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Research V6 development
[unix-history] / usr / source / c / c00.c
#
/* C compiler
*
*
*
* Called from cc:
* c0 source temp1 temp2 [ profileflag ]
* temp1 contains some ascii text and the binary expression
* trees. Each tree is introduced by the # character.
* Strings are put on temp2, which cc tacks onto
* temp1 for assembly.
*/
#include "c0h.c"
int isn 1;
int stflg 1;
int peeksym -1;
int line 1;
int debug 0;
int dimp 0;
struct tname funcblk { NAME, 0, 0, REG, 0, 0 };
int *treespace { osspace };
struct kwtab {
char *kwname;
int kwval;
} kwtab[]
{
"int", INT,
"char", CHAR,
"float", FLOAT,
"double", DOUBLE,
"struct", STRUCT,
"long", LONG,
"auto", AUTO,
"extern", EXTERN,
"static", STATIC,
"register", REG,
"goto", GOTO,
"return", RETURN,
"if", IF,
"while", WHILE,
"else", ELSE,
"switch", SWITCH,
"case", CASE,
"break", BREAK,
"continue", CONTIN,
"do", DO,
"default", DEFAULT,
"for", FOR,
"sizeof", SIZEOF,
0, 0,
};
main(argc, argv)
char *argv[];
{
extern fin;
register char *sp;
register i;
register struct kwtab *ip;
if(argc<3) {
error("Arg count");
exit(1);
}
if((fin=open(argv[1],0))<0) {
error("Can't find %s", argv[1]);
exit(1);
}
if (fcreat(argv[2], obuf)<0 || fcreat(argv[3], sbuf)<0) {
error("Can't create temp");
exit(1);
}
if (argc>4)
proflg++;
/*
* The hash table locations of the keywords
* are marked; if an identifier hashes to one of
* these locations, it is looked up in in the keyword
* table first.
*/
for (ip=kwtab; (sp = ip->kwname); ip++) {
i = 0;
while (*sp)
i =+ *sp++;
hshtab[i%hshsiz].hflag = FKEYW;
}
while(!eof) {
extdef();
blkend();
}
outcode("B", EOF);
strflg++;
outcode("B", EOF);
fflush(obuf);
fflush(sbuf);
exit(nerror!=0);
}
/*
* Look up the identifier in symbuf in the symbol table.
* If it hashes to the same spot as a keyword, try the keyword table
* first. An initial "." is ignored in the hash.
* Return is a ptr to the symbol table entry.
*/
lookup()
{
int ihash;
register struct hshtab *rp;
register char *sp, *np;
ihash = 0;
sp = symbuf;
if (*sp=='.')
sp++;
while (sp<symbuf+ncps)
ihash =+ *sp++;
rp = &hshtab[ihash%hshsiz];
if (rp->hflag&FKEYW)
if (findkw())
return(KEYW);
while (*(np = rp->name)) {
for (sp=symbuf; sp<symbuf+ncps;)
if (*np++ != *sp++)
goto no;
csym = rp;
return(NAME);
no:
if (++rp >= &hshtab[hshsiz])
rp = hshtab;
}
if(++hshused >= hshsiz) {
error("Symbol table overflow");
exit(1);
}
rp->hclass = 0;
rp->htype = 0;
rp->hoffset = 0;
rp->dimp = 0;
rp->hflag =| xdflg;
sp = symbuf;
for (np=rp->name; sp<symbuf+ncps;)
*np++ = *sp++;
csym = rp;
return(NAME);
}
/*
* Search the keyword table.
* Ignore initial "." to avoid member-of-structure
* problems.
*/
findkw()
{
register struct kwtab *kp;
register char *p1, *p2;
char *wp;
wp = symbuf;
if (*wp=='.')
wp++;
for (kp=kwtab; (p2 = kp->kwname); kp++) {
p1 = wp;
while (*p1 == *p2++)
if (*p1++ == '\0') {
cval = kp->kwval;
return(1);
}
}
return(0);
}
/*
* Return the next symbol from the input.
* peeksym is a pushed-back symbol, peekc is a pushed-back
* character (after peeksym).
* mosflg means that the next symbol, if an identifier,
* is a member of structure or a structure tag, and it
* gets a "." prepended to it to distinguish
* it from other identifiers.
*/
symbol() {
register c;
register char *sp;
if (peeksym>=0) {
c = peeksym;
peeksym = -1;
if (c==NAME)
mosflg = 0;
return(c);
}
if (peekc) {
c = peekc;
peekc = 0;
} else
if (eof)
return(EOF);
else
c = getchar();
loop:
switch(ctab[c]) {
case INSERT: /* ignore newlines */
inhdr = 1;
c = getchar();
goto loop;
case NEWLN:
if (!inhdr)
line++;
inhdr = 0;
case SPACE:
c = getchar();
goto loop;
case EOF:
eof++;
return(0);
case PLUS:
return(subseq(c,PLUS,INCBEF));
case MINUS:
return(subseq(c,subseq('>',MINUS,ARROW),DECBEF));
case ASSIGN:
if (subseq(' ',0,1)) return(ASSIGN);
c = symbol();
if (c>=PLUS && c<=EXOR) {
if (spnextchar() != ' '
&& (c==MINUS || c==AND || c==TIMES)) {
error("Warning: assignment operator assumed");
nerror--;
}
return(c+ASPLUS-PLUS);
}
if (c==ASSIGN)
return(EQUAL);
peeksym = c;
return(ASSIGN);
case LESS:
if (subseq(c,0,1)) return(LSHIFT);
return(subseq('=',LESS,LESSEQ));
case GREAT:
if (subseq(c,0,1)) return(RSHIFT);
return(subseq('=',GREAT,GREATEQ));
case EXCLA:
return(subseq('=',EXCLA,NEQUAL));
case DIVIDE:
if (subseq('*',1,0))
return(DIVIDE);
while ((c = spnextchar()) != EOF) {
peekc = 0;
if (c=='*') {
if (spnextchar() == '/') {
peekc = 0;
c = getchar();
goto loop;
}
}
}
eof++;
error("Nonterminated comment");
return(0);
case PERIOD:
case DIGIT:
peekc = c;
if ((c=getnum(c=='0'?8:10)) == FCON)
cval = isn++;
return(c);
case DQUOTE:
return(getstr());
case SQUOTE:
return(getcc());
case LETTER:
sp = symbuf;
if (mosflg) {
*sp++ = '.';
mosflg = 0;
}
while(ctab[c]==LETTER || ctab[c]==DIGIT) {
if (sp<symbuf+ncps) *sp++ = c;
c = getchar();
}
while(sp<symbuf+ncps)
*sp++ = '\0';
peekc = c;
if ((c=lookup())==KEYW && cval==SIZEOF)
c = SIZEOF;
return(c);
case AND:
return(subseq('&', AND, LOGAND));
case OR:
return(subseq('|', OR, LOGOR));
case UNKN:
error("Unknown character");
c = getchar();
goto loop;
}
return(ctab[c]);
}
/*
* If the next input character is c, return a and advance.
* Otherwise push back the character and return a.
*/
subseq(c,a,b)
{
if (spnextchar() != c)
return(a);
peekc = 0;
return(b);
}
/*
* Read a double-quoted string, placing it on the
* string buffer.
*/
getstr()
{
register int c;
register char *sp;
nchstr = 1;
sp = savstr;
while((c=mapch('"')) >= 0) {
nchstr++;
if (sp >= &savstr[STRSIZ]) {
sp = savstr;
error("String too long");
}
*sp++ = c;
}
strptr = sp;
cval = isn++;
return(STRING);
}
/*
* Write out a string, either in-line
* or in the string temp file labelled by
* lab.
*/
putstr(lab)
{
register char *sp;
if (lab) {
strflg++;
outcode("BNB", LABEL, lab, BDATA);
} else
outcode("B", BDATA);
for (sp = savstr; sp<strptr; )
outcode("1N", *sp++ & 0377);
outcode("100");
strflg = 0;
}
/*
* read a single-quoted character constant.
* The routine is sensitive to the layout of
* characters in a word.
*/
getcc()
{
register int c, cc;
register char *ccp;
cval = 0;
ccp = &cval;
cc = 0;
while((c=mapch('\'')) >= 0)
if(cc++ < NCPW)
*ccp++ = c;
if(cc>NCPW)
error("Long character constant");
return(CON);
}
/*
* Read a character in a string or character constant,
* detecting the end of the string.
* It implements the escape sequences.
*/
mapch(ac)
{
register int a, c, n;
static mpeek;
c = ac;
if (a = mpeek)
mpeek = 0;
else
a = getchar();
loop:
if (a==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 'b':
return('\b');
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
n = 0;
c = 0;
while (++c<=3 && '0'<=a && a<='7') {
n =<< 3;
n =+ a-'0';
a = getchar();
}
mpeek = a;
return(n);
case 'r':
return('\r');
case '\n':
if (!inhdr)
line++;
inhdr = 0;
a = getchar();
goto loop;
}
}
return(a);
}
/*
* Read an expression and return a pointer to its tree.
* It's the classical bottom-up, priority-driven scheme.
* The initflg prevents the parse from going past
* "," or ":" because those delimitesrs are special
* in initializer (and some other) expressions.
*/
tree()
{
#define SEOF 200
#define SSIZE 20
int *op, opst[SSIZE], *pp, prst[SSIZE];
register int andflg, o;
register struct hshtab *cs;
int p, ps, os;
space = treespace;
op = opst;
pp = prst;
cp = cmst;
*op = SEOF;
*pp = 06;
andflg = 0;
advanc:
switch (o=symbol()) {
case NAME:
cs = csym;
if (cs->hclass==0 && cs->htype==0)
if(nextchar()=='(') {
/* set function */
cs->hclass = EXTERN;
cs->htype = FUNC;
} else if (initflg)
cs->hclass = EXTERN;
else {
/* set label */
cs->htype = ARRAY;
if (cs->hoffset==0)
cs->hoffset = isn++;
}
*cp++ = copname(cs);
goto tand;
case FCON:
if (!initflg)
outcode("BBNB1N1N1N1N0B", DATA,LABEL,
cval, WDATA, fcval, PROG);
case CON:
case SFCON:
*cp++ = block(1,o,(o==CON?INT:DOUBLE),0,cval);
goto tand;
/* fake a static char array */
case STRING:
putstr(cval);
*cp++ = block(3, NAME, ARRAY+CHAR,0,STATIC,0,cval);
tand:
if(cp>=cmst+cmsiz) {
error("Expression overflow");
exit(1);
}
if (andflg)
goto syntax;
andflg = 1;
goto advanc;
case INCBEF:
case DECBEF:
if (andflg)
o =+ 2;
goto oponst;
case COMPL:
case EXCLA:
case SIZEOF:
if (andflg)
goto syntax;
goto oponst;
case MINUS:
if (!andflg) {
if ((peeksym=symbol())==FCON) {
fcval = - fcval;
goto advanc;
}
if (peeksym==SFCON) {
fcval = - fcval;
cval =^ 0100000;
goto advanc;
}
o = NEG;
}
andflg = 0;
goto oponst;
case AND:
case TIMES:
if (andflg)
andflg = 0; else
if(o==AND)
o = AMPER;
else
o = STAR;
goto oponst;
case LPARN:
if (andflg) {
o = symbol();
if (o==RPARN)
o = MCALL;
else {
peeksym = o;
o = CALL;
andflg = 0;
}
}
goto oponst;
case RBRACK:
case RPARN:
if (!andflg)
goto syntax;
goto oponst;
case DOT:
case ARROW:
mosflg++;
break;
}
/* binaries */
if (!andflg)
goto syntax;
andflg = 0;
oponst:
p = (opdope[o]>>9) & 077;
if ((o==COMMA || o==COLON) && initflg)
p = 05;
opon1:
ps = *pp;
if (p>ps || p==ps && (opdope[o]&RASSOC)!=0) {
switch (o) {
case INCAFT:
case DECAFT:
p = 37;
break;
case LPARN:
case LBRACK:
case CALL:
p = 04;
}
if (op >= &opst[SSIZE-1]) {
error("expression overflow");
exit(1);
}
*++op = o;
*++pp = p;
goto advanc;
}
--pp;
switch (os = *op--) {
case SEOF:
peeksym = o;
build(0); /* flush conversions */
return(*--cp);
case CALL:
if (o!=RPARN)
goto syntax;
build(os);
goto advanc;
case MCALL:
*cp++ = block(0,0,0,0); /* 0 arg call */
os = CALL;
break;
case INCBEF:
case INCAFT:
case DECBEF:
case DECAFT:
*cp++ = block(1, CON, INT, 0, 1);
break;
case LPARN:
if (o!=RPARN)
goto syntax;
goto advanc;
case LBRACK:
if (o!=RBRACK)
goto syntax;
build(LBRACK);
goto advanc;
}
build(os);
goto opon1;
syntax:
error("Expression syntax");
errflush(o);
return(0);
}
/*
* Generate a tree node for a name.
* All the relevant info from the symbol table is
* copied out, including the name if it's an external.
* This is because the symbol table is gone in the next
* pass, so a ptr isn't sufficient.
*/
copname(acs)
struct hshtab *acs;
{
register struct hshtab *cs;
register struct tname *tp;
register char *cp1;
int i;
char *cp2;
cs = acs;
tp = gblock(sizeof(*tp)/NCPW);
tp->op = NAME;
tp->type = cs->htype;
tp->dimp = cs->hdimp;
if ((tp->class = cs->hclass)==0)
tp->class = STATIC;
tp->offset = 0;
tp->nloc = cs->hoffset;
if (cs->hclass==EXTERN) {
gblock((ncps-NCPW)/NCPW);
cp1 = tp->nname;
cp2 = cs->name;
i = ncps;
do {
*cp1++ = *cp2++;
} while (--i);
}
if (cs->hflag&FFIELD)
tp->class = FMOS;
return(tp);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.