c5.y

用于lex和yacc的c++及c语言的文法,可用来构造C++语言的编译器

        | basic_declaration_specifier declaration_qualifier
        | basic_declaration_specifier basic_type_name
        ;

basic_type_specifier:
        basic_type_name            /* Arithmetic or void */
        | type_qualifier_list  basic_type_name
        | basic_type_specifier type_qualifier
        | basic_type_specifier basic_type_name
        ;

sue_declaration_specifier:          /* Storage Class + struct/union/enum */
        declaration_qualifier_list  elaborated_type_name
        | sue_type_specifier        storage_class
        | sue_declaration_specifier declaration_qualifier
        ;

sue_type_specifier:
        elaborated_type_name              /* struct/union/enum */
        | type_qualifier_list elaborated_type_name
        | sue_type_specifier  type_qualifier
        ;


typedef_declaration_specifier:       /*Storage Class + typedef types */
        typedef_type_specifier          storage_class
        | declaration_qualifier_list    TYPEDEFname
        | typedef_declaration_specifier declaration_qualifier
        ;

typedef_type_specifier:              /* typedef types */
        TYPEDEFname
        | type_qualifier_list    TYPEDEFname
        | typedef_type_specifier type_qualifier
        ;

storage_class:
        TYPEDEF
        | EXTERN
        | STATIC
        | AUTO
        | REGISTER
        ;

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

elaborated_type_name:
        aggregate_name
        | enum_name
        ;

aggregate_name:
        aggregate_key '{'  member_declaration_list '}'
        | aggregate_key identifier_or_typedef_name
                '{'  member_declaration_list '}'
        | aggregate_key identifier_or_typedef_name
        ;

aggregate_key:
        STRUCT
        | UNION
        ;

 member_declaration_list:
        member_declaration
        |  member_declaration_list member_declaration
        ;

member_declaration:
        member_declaring_list ';'
        | member_default_declaring_list ';'
        ;

member_default_declaring_list:        /* doesn't redeclare typedef*/
        type_qualifier_list member_identifier_declarator
        | member_default_declaring_list ',' member_identifier_declarator
        ;

member_declaring_list:
        type_specifier member_declarator
        | member_declaring_list ',' member_declarator
        ;


member_declarator:
        declarator bit_field_size_opt
        | bit_field_size
        ;

member_identifier_declarator:
        identifier_declarator {} bit_field_size_opt
        | bit_field_size
        ;

bit_field_size_opt:
        /* nothing */
        | bit_field_size
        ;

bit_field_size:
        ':' constant_expression
        ;

enum_name:
        ENUM '{' enumerator_list '}'
        | ENUM identifier_or_typedef_name '{' enumerator_list '}'
        | ENUM identifier_or_typedef_name
        ;



enumerator_list:
        identifier_or_typedef_name enumerator_value_opt
        | enumerator_list ',' identifier_or_typedef_name enumerator_value_opt
        ;

enumerator_value_opt:
        /* Nothing */
        | '=' constant_expression
        ;

parameter_type_list:
        parameter_list
        | parameter_list ',' ELLIPSIS
        ;

parameter_list:
        parameter_declaration
        | parameter_list ',' parameter_declaration
        ;

parameter_declaration:
        declaration_specifier
        | declaration_specifier abstract_declarator
        | declaration_specifier identifier_declarator
        | declaration_specifier parameter_typedef_declarator
        | declaration_qualifier_list
        | declaration_qualifier_list abstract_declarator
        | declaration_qualifier_list identifier_declarator
        | type_specifier
        | type_specifier abstract_declarator
        | type_specifier identifier_declarator
        | type_specifier parameter_typedef_declarator
        | type_qualifier_list
        | type_qualifier_list abstract_declarator
        | type_qualifier_list identifier_declarator
        ;

    /*  ANSI  C  section  3.7.1  states  "An identifier declared as a
    typedef name shall not be redeclared as a parameter".  Hence  the
    following is based only on IDENTIFIERs */

identifier_list:
        IDENTIFIER
        | identifier_list ',' IDENTIFIER
        ;

identifier_or_typedef_name:
        IDENTIFIER
        | TYPEDEFname
        ;

type_name:
        type_specifier
        | type_specifier abstract_declarator
        | type_qualifier_list
        | type_qualifier_list abstract_declarator
        ;

initializer_opt:
        /* nothing */
        | '=' initializer
        ;

initializer:
        '{' initializer_list '}'
        | '{' initializer_list ',' '}'
        | assignment_expression
        ;

initializer_list:
        initializer
        | initializer_list ',' initializer
        ;


/*************************** STATEMENTS *******************************/
statement:
        labeled_statement
        | compound_statement
        | expression_statement
        | selection_statement
        | iteration_statement
        | jump_statement
        ;

labeled_statement:
        identifier_or_typedef_name ':' statement
        | CASE constant_expression ':' statement
        | DEFAULT ':' statement
        ;

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

declaration_list:
        declaration
        | declaration_list declaration
        ;

statement_list:
        statement
        | statement_list statement
        ;

expression_statement:
        comma_expression_opt ';'
        ;

selection_statement:
          IF '(' comma_expression ')' statement
        | IF '(' comma_expression ')' statement ELSE statement
        | SWITCH '(' comma_expression ')' statement
        ;

iteration_statement:
        WHILE '(' comma_expression ')' statement
        | DO statement WHILE '(' comma_expression ')' ';'
        | FOR '(' comma_expression_opt ';' comma_expression_opt ';'
                comma_expression_opt ')' statement
        ;

jump_statement:
        GOTO identifier_or_typedef_name ';'
        | CONTINUE ';'
        | BREAK ';'
        | RETURN comma_expression_opt ';'
        ;


/***************************** EXTERNAL DEFINITIONS *****************************/

translation_unit:
        external_definition
        | translation_unit external_definition
        ;

external_definition:
        function_definition
        | declaration
        ;

function_definition:
                                     identifier_declarator compound_statement
        | declaration_specifier      identifier_declarator compound_statement
        | type_specifier             identifier_declarator compound_statement
        | declaration_qualifier_list identifier_declarator compound_statement
        | type_qualifier_list        identifier_declarator compound_statement

        |                            old_function_declarator compound_statement
        | declaration_specifier      old_function_declarator compound_statement
        | type_specifier             old_function_declarator compound_statement
        | declaration_qualifier_list old_function_declarator compound_statement
        | type_qualifier_list        old_function_declarator compound_statement

        |                            old_function_declarator declaration_list
                compound_statement
        | declaration_specifier      old_function_declarator declaration_list
                compound_statement
        | type_specifier             old_function_declarator declaration_list
                compound_statement
        | declaration_qualifier_list old_function_declarator declaration_list
                compound_statement
        | type_qualifier_list        old_function_declarator declaration_list
                compound_statement
        ;

declarator:
        identifier_declarator
        | typedef_declarator
        ;

typedef_declarator:
        paren_typedef_declarator          /* would be ambiguous as parameter*/
        | parameter_typedef_declarator    /* not ambiguous as param*/
        ;

parameter_typedef_declarator:
        TYPEDEFname
        | TYPEDEFname postfixing_abstract_declarator
        | clean_typedef_declarator
        ;

    /*  The  following have at least one '*'. There is no (redundant)
    '(' between the '*' and the TYPEDEFname. */

clean_typedef_declarator:
        clean_postfix_typedef_declarator
        | '*' parameter_typedef_declarator
        | '*' type_qualifier_list parameter_typedef_declarator
        ;

clean_postfix_typedef_declarator:
        '(' clean_typedef_declarator ')'
        | '(' clean_typedef_declarator ')' postfixing_abstract_declarator
        ;

    /* The following have a redundant '(' placed immediately  to  the
    left of the TYPEDEFname */

paren_typedef_declarator:
        paren_postfix_typedef_declarator
        | '*' '(' simple_paren_typedef_declarator ')' /* redundant paren */
        | '*' type_qualifier_list
                '(' simple_paren_typedef_declarator ')' /* redundant paren */
        | '*' paren_typedef_declarator
        | '*' type_qualifier_list paren_typedef_declarator
        ;

paren_postfix_typedef_declarator: /* redundant paren to left of tname*/
        '(' paren_typedef_declarator ')'
        | '(' simple_paren_typedef_declarator postfixing_abstract_declarator ')' /* redundant paren */
        | '(' paren_typedef_declarator ')' postfixing_abstract_declarator
        ;

simple_paren_typedef_declarator:
        TYPEDEFname
        | '(' simple_paren_typedef_declarator ')'
        ;

identifier_declarator:
        unary_identifier_declarator
        | paren_identifier_declarator
        ;

unary_identifier_declarator:
        postfix_identifier_declarator
        | '*' identifier_declarator
        | '*' type_qualifier_list identifier_declarator
        ;

postfix_identifier_declarator:
        paren_identifier_declarator postfixing_abstract_declarator
        | '(' unary_identifier_declarator ')'
        | '(' unary_identifier_declarator ')' postfixing_abstract_declarator
        ;

paren_identifier_declarator:
        IDENTIFIER
        | '(' paren_identifier_declarator ')'
        ;

old_function_declarator:
        postfix_old_function_declarator
        | '*' old_function_declarator
        | '*' type_qualifier_list old_function_declarator
        ;

postfix_old_function_declarator:
        paren_identifier_declarator '(' identifier_list ')'
        | '(' old_function_declarator ')'
        | '(' old_function_declarator ')' postfixing_abstract_declarator
        ;

abstract_declarator:
        unary_abstract_declarator
        | postfix_abstract_declarator
        | postfixing_abstract_declarator
        ;

postfixing_abstract_declarator:
        array_abstract_declarator
        | '(' ')'
        | '(' parameter_type_list ')'
        ;

array_abstract_declarator:
        '[' ']'
        | '[' constant_expression ']'
        | array_abstract_declarator '[' constant_expression ']'
        ;

unary_abstract_declarator:
        '*'
        | '*' type_qualifier_list
        | '*' abstract_declarator
        | '*' type_qualifier_list abstract_declarator
        ;

postfix_abstract_declarator:
        '(' unary_abstract_declarator ')'
        | '(' postfix_abstract_declarator ')'
        | '(' postfixing_abstract_declarator ')'
        | '(' unary_abstract_declarator ')' postfixing_abstract_declarator
        ;

%%
/* ----end of grammar----*/


yyerror(string)
char*string;
{
    printf("parser error: %s\n", string);
}


main()
{
    yyparse();
}