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Annotation of src/usr.bin/awk/awkgram.y, Revision 1.14

1.14    ! millert     1: /*     $OpenBSD: awkgram.y,v 1.13 2020/06/10 21:05:02 millert Exp $    */
1.1       tholo       2: /****************************************************************
1.4       kstailey    3: Copyright (C) Lucent Technologies 1997
1.1       tholo       4: All Rights Reserved
                      5:
                      6: Permission to use, copy, modify, and distribute this software and
                      7: its documentation for any purpose and without fee is hereby
                      8: granted, provided that the above copyright notice appear in all
                      9: copies and that both that the copyright notice and this
                     10: permission notice and warranty disclaimer appear in supporting
1.4       kstailey   11: documentation, and that the name Lucent Technologies or any of
                     12: its entities not be used in advertising or publicity pertaining
                     13: to distribution of the software without specific, written prior
                     14: permission.
                     15:
                     16: LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
                     17: INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
                     18: IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
                     19: SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
                     20: WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
                     21: IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
                     22: ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
                     23: THIS SOFTWARE.
1.1       tholo      24: ****************************************************************/
                     25:
                     26: %{
                     27: #include <stdio.h>
                     28: #include <string.h>
                     29: #include "awk.h"
                     30:
                     31: void checkdup(Node *list, Cell *item);
                     32: int yywrap(void) { return(1); }
                     33:
                     34: Node   *beginloc = 0;
                     35: Node   *endloc = 0;
1.12      millert    36: bool   infunc  = false;        /* = true if in arglist or body of func */
                     37: int    inloop  = 0;    /* >= 1 if in while, for, do; can't be bool, since loops can next */
1.1       tholo      38: char   *curfname = 0;  /* current function name */
                     39: Node   *arglist = 0;   /* list of args for current function */
                     40: %}
                     41:
                     42: %union {
                     43:        Node    *p;
                     44:        Cell    *cp;
1.3       millert    45:        int     i;
1.1       tholo      46:        char    *s;
                     47: }
                     48:
                     49: %token <i>     FIRSTTOKEN      /* must be first */
                     50: %token <p>     PROGRAM PASTAT PASTAT2 XBEGIN XEND
                     51: %token <i>     NL ',' '{' '(' '|' ';' '/' ')' '}' '[' ']'
                     52: %token <i>     ARRAY
                     53: %token <i>     MATCH NOTMATCH MATCHOP
1.13      millert    54: %token <i>     FINAL DOT ALL CCL NCCL CHAR OR STAR QUEST PLUS EMPTYRE ZERO
1.1       tholo      55: %token <i>     AND BOR APPEND EQ GE GT LE LT NE IN
1.11      millert    56: %token <i>     ARG BLTIN BREAK CLOSE CONTINUE DELETE DO EXIT FOR FUNC
1.14    ! millert    57: %token <i>     GENSUB SUB GSUB IF INDEX LSUBSTR MATCHFCN NEXT NEXTFILE
1.1       tholo      58: %token <i>     ADD MINUS MULT DIVIDE MOD
                     59: %token <i>     ASSIGN ASGNOP ADDEQ SUBEQ MULTEQ DIVEQ MODEQ POWEQ
                     60: %token <i>     PRINT PRINTF SPRINTF
                     61: %token <p>     ELSE INTEST CONDEXPR
                     62: %token <i>     POSTINCR PREINCR POSTDECR PREDECR
1.4       kstailey   63: %token <cp>    VAR IVAR VARNF CALL NUMBER STRING
1.1       tholo      64: %token <s>     REGEXPR
                     65:
                     66: %type  <p>     pas pattern ppattern plist pplist patlist prarg term re
                     67: %type  <p>     pa_pat pa_stat pa_stats
                     68: %type  <s>     reg_expr
                     69: %type  <p>     simple_stmt opt_simple_stmt stmt stmtlist
                     70: %type  <p>     var varname funcname varlist
                     71: %type  <p>     for if else while
                     72: %type  <i>     do st
                     73: %type  <i>     pst opt_pst lbrace rbrace rparen comma nl opt_nl and bor
                     74: %type  <i>     subop print
1.11      millert    75: %type  <cp>    string
1.1       tholo      76:
                     77: %right ASGNOP
                     78: %right '?'
                     79: %right ':'
                     80: %left  BOR
                     81: %left  AND
                     82: %left  GETLINE
                     83: %nonassoc APPEND EQ GE GT LE LT NE MATCHOP IN '|'
1.11      millert    84: %left  ARG BLTIN BREAK CALL CLOSE CONTINUE DELETE DO EXIT FOR FUNC
1.1       tholo      85: %left  GSUB IF INDEX LSUBSTR MATCHFCN NEXT NUMBER
                     86: %left  PRINT PRINTF RETURN SPLIT SPRINTF STRING SUB SUBSTR
                     87: %left  REGEXPR VAR VARNF IVAR WHILE '('
                     88: %left  CAT
                     89: %left  '+' '-'
                     90: %left  '*' '/' '%'
1.10      millert    91: %left  NOT UMINUS UPLUS
1.1       tholo      92: %right POWER
                     93: %right DECR INCR
                     94: %left  INDIRECT
                     95: %token LASTTOKEN       /* must be last */
                     96:
                     97: %%
                     98:
                     99: program:
                    100:          pas   { if (errorflag==0)
                    101:                        winner = (Node *)stat3(PROGRAM, beginloc, $1, endloc); }
1.6       millert   102:        | error { yyclearin; bracecheck(); SYNTAX("bailing out"); }
1.1       tholo     103:        ;
                    104:
                    105: and:
                    106:          AND | and NL
                    107:        ;
                    108:
                    109: bor:
                    110:          BOR | bor NL
                    111:        ;
                    112:
                    113: comma:
                    114:          ',' | comma NL
                    115:        ;
                    116:
                    117: do:
                    118:          DO | do NL
                    119:        ;
                    120:
                    121: else:
                    122:          ELSE | else NL
                    123:        ;
                    124:
                    125: for:
                    126:          FOR '(' opt_simple_stmt ';' opt_nl pattern ';' opt_nl opt_simple_stmt rparen {inloop++;} stmt
                    127:                { --inloop; $$ = stat4(FOR, $3, notnull($6), $9, $12); }
                    128:        | FOR '(' opt_simple_stmt ';'  ';' opt_nl opt_simple_stmt rparen {inloop++;} stmt
                    129:                { --inloop; $$ = stat4(FOR, $3, NIL, $7, $10); }
                    130:        | FOR '(' varname IN varname rparen {inloop++;} stmt
                    131:                { --inloop; $$ = stat3(IN, $3, makearr($5), $8); }
                    132:        ;
                    133:
                    134: funcname:
                    135:          VAR   { setfname($1); }
                    136:        | CALL  { setfname($1); }
                    137:        ;
                    138:
                    139: if:
                    140:          IF '(' pattern rparen         { $$ = notnull($3); }
                    141:        ;
                    142:
                    143: lbrace:
                    144:          '{' | lbrace NL
                    145:        ;
                    146:
                    147: nl:
                    148:          NL | nl NL
                    149:        ;
                    150:
                    151: opt_nl:
                    152:          /* empty */   { $$ = 0; }
                    153:        | nl
                    154:        ;
                    155:
                    156: opt_pst:
                    157:          /* empty */   { $$ = 0; }
                    158:        | pst
                    159:        ;
                    160:
                    161:
                    162: opt_simple_stmt:
                    163:          /* empty */                   { $$ = 0; }
                    164:        | simple_stmt
                    165:        ;
                    166:
                    167: pas:
                    168:          opt_pst                       { $$ = 0; }
                    169:        | opt_pst pa_stats opt_pst      { $$ = $2; }
                    170:        ;
                    171:
                    172: pa_pat:
                    173:          pattern       { $$ = notnull($1); }
                    174:        ;
                    175:
                    176: pa_stat:
                    177:          pa_pat                        { $$ = stat2(PASTAT, $1, stat2(PRINT, rectonode(), NIL)); }
                    178:        | pa_pat lbrace stmtlist '}'    { $$ = stat2(PASTAT, $1, $3); }
1.9       millert   179:        | pa_pat ',' opt_nl pa_pat              { $$ = pa2stat($1, $4, stat2(PRINT, rectonode(), NIL)); }
                    180:        | pa_pat ',' opt_nl pa_pat lbrace stmtlist '}'  { $$ = pa2stat($1, $4, $6); }
1.1       tholo     181:        | lbrace stmtlist '}'           { $$ = stat2(PASTAT, NIL, $2); }
                    182:        | XBEGIN lbrace stmtlist '}'
                    183:                { beginloc = linkum(beginloc, $3); $$ = 0; }
                    184:        | XEND lbrace stmtlist '}'
                    185:                { endloc = linkum(endloc, $3); $$ = 0; }
1.12      millert   186:        | FUNC funcname '(' varlist rparen {infunc = true;} lbrace stmtlist '}'
                    187:                { infunc = false; curfname=0; defn((Cell *)$2, $4, $8); $$ = 0; }
1.1       tholo     188:        ;
                    189:
                    190: pa_stats:
                    191:          pa_stat
                    192:        | pa_stats opt_pst pa_stat      { $$ = linkum($1, $3); }
                    193:        ;
                    194:
                    195: patlist:
                    196:          pattern
                    197:        | patlist comma pattern         { $$ = linkum($1, $3); }
                    198:        ;
                    199:
                    200: ppattern:
                    201:          var ASGNOP ppattern           { $$ = op2($2, $1, $3); }
                    202:        | ppattern '?' ppattern ':' ppattern %prec '?'
                    203:                { $$ = op3(CONDEXPR, notnull($1), $3, $5); }
                    204:        | ppattern bor ppattern %prec BOR
                    205:                { $$ = op2(BOR, notnull($1), notnull($3)); }
                    206:        | ppattern and ppattern %prec AND
                    207:                { $$ = op2(AND, notnull($1), notnull($3)); }
                    208:        | ppattern MATCHOP reg_expr     { $$ = op3($2, NIL, $1, (Node*)makedfa($3, 0)); }
                    209:        | ppattern MATCHOP ppattern
                    210:                { if (constnode($3))
                    211:                        $$ = op3($2, NIL, $1, (Node*)makedfa(strnode($3), 0));
                    212:                  else
                    213:                        $$ = op3($2, (Node *)1, $1, $3); }
                    214:        | ppattern IN varname           { $$ = op2(INTEST, $1, makearr($3)); }
                    215:        | '(' plist ')' IN varname      { $$ = op2(INTEST, $2, makearr($5)); }
                    216:        | ppattern term %prec CAT       { $$ = op2(CAT, $1, $2); }
                    217:        | re
                    218:        | term
                    219:        ;
                    220:
                    221: pattern:
                    222:          var ASGNOP pattern            { $$ = op2($2, $1, $3); }
                    223:        | pattern '?' pattern ':' pattern %prec '?'
                    224:                { $$ = op3(CONDEXPR, notnull($1), $3, $5); }
                    225:        | pattern bor pattern %prec BOR
                    226:                { $$ = op2(BOR, notnull($1), notnull($3)); }
                    227:        | pattern and pattern %prec AND
                    228:                { $$ = op2(AND, notnull($1), notnull($3)); }
                    229:        | pattern EQ pattern            { $$ = op2($2, $1, $3); }
                    230:        | pattern GE pattern            { $$ = op2($2, $1, $3); }
                    231:        | pattern GT pattern            { $$ = op2($2, $1, $3); }
                    232:        | pattern LE pattern            { $$ = op2($2, $1, $3); }
                    233:        | pattern LT pattern            { $$ = op2($2, $1, $3); }
                    234:        | pattern NE pattern            { $$ = op2($2, $1, $3); }
                    235:        | pattern MATCHOP reg_expr      { $$ = op3($2, NIL, $1, (Node*)makedfa($3, 0)); }
                    236:        | pattern MATCHOP pattern
                    237:                { if (constnode($3))
                    238:                        $$ = op3($2, NIL, $1, (Node*)makedfa(strnode($3), 0));
                    239:                  else
                    240:                        $$ = op3($2, (Node *)1, $1, $3); }
                    241:        | pattern IN varname            { $$ = op2(INTEST, $1, makearr($3)); }
                    242:        | '(' plist ')' IN varname      { $$ = op2(INTEST, $2, makearr($5)); }
1.11      millert   243:        | pattern '|' GETLINE var       {
1.6       millert   244:                        if (safe) SYNTAX("cmd | getline is unsafe");
1.5       millert   245:                        else $$ = op3(GETLINE, $4, itonp($2), $1); }
1.11      millert   246:        | pattern '|' GETLINE           {
1.6       millert   247:                        if (safe) SYNTAX("cmd | getline is unsafe");
1.5       millert   248:                        else $$ = op3(GETLINE, (Node*)0, itonp($2), $1); }
1.1       tholo     249:        | pattern term %prec CAT        { $$ = op2(CAT, $1, $2); }
                    250:        | re
                    251:        | term
                    252:        ;
                    253:
                    254: plist:
                    255:          pattern comma pattern         { $$ = linkum($1, $3); }
                    256:        | plist comma pattern           { $$ = linkum($1, $3); }
                    257:        ;
                    258:
                    259: pplist:
                    260:          ppattern
                    261:        | pplist comma ppattern         { $$ = linkum($1, $3); }
                    262:        ;
                    263:
                    264: prarg:
                    265:          /* empty */                   { $$ = rectonode(); }
                    266:        | pplist
                    267:        | '(' plist ')'                 { $$ = $2; }
                    268:        ;
                    269:
                    270: print:
                    271:          PRINT | PRINTF
                    272:        ;
                    273:
                    274: pst:
                    275:          NL | ';' | pst NL | pst ';'
                    276:        ;
                    277:
                    278: rbrace:
                    279:          '}' | rbrace NL
                    280:        ;
                    281:
                    282: re:
                    283:           reg_expr
                    284:                { $$ = op3(MATCH, NIL, rectonode(), (Node*)makedfa($1, 0)); }
                    285:        | NOT re        { $$ = op1(NOT, notnull($2)); }
                    286:        ;
                    287:
                    288: reg_expr:
                    289:          '/' {startreg();} REGEXPR '/'         { $$ = $3; }
                    290:        ;
                    291:
                    292: rparen:
                    293:          ')' | rparen NL
                    294:        ;
                    295:
                    296: simple_stmt:
1.11      millert   297:          print prarg '|' term          {
1.6       millert   298:                        if (safe) SYNTAX("print | is unsafe");
1.5       millert   299:                        else $$ = stat3($1, $2, itonp($3), $4); }
1.4       kstailey  300:        | print prarg APPEND term       {
1.6       millert   301:                        if (safe) SYNTAX("print >> is unsafe");
1.5       millert   302:                        else $$ = stat3($1, $2, itonp($3), $4); }
1.4       kstailey  303:        | print prarg GT term           {
1.6       millert   304:                        if (safe) SYNTAX("print > is unsafe");
1.5       millert   305:                        else $$ = stat3($1, $2, itonp($3), $4); }
1.1       tholo     306:        | print prarg                   { $$ = stat3($1, $2, NIL, NIL); }
                    307:        | DELETE varname '[' patlist ']' { $$ = stat2(DELETE, makearr($2), $4); }
                    308:        | DELETE varname                 { $$ = stat2(DELETE, makearr($2), 0); }
                    309:        | pattern                       { $$ = exptostat($1); }
1.6       millert   310:        | error                         { yyclearin; SYNTAX("illegal statement"); }
1.1       tholo     311:        ;
                    312:
                    313: st:
                    314:          nl
                    315:        | ';' opt_nl
                    316:        ;
                    317:
                    318: stmt:
1.6       millert   319:          BREAK st              { if (!inloop) SYNTAX("break illegal outside of loops");
1.1       tholo     320:                                  $$ = stat1(BREAK, NIL); }
1.6       millert   321:        | CONTINUE st           {  if (!inloop) SYNTAX("continue illegal outside of loops");
1.1       tholo     322:                                  $$ = stat1(CONTINUE, NIL); }
                    323:        | do {inloop++;} stmt {--inloop;} WHILE '(' pattern ')' st
                    324:                { $$ = stat2(DO, $3, notnull($7)); }
                    325:        | EXIT pattern st       { $$ = stat1(EXIT, $2); }
                    326:        | EXIT st               { $$ = stat1(EXIT, NIL); }
                    327:        | for
                    328:        | if stmt else stmt     { $$ = stat3(IF, $1, $2, $4); }
                    329:        | if stmt               { $$ = stat3(IF, $1, $2, NIL); }
                    330:        | lbrace stmtlist rbrace { $$ = $2; }
                    331:        | NEXT st       { if (infunc)
1.6       millert   332:                                SYNTAX("next is illegal inside a function");
1.1       tholo     333:                          $$ = stat1(NEXT, NIL); }
                    334:        | NEXTFILE st   { if (infunc)
1.6       millert   335:                                SYNTAX("nextfile is illegal inside a function");
1.1       tholo     336:                          $$ = stat1(NEXTFILE, NIL); }
                    337:        | RETURN pattern st     { $$ = stat1(RETURN, $2); }
                    338:        | RETURN st             { $$ = stat1(RETURN, NIL); }
                    339:        | simple_stmt st
                    340:        | while {inloop++;} stmt        { --inloop; $$ = stat2(WHILE, $1, $3); }
                    341:        | ';' opt_nl            { $$ = 0; }
                    342:        ;
                    343:
                    344: stmtlist:
                    345:          stmt
                    346:        | stmtlist stmt         { $$ = linkum($1, $2); }
                    347:        ;
                    348:
                    349: subop:
                    350:          SUB | GSUB
                    351:        ;
                    352:
1.11      millert   353: string:
                    354:          STRING
                    355:        | string STRING         { $$ = catstr($1, $2); }
                    356:        ;
                    357:
1.1       tholo     358: term:
1.5       millert   359:          term '/' ASGNOP term          { $$ = op2(DIVEQ, $1, $4); }
                    360:        | term '+' term                 { $$ = op2(ADD, $1, $3); }
1.1       tholo     361:        | term '-' term                 { $$ = op2(MINUS, $1, $3); }
                    362:        | term '*' term                 { $$ = op2(MULT, $1, $3); }
                    363:        | term '/' term                 { $$ = op2(DIVIDE, $1, $3); }
                    364:        | term '%' term                 { $$ = op2(MOD, $1, $3); }
                    365:        | term POWER term               { $$ = op2(POWER, $1, $3); }
                    366:        | '-' term %prec UMINUS         { $$ = op1(UMINUS, $2); }
1.10      millert   367:        | '+' term %prec UMINUS         { $$ = op1(UPLUS, $2); }
1.1       tholo     368:        | NOT term %prec UMINUS         { $$ = op1(NOT, notnull($2)); }
1.5       millert   369:        | BLTIN '(' ')'                 { $$ = op2(BLTIN, itonp($1), rectonode()); }
                    370:        | BLTIN '(' patlist ')'         { $$ = op2(BLTIN, itonp($1), $3); }
                    371:        | BLTIN                         { $$ = op2(BLTIN, itonp($1), rectonode()); }
1.4       kstailey  372:        | CALL '(' ')'                  { $$ = op2(CALL, celltonode($1,CVAR), NIL); }
                    373:        | CALL '(' patlist ')'          { $$ = op2(CALL, celltonode($1,CVAR), $3); }
1.7       millert   374:        | CLOSE term                    { $$ = op1(CLOSE, $2); }
1.1       tholo     375:        | DECR var                      { $$ = op1(PREDECR, $2); }
                    376:        | INCR var                      { $$ = op1(PREINCR, $2); }
                    377:        | var DECR                      { $$ = op1(POSTDECR, $1); }
                    378:        | var INCR                      { $$ = op1(POSTINCR, $1); }
1.14    ! millert   379:        | GENSUB '(' reg_expr comma pattern comma pattern ')'
        !           380:                { $$ = op5(GENSUB, NIL, (Node*)makedfa($3, 1), $5, $7, rectonode()); }
        !           381:        | GENSUB '(' pattern comma pattern comma pattern ')'
        !           382:                { if (constnode($3))
        !           383:                        $$ = op5(GENSUB, NIL, (Node *)makedfa(strnode($3), 1), $5, $7, rectonode());
        !           384:                  else
        !           385:                        $$ = op5(GENSUB, (Node *)1, $3, $5, $7, rectonode());
        !           386:                }
        !           387:        | GENSUB '(' reg_expr comma pattern comma pattern comma pattern ')'
        !           388:                { $$ = op5(GENSUB, NIL, (Node*)makedfa($3, 1), $5, $7, $9); }
        !           389:        | GENSUB '(' pattern comma pattern comma pattern comma pattern ')'
        !           390:                { if (constnode($3))
        !           391:                        $$ = op5(GENSUB, NIL, (Node *)makedfa(strnode($3),1), $5,$7,$9);
        !           392:                  else
        !           393:                        $$ = op5(GENSUB, (Node *)1, $3, $5, $7, $9);
        !           394:                }
1.5       millert   395:        | GETLINE var LT term           { $$ = op3(GETLINE, $2, itonp($3), $4); }
                    396:        | GETLINE LT term               { $$ = op3(GETLINE, NIL, itonp($2), $3); }
1.1       tholo     397:        | GETLINE var                   { $$ = op3(GETLINE, $2, NIL, NIL); }
                    398:        | GETLINE                       { $$ = op3(GETLINE, NIL, NIL, NIL); }
                    399:        | INDEX '(' pattern comma pattern ')'
                    400:                { $$ = op2(INDEX, $3, $5); }
                    401:        | INDEX '(' pattern comma reg_expr ')'
1.6       millert   402:                { SYNTAX("index() doesn't permit regular expressions");
1.1       tholo     403:                  $$ = op2(INDEX, $3, (Node*)$5); }
                    404:        | '(' pattern ')'               { $$ = $2; }
                    405:        | MATCHFCN '(' pattern comma reg_expr ')'
                    406:                { $$ = op3(MATCHFCN, NIL, $3, (Node*)makedfa($5, 1)); }
                    407:        | MATCHFCN '(' pattern comma pattern ')'
                    408:                { if (constnode($5))
                    409:                        $$ = op3(MATCHFCN, NIL, $3, (Node*)makedfa(strnode($5), 1));
                    410:                  else
                    411:                        $$ = op3(MATCHFCN, (Node *)1, $3, $5); }
1.4       kstailey  412:        | NUMBER                        { $$ = celltonode($1, CCON); }
1.1       tholo     413:        | SPLIT '(' pattern comma varname comma pattern ')'     /* string */
                    414:                { $$ = op4(SPLIT, $3, makearr($5), $7, (Node*)STRING); }
                    415:        | SPLIT '(' pattern comma varname comma reg_expr ')'    /* const /regexp/ */
                    416:                { $$ = op4(SPLIT, $3, makearr($5), (Node*)makedfa($7, 1), (Node *)REGEXPR); }
                    417:        | SPLIT '(' pattern comma varname ')'
                    418:                { $$ = op4(SPLIT, $3, makearr($5), NIL, (Node*)STRING); }  /* default */
                    419:        | SPRINTF '(' patlist ')'       { $$ = op1($1, $3); }
1.11      millert   420:        | string                        { $$ = celltonode($1, CCON); }
1.1       tholo     421:        | subop '(' reg_expr comma pattern ')'
                    422:                { $$ = op4($1, NIL, (Node*)makedfa($3, 1), $5, rectonode()); }
                    423:        | subop '(' pattern comma pattern ')'
                    424:                { if (constnode($3))
                    425:                        $$ = op4($1, NIL, (Node*)makedfa(strnode($3), 1), $5, rectonode());
                    426:                  else
                    427:                        $$ = op4($1, (Node *)1, $3, $5, rectonode()); }
                    428:        | subop '(' reg_expr comma pattern comma var ')'
                    429:                { $$ = op4($1, NIL, (Node*)makedfa($3, 1), $5, $7); }
                    430:        | subop '(' pattern comma pattern comma var ')'
                    431:                { if (constnode($3))
                    432:                        $$ = op4($1, NIL, (Node*)makedfa(strnode($3), 1), $5, $7);
                    433:                  else
                    434:                        $$ = op4($1, (Node *)1, $3, $5, $7); }
                    435:        | SUBSTR '(' pattern comma pattern comma pattern ')'
                    436:                { $$ = op3(SUBSTR, $3, $5, $7); }
                    437:        | SUBSTR '(' pattern comma pattern ')'
                    438:                { $$ = op3(SUBSTR, $3, $5, NIL); }
                    439:        | var
                    440:        ;
                    441:
                    442: var:
                    443:          varname
                    444:        | varname '[' patlist ']'       { $$ = op2(ARRAY, makearr($1), $3); }
1.4       kstailey  445:        | IVAR                          { $$ = op1(INDIRECT, celltonode($1, CVAR)); }
1.1       tholo     446:        | INDIRECT term                 { $$ = op1(INDIRECT, $2); }
1.11      millert   447:        ;
1.1       tholo     448:
                    449: varlist:
                    450:          /* nothing */         { arglist = $$ = 0; }
1.4       kstailey  451:        | VAR                   { arglist = $$ = celltonode($1,CVAR); }
1.1       tholo     452:        | varlist comma VAR     {
                    453:                        checkdup($1, $3);
1.4       kstailey  454:                        arglist = $$ = linkum($1,celltonode($3,CVAR)); }
1.1       tholo     455:        ;
                    456:
                    457: varname:
1.4       kstailey  458:          VAR                   { $$ = celltonode($1, CVAR); }
1.5       millert   459:        | ARG                   { $$ = op1(ARG, itonp($1)); }
1.1       tholo     460:        | VARNF                 { $$ = op1(VARNF, (Node *) $1); }
                    461:        ;
                    462:
                    463:
                    464: while:
                    465:          WHILE '(' pattern rparen      { $$ = notnull($3); }
                    466:        ;
                    467:
                    468: %%
                    469:
                    470: void setfname(Cell *p)
                    471: {
                    472:        if (isarr(p))
1.6       millert   473:                SYNTAX("%s is an array, not a function", p->nval);
1.4       kstailey  474:        else if (isfcn(p))
1.6       millert   475:                SYNTAX("you can't define function %s more than once", p->nval);
1.1       tholo     476:        curfname = p->nval;
                    477: }
                    478:
                    479: int constnode(Node *p)
                    480: {
                    481:        return isvalue(p) && ((Cell *) (p->narg[0]))->csub == CCON;
                    482: }
                    483:
                    484: char *strnode(Node *p)
                    485: {
                    486:        return ((Cell *)(p->narg[0]))->sval;
                    487: }
                    488:
                    489: Node *notnull(Node *n)
                    490: {
                    491:        switch (n->nobj) {
                    492:        case LE: case LT: case EQ: case NE: case GT: case GE:
                    493:        case BOR: case AND: case NOT:
                    494:                return n;
                    495:        default:
                    496:                return op2(NE, n, nullnode);
                    497:        }
                    498: }
                    499:
                    500: void checkdup(Node *vl, Cell *cp)      /* check if name already in list */
                    501: {
                    502:        char *s = cp->nval;
                    503:        for ( ; vl; vl = vl->nnext) {
                    504:                if (strcmp(s, ((Cell *)(vl->narg[0]))->nval) == 0) {
1.6       millert   505:                        SYNTAX("duplicate argument %s", s);
1.1       tholo     506:                        break;
                    507:                }
                    508:        }
                    509: }