diff options
| -rw-r--r-- | usr.bin/xlint/lint1/tree.c | 63 |
1 files changed, 52 insertions, 11 deletions
diff --git a/usr.bin/xlint/lint1/tree.c b/usr.bin/xlint/lint1/tree.c index 592070b366f..5e1346ca952 100644 --- a/usr.bin/xlint/lint1/tree.c +++ b/usr.bin/xlint/lint1/tree.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tree.c,v 1.15 2005/11/28 04:57:26 cloder Exp $ */ +/* $OpenBSD: tree.c,v 1.16 2005/11/28 22:29:57 cloder Exp $ */ /* $NetBSD: tree.c,v 1.12 1995/10/02 17:37:57 jpo Exp $ */ /* @@ -33,7 +33,7 @@ */ #ifndef lint -static char rcsid[] = "$OpenBSD: tree.c,v 1.15 2005/11/28 04:57:26 cloder Exp $"; +static char rcsid[] = "$OpenBSD: tree.c,v 1.16 2005/11/28 22:29:57 cloder Exp $"; #endif #include <stdlib.h> @@ -77,6 +77,7 @@ static tnode_t *foldtst(tnode_t *); static tnode_t *foldflt(tnode_t *); static tnode_t *chkfarg(type_t *, tnode_t *); static tnode_t *parg(int, type_t *, tnode_t *); +static int chkdbz(op_t, tnode_t *); static void nulleff(tnode_t *); static void displexpr(tnode_t *, int); static void chkaidx(tnode_t *, int); @@ -2522,6 +2523,52 @@ bldasgn(op_t op, tnode_t *ln, tnode_t *rn) return (ntn); } + +/* + * Check for division by zero. Returns 1 if a division by zero is + * present, 0 otherwise. + */ +static int +chkdbz(op_t op, tnode_t *rn) +{ + quad_t q; + ldbl_t r; + int code; + + switch (op) { + case DIV: + case DIVASS: + code = 139; /* division by 0 */ + break; + case MOD: + case MODASS: + code = 140; /* modular division by 0 */ + break; + default: + return 0; + } + + /* no way of checking unless right side is a constant */ + if (rn->tn_op != CON) + return 0; + + if (isftyp(rn->tn_type->t_tspec)) { + if (rn->tn_val->v_ldbl == 0.0) { + /* division by 0 */ + error(code); + return 1; + } + } else { + if (rn->tn_val->v_quad == 0) { + /* division by 0 */ + error(code); + return 1; + } + } + + return 0; +} + /* * Get length of type tp->t_subt. */ @@ -2648,18 +2695,14 @@ fold(tnode_t *tn) ovfl = 1; break; case DIV: - if (sr == 0) { - /* division by 0 */ - error(139); + if (chkdbz(tn->tn_op, tn)) { q = utyp ? UQUAD_MAX : QUAD_MAX; } else { q = utyp ? ul / ur : sl / sr; } break; case MOD: - if (sr == 0) { - /* modulus by 0 */ - error(140); + if (chkdbz(tn->tn_op, tn)) { q = 0; } else { q = utyp ? ul % ur : sl % sr; @@ -2847,9 +2890,7 @@ foldflt(tnode_t *tn) v->v_ldbl = l * r; break; case DIV: - if (r == 0.0) { - /* division by 0 */ - error(139); + if (chkdbz(tn->tn_op, tn)) { if (t == FLOAT) { v->v_ldbl = l < 0 ? -FLT_MAX : FLT_MAX; } else if (t == DOUBLE) { |