o input.c input.y])
+
+AT_CLEANUP
+
+
+
+## -------------------------------- ##
+## Extra lookahead sets in report.  ##
+## -------------------------------- ##
+
+AT_SETUP([[Extra lookahead sets in report]])
+
+# Bison prints each reduction's lookahead set only next to the associated
+# state's one item that (1) is associated with the same rule as the reduction
+# and (2) has its dot at the end of its RHS.  Previously, Bison also
+# erroneously printed the lookahead set next to all of the state's other items
+# associated with the same rule.  This bug affected only the `.output' file and
+# not the generated parser source code.
+
+AT_DATA([[input.y]],
+[[%%
+start: a | 'a' a 'a' ;
+a: 'a' ;
+]])
+
+AT_BISON_CHECK([[--report=all input.y]])
+AT_CHECK([[sed -n '/^state 1$/,/^state 2$/p' input.output]], [[0]],
+[[state 1
+
+    2 start: 'a' . a 'a'
+    3 a: . 'a'
+    3  | 'a' .  [$end]
+
+    'a'  shift, and go to state 4
+
+    $default  reduce using rule 3 (a)
+
+    a  go to state 5
+
+
+state 2
+]])
+
+AT_CLEANUP
+
+
+
+## ---------------------------------------- ##
+## Token number in precedence declaration.  ##
+## ---------------------------------------- ##
+
+AT_SETUP([[Token number in precedence declaration]])
+
+# POSIX says token numbers can be declared in %left, %right, and %nonassoc, but
+# we lost this in Bison 1.50.
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+  #include <stdio.h>
+  void yyerror (char const *);
+  int yylex (void);
+%}
+
+%error-verbose
+%right END 0
+%left TK1 1 TK2 2 "tok alias" 3
+
+%%
+
+start:
+    TK1 sr_conflict "tok alias"
+  | start %prec END
+  ;
+sr_conflict:
+  TK2
+  | TK2 "tok alias"
+  ;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+int
+yylex (void)
+{
+  static int const input[] = { 1, 2, 3, 0 };
+  static int const *inputp = input;
+  return *inputp++;
+}
+
+int
+main (void)
+{
+  return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o input.c input.y]], [[0]],,
+[[input.y:23.5-19: warning: rule useless in parser due to conflicts: start: start
+input.y:27.5-19: warning: rule useless in parser due to conflicts: sr_conflict: TK2 "tok alias"
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]])
 
 AT_CLEANUP
 
 
 
 ## --------------------------- ##
-## Undeclared string literal.  ##
+## parse-gram.y: LALR = IELR.  ##
 ## --------------------------- ##
 
-AT_SETUP([Undeclared string literal])
+# If parse-gram.y's LALR and IELR parser tables ever begin to differ, we
+# need to fix parse-gram.y or start using IELR.
 
-# Bison once allowed a string literal to be used in the grammar without any
-# declaration assigning it as an alias of another token.
+AT_SETUP([[parse-gram.y: LALR = IELR]])
 
-AT_DATA([input.y],
-[[%%
-start: "abc";
+# Avoid differences in synclines by telling bison that the output files
+# have the same name.
+[cp $abs_top_srcdir/src/parse-gram.y input.y]
+AT_BISON_CHECK([[-o input.c -Dlr.type=lalr input.y]])
+[mv input.c lalr.c]
+AT_BISON_CHECK([[-o input.c -Dlr.type=ielr input.y]])
+[mv input.c ielr.c]
+AT_CHECK([[diff -u lalr.c ielr.c]])
+
+AT_CLEANUP
+
+
+
+## --------------------------------------- ##
+## %error-verbose and YYSTACK_USE_ALLOCA.  ##
+## --------------------------------------- ##
+
+AT_SETUP([[%error-verbose and YYSTACK_USE_ALLOCA]])
+
+AT_DATA_GRAMMAR([input.y],
+[[%code {
+  #include <stdio.h>
+  void yyerror (char const *);
+  int yylex (void);
+  #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'
+;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+int
+yylex (void)
+{
+  /* Induce two syntax error messages (which requires full error
+     recovery by shifting 3 tokens) in order to detect any loss of the
+     reallocated buffer.  */
+  static char const *input = "abc";
+  return *input++;
+}
+
+int
+main (void)
+{
+  return yyparse ();
+}
+]])
+
+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_DATA_GRAMMAR([input.y],
+[[%code {
+  #include <stdio.h>
+  void yyerror (char const *);
+  int yylex (void);
+
+  /* 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"
+;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+int
+yylex (void)
+{
+  /* Induce two syntax error messages (which requires full error
+     recovery by shifting 3 tokens).  */
+  static char const *input = "abc";
+  return *input++;
+}
+
+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_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>
+  void yyerror (char const *);
+  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"); } ;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+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]])
 
-AT_CHECK([bison -t -o input.c input.y], [1], [],
-[[input.y:2.8-12: "abc" undeclared
+# 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_DATA_GRAMMAR([input.y],
+[[%code {
+  #include <stdio.h>
+  void yyerror (char const *);
+  int yylex (void);
+  #define YYMAXDEPTH 8
+}
+
+%error-verbose
+
+%%
+
+S: A A A A A A A A A ;
+A: /*empty*/ | 'a' ;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+int
+yylex (void)
+{
+  static char const *input = "]$1[";
+  return *input++;
+}
+
+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]])
+
+])
+
+# 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])
+
 AT_CLEANUP