Grammar railroad diagram

[mingodad]

I've just added FrontC grammar to https://mingodad.github.io/parsertl-playground/playground/ an Yacc/Lex compatible online editor/tester that can also generate an EBNF understood by (IPV4) https://rr.red-dove.com/ui or (IPV6) https://www.bottlecaps.de/rr/ui to generate a nice navigable railroad diagram (see instructions bellow).

There is a good collection of grammars there (to see the FrontC select FrontC parser from Examples then click Parse to see a parser tree for the content in Input Source).

//
// EBNF to be viewd at
//    (IPV6) https://www.bottlecaps.de/rr/ui
//    (IPV4) https://rr.red-dove.com/ui
//
// Copy and paste this at one of the urls shown above in the 'Edit Grammar' tab
// then click the 'View Diagram' tab.
//

file::=
	  globals

globals::=
	  /*%empty*/
	| globals global

typedef::=
	  TYPEDEF typedef_type typedef_defs
	| gcc_attribute TYPEDEF typedef_type typedef_defs

global::=
	  global_type global_defs SEMICOLON
	| global_type global_proto body
	| global_type global_proto basic_asm opt_gcc_attributes SEMICOLON
	| global_type old_proto old_pardefs body
	| global_type SEMICOLON
	| typedef SEMICOLON

global_type::=
	  global_mod_list_zom global_qual
	| global_mod_list_zom comp_type global_mod_list_zom
	| global_mod_list_zom NAMED_TYPE global_mod_list_zom
	| global_mod_list_zom

global_mod_list_zom::=
	  /*%empty*/
	| global_mod global_mod_list_zom

global_mod::=
	  STATIC
	| CONST
	| VOLATILE
	| EXTERN
	| gcc_attribute

global_qual::=
	  qual_type
	| global_qual qual_type
	| global_qual global_mod

global_defs::=
	  global_def
	| global_defs COMMA global_def

global_def::=
	  global_dec opt_gcc_attributes
	| global_dec opt_gcc_attributes EQ init_expression

global_dec::=
	  IDENT
	| LPAREN global_dec RPAREN
	| STAR global_dec
	| STAR CONST global_dec
	| STAR VOLATILE global_dec
	| STAR RESTRICT global_dec
	| STAR gcc_attributes global_dec
	| global_dec LBRACKET comma_expression RBRACKET
	| global_dec LBRACKET RBRACKET
	| global_dec LPAREN parameters RPAREN
	| LPAREN global_dec RPAREN LPAREN parameters RPAREN
	| global_dec LPAREN old_parameters RPAREN
	| LPAREN global_dec RPAREN LPAREN old_parameters RPAREN

global_proto::=
	  global_dec opt_gcc_attributes

old_proto::=
	  global_dec opt_gcc_attributes

old_parameters::=
	  old_pardecs
	| old_pardecs ELLIPSIS

old_pardecs::=
	  IDENT
	| old_pardecs COMMA IDENT
	| old_pardecs COMMA NAMED_TYPE

old_pardefs::=
	  old_pardef
	| old_pardefs old_pardef

old_pardef::=
	  old_type old_defs SEMICOLON

old_type::=
	  old_mods_opt NAMED_TYPE old_mods_opt
	| old_mods_opt comp_type old_mods_opt
	| old_mods_opt old_qual

old_mods_opt::=
	  /*%empty*/
	| CONST
	| REGISTER

old_qual::=
	  qual_type
	| old_qual qual_type
	| old_qual CONST
	| old_qual REGISTER

old_defs::=
	  old_def
	| old_defs COMMA old_def

old_def::=
	  old_dec

old_dec::=
	  IDENT
	| STAR old_dec
	| STAR CONST old_dec
	| STAR VOLATILE old_dec
	| old_dec LBRACKET comma_expression RBRACKET
	| old_dec LBRACKET RBRACKET
	| old_dec LPAREN parameters RPAREN
	| LPAREN old_dec RPAREN LPAREN parameters RPAREN
	| LPAREN old_dec RPAREN

local::=
	  local_type local_defs SEMICOLON

local_type::=
	  local_mod_list_opt local_qual
	| local_mod_list_opt comp_type local_mod_list_opt
	| local_mod_list_opt NAMED_TYPE local_mod_list_opt

local_mod_list_opt::=
	  /*%empty*/
	| local_mod_list

local_mod_list::=
	  local_mod
	| local_mod_list local_mod

local_mod::=
	  STATIC
	| AUTO
	| CONST
	| VOLATILE
	| REGISTER
	| EXTERN
	| gcc_attribute

local_qual::=
	  qual_type
	| local_qual qual_type
	| local_qual local_mod

local_defs::=
	  local_def
	| local_defs COMMA local_def

local_def::=
	  local_dec opt_gcc_attributes
	| local_dec opt_gcc_attributes EQ init_expression

local_dec::=
	  IDENT
	| NAMED_TYPE
	| STAR local_dec
	| STAR RESTRICT local_dec
	| STAR CONST local_dec
	| STAR VOLATILE local_dec
	| STAR gcc_attributes local_dec
	| local_dec LBRACKET comma_expression RBRACKET
	| local_dec LBRACKET RBRACKET
	| local_dec LPAREN parameters RPAREN
	| LPAREN local_dec RPAREN LPAREN parameters RPAREN
	| LPAREN local_dec RPAREN

typedef_type::=
	  typedef_sub
	| CONST typedef_sub
	| VOLATILE typedef_sub

typedef_sub::=
	  NAMED_TYPE
	| comp_type
	| typedef_qual
	| IDENT
	| NAMED_TYPE CONST
	| NAMED_TYPE VOLATILE
	| comp_type CONST
	| comp_type VOLATILE
	| IDENT CONST
	| IDENT VOLATILE

typedef_qual::=
	  qual_type
	| typedef_qual qual_type
	| typedef_qual CONST
	| typedef_qual VOLATILE

typedef_defs::=
	  typedef_def
	| typedef_defs COMMA typedef_def

typedef_def::=
	  typedef_dec opt_gcc_attributes

typedef_dec::=
	  IDENT
	| NAMED_TYPE
	| STAR typedef_dec
	| STAR RESTRICT typedef_dec
	| STAR CONST typedef_dec
	| STAR VOLATILE typedef_dec
	| STAR gcc_attributes typedef_dec
	| typedef_dec LBRACKET comma_expression RBRACKET
	| typedef_dec LBRACKET RBRACKET
	| typedef_dec LPAREN parameters RPAREN
	| LPAREN typedef_dec RPAREN LPAREN parameters RPAREN
	| LPAREN typedef_dec RPAREN

field_list::=
	  /*%empty*/
	| field_list field

field::=
	  field_type field_defs opt_gcc_attributes SEMICOLON
	| field_mod_list_opt struct_type field_mod_list_opt field_defs SEMICOLON
	| field_mod_list_opt struct_type field_mod_list_opt SEMICOLON
	| field_mod_list_opt union_type field_mod_list_opt field_defs SEMICOLON
	| field_mod_list_opt union_type field_mod_list_opt SEMICOLON

field_type::=
	  field_mod_list_opt field_qual
	| field_mod_list_opt enum_type field_mod_list_opt
	| field_mod_list_opt NAMED_TYPE field_mod_list_opt

field_mod_list_opt::=
	  /*%empty*/
	| field_mod_list

field_mod_list::=
	  field_mod
	| field_mod_list field_mod

field_mod::=
	  CONST
	| VOLATILE
	| gcc_attribute

field_qual::=
	  qual_type
	| field_qual qual_type
	| field_qual field_mod

field_defs::=
	  field_def
	| field_defs COMMA field_def

field_def::=
	  field_dec

field_dec::=
	  IDENT
	| NAMED_TYPE
	| STAR field_dec
	| STAR RESTRICT field_dec
	| STAR CONST field_dec
	| STAR VOLATILE field_dec
	| STAR gcc_attributes field_dec
	| field_dec LBRACKET comma_expression RBRACKET
	| field_dec LBRACKET RBRACKET
	| field_dec LPAREN parameters RPAREN
	| LPAREN field_dec RPAREN LPAREN parameters RPAREN
	| LPAREN field_dec RPAREN
	| option_IDENT_ COLON expression

parameters::=
	  /*%empty*/
	| param_list
	| param_list COMMA ELLIPSIS

param_list::=
	  param_list COMMA param
	| param

param::=
	  param_type param_def

param_type::=
	  param_mods_opt NAMED_TYPE param_mods_opt
	| param_mods_opt comp_type param_mods_opt
	| param_mods_opt param_qual

param_mods_opt::=
	  /*%empty*/
	| param_mods

param_mods::=
	  param_mod
	| param_mods param_mod

param_mod::=
	  CONST
	| REGISTER
	| VOLATILE
	| gcc_attribute

param_qual::=
	  qual_type
	| param_qual qual_type
	| param_qual CONST
	| param_qual REGISTER
	| param_qual VOLATILE
	| param_qual gcc_attribute

param_def::=
	  param_dec

param_dec::=
	  /*%empty*/
	| IDENT
	| NAMED_TYPE
	| STAR param_dec
	| STAR RESTRICT param_dec
	| STAR CONST param_dec
	| STAR VOLATILE param_dec
	| STAR gcc_attributes param_dec
	| param_dec LBRACKET global_mod_list_zom comma_expression RBRACKET
	| param_dec LBRACKET global_mod_list_zom RBRACKET
	| LPAREN param_dec RPAREN LPAREN parameters RPAREN
	| LPAREN param_dec RPAREN

only_type::=
	  only_type_type only_def

only_type_type::=
	  only_mod_list_opt only_qual
	| only_mod_list_opt comp_type only_mod_list_opt
	| only_mod_list_opt NAMED_TYPE only_mod_list_opt

only_mod_list_opt::=
	  /*%empty*/
	| only_mod_list

only_qual::=
	  qual_type
	| only_qual qual_type
	| only_qual only_mod

only_mod_list::=
	  only_mod
	| only_mod_list only_mod

only_mod::=
	  CONST
	| VOLATILE
	| gcc_attribute

only_def::=
	  only_dec

only_dec::=
	  /*%empty*/
	| STAR only_dec
	| STAR RESTRICT only_dec
	| STAR CONST only_dec
	| STAR VOLATILE only_dec
	| STAR gcc_attributes only_dec
	| only_dec LBRACKET comma_expression RBRACKET
	| only_dec LBRACKET RBRACKET
	| LPAREN only_dec RPAREN LPAREN parameters RPAREN
	| LPAREN only_dec RPAREN

qual_type::=
	  VOID
	| BOOL
	| CHAR
	| INT
	| FLOAT
	| DOUBLE
	| BUILTIN_TYPE
	| COMPLEX
	| LONG
	| SHORT
	| SIGNED
	| UNSIGNED

comp_type::=
	  struct_type
	| union_type
	| enum_type

struct_type::=
	  STRUCT type_name
	| STRUCT LBRACE field_list RBRACE
	| STRUCT type_name LBRACE field_list RBRACE

union_type::=
	  UNION type_name
	| UNION LBRACE field_list RBRACE
	| UNION type_name LBRACE field_list RBRACE

enum_type::=
	  ENUM type_name
	| ENUM LBRACE enum_list RBRACE
	| ENUM LBRACE enum_list COMMA RBRACE
	| ENUM type_name LBRACE enum_list RBRACE

type_name::=
	  IDENT
	| NAMED_TYPE

enum_list::=
	  enum_name
	| enum_list COMMA enum_name

enum_name::=
	  IDENT
	| IDENT EQ expression

init_expression::=
	  LBRACE compound_comma_expression RBRACE
	| expression

compound_expression::=
	  LBRACE compound_comma_expression RBRACE
	| expression
	| DOT type_name EQ expression

compound_comma_expression::=
	  compound_expression
	| compound_comma_expression COMMA compound_expression
	| compound_comma_expression COMMA

opt_expression::=
	  /*%empty*/
	| comma_expression

comma_expression::=
	  expression
	| comma_expression COMMA expression

expression::=
	  LPAREN EXTENSION expression RPAREN
	| constant
	| IDENT
	| SIZEOF expression
	| SIZEOF LPAREN only_type RPAREN
	| PLUS expression
	| MINUS expression
	| STAR expression
	| AND expression
	| EXCLAM expression
	| TILDE expression
	| PLUS_PLUS expression
	| expression PLUS_PLUS
	| MINUS_MINUS expression
	| expression MINUS_MINUS
	| expression ARROW IDENT
	| expression ARROW NAMED_TYPE
	| expression DOT IDENT
	| expression DOT NAMED_TYPE
	| LPAREN body RPAREN
	| LPAREN comma_expression RPAREN
	| LPAREN only_type RPAREN expression
	| expression LPAREN opt_expression RPAREN
	| expression LBRACKET comma_expression RBRACKET
	| expression QUEST expression COLON expression
	| expression PLUS expression
	| expression MINUS expression
	| expression STAR expression
	| expression SLASH expression
	| expression PERCENT expression
	| expression AND_AND expression
	| expression PIPE_PIPE expression
	| expression AND expression
	| expression PIPE expression
	| expression CIRC expression
	| expression EQ_EQ expression
	| expression EXCLAM_EQ expression
	| expression INF expression
	| expression SUP expression
	| expression INF_EQ expression
	| expression SUP_EQ expression
	| expression INF_INF expression
	| expression SUP_SUP expression
	| expression EQ expression
	| expression PLUS_EQ expression
	| expression MINUS_EQ expression
	| expression STAR_EQ expression
	| expression SLASH_EQ expression
	| expression PERCENT_EQ expression
	| expression AND_EQ expression
	| expression PIPE_EQ expression
	| expression CIRC_EQ expression
	| expression INF_INF_EQ expression
	| expression SUP_SUP_EQ expression

constant::=
	  CST_INT
	| CST_FLOAT
	| CST_CHAR
	| string_list

string_list::=
	  CST_STRING
	| string_list CST_STRING

body_begin::=
	  LBRACE

body_middle::=
	  opt_locals opt_stats

body::=
	  body_begin body_middle RBRACE

opt_locals::=
	  /*%empty*/
	| locals

locals::=
	  local
	| locals local

opt_stats::=
	  /*%empty*/
	| stats

stats::=
	  statement
	| stats statement

statement::=
	  SEMICOLON
	| comma_expression SEMICOLON
	| body
	| IF LPAREN comma_expression RPAREN statement
	| IF LPAREN comma_expression RPAREN statement ELSE statement
	| SWITCH LPAREN comma_expression RPAREN statement
	| WHILE LPAREN comma_expression RPAREN statement
	| DO statement WHILE LPAREN comma_expression RPAREN SEMICOLON
	| FOR LPAREN opt_expression SEMICOLON opt_expression SEMICOLON opt_expression RPAREN statement
	| IDENT COLON statement
	| CASE expression COLON statement
	| DEFAULT COLON statement
	| RETURN SEMICOLON
	| RETURN expression SEMICOLON
	| BREAK SEMICOLON
	| CONTINUE SEMICOLON
	| GOTO IDENT SEMICOLON
	| ASM LPAREN CST_STRING RPAREN SEMICOLON
	| ASM LPAREN CST_STRING gnu_asm_io gnu_asm_io opt_gnu_asm_mods RPAREN SEMICOLON

basic_asm::=
	  ASM option_VOLATILE_ opt_gcc_attributes LPAREN string_list RPAREN

gnu_asm_io::=
	  COLON gnu_asm_args

gnu_asm_args::=
	  gnu_asm_arg
	| gnu_asm_args COMMA gnu_asm_arg

gnu_asm_arg::=
	  CST_STRING LPAREN expression RPAREN
	| LBRACKET IDENT RBRACKET CST_STRING LPAREN expression RPAREN

opt_gnu_asm_mods::=
	  /*%empty*/
	| COLON gnu_asm_mods

gnu_asm_mods::=
	  CST_STRING
	| gnu_asm_mods COMMA CST_STRING

opt_gcc_attributes::=
	  /*%empty*/
	| gcc_attributes

gcc_attributes::=
	  gcc_attribute
	| gcc_attributes gcc_attribute

gcc_attribute::=
	  ATTRIBUTE LPAREN LPAREN opt_gnu_args RPAREN RPAREN
	| EXTENSION
	| INLINE

opt_gnu_args::=
	  /*%empty*/
	| gnu_args

gnu_args::=
	  gnu_arg
	| gnu_args COMMA gnu_arg

gnu_arg::=
	  gnu_id
	| local_type
	| constant
	| gnu_id LPAREN opt_gnu_args RPAREN

gnu_id::=
	  IDENT
	| GNU_ATTRS

option_IDENT_::=
	  /*%empty*/
	| IDENT

option_VOLATILE_::=
	  /*%empty*/
	| VOLATILE


//Tokens

AUTO ::= "auto"
CONST ::= "const"|"__const"
STATIC ::= "static"
EXTERN ::= "extern"
LONG ::= "long"
COMPLEX ::= "_Complex"
BUILTIN_TYPE ::= "__float128"
BUILTIN_TYPE ::= "__float80"
BUILTIN_TYPE ::= "__ibm128"
BUILTIN_TYPE ::= "_Float16"
BUILTIN_TYPE ::= "_Float32"
BUILTIN_TYPE ::= "_Float32x"
BUILTIN_TYPE ::= "_Float64"
BUILTIN_TYPE ::= "_Float64x"
BUILTIN_TYPE ::= "_Float80"
BUILTIN_TYPE ::= "_Float128"
BUILTIN_TYPE ::= "_Float128x"
BUILTIN_TYPE ::= "_Ibm128"
SHORT ::= "short"
REGISTER ::= "register"
SIGNED ::= "signed"
UNSIGNED ::= "unsigned"
VOLATILE ::= "volatile"
INLINE ::= "inline"
RESTRICT ::= "__restrict"
RESTRICT ::= "restrict"
CHAR ::= "char"
BOOL ::= "_Bool"
INT ::= "int"
FLOAT ::= "float"
DOUBLE ::= "double"
VOID ::= "void"
ENUM ::= "enum"
STRUCT ::= "struct"
TYPEDEF ::= "typedef"
UNION ::= "union"
BREAK ::= "break"
CONTINUE ::= "continue"
GOTO ::= "goto"
RETURN ::= "return"
SWITCH ::= "switch"
CASE ::= "case"
DEFAULT ::= "default"
WHILE ::= "while"
DO ::= "do"
FOR ::= "for"
IF ::= "if"
ELSE ::= "else"
ASM ::= "asm"|"__asm__"
SIZEOF ::= "sizeof"

//Specific ::= /*** ***/ ::= GNU
ATTRIBUTE ::= "__attribute__"
EXTENSION ::= "__extension__"
INLINE ::= "__inline"
//GNU_ATTRS ::= GNU_ATTRS

ELLIPSIS ::= "..."
PLUS_EQ ::= "+="
MINUS_EQ ::= "-="
STAR_EQ ::= "*="
SLASH_EQ ::= "/="
PERCENT_EQ ::= "%="
PIPE_EQ ::= "|="
AND_EQ ::= "&="
CIRC_EQ ::= "^="
INF_INF_EQ ::= "<<="
SUP_SUP_EQ ::= ">>="
INF_INF ::= "<<"
SUP_SUP ::= ">>"
EQ_EQ ::= "=="
EXCLAM_EQ ::= "!="
INF_EQ ::= "<="
SUP_EQ ::= ">="
EQ ::= "="
INF ::= "<"
SUP ::= ">"
PLUS_PLUS ::= "++"
MINUS_MINUS ::= "--"
ARROW ::= "->"
PLUS ::= "+"
MINUS ::= "-"
STAR ::= "*"
SLASH ::= "/"
PERCENT ::= "%"
EXCLAM ::= "!"
AND_AND ::= "&&"
PIPE_PIPE ::= "||"
AND ::= "&"
PIPE ::= "|"
CIRC ::= "^"
QUEST ::= "?"
COLON ::= ":"
TILDE ::= "~"

LBRACE ::= "{"
RBRACE ::= "}"
LBRACKET ::= "["
RBRACKET ::= "]"
LPAREN ::= "("
RPAREN ::= ")"
SEMICOLON ::= ";"
COMMA ::= ","
DOT ::= "."