编译原理之（2）c++词法文件，语法文件.

C++词法文件

发信站: 瀚海星云 (2005年11月22日15:52:16 星期二), 站内信件 WWWPOST

http://www.empathy.com/pccts/roskind.html

This lexer description was written by James A. Roskind. Copying

of this file, as a whole, is permitted providing this notice is

intact and applicable in all complete copies. Direct

translations as a whole to other lexer generator input languages

(or lexical description languages) is permitted provided that

this notice is intact and applicable in all such copies, along

with a disclaimer that the contents are a translation. The

reproduction of derived files or text, such as modified versions

of this file, or the output of scanner generators, is permitted,

provided the resulting work includes the copyright notice

products must also provide the notice "Portions Copyright (c)

1989, 1990 James A. Roskind" in a manner appropriate to the

utility, and in keeping with copyright law (e.g.: EITHER

displayed when first invoked/executed; OR displayed continuously

on display terminal; OR via placement in the object code in form

readable in a printout, with or near the title of the work, or at

the end of the file). No royalties, licenses or commissions of

any kind are required to copy this file, its translations, or

derivative products, when the copies are made in compliance with

this notice. Persons or corporations that do make copies in

compliance with this notice may charge whatever price is

agreeable to a buyer, for such copies or derivative works. THIS

FILE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED

WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES

OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

James A. Roskind

Independent Consultant

516 Latania Palm Drive

Indialantic FL, 32903

(407)729-4348

jar@hq.ileaf.com

!uunet!leafusa!jar

---end of copyright notice---

COMMENTS-

My goal is to see software developers adopt my C++ grammar as a

standard until such time as a better standard is accessible. The

only way to get it to become a standard, is to be sure that people

know that derivations are based on a specific work. The intent of

releasing this Flex input file is to facilitate experimentation with

my C++ grammar. The intent of the copyright notice is to allow

arbitrary commercial and non-commercial use of this file, as long as

reference is given to my standardization effort. Without reference

to a specific standard, many alternative grammars would develop. By

referring to the standard, the C++ grammar is given publicity, which

should lead to further use in compatible products and systems. The

benefits of such a standard to commercial products (browsers,

beautifiers, translators, compilers,

) should be obvious to the

developers, in that other compatible products will emerge, and the

value of all conforming products will rise. Most developers are

aware of the value of acquiring a fairly complete grammar for a

language, and the copyright notice (and the resulting affiliation

with my work) should not be too high a price to pay. By copyrighting

my work, I have some minor control over what this standard is, and I

can (hopefully) keep it from degrading without my approval. I will

consistently attempt to provide upgraded grammars that are compliant

with the current art, and the ANSI C++ Committee recommendation in

particular. A developer is never prevented from modifying the

grammar or this file to improve it in whatever way is seen fit. There

is also no restriction on the sale of copies, or derivative works,

providing the request in the copyright notice are satisfied.

If you are not "copying" my work, but are rather only abstracting

some of my work, an acknowledgment with references to such a standard

would be appreciated. Specifically, agreements with my grammar and

its resolution of otherwise ambiguous constructs, should be noted.

Simply put: "make whatever use you would like of the grammar and this

file, but include the ``portions Copyright

'' as a reference to

this standard."

/* Last modified 7/4/91, Version 2.0 */

/* File cpp5.l, becomes lex.yy.c after processing by FLEX */

/* This file is a dramatically cut down version of the FLEX input file

used in my ANSI C Preprocessor. The executable version of my

preprocessor is available on many platforms (shareware), but this is

the only source extract that is currently being distributed. If you

need a full ANSI C preprocessor, with extensive diagnostic

capabilities and customization facilities, please contact me at the

addresses given above. Current platforms include IBMPC (DOS/OS2), Sun

(SPARC and Motorola), and IBM R/6000.

end of commercial

announcement.

This file is being distributed to facilitate experimentation and use

of my C and C++ grammar.

Comment removal must be done during the lexing, as context (such as

enclosure in string literals) must be observed. For this cut-down

lexer, we will assume that comments have been removed (don't assume

this if you are writing a compiler or browser!).

/* For each IDENTIFIER like string that is found, there are several

distinct interpretations that can be applied:

1) The preprocessor may interpret the string as a "keyword" in a

directive (eg: "pragma" or "include", "defined").

2) The parser may interpret the string as a keyword. (eg: "int").

3) Both parser and preprocessor may interpret the string as a keyword

(eg: "if").

Since this file is based on source that actually lexically analyses

text for both preprocessing and parsing, macro definitions were used

throughout. The macro definitions supplied here have been customized

to a C++ parse only, and all preprocessor keywords are passed as

IDENTIFIER or TYPEDEFname. Also, since there is no symbol table to

interrogate to decide whether a string is a TYPEDEFname, I simply

assume that any identifier beginning with an upper case letter is a

TYPEDEFname. This hack should allow you to check out how code

segments are parsed using my grammar. Unfortunately, if you really

want to parse major league code, you have to write a symbol table, and

maintain appropriate scoping information.

/* Included code before lex code */

/*************** Includes and Defines *****************************/

#include "y.tab.h" /* YACC generated definitions based on C++ grammar */

typedef char * YYSTYPE; /* interface with lexer: should be in header

file*/

char * yylval; /* We will always point at the text of the lexeme.

This makes it easy to print out nice trees when YYDEBUG is

enabled. (see C++ grammar file and its definition of

YYDEBUG_LEXER_TEXT to be "yylval" */

#define WHITE_RETURN(x) /* do nothing */

#define NEW_LINE_RETURN() WHITE_RETURN('\n')

#define PA_KEYWORD_RETURN(x) RETURN_VAL(x) /* standard C PArser Keyword */

#define CPP_KEYWORD_RETURN(x) PA_KEYWORD_RETURN(x) /* C++ keyword */

#define PPPA_KEYWORD_RETURN(x) RETURN_VAL(x) /* both PreProcessor and PArser

keyword */

#define PP_KEYWORD_RETURN(x) IDENTIFIER_RETURN()

#define IDENTIFIER_RETURN() RETURN_VAL(isaTYPE(yytext)?TYPEDEFname:IDENTIFIER)

#define PPOP_RETURN(x) RETURN_VAL((int)*yytext) /* PreProcess and

Parser operator */

#define NAMED_PPOP_RETURN(x) /* error: PreProcessor ONLY operator; Do nothing */

#define ASCIIOP_RETURN(x) RETURN_VAL((int)*yytext) /* a single character

operator */

#define NAMEDOP_RETURN(x) RETURN_VAL(x) /* a multichar

operator, with a name */

#define NUMERICAL_RETURN(x) RETURN_VAL(x) /* some sort of constant */

#define LITERAL_RETURN(x) RETURN_VAL(x) /* a string literal */

#define RETURN_VAL(x) yylval = yytext; return(x);

identifier [a-zA-Z_][0-9a-zA-Z_]*

exponent_part [eE][-+]?[0-9]+

fractional_constant ([0-9]*"."[0-9]+)|([0-9]+".")

floating_constant

(({fractional_constant}{exponent_part}?)|([0-9]+{exponent_part}))[FfLl]?

integer_suffix_opt ([uU]?[lL]?)|([lL][uU])

decimal_constant [1-9][0-9]*{integer_suffix_opt}

octal_constant "0"[0-7]*{integer_suffix_opt}

hex_constant "0"[xX][0-9a-fA-F]+{integer_suffix_opt}

simple_escape [abfnrtv'"?\\]

octal_escape [0-7]{1,3}

hex_escape "x"[0-9a-fA-F]+

escape_sequence [\\]({simple_escape}|{octal_escape}|{hex_escape})

c_char [^'\\\n]|{escape_sequence}

s_char [^"\\\n]|{escape_sequence}

h_tab [\011]

form_feed [\014]

v_tab [\013]

c_return [\015]

horizontal_white [ ]|{h_tab}

{horizontal_white}+ {

WHITE_RETURN(' ');

}

({v_tab}|{c_return}|{form_feed})+ {

WHITE_RETURN(' ');

}

({horizontal_white}|{v_tab}|{c_return}|{form_feed})*"\n" {

NEW_LINE_RETURN();

}

auto {PA_KEYWORD_RETURN(AUTO);}

break {PA_KEYWORD_RETURN(BREAK);}

case {PA_KEYWORD_RETURN(CASE);}

char {PA_KEYWORD_RETURN(CHAR);}

const {PA_KEYWORD_RETURN(CONST);}

continue {PA_KEYWORD_RETURN(CONTINUE);}

default {PA_KEYWORD_RETURN(DEFAULT);}

define {PP_KEYWORD_RETURN(DEFINE);}

defined {PP_KEYWORD_RETURN(OPDEFINED);}

do {PA_KEYWORD_RETURN(DO);}

double {PA_KEYWORD_RETURN(DOUBLE);}

elif {PP_KEYWORD_RETURN(ELIF);}

else {PPPA_KEYWORD_RETURN(ELSE);}

endif {PP_KEYWORD_RETURN(ENDIF);}

enum {PA_KEYWORD_RETURN(ENUM);}

error {PP_KEYWORD_RETURN(ERROR);}

extern {PA_KEYWORD_RETURN(EXTERN);}

float {PA_KEYWORD_RETURN(FLOAT);}

for {PA_KEYWORD_RETURN(FOR);}

goto {PA_KEYWORD_RETURN(GOTO);}

if {PPPA_KEYWORD_RETURN(IF);}

ifdef {PP_KEYWORD_RETURN(IFDEF);}

ifndef {PP_KEYWORD_RETURN(IFNDEF);}

include {PP_KEYWORD_RETURN(INCLUDE); }

int {PA_KEYWORD_RETURN(INT);}

line {PP_KEYWORD_RETURN(LINE);}

long {PA_KEYWORD_RETURN(LONG);}

pragma {PP_KEYWORD_RETURN(PRAGMA);}

return {PA_KEYWORD_RETURN(RETURN);}

short {PA_KEYWORD_RETURN(SHORT);}

signed {PA_KEYWORD_RETURN(SIGNED);}

sizeof {PA_KEYWORD_RETURN(SIZEOF);}

static {PA_KEYWORD_RETURN(STATIC);}

struct {PA_KEYWORD_RETURN(STRUCT);}

switch {PA_KEYWORD_RETURN(SWITCH);}

typedef {PA_KEYWORD_RETURN(TYPEDEF);}

undef {PP_KEYWORD_RETURN(UNDEF);}

union {PA_KEYWORD_RETURN(UNION);}

unsigned {PA_KEYWORD_RETURN(UNSIGNED);}

void {PA_KEYWORD_RETURN(VOID);}

volatile {PA_KEYWORD_RETURN(VOLATILE);}

while {PA_KEYWORD_RETURN(WHILE);}

class {CPP_KEYWORD_RETURN(CLASS);}

delete {CPP_KEYWORD_RETURN(DELETE);}

friend {CPP_KEYWORD_RETURN(FRIEND);}

inline {CPP_KEYWORD_RETURN(INLINE);}

new {CPP_KEYWORD_RETURN(NEW);}

operator {CPP_KEYWORD_RETURN(OPERATOR);}

overload {CPP_KEYWORD_RETURN(OVERLOAD);}

protected {CPP_KEYWORD_RETURN(PROTECTED);}

private {CPP_KEYWORD_RETURN(PRIVATE);}

public {CPP_KEYWORD_RETURN(PUBLIC);}

this {CPP_KEYWORD_RETURN(THIS);}

virtual {CPP_KEYWORD_RETURN(VIRTUAL);}

{identifier} {IDENTIFIER_RETURN();}

{decimal_constant} {NUMERICAL_RETURN(INTEGERconstant);}

{octal_constant} {NUMERICAL_RETURN(OCTALconstant);}

{hex_constant} {NUMERICAL_RETURN(HEXconstant);}

{floating_constant} {NUMERICAL_RETURN(FLOATINGconstant);}

"L"?[']{c_char}+['] {

NUMERICAL_RETURN(CHARACTERconstant);

}

"L"?["]{s_char}*["] {

LITERAL_RETURN(STRINGliteral);}

"(" {PPOP_RETURN(LP);}

")" {PPOP_RETURN(RP);}

"," {PPOP_RETURN(COMMA);}

"#" {NAMED_PPOP_RETURN('#') ;}

"##" {NAMED_PPOP_RETURN(POUNDPOUND);}

"{" {ASCIIOP_RETURN(LC);}

"}" {ASCIIOP_RETURN(RC);}

"[" {ASCIIOP_RETURN(LB);}

"]" {ASCIIOP_RETURN(RB);}

"." {ASCIIOP_RETURN(DOT);}

"&" {ASCIIOP_RETURN(AND);}

"*" {ASCIIOP_RETURN(STAR);}

"+" {ASCIIOP_RETURN(PLUS);}

"-" {ASCIIOP_RETURN(MINUS);}

"~" {ASCIIOP_RETURN(NEGATE);}

"!" {ASCIIOP_RETURN(NOT);}

"/" {ASCIIOP_RETURN(DIV);}

"%" {ASCIIOP_RETURN(MOD);}

"<" {ASCIIOP_RETURN(LT);}

">" {ASCIIOP_RETURN(GT);}

"^" {ASCIIOP_RETURN(XOR);}

"|" {ASCIIOP_RETURN(PIPE);}

"?" {ASCIIOP_RETURN(QUESTION);}

":" {ASCIIOP_RETURN(COLON);}

";" {ASCIIOP_RETURN(SEMICOLON);}

"=" {ASCIIOP_RETURN(ASSIGN);}

".*" {NAMEDOP_RETURN(DOTstar);}

"::" {NAMEDOP_RETURN(CLCL);}

"->" {NAMEDOP_RETURN(ARROW);}

"->*" {NAMEDOP_RETURN(ARROWstar);}

"++" {NAMEDOP_RETURN(ICR);}

"--" {NAMEDOP_RETURN(DECR);}

"<<" {NAMEDOP_RETURN(LS);}

">>" {NAMEDOP_RETURN(RS);}

"<=" {NAMEDOP_RETURN(LE);}

">=" {NAMEDOP_RETURN(GE);}

"==" {NAMEDOP_RETURN(EQ);}

"!=" {NAMEDOP_RETURN(NE);}

"&&" {NAMEDOP_RETURN(ANDAND);}

"||" {NAMEDOP_RETURN(OROR);}

"*=" {NAMEDOP_RETURN(MULTassign);}

"/=" {NAMEDOP_RETURN(DIVassign);}

"%=" {NAMEDOP_RETURN(MODassign);}

"+=" {NAMEDOP_RETURN(PLUSassign);}

"-=" {NAMEDOP_RETURN(MINUSassign);}

"<<=" {NAMEDOP_RETURN(LSassign);}

">>=" {NAMEDOP_RETURN(RSassign);}

"&=" {NAMEDOP_RETURN(ANDassign);}

"^=" {NAMEDOP_RETURN(ERassign);}

"|=" {NAMEDOP_RETURN(ORassign);}

" {NAMEDOP_RETURN(ELLIPSIS);}

/* I won't bother to provide any error recovery. I won't even handle

unknown characters */

/*******************************************************************/

int isaTYPE(string)

char * string;

{

/* We should really be maintaining a symbol table, and be

carefully keeping track of what the current scope is (or in the

case of "rescoped" stuff, what scope to look in). Since the

grammar is not annotated with actions to track transitions to

various scopes, and there is no symbol table, we will supply a

hack to allow folks to test the grammar out. THIS IS NOT A

COMPLETE IMPLEMENTATION!!!! */

return ('A' <= string[0] && 'Z' >= string[0]);

}

C++语法文件
发信站: 瀚海星云 (2005年11月22日15:52:43 星期二), 站内信件 WWWPOST

%{

    /* Copyright (C) 1989-1991 James A. Roskind, All rights reserved.
    This grammar was developed  and  written  by  James  A.  Roskind.
    Copying  of  this  grammar  description, as a whole, is permitted
    providing this notice is intact and applicable  in  all  complete
    copies.   Translations as a whole to other parser generator input
    languages  (or  grammar  description  languages)   is   permitted
    provided  that  this  notice is intact and applicable in all such
    copies,  along  with  a  disclaimer  that  the  contents  are   a
    translation.   The reproduction of derived text, such as modified
    versions of this grammar, or the output of parser generators,  is
    permitted,  provided  the  resulting  work includes the copyright
    notice "Portions Copyright (c)  1989,  1990  James  A.  Roskind".
    Derived products, such as compilers, translators, browsers, etc.,
    that  use  this  grammar,  must also provide the notice "Portions
    Copyright  (c)  1989,  1990  James  A.  Roskind"  in   a   manner
    appropriate  to  the  utility,  and in keeping with copyright law
    (e.g.: EITHER displayed when first invoked/executed; OR displayed
    continuously on display terminal; OR via placement in the  object
    code  in  form  readable in a printout, with or near the title of
    the work, or at the end of the file).  No royalties, licenses  or
    commissions  of  any  kind are required to copy this grammar, its
    translations, or derivative products, when the copies are made in
    compliance with this notice. Persons or corporations that do make
    copies in compliance with this notice may charge  whatever  price
    is  agreeable  to  a  buyer, for such copies or derivative works.
    THIS GRAMMAR IS PROVIDED ``AS IS'' AND  WITHOUT  ANY  EXPRESS  OR
    IMPLIED  WARRANTIES,  INCLUDING,  WITHOUT LIMITATION, THE IMPLIED
    WARRANTIES  OF  MERCHANTABILITY  AND  FITNESS  FOR  A  PARTICULAR
    PURPOSE.

    James A. Roskind
    Independent Consultant
    516 Latania Palm Drive
    Indialantic FL, 32903
    (407)729-4348
    jar@hq.ileaf.com

    ---end of copyright notice---

MOTIVATION-

My  goal  is  to  see  software  developers  adopt  this grammar as a
standard until such time as a better  standard  is  accessible.   The
only  way  to  get it to become a standard, is to be sure that people
know that derivations are based on a specific work.   The  intent  of
releasing  this  grammar is to provide a publicly accessible standard
grammar for C++.  The intent of the  copyright  notice  is  to  allow
arbitrary  commercial  and non-commercial use of the grammar, as long
as reference is given to the original standard.  Without reference to
a specific standard, many alternative  grammars  would  develop.   By
referring  to  the  standard,  this grammar is given publicity, which
should lead to further use in compatible products and  systems.   The
benefits  of  such  a  standard  to  commercial  products  (browsers,
beautifiers, translators, compilers, ...) should be  obvious  to  the
developers,  in  that  other compatible products will emerge, and the
value of all conforming products  will  rise.   Most  developers  are
aware  of  the  value  of  acquiring  a fairly complete grammar for a
language, and the copyright notice  (and  the  resulting  affiliation
with my work) should not be too high a price to pay.  By copyrighting
this  grammar,  I have some minor control over what this standard is,
and I can (hopefully) keep it from degrading without my approval.   I
will  consistently  attempt  to  provide  upgraded  grammars that are
compliant  with  the  current  art,  and  the  ANSI   C++   Committee
recommendation  in  particular.   A developer is never prevented from
modifying the grammar to improve it in  whatever  way  is  seen  fit.
There  is  also  no  restriction on the sale of copies, or derivative
works, providing the requests in the copyright notice are satisfied.

If you are not "copying" my work, but  are  rather  only  abstracting
some  of  the  standard,  an acknowledgment with references to such a
standard would be appreciated.  Specifically,  agreements  with  this
standard  as  to  the  resolution  of otherwise ambiguous constructs,
should be noted.

Simply put: "make whatever use you would like  of  the  grammar,  but
include  the  ``portions  Copyright  ...''  as  a  reference  to this
standard."

*/

/* Last modified 7/4/91, Version 2.0  */

/* File CPP5.Y is translated by YACC to Y.TAB.C */

/*  ACKNOWLEDGMENT: Without Bjarne Stroustrup and his many co-workers
at Bell Labs, there would be no C++ Language for which to  provide  a
syntax  description. Bjarne has also been especially helpful and open
in discussions, and by permitting me to review  his  texts  prior  to
their publication, allowed me a wonderful vantage point of clarity.

Without  the effort expended by the ANSI C standardizing committee, I
would have been lost.  Although the ANSI C standard does not  include
a  fully disambiguated syntax description, the committee has at least
provided most of the disambiguating rules in  narratives.   This  C++
grammar  is intended to be a superset of an ANSI C compatible grammar
that is provided in an related file.

Several reviewers have also  recently  critiqued  this  grammar,  the
related  C  grammar,  and  or  assisted  in  discussions  during it's
preparation.  These reviewers are certainly not responsible  for  the
errors  I  have committed here, but they are responsible for allowing
me  to  provide  fewer  errors.   These  colleagues  include:   Bruce
Blodgett,  Mark Langley, Joe Fialli, Greg Perkins, Ron Guilmette, and
Eric Krohn. */

/* Required fixes from last release :

done: 0) Allow direct call to destructors

done: 1) Allow placement of declarations in labeled statements.   The
easiest  fix involves using a larger variance from the C grammar, and
simply making "statement" include declarations.  Note that it  should
also  be  legal  for  declarations  to  be  in  the  branches  of  if
statements, as long as there is no other code in the block (I think).
Consider:

        ...
        {
           if (0 == a)
                int b=5;
           else
                int c=4;
         }

1) template support: Not  done:  pending  syntax  specification  from
ANSI.  (This looks like a major effort, as ANSI has decided to extend
the  "TYPEDEFname"-feedback-to-the-lexer-hack  to  support   template
names as a new kind of terminal token.)

2)  exception  handling:  Not done: pending syntax specification from
ANSI (but it doesn't look hard)

done: 3) Support nested types, including identifier::name,  where  we
realize  that  identifier was a hidden type.  Force the lexer to keep
pace in this situation.   This  will  require  an  extension  of  the
yacc-lex feedback loop.

done: 4) Support nested types even when derivations are used in class
definitions.

5)  Provide  advanced  tutorial  on  YACC  conflicts:  almost done in
documentation about machine generated documentation.

done: 6) Allow declaration specifiers to be left out of  declarations
at file and structure scope so that operator conversion functions can
be  declared and/or defined.  Note that checking to see that it was a
function type that does not require declaration_specifiers is  now  a
constraint  check,  and  not  a  syntax  issue.  Within function body
scopes, declaration specifiers are required, and this is critical  to
distinguishing expressions.

*/

%}

/*

Interesting ambiguity:
Usually
        typename ( typename2 ) ...
or
        typename ( typename2 [4] ) ...
etc.
is a redeclaration of typename2.

Inside  a structure elaboration, it is sometimes the declaration of a
constructor!  Note, this only  counts  if  typename  IS  the  current
containing  class name. (Note this can't conflict with ANSI C because
ANSI C would call it a redefinition, but  claim  it  is  semantically
illegal because you can't have a member declared the same type as the
containing struct!) Since the ambiguity is only reached when a ';' is
found,   there  is  no  problem  with  the  fact  that  the  semantic
interpretation  is  providing  the  true  resolution.   As  currently
implemented, the constructor semantic actions must be able to process
an  ordinary  declaration.  I may reverse this in the future, to ease
semantic implementation.

*/

/*

INTRO TO ANSI C GRAMMAR (provided in a separate file):

The refined grammar resolves several typedef ambiguities in the draft
proposed ANSI C standard syntax down to 1 shift/reduce  conflict,  as
reported by a YACC process.  Note that the one shift reduce conflicts
is  the  traditional  if-if-else conflict that is not resolved by the
grammar.  This ambiguity can be removed using the method described in
the Dragon Book (2nd edition), but this does  not  appear  worth  the
effort.

There  was quite a bit of effort made to reduce the conflicts to this
level, and an additional effort was made to make  the  grammar  quite
similar  to  the  C++ grammar being developed in parallel.  Note that
this grammar resolves the following ANSI C ambiguities:

ANSI C section 3.5.6, "If the [typedef  name]  is  redeclared  at  an
inner  scope,  the  type specifiers shall not be omitted in the inner
declaration".  Supplying type specifiers prevents consideration of  T
as a typedef name in this grammar.  Failure to supply type specifiers
forced the use of the TYPEDEFname as a type specifier.  This is taken
to an (unnecessary) extreme by this implementation.  The ambiguity is
only  a  problem  with  the first declarator in a declaration, but we
restrict  ALL  declarators  whenever  the  users  fails  to   use   a
type_specifier.

ANSI C section 3.5.4.3, "In a parameter declaration, a single typedef
name  in  parentheses  is  taken  to  be  an abstract declarator that
specifies a function  with  a  single  parameter,  not  as  redundant
parentheses  around  the  identifier".  This is extended to cover the
following cases:

typedef float T;
int noo(const (T[5]));
int moo(const (T(int)));
...

Where again the '(' immediately to the left of 'T' is interpreted  as
being  the  start  of  a  parameter type list, and not as a redundant
paren around a redeclaration of T.  Hence an equivalent code fragment
is:

typedef float T;
int noo(const int identifier1 (T identifier2 [5]));
int moo(const int identifier1 (T identifier2 (int identifier3)));
...

*/

%{
/*************** Includes and Defines *****************************/
#define YYDEBUG_LEXER_TEXT (yylval) /* our lexer loads this up each time.
     We are telling the graphical debugger
     where to find the spelling of the
     tokens.*/
#define YYDEBUG 1        /* get the pretty debugging code to compile*/
#define YYSTYPE  char *  /* interface with flex: should be in header file */

/*************** Standard ytab.c continues here *********************/
%}

/*************************************************************************/

/* This group is used by the C/C++ language parser */
%token AUTO            DOUBLE          INT             STRUCT
%token BREAK           ELSE            LONG            SWITCH
%token CASE            ENUM            REGISTER        TYPEDEF
%token CHAR            EXTERN          RETURN          UNION
%token CONST           FLOAT           SHORT           UNSIGNED
%token CONTINUE        FOR             SIGNED          VOID
%token DEFAULT         GOTO            SIZEOF          VOLATILE
%token DO              IF              STATIC          WHILE

/* The following are used in C++ only.  ANSI C would call these IDENTIFIERs */
%token NEW             DELETE
%token THIS
%token OPERATOR
%token CLASS
%token PUBLIC          PROTECTED       PRIVATE
%token VIRTUAL         FRIEND
%token INLINE          OVERLOAD

/* ANSI C Grammar suggestions */
%token IDENTIFIER              STRINGliteral
%token FLOATINGconstant        INTEGERconstant        CHARACTERconstant
%token OCTALconstant           HEXconstant

/* New Lexical element, whereas ANSI C suggested non-terminal */
%token TYPEDEFname

/* Multi-Character operators */
%token  ARROW            /*    ->                              */
%token  ICR DECR         /*    ++      --                      */
%token  LS RS            /*    <<      >>                      */
%token  LE GE EQ NE      /*    <=      >=      ==      !=      */
%token  ANDAND OROR      /*    &&      ||                      */
%token  ELLIPSIS         /*    ...                             */
                 /* Following are used in C++, not ANSI C        */
%token  CLCL             /*    ::                              */
%token  DOTstar ARROWstar/*    .*       ->*                    */

/* modifying assignment operators */
%token MULTassign  DIVassign    MODassign   /*   *=      /=      %=      */
%token PLUSassign  MINUSassign              /*   +=      -=              */
%token LSassign    RSassign                 /*   <<=     >>=             */
%token ANDassign   ERassign     ORassign    /*   &=      ^=      |=      */

/*************************************************************************/

%start translation_unit

/*************************************************************************/

%%

/*********************** CONSTANTS *********************************/
constant:
        INTEGERconstant
        | FLOATINGconstant
        /*  We  are not including ENUMERATIONconstant here because we
          are treating it like a variable with a type of "enumeration
          constant".  */
        | OCTALconstant
        | HEXconstant
        | CHARACTERconstant
        ;

string_literal_list:
                STRINGliteral
                | string_literal_list STRINGliteral
                ;

/************************* EXPRESSIONS ********************************/

    /* Note that I provide  a  "scope_opt_identifier"  that  *cannot*
    begin  with ::.  This guarantees we have a viable declarator, and
    helps to disambiguate :: based uses in the grammar.  For example:

            ...
            {
            int (* ::b()); // must be an expression
            int (T::b); // officially a declaration, which fails on
constraint grounds

    This *syntax* restriction reflects the current syntax in the ANSI
    C++ Working Papers.   This  means  that  it  is  *incorrect*  for
    parsers to misparse the example:

            int (* ::b()); // must be an expression

    as a declaration, and then report a constraint error.

    In contrast, declarations such as:

        class T;
        class A;
        class B;
        main(){
              T( F());  // constraint error: cannot declare local function
              T (A::B::a); // constraint error: cannot declare member as a
local value

    are  *parsed*  as  declarations,  and *then* given semantic error
    reports.  It is incorrect for a parser to "change its mind" based
    on constraints.  If your C++ compiler claims  that  the  above  2
    lines are expressions, then *I* claim that they are wrong. */

paren_identifier_declarator:
        scope_opt_identifier
        | scope_opt_complex_name
        | '(' paren_identifier_declarator ')'
        ;

    /* Note that CLCL IDENTIFIER is NOT part of scope_opt_identifier,
    but  it  is  part of global_opt_scope_opt_identifier.  It is ONLY
    valid for referring to an identifier, and NOT valid for declaring
    (or importing an external declaration of)  an  identifier.   This
    disambiguates  the  following  code,  which  would  otherwise  be
    syntactically and semantically ambiguous:

            class base {
                static int i; // element i;
                float member_function(void);
                };
            base i; // global i
            float base::member_function(void) {
                i; // refers to static int element "i" of base
                ::i; // refers to global "i", with type "base"
                    {
                    base :: i; // import of global "i", like "base (::i);"?
                                // OR reference to global??
                    }
                }
        */

primary_expression:
        global_opt_scope_opt_identifier
        | global_opt_scope_opt_complex_name
        | THIS   /* C++, not ANSI C */
        | constant
        | string_literal_list
        | '(' comma_expression ')'
        ;

    /* I had to disallow struct, union, or enum  elaborations  during
    operator_function_name.   The  ANSI  C++  Working  paper is vague
    about whether this should be part of the syntax, or a constraint.
    The ambiguities that resulted were more than LALR  could  handle,
    so  the  easiest  fix was to be more specific.  This means that I
    had to in-line expand type_specifier_or_name far  enough  that  I
    would  be  able to exclude elaborations.  This need is what drove
    me to distinguish a whole series of tokens based on whether  they
    include elaborations:

         struct A { ... }

    or simply a reference to an aggregate or enumeration:

         enum A

    The  latter,  as  well  an  non-aggregate  types are what make up
    non_elaborating_type_specifier */

    /* Note that the following does not include  type_qualifier_list.
    Hence,   whenever   non_elaborating_type_specifier  is  used,  an
    adjacent rule is supplied containing type_qualifier_list.  It  is
    not  generally  possible  to  know  immediately  (i_e., reduce) a
    type_qualifier_list, as a TYPEDEFname that follows might  not  be
    part of a type specifier, but might instead be "TYPEDEFname ::*".
    */

non_elaborating_type_specifier:
        sue_type_specifier
        | basic_type_specifier
        | typedef_type_specifier

        | basic_type_name
        | TYPEDEFname
        | global_or_scoped_typedefname
        ;

    /*  The  following  introduces  MANY  conflicts.   Requiring  and
    allowing '(' ')' around the `type' when the type is complex would
    help a lot. */

operator_function_name:
        OPERATOR any_operator
        | OPERATOR type_qualifier_list            operator_function_ptr_opt
        | OPERATOR non_elaborating_type_specifier operator_function_ptr_opt
        ;

    /* The following causes several ambiguities on *  and  &.   These
    conflicts  would also be removed if parens around the `type' were
    required in the derivations for operator_function_name */

    /*  Interesting  aside:  The  use  of  right  recursion  in   the
    production  for  operator_function_ptr_opt gives both the correct
    parsing, AND removes a conflict!   Right  recursion  permits  the
    parser  to  defer  reductions  (a.k.a.:  delay  resolution),  and
    effectively make a second pass! */

operator_function_ptr_opt:
        /* nothing */
        | unary_modifier        operator_function_ptr_opt
        | asterisk_or_ampersand operator_function_ptr_opt
        ;

    /* List of operators we can overload */
any_operator:
        '+'
        | '-'
        | '*'
        | '/'
        | '%'
        | '^'
        | '&'
        | '|'
        | '~'
        | '!'
        | '<'
        | '>'
        | LS
        | RS
        | ANDAND
        | OROR
        | ARROW
        | ARROWstar
        | '.'
        | DOTstar
        | ICR
        | DECR
        | LE
        | GE
        | EQ
        | NE
        | assignment_operator
        | '(' ')'
        | '[' ']'
        | NEW
        | DELETE
        | ','
        ;

    /* The following production for type_qualifier_list was specially
    placed BEFORE the definition of postfix_expression to  resolve  a
    reduce-reduce    conflict    set    correctly.    Note   that   a
    type_qualifier_list is only used  in  a  declaration,  whereas  a
    postfix_expression is clearly an example of an expression.  Hence
    we  are helping with the "if it can be a declaration, then it is"
    rule.  The reduce conflicts are on ')', ',' and '='.  Do not move
    the following productions */

type_qualifier_list_opt:
        /* Nothing */
        | type_qualifier_list
        ;

    /*  Note  that  the next set of productions in this grammar gives
    post-increment a higher precedence that pre-increment.   This  is
    not  clearly  stated  in  the  C++  Reference manual, and is only
    implied by the grammar in the ANSI C Standard. */

    /* I *DON'T* use  argument_expression_list_opt  to  simplify  the
    grammar  shown  below.   I am deliberately deferring any decision
    until    *after*     the     closing     paren,     and     using
    "argument_expression_list_opt" would commit prematurely.  This is
    critical to proper conflict resolution. */

    /*  The  {}  in  the following rules allow the parser to tell the
    lexer to search for the member name  in  the  appropriate  scope,
    much the way the CLCL operator works.*/

postfix_expression:
        primary_expression
        | postfix_expression '[' comma_expression ']'
        | postfix_expression '(' ')'
        | postfix_expression '(' argument_expression_list ')'
        | postfix_expression {} '.'   member_name
        | postfix_expression {} ARROW member_name
        | postfix_expression ICR
        | postfix_expression DECR

                /* The next 4 rules are the source of cast ambiguity */
        | TYPEDEFname                  '(' ')'
        | global_or_scoped_typedefname '(' ')'
        | TYPEDEFname                  '(' argument_expression_list ')'
        | global_or_scoped_typedefname '(' argument_expression_list ')'
        | basic_type_name '(' assignment_expression ')'
            /* If the following rule is added to the  grammar,  there
            will  be 3 additional reduce-reduce conflicts.  They will
            all be resolved in favor of NOT using the following rule,
            so no harm will be done.   However,  since  the  rule  is
            semantically  illegal  we  will  omit  it  until  we  are
            enhancing the grammar for error recovery */
/*      | basic_type_name '(' ')'  /* Illegal: no such constructor*/
        ;

    /* The last two productions in the next set are questionable, but
    do not induce any conflicts.  I need to ask X3J16 :  Having  them
    means that we have complex member function deletes like:

          const unsigned int :: ~ const unsigned int
    */

member_name:
        scope_opt_identifier
        | scope_opt_complex_name
        | basic_type_name CLCL '~' basic_type_name  /* C++, not ANSI C */

        | declaration_qualifier_list  CLCL '~'   declaration_qualifier_list
        | type_qualifier_list         CLCL '~'   type_qualifier_list
        ;

argument_expression_list:
        assignment_expression
        | argument_expression_list ',' assignment_expression
        ;

unary_expression:
        postfix_expression
        | ICR  unary_expression
        | DECR unary_expression
        | asterisk_or_ampersand cast_expression
        | '-'                   cast_expression
        | '+'                   cast_expression
        | '~'                   cast_expression
        | '!'                   cast_expression
        | SIZEOF unary_expression
        | SIZEOF '(' type_name ')'
        | allocation_expression
        ;

    /* Note that I could have moved the  newstore  productions  to  a
    lower  precedence  level  than  multiplication  (binary '*'), and
    lower than bitwise AND (binary '&').  These moves  are  the  nice
    way  to  disambiguate a trailing unary '*' or '&' at the end of a
    freestore expression.  Since the freestore expression (with  such
    a  grammar  and  hence  precedence  given)  can never be the left
    operand of a binary '*' or '&', the ambiguity would  be  removed.
    These  problems  really  surface when the binary operators '*' or
    '&' are overloaded, but this must be syntactically  disambiguated
    before the semantic checking is performed...  Unfortunately, I am
    not  creating  the language, only writing a grammar that reflects
    its specification, and  hence  I  cannot  change  its  precedence
    assignments.   If  I  had  my  druthers,  I would probably prefer
    surrounding the type with parens all the time, and  avoiding  the
    dangling * and & problem all together.*/

       /* Following are C++, not ANSI C */
allocation_expression:
        global_opt_scope_opt_operator_new
'(' type_name ')'
                operator_new_initializer_opt

        | global_opt_scope_opt_operator_new '(' argument_expression_list ')'
'(' type_name ')'
                operator_new_initializer_opt

                /* next two rules are the source of * and & ambiguities */
        | global_opt_scope_opt_operator_new
operator_new_type
        | global_opt_scope_opt_operator_new '(' argument_expression_list ')'
operator_new_type
        ;

       /* Following are C++, not ANSI C */
global_opt_scope_opt_operator_new:
        NEW
        | global_or_scope NEW
        ;

operator_new_type:
        type_qualifier_list              operator_new_declarator_opt
                        operator_new_initializer_opt

        | non_elaborating_type_specifier operator_new_declarator_opt
                        operator_new_initializer_opt
        ;


    /*  Right  recursion  is critical in the following productions to
    avoid a conflict on TYPEDEFname */

operator_new_declarator_opt:
        /* Nothing */
        | operator_new_array_declarator
        | asterisk_or_ampersand operator_new_declarator_opt
        | unary_modifier        operator_new_declarator_opt
        ;

operator_new_array_declarator:
                                        '['                  ']'
        |                               '[' comma_expression ']'
        | operator_new_array_declarator '[' comma_expression ']'
        ;

operator_new_initializer_opt:
        /* Nothing */
        | '('                          ')'
        | '(' argument_expression_list ')'
        ;

cast_expression:
        unary_expression
        | '(' type_name ')' cast_expression
        ;

    /* Following are C++, not ANSI C */
deallocation_expression:
        cast_expression
        | global_opt_scope_opt_delete deallocation_expression
        | global_opt_scope_opt_delete '[' comma_expression ']'
deallocation_expression  /* archaic C++, what a concept */
        | global_opt_scope_opt_delete '[' ']' deallocation_expression
        ;

    /* Following are C++, not ANSI C */
global_opt_scope_opt_delete:
        DELETE
        | global_or_scope DELETE
        ;

    /* Following are C++, not ANSI C */
point_member_expression:
        deallocation_expression
        | point_member_expression DOTstar  deallocation_expression
        | point_member_expression ARROWstar  deallocation_expression
        ;

multiplicative_expression:
        point_member_expression
        | multiplicative_expression '*' point_member_expression
        | multiplicative_expression '/' point_member_expression
        | multiplicative_expression '%' point_member_expression
        ;

additive_expression:
        multiplicative_expression
        | additive_expression '+' multiplicative_expression
        | additive_expression '-' multiplicative_expression
        ;

shift_expression:
        additive_expression
        | shift_expression LS additive_expression
        | shift_expression RS additive_expression
        ;

relational_expression:
        shift_expression
        | relational_expression '<' shift_expression
        | relational_expression '>' shift_expression
        | relational_expression LE  shift_expression
        | relational_expression GE  shift_expression
        ;

equality_expression:
        relational_expression
        | equality_expression EQ relational_expression
        | equality_expression NE relational_expression
        ;

AND_expression:
        equality_expression
        | AND_expression '&' equality_expression
        ;

exclusive_OR_expression:
        AND_expression
        | exclusive_OR_expression '^' AND_expression
        ;

inclusive_OR_expression:
        exclusive_OR_expression
        | inclusive_OR_expression '|' exclusive_OR_expression
        ;

logical_AND_expression:
        inclusive_OR_expression
        | logical_AND_expression ANDAND inclusive_OR_expression
        ;

logical_OR_expression:
        logical_AND_expression
        | logical_OR_expression OROR logical_AND_expression
        ;

conditional_expression:
        logical_OR_expression

        | logical_OR_expression '?' comma_expression ':'
                conditional_expression
        ;

assignment_expression:
        conditional_expression
        | unary_expression assignment_operator assignment_expression
        ;

assignment_operator:
        '='
        | MULTassign
        | DIVassign
        | MODassign
        | PLUSassign
        | MINUSassign
        | LSassign
        | RSassign
        | ANDassign
        | ERassign
        | ORassign
        ;

comma_expression:
        assignment_expression
        | comma_expression ',' assignment_expression
        ;

constant_expression:
        conditional_expression
        ;

    /* The following was used for clarity */
comma_expression_opt:
        /* Nothing */
        | comma_expression
        ;

/******************************* DECLARATIONS *********************************/

    /*  The  following are notably different from the ANSI C Standard
    specified grammar, but  are  present  in  my  ANSI  C  compatible
    grammar.  The changes were made to disambiguate typedefs presence
    in   declaration_specifiers   (vs.    in   the   declarator   for
    redefinition); to allow struct/union/enum/class tag  declarations
    without  declarators,  and  to  better  reflect  the  parsing  of
    declarations    (declarators    must     be     combined     with
    declaration_specifiers  ASAP, so that they can immediately become
    visible in the current scope). */

declaration:
        declaring_list ';'
        | default_declaring_list ';'
        | sue_declaration_specifier ';' { /* this is constraint error, as it
                                        includes a storage class!?!*/ }
        | sue_type_specifier ';'
        | sue_type_specifier_elaboration ';'
        ;

    /* Note that if a typedef were  redeclared,  then  a  declaration
    specifier  must be supplied (re: ANSI C spec).  The following are
    declarations wherein no declaration_specifier  is  supplied,  and
    hence the 'default' must be used.  An example of this is

        const a;

    which by default, is the same as:

        const int a;

    `a' must NOT be a typedef in the above example. */

    /*  The  presence of `{}' in the following rules indicates points
    at which the symbol table MUST be updated so that  the  tokenizer
    can  IMMEDIATELY  continue  to  maintain  the  proper distinction
    between a TYPEDEFname and an IDENTIFIER. */

default_declaring_list:  /* Can't  redeclare typedef names */
        declaration_qualifier_list   identifier_declarator {} initializer_opt
        | type_qualifier_list        identifier_declarator {} initializer_opt
        | default_declaring_list ',' identifier_declarator {} initializer_opt

        | declaration_qualifier_list constructed_identifier_declarator
        | type_qualifier_list        constructed_identifier_declarator
        | default_declaring_list ',' constructed_identifier_declarator
        ;

    /* Note how type_qualifier_list is  NOT  used  in  the  following
    productions.    Qualifiers   are   NOT   sufficient  to  redefine
    typedef-names (as prescribed by the ANSI C standard).*/

declaring_list:
        declaration_specifier          declarator {} initializer_opt
        | type_specifier               declarator {} initializer_opt
        | basic_type_name              declarator {} initializer_opt
        | TYPEDEFname                  declarator {} initializer_opt
        | global_or_scoped_typedefname declarator {} initializer_opt
        | declaring_list ','           declarator {} initializer_opt

        | declaration_specifier        constructed_declarator
        | type_specifier               constructed_declarator
        | basic_type_name              constructed_declarator
        | TYPEDEFname                  constructed_declarator
        | global_or_scoped_typedefname constructed_declarator
        | declaring_list ','           constructed_declarator
        ;

    /* Declarators with  parenthesized  initializers  present  a  big
    problem.  Typically  a  declarator  that looks like: "*a(...)" is
    supposed to bind FIRST to the "(...)", and then to the "*".  This
    binding  presumes  that  the  "(...)" stuff is a prototype.  With
    constructed declarators, we must (officially) finish the  binding
    to the "*" (finishing forming a good declarator) and THEN connect
    with  the argument list. Unfortunately, by the time we realize it
    is an argument list (and not a  prototype)  we  have  pushed  the
    separate  declarator  tokens  "*"  and  "a"  onto  the yacc stack
    WITHOUT combining them. The solution is to use odd productions to
    carry  the  incomplete  declarator  along  with   the   "argument
    expression  list" back up the yacc stack.  We would then actually
    instantiate the symbol table after we have  fully  decorated  the
    symbol  with all the leading "*" stuff.  Actually, since we don't
    have all the type information in one spot till  we  reduce  to  a
    declaring_list,  this delay is not a problem.  Note that ordinary
    initializers REQUIRE (ANSI C Standard) that the symbol be  placed
    into  the symbol table BEFORE its initializer is read, but in the
    case of parenthesized initializers,  this  is  not  possible  (we
    don't  even  know  we  have  an  initializer till have passed the
    opening "(". ) */

constructed_declarator:
        nonunary_constructed_identifier_declarator
        | constructed_paren_typedef_declarator
        | simple_paren_typedef_declarator '(' argument_expression_list ')'

        | simple_paren_typedef_declarator postfixing_abstract_declarator
                                          '(' argument_expression_list ')'
/* constraint error */

        | constructed_parameter_typedef_declarator
        | asterisk_or_ampersand constructed_declarator
        | unary_modifier        constructed_declarator
        ;

constructed_paren_typedef_declarator:
        '(' paren_typedef_declarator ')'
                    '(' argument_expression_list ')'

        | '(' paren_typedef_declarator ')' postfixing_abstract_declarator
                   '(' argument_expression_list ')'

        | '(' simple_paren_typedef_declarator postfixing_abstract_declarator ')'
                   '(' argument_expression_list ')'

        | '(' TYPEDEFname postfixing_abstract_declarator ')'
                   '(' argument_expression_list ')'
        ;

constructed_parameter_typedef_declarator:
        TYPEDEFname    '(' argument_expression_list ')'

        | TYPEDEFname  postfixing_abstract_declarator
                       '(' argument_expression_list ')'  /* constraint error */

        | '(' clean_typedef_declarator ')'
                       '(' argument_expression_list ')'

        | '(' clean_typedef_declarator ')'  postfixing_abstract_declarator
                       '(' argument_expression_list ')'
        ;

constructed_identifier_declarator:
        nonunary_constructed_identifier_declarator
        | asterisk_or_ampersand constructed_identifier_declarator
        | unary_modifier        constructed_identifier_declarator
        ;

    /* The following are restricted to NOT  begin  with  any  pointer
    operators.   This  includes both "*" and "T::*" modifiers.  Aside
    from  this  restriction,   the   following   would   have   been:
    identifier_declarator '(' argument_expression_list ')' */

nonunary_constructed_identifier_declarator:
        paren_identifier_declarator   '(' argument_expression_list ')'

        | paren_identifier_declarator postfixing_abstract_declarator
                       '(' argument_expression_list ')'  /* constraint error*/

        | '(' unary_identifier_declarator ')'
                       '(' argument_expression_list ')'

        | '(' unary_identifier_declarator ')' postfixing_abstract_declarator
                       '(' argument_expression_list ')'
        ;

declaration_specifier:
        basic_declaration_specifier          /* Arithmetic or void */
        | sue_declaration_specifier          /* struct/union/enum/class */
        | typedef_declaration_specifier      /* typedef*/
        ;

type_specifier:
        basic_type_specifier                 /* Arithmetic or void */
        | sue_type_specifier                 /* Struct/Union/Enum/Class */
        | sue_type_specifier_elaboration     /* elaborated
Struct/Union/Enum/Class */
        | typedef_type_specifier             /* Typedef */
        ;

declaration_qualifier_list:  /* storage class and optional const/volatile */
        storage_class
        | type_qualifier_list storage_class
        | declaration_qualifier_list declaration_qualifier
        ;

type_qualifier_list:
        type_qualifier
        | type_qualifier_list type_qualifier
        ;

declaration_qualifier:
        storage_class
        | type_qualifier                  /* const or volatile */
        ;

type_qualifier:
        CONST
        | VOLATILE
        ;

basic_declaration_specifier:      /*Storage Class+Arithmetic or void*/
        declaration_qualifier_list    basic_type_name
        | basic_type_specifier        storage_class
        | basic_type_name             storage_class
        | basic_declaration_specifier declaration_qualifier
        | basic_declaration_specifier basic_type_name
        ;

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

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

sue_type_specifier_elaboration:
        elaborated_type_name_elaboration     /* elaborated
struct/union/enum/class */
        | type_qualifier_list elaborated_type_name_elaboration
        | sue_type_specifier_elaboration type_qualifier
        ;

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

typedef_declaration_specifier:       /*Storage Class + typedef types */
        declaration_qualifier_list   TYPEDEFname
        | declaration_qualifier_list global_or_scoped_typedefname

        | typedef_type_specifier       storage_class
        | TYPEDEFname                  storage_class
        | global_or_scoped_typedefname storage_class

        | typedef_declaration_specifier declaration_qualifier
        ;

typedef_type_specifier:              /* typedef types */
        type_qualifier_list      TYPEDEFname
        | type_qualifier_list    global_or_scoped_typedefname

        | TYPEDEFname                  type_qualifier
        | global_or_scoped_typedefname type_qualifier

        | typedef_type_specifier type_qualifier
        ;

/*  There  are  really  several distinct sets of storage_classes. The
sets vary depending on whether the declaration is at file scope, is a
declaration within a struct/class, is within a function body, or in a
function declaration/definition (prototype  parameter  declarations).
They   are   grouped  here  to  simplify  the  grammar,  and  can  be
semantically checked.  Note that this  approach  tends  to  ease  the
syntactic restrictions in the grammar slightly, but allows for future
language  development,  and tends to provide superior diagnostics and
error recovery (i_e.: a syntax error does not disrupt the parse).

                File    File    Member  Member  Local   Local  Formal
                Var     Funct   Var     Funct   Var     Funct  Params
TYPEDEF         x       x       x       x       x       x
EXTERN          x       x                       x       x
STATIC          x       x       x       x       x
AUTO                                            x              x
REGISTER                                        x              x
FRIEND                                  x
OVERLOAD                x               x               x
INLINE                  x               x               x
VIRTUAL                                 x               x
*/

storage_class:
        EXTERN
        | TYPEDEF
        | STATIC
        | AUTO
        | REGISTER
        | FRIEND   /* C++, not ANSI C */
        | OVERLOAD /* C++, not ANSI C */
        | INLINE   /* C++, not ANSI C */
        | VIRTUAL  /* C++, not ANSI C */
        ;

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

elaborated_type_name_elaboration:
        aggregate_name_elaboration
        | enum_name_elaboration
        ;

elaborated_type_name:
        aggregate_name
        | enum_name
        ;

    /* Since the expression "new type_name" MIGHT use  an  elaborated
    type  and a derivation, it MIGHT have a ':'.  This fact conflicts
    with the requirement that a new expression can be placed  between
    a '?' and a ':' in a conditional expression (at least it confuses
    LR(1)   parsers).   Hence   the   aggregate_name_elaboration   is
    responsible for a series of SR conflicts on ':'.*/

    /* The intermediate actions {}  represent  points  at  which  the
    database  of  typedef  names  must  be  updated  in C++.  This is
    critical to the lexer, which must begin to tokenize based on this
    new information. */

aggregate_name_elaboration:
        aggregate_name derivation_opt  '{' member_declaration_list_opt '}'
        | aggregate_key derivation_opt '{' member_declaration_list_opt '}'
        ;

    /* We distinguish between the above, which  support  elaboration,
    and  this  set  of  productions  so  that  we can provide special
    declaration specifiers for operator_new_type, and for  conversion
    functions.  Note that without this restriction a large variety of
    conflicts  appear  when  processing  operator_new and conversions
    operators (which can be  followed  by  a  ':'  in  a  ternary  ?:
    expression) */

    /*  Note that at the end of each of the following rules we should
    be sure that the tag name is  in,  or  placed  in  the  indicated
    scope.   If  no  scope  is  specified, then we must add it to our
    current scope IFF it cannot  be  found  in  an  external  lexical
    scope. */

aggregate_name:
                             aggregate_key tag_name
        | global_scope scope aggregate_key tag_name
        | global_scope       aggregate_key tag_name
        | scope              aggregate_key tag_name
        ;

derivation_opt:
        /* nothing */
        | ':' derivation_list
        ;

derivation_list:
        parent_class
        | derivation_list ',' parent_class
        ;

parent_class:
                                       global_opt_scope_opt_typedefname
        | VIRTUAL access_specifier_opt global_opt_scope_opt_typedefname
        | access_specifier virtual_opt global_opt_scope_opt_typedefname
        ;

virtual_opt:
        /* nothing */
        | VIRTUAL
        ;

access_specifier_opt:
        /* nothing */
        | access_specifier
        ;

access_specifier:
        PUBLIC
        | PRIVATE
        | PROTECTED
        ;

aggregate_key:
        STRUCT
        | UNION
        | CLASS /* C++, not ANSI C */
        ;

    /* Note that an empty list is ONLY allowed under C++. The grammar
    can  be modified so that this stands out.  The trick is to define
    member_declaration_list, and have that referenced for non-trivial
    lists. */

member_declaration_list_opt:
        /* nothing */
        | member_declaration_list_opt member_declaration
        ;

member_declaration:
        member_declaring_list ';'
        | member_default_declaring_list ';'

        | access_specifier ':'               /* C++, not ANSI C */

        | new_function_definition            /* C++, not ANSI C */
        | constructor_function_in_class      /* C++, not ANSI C */

        | sue_type_specifier             ';' /* C++, not ANSI C */
        | sue_type_specifier_elaboration ';' /* C++, not ANSI C */
        | identifier_declarator          ';' /* C++, not ANSI C
                                                access modification
                                                conversion functions,
                                                unscoped destructors */

        | typedef_declaration_specifier ';' /* friend T */       /* C++, not
ANSI C */
        | sue_declaration_specifier ';'     /* friend class C*/  /* C++, not
ANSI C */
        ;

member_default_declaring_list:        /* doesn't redeclare typedef*/
        type_qualifier_list
                identifier_declarator member_pure_opt

        | declaration_qualifier_list
                identifier_declarator member_pure_opt /* C++, not ANSI C */

        | member_default_declaring_list ','
                identifier_declarator member_pure_opt

        | type_qualifier_list                bit_field_identifier_declarator
        | declaration_qualifier_list         bit_field_identifier_declarator
/* C++, not ANSI C */
        | member_default_declaring_list ','  bit_field_identifier_declarator
        ;

    /* There is a conflict when "struct A" is used as  a  declaration
    specifier,  and  there  is a chance that a bit field name will be
    provided.  To fix this syntactically would require distinguishing
    non_elaborating_declaration_specifiers   the   way   I    handled
    non_elaborating_type_specifiers.   I   think  this  should  be  a
    constraint error anyway :-). */

member_declaring_list:        /* Can possibly redeclare typedefs */
        type_specifier                 declarator member_pure_opt
        | basic_type_name              declarator member_pure_opt

        | global_or_scoped_typedefname declarator member_pure_opt
        | member_conflict_declaring_item
        | member_declaring_list ','    declarator member_pure_opt

        | type_specifier                bit_field_declarator
        | basic_type_name               bit_field_declarator
        | TYPEDEFname                   bit_field_declarator
        | global_or_scoped_typedefname  bit_field_declarator
        | declaration_specifier         bit_field_declarator /* constraint
violation: storage class used */
        | member_declaring_list ','     bit_field_declarator
        ;

    /* The following conflict with constructors-
      member_conflict_declaring_item:
        TYPEDEFname             declarator member_pure_opt
        | declaration_specifier declarator member_pure_opt /* C++, not ANSI C * /
        ;
    so we inline expand declarator to get the following productions...
    */
member_conflict_declaring_item:
        TYPEDEFname             identifier_declarator            member_pure_opt
        | TYPEDEFname           parameter_typedef_declarator     member_pure_opt
        | TYPEDEFname           simple_paren_typedef_declarator  member_pure_opt

        | declaration_specifier identifier_declarator            member_pure_opt
        | declaration_specifier parameter_typedef_declarator     member_pure_opt
        | declaration_specifier simple_paren_typedef_declarator  member_pure_opt

        | member_conflict_paren_declaring_item
        ;

    /* The following still conflicts with constructors-
      member_conflict_paren_declaring_item:
        TYPEDEFname             paren_typedef_declarator     member_pure_opt
        | declaration_specifier paren_typedef_declarator     member_pure_opt
        ;
    so paren_typedef_declarator is expanded inline to get...*/

member_conflict_paren_declaring_item:
        TYPEDEFname   asterisk_or_ampersand
                '(' simple_paren_typedef_declarator ')' member_pure_opt
        | TYPEDEFname unary_modifier
                '(' simple_paren_typedef_declarator ')' member_pure_opt
        | TYPEDEFname asterisk_or_ampersand
                '(' TYPEDEFname ')'                     member_pure_opt
        | TYPEDEFname unary_modifier
                '(' TYPEDEFname ')'                     member_pure_opt
        | TYPEDEFname asterisk_or_ampersand
                 paren_typedef_declarator               member_pure_opt
        | TYPEDEFname unary_modifier
                 paren_typedef_declarator               member_pure_opt

        | declaration_specifier asterisk_or_ampersand
                '(' simple_paren_typedef_declarator ')' member_pure_opt
        | declaration_specifier unary_modifier
                '(' simple_paren_typedef_declarator ')' member_pure_opt
        | declaration_specifier asterisk_or_ampersand
                '(' TYPEDEFname ')'                     member_pure_opt
        | declaration_specifier unary_modifier
                '(' TYPEDEFname ')'                     member_pure_opt
        | declaration_specifier asterisk_or_ampersand
                paren_typedef_declarator                member_pure_opt
        | declaration_specifier unary_modifier
                paren_typedef_declarator                member_pure_opt

        | member_conflict_paren_postfix_declaring_item
        ;

    /* but we still have the following conflicts with constructors-
   member_conflict_paren_postfix_declaring_item:
      TYPEDEFname             postfix_paren_typedef_declarator member_pure_opt
      | declaration_specifier postfix_paren_typedef_declarator member_pure_opt
      ;
    so we expand paren_postfix_typedef inline and get...*/

member_conflict_paren_postfix_declaring_item:
        TYPEDEFname     '(' paren_typedef_declarator ')'
                                                           member_pure_opt
        | TYPEDEFname   '(' simple_paren_typedef_declarator
                        postfixing_abstract_declarator ')' member_pure_opt
        | TYPEDEFname   '(' TYPEDEFname
                        postfixing_abstract_declarator ')' member_pure_opt
        | TYPEDEFname   '(' paren_typedef_declarator ')'
                        postfixing_abstract_declarator     member_pure_opt

        | declaration_specifier '(' paren_typedef_declarator ')'
                                                           member_pure_opt
        | declaration_specifier '(' simple_paren_typedef_declarator
                        postfixing_abstract_declarator ')' member_pure_opt
        | declaration_specifier '(' TYPEDEFname
                        postfixing_abstract_declarator ')' member_pure_opt
        | declaration_specifier '(' paren_typedef_declarator ')'
                        postfixing_abstract_declarator     member_pure_opt
        ;
    /* ...and we are done.  Now all  the  conflicts  appear  on  ';',
    which can be semantically evaluated/disambiguated */

member_pure_opt:
        /* nothing */
        | '=' OCTALconstant /* C++, not ANSI C */ /* Pure function*/
        ;

    /*  Note  that  bit  field  names, where redefining TYPEDEFnames,
    cannot be parenthesized in C++ (due to  ambiguities),  and  hence
    this  part of the grammar is simpler than ANSI C. :-) The problem
    occurs because:

         TYPEDEFname ( TYPEDEFname) : .....

    doesn't look like a bit field, rather it looks like a constructor
    definition! */

bit_field_declarator:
        bit_field_identifier_declarator
        | TYPEDEFname {} ':' constant_expression
        ;

    /* The actions taken in the "{}" above and below are intended  to
    allow  the  symbol  table  to  be  updated when the declarator is
    complete.  It is critical for code like:

            foo : sizeof(foo + 1);
    */

bit_field_identifier_declarator:
                                   ':' constant_expression
        | identifier_declarator {} ':' constant_expression
        ;

enum_name_elaboration:
        global_opt_scope_opt_enum_key '{' enumerator_list '}'
        | enum_name                   '{' enumerator_list '}'
        ;

    /* As with structures, the distinction between "elaborating"  and
    "non-elaborating"  enum  types  is  maintained.  In actuality, it
    probably does not cause much in the way of conflicts, since a ':'
    is not allowed.  For symmetry, we maintain the distinction.   The
    {}  actions are intended to allow the symbol table to be updated.
    These updates are significant to code such as:

        enum A { first=sizeof(A)};
    */

enum_name:
        global_opt_scope_opt_enum_key tag_name
        ;

global_opt_scope_opt_enum_key:
        ENUM
        | global_or_scope ENUM
        ;

enumerator_list:
        enumerator_list_no_trailing_comma
        | enumerator_list_no_trailing_comma ',' /* C++, not ANSI C */
        ;

    /* Note that we do not need to rush to add an enumerator  to  the
    symbol  table  until  *AFTER* the enumerator_value_opt is parsed.
    The enumerated value is only in scope  AFTER  its  definition  is
    complete.   Hence the following is legal: "enum {a, b=a+10};" but
    the following is (assuming no external matching of names) is  not
    legal:  "enum {c, d=sizeof(d)};" ("d" not defined when sizeof was
    applied.) This is  notably  contrasted  with  declarators,  which
    enter scope as soon as the declarator is complete. */

enumerator_list_no_trailing_comma:
        enumerator_name enumerator_value_opt
        | enumerator_list_no_trailing_comma ',' enumerator_name
enumerator_value_opt
        ;

enumerator_name:
        IDENTIFIER
        | TYPEDEFname
        ;

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

    /*  We special case the lone type_name which has no storage class
    (even though it should be an example of  a  parameter_type_list).
    This helped to disambiguate type-names in parenthetical casts.*/

parameter_type_list:
        '(' ')'                             type_qualifier_list_opt
        | '(' type_name ')'                 type_qualifier_list_opt
        | '(' type_name initializer ')'     type_qualifier_list_opt /* C++,
not ANSI C */
        | '(' named_parameter_type_list ')' type_qualifier_list_opt
        ;

    /* The following are used in old style function definitions, when
    a complex return type includes the "function returning" modifier.
    Note  the  subtle  distinction  from  parameter_type_list.  These
    parameters are NOT the parameters for the function being defined,
    but are simply part of the type definition.  An example would be:

        int(*f(   a  ))(float) long a; {...}

    which is equivalent to the full new style definition:

        int(*f(long a))(float) {...}

    The   type   list    `(float)'    is    an    example    of    an
    old_parameter_type_list.   The  bizarre point here is that an old
    function definition declarator can be followed by  a  type  list,
    which  can  start  with a qualifier `const'.  This conflicts with
    the new syntactic construct for const member  functions!?!  As  a
    result,  an  old  style function definition cannot be used in all
    cases for a member function.  */

old_parameter_type_list:
        '(' ')'
        | '(' type_name ')'
        | '(' type_name initializer ')'  /* C++, not ANSI C */
        | '(' named_parameter_type_list ')'
        ;

named_parameter_type_list:  /* WARNING: excludes lone type_name*/
        parameter_list
        | parameter_list comma_opt_ellipsis
        | type_name comma_opt_ellipsis
        | type_name initializer comma_opt_ellipsis  /* C++, not ANSI C */
        | ELLIPSIS /* C++, not ANSI C */
        ;

comma_opt_ellipsis:
        ELLIPSIS       /* C++, not ANSI C */
        | ',' ELLIPSIS
        ;

parameter_list:
        non_casting_parameter_declaration
        | non_casting_parameter_declaration initializer /* C++, not ANSI C */
        | type_name             ',' parameter_declaration
        | type_name initializer ',' parameter_declaration  /* C++, not ANSI C */
        | parameter_list        ',' parameter_declaration
        ;

    /* There is some very subtle disambiguation going  on  here.   Do
    not be tempted to make further use of the following production in
    parameter_list,  or else the conflict count will grow noticeably.
    Specifically, the next set  of  rules  has  already  been  inline
    expanded for the first parameter in a parameter_list to support a
    deferred disambiguation. The subtle disambiguation has to do with
    contexts where parameter type lists look like old-style-casts. */

parameter_declaration:
        type_name
        | type_name                         initializer  /* C++, not ANSI C */
        | non_casting_parameter_declaration
        | non_casting_parameter_declaration initializer /* C++, not ANSI C */
        ;

    /* There is an LR ambiguity between old-style parenthesized casts
    and parameter-type-lists.  This tends to happen in contexts where
    either  an  expression or a parameter-type-list is possible.  For
    example, assume that T is an  externally  declared  type  in  the
    code:

           int (T ((int

    it might continue:

           int (T ((int)0));

    which would make it:

           (int) (T) (int)0 ;

    which  is  an  expression,  consisting  of  a  series  of  casts.
    Alternatively, it could be:

           int (T ((int a)));

    which would make it the redeclaration of T, equivalent to:

           int T (dummy_name (int a));

    if we see a type that either has a named variable (in  the  above
    case "a"), or a storage class like:

           int (T ((int register

    then  we  know  it  can't  be  a cast, and it is "forced" to be a
    parameter_list.

    It is not yet clear that the ANSI C++ committee would  decide  to
    place this disambiguation into the syntax, rather than leaving it
    as  a  constraint check (i.e., a valid parser would have to parse
    everything as though it were  a  parameter  list  (in  these  odd
    contexts),  and  then  give an error if is to a following context
    (like "0" above) that invalidated this syntax evaluation. */

    /* One big thing implemented here is that a TYPEDEFname CANNOT be
    redeclared when we don't have declaration_specifiers! Notice that
    when we do use a TYPEDEFname based declarator, only the "special"
    (non-ambiguous  in  this  context)  typedef_declarator  is  used.
    Everything else that is "missing" shows up as a type_name. */

non_casting_parameter_declaration: /*have names or storage classes */
        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 identifier_declarator
        | type_specifier parameter_typedef_declarator

        | basic_type_name identifier_declarator
        | basic_type_name parameter_typedef_declarator

        | TYPEDEFname                   identifier_declarator
        | TYPEDEFname                   parameter_typedef_declarator

        | global_or_scoped_typedefname  identifier_declarator
        | global_or_scoped_typedefname  parameter_typedef_declarator

        | type_qualifier_list identifier_declarator
        ;

type_name:
        type_specifier
        | basic_type_name
        | TYPEDEFname
        | global_or_scoped_typedefname
        | type_qualifier_list

        | type_specifier               abstract_declarator
        | basic_type_name              abstract_declarator
        | TYPEDEFname                  abstract_declarator
        | global_or_scoped_typedefname abstract_declarator
        | type_qualifier_list          abstract_declarator
        ;

initializer_opt:
        /* nothing */
        | initializer
        ;

initializer:
        '=' initializer_group
        ;

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

initializer_list:
        initializer_group
        | initializer_list ',' initializer_group
        ;

/*************************** STATEMENTS *******************************/

statement:
        labeled_statement
        | compound_statement
        | expression_statement
        | selection_statement
        | iteration_statement
        | jump_statement
        | declaration /* C++, not ANSI C */
        ;

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

    /*  I sneak declarations into statement_list to support C++.  The
    grammar is a little clumsy this  way,  but  the  violation  of  C
    syntax is heavily localized */

compound_statement:
        '{' statement_list_opt '}'
        ;

declaration_list:
        declaration
        | declaration_list declaration
        ;

statement_list_opt:
        /* nothing */
        | statement_list_opt 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_opt ')' statement
        | DO statement WHILE '(' comma_expression ')' ';'

        | FOR '(' comma_expression_opt ';' comma_expression_opt ';'
                comma_expression_opt ')' statement

        | FOR '(' declaration        comma_expression_opt ';'
                comma_expression_opt ')' statement  /* C++, not ANSI C */
        ;

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

    /*  The  following  actions should update the symbol table in the
    "label" name space */

label:
        IDENTIFIER
        | TYPEDEFname
        ;

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

translation_unit:
        /* nothing */
        | translation_unit external_definition
        ;

external_definition:
        function_declaration                         /* C++, not ANSI C*/
        | function_definition
        | declaration
        | linkage_specifier function_declaration     /* C++, not ANSI C*/
        | linkage_specifier function_definition      /* C++, not ANSI C*/
        | linkage_specifier declaration              /* C++, not ANSI C*/
        | linkage_specifier '{' translation_unit '}' /* C++, not ANSI C*/
        ;

linkage_specifier:
        EXTERN STRINGliteral
        ;

    /* Note that declaration_specifiers are left out of the following
    function declarations.  Such omission is illegal in ANSI C. It is
    sometimes necessary in C++, in instances  where  no  return  type
    should be specified (e_g., a conversion operator).*/

function_declaration:
        identifier_declarator ';'   /*  semantically  verify  it is a
                                    function, and (if ANSI says  it's
                                    the  law for C++ also...) that it
                                    is something that  can't  have  a
                                    return  type  (like  a conversion
                                    function, or a destructor */

        | constructor_function_declaration ';'
        ;

function_definition:
        new_function_definition
        | old_function_definition
        | constructor_function_definition
        ;

    /* Note that in ANSI C, function definitions *ONLY* are presented
    at file scope.  Hence, if there is a typedefname  active,  it  is
    illegal  to  redeclare  it  (there  is no enclosing scope at file
    scope).

    In  contrast,  C++  allows   function   definitions   at   struct
    elaboration scope, and allows tags that are defined at file scope
    (and  hence  look like typedefnames) to be redeclared to function
    calls.  Hence several of the rules are "partially C++  only".   I
    could  actually  build separate rules for typedef_declarators and
    identifier_declarators, and mention that  the  typedef_declarator
    rules represent the C++ only features.

    In  some  sense,  this  is  haggling, as I could/should have left
    these as constraints in the ANSI C grammar, rather than as syntax
    requirements.  */

new_function_definition:
                                       identifier_declarator compound_statement
        | declaration_specifier                   declarator
compound_statement /* partially C++ only */
        | type_specifier                          declarator
compound_statement /* partially C++ only */
        | basic_type_name                         declarator
compound_statement /* partially C++ only */
        | TYPEDEFname                             declarator
compound_statement /* partially C++ only */
        | global_or_scoped_typedefname            declarator
compound_statement /* partially C++ only */
        | declaration_qualifier_list   identifier_declarator compound_statement
        | type_qualifier_list          identifier_declarator compound_statement
        ;

    /* Note that I do not support redeclaration of TYPEDEFnames  into
    function  names  as I did in new_function_definitions (see note).
    Perhaps I should do it, but for now, ignore the issue. Note  that
    this  is  a  non-problem  with  ANSI  C,  as  tag  names  are not
    considered TYPEDEFnames. */

old_function_definition:
                                       old_function_declarator {}
old_function_body
        | declaration_specifier        old_function_declarator {}
old_function_body
        | type_specifier               old_function_declarator {}
old_function_body
        | basic_type_name              old_function_declarator {}
old_function_body
        | TYPEDEFname                  old_function_declarator {}
old_function_body
        | global_or_scoped_typedefname old_function_declarator {}
old_function_body
        | declaration_qualifier_list   old_function_declarator {}
old_function_body
        | type_qualifier_list          old_function_declarator {}
old_function_body
        ;

old_function_body:
        declaration_list compound_statement
        | compound_statement
        ;

    /*    Verify    via    constraints     that     the     following
        declaration_specifier           is          really          a
        typedef_declaration_specifier, consisting of:

        ... TYPEDEFname :: TYPEDEFname

    optionally *preceded* by a "inline" keyword.   Use  care  not  to
    support "inline" as a postfix!

    Similarly, the global_or_scoped_typedefname must be:

        ... TYPEDEFname :: TYPEDEFname

    with matching names at the end of the list.

    We  use the more general form to prevent a syntax conflict with a
    typical    function    definition    (which    won't    have    a
    constructor_init_list) */

constructor_function_definition:
        global_or_scoped_typedefname parameter_type_list
                     constructor_init_list_opt compound_statement

        | declaration_specifier      parameter_type_list
                     constructor_init_list_opt compound_statement
        ;

    /*  Same  comments  as  seen  for constructor_function_definition
    apply here */

constructor_function_declaration:
        global_or_scoped_typedefname parameter_type_list  /* wasteful
redeclaration; used for friend decls.  */

        | declaration_specifier      parameter_type_list  /* request to
inline, no definition */
        ;

    /* The following use of declaration_specifiers are made to  allow
    for  a TYPEDEFname preceded by an INLINE modifier. This fact must
    be verified semantically.  It should also be  verified  that  the
    TYPEDEFname  is  ACTUALLY  the  class name being elaborated. Note
    that we could break out typedef_declaration_specifier from within
    declaration_specifier, and we  might  narrow  down  the  conflict
    region a bit. A second alternative (to what is done) for cleaning
    up  this  stuff  is  to  let the tokenizer specially identify the
    current class being elaborated as a special token, and not just a
    typedefname. Unfortunately, things would get very  confusing  for
    the  lexer,  as  we may pop into enclosed tag elaboration scopes;
    into function definitions; or into both recursively! */

    /* I should make the following  rules  easier  to  annotate  with
    scope  entry  and exit actions.  Note how hard it is to establish
    the scope when you don't even know what the decl_spec is!! It can
    be done with $-1 hacking, but I should not encourage users to  do
    this directly. */

constructor_function_in_class:
        declaration_specifier   constructor_parameter_list_and_body
        | TYPEDEFname           constructor_parameter_list_and_body
        ;

    /* The following conflicts with member declarations-
    constructor_parameter_list_and_body:
          parameter_type_list ';'
          | parameter_type_list constructor_init_list_opt compound_statement
          ;
    so parameter_type_list was expanded inline to get */

    /* C++, not ANSI C */
constructor_parameter_list_and_body:
          '('                           ')' type_qualifier_list_opt ';'
        | '(' type_name initializer     ')' type_qualifier_list_opt ';'
        | '(' named_parameter_type_list ')' type_qualifier_list_opt ';'
        | '('                           ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement
        | '(' type_name initializer     ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement
        | '(' named_parameter_type_list ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | constructor_conflicting_parameter_list_and_body
        ;

    /* The following conflicted with member declaration-
    constructor_conflicting_parameter_list_and_body:
        '('   type_name ')'                 type_qualifier_list_opt ';'
        | '(' type_name ')'                 type_qualifier_list_opt
                constructor_init_list_opt compound_statement
        ;
    so type_name was inline expanded to get the following... */

    /*  Note  that by inline expanding type_qualifier_opt in a few of
    the following rules I can transform 3  RR  conflicts  into  3  SR
    conflicts.  Since  all the conflicts have a look ahead of ';', it
    doesn't  really  matter  (also,  there  are  no   bad   LALR-only
    components in the conflicts) */

constructor_conflicting_parameter_list_and_body:
        '(' type_specifier                 ')' type_qualifier_list_opt
                ';'
        | '(' basic_type_name              ')' type_qualifier_list_opt
                ';'

        | '(' TYPEDEFname                  ')' type_qualifier_list_opt
                ';'

        | '(' global_or_scoped_typedefname ')' type_qualifier_list_opt
                ';'

        | '(' type_qualifier_list          ')' type_qualifier_list_opt
                ';'

        | '(' type_specifier               abstract_declarator ')'
type_qualifier_list_opt
                ';'
        | '(' basic_type_name              abstract_declarator ')'
type_qualifier_list_opt
                ';'

        /* missing entry posted below */

        | '(' global_or_scoped_typedefname abstract_declarator ')'
type_qualifier_list_opt
                ';'
        | '(' type_qualifier_list          abstract_declarator ')'
type_qualifier_list_opt
                ';'

        | '(' type_specifier               ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' basic_type_name              ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' TYPEDEFname                  ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' global_or_scoped_typedefname ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' type_qualifier_list           ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' type_specifier  abstract_declarator ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' basic_type_name abstract_declarator ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        /* missing entry posted below */

        | '(' global_or_scoped_typedefname abstract_declarator ')'
type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' type_qualifier_list          abstract_declarator ')'
type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | constructor_conflicting_typedef_declarator
        ;

    /* The following have ambiguities with member declarations-
    constructor_conflicting_typedef_declarator:
      '(' TYPEDEFname abstract_declarator ')' type_qualifier_list_opt
                ';'
      |  '(' TYPEDEFname abstract_declarator ')' type_qualifier_list_opt
                constructor_init_list_opt compound_statement
      ;
    which can be deferred by expanding abstract_declarator, and in two
    cases parameter_qualifier_list, resulting in ...*/

constructor_conflicting_typedef_declarator:
        '(' TYPEDEFname unary_abstract_declarator          ')'
type_qualifier_list_opt
                ';'

        | '(' TYPEDEFname unary_abstract_declarator       ')'
type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' TYPEDEFname postfix_abstract_declarator     ')'
type_qualifier_list_opt
                ';'

        | '(' TYPEDEFname postfix_abstract_declarator     ')'
type_qualifier_list_opt
                constructor_init_list_opt compound_statement

        | '(' TYPEDEFname postfixing_abstract_declarator  ')'
type_qualifier_list_opt
                ';'

        | '(' TYPEDEFname postfixing_abstract_declarator  ')'
type_qualifier_list_opt
                constructor_init_list_opt compound_statement
        ;

constructor_init_list_opt:
        /* nothing */
        | constructor_init_list
        ;

constructor_init_list:
        ':' constructor_init
        | constructor_init_list ',' constructor_init
        ;

constructor_init:
        IDENTIFIER   '(' argument_expression_list ')'
        | IDENTIFIER '('                          ')'

        | TYPEDEFname '(' argument_expression_list ')'
        | TYPEDEFname '('                          ')'
        | global_or_scoped_typedefname '(' argument_expression_list ')'
        | global_or_scoped_typedefname '('                          ')'

        | '(' argument_expression_list ')' /* Single inheritance ONLY*/
        | '(' ')' /* Is this legal? It might be default! */
        ;

declarator:
        identifier_declarator
        | typedef_declarator
        ;

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

parameter_typedef_declarator:
        TYPEDEFname
        | TYPEDEFname postfixing_abstract_declarator
        | clean_typedef_declarator
        ;

    /*  The  following  have  at  least  one  '*'or '&'.  There is no
    (redundant) '(' between the '*'/'&'  and  the  TYPEDEFname.  This
    definition  is  critical  in  that  a redundant paren that it too
    close to the TYPEDEFname (i.e.,  nothing  between  them  at  all)
    would  make  the TYPEDEFname into a parameter list, rather than a
    declarator.*/

clean_typedef_declarator:
        clean_postfix_typedef_declarator
        | asterisk_or_ampersand parameter_typedef_declarator
        | unary_modifier        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.  This opens up the possibility that the
    TYPEDEFname is really the start of a parameter list, and *not*  a
    declarator*/

paren_typedef_declarator:
        postfix_paren_typedef_declarator
        | asterisk_or_ampersand '(' simple_paren_typedef_declarator ')'
        | unary_modifier        '(' simple_paren_typedef_declarator ')'
        | asterisk_or_ampersand '(' TYPEDEFname ')' /* redundant paren */
        | unary_modifier        '(' TYPEDEFname ')' /* redundant paren */
        | asterisk_or_ampersand paren_typedef_declarator
        | unary_modifier        paren_typedef_declarator
        ;

postfix_paren_typedef_declarator:
        '(' paren_typedef_declarator ')'
        | '(' simple_paren_typedef_declarator postfixing_abstract_declarator ')'
        | '(' TYPEDEFname postfixing_abstract_declarator ')'              /*
redundant paren */
        | '(' paren_typedef_declarator ')' postfixing_abstract_declarator
        ;

    /*  The following excludes lone TYPEDEFname to help in a conflict
    resolution.  We have special cased lone  TYPEDEFname  along  side
    all uses of simple_paren_typedef_declarator */

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

identifier_declarator:
        unary_identifier_declarator
        | paren_identifier_declarator
        ;

    /*  The  following  allows  "function return array of" as well as
    "array of function returning".  It COULD be cleaned  up  the  way
    abstract  declarators  have been.  This change might make it hard
    to recover from user's syntax errors, whereas now they appear  as
    simple constraint errors. */

unary_identifier_declarator:
        postfix_identifier_declarator
        | asterisk_or_ampersand identifier_declarator
        | unary_modifier        identifier_declarator
        ;

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

old_function_declarator:
        postfix_old_function_declarator
        | asterisk_or_ampersand old_function_declarator
        | unary_modifier      old_function_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.

    Instead  of identifier_lists, an argument_expression_list is used
    in  old  style  function   definitions.    The   ambiguity   with
    constructors   required   the  use  of  argument  lists,  with  a
    constraint verification of the list (e_g.: check to see that  the
    "expressions" consisted of lone identifiers).

    An interesting ambiguity appeared:
        const constant=5;
        int foo(constant) ...

    Is  this an old function definition or constructor?  The decision
    is made later by THIS grammar based on trailing context :-). This
    ambiguity is probably what caused many parsers to give up on  old
    style function definitions. */

postfix_old_function_declarator:
        paren_identifier_declarator '(' argument_expression_list ')'
        | '(' old_function_declarator ')'
        | '(' old_function_declarator ')' old_postfixing_abstract_declarator
        ;

old_postfixing_abstract_declarator:
        array_abstract_declarator /* array modifiers */
        | old_parameter_type_list  /* function returning modifiers */
        ;

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:
        asterisk_or_ampersand
        | unary_modifier
        | asterisk_or_ampersand abstract_declarator
        | unary_modifier        abstract_declarator
        ;

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

asterisk_or_ampersand:
        '*'
        | '&'
        ;

unary_modifier:
        scope '*' type_qualifier_list_opt
        | asterisk_or_ampersand type_qualifier_list
        ;

/************************* NESTED SCOPE SUPPORT ******************************/

    /*  The  actions taken in the rules that follow involve notifying
    the lexer that it should use the scope specified to determine  if
    the  next  IDENTIFIER  token is really a TYPEDEFname token.  Note
    that the actions must be taken before the parse has a  chance  to
    "look-ahead" at the token that follows the "::", and hence should
    be  done  during  a  reduction to "scoping_name" (which is always
    followed by CLCL).  Since we are defining an  LR(1)  grammar,  we
    are  assured  that  an action specified *before* the :: will take
    place before the :: is shifted, and hence before the  token  that
    follows the CLCL is scanned/lexed. */

    /*  Note that at the end of each of the following rules we should
    be sure that the tag name is  in,  or  placed  in  the  indicated
    scope.   If  no  scope  is  specified, then we must add it to our
    current scope IFF it cannot  be  found  in  an  external  lexical
    scope. */

scoping_name:
        tag_name
        | aggregate_key tag_name /* also update symbol table here by
notifying it about a (possibly) new tag*/
        ;

scope:
        scoping_name CLCL
        | scope scoping_name  CLCL
        ;

    /*  Don't try to simplify the count of non-terminals by using one
    of the other definitions of  "IDENTIFIER  or  TYPEDEFname"  (like
    "label").   If you reuse such a non-terminal, 2 RR conflicts will
    appear. The conflicts are LALR-only. The underlying cause of  the
    LALR-only   conflict   is  that  labels,  are  followed  by  ':'.
    Similarly, structure elaborations which provide a derivation have
    have ':' just  after  tag_name  This  reuse,  with  common  right
    context, is too much for an LALR parser. */

tag_name:
        IDENTIFIER
        | TYPEDEFname
        ;

global_scope:
        { /*scan for upcoming name in file scope */ } CLCL
        ;

global_or_scope:
        global_scope
        | scope
        | global_scope scope
        ;

    /*  The  following can be used in an identifier based declarator.
    (Declarators  that  redefine  an  existing  TYPEDEFname   require
    special  handling,  and are not included here).  In addition, the
    following are valid "identifiers" in  an  expression,  whereas  a
    TYPEDEFname is NOT.*/

scope_opt_identifier:
                IDENTIFIER
        | scope IDENTIFIER  /* C++ not ANSI C */
        ;

scope_opt_complex_name:
                complex_name
        | scope complex_name
        ;

complex_name:
        '~' TYPEDEFname
        | operator_function_name
        ;

    /*  Note that the derivations for global_opt_scope_opt_identifier
    and global_opt_scope_opt_complex_name must be  placed  after  the
    derivation:

       paren_identifier_declarator : scope_opt_identifier

    There  are several states with RR conflicts on "(", ")", and "[".
    In these states we give up and assume a declaration, which  means
    resolving   in  favor  of  paren_identifier_declarator.  This  is
    basically the "If it can be  a  declaration  rule...",  with  our
    finite cut off. */

global_opt_scope_opt_identifier:
        global_scope scope_opt_identifier
        |            scope_opt_identifier
        ;

global_opt_scope_opt_complex_name:
        global_scope scope_opt_complex_name
        |            scope_opt_complex_name
        ;

    /*  Note  that we exclude a lone TYPEDEFname.  When all alone, it
    gets involved in a lot of ambiguities (re: function like cast  vs
    declaration),   and  hence  must  be  special  cased  in  several
    contexts. Note that generally every use of scoped_typedefname  is
    accompanied by a parallel production using lone TYPEDEFname */

scoped_typedefname:
        scope TYPEDEFname
        ;

global_or_scoped_typedefname:
                       scoped_typedefname
        | global_scope scoped_typedefname
        | global_scope TYPEDEFname
        ;

global_opt_scope_opt_typedefname:
        TYPEDEFname
        | global_or_scoped_typedefname
        ;

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

main()
{
    yyparse();
}

Published on Jul 11, 2007 in categories

上一篇编译原理之（1）c的lex词法文件和yacc语法文件.
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