+/* C compiler
+
+Copyright 1972 Bell Telephone Laboratories, Inc.
+
+*/
+
+ossiz 250;
+ospace() {} /* fake */
+
+init(s, t)
+char s[]; {
+ extern lookup, symbuf, namsiz;
+ char symbuf[], sp[];
+ int np[], i;
+
+ i = namsiz;
+ sp = symbuf;
+ while(i--)
+ if ((*sp++ = *s++)=='\0') --s;
+ np = lookup();
+ *np++ = 1;
+ *np = t;
+}
+
+main(argc, argv)
+int argv[]; {
+ extern init, flush;
+ extern extdef, eof, open, creat;
+ extern fout, fin, error, exit, nerror, tmpfil;
+
+ if(argc<4) {
+ error("Arg count");
+ exit(1);
+ }
+ if((fin=open(argv[1],0))<0) {
+ error("Can't find %s", argv[1]);
+ exit(1);
+ }
+ if((fout=creat(argv[2], 017))<0) {
+ error("Can't create %s", argv[2]);
+ exit(1);
+ }
+ tmpfil = argv[3];
+ init("int", 0);
+ init("char", 1);
+ init("float", 2);
+ init("double", 3);
+/* init("long", 4); */
+ init("auto", 5);
+ init("extern", 6);
+ init("static", 7);
+ init("goto", 10);
+ init("return", 11);
+ init("if", 12);
+ init("while", 13);
+ init("else", 14);
+ init("switch", 15);
+ init("case", 16);
+ init("break", 17);
+ init("continue", 18);
+ init("do", 19);
+ init("default", 20);
+ while(!eof) {
+ extdef();
+ blkend();
+ }
+ flush();
+ flshw();
+ exit(nerror!=0);
+}
+
+lookup() {
+ extern hshtab[], hshsiz, pssiz, symbuf[];
+ extern hshlen, hshused, exit, error, nwps;
+ auto i, j, np[], sp[], rp[];
+
+ i = 0;
+ sp = symbuf;
+ j = nwps;
+ while(j--)
+ i =+ *sp++;
+ if (i<0) i = -i;
+ i =% hshsiz;
+ i =* pssiz;
+ while(*(np = &hshtab[i+4])) {
+ sp = symbuf;
+ j = nwps;
+ while(j--)
+ if (*np++ != *sp++) goto no;
+ return(&hshtab[i]);
+no: if ((i =+ pssiz) >= hshlen) i = 0;
+ }
+ if(hshused++ > hshsiz) {
+ error("Symbol table overflow");
+ exit(1);
+ }
+ rp = np = &hshtab[i];
+ sp = symbuf;
+ j = 4;
+ while(j--)
+ *np++ = 0;
+ j = nwps;
+ while(j--)
+ *np++ = *sp++;
+ return(rp);
+}
+
+symbol() {
+ extern peeksym, peekc, eof, getchar, subseq, error, line;
+ extern csym[], getstr, symbuf, namsiz, lookup[], ctab, cval;
+ auto b, c;
+ char symbuf[], sp[], ctab[];
+
+ if (peeksym>=0) {
+ c = peeksym;
+ peeksym = -1;
+ return(c);
+ }
+ if (peekc) {
+ c = peekc;
+ peekc = 0;
+ } else
+ if (eof)
+ return(0); else
+ c = getchar();
+loop:
+ switch(ctab[c]) {
+
+ case 125: /* newline */
+ line++;
+
+ case 126: /* white space */
+ c = getchar();
+ goto loop;
+
+ case 0: /* EOF */
+ eof++;
+ return(0);
+
+ case 40: /* + */
+ return(subseq(c,40,30));
+
+ case 41: /* - */
+ return(subseq(c,41,31));
+
+ case 80: /* = */
+ if (subseq(' ',0,1)) return(80);
+ c = symbol();
+ if (c>=40 & c<=49)
+ return(c+30);
+ if (c==80)
+ return(60);
+ peeksym = c;
+ return(80);
+
+ case 63: /* < */
+ if (subseq(c,0,1)) return(46);
+ return(subseq('=',63,62));
+
+ case 65: /* > */
+ if (subseq(c,0,1)) return(45);
+ return(subseq('=',65,64));
+
+ case 34: /* ! */
+ return(subseq('=',34,61));
+
+ case 43: /* / */
+ if (subseq('*',1,0))
+ return(43);
+com:
+ c = getchar();
+com1:
+ if (c=='\0') {
+ eof++;
+ error("Nonterminated comment");
+ return(0);
+ }
+ if (c=='\n')
+ line++;
+ if (c!='*')
+ goto com;
+ c = getchar();
+ if (c!='/')
+ goto com1;
+ c = getchar();
+ goto loop;
+
+ case 124: /* number */
+ cval = 0;
+ if (c=='0')
+ b = 8; else
+ b = 10;
+ while(ctab[c]==124) {
+ cval = cval*b + c -'0';
+ c = getchar();
+ }
+ peekc = c;
+ return(21);
+
+ case 122: /* " */
+ return(getstr());
+
+ case 121: /* ' */
+ return(getcc());
+
+ case 123: /* letter */
+ sp = symbuf;
+ while(ctab[c]==123 | ctab[c]==124) {
+ if (sp<symbuf+namsiz) *sp++ = c;
+ c = getchar();
+ }
+ while(sp<symbuf+namsiz)
+ *sp++ = '\0';
+ peekc = c;
+ csym = lookup();
+ if (csym[0]==1) { /* keyword */
+ cval = csym[1];
+ return(19);
+ }
+ return(20);
+
+ case 127: /* unknown */
+ error("Unknown character");
+ c = getchar();
+ goto loop;
+
+ }
+ return(ctab[c]);
+}
+
+subseq(c,a,b) {
+ extern getchar, peekc;
+
+ if (!peekc)
+ peekc = getchar();
+ if (peekc != c)
+ return(a);
+ peekc = 0;
+ return(b);
+}
+getstr() {
+ extern isn, cval;
+ auto c;
+
+ printf(".data;L%d:.byte ", cval=isn++);
+ while((c=mapch('"')) >= 0)
+ printf("%o,", c);
+ printf("0;.even;.text\n");
+ return(22);
+}
+
+getcc()
+{
+ extern cval, ncpw;
+ auto c, cc;
+ char cp[];
+
+ cval = 0;
+ cp = &cval;
+ cc = 0;
+ while((c=mapch('\'')) >= 0)
+ if(cc++ < ncpw)
+ *cp++ = c;
+ if(cc>ncpw)
+ error("Long character constant");
+ return(21);
+}
+
+mapch(c)
+{
+ extern peekc, line;
+ auto a;
+
+ if((a=getchar())==c)
+ return(-1);
+ switch(a) {
+
+ case '\n':
+ case 0:
+ error("Nonterminated string");
+ peekc = a;
+ return(-1);
+
+ case '\\':
+ switch (a=getchar()) {
+
+ case 't':
+ return('\t');
+
+ case 'n':
+ return('\n');
+
+ case '0':
+ return('\0');
+
+ case 'r':
+ return('\r');
+
+ case '\n':
+ line++;
+ return('\n');
+ }
+
+ }
+ return(a);
+}
+
+tree() {
+ extern symbol, block, csym[], ctyp, isn,
+ peeksym, opdope[], build, error, cp[], cmst[],
+ space, ospace, cval, ossiz, exit, errflush, cmsiz;
+
+ auto op[], opst[20], pp[], prst[20], andflg, o,
+ p, ps, os;
+
+ space = ospace;
+ op = opst;
+ pp = prst;
+ cp = cmst;
+ *op = 200; /* stack EOF */
+ *pp = 06;
+ andflg = 0;
+
+advanc:
+ switch (o=symbol()) {
+
+ /* name */
+ case 20:
+ if (*csym==0)
+ if((peeksym=symbol())==6)
+ *csym = 6; /* extern */
+ else {
+ if(csym[2]==0) /* unseen so far */
+ csym[2] = isn++;
+ }
+ if(*csym==6) /* extern */
+ *cp++ = block(5,20,csym[1],0,*csym,
+ csym[4],csym[5],csym[6],csym[7]);
+ else
+ *cp++ = block(2,20,csym[1],0,*csym,csym[2]);
+ goto tand;
+
+ /* short constant */
+ case 21:
+ case21:
+ *cp++ = block(1,21,ctyp,0,cval);
+ goto tand;
+
+ /* string constant */
+ case 22:
+ *cp++ = block(1,22,17,0,cval);
+
+tand:
+ if(cp>=cmst+cmsiz) {
+ error("Expression overflow");
+ exit(1);
+ }
+ if (andflg)
+ goto syntax;
+ andflg = 1;
+ goto advanc;
+
+ /* ++, -- */
+ case 30:
+ case 31:
+ if (andflg)
+ o =+ 2;
+ goto oponst;
+
+ /* ! */
+ case 34:
+ if (andflg)
+ goto syntax;
+ goto oponst;
+
+ /* - */
+ case 41:
+ if (!andflg) {
+ peeksym = symbol();
+ if (peeksym==21) {
+ peeksym = -1;
+ cval = -cval;
+ goto case21;
+ }
+ o = 37;
+ }
+ andflg = 0;
+ goto oponst;
+
+ /* & */
+ /* * */
+ case 47:
+ case 42:
+ if (andflg)
+ andflg = 0; else
+ if(o==47)
+ o = 35;
+ else
+ o = 36;
+ goto oponst;
+
+ /* ( */
+ case 6:
+ if (andflg) {
+ o = symbol();
+ if (o==7)
+ o = 101; else {
+ peeksym = o;
+ o = 100;
+ andflg = 0;
+ }
+ }
+ goto oponst;
+
+ /* ) */
+ /* ] */
+ case 5:
+ case 7:
+ if (!andflg)
+ goto syntax;
+ goto oponst;
+ }
+
+ /* binaries */
+ if (!andflg)
+ goto syntax;
+ andflg = 0;
+
+oponst:
+ p = (opdope[o]>>9) & 077;
+opon1:
+ ps = *pp;
+ if (p>ps | p==ps & (opdope[o]&0200)!=0) { /* right-assoc */
+putin:
+ switch (o) {
+
+ case 6: /* ( */
+ case 4: /* [ */
+ case 100: /* call */
+ p = 04;
+ }
+ if(op>=opst+20) { /* opstack size */
+ error("expression overflow");
+ exit(1);
+ }
+ *++op = o;
+ *++pp = p;
+ goto advanc;
+ }
+ --pp;
+ switch (os = *op--) {
+
+ /* EOF */
+ case 200:
+ peeksym = o;
+ return(*--cp);
+
+ /* call */
+ case 100:
+ if (o!=7)
+ goto syntax;
+ build(os);
+ goto advanc;
+
+ /* mcall */
+ case 101:
+ *cp++ = 0; /* 0 arg call */
+ os = 100;
+ goto fbuild;
+
+ /* ( */
+ case 6:
+ if (o!=7)
+ goto syntax;
+ goto advanc;
+
+ /* [ */
+ case 4:
+ if (o!=5)
+ goto syntax;
+ build(4);
+ goto advanc;
+ }
+fbuild:
+ build(os);
+ goto opon1;
+
+syntax:
+ error("Expression syntax");
+ errflush(o);
+ return(0);
+}
+
+declare(kw) {
+ extern csym[], symbol, paraml[], parame[];
+ extern error, cval, errflush, peeksym, exit;
+ int t[], n, o;
+
+ while((o=symbol())==20) { /* name */
+ if(kw>=5) { /* type or sort? */
+ if(*csym>0)
+ error("%p redeclared", csym[4]);
+ *csym = kw;
+ } else {
+ if ((csym[1]&017)!=0)
+ error("%p redeclared", &csym[4]);
+ csym[1] =| csym[1]&0760 | kw;
+ if (*csym==0)
+ *csym = -2;
+ }
+ while((o=symbol())==4) { /* [ */
+ if((o=symbol())==21) { /* const */
+ if(csym[1]>=020)
+ error("Bad vector");
+ csym[3] = cval;
+ o = symbol();
+ }
+ if (o!=5) /* ] */
+ goto syntax;
+ csym[1] =+ 020;
+ }
+ if(kw==8) { /* parameter */
+ *csym = -1;
+ if (paraml==0)
+ paraml = csym;
+ else
+ *parame = csym;
+ parame = csym;
+ }
+ if (o!=9) /* , */
+ break;
+ }
+ if(o==1 & kw!=8 | o==7 & kw==8)
+ return;
+syntax:
+ error("Declaration syntax");
+ errflush(o);
+}
+
+/* storage */
+
+regtab 0;
+efftab 1;
+cctab 2;
+sptab 3;
+symbuf[4];
+pssiz 8;
+namsiz 8;
+nwps 4;
+hshused 0;
+hshsiz 100;
+hshlen 800; /* 8*hshsiz */
+hshtab[800];
+space 0;
+cp 0;
+cmsiz 40;
+cmst[40];
+ctyp 0;
+isn 1;
+swsiz 120;
+swtab[120];
+swp 0;
+contlab 0;
+brklab 0;
+deflab 0;
+nreg 4;
+maprel[] 60,61,64,65,62,63,68,69,66,67;
+nauto 0;
+stack 0;
+peeksym 0177777;
+peekc 0;
+eof 0;
+line 1;
+csym 0;
+cval 0;
+ncpw 2;
+nerror 0;
+paraml;
+parame;
+tmpfil;
+
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