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cc: simplify macexpand() and off-by-one error

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the caller of macexpand() needs one more byte in
the buffer to append peekc.

make macexpand() actually check for buffer overflow.

just use strdup() to duplicate include file name
instead of the hunk dance.

move GETC() macro in cc.h
This commit is contained in:
cinap_lenrek 2020-04-25 22:16:44 +02:00
parent 4adb1d68d1
commit 7feab4dc59
4 changed files with 13 additions and 18 deletions
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2
sys/src/cmd/cc/cc.h
View file

@ -143,6 +143,8 @@ EXTERN struct
int c;
} fi;
#define GETC() ((--fi.c < 0)? filbuf(): (*fi.p++ & 0xff))
struct Io
{
Io* link;

3
sys/src/cmd/cc/lex.c
View file

@ -430,7 +430,6 @@ syminit(Sym *s)
#define EOF (-1)
#define IGN (-2)
#define ESC (1<<20)
#define GETC() ((--fi.c < 0)? filbuf(): (*fi.p++ & 0xff))
enum
{
@ -756,7 +755,7 @@ talph:
if(s->macro) {
newio();
cp = ionext->b;
macexpand(s, cp, sizeof(ionext->b));
macexpand(s, cp, sizeof(ionext->b)-1);
pushio();
ionext->link = iostack;
iostack = ionext;

2
sys/src/cmd/cc/lexbody
View file

@ -238,7 +238,7 @@ l1:
if(s->macro) {
newio();
cp = ionext->b;
macexpand(s, cp, sizeof(ionext->b));
macexpand(s, cp, sizeof(ionext->b)-1);
pushio();
ionext->link = iostack;
iostack = ionext;

24
sys/src/cmd/cc/macbody
View file

@ -350,7 +350,7 @@ macdef(void)
}
base = allocn(base, len, 1);
base[len++] = c;
c = ((--fi.c < 0)? filbuf(): (*fi.p++ & 0xff));
c = GETC();
if(c == '\n')
lineno++;
if(c == -1) {
@ -387,7 +387,10 @@ macexpand(Sym *s, char *b, int blen)
char *arg[NARG], *cp, *ob, *eb, *ecp, dots;
if(*s->macro == 0) {
b[blen-1] = 0;
strncpy(b, s->macro+1, blen);
if(b[blen-1] != '\0')
goto toobig;
if(debug['m'])
print("#expand %s %s\n", s->name, b);
return;
@ -573,32 +576,23 @@ macinc(void)
if(c != '\n')
goto bad;
f = -1;
c = 0;
for(i=0; i<ninclude; i++) {
if(i == 0 && c0 == '>')
continue;
c = snprint(symb, NSYMB, "%s/%s", include[i], str)+1;
if(strncmp(symb, "./", 2) == 0){
c = snprint(symb, NSYMB, "%s/%s", include[i], str);;
while(strncmp(symb, "./", 2) == 0){
c -= 2;
memmove(symb, symb+2, c);
memmove(symb, symb+2, c+1);
}
f = open(symb, 0);
if(f >= 0)
break;
}
if(f < 0)
c = snprint(symb, NSYMB, "%s", str)+1;
while(c & 3)
c++;
while(nhunk < c)
gethunk();
hp = hunk;
memmove(hunk, symb, c);
nhunk -= c;
hunk += c;
snprint(symb, NSYMB, "%s", str);
newio();
pushio();
newfile(hp, f);
newfile(strdup(symb), f);
return;
bad: