GRAMMAR

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

primary_expression
	: IDENTIFIER
	| CONSTANT
	| CHAR_LITERAL
	| '(' expression ')'
	;

postfix_expression
	: primary_expression
	| postfix_expression '(' ')'
	| postfix_expression '(' argument_expression_list ')'
	| postfix_expression INC_OP
	| postfix_expression DEC_OP
	;

argument_expression_list
	: assignment_expression
	| argument_expression_list ',' assignment_expression
	;

unary_expression
	: postfix_expression
	| INC_OP unary_expression
	| DEC_OP unary_expression
	| unary_operator cast_expression
	| SIZEOF '(' type_name ')'
	| SIZEOF unary_expression
	;

unary_operator
	: '+'
	| '-'
	| '~'
	| '!'
	;

cast_expression
	: unary_expression
	| '(' type_name ')' cast_expression
	;

multiplicative_expression
	: cast_expression
	| multiplicative_expression '*' cast_expression
	| multiplicative_expression '/' cast_expression
	| multiplicative_expression '%' cast_expression
	;

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

shift_expression
	: additive_expression
	| shift_expression LEFT_OP additive_expression
	| shift_expression RIGHT_OP additive_expression
	;

relational_expression
	: shift_expression
	| relational_expression '<' shift_expression
	| relational_expression '>' shift_expression
	| relational_expression LE_OP shift_expression
	| relational_expression GE_OP shift_expression
	;

equality_expression
	: relational_expression
	| equality_expression EQ_OP relational_expression
	| equality_expression NE_OP relational_expression
	;

and_expression
	: equality_expression
	| and_expression '&' equality_expression
	;

exclusive_or_expression
	: and_expression
	| exclusive_or_expression '^' and_expression
	;

inclusive_or_expression
	: exclusive_or_expression
	| inclusive_or_expression '|' exclusive_or_expression
	;

logical_and_expression
	: inclusive_or_expression
	| logical_and_expression AND_OP inclusive_or_expression
	;

logical_or_expression
	: logical_and_expression
	| logical_or_expression OR_OP logical_and_expression
	;

conditional_expression
	: logical_or_expression
	| logical_or_expression '?' expression ':' conditional_expression
	;

assignment_expression
	: conditional_expression
	| unary_expression assignment_operator assignment_expression
	;

assignment_operator
	: '='
	| MUL_ASSIGN
	| DIV_ASSIGN
	| MOD_ASSIGN
	| ADD_ASSIGN
	| SUB_ASSIGN
	| LEFT_ASSIGN
	| RIGHT_ASSIGN
	| AND_ASSIGN
	| XOR_ASSIGN
	| OR_ASSIGN
	;

expression
	: assignment_expression
	;

constant_expression
	: conditional_expression
	;

declaration
	:  declaration_specifiers init_declarator ';'
	;

declaration_specifiers
	| specifier_list
	;


init_declarator
	: IDENTIFIER
	| IDENTIFIER '=' initializer
	;

type_specifier
	: VOID
	| CHAR
	| SHORT
	| INT
	| LONG
	| FLOAT
	| DOUBLE
	| SIGNED
	| UNSIGNED
	;


specifier_list
	: type_specifier specifier_list
	| type_specifier
	;

type_name
	: specifier_list
	;


parameter_list
	: parameter_declaration
	| parameter_list ',' parameter_declaration
	;

parameter_declaration
	: declaration_specifiers IDENTIFIER
	| declaration_specifiers
	;

initializer
	: assignment_expression
	;

statement
	: compound_statement
	| expression_statement
	| selection_statement
	| iteration_statement
	| jump_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
	| FOR '(' expression_statement expression_statement expression ')' statement
	;

jump_statement
	: CONTINUE ';'
	| BREAK ';'
	| RETURN ';'
	| RETURN expression ';'
	;

translation_unit
	: external_declaration
	| translation_unit external_declaration
	;

external_declaration
	: function_definition
	| declaration
	;

function_definition
	: FUNC declaration_specifiers IDENTIFIER '(' parameter_list ')' ';'
	: FUNC declaration_specifiers IDENTIFIER '(' parameter_list ')' compound_statement
	;