bison

Compile a bison definition file

$ bison [path/to/file.y]

$ bison [[-t|--debug]] [path/to/file.y]

$ bison [[-o|--output]] [path/to/output.c] [path/to/file.y]

$ bison [[-v|--verbose]]

bison [OPTION]... [FILE.y]

-d, --defines[=FILE]
    Also create FILE.h (or FILE.output.h if using -o); also output macro definitions there

-l, --no-lines
    Don't generate '#line' directives in output

-o, --output=FILE
    Name of the output file (default: FILE.tab.c)

-t, --debug
    Instrument the parser for tracing (yydebug)

-v, --verbose
    Create FILE.output describing parser states and conflicts

-V, --version
    Display version info and exit

-h, --help
    Display this help and exit

--file-prefix=STRING
    Use STRING as prefix of output files

-p, --name-prefix=STRING
    Prefix parser function names with STRING

-S, --skeleton=FILE
    Specify skeleton template FILE

--language=LANGUAGE
    Generate parser in LANGUAGE (c, c++, java)

-W, --warnings[=CATEGORY]
    Report warnings in specified categories

Bison is a general-purpose parser generator that converts an annotated LALR(1) context-free grammar specification into a C, C++, or other language parser implementation.

It reads a grammar file (typically ending in .y) defining tokens, rules, and actions, then outputs source code for a deterministic parser that recognizes valid input sequences. Bison extends Yacc with features like push parsers, locations tracking, and multiple output languages.

Commonly paired with Flex for lexical analysis, it powers tools from compilers (GCC) to interpreters. Users define %token declarations, precedence rules to resolve shift/reduce conflicts, and semantic actions in C blocks. Bison reports parser states, conflicts, and generates tables for efficient runtime parsing.

Resolves some shift/reduce and reduce/reduce conflicts automatically but warns; ambiguous grammars may require %left/%right/%nonassoc precedence. LALR(1) limitation: cannot handle all nondeterministic grammars. Debug traces require recompilation with yydebug=1.

Generates FILE.tab.c (parser), FILE.tab.h (with -d), FILE.output (with -v for conflicts/states), FILE.dot (graph with --graph).

%{ #include <stdio.h> %}
%% start : expr { printf("Result: %d\n", $1); } ;
expr : expr '+' expr { $$ = $1 + $3; } | NUM ;
NUM : '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9' { $$ = $1 - '0'; } ;
%%