Annotation of 41BSD/cmd/pxp/yyget.c, revision 1.1.1.1

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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