V2/c/nc0/c02.c
function() {
extern declare, blkhed, blkend;
extern printf, statement, peeksym, cval, symbol, retseq;
extern paraml;
auto o;
printf(".text; 1:mov r5,-(sp); mov sp,r5\n");
declare(8);
declist();
statement(1);
retseq();
}
extdef() {
extern eof, function, cval;
extern symbol, block, printf, pname, errflush, csym[];
extern error;
auto o, c, cs[];
char s[];
if(((o=symbol())==0) | o==1) /* EOF */
return;
if(o!=20)
goto syntax;
csym[0] = 6;
cs = &csym[4];
printf(".globl %p\n", cs);
s = ".data; %p:1f\n";
switch(o=symbol()) {
case 6: /* ( */
printf(s, cs);
function();
return;
case 21: /* const */
printf(".data; %p: %o\n", cs, cval);
if((o=symbol())!=1) /* ; */
goto syntax;
return;
case 1: /* ; */
printf(".bss; %p: .=.+2\n", cs);
return;
case 4: /* [ */
c = 0;
if((o=symbol())==21) { /* const */
c = cval<<1;
o = symbol();
}
if(o!=5) /* ] */
goto syntax;
printf(s, cs);
if((o=symbol())==1) { /* ; */
printf(".bss; 1:.=.+%o\n", c);
return;
}
printf("1:");
while(o==21) { /* const */
printf("%o\n", cval);
c =- 2;
if((o=symbol())==1) /* ; */
goto done;
if(o!=9) /* , */
goto syntax;
else
o = symbol();
}
goto syntax;
done:
if(c>0)
printf(".=.+%o\n", c);
return;
case 0: /* EOF */
return;
}
syntax:
error("External definition syntax");
errflush(o);
statement(0);
}
statement(d) {
extern symbol, error, blkhed, eof, peeksym;
extern blkend, csym[], rcexpr, block[], tree[], regtab[];
extern retseq, jumpc, jump, label, contlab, brklab, cval;
extern swp[], isn, pswitch, peekc, slabel;
extern efftab[], declare, deflab, errflush, swtab[], swsiz, branch;
int o, o1, o2, o3, np[];
stmt:
switch(o=symbol()) {
/* EOF */
case 0:
error("Unexpected EOF");
/* ; */
case 1:
/* } */
case 3:
return;
/* { */
case 2: {
if(d)
blkhed();
while (!eof) {
if ((o=symbol())==3) /* } */
goto bend;
peeksym = o;
statement(0);
}
error("Missing '}'");
bend:
return;
}
/* keyword */
case 19:
switch(cval) {
/* goto */
case 10:
o1 = block(1,102,0,0,tree());
rcexpr(o1, regtab);
goto semi;
/* return */
case 11:
if((peeksym=symbol())==6) /* ( */
rcexpr(pexpr(), regtab);
retseq();
goto semi;
/* if */
case 12:
jumpc(pexpr(), o1=isn++, 0);
statement(0);
if ((o=symbol())==19 & cval==14) { /* else */
o2 = isn++;
(easystmt()?branch:jump)(o2);
label(o1);
statement(0);
label(o2);
return;
}
peeksym = o;
label(o1);
return;
/* while */
case 13:
o1 = contlab;
o2 = brklab;
label(contlab = isn++);
jumpc(pexpr(), brklab=isn++, 0);
o3 = easystmt();
statement(0);
(o3?branch:jump)(contlab);
label(brklab);
contlab = o1;
brklab = o2;
return;
/* break */
case 17:
if(brklab==0)
error("Nothing to break from");
jump(brklab);
goto semi;
/* continue */
case 18:
if(contlab==0)
error("Nothing to continue");
jump(contlab);
goto semi;
/* do */
case 19:
o1 = contlab;
o2 = brklab;
contlab = isn++;
brklab = isn++;
label(o3 = isn++);
statement(0);
label(contlab);
contlab = o1;
if ((o=symbol())==19 & cval==13) { /* while */
jumpc(tree(), o3, 1);
label(brklab);
brklab = o2;
goto semi;
}
goto syntax;
/* case */
case 16:
if ((o=symbol())!=21) /* constant */
goto syntax;
if ((o=symbol())!=8) /* : */
goto syntax;
if (swp==0) {
error("Case not in switch");
goto stmt;
}
if(swp>=swtab+swsiz) {
error("Switch table overflow");
} else {
*swp++ = isn;
*swp++ = cval;
label(isn++);
}
goto stmt;
/* switch */
case 15:
o1 = brklab;
brklab = isn++;
np = pexpr();
if (np[1]>1 & np[1]<16)
error("Integer required");
rcexpr(np, regtab);
pswitch();
brklab = o1;
return;
/* default */
case 20:
if (swp==0)
error("Default not in switch");
if ((o=symbol())!=8) /* : */
goto syntax;
deflab = isn++;
label(deflab);
goto stmt;
}
error("Unknown keyword");
goto syntax;
/* name */
case 20:
if (peekc==':') {
peekc = 0;
if (csym[0]>0) {
error("Redefinition");
goto stmt;
}
csym[0] = 2;
csym[1] = 020; /* int[] */
if (csym[2]==0)
csym[2] = isn++;
slabel();
goto stmt;
}
}
peeksym = o;
rcexpr(tree(), efftab);
goto semi;
semi:
if ((o=symbol())!=1) /* ; */
goto syntax;
return;
syntax:
error("Statement syntax");
errflush(o);
goto stmt;
}
pexpr()
{
auto o, t;
if ((o=symbol())!=6) /* ( */
goto syntax;
t = tree();
if ((o=symbol())!=7) /* ) */
goto syntax;
return(t);
syntax:
error("Statement syntax");
errflush(o);
return(0);
}
pswitch() {
extern swp[], isn, swtab[], printf, deflab, statement, brklab;
extern label;
int sswp[], dl, cv, swlab;
sswp = swp;
if (swp==0)
swp = swtab;
swlab = isn++;
printf("jsr pc,bswitch; l%d\n", swlab);
dl = deflab;
deflab = 0;
statement(0);
if (!deflab) {
deflab = isn++;
label(deflab);
}
printf("L%d:.data;L%d:", brklab, swlab);
while(swp>sswp & swp>swtab) {
cv = *--swp;
printf("%o; l%d\n", cv, *--swp);
}
printf("L%d; 0\n.text\n", deflab);
deflab = dl;
swp = sswp;
}
blkhed()
{
extern symbol, cval, declare, peeksym, paraml[], parame[];
extern error, length, rlength, setstk, defvec, isn, defstat;
extern stack, hshtab[], hshsiz, pssiz;
int o, al, pl, cs[], hl;
declist();
stack = al = -2;
pl = 4;
while(paraml) {
*parame = 0;
paraml = *(cs = paraml);
cs[2] = pl;
*cs = 10;
pl =+ rlength(cs[1]);
}
cs = hshtab;
hl = hshsiz;
while(hl--) {
if (cs[4])
switch(cs[0]) {
/* sort unmentioned */
case 0177776: /* -2 */
cs[0] = 5; /* auto */
/* auto */
case 5:
if (cs[3]) { /* vector */
al =- (cs[3]*length(cs[1]-020)+1) & 077776;
setstk(al);
defvec(al);
}
cs[2] = al;
al =- rlength(cs[1]);
goto loop;
/* parameter */
case 10:
cs[0] = 5;
goto loop;
/* static */
case 7:
cs[2] = isn++;
defstat(cs);
goto loop;
loop:;
}
cs = cs+pssiz;
}
setstk(al);
}
blkend() {
extern hshtab[], hshsiz, pssiz, hshused;
auto i, hl;
i = 0;
hl = hshsiz;
while(hl--) {
if(hshtab[i+4])
if (hshtab[i]==0)
error("%p undefined", &hshtab[i+4]);
if(hshtab[i]!=1) { /* not keyword */
hshused--;
hshtab[i+4] = 0;
}
i =+ pssiz;
}
}
errflush(o) {
extern symbol, peeksym, eof;
while(o>3) /* ; { } */
o = symbol();
peeksym = o;
}
declist()
{
extern peeksym, peekc, csym[], cval;
auto o;
while((o=symbol())==19 & cval<10)
declare(cval);
peeksym = o;
}
easystmt()
{
extern peeksym, peekc, cval;
if((peeksym=symbol())==20) /* name */
return(peekc!=':'); /* not label */
if (peeksym==19) { /* keyword */
switch(cval)
case 10: /* goto */
case 11: /* return */
case 17: /* break */
case 18: /* continue */
return(1);
return(0);
}
return(peeksym!=2); /* { */
}
branch(lab)
{
printf("br L%d\n", lab);
}