文法改进

program à

       external_declaration

      | program external_declaration

external_declaration à

      function_definition

      | declaration

     

function_definition à type_specifier declarator compound_statement

type_specifier à

      VOID

      | CHAR

      | INT

      | FLOAT

declarator

      pointer direct_declarator

      | direct_declarator

Pointerà

      '*'

      | '*' pointer

direct_declarator

      IDENTIFIER

   |direct_declarator’[‘ ‘]’

      |direct_declarator ’[’ constant_expression ’]’

      | IDENTIFIER '(' parameter_list ')'

| IDENTIFIER '('  ')'

      |direct_declarator  ‘,’  identifier_list

identifier_list

      : IDENTIFIER

      | identifier_list ',' IDENTIFIER

constant_expressionà

      conditional_expression

parameter_list à

       parameter_declaration

      | parameter_list ',' parameter_declaration


parameter_declaration à

      declaration_specifiers  IDENTIFIER

compound_statement à

       '{' '}'

      | '{' statement_list '}'

      | '{' declaration_list statement_list '}'

declaration_list à

       declaration

      | declaration_list declaration

Declarationà

       init_declarator

      | init_declarator_list ',' init_declarator

init_declarator à

       declarator

      | declarator '=' initializer

Initializer à

       assignment_expression

      | '{' initializer_list '}'

      | '{' initializer_list ',' '}'

initializer_list à

       initializer

      | initializer_list ',' initializer

statement_listà

      statement

      | statement_list statement

Statement à

      | compound_statement

      | expression_statement

      | selection_statement

      | iteration_statement

      | jump_statement

expression_statement à

      ';'

      | expression ';'

selection_statement

      : IF '(' expression ')' statement

      | IF '(' expression ')' statement ELSE statement

iteration_statementà

       WHILE '(' expression ')' statement

      | FOR '(' expression_statement expression_statement ')' statement

      | FOR '(' expression_statement expression_statement expression ')' statement

jump_statement

      | CONTINUE ';'

      | BREAK ';'

      | RETURN ';'

      | RETURN expression ';'

expression

      : assignment_expression

      | expression ',' assignment_expression

assignment_expression à

      conditional_expression

      | unary_expression assignment_operator assignment_expression

conditional_expression à

       logical_or_expression

      | logical_or_expression '?' expression ':' conditional_expression

logical_or_expression à

      logical_and_expression

      | logical_or_expression OR_OP logical_and_expression

logical_and_expression

      : inclusive_or_expression

      | logical_and_expression AND_OP inclusive_or_expression

inclusive_or_expressionà

      exclusive_or_expression

      | inclusive_or_expression '|' exclusive_or_expression

exclusive_or_expression

      : and_expression

      | exclusive_or_expression '^' and_expression

and_expression

      : equality_expression

      | and_expression '&' equality_expression

equality_expression

      : relational_expression

      | equality_expression EQ_OP relational_expression

      | equality_expression NE_OP relational_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

shift_expression

      : additive_expression

      | shift_expression LEFT_OP additive_expression

      | shift_expression RIGHT_OP additive_expression

additive_expression

      : multiplicative_expression

      | additive_expression '+' multiplicative_expression

      | additive_expression '-' multiplicative_expression

multiplicative_expression

      : cast_expression

      | multiplicative_expression '*' cast_expression

      | multiplicative_expression '/' cast_expression

      | multiplicative_expression '%' cast_expression

cast_expression

      : unary_expression

      | '(' type_name ')' cast_expression

unary_expression

      : postfix_expression

      | INC_OP unary_expression

      | DEC_OP unary_expression

      | unary_operator cast_expression

      | SIZEOF unary_expression

      | SIZEOF '(' type_name ')'

postfix_expression à

      : primary_expression

      | postfix_expression '[' expression ']'

      | postfix_expression '(' ')'

      | postfix_expression '(' argument_expression_list ')'

      | postfix_expression '.' IDENTIFIER

      | postfix_expression PTR_OP IDENTIFIER

      | postfix_expression INC_OP

      | postfix_expression DEC_OP

primary_expression à

      IDENTIFIER

      | CONSTANT

      | STRING_LITERAL

      | '(' expression ')'

argument_expression_list

      : assignment_expression

      | argument_expression_list ',' assignment_expression

unary_operator

      : '&'

      | '*'

      | '+'

      | '-'

      | '~'

      | '!'

storage_class_specifier à

       TYPEDEF

      | EXTERN

      | STATIC

      | AUTO

      | REGISTER

struct_or_union_specifier

      : struct_or_union IDENTIFIER '{' struct_declaration_list '}'

      | struct_or_union '{' struct_declaration_list '}'

      | struct_or_union IDENTIFIER

struct_or_union

      : STRUCT

      | UNION

struct_declaration_list

      : struct_declaration

      | struct_declaration_list struct_declaration

struct_declaration

      : specifier_qualifier_list struct_declarator_list ';'

specifier_qualifier_list à

       type_specifier specifier_qualifier_list

      | type_specifier

      | type_qualifier specifier_qualifier_list

      | type_qualifier

     

struct_declarator_list à

       struct_declarator

      | struct_declarator_list ',' struct_declarator

     

struct_declarator à

      : declarator

      | ':' constant_expression

      | declarator ':' constant_expression

     

enum_specifier à

       ENUM '{' enumerator_list '}'

      | ENUM IDENTIFIER '{' enumerator_list '}'

      | ENUM IDENTIFIER

     

enumerator_list à

       enumerator

      | enumerator_list ',' enumerator

     

Enumerator à

       IDENTIFIER

      | IDENTIFIER '=' constant_expression

     

type_qualifier à

       CONST

      | VOLATILE

     

type_qualifier_list à

       type_qualifier

      | type_qualifier_list type_qualifier

     

parameter_type_list à

       parameter_list

      | parameter_list ',' ELLIPSIS

     

parameter_list à

      : parameter_declaration

      | parameter_list ',' parameter_declaration

     

type_name à

       specifier_qualifier_list

      | specifier_qualifier_list abstract_declarator

     

abstract_declarator à

       pointer

      | direct_abstract_declarator

      | pointer direct_abstract_declarator

     

     

原文地址:https://www.cnblogs.com/lgy520/p/6128205.html