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Annotation of 41BSD/cmd/pxp/yyget.c, revision 1.1

1.1     ! root        1: /* Copyright (c) 1979 Regents of the University of California */
        !             2: /*
        !             3:  * pi - Pascal interpreter code translator
        !             4:  *
        !             5:  * Charles Haley, Bill Joy UCB
        !             6:  * Version 1.1 February 1978
        !             7:  *
        !             8:  *
        !             9:  * pxp - Pascal execution profiler
        !            10:  *
        !            11:  * Bill Joy UCB
        !            12:  * Version 1.1 February 1978
        !            13:  */
        !            14: 
        !            15: #include "0.h"
        !            16: #include "yy.h"
        !            17: 
        !            18: #ifdef PXP
        !            19: int    yytokcnt;
        !            20: #endif
        !            21: 
        !            22: /*
        !            23:  * Readch returns the next
        !            24:  * character from the current
        !            25:  * input line or -1 on end-of-file.
        !            26:  * It also maintains yycol for use in
        !            27:  * printing error messages.
        !            28:  */
        !            29: readch()
        !            30: {
        !            31:        register i, c;
        !            32: 
        !            33:        if (*bufp == '\n' && bufp >= charbuf) {
        !            34: #ifdef PXP
        !            35:                yytokcnt = 0;
        !            36: #endif
        !            37:                if (getline() < 0)
        !            38:                        return (-1);
        !            39:        }
        !            40:        c = *++bufp;
        !            41:        if (c == '\t')
        !            42:                yycol = ((yycol + 8) & ~7);
        !            43:        else
        !            44:                yycol++;
        !            45:        return (c);
        !            46: }
        !            47: 
        !            48: /*
        !            49:  * Definitions of the structures used for the
        !            50:  * include facility.  The variable "ibp" points
        !            51:  * to the getc buffer of the current input file.
        !            52:  * There are "inclev + 1" current include files,
        !            53:  * and information in saved in the incs stack
        !            54:  * whenever a new level of include nesting occurs.
        !            55:  *
        !            56:  * Ibp in the incs structure saves the pointer
        !            57:  * to the previous levels input buffer;
        !            58:  * filename saves the previous file name;
        !            59:  * Printed saves whether the previous file name
        !            60:  * had been printed before this nesting occurred;
        !            61:  * and yyline is the line we were on on the previous file.
        !            62:  */
        !            63: 
        !            64: #define        MAXINC  10
        !            65: 
        !            66: struct inc {
        !            67:        FILE    *ibp;
        !            68:        char    *filename;
        !            69:        int     Printed;
        !            70:        int     yyline;
        !            71:        int     yyLinpt;
        !            72: } incs[MAXINC];
        !            73: 
        !            74: extern char printed;
        !            75: 
        !            76: int    inclev  = -1;
        !            77: 
        !            78: #ifdef PXP
        !            79: /*
        !            80:  * These initializations survive only if
        !            81:  * pxp is asked to pretty print one file.
        !            82:  * Otherwise they are destroyed by the initial
        !            83:  * call to getline.
        !            84:  */
        !            85: char   charbuf[CBSIZE] = " program x(output);\n";
        !            86: int    yycol = 8;
        !            87: char   *bufp = charbuf;
        !            88: 
        !            89: #endif
        !            90: /*
        !            91:  * YyLinpt is the seek pointer to the beginning of the
        !            92:  * next line in the file.
        !            93:  */
        !            94: int    yyLinpt;
        !            95: 
        !            96: /*
        !            97:  * Getline places the next line
        !            98:  * from the input stream in the
        !            99:  * line buffer, returning -1 at YEOF.
        !           100:  */
        !           101: getline()
        !           102: {
        !           103:        register char *cp;
        !           104:        register CHAR c;
        !           105: #ifdef PXP
        !           106:        static char ateof;
        !           107: #endif
        !           108:        register FILE *ib;
        !           109:        int i;
        !           110: 
        !           111:        if (opt('l') && yyprtd == 0)
        !           112:                yyoutline();
        !           113:        yyprtd = 0;
        !           114: top:
        !           115:        yylinpt = yyLinpt;
        !           116:        yyline++;
        !           117:        yyseqid++;
        !           118:        cp = charbuf;
        !           119:        ib = ibp;
        !           120:        i = sizeof charbuf - 1;
        !           121:        for (;;) {
        !           122:                c = getc(ib);
        !           123:                if (c == EOF) {
        !           124:                        if (uninclud())
        !           125:                                goto top;
        !           126: #ifdef PXP
        !           127:                        if (ateof == 0 && bracket) {
        !           128:                                strcpy(charbuf, "begin end.\n");
        !           129:                                ateof = 1;
        !           130:                                goto out;
        !           131:                        }
        !           132: #endif
        !           133:                        bufp = "\n";
        !           134:                        yyline--;
        !           135:                        yyseqid--;
        !           136:                        yyprtd = 1;
        !           137:                        return (-1);
        !           138:                }
        !           139:                *cp++ = c;
        !           140:                if (c == '\n')
        !           141:                        break;
        !           142:                if (--i == 0) {
        !           143:                        line = yyline;
        !           144:                        error("Input line too long - QUIT");
        !           145:                        pexit(DIED);
        !           146:                }
        !           147:        }
        !           148:        *cp = 0;
        !           149:        yyLinpt = yylinpt + cp - charbuf;
        !           150:        if (includ())
        !           151:                goto top;
        !           152: #ifdef PXP
        !           153:        if (cp == &charbuf[1])
        !           154:                commnl();
        !           155:        else if (cp == &charbuf[2])
        !           156:                switch (charbuf[0]) {
        !           157:                        case ' ':
        !           158:                                commnlbl();
        !           159:                                break;
        !           160:                        case '\f':
        !           161:                                commform();
        !           162:                }
        !           163: #endif
        !           164:        if (opt('u'))
        !           165:                setuflg();
        !           166: out:
        !           167:        bufp = charbuf - 1;
        !           168:        yycol = 8;
        !           169:        return (1);
        !           170: }
        !           171: 
        !           172: /*
        !           173:  * Check an input line to see if it is a "#include" pseudo-statement.
        !           174:  * We allow arbitrary blanks in the line and the file name
        !           175:  * may be delimited by either 's or "s.  A single semicolon
        !           176:  * may be placed after the name, but nothing else is allowed
        !           177:  */
        !           178: includ()
        !           179: {
        !           180:        register char *cp, *dp;
        !           181:        char ch;
        !           182:        register struct inc *ip;
        !           183: 
        !           184:        cp = charbuf;
        !           185:        if (*cp++ != '#')
        !           186:                return (0);
        !           187:        cp = skipbl(cp);
        !           188:        for (dp = "include"; *dp; dp++)
        !           189:                if (*dp != *cp++)
        !           190:                        return (0);
        !           191:        line = yyline;
        !           192:        cp = skipbl(cp);
        !           193:        ch = *cp++;
        !           194:        if (ch != '\'' && ch != '"') {
        !           195:                /*
        !           196:                 * This should be a yerror flagging the place
        !           197:                 * but its not worth figuring out the column.
        !           198:                 */
        !           199:                line = yyline;
        !           200:                error("Include syntax error - expected ' or \" not found - QUIT");
        !           201:                pexit(DIED);
        !           202:        }
        !           203:        for (dp = cp; *dp != ch; dp++)
        !           204:                if (*dp == 0) {
        !           205:                        line = yyline;
        !           206:                        error("Missing closing %c for include file name - QUIT", ch);
        !           207:                        pexit(DIED);
        !           208:                }
        !           209:        *dp++ = 0;
        !           210: /*
        !           211:        if (*dp == ';')
        !           212:                dp++;
        !           213:        dp = skipbl(dp);
        !           214:        if (*dp != '\n') {
        !           215:                line = yyline;
        !           216:                error("Garbage after filename in include");
        !           217:                pexit(DIED);
        !           218:        }
        !           219: */
        !           220:        if (!dotted(cp, 'i')) {
        !           221:                line = yyline;
        !           222:                error("Include filename must end in .i");
        !           223:        }
        !           224: #ifdef PXP
        !           225:        commincl(cp, ch);
        !           226:        if (noinclude)
        !           227:                return (1);
        !           228: #endif
        !           229:        inclev++;
        !           230:        if (inclev > MAXINC) {
        !           231:                line = yyline;
        !           232:                error("Absurdly deep include nesting - QUIT");
        !           233:                pexit(DIED);
        !           234:        }
        !           235:        ip = &incs[inclev];
        !           236:        ip->filename = filename;
        !           237:        filename = savestr(cp);
        !           238: /*
        !           239:  *     left over from before stdio
        !           240:  *
        !           241:  *     cp = malloc(518);
        !           242:  *     if (cp == -1) {
        !           243:  *             error("Ran out of memory (include)");
        !           244:  *             pexit(DIED);
        !           245:  *     }
        !           246:  *
        !           247:  */
        !           248:        ip->ibp = ibp;
        !           249:        if ( ( ibp = fopen(filename, "r" ) ) == NULL ) {
        !           250:                perror(filename);
        !           251:                pexit(DIED);
        !           252:        }
        !           253:        if (inpflist(filename)) {
        !           254: #ifdef PI
        !           255:                opush('l');
        !           256: #endif
        !           257: #ifdef PXP
        !           258:                opush('z');
        !           259: #endif
        !           260:        }
        !           261:        ip->Printed = printed;
        !           262:        printed = 0;
        !           263:        ip->yyline = yyline;
        !           264:        yyline = 0;
        !           265:        ip->yyLinpt = yyLinpt;
        !           266:        yyLinpt = 0;
        !           267: /*
        !           268:  *     left over from before stdio
        !           269:  *
        !           270:  *     ip->ibp = ibp;
        !           271:  *     ibp = cp;
        !           272:  *
        !           273:  */
        !           274:        return (1);
        !           275: }
        !           276: 
        !           277: skipbl(ocp)
        !           278:        char *ocp;
        !           279: {
        !           280:        register char *cp;
        !           281: 
        !           282:        cp = ocp;
        !           283:        while (*cp == ' ' || *cp == '\t')
        !           284:                cp++;
        !           285:        return (cp);
        !           286: }
        !           287: 
        !           288: 
        !           289: /*
        !           290:  * At the end of an include,
        !           291:  * close the file, free the input buffer,
        !           292:  * and restore the environment before
        !           293:  * the "push", including the value of
        !           294:  * the z option for pxp and the l option for pi.
        !           295:  */
        !           296: uninclud()
        !           297: {
        !           298:        register struct inc *ip;
        !           299: 
        !           300:        if (inclev < 0)
        !           301:                return (0);
        !           302: /*
        !           303:  *     left over from before stdio: becomes fclose ( ibp )
        !           304:  *
        !           305:  *     close(ibp[0]);
        !           306:  *     free(ibp);
        !           307:  *
        !           308:  */
        !           309:        fclose ( ibp );
        !           310:        ip = &incs[inclev];
        !           311:        ibp = ip->ibp;
        !           312:        yyline = ip->yyline;
        !           313:        if (inpflist(filename)) {
        !           314: #ifdef PI
        !           315:                opop('l');
        !           316: #endif
        !           317: #ifdef PXP
        !           318:                opop('z');
        !           319: #endif
        !           320:        }
        !           321:        filename = ip->filename;
        !           322:        yyLinpt = ip->yyLinpt;
        !           323:        /*
        !           324:         * If we printed out the nested name,
        !           325:         * then we should print all covered names again.
        !           326:         * If we didn't print out the nested name
        !           327:         * we print the uncovered name only if it
        !           328:         * has not been printed before (unstack).
        !           329:         */
        !           330:        if (printed) {
        !           331:                printed = 0;
        !           332:                while (ip >= incs) {
        !           333:                        ip->Printed = 0;
        !           334:                        ip--;
        !           335:                }
        !           336:        } else
        !           337:                printed = ip->Printed;
        !           338:        inclev--;
        !           339:        return (1);
        !           340: }

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