c-parser.y

/* https://www.lysator.liu.se/c/ANSI-C-grammar-y.html */

%token IDENTIFIER CONSTANT
%token LE_OP GE_OP EQ_OP NE_OP

%token INT

%token IF ELSE WHILE GOTO RETURN

%start translation_unit

%type <unit> translation_unit

%%

primary_expression
    : IDENTIFIER { }
    | CONSTANT { }
    | '(' expression ')' { }
    ;

postfix_expression
    : primary_expression { }
    | postfix_expression '(' ')' { }
    | postfix_expression '(' argument_expression_list ')' { }
    ;

argument_expression_list
    : assignment_expression { }
    | argument_expression_list ',' assignment_expression { }
    ;

unary_expression
    : postfix_expression { }
    | '+' unary_expression { }
    | '-' unary_expression { }
    ;

multiplicative_expression
    : unary_expression { }
    | multiplicative_expression '*' unary_expression { }
    | multiplicative_expression '/' unary_expression { }
    | multiplicative_expression '%' unary_expression { }
    ;

additive_expression
    : multiplicative_expression { }
    | additive_expression '+' multiplicative_expression { }
    | additive_expression '-' multiplicative_expression { }
    ;

relational_expression
    : additive_expression { }
    | relational_expression '<' additive_expression { }
    | relational_expression '>' additive_expression { }
    | relational_expression LE_OP additive_expression { }
    | relational_expression GE_OP additive_expression { }
    ;

equality_expression
    : relational_expression { }
    | equality_expression EQ_OP relational_expression { }
    | equality_expression NE_OP relational_expression { }
    ;

assignment_expression
    : equality_expression { }
    | unary_expression '=' assignment_expression { }
    ;

expression
    : assignment_expression { }
    | expression ',' assignment_expression { }
    ;

declaration
    : type_specifier ';' { }
    | type_specifier declarator_list ';' { }
    ;

declarator_list
    : declarator { }
    | declarator_list ',' declarator { }
    ;

type_specifier
    : INT { }
    ;

declarator
    : IDENTIFIER { }
    ;

function_declaration
    : type_specifier declarator '(' ')' ';' { }
    | type_specifier declarator '(' parameter_type_list ')' ';' { }
    | type_specifier declarator '(' identifier_list ')' ';' { }
    ;

parameter_type_list
    : parameter_list { }
    ;

parameter_list
    : parameter_declaration { }
    | parameter_list ',' parameter_declaration { }
    ;

parameter_declaration
    : type_specifier declarator { }
    | type_specifier { }
    ;

identifier_list
    : IDENTIFIER { }
    | identifier_list ',' IDENTIFIER { }
    ;

statement
    : labeled_statement { }
    | compound_statement { }
    | expression_statement { }
    | selection_statement { }
    | iteration_statement { }
    | jump_statement { }
    ;

labeled_statement
    : IDENTIFIER ':' statement { }
    ;

compound_statement
    : '{' '}' { }
    | '{' statement_list '}' { }
    | '{' declaration_list '}' { }
    | '{' declaration_list statement_list '}' { }
    ;

declaration_list
    : declaration { }
    | declaration_list declaration { }
    ;

statement_list
    : statement { }
    | statement_list statement { }
    ;

expression_statement
    : ';' { }
    | expression ';' { }
    ;

selection_statement
    : IF '(' expression ')' statement { }
    | IF '(' expression ')' statement ELSE statement { }
    ;

iteration_statement
    : WHILE '(' expression ')' statement { }
    ;

jump_statement
    : GOTO IDENTIFIER ';' { }
    | RETURN ';' { }
    | RETURN expression ';' { }
    ;

translation_unit
    : external_declaration { }
    | translation_unit external_declaration { }
    ;

external_declaration
    : function_definition { }
    | function_declaration { }
    ;

function_definition
    : type_specifier declarator declaration_list compound_statement { }
    | type_specifier declarator compound_statement { }
    ;