X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/1c59e0a1212dd654259d9aca83838c77c8dab53e..c70fdfcd207a394121c7dac271bbd04ce2a91c98:/doc/bison.texinfo diff --git a/doc/bison.texinfo b/doc/bison.texinfo index 5f7b6c38..a8c60bc4 100644 --- a/doc/bison.texinfo +++ b/doc/bison.texinfo @@ -243,6 +243,8 @@ Parser C-Language Interface which reads tokens. * Error Reporting:: You must supply a function @code{yyerror}. * Action Features:: Special features for use in actions. +* Internationalization:: How to let the parser speak in the user's + native language. The Lexical Analyzer Function @code{yylex} @@ -1187,14 +1189,7 @@ start with a function called @code{main}; you have to provide this, and arrange for it to call @code{yyparse} or the parser will never run. @xref{Interface, ,Parser C-Language Interface}. -If your code defines a C preprocessor macro @code{_} (a single -underscore), Bison assumes that it can be used to translate -English-language strings to the user's preferred language using a -function-like syntax, e.g., @code{_("syntax error")}. Otherwise, -Bison defines a no-op macro by that name that merely returns its -argument, so strings are not translated. - -Aside from @code{_} and the token type names and the symbols in the actions you +Aside from the token type names and the symbols in the actions you write, all symbols defined in the Bison parser file itself begin with @samp{yy} or @samp{YY}. This includes interface functions such as the lexical analyzer function @code{yylex}, the error reporting @@ -4250,6 +4245,8 @@ in the grammar file, you are likely to run into trouble. which reads tokens. * Error Reporting:: You must supply a function @code{yyerror}. * Action Features:: Special features for use in actions. +* Internationalization:: How to let the parser speak in the user's + native language. @end menu @node Parser Function @@ -4812,6 +4809,84 @@ of the @var{n}th component of the current rule. @xref{Locations, , Tracking Locations}. @end deffn +@node Internationalization +@section Parser Internationalization +@cindex internationalization +@cindex i18n +@cindex NLS +@cindex gettext +@cindex bison-po + +A Bison-generated parser can print diagnostics, including error and +tracing messages. By default, they appear in English. However, Bison +also supports outputting diagnostics in the user's native language. +To make this work, the user should set the usual environment +variables. @xref{Using gettextized software, , User influence on +@code{gettext}, libc, The GNU C Library Reference Manual}. For +example, the shell command @samp{export LC_ALL=fr_CA.UTF-8} might set +the user's locale to French Canadian using the @acronym{UTF}-8 +encoding. The exact set of available locales depends on the user's +installation. + +The maintainer of a package that uses a Bison-generated parser enables +the internationalization of the parser's output through the following +steps. Here we assume a package that uses @acronym{GNU} Autoconf and +@acronym{GNU} Automake. + +@enumerate +@item +Into the directory containing the @acronym{GNU} Autoconf macros used +by the package---often called @file{m4}---copy the +@file{bison-i18n.m4} file installed by Bison under +@samp{share/aclocal/bison-i18n.m4} in Bison's installation directory. +For example: + +@example +cp /usr/local/share/aclocal/bison-i18n.m4 m4/bison-i18n.m4 +@end example + +@item +In the top-level @file{configure.ac}, after the @code{AM_GNU_GETTEXT} +invocation, add an invocation of @code{BISON_I18N}. This macro is +defined in the file @file{bison-i18n.m4} that you copied earlier. It +causes @samp{configure} to find the value of the +@code{BISON_LOCALEDIR} variable. + +@item +In the @code{main} function of your program, designate the directory +containing Bison's runtime message catalog, through a call to +@samp{bindtextdomain} with domain name @samp{bison-runtime}. +For example: + +@example +bindtextdomain ("bison-runtime", BISON_LOCALEDIR); +@end example + +Typically this appears after any other call @code{bindtextdomain +(PACKAGE, LOCALEDIR)} that your package already has. Here we rely on +@samp{BISON_LOCALEDIR} to be defined as a string through the +@file{Makefile}. + +@item +In the @file{Makefile.am} that controls the compilation of the @code{main} +function, make @samp{BISON_LOCALEDIR} available as a C preprocessor macro, +either in @samp{DEFS} or in @samp{AM_CPPFLAGS}. For example: + +@example +DEFS = @@DEFS@@ -DBISON_LOCALEDIR='"$(BISON_LOCALEDIR)"' +@end example + +or: + +@example +AM_CPPFLAGS = -DBISON_LOCALEDIR='"$(BISON_LOCALEDIR)"' +@end example + +@item +Finally, invoke the command @command{autoreconf} to generate the build +infrastructure. +@end enumerate + @node Algorithm @chapter The Bison Parser Algorithm @@ -5496,6 +5571,13 @@ return_spec: ; @end example +For a more detailed exposition of @acronym{LALR}(1) parsers and parser +generators, please see: +Frank DeRemer and Thomas Pennello, Efficient Computation of +@acronym{LALR}(1) Look-Ahead Sets, @cite{@acronym{ACM} Transactions on +Programming Languages and Systems}, Vol.@: 4, No.@: 4 (October 1982), +pp.@: 615--649 @uref{http://doi.acm.org/10.1145/69622.357187}. + @node Generalized LR Parsing @section Generalized @acronym{LR} (@acronym{GLR}) Parsing @cindex @acronym{GLR} parsing @@ -6568,6 +6650,9 @@ Print a summary of the command-line options to Bison and exit. @itemx --version Print the version number of Bison and exit. +@item --print-localedir +Print the name of the directory containing locale-dependent data. + @need 1750 @item -y @itemx --yacc @@ -6707,6 +6792,7 @@ the corresponding short option. \line{ --no-lines \leaderfill -l} \line{ --no-parser \leaderfill -n} \line{ --output \leaderfill -o} +\line{ --print-localedir} \line{ --token-table \leaderfill -k} \line{ --verbose \leaderfill -v} \line{ --version \leaderfill -V} @@ -6725,6 +6811,7 @@ the corresponding short option. --no-lines -l --no-parser -n --output=@var{outfile} -o @var{outfile} +--print-localedir --token-table -k --verbose -v --version -V @@ -6785,7 +6872,7 @@ int yyparse (void); @c - Always pure @c - initial action -The C++ parser LALR(1) skeleton is named @file{lalr1.cc}. To select +The C++ parser @acronym{LALR}(1) skeleton is named @file{lalr1.cc}. To select it, you may either pass the option @option{--skeleton=lalr1.cc} to Bison, or include the directive @samp{%skeleton "lalr1.cc"} in the grammar preamble. When run, @command{bison} will create several @@ -7360,10 +7447,12 @@ preceding tokens. Comments would be treated equally. @comment file: calc++-scanner.ll @example +%@{ +# define YY_USER_ACTION yylloc->columns (yyleng); +%@} %% %@{ yylloc->step (); -# define YY_USER_ACTION yylloc->columns (yyleng); %@} @{blank@}+ yylloc->step (); [\n]+ yylloc->lines (yyleng); yylloc->step ();