/*
   Changes by Gunnar Ritter, Freiburg i. Br., Germany, December 2002.
  
   Sccsid @(#)awk.g.y	1.9 (gritter) 5/14/06>
 */
/* UNIX(R) Regular Expression Tools

   Copyright (C) 2001 Caldera International, Inc.
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to:
       Free Software Foundation, Inc.
       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/*		copyright	"%c%" 	*/

/*	from RCS Header: awk.g.y 1.2 91/06/25 	*/

%{
#include "awk.h"
#include <unistd.h>
#include <stdint.h>
#include <pfmt.h>
int yywrap(void) { return(1); }
#ifndef	DEBUG
#	define	PUTS(x)
#endif
Node	*beginloc = 0, *endloc = 0;
int	infunc	= 0;	/* = 1 if in arglist or body of func */
unsigned char	*curfname = 0;
Node	*arglist = 0;	/* list of args for current function */
static void setfname(Cell *);
static int constnode(Node *);
static unsigned char *strnode(Node *);
static Node *notnull(Node *);
extern	const char illstat[];

extern int	yylex(void);
%}

%union {
	Node	*p;
	Cell	*cp;
	intptr_t	i;
	unsigned char	*s;
}

%token	<i>	FIRSTTOKEN	/* must be first */
%token	<p>	PROGRAM PASTAT PASTAT2 XBEGIN XEND
%token	<i>	NL ',' '{' '(' '|' ';' '/' ')' '}' '[' ']'
%token	<i>	ARRAY
%token	<i>	MATCH NOTMATCH MATCHOP
%token	<i>	FINAL DOT ALL CCL NCCL CHAR MCHAR OR STAR QUEST PLUS
%token	<i>	AND BOR APPEND EQ GE GT LE LT NE IN
%token	<i>	ARG BLTIN BREAK CONTINUE DELETE DO EXIT FOR FUNC 
%token	<i>	SUB GSUB IF INDEX LSUBSTR MATCHFCN NEXT
%token	<i>	ADD MINUS MULT DIVIDE MOD
%token	<i>	ASSIGN ASGNOP ADDEQ SUBEQ MULTEQ DIVEQ MODEQ POWEQ
%token	<i>	PRINT PRINTF SPRINTF
%token	<p>	ELSE INTEST CONDEXPR
%token	<i>	POSTINCR PREINCR POSTDECR PREDECR
%token	<cp>	VAR IVAR VARNF CALL NUMBER STRING FIELD
%token	<s>	REGEXPR

%type	<p>	pas pattern ppattern plist pplist patlist prarg term re
%type	<p>	pa_pat pa_stat pa_stats
%type	<s>	reg_expr
%type	<p>	simple_stmt opt_simple_stmt stmt stmtlist
%type	<p>	var varname funcname varlist
%type	<p>	for if while
%type	<i>	pst opt_pst lbrace rparen comma nl opt_nl and bor
%type	<i>	subop print

%right	ASGNOP
%right	'?'
%right	':'
%left	BOR
%left	AND
%left	GETLINE
%nonassoc APPEND EQ GE GT LE LT NE MATCHOP IN '|'
%left	ARG BLTIN BREAK CALL CONTINUE DELETE DO EXIT FOR FIELD FUNC 
%left	GSUB IF INDEX LSUBSTR MATCHFCN NEXT NUMBER
%left	PRINT PRINTF RETURN SPLIT SPRINTF STRING SUB SUBSTR
%left	REGEXPR VAR VARNF IVAR WHILE '('
%left	CAT
%left	'+' '-'
%left	'*' '/' '%'
%left	NOT UMINUS
%right	POWER
%right	DECR INCR
%left	INDIRECT
%token	LASTTOKEN	/* must be last */

%%

program:
	  pas	{ if (errorflag==0)
			winner = (Node *)stat3(PROGRAM, beginloc, $1, endloc); }
	| error	{ yyclearin; bracecheck(); vyyerror(":95:Bailing out"); }
	;

and:
	  AND | and NL
	;

bor:
	  BOR | bor NL
	;

comma:
	  ',' | comma NL
	;

do:
	  DO { } | do NL
	;

else:
	  ELSE { } | else NL
	;

for:
	  FOR '(' opt_simple_stmt ';' pattern ';' opt_simple_stmt rparen stmt
		{ $$ = stat4(FOR, $3, notnull($5), $7, $9); }
	| FOR '(' opt_simple_stmt ';'  ';' opt_simple_stmt rparen stmt
		{ $$ = stat4(FOR, $3, NIL, $6, $8); }
	| FOR '(' varname IN varname rparen stmt
		{ $$ = stat3(IN, $3, makearr($5), $7); }
	;

funcname:
	  VAR	{ setfname($1); }
	| CALL	{ setfname($1); }
	;

if:
	  IF '(' pattern rparen		{ $$ = notnull($3); }
	;

lbrace:
	  '{' | lbrace NL
	;

nl:
	  NL | nl NL
	;

opt_nl:
	  /* empty */	{ $$ = 0; }
	| nl
	;

opt_pst:
	  /* empty */	{ $$ = 0; }
	| pst
	;


opt_simple_stmt:
	  /* empty */			{ $$ = 0; }
	| simple_stmt
	;

pas:
	  opt_pst			{ $$ = 0; }
	| opt_pst pa_stats opt_pst	{ $$ = $2; }
	;

pa_pat:
	  pattern	{ $$ = notnull($1); }
	;

pa_stat:
	  pa_pat			{ $$ = stat2(PASTAT, $1, stat2(PRINT, rectonode(), NIL)); }
	| pa_pat lbrace stmtlist '}'	{ $$ = stat2(PASTAT, $1, $3); }
	| pa_pat ',' pa_pat		{ $$ = pa2stat($1, $3, stat2(PRINT, rectonode(), NIL)); }
	| pa_pat ',' pa_pat lbrace stmtlist '}'	{ $$ = pa2stat($1, $3, $5); }
	| lbrace stmtlist '}'		{ $$ = stat2(PASTAT, NIL, $2); }
	| XBEGIN lbrace stmtlist '}'
		{ beginloc = linkum(beginloc, $3); $$ = 0; }
	| XEND lbrace stmtlist '}'
		{ endloc = linkum(endloc, $3); $$ = 0; }
	| FUNC funcname '(' varlist rparen {infunc++;} lbrace stmtlist '}'
		{ infunc--; curfname=0; defn((Cell *)$2, $4, $8); $$ = 0; }
	;

pa_stats:
	  pa_stat
	| pa_stats opt_pst pa_stat	{ $$ = linkum($1, $3); }
	;

patlist:
	  pattern
	| patlist comma pattern	{ $$ = linkum($1, $3); }
	;

ppattern:
	  var ASGNOP ppattern		{ $$ = op2($2, $1, $3); }
	| ppattern '?' ppattern ':' ppattern %prec '?'
	 	{ $$ = op3(CONDEXPR, notnull($1), $3, $5); }
	| ppattern bor ppattern %prec BOR
		{ $$ = op2(BOR, notnull($1), notnull($3)); }
	| ppattern and ppattern %prec AND
		{ $$ = op2(AND, notnull($1), notnull($3)); }
	| ppattern MATCHOP reg_expr	{ $$ = op3($2, NIL, $1, (Node*)makedfa($3, 0)); }
	| ppattern MATCHOP ppattern
		{ if (constnode($3))
			$$ = op3($2, NIL, $1, (Node*)makedfa(strnode($3), 0));
		  else
			$$ = op3($2, (Node *)1, $1, $3); }
	| ppattern IN varname		{ $$ = op2(INTEST, $1, makearr($3)); }
	| '(' plist ')' IN varname	{ $$ = op2(INTEST, $2, makearr($5)); }
	| ppattern term %prec CAT	{ $$ = op2(CAT, $1, $2); }
	| re
	| term
	;

pattern:
	  var ASGNOP pattern		{ $$ = op2($2, $1, $3); }
	| pattern '?' pattern ':' pattern %prec '?'
	 	{ $$ = op3(CONDEXPR, notnull($1), $3, $5); }
	| pattern bor pattern %prec BOR
		{ $$ = op2(BOR, notnull($1), notnull($3)); }
	| pattern and pattern %prec AND
		{ $$ = op2(AND, notnull($1), notnull($3)); }
	| NOT pattern
		{ $$ = op1(NOT, op2(NE,$2,valtonode(lookup("$zero&null",symtab),CCON))); }
	| pattern EQ pattern		{ $$ = op2($2, $1, $3); }
	| pattern GE pattern		{ $$ = op2($2, $1, $3); }
	| pattern GT pattern		{ $$ = op2($2, $1, $3); }
	| pattern LE pattern		{ $$ = op2($2, $1, $3); }
	| pattern LT pattern		{ $$ = op2($2, $1, $3); }
	| pattern NE pattern		{ $$ = op2($2, $1, $3); }
	| pattern MATCHOP reg_expr	{ $$ = op3($2, NIL, $1, (Node*)makedfa($3, 0)); }
	| pattern MATCHOP pattern
		{ if (constnode($3))
			$$ = op3($2, NIL, $1, (Node*)makedfa(strnode($3), 0));
		  else
			$$ = op3($2, (Node *)1, $1, $3); }
	| pattern IN varname		{ $$ = op2(INTEST, $1, makearr($3)); }
	| '(' plist ')' IN varname	{ $$ = op2(INTEST, $2, makearr($5)); }
	| pattern '|' GETLINE var	{ $$ = op3(GETLINE, $4, (Node*)$2, $1); }
	| pattern '|' GETLINE		{ $$ = op3(GETLINE, (Node*)0, (Node*)$2, $1); }
	| pattern term %prec CAT	{ $$ = op2(CAT, $1, $2); }
	| re
	| term
	;

plist:
	  pattern comma pattern		{ $$ = linkum($1, $3); }
	| plist comma pattern		{ $$ = linkum($1, $3); }
	;

pplist:
	  ppattern
	| pplist comma ppattern		{ $$ = linkum($1, $3); }
	;

prarg:
	  /* empty */			{ $$ = rectonode(); }
	| pplist
	| '(' plist ')'			{ $$ = $2; }
	;

print:
	  PRINT | PRINTF
	;

pst:
	  NL | ';' | pst NL | pst ';'
	;

rbrace:
	  '}' { } | rbrace NL
	;

re:
	 reg_expr
		{ $$ = op3(MATCH, NIL, rectonode(), (Node*)makedfa($1,0)); }
	| NOT re	{$$ = op1(NOT, notnull($2)); }
	;

reg_expr:
	  '/' {startreg();} REGEXPR '/'		{ $$ = $3; }
	;

rparen:
	  ')' | rparen NL
	;

simple_stmt:
	  print prarg '|' term		{ $$ = stat3($1, $2, (Node *) $3, $4); }
	| print prarg APPEND term	{ $$ = stat3($1, $2, (Node *) $3, $4); }
	| print prarg GT term		{ $$ = stat3($1, $2, (Node *) $3, $4); }
	| print prarg			{ $$ = stat3($1, $2, NIL, NIL); }
	| DELETE varname '[' patlist ']' { $$ = stat2(DELETE, makearr($2), $4); }
	| DELETE varname		{ yyclearin; vyyerror(":96:You can only delete array[element]"); $$ = stat1(DELETE, $2); }
	| pattern			{ $$ = exptostat($1); }
	| error				{ yyclearin; vyyerror(illstat); }
	;

st:
	  nl { } | ';' opt_nl { }
	;

stmt:
	  BREAK st		{ $$ = stat1(BREAK, NIL); }
	| CONTINUE st		{ $$ = stat1(CONTINUE, NIL); }
	| do stmt WHILE '(' pattern ')' st
		{ $$ = stat2(DO, $2, notnull($5)); }
	| EXIT pattern st	{ $$ = stat1(EXIT, $2); }
	| EXIT st		{ $$ = stat1(EXIT, NIL); }
	| for
	| if stmt else stmt	{ $$ = stat3(IF, $1, $2, $4); }
	| if stmt		{ $$ = stat3(IF, $1, $2, NIL); }
	| lbrace stmtlist rbrace { $$ = $2; }
	| NEXT st	{ if (infunc)
				vyyerror(":97:Next is illegal inside a function");
			  $$ = stat1(NEXT, NIL); }
	| RETURN pattern st	{ $$ = stat1(RETURN, $2); }
	| RETURN st		{ $$ = stat1(RETURN, NIL); }
	| simple_stmt st
	| while stmt		{ $$ = stat2(WHILE, $1, $2); }
	| ';' opt_nl		{ $$ = 0; }
	;

stmtlist:
	  stmt
	| stmtlist stmt		{ $$ = linkum($1, $2); }
	;

subop:
	  SUB | GSUB
	;

term:
	  term '+' term			{ $$ = op2(ADD, $1, $3); }
	| term '-' term			{ $$ = op2(MINUS, $1, $3); }
	| term '*' term			{ $$ = op2(MULT, $1, $3); }
	| term '/' term			{ $$ = op2(DIVIDE, $1, $3); }
	| term '%' term			{ $$ = op2(MOD, $1, $3); }
	| term POWER term		{ $$ = op2(POWER, $1, $3); }
	| '-' term %prec UMINUS		{ $$ = op1(UMINUS, $2); }
	| '+' term %prec UMINUS		{ $$ = $2; }
	| NOT term %prec UMINUS		{ $$ = op1(NOT, notnull($2)); }
	| BLTIN '(' ')'			{ $$ = op2(BLTIN, (Node *) $1, rectonode()); }
	| BLTIN '(' patlist ')'		{ $$ = op2(BLTIN, (Node *) $1, $3); }
	| BLTIN				{ $$ = op2(BLTIN, (Node *) $1, rectonode()); }
	| CALL '(' ')'			{ $$ = op2(CALL, valtonode($1,CVAR), NIL); }
	| CALL '(' patlist ')'		{ $$ = op2(CALL, valtonode($1,CVAR), $3); }
	| DECR var			{ $$ = op1(PREDECR, $2); }
	| INCR var			{ $$ = op1(PREINCR, $2); }
	| var DECR			{ $$ = op1(POSTDECR, $1); }
	| var INCR			{ $$ = op1(POSTINCR, $1); }
	| GETLINE var LT term		{ $$ = op3(GETLINE, $2, (Node *)$3, $4); }
	| GETLINE LT term		{ $$ = op3(GETLINE, NIL, (Node *)$2, $3); }
	| GETLINE var			{ $$ = op3(GETLINE, $2, NIL, NIL); }
	| GETLINE			{ $$ = op3(GETLINE, NIL, NIL, NIL); }
	| INDEX '(' pattern comma pattern ')'
		{ $$ = op2(INDEX, $3, $5); }
	| INDEX '(' pattern comma reg_expr ')'
		{ vyyerror(":98:Index() doesn't permit regular expressions");
		  $$ = op2(INDEX, $3, (Node*)$5); }
	| '(' pattern ')'		{ $$ = $2; }
	| MATCHFCN '(' pattern comma reg_expr ')'
		{ $$ = op3(MATCHFCN, NIL, $3, (Node*)makedfa($5, 1)); }
	| MATCHFCN '(' pattern comma pattern ')'
		{ if (constnode($5))
			$$ = op3(MATCHFCN, NIL, $3, (Node*)makedfa(strnode($5), 1));
		  else
			$$ = op3(MATCHFCN, (Node *)1, $3, $5); }
	| NUMBER			{ $$ = valtonode($1, CCON); }
	| SPLIT '(' pattern comma varname comma pattern ')'     /* string */
		{ $$ = op4(SPLIT, $3, makearr($5), $7, (Node*)STRING); }
	| SPLIT '(' pattern comma varname comma reg_expr ')'    /* const /regexp/ */
		{ $$ = op4(SPLIT, $3, makearr($5), (Node*)makedfa($7, 1), (Node *)REGEXPR); }
	| SPLIT '(' pattern comma varname ')'
		{ $$ = op4(SPLIT, $3, makearr($5), NIL, (Node*)STRING); }  /* default */
	| SPRINTF '(' patlist ')'	{ $$ = op1($1, $3); }
	| STRING	 		{ $$ = valtonode($1, CCON); }
	| subop '(' reg_expr comma pattern ')'
		{ $$ = op4($1, NIL, (Node*)makedfa($3, 1), $5, rectonode()); }
	| subop '(' pattern comma pattern ')'
		{ if (constnode($3))
			$$ = op4($1, NIL, (Node*)makedfa(strnode($3), 1), $5, rectonode());
		  else
			$$ = op4($1, (Node *)1, $3, $5, rectonode()); }
	| subop '(' reg_expr comma pattern comma var ')'
		{ $$ = op4($1, NIL, (Node*)makedfa($3, 1), $5, $7); }
	| subop '(' pattern comma pattern comma var ')'
		{ if (constnode($3))
			$$ = op4($1, NIL, (Node*)makedfa(strnode($3), 1), $5, $7);
		  else
			$$ = op4($1, (Node *)1, $3, $5, $7); }
	| SUBSTR '(' pattern comma pattern comma pattern ')'
		{ $$ = op3(SUBSTR, $3, $5, $7); }
	| SUBSTR '(' pattern comma pattern ')'
		{ $$ = op3(SUBSTR, $3, $5, NIL); }
	| var
	;

var:
	  varname
	| varname '[' patlist ']'	{ $$ = op2(ARRAY, makearr($1), $3); }
	| FIELD				{ $$ = valtonode($1, CFLD); }
	| IVAR				{ $$ = op1(INDIRECT, valtonode($1, CVAR)); }
	| INDIRECT term	 		{ $$ = op1(INDIRECT, $2); }
	;	

varlist:
	  /* nothing */		{ arglist = $$ = 0; }
	| VAR			{ arglist = $$ = valtonode($1,CVAR); }
	| varlist comma VAR	{ arglist = $$ = linkum($1,valtonode($3,CVAR)); }
	;

varname:
	  VAR			{ $$ = valtonode($1, CVAR); }
	| ARG 			{ $$ = op1(ARG, (Node *) $1); }
	| VARNF			{ $$ = op1(VARNF, (Node *) $1); }
	;


while:
	  WHILE '(' pattern rparen	{ $$ = notnull($3); }
	;

%%

static void
setfname(Cell *p)
{
	if (isarr(p))
		vyyerror(":99:%s is an array, not a function", p->nval);
	else if (isfunc(p))
		vyyerror(":100:You cannot define function %s more than once", p->nval);
	curfname = p->nval;
}

static int
constnode(Node *p)
{
	return p->ntype == NVALUE && ((Cell *) (p->narg[0]))->csub == CCON;
}

static unsigned char *strnode(Node *p)
{
	return ((Cell *)(p->narg[0]))->sval;
}

static Node *notnull(Node *n)
{
	switch (n->nobj) {
	case LE: case LT: case EQ: case NE: case GT: case GE:
	case BOR: case AND: case NOT:
		return n;
	default:
		return op2(NE, n, nullnode);
	}
}