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cpp: fix mutually recursive macros

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Handle cases where parameterless macros expand to each other:

	#define FOO BAR
	#define BAR FOO
	FOO

There were cases where the macros didn't make it into the hidesets,
and we would recurse infinitely. This fixes that.
This commit is contained in:
Ori Bernstein 2020-07-13 18:50:14 -07:00
parent 77ddc8c654
commit 0366f11300
2 changed files with 13 additions and 13 deletions
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2
sys/src/cmd/cpp/cpp.h
View file

@ -110,7 +110,7 @@ void doif(Tokenrow *, enum kwtype);
void expand(Tokenrow *, Nlist *);
void builtin(Tokenrow *, int);
int gatherargs(Tokenrow *, Tokenrow **, int, int *);
void substargs(Nlist *, Tokenrow *, Tokenrow **);
void substargs(Nlist *, Tokenrow *, Tokenrow **, int);
void expandrow(Tokenrow *, char *);
void maketokenrow(int, Tokenrow *);
Tokenrow *copytokenrow(Tokenrow *, Tokenrow *);

24
sys/src/cmd/cpp/macro.c
View file

@ -169,9 +169,8 @@ expandrow(Tokenrow *trp, char *flag)
}
if (np->flag&ISMAC)
builtin(trp, np->val);
else {
else
expand(trp, np);
}
tp = trp->tp;
}
if (flag)
@ -186,18 +185,17 @@ expandrow(Tokenrow *trp, char *flag)
void
expand(Tokenrow *trp, Nlist *np)
{
Tokenrow ntr;
int ntokc, narg, i;
Token *tp;
int ntokc, narg, i, hs;
Tokenrow *atr[NARG+1];
int hs;
Tokenrow ntr;
Token *tp;
copytokenrow(&ntr, np->vp); /* copy macro value */
if (np->ap==NULL) { /* parameterless */
ntokc = 1;
/* substargs for handling # and ## */
atr[0] = nil;
substargs(np, &ntr, atr);
substargs(np, &ntr, atr, trp->tp->hideset);
} else {
ntokc = gatherargs(trp, atr, (np->flag&ISVARMAC) ? rowlen(np->ap) : 0, &narg);
if (narg<0) { /* not actually a call (no '(') */
@ -210,12 +208,13 @@ expand(Tokenrow *trp, Nlist *np)
trp->tp += ntokc;
return;
}
substargs(np, &ntr, atr); /* put args into replacement */
substargs(np, &ntr, atr, trp->tp->hideset); /* put args into replacement */
for (i=0; i<narg; i++) {
dofree(atr[i]->bp);
dofree(atr[i]);
}
}
hs = newhideset(trp->tp->hideset, np);
for (tp=ntr.bp; tp<ntr.lp; tp++) { /* distribute hidesets */
if (tp->type==NAME) {
@ -343,19 +342,20 @@ ispaste(Tokenrow *rtr, Token **ap, Token **an, int *ntok)
}
return 0;
}
/*
* substitute the argument list into the replacement string
* This would be simple except for ## and #
*/
void
substargs(Nlist *np, Tokenrow *rtr, Tokenrow **atr)
substargs(Nlist *np, Tokenrow *rtr, Tokenrow **atr, int hideset)
{
Tokenrow ttr, rp, rn;
Token *tp, *ap, *an, *pp, *pn;
int ntok, argno, hs;
for (rtr->tp=rtr->bp; rtr->tp<rtr->lp; ) {
if(rtr->tp->hideset && checkhideset(rtr->tp->hideset, np)) {
if(rtr->tp->hideset && checkhideset(hideset, np)) {
rtr->tp++;
} else if (rtr->tp->type==SHARP) { /* string operator */
tp = rtr->tp;
@ -405,10 +405,10 @@ substargs(Nlist *np, Tokenrow *rtr, Tokenrow **atr)
*ttr.tp = *rtr->tp;
hs = newhideset(rtr->tp->hideset, np);
if(ttr.tp->hideset == 0)
if(hideset == 0)
ttr.tp->hideset = hs;
else
ttr.tp->hideset = unionhideset(ttr.tp->hideset, hs);
ttr.tp->hideset = unionhideset(hideset, hs);
expandrow(&ttr, (char*)np->name);
for(tp = ttr.bp; tp != ttr.lp; tp++)
if(tp->type == COMMA)