Convert multiple variable definition warnings to complaints.

[bison.git] / doc / bison.texinfo

diff --git a/doc/bison.texinfo b/doc/bison.texinfo
index a02d07607b655bd85da5d75820fd457804cccc01..3c63a19a9666f2e1cc5226a92b7af2f10a9e27f5 100644 (file)
--- a/doc/bison.texinfo
+++ b/doc/bison.texinfo
@@ -3048,8 +3048,8 @@ A @dfn{nonterminal symbol} stands for a class of syntactically
 equivalent groupings.  The symbol name is used in writing grammar rules.
 By convention, it should be all lower case.
 
 equivalent groupings.  The symbol name is used in writing grammar rules.
 By convention, it should be all lower case.
 

-Symbol names can contain letters, underscores, period, and (not at the
-beginning) digits and dashes.  Dashes in symbol names are a GNU
+Symbol names can contain letters, underscores, periods, dashes, and (not
+at the beginning) digits.  Dashes in symbol names are a GNU

 extension, incompatible with @acronym{POSIX} Yacc.  Terminal symbols
 that contain periods or dashes make little sense: since they are not
 valid symbols (in most programming languages) they are not exported as
 extension, incompatible with @acronym{POSIX} Yacc.  Terminal symbols
 that contain periods or dashes make little sense: since they are not
 valid symbols (in most programming languages) they are not exported as


@@ -4837,7 +4837,8 @@ The possible choices for @var{variable}, as well as their meanings, depend on
 the selected target language and/or the parser skeleton (@pxref{Decl
 Summary,,%language}, @pxref{Decl Summary,,%skeleton}).
 
 the selected target language and/or the parser skeleton (@pxref{Decl
 Summary,,%language}, @pxref{Decl Summary,,%skeleton}).
 

-Bison will warn if a @var{variable} is defined multiple times.
+It is an error if a @var{variable} is defined by @code{%define} multiple
+times, but @ref{Bison Options,,-D @var{name}[=@var{value}]}.

 
 Omitting @code{"@var{value}"} is always equivalent to specifying it as
 @code{""}.
 
 Omitting @code{"@var{value}"} is always equivalent to specifying it as
 @code{""}.


@@ -7982,8 +7983,32 @@ already defined, so that the debugging facilities are compiled.
 
 @item -D @var{name}[=@var{value}]
 @itemx --define=@var{name}[=@var{value}]
 
 @item -D @var{name}[=@var{value}]
 @itemx --define=@var{name}[=@var{value}]

-Same as running @samp{%define @var{name} "@var{value}"} (@pxref{Decl
-Summary, ,%define}).
+@item -F @var{name}[=@var{value}]
+@itemx --force-define=@var{name}[=@var{value}]
+Each of these is equivalent to @samp{%define @var{name} "@var{value}"}
+(@pxref{Decl Summary, ,%define}) except that Bison processes multiple
+definitions for the same @var{name} as follows:
+
+@itemize
+@item
+Bison quietly ignores all command-line definitions for @var{name} except
+the last.
+@item
+If that command-line definition is specified by a @code{-D} or
+@code{--define}, Bison reports an error for any @code{%define}
+definition for @var{name}.
+@item
+If that command-line definition is specified by a @code{-F} or
+@code{--force-define} instead, Bison quietly ignores all @code{%define}
+definitions for @var{name}.
+@item
+Otherwise, Bison reports an error if there are multiple @code{%define}
+definitions for @var{name}.
+@end itemize
+
+You should avoid using @code{-F} and @code{--force-define} in your
+makefiles unless you are confident that it is safe to quietly ignore any
+conflicting @code{%define} that may be added to the grammar file.

 
 @item -L @var{language}
 @itemx --language=@var{language}
 
 @item -L @var{language}
 @itemx --language=@var{language}


@@ -8109,9 +8134,9 @@ More user feedback will help to stabilize it.)
 @section Option Cross Key
 
 Here is a list of options, alphabetized by long option, to help you find
 @section Option Cross Key
 
 Here is a list of options, alphabetized by long option, to help you find

-the corresponding short option.
+the corresponding short option and directive.

 
 

-@multitable {@option{--defines=@var{defines-file}}} {@option{-D @var{name}[=@var{value}]}} {@code{%nondeterministic-parser}}
+@multitable {@option{--force-define=@var{name}[=@var{value}]}} {@option{-F @var{name}[=@var{value}]}} {@code{%nondeterministic-parser}}

 @headitem Long Option @tab Short Option @tab Bison Directive
 @include cross-options.texi
 @end multitable
 @headitem Long Option @tab Short Option @tab Bison Directive
 @include cross-options.texi
 @end multitable


@@ -8735,8 +8760,8 @@ parser's to get the set of defined tokens.
 @example
 %@{                                            /* -*- C++ -*- */
 # include <cstdlib>
 @example
 %@{                                            /* -*- C++ -*- */
 # include <cstdlib>

-# include <errno.h>
-# include <limits.h>
+# include <cerrno>
+# include <climits>

 # include <string>
 # include "calc++-driver.hh"
 # include "calc++-parser.hh"
 # include <string>
 # include "calc++-driver.hh"
 # include "calc++-parser.hh"


@@ -9008,7 +9033,7 @@ The first, inclusive, position of the range, and the first beyond.
 @end deftypeivar
 
 @deftypeop {Constructor} {Location} {} Location (Position @var{loc})
 @end deftypeivar
 
 @deftypeop {Constructor} {Location} {} Location (Position @var{loc})

-Create a @code{Location} denoting an empty range located at a given point. 
+Create a @code{Location} denoting an empty range located at a given point.

 @end deftypeop
 
 @deftypeop {Constructor} {Location} {} Location (Position @var{begin}, Position @var{end})
 @end deftypeop
 
 @deftypeop {Constructor} {Location} {} Location (Position @var{begin}, Position @var{end})


@@ -9222,12 +9247,12 @@ Return immediately from the parser, indicating success.
 @end deffn
 
 @deffn {Statement} {return YYERROR;}
 @end deffn
 
 @deffn {Statement} {return YYERROR;}

-Start error recovery without printing an error message. 
+Start error recovery without printing an error message.

 @xref{Error Recovery}.
 @end deffn
 
 @deffn {Statement} {return YYFAIL;}
 @xref{Error Recovery}.
 @end deffn
 
 @deffn {Statement} {return YYFAIL;}

-Print an error message and start error recovery. 
+Print an error message and start error recovery.

 @xref{Error Recovery}.
 @end deffn
 
 @xref{Error Recovery}.
 @end deffn