* data/lalr1.cc: Move the body of the ctor and dtor into the

[bison.git] / doc / bison.texinfo

diff --git a/doc/bison.texinfo b/doc/bison.texinfo
index 36ee6470a2b46fca4368c58f7d247a5274c397c3..01dccb418bcea8ca898ef758154f4c9234e39512 100644 (file)
--- a/doc/bison.texinfo
+++ b/doc/bison.texinfo
@@ -145,9 +145,9 @@ The Concepts of Bison
 
 Writing @acronym{GLR} Parsers
 
 
 Writing @acronym{GLR} Parsers
 

-* Simple GLR Parsers::          Using @acronym{GLR} parsers on unambiguous grammars
-* Merging GLR Parses::          Using @acronym{GLR} parsers to resolve ambiguities
-* Compiler Requirements::       @acronym{GLR} parsers require a modern C compiler
+* Simple GLR Parsers::       Using @acronym{GLR} parsers on unambiguous grammars
+* Merging GLR Parses::       Using @acronym{GLR} parsers to resolve ambiguities
+* Compiler Requirements::    @acronym{GLR} parsers require a modern C compiler

 
 Examples
 
 
 Examples
 


@@ -225,6 +225,7 @@ Tracking Locations
 
 Bison Declarations
 
 
 Bison Declarations
 

+* Require Decl::      Requiring a Bison version.

 * Token Decl::        Declaring terminal symbols.
 * Precedence Decl::   Declaring terminals with precedence and associativity.
 * Union Decl::        Declaring the set of all semantic value types.
 * Token Decl::        Declaring terminal symbols.
 * Precedence Decl::   Declaring terminals with precedence and associativity.
 * Union Decl::        Declaring the set of all semantic value types.


@@ -732,9 +733,9 @@ user-defined function on the resulting values to produce an arbitrary
 merged result.
 
 @menu
 merged result.
 
 @menu

-* Simple GLR Parsers::          Using @acronym{GLR} parsers on unambiguous grammars
-* Merging GLR Parses::          Using @acronym{GLR} parsers to resolve ambiguities
-* Compiler Requirements::       @acronym{GLR} parsers require a modern C compiler
+* Simple GLR Parsers::       Using @acronym{GLR} parsers on unambiguous grammars
+* Merging GLR Parses::       Using @acronym{GLR} parsers to resolve ambiguities
+* Compiler Requirements::    @acronym{GLR} parsers require a modern C compiler

 @end menu
 
 @node Simple GLR Parsers
 @end menu
 
 @node Simple GLR Parsers


@@ -3548,6 +3549,7 @@ it explicitly (@pxref{Language and Grammar, ,Languages and Context-Free
 Grammars}).
 
 @menu
 Grammars}).
 
 @menu

+* Require Decl::      Requiring a Bison version.

 * Token Decl::        Declaring terminal symbols.
 * Precedence Decl::   Declaring terminals with precedence and associativity.
 * Union Decl::        Declaring the set of all semantic value types.
 * Token Decl::        Declaring terminal symbols.
 * Precedence Decl::   Declaring terminals with precedence and associativity.
 * Union Decl::        Declaring the set of all semantic value types.


@@ -3560,6 +3562,20 @@ Grammars}).
 * Decl Summary::      Table of all Bison declarations.
 @end menu
 
 * Decl Summary::      Table of all Bison declarations.
 @end menu
 

+@node Require Decl
+@subsection Require a Version of Bison
+@cindex version requirement
+@cindex requiring a version of Bison
+@findex %require
+
+You may require the minimum version of Bison to process the grammar.  If
+the requirement is not met, @command{bison} exits with an error (exit
+status 63).
+
+@example
+%require "@var{version}"
+@end example
+

 @node Token Decl
 @subsection Token Type Names
 @cindex declaring token type names
 @node Token Decl
 @subsection Token Type Names
 @cindex declaring token type names


@@ -3794,28 +3810,28 @@ For instance, if your locations use a file name, you may use
 @cindex freeing discarded symbols
 @findex %destructor
 
 @cindex freeing discarded symbols
 @findex %destructor
 

-Some symbols can be discarded by the parser.  During error
-recovery (@pxref{Error Recovery}), symbols already pushed
-on the stack and tokens coming from the rest of the file
-are discarded until the parser falls on its feet.  If the parser
-runs out of memory, all the symbols on the stack must be discarded.
-Even if the parser succeeds, it must discard the start symbol.
+Some symbols can be discarded by the parser.  During error recovery
+(@pxref{Error Recovery}), symbols already pushed on the stack and tokens
+coming from the rest of the file are discarded until the parser falls on
+its feet.  If the parser runs out of memory, all the symbols on the
+stack must be discarded.  Even if the parser succeeds, it must discard
+the start symbol.

 
 When discarded symbols convey heap based information, this memory is
 lost.  While this behavior can be tolerable for batch parsers, such as
 
 When discarded symbols convey heap based information, this memory is
 lost.  While this behavior can be tolerable for batch parsers, such as

-in traditional compilers, it is unacceptable for programs like shells
-or protocol implementations that may parse and execute indefinitely.
+in traditional compilers, it is unacceptable for programs like shells or
+protocol implementations that may parse and execute indefinitely.

 
 The @code{%destructor} directive defines code that
 is called when a symbol is discarded.
 
 @deffn {Directive} %destructor @{ @var{code} @} @var{symbols}
 @findex %destructor
 
 The @code{%destructor} directive defines code that
 is called when a symbol is discarded.
 
 @deffn {Directive} %destructor @{ @var{code} @} @var{symbols}
 @findex %destructor

-Invoke @var{code} whenever the parser discards one of the
-@var{symbols}.  Within @var{code}, @code{$$} designates the semantic
-value associated with the discarded symbol.  The additional
-parser parameters are also available
-(@pxref{Parser Function, , The Parser Function @code{yyparse}}).
+Invoke @var{code} whenever the parser discards one of the @var{symbols}.
+Within @var{code}, @code{$$} designates the semantic value associated
+with the discarded symbol.  The additional parser parameters are also
+available (@pxref{Parser Function, , The Parser Function
+@code{yyparse}}).

 
 @strong{Warning:} as of Bison 2.1, this feature is still
 experimental, as there has not been enough user feedback.  In particular,
 
 @strong{Warning:} as of Bison 2.1, this feature is still
 experimental, as there has not been enough user feedback.  In particular,


@@ -4157,6 +4173,11 @@ Request a pure (reentrant) parser program (@pxref{Pure Decl, ,A Pure
 (Reentrant) Parser}).
 @end deffn
 
 (Reentrant) Parser}).
 @end deffn
 

+@deffn {Directive} %require "@var{version}"
+Require version @var{version} or higher of Bison.  @xref{Require Decl, ,
+Require a Version of Bison}.
+@end deffn
+

 @deffn {Directive} %token-table
 Generate an array of token names in the parser file.  The name of the
 array is @code{yytname}; @code{yytname[@var{i}]} is the name of the
 @deffn {Directive} %token-table
 Generate an array of token names in the parser file.  The name of the
 array is @code{yytname}; @code{yytname[@var{i}]} is the name of the


@@ -7275,13 +7296,16 @@ calcxx_driver::error (const std::string& m)
 @node Calc++ Parser
 @subsection Calc++ Parser
 
 @node Calc++ Parser
 @subsection Calc++ Parser
 

-The parser definition file @file{calc++-parser.yy} starts by asking
-for the C++ LALR(1) skeleton, the creation of the parser header file, and
-specifies the name of the parser class.
+The parser definition file @file{calc++-parser.yy} starts by asking for
+the C++ LALR(1) skeleton, the creation of the parser header file, and
+specifies the name of the parser class.  Because the C++ skeleton
+changed several times, it is safer to require the version you designed
+the grammar for.

 
 @comment file: calc++-parser.yy
 @example
 %skeleton "lalr1.cc"                          /*  -*- C++ -*- */
 
 @comment file: calc++-parser.yy
 @example
 %skeleton "lalr1.cc"                          /*  -*- C++ -*- */

+%require "2.1a"

 %defines
 %define "parser_class_name" "calcxx_parser"
 @end example
 %defines
 %define "parser_class_name" "calcxx_parser"
 @end example


@@ -7968,6 +7992,11 @@ Bison declaration to request a pure (reentrant) parser.
 @xref{Pure Decl, ,A Pure (Reentrant) Parser}.
 @end deffn
 
 @xref{Pure Decl, ,A Pure (Reentrant) Parser}.
 @end deffn
 

+@deffn {Directive} %require "@var{version}"
+Require version @var{version} or higher of Bison.  @xref{Require Decl, ,
+Require a Version of Bison}.
+@end deffn
+

 @deffn {Directive} %right
 Bison declaration to assign right associativity to token(s).
 @xref{Precedence Decl, ,Operator Precedence}.
 @deffn {Directive} %right
 Bison declaration to assign right associativity to token(s).
 @xref{Precedence Decl, ,Operator Precedence}.