Annex A (informative) Grammar summary [gram]

A.12 Preprocessing directives [gram.cpp]

preprocessing-file:
	group
	module-file

module-file:
	pp-global-module-fragment pp-module group pp-private-module-fragment

pp-global-module-fragment:
	module ; new-line group

pp-private-module-fragment:
	module : private ; new-line group

group:
	group-part
	group group-part

group-part:
	control-line
	if-section
	text-line
	# conditionally-supported-directive

control-line:
	# include pp-tokens new-line
	pp-import
	# define  identifier replacement-list new-line
	# define  identifier lparen identifier-list ) replacement-list new-line
	# define  identifier lparen ... ) replacement-list new-line
	# define  identifier lparen identifier-list , ... ) replacement-list new-line
	# undef   identifier new-line
	# line    pp-tokens new-line
	# error   pp-tokens new-line
	# pragma  pp-tokens new-line
	# new-line

if-section:
	if-group elif-groups else-group endif-line

if-group:
	# if      constant-expression new-line group
	# ifdef   identifier new-line group
	# ifndef  identifier new-line group

elif-groups:
	elif-group
	elif-groups elif-group

elif-group:
	# elif    constant-expression new-line group

else-group:
	# else    new-line group

endif-line:
	# endif   new-line

text-line:
	pp-tokens new-line

conditionally-supported-directive:
	pp-tokens new-line

lparen:
	a ( character not immediately preceded by white-space

identifier-list:
	identifier
	identifier-list , identifier

replacement-list:
	pp-tokens

pp-tokens:
	preprocessing-token
	pp-tokens preprocessing-token

new-line:
	the new-line character

defined-macro-expression:
	defined identifier
	defined ( identifier )

h-preprocessing-token:
	any preprocessing-token other than >

h-pp-tokens:
	h-preprocessing-token
	h-pp-tokens h-preprocessing-token

header-name-tokens:
	string-literal
	< h-pp-tokens >

has-include-expression:
	_­_­has_­include ( header-name )
	_­_­has_­include ( header-name-tokens )

has-attribute-expression:
	_­_­has_­cpp_­attribute ( pp-tokens )

pp-module:
	export module pp-tokens ; new-line

pp-import:
	export import header-name pp-tokens ; new-line
	export import header-name-tokens pp-tokens ; new-line
	export import pp-tokens ; new-line

va-opt-replacement:
	__VA_­OPT__ ( pp-tokens )