version 3.3.2

* NEWS: Record release date.

.prev-version

@@ -1 +1 @@
-3.2.2
+3.3.1

.travis.yml

@@ -8,7 +8,8 @@ language: cpp
 env:
   global:
     # ICC serial number.
-    secure: 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
+    # See https://github.com/nemequ/icc-travis.
+    secure: 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
 
 matrix:
   include:

NEWS

@@ -1,6 +1,26 @@
 GNU Bison NEWS
 
-* Noteworthy changes in release 3.2.90 (2019-01-12) [beta]
+* Noteworthy changes in release 3.3.2 (2019-02-03) [stable]
+
+** Bug fixes
+
+  Bison 3.3 failed to generate parsers for grammars with unused nonterminal
+  symbols.
+
+* Noteworthy changes in release 3.3.1 (2019-01-27) [stable]
+
+** Changes
+
+  The option -y/--yacc used to imply -Werror=yacc, which turns uses of Bison
+  extensions into errors.  It now makes them simple warnings (-Wyacc).
+
+* Noteworthy changes in release 3.3 (2019-01-26) [stable]
+
+  A new mailing list was created, Bison Announce.  It is low traffic, and is
+  only about announcing new releases and important messages (e.g., polls
+  about major decisions to make).
+
+  https://lists.gnu.org/mailman/listinfo/bison-announce
 
 ** Backward incompatible changes
 
@@ -9,6 +29,11 @@ GNU Bison NEWS
 
 ** Deprecated features
 
+  A new feature, --update (see below) helps adjusting existing grammars to
+  deprecations.
+
+*** Deprecated directives
+
   The %error-verbose directive is deprecated in favor of '%define
   parse.error verbose' since Bison 3.0, but no warning was issued.
 
@@ -16,9 +41,19 @@ GNU Bison NEWS
   api.prefix {xx}' since Bison 3.0, but no warning was issued.  These
   directives are slightly different, you might need to adjust your code.
   %name-prefix renames only symbols with external linkage, while api.prefix
-  also renames types and macros, including @code{YYDEBUG},
-  @code{YYTOKENTYPE}, @code{yytokentype}, @code{YYSTYPE}, @code{YYLTYPE},
-  etc.
+  also renames types and macros, including YYDEBUG, YYTOKENTYPE,
+  yytokentype, YYSTYPE, YYLTYPE, etc.
+
+  Users of Flex that move from '%name-prefix "xx"' to '%define api.prefix
+  {xx}' will typically have to update YY_DECL from
+
+    #define YY_DECL int xxlex (YYSTYPE *yylval, YYLTYPE *yylloc)
+
+  to
+
+    #define YY_DECL int xxlex (XXSTYPE *yylval, XXLTYPE *yylloc)
+
+*** Deprecated %define variable names
 
   The following variables, mostly related to parsers in Java, have been
   renamed for consistency.  Backward compatibility is ensured, but upgrading
@@ -35,14 +70,66 @@ GNU Bison NEWS
 
 ** New features
 
+*** Generation of fix-its for IDEs/Editors
+
+  When given the new option -ffixit (aka -fdiagnostics-parseable-fixits),
+  bison now generates machine readable editing instructions to fix some
+  issues.  Currently, this is mostly limited to updating deprecated
+  directives and removing duplicates.  For instance:
+
+    $ cat foo.y
+    %error-verbose
+    %define parser_class_name "Parser"
+    %define api.parser.class "Parser"
+    %%
+    exp:;
+
+  See the "fix-it:" lines below:
+
+    $ bison -ffixit foo.y
+    foo.y:1.1-14: warning: deprecated directive, use '%define parse.error verbose' [-Wdeprecated]
+     %error-verbose
+     ^~~~~~~~~~~~~~
+    fix-it:"foo.y":{1:1-1:15}:"%define parse.error verbose"
+    foo.y:2.1-34: warning: deprecated directive, use '%define api.parser.class {Parser}' [-Wdeprecated]
+     %define parser_class_name "Parser"
+     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    fix-it:"foo.y":{2:1-2:35}:"%define api.parser.class {Parser}"
+    foo.y:3.1-33: error: %define variable 'api.parser.class' redefined
+     %define api.parser.class "Parser"
+     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    foo.y:2.1-34:     previous definition
+     %define parser_class_name "Parser"
+     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    fix-it:"foo.y":{3:1-3:34}:""
+    foo.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
+
+  This uses the same output format as GCC and Clang.
+
+*** Updating grammar files
+
+  Fixes can be applied on the fly.  The previous example ends with the
+  suggestion to re-run bison with the option -u/--update, which results in a
+  cleaner grammar file.
+
+    $ bison --update foo.y
+    [...]
+    bison: file 'foo.y' was updated (backup: 'foo.y~')
+
+    $ cat foo.y
+    %define parse.error verbose
+    %define api.parser.class {Parser}
+    %%
+    exp:;
+
 *** Bison is now relocatable
 
   If you pass '--enable-relocatable' to 'configure', Bison is relocatable.
 
   A relocatable program can be moved or copied to a different location on
   the file system.  It can also be used through mount points for network
-  sharing.  It is possible to make symlinks to the installed and moved
-  programs, and invoke them through the symlink.
+  sharing.  It is possible to make symbolic links to the installed and moved
+  programs, and invoke them through the symbolic link.
 
 *** %expect and %expect-rr modifiers on individual rules
 
@@ -121,7 +208,7 @@ GNU Bison NEWS
 *** C++: Actual token constructors
 
   When variants and token constructors are enabled, in addition to the
-  type-safe named token constructors (make_ID, amke_INT, etc.), we now
+  type-safe named token constructors (make_ID, make_INT, etc.), we now
   generate genuine constructors for symbol_type.
 
   For instance with these declarations
@@ -136,17 +223,18 @@ GNU Bison NEWS
     symbol_type (int token, const int&);
     symbol_type (int token);
 
-  which should be used in a Flex-scanner as follows.
-
-    %%
-    [a-z]+   return yy::parser::symbol_type (ID, yytext);
-    [0-9]+   return yy::parser::symbol_type (INT, text_to_int (yytext);
-    ":"      return yy::parser::symbol_type (’:’);
-    <<EOF>>  return yy::parser::symbol_type (0);
-
   Correct matching between token types and value types is checked via
-  'assert'.  For instance, 'symbol_type (ID, 42)' would abort (while
-  'make_ID (42)' would not even compile).
+  'assert'; for instance, 'symbol_type (ID, 42)' would abort.  Named
+  constructors are preferable, as they offer better type safety (for
+  instance 'make_ID (42)' would not even compile), but symbol_type
+  constructors may help when token types are discovered at run-time, e.g.,
+
+     [a-z]+   {
+                if (auto i = lookup_keyword (yytext))
+                  return yy::parser::symbol_type (i);
+                else
+                  return yy::parser::make_ID (yytext);
+              }
 
 *** C++: Variadic emplace
 
@@ -238,7 +326,7 @@ GNU Bison NEWS
   where TAG denotes a type tag such as ‘<ival>’, ID denotes an identifier
   such as ‘NUM’, NUMBER a decimal or hexadecimal integer such as ‘300’ or
   ‘0x12d’, CHAR a character literal such as ‘'+'’, and STRING a string
-  literal such as ‘"number"’.  The postfix quantifiers are ‘?’ (zero or
+  literal such as ‘"number"’.  The post-fix quantifiers are ‘?’ (zero or
   one), ‘*’ (zero or more) and ‘+’ (one or more).
 
 * Noteworthy changes in release 3.2.4 (2018-12-24) [stable]
@@ -3395,10 +3483,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  LocalWords:  pragmas noreturn untyped Rozenman unexpanded Wojciech Polak
  LocalWords:  Alexandre MERCHANTABILITY yytype emplace ptr automove lvalues
  LocalWords:  nonterminal yy args Pragma dereference yyformat rhs docdir
- LocalWords:  Redeclarations rpcalc Autoconf YFLAGS Makefiles PROG
- LocalWords:  Heimbigner AST src ast Makefile srcdir MinGW
+ LocalWords:  Redeclarations rpcalc Autoconf YFLAGS Makefiles PROG DECL num
+ LocalWords:  Heimbigner AST src ast Makefile srcdir MinGW xxlex XXSTYPE
+ LocalWords:  XXLTYPE strictfp IDEs ffixit fdiagnostics parseable fixits
+ LocalWords:  Wdeprecated yytext Variadic variadic yyrhs yyphrs RCS README
+ LocalWords:  noexcept constexpr ispell american deprecations
 
 Local Variables:
+ispell-dictionary: "american"
 mode: outline
 fill-column: 76
 End:

THANKS

@@ -18,6 +18,7 @@ Antonio Silva Correia     [email protected]
 Arnold Robbins            [email protected]
 Art Haas                  [email protected]
 Askar Safin               [email protected]
+Balázs Scheidler          [email protected]
 Baron Schwartz            [email protected]
 Ben Pfaff                 [email protected]
 Benoit Perrot             [email protected]

TODO

@@ -1,5 +1,7 @@
 * Bison 3.4
 ** injection rules
+** glr.cc
+move glr.c into the yy namespace
 ** improve syntax errors (UTF-8, internationalization)
 Bison depends on the current locale.  For instance:
 

bootstrap.conf

@@ -17,7 +17,7 @@
 
 # gnulib modules used by this package.
 gnulib_modules='
-  argmatch assert
+  argmatch array-list assert
   bitsetv
   calloc-posix close closeout config-h c-strcase
   configmake
@@ -26,7 +26,9 @@ gnulib_modules='
   getopt-gnu
   gettext git-version-gen gitlog-to-changelog
   gpl-3.0 hash inttypes isnan javacomp-script
-  javaexec-script ldexpl malloc-gnu
+  javaexec-script
+  ldexpl
+  malloc-gnu
   mbswidth
   non-recursive-gnulib-prefix-hack
   obstack
@@ -36,6 +38,7 @@ gnulib_modules='
   readme-release
   realloc-posix
   relocatable-prog relocatable-script
+  rename
   spawn-pipe stdbool stpcpy strdup-posix strerror strverscmp
   timevar
   unistd unistd-safer unlink unlocked-io
@@ -44,6 +47,7 @@ gnulib_modules='
   xalloc
   xalloc-die
   xconcat-filename
+  xlist
   xmemdup0
   xstrndup
 

build-aux/cross-options.pl

@@ -48,7 +48,11 @@ while (<STDIN>)
             # are strings and have the same syntax as on the command line.
             if ($dir_arg eq 'name[=value]')
             {
-                $dir_arg = '@var{name} ["@var{value}"]';
+                # -D/-F do not add quotes to the argument.
+                $dir_arg =
+                    $dir eq "%define"
+                    ? '@var{name} [@var{value}]'
+                    : '@var{name} ["@var{value}"]';
             }
             else
             {

cfg.mk

@@ -160,6 +160,7 @@ exclude = \
   $(foreach a,$(1),$(eval $(subst $$,$$$$,exclude_file_name_regexp--sc_$(a))))
 $(call exclude,                                                                 \
   bindtextdomain=^lib/main.c$$                                                  \
+  cast_of_argument_to_free=^src/muscle-tab.c$$                                  \
   preprocessor_indentation=^data/|^lib/|^src/parse-gram.[ch]$$                  \
   program_name=^lib/main.c$$                                                    \
   prohibit_always-defined_macros=^data/skeletons/yacc.c$$                       \

configure.ac

@@ -96,9 +96,11 @@ AM_CONDITIONAL([ENABLE_GCC_WARNINGS], [test "$enable_gcc_warnings" = yes])
 if test "$enable_gcc_warnings" = yes; then
   warn_common='-Wall -Wextra -Wno-sign-compare -Wcast-align
     -fparse-all-comments -Wdocumentation
-    -Wformat -Wnull-dereference -Wpointer-arith -Wwrite-strings'
-  warn_c='-Wbad-function-cast -Wshadow -Wstrict-prototypes'
-  warn_cxx='-Wnoexcept'
+    -Wformat -Wimplicit-fallthrough -Wnull-dereference
+    -Wpointer-arith -Wshadow
+    -Wwrite-strings'
+  warn_c='-Wbad-function-cast -Wstrict-prototypes'
+  warn_cxx='-Wextra-semi -Wnoexcept -Wundefined-func-template -Wweak-vtables'
   # Warnings for the test suite only.
   #
   # -fno-color-diagnostics: Clang's use of colors in the error

data/README

@@ -75,48 +75,75 @@ skeletons.
 
 ## Symbols
 
+### `b4_symbol(NUM, FIELD)`
 In order to unify the handling of the various aspects of symbols (tag, type
 name, whether terminal, etc.), bison.exe defines one macro per (token,
 field), where field can `has_id`, `id`, etc.: see
-src/output.c:prepare_symbols_definitions().
+`prepare_symbols_definitions()` in `src/output.c`.
 
-The various FIELDS are:
+The macro `b4_symbol(NUM, FIELD)` gives access to the following FIELDS:
+
+- `has_id`: 0 or 1.
 
-- has_id: 0 or 1.
   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.
+
+- `id`: string
+  If has_id, the id (prefixed by api.token.prefix if defined), otherwise
+  defined as empty.  Guaranteed to be usable as a C identifier.
+
+- `tag`: string.
   A representation of the symbol.  Can be 'foo', 'foo.id', '"foo"' etc.
-- user_number: integer
+
+- `user_number`: integer
   The external number as used by yylex.  Can be ASCII code when a character,
   some number chosen by bison, or some user number in the case of
   %token FOO <NUM>.  Corresponds to yychar in yacc.c.
-- is_token: 0 or 1
+
+- `is_token`: 0 or 1
   Whether this is a terminal symbol.
-- number: integer
+
+- `number`: integer
   The internal number (computed from the external number by yytranslate).
   Corresponds to yytoken in yacc.c.  This is the same number that serves as
   key in b4_symbol(NUM, FIELD).
-- has_type: 0, 1
+
+  In bison, symbols are first assigned increasing numbers in order of
+  appearance (but tokens first, then nterms).  After grammar reduction,
+  unused nterms are then renumbered to appear last (i.e., first tokens, then
+  used nterms and finally unused nterms).  This final number NUM is the one
+  contained in this field, and it is the one used as key in `b4_symbol(NUM,
+  FIELD)`.
+
+  The code of the rule actions, however, is emitted before we know what
+  symbols are unused, so they use the original numbers.  To avoid confusion,
+  they actually use "orig NUM" instead of just "NUM".  bison also emits
+  definitions for `b4_symbol(orig NUM, number)` that map from original
+  numbers to the new ones.  `b4_symbol` actually resolves `orig NUM` in the
+  other case, i.e., `b4_symbol(orig 42, tag)` would return the tag of the
+  symbols whose original number was 42.
+
+- `has_type`: 0, 1
   Whether has a semantic value.
-- type_tag: string
+
+- `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
+
+- `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
-- printer_line: integer
+
+- `has_printer`: 0, 1
+- `printer`: string
+- `printer_file`: string
+- `printer_line`: integer
   If the symbol has a printer, everything about it.
-- has_destructor, destructor, destructor_file, destructor_line
+
+- `has_destructor`, `destructor`, `destructor_file`, `destructor_line`
   Likewise.
 
-### b4_symbol_value(VAL, [SYMBOL-NUM], [TYPE-TAG])
+### `b4_symbol_value(VAL, [SYMBOL-NUM], [TYPE-TAG])`
 Expansion of $$, $1, $<TYPE-TAG>3, etc.
 
 The semantic value from a given VAL.
@@ -127,14 +154,14 @@ The semantic value from a given VAL.
 The result can be used safely, it is put in parens to avoid nasty precedence
 issues.
 
-### b4_lhs_value(SYMBOL-NUM, [TYPE])
+### `b4_lhs_value(SYMBOL-NUM, [TYPE])`
 Expansion of `$$` or `$<TYPE>$`, for symbol `SYMBOL-NUM`.
 
-### b4_rhs_data(RULE-LENGTH, POS)
+### `b4_rhs_data(RULE-LENGTH, POS)`
 The data corresponding to the symbol `#POS`, where the current rule has
 `RULE-LENGTH` symbols on RHS.
 
-### b4_rhs_value(RULE-LENGTH, POS, SYMBOL-NUM, [TYPE])
+### `b4_rhs_value(RULE-LENGTH, POS, SYMBOL-NUM, [TYPE])`
 Expansion of `$<TYPE>POS`, where the current rule has `RULE-LENGTH` symbols
 on RHS.
 

data/skeletons/bison.m4

@@ -389,17 +389,28 @@ m4_define([b4_glr_cc_if],
 #
 # The following macros provide access to symbol related values.
 
-# _b4_symbol(NUM, FIELD)
-# ----------------------
+# __b4_symbol(NUM, FIELD)
+# -----------------------
 # Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
 # undefined.
-m4_define([_b4_symbol],
+m4_define([__b4_symbol],
 [m4_indir([b4_symbol($1, $2)])])
 
 
+# _b4_symbol(NUM, FIELD)
+# ----------------------
+# Recover a FIELD about symbol #NUM (or "orig NUM").  Fails if
+# undefined.
+m4_define([_b4_symbol],
+[m4_ifdef([b4_symbol($1, number)],
+          [__b4_symbol(m4_indir([b4_symbol($1, number)]), $2)],
+          [__b4_symbol([$1], [$2])])])
+
+
+
 # b4_symbol(NUM, FIELD)
 # ---------------------
-# Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
+# Recover a FIELD about symbol #NUM (or "orig NUM").  Fails if
 # undefined.  If FIELD = id, prepend the token prefix.
 m4_define([b4_symbol],
 [m4_case([$2],
@@ -480,7 +491,9 @@ m4_popdef([b4_actions_])dnl
 
 # _b4_symbol_case(SYMBOL-NUM)
 # ---------------------------
-# Issue a "case NUM" for SYMBOL-NUM.
+# Issue a "case NUM" for SYMBOL-NUM.  Ends with its EOL to make it
+# easier to use with m4_map, but then, use []dnl to suppress the last
+# one.
 m4_define([_b4_symbol_case],
 [case b4_symbol([$1], [number]): b4_symbol_tag_comment([$1])])
 ])

data/skeletons/c++.m4

@@ -77,11 +77,13 @@ m4_define([b4_cxx_portability],
 // Support noexcept when possible.
 #if 201103L <= YY_CPLUSPLUS
 # define YY_NOEXCEPT noexcept
+# define YY_NOTHROW
 #else
 # define YY_NOEXCEPT
-#endif[]dnl
+# define YY_NOTHROW throw ()
+#endif
 
-// Support noexcept when possible.
+// Support constexpr when possible.
 #if 201703 <= YY_CPLUSPLUS
 # define YY_CONSTEXPR constexpr
 #else
@@ -217,7 +219,14 @@ m4_define([b4_public_types_declare],
       syntax_error (]b4_locations_if([const location_type& l, ])[const std::string& m)
         : std::runtime_error (m)]b4_locations_if([
         , location (l)])[
-      {}]b4_locations_if([
+      {}
+
+      syntax_error (const syntax_error& s)
+        : std::runtime_error (s.what ())]b4_locations_if([
+        , location (s.location)])[
+      {}
+
+      ~syntax_error () YY_NOEXCEPT YY_NOTHROW;]b4_locations_if([
 
       location_type location;])[
     };
@@ -260,7 +269,10 @@ m4_define([b4_symbol_type_define],
       typedef Base super_type;
 
       /// Default constructor.
-      basic_symbol ();
+      basic_symbol ()
+        : value ()]b4_locations_if([
+        , location ()])[
+      {}
 
 #if 201103L <= YY_CPLUSPLUS
       /// Move constructor.
@@ -282,10 +294,29 @@ m4_define([b4_symbol_type_define],
                     YY_RVREF (location_type) l])[);
 ]])[
       /// Destroy the symbol.
-      ~basic_symbol ();
+      ~basic_symbol ()
+      {
+        clear ();
+      }
 
       /// Destroy contents, and record that is empty.
-      void clear ();
+      void clear ()
+      {]b4_variant_if([[
+        // User destructor.
+        symbol_number_type yytype = this->type_get ();
+        basic_symbol<Base>& yysym = *this;
+        (void) yysym;
+        switch (yytype)
+        {
+]b4_symbol_foreach([b4_symbol_destructor])dnl
+[       default:
+          break;
+        }
+
+        // Type destructor.
+]b4_symbol_variant([[yytype]], [[value]], [[template destroy]])])[
+        Base::clear ();
+      }
 
       /// Whether empty.
       bool empty () const YY_NOEXCEPT;
@@ -352,7 +383,7 @@ m4_define([b4_symbol_type_define],
       typedef basic_symbol<by_type> super_type;
 
       /// Empty symbol.
-      symbol_type () {};
+      symbol_type () {}
 
       /// Constructor for valueless symbols, and symbols from each type.
 ]b4_type_foreach([_b4_token_constructor_define])dnl
@@ -365,12 +396,6 @@ m4_define([b4_symbol_type_define],
 # Provide the implementation needed by the public types.
 m4_define([b4_public_types_define],
 [[  // basic_symbol.
-  template <typename Base>
-  ]b4_parser_class[::basic_symbol<Base>::basic_symbol ()
-    : value ()]b4_locations_if([
-    , location ()])[
-  {}
-
 #if 201103L <= YY_CPLUSPLUS
   template <typename Base>
   ]b4_parser_class[::basic_symbol<Base>::basic_symbol (basic_symbol&& that)
@@ -416,32 +441,6 @@ m4_define([b4_public_types_define],
     (void) v;
     ]b4_symbol_variant([this->type_get ()], [value], [YY_MOVE_OR_COPY], [YY_MOVE (v)])])[}]])[
 
-  template <typename Base>
-  ]b4_parser_class[::basic_symbol<Base>::~basic_symbol ()
-  {
-    clear ();
-  }
-
-  template <typename Base>
-  void
-  ]b4_parser_class[::basic_symbol<Base>::clear ()
-  {]b4_variant_if([[
-    // User destructor.
-    symbol_number_type yytype = this->type_get ();
-    basic_symbol<Base>& yysym = *this;
-    (void) yysym;
-    switch (yytype)
-    {
-]b4_symbol_foreach([b4_symbol_destructor])dnl
-[   default:
-      break;
-    }
-
-    // Type destructor.
-  ]b4_symbol_variant([[yytype]], [[value]], [[template destroy]])])[
-    Base::clear ();
-  }
-
   template <typename Base>
   bool
   ]b4_parser_class[::basic_symbol<Base>::empty () const YY_NOEXCEPT
@@ -517,7 +516,7 @@ m4_define([b4_public_types_define],
 ])
 
 
-# b4_tolen_constructor_define
+# b4_token_constructor_define
 # ----------------------------
 # Define symbol constructors for all the value types.
 # Use at class-level.  Redefined in variant.hh.

data/skeletons/glr.c

@@ -590,7 +590,10 @@ yytnamerr (char *yyres, const char *yystr)
           case '\\':
             if (*++yyp != '\\')
               goto do_not_strip_quotes;
-            /* Fall through.  */
+            else
+              goto append;
+
+          append:
           default:
             if (yyres)
               yyres[yyn] = *yyp;

data/skeletons/glr.cc

@@ -160,6 +160,9 @@ m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
   ]b4_parser_class::~b4_parser_class[ ()
   {}
 
+  ]b4_parser_class[::syntax_error::~syntax_error () YY_NOEXCEPT YY_NOTHROW
+  {}
+
   int
   ]b4_parser_class[::operator() ()
   {
@@ -246,9 +249,12 @@ b4_percent_code_get([[requires]])[
 #include <stdexcept>
 #include <string>
 
-]m4_ifdef([b4_location_file],
+]b4_cxx_portability[
+]m4_ifdef([b4_location_include],
           [[# include ]b4_location_include])[
+]b4_variant_if([b4_variant_includes])[
 
+]b4_attribute_define[
 ]b4_null_define[
 
 // Whether we are compiled with exception support.
@@ -263,6 +269,7 @@ b4_percent_code_get([[requires]])[
 ]b4_YYDEBUG_define[
 
 ]b4_namespace_open[
+
 ]b4_bison_locations_if([m4_ifndef([b4_location_file],
                                   [b4_location_define])])[
 

data/skeletons/lalr1.cc

@@ -110,7 +110,7 @@ b4_dollar_pushdef([yysym.value],
                   [$1],
                   [],
                   [yysym.location])dnl
-      _b4_symbol_case([$1])
+      _b4_symbol_case([$1])[]dnl
 b4_syncline([b4_symbol([$1], [$2_line])], [b4_symbol([$1], [$2_file])])
         b4_symbol([$1], [$2])
 b4_syncline([@oline@], [@ofile@])
@@ -532,7 +532,10 @@ m4_if(b4_prefix, [yy], [],
             case '\\':
               if (*++yyp != '\\')
                 goto do_not_strip_quotes;
-              // Fall through.
+              else
+                goto append;
+
+            append:
             default:
               yyr += *yyp;
               break;
@@ -559,6 +562,8 @@ m4_if(b4_prefix, [yy], [],
   ]b4_parser_class::~b4_parser_class[ ()
   {}
 
+  ]b4_parser_class[::syntax_error::~syntax_error () YY_NOEXCEPT YY_NOTHROW
+  {}
 
   /*---------------.
   | Symbol types.  |
@@ -659,10 +664,12 @@ m4_if(b4_prefix, [yy], [],
     std::ostream& yyoutput = yyo;
     YYUSE (yyoutput);
     symbol_number_type yytype = yysym.type_get ();
+#if defined __GNUC__ && ! defined __clang__ && ! defined __ICC && __GNUC__ * 100 + __GNUC_MINOR__ <= 408
     // Avoid a (spurious) G++ 4.8 warning about "array subscript is
     // below array bounds".
     if (yysym.empty ())
       std::abort ();
+#endif
     yyo << (yytype < yyntokens_ ? "token" : "nterm")
         << ' ' << yytname_[yytype] << " ("]b4_locations_if([
         << yysym.location << ": "])[;
@@ -896,8 +903,8 @@ b4_dollar_popdef])[]dnl
 [
       // Default location.
       {
-        slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
-        YYLLOC_DEFAULT (yylhs.location, slice, yylen);
+        stack_type::slice range (yystack_, yylen);
+        YYLLOC_DEFAULT (yylhs.location, range, yylen);
         yyerror_range[1].location = yylhs.location;
       }]])[
 

data/skeletons/stack.hh

@@ -122,33 +122,32 @@ m4_define([b4_stack_define],
         return seq_.rend ();
       }
 
+      /// Present a slice of the top of a stack.
+      class slice
+      {
+      public:
+        slice (const stack& stack, int range)
+          : stack_ (stack)
+          , range_ (range)
+        {}
+
+        const T&
+        operator[] (int i) const
+        {
+          return stack_[range_ - i];
+        }
+
+      private:
+        const stack& stack_;
+        int range_;
+      };
+
     private:
       stack (const stack&);
       stack& operator= (const stack&);
       /// The wrapped container.
       S seq_;
     };
-
-    /// Present a slice of the top of a stack.
-    template <typename T, typename S = stack<T> >
-    class slice
-    {
-    public:
-      slice (const S& stack, int range)
-        : stack_ (stack)
-        , range_ (range)
-      {}
-
-      const T&
-      operator[] (int i) const
-      {
-        return stack_[range_ - i];
-      }
-
-    private:
-      const S& stack_;
-      int range_;
-    };
 ]])
 
 m4_ifdef([b4_stack_file],

data/skeletons/yacc.c

@@ -1066,7 +1066,10 @@ yytnamerr (char *yyres, const char *yystr)
           case '\\':
             if (*++yyp != '\\')
               goto do_not_strip_quotes;
-            /* Fall through.  */
+            else
+              goto append;
+
+          append:
           default:
             if (yyres)
               yyres[yyn] = *yyp;

doc/bison.texi

@@ -4278,16 +4278,16 @@ final action does not use @code{$3}).  Bison reports these errors when the
 Bison}):
 
 @example
-$ bison -Wmidrule-value mid.y
+$ @kbd{bison -Wmidrule-value mid.y}
 @group
 mid.y:2.6-13: warning: unset value: $$
  exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
-      ^^^^^^^^
+      ^~~~~~~~
 @end group
 @group
 mid.y:2.19-31: warning: unused value: $3
  exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
-                   ^^^^^^^^^^^^^
+                   ^~~~~~~~~~~~~
 @end group
 @end example
 
@@ -6650,6 +6650,28 @@ For example, if you use @samp{%define api.prefix @{c@}}, the names become
 @code{cparse}, @code{clex}, @dots{}, @code{CSTYPE}, @code{CLTYPE}, and so
 on.
 
+Users of Flex must update the signature of the generated @code{yylex}
+function.  Since the Flex scanner usually includes the generated header of
+the parser (to get the definitions of the tokens, etc.), the most convenient
+way is to insert the declaration of @code{yylex} in the @code{provides}
+section:
+
+@example
+%define api.prefix @{c@}
+// Emitted in the header file, after the definition of YYSTYPE.
+%code provides
+@{
+  // Tell Flex the expected prototype of yylex.
+  #define YY_DECL                             \
+    int clex (CSTYPE *yylval, CLTYPE *yylloc)
+
+  // Declare the scanner.
+  YY_DECL;
+@}
+@end example
+
+@sp 1
+
 The @code{%define} variable @code{api.prefix} works in two different ways.
 In the implementation file, it works by adding macro definitions to the
 beginning of the parser implementation file, defining @code{yyparse} as
@@ -9309,7 +9331,7 @@ calc.y: warning: 1 nonterminal useless in grammar [-Wother]
 calc.y: warning: 1 rule useless in grammar [-Wother]
 calc.y:19.1-7: warning: nonterminal useless in grammar: useless [-Wother]
  useless: STR;
- ^^^^^^^
+ ^~~~~~~
 calc.y: warning: 7 shift/reduce conflicts [-Wconflicts-sr]
 @end example
 
@@ -9842,12 +9864,12 @@ Used to output an xhtml enhancement of the @samp{.output} file.
 
 Sample usage (requires @command{xsltproc}):
 @example
-$ bison -x gr.y
+$ @kbd{bison -x gr.y}
 @group
-$ bison --print-datadir
+$ @kbd{bison --print-datadir}
 /usr/local/share/bison
 @end group
-$ xsltproc /usr/local/share/bison/xslt/xml2xhtml.xsl gr.xml >gr.html
+$ @kbd{xsltproc /usr/local/share/bison/xslt/xml2xhtml.xsl gr.xml >gr.html}
 @end example
 
 @c ================================================= Tracing
@@ -10247,28 +10269,65 @@ Print the name of the directory containing locale-dependent data.
 @item --print-datadir
 Print the name of the directory containing skeletons and XSLT.
 
+@item -u
+@item --update
+Update the grammar file (remove duplicates, update deprecated directives,
+etc.) and exit (i.e., do not generate any of the output files).  Leaves a
+backup of the original file with a @code{~} appended.  For instance:
+
+@example
+@group
+$ @kbd{cat foo.y}
+%error-verbose
+%define parse.error verbose
+%%
+exp:;
+@end group
+@group
+$ @kbd{bison -u foo.y}
+foo.y:1.1-14: warning: deprecated directive, use '%define parse.error verbose' [-Wdeprecated]
+ %error-verbose
+ ^~~~~~~~~~~~~~
+foo.y:2.1-27: error: %define variable 'parse.error' redefined
+ %define parse.error verbose
+ ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+foo.y:1.1-14:     previous definition
+ %error-verbose
+ ^~~~~~~~~~~~~~
+bison: file 'foo.y' was updated (backup: 'foo.y~')
+@end group
+@group
+$ @kbd{cat foo.y}
+%define parse.error verbose
+%%
+exp:;
+@end group
+@end example
+
+See the documentation of @option{--feature=fixit} below for more details.
+
 @item -y
 @itemx --yacc
-Act more like the traditional Yacc command.  This can cause different
-diagnostics to be generated, and may change behavior in other minor
-ways.  Most importantly, imitate Yacc's output file name conventions,
-so that the parser implementation file is called @file{y.tab.c}, and
-the other outputs are called @file{y.output} and @file{y.tab.h}.
-Also, if generating a deterministic parser in C, generate
-@code{#define} statements in addition to an @code{enum} to associate
-token numbers with token names.  Thus, the following shell script can
-substitute for Yacc, and the Bison distribution contains such a script
-for compatibility with POSIX:
+Act more like the traditional @command{yacc} command.  This can cause
+different diagnostics to be generated (it implies @option{-Wyacc}), and may
+change behavior in other minor ways.  Most importantly, imitate Yacc's
+output file name conventions, so that the parser implementation file is
+called @file{y.tab.c}, and the other outputs are called @file{y.output} and
+@file{y.tab.h}.  Also, if generating a deterministic parser in C, generate
+@code{#define} statements in addition to an @code{enum} to associate token
+numbers with token names.  Thus, the following shell script can substitute
+for Yacc, and the Bison distribution contains such a script for
+compatibility with POSIX:
 
 @example
 #! /bin/sh
 bison -y "$@@"
 @end example
 
-The @option{-y}/@option{--yacc} option is intended for use with
-traditional Yacc grammars.  If your grammar uses a Bison extension
-like @samp{%glr-parser}, Bison might not be Yacc-compatible even if
-this option is specified.
+The @option{-y}/@option{--yacc} option is intended for use with traditional
+Yacc grammars.  If your grammar uses Bison extensions like
+@samp{%glr-parser}, Bison might not be Yacc-compatible even if this option
+is specified.
 
 @item -W [@var{category}]
 @itemx --warnings[=@var{category}]
@@ -10353,17 +10412,17 @@ Bison reports:
 @group
 warning: useless precedence and associativity for "="
  %nonassoc "="
-           ^^^
+           ^~~
 @end group
 @group
 warning: useless associativity for "*", use %precedence
  %left "*"
-       ^^^
+       ^~~
 @end group
 @group
 warning: useless precedence for "("
  %precedence "("
-             ^^^
+             ^~~
 @end group
 @end example
 
@@ -10412,8 +10471,8 @@ the following commands are @emph{not} equivalent, as the first will not treat
 S/R conflicts as errors.
 
 @example
-$ bison -Werror=yacc,conflicts-sr input.y
-$ bison -Werror=yacc,error=conflicts-sr input.y
+$ @kbd{bison -Werror=yacc,conflicts-sr input.y}
+$ @kbd{bison -Werror=yacc,error=conflicts-sr input.y}
 @end example
 
 @item -Wno-error
@@ -10449,27 +10508,27 @@ When invoked with @option{-fcaret} (or nothing), Bison will report:
 @group
 in.y:3.20-23: error: ambiguous reference: '$exp'
  exp: exp '+' exp @{ $exp = $1 + $2; @};
-                    ^^^^
+                    ^~~~
 @end group
 @group
 in.y:3.1-3:       refers to: $exp at $$
  exp: exp '+' exp @{ $exp = $1 + $2; @};
- ^^^
+ ^~~
 @end group
 @group
 in.y:3.6-8:       refers to: $exp at $1
  exp: exp '+' exp @{ $exp = $1 + $2; @};
-      ^^^
+      ^~~
 @end group
 @group
 in.y:3.14-16:     refers to: $exp at $3
  exp: exp '+' exp @{ $exp = $1 + $2; @};
-              ^^^
+              ^~~
 @end group
 @group
 in.y:3.32-33: error: $2 of 'exp' has no declared type
  exp: exp '+' exp @{ $exp = $1 + $2; @};
-                                ^^
+                                ^~
 @end group
 @end example
 
@@ -10487,6 +10546,61 @@ in.y:3.32-33: error: $2 of ‘exp’ has no declared type
 
 This option is activated by default.
 
+@item fixit
+@itemx diagnostics-parseable-fixits
+Show machine-readable fixes, in a manner similar to GCC's and Clang's
+@option{-fdiagnostics-parseable-fixits}.
+
+Fix-its are generated for duplicate directives:
+
+@example
+@group
+$ @kbd{cat foo.y}
+%define api.prefix @{foo@}
+%define api.prefix @{bar@}
+%%
+exp:;
+@end group
+
+@group
+$ @kbd{bison -ffixit foo.y}
+foo.y:2.1-24: error: %define variable 'api.prefix' redefined
+ %define api.prefix @{bar@}
+ ^~~~~~~~~~~~~~~~~~~~~~~~
+foo.y:1.1-24:     previous definition
+ %define api.prefix @{foo@}
+ ^~~~~~~~~~~~~~~~~~~~~~~~
+fix-it:"foo.y":@{2:1-2:25@}:""
+foo.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
+@end group
+@end example
+
+They are also generated to update deprecated directives, unless
+@option{-Wno-deprecated} was given:
+
+@example
+@group
+$ @kbd{cat /tmp/foo.yy}
+%error-verbose
+%name-prefix "foo"
+%%
+exp:;
+@end group
+@group
+$ @kbd{bison foo.y}
+foo.y:1.1-14: warning: deprecated directive, use '%define parse.error verbose' [-Wdeprecated]
+ %error-verbose
+ ^~~~~~~~~~~~~~
+foo.y:2.1-18: warning: deprecated directive, use '%define api.prefix @{foo@}' [-Wdeprecated]
+ %name-prefix "foo"
+ ^~~~~~~~~~~~~~~~~~
+foo.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
+@end group
+@end example
+
+The fix-its are applied by @command{bison} itself when given the option
+@option{-u}/@option{--update}.  See its documentation above.
+
 @end table
 @end table
 
@@ -10926,10 +11040,10 @@ int main ()
 Compile, and run!
 
 @example
-$ bison simple.yy -o simple.cc
-$ g++ -std=c++14 simple.cc -o simple
+$ @kbd{bison simple.yy -o simple.cc}
+$ @kbd{g++ -std=c++14 simple.cc -o simple}
 @group
-$ ./simple
+$ @kbd{./simple}
 @{I have three numbers for you., 1, 2, 3, And that's all!@}
 @end group
 @end example

examples/test

@@ -15,6 +15,9 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+SHELL=/bin/sh
+export SHELL
+
 me=$(basename "$1" .test)
 medir=$(dirname "$1" | sed -e 's,.*examples/,,')
 

lib/.gitignore

@@ -8,6 +8,10 @@
 /alignof.h
 /alloca.h
 /alloca.in.h
+/allocator.c
+/allocator.h
+/areadlink.c
+/areadlink.h
 /arg-nonnull.h
 /argmatch.c
 /argmatch.h
@@ -18,6 +22,11 @@
 /binary-io.h
 /bitrotate.c
 /bitrotate.h
+/bitset.c
+/bitset.h
+/bitset/
+/bitsetv.c
+/bitsetv.h
 /c++defs.h
 /c-ctype.c
 /c-ctype.h
@@ -26,6 +35,9 @@
 /c-strcaseeq.h
 /c-strncasecmp.c
 /calloc.c
+/canonicalize-lgpl.c
+/careadlinkat.c
+/careadlinkat.h
 /charset.alias
 /cloexec.c
 /cloexec.h
@@ -78,6 +90,8 @@
 /fseterr.h
 /fstat.c
 /getdtablesize.c
+/gethrxtime.c
+/gethrxtime.h
 /getopt-cdefs.in.h
 /getopt-core.h
 /getopt-ext.h
@@ -90,7 +104,16 @@
 /getopt_int.h
 /getprogname.c
 /getprogname.h
+/getrusage.c
 /gettext.h
+/gettime.c
+/gettimeofday.c
+/gl_array_list.c
+/gl_array_list.h
+/gl_list.c
+/gl_list.h
+/gl_xlist.c
+/gl_xlist.h
 /gnulib.mk
 /hard-locale.c
 /hard-locale.h
@@ -112,6 +135,8 @@
 /limits.in.h
 /localcharset.c
 /localcharset.h
+/localtime-buffer.c
+/localtime-buffer.h
 /lstat.c
 /malloc.c
 /malloca.c
@@ -150,17 +175,23 @@
 /printf.c
 /progname.c
 /progname.h
+/progreloc.c
 /quote.h
 /quotearg.c
 /quotearg.h
 /raise.c
 /rawmemchr.c
 /rawmemchr.valgrind
+/readlink.c
 /realloc.c
 /ref-add.sed
 /ref-del.sed
+/relocatable.c
+/relocatable.h
+/relocwrapper.c
 /sched.h
 /sched.in.h
+/setenv.c
 /sig-handler.c
 /sig-handler.h
 /sigaction.c
@@ -190,6 +221,8 @@
 /spawnp.c
 /sprintf.c
 /stamp-h1
+/stat-time.c
+/stat-time.h
 /stat-w32.c
 /stat-w32.h
 /stat.c
@@ -223,13 +256,20 @@
 /strverscmp.c
 /sys
 /sys_ioctl.in.h
+/sys_resource.in.h
 /sys_socket.in.h
 /sys_stat.in.h
+/sys_time.in.h
+/sys_times.in.h
 /sys_types.in.h
 /sys_wait.in.h
 /sysexits.in.h
 /time.h
 /time.in.h
+/timespec.c
+/timespec.h
+/timevar.c
+/timevar.h
 /unistd--.h
 /unistd-safer.h
 /unistd.c
@@ -267,45 +307,14 @@
 /xmalloc.c
 /xmemdup0.c
 /xmemdup0.h
+/xreadlink.c
+/xreadlink.h
 /xsize.c
 /xsize.h
 /xstrndup.c
 /xstrndup.h
-/stat-time.c
-/stat-time.h
-/timevar.c
-/timevar.h
-/sys_time.in.h
-/sys_times.in.h
-/gethrxtime.c
-/gethrxtime.h
-/getrusage.c
-/gettime.c
-/gettimeofday.c
-/localtime-buffer.c
-/localtime-buffer.h
-/sys_resource.in.h
-/timespec.c
-/timespec.h
 /xtime.c
 /xtime.h
-/bitset.c
-/bitset.h
-/bitset/
-/bitsetv.c
-/bitsetv.h
-/allocator.c
-/allocator.h
-/areadlink.c
-/areadlink.h
-/canonicalize-lgpl.c
-/careadlinkat.c
-/careadlinkat.h
-/progreloc.c
-/readlink.c
-/relocatable.c
-/relocatable.h
-/relocwrapper.c
-/setenv.c
-/xreadlink.c
-/xreadlink.h
+/rename.c
+/rmdir.c
+/same-inode.h

po/POTFILES.in

@@ -1,6 +1,7 @@
 src/complain.c
 src/conflicts.c
 src/files.c
+src/fixits.c
 src/getargs.c
 src/gram.c
 src/graphviz.c

src/complain.c

@@ -28,6 +28,7 @@
 
 #include "complain.h"
 #include "files.h"
+#include "fixits.h"
 #include "getargs.h"
 #include "quote.h"
 
@@ -278,15 +279,18 @@ error_message (const location *loc, warnings flags, const char *prefix,
         *indent_ptr = pos;
       else if (*indent_ptr > pos)
         fprintf (stderr, "%*s", *indent_ptr - pos, "");
-      indent_ptr = 0;
+      indent_ptr = NULL;
     }
 
   if (prefix)
     fprintf (stderr, "%s: ", prefix);
 
   vfprintf (stderr, message, args);
-  if (! (flags & silent))
+  /* Print the type of warning, only if this is not a sub message
+     (in which case the prefix is null).  */
+  if (! (flags & silent) && prefix)
     warnings_print_categories (flags, stderr);
+
   {
     size_t l = strlen (message);
     if (l < 2 || message[l - 2] != ':' || message[l - 1] != ' ')
@@ -393,6 +397,9 @@ deprecated_directive (location const *loc, char const *old, char const *upd)
     complain (loc, Wdeprecated,
               _("deprecated directive: %s, use %s"),
               quote (old), quote_n (1, upd));
+  /* Register updates only if -Wdeprecated is enabled.  */
+  if (warnings_flag[warning_deprecated] != severity_disabled)
+    fixits_register (loc, upd);
 }
 
 void
@@ -400,7 +407,24 @@ duplicate_directive (char const *directive,
                      location first, location second)
 {
   unsigned i = 0;
-  complain (&second, complaint, _("only one %s allowed per rule"), directive);
+  if (feature_flag & feature_caret)
+    complain_indent (&second, Wother, &i, _("duplicate directive"));
+  else
+    complain_indent (&second, Wother, &i, _("duplicate directive: %s"), quote (directive));
   i += SUB_INDENT;
-  complain_indent (&first, complaint, &i, _("previous declaration"));
+  complain_indent (&first, Wother, &i, _("previous declaration"));
+  fixits_register (&second, "");
+}
+
+void
+duplicate_rule_directive (char const *directive,
+                          location first, location second)
+{
+  unsigned i = 0;
+  complain_indent (&second, complaint, &i,
+                   _("only one %s allowed per rule"), directive);
+  i += SUB_INDENT;
+  complain_indent (&first, complaint, &i,
+                   _("previous declaration"));
+  fixits_register (&second, "");
 }

src/complain.h

@@ -126,10 +126,14 @@ void bison_directive (location const *loc, char const *directive);
 void deprecated_directive (location const *loc,
                            char const *obsolete, char const *updated);
 
-/** Report a repeated directive for a rule.  */
+/** Report a repeated directive.  */
 void duplicate_directive (char const *directive,
                           location first, location second);
 
+/** Report a repeated directive for a rule.  */
+void duplicate_rule_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.  */

src/files.c

@@ -43,7 +43,9 @@
 
 char const *spec_outfile = NULL;       /* for -o. */
 char const *spec_file_prefix = NULL;   /* for -b. */
+location spec_file_prefix_loc = EMPTY_LOCATION_INIT;
 char const *spec_name_prefix = NULL;   /* for -p. */
+location spec_name_prefix_loc = EMPTY_LOCATION_INIT;
 char *spec_verbose_file = NULL;  /* for --verbose. */
 char *spec_graph_file = NULL;    /* for -g. */
 char *spec_xml_file = NULL;      /* for -x. */
@@ -115,14 +117,12 @@ concat2 (char const *str1, char const *str2)
 FILE *
 xfopen (const char *name, const char *mode)
 {
-  FILE *ptr;
-
-  ptr = fopen_safer (name, mode);
-  if (!ptr)
+  FILE *res = fopen_safer (name, mode);
+  if (!res)
     error (EXIT_FAILURE, get_errno (),
            _("%s: cannot open"), quotearg_colon (name));
 
-  return ptr;
+  return res;
 }
 
 /*-------------------------------------------------------------.
@@ -243,19 +243,18 @@ file_name_split (const char *file_name,
     }
 }
 
+/* Compute ALL_BUT_EXT and ALL_BUT_TAB_EXT from SPEC_OUTFILE or
+   GRAMMAR_FILE.
+
+   The precise -o name will be used for FTABLE.  For other output
+   files, remove the ".c" or ".tab.c" suffix.  */
 
 static void
 compute_file_name_parts (void)
 {
-  const char *base, *tab, *ext;
-
-  /* Compute ALL_BUT_EXT and ALL_BUT_TAB_EXT from SPEC_OUTFILE
-     or GRAMMAR_FILE.
-
-     The precise -o name will be used for FTABLE.  For other output
-     files, remove the ".c" or ".tab.c" suffix.  */
   if (spec_outfile)
     {
+      const char *base, *tab, *ext;
       file_name_split (spec_outfile, &base, &tab, &ext);
       dir_prefix = xstrndup (spec_outfile, base - spec_outfile);
 
@@ -275,6 +274,7 @@ compute_file_name_parts (void)
     }
   else
     {
+      const char *base, *tab, *ext;
       file_name_split (grammar_file, &base, &tab, &ext);
 
       if (spec_file_prefix)
@@ -285,7 +285,7 @@ compute_file_name_parts (void)
                       last_component (spec_file_prefix) - spec_file_prefix);
           all_but_tab_ext = xstrdup (spec_file_prefix);
         }
-      else if (yacc_flag)
+      else if (! location_empty (yacc_loc))
         {
           /* If --yacc, then the output is 'y.tab.c'.  */
           dir_prefix = xstrdup ("");
@@ -306,7 +306,7 @@ compute_file_name_parts (void)
         all_but_ext = xstrdup (all_but_tab_ext);
 
       /* Compute the extensions from the grammar file name.  */
-      if (ext && !yacc_flag)
+      if (ext && location_empty (yacc_loc))
         compute_exts_from_gf (ext);
     }
 }
@@ -374,16 +374,13 @@ output_file_name_check (char **file_name, bool source)
       conflict = true;
     }
   else
-    {
-      int i;
-      for (i = 0; i < generated_files_size; i++)
-        if (STREQ (generated_files[i].name, *file_name))
-          {
-            complain (NULL, Wother, _("conflicting outputs to file %s"),
-                      quote (generated_files[i].name));
-            conflict = true;
-          }
-    }
+    for (int i = 0; i < generated_files_size; i++)
+      if (STREQ (generated_files[i].name, *file_name))
+        {
+          complain (NULL, Wother, _("conflicting outputs to file %s"),
+                    quote (generated_files[i].name));
+          conflict = true;
+        }
   if (conflict)
     {
       free (*file_name);
@@ -401,8 +398,7 @@ output_file_name_check (char **file_name, bool source)
 void
 unlink_generated_sources (void)
 {
-  int i;
-  for (i = 0; i < generated_files_size; i++)
+  for (int i = 0; i < generated_files_size; i++)
     if (generated_files[i].is_source)
       /* Ignore errors.  The file might not even exist.  */
       unlink (generated_files[i].name);
@@ -418,10 +414,7 @@ output_file_names_free (void)
   free (spec_defines_file);
   free (parser_file_name);
   free (dir_prefix);
-  {
-    int i;
-    for (i = 0; i < generated_files_size; i++)
-      free (generated_files[i].name);
-  }
+  for (int i = 0; i < generated_files_size; i++)
+    free (generated_files[i].name);
   free (generated_files);
 }

src/files.h

@@ -21,6 +21,7 @@
 #ifndef FILES_H_
 # define FILES_H_
 
+# include "location.h"
 # include "uniqstr.h"
 
 /* File name specified with -o for the output file, or 0 if no -o.  */
@@ -31,9 +32,11 @@ extern char *parser_file_name;
 
 /* Symbol prefix specified with -p, or 0 if no -p.  */
 extern const char *spec_name_prefix;
+extern location spec_name_prefix_loc;
 
 /* File name prefix specified with -b, or 0 if no -b.  */
 extern char const *spec_file_prefix;
+extern location spec_file_prefix_loc;
 
 /* --verbose. */
 extern char *spec_verbose_file;
@@ -55,7 +58,7 @@ extern char *dir_prefix;
    and therefore GCC warns about a name clash. */
 extern uniqstr grammar_file;
 
-/* The current file name.  Might change with %include, or with #line.  */
+/* The current file name.  Might change with #line.  */
 extern uniqstr current_file;
 
 /* The computed base for output file names.  */

src/fixits.c

@@ -0,0 +1,212 @@
+/* Support for fixing grammar files.
+
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This file is part of Bison, the GNU Compiler Compiler.
+
+   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/>.  */
+
+#include <config.h>
+
+#include "fixits.h"
+
+#include "system.h"
+
+#include "error.h"
+#include "get-errno.h"
+#include "getargs.h"
+#include "gl_array_list.h"
+#include "gl_xlist.h"
+#include "progname.h"
+#include "quote.h"
+#include "quotearg.h"
+#include "vasnprintf.h"
+
+#include "files.h"
+
+typedef struct
+{
+  location location;
+  char *fix;
+} fixit;
+
+gl_list_t fixits = NULL;
+
+static fixit *
+fixit_new (location const *loc, char const* fix)
+{
+  fixit *res = xmalloc (sizeof *res);
+  res->location = *loc;
+  res->fix = xstrdup (fix);
+  return res;
+}
+
+
+static void
+fixit_free (fixit *f)
+{
+  free (f->fix);
+  free (f);
+}
+
+
+/* GCC and Clang follow the same pattern.
+   https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Message-Formatting-Options.html
+   http://clang.llvm.org/docs/UsersManual.html#cmdoption-fdiagnostics-parseable-fixits */
+static void
+fixit_print (fixit const *f, FILE *out)
+{
+  fprintf (out, "fix-it:%s:{%d:%d-%d:%d}:%s\n",
+           quotearg_n_style (1, c_quoting_style, f->location.start.file),
+           f->location.start.line, f->location.start.column,
+           f->location.end.line, f->location.end.column,
+           quotearg_n_style (2, c_quoting_style, f->fix));
+}
+
+
+void
+fixits_register (location const *loc, char const* fix)
+{
+  if (!fixits)
+    fixits = gl_list_create_empty (GL_ARRAY_LIST,
+                                   /* equals */ NULL,
+                                   /* hashcode */ NULL,
+                                   (gl_listelement_dispose_fn) fixit_free,
+                                   true);
+  fixit *f = fixit_new (loc, fix);
+  gl_list_add_last (fixits, f);
+  if (feature_flag & feature_fixit_parsable)
+    fixit_print (f, stderr);
+}
+
+
+bool
+fixits_empty (void)
+{
+  return !fixits;
+}
+
+
+void
+fixits_run (void)
+{
+  if (!fixits)
+    return;
+
+  /* This is not unlike what is done in location_caret.  */
+  uniqstr input = ((fixit *) gl_list_get_at (fixits, 0))->location.start.file;
+  /* Backup the file. */
+  char buf[256];
+  size_t len = sizeof (buf);
+  char *backup = asnprintf (buf, &len, "%s~", input);
+  if (!backup)
+    xalloc_die ();
+  if (rename (input, backup))
+    error (EXIT_FAILURE, get_errno (),
+           _("%s: cannot backup"), quotearg_colon (input));
+  FILE *in = xfopen (backup, "r");
+  FILE *out = xfopen (input, "w");
+  size_t line = 1;
+  size_t offset = 1;
+  fixit const *f = NULL;
+  gl_list_iterator_t iter = gl_list_iterator (fixits);
+  while (gl_list_iterator_next (&iter, (const void**) &f, NULL))
+    {
+      /* Look for the correct line. */
+      while (line < f->location.start.line)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          if (c == '\n')
+            {
+              ++line;
+              offset = 1;
+            }
+          putc (c, out);
+        }
+      /* Look for the right offset. */
+      while (offset < f->location.start.column)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          ++offset;
+          putc (c, out);
+        }
+
+      /* Paste the fix instead. */
+      fputs (f->fix, out);
+
+      /* Skip the bad input. */
+      while (line < f->location.end.line)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          if (c == '\n')
+            {
+              ++line;
+              offset = 1;
+            }
+        }
+      while (offset < f->location.end.column)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          ++offset;
+        }
+      /* If erasing the content of a full line, also remove the
+         end-of-line. */
+      if (f->fix[0] == 0 && f->location.start.column == 1)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          else if (c == '\n')
+            {
+              ++line;
+              offset = 1;
+            }
+          else
+            ungetc (c, in);
+        }
+    }
+  /* Paste the rest of the file.  */
+  {
+    int c;
+    while ((c = getc (in)) != EOF)
+      putc (c, out);
+  }
+
+  gl_list_iterator_free (&iter);
+  xfclose (out);
+  xfclose (in);
+  fprintf (stderr, "%s: file %s was updated (backup: %s)\n",
+           program_name, quote_n (0, input), quote_n (1, backup));
+  if (backup != buf)
+    free (backup);
+}
+
+
+/* Free the registered fixits.  */
+void fixits_free (void)
+{
+  if (fixits)
+    {
+      gl_list_free (fixits);
+      fixits = NULL;
+    }
+}

src/fixits.h

@@ -0,0 +1,35 @@
+/* Support for fixing grammar files.
+
+   Copyright (C) 2019 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/>.  */
+
+#ifndef FIXITS_H_
+# define FIXITS_H_ 1
+
+# include "location.h"
+
+/* Declare a fix to apply.  */
+void fixits_register (location const *loc, char const* update);
+
+/* Apply the fixits: update the source file.  */
+void fixits_run (void);
+
+/* Whether there are no fixits. */
+bool fixits_empty (void);
+
+/* Free the registered fixits.  */
+void fixits_free (void);
+
+#endif /* !FIXITS_H_ */

src/getargs.c

@@ -36,12 +36,13 @@
 #include "quote.h"
 #include "uniqstr.h"
 
-bool defines_flag;
-bool graph_flag;
-bool xml_flag;
-bool no_lines_flag;
-bool token_table_flag;
-bool yacc_flag; /* for -y */
+bool defines_flag = false;
+bool graph_flag = false;
+bool xml_flag = false;
+bool no_lines_flag = false;
+bool token_table_flag = false;
+location yacc_loc = EMPTY_LOCATION_INIT;
+bool update_flag = false; /* for -u */
 
 bool nondeterministic_parser = false;
 bool glr_parser = false;
@@ -228,6 +229,7 @@ static const char * const feature_args[] =
 {
   "none",
   "caret", "diagnostics-show-caret",
+  "fixit", "diagnostics-parseable-fixits",
   "all",
   0
 };
@@ -236,6 +238,7 @@ static const int feature_types[] =
 {
   feature_none,
   feature_caret, feature_caret,
+  feature_fixit_parsable, feature_fixit_parsable,
   feature_all
 };
 
@@ -281,7 +284,10 @@ Operation modes:\n\
   -h, --help                 display this help and exit\n\
   -V, --version              output version information and exit\n\
       --print-localedir      output directory containing locale-dependent data\n\
+                             and exit\n\
       --print-datadir        output directory containing skeletons and XSLT\n\
+                             and exit\n\
+  -u, --update               apply fixes to the source grammar file and exit\n\
   -y, --yacc                 emulate POSIX Yacc\n\
   -W, --warnings[=CATEGORY]  report the warnings falling in CATEGORY\n\
   -f, --feature[=FEATURE]    activate miscellaneous features\n\
@@ -476,6 +482,7 @@ static char const short_options[] =
   "p:"
   "r:"
   "t"
+  "u"   /* --update */
   "v"
   "x::"
   "y"
@@ -497,6 +504,7 @@ static struct option const long_options[] =
   { "version",         no_argument,       0,   'V' },
   { "print-localedir", no_argument,       0,   PRINT_LOCALEDIR_OPTION },
   { "print-datadir",   no_argument,       0,   PRINT_DATADIR_OPTION   },
+  { "update",          no_argument,       0,   'u' },
   { "warnings",        optional_argument, 0,   'W' },
 
   /* Parser. */
@@ -682,6 +690,10 @@ getargs (int argc, char *argv[])
                                       MUSCLE_PERCENT_DEFINE_D);
         break;
 
+      case 'u':
+        update_flag = true;
+        break;
+
       case 'v':
         report_flag |= report_states;
         break;
@@ -696,8 +708,8 @@ getargs (int argc, char *argv[])
         break;
 
       case 'y':
-        warning_argmatch ("error=yacc", 0, 6);
-        yacc_flag = true;
+        warning_argmatch ("yacc", 0, 0);
+        yacc_loc = command_line_location ();
         break;
 
       case LOCATIONS_OPTION:

src/getargs.h

@@ -39,8 +39,8 @@ extern bool graph_flag;                 /* for -g */
 extern bool xml_flag;                   /* for -x */
 extern bool no_lines_flag;              /* for -l */
 extern bool token_table_flag;           /* for -k */
-extern bool yacc_flag;                  /* for -y */
-
+extern location yacc_loc;               /* for -y */
+extern bool update_flag;                /* for -u */
 
 /* GLR_PARSER is true if the input file says to use the GLR
    (Generalized LR) parser, and to output some additional information
@@ -114,9 +114,10 @@ extern int trace_flag;
 
 enum feature
   {
-    feature_none  = 0,         /**< No additional feature.  */
-    feature_caret = 1 << 0,    /**< Enhance the output of errors with carets.  */
-    feature_all   = ~0         /**< All above features.  */
+    feature_none           = 0,       /**< No additional feature.  */
+    feature_caret          = 1 << 0,  /**< Output errors with carets.  */
+    feature_fixit_parsable = 1 << 1,  /**< Issue instructions to fix the sources.  */
+    feature_all            = ~0       /**< All above features.  */
   };
 /** What additional features to use.  */
 extern int feature_flag;

src/lalr.c

@@ -329,7 +329,7 @@ state_lookahead_tokens_count (state *s, bool default_reduction_only_for_accept)
           && default_reduction_only_for_accept))
     n_lookahead_tokens += rp->num;
   else
-    s->consistent = 1;
+    s->consistent = true;
 
   return n_lookahead_tokens;
 }

src/local.mk

@@ -46,6 +46,8 @@ src_bison_SOURCES =                             \
   src/derives.h                                 \
   src/files.c                                   \
   src/files.h                                   \
+  src/fixits.c                                  \
+  src/fixits.h                                  \
   src/flex-scanner.h                            \
   src/getargs.c                                 \
   src/getargs.h                                 \

src/location.c

@@ -209,13 +209,20 @@ location_caret (location loc, FILE *out)
           /* Print the carets (at least one), with the same indent as above.*/
           fprintf (out, " %*s", loc.start.column - 1, "");
           for (i = loc.start.column; i == loc.start.column || i < len; ++i)
-            putc ('^', out);
+            putc (i == loc.start.column ? '^' : '~', out);
           }
         putc ('\n', out);
       }
   }
 }
 
+bool
+location_empty (location loc)
+{
+  return !loc.start.file && !loc.start.line && !loc.start.column
+    && !loc.end.file && !loc.end.line && !loc.end.column;
+}
+
 void
 boundary_set_from_string (boundary *bound, char *loc_str)
 {

src/location.h

@@ -126,6 +126,9 @@ location_cmp (location a, location b)
   return res;
 }
 
+/* Whether this is the empty location.  */
+bool location_empty (location loc);
+
 /* LOC_STR must be formatted as 'file:line.column', it will be modified.  */
 void boundary_set_from_string (boundary *bound, char *loc_str);
 

src/main.c

@@ -35,6 +35,7 @@
 #include "conflicts.h"
 #include "derives.h"
 #include "files.h"
+#include "fixits.h"
 #include "getargs.h"
 #include "gram.h"
 #include "lalr.h"
@@ -154,31 +155,34 @@ main (int argc, char *argv[])
 
   print_precedence_warnings ();
 
-  /* Output file names. */
-  compute_output_file_names ();
-
-  /* Output the detailed report on the grammar.  */
-  if (report_flag)
+  if (!update_flag)
     {
-      timevar_push (tv_report);
-      print_results ();
-      timevar_pop (tv_report);
-    }
+      /* Output file names. */
+      compute_output_file_names ();
 
-  /* Output the graph.  */
-  if (graph_flag)
-    {
-      timevar_push (tv_graph);
-      print_graph ();
-      timevar_pop (tv_graph);
-    }
+      /* Output the detailed report on the grammar.  */
+      if (report_flag)
+        {
+          timevar_push (tv_report);
+          print_results ();
+          timevar_pop (tv_report);
+        }
 
-  /* Output xml.  */
-  if (xml_flag)
-    {
-      timevar_push (tv_xml);
-      print_xml ();
-      timevar_pop (tv_xml);
+      /* Output the graph.  */
+      if (graph_flag)
+        {
+          timevar_push (tv_graph);
+          print_graph ();
+          timevar_pop (tv_graph);
+        }
+
+      /* Output xml.  */
+      if (xml_flag)
+        {
+          timevar_push (tv_xml);
+          print_xml ();
+          timevar_pop (tv_xml);
+        }
     }
 
   /* Stop if there were errors, to avoid trashing previous output
@@ -192,9 +196,12 @@ main (int argc, char *argv[])
   timevar_pop (tv_free);
 
   /* Output the tables and the parser to ftable.  In file output.  */
-  timevar_push (tv_parser);
-  output ();
-  timevar_pop (tv_parser);
+  if (!update_flag)
+    {
+      timevar_push (tv_parser);
+      output ();
+      timevar_pop (tv_parser);
+    }
 
   timevar_push (tv_free);
   nullable_free ();
@@ -210,7 +217,6 @@ main (int argc, char *argv[])
      contains things such as user actions, prologue, epilogue etc.  */
   gram_scanner_free ();
   muscle_free ();
-  uniqstrs_free ();
   code_scanner_free ();
   skel_scanner_free ();
   quotearg_free ();
@@ -227,5 +233,18 @@ main (int argc, char *argv[])
 
   cleanup_caret ();
 
+  /* Fix input file now, even if there are errors: that's less
+     warnings in the following runs.  */
+  if (!fixits_empty ())
+    {
+      if (update_flag)
+        fixits_run ();
+      else
+        complain (NULL, Wother,
+                  _("fix-its can be applied.  Rerun with option '--update'."));
+      fixits_free ();
+    }
+  uniqstrs_free ();
+
   return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 }

src/muscle-tab.c

@@ -24,6 +24,7 @@
 
 #include "complain.h"
 #include "files.h"
+#include "fixits.h"
 #include "getargs.h"
 #include "muscle-tab.h"
 #include "quote.h"
@@ -429,12 +430,14 @@ define_directive (char const *assignment,
 /** If the \a variable name is obsolete, return the name to use,
  * otherwise \a variable.  If the \a value is obsolete, update it too.
  *
- * Allocates the returned value.  */
+ * Allocates the returned value if needed, otherwise the returned
+ * value is exactly \a variable.  */
 static
-char *
-muscle_percent_variable_update (char const *variable, location variable_loc,
+char const *
+muscle_percent_variable_update (char const *variable,
                                 muscle_kind kind,
-                                char const **value)
+                                char const **value,
+                                char **old, char **upd)
 {
   typedef struct
   {
@@ -444,8 +447,15 @@ muscle_percent_variable_update (char const *variable, location variable_loc,
   } conversion_type;
   const conversion_type conversion[] =
   {
+    { "%error-verbose",             "parse.error=verbose",       muscle_keyword },
+    { "%error_verbose",             "parse.error=verbose",       muscle_keyword },
+    { "abstract",                   "api.parser.abstract",       muscle_keyword },
+    { "annotations",                "api.parser.annotations",    muscle_code },
     { "api.push_pull",              "api.push-pull",             muscle_keyword },
     { "api.tokens.prefix",          "api.token.prefix",          muscle_code },
+    { "extends",                    "api.parser.extends",        muscle_keyword },
+    { "final",                      "api.parser.final",          muscle_keyword },
+    { "implements",                 "api.parser.implements",     muscle_keyword },
     { "lex_symbol",                 "api.token.constructor",     -1 },
     { "location_type",              "api.location.type",         muscle_code },
     { "lr.default-reductions",      "lr.default-reduction",      muscle_keyword },
@@ -453,16 +463,11 @@ muscle_percent_variable_update (char const *variable, location variable_loc,
     { "lr.keep_unreachable_states", "lr.keep-unreachable-state", muscle_keyword },
     { "namespace",                  "api.namespace",             muscle_code },
     { "parser_class_name",          "api.parser.class",          muscle_code },
+    { "public",                     "api.parser.public",         muscle_keyword },
+    { "strictfp",                   "api.parser.strictfp",       muscle_keyword },
     { "stype",                      "api.value.type",            -1 },
     { "variant=",                   "api.value.type=variant",    -1 },
     { "variant=true",               "api.value.type=variant",    -1 },
-    { "abstract",                   "api.parser.abstract",       muscle_keyword },
-    { "annotations",                "api.parser.annotations",    muscle_code },
-    { "extends",                    "api.parser.extends",        muscle_keyword },
-    { "final",                      "api.parser.final",          muscle_keyword },
-    { "implements",                 "api.parser.implements",     muscle_keyword },
-    { "public",                     "api.parser.public",         muscle_keyword },
-    { "strictfp",                   "api.parser.strictfp",       muscle_keyword },
     { NULL, NULL, -1, }
   };
 
@@ -474,22 +479,25 @@ muscle_percent_variable_update (char const *variable, location variable_loc,
              && STREQ (eq + 1, *value))
           : STREQ (c->obsolete, variable))
         {
-          char *old = define_directive (c->obsolete, kind, *value);
-          char *upd = define_directive (c->updated, c->kind, *value);
-          deprecated_directive (&variable_loc, old, upd);
-          free (old);
-          free (upd);
-          char *res = xstrdup (c->updated);
-          char *eq2 = strchr (res, '=');
-          if (eq2)
-            {
-              *eq2 = '\0';
-              *value = eq2 + 1;
-            }
-          return res;
+          /* Generate the deprecation warning. */
+          *old = c->obsolete[0] == '%'
+            ? xstrdup (c->obsolete)
+            : define_directive (c->obsolete, kind, *value);
+          *upd = define_directive (c->updated, c->kind, *value);
+          /* Update the variable and its value.  */
+          {
+            char *res = xstrdup (c->updated);
+            char *eq2 = strchr (res, '=');
+            if (eq2)
+              {
+                *eq2 = '\0';
+                *value = eq2 + 1;
+              }
+            return res;
+          }
         }
     }
-  return xstrdup (variable);
+  return variable;
 }
 
 void
@@ -499,8 +507,11 @@ muscle_percent_define_insert (char const *var, location variable_loc,
                               muscle_percent_define_how how)
 {
   /* Backward compatibility.  */
-  char *variable
-    = muscle_percent_variable_update (var, variable_loc, kind, &value);
+  char *old = NULL;
+  char *upd = NULL;
+  char const *variable
+    = muscle_percent_variable_update (var, kind,
+                                      &value, &old, &upd);
   uniqstr name = muscle_name (variable, NULL);
   uniqstr loc_name = muscle_name (variable, "loc");
   uniqstr syncline_name = muscle_name (variable, "syncline");
@@ -508,21 +519,33 @@ muscle_percent_define_insert (char const *var, location variable_loc,
   uniqstr kind_name = muscle_name (variable, "kind");
 
   /* Command-line options are processed before the grammar file.  */
-  if (how == MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE
-      && muscle_find_const (name))
+  bool warned = false;
+  if (how == MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE)
     {
-      muscle_percent_define_how how_old = atoi (muscle_find_const (how_name));
-      if (how_old == MUSCLE_PERCENT_DEFINE_F)
-        goto end;
-      unsigned i = 0;
-      complain_indent (&variable_loc, complaint, &i,
-                       _("%%define variable %s redefined"),
-                       quote (variable));
-      i += SUB_INDENT;
-      location loc = muscle_percent_define_get_loc (variable);
-      complain_indent (&loc, complaint, &i, _("previous definition"));
+      char const *current_value = muscle_find_const (name);
+      if (current_value)
+        {
+          muscle_percent_define_how how_old
+            = atoi (muscle_find_const (how_name));
+          if (how_old == MUSCLE_PERCENT_DEFINE_F)
+            goto end;
+          unsigned i = 0;
+          /* If assigning the same value, make it a warning.  */
+          warnings warn = STREQ (value, current_value) ? Wother : complaint;
+          complain_indent (&variable_loc, warn, &i,
+                           _("%%define variable %s redefined"),
+                           quote (variable));
+          i += SUB_INDENT;
+          location loc = muscle_percent_define_get_loc (variable);
+          complain_indent (&loc, warn, &i, _("previous definition"));
+          fixits_register (&variable_loc, "");
+          warned = true;
+        }
     }
 
+  if (!warned && old && upd)
+    deprecated_directive (&variable_loc, old, upd);
+
   MUSCLE_INSERT_STRING (name, value);
   muscle_insert (loc_name, "");
   muscle_location_grow (loc_name, variable_loc);
@@ -533,7 +556,10 @@ muscle_percent_define_insert (char const *var, location variable_loc,
   MUSCLE_INSERT_INT (how_name, how);
   MUSCLE_INSERT_STRING (kind_name, muscle_kind_string (kind));
  end:
-  free (variable);
+  free (old);
+  free (upd);
+  if (variable != var)
+    free ((char *) variable);
 }
 
 /* This is used for backward compatibility, e.g., "%define api.pure"

src/output.c

@@ -38,6 +38,7 @@
 #include "muscle-tab.h"
 #include "output.h"
 #include "reader.h"
+#include "reduce.h"
 #include "scan-code.h"    /* max_left_semantic_context */
 #include "scan-skel.h"
 #include "symtab.h"
@@ -414,6 +415,14 @@ merger_output (FILE *out)
 static void
 prepare_symbol_definitions (void)
 {
+  /* Map "orig NUM" to new numbers.  See data/README.  */
+  for (symbol_number i = ntokens; i < nsyms + nuseless_nonterminals; ++i)
+    {
+      obstack_printf (&format_obstack, "symbol(orig %d, number)", i);
+      const char *key = obstack_finish0 (&format_obstack);
+      MUSCLE_INSERT_INT (key, nterm_map ? nterm_map[i - ntokens] : i);
+    }
+
   for (int i = 0; i < nsyms; ++i)
     {
       symbol *sym = symbols[i];
@@ -665,7 +674,7 @@ prepare (void)
   MUSCLE_INSERT_BOOL ("tag_seen_flag", tag_seen);
   MUSCLE_INSERT_BOOL ("token_table_flag", token_table_flag);
   MUSCLE_INSERT_BOOL ("use_push_for_pull_flag", use_push_for_pull_flag);
-  MUSCLE_INSERT_BOOL ("yacc_flag", yacc_flag);
+  MUSCLE_INSERT_BOOL ("yacc_flag", !location_empty (yacc_loc));
 
   /* File names.  */
   if (spec_name_prefix)

src/parse-gram.h

@@ -1,8 +1,9 @@
-/* A Bison parser, made by GNU Bison 3.2.1.108-19b4e.  */
+/* A Bison parser, made by GNU Bison 3.2.90.23-0bbcb-dirty.  */
 
 /* Bison interface for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2015, 2018 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2019 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
@@ -51,11 +52,11 @@
 extern int gram_debug;
 #endif
 /* "%code requires" blocks.  */
-#line 21 "src/parse-gram.y" /* yacc.c:1917  */
+#line 21 "src/parse-gram.y" /* yacc.c:1921  */
 
   #include "symlist.h"
   #include "symtab.h"
-#line 218 "src/parse-gram.y" /* yacc.c:1917  */
+#line 239 "src/parse-gram.y" /* yacc.c:1921  */
 
   typedef enum
   {
@@ -64,7 +65,7 @@ extern int gram_debug;
     param_parse  = 1 << 1,
     param_both   = param_lex | param_parse
   } param_type;
-#line 660 "src/parse-gram.y" /* yacc.c:1917  */
+#line 682 "src/parse-gram.y" /* yacc.c:1921  */
 
   #include "muscle-tab.h"
   typedef struct
@@ -73,7 +74,7 @@ extern int gram_debug;
     muscle_kind kind;
   } value_type;
 
-#line 77 "src/parse-gram.h" /* yacc.c:1917  */
+#line 78 "src/parse-gram.h" /* yacc.c:1921  */
 
 /* Token type.  */
 #ifndef GRAM_TOKENTYPE
@@ -98,43 +99,44 @@ extern int gram_debug;
     PERCENT_DEFAULT_PREC = 272,
     PERCENT_DEFINE = 273,
     PERCENT_DEFINES = 274,
-    PERCENT_EXPECT = 275,
-    PERCENT_EXPECT_RR = 276,
-    PERCENT_FLAG = 277,
-    PERCENT_FILE_PREFIX = 278,
-    PERCENT_GLR_PARSER = 279,
-    PERCENT_INITIAL_ACTION = 280,
-    PERCENT_LANGUAGE = 281,
-    PERCENT_NAME_PREFIX = 282,
-    PERCENT_NO_DEFAULT_PREC = 283,
-    PERCENT_NO_LINES = 284,
-    PERCENT_NONDETERMINISTIC_PARSER = 285,
-    PERCENT_OUTPUT = 286,
-    PERCENT_REQUIRE = 287,
-    PERCENT_SKELETON = 288,
-    PERCENT_START = 289,
-    PERCENT_TOKEN_TABLE = 290,
-    PERCENT_VERBOSE = 291,
-    PERCENT_YACC = 292,
-    BRACED_CODE = 293,
-    BRACED_PREDICATE = 294,
-    BRACKETED_ID = 295,
-    CHAR = 296,
-    EPILOGUE = 297,
-    EQUAL = 298,
-    ID = 299,
-    ID_COLON = 300,
-    PERCENT_PERCENT = 301,
-    PIPE = 302,
-    PROLOGUE = 303,
-    SEMICOLON = 304,
-    TAG = 305,
-    TAG_ANY = 306,
-    TAG_NONE = 307,
-    INT = 308,
-    PERCENT_PARAM = 309,
-    PERCENT_UNION = 310,
-    PERCENT_EMPTY = 311
+    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_EMPTY = 312
   };
 #endif
 
@@ -161,9 +163,9 @@ union GRAM_STYPE
   /* "integer"  */
   int INT;
   /* int.opt  */
-  int yytype_78;
+  int yytype_79;
   /* named_ref.opt  */
-  named_ref* yytype_90;
+  named_ref* yytype_91;
   /* "%param"  */
   param_type PERCENT_PARAM;
   /* token_decl  */
@@ -179,7 +181,7 @@ union GRAM_STYPE
   /* string_as_id  */
   symbol* string_as_id;
   /* string_as_id.opt  */
-  symbol* yytype_97;
+  symbol* yytype_98;
   /* generic_symlist  */
   symbol_list* generic_symlist;
   /* generic_symlist_item  */
@@ -189,17 +191,25 @@ union GRAM_STYPE
   /* token_decls  */
   symbol_list* token_decls;
   /* token_decl.1  */
-  symbol_list* yytype_76;
+  symbol_list* yytype_77;
   /* token_decls_for_prec  */
   symbol_list* token_decls_for_prec;
   /* token_decl_for_prec.1  */
-  symbol_list* yytype_80;
+  symbol_list* yytype_81;
   /* symbol_decls  */
   symbol_list* symbol_decls;
   /* symbol_decl.1  */
-  symbol_list* yytype_83;
+  symbol_list* yytype_84;
+  /* "%error-verbose"  */
+  uniqstr PERCENT_ERROR_VERBOSE;
   /* "%<flag>"  */
   uniqstr PERCENT_FLAG;
+  /* "%file-prefix"  */
+  uniqstr PERCENT_FILE_PREFIX;
+  /* "%name-prefix"  */
+  uniqstr PERCENT_NAME_PREFIX;
+  /* "%yacc"  */
+  uniqstr PERCENT_YACC;
   /* "[identifier]"  */
   uniqstr BRACKETED_ID;
   /* "identifier"  */
@@ -209,7 +219,7 @@ union GRAM_STYPE
   /* "<tag>"  */
   uniqstr TAG;
   /* tag.opt  */
-  uniqstr yytype_70;
+  uniqstr yytype_71;
   /* tag  */
   uniqstr tag;
   /* variable  */
@@ -218,7 +228,7 @@ union GRAM_STYPE
   unsigned char CHAR;
   /* value  */
   value_type value;
-#line 222 "src/parse-gram.h" /* yacc.c:1917  */
+#line 232 "src/parse-gram.h" /* yacc.c:1921  */
 };
 
 typedef union GRAM_STYPE GRAM_STYPE;

src/parse-gram.y

@@ -43,8 +43,9 @@
   #include "named-ref.h"
   #include "quotearg.h"
   #include "reader.h"
-  #include "scan-gram.h"
   #include "scan-code.h"
+  #include "scan-gram.h"
+  #include "vasnprintf.h"
   #include "xmemdup0.h"
 
   static int current_prec = 0;
@@ -81,11 +82,26 @@
      string from the scanner (should be CODE). */
   static char const *translate_code_braceless (char *code, location loc);
 
+  /* Handle a %error-verbose directive.  */
+  static void handle_error_verbose (location const *loc, char const *directive);
+
+  /* Handle a %file-prefix directive.  */
+  static void handle_file_prefix (location const *loc,
+                                  location const *dir_loc,
+                                  char const *directive, char const *value);
+
+  /* Handle a %name-prefix directive.  */
+  static void handle_name_prefix (location const *loc,
+                                  char const *directive, char const *value);
+
   /* Handle a %require directive.  */
-  static void do_require (location const *loc, char const *version);
+  static void handle_require (location const *loc, char const *version);
 
   /* Handle a %skeleton directive.  */
-  static void do_skeleton (location const *loc, char const *skel);
+  static void handle_skeleton (location const *loc, char const *skel);
+
+  /* Handle a %yacc directive.  */
+  static void handle_yacc (location const *loc, char const *directive);
 
   static void gram_error (location const *, char const *);
 
@@ -146,6 +162,7 @@
   PERCENT_DEFAULT_PREC    "%default-prec"
   PERCENT_DEFINE          "%define"
   PERCENT_DEFINES         "%defines"
+  PERCENT_ERROR_VERBOSE   "%error-verbose"
   PERCENT_EXPECT          "%expect"
   PERCENT_EXPECT_RR       "%expect-rr"
   PERCENT_FLAG            "%<flag>"
@@ -190,7 +207,11 @@
 %printer { fputs (quotearg_style (c_quoting_style, $$), yyo); } STRING
 %printer { fprintf (yyo, "{\n%s\n}", $$); } <char*>
 
-%type <uniqstr> BRACKETED_ID ID ID_COLON PERCENT_FLAG TAG tag tag.opt variable
+%type <uniqstr>
+  BRACKETED_ID ID ID_COLON
+  PERCENT_ERROR_VERBOSE PERCENT_FILE_PREFIX PERCENT_FLAG PERCENT_NAME_PREFIX
+  PERCENT_YACC
+  TAG tag tag.opt variable
 %printer { fputs ($$, yyo); } <uniqstr>
 %printer { fprintf (yyo, "[%s]", $$); } BRACKETED_ID
 %printer { fprintf (yyo, "%s:", $$); } ID_COLON
@@ -284,7 +305,7 @@ prologue_declaration:
     }
 | "%define" variable value
     {
-      muscle_percent_define_insert ($2, @2, $3.kind, $3.chars,
+      muscle_percent_define_insert ($2, @$, $3.kind, $3.chars,
                                     MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
     }
 | "%defines"                       { defines_flag = true; }
@@ -293,9 +314,10 @@ prologue_declaration:
       defines_flag = true;
       spec_defines_file = xstrdup ($2);
     }
+| "%error-verbose"                 { handle_error_verbose (&@$, $1); }
 | "%expect" INT                    { expected_sr_conflicts = $2; }
 | "%expect-rr" INT                 { expected_rr_conflicts = $2; }
-| "%file-prefix" STRING            { spec_file_prefix = $2; }
+| "%file-prefix" STRING            { handle_file_prefix (&@$, &@1, $1, $2); }
 | "%glr-parser"
     {
       nondeterministic_parser = true;
@@ -307,16 +329,16 @@ prologue_declaration:
       code_scanner_last_string_free ();
     }
 | "%language" STRING            { language_argmatch ($2, grammar_prio, @1); }
-| "%name-prefix" STRING         { spec_name_prefix = $2; }
+| "%name-prefix" STRING         { handle_name_prefix (&@$, $1, $2); }
 | "%no-lines"                   { no_lines_flag = true; }
 | "%nondeterministic-parser"    { nondeterministic_parser = true; }
 | "%output" STRING              { spec_outfile = $2; }
 | "%param" { current_param = $1; } params { current_param = param_none; }
-| "%require" STRING             { do_require (&@2, $2); }
-| "%skeleton" STRING            { do_skeleton (&@2, $2); }
+| "%require" STRING             { handle_require (&@2, $2); }
+| "%skeleton" STRING            { handle_skeleton (&@2, $2); }
 | "%token-table"                { token_table_flag = true; }
 | "%verbose"                    { report_flag |= report_states; }
-| "%yacc"                       { yacc_flag = true; }
+| "%yacc"                       { handle_yacc (&@$, $1); }
 | error ";"                     { current_class = unknown_sym; yyerrok; }
 | /*FIXME: Err?  What is this horror doing here? */ ";"
 ;
@@ -847,7 +869,74 @@ add_param (param_type type, char *decl, location loc)
 
 
 static void
-do_require (location const *loc, char const *version)
+handle_error_verbose (location const *loc, char const *directive)
+{
+  bison_directive (loc, directive);
+  muscle_percent_define_insert (directive, *loc, muscle_keyword, "",
+                                MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
+}
+
+
+static void
+handle_file_prefix (location const *loc,
+                    location const *dir_loc,
+                    char const *directive, char const *value)
+{
+  bison_directive (loc, directive);
+  bool warned = false;
+
+  if (location_empty (spec_file_prefix_loc))
+    {
+      spec_file_prefix_loc = *loc;
+      spec_file_prefix = value;
+    }
+  else
+    {
+      duplicate_directive (directive, spec_file_prefix_loc, *loc);
+      warned = true;
+    }
+
+  if (!warned
+      && STRNEQ (directive, "%file-prefix"))
+    deprecated_directive (dir_loc, directive, "%file-prefix");
+}
+
+static void
+handle_name_prefix (location const *loc,
+                    char const *directive, char const *value)
+{
+  bison_directive (loc, directive);
+
+  char buf1[1024];
+  size_t len1 = sizeof (buf1);
+  char *old = asnprintf (buf1, &len1, "%s\"%s\"", directive, value);
+  if (!old)
+    xalloc_die ();
+
+  if (location_empty (spec_name_prefix_loc))
+    {
+      spec_name_prefix = value;
+      spec_name_prefix_loc = *loc;
+
+      char buf2[1024];
+      size_t len2 = sizeof (buf2);
+      char *new = asnprintf (buf2, &len2, "%%define api.prefix {%s}", value);
+      if (!new)
+        xalloc_die ();
+      deprecated_directive (loc, old, new);
+      if (new != buf2)
+        free (new);
+    }
+  else
+    duplicate_directive (old, spec_file_prefix_loc, *loc);
+
+  if (old != buf1)
+    free (old);
+}
+
+
+static void
+handle_require (location const *loc, char const *version)
 {
   /* Changes of behavior are only on minor version changes, so "3.0.5"
      is the same as "3.0". */
@@ -885,7 +974,7 @@ do_require (location const *loc, char const *version)
 }
 
 static void
-do_skeleton (location const *loc, char const *skel)
+handle_skeleton (location const *loc, char const *skel)
 {
   char const *skeleton_user = skel;
   if (strchr (skeleton_user, '/'))
@@ -909,6 +998,25 @@ do_skeleton (location const *loc, char const *skel)
   skeleton_arg (skeleton_user, grammar_prio, *loc);
 }
 
+static void
+handle_yacc (location const *loc, char const *directive)
+{
+  bison_directive (loc, directive);
+  bool warned = false;
+
+  if (location_empty (yacc_loc))
+    yacc_loc = *loc;
+  else
+    {
+      duplicate_directive (directive, yacc_loc, *loc);
+      warned = true;
+    }
+
+  if (!warned
+      && STRNEQ (directive, "%fixed-output-files")
+      && STRNEQ (directive, "%yacc"))
+    deprecated_directive (loc, directive, "%fixed-output-files");
+}
 
 static void
 gram_error (location const *loc, char const *msg)

src/reader.c

@@ -467,8 +467,8 @@ grammar_current_rule_prec_set (symbol *precsym, location loc)
      not defined separately as a token.  */
   symbol_class_set (precsym, token_sym, loc, false);
   if (current_rule->ruleprec)
-    duplicate_directive ("%prec",
-                         current_rule->ruleprec->location, loc);
+    duplicate_rule_directive ("%prec",
+                              current_rule->ruleprec->location, loc);
   else
     current_rule->ruleprec = precsym;
 }
@@ -483,8 +483,8 @@ grammar_current_rule_empty_set (location loc)
   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);
+    duplicate_rule_directive ("%empty",
+                              current_rule->percent_empty_loc, loc);
   else
     current_rule->percent_empty_loc = loc;
 }
@@ -501,8 +501,8 @@ 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)
-    duplicate_directive ("%dprec",
-                         current_rule->dprec_location, loc);
+    duplicate_rule_directive ("%dprec",
+                              current_rule->dprec_location, loc);
   else
     {
       current_rule->dprec = dprec;
@@ -520,8 +520,8 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
     complain (&loc, Wother, _("%s affects only GLR parsers"),
               "%merge");
   if (current_rule->merger != 0)
-    duplicate_directive ("%merge",
-                         current_rule->merger_declaration_location, loc);
+    duplicate_rule_directive ("%merge",
+                              current_rule->merger_declaration_location, loc);
   else
     {
       current_rule->merger = get_merge_function (name);

src/reduce.c

@@ -259,22 +259,23 @@ reduce_grammar_tables (void)
 | Remove useless nonterminals.  |
 `------------------------------*/
 
+symbol_number *nterm_map = NULL;
+
 static void
 nonterminals_reduce (void)
 {
+  nterm_map = xnmalloc (nvars, sizeof *nterm_map);
   /* Map the nonterminals to their new index: useful first, useless
      afterwards.  Kept for later report.  */
-
-  symbol_number *nontermmap = xnmalloc (nvars, sizeof *nontermmap);
   {
     symbol_number n = ntokens;
     for (symbol_number i = ntokens; i < nsyms; ++i)
       if (bitset_test (V, i))
-        nontermmap[i - ntokens] = n++;
+        nterm_map[i - ntokens] = n++;
     for (symbol_number i = ntokens; i < nsyms; ++i)
       if (!bitset_test (V, i))
         {
-          nontermmap[i - ntokens] = n++;
+          nterm_map[i - ntokens] = n++;
           if (symbols[i]->content->status != used)
             complain (&symbols[i]->location, Wother,
                       _("nonterminal useless in grammar: %s"),
@@ -282,32 +283,30 @@ nonterminals_reduce (void)
         }
   }
 
-
   /* Shuffle elements of tables indexed by symbol number.  */
   {
     symbol **symbols_sorted = xnmalloc (nvars, sizeof *symbols_sorted);
     for (symbol_number i = ntokens; i < nsyms; ++i)
-      symbols[i]->content->number = nontermmap[i - ntokens];
+      symbols[i]->content->number = nterm_map[i - ntokens];
     for (symbol_number i = ntokens; i < nsyms; ++i)
-      symbols_sorted[nontermmap[i - ntokens] - ntokens] = symbols[i];
+      symbols_sorted[nterm_map[i - ntokens] - ntokens] = symbols[i];
     for (symbol_number i = ntokens; i < nsyms; ++i)
       symbols[i] = symbols_sorted[i - ntokens];
     free (symbols_sorted);
   }
 
+  /* Update nonterminal numbers in the RHS of the rules.  LHS are
+     pointers to the symbol structure, they don't need renumbering. */
   {
     for (rule_number r = 0; r < nrules; ++r)
       for (item_number *rhsp = rules[r].rhs; 0 <= *rhsp; ++rhsp)
         if (ISVAR (*rhsp))
-          *rhsp =  symbol_number_as_item_number (nontermmap[*rhsp
-                                                            - ntokens]);
-    accept->content->number = nontermmap[accept->content->number - ntokens];
+          *rhsp = symbol_number_as_item_number (nterm_map[*rhsp - ntokens]);
+    accept->content->number = nterm_map[accept->content->number - ntokens];
   }
 
   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
-
-  free (nontermmap);
 }
 
 
@@ -433,4 +432,6 @@ reduce_free (void)
   bitset_free (V);
   bitset_free (V1);
   bitset_free (P);
+  free (nterm_map);
+  nterm_map = NULL;
 }

src/reduce.h

@@ -32,6 +32,11 @@ bool reduce_nonterminal_useless_in_grammar (const sym_content *sym);
 
 void reduce_free (void);
 
+/** Map initial nterm numbers to the new ones.  Built by
+ * reduce_grammar.  Size nvars + nuseless_nonterminals.  */
+extern symbol_number *nterm_map;
+
 extern unsigned nuseless_nonterminals;
 extern unsigned nuseless_productions;
+
 #endif /* !REDUCE_H_ */

src/scan-code.l

@@ -648,7 +648,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
               untyped_var_seen = true;
           }
 
-        obstack_printf (&obstack_for_string, "]b4_lhs_value(%d, ",
+        obstack_printf (&obstack_for_string, "]b4_lhs_value(orig %d, ",
                         sym->content.sym->content->number);
         obstack_quote (&obstack_for_string, type_name);
         obstack_sgrow (&obstack_for_string, ")[");
@@ -677,7 +677,9 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
                         "]b4_rhs_value(%d, %d, ",
                         effective_rule_length, n);
         if (sym)
-          obstack_printf (&obstack_for_string, "%d, ", sym->content.sym->content->number);
+          obstack_printf (&obstack_for_string, "%s%d, ",
+                          sym->content.sym->content->class == nterm_sym ? "orig " : "",
+                          sym->content.sym->content->number);
         else
           obstack_sgrow (&obstack_for_string, "[], ");
 

src/scan-gram.l

@@ -76,18 +76,17 @@ static size_t no_cr_read (FILE *, char *, size_t);
 
 #define DEPRECATED(Msg)                                         \
   do {                                                          \
-    size_t i;                                                   \
     deprecated_directive (loc, yytext, Msg);                    \
     scanner_cursor.column -= mbsnwidth (Msg, strlen (Msg), 0);  \
-    for (i = strlen (Msg); i != 0; --i)                         \
+    for (size_t i = strlen (Msg); i != 0; --i)                  \
       unput (Msg[i - 1]);                                       \
   } while (0)
 
 /* A string representing the most recently saved token.  */
-static char *last_string;
+static char *last_string = NULL;
 
 /* Bracketed identifier. */
-static uniqstr bracketed_id_str = 0;
+static uniqstr bracketed_id_str = NULL;
 static location bracketed_id_loc;
 static boundary bracketed_id_start;
 static int bracketed_id_context_state = 0;
@@ -145,7 +144,8 @@ splice   (\\[ \f\t\v]*\n)*
 
 /* An equal sign, with optional leading whitespaces. This is used in some
    deprecated constructs. */
-eqopt    ([[:space:]]*=)?
+sp       [[:space:]]*
+eqopt    ({sp}=)?
 
 %%
 %{
@@ -228,8 +228,8 @@ eqopt    ([[:space:]]*=)?
   "%empty"                          return BISON_DIRECTIVE (EMPTY);
   "%expect"                         return BISON_DIRECTIVE (EXPECT);
   "%expect-rr"                      return BISON_DIRECTIVE (EXPECT_RR);
-  "%file-prefix"                    return BISON_DIRECTIVE (FILE_PREFIX);
-  "%fixed-output-files"             return BISON_DIRECTIVE (YACC);
+  "%file-prefix"                    RETURN_VALUE (PERCENT_FILE_PREFIX, uniqstr_new (yytext));
+  "%fixed-output-files"             RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
   "%initial-action"                 return BISON_DIRECTIVE (INITIAL_ACTION);
   "%glr-parser"                     return BISON_DIRECTIVE (GLR_PARSER);
   "%language"                       return BISON_DIRECTIVE (LANGUAGE);
@@ -259,25 +259,22 @@ eqopt    ([[:space:]]*=)?
   "%type"                           return PERCENT_TYPE;
   "%union"                          return PERCENT_UNION;
   "%verbose"                        return BISON_DIRECTIVE (VERBOSE);
-  "%yacc"                           return BISON_DIRECTIVE (YACC);
+  "%yacc"                           RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
 
   /* Deprecated since Bison 3.0 (2013-07-25), but the warning is
      issued only since Bison 3.3. */
-  "%error-verbose"                  DEPRECATED ("%define parse.error verbose");
+  "%error-verbose"                  RETURN_VALUE (PERCENT_ERROR_VERBOSE, uniqstr_new (yytext));
 
   /* Deprecated since Bison 2.6 (2012-07-19), but the warning is
      issued only since Bison 3.3. */
-  "%name"[-_]"prefix"{eqopt} {
-    deprecated_directive (loc, yytext, "%define api.prefix");
-    return BISON_DIRECTIVE (NAME_PREFIX);
-  }
+  "%name"[-_]"prefix"{eqopt}{sp}    RETURN_VALUE (PERCENT_NAME_PREFIX, uniqstr_new (yytext));
 
   /* Deprecated since Bison 2.7.90, 2012. */
   "%default"[-_]"prec"              DEPRECATED ("%default-prec");
-  "%error"[-_]"verbose"             DEPRECATED ("%define parse.error verbose");
+  "%error"[-_]"verbose"             RETURN_VALUE (PERCENT_ERROR_VERBOSE, uniqstr_new (yytext));
   "%expect"[-_]"rr"                 DEPRECATED ("%expect-rr");
-  "%file-prefix"{eqopt}             DEPRECATED ("%file-prefix");
-  "%fixed"[-_]"output"[-_]"files"   DEPRECATED ("%fixed-output-files");
+  "%file-prefix"{eqopt}             RETURN_VALUE (PERCENT_FILE_PREFIX, uniqstr_new (yytext));
+  "%fixed"[-_]"output"[-_]"files"   RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
   "%no"[-_]"default"[-_]"prec"      DEPRECATED ("%no-default-prec");
   "%no"[-_]"lines"                  DEPRECATED ("%no-lines");
   "%output"{eqopt}                  DEPRECATED ("%output");

src/state.c

@@ -143,7 +143,7 @@ state_new (symbol_number accessing_symbol,
   res->reductions = NULL;
   res->errs = NULL;
   res->state_list = NULL;
-  res->consistent = 0;
+  res->consistent = false;
   res->solved_conflicts = NULL;
   res->solved_conflicts_xml = NULL;
 

src/state.h

@@ -81,6 +81,8 @@
 #ifndef STATE_H_
 # define STATE_H_
 
+# include <stdbool.h>
+
 # include <bitset.h>
 
 # include "gram.h"
@@ -208,9 +210,9 @@ struct state
      store in this member a reference to the node containing each state.  */
   struct state_list *state_list;
 
-  /* If non-zero, then no lookahead sets on reduce actions are needed to
-     decide what to do in state S.  */
-  char consistent;
+  /* Whether no lookahead sets on reduce actions are needed to decide
+     what to do in state S.  */
+  bool consistent;
 
   /* If some conflicts were solved thanks to precedence/associativity,
      a human readable description of the resolution.  */

tests/actions.at

@@ -130,7 +130,7 @@ 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]],
@@ -144,10 +144,10 @@ 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])
@@ -170,12 +170,39 @@ exp:
 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
+             ^~~~~~
+one.y:11.3-8:       previous declaration
    %empty {} %empty
-   ^^^^^^
+   ^~~~~~
+one.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
 ]])
 
+AT_BISON_CHECK([-fcaret -u 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
+   ^~~~~~
+bison: file 'one.y' was updated (backup: 'one.y~')
+]])
+
+AT_CHECK([cat one.y], [],
+[[%code top {
+/* Load config.h, and adjust to the compiler.
+  We used to do it here, but each time we add a new line,
+  we have to adjust all the line numbers in error messages.
+  It's simpler to use a constant include to a varying file.  */
+#include <testsuite.h>
+}
+
+%%
+exp:
+  %empty {} @&t@
+;
+]])
+
+
 AT_DATA_GRAMMAR([[two.y]],
 [[%%
 exp:
@@ -188,13 +215,13 @@ exp:
 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
@@ -516,7 +543,7 @@ AT_DATA_GRAMMAR([[input.y]],
 
 #define YYINITDEPTH 10
 #define YYMAXDEPTH 10
-#define RANGE(Location) ]AT_LALR1_CC_IF([(Location).begin.line, (Location).end.line],
+#define RANGE(Location) ]AT_CXX_IF([(Location).begin.line, (Location).end.line],
       [(Location).first_line, (Location).last_line])[
 
 #define USE(SYM)
@@ -545,8 +572,8 @@ AT_LALR1_CC_IF([typedef yy::location YYLTYPE;])[
 /* FIXME: This %printer isn't actually tested.  */
 %printer
   {
-    ]AT_LALR1_CC_IF([yyo << $$;],
-                    [fprintf (yyo, "%d", $$)])[;
+    ]AT_CXX_IF([yyo << $$;],
+               [fprintf (yyo, "%d", $$)])[;
   }
   '(' 'x' 'y' ')' ';' thing line input '!' raise check-spontaneous-errors END
 
@@ -707,9 +734,8 @@ static
   fprintf (stderr, " (%d@%d-%d)\n", c, RANGE (]AT_LOC[));
   return source[c];
 }
-]AT_LALR1_CC_IF(
-[static bool yydebug;
-int
+]AT_LALR1_CC_IF([static bool yydebug;])[
+]AT_CXX_IF([int
 yyparse ()
 {
   yy::parser parser;
@@ -972,11 +998,14 @@ AT_CLEANUP
 AT_CHECK_PRINTER_AND_DESTRUCTOR([])
 AT_CHECK_PRINTER_AND_DESTRUCTOR([], [ with union])
 
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser], [ 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([%glr-parser])
-AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser], [ with union])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "glr.cc"])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "glr.cc"], [ with union])
 
 
 
@@ -1514,16 +1543,16 @@ input.y:32.3-23: warning: unused value: $3 [-Wother]
 AT_BISON_CHECK([-fcaret -o input.c input.y], 0,,
 [[input.y:24.57-59: warning: useless %destructor for type <*> [-Wother]
  %printer    { #error "<*> printer should not be used" } <*>
-                                                         ^^^
+                                                         ^~~
 input.y:24.57-59: warning: useless %printer for type <*> [-Wother]
  %printer    { #error "<*> printer should not be used" } <*>
-                                                         ^^^
+                                                         ^~~
 input.y:33.3-23: warning: unset value: $$ [-Wother]
    {           @$ = 4; } // Only used.
-   ^^^^^^^^^^^^^^^^^^^^^
+   ^~~~~~~~~~~~~~~~~~~~~
 input.y:32.3-23: warning: unused value: $3 [-Wother]
    { USE ($$); @$ = 3; } // Only set.
-   ^^^^^^^^^^^^^^^^^^^^^
+   ^~~~~~~~~~~~~~~~~~~~~
 ]])
 
 AT_COMPILE([input])

tests/c++.at

@@ -249,13 +249,13 @@ exp:
 AT_BISON_CHECK([[-fcaret input.yy]], [0], [],
 [[input.yy:16.33-34: warning: multiple occurrences of $2 with api.value.automove [-Wother]
  | "twice" exp       { $$ = $2 + $2; }
-                                 ^^
+                                 ^~
 input.yy:17.33-36: warning: multiple occurrences of $2 with api.value.automove [-Wother]
  | "thrice" exp[val] { $$ = $2 + $val + $2; }
-                                 ^^^^
+                                 ^~~~
 input.yy:17.40-41: warning: multiple occurrences of $2 with api.value.automove [-Wother]
  | "thrice" exp[val] { $$ = $2 + $val + $2; }
-                                        ^^
+                                        ^~
 ]])
 
 AT_BISON_OPTION_POPDEFS
@@ -420,8 +420,7 @@ namespace yy
 {
   static
   ]AT_YYLEX_PROTOTYPE[
-  {]AT_LOCATION_IF([
-    typedef parser::location_type location;])[
+  {
     // The 5 is a syntax error whose recovery requires that we discard
     // the lookahead.  This tests a regression, see
     // <http://savannah.gnu.org/support/?108481>.
@@ -1243,7 +1242,8 @@ yylex (yy::parser::semantic_type *lvalp)
   default:
     lvalp->]AT_VARIANT_IF([build<Object> (res)],
                           [obj = new Object (res)])[;
-    // Fall through.
+    goto zero;
+  zero:
   case 0:
     return res;
   }

tests/conflicts.at

@@ -246,16 +246,16 @@ f: B
 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
@@ -1367,7 +1367,7 @@ b: %expect-rr 4
 AT_BISON_CHECK([-fcaret -o input.c input.y], 1, [],
 [[input.y:12.4-15: error: reduce/reduce conflicts for rule 8: 3 found, 4 expected
  b: %expect-rr 4
-    ^^^^^^^^^^^^
+    ^~~~~~~~~~~~
 ]])
 AT_CLEANUP
 
@@ -1396,7 +1396,7 @@ b: %expect-rr 2
 AT_BISON_CHECK([-fcaret -o input.c input.y], 1, [],
 [[input.y:12.4-15: error: reduce/reduce conflicts for rule 8: 3 found, 2 expected
  b: %expect-rr 2
-    ^^^^^^^^^^^^
+    ^~~~~~~~~~~~
 ]])
 AT_CLEANUP
 

tests/headers.at

@@ -85,7 +85,8 @@ exp: %empty;
 ]])
 
 AT_BISON_CHECK([--defines -o input.c input.y], [], [],
-[[input.y:11.1-12: warning: deprecated directive: '%name-prefix', use '%define api.prefix' [-Wdeprecated]
+[[input.y:11.1-18: warning: deprecated directive: '%name-prefix "my_"', use '%define api.prefix {my_}' [-Wdeprecated]
+input.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
 ]])
 
 # YYLTYPE should be defined, and MY_LLOC declared.
@@ -125,7 +126,7 @@ AT_BISON_OPTION_PUSHDEFS([$1])
 AT_DATA_GRAMMAR([input.y],
 [[$1
 %define parse.error verbose
-]AT_VARIANT_IF([], [%union {int integer;}])[
+]AT_VARIANT_IF([%token <int> 'x'], [%union {int integer;}])[
 %code {
 ]AT_PUSH_IF([[
 #if defined __GNUC__ && 7 == __GNUC__
@@ -329,6 +330,7 @@ AT_CHECK([[$PERL -n -0777 -e '
       |YY_MOVE_OR_COPY
       |YY_MOVE_REF
       |YY_NOEXCEPT
+      |YY_NOTHROW
       |YY_NULLPTR
       |YY_RVREF
       |YY_\w+_INCLUDED

tests/local.at

@@ -707,8 +707,9 @@ if test "$POSIXLY_CORRECT_IS_EXPORTED" = false; then
   # Build expected stderr up to and including the "warnings being
   # treated as errors" message.
   ]AT_DATA([[experr]], [$4])[
-  $PERL -pi -e 's{(.*): warning: (.*)\[-W(.*)\]$}
-                 {$][1: error: $][2\@<:@-Werror=$][3@:>@}' experr
+  $PERL -pi -e 's{(.*): warning:}{$][1: error:};' \
+            -e 's{\[-W(.*)\]$}{@<:@-Werror=$][1@:>@}' \
+                 experr
   ]AT_CHECK([[sed 's,.*/$,,' stderr 1>&2]], [[0]], [[]], [experr])[
 
   # Now check --warnings=error.

tests/named-refs.at

@@ -254,16 +254,16 @@ exp:
 AT_BISON_CHECK([-fcaret -o test.c test.y], 1, [],
 [[test.y:52.51-60: error: invalid reference: '$<ival>lo9'
  | exp[x] '+' { $<ival>$ = $x; } [l] exp[r] { $$ = $<ival>lo9 + $r; }
-                                                   ^^^^^^^^^^
+                                                   ^~~~~~~~~~
 test.y:52.3-68:      symbol not found in production: lo9
  | exp[x] '+' { $<ival>$ = $x; } [l] exp[r] { $$ = $<ival>lo9 + $r; }
-   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:53.51-60: warning: misleading reference: '$<ival>exp' [-Wother]
  | exp[x] '-' { $<ival>$ = $x; } [l] exp[r] { $$ = $<ival>exp - $r; }
-                                                   ^^^^^^^^^^
+                                                   ^~~~~~~~~~
 test.y:44.1-3:       refers to: $exp at $$
  exp:
- ^^^
+ ^~~
 test.y:53.7:         possibly meant: $x, hiding $exp at $1
  | exp[x] '-' { $<ival>$ = $x; } [l] exp[r] { $$ = $<ival>exp - $r; }
        ^
@@ -272,19 +272,19 @@ test.y:53.41:        possibly meant: $r, hiding $exp at $4
                                          ^
 test.y:54.51-52: error: $l of 'exp' has no declared type
  | exp[x] '*' { $<ival>$ = $x; } [l] exp[r] { $$ = $l * $r; }
-                                                   ^^
+                                                   ^~
 test.y:57.40-43: error: invalid reference: '$r12'
  | exp[l] '^' exp[r]  { $$ = power ($l, $r12); }
-                                        ^^^^
+                                        ^~~~
 test.y:57.3-47:      symbol not found in production: r12
  | exp[l] '^' exp[r]  { $$ = power ($l, $r12); }
-   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:58.29-33: error: invalid reference: '$expo'
  | '(' exp ')'        { $$ = $expo;           }
-                             ^^^^^
+                             ^~~~~
 test.y:58.3-46:      symbol not found in production: expo
  | '(' exp ')'        { $$ = $expo;           }
-   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ]])
 AT_BISON_OPTION_POPDEFS
 AT_CLEANUP
@@ -423,121 +423,121 @@ test.y:45.41-46:     possibly meant: $[then-a].f at $4
 AT_BISON_CHECK([-fcaret -o test.c test.y], 1, [],
 [[test.y:24.36-41: error: invalid reference: '$cond1'
            { $if_stmt1 = new IfStmt($cond1, $then.f1, $else); };
-                                    ^^^^^^
+                                    ^~~~~~
 test.y:23.11-24.62:  symbol not found in production: cond1
  if_stmt1: IF expr[cond] THEN stmt[then] ELSE stmt.list[else] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:26.43-53: error: invalid reference: '$stmt.field'
            { $if_stmt2 = new IfStmt($cond, $stmt.field, 0); };
-                                           ^^^^^^^^^^^
+                                           ^~~~~~~~~~~
 test.y:25.11-26.60:  symbol not found in production: stmt
  if_stmt2: IF expr[cond] THEN stmt[then] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:25.35-38:     possibly meant: $then.field, hiding $stmt.field at $4
  if_stmt2: IF expr[cond] THEN stmt[then] FI
-                                   ^^^^
+                                   ^~~~
 test.y:28.43-52: error: invalid reference: '$stmt.list'
            { $if_stmt3 = new IfStmt($cond, $stmt.list, 0); };
-                                           ^^^^^^^^^^
+                                           ^~~~~~~~~~
 test.y:27.11-28.59:  symbol not found in production: stmt
  if_stmt3: IF expr[cond] THEN stmt.list FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:27.30-38:     possibly meant: $[stmt.list] at $4
  if_stmt3: IF expr[cond] THEN stmt.list FI
-                              ^^^^^^^^^
+                              ^~~~~~~~~
 test.y:30.43-46: error: ambiguous reference: '$xyz'
            { $if_stmt4 = new IfStmt($cond, $xyz, $cond); };
-                                           ^^^^
+                                           ^~~~
 test.y:29.35-37:     refers to: $xyz at $4
  if_stmt4: IF expr[cond] THEN stmt[xyz] ELSE stmt[xyz] FI
-                                   ^^^
+                                   ^~~
 test.y:29.50-52:     refers to: $xyz at $6
  if_stmt4: IF expr[cond] THEN stmt[xyz] ELSE stmt[xyz] FI
-                                                  ^^^
+                                                  ^~~
 test.y:32.43-52: error: invalid reference: '$stmt.list'
            { $if_stmt5 = new IfStmt($cond, $stmt.list, $else); };
-                                           ^^^^^^^^^^
+                                           ^~~~~~~~~~
 test.y:31.11-32.63:  symbol not found in production: stmt
  if_stmt5: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:31.40-43:     possibly meant: $then, hiding $[stmt.list] at $4
  if_stmt5: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-                                        ^^^^
+                                        ^~~~
 test.y:31.61-64:     possibly meant: $else, hiding $[stmt.list] at $6
  if_stmt5: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-                                                             ^^^^
+                                                             ^~~~
 test.y:34.43-58: error: invalid reference: '$stmt.list.field'
            { $if_stmt6 = new IfStmt($cond, $stmt.list.field, $else); };
-                                           ^^^^^^^^^^^^^^^^
+                                           ^~~~~~~~~~~~~~~~
 test.y:33.11-34.69:  symbol not found in production: stmt
  if_stmt6: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:33.40-43:     possibly meant: $then.field, hiding $[stmt.list].field at $4
  if_stmt6: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-                                        ^^^^
+                                        ^~~~
 test.y:33.61-64:     possibly meant: $else.field, hiding $[stmt.list].field at $6
  if_stmt6: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-                                                             ^^^^
+                                                             ^~~~
 test.y:36.43-54: error: invalid reference: '$[stmt.list]'
            { $if_stmt7 = new IfStmt($cond, $[stmt.list].field, $else); };
-                                           ^^^^^^^^^^^^
+                                           ^~~~~~~~~~~~
 test.y:35.11-36.71:  symbol not found in production: stmt.list
  if_stmt7: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:35.40-43:     possibly meant: $then, hiding $[stmt.list] at $4
  if_stmt7: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-                                        ^^^^
+                                        ^~~~
 test.y:35.61-64:     possibly meant: $else, hiding $[stmt.list] at $6
  if_stmt7: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-                                                             ^^^^
+                                                             ^~~~
 test.y:38.43-49: error: invalid reference: '$then.1'
            { $if_stmt8 = new IfStmt($cond, $then.1, $else); };
-                                           ^^^^^^^
+                                           ^~~~~~~
 test.y:37.11-38.60:  symbol not found in production: then
  if_stmt8: IF expr[cond] THEN stmt.list[then.1] ELSE stmt.list[else] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:37.40-45:     possibly meant: $[then.1] at $4
  if_stmt8: IF expr[cond] THEN stmt.list[then.1] ELSE stmt.list[else] FI
-                                        ^^^^^^
+                                        ^~~~~~
 test.y:40.43-55: error: invalid reference: '$then.1.field'
            { $if_stmt9 = new IfStmt($cond, $then.1.field, $else); };
-                                           ^^^^^^^^^^^^^
+                                           ^~~~~~~~~~~~~
 test.y:39.11-40.66:  symbol not found in production: then
  if_stmt9: IF expr[cond] THEN stmt.list[then.1] ELSE stmt.list[else] FI
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:39.40-45:     possibly meant: $[then.1].field at $4
  if_stmt9: IF expr[cond] THEN stmt.list[then.1] ELSE stmt.list[else] FI
-                                        ^^^^^^
+                                        ^~~~~~
 test.y:42.44-50: error: invalid reference: '$stmt.x'
            { $if_stmt10 = new IfStmt($cond, $stmt.x, 0); };
-                                            ^^^^^^^
+                                            ^~~~~~~
 test.y:41.12-42.57:  symbol not found in production: stmt
  if_stmt10: IF expr[cond] THEN stmt[stmt.x] FI
-            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:41.36-41:     possibly meant: $[stmt.x].x, hiding $stmt.x at $4
  if_stmt10: IF expr[cond] THEN stmt[stmt.x] FI
-                                    ^^^^^^
+                                    ^~~~~~
 test.y:41.36-41:     possibly meant: $[stmt.x] at $4
  if_stmt10: IF expr[cond] THEN stmt[stmt.x] FI
-                                    ^^^^^^
+                                    ^~~~~~
 test.y:44.13-22: error: invalid reference: '$if-stmt-a'
            { $if-stmt-a = new IfStmt($cond, $then, $else); };
-             ^^^^^^^^^^
+             ^~~~~~~~~~
 test.y:43.12-44.59:  symbol not found in production: if
  if-stmt-a: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
-            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:43.1-9:       possibly meant: $[if-stmt-a] at $$
  if-stmt-a: IF expr[cond] THEN stmt.list[then] ELSE stmt.list[else] FI
- ^^^^^^^^^
+ ^~~~~~~~~
 test.y:46.46-54: error: invalid reference: '$then-a.f'
            { $[if-stmt-b] = new IfStmt($cond, $then-a.f, $else); };
-                                              ^^^^^^^^^
+                                              ^~~~~~~~~
 test.y:45.12-46.65:  symbol not found in production: then
  if-stmt-b: IF expr[cond] THEN if-stmt-a[then-a] ELSE stmt.list[else] FI
-            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.y:45.41-46:     possibly meant: $[then-a].f at $4
  if-stmt-b: IF expr[cond] THEN if-stmt-a[then-a] ELSE stmt.list[else] FI
-                                         ^^^^^^
+                                         ^~~~~~
 ]])
 
 AT_CLEANUP

tests/push.at

@@ -154,7 +154,7 @@ start: ;
 AT_BISON_OPTION_POPDEFS
 
 AT_BISON_CHECK([[input.y]], [[1]], [],
-[[input.y:2.9-21: error: %define variable 'api.push-pull' is not used
+[[input.y:2.1-26: error: %define variable 'api.push-pull' is not used
 ]])
 
 AT_CLEANUP

tests/reduce.at

@@ -134,31 +134,31 @@ AT_BISON_CHECK([[-fcaret input.y]], 0, [],
 input.y: warning: 9 rules useless in grammar [-Wother]
 input.y:6.1-8: warning: nonterminal useless in grammar: useless1 [-Wother]
  useless1: '1';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:7.1-8: warning: nonterminal useless in grammar: useless2 [-Wother]
  useless2: '2';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:8.1-8: warning: nonterminal useless in grammar: useless3 [-Wother]
  useless3: '3';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:9.1-8: warning: nonterminal useless in grammar: useless4 [-Wother]
  useless4: '4';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:10.1-8: warning: nonterminal useless in grammar: useless5 [-Wother]
  useless5: '5';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:11.1-8: warning: nonterminal useless in grammar: useless6 [-Wother]
  useless6: '6';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:12.1-8: warning: nonterminal useless in grammar: useless7 [-Wother]
  useless7: '7';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:13.1-8: warning: nonterminal useless in grammar: useless8 [-Wother]
  useless8: '8';
- ^^^^^^^^
+ ^~~~~~~~
 input.y:14.1-8: warning: nonterminal useless in grammar: useless9 [-Wother]
  useless9: '9';
- ^^^^^^^^
+ ^~~~~~~~
 ]])
 
 
@@ -199,6 +199,88 @@ AT_CLEANUP
 
 
 
+## --------------- ##
+## Useless Parts.  ##
+## --------------- ##
+
+AT_SETUP([Useless Parts])
+
+# We used to emit code that used symbol numbers before the useless
+# symbol elimination, hence before the renumbering of the useful
+# symbols.  As a result, the evaluation of the skeleton failed because
+# it used non existing symbol numbers.  Which is the happy scenario:
+# we could use numbers of other existing symbols...
+# http://lists.gnu.org/archive/html/bug-bison/2019-01/msg00044.html
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA([[input.y]],
+[[%code {
+  ]AT_YYERROR_DECLARE_EXTERN[
+  ]AT_YYLEX_DECLARE_EXTERN[
+}
+%union { void* ptr; }
+%type <ptr> used1
+%type <ptr> used2
+
+%%
+start
+ : used1
+ ;
+
+used1
+ : used2 { $$ = $1; }
+ ;
+
+unused
+ : used2
+ ;
+
+used2
+ : { $$ = YY_NULLPTR; }
+ ;
+]])
+
+AT_BISON_CHECK([[-fcaret -rall -o input.c input.y]], 0, [],
+[[input.y: warning: 1 nonterminal useless in grammar [-Wother]
+input.y: warning: 1 rule useless in grammar [-Wother]
+input.y:18.1-6: warning: nonterminal useless in grammar: unused [-Wother]
+ unused
+ ^~~~~~
+]])
+
+
+AT_CHECK([[sed -n '/^State 0/q;/^$/!p' input.output]], 0,
+[[Nonterminals useless in grammar
+   unused
+Rules useless in grammar
+    4 unused: used2
+Grammar
+    0 $accept: start $end
+    1 start: used1
+    2 used1: used2
+    3 used2: %empty
+Terminals, with rules where they appear
+$end (0) 0
+error (256)
+Nonterminals, with rules where they appear
+$accept (3)
+    on left: 0
+start (4)
+    on left: 1, on right: 0
+used1 <ptr> (5)
+    on left: 2, on right: 1
+used2 <ptr> (6)
+    on left: 3, on right: 2
+]])
+
+# Make sure the generated parser is correct.
+AT_COMPILE([input.o])
+
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+
+
+
 ## ------------------- ##
 ## Reduced Automaton.  ##
 ## ------------------- ##
@@ -240,13 +322,13 @@ AT_BISON_CHECK([[-fcaret not-reduced.y]], 0, [],
 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_reachable: useful  { /* A not reachable action. */ }
- ^^^^^^^^^^^^^
+ ^~~~~~~~~~~~~
 not-reduced.y:17.1-14: warning: nonterminal useless in grammar: non_productive [-Wother]
  non_productive: non_productive useless_token
- ^^^^^^^^^^^^^^
+ ^~~~~~~~~~~~~~
 not-reduced.y:11.6-57: warning: rule useless in grammar [-Wother]
     | non_productive    { /* A non productive action. */ }
-      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ]])
 
 AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' not-reduced.output]], 0,
@@ -319,13 +401,13 @@ AT_BISON_CHECK([[-fcaret input.y]], 0, [],
 input.y: warning: 3 rules useless in grammar [-Wother]
 input.y:6.1-11: warning: nonterminal useless in grammar: underivable [-Wother]
  underivable: indirection;
- ^^^^^^^^^^^
+ ^~~~~~~~~~~
 input.y:7.1-11: warning: nonterminal useless in grammar: indirection [-Wother]
  indirection: underivable;
- ^^^^^^^^^^^
+ ^~~~~~~~~~~
 input.y:5.15-25: warning: rule useless in grammar [-Wother]
  exp: useful | underivable;
-               ^^^^^^^^^^^
+               ^~~~~~~~~~~
 ]])
 
 AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,

tests/regression.at

@@ -454,10 +454,10 @@ input.y:22.16-63: warning: symbol "\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!" used
 AT_BISON_CHECK([-fcaret -o input.c input.y], [[0]], [[]],
 [[input.y:22.8-14: warning: symbol SPECIAL redeclared [-Wother]
  %token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
-        ^^^^^^^
+        ^~~~~~~
 input.y:22.16-63: warning: symbol "\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!" used more than once as a literal string [-Wother]
  %token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
-                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ]])
 AT_COMPILE([input])
 

tests/types.at

@@ -32,7 +32,7 @@ exp: %empty;
 ]])
 
 AT_BISON_CHECK([[input.y]], [[1]], [[]],
-[[input.y:2.9-22: error: '%union' and '%define api.value.type' cannot be used together
+[[input.y:2.1-38: error: '%union' and '%define api.value.type' cannot be used together
 ]])
 
 AT_CLEANUP
@@ -51,7 +51,7 @@ 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
+[[input.y:2.1-28: error: '%yacc' and '%define api.value.type "union"' cannot be used together
 ]])
 
 AT_CLEANUP