.! .! RUNOFF source file for BISON.HLP .! .! This is a RUNOFF input file which will produce a VMS help file .! for the VMS HELP library. .! .! Eric Youngdale and Wilfred J. Hansen (wjh+@cmu.edu). .! .literal .end literal .no paging .no flags all .right margin 70 .left margin 1 .indent -1 1 BISON .skip The BISON command invokes the GNU BISON parser generator. .skip .literal BISON file-spec .end literal .skip .indent -1 2 Parameters .skip file-spec .skip Here file-spec is the grammar file name, which usually ends in .y. The parser file's name is made by replacing the .y with _tab.c. Thus, the command bison foo.y yields foo_tab.c. .skip .indent -1 2 Qualifiers .skip The following is the list of available qualifiers for BISON: .literal /DEBUG /DEFINES /FILE_PREFIX=prefix /FIXED_OUTFILES /NAME_PREFIX=prefix /NOLINES /NOPARSER /OUTPUT=outfilefile /RAW /TOKEN_TABLE /VERBOSE /VERSION /YACC .end literal .skip .indent -1 2 /DEBUG .skip In the parser file, define the macro YYDEBUG to 1 if it is not already defined, so that the debugging facilities are compiled. .skip .indent -1 2 /DEFINES .skip Write an extra output file containing macro definitions for the token type names defined in the grammar and the semantic value type YYSTYPE, as well as a extern variable declarations. .skip If the parser output file is named "name.c" then this file is named "name.h". .skip This output file is essential if you wish to put the definition of yylex in a separate source file, because yylex needs to be able to refer to token type codes and the variable yylval. .skip .indent -1 2 /FILE_PREFIX .skip .literal /FILIE_PREFIX=prefix .end literal .skip Specify a prefix to use for all Bison output file names. The names are chosen as if the input file were named prefix.c .skip .indent -1 2 /FIXED_OUTFILES .skip Equivalent to /OUTPUT=y_tab.c; the parser output file is called y_tab.c, and the other outputs are called y.output and y_tab.h. The purpose of this switch is to imitate Yacc's output file name conventions. The /YACC qualifier is functionally equivalent to /FIXED_OUTFILES. The following command definition will work as a substitute for Yacc: .literal $YACC:==BISON/FIXED_OUTFILES .end literal .skip .indent -1 2 /NAME_PREFIX .skip .literal /NAME_PREFIX=prefix .end literal .skip Rename the external symbols used in the parser so that they start with "prefix" instead of "yy". The precise list of symbols renamed is yyparse, yylex, yyerror, yylval, yychar and yydebug. For example, if you use /NAME_PREFIX="c", the names become cparse, clex, and so on. .skip .indent -1 2 /NOLINES .skip Don't put any "#line" preprocessor commands in the parser file. Ordinarily Bison puts them in the parser file so that the C compiler and debuggers will associate errors with your source file, the grammar file. This option causes them to associate errors with the parser file, treating it an independent source file in its own right. .skip .indent -1 2 /NOPARSER .skip Do not generate the parser code into the output; generate only declarations. The generated name_tab.c file will have only constant declarations. In addition, a name.act file is generated containing a switch statement body containing all the translated actions. .skip .indent -1 2 /OUTPUT .skip .literal /OUTPUT=outfile .end literal .skip Specify the name "outfile" for the parser file. .skip .indent -1 2 /RAW .skip When this switch is specified, the .tab.h file defines the tokens to have the bison token numbers rather than the yacc compatible numbers. To employ this switch you would have to have your own parser. .skip .indent -1 2 /TOKEN_TABLE .skip This switch causes the name_tab.c output to include a list of token names in order by their token numbers; this is defined in the array yytname. Also generated are #defines for YYNTOKENS, YYNNTS, YYNRULES, and YYNSTATES. .skip .indent -1 2 /VERBOSE .skip Write an extra output file containing verbose descriptions of the parser states and what is done for each type of look-ahead token in that state. .skip This file also describes all the conflicts, both those resolved by operator precedence and the unresolved ones. .skip The file's name is made by removing _tab.c or .c from the parser output file name, and adding .output instead. .skip Therefore, if the input file is foo.y, then the parser file is called foo_tab.c by default. As a consequence, the verbose output file is called foo.output. .skip .indent -1 2 /VERSION .skip Print the version number of Bison. .skip .indent -1 2 /YACC .skip See /FIXED_OUTFILES. .skip .indent -1