version 3.6.91

* NEWS: Record release date.

.prev-version

@@ -1 +1 @@
-3.6.4
+3.6.90

NEWS

@@ -1,5 +1,12 @@
 GNU Bison NEWS
 
+* Noteworthy changes in release 3.6.91 (2020-07-09) [beta]
+
+** Bug fixes
+
+  Portability issues.
+
+
 * Noteworthy changes in release 3.6.90 (2020-07-04) [beta]
 
 ** Deprecated features
@@ -27,8 +34,11 @@ GNU Bison NEWS
     First derivation     exp ::=[ exp ::=[ exp '+' exp • ] '/' exp ]
     Second derivation    exp ::=[ exp '+' exp ::=[ exp • '/' exp ] ]
 
+  When Bison is installed with text styling enabled, the example is actually
+  shown twice, with colors highlighting the ambiguity.
+
   This is a shift/reduce conflict caused by none of the operators having
-  precedence, so the example can be parsed in the two ways shown.   When
+  precedence, so the example can be parsed in the two ways shown.  When
   bison cannot find an example that can be derived in two ways, it instead
   generates two examples that are the same up until the dot:
 
@@ -40,6 +50,11 @@ GNU Bison NEWS
   In these cases, the parser usually doesn't have enough lookahead to
   differentiate the two given examples.
 
+  The counterexamples are "focused": in two different ways.  First, they do
+  not clutter the output with all the derivations from the start symbol,
+  rather they start on the "conflicted nonterminal". They go straight to the
+  point.  Second, they don't "expand" nonterminal symbols uselessly.
+
 *** File prefix mapping
 
   Contributed by Joshua Watt.

README-hacking.md

@@ -211,6 +211,8 @@ assert/abort), and all the --trace output which is meant for the maintainers
 only.
 
 ## Vocabulary
+- "lookahead", not "look-ahead".
+- "midrule", not "mid-rule".
 - "nonterminal", not "variable" or "non-terminal" or "non terminal".
   Abbreviated as "nterm".
 - "shift/reduce" and "reduce/reduce", not "shift-reduce" or "shift reduce",

data/README.md

@@ -86,7 +86,7 @@ The macro `b4_symbol(NUM, FIELD)` gives access to the following FIELDS:
 - `has_id`: 0 or 1
   Whether the symbol has an `id`.
 
-- `id`: string
+- `id`: string (e.g., `exp`, `NUM`, or `TOK_NUM` with api.token.prefix)
   If `has_id`, the name of the token kind (prefixed by api.token.prefix if
   defined), otherwise empty.  Guaranteed to be usable as a C identifier.
   This is used to define the token kind (i.e., the enum used by the return
@@ -105,9 +105,9 @@ The macro `b4_symbol(NUM, FIELD)` gives access to the following FIELDS:
 - `is_token`: 0 or 1
   Whether this is a terminal symbol.
 
-- `kind_base`: string
+- `kind_base`: string (e.g., `YYSYMBOL_exp`, `YYSYMBOL_NUM`)
   The base of the symbol kind, i.e., the enumerator of this symbol (token or
-  nonterminal) which is mapping to its `number`.
+  nonterminal) which is mapped to its `number`.
 
 - `kind`: string
   Same as `kind_base`, but possibly with a prefix in some languages.  E.g.,

data/skeletons/c++.m4

@@ -594,11 +594,12 @@ m4_define([b4_yytranslate_define],
     {
   ]b4_translate[
     };
-    const int code_max_ = ]b4_code_max[;
+    // Last valid token kind.
+    const int code_max = ]b4_code_max[;
 
     if (t <= 0)
       return symbol_kind::]b4_symbol_prefix[YYEOF;
-    else if (t <= code_max_)
+    else if (t <= code_max)
       return YY_CAST (symbol_kind_type, translate_table[t]);
     else
       return symbol_kind::]b4_symbol_prefix[YYUNDEF;]])[

data/skeletons/glr.c

@@ -333,7 +333,7 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
    accessed by $0, $-1, etc., in any rule.  */
 #define YYMAXLEFT ]b4_max_left_semantic_context[
 
-/* YYMAXUTOK -- Last valid token number (for yychar).  */
+/* YYMAXUTOK -- Last valid token kind.  */
 #define YYMAXUTOK   ]b4_code_max[
 
 /* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM

data/skeletons/lalr1.d

@@ -428,8 +428,9 @@ b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
    */
   public bool parse ()
   {
-    /// Lookahead and lookahead in internal form.
+    // Lookahead token kind.
     int yychar = TokenKind.YYEMPTY;
+    // Lookahead symbol kind.
     SymbolKind yytoken = ]b4_symbol(-2, kind)[;
 
     /* State.  */
@@ -841,11 +842,12 @@ m4_popdef([b4_at_dollar])])dnl
   ]b4_translate[
     @};
 
-    immutable int code_max_ = ]b4_code_max[;
+    // Last valid token kind.
+    immutable int code_max = ]b4_code_max[;
 
     if (t <= 0)
       return ]b4_symbol(0, kind)[;
-    else if (t <= code_max_)
+    else if (t <= code_max)
       {
         import std.conv : to;
         return to!SymbolKind (translate_table[t]);

data/skeletons/lalr1.java

@@ -53,8 +53,9 @@ b4_use_push_for_pull_if([
 # allows them to be defined either in parse() when doing pull parsing,
 # or as class instance variable when doing push parsing.
 m4_define([b4_define_state],[[
-    /* Lookahead and lookahead in internal form.  */
+    /* Lookahead token kind.  */
     int yychar = YYEMPTY_;
+    /* Lookahead symbol kind.  */
     SymbolKind yytoken = null;
 
     /* State.  */
@@ -1078,17 +1079,18 @@ b4_dollar_popdef[]dnl
 
   /* YYTRANSLATE_(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
      as returned by yylex, with out-of-bounds checking.  */
-  private static final SymbolKind yytranslate_ (int t)
+  private static final SymbolKind yytranslate_(int t)
 ]b4_api_token_raw_if(dnl
 [[  {
     return SymbolKind.get(t);
   }
 ]],
 [[  {
-    int code_max_ = ]b4_code_max[;
+    // Last valid token kind.
+    int code_max = ]b4_code_max[;
     if (t <= 0)
       return ]b4_symbol(0, kind)[;
-    else if (t <= code_max_)
+    else if (t <= code_max)
       return SymbolKind.get(yytranslate_table_[t]);
     else
       return ]b4_symbol(2, kind)[;

data/skeletons/yacc.c

@@ -48,6 +48,10 @@ m4_define([b4_pure_if],
 ## api.push-pull.  ##
 ## --------------- ##
 
+# b4_pull_if, b4_push_if
+# ----------------------
+# Whether the pull/push APIs are needed.  Both can be enabled.
+
 b4_percent_define_default([[api.push-pull]], [[pull]])
 b4_percent_define_check_values([[[[api.push-pull]],
                                  [[pull]], [[push]], [[both]]]])
@@ -155,7 +159,7 @@ m4_define([b4_rhs_location],
 # Declare the variables that are global, or local to YYPARSE if
 # pure-parser.
 m4_define([b4_declare_scanner_communication_variables], [[
-/* The lookahead symbol.  */
+/* Lookahead token kind.  */
 int yychar;
 
 ]b4_pure_if([[
@@ -571,6 +575,7 @@ union yyalloc
 /* YYNSTATES -- Number of states.  */
 #define YYNSTATES  ]b4_states_number[
 
+/* YYMAXUTOK -- Last valid token kind.  */
 #define YYMAXUTOK   ]b4_code_max[
 
 
@@ -1544,7 +1549,7 @@ yyparse (]m4_ifset([b4_parse_param], [b4_formals(b4_parse_param)], [void])[)]])[
   int yyn;
   /* The return value of yyparse.  */
   int yyresult;
-  /* Lookahead token as an internal (translated) token number.  */
+  /* Lookahead symbol kind.  */
   yysymbol_kind_t yytoken = ]b4_symbol(-2, kind)[;
   /* The variables used to return semantic value and location from the
      action routines.  */

doc/bison.texi

@@ -1677,6 +1677,31 @@ Here are the C and Bison declarations for the Reverse Polish Notation
 calculator.  As in C, comments are placed between @samp{/*@dots{}*/} or
 after @samp{//}.
 
+@ignore
+@comment file: rpcalc.y
+@example
+/* Parser for rpcalc.   -*- C -*-
+
+   Copyright (C) 1988-1993, 1995, 1998-2015, 2018-2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: rpcalc.y
 @example
 /* Reverse Polish Notation calculator. */
@@ -2538,6 +2563,31 @@ Note that multiple assignment and nested function calls are permitted.
 
 Here are the C and Bison declarations for the multi-function calculator.
 
+@ignore
+@comment file: mfcalc.y
+@example
+/* Parser for mfcalc.   -*- C -*-
+
+   Copyright (C) 1988-1993, 1995, 1998-2015, 2018-2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: mfcalc.y: 1
 @example
 @group
@@ -2642,6 +2692,31 @@ The symbol table itself consists of a linked list of records.  Its
 definition, which is kept in the header @file{calc.h}, is as follows.  It
 provides for either functions or variables to be placed in the table.
 
+@ignore
+@comment file: calc.h
+@example
+/* Functions for mfcalc.   -*- C -*-
+
+   Copyright (C) 1988-1993, 1995, 1998-2015, 2018-2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: calc.h
 @example
 @group
@@ -11745,6 +11820,30 @@ A Bison file has three parts.  In the first part, the prologue, we start by
 making sure we run a version of Bison which is recent enough, and that we
 generate C++.
 
+@ignore
+@comment file: c++/simple.yy: 1
+@example
+/* Simple variant-based parser.   -*- C++ -*-
+
+   Copyright (C) 2018-2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: c++/simple.yy: 1
 @example
 %require "3.2"
@@ -12817,6 +12916,30 @@ The declaration of this driver class, in @file{driver.hh}, is as follows.
 The first part includes the CPP guard and imports the required standard
 library components, and the declaration of the parser class.
 
+@ignore
+@comment file: calc++/driver.hh
+@example
+/* Driver for calc++.   -*- C++ -*-
+
+   Copyright (C) 2005--2015, 2018--2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: calc++/driver.hh
 @example
 #ifndef DRIVER_HH
@@ -12889,6 +13012,30 @@ member functions to open and close the scanning phase.
 
 The implementation of the driver (@file{driver.cc}) is straightforward.
 
+@ignore
+@comment file: calc++/driver.cc
+@example
+/* Driver for calc++.   -*- C++ -*-
+
+   Copyright (C) 2005--2015, 2018--2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: calc++/driver.cc
 @example
 #include "driver.hh"
@@ -12932,6 +13079,30 @@ parser skeleton, the creation of the parser header file.  Because the C++
 skeleton changed several times, it is safer to require the version you
 designed the grammar for.
 
+@ignore
+@comment file: calc++/parser.yy
+@example
+/* Parser for calc++.   -*- C++ -*-
+
+   Copyright (C) 2005--2015, 2018--2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: calc++/parser.yy
 @example
 %skeleton "lalr1.cc" // -*- C++ -*-
@@ -13120,6 +13291,30 @@ yy::parser::error (const location_type& l, const std::string& m)
 In addition to standard headers, the Flex scanner includes the driver's,
 then the parser's to get the set of defined tokens.
 
+@ignore
+@comment file: calc++/scanner.ll
+@example
+/* Scanner for calc++.   -*- C++ -*-
+
+   Copyright (C) 2005--2015, 2018--2020 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/>.  */
+@end example
+@end ignore
+
 @comment file: calc++/scanner.ll
 @example
 %@{ /* -*- C++ -*- */
@@ -13293,7 +13488,7 @@ The rules are simple.  The driver is used to report errors.
 You should keep your rules simple, both in the parser and in the scanner.
 Throwing from the auxiliary functions is then very handy to report errors.
 
-@comment file: scanner.ll
+@comment file: calc++/scanner.ll
 @example
 @group
 yy::parser::symbol_type
@@ -13343,7 +13538,31 @@ driver::scan_end ()
 
 The top level file, @file{calc++.cc}, poses no problem.
 
-@comment file: calc++.cc
+@ignore
+@comment file: calc++/calc++.cc
+@example
+/* Main for calc++.   -*- C++ -*-
+
+   Copyright (C) 2005--2015, 2018--2020 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/>.  */
+@end example
+@end ignore
+
+@comment file: calc++/calc++.cc
 @example
 #include <iostream>
 #include "driver.hh"

examples/c/bistromathic/parse.y

@@ -1,5 +1,25 @@
-%require "3.6"
+/* Parser and scanner for bistromathic.   -*- C -*-
 
+   Copyright (C) 2019-2020 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/>.  */
+
+%require "3.7"
+
+// Emitted on top of the implementation file.
 %code top {
   #include <ctype.h>  // isdigit
   #include <locale.h> // LC_ALL
@@ -24,6 +44,7 @@
   #endif
 }
 
+// Emitted in the header file, before the definition of YYSTYPE.
 %code requires {
   // Function type.
   typedef double (func_t) (double);
@@ -46,6 +67,7 @@
   symrec *getsym (char const *name);
 }
 
+// Emitted in the header file, after the definition of YYSTYPE.
 %code provides {
 # ifndef __attribute__
 #  ifndef __GNUC__
@@ -57,6 +79,7 @@
     __attribute__ ((__format__ (__printf__, 2, 3)));
 }
 
+// Emitted in the implementation file.
 %code {
   #if defined ENABLE_NLS && ENABLE_NLS
   # define _(Msgid)  gettext (Msgid)
@@ -68,6 +91,9 @@
   int done = 0;
 }
 
+// Include the header in the implementation rather than duplicating it.
+%define api.header.include {"parse.h"}
+
 // Don't share global variables between the scanner and the parser.
 %define api.pure full
 

examples/c/lexcalc/parse.y

@@ -1,3 +1,22 @@
+/* Parser for lexcalc.   -*- C -*-
+
+   Copyright (C) 2018-2020 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/>.  */
+
 // Prologue (directives).
 %expect 0
 
@@ -19,6 +38,9 @@
 #include <stdlib.h> // getenv.
 }
 
+// Include the header in the implementation rather than duplicating it.
+%define api.header.include {"parse.h"}
+
 // Don't share global variables between the scanner and the parser.
 %define api.pure full
 

examples/c/lexcalc/scan.l

@@ -1,4 +1,23 @@
-/* Prologue (directives).   -*- C -*- */
+/* Scanner for lexcalc.   -*- C -*-
+
+   Copyright (C) 2018-2020 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/>.  */
+
+/* Prologue (directives). */
 
 /* Disable Flex features we don't need, to avoid warnings. */
 %option nodefault noinput nounput noyywrap

examples/c/pushcalc/calc.y

@@ -1,3 +1,22 @@
+/* Parser and scanner for pushcalc.   -*- C -*-
+
+   Copyright (C) 2020 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/>.  */
+
 %code top {
   #include <ctype.h>  /* isdigit. */
   #include <stdio.h>  /* printf. */

examples/c/reccalc/parse.y

@@ -1,3 +1,22 @@
+/* Parser for reccalc.   -*- C -*-
+
+   Copyright (C) 2019-2020 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/>.  */
+
 // Prologue (directives).
 %expect 0
 
@@ -46,14 +65,29 @@
   result parse (void);
 }
 
+// Include the header in the implementation rather than duplicating it.
+%define api.header.include {"parse.h"}
+
+// Don't share global variables between the scanner and the parser.
 %define api.pure full
+
+// To avoid name clashes (e.g., with C's EOF) prefix token definitions
+// with TOK_ (e.g., TOK_EOF).
 %define api.token.prefix {TOK_}
+
+// Generate YYSTYPE from the types assigned to symbols.
 %define api.value.type union
-%define parse.error verbose
+
+// Error messages with "unexpected XXX, expected XXX...".
+%define parse.error detailed
+
+// Enable run-time traces (yydebug).
 %define parse.trace
+
+// Generate the parser description file (parse.output).
 %verbose
 
- // Scanner and error count are exchanged between main, yyparse and yylex.
+// Scanner and error count are exchanged between main, yyparse and yylex.
 %param {yyscan_t scanner}{result *res}
 
 %token

examples/c/reccalc/scan.l

@@ -1,3 +1,22 @@
+/* Scanner for reccalc.   -*- C -*-
+
+   Copyright (C) 2019-2020 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/>.  */
+
 /* Prologue (directives).   -*- C -*- */
 
 /* Disable Flex features we don't need, to avoid warnings. */

examples/d/calc.y

@@ -1,3 +1,22 @@
+/* Parser and scanner for calc in D.   -*- D -*-
+
+   Copyright (C) 2018-2020 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/>.  */
+
 %language "D"
 
 %define api.parser.class {Calc}

examples/java/calc/Calc.y

@@ -1,3 +1,22 @@
+/* Parser and scanner for calc in Java.   -*- Java -*-
+
+   Copyright (C) 2018-2020 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/>.  */
+
 %language "Java"
 
 %define api.parser.class {Calc}

examples/java/simple/Calc.y

@@ -1,3 +1,22 @@
+/* Simple parser and scanner in Java.   -*- Java -*-
+
+   Copyright (C) 2018-2020 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/>.  */
+
 %language "Java"
 
 %define api.parser.class {Calc}

lib/.gitignore

@@ -20,6 +20,7 @@
 /assure.h
 /attribute.h
 /basename-lgpl.c
+/basename-lgpl.h
 /basename.c
 /binary-io.c
 /binary-io.h

m4/.gitignore

@@ -13,7 +13,6 @@
 /codeset.m4
 /config-h.m4
 /configmake.m4
-/dirname.m4
 /double-slash-root.m4
 /dup2.m4
 /eealloc.m4

src/parse-gram.c

@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.6.4.130-76c4d.  */
+/* A Bison parser, made by GNU Bison 3.6.90.  */
 
 /* Bison implementation for Yacc-like parsers in C
 
@@ -49,7 +49,7 @@
 #define YYBISON 1
 
 /* Bison version.  */
-#define YYBISON_VERSION "3.6.4.130-76c4d"
+#define YYBISON_VERSION "3.6.90"
 
 /* Skeleton name.  */
 #define YYSKELETON_NAME "yacc.c"
@@ -234,6 +234,10 @@ typedef enum yysymbol_kind_t yysymbol_kind_t;
   #include "scan-code.h"
   #include "scan-gram.h"
 
+  /* Pretend to be at least that version, to check features published
+     in that version while developping it.  */
+  static const char* api_version = "3.7";
+
   static int current_prec = 0;
   static location current_lhs_loc;
   static named_ref *current_lhs_named_ref;
@@ -623,6 +627,7 @@ union yyalloc
 /* YYNSTATES -- Number of states.  */
 #define YYNSTATES  167
 
+/* YYMAXUTOK -- Last valid token kind.  */
 #define YYMAXUTOK   315
 
 
@@ -634,19 +639,19 @@ union yyalloc
   /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
 static const yytype_int16 yyrline[] =
 {
-       0,   308,   308,   317,   318,   322,   323,   329,   333,   338,
+       0,   312,   312,   321,   322,   326,   327,   333,   337,   342,
-     339,   340,   341,   342,   343,   344,   349,   354,   355,   356,
+     343,   344,   345,   346,   347,   348,   353,   358,   359,   360,
-     357,   358,   359,   359,   360,   361,   362,   363,   364,   365,
+     361,   362,   363,   363,   364,   365,   366,   367,   368,   369,
-     366,   367,   371,   372,   381,   382,   386,   397,   401,   405,
+     370,   371,   375,   376,   385,   386,   390,   401,   405,   409,
-     413,   423,   424,   434,   435,   441,   454,   454,   459,   459,
+     417,   427,   428,   438,   439,   445,   458,   458,   463,   463,
-     464,   468,   478,   479,   480,   481,   485,   486,   491,   492,
+     468,   472,   482,   483,   484,   485,   489,   490,   495,   496,
-     496,   497,   501,   502,   503,   516,   525,   529,   533,   541,
+     500,   501,   505,   506,   507,   520,   529,   533,   537,   545,
-     542,   546,   559,   560,   565,   566,   567,   585,   589,   593,
+     546,   550,   563,   564,   569,   570,   571,   589,   593,   597,
-     601,   603,   608,   615,   625,   629,   633,   641,   646,   658,
+     605,   607,   612,   619,   629,   633,   637,   645,   650,   662,
-     659,   665,   666,   667,   674,   674,   682,   683,   684,   689,
+     663,   669,   670,   671,   678,   678,   686,   687,   688,   693,
-     692,   694,   696,   698,   700,   702,   704,   706,   708,   713,
+     696,   698,   700,   702,   704,   706,   708,   710,   712,   717,
-     714,   723,   747,   748,   749,   750,   762,   764,   788,   793,
+     718,   727,   751,   752,   753,   754,   766,   768,   792,   797,
-     794,   799,   807,   808
+     798,   803,   811,   812
 };
 #endif
 
@@ -1748,7 +1753,7 @@ yydestruct (const char *yymsg,
 int
 yyparse (void)
 {
-/* The lookahead symbol.  */
+/* Lookahead token kind.  */
 int yychar;
 
 
@@ -1803,7 +1808,7 @@ YYLTYPE yylloc = yyloc_default;
   int yyn;
   /* The return value of yyparse.  */
   int yyresult;
-  /* Lookahead token as an internal (translated) token number.  */
+  /* Lookahead symbol kind.  */
   yysymbol_kind_t yytoken = YYSYMBOL_YYEMPTY;
   /* The variables used to return semantic value and location from the
      action routines.  */
@@ -3070,9 +3075,6 @@ handle_require (location const *loc, char const *version_quoted)
     }
   else
     {
-      /* Pretend to be at least that version, to check features published
-         in that version while developping it.  */
-      const char* api_version = "3.6";
       const char* package_version =
         0 < strverscmp (api_version, PACKAGE_VERSION)
         ? api_version : PACKAGE_VERSION;

src/parse-gram.h

@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.6.4.130-76c4d.  */
+/* A Bison parser, made by GNU Bison 3.6.90.  */
 
 /* Bison interface for Yacc-like parsers in C
 

src/parse-gram.y

@@ -58,6 +58,10 @@
   #include "scan-code.h"
   #include "scan-gram.h"
 
+  /* Pretend to be at least that version, to check features published
+     in that version while developping it.  */
+  static const char* api_version = "3.7";
+
   static int current_prec = 0;
   static location current_lhs_loc;
   static named_ref *current_lhs_named_ref;
@@ -691,8 +695,8 @@ rhs:
                                   current_lhs_named_ref); }
 | rhs symbol named_ref.opt
     { grammar_current_rule_symbol_append ($2, @2, $3); }
-| rhs tag.opt "{...}"[act] named_ref.opt[name]
+| rhs tag.opt "{...}"[action] named_ref.opt[name]
-    { grammar_current_rule_action_append ($act, @act, $name, $[tag.opt]); }
+    { grammar_current_rule_action_append ($action, @action, $name, $[tag.opt]); }
 | rhs "%?{...}"
     { grammar_current_rule_predicate_append ($2, @2); }
 | rhs "%empty"
@@ -1082,9 +1086,6 @@ handle_require (location const *loc, char const *version_quoted)
     }
   else
     {
-      /* Pretend to be at least that version, to check features published
-         in that version while developping it.  */
-      const char* api_version = "3.6";
       const char* package_version =
         0 < strverscmp (api_version, PACKAGE_VERSION)
         ? api_version : PACKAGE_VERSION;

src/reader.c

@@ -695,12 +695,10 @@ packgram (void)
 }
 
 
-/*------------------------------------------------------------------.
+/*--------------------------------------------------------------.
-| Read in the grammar specification and record it in the format     |
+| Read in the grammar specification and record it in the format |
-| described in gram.h.  All actions are copied into ACTION_OBSTACK, |
+| described in gram.h.                                          |
-| in each case forming the body of a C function (YYACTION) which    |
+`--------------------------------------------------------------*/
-| contains a switch statement to decide which action to execute.    |
-`------------------------------------------------------------------*/
 
 void
 reader (const char *gram)

src/scan-code.h

@@ -145,6 +145,7 @@ void code_props_symbol_action_init (code_props *self, char const *code,
                                     location code_loc);
 
 /**
+ * \param  type   type for midrule actions
  * \pre
  *   - <tt>self != NULL</tt>.
  *   - <tt>code != NULL</tt>.