Below is a recapitulation of the grammar that was given throughout the earlier part of this appendix. It has exactly the same content, but is in different order.
The grammar has undefined terminal symbols integer-constant, character-constant, floating-constant, identifier, string, and enumeration-constant; the typewriter style words and symbols are terminals given literally. This grammar can be transformed mechanically into input acceptable for an automatic parser-generator. Besides adding whatever syntactic marking is used to indicate alternatives in productions, it is necessary to expand the “one of” constructions, and (depending on the rules of the parser-generator) to duplicate each production with an opt symbol, once with the symbol and once without. With one further change, namely deleting the production typedef-name: identifier and making typedef-name a terminal symbol, this grammar is acceptable to the YACC parser-generator. It has only one conflict, generated by the if-else ambiguity.
translation-unit:
external-declaration
translation-unit external-declaration
external-declaration:
function-definition
declaration
function-definition:
declaration-specifiersopt declarator declaration-listopt compound-statement
declaration:
declaration-specifiers init-declarator-listopt;
declaration-list:
declaration
declaration-list declaration
declaration-specifiers:
storage-class-specifier declaration-specifiersopt
type-specifier declaration-specifiersopt
type-qualifier declaration-specifiersopt
storage-class specifier: one of
auto register static extern typedef
type specifier: one of
void char short int long float double signed
unsigned struct-or-union-specifier enum-specifier typedef-name
type-qualifier: one of
const volatile
struct-or-union-specifier:
struct-or-union identifieropt { struct-declaration-list }
struct-or-union identifier
struct-or-union: one of
struct union
struct-declaration-list:
struct declaration
struct-declaration-list struct declaration
init-declarator-list:
init-declarator
init-declarator-list, init-declarator
init-declarator:
declarator
declarator = initializer
struct-declaration:
specifier-qualifier-list struct-declarator-list;
specifier-qualifier-list:
type-specifier specifier-qualifier-listopt
type-qualifier specifier-qualifier-listopt
struct-declarator-list:
struct-declarator
struct-declarator-list , struct-declarator
struct-declarator:
declarator
declaratoropt : constant-expression
enum-specifier:
enum identifieropt { enumerator-list }
enum identifier
enumerator-list:
enumerator
enumerator-list , enumerator
enumerator:
identifier
identifier = constant-expression
declarator:
pointeropt direct-declarator
direct-declarator:
identifier
(declarator)
direct-declarator [ constant-expressionopt ]
direct-declarator ( parameter-type-list )
direct-declarator ( identifier-listopt )
pointer:
* type-qualifier-listopt
* type-qualifier-listopt pointer
type-qualifier-list:
type-qualifier
type-qualifier-list type-qualifier
parameter-type-list:
parameter-list
parameter-list , …
parameter-list:
parameter-declaration
parameter-list , parameter-declaration
parameter-declaration:
declaration-specifiers declarator
declaration-specifiers abstract-declaratoropt
identifier-list:
identifier
identifier-list , identifier
initializer:
assignment-expression
{ initializer-list }
{ initializer-list , }
initializer-list:
initializer
initializer-list , initializer
type-name:
specifier-qualifier-list abstract-declaratoropt
abstract-declarator:
pointer
pointeropt direct-abstract-declarator
direct-abstract-declarator:
( abstract-declarator )
direct-abstract-declaratoropt [constant-expressionopt]
direct-abstract-declaratoropt (parameter-type-listopt)
typedef-name:
identifier
statement:
labeled-statement
expression-statement
compound-statement
selection-statement
iteration-statement
jump-statement
labeled-statement:
identifier : statement
case constant-expression : statement
default : statement
expression-statement:
expressionopt;
compound-statement:
{ declaration-listopt statement-listopt }
statement-list:
statement
statement-list statement
selection-statement:
if (expression) statement
if (expression) statement else statement
switch (expression) statement
iteration-statement:
while (expression) statement
do statement while (expression);
for (expressionopt; expressionopt; expressionopt) statement
jump-statement:
goto identifier;
continue;
break;
return expressionopt;
expression:
assignment-expression
expression , assignment-expression
assignment-expression:
conditional-expression
unary-expression assignment-operator assignment-expression
assignment-operator: one of
= *= /= %= += -= <<= >>= &= ^= |=
conditional-expression:
logical-OR-expression
logical-OR-expression ? expression : conditional-expression
constant-expression:
conditional-expression
logical-OR-expression:
logical-AND-expression
logical-OR-expression || logical-AND-expression
logical-AND-expression:
inclusive-OR-expression
logical-AND-expression && inclusive-OR-expression
inclusive-OR-expression:
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 == relational-expression
equality-expression != relational-expression
relational-expression:
shift-expression
relational-expression < shift-expression
relational-expression > shift-expression
relational-expression <= shift-expression
relational-expression >= shift-expression
shift-expression:
additive-expression
shift-expression << additive-expression
shift-expression >> additive-expression
additive-expression:
multiplicative-expression
additive-expression + multiplicative-expression
additive-expression - multiplicative-expression
multiplicative-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
++unary expression
–unary expression
unary-operator cast-expression
sizeof unary-expression
sizeof (type-name)
unary operator: one of
& * + - ~ !
postfix-expression:
primary-expression
postfix-expression[expression]
postfix-expression(argument-expression-listopt)
postfix-expression.identifier
postfix-expression->+identifier
postfix-expression++
postfix-expression–
primary-expression:
identifier
constant
string
(expression)
argument-expression-list:
assignment-expression
assignment-expression-list , assignment-expression
constant:
integer-constant
character-constant
floating-constant
enumeration-constant
The following grammar for the preprocessor summarizes the structure of control lines, but is not suitable for mechanized parsing. It includes the symbol text, which means ordinary program text, non-conditional preprocessor control lines, or complete preprocessor conditional instructions.
control-line:
# define identifier token-sequence
# define identifier(identifier, … , identifier) token-sequence
# undef identifier
# include <filename>
# include “filename”
# line constant “filename”
# line constant
# error token-sequenceopt
# pragma token-sequenceopt
#
preprocessor-conditional
preprocessor-conditional:
if-line text elif-parts else-partopt #endif
if-line:
# if constant-expression
# ifdef identifier
# ifndef identifier
elif-parts:
elif-line text
elif-partsopt
elif-line:
# elif constant-expression
else-part:
else-line text
else-line:
#else
A.13 Grammar
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