version 2.7.90

* NEWS: Record release date.
style: syntax-check fixes
2026-08-08 18:25:13 +00:00 · 2013-05-30 15:02:52 +02:00 · 2013-05-30 14:10:05 +02:00 · 2013-05-30 11:07:57 +02:00 · 2013-05-30 11:07:57 +02:00 · 2013-05-30 11:07:57 +02:00
89 changed files with 4770 additions and 3086 deletions
@@ -1 +1 @@
-2.7
+2.7.1
@@ -32,8 +32,8 @@ EXTRA_DIST = .prev-version .version \
 ## version of Bison nearby...
 BISON = $(top_builddir)/tests/bison
 BISON_IN = $(top_srcdir)/tests/bison.in
-YACC = $(BISON) -y
-AM_YFLAGS = -d -v --warnings=all,error --report=all
+YACC = $(BISON) -o y.tab.c
+AM_YFLAGS = -d -v -Werror -Wall -Wno-yacc --report=all

 # Initialization before completion by local.mk's.
 AM_CFLAGS = $(WARN_CFLAGS)
@@ -78,11 +78,11 @@ dist-hook: gen-ChangeLog

 .PHONY: update-b4-copyright update-package-copyright-year
 update-b4-copyright:
-	find $(srcdir)/data -type f          \
+	$(AM_V_GEN)find $(srcdir)/data -type f          \
 	  | xargs $(srcdir)/build-aux/$@
 	@echo 'warning: src/parse-gram.[hc] may need to be regenerated.'
 update-package-copyright-year:
-	$(srcdir)/build-aux/$@ $(srcdir)/configure.ac
+	$(AM_V_GEN)$(srcdir)/build-aux/$@ $(srcdir)/configure.ac

 gen_start_date = 2012-01-16
 .PHONY: gen-ChangeLog
@@ -1,17 +1,9 @@
 GNU Bison NEWS

-* Noteworthy changes in release ?.? (????-??-??) [?]
+* Noteworthy changes in release 2.7.90 (2013-05-30) [beta]

 ** WARNING: Future backward-incompatibilities!

-  Bison will stop adding a semicolon at the end of the actions (as announced
-  in the release 2.5):
-
-    foo.y:2.22: warning: a ';' might be needed at the end of action code
-     exp: "num" { $$ = $1 }
-                          ^
-    foo.y:2.22:     future versions of Bison will not add the ';'
-
  Like other GNU packages, Bison will start using some of the C99 features
  for its own code, especially the definition of variables after statements.
  The generated C parsers still aim at C90.
@@ -28,9 +20,32 @@ GNU Bison NEWS
  Support for YYLEX_PARAM and YYPARSE_PARAM is removed (deprecated in Bison
  1.875): use %lex-param, %parse-param, or %param.

+  Missing semicolons at the end of actions are no longer added (as announced
+  in the release 2.5).
+
+*** Use of YACC='bison -y'
+
+  TL;DR: With Autoconf <= 2.69, pass -Wno-yacc to (AM_)YFLAGS if you use
+  Bison extensions.
+
+  Traditional Yacc generates 'y.tab.c' whatever the name of the input file.
+  Therefore Makefiles written for Yacc expect 'y.tab.c' (and possibly
+  'y.tab.h' and 'y.outout') to be generated from 'foo.y'.
+
+  To this end, for ages, AC_PROG_YACC, Autoconf's macro to look for an
+  implementation of Yacc, was using Bison as 'bison -y'.  While it does
+  ensure compatible output file names, it also enables warnings for
+  incompatibilities with POSIX Yacc.  In other words, 'bison -y' triggers
+  warnings for Bison extensions.
+
+  Autoconf 2.70+ fixes this incompatibility by using YACC='bison -o y.tab.c'
+  (which also generates 'y.tab.h' and 'y.output' when needed).
+  Alternatively, disable Yacc warnings by passing '-Wno-yacc' to your Yacc
+  flags (YFLAGS, or AM_YFLAGS with Automake).
+
 ** Bug fixes

-*** The epilogue is no longer affected by internal #defines
+*** The epilogue is no longer affected by internal #defines (glr.c)

  The glr.c skeleton uses defines such as #define yylval (yystackp->yyval) in
  generated code.  These weren't properly undefined before the inclusion of
@@ -39,7 +54,7 @@ GNU Bison NEWS

    int yylex (YYSTYPE *yylval);

-  This is has been fixed: yylval, yynerrs, yychar, and yylloc are now valid
+  This is fixed: yylval, yynerrs, yychar, and yylloc are now valid
  identifiers for user-provided variables.

 *** stdio.h is no longer needed when locations are enabled (yacc.c)
@@ -47,6 +62,8 @@ GNU Bison NEWS
  Changes in Bison 2.7 introduced a dependency on FILE and fprintf when
  locations are enabled.  This is fixed.

+*** Warnings about useless %pure-parser/%define api.pure are restored
+
 ** Diagnostics reported by Bison

  Most of these features were contributed by Théophile Ranquet and Victor
@@ -58,6 +75,29 @@ GNU Bison NEWS
  activated by default.  The old format can still be used by invoking Bison
  with -fno-caret (or -fnone).

+  Some error messages that reproduced excerpts of the grammar are now using
+  the caret information only.  For instance on:
+
+    %%
+    exp: 'a' | 'a';
+
+  Bison 2.7 reports:
+
+    in.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+    in.y:2.12-14: warning: rule useless in parser due to conflicts: exp: 'a' [-Wother]
+
+  Now bison reports:
+
+    in.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+    in.y:2.12-14: warning: rule useless in parser due to conflicts [-Wother]
+     exp: 'a' | 'a';
+                ^^^
+
+  and "bison -fno-caret" reports:
+
+    in.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+    in.y:2.12-14: warning: rule useless in parser due to conflicts [-Wother]
+
 *** Enhancements of the -Werror option

  The -Werror=CATEGORY option is now recognized, and will treat specified
@@ -198,12 +238,10 @@ GNU Bison NEWS
    bar.y: error: shift/reduce conflicts: 1 found, 0 expected
    bar.y: error: reduce/reduce conflicts: 2 found, 0 expected

-*** Useless precedence
+** Incompatibilities with POSIX Yacc

-  Bison now warns about symbols with a declared precedence but no declared
-  associativity (i.e. declared with %precedence), and whose precedence is
-  never used.  In that case, the symbol can be safely declared with %token
-  instead, without modifying the parsing tables.
+  The 'yacc' category is no longer part of '-Wall', enable it explicitly
+  with '-Wyacc'.

 ** Additional yylex/yyparse arguments

@@ -220,6 +258,262 @@ GNU Bison NEWS

    %param {arg1_type *arg1} {arg2_type *arg2}

+** Types of values for %define variables
+
+  Bison used to make no difference between '%define foo bar' and '%define
+  foo "bar"'.  The former is now called a 'keyword value', and the latter a
+  'string value'.  A third kind was added: 'code values', such as '%define
+  foo {bar}'.
+
+  Keyword variables are used for fixed value sets, e.g.,
+
+    %define lr.type lalr
+
+  Code variables are used for value in the target language, e.g.,
+
+    %define api.value.type {struct semantic_type}
+
+  String variables are used remaining cases, e.g. file names.
+
+** Variable api.token.prefix
+
+  The variable api.token.prefix changes the way tokens are identified in
+  the generated files.  This is especially useful to avoid collisions
+  with identifiers in the target language.  For instance
+
+    %token FILE for ERROR
+    %define api.token.prefix {TOK_}
+    %%
+    start: FILE for ERROR;
+
+  will generate the definition of the symbols TOK_FILE, TOK_for, and
+  TOK_ERROR in the generated sources.  In particular, the scanner must
+  use these prefixed token names, although the grammar itself still
+  uses the short names (as in the sample rule given above).
+
+** Variable api.value.type
+
+  This new %define variable supersedes the #define macro YYSTYPE.  The use
+  of YYSTYPE is discouraged.  In particular, #defining YYSTYPE *and* either
+  using %union or %defining api.value.type results in undefined behavior.
+
+  Either define api.value.type, or use "%union":
+
+    %union
+    {
+      int ival;
+      char *sval;
+    }
+    %token <ival> INT "integer"
+    %token <sval> STRING "string"
+    %printer { fprintf (yyo, "%d", $$); } <ival>
+    %destructor { free ($$); } <sval>
+
+    /* In yylex().  */
+    yylval.ival = 42; return INT;
+    yylval.sval = "42"; return STRING;
+
+  The %define variable api.value.type supports both keyword and code values.
+
+  The keyword value 'union' means that the user provides genuine types, not
+  union member names such as "ival" and "sval" above (WARNING: will fail if
+  -y/--yacc/%yacc is enabled).
+
+    %define api.value.type union
+    %token <int> INT "integer"
+    %token <char *> STRING "string"
+    %printer { fprintf (yyo, "%d", $$); } <int>
+    %destructor { free ($$); } <char *>
+
+    /* In yylex().  */
+    yylval.INT = 42; return INT;
+    yylval.STRING = "42"; return STRING;
+
+  The keyword value variant is somewhat equivalent, but for C++ special
+  provision is made to allow classes to be used (more about this below).
+
+    %define api.value.type variant
+    %token <int> INT "integer"
+    %token <std::string> STRING "string"
+
+  Code values (in braces) denote user defined types.  This is where YYSTYPE
+  used to be used.
+
+    %code requires
+    {
+      struct my_value
+      {
+        enum
+        {
+          is_int, is_string
+        } kind;
+        union
+        {
+          int ival;
+          char *sval;
+        } u;
+      };
+    }
+    %define api.value.type {struct my_value}
+    %token <u.ival> INT "integer"
+    %token <u.sval> STRING "string"
+    %printer { fprintf (yyo, "%d", $$); } <u.ival>
+    %destructor { free ($$); } <u.sval>
+
+    /* In yylex().  */
+    yylval.u.ival = 42; return INT;
+    yylval.u.sval = "42"; return STRING;
+
+** Variable parse.error
+
+  This variable controls the verbosity of error messages.  The use of the
+  %error-verbose directive is deprecated in favor of "%define parse.error
+  verbose".
+
+** Renamed %define variables
+
+  The following variables have been renamed for consistency.  Backward
+  compatibility is ensured, but upgrading is recommended.
+
+    lr.default-reductions      -> lr.default-reduction
+    lr.keep-unreachable-states -> lr.keep-unreachable-state
+    namespace                  -> api.namespace
+    stype                      -> api.value.type
+
+** Semantic predicates
+
+  Contributed by Paul Hilfinger.
+
+  The new, experimental, semantic-predicate feature allows actions of the
+  form "%?{ BOOLEAN-EXPRESSION }", which cause syntax errors (as for
+  YYERROR) if the expression evaluates to 0, and are evaluated immediately
+  in GLR parsers, rather than being deferred.  The result is that they allow
+  the programmer to prune possible parses based on the values of run-time
+  expressions.
+
+** The directive %expect-rr is now an error in non GLR mode
+
+  It used to be an error only if used in non GLR mode, _and_ if there are
+  reduce/reduce conflicts.
+
+** Tokens are numbered in their order of appearance
+
+  Contributed by Valentin Tolmer.
+
+  With '%token A B', A had a number less than the one of B.  However,
+  precedence declarations used to generate a reversed order.  This is now
+  fixed, and introducing tokens with any of %token, %left, %right,
+  %precedence, or %nonassoc yields the same result.
+
+  When mixing declarations of tokens with a litteral character (e.g., 'a')
+  or with an identifier (e.g., B) in a precedence declaration, Bison
+  numbered the litteral characters first.  For example
+
+    %right A B 'c' 'd'
+
+  would lead to the tokens declared in this order: 'c' 'd' A B.  Again, the
+  input order is now preserved.
+
+  These changes were made so that one can remove useless precedence and
+  associativity declarations (i.e., map %nonassoc, %left or %right to
+  %precedence, or to %token) and get exactly the same output.
+
+** Useless precedence and associativity
+
+  Contributed by Valentin Tolmer.
+
+  When developing and maintaining a grammar, useless associativity and
+  precedence directives are common.  They can be a nuisance: new ambiguities
+  arising are sometimes masked because their conflicts are resolved due to
+  the extra precedence or associativity information.  Furthermore, it can
+  hinder the comprehension of a new grammar: one will wonder about the role
+  of a precedence, where in fact it is useless.  The following changes aim
+  at detecting and reporting these extra directives.
+
+*** Precedence warning category
+
+  A new category of warning, -Wprecedence, was introduced. It flags the
+  useless precedence and associativity directives.
+
+*** Useless associativity
+
+  Bison now warns about symbols with a declared associativity that is never
+  used to resolve conflicts.  In that case, using %precedence is sufficient;
+  the parsing tables will remain unchanged.  Solving these warnings may raise
+  useless precedence warnings, as the symbols no longer have associativity.
+  For example:
+
+    %left '+'
+    %left '*'
+    %%
+    exp:
+      "number"
+    | exp '+' "number"
+    | exp '*' exp
+    ;
+
+  will produce a
+
+    warning: useless associativity for '+', use %precedence [-Wprecedence]
+     %left '+'
+           ^^^
+
+*** Useless precedence
+
+  Bison now warns about symbols with a declared precedence and no declared
+  associativity (i.e., declared with %precedence), and whose precedence is
+  never used.  In that case, the symbol can be safely declared with %token
+  instead, without modifying the parsing tables.  For example:
+
+    %precedence '='
+    %%
+    exp: "var" '=' "number";
+
+  will produce a
+
+    warning: useless precedence for '=' [-Wprecedence]
+     %precedence '='
+                 ^^^
+
+*** Useless precedence and associativity
+
+  In case of both useless precedence and associativity, the issue is flagged
+  as follows:
+
+    %nonassoc '='
+    %%
+    exp: "var" '=' "number";
+
+  The warning is:
+
+    warning: useless precedence and associativity for '=' [-Wprecedence]
+     %nonassoc '='
+               ^^^
+
+** Empty rules
+
+  With help from Joel E. Denny and Gabriel Rassoul.
+
+  Empty rules (i.e., with an empty right-hand side) can now be explicitly
+  marked by the new %empty directive.  Using %empty on a non-empty rule is
+  an error.  The new -Wempty-rule warning reports empty rules without
+  %empty.  On the following grammar:
+
+    %%
+    s: a b c;
+    a: ;
+    b: %empty;
+    c: 'a' %empty;
+
+  bison reports:
+
+    3.4-5: warning: empty rule without %empty [-Wempty-rule]
+     a: {}
+        ^^
+    5.8-13: error: %empty on non-empty rule
+     c: 'a' %empty {};
+            ^^^^^^
+
 ** Java skeleton improvements

  Contributed by Paolo Bonzini.
@@ -249,59 +543,66 @@ GNU Bison NEWS
  used by the scanner, or rejecting invalid combinations from a
  factory invoked by the user actions).

-** Renamed %define variables
+*** %define api.value.type variant

-  The following variables have been renamed for consistency.  Backward
-  compatibility is ensured, but upgrading is recommended.
+  This is based on a submission from Michiel De Wilde.  With help
+  from Théophile Ranquet.

-    lr.default-reductions      -> lr.default-reduction
-    lr.keep-unreachable-states -> lr.keep-unreachable-state
-    namespace                  -> api.namespace
-    stype                      -> api.value.type
+  In this mode, complex C++ objects can be used as semantic values.  For
+  instance:

-** Variable api.token.prefix
-
-  The variable api.token.prefix changes the way tokens are identified in
-  the generated files.  This is especially useful to avoid collisions
-  with identifiers in the target language.  For instance
-
-    %token FILE for ERROR
-    %define api.token.prefix "TOK_"
+    %token <::std::string> TEXT;
+    %token <int> NUMBER;
+    %token SEMICOLON ";"
+    %type <::std::string> item;
+    %type <::std::list<std::string>> list;
    %%
-    start: FILE for ERROR;
+    result:
+      list  { std::cout << $1 << std::endl; }
+    ;

-  will generate the definition of the symbols TOK_FILE, TOK_for, and
-  TOK_ERROR in the generated sources.  In particular, the scanner must
-  use these prefixed token names, although the grammar itself still
-  uses the short names (as in the sample rule given above).
+    list:
+      %empty        { /* Generates an empty string list. */ }
+    | list item ";" { std::swap ($$, $1); $$.push_back ($2); }
+    ;

-** Variable parse.error
+    item:
+      TEXT    { std::swap ($$, $1); }
+    | NUMBER  { $$ = string_cast ($1); }
+    ;

-  This variable controls the verbosity of error messages.  The use of the
-  %error-verbose directive is deprecated in favor of "%define parse.error
-  verbose".
+*** %define api.token.constructor

-** Semantic predicates
+  When variants are enabled, Bison can generate functions to build the
+  tokens.  This guarantees that the token type (e.g., NUMBER) is consistent
+  with the semantic value (e.g., int):

-  Contributed by Paul Hilfinger.
+    parser::symbol_type yylex ()
+    {
+      parser::location_type loc = ...;
+      ...
+      return parser::make_TEXT ("Hello, world!", loc);
+      ...
+      return parser::make_NUMBER (42, loc);
+      ...
+      return parser::make_SEMICOLON (loc);
+      ...
+    }

-  The new, experimental, semantic-predicate feature allows actions of the
-  form "%?{ BOOLEAN-EXPRESSION }", which cause syntax errors (as for
-  YYERROR) if the expression evaluates to 0, and are evaluated immediately
-  in GLR parsers, rather than being deferred.  The result is that they allow
-  the programmer to prune possible parses based on the values of run-time
-  expressions.
+*** C++ locations

-** The directive %expect-rr is now an error in non GLR mode
+  There are operator- and operator-= for 'location'.  Negative line/column
+  increments can no longer underflow the resulting value.

-  It used to be an error only if used in non GLR mode, _and_ if there are
-  reduce/reduce conflicts.
+* Noteworthy changes in release 2.7.1 (2013-04-15) [stable]

-** Token numbering has changed to preserve the user-defined order
+** Bug fixes

-  When declaring %token A B, the numbering for A is inferior to B. Up to now,
-  when declaring associativity at the same time, with %left (or %right,
-  %precedence, %nonassoc), B was inferior to A.
+*** Fix compiler attribute portability (yacc.c)
+
+  With locations enabled, __attribute__ was used unprotected.
+
+*** Fix some compiler warnings (lalr1.cc)

 * Noteworthy changes in release 2.7 (2012-12-12) [stable]

@@ -353,8 +654,8 @@ GNU Bison NEWS
     exp: exp '+' exp { $exp = $1 + $3; };
                  ^^^

-  The default behaviour for now is still not to display these unless
-  explictly asked with -fcaret (or -fall). However, in a later release, it
+  The default behavior for now is still not to display these unless
+  explicitly asked with -fcaret (or -fall). However, in a later release, it
  will be made the default behavior (but may still be deactivated with
  -fno-caret).

@@ -441,7 +742,7 @@ GNU Bison NEWS

  Other issues in the test suite have been addressed.

-  Nul characters are correctly displayed in error messages.
+  Null characters are correctly displayed in error messages.

  When possible, yylloc is correctly initialized before calling yylex.  It
  is no longer necessary to initialize it in the %initial-action.
@@ -2357,7 +2658,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 LocalWords:  Automake TMPDIR LESSEQ ylwrap endif yydebug YYTOKEN YYLSP ival hh
 LocalWords:  extern YYTOKENTYPE TOKENTYPE yytokentype tokentype STYPE lval pdf
 LocalWords:  lang yyoutput dvi html ps POSIX lvalp llocp Wother nterm arg init
- LocalWords:  TOK calc yyo fval Wconflicts
+ LocalWords:  TOK calc yyo fval Wconflicts parsers yystackp yyval yynerrs
+ LocalWords:  Théophile Ranquet Santet fno fnone stype associativity Tolmer
+ LocalWords:  Wprecedence Rassoul Wempty Paolo Bonzini parser's Michiel loc
+ LocalWords:  redeclaration sval fcaret reentrant XSLT xsl Wmaybe yyvsp Tedi
+ LocalWords:  pragmas noreturn untyped Rozenman unexpanded Wojciech Polak
+ LocalWords:  Alexandre MERCHANTABILITY yytype

 Local Variables:
 mode: outline
@@ -30,7 +30,7 @@ not answer them, please send mail to <[email protected]>.

 * Bug reports
 Please send bug reports to <[email protected]>.  Please include the
-version number from `bison --version', and a complete, self-contained
+version number from 'bison --version', and a complete, self-contained
 test case in each bug report.

 * Copyright statements
@@ -9,7 +9,7 @@ Bison supports the @N construction, which gives you access to
 the starting and ending line number and character number associated
 with any of the symbols in the current rule.

-Also, Bison supports the command `%expect N' which says not to mention
+Also, Bison supports the command '%expect N' which says not to mention
 the conflicts if there are N shift/reduce conflicts and no reduce/reduce
 conflicts.

@@ -29,6 +29,7 @@ Cris Bailiff              [email protected]
 Cris van Pelt             [email protected]
 Csaba Raduly              [email protected]
 Dagobert Michelsen        [email protected]
+Daniel Frużyński          [email protected]
 Daniel Hagerty            [email protected]
 David J. MacKenzie        [email protected]
 David Kastrup             [email protected]
@@ -37,6 +38,7 @@ Derek M. Jones            [email protected]
 Di-an Jan                 [email protected]
 Dick Streefland           [email protected]
 Didier Godefroy           [email protected]
+Efi Fogel                 [email protected]
 Enrico Scholz             [email protected]
 Eric Blake                [email protected]
 Evgeny Stambulchik        [email protected]
@@ -44,6 +46,7 @@ Fabrice Bauzac            [email protected]
 Florian Krohm             [email protected]
 Frank Heckenbach          [email protected]
 Frans Englich             [email protected]
+Gabriel Rassoul           [email protected]
 Georg Sauthoff            [email protected]
 George Neuner             [email protected]
 Gilles Espinasse          [email protected]
@@ -97,6 +100,7 @@ Peter Eisentraut          [email protected]
 Peter Fales               [email protected]
 Peter Hamorsky            [email protected]
 Peter Simons              [email protected]
+Petr Machata              [email protected]
 Piotr Gackiewicz          [email protected]
 Quentin Hocquet           [email protected]
 Quoc Peyrot               [email protected]
@@ -106,6 +110,7 @@ Ralf Wildenhues           [email protected]
 Richard Stallman          [email protected]
 Rob Vermaas               [email protected]
 Robert Anisko             [email protected]
+Rob Conde                 [email protected]
 Roland Levillain          [email protected]
 Satya Kiran Popuri        [email protected]
 Sebastian Setzer          [email protected]
@@ -126,6 +131,7 @@ Tommy Nordgren            [email protected]
 Troy A. Johnson           [email protected]
 Tys Lefering              [email protected]
 Valentin Tolmer           [email protected]
+Victor Khomenko           [email protected]
 Vin Shelton               [email protected]
 W.C.A. Wijngaards         [email protected]
 Wayne Green               [email protected]
@@ -1,16 +1,27 @@
 * Short term
 ** Graphviz display code thoughts
 The code for the --graph option is over two files: print_graph, and
-graphviz. I believe this is because Bison used to also produce VCG graphs,
-but since this is no longer true, maybe we could consider these files for
-fusion.
+graphviz. This is because Bison used to also produce VCG graphs, but since
+this is no longer true, maybe we could consider these files for fusion.

-Little effort factoring seems to have been given to factoring in these files,
-and their print-xml and print counterpart. We would very much like to re-use
-the pretty format of states from .output in the .dot
+An other consideration worth noting is that print_graph.c (correct me if I
+am wrong) should contain generic functions, whereas graphviz.c and other
+potential files should contain just the specific code for that output
+format. It will probably prove difficult to tell if the implementation is
+actually generic whilst only having support for a single format, but it
+would be nice to keep stuff a bit tidier: right now, the construction of the
+bitset used to show reductions is in the graphviz-specific code, and on the
+opposite side we have some use of \l, which is graphviz-specific, in what
+should be generic code.

-Also, the underscore in print_graph.[ch] isn't very fitting considering
-the dashes in the other filenames.
+Little effort seems to have been given to factoring these files and their
+rint{,-xml} counterpart. We would very much like to re-use the pretty format
+of states from .output for the graphs, etc.
+
+Also, the underscore in print_graph.[ch] isn't very fitting considering the
+dashes in the other filenames.
+
+Since graphviz dies on medium-to-big grammars, maybe consider an other tool?

 ** push-parser
 Check it too when checking the different kinds of parsers.  And be
@@ -165,13 +176,13 @@ part of $default.  Should we make the two reductions explicit, or just
 keep $default?  See the following point.

 ** Disabled Reductions
-See `tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
+See 'tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
 what we want to do.

 ** Documentation
 Extend with error productions.  The hard part will probably be finding
 the right rule so that a single state does not exhibit too many yet
-undocumented ``features''.  Maybe an empty action ought to be
+undocumented ''features''.  Maybe an empty action ought to be
 presented too.  Shall we try to make a single grammar with all these
 features, or should we have several very small grammars?

@@ -232,9 +243,9 @@ into
        exp: exp '+' exp | exp '&' exp;

 when there are no actions.  This can significantly speed up some
-grammars.  I can't find the papers.  In particular the book `LR
+grammars.  I can't find the papers.  In particular the book 'LR
 parsing: Theory and Practice' is impossible to find, but according to
-`Parsing Techniques: a Practical Guide', it includes information about
+'Parsing Techniques: a Practical Guide', it includes information about
 this issue.  Does anybody have it?


@@ -1,6 +1,6 @@
 #! /bin/sh
 # Print a version string.
-scriptversion=2012-12-28.10; # UTC
+scriptversion=2013-05-08.20; # UTC

 # Bootstrap this package from checked-out sources.

@@ -140,20 +140,21 @@ po_download_command_format2=\
 "wget --mirror -nd -q -np -A.po -P '%s' \
 http://translationproject.org/latest/%s/"

+# Prefer a non-empty tarname (4th argument of AC_INIT if given), else
+# fall back to the package name (1st argument with munging)
 extract_package_name='
-  /^AC_INIT(/{
-     /.*,.*,.*, */{
-       s///
-       s/[][]//g
-       s/)$//
+  /^AC_INIT(\[*/{
+     s///
+     /^[^,]*,[^,]*,[^,]*,[ []*\([^][ ,)]\)/{
+       s//\1/
+       s/[],)].*//
       p
       q
     }
-     s/AC_INIT(\[*//
-     s/]*,.*//
+     s/[],)].*//
     s/^GNU //
     y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/
-     s/[^A-Za-z0-9_]/-/g
+     s/[^abcdefghijklmnopqrstuvwxyz0123456789_]/-/g
     p
  }
 '
@@ -306,34 +307,34 @@ if test -n "$checkout_only_file" && test ! -r "$checkout_only_file"; then
  die "Bootstrapping from a non-checked-out distribution is risky."
 fi

-# Ensure that lines starting with ! sort last, per gitignore conventions
-# for whitelisting exceptions after a more generic blacklist pattern.
-sort_patterns() {
-  sort -u "$@" | sed '/^!/ {
-    H
-    d
-  }
-  $ {
-    P
-    x
-    s/^\n//
-  }' | sed '/^$/d'
+# Strip blank and comment lines to leave significant entries.
+gitignore_entries() {
+  sed '/^#/d; /^$/d' "$@"
 }

-# If $STR is not already on a line by itself in $FILE, insert it,
-# sorting the new contents of the file and replacing $FILE with the result.
-insert_sorted_if_absent() {
+# If $STR is not already on a line by itself in $FILE, insert it at the start.
+# Entries are inserted at the start of the ignore list to ensure existing
+# entries starting with ! are not overridden.  Such entries support
+# whitelisting exceptions after a more generic blacklist pattern.
+insert_if_absent() {
  file=$1
  str=$2
  test -f $file || touch $file
-  echo "$str" | sort_patterns - $file | cmp -s - $file > /dev/null \
-    || { echo "$str" | sort_patterns - $file > $file.bak \
-      && mv $file.bak $file; } \
-    || die "insert_sorted_if_absent $file $str: failed"
+  test -r $file || die "Error: failed to read ignore file: $file"
+  duplicate_entries=$(gitignore_entries $file | sort | uniq -d)
+  if [ "$duplicate_entries" ] ; then
+    die "Error: Duplicate entries in $file: " $duplicate_entries
+  fi
+  linesold=$(gitignore_entries $file | wc -l)
+  linesnew=$(echo "$str" | gitignore_entries - $file | sort -u | wc -l)
+  if [ $linesold != $linesnew ] ; then
+    { echo "$str" | cat - $file > $file.bak && mv $file.bak $file; } \
+      || die "insert_if_absent $file $str: failed"
+  fi
 }

 # Adjust $PATTERN for $VC_IGNORE_FILE and insert it with
-# insert_sorted_if_absent.
+# insert_if_absent.
 insert_vc_ignore() {
  vc_ignore_file="$1"
  pattern="$2"
@@ -344,7 +345,7 @@ insert_vc_ignore() {
    # .gitignore entry.
    pattern=$(echo "$pattern" | sed s,^,/,);;
  esac
-  insert_sorted_if_absent "$vc_ignore_file" "$pattern"
+  insert_if_absent "$vc_ignore_file" "$pattern"
 }

 # Die if there is no AC_CONFIG_AUX_DIR($build_aux) line in configure.ac.
@@ -630,9 +631,13 @@ esac
 if $bootstrap_sync; then
  cmp -s "$0" "$GNULIB_SRCDIR/build-aux/bootstrap" || {
    echo "$0: updating bootstrap and restarting..."
+    case $(sh -c 'echo "$1"' -- a) in
+      a) ignored=--;;
+      *) ignored=ignored;;
+    esac
    exec sh -c \
      'cp "$1" "$2" && shift && exec "${CONFIG_SHELL-/bin/sh}" "$@"' \
-      -- "$GNULIB_SRCDIR/build-aux/bootstrap" \
+      $ignored "$GNULIB_SRCDIR/build-aux/bootstrap" \
      "$0" "$@" --no-bootstrap-sync
  }
 fi
@@ -1,5 +1,3 @@
-## Makefile for Bison testsuite.
-
 # Copyright (C) 2000-2013 Free Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
@@ -135,7 +135,7 @@ _sed_rm_comments_q = $(subst ','\'',$(_sed_remove_comments))

 _space_before_paren_exempt =? \\n\\$$
 _space_before_paren_exempt = \
-  (^ *\#|\\n\\$$|%s\(to %s|(date|group|character)\(s\))
+  (^ *\#|(LA)?LR\([01]\)|percent_(code|define)|b4_syncline|m4_(define|init)|symbol)
 # Ensure that there is a space before each open parenthesis in C code.
 sc_space_before_open_paren:
 	@if $(VC_LIST_EXCEPT) | grep -l '\.[ch]$$' > /dev/null; then	\
@@ -175,5 +175,6 @@ $(call exclude,								\
  prohibit_strcmp=^doc/bison\.texi|tests/local\.at$$			\
  prohibit_tab_based_indentation=\.(am|mk)$$|^djgpp/|^\.git		\
  require_config_h_first=^(lib/yyerror|data/(glr|yacc))\.c$$		\
+  space_before_open_paren=^(data/|djgpp/)                               \
  unmarked_diagnostics=^(djgpp/|doc/bison.texi$$|tests/c\+\+\.at$$)	\
 )
@@ -18,7 +18,7 @@
 # In order for some versions of Sun Studio to compile our C++ test cases
 # correctly, we need Autoconf 2.64 or better to handle the restrict
 # keyword in at least string.h from gnulib.  We need Autoconf 2.68 or
-# better to avoid a typo in the `configure --help' entry for the YACC
+# better to avoid a typo in the 'configure --help' entry for the YACC
 # environment variable.
 AC_PREREQ([2.68])
 m4_pattern_forbid([^gl_[A-Z]])
@@ -91,7 +91,7 @@ if test "$enable_gcc_warnings" = yes; then
  # -fno-color-diagnostics: Clang's use of colors in the error
  # messages is confusing the tests looking at the compiler's output
  # (e.g., synclines.at).
-  warn_tests='-Wundef -pedantic -fno-color-diagnostics'
+  warn_tests='-Wundef -pedantic -Wsign-compare -fno-color-diagnostics'

  AC_LANG_PUSH([C])
  # Clang supports many of GCC's -W options, but only issues warnings
@@ -143,9 +143,11 @@ if test "$enable_gcc_warnings" = yes; then
    gl_WARN_ADD([$i], [WARN_CXXFLAGS_TEST])
  done
  # Clang++ 3.2+ reject C code generated by Flex.
-  gl_WARN_ADD([-Wno-null-conversion], [WARN_NO_NULL_CONVERSION_CXXFLAGS])
-  # Variants break strict aliasing analysis.
-  gl_WARN_ADD([-fno-strict-aliasing], [NO_STRICT_ALIAS_CXXFLAGS])
+  gl_WARN_ADD([-Wno-null-conversion], [FLEX_SCANNER_CXXFLAGS])
+  # So does G++ 4.8...
+  gl_WARN_ADD([-Wno-sign-compare], [FLEX_SCANNER_CXXFLAGS])
+  # ... possiby in std=c++11 mode.
+  gl_WARN_ADD([-Wno-zero-as-null-pointer-constant], [FLEX_SCANNER_CXXFLAGS])
  CXXFLAGS=$save_CXXFLAGS
  AC_LANG_POP([C++])
 fi
@@ -220,7 +222,7 @@ AC_SUBST([aclocaldir])
 AC_CONFIG_FILES([etc/bench.pl], [chmod +x etc/bench.pl])

 # Initialize the test suite.
-AC_CONFIG_TESTDIR([tests], [$ac_abs_top_builddir/tests])
+AC_CONFIG_TESTDIR(tests)
 AC_CONFIG_FILES([tests/atlocal])
 AC_CONFIG_FILES([tests/bison], [chmod +x tests/bison])
 AC_CHECK_PROGS([VALGRIND], [valgrind])
@@ -27,7 +27,7 @@ Currently, the supported skeletons are:
 These skeletons are the only ones supported by the Bison team.
 Because the interface between skeletons and the bison program is not
 finished, *we are not bound to it*.  In particular, Bison is not
-mature enough for us to consider that ``foreign skeletons'' are
+mature enough for us to consider that "foreign skeletons" are
 supported.

 * m4sugar
@@ -85,6 +85,20 @@ m4_changecom([#])
 ])


+# b4_divert_kill(CODE)
+# --------------------
+# Expand CODE for its side effects, discard its output.
+m4_define([b4_divert_kill],
+[m4_divert_text([KILL], [$1])])
+
+
+# b4_define_silent(MACRO, CODE)
+# -----------------------------
+# Same as m4_define, but throw away the expansion of CODE.
+m4_define([b4_define_silent],
+[m4_define([$1], [b4_divert_kill([$2])])])
+
+
 ## ---------------- ##
 ## Error handling.  ##
 ## ---------------- ##
@@ -313,7 +327,7 @@ m4_define([b4_define_flag_if],
 # _b4_define_flag_if($1, $2, FLAG)
 # --------------------------------
 # Work around the impossibility to define macros inside macros,
-# because issuing `[$1]' is not possible in M4.  GNU M4 should provide
+# because issuing '[$1]' is not possible in M4.  GNU M4 should provide
 # $$1 a la M5/TeX.
 m4_define([_b4_define_flag_if],
 [m4_if([$1$2], $[1]$[2], [],
@@ -347,6 +361,7 @@ b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 #   Whether the symbol has an id.
 # - id: string
 #   If has_id, the id.  Guaranteed to be usable as a C identifier.
+#   Prefixed by api.token.prefix if defined.
 # - tag: string.
 #   A representat of the symbol.  Can be 'foo', 'foo.id', '"foo"' etc.
 # - user_number: integer
@@ -357,9 +372,13 @@ b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 #   The internalized number (used after yytranslate).
 # - has_type: 0, 1
 #   Whether has a semantic value.
+# - type_tag: string
+#   When api.value.type=union, the generated name for the union member.
+#   yytype_INT etc. for symbols that has_id, otherwise yytype_1 etc.
 # - type
 #   If it has a semantic value, its type tag, or, if variant are used,
 #   its type.
+#   In the case of api.value.type=union, type is the real type (e.g. int).
 # - has_printer: 0, 1
 # - printer: string
 # - printer_file: string
@@ -442,6 +461,24 @@ m4_define([b4_symbol_destructor], [b4_symbol_action([$1], [destructor])])
 m4_define([b4_symbol_printer],    [b4_symbol_action([$1], [printer])])


+# b4_symbol_actions(KIND, [TYPE = yytype])
+# ----------------------------------------
+# Emit the symbol actions for KIND ("printer" or "destructor").
+# Dispatch on TYPE.
+m4_define([b4_symbol_actions],
+[m4_pushdef([b4_actions_], m4_expand([b4_symbol_foreach([b4_symbol_$1])]))dnl
+m4_ifval(m4_defn([b4_actions_]),
+[switch (m4_default([$2], [yytype]))
+    {
+      m4_defn([b4_actions_])
+      default:
+        break;
+    }dnl
+],
+[YYUSE (m4_default([$2], [yytype]));])dnl
+m4_popdef([b4_actions_])dnl
+])
+
 # b4_symbol_case_(SYMBOL-NUM)
 # ---------------------------
 # Issue a "case NUM" for SYMBOL-NUM.
@@ -577,14 +614,14 @@ m4_define([b4_define_user_code],
 # b4_user_initial_action
 # b4_user_post_prologue
 # b4_user_pre_prologue
-# b4_user_stype
+# b4_user_union_members
 # ----------------------
 # Macros that issue user code, ending with synclines.
 b4_define_user_code([actions])
 b4_define_user_code([initial_action])
 b4_define_user_code([post_prologue])
 b4_define_user_code([pre_prologue])
-b4_define_user_code([stype])
+b4_define_user_code([union_members])


 # b4_check_user_names(WHAT, USER-LIST, BISON-NAMESPACE)
@@ -665,9 +702,9 @@ m4_define([b4_percent_define_use],
 #   b4_percent_define_get([[foo]])
 m4_define([b4_percent_define_get],
 [b4_percent_define_use([$1])dnl
-m4_ifdef([b4_percent_define(]$1[)],
-         [m4_indir([b4_percent_define(]$1[)])],
-         [$2])])
+b4_percent_define_ifdef_([$1],
+                         [m4_indir([b4_percent_define(]$1[)])],
+                         [$2])])

 # b4_percent_define_get_loc(VARIABLE)
 # -----------------------------------
@@ -686,7 +723,21 @@ m4_define([b4_percent_define_get_loc],
          [m4_pushdef([b4_loc], m4_indir([b4_percent_define_loc(]$1[)]))dnl
 b4_loc[]dnl
 m4_popdef([b4_loc])],
-          [b4_fatal([[b4_percent_define_get_loc: undefined %%define variable '%s']], [$1])])])
+          [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_get_kind(VARIABLE)
+# ------------------------------------
+# Get the kind (code, keyword, string) of VARIABLE, i.e., how its
+# value was defined (braces, not delimiters, quotes).
+#
+# If the %define variable VARIABLE is undefined, complain fatally
+# since that's a Bison or skeleton error.  Don't record this as a
+# Bison usage of VARIABLE as there's no reason to suspect that the
+# user-supplied value has yet influenced the output.
+m4_define([b4_percent_define_get_kind],
+[m4_ifdef([b4_percent_define_kind(]$1[)],
+          [m4_indir([b4_percent_define_kind(]$1[)])],
+          [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])

 # b4_percent_define_get_syncline(VARIABLE)
 # ----------------------------------------
@@ -703,7 +754,20 @@ m4_popdef([b4_loc])],
 m4_define([b4_percent_define_get_syncline],
 [m4_ifdef([b4_percent_define_syncline(]$1[)],
          [m4_indir([b4_percent_define_syncline(]$1[)])],
-          [b4_fatal([[b4_percent_define_get_syncline: undefined %%define variable '%s']], [$1])])])
+          [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_ifdef_(VARIABLE, IF-TRUE, [IF-FALSE])
+# ------------------------------------------------------
+# If the %define variable VARIABLE is defined, expand IF-TRUE, else expand
+# IF-FALSE.  Don't record usage of VARIABLE.
+#
+# For example:
+#
+#   b4_percent_define_ifdef_([[foo]], [[it's defined]], [[it's undefined]])
+m4_define([b4_percent_define_ifdef_],
+[m4_ifdef([b4_percent_define(]$1[)],
+          [$2],
+          [$3])])

 # b4_percent_define_ifdef(VARIABLE, IF-TRUE, [IF-FALSE])
 # ------------------------------------------------------
@@ -716,9 +780,9 @@ m4_define([b4_percent_define_get_syncline],
 #
 #   b4_percent_define_ifdef([[foo]], [[it's defined]], [[it's undefined]])
 m4_define([b4_percent_define_ifdef],
-[m4_ifdef([b4_percent_define(]$1[)],
-          [b4_percent_define_use([$1])$2],
-          [$3])])
+[b4_percent_define_ifdef_([$1],
+                         [b4_percent_define_use([$1])$2],
+                         [$3])])


 ## --------- ##
@@ -747,11 +811,11 @@ m4_define([b4_percent_define_flag_if],
                                           [[invalid value for %%define Boolean variable '%s']],
                                           [$1])],
                           [[b4_percent_define_flag_if($1)]])])],
-  [b4_fatal([[b4_percent_define_flag_if: undefined %%define variable '%s']], [$1])])])
+  [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])


-# b4_percent_define_default(VARIABLE, DEFAULT)
-# --------------------------------------------
+# b4_percent_define_default(VARIABLE, DEFAULT, [KIND = keyword])
+# --------------------------------------------------------------
 # Mimic muscle_percent_define_default in ../src/muscle-tab.h exactly.  That is,
 # if the %define variable VARIABLE is undefined, set its value to DEFAULT.
 # Don't record this as a Bison usage of VARIABLE as there's no reason to
@@ -761,8 +825,10 @@ m4_define([b4_percent_define_flag_if],
 #
 #   b4_percent_define_default([[foo]], [[default value]])
 m4_define([b4_percent_define_default],
-[m4_ifndef([b4_percent_define(]$1[)],
+[b4_percent_define_ifdef_([$1], [],
           [m4_define([b4_percent_define(]$1[)], [$2])dnl
+            m4_define([b4_percent_define_kind(]$1[)],
+                      [m4_default([$3], [keyword])])dnl
            m4_define([b4_percent_define_loc(]$1[)],
                      [[[[<skeleton default value>:-1.-1]],
                        [[<skeleton default value>:-1.-1]]]])dnl
@@ -772,8 +838,8 @@ m4_define([b4_percent_define_default],
 # b4_percent_define_if_define(NAME, [VARIABLE = NAME])
 # ----------------------------------------------------
 # Define b4_NAME_if that executes its $1 or $2 depending whether
-# VARIABLE was %defined.  The characters `.' and `-' in VARIABLE are mapped
-# to `_'.
+# VARIABLE was %defined.  The characters '.' and `-' in VARIABLE are mapped
+# to '_'.
 m4_define([b4_percent_define_if_define_],
 [m4_define(m4_bpatsubst([b4_$1_if], [[-.]], [_]),
           [b4_percent_define_flag_if(m4_default([$2], [$1]),
@@ -783,6 +849,21 @@ m4_define([b4_percent_define_if_define],
 b4_percent_define_if_define_([$1], [$2], $[1], $[2])])


+# b4_percent_define_check_kind(VARIABLE, KIND, [DIAGNOSTIC = complain])
+# ---------------------------------------------------------------------
+m4_define([b4_percent_define_check_kind],
+[b4_percent_define_ifdef_([$1],
+  [m4_if(b4_percent_define_get_kind([$1]), [$2], [],
+    [b4_error([m4_default([$3], [complain])],
+              b4_percent_define_get_loc([$1]),
+              [m4_case([$2],
+                 [code], [[%%define variable '%s' requires '{...}' values]],
+                 [keyword], [[%%define variable '%s' requires keyword values]],
+                 [string], [[%%define variable '%s' requires '"..."' values]])],
+              [$1])])])dnl
+])
+
+
 # b4_percent_define_check_values(VALUES)
 # --------------------------------------
 # Mimic muscle_percent_define_check_values in ../src/muscle-tab.h exactly
@@ -804,8 +885,9 @@ m4_define([b4_percent_define_check_values],
            [_b4_percent_define_check_values(b4_sublist)])])

 m4_define([_b4_percent_define_check_values],
-[m4_ifdef([b4_percent_define(]$1[)],
-  [m4_pushdef([b4_good_value], [0])dnl
+[b4_percent_define_ifdef_([$1],
+  [b4_percent_define_check_kind(]$1[, [keyword], [deprecated])dnl
+   m4_pushdef([b4_good_value], [0])dnl
   m4_if($#, 1, [],
         [m4_foreach([b4_value], m4_dquote(m4_shift($@)),
                     [m4_if(m4_indir([b4_percent_define(]$1[)]), b4_value,
@@ -820,7 +902,7 @@ m4_define([_b4_percent_define_check_values],
                                     [[accepted value: '%s']],
                                     m4_dquote(b4_value))])])dnl
   m4_popdef([b4_good_value])],
-  [b4_fatal([[b4_percent_define_check_values: undefined %%define variable '%s']], [$1])])])
+  [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])

 # b4_percent_code_get([QUALIFIER])
 # --------------------------------
@@ -861,10 +943,6 @@ m4_define([b4_percent_code_ifdef],
 ## Common variables.  ##
 ## ------------------ ##

-# Default values for %define.
-# ---------------------------
-# If the api.token.prefix, it is empty.
-m4_percent_define_default([[api.token.prefix]], [[]])

 # b4_parse_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
 # b4_parse_trace_if([IF-DEBUG-TRACES-ARE-ENABLED], [IF-NOT])
@@ -904,9 +982,11 @@ b4_error_verbose_if([m4_define([b4_token_table_flag], [1])])
 # b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
 # ----------------------------------------------
 b4_percent_define_if_define([variant])
-m4_case(b4_percent_define_get([[api.value.type]]),
-        [variant], [m4_define([b4_variant_flag], [[1]])],
-                   [m4_define([b4_variant_flag], [[0]])])
+m4_define([b4_variant_flag], [[0]])
+b4_percent_define_ifdef([[api.value.type]],
+   [m4_case(b4_percent_define_get_kind([[api.value.type]]), [keyword],
+            [m4_case(b4_percent_define_get([[api.value.type]]), [variant],
+                    [m4_define([b4_variant_flag], [[1]])])])])
 b4_define_flag_if([variant])


@@ -941,10 +1021,43 @@ m4_define_default([b4_parse_param], [])
 m4_define_default([b4_location_initial_column], [1])
 m4_define_default([b4_location_initial_line],   [1])

-# Sanity checks.
+
+## --------------- ##
+## Sanity checks.  ##
+## --------------- ##
+
+# api.location.prefix={...} (Java and C++).
+b4_percent_define_check_kind([api.location.type], [code], [deprecated])
+
+# api.position.prefix={...} (Java).
+b4_percent_define_check_kind([api.position.type], [code], [deprecated])
+
+# api.prefix >< %name-prefix.
+b4_percent_define_check_kind([api.prefix], [code], [deprecated])
 b4_percent_define_ifdef([api.prefix],
 [m4_ifdef([b4_prefix],
 [b4_complain_at(b4_percent_define_get_loc([api.prefix]),
                [['%s' and '%s' cannot be used together]],
                [%name-prefix],
                [%define api.prefix])])])
+
+# api.token.prefix={...}
+# Make it a warning for those who used betas of Bison 3.0.
+b4_percent_define_check_kind([api.token.prefix], [code], [deprecated])
+
+# api.value.type >< %union.
+b4_percent_define_ifdef([api.value.type],
+[m4_ifdef([b4_union_members],
+[b4_complain_at(b4_percent_define_get_loc([api.value.type]),
+                [['%s' and '%s' cannot be used together]],
+                [%union],
+                [%define api.value.type])])])
+
+# api.value.type=union >< %yacc.
+b4_percent_define_ifdef([api.value.type],
+[m4_if(b4_percent_define_get([api.value.type]), [union],
+[b4_yacc_if(dnl
+[b4_complain_at(b4_percent_define_get_loc([api.value.type]),
+                [['%s' and '%s' cannot be used together]],
+                [%yacc],
+                [%define api.value.type "union"])])])])
@@ -25,6 +25,12 @@ m4_include(b4_pkgdatadir/[c.m4])
 m4_define([b4_comment],
 [b4_comment_([$1], [$2// ], [$2// ])])

+## -------- ##
+## Checks.  ##
+## -------- ##
+
+b4_percent_define_check_kind([api.namespace], [code], [deprecated])
+b4_percent_define_check_kind([parser_class_name], [code], [deprecated])

 ## ---------------- ##
 ## Default values.  ##
@@ -38,6 +44,7 @@ b4_percent_define_default([[parser_class_name]], [[parser]])
 # b4_percent_define_default([[api.location.type]], [[location]])

 b4_percent_define_default([[filename_type]], [[std::string]])
+# Make it a warning for those who used betas of Bison 3.0.
 b4_percent_define_default([[api.namespace]], m4_defn([b4_prefix]))

 b4_percent_define_default([[global_tokens_and_yystype]], [[false]])
@@ -54,8 +61,8 @@ b4_percent_define_default([[define_location_comparison]],
 m4_define([b4_namespace_ref], [b4_percent_define_get([[api.namespace]])])


-# Don't permit an empty b4_namespace_ref.  Any `::parser::foo' appended to it
-# would compile as an absolute reference with `parser' in the global namespace.
+# Don't permit an empty b4_namespace_ref.  Any '::parser::foo' appended to it
+# would compile as an absolute reference with 'parser' in the global namespace.
 # b4_namespace_open would open an anonymous namespace and thus establish
 # internal linkage.  This would compile.  However, it's cryptic, and internal
 # linkage for the parser would be specified in all translation units that
@@ -112,19 +119,24 @@ m4_define([b4_token_enums],
 ## Semantic Values.  ##
 ## ----------------- ##

-# b4_semantic_type_declare
-# ------------------------
+
+
+# b4_value_type_declare
+# ---------------------
 # Declare semantic_type.
-m4_define([b4_semantic_type_declare],
+m4_define([b4_value_type_declare],
+[b4_value_type_setup[]dnl
 [    /// Symbol semantic values.
-m4_ifdef([b4_stype],
-[    union semantic_type
+]m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+[code],
+[[    typedef ]b4_percent_define_get([[api.value.type]])[ semantic_type;]],
+[m4_bmatch(b4_percent_define_get([[api.value.type]]),
+[union\|union-directive],
+[[    union semantic_type
    {
-b4_user_stype
-    };],
-[m4_if(b4_tag_seen_flag, 0,
-[[    typedef int semantic_type;]],
-[[    typedef ]b4_api_PREFIX[STYPE semantic_type;]])])])
+    ]b4_user_union_members[
+    };]])])dnl
+])


 # b4_public_types_declare
@@ -133,7 +145,7 @@ b4_user_stype
 # Depending on %define token_lex, may be output in the header or source file.
 m4_define([b4_public_types_declare],
 [[#ifndef ]b4_api_PREFIX[STYPE
-]b4_semantic_type_declare[
+]b4_value_type_declare[
 #else
    typedef ]b4_api_PREFIX[STYPE semantic_type;
 #endif]b4_locations_if([
@@ -520,3 +532,13 @@ m4_define([b4_yylloc_default_define],
    while (/*CONSTCOND*/ false)
 # endif
 ]])
+
+## -------- ##
+## Checks.  ##
+## -------- ##
+
+b4_token_ctor_if([b4_variant_if([],
+  [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
+               [cannot use '%s' without '%s'],
+               [%define api.token.constructor],
+               [%define api.value.type variant]))])])
@@ -150,7 +150,7 @@ m4_popdef([$1])dnl

 # b4_parse_param_use([VAL], [LOC])
 # --------------------------------
-# `YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
+# 'YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
 m4_define([b4_parse_param_use],
 [m4_ifvaln([$1], [  YYUSE ([$1]);])dnl
 b4_locations_if([m4_ifvaln([$2], [  YYUSE ([$2]);])])dnl
@@ -182,7 +182,7 @@ m4_define([b4_int_type],
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])

@@ -199,6 +199,31 @@ m4_define([b4_table_value_equals],
       [(!!(($2) == ($3)))])])


+## ----------------- ##
+## Compiler issues.  ##
+## ----------------- ##
+
+# b4_attribute_define
+# -------------------
+# Provide portability for __attribute__.
+m4_define([b4_attribute_define],
+[#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if (! defined __GNUC__ || __GNUC__ < 2 \
+      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
+#  define __attribute__(Spec) /* empty */
+# endif
+#endif
+
+/* Suppress unused-variable warnings by "using" E.  */
+#if ! defined lint || defined __GNUC__
+# define YYUSE(E) ((void) (E))
+#else
+# define YYUSE(E) /* empty */
+#endif
+])
+
+
 ## ---------##
 ## Values.  ##
 ## ---------##
@@ -421,12 +446,7 @@ m4_ifset([b4_parse_param], [, b4_parse_param]))[
    yymsg = "Deleting";
  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);

-  switch (yytype)
-    {
-]b4_symbol_foreach([b4_symbol_destructor])dnl
-[      default:
-        break;
-    }
+  ]b4_symbol_actions([destructor])[
 }]dnl
 ])

@@ -459,12 +479,7 @@ m4_if(b4_skeleton, ["yacc.c"],
    YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
 # endif
 ]])dnl
-[  switch (yytype)
-    {
-]b4_symbol_foreach([b4_symbol_printer])dnl
-[      default:
-        break;
-    }
+  b4_symbol_actions([printer])[
 }


@@ -492,28 +507,154 @@ b4_locations_if([, yylocationp])[]b4_user_args[);
 }]dnl
 ])

+
+## ---------------- ##
+## api.value.type.  ##
+## ---------------- ##
+
+
+# ---------------------- #
+# api.value.type=union.  #
+# ---------------------- #
+
+# b4_symbol_type_register(SYMBOL-NUM)
+# -----------------------------------
+# Symbol SYMBOL-NUM has a type (for variant) instead of a type-tag.
+# Extend the definition of %union's body with a field of that type,
+# and extend the symbol's "type" field to point to the field name,
+# instead of the type name.
+m4_define([b4_symbol_type_register],
+[m4_define([b4_symbol($1, type_tag)],
+           [b4_symbol_if([$1], [has_id],
+                         [b4_symbol([$1], [id])],
+                         [yytype_[]b4_symbol([$1], [number])])])dnl
+m4_append([b4_user_union_members],
+m4_expand([
+  b4_symbol_tag_comment([$1])dnl
+  b4_symbol([$1], [type]) b4_symbol([$1], [type_tag]);]))
+])
+
+
+# b4_type_define_tag(SYMBOL1-NUM, ...)
+# ------------------------------------
+# For the batch of symbols SYMBOL1-NUM... (which all have the same
+# type), enhance the %union definition for each of them, and set
+# there "type" field to the field tag name, instead of the type name.
+m4_define([b4_type_define_tag],
+[b4_symbol_if([$1], [has_type],
+              [m4_map([b4_symbol_type_register], [$@])])
+])
+
+
+# b4_symbol_value_union(VAL, [TYPE])
+# ----------------------------------
+# Same of b4_symbol_value, but when api.value.type=union.
+m4_define([b4_symbol_value_union],
+[m4_ifval([$2],
+          [(*($2*)(&$1))],
+          [$1])])
+])
+
+
+# b4_value_type_setup_union
+# -------------------------
+# Setup support for api.value.type=union.  Symbols are defined with a
+# type instead of a union member name: build the corresponding union,
+# and give the symbols their tag.
+m4_define([b4_value_type_setup_union],
+[m4_define([b4_union_members])
+b4_type_foreach([b4_type_define_tag])
+m4_copy_force([b4_symbol_value_union], [b4_symbol_value])
+])
+
+
+# ---------------- #
+# api.value.type.  #
+# ---------------- #
+
+
+# b4_value_type_setup_variant
+# ---------------------------
+# Setup support for api.value.type=variant.  By default, fail, specialized
+# by other skeletons.
+m4_define([b4_value_type_setup_variant],
+[b4_complain_at(b4_percent_define_get_loc([[api.value.type]]),
+                [['%s' does not support '%s']],
+                [b4_skeleton],
+                [%define api.value.type variant])])
+
+
+# _b4_value_type_setup_keyword
+# ----------------------------
+# api.value.type is defined with a keyword/string syntax.  Check if
+# that is properly defined, and prepare its use.
+m4_define([_b4_value_type_setup_keyword],
+[b4_percent_define_check_values([[[[api.value.type]],
+                                  [[none]],
+                                  [[union]],
+                                  [[union-directive]],
+                                  [[variant]],
+                                  [[yystype]]]])dnl
+m4_case(b4_percent_define_get([[api.value.type]]),
+        [union],   [b4_value_type_setup_union],
+        [variant], [b4_value_type_setup_variant])])
+
+
+# b4_value_type_setup
+# -------------------
+# Check if api.value.type is properly defined, and possibly prepare
+# its use.
+b4_define_silent([b4_value_type_setup],
+[# Define default value.
+b4_percent_define_ifdef([[api.value.type]], [],
+[# %union => api.value.type=union-directive
+m4_ifdef([b4_union_members],
+[m4_define([b4_percent_define_kind(api.value.type)], [keyword])
+m4_define([b4_percent_define(api.value.type)], [union-directive])],
+[# no tag seen => api.value.type={int}
+m4_if(b4_tag_seen_flag, 0,
+[m4_define([b4_percent_define_kind(api.value.type)], [code])
+m4_define([b4_percent_define(api.value.type)], [int])],
+[# otherwise api.value.type=yystype
+m4_define([b4_percent_define_kind(api.value.type)], [keyword])
+m4_define([b4_percent_define(api.value.type)], [yystype])])])])
+
+# Set up.
+m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+   [keyword\|string], [_b4_value_type_setup_keyword])
+])
+
+
 ## -------------- ##
 ## Declarations.  ##
 ## -------------- ##

+
 # b4_value_type_define
 # --------------------
 m4_define([b4_value_type_define],
-[[/* Value type.  */
-#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
-]m4_ifdef([b4_stype],
-[[typedef union ]b4_union_name[ ]b4_api_PREFIX[STYPE;
-union ]b4_union_name[
-{
-]b4_user_stype[
-};
-# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]],
-[m4_if(b4_tag_seen_flag, 0,
-[[typedef int ]b4_api_PREFIX[STYPE;
-# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]])])[
+[b4_value_type_setup[]dnl
+/* Value type.  */
+m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+[code],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef ]b4_percent_define_get([[api.value.type]])[ ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
 # define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
 #endif
-]])
+]],
+[m4_bmatch(b4_percent_define_get([[api.value.type]]),
+[union\|union-directive],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef union ]b4_union_name[ ]b4_api_PREFIX[STYPE;
+union ]b4_union_name[
+{
+]b4_user_union_members[
+};
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
+# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
+#endif
+]])])])


 # b4_location_type_define
@@ -549,7 +690,7 @@ b4_pure_if([], [[extern ]b4_api_PREFIX[STYPE ]b4_prefix[lval;


 # b4_YYDEBUG_define
-# ------------------
+# -----------------
 m4_define([b4_YYDEBUG_define],
 [[/* Debug traces.  */
 ]m4_if(b4_api_prefix, [yy],
@@ -246,13 +246,6 @@ b4_percent_code_get[]dnl
 # endif
 #endif

-/* Suppress unused-variable warnings by "using" E.  */
-#ifdef __GNUC__
-# define YYUSE(E) ((void) (E))
-#else
-# define YYUSE(E) /* empty */
-#endif
-
 #ifndef YYFREE
 # define YYFREE free
 #endif
@@ -281,17 +274,7 @@ b4_percent_code_get[]dnl
 # define YYLONGJMP(Env, Val) (longjmp (Env, Val), YYASSERT (0))
 #endif

-/*-----------------.
-| GCC extensions.  |
-`-----------------*/
-
-#ifndef __attribute__
-/* This feature is available in gcc versions 2.5 and later.  */
-# if (! defined __GNUC__ || __GNUC__ < 2 \
-      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
-#  define __attribute__(Spec) /* empty */
-# endif
-#endif
+]b4_attribute_define[

 #ifndef YYASSERT
 # define YYASSERT(Condition) ((void) ((Condition) || (abort (), 0)))
@@ -43,12 +43,6 @@
 #   user must initialize the first positions (in particular the
 #   filename member).

-b4_token_ctor_if([b4_variant_if([],
-  [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
-               [cannot use '%s' without '%s'],
-               [%define api.token.constructor],
-               [%define api.value.type variant]))])])
-
 # We require a pure interface.
 m4_define([b4_pure_flag],      [1])

@@ -193,12 +187,7 @@ m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
    std::ostream& yyoutput = debug_stream ();
    std::ostream& yyo = yyoutput;
    YYUSE (yyo);
-    switch (yytype)
-      {
-]b4_symbol_foreach([b4_symbol_printer])dnl
-[        default:
-          break;
-      }
+    ]b4_symbol_actions([printer])[
  }


@@ -103,7 +103,7 @@ m4_define([b4_int_type],
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])

@@ -169,6 +169,22 @@ m4_define([b4_predicate_case], [  case $1:
    ])


+## -------- ##
+## Checks.  ##
+## -------- ##
+
+b4_percent_define_check_kind([[api.value.type]],    [code], [deprecated])
+
+b4_percent_define_check_kind([[annotations]],       [code], [deprecated])
+b4_percent_define_check_kind([[extends]],           [code], [deprecated])
+b4_percent_define_check_kind([[implements]],        [code], [deprecated])
+b4_percent_define_check_kind([[init_throws]],       [code], [deprecated])
+b4_percent_define_check_kind([[lex_throws]],        [code], [deprecated])
+b4_percent_define_check_kind([[parser_class_name]], [code], [deprecated])
+b4_percent_define_check_kind([[throws]],            [code], [deprecated])
+
+
+
 ## ---------------- ##
 ## Default values.  ##
 ## ---------------- ##
@@ -17,6 +17,8 @@

 m4_include(b4_pkgdatadir/[c++.m4])

+# api.value.type=variant is valid.
+m4_define([b4_value_type_setup_variant])

 # b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
 # --------------------------------------------------------------
@@ -38,13 +40,14 @@ m4_define([b4_integral_parser_table_define],
  };dnl
 ])

-
 # b4_symbol_value_template(VAL, [TYPE])
 # -------------------------------------
 # Same as b4_symbol_value, but used in a template method.  It makes
-# a difference when using variants.
+# a difference when using variants.  Note that b4_value_type_setup_union
+# overrides b4_symbol_value, so we must override it again.
 m4_copy([b4_symbol_value], [b4_symbol_value_template])
-
+m4_append([b4_value_type_setup_union],
+          [m4_copy_force([b4_symbol_value_union], [b4_symbol_value_template])])

 # b4_lhs_value([TYPE])
 # --------------------
@@ -201,6 +204,10 @@ b4_location_define])])[
    void error (const syntax_error& err);

  private:
+    /// This class is not copyable.
+    ]b4_parser_class_name[ (const ]b4_parser_class_name[&);
+    ]b4_parser_class_name[& operator= (const ]b4_parser_class_name[&);
+
    /// State numbers.
    typedef int state_type;

@@ -591,13 +598,7 @@ m4_if(b4_prefix, [yy], [],
      YY_SYMBOL_PRINT (yymsg, yysym);]b4_variant_if([], [

    // User destructor.
-    symbol_number_type yytype = yysym.type_get ();
-    switch (yytype)
-      {
-]b4_symbol_foreach([b4_symbol_destructor])dnl
-[       default:
-          break;
-      }])[
+    b4_symbol_actions([destructor], [yysym.type_get ()])])[
  }

 #if ]b4_api_PREFIX[DEBUG
@@ -612,12 +613,7 @@ m4_if(b4_prefix, [yy], [],
    yyo << (yytype < yyntokens_ ? "token" : "nterm")
        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
        << yysym.location << ": "])[;
-    switch (yytype)
-      {
-]b4_symbol_foreach([b4_symbol_printer])dnl
-[       default:
-          break;
-      }
+    ]b4_symbol_actions([printer])[
    yyo << ')';
  }
 #endif
@@ -737,7 +733,7 @@ b4_dollar_popdef])[]dnl
       yynewstate, since the latter expects the semantical and the
       location values to have been already stored, initialize these
       stacks with a primary value.  */
-    yystack_ = stack_type (0);
+    yystack_.clear ();
    yypush_ (YY_NULL, 0, yyla);

    // A new symbol was pushed on the stack.
@@ -824,7 +820,7 @@ b4_dollar_popdef])[]dnl
       variants.  */
    b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])],[
    /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+       '$$ = $1'.  Otherwise, use the top of the stack.

       Otherwise, the following line sets YYLHS.VALUE to garbage.
       This behavior is undocumented and Bison
@@ -375,7 +375,7 @@ b4_lexer_if([[
    ]b4_locations_if([b4_location_type[ yyloc = yylloc (yystack, yylen);]])[

    /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+       '$$ = $1'.  Otherwise, use the top of the stack.

       Otherwise, the following line sets YYVAL to garbage.
       This behavior is undocumented and Bison
@@ -25,8 +25,7 @@ m4_define([b4_position_define],
 [[  /// Abstract a position.
  class position
  {
-  public:
-]m4_ifdef([b4_location_constructors], [[
+  public:]m4_ifdef([b4_location_constructors], [[
    /// Construct a position.
    explicit position (]b4_percent_define_get([[filename_type]])[* f = YY_NULL,
                       unsigned int l = ]b4_location_initial_line[u,
@@ -53,14 +52,17 @@ m4_define([b4_position_define],
    /// (line related) Advance to the COUNT next lines.
    void lines (int count = 1)
    {
-      column = ]b4_location_initial_column[u;
-      line += count;
+      if (count)
+        {
+          column = ]b4_location_initial_column[u;
+          line = add_ (line, count, ]b4_location_initial_line[);
+        }
    }

    /// (column related) Advance to the COUNT next columns.
    void columns (int count = 1)
    {
-      column = std::max (]b4_location_initial_column[u, column + count);
+      column = add_ (column, count, ]b4_location_initial_column[);
    }
    /** \} */

@@ -70,36 +72,44 @@ m4_define([b4_position_define],
    unsigned int line;
    /// Current column number.
    unsigned int column;
+
+  private:
+    /// Compute max(min, lhs+rhs) (provided min <= lhs).
+    static unsigned int add_ (unsigned int lhs, int rhs, unsigned int min)
+    {
+      return (0 < rhs || -static_cast<unsigned int>(rhs) < lhs
+              ? rhs + lhs
+              : min);
+    }
  };

  /// Add and assign a position.
  inline position&
-  operator+= (position& res, const int width)
+  operator+= (position& res, int width)
  {
    res.columns (width);
    return res;
  }

  /// Add two position objects.
-  inline const position
-  operator+ (const position& begin, const int width)
+  inline position
+  operator+ (position res, int width)
  {
-    position res = begin;
    return res += width;
  }

  /// Add and assign a position.
  inline position&
-  operator-= (position& res, const int width)
+  operator-= (position& res, int width)
  {
    return res += -width;
  }

  /// Add two position objects.
-  inline const position
-  operator- (const position& begin, const int width)
+  inline position
+  operator- (position res, int width)
  {
-    return begin + -width;
+    return res -= width;
  }
 ]b4_percent_define_flag_if([[define_location_comparison]], [[
  /// Compare two position objects.
@@ -186,13 +196,13 @@ m4_define([b4_location_define],
    }

    /// Extend the current location to the COUNT next columns.
-    void columns (unsigned int count = 1)
+    void columns (int count = 1)
    {
      end += count;
    }

    /// Extend the current location to the COUNT next lines.
-    void lines (unsigned int count = 1)
+    void lines (int count = 1)
    {
      end.lines (count);
    }
@@ -207,26 +217,35 @@ m4_define([b4_location_define],
  };

  /// Join two location objects to create a location.
-  inline const location operator+ (const location& begin, const location& end)
+  inline location operator+ (location res, const location& end)
  {
-    location res = begin;
    res.end = end.end;
    return res;
  }

-  /// Add two location objects.
-  inline const location operator+ (const location& begin, unsigned int width)
+  /// Change end position in place.
+  inline location& operator+= (location& res, int width)
  {
-    location res = begin;
    res.columns (width);
    return res;
  }

-  /// Add and assign a location.
-  inline location& operator+= (location& res, unsigned int width)
+  /// Change end position.
+  inline location operator+ (location res, int width)
  {
-    res.columns (width);
-    return res;
+    return res += width;
+  }
+
+  /// Change end position in place.
+  inline location& operator-= (location& res, int width)
+  {
+    return res += -width;
+  }
+
+  /// Change end position.
+  inline location operator- (const location& begin, int width)
+  {
+    return begin + -width;
  }
 ]b4_percent_define_flag_if([[define_location_comparison]], [[
  /// Compare two location objects.
@@ -72,6 +72,12 @@ m4_define([b4_stack_define],
        seq_.pop_back ();
    }

+    void
+    clear ()
+    {
+      seq_.clear ();
+    }
+
    inline
    typename S::size_type
    size () const
@@ -94,6 +100,8 @@ m4_define([b4_stack_define],
    }

  private:
+    stack (const stack&);
+    stack& operator= (const stack&);
    /// The wrapped container.
    S seq_;
  };
@@ -26,7 +26,7 @@
 # YYTYPE.
 m4_define([b4_symbol_variant],
 [m4_pushdef([b4_dollar_dollar],
-            [$2.$3< $][3 >(m4_shift3($@))])dnl
+            [$2.$3< $][3 > (m4_shift3($@))])dnl
  switch ($1)
    {
 b4_type_foreach([b4_type_action_])[]dnl
@@ -63,7 +63,7 @@ m4_define([b4_char_sizeof],
 [b4_symbol_if([$1], [has_type],
 [
 m4_map([      b4_symbol_tag_comment], [$@])dnl
-      char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@};
+      char _b4_char_sizeof_dummy@{sizeof(b4_symbol([$1], [type]))@};
 ])])


@@ -95,22 +95,22 @@ m4_define([b4_variant_define],

    /// Empty construction.
    variant ()]b4_parse_assert_if([
-      : tname (YY_NULL)])[
+      : yytname_ (YY_NULL)])[
    {}

    /// Construct and fill.
    template <typename T>
    variant (const T& t)]b4_parse_assert_if([
-      : tname (typeid (T).name ())])[
+      : yytname_ (typeid (T).name ())])[
    {
      YYASSERT (sizeof (T) <= S);
-      new (buffer.raw) T (t);
+      new (yyas_<T> ()) T (t);
    }

    /// Destruction, allowed only if empty.
    ~variant ()
    {]b4_parse_assert_if([
-      YYASSERT (!tname);
+      YYASSERT (!yytname_);
    ])[}

    /// Instantiate an empty \a T in here.
@@ -118,10 +118,10 @@ m4_define([b4_variant_define],
    T&
    build ()
    {]b4_parse_assert_if([
-      YYASSERT (!tname);
+      YYASSERT (!yytname_);
      YYASSERT (sizeof (T) <= S);
-      tname = typeid (T).name ();])[
-      return *new (buffer.raw) T;
+      yytname_ = typeid (T).name ();])[
+      return *new (yyas_<T> ()) T;
    }

    /// Instantiate a \a T in here from \a t.
@@ -129,10 +129,10 @@ m4_define([b4_variant_define],
    T&
    build (const T& t)
    {]b4_parse_assert_if([
-      YYASSERT (!tname);
+      YYASSERT (!yytname_);
      YYASSERT (sizeof (T) <= S);
-      tname = typeid (T).name ();])[
-      return *new (buffer.raw) T (t);
+      yytname_ = typeid (T).name ();])[
+      return *new (yyas_<T> ()) T (t);
    }

    /// Accessor to a built \a T.
@@ -140,9 +140,9 @@ m4_define([b4_variant_define],
    T&
    as ()
    {]b4_parse_assert_if([
-      YYASSERT (tname == typeid (T).name ());
+      YYASSERT (yytname_ == typeid (T).name ());
      YYASSERT (sizeof (T) <= S);])[
-      return reinterpret_cast<T&> (buffer.raw);
+      return *yyas_<T> ();
    }

    /// Const accessor to a built \a T (for %printer).
@@ -150,9 +150,9 @@ m4_define([b4_variant_define],
    const T&
    as () const
    {]b4_parse_assert_if([
-      YYASSERT (tname == typeid (T).name ());
+      YYASSERT (yytname_ == typeid (T).name ());
      YYASSERT (sizeof (T) <= S);])[
-      return reinterpret_cast<const T&> (buffer.raw);
+      return *yyas_<T> ();
    }

    /// Swap the content with \a other, of same type.
@@ -167,9 +167,9 @@ m4_define([b4_variant_define],
    void
    swap (self_type& other)
    {]b4_parse_assert_if([
-      YYASSERT (tname);
-      YYASSERT (tname == other.tname);])[
-      std::swap (as<T>(), other.as<T>());
+      YYASSERT (yytname_);
+      YYASSERT (yytname_ == other.yytname_);])[
+      std::swap (as<T> (), other.as<T> ());
    }

    /// Move the content of \a other to this.
@@ -179,10 +179,10 @@ m4_define([b4_variant_define],
    void
    move (self_type& other)
    {]b4_parse_assert_if([
-      YYASSERT (!tname);])[
-      build<T>();
-      swap<T>(other);
-      other.destroy<T>();
+      YYASSERT (!yytname_);])[
+      build<T> ();
+      swap<T> (other);
+      other.destroy<T> ();
    }

    /// Copy the content of \a other to this.
@@ -199,7 +199,7 @@ m4_define([b4_variant_define],
    destroy ()
    {
      as<T> ().~T ();]b4_parse_assert_if([
-      tname = YY_NULL;])[
+      yytname_ = YY_NULL;])[
    }

  private:
@@ -207,17 +207,34 @@ m4_define([b4_variant_define],
    self_type& operator=(const self_type&);
    variant (const self_type&);

-    /// A buffer large enough to store any of the semantic values.
-    /// Long double is chosen as it has the strongest alignment
-    /// constraints.
+    /// Accessor to raw memory as \a T.
+    template <typename T>
+    T*
+    yyas_ ()
+    {
+      void *yyp = yybuffer_.yyraw;
+      return static_cast<T*> (yyp);
+     }
+
+    /// Const accessor to raw memory as \a T.
+    template <typename T>
+    const T*
+    yyas_ () const
+    {
+      const void *yyp = yybuffer_.yyraw;
+      return static_cast<const T*> (yyp);
+     }
+
    union
    {
-      long double align_me;
-      char raw[S];
-    } buffer;]b4_parse_assert_if([
+      /// Strongest alignment constraints.
+      long double yyalign_me;
+      /// A buffer large enough to store any of the semantic values.
+      char yyraw[S];
+    } yybuffer_;]b4_parse_assert_if([

    /// Whether the content is built: if defined, the name of the stored type.
-    const char* tname;])[
+    const char *yytname_;])[
  };
 ]])

@@ -227,16 +244,16 @@ m4_define([b4_variant_define],
 ## -------------------------- ##


-# b4_semantic_type_declare
-# ------------------------
+# b4_value_type_declare
+# ---------------------
 # Declare semantic_type.
-m4_define([b4_semantic_type_declare],
-[    /// An auxiliary type to compute the largest semantic type.
+m4_define([b4_value_type_declare],
+[[    /// An auxiliary type to compute the largest semantic type.
    union union_type
    {]b4_type_foreach([b4_char_sizeof])[};

    /// Symbol semantic values.
-    typedef variant<sizeof(union_type)> semantic_type;dnl
+    typedef variant<sizeof(union_type)> semantic_type;][]dnl
 ])


@@ -246,7 +263,7 @@ m4_define([b4_semantic_type_declare],
 # ----------------------------
 m4_define([b4_symbol_value],
 [m4_ifval([$2],
-          [$1.as< $2 >()],
+          [$1.as< $2 > ()],
          [$1])])

 # b4_symbol_value_template(VAL, [TYPE])
@@ -254,7 +271,7 @@ m4_define([b4_symbol_value],
 # Same as b4_symbol_value, but used in a template method.
 m4_define([b4_symbol_value_template],
 [m4_ifval([$2],
-          [$1.template as< $2 >()],
+          [$1.template as< $2 > ()],
          [$1])])


@@ -311,7 +328,7 @@ b4_join(b4_symbol_if([$1], [has_type],


 # b4_basic_symbol_constructor_declare
-# ----------------------------------
+# -----------------------------------
 # Generate a constructor declaration for basic_symbol from given type.
 m4_define([b4_basic_symbol_constructor_declare],
 [[
@@ -373,7 +373,7 @@
 </xsl:template>

 <xsl:template match="empty">
-  <xsl:text> /* empty */</xsl:text>
+  <xsl:text> %empty</xsl:text>
 </xsl:template>

 <xsl:template match="lookaheads">
@@ -143,7 +143,6 @@ m4_define([b4_rhs_value],
          [b4_symbol_value([yyvsp@{b4_subtract([$2], [$1])@}], [$3])])


-
 ## ----------- ##
 ## Locations.  ##
 ## ----------- ##
@@ -200,7 +199,7 @@ static YYLTYPE yyloc_default][]b4_yyloc_default[;]])])[
 #endif

 /* The semantic value of the lookahead symbol.  */
-YYSTYPE yylval YY_INITIAL_VALUE(yyval_default);]b4_locations_if([[
+YYSTYPE yylval YY_INITIAL_VALUE (yyval_default);]b4_locations_if([[

 /* Location data for the lookahead symbol.  */
 YYLTYPE yylloc]b4_pure_if([ = yyloc_default], [b4_yyloc_default])[;
@@ -223,9 +222,9 @@ m4_define([b4_declare_parser_state_variables], [b4_pure_if([[
    int yyerrstatus;

    /* The stacks and their tools:
-       `yyss': related to states.
-       `yyvs': related to semantic values.]b4_locations_if([[
-       `yyls': related to locations.]])[
+       'yyss': related to states.
+       'yyvs': related to semantic values.]b4_locations_if([[
+       'yyls': related to locations.]])[

       Refer to the stacks through separate pointers, to allow yyoverflow
       to reallocate them elsewhere.  */
@@ -431,12 +430,7 @@ typedef short int yytype_int16;
 # endif
 #endif

-/* Suppress unused-variable warnings by "using" E.  */
-#ifdef __GNUC__
-# define YYUSE(E) ((void) (E))
-#else
-# define YYUSE(E) /* empty */
-#endif
+]b4_attribute_define[

 #if ]b4_lac_if([[1]], [[! defined yyoverflow || YYERROR_VERBOSE]])[

@@ -468,7 +462,7 @@ b4_push_if([], [b4_lac_if([], [[
 # endif]])])[

 # ifdef YYSTACK_ALLOC
-   /* Pacify GCC's `empty if-body' warning.  */
+   /* Pacify GCC's 'empty if-body' warning.  */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
 #  ifndef YYSTACK_ALLOC_MAXIMUM
    /* The OS might guarantee only one guard page at the bottom of the stack,
@@ -1654,7 +1648,7 @@ yyreduce:
  yylen = yyr2[yyn];

  /* If YYLEN is nonzero, implement the default value of the action:
-     `$$ = $1'.
+     '$$ = $1'.

     Otherwise, the following line sets YYVAL to garbage.
     This behavior is undocumented and Bison
@@ -1702,7 +1696,7 @@ yyreduce:
  *++yyvsp = yyval;]b4_locations_if([
  *++yylsp = yyloc;])[

-  /* Now `shift' the result of the reduction.  Determine what state
+  /* Now 'shift' the result of the reduction.  Determine what state
     that goes to, based on the state we popped back to and the rule
     number reduced by.  */

@@ -37,7 +37,7 @@ MOSTLYCLEANFILES += $(top_srcdir)/doc/*.t
 CROSS_OPTIONS_PL = $(top_srcdir)/build-aux/cross-options.pl
 CROSS_OPTIONS_TEXI = $(top_srcdir)/doc/cross-options.texi
 $(CROSS_OPTIONS_TEXI): doc/bison.help $(CROSS_OPTIONS_PL)
-# Create $@~ which is the previous contents.  Don't use `mv' here so
+# Create $@~ which is the previous contents.  Don't use 'mv' here so
 # that even if we are interrupted, the file is still available for
 # diff in the next run.  Note that $@ might not exist yet.
 	$(AM_V_GEN){ test ! -f $@ || cat $@; } >$@~
@@ -204,9 +204,9 @@ Format the list of directives for Bison for bench named C<$bench>.
 sub directives($@)
 {
  my ($bench, @directive) = @_;
-  my $res = "/* Directives for bench `$bench'. */\n";
+  my $res = "/* Directives for bench '$bench'. */\n";
  $res .= join ("\n", @directive) . "\n";
-  $res .= "/* End of directives for bench `$bench'. */\n";
+  $res .= "/* End of directives for bench '$bench'. */\n";
  return $res;
 }

@@ -44,32 +44,31 @@ CLEANFILES +=                                   \
 # Avoid using BUILT_SOURCES which is too global.
 $(examples_calc___calc___OBJECTS): $(calc_sources_generated)

-calc_sources_extracted =			\
-  examples/calc++/calc++-driver.cc		\
-  examples/calc++/calc++-driver.hh		\
-  examples/calc++/calc++-scanner.ll		\
+calc_sources_extracted =                        \
+  examples/calc++/calc++-driver.cc              \
+  examples/calc++/calc++-driver.hh              \
+  examples/calc++/calc++-scanner.ll             \
  examples/calc++/calc++.cc
-calc_extracted =				\
-  $(calc_sources_extracted)			\
+calc_extracted =                                \
+  $(calc_sources_extracted)                     \
  examples/calc++/calc++-parser.yy
 extracted += $(calc_extracted)
-calc_sources_generated =			\
-  examples/calc++/calc++-parser.cc		\
-  examples/calc++/calc++-parser.hh		\
-  examples/calc++/location.hh			\
-  examples/calc++/position.hh			\
+calc_sources_generated =                        \
+  examples/calc++/calc++-parser.cc              \
+  examples/calc++/calc++-parser.hh              \
+  examples/calc++/location.hh                   \
+  examples/calc++/position.hh                   \
  examples/calc++/stack.hh
-calc_sources =					\
-  $(calc_sources_extracted)			\
+calc_sources =                                  \
+  $(calc_sources_extracted)                     \
  $(calc_sources_generated)

 if BISON_CXX_WORKS
 check_PROGRAMS += examples/calc++/calc++
-nodist_examples_calc___calc___SOURCES =		\
+nodist_examples_calc___calc___SOURCES =         \
  $(calc_sources)

 examples_calc___calc___CPPFLAGS = -I$(top_builddir)/examples/calc++
-examples_calc___calc___CXXFLAGS =			\
-  $(AM_CXXFLAGS) $(WARN_NO_NULL_CONVERSION_CXXFLAGS)
+examples_calc___calc___CXXFLAGS = $(AM_CXXFLAGS) $(FLEX_SCANNER_CXXFLAGS)
 dist_TESTS += examples/calc++/calc++.test
 endif
@@ -17,7 +17,6 @@ dist_noinst_SCRIPTS = examples/extexi examples/test
 TEST_LOG_COMPILER = $(top_srcdir)/examples/test

 AM_CXXFLAGS =							\
-  $(NO_STRICT_ALIAS_CXXFLAGS)					\
  $(WARN_CXXFLAGS) $(WARN_CXXFLAGS_TEST) $(WERROR_CXXFLAGS)

 ## ------------ ##
@@ -17,7 +17,7 @@


 /* Bison depends on libiberty's implementation of bitsets, which
-   requires a `libiberty.h' file.  This file provides the minimum
+   requires a 'libiberty.h' file.  This file provides the minimum
   services.  */

 #ifndef BISON_LIBIBERTY_H_
@@ -36,7 +36,7 @@
       Timing variables may be pushed onto the stack; elapsed time is
       attributed to the topmost timing variable on the stack.  When
       another variable is pushed on, the previous topmost variable is
-       `paused' until the pushed variable is popped back off.
+       'paused' until the pushed variable is popped back off.

     - As a standalone timer, using timevar_start and timevar_stop.
       All time elapsed between the two calls is attributed to the
@@ -60,7 +60,7 @@ Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits)
 }

 void
-Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file)
+Sbitset__fprint (Sbitset self, Sbitset__Index nbits, FILE *file)
 {
  Sbitset__Index i;
  Sbitset itr;
@@ -44,31 +44,31 @@ void Sbitset__delete (Sbitset self);

 bool Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits);

-void Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file);
+void Sbitset__fprint (Sbitset self, Sbitset__Index nbits, FILE *file);

 # define Sbitset__set(SELF, INDEX)                                      \
  do {                                                                  \
    *Sbitset__byteAddress ((SELF), (INDEX)) =                           \
      *Sbitset__byteAddress ((SELF), (INDEX)) | Sbitset__bit_mask (INDEX); \
-  } while(0)
+  } while (0)

 # define Sbitset__reset(SELF, INDEX)                                    \
  do {                                                                  \
    *Sbitset__byteAddress ((SELF), (INDEX)) =                           \
      *Sbitset__byteAddress ((SELF), (INDEX)) & ~Sbitset__bit_mask (INDEX); \
-  } while(0)
+  } while (0)

 /* NBITS is the size of the bitset.  More than NBITS bits might be reset.  */
 # define Sbitset__zero(SELF, NBITS)             \
  do {                                          \
    memset (SELF, 0, Sbitset__nbytes (NBITS));  \
-  } while(0)
+  } while (0)

 /* NBITS is the size of the bitset.  More than NBITS bits might be set.  */
 # define Sbitset__ones(SELF, NBITS)                     \
  do {                                                  \
    memset (SELF, UCHAR_MAX, Sbitset__nbytes (NBITS));  \
-  } while(0)
+  } while (0)

 /* NBITS is the size of every bitset.  More than NBITS bits might be set.  */
 # define Sbitset__or(SELF, OTHER1, OTHER2, NBITS)                       \
@@ -79,7 +79,7 @@ void Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file);
    Sbitset end_self = ptr_self + Sbitset__nbytes (NBITS);              \
    for (; ptr_self < end_self; ++ptr_self, ++ptr_other1, ++ptr_other2) \
      *ptr_self = *ptr_other1 | *ptr_other2;                            \
-  } while(0)
+  } while (0)

 # define SBITSET__FOR_EACH(SELF, NBITS, ITER, INDEX)                    \
  for ((ITER) = (SELF); (ITER) < (SELF) + Sbitset__nbytes (NBITS); ++(ITER)) \
@@ -22,6 +22,7 @@
 #include <config.h>
 #include "system.h"

+#include <argmatch.h>
 #include <stdarg.h>
 #include <progname.h>

@@ -30,42 +31,199 @@
 #include "getargs.h"
 #include "quote.h"

-warnings warnings_flag =
-  Wconflicts_sr | Wconflicts_rr | Wdeprecated  | Wother;
-
-warnings errors_flag;
-
 err_status complaint_status = status_none;
+
+bool warnings_are_errors = false;
+
+/** Diagnostics severity.  */
+typedef enum
+  {
+    severity_disabled = 0,
+    severity_unset = 1,
+    severity_warning = 2,
+    severity_error = 3,
+    severity_fatal = 4
+  } severity;
+
+
+/** For each warning type, its severity.  */
+static severity warnings_flag[warnings_size];
+
 static unsigned *indent_ptr = 0;

-void
-warnings_print_categories (warnings warn_flags)
-{
-  if (! (warn_flags & silent))
-    {
-      char const *warn_names[] =
-        {
-          "midrule-values",
-          "yacc",
-          "conflicts-sr",
-          "conflicts-rr",
-          "deprecated",
-          "other"
-        };
+/*------------------------.
+| --warnings's handling.  |
+`------------------------*/

-      bool any = false;
-      int i;
-      for (i = 0; i < ARRAY_CARDINALITY (warn_names); ++i)
-        if (warn_flags & 1 << i)
-          {
-            bool err = warn_flags & errors_flag;
-            fprintf (stderr, "%s-W", any ? ", " : " [");
-            fprintf (stderr, "%s%s", err ? "error=" : "" , warn_names[i]);
-            any = true;
-          }
-      if (any)
-        fprintf (stderr, "]");
+static const char * const warnings_args[] =
+{
+  "none",
+  "midrule-values",
+  "yacc",
+  "conflicts-sr",
+  "conflicts-rr",
+  "deprecated",
+  "empty-rule",
+  "precedence",
+  "other",
+  "all",
+  "error",
+  "everything",
+  0
+};
+
+static const int warnings_types[] =
+{
+  Wnone,
+  Wmidrule_values,
+  Wyacc,
+  Wconflicts_sr,
+  Wconflicts_rr,
+  Wdeprecated,
+  Wempty_rule,
+  Wprecedence,
+  Wother,
+  Wall,
+  Werror,
+  Weverything
+};
+
+ARGMATCH_VERIFY (warnings_args, warnings_types);
+
+void
+warning_argmatch (char const *arg, size_t no, size_t err)
+{
+  int value = XARGMATCH ("--warning", arg + no + err,
+                         warnings_args, warnings_types);
+
+  /* -Wnone == -Wno-everything, and -Wno-none == -Weverything.  */
+  if (!value)
+    {
+      value = Weverything;
+      no = !no;
    }
+
+  if (no)
+    {
+      size_t b;
+      for (b = 0; b < warnings_size; ++b)
+        if (value & 1 << b)
+          {
+            if (err)
+              {
+                /* -Wno-error=foo: if foo enabled as an error,
+                   make it a warning.  */
+                if (warnings_flag[b] == severity_error)
+                  warnings_flag[b] = severity_warning;
+              }
+            else
+              /* -Wno-foo.  */
+              warnings_flag[b] = severity_disabled;
+          }
+    }
+  else
+    {
+      size_t b;
+      for (b = 0; b < warnings_size; ++b)
+        if (value & 1 << b)
+          /* -Wfoo and -Werror=foo. */
+          warnings_flag[b] = err ? severity_error : severity_warning;
+    }
+}
+
+/** Decode a comma-separated list of arguments from -W.
+ *
+ *  \param args     comma separated list of effective subarguments to decode.
+ *                  If 0, then activate all the flags.
+ */
+
+void
+warnings_argmatch (char *args)
+{
+  if (args)
+    for (args = strtok (args, ","); args; args = strtok (NULL, ","))
+      if (STREQ (args, "error"))
+        warnings_are_errors = true;
+      else if (STREQ (args, "no-error"))
+        {
+          warnings_are_errors = false;
+          warning_argmatch ("no-error=everything", 3, 6);
+        }
+      else
+        {
+          size_t no = STRPREFIX_LIT ("no-", args) ? 3 : 0;
+          size_t err = STRPREFIX_LIT ("error=", args + no) ? 6 : 0;
+
+          warning_argmatch (args, no, err);
+        }
+  else
+    warning_argmatch ("all", 0, 0);
+}
+
+
+/*-----------.
+| complain.  |
+`-----------*/
+
+void
+complain_init (void)
+{
+  warnings warnings_default =
+    Wconflicts_sr | Wconflicts_rr | Wdeprecated | Wother;
+
+  size_t b;
+  for (b = 0; b < warnings_size; ++b)
+    warnings_flag[b] = (1 << b & warnings_default
+                        ? severity_warning
+                        : severity_unset);
+}
+
+static severity
+warning_severity (warnings flags)
+{
+  if (flags & fatal)
+    return severity_fatal;
+  else if (flags & complaint)
+    return severity_error;
+  else
+    {
+      severity res = severity_disabled;
+      size_t b;
+      for (b = 0; b < warnings_size; ++b)
+        if (flags & 1 << b)
+          res = res < warnings_flag[b] ? warnings_flag[b] : res;
+      if (res == severity_warning && warnings_are_errors)
+        res = severity_error;
+      return res;
+    }
+}
+
+bool
+warning_is_unset (warnings flags)
+{
+  size_t b;
+  for (b = 0; b < warnings_size; ++b)
+    if (flags & 1 << b && warnings_flag[b] != severity_unset)
+      return false;
+  return true;
+}
+
+/** Display a "[-Wyacc]" like message on \a f.  */
+
+static void
+warnings_print_categories (warnings warn_flags, FILE *f)
+{
+  /* Display only the first match, the second is "-Wall".  */
+  size_t i;
+  for (i = 0; warnings_args[i]; ++i)
+    if (warn_flags & warnings_types[i])
+      {
+        severity s = warning_severity (warnings_types[i]);
+        fprintf (f, " [-W%s%s]",
+                 s == severity_error ? "error=" : "",
+                 warnings_args[i]);
+        return;
+      }
 }

 /** Report an error message.
@@ -88,7 +246,7 @@ error_message (const location *loc, warnings flags, const char *prefix,
  unsigned pos = 0;

  if (loc)
-    pos += location_print (stderr, *loc);
+    pos += location_print (*loc, stderr);
  else
    pos += fprintf (stderr, "%s", current_file ? current_file : program_name);
  pos += fprintf (stderr, ": ");
@@ -108,7 +266,8 @@ error_message (const location *loc, warnings flags, const char *prefix,
    fprintf (stderr, "%s: ", prefix);

  vfprintf (stderr, message, args);
-  warnings_print_categories (flags);
+  if (! (flags & silent))
+    warnings_print_categories (flags, stderr);
  {
    size_t l = strlen (message);
    if (l < 2 || message[l - 2] != ':' || message[l - 1] != ' ')
@@ -116,29 +275,34 @@ error_message (const location *loc, warnings flags, const char *prefix,
        putc ('\n', stderr);
        fflush (stderr);
        if (loc && feature_flag & feature_caret && !(flags & no_caret))
-          location_caret (stderr, *loc);
+          location_caret (*loc, stderr);
      }
  }
  fflush (stderr);
 }

-/** Raise a complaint. That can be a fatal error, a complaint or just a
+/** Raise a complaint. That can be a fatal error, an error or just a
    warning.  */
-static inline void
+
+static void
 complains (const location *loc, warnings flags, const char *message,
           va_list args)
 {
-  const char* prefix =
-    flags & fatal ? _("fatal error")
-    : flags & (errors_flag | complaint) ? _("error")
-    : _("warning");
-
+  severity s = warning_severity (flags);
  if ((flags & complaint) && complaint_status < status_complaint)
    complaint_status = status_complaint;
-  else if ((flags & (warnings_flag & errors_flag)) && ! complaint_status)
-    complaint_status = status_warning_as_error;
-  if (flags & (warnings_flag | fatal | complaint))
-    error_message (loc, flags, prefix, message, args);
+
+  if (severity_warning <= s)
+    {
+      const char* prefix =
+        s == severity_fatal ? _("fatal error")
+        : s == severity_error ? _("error")
+        : _("warning");
+      if (severity_error <= s && ! complaint_status)
+        complaint_status = status_warning_as_error;
+      error_message (loc, flags, prefix, message, args);
+    }
+
  if (flags & fatal)
    exit (EXIT_FAILURE);
 }
@@ -189,7 +353,6 @@ complain_args (location const *loc, warnings w, unsigned *indent,
    complain (loc, fatal, "too many arguments for complains");
    break;
  }
-
 }

 void
@@ -204,3 +367,13 @@ deprecated_directive (location const *loc, char const *old, char const *upd)
              _("deprecated directive: %s, use %s"),
              quote (old), quote_n (1, upd));
 }
+
+void
+duplicate_directive (char const *directive,
+                     location first, location second)
+{
+  unsigned i = 0;
+  complain (&second, complaint, _("only one %s allowed per rule"), directive);
+  i += SUB_INDENT;
+  complain_indent (&first, complaint, &i, _("previous declaration"));
+}
@@ -28,15 +28,67 @@
 | --warnings.  |
 `-------------*/

+/** The bits assigned to each warning type.  */
 typedef enum
  {
-    Wnone             = 0,       /**< Issue no warnings.  */
-    Wmidrule_values   = 1 << 0,  /**< Unset or unused midrule values.  */
-    Wyacc             = 1 << 1,  /**< POSIXME.  */
-    Wconflicts_sr     = 1 << 2,  /**< S/R conflicts.  */
-    Wconflicts_rr     = 1 << 3,  /**< R/R conflicts.  */
-    Wdeprecated       = 1 << 4,  /**< Obsolete constructs.  */
-    Wother            = 1 << 5,  /**< All other warnings.  */
+    warning_midrule_values, /**< Unset or unused midrule values.  */
+    warning_yacc,           /**< POSIXME.  */
+    warning_conflicts_sr,   /**< S/R conflicts.  */
+    warning_conflicts_rr,   /**< R/R conflicts.  */
+    warning_empty_rule,     /**< Implicitly empty rules.  */
+    warning_deprecated,     /**< Obsolete constructs.  */
+    warning_precedence,     /**< Useless precedence and associativity.  */
+    warning_other,          /**< All other warnings.  */
+
+    warnings_size           /**< The number of warnings.  Must be last.  */
+  } warning_bit;
+
+/** Whether -Werror was set. */
+extern bool warnings_are_errors;
+
+/** Decode a single argument from -W.
+ *
+ *  \param arg      the subarguments to decode.
+ *                  If null, then activate all the flags.
+ *  \param no       length of the potential "no-" prefix.
+ *                  Can be 0 or 3. If 3, negate the action of the subargument.
+ *  \param err      length of a potential "error=".
+ *                  Can be 0 or 6. If 6, treat the subargument as a CATEGORY.
+ *
+ *  If VALUE != 0 then KEY sets flags and no-KEY clears them.
+ *  If VALUE == 0 then KEY clears all flags from \c all and no-KEY sets all
+ *  flags from \c all.  Thus no-none = all and no-all = none.
+ */
+void warning_argmatch (char const *arg, size_t no, size_t err);
+
+/** Decode a comma-separated list of arguments from -W.
+ *
+ *  \param args     comma separated list of effective subarguments to decode.
+ *                  If 0, then activate all the flags.
+ */
+void warnings_argmatch (char *args);
+
+
+/*-----------.
+| complain.  |
+`-----------*/
+
+/** Initialize this module.  */
+void complain_init (void);
+
+typedef enum
+  {
+    /**< Issue no warnings.  */
+    Wnone             = 0,
+
+    Wmidrule_values   = 1 << warning_midrule_values,
+    Wyacc             = 1 << warning_yacc,
+    Wconflicts_sr     = 1 << warning_conflicts_sr,
+    Wconflicts_rr     = 1 << warning_conflicts_rr,
+    Wdeprecated       = 1 << warning_deprecated,
+    Wempty_rule       = 1 << warning_empty_rule,
+    Wprecedence       = 1 << warning_precedence,
+    Wother            = 1 << warning_other,

    Werror            = 1 << 10, /** This bit is no longer used. */

@@ -46,17 +98,13 @@ typedef enum
    no_caret          = 1 << 14, /**< Do not display caret location.  */

    /**< All above warnings.  */
-    Wall              = ~complaint & ~fatal & ~silent
+    Weverything       = ~complaint & ~fatal & ~silent,
+    Wall              = Weverything & ~Wyacc
  } warnings;

-/** What warnings are issued.  */
-extern warnings warnings_flag;
-
-/** What warnings are made errors.  */
-extern warnings errors_flag;
-
-/** Display a "[-Wyacc]" like message on stderr.  */
-void warnings_print_categories (warnings warn_flags);
+/** Whether the warnings of \a flags are all unset.
+    (Never enabled, never disabled). */
+bool warning_is_unset (warnings flags);

 /** Make a complaint, with maybe a location.  */
 void complain (location const *loc, warnings flags, char const *message, ...)
@@ -76,6 +124,10 @@ void complain_indent (location const *loc, warnings flags, unsigned *indent,
 void deprecated_directive (location const *loc,
                           char const *obsolete, char const *updated);

+/** Report a repeated directive for a rule.  */
+void duplicate_directive (char const *directive,
+                          location first, location second);
+
 /** Warnings treated as errors shouldn't stop the execution as regular errors
    should (because due to their nature, it is safe to go on). Thus, there are
    three possible execution statuses.  */
@@ -403,7 +403,7 @@ conflicts_solve (void)
      set_conflicts (states[i], errors);

      /* For uniformity of the code, make sure all the states have a valid
-         `errs' member.  */
+         'errs' member.  */
      if (!states[i]->errs)
        states[i]->errs = errs_new (0, 0);
    }
@@ -34,7 +34,7 @@
 #include "getargs.h"
 #include "gram.h"

-/* Initializing some values below (such SPEC_NAME_PREFIX to `yy') is
+/* Initializing some values below (such SPEC_NAME_PREFIX to 'yy') is
   tempting, but don't do that: for the time being our handling of the
   %directive vs --option leaves precedence to the options by deciding
   that if a %directive sets a variable which is really set (i.e., not
@@ -58,20 +58,20 @@ uniqstr grammar_file = NULL;
 uniqstr current_file = NULL;

 /* If --output=dir/foo.c was specified,
-   DIR_PREFIX is `dir/' and ALL_BUT_EXT and ALL_BUT_TAB_EXT are `dir/foo'.
+   DIR_PREFIX is 'dir/' and ALL_BUT_EXT and ALL_BUT_TAB_EXT are 'dir/foo'.

-   If --output=dir/foo.tab.c was specified, DIR_PREFIX is `dir/',
-   ALL_BUT_EXT is `dir/foo.tab', and ALL_BUT_TAB_EXT is `dir/foo'.
+   If --output=dir/foo.tab.c was specified, DIR_PREFIX is 'dir/',
+   ALL_BUT_EXT is 'dir/foo.tab', and ALL_BUT_TAB_EXT is 'dir/foo'.

   If --output was not specified but --file-prefix=dir/foo was specified,
-   ALL_BUT_EXT = `foo.tab' and ALL_BUT_TAB_EXT = `foo'.
+   ALL_BUT_EXT = 'foo.tab' and ALL_BUT_TAB_EXT = 'foo'.

   If neither --output nor --file was specified but the input grammar
-   is name dir/foo.y, ALL_BUT_EXT and ALL_BUT_TAB_EXT are `foo'.
+   is name dir/foo.y, ALL_BUT_EXT and ALL_BUT_TAB_EXT are 'foo'.

   If neither --output nor --file was specified, DIR_PREFIX is the
   empty string (meaning the current directory); otherwise it is
-   `dir/'.  */
+   'dir/'.  */

 char *all_but_ext;
 static char *all_but_tab_ext;
@@ -79,7 +79,7 @@ char *dir_prefix;

 /* C source file extension (the parser source).  */
 static char *src_extension = NULL;
-/* Header file extension (if option ``-d'' is specified).  */
+/* Header file extension (if option '`-d'' is specified).  */
 static char *header_extension = NULL;

 /*-----------------------------------------------------------------.
@@ -191,7 +191,7 @@ compute_exts_from_src (const char *ext)
   *EXT points to the last period in the basename, or NULL if none.

   If there is no *EXT, *TAB is NULL.  Otherwise, *TAB points to
-   `.tab' or `_tab' if present right before *EXT, or is NULL. *TAB
+   '.tab' or '_tab' if present right before *EXT, or is NULL. *TAB
   cannot be equal to *BASE.

   None are allocated, they are simply pointers to parts of FILE_NAME.
@@ -222,7 +222,7 @@ file_name_split (const char *file_name,
  *ext = strrchr (*base, '.');
  *tab = NULL;

-  /* If there is an extension, check if there is a `.tab' part right
+  /* If there is an extension, check if there is a '.tab' part right
     before.  */
  if (*ext)
    {
@@ -270,7 +270,7 @@ compute_file_name_parts (void)

      if (spec_file_prefix)
        {
-          /* If --file-prefix=foo was specified, ALL_BUT_TAB_EXT = `foo'.  */
+          /* If --file-prefix=foo was specified, ALL_BUT_TAB_EXT = 'foo'.  */
          dir_prefix =
            xstrndup (spec_file_prefix,
                      last_component (spec_file_prefix) - spec_file_prefix);
@@ -278,14 +278,14 @@ compute_file_name_parts (void)
        }
      else if (yacc_flag)
        {
-          /* If --yacc, then the output is `y.tab.c'.  */
+          /* If --yacc, then the output is 'y.tab.c'.  */
          dir_prefix = xstrdup ("");
          all_but_tab_ext = xstrdup ("y");
        }
      else
        {
          /* Otherwise, ALL_BUT_TAB_EXT is computed from the input
-             grammar: `foo/bar.yy' => `bar'.  */
+             grammar: 'foo/bar.yy' => 'bar'.  */
          dir_prefix = xstrdup ("");
          all_but_tab_ext =
            xstrndup (base, (strlen (base) - (ext ? strlen (ext) : 0)));
@@ -61,7 +61,6 @@ int skeleton_prio = default_prio;
 const char *skeleton = NULL;
 int language_prio = default_prio;
 struct bison_language const *language = &valid_languages[0];
-const char *include = NULL;

 /** Decode an option's key.
 *
@@ -74,8 +73,6 @@ const char *include = NULL;
 *                  If null, then activate all the flags.
 *  \param no       length of the potential "no-" prefix.
 *                  Can be 0 or 3. If 3, negate the action of the subargument.
- *  \param err      length of a potential "error=".
- *                  Can be 0 or 6. If 6, treat the subargument as a CATEGORY
 *
 *  If VALUE != 0 then KEY sets flags and no-KEY clears them.
 *  If VALUE == 0 then KEY clears all flags from \c all and no-KEY sets all
@@ -84,36 +81,23 @@ const char *include = NULL;
 static void
 flag_argmatch (const char *option,
               const char * const keys[], const int values[],
-               int all, int *flags, char *arg, size_t no, size_t err)
+               int all, int *flags, char *arg, size_t no)
 {
-  int value = 0;
-  if (!err || arg[no + err++] != '\0')
-    value = XARGMATCH (option, arg + no + err, keys, values);
+  int value = XARGMATCH (option, arg + no, keys, values);

-  if (value)
+  /* -rnone == -rno-all, and -rno-none == -rall.  */
+  if (!value)
    {
-      if (no)
-        *flags &= ~value;
-      else
-        {
-          if (err)
-            warnings_flag |= value;
-          *flags |= value;
-        }
+      value = all;
+      no = !no;
    }
+
+  if (no)
+    *flags &= ~value;
  else
-    {
-      /* With a simpler 'if (no)' version, -Werror means -Werror=all
-         (or rather, -Werror=no-none, but that syntax is invalid).
-         The difference is:
-         - Werror activates all errors, but not the warnings
-         - Werror=all activates errors, and all warnings */
-      if (no ? !err : err)
-        *flags |= all;
-      else
-        *flags &= ~all;
-    }
+    *flags |= value;
 }
+
 /** Decode an option's set of keys.
 *
 *  \param option   option being decoded.
@@ -133,16 +117,14 @@ flags_argmatch (const char *option,
    for (args = strtok (args, ","); args; args = strtok (NULL, ","))
      {
        size_t no = STRPREFIX_LIT ("no-", args) ? 3 : 0;
-        size_t err = STRPREFIX_LIT ("error", args + no) ? 5 : 0;
-
        flag_argmatch (option, keys,
-                       values, all, err ? &errors_flag : flags,
-                       args, no, err);
+                       values, all, flags, args, no);
      }
  else
    *flags |= all;
 }

+
 /** Decode a set of sub arguments.
 *
 *  \param FlagName  the flag familly to update.
@@ -196,8 +178,6 @@ ARGMATCH_VERIFY (report_args, report_types);

 static const char * const trace_args[] =
 {
-  /* In a series of synonyms, present the most meaningful first, so
-     that argmatch_valid be more readable.  */
  "none       - no traces",
  "scan       - grammar scanner traces",
  "parse      - grammar parser traces",
@@ -238,41 +218,6 @@ static const int trace_types[] =
 ARGMATCH_VERIFY (trace_args, trace_types);


-/*------------------------.
-| --warnings's handling.  |
-`------------------------*/
-
-static const char * const warnings_args[] =
-{
-  /* In a series of synonyms, present the most meaningful first, so
-     that argmatch_valid be more readable.  */
-  "none            - no warnings",
-  "midrule-values  - unset or unused midrule values",
-  "yacc            - incompatibilities with POSIX Yacc",
-  "conflicts-sr    - S/R conflicts",
-  "conflicts-rr    - R/R conflicts",
-  "deprecated      - obsolete constructs",
-  "other           - all other warnings",
-  "all             - all of the above",
-  "error           - warnings are errors",
-  0
-};
-
-static const int warnings_types[] =
-{
-  Wnone,
-  Wmidrule_values,
-  Wyacc,
-  Wconflicts_sr,
-  Wconflicts_rr,
-  Wdeprecated,
-  Wother,
-  Wall,
-  Werror
-};
-
-ARGMATCH_VERIFY (warnings_args, warnings_types);
-
 /*-----------------------.
 | --feature's handling.  |
 `-----------------------*/
@@ -304,7 +249,7 @@ static void
 usage (int status)
 {
  if (status != 0)
-    fprintf (stderr, _("Try `%s --help' for more information.\n"),
+    fprintf (stderr, _("Try '%s --help' for more information.\n"),
             program_name);
  else
    {
@@ -346,7 +291,7 @@ Parser:\n\
  -L, --language=LANGUAGE          specify the output programming language\n\
  -S, --skeleton=FILE              specify the skeleton to use\n\
  -t, --debug                      instrument the parser for tracing\n\
-                                   same as `-Dparse.trace'\n\
+                                   same as '-Dparse.trace'\n\
      --locations                  enable location support\n\
  -D, --define=NAME[=VALUE]        similar to '%define NAME \"VALUE\"'\n\
  -F, --force-define=NAME[=VALUE]  override '%define NAME \"VALUE\"'\n\
@@ -365,7 +310,7 @@ Output:\n\
  -d                         likewise but cannot specify FILE (for POSIX Yacc)\n\
  -r, --report=THINGS        also produce details on the automaton\n\
      --report-file=FILE     write report to FILE\n\
-  -v, --verbose              same as `--report=state'\n\
+  -v, --verbose              same as '--report=state'\n\
  -b, --file-prefix=PREFIX   specify a PREFIX for output files\n\
  -o, --output=FILE          leave output to FILE\n\
  -g, --graph[=FILE]         also output a graph of the automaton\n\
@@ -376,35 +321,37 @@ Output:\n\

      fputs (_("\
 Warning categories include:\n\
-  `midrule-values'    unset or unused midrule values\n\
-  `yacc'              incompatibilities with POSIX Yacc\n\
-  `conflicts-sr'      S/R conflicts (enabled by default)\n\
-  `conflicts-rr'      R/R conflicts (enabled by default)\n\
-  `deprecated'        obsolete constructs\n\
-  `other'             all other warnings (enabled by default)\n\
-  `all'               all the warnings\n\
-  `no-CATEGORY'       turn off warnings in CATEGORY\n\
-  `none'              turn off all the warnings\n\
-  `error[=CATEGORY]'  treat warnings as errors\n\
+  'midrule-values'    unset or unused midrule values\n\
+  'yacc'              incompatibilities with POSIX Yacc\n\
+  'conflicts-sr'      S/R conflicts (enabled by default)\n\
+  'conflicts-rr'      R/R conflicts (enabled by default)\n\
+  'deprecated'        obsolete constructs\n\
+  'empty-rule'        empty rules without %empty\n\
+  'precedence'        useless precedence and associativity\n\
+  'other'             all other warnings (enabled by default)\n\
+  'all'               all the warnings except 'yacc'\n\
+  'no-CATEGORY'       turn off warnings in CATEGORY\n\
+  'none'              turn off all the warnings\n\
+  'error[=CATEGORY]'  treat warnings as errors\n\
 "), stdout);
      putc ('\n', stdout);

      fputs (_("\
 THINGS is a list of comma separated words that can include:\n\
-  `state'        describe the states\n\
-  `itemset'      complete the core item sets with their closure\n\
-  `lookahead'    explicitly associate lookahead tokens to items\n\
-  `solved'       describe shift/reduce conflicts solving\n\
-  `all'          include all the above information\n\
-  `none'         disable the report\n\
+  'state'        describe the states\n\
+  'itemset'      complete the core item sets with their closure\n\
+  'lookahead'    explicitly associate lookahead tokens to items\n\
+  'solved'       describe shift/reduce conflicts solving\n\
+  'all'          include all the above information\n\
+  'none'         disable the report\n\
 "), stdout);
      putc ('\n', stdout);

      fputs (_("\
 FEATURE is a list of comma separated words that can include:\n\
-  `caret'        show errors with carets\n\
-  `all'          all of the above\n\
-  `none'         disable all of the above\n\
+  'caret'        show errors with carets\n\
+  'all'          all of the above\n\
+  'none'         disable all of the above\n\
  "), stdout);

      putc ('\n', stdout);
@@ -517,12 +464,10 @@ static char const short_options[] =
  "b:"
  "d"
  "f::"
-  "e"
  "g::"
  "h"
  "k"
  "l"
-  "n"
  "o:"
  "p:"
  "r:"
@@ -552,7 +497,6 @@ static struct option const long_options[] =

  /* Parser. */
  { "name-prefix",   required_argument,   0,   'p' },
-  { "include",       required_argument,   0,   'I' },

  /* Output. */
  { "file-prefix", required_argument,   0,   'b' },
@@ -581,7 +525,6 @@ static struct option const long_options[] =
  { "force-define",   required_argument,         0,   'F' },
  { "locations",      no_argument,               0, LOCATIONS_OPTION },
  { "no-lines",       no_argument,               0,   'l' },
-  { "raw",            no_argument,               0,     0 },
  { "skeleton",       required_argument,         0,   'S' },
  { "language",       required_argument,         0,   'L' },
  { "token-table",    no_argument,               0,   'k' },
@@ -590,7 +533,7 @@ static struct option const long_options[] =
 };

 /* Under DOS, there is no difference on the case.  This can be
-   troublesome when looking for `.tab' etc.  */
+   troublesome when looking for '.tab' etc.  */
 #ifdef MSDOS
 # define AS_FILE_NAME(File) (strlwr (File), (File))
 #else
@@ -626,24 +569,36 @@ getargs (int argc, char *argv[])
        /* Certain long options cause getopt_long to return 0.  */
        break;

-      case 'D': /* -DNAME[=VALUE]. */
-      case 'F': /* -FNAME[=VALUE]. */
+      case 'D': /* -DNAME[=(VALUE|"VALUE"|{VALUE})]. */
+      case 'F': /* -FNAME[=(VALUE|"VALUE"|{VALUE})]. */
        {
-          char* name = optarg;
-          char* value = strchr (optarg, '=');
+          char *name = optarg;
+          char *value = strchr (optarg, '=');
+          muscle_kind kind = muscle_keyword;
          if (value)
-            *value++ = 0;
+            {
+              char *end = value + strlen (value) - 1;
+              *value++ = 0;
+              if (*value == '{' && *end == '}')
+                {
+                  kind = muscle_code;
+                  ++value;
+                  *end = 0;
+                }
+              else if (*value == '"' && *end == '"')
+                {
+                  kind = muscle_string;
+                  ++value;
+                  *end = 0;
+                }
+            }
          muscle_percent_define_insert (name, command_line_location (),
-                                        value ? value : "",
+                                        kind, value ? value : "",
                                        c == 'D' ? MUSCLE_PERCENT_DEFINE_D
                                                 : MUSCLE_PERCENT_DEFINE_F);
        }
        break;

-      case 'I':
-        include = AS_FILE_NAME (optarg);
-        break;
-
      case 'L':
        language_argmatch (optarg, command_line_prio,
                           command_line_location ());
@@ -667,7 +622,7 @@ getargs (int argc, char *argv[])
        break;

      case 'W':
-        FLAGS_ARGMATCH (warnings, optarg, Wall);
+        warnings_argmatch (optarg);
        break;

      case 'b':
@@ -718,7 +673,8 @@ getargs (int argc, char *argv[])

      case 't':
        muscle_percent_define_insert ("parse.trace",
-                                      command_line_location (), "",
+                                      command_line_location (),
+                                      muscle_keyword, "",
                                      MUSCLE_PERCENT_DEFINE_D);
        break;

@@ -736,8 +692,7 @@ getargs (int argc, char *argv[])
        break;

      case 'y':
-        warnings_flag |= Wyacc;
-        errors_flag |= Wyacc;
+        warning_argmatch ("error=yacc", 0, 6);
        yacc_flag = true;
        break;

@@ -121,6 +121,7 @@ enum feature
 /** What additional features to use.  */
 extern int feature_flag;

+
 /** Process the command line arguments.
 *
 *  \param argc   size of \a argv
@@ -93,16 +93,14 @@ rule_rhs_length (rule const *r)
 void
 rule_rhs_print (rule const *r, FILE *out)
 {
-  if (*r->rhs >= 0)
+  if (0 <= *r->rhs)
    {
      item_number *rp;
      for (rp = r->rhs; *rp >= 0; rp++)
        fprintf (out, " %s", symbols[*rp]->tag);
    }
  else
-    {
-      fprintf (out, " /* %s */", _("empty"));
-    }
+    fputs (" %empty", out);
 }

 static void
@@ -125,13 +123,6 @@ rule_rhs_print_xml (rule const *r, FILE *out, int level)
    }
 }

-static void
-rule_print (rule const *r, FILE *out)
-{
-  fprintf (out, "%s:", r->lhs->tag);
-  rule_rhs_print (r, out);
-}
-
 void
 ritem_print (FILE *out)
 {
@@ -289,8 +280,8 @@ grammar_dump (FILE *out, const char *title)
    rule_number r;
    for (r = 0; r < nrules + nuseless_productions; r++)
      {
-        fprintf (out, "%-5d  ", r);
-        rule_print (&rules[r], out);
+        fprintf (out, "%-5d  %s:", r, rules[r].lhs->tag);
+        rule_rhs_print (&rules[r], out);
        fprintf (out, "\n");
      }
  }
@@ -300,24 +291,10 @@ grammar_dump (FILE *out, const char *title)
 void
 grammar_rules_useless_report (const char *message)
 {
-  warnings w = Wother;
-  if (warnings_flag & w)
-    {
-      rule_number r;
-      for (r = 0; r < nrules ; ++r)
-        if (!rules[r].useful)
-          {
-            if (feature_flag & feature_caret)
-              complain (&rules[r].location, w, "%s", message);
-            else
-              {
-                complain (&rules[r].location, w | silent, "%s: ", message);
-                rule_print (&rules[r], stderr);
-                warnings_print_categories (w);
-                fprintf (stderr, "\n");
-              }
-          }
-    }
+  rule_number r;
+  for (r = 0; r < nrules ; ++r)
+    if (!rules[r].useful)
+      complain (&rules[r].location, Wother, "%s", message);
 }

 void
@@ -35,7 +35,7 @@

   The rules receive rule numbers 1 to NRULES in the order they are
   written.  More precisely Bison augments the grammar with the
-   initial rule, `$accept: START-SYMBOL $end', which is numbered 1,
+   initial rule, '$accept: START-SYMBOL $end', which is numbered 1,
   all the user rules are 2, 3 etc.  Each time a rule number is
   presented to the user, we subtract 1, so *displayed* rule numbers
   are 0, 1, 2...
@@ -61,7 +61,7 @@
   RULES[R].prec -- the symbol providing the precedence level of R.

   RULES[R].precsym -- the symbol attached (via %prec) to give its
-   precedence to R.  Of course, if set, it is equal to `prec', but we
+   precedence to R.  Of course, if set, it is equal to 'prec', but we
   need to distinguish one from the other when reducing: a symbol used
   in a %prec is not useless.

@@ -205,11 +205,11 @@ extern rule *rules;
 /* A function that selects a rule.  */
 typedef bool (*rule_filter) (rule const *);

-/* Return true IFF the rule has a `number' smaller than NRULES.  That is, it is
+/* Return true IFF the rule has a 'number' smaller than NRULES.  That is, it is
   useful in the grammar.  */
 bool rule_useful_in_grammar_p (rule const *r);

-/* Return true IFF the rule has a `number' higher than NRULES.  That is, it is
+/* Return true IFF the rule has a 'number' higher than NRULES.  That is, it is
   useless in the grammar.  */
 bool rule_useless_in_grammar_p (rule const *r);

@@ -262,8 +262,8 @@ void grammar_rules_print_xml (FILE *out, int level);
 void grammar_dump (FILE *out, const char *title);

 /* Report on STDERR the rules that are not flagged USEFUL, using the
-   MESSAGE (which can be `rule useless in grammar' when invoked after grammar
-   reduction, or `rule useless in parser due to conflicts' after conflicts
+   MESSAGE (which can be 'rule useless in grammar' when invoked after grammar
+   reduction, or 'rule useless in parser due to conflicts' after conflicts
   were taken into account).  */
 void grammar_rules_useless_report (const char *message);

@@ -342,7 +342,7 @@ state_lookahead_tokens_count (state *s, bool default_reduction_only_for_accept)
  /* We need a lookahead either to distinguish different reductions
     (i.e., there are two or more), or to distinguish a reduction from a
     shift.  Otherwise, it is straightforward, and the state is
-     `consistent'.  However, do not treat a state with any reductions as
+     'consistent'.  However, do not treat a state with any reductions as
     consistent unless it is the accepting state (because there is never
     a lookahead token that makes sense there, and so no lookahead token
     should be read) if the user has otherwise disabled default
@@ -96,10 +96,8 @@ location_compute (location *loc, boundary *cur, char const *token, size_t size)
 }


-/* Output to OUT the location LOC.
-   Warning: it uses quotearg's slot 3.  */
 unsigned
-location_print (FILE *out, location loc)
+location_print (location loc, FILE *out)
 {
  unsigned res = 0;
  int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
@@ -161,7 +159,7 @@ cleanup_caret ()
 }

 void
-location_caret (FILE *out, location loc)
+location_caret (location loc, FILE *out)
 {
  /* FIXME: find a way to support multifile locations, and only open once each
     file. That would make the procedure future-proof.  */
@@ -221,7 +219,7 @@ void
 boundary_set_from_string (boundary *bound, char *loc_str)
 {
  /* Must search in reverse since the file name field may
-   * contain `.' or `:'.  */
+   * contain '.' or ':'.  */
  char *delim = strrchr (loc_str, '.');
  aver (delim);
  *delim = '\0';
@@ -20,6 +20,10 @@
 #ifndef LOCATION_H_
 # define LOCATION_H_

+# include <stdbool.h>
+# include <stdio.h>
+# include <string.h> /* strcmp */
+
 # include "uniqstr.h"

 /* A boundary between two characters.  */
@@ -98,16 +102,17 @@ extern location const empty_location;
 void location_compute (location *loc,
                       boundary *cur, char const *token, size_t size);

-/* Print location to file. Return number of actually printed
-   characters.  */
-unsigned location_print (FILE *out, location loc);
+/* Print location to file.
+   Return number of actually printed characters.
+   Warning: uses quotearg's slot 3. */
+unsigned location_print (location loc, FILE *out);

 /* Free any allocated ressources and close any open file handles that are
   left-over by the usage of location_caret.  */
 void cleanup_caret (void);

 /* Output to OUT the line and caret corresponding to location LOC.  */
-void location_caret (FILE *out, location loc);
+void location_caret (location loc, FILE *out);

 /* Return -1, 0, 1, depending whether a is before, equal, or
   after b.  */
@@ -120,7 +125,7 @@ location_cmp (location a, location b)
  return res;
 }

-/* LOC_STR must be formatted as `file:line.column', it will be modified.  */
+/* LOC_STR must be formatted as 'file:line.column', it will be modified.  */
 void boundary_set_from_string (boundary *bound, char *loc_str);

 #endif /* ! defined LOCATION_H_ */
@@ -76,6 +76,7 @@ main (int argc, char *argv[])

  uniqstrs_new ();
  muscle_init ();
+  complain_init ();

  getargs (argc, argv);

@@ -146,8 +147,6 @@ main (int argc, char *argv[])

  print_precedence_warnings ();

-  print_assoc_warnings ();
-
  /* Output file names. */
  compute_output_file_names ();

@@ -28,6 +28,31 @@
 #include "muscle-tab.h"
 #include "quote.h"

+muscle_kind
+muscle_kind_new (char const *k)
+{
+  if (STREQ (k, "code"))
+    return muscle_code;
+  else if (STREQ (k, "keyword"))
+    return muscle_keyword;
+  else if (STREQ (k, "string"))
+    return muscle_string;
+  aver (0);
+}
+
+char const *
+muscle_kind_string (muscle_kind k)
+{
+  switch (k)
+    {
+    case muscle_code:    return "code";
+    case muscle_keyword: return "keyword";
+    case muscle_string:  return "string";
+    }
+  aver (0);
+}
+
+
 /* A key-value pair, along with storage that can be reclaimed when
   this pair is no longer needed.  */
 typedef struct
@@ -35,8 +60,21 @@ typedef struct
  char const *key;
  char const *value;
  char *storage;
+  muscle_kind kind;
 } muscle_entry;

+
+/* The name of muscle for the %define variable VAR (corresponding to
+   FIELD, if defined).  */
+static uniqstr
+muscle_name (char const *var, char const *field)
+{
+  if (field)
+    return UNIQSTR_CONCAT ("percent_define_", field, "(", var, ")");
+  else
+    return UNIQSTR_CONCAT ("percent_define(", var, ")");
+}
+
 /* An obstack used to create some entries.  */
 struct obstack muscle_obstack;

@@ -60,10 +98,18 @@ hash_muscle (const void *x, size_t tablesize)
  return hash_string (m->key, tablesize);
 }

-/*-----------------------------------------------------------------.
-| Create the MUSCLE_TABLE, and initialize it with default values.  |
-| Also set up the MUSCLE_OBSTACK.                                  |
-`-----------------------------------------------------------------*/
+/* Create a fresh muscle name KEY, and insert in the hash table.  */
+static void *
+muscle_entry_new (char const *key)
+{
+  muscle_entry *res = xmalloc (sizeof *res);
+  res->key = key;
+  res->value = NULL;
+  res->storage = NULL;
+  if (!hash_insert (muscle_table, res))
+    xalloc_die ();
+  return res;
+}

 static void
 muscle_entry_free (void *entry)
@@ -87,10 +133,6 @@ muscle_init (void)
 }


-/*------------------------------------------------------------.
-| Free all the memory consumed by the muscle machinery only.  |
-`------------------------------------------------------------*/
-
 void
 muscle_free (void)
 {
@@ -98,71 +140,64 @@ muscle_free (void)
  obstack_free (&muscle_obstack, NULL);
 }

+/* Look for the muscle named KEY.  Return NULL if does not exist.  */
+static
+muscle_entry *
+muscle_lookup (char const *key)
+{
+  muscle_entry probe;
+  probe.key = key;
+  return hash_lookup (muscle_table, &probe);
+}


-/*------------------------------------------------------------.
-| Insert (KEY, VALUE).  If KEY already existed, overwrite the |
-| previous value.                                             |
-`------------------------------------------------------------*/
-
 void
 muscle_insert (char const *key, char const *value)
 {
-  muscle_entry probe;
-  muscle_entry *entry;
-
-  probe.key = key;
-  entry = hash_lookup (muscle_table, &probe);
-
-  if (!entry)
-    {
-      /* First insertion in the hash. */
-      entry = xmalloc (sizeof *entry);
-      entry->key = key;
-      if (!hash_insert (muscle_table, entry))
-        xalloc_die ();
-    }
-  else
+  muscle_entry *entry = muscle_lookup (key);
+  if (entry)
    free (entry->storage);
+  else
+    /* First insertion in the hash. */
+    entry = muscle_entry_new (key);
  entry->value = value;
  entry->storage = NULL;
 }


-/*-------------------------------------------------------------------.
-| Append VALUE to the current value of KEY.  If KEY did not already  |
-| exist, create it.  Use MUSCLE_OBSTACK.  De-allocate the previously |
-| associated value.  Copy VALUE and SEPARATOR.                       |
-`-------------------------------------------------------------------*/
+/* Append VALUE to the current value of KEY.  If KEY did not already
+   exist, create it.  Use MUSCLE_OBSTACK.  De-allocate the previously
+   associated value.  Copy VALUE and SEPARATOR.  If VALUE does not end
+   with TERMINATOR, append one.  */

-void
-muscle_grow (const char *key, const char *val, const char *separator)
+static void
+muscle_grow (const char *key, const char *val,
+             const char *separator, const char *terminator)
 {
-  muscle_entry probe;
-  muscle_entry *entry = NULL;
+  muscle_entry *entry = muscle_lookup (key);
+  size_t vals = strlen (val);
+  size_t terms = strlen (terminator);

-  probe.key = key;
-  entry = hash_lookup (muscle_table, &probe);
-
-  if (!entry)
+  if (entry)
    {
-      /* First insertion in the hash. */
-      entry = xmalloc (sizeof *entry);
-      entry->key = key;
-      if (!hash_insert (muscle_table, entry))
-        xalloc_die ();
-      entry->value = entry->storage = xstrdup (val);
+      obstack_sgrow (&muscle_obstack, entry->value);
+      obstack_sgrow (&muscle_obstack, separator);
+      free (entry->storage);
    }
  else
-    {
-      /* Grow the current value. */
-      char *new_val;
-      obstack_printf (&muscle_obstack, "%s%s%s", entry->value, separator, val);
-      free (entry->storage);
-      new_val = obstack_finish0 (&muscle_obstack);
-      entry->value = entry->storage = xstrdup (new_val);
-      obstack_free (&muscle_obstack, new_val);
-    }
+    entry = muscle_entry_new (key);
+
+  obstack_sgrow (&muscle_obstack, val);
+
+  if (terms <= vals
+      && STRNEQ (val + vals - terms, terminator))
+    obstack_sgrow (&muscle_obstack, terminator);
+
+  {
+    char *new_val = obstack_finish0 (&muscle_obstack);
+    entry->value = entry->storage = xstrdup (new_val);
+    obstack_free (&muscle_obstack, new_val);
+  }
 }

 /*------------------------------------------------------------------.
@@ -179,7 +214,7 @@ muscle_syncline_grow (char const *key, location loc)
                 quotearg_style (c_quoting_style, loc.start.file));
  obstack_sgrow (&muscle_obstack, ")[");
  extension = obstack_finish0 (&muscle_obstack);
-  muscle_grow (key, extension, "");
+  muscle_grow (key, extension, "", "");
  obstack_free (&muscle_obstack, extension);
 }

@@ -193,12 +228,13 @@ void
 muscle_code_grow (const char *key, const char *val, location loc)
 {
  muscle_syncline_grow (key, loc);
-  muscle_grow (key, val, "\n");
+  muscle_grow (key, val, "\n", "\n");
 }


-void muscle_pair_list_grow (const char *muscle,
-                            const char *a1, const char *a2)
+void
+muscle_pair_list_grow (const char *muscle,
+                       const char *a1, const char *a2)
 {
  char *pair;
  obstack_sgrow (&muscle_obstack, "[");
@@ -207,54 +243,33 @@ void muscle_pair_list_grow (const char *muscle,
  obstack_quote (&muscle_obstack, a2);
  obstack_sgrow (&muscle_obstack, "]");
  pair = obstack_finish0 (&muscle_obstack);
-  muscle_grow (muscle, pair, ",\n");
+  muscle_grow (muscle, pair, ",\n", "");
  obstack_free (&muscle_obstack, pair);
 }


-/*----------------------------------------------------------------------------.
-| Find the value of muscle KEY.  Unlike MUSCLE_FIND, this is always reliable  |
-| to determine whether KEY has a value.                                       |
-`----------------------------------------------------------------------------*/
-
 char const *
 muscle_find_const (char const *key)
 {
-  muscle_entry probe;
-  muscle_entry *result = NULL;
-
-  probe.key = key;
-  result = hash_lookup (muscle_table, &probe);
-  if (result)
-    return result->value;
-  return NULL;
+  muscle_entry *entry = muscle_lookup (key);
+  return entry ? entry->value : NULL;
 }


-/*----------------------------------------------------------------------------.
-| Find the value of muscle KEY.  Abort if muscle_insert was invoked more      |
-| recently than muscle_grow for KEY since muscle_find can't return a          |
-| char const *.                                                               |
-`----------------------------------------------------------------------------*/
-
 char *
 muscle_find (char const *key)
 {
-  muscle_entry probe;
-  muscle_entry *result = NULL;
-
-  probe.key = key;
-  result = hash_lookup (muscle_table, &probe);
-  if (result)
+  muscle_entry *entry = muscle_lookup (key);
+  if (entry)
    {
-      aver (result->value == result->storage);
-      return result->storage;
+      aver (entry->value == entry->storage);
+      return entry->storage;
    }
  return NULL;
 }


-/* In the format `file_name:line.column', append BOUND to MUSCLE.  Use
+/* In the format 'file_name:line.column', append BOUND to MUSCLE.  Use
   digraphs for special characters in the file name.  */

 static void
@@ -265,12 +280,12 @@ muscle_boundary_grow (char const *key, boundary bound)
  obstack_escape (&muscle_obstack, bound.file);
  obstack_printf (&muscle_obstack, ":%d.%d]]", bound.line, bound.column);
  extension = obstack_finish0 (&muscle_obstack);
-  muscle_grow (key, extension, "");
+  muscle_grow (key, extension, "", "");
  obstack_free (&muscle_obstack, extension);
 }


-/* In the format `[[file_name:line.column]], [[file_name:line.column]]',
+/* In the format '[[file_name:line.column]], [[file_name:line.column]]',
   append LOC to MUSCLE.  Use digraphs for special characters in each
   file name.  */

@@ -278,7 +293,7 @@ static void
 muscle_location_grow (char const *key, location loc)
 {
  muscle_boundary_grow (key, loc.start);
-  muscle_grow (key, "", ", ");
+  muscle_grow (key, "", ", ", "");
  muscle_boundary_grow (key, loc.end);
 }

@@ -329,10 +344,9 @@ string_decode (char const *key)

 /* Reverse of muscle_location_grow.  */
 static location
-location_decode (char const *key)
+location_decode (char const *value)
 {
  location loc;
-  char const *value = muscle_find_const (key);
  aver (value);
  aver (*value == '[');
  aver (*++value == '[');
@@ -377,11 +391,11 @@ void
 muscle_user_name_list_grow (char const *key, char const *user_name,
                            location loc)
 {
-  muscle_grow (key, "[[[[", ",");
-  muscle_grow (key, user_name, "");
-  muscle_grow (key, "]], ", "");
+  muscle_grow (key, "[[[[", ",", "");
+  muscle_grow (key, user_name, "", "");
+  muscle_grow (key, "]], ", "", "");
  muscle_location_grow (key, loc);
-  muscle_grow (key, "]]", "");
+  muscle_grow (key, "]]", "", "");
 }


@@ -475,16 +489,17 @@ muscle_percent_variable_update (char const *variable, location variable_loc,

 void
 muscle_percent_define_insert (char const *var, location variable_loc,
+                              muscle_kind kind,
                              char const *value,
                              muscle_percent_define_how how)
 {
  /* Backward compatibility.  */
  char *variable = muscle_percent_variable_update (var, variable_loc, &value);
-  char const *name = UNIQSTR_CONCAT ("percent_define(", variable, ")");
-  char const *loc_name = UNIQSTR_CONCAT ("percent_define_loc(", variable, ")");
-  char const *syncline_name =
-    UNIQSTR_CONCAT ("percent_define_syncline(", variable, ")");
-  char const *how_name = UNIQSTR_CONCAT ("percent_define_how(", variable, ")");
+  uniqstr name = muscle_name (variable, NULL);
+  uniqstr loc_name = muscle_name (variable, "loc");
+  uniqstr syncline_name = muscle_name (variable, "syncline");
+  uniqstr how_name = muscle_name (variable, "how");
+  uniqstr kind_name = muscle_name (variable, "kind");

  /* Command-line options are processed before the grammar file.  */
  if (how == MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE
@@ -510,6 +525,7 @@ muscle_percent_define_insert (char const *var, location variable_loc,
  muscle_user_name_list_grow ("percent_define_user_variables", variable,
                              variable_loc);
  MUSCLE_INSERT_INT (how_name, how);
+  MUSCLE_INSERT_STRING (kind_name, muscle_kind_string (kind));
 end:
  free (variable);
 }
@@ -520,85 +536,119 @@ void
 muscle_percent_define_ensure (char const *variable, location loc,
                              bool value)
 {
+  uniqstr name = muscle_name (variable, NULL);
  char const *val = value ? "" : "false";
-  char const *name = UNIQSTR_CONCAT ("percent_define(", variable, ")");

-  /* %pure-parser is deprecated in favor of `%define api.pure', so use
-     `%define api.pure' in a backward-compatible manner here.  First,
-     don't complain if %pure-parser is specified multiple times.  */
-  if (!muscle_find_const (name))
-    muscle_percent_define_insert (variable, loc, val,
-                                  MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
-  /* In all cases, use api.pure now so that the backend doesn't complain if
-     the skeleton ignores api.pure, but do warn now if there's a previous
-     conflicting definition from an actual %define.  */
-  if (muscle_percent_define_flag_if (variable) != value)
-    muscle_percent_define_insert (variable, loc, val,
+  /* Don't complain is VARIABLE is already defined, but be sure to set
+     its value to VAL.  */
+  if (!muscle_find_const (name)
+      || muscle_percent_define_flag_if (variable) != value)
+    muscle_percent_define_insert (variable, loc, muscle_keyword, val,
                                  MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 }

+/* Mark %define VARIABLE as used.  */
+static void
+muscle_percent_define_use (char const *variable)
+{
+  muscle_insert (muscle_name (variable, "bison_variables"), "");
+}
+
+/* The value of %define variable VARIABLE (corresponding to FIELD, if
+   defined).  Do not register as used, but diagnose unset variables.  */
+
+char const *
+muscle_percent_define_get_raw (char const *variable, char const *field)
+{
+  uniqstr name = muscle_name (variable, field);
+  char const *res = muscle_find_const (name);
+  if (!res)
+    complain (NULL, fatal, _("%s: undefined %%define variable %s"),
+              "muscle_percent_define_get_raw", quote (variable));
+  return res;
+}
+
 char *
 muscle_percent_define_get (char const *variable)
 {
-  char const *name = UNIQSTR_CONCAT ("percent_define(", variable, ")");
-  char const *usage_name =
-    UNIQSTR_CONCAT ("percent_define_bison_variables(", variable, ")");
+  uniqstr name = muscle_name (variable, NULL);
  char *value = string_decode (name);
  if (!value)
    value = xstrdup ("");
-
-  muscle_insert (usage_name, "");
+  muscle_percent_define_use (variable);
  return value;
 }

+/* The kind of VARIABLE.  An error if undefined.  */
+static muscle_kind
+muscle_percent_define_get_kind (char const *variable)
+{
+  return muscle_kind_new (muscle_percent_define_get_raw (variable, "kind"));
+}
+
+/* Check the kind of VARIABLE.  An error if undefined.  */
+static void
+muscle_percent_define_check_kind (char const *variable, muscle_kind kind)
+{
+  if (muscle_percent_define_get_kind (variable) != kind)
+    {
+      location loc = muscle_percent_define_get_loc (variable);
+      switch (kind)
+        {
+        case muscle_code:
+          complain (&loc, Wdeprecated,
+                    "%%define variable '%s' requires '{...}' values",
+                    variable);
+          break;
+        case muscle_keyword:
+          complain (&loc, Wdeprecated,
+                    "%%define variable '%s' requires keyword values",
+                    variable);
+          break;
+        case muscle_string:
+          complain (&loc, Wdeprecated,
+                    "%%define variable '%s' requires '\"...\"' values",
+                    variable);
+          break;
+        }
+    }
+}
+
+
 location
 muscle_percent_define_get_loc (char const *variable)
 {
-  char const *loc_name = UNIQSTR_CONCAT ("percent_define_loc(", variable, ")");
-  if (!muscle_find_const (loc_name))
-    complain (NULL, fatal, _("%s: undefined %%define variable %s"),
-              "muscle_percent_define_get_loc", quote (variable));
-  return location_decode (loc_name);
+  return location_decode (muscle_percent_define_get_raw (variable, "loc"));
 }

 char const *
 muscle_percent_define_get_syncline (char const *variable)
 {
-  char const *syncline_name =
-    UNIQSTR_CONCAT ("percent_define_syncline(", variable, ")");
-  char const *syncline = muscle_find_const (syncline_name);
-  if (!syncline)
-    complain (NULL, fatal, _("%s: undefined %%define variable %s"),
-              "muscle_percent_define_get_syncline", quote (variable));
-  return syncline;
+  return muscle_percent_define_get_raw (variable, "syncline");
 }

 bool
 muscle_percent_define_ifdef (char const *variable)
 {
-  char const *name = UNIQSTR_CONCAT ("percent_define(", variable, ")");
-  char const *usage_name =
-    UNIQSTR_CONCAT ("percent_define_bison_variables(", variable, ")");
-  char const *value = muscle_find_const (name);
-  if (value)
+  if (muscle_find_const (muscle_name (variable, NULL)))
    {
-      muscle_insert (usage_name, "");
+      muscle_percent_define_use (variable);
      return true;
    }
-
-  return false;
+  else
+    return false;
 }

 bool
 muscle_percent_define_flag_if (char const *variable)
 {
-  char const *invalid_boolean_name =
-    UNIQSTR_CONCAT ("percent_define_invalid_boolean(", variable, ")");
+  uniqstr invalid_boolean_name = muscle_name (variable, "invalid_boolean");
  bool result = false;

  if (muscle_percent_define_ifdef (variable))
    {
      char *value = muscle_percent_define_get (variable);
+      muscle_percent_define_check_kind (variable, muscle_keyword);
      if (value[0] == '\0' || STREQ (value, "true"))
        result = true;
      else if (STREQ (value, "false"))
@@ -623,20 +673,21 @@ muscle_percent_define_flag_if (char const *variable)
 void
 muscle_percent_define_default (char const *variable, char const *value)
 {
-  char const *name = UNIQSTR_CONCAT ("percent_define(", variable, ")");
-  char const *loc_name = UNIQSTR_CONCAT ("percent_define_loc(", variable, ")");
-  char const *syncline_name =
-    UNIQSTR_CONCAT ("percent_define_syncline(", variable, ")");
+  uniqstr name = muscle_name (variable, NULL);
  if (!muscle_find_const (name))
    {
-      location loc;
      MUSCLE_INSERT_STRING (name, value);
-      loc.start.file = loc.end.file = "<default value>";
-      loc.start.line = loc.end.line = -1;
-      loc.start.column = loc.end.column = -1;
-      muscle_insert (loc_name, "");
-      muscle_location_grow (loc_name, loc);
-      muscle_insert (syncline_name, "");
+      MUSCLE_INSERT_STRING (muscle_name (variable, "kind"), "keyword");
+      {
+        uniqstr loc_name = muscle_name (variable, "loc");
+        location loc;
+        loc.start.file = loc.end.file = "<default value>";
+        loc.start.line = loc.end.line = -1;
+        loc.start.column = loc.end.column = -1;
+        muscle_insert (loc_name, "");
+        muscle_location_grow (loc_name, loc);
+      }
+      muscle_insert (muscle_name (variable, "syncline"), "");
    }
 }

@@ -646,8 +697,9 @@ muscle_percent_define_check_values (char const * const *values)
  for (; *values; ++values)
    {
      char const * const *variablep = values;
-      char const *name = UNIQSTR_CONCAT ("percent_define(", *variablep, ")");
+      uniqstr name = muscle_name (*variablep, NULL);
      char *value = string_decode (name);
+      muscle_percent_define_check_kind (*variablep, muscle_keyword);
      if (value)
        {
          for (++values; *values; ++values)
@@ -664,7 +716,7 @@ muscle_percent_define_check_values (char const * const *values)
                               quote (*variablep), quote_n (1, value));
              i += SUB_INDENT;
              for (values = variablep + 1; *values; ++values)
-                complain_indent (&loc, complaint | no_caret, &i,
+                complain_indent (&loc, complaint | no_caret | silent, &i,
                                 _("accepted value: %s"), quote (*values));
            }
          else
@@ -711,11 +763,6 @@ muscle_m4_output_processor (void *entry, void *out)
 }


-/*----------------------------------------------------------------.
-| Output the definition of all the current muscles into a list of |
-| m4_defines.                                                     |
-`----------------------------------------------------------------*/
-
 void
 muscles_m4_output (FILE *out)
 {
@@ -24,10 +24,41 @@

 # include "location.h"

+/* The kind of value associated to this muscle, depending on the
+   syntax of the value: keyword (no delimiter, e.g., true), string
+   (double quotes, e.g., "foo.h"), or code (braces, e.g., {int}).  */
+typedef enum
+{
+  muscle_code,
+  muscle_keyword,
+  muscle_string
+} muscle_kind;
+
+/* Conversion from string.  */
+muscle_kind muscle_kind_new (char const *k);
+
+/* Conversion to string.  */
+char const *muscle_kind_string (muscle_kind k);
+
+
+/* Create the MUSCLE_TABLE, and initialize it with default values.
+   Also set up the MUSCLE_OBSTACK.  */
 void muscle_init (void);
+
+/* Insert (KEY, VALUE).  If KEY already existed, overwrite the
+   previous value.  Otherwise create as a muscle_string type.  */
 void muscle_insert (char const *key, char const *value);
+
+/* Find the value of muscle KEY.  Unlike MUSCLE_FIND, this is always
+   reliable to determine whether KEY has a value.  */
 char const *muscle_find_const (char const *key);
+
+/* Find the value of muscle KEY.  Abort if muscle_insert was invoked
+   more recently than muscle_grow for KEY since muscle_find can't
+   return a char const *.  */
 char *muscle_find (char const *key);
+
+/* Free all the memory consumed by the muscle machinery only.  */
 void muscle_free (void);


@@ -47,14 +78,14 @@ extern struct obstack muscle_obstack;
  } while (0)

 # define MUSCLE_INSERT_INT(Key, Value)          \
-  MUSCLE_INSERTF(Key, "%d", Value)
+  MUSCLE_INSERTF (Key, "%d", Value)

 # define MUSCLE_INSERT_LONG_INT(Key, Value)     \
-  MUSCLE_INSERTF(Key, "%ld", Value)
+  MUSCLE_INSERTF (Key, "%ld", Value)

 /* Key -> Value, but don't apply escaping to Value. */
 # define MUSCLE_INSERT_STRING_RAW(Key, Value)   \
-  MUSCLE_INSERTF(Key, "%s", Value)
+  MUSCLE_INSERTF (Key, "%s", Value)

 /* Key -> Value, applying M4 escaping to Value. */
 # define MUSCLE_INSERT_STRING(Key, Value)                       \
@@ -63,23 +94,14 @@ extern struct obstack muscle_obstack;
    muscle_insert (Key, obstack_finish0 (&muscle_obstack));     \
  } while (0)

+/* Key -> Value, applying C escaping to Value (and then M4). */
 # define MUSCLE_INSERT_C_STRING(Key, Value)                     \
-  do {                                                          \
-    obstack_escape (&muscle_obstack,                            \
-                    quotearg_style (c_quoting_style, Value));   \
-    muscle_insert (Key, obstack_finish0 (&muscle_obstack));     \
-  } while (0)
-
-/* Append VALUE to the current value of KEY.  If KEY did not already
-   exist, create it.  Use MUSCLE_OBSTACK.  De-allocate the previously
-   associated value.  Copy VALUE and SEPARATOR.  */
-
-void muscle_grow (const char *key, const char *value, const char *separator);
+  MUSCLE_INSERT_STRING (Key, quotearg_style (c_quoting_style, Value))


 /* Append VALUE to the current value of KEY, using muscle_grow.  But
-   in addition, issue a synchronization line for the location LOC.  */
-
+   in addition, issue a synchronization line for the location LOC.
+   Be sure to append on a new line.  */
 void muscle_code_grow (const char *key, const char *value, location loc);


@@ -92,14 +114,15 @@ void muscle_pair_list_grow (const char *muscle,

 /* Grow KEY for the occurrence of the name USER_NAME at LOC appropriately for
   use with b4_check_user_names in ../data/bison.m4.  USER_NAME is not escaped
-   with digraphs, so it must not contain `[' or `]'.  */
+   with digraphs, so it must not contain '[' or ']'.  */
 void muscle_user_name_list_grow (char const *key, char const *user_name,
                                 location loc);

 /* Indicates whether a variable's value was specified with -D/--define, with
   -F/--force-define, or in the grammar file.  */
 typedef enum {
-  MUSCLE_PERCENT_DEFINE_D = 0, MUSCLE_PERCENT_DEFINE_F,
+  MUSCLE_PERCENT_DEFINE_D = 0,
+  MUSCLE_PERCENT_DEFINE_F,
  MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE
 } muscle_percent_define_how;

@@ -113,6 +136,7 @@ typedef enum {
   this as a user occurrence of VARIABLE by invoking
   muscle_user_name_list_grow.  */
 void muscle_percent_define_insert (char const *variable, location variable_loc,
+                                   muscle_kind kind,
                                   char const *value,
                                   muscle_percent_define_how how);

@@ -186,6 +210,8 @@ void muscle_percent_define_check_values (char const * const *values);
 void muscle_percent_code_grow (char const *qualifier, location qualifier_loc,
                               char const *code, location code_loc);

+/* Output the definition of all the current muscles into a list of
+   m4_defines.  */
 void muscles_m4_output (FILE *out);

 #endif /* not MUSCLE_TAB_H_ */
@@ -90,20 +90,19 @@ Name (char const *name,                                                 \
                                                                        \
  lmin = min;                                                           \
  lmax = max;                                                           \
-  /* Build `NAME_min' and `NAME_max' in the obstack. */                 \
+  /* Build 'NAME_min' and 'NAME_max' in the obstack. */                 \
  obstack_printf (&format_obstack, "%s_min", name);                     \
  MUSCLE_INSERT_LONG_INT (obstack_finish0 (&format_obstack), lmin);     \
  obstack_printf (&format_obstack, "%s_max", name);                     \
  MUSCLE_INSERT_LONG_INT (obstack_finish0 (&format_obstack), lmax);     \
 }

-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_unsigned_int_table, unsigned int)
-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_int_table, int)
-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_base_table, base_number)
-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_rule_number_table, rule_number)
-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_symbol_number_table, symbol_number)
-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_state_number_table, state_number)
-
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_unsigned_int_table, unsigned int)
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_int_table, int)
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_base_table, base_number)
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_rule_number_table, rule_number)
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_symbol_number_table, symbol_number)
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_state_number_table, state_number)

 /*----------------------------------------------------------------.
 | Print to OUT a representation of CP quoted and escaped for M4.  |
@@ -227,7 +226,7 @@ prepare_rules (void)
      /* LHS of the rule R. */
      r1[r] = rules[r].lhs->number;
      /* Length of rule R's RHS. */
-      r2[r] = rule_rhs_length(&rules[r]);
+      r2[r] = rule_rhs_length (&rules[r]);
      /* Line where rule was defined. */
      rline[r] = rules[r].location.start.line;
      /* Dynamic precedence (GLR).  */
@@ -417,31 +416,31 @@ prepare_symbol_definitions (void)

      /* Whether the symbol has an identifier.  */
      value = symbol_id_get (sym);
-      SET_KEY("has_id");
+      SET_KEY ("has_id");
      MUSCLE_INSERT_INT (key, !!value);

      /* Its identifier.  */
-      SET_KEY("id");
+      SET_KEY ("id");
      MUSCLE_INSERT_STRING (key, value ? value : "");

      /* Its tag.  Typically for documentation purpose.  */
-      SET_KEY("tag");
+      SET_KEY ("tag");
      MUSCLE_INSERT_STRING (key, sym->tag);

-      SET_KEY("user_number");
+      SET_KEY ("user_number");
      MUSCLE_INSERT_INT (key, sym->user_token_number);

-      SET_KEY("is_token");
+      SET_KEY ("is_token");
      MUSCLE_INSERT_INT (key,
                         i < ntokens && sym != errtoken && sym != undeftoken);

-      SET_KEY("number");
+      SET_KEY ("number");
      MUSCLE_INSERT_INT (key, sym->number);

-      SET_KEY("has_type");
+      SET_KEY ("has_type");
      MUSCLE_INSERT_INT (key, !!sym->type_name);

-      SET_KEY("type");
+      SET_KEY ("type");
      MUSCLE_INSERT_STRING (key, sym->type_name ? sym->type_name : "");

      {
@@ -451,18 +450,18 @@ prepare_symbol_definitions (void)
            /* "printer", not "%printer".  */
            char const *pname = code_props_type_string (j) + 1;
            code_props const *p = symbol_code_props_get (sym, j);
-            SET_KEY2("has", pname);
+            SET_KEY2 ("has", pname);
            MUSCLE_INSERT_INT (key, !!p->code);

            if (p->code)
              {
-                SET_KEY2(pname, "file");
+                SET_KEY2 (pname, "file");
                MUSCLE_INSERT_STRING (key, p->location.start.file);

-                SET_KEY2(pname, "line");
+                SET_KEY2 (pname, "line");
                MUSCLE_INSERT_INT (key, p->location.start.line);

-                SET_KEY(pname);
+                SET_KEY (pname);
                MUSCLE_INSERT_STRING_RAW (key, p->code);
              }
          }
@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 2.7.1021-bb417-dirty.  */
+/* A Bison parser, made by GNU Bison 2.7.90.  */

 /* Bison interface for Yacc-like parsers in C

@@ -48,10 +48,12 @@
 extern int gram_debug;
 #endif
 /* "%code requires" blocks.  */
-#line 223 "src/parse-gram.y" /* yacc.c:1932  */
+#line 21 "src/parse-gram.y" /* yacc.c:1926  */
+
+  #include "symlist.h"
+  #include "symtab.h"
+#line 221 "src/parse-gram.y" /* yacc.c:1926  */

-# ifndef PARAM_TYPE
-#  define PARAM_TYPE
  typedef enum
  {
    param_none   = 0,
@@ -59,10 +61,10 @@ extern int gram_debug;
    param_parse  = 1 << 1,
    param_both   = param_lex | param_parse
  } param_type;
-# endif
+#line 645 "src/parse-gram.y" /* yacc.c:1926  */
+#include "muscle-tab.h"

-
-#line 66 "src/parse-gram.h" /* yacc.c:1932  */
+#line 68 "src/parse-gram.h" /* yacc.c:1926  */

 /* Token type.  */
 #ifndef GRAM_TOKENTYPE
@@ -71,143 +73,97 @@ extern int gram_debug;
  {
    GRAM_EOF = 0,
    STRING = 258,
-    INT = 259,
-    PERCENT_TOKEN = 260,
-    PERCENT_NTERM = 261,
-    PERCENT_TYPE = 262,
-    PERCENT_DESTRUCTOR = 263,
-    PERCENT_PRINTER = 264,
-    PERCENT_LEFT = 265,
-    PERCENT_RIGHT = 266,
-    PERCENT_NONASSOC = 267,
-    PERCENT_PRECEDENCE = 268,
-    PERCENT_PREC = 269,
-    PERCENT_DPREC = 270,
-    PERCENT_MERGE = 271,
-    PERCENT_CODE = 272,
-    PERCENT_DEFAULT_PREC = 273,
-    PERCENT_DEFINE = 274,
-    PERCENT_DEFINES = 275,
-    PERCENT_ERROR_VERBOSE = 276,
-    PERCENT_EXPECT = 277,
-    PERCENT_EXPECT_RR = 278,
-    PERCENT_FLAG = 279,
-    PERCENT_FILE_PREFIX = 280,
-    PERCENT_GLR_PARSER = 281,
-    PERCENT_INITIAL_ACTION = 282,
-    PERCENT_LANGUAGE = 283,
-    PERCENT_NAME_PREFIX = 284,
-    PERCENT_NO_DEFAULT_PREC = 285,
-    PERCENT_NO_LINES = 286,
-    PERCENT_NONDETERMINISTIC_PARSER = 287,
-    PERCENT_OUTPUT = 288,
-    PERCENT_REQUIRE = 289,
-    PERCENT_SKELETON = 290,
-    PERCENT_START = 291,
-    PERCENT_TOKEN_TABLE = 292,
-    PERCENT_VERBOSE = 293,
-    PERCENT_YACC = 294,
-    BRACED_CODE = 295,
-    BRACED_PREDICATE = 296,
-    BRACKETED_ID = 297,
-    CHAR = 298,
-    EPILOGUE = 299,
-    EQUAL = 300,
-    ID = 301,
-    ID_COLON = 302,
-    PERCENT_PERCENT = 303,
-    PIPE = 304,
-    PROLOGUE = 305,
-    SEMICOLON = 306,
-    TAG = 307,
-    TAG_ANY = 308,
-    TAG_NONE = 309,
+    PERCENT_TOKEN = 259,
+    PERCENT_NTERM = 260,
+    PERCENT_TYPE = 261,
+    PERCENT_DESTRUCTOR = 262,
+    PERCENT_PRINTER = 263,
+    PERCENT_LEFT = 264,
+    PERCENT_RIGHT = 265,
+    PERCENT_NONASSOC = 266,
+    PERCENT_PRECEDENCE = 267,
+    PERCENT_PREC = 268,
+    PERCENT_DPREC = 269,
+    PERCENT_MERGE = 270,
+    PERCENT_CODE = 271,
+    PERCENT_DEFAULT_PREC = 272,
+    PERCENT_DEFINE = 273,
+    PERCENT_DEFINES = 274,
+    PERCENT_ERROR_VERBOSE = 275,
+    PERCENT_EXPECT = 276,
+    PERCENT_EXPECT_RR = 277,
+    PERCENT_FLAG = 278,
+    PERCENT_FILE_PREFIX = 279,
+    PERCENT_GLR_PARSER = 280,
+    PERCENT_INITIAL_ACTION = 281,
+    PERCENT_LANGUAGE = 282,
+    PERCENT_NAME_PREFIX = 283,
+    PERCENT_NO_DEFAULT_PREC = 284,
+    PERCENT_NO_LINES = 285,
+    PERCENT_NONDETERMINISTIC_PARSER = 286,
+    PERCENT_OUTPUT = 287,
+    PERCENT_REQUIRE = 288,
+    PERCENT_SKELETON = 289,
+    PERCENT_START = 290,
+    PERCENT_TOKEN_TABLE = 291,
+    PERCENT_VERBOSE = 292,
+    PERCENT_YACC = 293,
+    BRACED_CODE = 294,
+    BRACED_PREDICATE = 295,
+    BRACKETED_ID = 296,
+    CHAR = 297,
+    EPILOGUE = 298,
+    EQUAL = 299,
+    ID = 300,
+    ID_COLON = 301,
+    PERCENT_PERCENT = 302,
+    PIPE = 303,
+    PROLOGUE = 304,
+    SEMICOLON = 305,
+    TAG = 306,
+    TAG_ANY = 307,
+    TAG_NONE = 308,
+    INT = 309,
    PERCENT_PARAM = 310,
-    PERCENT_UNION = 311
+    PERCENT_UNION = 311,
+    PERCENT_EMPTY = 312
  };
 #endif
-/* Tokens.  */
-#define GRAM_EOF 0
-#define STRING 258
-#define INT 259
-#define PERCENT_TOKEN 260
-#define PERCENT_NTERM 261
-#define PERCENT_TYPE 262
-#define PERCENT_DESTRUCTOR 263
-#define PERCENT_PRINTER 264
-#define PERCENT_LEFT 265
-#define PERCENT_RIGHT 266
-#define PERCENT_NONASSOC 267
-#define PERCENT_PRECEDENCE 268
-#define PERCENT_PREC 269
-#define PERCENT_DPREC 270
-#define PERCENT_MERGE 271
-#define PERCENT_CODE 272
-#define PERCENT_DEFAULT_PREC 273
-#define PERCENT_DEFINE 274
-#define PERCENT_DEFINES 275
-#define PERCENT_ERROR_VERBOSE 276
-#define PERCENT_EXPECT 277
-#define PERCENT_EXPECT_RR 278
-#define PERCENT_FLAG 279
-#define PERCENT_FILE_PREFIX 280
-#define PERCENT_GLR_PARSER 281
-#define PERCENT_INITIAL_ACTION 282
-#define PERCENT_LANGUAGE 283
-#define PERCENT_NAME_PREFIX 284
-#define PERCENT_NO_DEFAULT_PREC 285
-#define PERCENT_NO_LINES 286
-#define PERCENT_NONDETERMINISTIC_PARSER 287
-#define PERCENT_OUTPUT 288
-#define PERCENT_REQUIRE 289
-#define PERCENT_SKELETON 290
-#define PERCENT_START 291
-#define PERCENT_TOKEN_TABLE 292
-#define PERCENT_VERBOSE 293
-#define PERCENT_YACC 294
-#define BRACED_CODE 295
-#define BRACED_PREDICATE 296
-#define BRACKETED_ID 297
-#define CHAR 298
-#define EPILOGUE 299
-#define EQUAL 300
-#define ID 301
-#define ID_COLON 302
-#define PERCENT_PERCENT 303
-#define PIPE 304
-#define PROLOGUE 305
-#define SEMICOLON 306
-#define TAG 307
-#define TAG_ANY 308
-#define TAG_NONE 309
-#define PERCENT_PARAM 310
-#define PERCENT_UNION 311

 /* Value type.  */
 #if ! defined GRAM_STYPE && ! defined GRAM_STYPE_IS_DECLARED
 typedef union GRAM_STYPE GRAM_STYPE;
 union GRAM_STYPE
 {
-#line 109 "src/parse-gram.y" /* yacc.c:1932  */
-
-  assoc assoc;
-  char *code;
-  char const *chars;
-  int integer;
-  named_ref *named_ref;
-  symbol *symbol;
-  symbol_list *list;
-  uniqstr uniqstr;
-  unsigned char character;
-
-#line 247 "src/parse-gram.y" /* yacc.c:1932  */
-
-  param_type param;
-
-#line 423 "src/parse-gram.y" /* yacc.c:1932  */
+#line 182 "src/parse-gram.y" /* yacc.c:1926  */
+unsigned char character;
+#line 186 "src/parse-gram.y" /* yacc.c:1926  */
+char *code;
+#line 191 "src/parse-gram.y" /* yacc.c:1926  */
+uniqstr uniqstr;
+#line 199 "src/parse-gram.y" /* yacc.c:1926  */
+int integer;
+#line 203 "src/parse-gram.y" /* yacc.c:1926  */
+symbol *symbol;
+#line 208 "src/parse-gram.y" /* yacc.c:1926  */
+assoc assoc;
+#line 211 "src/parse-gram.y" /* yacc.c:1926  */
+symbol_list *list;
+#line 214 "src/parse-gram.y" /* yacc.c:1926  */
+named_ref *named_ref;
+#line 241 "src/parse-gram.y" /* yacc.c:1926  */
+param_type param;
+#line 409 "src/parse-gram.y" /* yacc.c:1926  */
 code_props_type code_type;
+#line 647 "src/parse-gram.y" /* yacc.c:1926  */

-#line 211 "src/parse-gram.h" /* yacc.c:1932  */
+  struct
+  {
+    char const *chars;
+    muscle_kind kind;
+  } value;
+
+#line 167 "src/parse-gram.h" /* yacc.c:1926  */
 };
 # define GRAM_STYPE_IS_TRIVIAL 1
 # define GRAM_STYPE_IS_DECLARED 1
@@ -1,4 +1,4 @@
-%{/* Bison Grammar Parser                             -*- C -*-
+/* Bison Grammar Parser                             -*- C -*-

   Copyright (C) 2002-2013 Free Software Foundation, Inc.

@@ -17,45 +17,35 @@
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

+%code requires
+{
+  #include "symlist.h"
+  #include "symtab.h"
+}
+
+%code top
+{
+  /* On column 0 to please syntax-check.  */
 #include <config.h>
-#include "system.h"
-
-#include "c-ctype.h"
-#include "complain.h"
-#include "conflicts.h"
-#include "files.h"
-#include "getargs.h"
-#include "gram.h"
-#include "muscle-tab.h"
-#include "named-ref.h"
-#include "quotearg.h"
-#include "reader.h"
-#include "symlist.h"
-#include "symtab.h"
-#include "scan-gram.h"
-#include "scan-code.h"
-#include "xmemdup0.h"
-
-#define YYLLOC_DEFAULT(Current, Rhs, N)  (Current) = lloc_default (Rhs, N)
-static YYLTYPE lloc_default (YYLTYPE const *, int);
-
-#define YY_LOCATION_PRINT(File, Loc) \
-          location_print (File, Loc)
-
-static void version_check (location const *loc, char const *version);
-
-/* Request detailed syntax error messages, and pass them to GRAM_ERROR.
-   FIXME: depends on the undocumented availability of YYLLOC.  */
-#undef  yyerror
-#define yyerror(Msg) \
-        gram_error (&yylloc, Msg)
-static void gram_error (location const *, char const *);
-
-static char const *char_name (char);
-%}
+}

 %code
 {
+  #include "system.h"
+
+  #include "c-ctype.h"
+  #include "complain.h"
+  #include "conflicts.h"
+  #include "files.h"
+  #include "getargs.h"
+  #include "gram.h"
+  #include "named-ref.h"
+  #include "quotearg.h"
+  #include "reader.h"
+  #include "scan-gram.h"
+  #include "scan-code.h"
+  #include "xmemdup0.h"
+
  static int current_prec = 0;
  static location current_lhs_location;
  static named_ref *current_lhs_named_ref;
@@ -66,20 +56,37 @@ static char const *char_name (char);
  /** Set the new current left-hand side symbol, possibly common
   * to several right-hand side parts of rule.
   */
-  static
-  void
-  current_lhs(symbol *sym, location loc, named_ref *ref)
-  {
-    current_lhs_symbol = sym;
-    current_lhs_location = loc;
-    /* In order to simplify memory management, named references for lhs
-       are always assigned by deep copy into the current symbol_list
-       node.  This is because a single named-ref in the grammar may
-       result in several uses when the user factors lhs between several
-       rules using "|".  Therefore free the parser's original copy.  */
-    free (current_lhs_named_ref);
-    current_lhs_named_ref = ref;
-  }
+  static void current_lhs (symbol *sym, location loc, named_ref *ref);
+
+  #define YYLLOC_DEFAULT(Current, Rhs, N)         \
+    (Current) = lloc_default (Rhs, N)
+  static YYLTYPE lloc_default (YYLTYPE const *, int);
+
+  #define YY_LOCATION_PRINT(File, Loc)            \
+    location_print (Loc, File)
+
+  /* Strip initial '{' and final '}' (must be first and last characters).
+     Return the result.  */
+  static char *strip_braces (char *code);
+
+  /* Convert CODE by calling code_props_plain_init if PLAIN, otherwise
+     code_props_symbol_action_init.  Call
+     gram_scanner_last_string_free to release the latest string from
+     the scanner (should be CODE). */
+  static char const *translate_code (char *code, location loc, bool plain);
+
+  /* Convert CODE by calling code_props_plain_init after having
+     stripped the first and last characters (expected to be '{', and
+     '}').  Call gram_scanner_last_string_free to release the latest
+     string from the scanner (should be CODE). */
+  static char const *translate_code_braceless (char *code, location loc);
+
+  static void version_check (location const *loc, char const *version);
+
+  static void gram_error (location const *, char const *);
+
+  /* A string that describes a char (e.g., 'a' -> "'a'").  */
+  static char const *char_name (char);

  #define YYTYPE_INT16 int_fast16_t
  #define YYTYPE_INT8 int_fast8_t
@@ -87,8 +94,8 @@ static char const *char_name (char);
  #define YYTYPE_UINT8 uint_fast8_t
 }

-%define api.prefix "gram_"
-%define api.pure
+%define api.prefix {gram_}
+%define api.pure full
 %define locations
 %define parse.error verbose
 %define parse.lac full
@@ -105,23 +112,9 @@ static char const *char_name (char);
  boundary_set (&@$.end, current_file, 1, 1);
 }

-%union
-{
-  assoc assoc;
-  char *code;
-  char const *chars;
-  int integer;
-  named_ref *named_ref;
-  symbol *symbol;
-  symbol_list *list;
-  uniqstr uniqstr;
-  unsigned char character;
-};
-
 /* Define the tokens together with their human representation.  */
 %token GRAM_EOF 0 "end of file"
 %token STRING     "string"
-%token INT        "integer"

 %token PERCENT_TOKEN       "%token"
 %token PERCENT_NTERM       "%nterm"
@@ -186,18 +179,16 @@ static char const *char_name (char);
 %token TAG_ANY         "<*>"
 %token TAG_NONE        "<>"

+%union {unsigned char character;}
 %type <character> CHAR
 %printer { fputs (char_name ($$), yyo); } CHAR

-/* braceless is not to be used for rule or symbol actions, as it
-   calls code_props_plain_init.  */
-%type <chars> STRING "%{...%}" EPILOGUE braceless content.opt
-%type <code> "{...}" "%?{...}"
-%printer { fputs (quotearg_style (c_quoting_style, $$), yyo); }
-         STRING
-%printer { fprintf (yyo, "{\n%s\n}", $$); }
-         braceless content.opt "{...}" "%{...%}" EPILOGUE
+%union {char *code;};
+%type <code> "{...}" "%?{...}" "%{...%}" EPILOGUE STRING
+%printer { fputs (quotearg_style (c_quoting_style, $$), yyo); } STRING
+%printer { fprintf (yyo, "{\n%s\n}", $$); } <code>

+%union {uniqstr uniqstr;}
 %type <uniqstr> BRACKETED_ID ID ID_COLON PERCENT_FLAG TAG tag variable
 %printer { fputs ($$, yyo); } <uniqstr>
 %printer { fprintf (yyo, "[%s]", $$); } BRACKETED_ID
@@ -205,15 +196,22 @@ static char const *char_name (char);
 %printer { fprintf (yyo, "%%%s", $$); } PERCENT_FLAG
 %printer { fprintf (yyo, "<%s>", $$); } TAG tag

-%type <integer> INT
+%union {int integer;};
+%token <integer> INT "integer"
 %printer { fprintf (yyo, "%d", $$); } <integer>

+%union {symbol *symbol;}
 %type <symbol> id id_colon string_as_id symbol symbol.prec
 %printer { fprintf (yyo, "%s", $$->tag); } <symbol>
 %printer { fprintf (yyo, "%s:", $$->tag); } id_colon

+%union {assoc assoc;};
 %type <assoc> precedence_declarator
+
+%union {symbol_list *list;}
 %type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
+
+%union {named_ref *named_ref;}
 %type <named_ref> named_ref.opt

 /*---------.
@@ -221,8 +219,6 @@ static char const *char_name (char);
 `---------*/
 %code requires
 {
-# ifndef PARAM_TYPE
-#  define PARAM_TYPE
  typedef enum
  {
    param_none   = 0,
@@ -230,7 +226,6 @@ static char const *char_name (char);
    param_parse  = 1 << 1,
    param_both   = param_lex | param_parse
  } param_type;
-# endif
 };
 %code
 {
@@ -243,20 +238,17 @@ static char const *char_name (char);
  static void add_param (param_type type, char *decl, location loc);
  static param_type current_param = param_none;
 };
-%union
-{
-  param_type param;
-}
+%union {param_type param;}
 %token <param> PERCENT_PARAM "%param";
 %printer
 {
  switch ($$)
    {
 #define CASE(In, Out)                                           \
-      case param_ ## In: fputs ("%" #Out, stderr); break
-      CASE(lex,   lex-param);
-      CASE(parse, parse-param);
-      CASE(both,  param);
+      case param_ ## In: fputs ("%" #Out, yyo); break
+      CASE (lex,   lex-param);
+      CASE (parse, parse-param);
+      CASE (both,  param);
 #undef CASE
      case param_none: aver (false); break;
    }
@@ -278,7 +270,7 @@ input:
        `------------------------------------*/

 prologue_declarations:
-  /* Nothing */
+  %empty
 | prologue_declarations prologue_declaration
 ;

@@ -286,21 +278,17 @@ prologue_declaration:
  grammar_declaration
 | "%{...%}"
    {
-      code_props plain_code;
-      code_props_plain_init (&plain_code, $1, @1);
-      code_props_translate_code (&plain_code);
-      gram_scanner_last_string_free ();
      muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
-                        plain_code.code, @1);
+                        translate_code ($1, @1, true), @1);
      code_scanner_last_string_free ();
    }
 | "%<flag>"
    {
      muscle_percent_define_ensure ($1, @1, true);
    }
-| "%define" variable content.opt
+| "%define" variable value
    {
-      muscle_percent_define_insert ($2, @2, $3,
+      muscle_percent_define_insert ($2, @2, $3.kind, $3.chars,
                                    MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
    }
 | "%defines"                       { defines_flag = true; }
@@ -311,7 +299,8 @@ prologue_declaration:
    }
 | "%error-verbose"
    {
-      muscle_percent_define_insert ("parse.error", @1, "verbose",
+      muscle_percent_define_insert ("parse.error", @1, muscle_keyword,
+                                    "verbose",
                                    MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
    }
 | "%expect" INT                    { expected_sr_conflicts = $2; }
@@ -324,11 +313,7 @@ prologue_declaration:
    }
 | "%initial-action" "{...}"
    {
-      code_props action;
-      code_props_symbol_action_init (&action, $2, @2);
-      code_props_translate_code (&action);
-      gram_scanner_last_string_free ();
-      muscle_code_grow ("initial_action", action.code, @2);
+      muscle_code_grow ("initial_action", translate_code ($2, @2, false), @2);
      code_scanner_last_string_free ();
    }
 | "%language" STRING            { language_argmatch ($2, grammar_prio, @1); }
@@ -405,16 +390,17 @@ grammar_declaration:
    {
      default_prec = false;
    }
-| "%code" braceless
+| "%code" "{...}"
    {
      /* Do not invoke muscle_percent_code_grow here since it invokes
         muscle_user_name_list_grow.  */
-      muscle_code_grow ("percent_code()", $2, @2);
+      muscle_code_grow ("percent_code()",
+                        translate_code_braceless ($2, @2), @2);
      code_scanner_last_string_free ();
    }
-| "%code" ID braceless
+| "%code" ID "{...}"
    {
-      muscle_percent_code_grow ($2, @2, $3, @3);
+      muscle_percent_code_grow ($2, @2, translate_code_braceless ($3, @3), @3);
      code_scanner_last_string_free ();
    }
 ;
@@ -434,15 +420,15 @@ code_props_type:
 %token PERCENT_UNION "%union";

 union_name:
-  /* Nothing. */ {}
-| ID             { muscle_code_grow ("union_name", $1, @1); }
+  %empty {}
+| ID     { muscle_code_grow ("union_name", $1, @1); }
 ;

 grammar_declaration:
-  "%union" union_name braceless
+  "%union" union_name "{...}"
    {
      union_seen = true;
-      muscle_code_grow ("stype", $3, @3);
+      muscle_code_grow ("union_members", translate_code_braceless ($3, @3), @3);
      code_scanner_last_string_free ();
    }
 ;
@@ -494,8 +480,8 @@ precedence_declarator:
 ;

 tag.opt:
-  /* Nothing. */ { current_type = NULL; }
-| TAG            { current_type = $1; tag_seen = true; }
+  %empty { current_type = NULL; }
+| TAG    { current_type = $1; tag_seen = true; }
 ;

 /* Just like symbols.1 but accept INT for the sake of POSIX.  */
@@ -507,8 +493,17 @@ symbols.prec:
 ;

 symbol.prec:
-  symbol     { $$ = $1; }
-| symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
+  symbol
+    {
+      $$ = $1;
+      symbol_class_set ($1, token_sym, @1, false);
+    }
+| symbol INT
+    {
+      $$ = $1;
+      symbol_user_token_number_set ($1, $2, @2);
+      symbol_class_set ($1, token_sym, @1, false);
+    }
 ;

 /* One or more symbols to be %typed. */
@@ -609,8 +604,9 @@ rhses.1:
 | rhses.1 ";"
 ;

+%token PERCENT_EMPTY "%empty";
 rhs:
-  /* Nothing.  */
+  %empty
    { grammar_current_rule_begin (current_lhs_symbol, current_lhs_location,
                                  current_lhs_named_ref); }
 | rhs symbol named_ref.opt
@@ -619,6 +615,8 @@ rhs:
    { grammar_current_rule_action_append ($2, @2, $3, false); }
 | rhs "%?{...}"
    { grammar_current_rule_action_append ($2, @2, NULL, true); }
+| rhs "%empty"
+    { grammar_current_rule_empty_set (@2); }
 | rhs "%prec" symbol
    { grammar_current_rule_prec_set ($3, @3); }
 | rhs "%dprec" INT
@@ -628,44 +626,47 @@ rhs:
 ;

 named_ref.opt:
-  /* Nothing. */ { $$ = 0; }
-|
-  BRACKETED_ID   { $$ = named_ref_new($1, @1); }
+  %empty         { $$ = 0; }
+| BRACKETED_ID   { $$ = named_ref_new ($1, @1); }
 ;

-/*---------------------------.
-| variable and content.opt.  |
-`---------------------------*/
+/*---------------------.
+| variable and value.  |
+`---------------------*/

 /* The STRING form of variable is deprecated and is not M4-friendly.
-   For example, M4 fails for `%define "[" "value"'.  */
+   For example, M4 fails for '%define "[" "value"'.  */
 variable:
  ID
 | STRING { $$ = uniqstr_new ($1); }
 ;

 /* Some content or empty by default. */
-content.opt:
-  /* Nothing. */   { $$ = ""; }
-| ID { $$ = $1; }
-| STRING
-;
-
-
-/*------------.
-| braceless.  |
-`------------*/
-
-braceless:
-  "{...}"
+%code requires {#include "muscle-tab.h"};
+%union
+{
+  struct
+  {
+    char const *chars;
+    muscle_kind kind;
+  } value;
+};
+%type <value> value;
+%printer
+{
+  switch ($$.kind)
    {
-      code_props plain_code;
-      $1[strlen ($1) - 1] = '\n';
-      code_props_plain_init (&plain_code, $1+1, @1);
-      code_props_translate_code (&plain_code);
-      gram_scanner_last_string_free ();
-      $$ = plain_code.code;
+    case muscle_code:    fprintf (yyo,  "{%s}",  $$.chars); break;
+    case muscle_keyword: fprintf (yyo,   "%s",   $$.chars); break;
+    case muscle_string:  fprintf (yyo, "\"%s\"", $$.chars); break;
    }
+} <value>;
+
+value:
+  %empty  { $$.kind = muscle_keyword; $$.chars = ""; }
+| ID      { $$.kind = muscle_keyword; $$.chars = $1; }
+| STRING  { $$.kind = muscle_string;  $$.chars = $1; }
+| "{...}" { $$.kind = muscle_code;    $$.chars = strip_braces ($1); }
 ;


@@ -707,14 +708,10 @@ string_as_id:
 ;

 epilogue.opt:
-  /* Nothing.  */
+  %empty
 | "%%" EPILOGUE
    {
-      code_props plain_code;
-      code_props_plain_init (&plain_code, $2, @2);
-      code_props_translate_code (&plain_code);
-      gram_scanner_last_string_free ();
-      muscle_code_grow ("epilogue", plain_code.code, @2);
+      muscle_code_grow ("epilogue", translate_code ($2, @2, true), @2);
      code_scanner_last_string_free ();
    }
 ;
@@ -750,6 +747,33 @@ lloc_default (YYLTYPE const *rhs, int n)
  return loc;
 }

+static
+char *strip_braces (char *code)
+{
+  code[strlen (code) - 1] = 0;
+  return code + 1;
+}
+
+static
+char const *
+translate_code (char *code, location loc, bool plain)
+{
+  code_props plain_code;
+  if (plain)
+    code_props_plain_init (&plain_code, code, loc);
+  else
+    code_props_symbol_action_init (&plain_code, code, loc);
+  code_props_translate_code (&plain_code);
+  gram_scanner_last_string_free ();
+  return plain_code.code;
+}
+
+static
+char const *
+translate_code_braceless (char *code, location loc)
+{
+  return translate_code (strip_braces (code), loc, true);
+}

 static void
 add_param (param_type type, char *decl, location loc)
@@ -832,3 +856,18 @@ char_name (char c)
      return quotearg_style (escape_quoting_style, buf);
    }
 }
+
+static
+void
+current_lhs (symbol *sym, location loc, named_ref *ref)
+{
+  current_lhs_symbol = sym;
+  current_lhs_location = loc;
+  /* In order to simplify memory management, named references for lhs
+     are always assigned by deep copy into the current symbol_list
+     node.  This is because a single named-ref in the grammar may
+     result in several uses when the user factors lhs between several
+     rules using "|".  Therefore free the parser's original copy.  */
+  free (current_lhs_named_ref);
+  current_lhs_named_ref = ref;
+}
@@ -45,7 +45,8 @@ struct escape_buf
  char *ptr;
  size_t size;
 };
-static struct escape_buf escape_bufs[3];
+enum { num_escape_bufs = 3 };
+static struct escape_buf escape_bufs[num_escape_bufs];


 /*--------------------------------.
@@ -209,7 +210,7 @@ print_errs (FILE *out, int level, state *s)


 /*-------------------------------------------------------------------------.
-| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be `default').  |
+| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be 'default').  |
 | If not ENABLED, the rule is masked by a shift or a reduce (S/R and       |
 | R/R conflicts).                                                          |
 `-------------------------------------------------------------------------*/
@@ -496,7 +497,6 @@ xml_escape (char const *str)
 void
 print_xml (void)
 {
-  state_number i;
  int level = 0;

  FILE *out = xfopen (spec_xml_file, "w");
@@ -522,8 +522,11 @@ print_xml (void)
  /* print automaton */
  fputc ('\n', out);
  xml_puts (out, level + 1, "<automaton>");
-  for (i = 0; i < nstates; i++)
-    print_state (out, level + 2, states[i]);
+  {
+    state_number i;
+    for (i = 0; i < nstates; i++)
+      print_state (out, level + 2, states[i]);
+  }
  xml_puts (out, level + 1, "</automaton>");

  bitset_free (no_reduce_set);
@@ -531,8 +534,11 @@ print_xml (void)

  xml_puts (out, 0, "</bison-xml-report>");

-  free (escape_bufs[0].ptr);
-  free (escape_bufs[1].ptr);
+  {
+    int i;
+    for (i = 0; i < num_escape_bufs; ++i)
+      free (escape_bufs[i].ptr);
+  }

  xfclose (out);
 }
@@ -206,7 +206,7 @@ print_errs (FILE *out, state *s)


 /*-------------------------------------------------------------------------.
-| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be `default').  |
+| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be 'default').  |
 | If not ENABLED, the rule is masked by a shift or a reduce (S/R and       |
 | R/R conflicts).                                                          |
 `-------------------------------------------------------------------------*/
@@ -514,7 +514,7 @@ print_results (void)
  print_grammar (out);

  /* If the whole state item sets, not only the kernels, are wanted,
-     `closure' will be run, which needs memory allocation/deallocation.   */
+     'closure' will be run, which needs memory allocation/deallocation.   */
  if (report_flag & report_itemsets)
    new_closure (nritems);
  /* Storage for print_reductions.  */
@@ -267,9 +267,9 @@ symbol_should_be_used (symbol_list const *s, bool *midrule_warning)
    return true;
  if ((s->midrule && s->midrule->action_props.is_value_used)
      || (s->midrule_parent_rule
-          && symbol_list_n_get (s->midrule_parent_rule,
-                                s->midrule_parent_rhs_index)
-               ->action_props.is_value_used))
+          && (symbol_list_n_get (s->midrule_parent_rule,
+                                 s->midrule_parent_rhs_index)
+              ->action_props.is_value_used)))
    {
      *midrule_warning = true;
      return true;
@@ -321,7 +321,7 @@ grammar_rule_check (const symbol_list *r)
        bool midrule_warning = false;
        if (!l->action_props.is_value_used
            && symbol_should_be_used (l, &midrule_warning)
-            /* The default action, $$ = $1, `uses' both.  */
+            /* The default action, $$ = $1, 'uses' both.  */
            && (r->action_props.code || (n != 0 && n != 1)))
          {
            warnings warn_flag = midrule_warning ? Wmidrule_values : Wother;
@@ -333,6 +333,18 @@ grammar_rule_check (const symbol_list *r)
      }
  }

+  /* Check that %empty => empty rule.  */
+  if (r->percent_empty_loc.start.file
+      && r->next && r->next->content.sym)
+    complain (&r->percent_empty_loc, complaint,
+              _("%%empty on non-empty rule"));
+
+  /* Check that empty rule => %empty.  */
+  if (!(r->next && r->next->content.sym)
+      && !r->midrule_parent_rule
+      && !r->percent_empty_loc.start.file)
+    complain (&r->location, Wempty_rule, _("empty rule without %%empty"));
+
  /* See comments in grammar_current_rule_prec_set for how POSIX
     mandates this complaint.  It's only for identifiers, so skip
     it for char literals and strings, which are always tokens.  */
@@ -430,8 +442,26 @@ grammar_current_rule_prec_set (symbol *precsym, location loc)
     token.  */
  symbol_class_set (precsym, token_sym, loc, false);
  if (current_rule->ruleprec)
-    complain (&loc, complaint, _("only one %s allowed per rule"), "%prec");
-  current_rule->ruleprec = precsym;
+    duplicate_directive ("%prec",
+                         current_rule->ruleprec->location, loc);
+  else
+    current_rule->ruleprec = precsym;
+}
+
+/* Set %empty for the current rule. */
+
+void
+grammar_current_rule_empty_set (location loc)
+{
+  /* If %empty is used and -Wno-empty-rule is not, then enable
+     -Wempty-rule.  */
+  if (warning_is_unset (Wempty_rule))
+    warning_argmatch ("empty-rule", 0, 0);
+  if (current_rule->percent_empty_loc.start.file)
+    duplicate_directive ("%empty",
+                         current_rule->percent_empty_loc, loc);
+  else
+    current_rule->percent_empty_loc = loc;
 }

 /* Attach dynamic precedence DPREC to the current rule. */
@@ -446,8 +476,13 @@ grammar_current_rule_dprec_set (int dprec, location loc)
    complain (&loc, complaint, _("%s must be followed by positive number"),
              "%dprec");
  else if (current_rule->dprec != 0)
-    complain (&loc, complaint, _("only one %s allowed per rule"), "%dprec");
-  current_rule->dprec = dprec;
+    duplicate_directive ("%dprec",
+                         current_rule->dprec_location, loc);
+  else
+    {
+      current_rule->dprec = dprec;
+      current_rule->dprec_location = loc;
+    }
 }

 /* Attach a merge function NAME with argument type TYPE to current
@@ -460,9 +495,13 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
    complain (&loc, Wother, _("%s affects only GLR parsers"),
              "%merge");
  if (current_rule->merger != 0)
-    complain (&loc, complaint, _("only one %s allowed per rule"), "%merge");
-  current_rule->merger = get_merge_function (name);
-  current_rule->merger_declaration_location = loc;
+    duplicate_directive ("%merge",
+                         current_rule->merger_declaration_location, loc);
+  else
+    {
+      current_rule->merger = get_merge_function (name);
+      current_rule->merger_declaration_location = loc;
+    }
 }

 /* Attach SYM to the current rule.  If needed, move the previous
@@ -477,7 +516,7 @@ grammar_current_rule_symbol_append (symbol *sym, location loc,
    grammar_midrule_action ();
  p = grammar_symbol_append (sym, loc);
  if (name)
-    assign_named_ref(p, name);
+    assign_named_ref (p, name);
  if (sym->status == undeclared || sym->status == used)
    sym->status = needed;
 }
@@ -507,7 +546,7 @@ packgram (void)
 {
  unsigned int itemno = 0;
  rule_number ruleno = 0;
-  symbol_list *p = grammar;
+  symbol_list *p;

  ritem = xnmalloc (nritems + 1, sizeof *ritem);

@@ -516,9 +555,8 @@ packgram (void)

  rules = xnmalloc (nrules, sizeof *rules);

-  while (p)
+  for (p = grammar; p; p = p->next)
    {
-      int rule_length = 0;
      symbol *ruleprec = p->ruleprec;
      record_merge_function_type (p->merger, p->content.sym->type_name,
                                  p->merger_declaration_location);
@@ -536,14 +574,14 @@ packgram (void)
      rules[ruleno].action_location = p->action_props.location;
      rules[ruleno].is_predicate = p->action_props.is_predicate;

-      /* If the midrule's $$ is set or its $n is used, remove the `$' from the
+      /* If the midrule's $$ is set or its $n is used, remove the '$' from the
         symbol name so that it's a user-defined symbol so that the default
         %destructor and %printer apply.  */
      if (p->midrule_parent_rule
          && (p->action_props.is_value_used
-              || symbol_list_n_get (p->midrule_parent_rule,
-                                    p->midrule_parent_rhs_index)
-                   ->action_props.is_value_used))
+              || (symbol_list_n_get (p->midrule_parent_rule,
+                                     p->midrule_parent_rhs_index)
+                  ->action_props.is_value_used)))
        p->content.sym->tag += 1;

      /* Don't check the generated rule 0.  It has no action, so some rhs
@@ -552,24 +590,27 @@ packgram (void)
      if (p != grammar)
        grammar_rule_check (p);

-      for (p = p->next; p && p->content.sym; p = p->next)
-        {
-          ++rule_length;
+      {
+        size_t rule_length = 0;
+        for (p = p->next; p->content.sym; p = p->next)
+          {
+            ++rule_length;

-          /* Don't allow rule_length == INT_MAX, since that might
-             cause confusion with strtol if INT_MAX == LONG_MAX.  */
-          if (rule_length == INT_MAX)
-            complain (&rules[ruleno].location, fatal, _("rule is too long"));
+            /* Don't allow rule_length == INT_MAX, since that might
+               cause confusion with strtol if INT_MAX == LONG_MAX.  */
+            if (rule_length == INT_MAX)
+              complain (&rules[ruleno].location, fatal, _("rule is too long"));

-          /* item_number = symbol_number.
-             But the former needs to contain more: negative rule numbers. */
-          ritem[itemno++] =
-            symbol_number_as_item_number (p->content.sym->number);
-          /* A rule gets by default the precedence and associativity
-             of its last token.  */
-          if (p->content.sym->class == token_sym && default_prec)
-            rules[ruleno].prec = p->content.sym;
-        }
+            /* item_number = symbol_number.
+               But the former needs to contain more: negative rule numbers. */
+            ritem[itemno++] =
+              symbol_number_as_item_number (p->content.sym->number);
+            /* A rule gets by default the precedence and associativity
+               of its last token.  */
+            if (p->content.sym->class == token_sym && default_prec)
+              rules[ruleno].prec = p->content.sym;
+          }
+      }

      /* If this rule has a %prec,
         the specified symbol's precedence replaces the default.  */
@@ -583,9 +624,6 @@ packgram (void)
      aver (itemno < ITEM_NUMBER_MAX);
      ++ruleno;
      aver (ruleno < RULE_NUMBER_MAX);
-
-      if (p)
-        p = p->next;
    }

  aver (itemno == nritems);
@@ -713,7 +751,7 @@ check_and_convert_grammar (void)
  /* Insert the initial rule, whose line is that of the first rule
     (not that of the start symbol):

-     accept: %start EOF.  */
+     $accept: %start $end.  */
  {
    symbol_list *p = symbol_list_sym_new (accept, empty_location);
    p->location = grammar->location;
@@ -726,7 +764,8 @@ check_and_convert_grammar (void)
    grammar = p;
  }

-  aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
+  aver (nsyms <= SYMBOL_NUMBER_MAXIMUM);
+  aver (nsyms == ntokens + nvars);

  /* Assign the symbols their symbol numbers.  Write #defines for the
     token symbols into FDEFINES if requested.  */
@@ -737,11 +776,11 @@ check_and_convert_grammar (void)
     action type checking.

     Before invoking grammar_rule_check (in packgram below) on any rule, make
-     sure all actions have already been scanned in order to set `used' flags.
+     sure all actions have already been scanned in order to set 'used' flags.
     Otherwise, checking that a midrule's $$ should be set will not always work
     properly because the check must forward-reference the midrule's parent
-     rule.  For the same reason, all the `used' flags must be set before
-     checking whether to remove `$' from any midrule symbol name (also in
+     rule.  For the same reason, all the 'used' flags must be set before
+     checking whether to remove '$' from any midrule symbol name (also in
     packgram).  */
  {
    symbol_list *sym;
@@ -47,6 +47,8 @@ void grammar_current_rule_begin (symbol *lhs, location loc,
                                 named_ref *lhs_named_ref);
 void grammar_current_rule_end (location loc);
 void grammar_midrule_action (void);
+/* Apply %empty to the current rule.  */
+void grammar_current_rule_empty_set (location loc);
 void grammar_current_rule_prec_set (symbol *precsym, location loc);
 void grammar_current_rule_dprec_set (int dprec, location loc);
 void grammar_current_rule_merge_set (uniqstr name, location loc);
@@ -49,7 +49,7 @@ static bitset P;
 static bitset V;

 /* Set of symbols used to define rule precedence (so they are
-   `useless', but no warning should be issued).  */
+   'useless', but no warning should be issued).  */
 static bitset V1;

 static rule_number nuseful_productions;
@@ -78,8 +78,9 @@ static bool untyped_var_seen;

 /* POSIX says that a tag must be both an id and a C union member, but
   historically almost any character is allowed in a tag.  We disallow
-   NUL and newline, as this simplifies our implementation.  */
-tag      [^\0\n>]+
+   NUL and newline, as this simplifies our implementation.  We allow
+   "->" as a means to dereference a pointer.  */
+tag      ([^\0\n>]|->)+

 /* Zero or more instances of backslash-newline.  Following GCC, allow
   white space between the backslash and the newline.  */
@@ -95,26 +96,6 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 %%

 %{
-  /* Nesting level of the current code in braces.  */
-  int braces_level = 0;
-
-  /* Whether a semicolon is probably needed.
-
-     The heuristic is that a semicolon is not needed after '{', '}',
-     ';', or a C preprocessor directive, and that whitespaces and
-     comments do not affect this flag.  Note that '{' does not need a
-     semicolon because of '{}'.  A semicolon may be needed before a
-     cpp directive, but don't bother.
-
-     While it is maintained in several start-conditions (factoring
-     opportunities), it is meaningful only for SC_RULE_ACTION. */
-  bool need_semicolon = false;
-
-  /* Whether in a C preprocessor directive.  Don't use a start condition
-     for this because, at the end of strings and comments, we still need
-     to know whether we're in a directive.  */
-  bool in_cpp = false;
-
  /* This scanner is special: it is invoked only once, henceforth
     is expected to return only once.  This initialization is
     therefore done once per action to translate. */
@@ -167,32 +148,14 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"

 <SC_RULE_ACTION,SC_SYMBOL_ACTION>
 {
-  "'" {
-    STRING_GROW;
-    BEGIN SC_CHARACTER;
-    need_semicolon = true;
-  }
-  "\"" {
-    STRING_GROW;
-    BEGIN SC_STRING;
-    need_semicolon = true;
-  }
-  "/"{splice}"*" {
-    STRING_GROW;
-    BEGIN SC_COMMENT;
-  }
-  "/"{splice}"/" {
-    STRING_GROW;
-    BEGIN SC_LINE_COMMENT;
-  }
+  "'"              STRING_GROW; BEGIN SC_CHARACTER;
+  "\""             STRING_GROW; BEGIN SC_STRING;
+  "/"{splice}"*"   STRING_GROW; BEGIN SC_COMMENT;
+  "/"{splice}"/"   STRING_GROW; BEGIN SC_LINE_COMMENT;
+
  [$@]  {
    complain (loc, Wother, _("stray '%s'"), yytext);
    obstack_escape (&obstack_for_string, yytext);
-    need_semicolon = true;
-  }
-  [\[\]]  {
-    obstack_escape (&obstack_for_string, yytext);
-    need_semicolon = true;
  }
 }

@@ -203,51 +166,13 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
    handle_action_dollar (self->rule, yytext, *loc);
    if (ref_tail_fields)
      obstack_sgrow (&obstack_for_string, ref_tail_fields);
-    need_semicolon = true;
  }
  "@"{ref} {
    ref_tail_fields = NULL;
    handle_action_at (self->rule, yytext, *loc);
    if (ref_tail_fields)
      obstack_sgrow (&obstack_for_string, ref_tail_fields);
-    need_semicolon = true;
  }
-
-  ";"  STRING_GROW;                 need_semicolon = false;
-  "{"  STRING_GROW; ++braces_level; need_semicolon = false;
-  "}"  {
-    bool outer_brace = --braces_level == 0;
-
-    /* As an undocumented Bison extension, append ';' before the last
-       brace in braced code, so that the user code can omit trailing
-       ';'.  But do not append ';' if emulating Yacc, since Yacc does
-       not append one.  This is deprecated since release 2.4.1.  */
-    if (outer_brace && !yacc_flag && language_prio == default_prio
-        && skeleton_prio == default_prio && need_semicolon && ! in_cpp)
-      {
-        unsigned int indent = 0;
-        complain_indent (loc, Wdeprecated, &indent,
-                         _("a ';' might be needed at the end of action code"));
-        indent += SUB_INDENT;
-        complain_indent (loc, Wdeprecated | silent | no_caret, &indent,
-                         _("future versions of Bison will not add the ';'"));
-        obstack_1grow (&obstack_for_string, ';');
-      }
-
-    STRING_GROW;
-    need_semicolon = false;
-  }
-
-  /* Preprocessing directives should only be recognized at the beginning
-     of lines, allowing whitespace including comments, but in C/C++,
-     '#' can only be the start of preprocessor directives or within
-     '#define' directives anyway, so don't bother with begin of line.  */
-  "#"       STRING_GROW; in_cpp = true;
-
-  {splice}  STRING_GROW;
-  [\n\r]    STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false;
-  [ \t\f]   STRING_GROW;
-  .         STRING_GROW; need_semicolon = true;
 }

 <SC_SYMBOL_ACTION>
@@ -671,7 +596,8 @@ fetch_type_name (char *cp, char const **type_name,
  if (*cp == '<')
    {
      *type_name = ++cp;
-      while (*cp != '>')
+      /* Series of non-'>' or "->".  */
+      while (*cp != '>' || cp[-1] == '-')
        ++cp;

      /* The '>' symbol will be later replaced by '\0'. Original
@@ -112,7 +112,12 @@ static void unexpected_newline (boundary, char const *);
 /* A identifier was just read in directives/rules.  Special state
    to capture the sequence 'identifier :'. */
 %x SC_AFTER_IDENTIFIER
- /* A complex tag, with nested angles brackets. */
+
+ /* POSIX says that a tag must be both an id and a C union member, but
+    historically almost any character is allowed in a tag.  We
+    disallow NUL, as this simplifies our implementation.  We match
+    angle brackets in nested pairs: several languages use them for
+    generics/template types.  */
 %x SC_TAG

 /* Four types of user code:
@@ -133,13 +138,6 @@ notletter [^.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]{-}[%\{]
 id        {letter}({letter}|[-0-9])*
 int       [0-9]+

-/* POSIX says that a tag must be both an id and a C union member, but
-   historically almost any character is allowed in a tag.  We disallow
-   NUL, as this simplifies our implementation.  We disallow angle
-   bracket to match them in nested pairs: several languages use them
-   for generics/template types.  */
-tag      [^\0<>]+
-
 /* Zero or more instances of backslash-newline.  Following GCC, allow
   white space between the backslash and the newline.  */
 splice   (\\[ \f\t\v]*\n)*
@@ -217,6 +215,7 @@ eqopt    ([[:space:]]*=)?
  "%defines"                        return PERCENT_DEFINES;
  "%destructor"                     return PERCENT_DESTRUCTOR;
  "%dprec"                          return PERCENT_DPREC;
+  "%empty"                          return PERCENT_EMPTY;
  "%error-verbose"                  return PERCENT_ERROR_VERBOSE;
  "%expect"                         return PERCENT_EXPECT;
  "%expect-rr"                      return PERCENT_EXPECT_RR;
@@ -324,13 +323,6 @@ eqopt    ([[:space:]]*=)?
  /* A type. */
  "<*>"       return TAG_ANY;
  "<>"        return TAG_NONE;
-  "<"{tag}">" {
-    obstack_grow (&obstack_for_string, yytext + 1, yyleng - 2);
-    STRING_FINISH;
-    val->uniqstr = uniqstr_new (last_string);
-    STRING_FREE;
-    return TAG;
-  }
  "<"         {
    nesting = 0;
    token_start = loc->start;
@@ -520,7 +512,7 @@ eqopt    ([[:space:]]*=)?
  "\"" {
    STRING_FINISH;
    loc->start = token_start;
-    val->chars = last_string;
+    val->code = last_string;
    BEGIN INITIAL;
    return STRING;
  }
@@ -558,10 +550,11 @@ eqopt    ([[:space:]]*=)?
  <<EOF>>   unexpected_eof (token_start, "'");
 }

-  /*-----------------------------------------------------------.
-  | Scanning a Bison nested tag.  The initial angle bracket is |
-  | already eaten.                                             |
-  `-----------------------------------------------------------*/
+
+
+  /*--------------------------------------------------------------.
+  | Scanning a tag.  The initial angle bracket is already eaten.  |
+  `--------------------------------------------------------------*/

 <SC_TAG>
 {
@@ -579,7 +572,7 @@ eqopt    ([[:space:]]*=)?
    STRING_GROW;
  }

-  [^<>]+ STRING_GROW;
+  ([^<>]|->)+ STRING_GROW;
  "<"+   STRING_GROW; nesting += yyleng;

  <<EOF>>   unexpected_eof (token_start, ">");
@@ -758,7 +751,7 @@ eqopt    ([[:space:]]*=)?
  "%}" {
    STRING_FINISH;
    loc->start = code_start;
-    val->chars = last_string;
+    val->code = last_string;
    BEGIN INITIAL;
    return PROLOGUE;
  }
@@ -777,7 +770,7 @@ eqopt    ([[:space:]]*=)?
  <<EOF>> {
    STRING_FINISH;
    loc->start = code_start;
-    val->chars = last_string;
+    val->code = last_string;
    BEGIN INITIAL;
    return EPILOGUE;
  }
@@ -72,7 +72,7 @@ static void fail_for_invalid_at (char const *at);
 "@@" fputc ('@', yyout);
 "@{" fputc ('[', yyout);
 "@}" fputc (']', yyout);
-"@`" continue;  /* Used by b4_cat in ../data/bison.m4.  */
+"@'" continue;  /* Used by b4_cat in ../data/bison.m4.  */
@\n  continue;

 "@oline@"  fprintf (yyout, "%d", out_lineno + 1);
@@ -83,7 +83,7 @@ static void fail_for_invalid_at (char const *at);
 "@output("      at_init (&argc, argv, &at_ptr, &at_output);

  /* This pattern must not match more than the previous @ patterns. */
-@[^@{}`(\n]*    fail_for_invalid_at (yytext);
+@[^@{}\'(\n]*   fail_for_invalid_at (yytext);
 \n              out_lineno++; ECHO;
 [^@\n]+         ECHO;

@@ -103,7 +103,7 @@ static void fail_for_invalid_at (char const *at);
  "@@"   obstack_1grow (&obstack_for_string, '@');
  "@{"   obstack_1grow (&obstack_for_string, '[');
  "@}"   obstack_1grow (&obstack_for_string, ']');
-  "@`"   continue; /* For starting an argument that begins with whitespace. */
+  "@'"   continue; /* For starting an argument that begins with whitespace. */
  @\n    continue;

  @[,)] {
@@ -183,6 +183,8 @@ flag (const char *arg)
  /* compare with values issued from b4_error */
  if (STREQ (arg, "complain"))
    return complaint;
+  else if (STREQ (arg, "deprecated"))
+    return Wdeprecated;
  else if (STREQ (arg, "fatal"))
    return fatal;
  else if (STREQ (arg, "note"))
@@ -36,18 +36,20 @@ symbol_list_sym_new (symbol *sym, location loc)
  res->content_type = SYMLIST_SYMBOL;
  res->content.sym = sym;
  res->location = res->sym_loc = loc;
+  res->named_ref = NULL;

  res->midrule = NULL;
  res->midrule_parent_rule = NULL;
  res->midrule_parent_rhs_index = 0;

-  code_props_none_init (&res->action_props);
-
+  /* Members used for LHS only.  */
  res->ruleprec = NULL;
+  res->percent_empty_loc = empty_location;
+  code_props_none_init (&res->action_props);
  res->dprec = 0;
+  res->dprec_location = empty_location;
  res->merger = 0;
-
-  res->named_ref = NULL;
+  res->merger_declaration_location = empty_location;

  res->next = NULL;

@@ -85,12 +87,17 @@ symbol_list_type_new (uniqstr type_name, location loc)
 void
 symbol_list_syms_print (const symbol_list *l, FILE *f)
 {
+  char const *sep = "";
  for (/* Nothing. */; l && l->content.sym; l = l->next)
    {
+      fputs (sep, f);
+      fputs (l->content_type == SYMLIST_SYMBOL ? "symbol: "
+             : l->content_type == SYMLIST_TYPE ? "type: "
+             : "invalid content_type: ",
+             f);
      symbol_print (l->content.sym, f);
-      fprintf (stderr, l->action_props.is_value_used ? " used" : " unused");
-      if (l && l->content.sym)
-        fprintf (f, ", ");
+      fputs (l->action_props.is_value_used ? " used" : " unused", f);
+      sep = ", ";
    }
 }

@@ -50,6 +50,9 @@ typedef struct symbol_list
  } content;
  location location;

+  /* Named reference. */
+  named_ref *named_ref;
+
  /* Proper location of the symbol, not all the rule */
  location sym_loc;

@@ -64,19 +67,26 @@ typedef struct symbol_list
  struct symbol_list *midrule_parent_rule;
  int midrule_parent_rhs_index;

+  /* ---------------------------------------------- */
+  /* Apply to the rule (attached to the LHS only).  */
+  /* ---------------------------------------------- */
+
+  /* Precedence/associativity.  */
+  symbol *ruleprec;
+
  /* The action is attached to the LHS of a rule, but action properties for
   * each RHS are also stored here.  */
  code_props action_props;

-  /* Precedence/associativity.  */
-  symbol *ruleprec;
+  /* The location of the first %empty for this rule, or \a
+     empty_location.  */
+  location percent_empty_loc;
+
  int dprec;
+  location dprec_location;
  int merger;
  location merger_declaration_location;

-  /* Named reference. */
-  named_ref *named_ref;
-
  /* The list.  */
  struct symbol_list *next;
 } symbol_list;
@@ -153,13 +153,13 @@ symbol_print (symbol const *s, FILE *f)
 {
  if (s)
    {
-      fprintf (f, "\"%s\"", s->tag);
+      fputs (s->tag, f);
      SYMBOL_ATTR_PRINT (type_name);
      SYMBOL_CODE_PRINT (destructor);
      SYMBOL_CODE_PRINT (printer);
    }
  else
-    fprintf (f, "<NULL>");
+    fputs ("<NULL>", f);
 }

 #undef SYMBOL_ATTR_PRINT
@@ -243,9 +243,12 @@ symbol_type_set (symbol *sym, uniqstr type_name, location loc)
    {
      if (sym->type_name)
        symbol_redeclaration (sym, "%type", sym->type_location, loc);
-      uniqstr_assert (type_name);
-      sym->type_name = type_name;
-      sym->type_location = loc;
+      else
+        {
+          uniqstr_assert (type_name);
+          sym->type_name = type_name;
+          sym->type_location = loc;
+        }
    }
 }

@@ -261,7 +264,8 @@ symbol_code_props_set (symbol *sym, code_props_type kind,
    symbol_redeclaration (sym, code_props_type_string (kind),
                          sym->props[kind].location,
                          code->location);
-  sym->props[kind] = *code;
+  else
+    sym->props[kind] = *code;
 }

 /*-----------------------------------------------------.
@@ -277,7 +281,8 @@ semantic_type_code_props_set (semantic_type *type,
    semantic_type_redeclaration (type, code_props_type_string (kind),
                                 type->props[kind].location,
                                 code->location);
-  type->props[kind] = *code;
+  else
+    type->props[kind] = *code;
 }

 /*---------------------------------------------------.
@@ -321,12 +326,15 @@ symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
 {
  if (a != undef_assoc)
    {
-      if (sym->prec != 0)
+      if (sym->prec)
        symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
                              loc);
-      sym->prec = prec;
-      sym->assoc = a;
-      sym->prec_location = loc;
+      else
+        {
+          sym->prec = prec;
+          sym->assoc = a;
+          sym->prec_location = loc;
+        }
    }

  /* Only terminals have a precedence. */
@@ -360,7 +368,8 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
    {
      if (sym->status == declared && !warned)
        complain (&loc, Wother, _("symbol %s redeclared"), sym->tag);
-      sym->status = declared;
+      else
+        sym->status = declared;
    }
 }

@@ -441,7 +450,7 @@ semantic_type_check_defined (semantic_type *sem_type)
  /* <*> and <> do not have to be "declared".  */
  if (sem_type->status == declared
      || !*sem_type->tag
-      || STREQ(sem_type->tag, "*"))
+      || STREQ (sem_type->tag, "*"))
    {
      int i;
      for (i = 0; i < 2; ++i)
@@ -615,8 +624,8 @@ symbol_translation (symbol *this)
          (this->user_token_number,
           symbols[token_translations[this->user_token_number]],
           this);
-
-      token_translations[this->user_token_number] = this->number;
+      else
+        token_translations[this->user_token_number] = this->number;
    }

  return true;
@@ -1057,27 +1066,40 @@ register_precedence (graphid first, graphid snd)
 }


-/*--------------------------------------------------.
-| Print a warning for unused precedence relations.  |
-`--------------------------------------------------*/
+/*---------------------------------------.
+| Deep clear a linked / adjacency list). |
+`---------------------------------------*/

-void
-print_precedence_warnings (void)
+static void
+linkedlist_free (symgraphlink *node)
+{
+  if (node)
+    {
+      while (node->next)
+        {
+          symgraphlink *tmp = node->next;
+          free (node);
+          node = tmp;
+        }
+      free (node);
+    }
+}
+
+/*----------------------------------------------.
+| Clear and destroy association tracking table. |
+`----------------------------------------------*/
+
+static void
+assoc_free (void)
 {
  int i;
-  if (!prec_nodes)
-    init_prec_nodes ();
  for (i = 0; i < nsyms; ++i)
    {
-      symbol *s = symbols[i];
-      if (s
-          && s->prec != 0
-          && !prec_nodes[i]->pred
-          && !prec_nodes[i]->succ
-          && s->assoc == precedence_assoc)
-        complain (&s->location, Wother,
-                  _("useless precedence for %s"), s->tag);
+      linkedlist_free (prec_nodes[i]->pred);
+      linkedlist_free (prec_nodes[i]->succ);
+      free (prec_nodes[i]);
    }
+  free (prec_nodes);
 }

 /*---------------------------------------.
@@ -1088,7 +1110,7 @@ static void
 init_assoc (void)
 {
  graphid i;
-  used_assoc = xcalloc(nsyms, sizeof(*used_assoc));
+  used_assoc = xcalloc (nsyms, sizeof *used_assoc);
  for (i = 0; i < nsyms; ++i)
    used_assoc[i] = false;
 }
@@ -1119,21 +1141,37 @@ register_assoc (graphid i, graphid j)
  used_assoc[j] = true;
 }

-/*------------------------------------------------------.
-| Print a warning for each unused symbol associativity. |
-`------------------------------------------------------*/
+/*--------------------------------------------------.
+| Print a warning for unused precedence relations.  |
+`--------------------------------------------------*/

 void
-print_assoc_warnings (void)
+print_precedence_warnings (void)
 {
-  graphid i;
+  int i;
+  if (!prec_nodes)
+    init_prec_nodes ();
  if (!used_assoc)
    init_assoc ();
  for (i = 0; i < nsyms; ++i)
    {
      symbol *s = symbols[i];
-      if (is_assoc_useless (s))
-        complain (&s->location, Wother,
-                  _("useless associativity for %s"), s->tag);
+      if (s
+          && s->prec != 0
+          && !prec_nodes[i]->pred
+          && !prec_nodes[i]->succ)
+        {
+          if (is_assoc_useless (s))
+            complain (&s->prec_location, Wprecedence,
+                      _("useless precedence and associativity for %s"), s->tag);
+          else if (s->assoc == precedence_assoc)
+            complain (&s->prec_location, Wprecedence,
+                      _("useless precedence for %s"), s->tag);
+        }
+      else if (is_assoc_useless (s))
+        complain (&s->prec_location, Wprecedence,
+                  _("useless associativity for %s, use %%precedence"), s->tag);
    }
+  free (used_assoc);
+  assoc_free ();
 }
@@ -128,9 +128,9 @@ struct symbol
 /** Undefined user number.  */
 # define USER_NUMBER_UNDEFINED -1

-/* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
-   this symbol has a literal string alias.  For instance, `%token foo
-   "foo"' has `"foo"' numbered regularly, and `foo' numbered as
+/* 'symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
+   this symbol has a literal string alias.  For instance, '%token foo
+   "foo"' has '"foo"' numbered regularly, and 'foo' numbered as
   USER_NUMBER_HAS_STRING_ALIAS.  */
 # define USER_NUMBER_HAS_STRING_ALIAS -9991

@@ -266,7 +266,8 @@ struct symgraph

 void register_precedence (graphid first, graphid snd);

-/** Print a warning for each symbol whose precedence is useless. */
+/** Print a warning for each symbol whose precedence and/or associativity
+ * is useless. */

 void print_precedence_warnings (void);

@@ -274,9 +275,7 @@ void print_precedence_warnings (void);
 | Symbol associativity  |
 `----------------------*/

-void register_assoc (int i, int j);
-
-void print_assoc_warnings (void);
+void register_assoc (graphid i, graphid j);

 /*-----------------.
 | Semantic types.  |
@@ -99,7 +99,7 @@ typedef size_t uintptr_t;
 #  endif
 # endif

-/* The __-protected variants of `format' and `printf' attributes
+/* The __-protected variants of 'format' and 'printf' attributes
   are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
 #  define __format__ format
@@ -35,7 +35,7 @@
 #include "tables.h"

 /* Several tables are indexed both by state and nonterminal numbers.
-   We call such an index a `vector'; i.e., a vector is either a state
+   We call such an index a 'vector'; i.e., a vector is either a state
   or a nonterminal number.

   Of course vector_number_t ought to be wide enough to contain
@@ -90,18 +90,18 @@ static base_number *width;

 /* For a given state, N = ACTROW[SYMBOL]:

-   If N = 0, stands for `run the default action'.
-   If N = MIN, stands for `raise a syntax error'.
-   If N > 0, stands for `shift SYMBOL and go to n'.
-   If N < 0, stands for `reduce -N'.  */
+   If N = 0, stands for 'run the default action'.
+   If N = MIN, stands for 'raise a syntax error'.
+   If N > 0, stands for 'shift SYMBOL and go to n'.
+   If N < 0, stands for 'reduce -N'.  */
 typedef int action_number;
 #define ACTION_NUMBER_MINIMUM INT_MIN

 static action_number *actrow;

 /* FROMS and TOS are reordered to be compressed.  ORDER[VECTOR] is the
-   new vector number of VECTOR.  We skip `empty' vectors (i.e.,
-   TALLY[VECTOR] = 0), and call these `entries'.  */
+   new vector number of VECTOR.  We skip 'empty' vectors (i.e.,
+   TALLY[VECTOR] = 0), and call these 'entries'.  */
 static vector_number *order;
 static int nentries;

@@ -105,7 +105,7 @@ uniqstr_print_processor (void *ustr, void *null ATTRIBUTE_UNUSED)


 int
-uniqstr_cmp(uniqstr l, uniqstr r)
+uniqstr_cmp (uniqstr l, uniqstr r)
 {
  return (l == r ? 0
          : !l ? -1
@@ -40,7 +40,7 @@ uniqstr uniqstr_vsprintf (char const *format, ...)

 /* Compare two uniqstr a la strcmp: negative for <, nul for =, and
   positive for >.  Undefined order, relies on addresses.  */
-int uniqstr_cmp(uniqstr u1, uniqstr u2);
+int uniqstr_cmp (uniqstr u1, uniqstr u2);

 /* Die if STR is not a uniqstr.  */
 void uniqstr_assert (char const *str);
@@ -64,6 +64,119 @@ AT_PARSER_CHECK([./input], 0,

 AT_CLEANUP

+## ----------------------- ##
+## Implicitly empty rule.  ##
+## ----------------------- ##
+
+AT_SETUP([Implicitly empty rule])
+
+AT_DATA_GRAMMAR([[1.y]],
+[[%%
+exp: a b;
+a: /* empty. */ {};
+// A mid-rule action does not count as an empty rule.
+b: {} {};
+]])
+
+AT_BISON_CHECK([-fcaret -Wempty-rule 1.y], [0], [],
+[[1.y:11.17-18: warning: empty rule without %empty [-Wempty-rule]
+ a: /* empty. */ {};
+                 ^^
+]])
+
+AT_DATA_GRAMMAR([[2.y]],
+[[%%
+exp: a b c;
+a: /* empty. */ {};
+b: %empty       {};
+c: /* empty. */ {};
+]])
+
+AT_BISON_CHECK([-fcaret 2.y], [0], [],
+[[2.y:11.17-18: warning: empty rule without %empty [-Wempty-rule]
+ a: /* empty. */ {};
+                 ^^
+2.y:13.17-18: warning: empty rule without %empty [-Wempty-rule]
+ c: /* empty. */ {};
+                 ^^
+]])
+
+AT_BISON_CHECK([-fcaret -Wno-empty-rule 2.y], [0])
+
+AT_CLEANUP
+
+## ------------------------ ##
+## Invalid uses of %empty.  ##
+## ------------------------ ##
+
+AT_SETUP([Invalid uses of %empty])
+
+AT_DATA_GRAMMAR([[one.y]],
+[[%%
+exp:
+  %empty {} %empty
+;
+]])
+
+AT_BISON_CHECK([-fcaret one.y], [1], [],
+[[one.y:11.13-18: error: only one %empty allowed per rule
+   %empty {} %empty
+             ^^^^^^
+one.y:11.3-8: previous declaration
+   %empty {} %empty
+   ^^^^^^
+]])
+
+AT_DATA_GRAMMAR([[two.y]],
+[[%%
+exp:
+  'a' %empty    {}
+| %empty 'a'    {}
+| %empty {}     {}
+;
+]])
+
+AT_BISON_CHECK([-fcaret two.y], [1], [],
+[[two.y:11.7-12: error: %empty on non-empty rule
+   'a' %empty    {}
+       ^^^^^^
+two.y:12.3-8: error: %empty on non-empty rule
+ | %empty 'a'    {}
+   ^^^^^^
+two.y:13.3-8: error: %empty on non-empty rule
+ | %empty {}     {}
+   ^^^^^^
+]])
+
+AT_CLEANUP
+
+## ---------------------- ##
+## Valid uses of %empty.  ##
+## ---------------------- ##
+
+AT_SETUP([Valid uses of %empty])
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[
+%debug
+%code
+{
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+}
+%%
+exp: %empty {}
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE[
+]AT_MAIN_DEFINE[
+]])
+
+AT_FULL_COMPILE([input])
+AT_PARSER_CHECK([./input])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP

 ## ------------------ ##
 ## Initial location.  ##
@@ -173,8 +286,8 @@ m4_popdef([AT_TEST])
 ## Location Print.  ##
 ## ---------------- ##

-# AT_TEST(SKELETON-NAME, DIRECTIVES, [MORE-DIRECTIVES], [LOCATION = 1.1])
-# -----------------------------------------------------------------------
+# AT_TEST(SKELETON-NAME, DIRECTIVES, [MORE-DIRECTIVES])
+# -----------------------------------------------------
 # Check that the initial location is correct.
 m4_pushdef([AT_TEST],
 [AT_SETUP([Location print: $1 $2])
@@ -192,7 +305,7 @@ AT_DATA_GRAMMAR([[input.y]],
 ]AT_YYLEX_DECLARE[
 }
 %%
-exp: /* empty */;
+exp: %empty;
 %%
 ]AT_YYERROR_DEFINE[
 ]AT_YYLEX_DEFINE[
@@ -415,7 +528,7 @@ AT_LALR1_CC_IF([typedef yy::location YYLTYPE;])[
 %%
 /*
   This grammar is made to exercise error recovery.
-   "Lines" starting with `(' support error recovery, with
+   "Lines" starting with '(' support error recovery, with
   ')' as synchronizing token.  Lines starting with 'x' can never
   be recovered from if in error.
 */
@@ -492,11 +605,11 @@ static
 {
  static unsigned int counter = 0;

-  int c = ]AT_VAL[]m4_ifval([$6], [.ival])[ = counter++;
+  unsigned int c = ]AT_VAL[]m4_ifval([$6], [.ival])[ = counter++;
  /* As in BASIC, line numbers go from 10 to 10.  */
  ]AT_LOC_FIRST_LINE[ = ]AT_LOC_FIRST_COLUMN[ = 10 * c;
  ]AT_LOC_LAST_LINE[ = ]AT_LOC_LAST_COLUMN[ = ]AT_LOC_FIRST_LINE[ + 9;
-  assert (0 <= c && c <= strlen (source));
+  assert (c <= strlen (source));
  if (source[c])
    fprintf (stderr, "sending: '%c'", source[c]);
  else
@@ -578,7 +691,7 @@ Successful parse.

 # Syntax errors caught by the parser
 # ----------------------------------
-# Exercise the discarding of stack top and input until `error'
+# Exercise the discarding of stack top and input until 'error'
 # can be reduced.
 #
 #     '(', 'x', 'x', 'x', 'x', 'x', ')',
@@ -735,13 +848,13 @@ AT_CLEANUP


 AT_CHECK_PRINTER_AND_DESTRUCTOR([])
-AT_CHECK_PRINTER_AND_DESTRUCTOR([], [with union])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([], [ with union])

 AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "lalr1.cc"])
-AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "lalr1.cc"], [with union])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "lalr1.cc"], [ with union])

 AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser])
-AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser], [with union])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser], [ with union])



@@ -1174,7 +1287,7 @@ AT_SETUP([Default %printer and %destructor are not for $accept])
 #   - The %printer and %destructor code generated for $accept would always be
 #     dead code because $accept is currently never shifted onto the stack.
 #   - $$ for $accept would always be of type YYSTYPE because it's not possible
-#     to declare `%type <field> $accept'.  (Also true for $undefined.)
+#     to declare '%type <field> $accept'.  (Also true for $undefined.)
 #   - Thus, the compiler might complain that the user code assumes the wrong
 #     type for $$ since the code might assume the type associated with a
 #     specific union field, which is especially reasonable in C++ since that
@@ -1494,115 +1607,6 @@ AT_TEST([glr.cc])

 m4_popdef([AT_TEST])

-## ----------------------------------------------- ##
-## Fix user actions without a trailing semicolon.  ##
-## ----------------------------------------------- ##
-
-AT_SETUP([[Fix user actions without a trailing semicolon]])
-
-# This feature is undocumented, but we accidentally broke it in 2.3a,
-# and there was a complaint at:
-# <http://lists.gnu.org/archive/html/bug-bison/2008-11/msg00001.html>.
-AT_BISON_OPTION_PUSHDEFS
-AT_DATA([input.y],
-[[%%
-start: test2 test1 test0 testc;
-
-test2
-: 'a' { semi;                   /* TEST:N:2 */ }
-| 'b' { if (0) {no_semi}        /* TEST:N:2 */ }
-| 'c' { if (0) {semi;}          /* TEST:N:2 */ }
-| 'd' { semi;   no_semi         /* TEST:Y:2 */ }
-| 'e' { semi(); no_semi()       /* TEST:Y:2 */ }
-| 'f' { semi[]; no_semi[]       /* TEST:Y:2 */ }
-| 'g' { semi++; no_semi++       /* TEST:Y:2 */ }
-| 'h' { {no_semi} no_semi       /* TEST:Y:2 */ }
-| 'i' { {semi;}   no_semi       /* TEST:Y:2 */ }
-;
-test1
-  : 'a' { semi;                 // TEST:N:1 ;
-} | 'b' { if (0) {no_semi}      // TEST:N:1 ;
-} | 'c' { if (0) {semi;}        // TEST:N:1 ;
-} | 'd' { semi;   no_semi       // TEST:Y:1 ;
-} | 'e' { semi(); no_semi()     // TEST:Y:1 ;
-} | 'f' { semi[]; no_semi[]     // TEST:Y:1 ;
-} | 'g' { semi++; no_semi++     // TEST:Y:1 ;
-} | 'h' { {no_semi} no_semi     // TEST:Y:1 ;
-} | 'i' { {semi;}   no_semi     // TEST:Y:1 ;
-} ;
-test0
-  : 'a' { semi;                 // TEST:N:1 {}
-} | 'b' { if (0) {no_semi}      // TEST:N:1 {}
-} | 'c' { if (0) {semi;}        // TEST:N:1 {}
-} | 'd' { semi;   no_semi       // TEST:Y:1 {}
-} | 'e' { semi(); no_semi()     // TEST:Y:1 {}
-} | 'f' { semi[]; no_semi[]     // TEST:Y:1 {}
-} | 'g' { semi++; no_semi++     // TEST:Y:1 {}
-} | 'h' { {no_semi} no_semi     // TEST:Y:1 {}
-} | 'i' { {semi;}   no_semi     // TEST:Y:1 {}
-} ;
-
-testc
-: 'a' {
-#define TEST_MACRO_N \
-[]"broken\" $ @ $$ @$ [];\
-string;"}
-| 'b' {
-no_semi
-#define TEST_MACRO_N \
-[]"broken\" $ @ $$ @$ [];\
-string;"}
-]])
-AT_BISON_OPTION_POPDEFS
-
-AT_BISON_CHECK([[-o input.c input.y]], [0], [],
-[[input.y:8.48: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:8.48:     future versions of Bison will not add the ';'
-input.y:9.48: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:9.48:     future versions of Bison will not add the ';'
-input.y:10.48: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:10.48:     future versions of Bison will not add the ';'
-input.y:11.48: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:11.48:     future versions of Bison will not add the ';'
-input.y:12.48: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:12.48:     future versions of Bison will not add the ';'
-input.y:13.48: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:13.48:     future versions of Bison will not add the ';'
-input.y:20.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:20.1:     future versions of Bison will not add the ';'
-input.y:21.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:21.1:     future versions of Bison will not add the ';'
-input.y:22.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:22.1:     future versions of Bison will not add the ';'
-input.y:23.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:23.1:     future versions of Bison will not add the ';'
-input.y:24.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:24.1:     future versions of Bison will not add the ';'
-input.y:25.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:25.1:     future versions of Bison will not add the ';'
-input.y:31.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:31.1:     future versions of Bison will not add the ';'
-input.y:32.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:32.1:     future versions of Bison will not add the ';'
-input.y:33.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:33.1:     future versions of Bison will not add the ';'
-input.y:34.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:34.1:     future versions of Bison will not add the ';'
-input.y:35.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:35.1:     future versions of Bison will not add the ';'
-input.y:36.1: warning: a ';' might be needed at the end of action code [-Wdeprecated]
-input.y:36.1:     future versions of Bison will not add the ';'
-]])
-
-AT_MATCHES_CHECK([input.c], [[/\* TEST:N:2 \*/ \}$]],       [[3]])
-AT_MATCHES_CHECK([input.c], [[/\* TEST:Y:2 \*/ ;\}$]],      [[6]])
-AT_MATCHES_CHECK([input.c], [[// TEST:N:1 [;{}]*\n\}$]],    [[6]])
-AT_MATCHES_CHECK([input.c], [[// TEST:Y:1 [;{}]*\n;\}$]],  [[12]])
-AT_MATCHES_CHECK([input.c], [[#define TEST_MACRO_N \\\n\[\]"broken\\" \$ \@ \$\$ \@\$ \[\];\\\nstring;"\}]], [[2]])
-
-AT_CLEANUP
-
-
 ## -------------------------------------------------- ##
 ## Destroying lookahead assigned by semantic action.  ##
 ## -------------------------------------------------- ##
@@ -1637,7 +1641,7 @@ AT_DATA_GRAMMAR([input.y],
 // that has set yychar might not always return normally.  Instead,
 // skeletons must translate before every use of yytoken.
 start: 'a' accept { USE($1); } ;
-accept: /*empty*/ {
+accept: %empty {
  assert (yychar == YYEMPTY);
  yychar = 'b';
  YYACCEPT;
@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

-# We need `config.h'.
+# We need 'config.h'.
 CPPFLAGS="-I$abs_top_builddir/lib @CPPFLAGS@"

 # Don't just check if $POSIXLY_CORRECT is set, as Bash, when launched
@@ -47,9 +47,6 @@ NO_WERROR_CXXFLAGS='@CXXFLAGS@ @WARN_CXXFLAGS@ @WARN_CXXFLAGS_TEST@'
  CFLAGS="$NO_WERROR_CFLAGS   @WERROR_CFLAGS@"
 CXXFLAGS="$NO_WERROR_CXXFLAGS @WERROR_CXXFLAGS@"

-# C++ variants break strict aliasing analysis.
-NO_STRICT_ALIAS_CXXFLAGS='@NO_STRICT_ALIAS_CXXFLAGS@'
-
 # If 'exit 77'; skip all C++ tests; otherwise ':'.
 BISON_CXX_WORKS='@BISON_CXX_WORKS@'

@@ -75,15 +72,6 @@ else
  CC_IS_CXX=0
 fi

-# In a similar way, handle --release
-if "$at_arg_release"; then
-  BISON_USE_PUSH_FOR_PULL=1
-  BISON_TEST_XML=1
-else
-  BISON_USE_PUSH_FOR_PULL=0
-  BISON_TEST_XML=0
-fi
-

 ## ------- ##
 ## Other.  ##
@@ -18,6 +18,68 @@
 AT_BANNER([[C++ Features.]])


+## --------------- ##
+## C++ Locations.  ##
+## --------------- ##
+
+AT_SETUP([C++ Locations])
+
+AT_BISON_OPTION_PUSHDEFS([%locations %skeleton "lalr1.cc"])
+AT_DATA_GRAMMAR([[input.y]],
+[[%code {#include <sstream>}
+%locations
+%debug
+%skeleton "lalr1.cc"
+%code
+{
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+}
+%%
+exp: %empty;
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE[
+
+template <typename T>
+bool
+check (const T& in, const std::string& s)
+{
+  std::stringstream os;
+  os << in;
+  if (os.str () != s)
+    {
+      std::cerr << "fail: " << os.str () << ", expected: " << s << std::endl;
+      return false;
+    }
+  return true;
+}
+
+int
+main (void)
+{
+  int fail = 0;
+  ]AT_YYLTYPE[ loc;  fail += check (loc, "1.1");
+  loc += 10;         fail += check (loc, "1.1-10");
+  loc += -5;         fail += check (loc, "1.1-5");
+  loc -= 5;          fail += check (loc, "1.1");
+  // Check that we don't go below.
+  // http://lists.gnu.org/archive/html/bug-bison/2013-02/msg00000.html
+  loc -= 10;         fail += check (loc, "1.1");
+
+  loc.columns (10); loc.lines (10); fail += check (loc, "1.1-11.0");
+  loc.lines (-2);                   fail += check (loc, "1.1-9.0");
+  loc.lines (-10);                  fail += check (loc, "1.1");
+  return !fail;
+}
+]])
+
+AT_FULL_COMPILE([input])
+AT_PARSER_CHECK([./input], 0)
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+
+
 ## --------------------------- ##
 ## C++ Variant-based Symbols.  ##
 ## --------------------------- ##
@@ -28,7 +90,7 @@ AT_KEYWORDS([variant])

 AT_BISON_OPTION_PUSHDEFS([%skeleton "lalr1.cc" %debug $1])
 # Store strings and integers in a list of strings.
-AT_DATA_GRAMMAR([list.yy],
+AT_DATA_GRAMMAR([list.y],
 [[%skeleton "lalr1.cc"
 %define api.value.type variant
 %define parse.assert
@@ -92,8 +154,7 @@ int main()
 }
 ]])

-AT_BISON_CHECK([-o list.cc list.yy])
-AT_COMPILE_CXX([list], [$NO_STRICT_ALIAS_CXXFLAGS list.cc])
+AT_FULL_COMPILE([list])
 AT_PARSER_CHECK([./list], 0, [],
 [12
 123
@@ -115,7 +176,7 @@ m4_pushdef([AT_TEST],

 AT_BISON_OPTION_PUSHDEFS([%skeleton "lalr1.cc" %debug $1])
 # Store strings and integers in a list of strings.
-AT_DATA_GRAMMAR([list.yy],
+AT_DATA_GRAMMAR([list.y],
 [[%debug
 %skeleton "lalr1.cc"
 %define api.value.type variant
@@ -250,8 +311,7 @@ namespace yy
 ]AT_MAIN_DEFINE[
 ]])

-AT_BISON_CHECK([-o list.cc list.yy])
-AT_COMPILE_CXX([list], [$NO_STRICT_ALIAS_CXXFLAGS list.cc])
+AT_FULL_COMPILE([list])
 AT_PARSER_CHECK([./list], 0,
 [(0, 1, 2, 4)
 ])
@@ -265,8 +325,8 @@ AT_TEST([%define parse.assert])
 AT_TEST([%locations %define parse.assert])
 AT_TEST([[%define parse.assert %code {\n#define TWO_STAGE_BUILD\n}]])
 AT_TEST([[%define parse.assert %define api.token.constructor]])
-AT_TEST([[%define parse.assert %define api.token.constructor %define api.token.prefix "TOK_"]])
-AT_TEST([[%locations %define parse.assert %define api.token.constructor %define api.token.prefix "TOK_"]])
+AT_TEST([[%define parse.assert %define api.token.constructor %define api.token.prefix {TOK_}]])
+AT_TEST([[%locations %define parse.assert %define api.token.constructor %define api.token.prefix {TOK_}]])

 m4_popdef([AT_TEST])

@@ -363,10 +423,10 @@ AT_CHECK_DOXYGEN([Private])
 # is specified, then Bison should accept the input, but compilation will fail,
 # so don't check compilation.
 m4_pushdef([AT_TEST],
-[AT_BISON_OPTION_PUSHDEFS([%language "C++" %define api.namespace "$1"])
+[AT_BISON_OPTION_PUSHDEFS([%language "C++" %define api.namespace {$1}])
 AT_DATA_GRAMMAR([[input.y]],
 [[%language "C++"
-%define api.namespace "]$1["
+%define api.namespace {]$1[}
 %union { int i; }
 %define global_tokens_and_yystype
 %locations
@@ -422,8 +482,8 @@ AT_CLEANUP
 AT_SETUP([[Syntactically invalid namespace references]])
 AT_TEST([[:foo:bar]], [[-]])
 AT_TEST([[foo: :bar]], [[-]])
-# This one is interesting because `[3]' is encoded as `@<:@3@:>@', which
-# contains single occurrences of `:'.
+# This one is interesting because '[3]' is encoded as '@<:@3@:>@', which
+# contains single occurrences of ':'.
 AT_TEST([[foo[3]::bar::baz]], [[-]])
 AT_TEST([[foo::bar,baz]], [[-]])
 AT_TEST([[foo::bar::(baz /* Pacify Emacs ) */]], [[-]])
@@ -615,14 +675,42 @@ $1
  /// A class that counts its number of instances.
  struct Object
  {
+    char val;
+
+    Object (char v)
+      : val (v)
+    {
+      Object::instances.push_back(this);
+      log (this, "Object::Object");
+    }
+
+    Object ()
+      : val ('?')
+    {
+      Object::instances.push_back(this);
+      log (this, "Object::Object");
+    }
+
+    Object& operator= (char v)
+    {
+      val = v;
+      return *this;
+    }
+
+    ~Object ()
+    {
+      Object::instances.remove (this);
+      log (this, "Object::~Object");
+    }
+
+    // Static part.
    typedef std::list<const Object*> objects;
    static objects instances;
-    char val;

    static bool
    empty ()
    {
-      return instances.empty();
+      return instances.empty ();
    }

    static void
@@ -645,26 +733,6 @@ $1
          std::cerr << " }" << std::endl;
        }
    }
-
-    Object (char v)
-      : val (v)
-    {
-      instances.push_back(this);
-      log (this, "Object::Object");
-    }
-
-    Object ()
-      : val ('?')
-    {
-      instances.push_back(this);
-      log (this, "Object::Object");
-    }
-
-    ~Object ()
-    {
-      instances.remove(this);
-      log (this, "Object::~Object");
-    }
  };
 }

@@ -727,11 +795,11 @@ item:
 // Not just 'E', otherwise we reduce when 'E' is the lookahead, and
 // then the stack is emptied, defeating the point of the test.
 | 'E' 'a' { YYUSE($][1); $][$ = $][2; }
-| 'R'  { $][$ = YY_NULL; ]AT_VARIANT_IF([], [delete $][1]; )[YYERROR; }
+| 'R'  { $][$ = 0; ]AT_VARIANT_IF([], [delete $][1]; )[YYERROR; }
 | 'p'  { $][$ = $][1; }
 | 's'  { $][$ = $][1; throw std::runtime_error ("reduction"); }
-| 'T'  { $][$ = YY_NULL; ]AT_VARIANT_IF([], [delete $][1]; )[YYABORT; }
-| error { $][$ = YY_NULL; yyerrok; }
+| 'T'  { $][$ = 0; ]AT_VARIANT_IF([], [delete $][1]; )[YYABORT; }
+| error { $][$ = 0; yyerrok; }
 ;
 %%

@@ -804,7 +872,7 @@ main (int argc, const char *argv[])
 }
 ]])
 AT_BISON_CHECK([[-o input.cc --report=all input.yy]])
-AT_COMPILE_CXX([input], [[$NO_STRICT_ALIAS_CXXFLAGS input.cc]])
+AT_COMPILE_CXX([[input]])

 AT_PARSER_CHECK([[./input aaaas]], [[2]], [[]],
 [[exception caught: reduction
@@ -27,11 +27,11 @@

 # _AT_DATA_CALC_Y($1, $2, $3, [BISON-DIRECTIVES])
 # -----------------------------------------------
-# Produce `calc.y' and, if %defines was specified, `calc-lex.c' or
-# `calc-lex.cc'.
+# Produce 'calc.y' and, if %defines was specified, 'calc-lex.c' or
+# 'calc-lex.cc'.
 #
 # Don't call this macro directly, because it contains some occurrences
-# of `$1' etc. which will be interpreted by m4.  So you should call it
+# of '$1' etc. which will be interpreted by m4.  So you should call it
 # with $1, $2, and $3 as arguments, which is what AT_DATA_CALC_Y does.
 #
 # When %defines is not passed, generate a single self-contained file.
@@ -72,10 +72,12 @@ main (int argc, const char **argv)
  int count = 0;
  int status;

-  /* This used to be alarm (10), but that isn't enough time for
-     a July 1995 vintage DEC Alphastation 200 4/100 system,
-     according to Nelson H. F. Beebe.  100 seconds is enough.  */
-  alarm (100);
+  /* This used to be alarm (10), but that isn't enough time for a July
+     1995 vintage DEC Alphastation 200 4/100 system, according to
+     Nelson H. F. Beebe.  100 seconds was enough for regular users,
+     but the Hydra build farm, which is heavily loaded needs more.  */
+
+  alarm (200);

  if (argc == 2)
    input = fopen (argv[1], "r");
@@ -88,8 +90,7 @@ main (int argc, const char **argv)
      return 3;
    }

-]AT_SKEL_CC_IF([], [m4_bmatch([$4], [%debug],
-[  ]AT_NAME_PREFIX[debug = 1;])])[
+]AT_SKEL_CC_IF([], [AT_DEBUG_IF([  ]AT_NAME_PREFIX[debug = 1;])])[
  status = ]AT_NAME_PREFIX[parse (]AT_PARAM_IF([[&result, &count]])[);
  if (fclose (input))
    perror ("fclose");
@@ -133,7 +134,7 @@ unget_char (]AT_YYLEX_PRE_FORMALS[ int c)
 {
  ]AT_USE_LEX_ARGS[;
 ]AT_LOCATION_IF([
-  /* Wrong when C == `\n'. */
+  /* Wrong when C == '\n'. */
  AT_LOC = last_yylloc;
 ])[
  ungetc (c, input);
@@ -365,8 +366,8 @@ m4_popdef([AT_CALC_LEX])

 # AT_DATA_CALC_Y([BISON-OPTIONS])
 # -------------------------------
-# Produce `calc.y' and, if %defines was specified, `calc-lex.c' or
-# `calc-lex.cc'.
+# Produce 'calc.y' and, if %defines was specified, 'calc-lex.c' or
+# 'calc-lex.cc'.
 m4_define([AT_DATA_CALC_Y],
 [_AT_DATA_CALC_Y($[1], $[2], $[3], [$1])
 ])
@@ -375,9 +376,9 @@ m4_define([AT_DATA_CALC_Y],

 # _AT_CHECK_CALC(BISON-OPTIONS, INPUT, [NUM-STDERR-LINES])
 # --------------------------------------------------------
-# Run `calc' on INPUT and expect no STDOUT nor STDERR.
+# Run 'calc' on INPUT and expect no STDOUT nor STDERR.
 #
-# If BISON-OPTIONS contains `%debug' but not `%glr-parser', then
+# If BISON-OPTIONS contains '%debug' but not '%glr-parser', then
 #
 # NUM-STDERR-LINES is the number of expected lines on stderr.
 # Currently this is ignored, though, since the output format is fluctuating.
@@ -396,7 +397,7 @@ AT_PARSER_CHECK([./calc input], 0, [], [stderr])
 #                      [NUM-STDERR-LINES],
 #                      [VERBOSE-AND-LOCATED-ERROR-MESSAGE])
 # ---------------------------------------------------------
-# Run `calc' on INPUT, and expect a `syntax error' message.
+# Run 'calc' on INPUT, and expect a 'syntax error' message.
 #
 # If INPUT starts with a slash, it is used as absolute input file name,
 # otherwise as contents.
@@ -404,14 +405,14 @@ AT_PARSER_CHECK([./calc input], 0, [], [stderr])
 # NUM-STDERR-LINES is the number of expected lines on stderr.
 # Currently this is ignored, though, since the output format is fluctuating.
 #
-# If BISON-OPTIONS contains `%location', then make sure the ERROR-LOCATION
+# If BISON-OPTIONS contains '%location', then make sure the ERROR-LOCATION
 # is correctly output on stderr.
 #
-# If BISON-OPTIONS contains `%define parse.error verbose', then make sure the
-# IF-YYERROR-VERBOSE message is properly output after `syntax error, '
+# If BISON-OPTIONS contains '%define parse.error verbose', then make sure the
+# IF-YYERROR-VERBOSE message is properly output after 'syntax error, '
 # on STDERR.
 #
-# If BISON-OPTIONS contains `%debug' but not `%glr', then NUM-STDERR-LINES
+# If BISON-OPTIONS contains '%debug' but not '%glr', then NUM-STDERR-LINES
 # is the number of expected lines on stderr.
 m4_define([_AT_CHECK_CALC_ERROR],
 [m4_bmatch([$3], [^/],
@@ -448,7 +449,7 @@ AT_DATA([[expout]],
 AT_YYERROR_SEES_LOC_IF([],
 [[sed 's/^[-0-9.]*: //' expout >at-expout
 mv at-expout expout]])
-# 4. If error-verbose is not used, strip the`, unexpected....' part.
+# 4. If error-verbose is not used, strip the', unexpected....' part.
 m4_bmatch([$1], [%define parse.error verbose], [],
 [[sed 's/syntax error, .*$/syntax error/' expout >at-expout
 mv at-expout expout]])
@@ -478,7 +479,7 @@ m4_define([AT_CHECK_SPACES],

 # AT_CHECK_CALC([BISON-OPTIONS])
 # ------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # BISON-OPTIONS, and performs several tests over the parser.
 m4_define([AT_CHECK_CALC],
 [m4_ifval([$2], [m4_fatal([$0: expected a single argument])])
@@ -538,7 +539,7 @@ _AT_CHECK_CALC_ERROR([$1], [1], [/dev/null], [4],
 #   - (* * *): nothing to pop, a lot to discard
 #   - (1 + 2 * *): some to pop and discard
 #
-# - test the action associated to `error'
+# - test the action associated to 'error'
 #
 # - check the lookahead that triggers an error is not discarded
 #   when we enter error recovery.  Below, the lookahead causing the
@@ -587,7 +588,7 @@ AT_BANNER([[Simple LALR(1) Calculator.]])

 # AT_CHECK_CALC_LALR([BISON-OPTIONS])
 # -----------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # BISON-OPTIONS, and performs several tests over the parser.
 m4_define([AT_CHECK_CALC_LALR],
 [AT_CHECK_CALC($@)])
@@ -606,17 +607,17 @@ AT_CHECK_CALC_LALR([%define api.pure full %locations])
 AT_CHECK_CALC_LALR([%define api.push-pull both %define api.pure full %locations])
 AT_CHECK_CALC_LALR([%define parse.error verbose %locations])

-AT_CHECK_CALC_LALR([%define parse.error verbose %locations %defines %define api.prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%define parse.error verbose %locations %defines %name-prefix "calc" %define api.token.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define parse.error verbose %locations %defines %define api.prefix {calc} %verbose %yacc])
+AT_CHECK_CALC_LALR([%define parse.error verbose %locations %defines %name-prefix "calc" %define api.token.prefix {TOK_} %verbose %yacc])

 AT_CHECK_CALC_LALR([%debug])
 AT_CHECK_CALC_LALR([%define parse.error verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%define parse.error verbose %debug %locations %defines %define api.prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define parse.error verbose %debug %locations %defines %define api.prefix {calc} %verbose %yacc])

 AT_CHECK_CALC_LALR([%define api.pure full %define parse.error verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%define api.push-pull both %define api.pure full %define parse.error verbose %debug %locations %defines %define api.prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define api.push-pull both %define api.pure full %define parse.error verbose %debug %locations %defines %define api.prefix {calc} %verbose %yacc])

-AT_CHECK_CALC_LALR([%define api.pure %define parse.error verbose %debug %locations %defines %define api.prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_LALR([%define api.pure %define parse.error verbose %debug %locations %defines %define api.prefix {calc} %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])


 # ----------------------- #
@@ -627,7 +628,7 @@ AT_BANNER([[Simple GLR Calculator.]])

 # AT_CHECK_CALC_GLR([BISON-OPTIONS])
 # ----------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # BISON-OPTIONS and %glr-parser, and performs several tests over the parser.
 m4_define([AT_CHECK_CALC_GLR],
 [AT_CHECK_CALC([%glr-parser] $@)])
@@ -638,7 +639,7 @@ AT_CHECK_CALC_GLR()
 AT_CHECK_CALC_GLR([%defines])
 AT_CHECK_CALC_GLR([%locations])
 AT_CHECK_CALC_GLR([%name-prefix "calc"])
-AT_CHECK_CALC_GLR([%define api.prefix "calc"])
+AT_CHECK_CALC_GLR([%define api.prefix {calc}])
 AT_CHECK_CALC_GLR([%verbose])
 AT_CHECK_CALC_GLR([%yacc])
 AT_CHECK_CALC_GLR([%define parse.error verbose])
@@ -650,12 +651,12 @@ AT_CHECK_CALC_GLR([%define parse.error verbose %locations %defines %name-prefix

 AT_CHECK_CALC_GLR([%debug])
 AT_CHECK_CALC_GLR([%define parse.error verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_GLR([%define parse.error verbose %debug %locations %defines %define api.prefix "calc" %define api.token.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_GLR([%define parse.error verbose %debug %locations %defines %define api.prefix {calc} %define api.token.prefix {TOK_} %verbose %yacc])

 AT_CHECK_CALC_GLR([%define api.pure %define parse.error verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])

 AT_CHECK_CALC_GLR([%define api.pure %define parse.error verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
-AT_CHECK_CALC_GLR([%define api.pure %define parse.error verbose %debug %locations %defines %define api.prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_GLR([%define api.pure %define parse.error verbose %debug %locations %defines %define api.prefix {calc} %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])


 # ----------------------------- #
@@ -669,26 +670,26 @@ AT_CHECK_CALC([%skeleton "lalr1.cc" %defines])

 # AT_CHECK_CALC_LALR1_CC([BISON-OPTIONS])
 # ---------------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # the C++ skeleton, and performs several tests over the parser.
 m4_define([AT_CHECK_CALC_LALR1_CC],
 [AT_CHECK_CALC([%language "C++"] $@)])

 AT_CHECK_CALC_LALR1_CC([])
 AT_CHECK_CALC_LALR1_CC([%locations])
-AT_CHECK_CALC_LALR1_CC([%locations %define api.location.type Span])
+AT_CHECK_CALC_LALR1_CC([%locations %define api.location.type {Span}])
 AT_CHECK_CALC_LALR1_CC([%defines %locations %define parse.error verbose %name-prefix "calc" %verbose %yacc])

-AT_CHECK_CALC_LALR1_CC([%locations %define parse.error verbose %define api.prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %define parse.error verbose %define api.prefix {calc} %verbose %yacc])
 AT_CHECK_CALC_LALR1_CC([%locations %define parse.error verbose %debug %name-prefix "calc" %verbose %yacc])

-AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %define parse.error verbose %debug %define api.prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %define parse.error verbose %debug %define api.prefix "calc" %define api.token.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %define parse.error verbose %debug %define api.prefix {calc} %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %define parse.error verbose %debug %define api.prefix {calc} %define api.token.prefix {TOK_} %verbose %yacc])

-AT_CHECK_CALC_LALR1_CC([%defines %locations %pure-parser %define parse.error verbose %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_LALR1_CC([%defines %locations %define parse.error verbose %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])

-AT_CHECK_CALC_LALR1_CC([%pure-parser %define parse.error verbose %debug %define api.prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
-AT_CHECK_CALC_LALR1_CC([%defines %locations %pure-parser %define parse.error verbose %debug %define api.prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_LALR1_CC([%define parse.error verbose %debug %define api.prefix {calc} %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_LALR1_CC([%defines %locations %define parse.error verbose %debug %define api.prefix {calc} %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])



@@ -703,22 +704,21 @@ AT_CHECK_CALC([%skeleton "glr.cc"])

 # AT_CHECK_CALC_GLR_CC([BISON-OPTIONS])
 # -------------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # the GLR C++ skeleton, and performs several tests over the parser.
 m4_define([AT_CHECK_CALC_GLR_CC],
 [AT_CHECK_CALC([%language "C++" %glr-parser] $@)])

 AT_CHECK_CALC_GLR_CC([])
 AT_CHECK_CALC_GLR_CC([%locations])
-AT_CHECK_CALC_GLR_CC([%locations %define api.location.type Span])
+AT_CHECK_CALC_GLR_CC([%locations %define api.location.type {Span}])
 AT_CHECK_CALC_GLR_CC([%defines %define parse.error verbose %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_GLR_CC([%define parse.error verbose %define api.prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR_CC([%define parse.error verbose %define api.prefix {calc} %verbose %yacc])

 AT_CHECK_CALC_GLR_CC([%debug])
+
 AT_CHECK_CALC_GLR_CC([%define parse.error verbose %debug %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR_CC([%define parse.error verbose %debug %name-prefix "calc" %define api.token.prefix {TOK_} %verbose %yacc])

-AT_CHECK_CALC_GLR_CC([%pure-parser %define parse.error verbose %debug %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_GLR_CC([%pure-parser %define parse.error verbose %debug %name-prefix "calc" %define api.token.prefix "TOK_" %verbose %yacc])
-
-AT_CHECK_CALC_GLR_CC([%locations %defines %pure-parser %define parse.error verbose %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
-AT_CHECK_CALC_GLR_CC([%locations %defines %pure-parser %define parse.error verbose %debug %define api.prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_GLR_CC([%locations %defines %define parse.error verbose %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_GLR_CC([%locations %defines %define parse.error verbose %debug %define api.prefix {calc} %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
@@ -17,42 +17,9 @@

 AT_BANNER([[Conflicts.]])

-## ------------------------------ ##
-## Useless associativity warning. ##
-## ------------------------------ ##
-
-AT_SETUP([Useless associativity warning])
-
-AT_DATA([[input.y]],
-[[%token T
-%left A B
-%right C
-%nonassoc D
-%precedence E
-
-%%
-e: T A T
- | T B T
- | T C T
- | T D T
- | T E T
-;
-]])
-
-AT_BISON_CHECK([input.y], 0, [],
-[[input.y:5.13: warning: useless precedence for E [-Wother]
-input.y:2.7: warning: useless associativity for A [-Wother]
-input.y:2.9: warning: useless associativity for B [-Wother]
-input.y:3.8: warning: useless associativity for C [-Wother]
-input.y:4.11: warning: useless associativity for D [-Wother]
-]])
-
-AT_CLEANUP
-
-
-## ------------------------ ##
-## Token declaration order. ##
-## ------------------------ ##
+## ------------------------- ##
+## Token declaration order.  ##
+## ------------------------- ##

 # This test checks that token are declared left to right when in a precedence
 # statement.
@@ -110,27 +77,7 @@ int main (void)
 }
 ]])

-AT_BISON_CHECK([-o input.c input.y], [], [],
-[[input.y:24.13: warning: useless precedence for R [-Wother]
-input.y:24.15: warning: useless precedence for S [-Wother]
-input.y:24.17: warning: useless precedence for T [-Wother]
-input.y:24.19: warning: useless precedence for U [-Wother]
-input.y:25.13: warning: useless precedence for V [-Wother]
-input.y:25.15: warning: useless precedence for W [-Wother]
-input.y:18.8: warning: useless associativity for E [-Wother]
-input.y:18.10: warning: useless associativity for F [-Wother]
-input.y:18.12: warning: useless associativity for G [-Wother]
-input.y:19.8: warning: useless associativity for H [-Wother]
-input.y:19.10: warning: useless associativity for I [-Wother]
-input.y:20.8: warning: useless associativity for J [-Wother]
-input.y:21.8: warning: useless associativity for K [-Wother]
-input.y:22.8: warning: useless associativity for L [-Wother]
-input.y:22.10: warning: useless associativity for M [-Wother]
-input.y:22.12: warning: useless associativity for N [-Wother]
-input.y:23.11: warning: useless associativity for O [-Wother]
-input.y:23.13: warning: useless associativity for P [-Wother]
-input.y:23.15: warning: useless associativity for Q [-Wother]
-]])
+AT_BISON_CHECK([-o input.c input.y])
 AT_COMPILE([input])

 AT_PARSER_CHECK([./input])
@@ -140,6 +87,127 @@ AT_BISON_OPTION_POPDEFS
 AT_CLEANUP


+## --------------------------------------------------- ##
+## Token declaration order: literals vs. identifiers.  ##
+## --------------------------------------------------- ##
+
+# This test checks that when several tokens are declared by the same keyword,
+# some of them defined as a character ('a'), others as simple textual reference
+# (A), they are declared correctly left to right.
+# Previously, the following test would declare the states in the order 'o' 'p'
+# M N, instead of M N 'o' 'p'.
+
+AT_SETUP([Token declaration order: literals vs. identifiers])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%token 'a' 'b' C D
+%token E F 'g' 'h'
+%right 'i' 'j' K L
+%right M N 'o' 'p'
+%%
+exp: 'a'
+   | 'b'
+   | C
+   | D
+   | E
+   | F
+   | 'g'
+   | 'h'
+   | 'i'
+   | 'j'
+   | K
+   | L
+   | M
+   | N
+   | 'o'
+   | 'p'
+;
+%%
+]])
+
+AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
+AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
+[[State 0
+
+    0 $accept: . exp $end
+    1 exp: . 'a'
+    2    | . 'b'
+    3    | . C
+    4    | . D
+    5    | . E
+    6    | . F
+    7    | . 'g'
+    8    | . 'h'
+    9    | . 'i'
+   10    | . 'j'
+   11    | . K
+   12    | . L
+   13    | . M
+   14    | . N
+   15    | . 'o'
+   16    | . 'p'
+
+    'a'  shift, and go to state 1
+    'b'  shift, and go to state 2
+    C    shift, and go to state 3
+    D    shift, and go to state 4
+    E    shift, and go to state 5
+    F    shift, and go to state 6
+    'g'  shift, and go to state 7
+    'h'  shift, and go to state 8
+    'i'  shift, and go to state 9
+    'j'  shift, and go to state 10
+    K    shift, and go to state 11
+    L    shift, and go to state 12
+    M    shift, and go to state 13
+    N    shift, and go to state 14
+    'o'  shift, and go to state 15
+    'p'  shift, and go to state 16
+
+    exp  go to state 17
+
+
+State 1
+]])
+
+AT_CLEANUP
+
+
+## ------------------------------- ##
+## Useless associativity warning.  ##
+## ------------------------------- ##
+
+AT_SETUP([Useless associativity warning])
+
+AT_DATA([[input.y]],
+[[%token EQ "=" PL "+" ST "*"  LP "("
+%nonassoc "="
+%left "+"
+%left "*"
+%precedence "("
+%%
+stmt:
+  exp
+| "var" "=" exp
+;
+
+exp:
+  exp "+" exp
+| exp "*" "num"
+| "(" exp ")"
+| "num"
+;
+]])
+
+AT_BISON_CHECK([-Wprecedence input.y], 0, [],
+[[input.y:2.1-9: warning: useless precedence and associativity for "=" [-Wprecedence]
+input.y:4.1-5: warning: useless associativity for "*", use %precedence [-Wprecedence]
+input.y:5.1-11: warning: useless precedence for "(" [-Wprecedence]
+]])
+
+AT_CLEANUP
+
+
 ## ---------------------------- ##
 ## Useless precedence warning.  ##
 ## ---------------------------- ##
@@ -147,7 +215,7 @@ AT_CLEANUP
 AT_SETUP([Useless precedence warning])

 AT_DATA([[input.y]],
-[[%token A B
+[[%token A B U V W X Y Z
 %precedence Z
 %left X
 %precedence Y
@@ -174,19 +242,19 @@ f: B
 ;
 ]])

-AT_BISON_CHECK([-fcaret -o input.c input.y], 0, [],
-[[input.y:2.13: warning: useless precedence for Z [-Wother]
- %precedence Z
-             ^
-input.y:5.7: warning: useless associativity for W [-Wother]
- %left W
-       ^
-input.y:6.8: warning: useless associativity for V [-Wother]
- %right V
-        ^
-input.y:7.11: warning: useless associativity for U [-Wother]
+AT_BISON_CHECK([-Wprecedence -fcaret -o input.c input.y], 0, [],
+[[input.y:7.1-9: warning: useless precedence and associativity for U [-Wprecedence]
 %nonassoc U
-           ^
+ ^^^^^^^^^
+input.y:6.1-6: warning: useless precedence and associativity for V [-Wprecedence]
+ %right V
+ ^^^^^^
+input.y:5.1-5: warning: useless precedence and associativity for W [-Wprecedence]
+ %left W
+ ^^^^^
+input.y:2.1-11: warning: useless precedence for Z [-Wprecedence]
+ %precedence Z
+ ^^^^^^^^^^^
 ]])

 AT_CLEANUP
@@ -211,7 +279,7 @@ e: 'e' | /* Nothing. */;
 ]])

 AT_BISON_CHECK([-o input.c input.y], 0, [],
-[[input.y:4.9: warning: rule useless in parser due to conflicts: e: /* empty */ [-Wother]
+[[input.y:4.9: warning: rule useless in parser due to conflicts [-Wother]
 ]])

 AT_BISON_CHECK([-fcaret -o input.c input.y], 0, [],
@@ -939,7 +1007,7 @@ cond:

 AT_BISON_CHECK([-o input.c input.y], 0, [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
-input.y:12.3-18: warning: rule useless in parser due to conflicts: cond: cond "then" cond [-Wother]
+input.y:12.3-18: warning: rule useless in parser due to conflicts [-Wother]
 ]])

 AT_CLEANUP
@@ -955,13 +1023,13 @@ AT_CLEANUP
 #    $end           reduce using rule 3 (num)
 #    $end           [reduce using rule 4 (id)]
 #
-# But when `reduce 3' is the default action, we'd produce:
+# But when 'reduce 3' is the default action, we'd produce:
 #
 #    $end           [reduce using rule 4 (id)]
 #    $default    reduce using rule 3 (num)
 #
 # In this precise case (a reduction is masked by the default
-# reduction), we make the `reduce 3' explicit:
+# reduction), we make the 'reduce 3' explicit:
 #
 #    $end           reduce using rule 3 (num)
 #    $end           [reduce using rule 4 (id)]
@@ -983,7 +1051,7 @@ id : '0';

 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 [[input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
-input.y:4.6-8: warning: rule useless in parser due to conflicts: id: '0' [-Wother]
+input.y:4.6-8: warning: rule useless in parser due to conflicts [-Wother]
 ]])

 # Check the contents of the report.
@@ -1196,10 +1264,10 @@ e:   e '+' e
   ;
 ]])

-AT_BISON_CHECK([-o input.c input.y], 0, [],
+AT_BISON_CHECK([-Wall -o input.c input.y], 0, [],
 [[input.y: warning: 4 shift/reduce conflicts [-Wconflicts-sr]
-input.y:1.7-9: warning: useless associativity for '+' [-Wother]
-input.y:2.7-9: warning: useless associativity for '*' [-Wother]
+input.y:1.1-5: warning: useless precedence and associativity for '+' [-Wprecedence]
+input.y:2.1-5: warning: useless precedence and associativity for '*' [-Wprecedence]
 ]])
 AT_CLEANUP

@@ -1303,13 +1371,13 @@ reported_conflicts:
 AT_BISON_CHECK([[--report=all input.y]], 0, [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
-input.y:12.5-20: warning: rule useless in parser due to conflicts: resolved_conflict: 'a' unreachable1 [-Wother]
-input.y:20.5-20: warning: rule useless in parser due to conflicts: unreachable1: 'a' unreachable2 [-Wother]
-input.y:21.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */ [-Wother]
-input.y:25.13: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
-input.y:25.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
-input.y:31.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a' [-Wother]
-input.y:32.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */ [-Wother]
+input.y:12.5-20: warning: rule useless in parser due to conflicts [-Wother]
+input.y:20.5-20: warning: rule useless in parser due to conflicts [-Wother]
+input.y:21.4: warning: rule useless in parser due to conflicts [-Wother]
+input.y:25.13: warning: rule useless in parser due to conflicts [-Wother]
+input.y:25.16: warning: rule useless in parser due to conflicts [-Wother]
+input.y:31.5-7: warning: rule useless in parser due to conflicts [-Wother]
+input.y:32.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])

 AT_CHECK([[cat input.output]], 0,
@@ -1318,13 +1386,13 @@ AT_CHECK([[cat input.output]], 0,
    2 resolved_conflict: 'a' unreachable1

    4 unreachable1: 'a' unreachable2
-    5             | /* empty */
+    5             | %empty

-    6 unreachable2: /* empty */
-    7             | /* empty */
+    6 unreachable2: %empty
+    7             | %empty

    9 reported_conflicts: 'a'
-   10                   | /* empty */
+   10                   | %empty


 State 4 conflicts: 1 shift/reduce
@@ -1338,17 +1406,17 @@ Grammar
    1 start: resolved_conflict 'a' reported_conflicts 'a'

    2 resolved_conflict: 'a' unreachable1
-    3                  | /* empty */
+    3                  | %empty

    4 unreachable1: 'a' unreachable2
-    5             | /* empty */
+    5             | %empty

-    6 unreachable2: /* empty */
-    7             | /* empty */
+    6 unreachable2: %empty
+    7             | %empty

    8 reported_conflicts: 'a'
    9                   | 'a'
-   10                   | /* empty */
+   10                   | %empty


 Terminals, with rules where they appear
@@ -1456,10 +1524,10 @@ AT_CHECK([[cat input.y >> input-keep.y]])
 AT_BISON_CHECK([[input-keep.y]], 0, [],
 [[input-keep.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
 input-keep.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
-input-keep.y:22.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */ [-Wother]
-input-keep.y:26.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
-input-keep.y:32.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a' [-Wother]
-input-keep.y:33.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */ [-Wother]
+input-keep.y:22.4: warning: rule useless in parser due to conflicts [-Wother]
+input-keep.y:26.16: warning: rule useless in parser due to conflicts [-Wother]
+input-keep.y:32.5-7: warning: rule useless in parser due to conflicts [-Wother]
+input-keep.y:33.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])

 AT_CLEANUP
@@ -1639,7 +1707,7 @@ exp: 'a' | 'a';
 AT_BISON_CHECK([[2.y]], [[0]], [],
 [[2.y: warning: %expect-rr applies only to GLR parsers [-Wother]
 2.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
-2.y:3.12-14: warning: rule useless in parser due to conflicts: exp: 'a' [-Wother]
+2.y:3.12-14: warning: rule useless in parser due to conflicts [-Wother]
 ]])

 AT_CLEANUP
@@ -403,68 +403,60 @@ dnl parses it as:
 dnl
 dnl   getline $!(4*0);
 dnl
-dnl That is, they shift `*' immediately and make it part of the getline
+dnl That is, they shift '*' immediately and make it part of the getline
 dnl argument.
 dnl
 dnl The grammar below using LALR(1) parses it as a syntax error.  So does
 dnl GNU AWK 3.0.6, 3.1.0, and 3.1.1.  They reduce the full getline expression
-dnl before shifting `*' even though `*' is not a valid lookahead.
+dnl before shifting '*' even though '*' is not a valid lookahead.
 dnl
 dnl GNU AWK 3.1.2, 3.1.3, 3.1.4, and 3.1.5 parse it as:
 dnl
 dnl   (getline $!4)*0;
 dnl
 dnl That is, like the other versions of GNU AWK, they reduce the full getline
-dnl expression before shifting `*'.  However, because of a different LHS on the
-dnl getline rule, `*' actually is a valid lookahead.  Solaris /usr/xpg4/bin/awk
+dnl expression before shifting '*'.  However, because of a different LHS on the
+dnl getline rule, '*' actually is a valid lookahead.  Solaris /usr/xpg4/bin/awk
 dnl and the Open Group awk specification seem to agree:
 dnl
 dnl   http://www.opengroup.org/pubs/online/7908799/xcu/awk.html
 dnl
 dnl /bin/nawk and /bin/awk on Solaris 10 report it as a syntax error, but they
-dnl don't like even `print $!4;'.
+dnl don't like even 'print $!4;'.
 [[LEX_GETLINE, '$', '!', YNUMBER, '*', YNUMBER, ';']],

 dnl BISON-STDERR
-[AT_COND_CASE([[canonical LR]],
-[[input.y: warning: 265 shift/reduce conflicts [-Wconflicts-sr]
-input.y:19.8-16: warning: useless associativity for FUNC_CALL [-Wother]
-input.y:21.8-14: warning: useless associativity for YNUMBER [-Wother]
-input.y:21.16-22: warning: useless associativity for YSTRING [-Wother]
-input.y:22.14-22: warning: useless associativity for APPEND_OP [-Wother]
-input.y:23.8-15: warning: useless associativity for ASSIGNOP [-Wother]
-input.y:23.33-41: warning: useless associativity for CONCAT_OP [-Wother]
-input.y:27.8-18: warning: useless associativity for LEX_GETLINE [-Wother]
-input.y:28.8-13: warning: useless associativity for LEX_IN [-Wother]
-input.y:29.23-31: warning: useless associativity for INCREMENT [-Wother]
-input.y:29.33-41: warning: useless associativity for DECREMENT [-Wother]
-input.y:30.8-18: warning: useless associativity for LEX_BUILTIN [-Wother]
-input.y:30.20-29: warning: useless associativity for LEX_LENGTH [-Wother]
-input.y:40.11-13: warning: useless associativity for ',' [-Wother]
-input.y:47.8-10: warning: useless associativity for '!' [-Wother]
-input.y:47.12-16: warning: useless associativity for UNARY [-Wother]
-input.y:50.7-9: warning: useless associativity for '$' [-Wother]
-input.y:51.7-9: warning: useless associativity for '(' [-Wother]
-input.y:51.11-13: warning: useless associativity for ')' [-Wother]]],
-[[input.y: warning: 65 shift/reduce conflicts [-Wconflicts-sr]
-input.y:19.8-16: warning: useless associativity for FUNC_CALL [-Wother]
-input.y:21.8-14: warning: useless associativity for YNUMBER [-Wother]
-input.y:21.16-22: warning: useless associativity for YSTRING [-Wother]
-input.y:22.14-22: warning: useless associativity for APPEND_OP [-Wother]
-input.y:23.8-15: warning: useless associativity for ASSIGNOP [-Wother]
-input.y:23.33-41: warning: useless associativity for CONCAT_OP [-Wother]
-input.y:27.8-18: warning: useless associativity for LEX_GETLINE [-Wother]
-input.y:28.8-13: warning: useless associativity for LEX_IN [-Wother]
-input.y:29.23-31: warning: useless associativity for INCREMENT [-Wother]
-input.y:29.33-41: warning: useless associativity for DECREMENT [-Wother]
-input.y:30.8-18: warning: useless associativity for LEX_BUILTIN [-Wother]
-input.y:30.20-29: warning: useless associativity for LEX_LENGTH [-Wother]
-input.y:40.11-13: warning: useless associativity for ',' [-Wother]
-input.y:47.8-10: warning: useless associativity for '!' [-Wother]
-input.y:47.12-16: warning: useless associativity for UNARY [-Wother]
-input.y:50.7-9: warning: useless associativity for '$' [-Wother]
-input.y:51.7-9: warning: useless associativity for '(' [-Wother]
-input.y:51.11-13: warning: useless associativity for ')' [-Wother]]])[
+[[input.y:66.10: warning: empty rule without %empty [-Wempty-rule]
+input.y:169.8: warning: empty rule without %empty [-Wempty-rule]
+input.y:174.12: warning: empty rule without %empty [-Wempty-rule]
+input.y:179.13: warning: empty rule without %empty [-Wempty-rule]
+input.y:187.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:201.8: warning: empty rule without %empty [-Wempty-rule]
+input.y:206.21: warning: empty rule without %empty [-Wempty-rule]
+input.y:220.20: warning: empty rule without %empty [-Wempty-rule]
+input.y:299.13: warning: empty rule without %empty [-Wempty-rule]
+input.y:322.9: warning: empty rule without %empty [-Wempty-rule]
+]AT_COND_CASE([[canonical LR]],
+[[input.y: warning: 265 shift/reduce conflicts [-Wconflicts-sr]]],
+[[input.y: warning: 65 shift/reduce conflicts [-Wconflicts-sr]]])[
+input.y:39.1-5: warning: useless associativity for FUNC_CALL, use %precedence [-Wprecedence]
+input.y:44.1-5: warning: useless associativity for YNUMBER, use %precedence [-Wprecedence]
+input.y:44.1-5: warning: useless associativity for YSTRING, use %precedence [-Wprecedence]
+input.y:42.1-9: warning: useless precedence and associativity for APPEND_OP [-Wprecedence]
+input.y:33.1-6: warning: useless associativity for ASSIGNOP, use %precedence [-Wprecedence]
+input.y:43.1-5: warning: useless associativity for CONCAT_OP, use %precedence [-Wprecedence]
+input.y:37.1-5: warning: useless precedence and associativity for LEX_GETLINE [-Wprecedence]
+input.y:38.1-9: warning: useless associativity for LEX_IN, use %precedence [-Wprecedence]
+input.y:49.1-5: warning: useless associativity for INCREMENT, use %precedence [-Wprecedence]
+input.y:49.1-5: warning: useless associativity for DECREMENT, use %precedence [-Wprecedence]
+input.y:39.1-5: warning: useless associativity for LEX_BUILTIN, use %precedence [-Wprecedence]
+input.y:39.1-5: warning: useless associativity for LEX_LENGTH, use %precedence [-Wprecedence]
+input.y:40.1-9: warning: useless precedence and associativity for ',' [-Wprecedence]
+input.y:47.1-6: warning: useless associativity for '!', use %precedence [-Wprecedence]
+input.y:47.1-6: warning: useless associativity for UNARY, use %precedence [-Wprecedence]
+input.y:50.1-5: warning: useless associativity for '$', use %precedence [-Wprecedence]
+input.y:51.1-5: warning: useless associativity for '(', use %precedence [-Wprecedence]
+input.y:51.1-5: warning: useless precedence and associativity for ')' [-Wprecedence]
 ]],

 dnl LAST-STATE
@@ -1403,23 +1395,39 @@ dnl INPUT
 [[]],

 dnl BISON-STDERR
-[AT_COND_CASE([[canonical LR]],
+[[input.y:128.12: warning: empty rule without %empty [-Wempty-rule]
+input.y:137.10: warning: empty rule without %empty [-Wempty-rule]
+input.y:142.8: warning: empty rule without %empty [-Wempty-rule]
+input.y:161.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:179.17: warning: empty rule without %empty [-Wempty-rule]
+input.y:205.16: warning: empty rule without %empty [-Wempty-rule]
+input.y:213.9: warning: empty rule without %empty [-Wempty-rule]
+input.y:225.6: warning: empty rule without %empty [-Wempty-rule]
+input.y:292.18: warning: empty rule without %empty [-Wempty-rule]
+input.y:294.19: warning: empty rule without %empty [-Wempty-rule]
+input.y:367.16: warning: empty rule without %empty [-Wempty-rule]
+input.y:373.11: warning: empty rule without %empty [-Wempty-rule]
+input.y:387.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:401.18: warning: empty rule without %empty [-Wempty-rule]
+input.y:413.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:443.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:471.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:474.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:489.15: warning: empty rule without %empty [-Wempty-rule]
+input.y:506.14: warning: empty rule without %empty [-Wempty-rule]
+input.y:587.9: warning: empty rule without %empty [-Wempty-rule]
+input.y:591.14: warning: empty rule without %empty [-Wempty-rule]
+]AT_COND_CASE([[canonical LR]],
 [[input.y: warning: 1876 shift/reduce conflicts [-Wconflicts-sr]
-input.y: warning: 144 reduce/reduce conflicts [-Wconflicts-rr]
-input.y:32.9-12: warning: useless associativity for HQUA [-Wother]
-input.y:53.8-14: warning: useless associativity for HASSIGN [-Wother]
-input.y:54.9-15: warning: useless associativity for HORELSE [-Wother]
-input.y:55.9-16: warning: useless associativity for HANDTHEN [-Wother]
-input.y:61.9-12: warning: useless associativity for HNOT [-Wother]
-input.y:68.7-11: warning: useless associativity for UNEAR [-Wother]]],
+input.y: warning: 144 reduce/reduce conflicts [-Wconflicts-rr]]],
 [[input.y: warning: 78 shift/reduce conflicts [-Wconflicts-sr]
-input.y: warning: 10 reduce/reduce conflicts [-Wconflicts-rr]
-input.y:32.9-12: warning: useless associativity for HQUA [-Wother]
-input.y:53.8-14: warning: useless associativity for HASSIGN [-Wother]
-input.y:54.9-15: warning: useless associativity for HORELSE [-Wother]
-input.y:55.9-16: warning: useless associativity for HANDTHEN [-Wother]
-input.y:61.9-12: warning: useless associativity for HNOT [-Wother]
-input.y:68.7-11: warning: useless associativity for UNEAR [-Wother]]])[
+input.y: warning: 10 reduce/reduce conflicts [-Wconflicts-rr]]])[
+input.y:72.1-5: warning: useless associativity for HQUA, use %precedence [-Wprecedence]
+input.y:53.1-6: warning: useless associativity for HASSIGN, use %precedence [-Wprecedence]
+input.y:54.1-5: warning: useless associativity for HORELSE, use %precedence [-Wprecedence]
+input.y:55.1-5: warning: useless associativity for HANDTHEN, use %precedence [-Wprecedence]
+input.y:61.1-5: warning: useless associativity for HNOT, use %precedence [-Wprecedence]
+input.y:68.1-5: warning: useless associativity for UNEAR, use %precedence [-Wprecedence]
 ]],

 dnl LAST-STATE
@@ -1585,7 +1593,7 @@ box "foo" above ljust == box ("foo" above ljust)

 %left LEFT RIGHT
 /* Give attributes that take an optional expression a higher
-precedence than left and right, so that eg `line chop left'
+precedence than left and right, so that eg 'line chop left'
 parses properly. */
 %left CHOP SOLID DASHED DOTTED UP DOWN FILL COLORED OUTLINED
 %left LABEL
@@ -1598,7 +1606,7 @@ parses properly. */
 /* these need to be lower than '-' */
 %left HEIGHT RADIUS WIDTH DIAMETER FROM TO AT THICKNESS

-/* these must have higher precedence than CHOP so that `label %prec CHOP'
+/* these must have higher precedence than CHOP so that 'label %prec CHOP'
 works */
 %left DOT_N DOT_E DOT_W DOT_S DOT_NE DOT_SE DOT_NW DOT_SW DOT_C
 %left DOT_START DOT_END TOP BOTTOM LEFT_CORNER RIGHT_CORNER
@@ -2001,88 +2009,93 @@ dnl without being followed by "of".)
 [[VARIABLE, '=', LABEL, LEFT, DOT_X]],

 dnl BISON-STDERR
-[[input.y:471.11-48: warning: rule useless in parser due to conflicts: path: ORDINAL LAST object_type relative_path [-Wother]
-input.y:19.8-12: warning: useless associativity for LABEL [-Wother]
-input.y:20.8-15: warning: useless associativity for VARIABLE [-Wother]
-input.y:21.8-13: warning: useless associativity for NUMBER [-Wother]
-input.y:22.8-11: warning: useless associativity for TEXT [-Wother]
-input.y:25.8-14: warning: useless associativity for ORDINAL [-Wother]
-input.y:30.8-11: warning: useless associativity for LAST [-Wother]
-input.y:31.8-9: warning: useless associativity for UP [-Wother]
-input.y:32.8-11: warning: useless associativity for DOWN [-Wother]
-input.y:35.8-10: warning: useless associativity for BOX [-Wother]
-input.y:36.8-13: warning: useless associativity for CIRCLE [-Wother]
-input.y:37.8-14: warning: useless associativity for ELLIPSE [-Wother]
-input.y:38.8-10: warning: useless associativity for ARC [-Wother]
-input.y:39.8-11: warning: useless associativity for LINE [-Wother]
-input.y:40.8-12: warning: useless associativity for ARROW [-Wother]
-input.y:42.8-13: warning: useless associativity for SPLINE [-Wother]
-input.y:43.8-13: warning: useless associativity for HEIGHT [-Wother]
-input.y:44.8-13: warning: useless associativity for RADIUS [-Wother]
-input.y:45.8-12: warning: useless associativity for WIDTH [-Wother]
-input.y:46.8-15: warning: useless associativity for DIAMETER [-Wother]
-input.y:47.8-11: warning: useless associativity for FROM [-Wother]
-input.y:48.8-9: warning: useless associativity for TO [-Wother]
-input.y:49.8-9: warning: useless associativity for AT [-Wother]
-input.y:53.8-12: warning: useless associativity for SOLID [-Wother]
-input.y:54.8-13: warning: useless associativity for DOTTED [-Wother]
-input.y:55.8-13: warning: useless associativity for DASHED [-Wother]
-input.y:56.8-11: warning: useless associativity for CHOP [-Wother]
-input.y:59.8-12: warning: useless associativity for LJUST [-Wother]
-input.y:60.8-12: warning: useless associativity for RJUST [-Wother]
-input.y:61.8-12: warning: useless associativity for ABOVE [-Wother]
-input.y:62.8-12: warning: useless associativity for BELOW [-Wother]
-input.y:63.8-9: warning: useless associativity for OF [-Wother]
-input.y:66.8-14: warning: useless associativity for BETWEEN [-Wother]
-input.y:67.8-10: warning: useless associativity for AND [-Wother]
-input.y:68.8-11: warning: useless associativity for HERE [-Wother]
-input.y:69.8-12: warning: useless associativity for DOT_N [-Wother]
-input.y:70.8-12: warning: useless associativity for DOT_E [-Wother]
-input.y:71.8-12: warning: useless associativity for DOT_W [-Wother]
-input.y:72.8-12: warning: useless associativity for DOT_S [-Wother]
-input.y:73.8-13: warning: useless associativity for DOT_NE [-Wother]
-input.y:74.8-13: warning: useless associativity for DOT_SE [-Wother]
-input.y:75.8-13: warning: useless associativity for DOT_NW [-Wother]
-input.y:76.8-13: warning: useless associativity for DOT_SW [-Wother]
-input.y:77.8-12: warning: useless associativity for DOT_C [-Wother]
-input.y:78.8-16: warning: useless associativity for DOT_START [-Wother]
-input.y:79.8-14: warning: useless associativity for DOT_END [-Wother]
-input.y:85.8-10: warning: useless associativity for SIN [-Wother]
-input.y:86.8-10: warning: useless associativity for COS [-Wother]
-input.y:87.8-12: warning: useless associativity for ATAN2 [-Wother]
-input.y:88.8-10: warning: useless associativity for LOG [-Wother]
-input.y:89.8-10: warning: useless associativity for EXP [-Wother]
-input.y:90.8-11: warning: useless associativity for SQRT [-Wother]
-input.y:91.8-12: warning: useless associativity for K_MAX [-Wother]
-input.y:92.8-12: warning: useless associativity for K_MIN [-Wother]
-input.y:93.8-10: warning: useless associativity for INT [-Wother]
-input.y:94.8-11: warning: useless associativity for RAND [-Wother]
-input.y:95.8-12: warning: useless associativity for SRAND [-Wother]
-input.y:98.8-10: warning: useless associativity for TOP [-Wother]
-input.y:99.8-13: warning: useless associativity for BOTTOM [-Wother]
-input.y:100.8-12: warning: useless associativity for UPPER [-Wother]
-input.y:101.8-12: warning: useless associativity for LOWER [-Wother]
-input.y:116.8-18: warning: useless associativity for LEFT_CORNER [-Wother]
-input.y:117.8-19: warning: useless associativity for RIGHT_CORNER [-Wother]
-input.y:118.8-12: warning: useless associativity for NORTH [-Wother]
-input.y:119.8-12: warning: useless associativity for SOUTH [-Wother]
-input.y:120.8-11: warning: useless associativity for EAST [-Wother]
-input.y:121.8-11: warning: useless associativity for WEST [-Wother]
-input.y:122.8-13: warning: useless associativity for CENTER [-Wother]
-input.y:123.8-10: warning: useless associativity for END [-Wother]
-input.y:124.8-12: warning: useless associativity for START [-Wother]
-input.y:127.8-11: warning: useless associativity for PLOT [-Wother]
-input.y:128.8-16: warning: useless associativity for THICKNESS [-Wother]
-input.y:129.8-11: warning: useless associativity for FILL [-Wother]
-input.y:130.8-14: warning: useless associativity for COLORED [-Wother]
-input.y:131.8-15: warning: useless associativity for OUTLINED [-Wother]
-input.y:134.8-14: warning: useless associativity for SPRINTF [-Wother]
-input.y:137.7-9: warning: useless associativity for '.' [-Wother]
-input.y:156.23-25: warning: useless associativity for '(' [-Wother]
-input.y:157.20-22: warning: useless associativity for '`' [-Wother]
-input.y:159.48-50: warning: useless associativity for '@<:@' [-Wother]
-input.y:170.7-9: warning: useless associativity for ',' [-Wother]
-input.y:181.8-10: warning: useless associativity for '!' [-Wother]
+[[input.y:202.19: warning: empty rule without %empty [-Wempty-rule]
+input.y:270.6: warning: empty rule without %empty [-Wempty-rule]
+input.y:292.12: warning: empty rule without %empty [-Wempty-rule]
+input.y:309.17: warning: empty rule without %empty [-Wempty-rule]
+input.y:382.13: warning: empty rule without %empty [-Wempty-rule]
+input.y:471.11-48: warning: rule useless in parser due to conflicts [-Wother]
+input.y:154.1-5: warning: useless associativity for LABEL, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for VARIABLE, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for NUMBER, use %precedence [-Wprecedence]
+input.y:141.1-5: warning: useless associativity for TEXT, use %precedence [-Wprecedence]
+input.y:157.1-5: warning: useless associativity for ORDINAL, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for LAST, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless associativity for UP, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless associativity for DOWN, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for BOX, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for CIRCLE, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for ELLIPSE, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for ARC, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for LINE, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for ARROW, use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for SPLINE, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for HEIGHT, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for RADIUS, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for WIDTH, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for DIAMETER, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for FROM, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for TO, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for AT, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless precedence and associativity for SOLID [-Wprecedence]
+input.y:153.1-5: warning: useless associativity for DOTTED, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless associativity for DASHED, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless associativity for CHOP, use %precedence [-Wprecedence]
+input.y:147.1-5: warning: useless precedence and associativity for LJUST [-Wprecedence]
+input.y:147.1-5: warning: useless precedence and associativity for RJUST [-Wprecedence]
+input.y:147.1-5: warning: useless precedence and associativity for ABOVE [-Wprecedence]
+input.y:147.1-5: warning: useless precedence and associativity for BELOW [-Wprecedence]
+input.y:176.1-5: warning: useless associativity for OF, use %precedence [-Wprecedence]
+input.y:176.1-5: warning: useless associativity for BETWEEN, use %precedence [-Wprecedence]
+input.y:177.1-5: warning: useless associativity for AND, use %precedence [-Wprecedence]
+input.y:157.1-5: warning: useless associativity for HERE, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_N, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_E, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_W, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_S, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_NE, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_SE, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_NW, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_SW, use %precedence [-Wprecedence]
+input.y:166.1-5: warning: useless associativity for DOT_C, use %precedence [-Wprecedence]
+input.y:167.1-5: warning: useless associativity for DOT_START, use %precedence [-Wprecedence]
+input.y:167.1-5: warning: useless associativity for DOT_END, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for SIN, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for COS, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for ATAN2, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for LOG, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for EXP, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for SQRT, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for K_MAX, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for K_MIN, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for INT, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for RAND, use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for SRAND, use %precedence [-Wprecedence]
+input.y:167.1-5: warning: useless associativity for TOP, use %precedence [-Wprecedence]
+input.y:167.1-5: warning: useless associativity for BOTTOM, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for UPPER, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for LOWER, use %precedence [-Wprecedence]
+input.y:167.1-5: warning: useless associativity for LEFT_CORNER, use %precedence [-Wprecedence]
+input.y:167.1-5: warning: useless associativity for RIGHT_CORNER, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for NORTH, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for SOUTH, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for EAST, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for WEST, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for CENTER, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for END, use %precedence [-Wprecedence]
+input.y:168.1-5: warning: useless associativity for START, use %precedence [-Wprecedence]
+input.y:140.1-5: warning: useless associativity for PLOT, use %precedence [-Wprecedence]
+input.y:162.1-5: warning: useless associativity for THICKNESS, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless associativity for FILL, use %precedence [-Wprecedence]
+input.y:153.1-5: warning: useless precedence and associativity for COLORED [-Wprecedence]
+input.y:153.1-5: warning: useless precedence and associativity for OUTLINED [-Wprecedence]
+input.y:141.1-5: warning: useless associativity for SPRINTF, use %precedence [-Wprecedence]
+input.y:137.1-5: warning: useless associativity for '.', use %precedence [-Wprecedence]
+input.y:156.1-5: warning: useless associativity for '(', use %precedence [-Wprecedence]
+input.y:157.1-5: warning: useless associativity for '`', use %precedence [-Wprecedence]
+input.y:159.1-5: warning: useless associativity for '@<:@', use %precedence [-Wprecedence]
+input.y:170.1-5: warning: useless associativity for ',', use %precedence [-Wprecedence]
+input.y:181.1-6: warning: useless associativity for '!', use %precedence [-Wprecedence]
 ]],

 dnl LAST-STATE
@@ -486,8 +486,8 @@ start:
   ;

 %%
-]AT_YYLEX_DEFINE(["a"])[
 ]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(["a"])[
 ]AT_MAIN_DEFINE[
 ]])
 AT_BISON_OPTION_POPDEFS
@@ -1015,17 +1015,17 @@ main (void)
  int exit_status = yyparse ();
  if (parent_rhs_before_value)
    {
-      fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+      fprintf (stderr, "'parent_rhs_before' destructor not called.\n");
      exit_status = 1;
    }
  if (merged_value)
    {
-      fprintf (stderr, "`merged' destructor not called.\n");
+      fprintf (stderr, "'merged' destructor not called.\n");
      exit_status = 1;
    }
  if (parent_rhs_after_value)
    {
-      fprintf (stderr, "`PARENT_RHS_AFTER' destructor not called.\n");
+      fprintf (stderr, "'PARENT_RHS_AFTER' destructor not called.\n");
      exit_status = 1;
    }
  return exit_status;
@@ -1449,7 +1449,7 @@ main (void)
  int exit_status = yyparse () != 1;
  if (parent_rhs_before_value)
    {
-      fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+      fprintf (stderr, "'parent_rhs_before' destructor not called.\n");
      exit_status = 1;
    }
  return exit_status;
@@ -1679,8 +1679,8 @@ start:
 b: 'b';
 d: /* nada.  */;
 %%
-]AT_YYLEX_DEFINE(["abc"])[
 ]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(["abc"])[
 ]AT_MAIN_DEFINE[
 ]])
 AT_BISON_OPTION_POPDEFS
@@ -117,9 +117,9 @@ AT_SETUP([Several parsers])
 # nor yy* identifiers in the header.  Check that headers are
 # self-contained, and can be compiled by a C++ compiler.
 m4_pushdef([AT_TEST],
-[AT_BISON_OPTION_PUSHDEFS([%define api.prefix "$1_" $2])
+[AT_BISON_OPTION_PUSHDEFS([%define api.prefix {$1_} $2])
 AT_DATA_GRAMMAR([$1.y],
-[[%define api.prefix "$1_"
+[[%define api.prefix {$1_}
 $2
 %error-verbose
 %union
@@ -20,6 +20,29 @@ AT_BANNER([[Input Processing.]])
 # Mostly test that we are robust to mistakes.


+## ----------------- ##
+## Invalid options.  ##
+## ----------------- ##
+
+AT_SETUP([Invalid options])
+
+AT_DATA([input.y],
+[[%%
+exp: '0'
+]])
+
+# We used to accept these, as -f, --report and others were sharing
+# their code with -W.
+AT_BISON_CHECK([-ferror=caret input.y], [1], [], [ignore])
+AT_BISON_CHECK([--report=error=itemsets input.y], [1], [], [ignore])
+
+# We used to accept any character after "-Werror", instead of ensuring
+# this is "=".
+AT_BISON_CHECK([-Werror?all input.y], [1], [], [ignore])
+
+AT_CLEANUP
+
+
 ## ---------------- ##
 ## Invalid inputs.  ##
 ## ---------------- ##
@@ -85,17 +108,17 @@ AT_SETUP([Invalid $n and @n])

 AT_DATA([input.y],
 [[%%
-exp: { $$ = $1 ; };
-exp: { @$ = @1 ; };
+exp: %empty { $$ = $1 ; };
+exp: %empty { @$ = @1 ; };
 ]])

 AT_BISON_CHECK([-fcaret input.y], [1], [],
-[[input.y:2.13-14: error: integer out of range: '$1'
- exp: { $$ = $1 ; };
-             ^^
-input.y:3.13-14: error: integer out of range: '@1'
- exp: { @$ = @1 ; };
-             ^^
+[[input.y:2.20-21: error: integer out of range: '$1'
+ exp: %empty { $$ = $1 ; };
+                    ^^
+input.y:3.20-21: error: integer out of range: '@1'
+ exp: %empty { @$ = @1 ; };
+                    ^^
 ]])

 AT_CLEANUP
@@ -114,7 +137,7 @@ AT_DATA([input.y],
 %%
 exp: foo { $$; } foo { $2; } foo
   | foo
-   | /* empty. */
+   | %empty
   ;
 ]])

@@ -131,9 +154,9 @@ input.y:5.6-32: warning: type clash on default action: <bar> != <> [-Wother]
 input.y:6.6-8: warning: type clash on default action: <bar> != <> [-Wother]
    | foo
      ^^^
-input.y:7.5: warning: empty rule for typed nonterminal, and no action [-Wother]
-    | /* empty. */
-     ^
+input.y:7.6-11: warning: empty rule for typed nonterminal, and no action [-Wother]
+    | %empty
+      ^^^^^^
 ]])

 AT_CLEANUP
@@ -169,7 +192,7 @@ start:
 ;

 a: INT | INT { } INT { } INT { };
-b: INT | /* empty */;
+b: INT | %empty;
 c: INT | INT { $]1[; } INT { $<integer>2; } INT { $<integer>4; };
 d: INT | INT { } INT { $]1[; } INT { $<integer>2; };
 e: INT | INT { } INT {  } INT { $]1[; };
@@ -197,9 +220,9 @@ input.y:11.18-20: warning: unused value: $][3 [-Wother]
 input.y:11.26-28: warning: unused value: $][5 [-Wother]
 a: INT | INT { } INT { } INT { };
                          ^^^
-input.y:12.9: warning: empty rule for typed nonterminal, and no action [-Wother]
- b: INT | /* empty */;
-         ^
+input.y:12.10-15: warning: empty rule for typed nonterminal, and no action [-Wother]
+ b: INT | %empty;
+          ^^^^^^
 ]]m4_ifval($2, [[[input.y:13.14-20: warning: unset value: $][$ [-Wmidrule-values]
 c: INT | INT { $][1; } INT { $<integer>2; } INT { $<integer>4; };
              ^^^^^^^
@@ -313,104 +336,67 @@ AT_CLEANUP

 AT_SETUP([Default %printer and %destructor redeclared])

-AT_DATA([[input.y]],
-[[%destructor { destroy ($$); } <*> <*>
-%printer { print ($$); } <*> <*>
+# AT_TEST([*])
+# ------------
+m4_pushdef([AT_TEST],
+[AT_DATA([[input.y]],
+[[%destructor { destroy ($$); } <$1> <$1>
+%printer { print ($$); } <$1> <$1>

-%destructor { destroy ($$); } <*>
-%printer { print ($$); } <*>
-
-%destructor { destroy ($$); } <> <>
-%printer { print ($$); } <> <>
-
-%destructor { destroy ($$); } <>
-%printer { print ($$); } <>
+%destructor { destroy ($$); } <$1>
+%printer { print ($$); } <$1>

 %%

-start: ;
+start: %empty;

-%destructor { destroy ($$); } <*>;
-%printer { print ($$); } <*>;
-
-%destructor { destroy ($$); } <>;
-%printer { print ($$); } <>;
+%destructor { destroy ($$); } <$1>;
+%printer { print ($$); } <$1>;
 ]])

 AT_BISON_CHECK([-fcaret input.y], [1], [],
-[[input.y:1.13-29: error: %destructor redeclaration for <*>
- %destructor { destroy ($$); } <*> <*>
-             ^^^^^^^^^^^^^^^^^
-input.y:1.13-29:     previous declaration
- %destructor { destroy ($$); } <*> <*>
-             ^^^^^^^^^^^^^^^^^
-input.y:2.10-24: error: %printer redeclaration for <*>
- %printer { print ($$); } <*> <*>
-          ^^^^^^^^^^^^^^^
-input.y:2.10-24:     previous declaration
- %printer { print ($$); } <*> <*>
-          ^^^^^^^^^^^^^^^
-input.y:4.13-29: error: %destructor redeclaration for <*>
- %destructor { destroy ($$); } <*>
-             ^^^^^^^^^^^^^^^^^
-input.y:1.13-29:     previous declaration
- %destructor { destroy ($$); } <*> <*>
-             ^^^^^^^^^^^^^^^^^
-input.y:5.10-24: error: %printer redeclaration for <*>
- %printer { print ($$); } <*>
-          ^^^^^^^^^^^^^^^
-input.y:2.10-24:     previous declaration
- %printer { print ($$); } <*> <*>
-          ^^^^^^^^^^^^^^^
-input.y:7.13-29: error: %destructor redeclaration for <>
+[[input.y:1.13-29: error: %destructor redeclaration for <>
 %destructor { destroy ($$); } <> <>
             ^^^^^^^^^^^^^^^^^
-input.y:7.13-29:     previous declaration
+input.y:1.13-29:     previous declaration
 %destructor { destroy ($$); } <> <>
             ^^^^^^^^^^^^^^^^^
-input.y:8.10-24: error: %printer redeclaration for <>
+input.y:2.10-24: error: %printer redeclaration for <>
 %printer { print ($$); } <> <>
          ^^^^^^^^^^^^^^^
-input.y:8.10-24:     previous declaration
+input.y:2.10-24:     previous declaration
 %printer { print ($$); } <> <>
          ^^^^^^^^^^^^^^^
-input.y:10.13-29: error: %destructor redeclaration for <>
+input.y:4.13-29: error: %destructor redeclaration for <>
 %destructor { destroy ($$); } <>
             ^^^^^^^^^^^^^^^^^
-input.y:7.13-29:      previous declaration
+input.y:1.13-29:     previous declaration
 %destructor { destroy ($$); } <> <>
             ^^^^^^^^^^^^^^^^^
-input.y:11.10-24: error: %printer redeclaration for <>
+input.y:5.10-24: error: %printer redeclaration for <>
 %printer { print ($$); } <>
          ^^^^^^^^^^^^^^^
-input.y:8.10-24:      previous declaration
+input.y:2.10-24:     previous declaration
 %printer { print ($$); } <> <>
          ^^^^^^^^^^^^^^^
-input.y:17.13-29: error: %destructor redeclaration for <*>
- %destructor { destroy ($$); } <*>;
-             ^^^^^^^^^^^^^^^^^
-input.y:4.13-29:      previous declaration
- %destructor { destroy ($$); } <*>
-             ^^^^^^^^^^^^^^^^^
-input.y:18.10-24: error: %printer redeclaration for <*>
- %printer { print ($$); } <*>;
-          ^^^^^^^^^^^^^^^
-input.y:5.10-24:      previous declaration
- %printer { print ($$); } <*>
-          ^^^^^^^^^^^^^^^
-input.y:20.13-29: error: %destructor redeclaration for <>
+input.y:11.13-29: error: %destructor redeclaration for <>
 %destructor { destroy ($$); } <>;
             ^^^^^^^^^^^^^^^^^
-input.y:10.13-29:     previous declaration
- %destructor { destroy ($$); } <>
+input.y:1.13-29:      previous declaration
+ %destructor { destroy ($$); } <> <>
             ^^^^^^^^^^^^^^^^^
-input.y:21.10-24: error: %printer redeclaration for <>
+input.y:12.10-24: error: %printer redeclaration for <>
 %printer { print ($$); } <>;
          ^^^^^^^^^^^^^^^
-input.y:11.10-24:     previous declaration
- %printer { print ($$); } <>
+input.y:2.10-24:      previous declaration
+ %printer { print ($$); } <> <>
          ^^^^^^^^^^^^^^^
 ]])
+])
+
+AT_TEST([], [], [])
+AT_TEST([], [*], [*])
+m4_popdef([AT_TEST])

 AT_CLEANUP

@@ -430,7 +416,7 @@ AT_DATA([[input.y]],

 %%

-start: ;
+start: %empty;

 %destructor { destroy ($$); } <field2> <field1>;
 %printer { print ($$); } <field2> <field1>;
@@ -440,17 +426,17 @@ AT_BISON_CHECK([input.y], [1], [],
 [[input.y:4.13-29: error: %destructor redeclaration for <field1>
 input.y:1.13-29:     previous declaration
 input.y:4.13-29: error: %destructor redeclaration for <field1>
-input.y:4.13-29:     previous declaration
+input.y:1.13-29:     previous declaration
 input.y:5.10-24: error: %printer redeclaration for <field2>
 input.y:2.10-24:     previous declaration
 input.y:5.10-24: error: %printer redeclaration for <field2>
-input.y:5.10-24:     previous declaration
+input.y:2.10-24:     previous declaration
 input.y:11.13-29: error: %destructor redeclaration for <field2>
 input.y:1.13-29:      previous declaration
 input.y:11.13-29: error: %destructor redeclaration for <field1>
-input.y:4.13-29:      previous declaration
+input.y:1.13-29:      previous declaration
 input.y:12.10-24: error: %printer redeclaration for <field2>
-input.y:5.10-24:      previous declaration
+input.y:2.10-24:      previous declaration
 input.y:12.10-24: error: %printer redeclaration for <field1>
 input.y:2.10-24:      previous declaration
 ]])
@@ -826,7 +812,7 @@ exp: '@<:@' '\1' two '$' '@' '{' oline output.or.oline.opt

 two: '\x000000000000000000000000000000000000000000000000000000000000000000002';
 oline: '@' 'o' 'l' 'i' 'n' 'e' '@' '_' '_' 'o' 'l' 'i' 'n' 'e' '_' '_';
-output.or.oline.opt: ;|oline;;|output;;;
+output.or.oline.opt: %empty;|oline;;|output;;;
 output: '#' 'o' 'u' 't' 'p' 'u' 't' ' ';
 %%
 /* Exercise M4 quoting: '@:>@@:>@', @<:@, 2.  */
@@ -908,7 +894,7 @@ m4_define([AT_CHECK_REQUIRE],
 AT_DATA_GRAMMAR([input.y],
 [[%require "$1";
 %%
-empty_file: /* empty */;
+empty_file: %empty;
 ]])
 AT_BISON_CHECK([-o input.c input.y], $2, [], ignore)
 AT_CLEANUP
@@ -1066,7 +1052,7 @@ AT_DATA([input.y],

 %%

-start: ;
+start: %empty;

 // Used to report a syntax error because it didn't see any kind of symbol
 // identifier.
@@ -1111,7 +1097,7 @@ AT_SETUP([%start after first rule])

 AT_DATA([input.y],
 [[%%
-false_start: ;
+false_start: %empty;
 start: false_start ;
 %start start;
 ]])
@@ -1132,7 +1118,7 @@ AT_SETUP([%prec takes a token])
 AT_DATA([input.y],
 [[%%
 start: PREC %prec PREC ;
-PREC: ;
+PREC: %empty;
 ]])

 AT_BISON_CHECK([input.y], [1], [],
@@ -1174,7 +1160,7 @@ AT_DATA([input-c.y],
 %code bad {}
 %code format {}
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[input-c.y]], [[1]], [],
 [[input-c.y:1.7: error: %code qualifier 'q' is not used
@@ -1188,7 +1174,7 @@ AT_DATA([input-c-glr.y],
 %code bad {}
 %code bad {}
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[input-c-glr.y]], [[1]], [],
 [[input-c-glr.y:1.7: error: %code qualifier 'q' is not used
@@ -1201,7 +1187,7 @@ AT_DATA([input-c++.y],
 %code bad {}
 %code q {}
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[input-c++.y]], [[1]], [],
 [[input-c++.y:1.7: error: %code qualifier 'q' is not used
@@ -1214,7 +1200,7 @@ AT_DATA([input-c++-glr.y],
 %code q {}
 %code q {}
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[input-c++-glr.y]], [[1]], [],
 [[input-c++-glr.y:1.7-9: error: %code qualifier 'bad' is not used
@@ -1227,7 +1213,7 @@ AT_DATA([special-char-@@.y],
 %code q {}
 %code q {}
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[special-char-@@.y]], [[1]], [],
 [[special-char-@@.y:1.7-9: error: %code qualifier 'bad' is not used
@@ -1240,7 +1226,7 @@ AT_DATA([special-char-@:>@.y],
 %code q {}
 %code q {}
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[special-char-@:>@.y]], [[1]], [],
 [[special-char-@:>@.y:1.7-9: error: %code qualifier 'bad' is not used
@@ -1251,6 +1237,45 @@ special-char-@:>@.y:3.7: error: %code qualifier 'q' is not used
 AT_CLEANUP


+## ---------------- ##
+## Multiple %code.  ##
+## ---------------- ##
+
+AT_SETUP([Multiple %code])
+
+# Make sure that repeated arguments to %code are separated by
+# end-of-lines.  At some point, a missing eol would leave synclines
+# appended to the previous value.  Here, we use CPP directive to
+# introduce dependency on the absence/presence of the eol.
+AT_BISON_OPTION_PUSHDEFS
+
+AT_DATA([input.y],
+[[%code {#include <assert.h>}
+%code {#define A B}
+%code {#define B C}
+%code {#define C D}
+%code {#define D 42}
+%code {
+  ]AT_YYERROR_DECLARE[
+  ]AT_YYLEX_DECLARE[
+}
+%%
+start: %empty;
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE[
+int main (void)
+{
+  assert (A == 42);
+  return 0;
+}
+]])
+AT_FULL_COMPILE([input])
+AT_PARSER_CHECK([./input])
+
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP()
+
 ## ---------------- ##
 ## %define errors.  ##
 ## ---------------- ##
@@ -1264,7 +1289,7 @@ AT_DATA([input-redefined.y],
 %define special1 "@:>@"
 %define special2 "@<:@"
 %%
-start: ;
+start: %empty;
 ]])

 AT_BISON_CHECK([[input-redefined.y]], [[1]], [],
@@ -1277,7 +1302,7 @@ input-redefined.y:2.9-11:      previous definition
 AT_DATA([input-unused.y],
 [[%define var "value"
 %%
-start: ;
+start: %empty;
 ]])

 AT_BISON_CHECK([[input-unused.y]], [[1]], [],
@@ -1305,7 +1330,7 @@ m4@&t@_divert_pop(0)
 AT_DATA([[input.y]],
 [[%define var-dfg "gram"
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-Dvar-dd=cmd-d1 -Dvar-dd=cmd-d2 \
                 -Fvar-ff=cmd-f1 -Fvar-ff=cmd-f2 \
@@ -1322,7 +1347,7 @@ var-fd: cmd-d
 AT_DATA([[input-dg.y]],
 [[%define var "gram"
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-Dvar=cmd-d input-dg.y]], [[1]], [],
 [[input-dg.y:1.9-11: error: %define variable 'var' redefined
@@ -1332,7 +1357,7 @@ AT_BISON_CHECK([[-Dvar=cmd-d input-dg.y]], [[1]], [],
 AT_DATA([[input-dg.y]],
 [[%define var "gram"
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-fcaret -Dvar=cmd-d input-dg.y]], [[1]], [],
 [[input-dg.y:1.9-11: error: %define variable 'var' redefined
@@ -1343,7 +1368,7 @@ AT_BISON_CHECK([[-fcaret -Dvar=cmd-d input-dg.y]], [[1]], [],

 AT_DATA([[input-unused.y]],
 [[%%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-Dunused-d -Funused-f input-unused.y]], [[1]], [],
 [[<command line>:2: error: %define variable 'unused-d' is not used
@@ -1360,10 +1385,10 @@ AT_SETUP([["%define" Boolean variables]])

 AT_DATA([Input.y],
 [[%language "Java"
-%define public "maybe"
-%define parser_class_name "Input"
+%define public maybe
+%define parser_class_name {Input}
 %%
-start: ;
+start: %empty;
 ]])

 AT_BISON_CHECK([[Input.y]], [1], [],
@@ -1372,6 +1397,72 @@ AT_BISON_CHECK([[Input.y]], [1], [],

 AT_CLEANUP

+## ------------------------ ##
+## %define code variables.  ##
+## ------------------------ ##
+
+AT_SETUP([["%define" code variables]])
+
+m4_pushdef([AT_TEST],
+[AT_DATA([input.yy],
+[[%skeleton "lalr1.cc" %locations
+%define api.location.type ]$1[quux]$2[
+%define api.namespace     ]$1[quux]$2[
+%define api.prefix        ]$1[quux]$2[
+%define api.token.prefix  ]$1[quux]$2[
+%token TOK // Otherwise api.token.prefix is unused.
+%%
+start: TOK;
+]])
+
+AT_BISON_CHECK([[input.yy]], [0], [],
+[[input.yy:2.9-25: warning: %define variable 'api.location.type' requires '{...}' values [-Wdeprecated]
+input.yy:4.9-18: warning: %define variable 'api.prefix' requires '{...}' values [-Wdeprecated]
+input.yy:5.9-24: warning: %define variable 'api.token.prefix' requires '{...}' values [-Wdeprecated]
+input.yy:3.9-21: warning: %define variable 'api.namespace' requires '{...}' values [-Wdeprecated]
+]])
+])
+
+AT_TEST([],  [])
+AT_TEST(["], ["])
+m4_popdef([AT_TEST])
+
+AT_CLEANUP
+
+
+## --------------------------- ##
+## %define keyword variables.  ##
+## --------------------------- ##
+
+AT_SETUP([["%define" keyword variables]])
+
+m4_pushdef([AT_TEST],
+[AT_DATA([input.y],
+[[%define api.pure                ]$1[true]$2[
+%define api.push-pull             ]$1[both]$2[
+%define lr.default-reduction      ]$1[most]$2[
+%define lr.keep-unreachable-state ]$1[true]$2[
+%define lr.type                   ]$1[lalr]$2[
+%%
+exp: %empty
+]])
+
+AT_BISON_CHECK([[input.y]], [0], [],
+[[input.y:5.9-15: warning: %define variable 'lr.type' requires keyword values [-Wdeprecated]
+input.y:3.9-28: warning: %define variable 'lr.default-reduction' requires keyword values [-Wdeprecated]
+input.y:4.9-33: warning: %define variable 'lr.keep-unreachable-state' requires keyword values [-Wdeprecated]
+input.y:2.9-21: warning: %define variable 'api.push-pull' requires keyword values [-Wdeprecated]
+input.y:1.9-16: warning: %define variable 'api.pure' requires keyword values [-Wdeprecated]
+]])
+])
+
+AT_TEST(["], ["])
+AT_TEST([{], [}])
+m4_popdef([AT_TEST])
+
+AT_CLEANUP
+
+
 ## ------------------------ ##
 ## %define enum variables.  ##
 ## ------------------------ ##
@@ -1386,7 +1477,7 @@ AT_SETUP([["%define" enum variables]])
 AT_DATA([[input.y]],
 [[%define lr.default-reduction bogus
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-fcaret input.y]], [[1]], [[]],
 [[input.y:1.9-28: error: invalid value for %define variable 'lr.default-reduction': 'bogus'
@@ -1401,7 +1492,7 @@ input.y:1.9-28:     accepted value: 'accepting'
 AT_DATA([[input.y]],
 [[%define api.push-pull neither
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-fcaret input.y]], [[1]], [[]],
 [[input.y:1.9-21: error: invalid value for %define variable 'api.push-pull': 'neither'
@@ -1425,10 +1516,10 @@ AT_DATA([[input.y]],
 [[%define api.push_pull both
 %define lr.keep_unreachable_states maybe
 %define namespace "foo"
-%define api.namespace "foo"
+%define api.namespace {foo}
 %define variant
 %%
-start: ;
+start: %empty;
 ]])
 AT_BISON_CHECK([[-fcaret input.y]], [1], [],
 [[input.y:1.9-21: warning: deprecated directive, use '%define api.push-pull both' [-Wdeprecated]
@@ -1441,7 +1532,7 @@ input.y:3.9-17: warning: deprecated directive, use '%define api.namespace foo' [
 %define namespace "foo"
         ^^^^^^^^^
 input.y:4.9-21: error: %define variable 'api.namespace' redefined
- %define api.namespace "foo"
+ %define api.namespace {foo}
         ^^^^^^^^^^^^^
 input.y:3.9-17:     previous definition
 %define namespace "foo"
@@ -1461,7 +1552,7 @@ AT_SETUP([[Unused %define api.pure]])

 # AT_CHECK_API_PURE(DECLS, VALUE)
 # -------------------------------
-# Make sure Bison reports that `%define api.pure VALUE' is unused when DECLS
+# Make sure Bison reports that '%define api.pure VALUE' is unused when DECLS
 # are specified.
 m4_define([AT_CHECK_API_PURE],
 [
@@ -1469,7 +1560,7 @@ AT_DATA([[input.y]],
 [[%define api.pure ]$2[
 ]$1[
 %%
-start: ;
+start: %empty;
 ]])

 AT_BISON_CHECK([[input.y]], [[1]], [],
@@ -1500,9 +1591,9 @@ m4_define([AT_CHECK_NAMESPACE_ERROR],
 AT_DATA([[input.y]],
 [[%language "C++"
 %defines
-%define api.namespace "]$1["
+%define api.namespace {]$1[}
 %%
-start: ;
+start: %empty;
 ]])

 AT_BISON_CHECK([[input.y]], [1], [],
@@ -1662,7 +1753,7 @@ AT_SETUP([[LAC: Errors for %define]])

 AT_DATA([[input.y]],
 [[%%
-start: ;
+start: %empty;
 ]])

 # parse.lac.* options are useless if LAC isn't actually activated.
@@ -1685,27 +1776,27 @@ AT_SETUP([[-Werror is not affected by -Wnone and -Wall]])

 AT_DATA([[input.y]],
 [[%%
-foo-bar: ;
+a: '0' { $$ = $; };
 ]])

 # -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 [-Wyacc]
+[[input.y:2.15: warning: stray '$' [-Wother]
 ]])
 AT_BISON_CHECK([[-W input.y]], [[0]], [[]],
-[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar [-Wyacc]
+[[input.y:2.15: warning: stray '$' [-Wother]
 ]])
 AT_BISON_CHECK([[-Wno-none input.y]], [[0]], [[]],
-[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar [-Wyacc]
+[[input.y:2.15: warning: stray '$' [-Wother]
 ]])

 # -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]],
-[[input.y:2.1-7: error: POSIX Yacc forbids dashes in symbol names: foo-bar [-Werror=yacc]
+AT_BISON_CHECK([[-Werror,none,other input.y]], [[1]], [[]],
+[[input.y:2.15: error: stray '$' [-Werror=other]
+]])
+AT_BISON_CHECK([[-Werror,no-all,other input.y]], [[1]], [[]],
+[[input.y:2.15: error: stray '$' [-Werror=other]
 ]])
-[mv stderr experr]
-AT_BISON_CHECK([[-Werror,no-all,yacc input.y]], [[1]], [[]], [[experr]])

 AT_CLEANUP

@@ -1722,17 +1813,17 @@ m4_pushdef([AT_TEST],
 [AT_DATA([[input.y]],
 [[$1
 %%
-exp: /* empty */;
+exp: %empty;
 ]])
 AT_BISON_CHECK([[$2 input.y]], [[1]], [[]],
 [[$3: error: '%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])
+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])

@@ -25,8 +25,8 @@ AT_BANNER([[Java Calculator.]])

 # _AT_DATA_JAVA_CALC_Y($1, $2, $3, [BISON-DIRECTIVES])
 # ----------------------------------------------------
-# Produce `calc.y'.  Don't call this macro directly, because it contains
-# some occurrences of `$1' etc. which will be interpreted by m4.  So
+# Produce 'calc.y'.  Don't call this macro directly, because it contains
+# some occurrences of '$1' etc. which will be interpreted by m4.  So
 # you should call it with $1, $2, and $3 as arguments, which is what
 # AT_DATA_JAVA_CALC_Y does.
 m4_define([_AT_DATA_JAVA_CALC_Y],
@@ -37,7 +37,7 @@ AT_DATA([Calc.y],
 [[/* Infix notation calculator--calc */
 %language "Java"
 %name-prefix "Calc"
-%define parser_class_name "Calc"
+%define parser_class_name {Calc}
 %define public

 ]$4[
@@ -206,7 +206,7 @@ AT_BISON_OPTION_POPDEFS

 # AT_DATA_CALC_Y([BISON-OPTIONS])
 # -------------------------------
-# Produce `calc.y'.
+# Produce 'calc.y'.
 m4_define([AT_DATA_JAVA_CALC_Y],
 [_AT_DATA_JAVA_CALC_Y($[1], $[2], $[3], [$1])
 ])
@@ -215,7 +215,7 @@ m4_define([AT_DATA_JAVA_CALC_Y],
 # _AT_CHECK_JAVA_CALC_ERROR(BISON-OPTIONS, INPUT,
 #                           [VERBOSE-AND-LOCATED-ERROR-MESSAGE])
 # --------------------------------------------------------------
-# Run `calc' on INPUT, and expect a `syntax error' message.
+# Run 'calc' on INPUT, and expect a 'syntax error' message.
 #
 # If INPUT starts with a slash, it is used as absolute input file name,
 # otherwise as contents.
@@ -240,7 +240,7 @@ AT_DATA([[expout]],
 AT_YYERROR_SEES_LOC_IF([],
 [[sed 's/^[-0-9.]*: //' expout >at-expout
 mv at-expout expout]])
-# 3. If error-verbose is not used, strip the`, unexpected....' part.
+# 3. If error-verbose is not used, strip the', unexpected....' part.
 m4_bmatch([$1], [%error-verbose], [],
 [[sed 's/syntax error, .*$/syntax error/' expout >at-expout
 mv at-expout expout]])
@@ -250,7 +250,7 @@ AT_CHECK([cat stderr], 0, [expout])

 # _AT_CHECK_JAVA_CALC([BISON-DIRECTIVES], [BISON-CODE])
 # -----------------------------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # BISON-DIRECTIVES, and performs several tests over the parser.
 m4_define([_AT_CHECK_JAVA_CALC],
 [# We use integers to avoid dependencies upon the precision of doubles.
@@ -310,7 +310,7 @@ _AT_CHECK_JAVA_CALC_ERROR([$1], [/dev/null],
 #   - (* * *): nothing to pop, a lot to discard
 #   - (1 + 2 * *): some to pop and discard
 #
-# - test the action associated to `error'
+# - test the action associated to 'error'
 #
 # - check the lookahead that triggers an error is not discarded
 #   when we enter error recovery.  Below, the lookahead causing the
@@ -342,7 +342,7 @@ AT_CLEANUP

 # AT_CHECK_JAVA_CALC([BISON-DIRECTIVES])
 # --------------------------------------
-# Start a testing chunk which compiles `calc' grammar with
+# Start a testing chunk which compiles 'calc' grammar with
 # BISON-DIRECTIVES, and performs several tests over the parser.
 # Run the test with and without %error-verbose.
 m4_define([AT_CHECK_JAVA_CALC],
@@ -461,13 +461,13 @@ AT_CHECK_JAVA_GREP([[class YYParser]])
 AT_CHECK_JAVA_MINIMAL([[%name-prefix "Prefix"]])
 AT_CHECK_JAVA_GREP([[class PrefixParser]])

-AT_CHECK_JAVA_MINIMAL([[%define api.token.prefix "TOK_"]])
+AT_CHECK_JAVA_MINIMAL([[%define api.token.prefix {TOK_}]])
 AT_CHECK_JAVA_GREP([[.*TOK_END.*]])

-AT_CHECK_JAVA_MINIMAL([[%define parser_class_name "ParserClassName"]])
+AT_CHECK_JAVA_MINIMAL([[%define parser_class_name {ParserClassName}]])
 AT_CHECK_JAVA_GREP([[class ParserClassName]])

-AT_CHECK_JAVA_MINIMAL([[%define package "user_java_package"]])
+AT_CHECK_JAVA_MINIMAL([[%define package {user_java_package}]])
 AT_CHECK_JAVA_GREP([[package user_java_package;]])

 AT_CLEANUP
@@ -530,7 +530,7 @@ AT_CHECK_JAVA_GREP([[public final strictfp class YYParser]])

 # FIXME: Can't do a Java compile because javacomp.sh is configured for 1.3
 AT_CHECK_JAVA_MINIMAL([[
-%define annotations "/*@Deprecated @SupressWarnings(\"unchecked\") @SupressWarnings({\"unchecked\", \"deprecation\"}) @SupressWarnings(value={\"unchecked\", \"deprecation\"})*/"
+%define annotations {/*@Deprecated @SupressWarnings("unchecked") @SupressWarnings({"unchecked", "deprecation"}) @SupressWarnings(value={"unchecked", "deprecation"})*/}
 %define public]])
 AT_CHECK_JAVA_GREP([[/\*@Deprecated @SupressWarnings("unchecked") @SupressWarnings({"unchecked", "deprecation"}) @SupressWarnings(value={"unchecked", "deprecation"})\*/ public class YYParser]])

@@ -543,15 +543,15 @@ AT_CLEANUP

 AT_SETUP([Java parser class extends and implements])

-AT_CHECK_JAVA_MINIMAL([[%define extends "Thread"]])
+AT_CHECK_JAVA_MINIMAL([[%define extends {Thread}]])
 AT_CHECK_JAVA_GREP([[class YYParser extends Thread]])

-AT_CHECK_JAVA_MINIMAL([[%define implements "Cloneable"]])
+AT_CHECK_JAVA_MINIMAL([[%define implements {Cloneable}]])
 AT_CHECK_JAVA_GREP([[class YYParser implements Cloneable]])

 AT_CHECK_JAVA_MINIMAL([[
-%define extends "Thread"
-%define implements "Cloneable"]])
+%define extends {Thread}
+%define implements {Cloneable}]])
 AT_CHECK_JAVA_GREP([[class YYParser extends Thread implements Cloneable]])

 AT_CLEANUP
@@ -643,9 +643,9 @@ AT_SETUP([Java throws specifications])

 m4_define([AT_JT_lex_throws_define], [m4_case(AT_JT_lex_throws,
        -1, [],
-         0, [[%define lex_throws ""]],
-         1, [[%define lex_throws "InterruptedException"]],
-         2, [[%define lex_throws "InterruptedException, IllegalAccessException"]])])
+         0, [[%define lex_throws {}]],
+         1, [[%define lex_throws {InterruptedException}]],
+         2, [[%define lex_throws {InterruptedException, IllegalAccessException}]])])

 m4_define([AT_JT_yylex_throws], [m4_case(AT_JT_lex_throws,
        -1, [[ throws java.io.IOException]],
@@ -662,9 +662,9 @@ m4_define([AT_JT_yylex_action], [m4_case(AT_JT_lex_throws,

 m4_define([AT_JT_throws_define], [m4_case(AT_JT_throws,
        -1, [],
-         0, [[%define throws ""]],
-         1, [[%define throws "ClassNotFoundException"]],
-         2, [[%define throws "ClassNotFoundException, InstantiationException"]])])
+         0, [[%define throws {}]],
+         1, [[%define throws {ClassNotFoundException}]],
+         2, [[%define throws {ClassNotFoundException, InstantiationException}]])])

 m4_define([AT_JT_yyaction_throws], [m4_case(AT_JT_throws,
        -1, [],
@@ -727,16 +727,16 @@ AT_CLEANUP
 AT_SETUP([Java constructor init and init_throws])

 AT_CHECK_JAVA_MINIMAL([[
-%define extends "Thread"
+%define extends {Thread}
 %code init { super("Test Thread"); if (true) throw new InterruptedException(); }
-%define init_throws "InterruptedException"
+%define init_throws {InterruptedException}
 %lex-param {int lex_param}]])
 AT_CHECK([[grep -q 'super("Test Thread"); if (true) throw new InterruptedException();' YYParser.java]])

 AT_CHECK_JAVA_MINIMAL_W_LEXER([[
-%define extends "Thread"
+%define extends {Thread}
 %code init { super("Test Thread"); if (true) throw new InterruptedException(); }
-%define init_throws "InterruptedException"]], [], [[return EOF;]])
+%define init_throws {InterruptedException}]], [], [[return EOF;]])
 AT_CHECK([[grep -q 'super("Test Thread"); if (true) throw new InterruptedException();' YYParser.java]])

 AT_CLEANUP
@@ -749,20 +749,20 @@ AT_CLEANUP
 AT_SETUP([Java value, position, and location types])

 AT_CHECK_JAVA_MINIMAL([[
-%define api.value.type "java.awt.Color"
+%define api.value.type {java.awt.Color}
 %type<java.awt.Color> start;
-%define api.location.type "MyLoc"
-%define api.position.type "MyPos"
+%define api.location.type {MyLoc}
+%define api.position.type {MyPos}
 %code { class MyPos {} }]], [[$$ = $<java.awt.Color>1;]], [[MyPos]])
 AT_CHECK([[grep 'java.awt.Color' YYParser.java]], [0], [ignore])
 AT_CHECK([[$EGREP -v ' */?\*' YYParser.java | grep 'Position']], [1], [ignore])
 AT_CHECK([[$EGREP -v ' */?\*' YYParser.java | grep 'Location']], [1], [ignore])

 AT_CHECK_JAVA_MINIMAL_W_LEXER([[
-%define api.value.type "java.awt.Color"
+%define api.value.type {java.awt.Color}
 %type<java.awt.Color> start;
-%define api.location.type "MyLoc"
-%define api.position.type "MyPos"
+%define api.location.type {MyLoc}
+%define api.position.type {MyPos}
 %code { class MyPos {} }]], [], [[return EOF;]], [],
 [[$$ = $<java.awt.Color>1;]],
 [[java.awt.Color]], [[MyPos]], [[MyLoc]])
@@ -37,7 +37,7 @@ m4_define([AT_SETUP_STRIP],
 [m4_bpatsubsts([$1],
      [%\(language\|skeleton\) "?\([^\" ]*\)"?],
        [\2],
-      [%define "?\([-A-Za-z0-9_.]+\)"? \("[^\"]+"\|[-A-Za-z0-9_.]+\)],
+      [%define "?\([-A-Za-z0-9_.]+\)"? \({[^\}]+}\|"[^\"]+"\|[-A-Za-z0-9_.]+\)],
        [\1=\2],
      [%define "?\([-A-Za-z0-9_.]+\)"?],
        [\1],
@@ -134,7 +134,7 @@ m4_define([AT_BISON_OPTION_PUSHDEFS],
 # _AT_BISON_OPTION_PUSHDEFS($1, $2, [BISON-OPTIONS])
 # --------------------------------------------------
 # This macro works around the impossibility to define macros
-# inside macros, because issuing `[$1]' is not possible in M4 :(.
+# inside macros, because issuing '[$1]' is not possible in M4 :(.
 # This sucks hard, GNU M4 should really provide M5-like $$1.
 m4_define([_AT_BISON_OPTION_PUSHDEFS],
 [m4_if([$1$2], $[1]$[2], [],
@@ -178,23 +178,25 @@ m4_bpatsubst([$3], [%parse-param { *\([^{}]*[^{} ]\) *}],

 m4_pushdef([AT_PURE_IF],
 [m4_bmatch([$3], [%define  *api\.pure\|%pure-parser],
-           [m4_bmatch([$3], [%define  *api\.pure *"?false"?], [$2], [$1])],
+           [m4_bmatch([$3], [%define  *api\.pure *false], [$2], [$1])],
           [$2])])
 # AT_NAME_PREFIX: also consider api.namespace.
 m4_pushdef([AT_NAME_PREFIX],
-[m4_bmatch([$3], [\(%define api\.\(namespace\|prefix\)\|%name-prefix\) ".*"],
-           [m4_bregexp([$3], [\(%define api\.\(namespace\|prefix\)\|%name-prefix\) "\([^""]*\)"], [\3])],
-           [yy])])
+[m4_bmatch([$3], [\(%define api\.\(namespace\|prefix\)\|%name-prefix\) .*],
+   [m4_bregexp([$3],
+     [\(%define api\.\(namespace\|prefix\)\|%name-prefix\) [\{\"]\([^\"\}]*\)[\"\}]],
+     [\3])],
+   [yy])])
 m4_pushdef([AT_TOKEN_CTOR_IF],
 [m4_bmatch([$3], [%define api\.token\.constructor], [$1], [$2])])
 m4_pushdef([AT_TOKEN_PREFIX],
-[m4_bmatch([$3], [%define api\.token\.prefix ".*"],
-           [m4_bregexp([$3], [%define api\.token\.prefix "\(.*\)"], [\1])])])
+[m4_bmatch([$3], [%define api\.token\.prefix {.*}],
+           [m4_bregexp([$3], [%define api\.token\.prefix {\(.*\)}], [\1])])])
 m4_pushdef([AT_VARIANT_IF],
-[m4_bmatch([$3], [%define api\.value\.type "?variant"?], [$1], [$2])])
+[m4_bmatch([$3], [%define api\.value\.type variant], [$1], [$2])])
 m4_pushdef([AT_API_prefix],
-[m4_bmatch([$3], [%define api\.prefix ".*"],
-           [m4_bregexp([$3], [%define api\.prefix "\([^""]*\)"], [\1])],
+[m4_bmatch([$3], [%define api\.prefix {.*}],
+           [m4_bregexp([$3], [%define api\.prefix {\([^\}]*\)}], [\1])],
           [yy])])
 m4_pushdef([AT_API_PREFIX],
 [m4_toupper(AT_API_prefix)])
@@ -205,7 +207,7 @@ m4_pushdef([AT_API_PREFIX],
 m4_pushdef([AT_YYERROR_ARG_LOC_IF],
 [AT_LOCATION_IF([AT_PURE_IF([m4_bmatch([$3],
                                       m4_quote(m4_join([\|],
-                                                        [%define api\.pure "?full"?],
+                                                        [%define api\.pure full],
                                                        [%glr-parser],
                                                        [%parse-param],
                                                        [%skeleton "?glr.c"?])),
@@ -317,6 +319,25 @@ AT_LOC_POPDEF])dnl
 ## Generating Grammar Files.  ##
 ## -------------------------- ##

+# _AT_LANG_DISPATCH(LANG, MACRO, ARGS)
+# ------------------------------------
+# Call the specialization of MACRO for LANG with ARGS.  Complain if
+# unavailable.
+m4_define([_AT_LANG_DISPATCH],
+[m4_ifdef([$2($1)],
+       [m4_indir([$2($1)], m4_shift2($@))],
+       [m4_fatal([$2: unknown language: $1])])])
+
+
+# AT_LANG_DISPATCH(MACRO, ARGS)
+# -----------------------------
+# Call the specialization of MACRO for AT_LANG with ARGS.  Complain if
+# unavailable.
+m4_define([AT_LANG_DISPATCH],
+[_AT_LANG_DISPATCH(AT_LANG, $@)])
+
+
+
 # AT_DATA_SOURCE_PROLOGUE
 # ------------------------
 # The prologue that should be included in any source code that is
@@ -406,24 +427,33 @@ static
 # AT_YYERROR_DEFINE
 # -------------------------
 # Must be called inside a AT_BISON_OPTION_PUSHDEFS/POPDEFS pair.
-m4_define([AT_YYERROR_FORMALS],
-[m4_case(AT_LANG,
-[c], [AT_YYERROR_ARG_LOC_IF([AT_YYLTYPE const * const llocp, ])AT_PARSE_PARAMS [const char *msg]])[]dnl
-])
+m4_define([AT_YYERROR_FORMALS],  [AT_LANG_DISPATCH([$0], $@)])
+m4_define([AT_YYERROR_PROTOTYPE],[AT_LANG_DISPATCH([$0], $@)])
+m4_define([AT_YYERROR_DECLARE_EXTERN], [AT_LANG_DISPATCH([$0], $@)])
+m4_define([AT_YYERROR_DECLARE],  [AT_LANG_DISPATCH([$0], $@)])
+m4_define([AT_YYERROR_DEFINE],   [AT_LANG_DISPATCH([$0], $@)])

-m4_define([AT_YYERROR_PROTOTYPE],
-[m4_case(AT_LANG,
-[c], [[void ]AT_NAME_PREFIX[error (]AT_YYERROR_FORMALS[)]])[]dnl
-])
+# AT_MAIN_DEFINE
+# --------------
+m4_define([AT_MAIN_DEFINE],   [AT_LANG_DISPATCH([$0], $@)])

-m4_define([AT_YYERROR_DECLARE_EXTERN],
-[m4_case(AT_LANG,
-[c], [AT_YYERROR_PROTOTYPE;])[]dnl
-])

-m4_define([AT_YYERROR_DECLARE],
-[m4_case(AT_LANG,
-[c], [#include <stdio.h>
+
+## --- ##
+## C.  ##
+## --- ##
+
+m4_define([AT_YYERROR_FORMALS(c)],
+[AT_YYERROR_ARG_LOC_IF([AT_YYLTYPE const * const llocp, ])AT_PARSE_PARAMS[const char *msg]])
+
+m4_define([AT_YYERROR_PROTOTYPE(c)],
+[[void ]AT_NAME_PREFIX[error (]AT_YYERROR_FORMALS[)]])
+
+m4_define([AT_YYERROR_DECLARE_EXTERN(c)],
+[AT_YYERROR_PROTOTYPE;])
+
+m4_define([AT_YYERROR_DECLARE(c)],
+[#include <stdio.h>
 ]AT_LOCATION_IF([[
 #if defined ]AT_YYLTYPE[_IS_TRIVIAL && ]AT_YYLTYPE[_IS_TRIVIAL
 static unsigned location_print (FILE *yyo, ]AT_YYLTYPE[ const * const yylocp);
@@ -432,12 +462,11 @@ static unsigned location_print (FILE *yyo, ]AT_YYLTYPE[ const * const yylocp);
 # endif
 #endif
 ]])[
-static AT_YYERROR_DECLARE_EXTERN])[]dnl
-])
+static AT_YYERROR_DECLARE_EXTERN])

-m4_define([AT_YYERROR_DEFINE],
-[m4_case(AT_LANG,
-[c], [[
+
+m4_define([AT_YYERROR_DEFINE(c)],
+[[
 ]AT_LOCATION_IF([[
 # if defined ]AT_YYLTYPE[_IS_TRIVIAL && ]AT_YYLTYPE[_IS_TRIVIAL
 /* Print *YYLOCP on YYO. */
@@ -478,34 +507,10 @@ AT_YYERROR_SEES_LOC_IF([[
  LOCATION_PRINT (stderr, ]AT_LOC[);
  fprintf (stderr, ": ");]])[
  fprintf (stderr, "%s\n", msg);
-}]],
-[c++], [[/* A C++ error reporting function.  */
-void
-]AT_NAME_PREFIX[::parser::error (]AT_LOCATION_IF([[const location_type& l, ]])[const std::string& m)
-{
-  std::cerr << ]AT_LOCATION_IF([l << ": " << ])[m << std::endl;
-}]],
-[java], [AT_LOCATION_IF([[public void yyerror (Calc.Location l, String s)
-{
-    if (l == null)
-      System.err.println (s);
-    else
-      System.err.println (l + ": " + s);
-  }
-]], [[
-  public void yyerror (String s)
-  {
-    System.err.println (s);
-  }]])],
-[m4_fatal([$0: invalid language: ]AT_LANG)])dnl
-])
+}]])


-# AT_MAIN_DEFINE
-# --------------
-m4_define([AT_MAIN_DEFINE],
-[m4_case(AT_LANG,
-[c],
+m4_define([AT_MAIN_DEFINE(c)],
 [[#include <stdlib.h> /* getenv. */
 #include <string.h> /* strcmp. */
 int
@@ -518,8 +523,27 @@ main (int argc, char const* argv[])
  (void) argc;
  (void) argv;]])[
  return ]AT_NAME_PREFIX[parse ();
-}]],
-[c++],
+}]])
+
+
+## ----- ##
+## C++.  ##
+## ----- ##
+
+# No need to declare, it's part of the class interface.
+m4_define([AT_YYERROR_DECLARE(c++)],        [])
+m4_define([AT_YYERROR_DECLARE_EXTERN(c++)], [])
+
+m4_define([AT_YYERROR_DEFINE(c++)],
+[[/* A C++ error reporting function.  */
+void
+]AT_NAME_PREFIX[::parser::error (]AT_LOCATION_IF([[const location_type& l, ]])[const std::string& m)
+{
+  std::cerr << ]AT_LOCATION_IF([l << ": " << ])[m << std::endl;
+}]])
+
+
+m4_define([AT_MAIN_DEFINE(c++)],
 [[#include <cstdlib> // getenv.
 #include <cstring> // strcmp.
 int
@@ -533,8 +557,30 @@ main (int argc, char const* argv[])
  (void) argc;
  (void) argv;]])[
  return p.parse ();
-}]],
-[java],
+}]])
+
+
+
+## ------ ##
+## Java.  ##
+## ------ ##
+
+m4_define([AT_YYERROR_DEFINE(java)],
+[AT_LOCATION_IF([[public void yyerror (Calc.Location l, String s)
+{
+    if (l == null)
+      System.err.println (s);
+    else
+      System.err.println (l + ": " + s);
+  }
+]], [[
+  public void yyerror (String s)
+  {
+    System.err.println (s);
+  }
+]])])
+
+m4_define([AT_MAIN_DEFINE(java)],
 [[class input
 {
  public static void main (String args[]) throws IOException
@@ -542,7 +588,8 @@ main (int argc, char const* argv[])
    YYParser p = new YYParser ();
    p.parse ();
  }
-}]])])
+}]])
+


 ## --------------- ##
@@ -554,7 +601,7 @@ main (int argc, char const* argv[])
 # High-level routine that may call bison several times, under different
 # conditions.
 #
-# Check Bison by invoking `bison BISON_ARGS'.  BISON_ARGS should not contain
+# Check Bison by invoking 'bison BISON_ARGS'.  BISON_ARGS should not contain
 # shell constructs (such as redirection or pipes) that would prevent
 # appending additional command-line arguments for bison. OTHER_AT_CHECK_ARGS
 # are the usual remaining arguments to AT_CHECK: STATUS, STDOUT, etc.
@@ -726,6 +773,7 @@ AT_CHECK(m4_join([ ],
                 [m4_bmatch([$1], [[.]], [], [$LIBS])]),
         0, [ignore], [ignore])])

+
 # AT_JAVA_COMPILE(SOURCES)
 # ------------------------
 # Compile SOURCES into Java class files.  Skip the test if java or javac
@@ -734,9 +782,10 @@ m4_define([AT_JAVA_COMPILE],
 [AT_KEYWORDS(java)
 AT_SKIP_IF([[test -z "$CONF_JAVAC"]])
 AT_SKIP_IF([[test -z "$CONF_JAVA"]])
-AT_CHECK([[$SHELL $abs_top_builddir/javacomp.sh ]$1],
+AT_CHECK([[$SHELL ../../../javacomp.sh ]$1],
         [[0]], [ignore], [ignore])])

+
 # AT_LANG_COMPILE(OUTPUT, [SOURCES = OUTPUT.c]
 # --------------------------------------------
 # Compile SOURCES into OUTPUT.  Skip if compiler does not work.
@@ -744,13 +793,11 @@ AT_CHECK([[$SHELL $abs_top_builddir/javacomp.sh ]$1],
 # If OUTPUT does not contain '.', assume that we are linking too,
 # otherwise pass "-c"; this is a hack.  The default SOURCES is OUTPUT
 # with trailing .o removed, and ".c"/".cc" appended.
-m4_define([AT_LANG_COMPILE],
-[m4_case(AT_LANG,
-[c],    [AT_COMPILE([$1], [$2])],
-[c++],  [AT_COMPILE_CXX([$1], [$2])],
-[java], [AT_JAVA_COMPILE([$1.java], [$2])],
-        [m4_fatal([unknown language: ]m4_defn([AT_LANG]))])[]dnl
-])
+m4_define([AT_LANG_COMPILE],  [AT_LANG_DISPATCH([$0], $@)])
+m4_define([AT_LANG_COMPILE(c)],    [AT_COMPILE([$1], [$2])])
+m4_define([AT_LANG_COMPILE(c++)],  [AT_COMPILE_CXX([$1], [$2])])
+m4_define([AT_LANG_COMPILE(java)], [AT_JAVA_COMPILE([$1.java], [$2])])
+

 # AT_FULL_COMPILE(OUTPUT, [OTHER1], [OTHER2])
 # -------------------------------------------
@@ -759,30 +806,31 @@ m4_define([AT_LANG_COMPILE],
 # OUTPUT-OTHER.c, OUTPUT-OTHER.cc, or OUTPUT-OTHER.java to OUTPUT or
 # OUTPUT.java along with it.  Relies on AT_SKEL_CC_IF and
 # AT_SKEL_JAVA_IF.
-m4_define([AT_FULL_COMPILE],
-[m4_case(AT_LANG,
-[java],
-  [AT_BISON_CHECK([-o $1.java $1.y])
-   AT_LANG_COMPILE([$1],
-                   m4_join([ ],
-                           [$1.java],
-                           m4_ifval($2, [[$1-$2.java]]),
-                           m4_ifval($3, [[$1-$3.java]])))],
-[c++],
-  [AT_BISON_CHECK([-o $1.cc $1.y])
-   AT_LANG_COMPILE([$1],
-                   m4_join([ ],
-                           [$1.cc],
-                           m4_ifval($2, [[$1-$2.cc]]),
-                           m4_ifval($3, [[$1-$3.cc]])))],
-[c],
-  [AT_BISON_CHECK([-o $1.c $1.y])
-   AT_LANG_COMPILE([$1],
-                   m4_join([ ],
-                           [$1.c],
-                           m4_ifval($2, [[$1-$2.c]]),
-                           m4_ifval($3, [[$1-$3.c]])))])
-])
+m4_define([AT_FULL_COMPILE],  [AT_LANG_DISPATCH([$0], $@)])
+m4_define([AT_FULL_COMPILE(c)],
+[AT_BISON_CHECK([-o $1.c $1.y])
+ AT_LANG_COMPILE([$1],
+                 m4_join([ ],
+                         [$1.c],
+                         m4_ifval($2, [[$1-$2.c]]),
+                         m4_ifval($3, [[$1-$3.c]])))])
+
+m4_define([AT_FULL_COMPILE(c++)],
+[AT_BISON_CHECK([-o $1.cc $1.y])
+ AT_LANG_COMPILE([$1],
+                 m4_join([ ],
+                         [$1.cc],
+                         m4_ifval($2, [[$1-$2.cc]]),
+                         m4_ifval($3, [[$1-$3.cc]])))])
+
+m4_define([AT_FULL_COMPILE(java)],
+[AT_BISON_CHECK([-o $1.java $1.y])
+ AT_LANG_COMPILE([$1],
+                 m4_join([ ],
+                         [$1.java],
+                         m4_ifval($2, [[$1-$2.java]]),
+                         m4_ifval($3, [[$1-$3.java]])))])
+



@@ -830,7 +878,7 @@ AT_PARSER_CHECK([./c-and-cxx])

 # AT_PARSER_CHECK(COMMAND, EXIT-STATUS, EXPOUT, EXPERR, [PRE])
 # ------------------------------------------------------------
-# So that we can run `./testsuite PREPARSER='valgrind -q' for instance.
+# So that we can run './testsuite PREPARSER='valgrind -q' for instance.
 #
 # Get rid of spurious messages when compiled with --coverage:
 # +profiling:/[...]/lib/fprintf.gcda:Merge mismatch for summaries
@@ -844,7 +892,7 @@ AT_CHECK([sed >&2 -e '/^profiling:.*:Merge mismatch for summaries/d' stderr],
 # AT_JAVA_PARSER_CHECK(COMMAND, EXIT-STATUS, EXPOUT, EXPERR, [PRE])
 # -----------------------------------------------------------------
 m4_define([AT_JAVA_PARSER_CHECK],
-[AT_CHECK([$5[ $SHELL $abs_top_builddir/javaexec.sh ]$1], [$2], [$3], [$4])])
+[AT_CHECK([$5[ $SHELL ../../../javaexec.sh ]$1], [$2], [$3], [$4])])


 # AT_TEST_TABLES_AND_PARSE(TITLE, COND-VALUE, TEST-SPEC,
@@ -872,16 +920,16 @@ m4_define([AT_JAVA_PARSER_CHECK],
 # that Bison exits with value 0, has no stdout, and has stderr
 # BISON-STDERR.
 #
-# If TEST-SPEC contains the attribute `last-state', check that the value
+# If TEST-SPEC contains the attribute 'last-state', check that the value
 # of TABLES-OR-LAST-STATE is the index of the last state generated for
 # the grammar; in other words, check the number of states (minus one).
-# Otherwise, check that everything in the `.output' file starting with
+# Otherwise, check that everything in the '.output' file starting with
 # the definition of state 0 is the same as the entire value of
 # TABLES-OR-LAST-STATE.
 #
 # Expand the M4 in OTHER-CHECKS to perform additional checks of the
-# `.output' file, which is named `input.output', and/or grammar file,
-# which is named `input.y'.
+# '.output' file, which is named 'input.output', and/or grammar file,
+# which is named 'input.y'.
 #
 # Finally, compile the generated parser and then run it using
 # AT_PARSER_CHECK with PARSER-EXIT-VALUE, PARSER-STDOUT, and
@@ -962,7 +1010,7 @@ yylex (void)

 m4_if(m4_index(m4_quote($3), [no-xml]), -1,
      [AT_BISON_CHECK],
-      [AT_BISON_CHECK_NO_XML])([[--report=all --defines -o input.c input.y]],
+      [AT_BISON_CHECK_NO_XML])([[-Wall --report=all --defines -o input.c input.y]],
                               [0], [], m4_dquote($7))

 m4_if(m4_index(m4_quote($3), [last-state]), -1,
@@ -1022,9 +1070,6 @@ m4_define([AT_SETUP],
 AT_ARG_OPTION([compile-c-with-cxx],
              [compile C parsers with the C++ compiler])

-AT_ARG_OPTION([release],
-              [check xml and use push for pull])
-
 AT_COLOR_TESTS

 AT_TESTED([bison])
@@ -63,7 +63,8 @@ TESTSUITE_AT =                                  \
  tests/sets.at                                 \
  tests/skeletons.at                            \
  tests/synclines.at                            \
-  tests/torture.at
+  tests/torture.at                              \
+  tests/types.at

 TESTSUITE = $(top_srcdir)/tests/testsuite

@@ -80,17 +81,8 @@ $(TESTSUITE): $(TESTSUITE_AT)
 ## Run the test suite.  ##
 ## -------------------- ##

-# Move into tests/ so that testsuite.dir etc. be created there.  If a suffix is
-# specified, create it in a corresponding subdirectory of tests/.
-RUN_TESTSUITE = dir=tests/$$suf						\
-		  && { test -d $$dir || mkdir $$dir; }			\
-		  && { test -f $$dir/atconfig				\
-			&& diff -q $$dir/atconfig tests/atconfig	\
-		      || cp tests/atconfig $$dir; }			\
-		  && { test -f $$dir/atlocal 				\
-			&& diff -q $$dir/atlocal tests/atlocal		\
-		      || cp tests/atlocal  $$dir; }			\
-		  && $(TESTSUITE) -C $$dir $$TESTSUITEFLAGS
+# Move into tests/ so that testsuite.dir etc. be created there.
+RUN_TESTSUITE = $(TESTSUITE) -C tests $(TESTSUITEFLAGS)
 check_SCRIPTS = $(BISON) tests/atconfig tests/atlocal
 RUN_TESTSUITE_deps = $(TESTSUITE) $(check_SCRIPTS)

@@ -108,26 +100,28 @@ installcheck-local: $(RUN_TESTSUITE_deps)
 # Be real mean with it.
 .PHONY: maintainer-check-g++
 maintainer-check-g++: $(RUN_TESTSUITE_deps)
-	suf=$@ $(RUN_TESTSUITE) --compile-c-with-cxx
+	$(RUN_TESTSUITE) --compile-c-with-cxx

 .PHONY: maintainer-check-posix
 maintainer-check-posix: $(RUN_TESTSUITE_deps)
-	suf=$@ $(RUN_TESTSUITE) POSIXLY_CORRECT=1 _POSIX2_VERSION=200112
+	$(RUN_TESTSUITE) POSIXLY_CORRECT=1 _POSIX2_VERSION=200112

 .PHONY: maintainer-check-valgrind
 maintainer-check-valgrind: $(RUN_TESTSUITE_deps)
 	test -z '$(VALGRIND)' ||					\
-	  suf=$@ $(RUN_TESTSUITE)					\
+	  $(RUN_TESTSUITE)						\
 	    PREBISON='$(VALGRIND_PREBISON)' PREPARSER='$(VALGRIND) -q'	\
 	    VALGRIND_OPTS='--leak-check=full --show-reachable=yes'

 .PHONY: maintainer-check
 maintainer-check: maintainer-check-posix maintainer-check-valgrind maintainer-check-g++

-.PHONY: maintainer-release-check
-maintainer-release-check:
-	$(MAKE) $(AM_MAKEFLAGS) 	\
-	  maintainer-check-g++		\
-	  maintainer-check-posix 	\
-	  maintainer-check-valgrind 	\
-	  TESTSUITEFLAGS+='--release'
+.PHONY: maintainer-push-check
+maintainer-push-check:
+	$(MAKE) $(AM_MAKEFLAGS) maintainer-check			\
+	  TESTSUITEFLAGS='BISON_USE_PUSH_FOR_PULL=1 $(TESTSUITEFLAGS)'
+
+.PHONY: maintainer-xml-check
+maintainer-xml-check:
+	$(MAKE) $(AM_MAKEFLAGS) maintainer-check		\
+	  TESTSUITEFLAGS='BISON_TEST_XML=1 $(TESTSUITEFLAGS)'
@@ -62,8 +62,13 @@ AT_CHECK_OUTPUT([foo.y], [], [-dv -o foo.c],
                [foo.c foo.h foo.output])
 AT_CHECK_OUTPUT([foo.y], [], [-dv -o foo.tab.c],
                [foo.output foo.tab.c foo.tab.h])
-AT_CHECK_OUTPUT([foo.y], [], [-dv -y],
-                [y.output y.tab.c y.tab.h])
+
+AT_CHECK_OUTPUT([foo.y], [], [-dv -g --xml -y],
+                [y.dot y.output y.tab.c y.tab.h y.xml])
+# With '-o y.tab.c', we expect 'y.output' etc. (for compatility with Yacc).
+AT_CHECK_OUTPUT([foo.y], [], [-dv -g --xml -o y.tab.c],
+                [y.dot y.output y.tab.c y.tab.h y.xml])
+
 AT_CHECK_OUTPUT([foo.y], [], [-dv -b bar],
                [bar.output bar.tab.c bar.tab.h])
 AT_CHECK_OUTPUT([foo.y], [], [-dv -g -o foo.c],
@@ -201,28 +201,6 @@ input.y:14.11-13: warning: rule useless in grammar [-Wother]
           ^^^
 ]])

-AT_BISON_CHECK([[input.y]], 0, [],
-[[input.y: warning: 9 nonterminals useless in grammar [-Wother]
-input.y: warning: 9 rules useless in grammar [-Wother]
-input.y:6.1-8: warning: nonterminal useless in grammar: useless1 [-Wother]
-input.y:7.1-8: warning: nonterminal useless in grammar: useless2 [-Wother]
-input.y:8.1-8: warning: nonterminal useless in grammar: useless3 [-Wother]
-input.y:9.1-8: warning: nonterminal useless in grammar: useless4 [-Wother]
-input.y:10.1-8: warning: nonterminal useless in grammar: useless5 [-Wother]
-input.y:11.1-8: warning: nonterminal useless in grammar: useless6 [-Wother]
-input.y:12.1-8: warning: nonterminal useless in grammar: useless7 [-Wother]
-input.y:13.1-8: warning: nonterminal useless in grammar: useless8 [-Wother]
-input.y:14.1-8: warning: nonterminal useless in grammar: useless9 [-Wother]
-input.y:6.11-13: warning: rule useless in grammar: useless1: '1' [-Wother]
-input.y:7.11-13: warning: rule useless in grammar: useless2: '2' [-Wother]
-input.y:8.11-13: warning: rule useless in grammar: useless3: '3' [-Wother]
-input.y:9.11-13: warning: rule useless in grammar: useless4: '4' [-Wother]
-input.y:10.11-13: warning: rule useless in grammar: useless5: '5' [-Wother]
-input.y:11.11-13: warning: rule useless in grammar: useless6: '6' [-Wother]
-input.y:12.11-13: warning: rule useless in grammar: useless7: '7' [-Wother]
-input.y:13.11-13: warning: rule useless in grammar: useless8: '8' [-Wother]
-input.y:14.11-13: warning: rule useless in grammar: useless9: '9' [-Wother]
-]])

 AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
 [[Nonterminals useless in grammar
@@ -317,16 +295,6 @@ not-reduced.y:17.17-18.63: warning: rule useless in grammar [-Wother]
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ]])

-AT_BISON_CHECK([[not-reduced.y]], 0, [],
-[[not-reduced.y: warning: 2 nonterminals useless in grammar [-Wother]
-not-reduced.y: warning: 3 rules useless in grammar [-Wother]
-not-reduced.y:14.1-13: warning: nonterminal useless in grammar: not_reachable [-Wother]
-not-reduced.y:11.6-19: warning: nonterminal useless in grammar: non_productive [-Wother]
-not-reduced.y:11.6-57: warning: rule useless in grammar: exp: non_productive [-Wother]
-not-reduced.y:14.16-56: warning: rule useless in grammar: not_reachable: useful [-Wother]
-not-reduced.y:17.17-18.63: warning: rule useless in grammar: non_productive: non_productive useless_token [-Wother]
-]])
-
 AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' not-reduced.output]], 0,
 [[Nonterminals useless in grammar
   not_reachable
@@ -397,9 +365,9 @@ AT_BISON_CHECK([[input.y]], 0, [],
 input.y: warning: 3 rules useless in grammar [-Wother]
 input.y:5.15-25: warning: nonterminal useless in grammar: underivable [-Wother]
 input.y:6.14-24: warning: nonterminal useless in grammar: indirection [-Wother]
-input.y:5.15-25: warning: rule useless in grammar: exp: underivable [-Wother]
-input.y:6.14-24: warning: rule useless in grammar: underivable: indirection [-Wother]
-input.y:7.14-24: warning: rule useless in grammar: indirection: underivable [-Wother]
+input.y:5.15-25: warning: rule useless in grammar [-Wother]
+input.y:6.14-24: warning: rule useless in grammar [-Wother]
+input.y:7.14-24: warning: rule useless in grammar [-Wother]
 ]])

 AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
@@ -965,7 +933,7 @@ S: 'a' A 'a'
 A: 'a' 'a' B
 ;
 B: 'a'
- | %prec 'a'
+ | %empty %prec 'a'
 ;
 c: 'a' 'a' 'b'
 | A
@@ -1565,8 +1533,8 @@ a: 'a' ;
   and multiple reductions.  The first reduction has more lookaheads than the
   second, so the first should always be preferred as the default reduction if
   enabled.  The second reduction has one lookahead.  */
-b: ;
-c: ;
+b: %empty;
+c: %empty;
 ]],
 dnl Visit each state mentioned above.
 [['a', 'a']],
@@ -263,11 +263,11 @@ AT_CHECK([cat input.output], [],

    0 $accept: expr $end

-    1 $@1: /* empty */
+    1 $@1: %empty

    2 expr: 'a' $@1 'b'

-    3 $@2: /* empty */
+    3 $@2: %empty

    4 expr: $@2 'c'

@@ -373,13 +373,13 @@ AT_DATA([input.y],
 %token  <operator>  LE 134  "<="
 %left  OR  "<="
 %%
-exp: ;
+exp: %empty;
 %%
 ]])

-AT_BISON_CHECK([-v -o input.c input.y], 0, [],
-[[input.y:1.29-32: warning: useless associativity for "||" [-Wother]
-input.y:2.29-32: warning: useless associativity for "<=" [-Wother]
+AT_BISON_CHECK([-v -Wall -o input.c input.y], 0, [],
+[[input.y:3.1-5: warning: useless precedence and associativity for "||" [-Wprecedence]
+input.y:3.1-5: warning: useless precedence and associativity for "<=" [-Wprecedence]
 ]])

 AT_CLEANUP
@@ -573,7 +573,7 @@ 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 ';'

@@ -721,7 +721,7 @@ AT_KEYWORDS([report])
 AT_DATA([input.y],
 [[%%
 statement:  struct_stat;
-struct_stat:  /* empty. */ | if else;
+struct_stat:  %empty | if else;
 if: "if" "const" "then" statement;
 else: "else" statement;
 %%
@@ -869,7 +869,7 @@ type: DATA
   | INVALID
   ;

-body: /* empty */
+body: %empty
   | body member
   ;

@@ -929,7 +929,7 @@ $1
 %token B

 %%
-program: /* empty */
+program: %empty
 | program e ';'
 | program error ';';

@@ -1145,15 +1145,15 @@ sr_conflict:
 ]AT_YYLEX_DEFINE([{ 1, 2, 3, 0 }])[
 ]AT_MAIN_DEFINE[
 ]])
-AT_BISON_OPTION_POPDEFS

-AT_BISON_CHECK([[-o input.c input.y]], [[0]],,
-[[input.y:24.5-19: warning: rule useless in parser due to conflicts: start: start [-Wother]
-input.y:28.5-19: warning: rule useless in parser due to conflicts: sr_conflict: TK2 "tok alias" [-Wother]
-input.y:18.7-9: warning: useless associativity for TK1 [-Wother]
+AT_BISON_CHECK([[-Wall -o input.c input.y]], [[0]],,
+[[input.y:24.5-19: warning: rule useless in parser due to conflicts [-Wother]
+input.y:28.5-19: warning: rule useless in parser due to conflicts [-Wother]
+input.y:18.1-5: warning: useless precedence and associativity for TK1 [-Wprecedence]
 ]])
 AT_COMPILE([[input]])
 AT_PARSER_CHECK([[./input]])
+AT_BISON_OPTION_POPDEFS

 AT_CLEANUP

@@ -86,7 +86,7 @@ AT_CHECK([[cat sets]], [],
      0  e $end
  e derives
      1  'e'
-      2  /* empty */
+      2  %empty
 NULLABLE
  $accept: no
  e: yes
@@ -100,10 +100,10 @@ FDERIVES
  $accept derives
      0  e $end
      1  'e'
-      2  /* empty */
+      2  %empty
  e derives
      1  'e'
-      2  /* empty */
+      2  %empty
 ]])

 AT_CLEANUP
@@ -113,7 +113,7 @@ AT_CLEANUP
 ## Broken Closure.  ##
 ## ---------------- ##

-# TC was once broken during a massive `simplification' of the code.
+# TC was once broken during a massive 'simplification' of the code.
 # It resulted in bison dumping core on the following grammar (the
 # computation of FIRSTS uses TC).  It managed to produce a pretty
 # exotic closure:
@@ -263,7 +263,7 @@ AT_CLEANUP
 # In some weird cases Bison could compute an incorrect final state
 # number.  This happens only if the $end token is used in the user
 # grammar, which is a very suspicious accidental feature introduced as
-# a side effect of allowing the user to name $end using `%token END 0
+# a side effect of allowing the user to name $end using '%token END 0
 # "end of file"'.

 AT_SETUP([Accept])
@@ -23,7 +23,7 @@ AT_BANNER([[User Actions.]])
 # --------------------------
 # Compile FILE expecting an error, and save in the file stdout the
 # normalized output.  Ignore the exit status, since some compilers
-# (e.g. c89 on IRIX 6.5) trigger warnings on `#error', instead of
+# (e.g. c89 on IRIX 6.5) trigger warnings on '#error', instead of
 # errors.
 m4_define([AT_SYNCLINES_COMPILE],
 [AT_CHECK([$CC $CFLAGS $CPPFLAGS -c $1], [ignore], [], [stderr])
@@ -35,6 +35,9 @@ m4_include([sets.at])
 # Testing grammar reduction.
 m4_include([reduce.at])

+# Testing conflicts detection and resolution.
+m4_include([conflicts.at])
+
 # Testing that #lines are correct.
 m4_include([synclines.at])

@@ -44,8 +47,8 @@ m4_include([headers.at])
 # Testing that user actions are properly performed.
 m4_include([actions.at])

-# Testing conflicts detection and resolution.
-m4_include([conflicts.at])
+# Testing semantic types support.
+m4_include([types.at])

 # Fulling testing (compilation and execution of the parser) on calc.
 m4_include([calc.at])
@@ -0,0 +1,230 @@
+# Value type.                                     -*- Autotest -*-
+
+# Copyright (C) 2013 Free Software Foundation, Inc.
+
+# 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 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, see <http://www.gnu.org/licenses/>.
+
+AT_BANNER([[Value type tests.]])
+
+
+## ----------------------------------- ##
+## %union vs. %define api.value.type.  ##
+## ----------------------------------- ##
+
+AT_SETUP([[%union vs. %define api.value.type]])
+
+AT_DATA([[input.y]],
+[[%union { int ival; }
+%define api.value.type union-directive
+%%
+exp: %empty;
+]])
+
+AT_BISON_CHECK([[input.y]], [[1]], [[]],
+[[input.y:2.9-22: error: '%union' and '%define api.value.type' cannot be used together
+]])
+
+AT_CLEANUP
+
+## ---------------------------------------- ##
+## %yacc vs. %define api.value.type union.  ##
+## ---------------------------------------- ##
+
+AT_SETUP([[%yacc vs. %define api.value.type union]])
+
+AT_DATA([[input.y]],
+[[%yacc
+%define api.value.type union
+%%
+exp: %empty;
+]])
+
+AT_BISON_CHECK([[input.y]], [[1]], [[]],
+[[input.y:2.9-22: error: '%yacc' and '%define api.value.type "union"' cannot be used together
+]])
+
+AT_CLEANUP
+
+
+## ---------------- ##
+## api.value.type.  ##
+## ---------------- ##
+
+# AT_TEST($1: BISON-DIRECTIVES,
+#         $2: MORE-BISON-DIRECTIVES,
+#         $3: PARSER-ACTION,
+#         $4: INPUT, $5: SCANNER-ACTION,
+#         $6: RESULT)
+# --------------------------------------
+# Compile the grammar and check the expected result.
+# BISON-DIRECTIVES are passed to AT_SETUP, contrary to MORE-BISON-DIRECTIVES.
+m4_pushdef([AT_TEST],
+[
+AT_SETUP([$1])
+AT_KEYWORDS([api.value.type])
+AT_BISON_OPTION_PUSHDEFS([%debug $1 $2])
+AT_DATA_GRAMMAR([test.y],
+[[%debug
+
+%code
+{
+# include <stdio.h>
+# include <stdlib.h>
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+}
+
+]$1[
+]$2[
+
+%%
+
+start: $3;
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE([$4], [$5])[
+]AT_MAIN_DEFINE[
+]])
+
+AT_FULL_COMPILE([[test]])
+AT_PARSER_CHECK([./test], 0, [$6
+], [stderr])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+])
+
+m4_foreach([b4_skel], [[yacc.c], [glr.c], [lalr1.cc], [glr.cc]],
+ [# A built-in type.
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type {double}],
+          [],
+          ['1' '2' { printf ("%2.1f\n", $1 + $2); }],
+          ["12"],
+          [AT_VAL = (res - '0') / 10.0],
+          [0.3])
+
+  # A typedef which looks like a Bison keyword, but it's using braces.
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type {variant}],
+          [%code requires { typedef double variant; }],
+          ['1' '2' { printf ("%2.1f\n", $1 + $2); }],
+          ["12"],
+          [AT_VAL = (res - '0') / 10.0],
+          [0.3])
+
+  # A user defined struct.
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type {struct foo}],
+          [%code requires { struct foo { float fval; int ival; }; }],
+          ['1' '2'
+             { printf ("%d %2.1f\n", $1.ival + $2.ival, $1.fval + $2.fval); }],
+          ["12"],
+          [AT_VAL.ival = (res - '0') * 10;
+           AT_VAL.fval = (res - '0') / 10.f],
+          [30 0.3])
+
+  # A user defined struct that uses pointers.
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type {struct bar}],
+          [%code requires
+           {
+             struct u
+             {
+               int ival;
+             };
+             struct bar
+             {
+               struct u *up;
+             };
+           }
+           %token <up->ival> '1' '2'
+           %printer { ]AT_SKEL_CC_IF([[yyoutput << $$]],
+                                     [[fprintf (yyo, "%d", $$)]])[; } <up->ival>
+           ],
+          ['1' '2'
+           {
+             printf ("%d %d\n", $1, $<up->ival>2);
+             free ($<up>1);
+             free ($<up>2);
+           }],
+          ["12"],
+          [AT_VAL.up = (struct u *) malloc (sizeof *AT_VAL.up);
+           assert (AT_VAL.up);
+           AT_VAL.up->ival = res - '0';],
+          [1 2])
+
+  # A user defined union.
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type {union foo}],
+          [%code requires { union foo { float fval; int ival; }; }],
+          ['1' '2' { printf ("%d %2.1f\n", $1.ival, $2.fval); }],
+          ["12"],
+          [if (res == '1')
+             AT_VAL.ival = 10;
+           else
+             AT_VAL.fval = .2f],
+          [10 0.2])
+
+  # A %union.
+  AT_TEST([%skeleton "]b4_skel["
+           %union { float fval; int ival; };],
+          [%token <ival> '1';
+           %token <fval> '2';],
+          ['1' '2' { printf ("%d %2.1f\n", $1, $2); }],
+          ["12"],
+          [if (res == '1')
+             AT_VAL.ival = 10;
+           else
+             AT_VAL.fval = 0.2f],
+          [10 0.2])
+
+  # A Bison-defined union.
+  # The tokens names are not available directly in C++, we use their
+  # user number to keep it simple between C and C++.
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type union],
+          [%token <int> ONE 101;
+           %token <float> TWO 102 THREE 103;
+           %printer { ]AT_SKEL_CC_IF([[yyoutput << $$]],
+                                     [[fprintf (yyo, "%d", $$)]])[; } <int>
+           %printer { ]AT_SKEL_CC_IF([[yyoutput << $$]],
+                                     [[fprintf (yyo, "%f", $$)]])[; } <float>
+          ],
+          [ONE TWO THREE { printf ("%d %2.1f %2.1f\n", $1, $2, $3); }],
+          [{ 101, 102, 103, EOF }],
+          [if (res == 101)
+             AT_VAL.ONE = 10;
+           else if (res == 102)
+             AT_VAL.TWO = .2f;
+           else if (res == 103)
+             AT_VAL.THREE = 3.3f],
+          [10 0.2 3.3])
+
+  # A Bison-defined variant, for lalr1.cc only.
+  m4_if(b4_skel, [lalr1.cc], [
+  AT_TEST([%skeleton "]b4_skel["
+           %define api.value.type variant],
+          [%token <int> '1';
+           %token <std::string> '2';],
+          ['1' '2' { std::cout << $1 << ", " << $2 << std::endl; }],
+          ["12"],
+          [if (res == '1')
+             AT_VAL.build(10);
+           else
+             AT_VAL.build<std::string>("two");],
+          [10, two])])
+])
+
+m4_popdef([AT_TEST])
@@ -1 +1 @@
 .7
 .7.1