doc: fixes.

[bison.git] / doc / bison.texinfo

diff --git a/doc/bison.texinfo b/doc/bison.texinfo
index 9b600785bccff927d2d8229049003aa7a7e2d952..a4474df7da3eb68c66e6d418d8ab180f99795a49 100644 (file)
--- a/doc/bison.texinfo
+++ b/doc/bison.texinfo
@@ -3804,8 +3804,11 @@ typedef struct YYLTYPE
 @} YYLTYPE;
 @end example
 
-At the beginning of the parsing, Bison initializes all these fields to 1
-for @code{yylloc}.
+When @code{YYLTYPE} is not defined, at the beginning of the parsing, Bison
+initializes all these fields to 1 for @code{yylloc}.  To initialize
+@code{yylloc} with a custom location type (or to chose a different
+initialization), use the @code{%initial-action} directive.  @xref{Initial
+Action Decl, , Performing Actions before Parsing}.
 
 @node Actions and Locations
 @subsection Actions and Locations
@@ -4837,7 +4840,8 @@ 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}).
 
-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 see @ref{Bison Options,,-D @var{name}[=@var{value}]}.
 
 Omitting @code{"@var{value}"} is always equivalent to specifying it as
 @code{""}.
@@ -7982,8 +7986,32 @@ already defined, so that the debugging facilities are compiled.
 
 @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}).
+@itemx -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}
@@ -8109,9 +8137,9 @@ 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
-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
@@ -8735,8 +8763,8 @@ parser's to get the set of defined tokens.
 @example
 %@{                                            /* -*- C++ -*- */
 # include <cstdlib>
-# include <errno.h>
-# include <limits.h>
+# include <cerrno>
+# include <climits>
 # include <string>
 # include "calc++-driver.hh"
 # include "calc++-parser.hh"
@@ -10530,6 +10558,10 @@ grammatically indivisible.  The piece of text it represents is a token.
 
 @bye
 
+@c Local Variables:
+@c fill-column: 76
+@c End:
+
 @c LocalWords: texinfo setfilename settitle setchapternewpage finalout
 @c LocalWords: ifinfo smallbook shorttitlepage titlepage GPL FIXME iftex
 @c LocalWords: akim fn cp syncodeindex vr tp synindex dircategory direntry