scc

commit ed1a8159a3f06e7c4da43567e8dee276d392f3bd
parent 42fd80186eb88ab683c82a866366d2c72657e1ac
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Mon,  1 Nov 2021 16:03:26 +0100

cc1: Fold pointer constants

The case of a pointer constant was missed in foldconst()
that implied a dangerous default case that generated a
dangling node without a specified value. To avoid having
this case in the future we add a default case with an
abort.

Diffstat:
M
src/cmd/cc/cc1/fold.c
 | 
4
++++

1 file changed, 4 insertions(+), 0 deletions(-)
diff --git a/src/cmd/cc/cc1/fold.c b/src/cmd/cc/cc1/fold.c
@@ -293,6 +293,7 @@ foldconst(int type, int op, Type *tp, Symbol *ls, Symbol *rs)
 		if (!foldint(op, &aux, ls->u.i, i))
 			return NULL;
 		break;
+	case PTR:
 	case UNSIGNED:
 		u = (rs) ? rs->u.u : 0u;
 		if (!folduint(op, &aux, ls->u.u, u))
@@ -303,6 +304,8 @@ foldconst(int type, int op, Type *tp, Symbol *ls, Symbol *rs)
 		if (!foldfloat(op, &aux, ls->u.f, f))
 			return NULL;
 		break;
+	default:
+		abort();
 	}
 	sym = newsym(NS_IDEN, NULL);
 	sym->flags |= SCONSTANT;
@@ -355,6 +358,7 @@ foldcast(Node *np, Node *l)
 	default:
 		return np;
 	}
+
 	DBG("FOLD cast %c->%c", oldtp->letter, newtp->letter);
 	freetree(np);
 	sym = newsym(NS_IDEN, NULL);