From: Thomas Haller Date: Wed, 27 Sep 2023 12:23:28 +0000 (+0200) Subject: netlink_linearize: avoid strict-overflow warning in netlink_gen_bitwise() X-Git-Tag: v1.1.0~164 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d07c874797295f425541464ac84864e591fc0614;p=thirdparty%2Fnftables.git netlink_linearize: avoid strict-overflow warning in netlink_gen_bitwise() With gcc-13.2.1-1.fc38.x86_64: $ gcc -Iinclude -c -o tmp.o src/netlink_linearize.c -Werror -Wstrict-overflow=5 -O3 src/netlink_linearize.c: In function ‘netlink_gen_bitwise’: src/netlink_linearize.c:1790:1: error: assuming signed overflow does not occur when changing X +- C1 cmp C2 to X cmp C2 -+ C1 [-Werror=strict-overflow] 1790 | } | ^ cc1: all warnings being treated as errors It also makes more sense this way, where "n" is the hight of the "binops" stack, and we check for a non-empty stack with "n > 0" and pop the last element with "binops[--n]". Signed-off-by: Thomas Haller Signed-off-by: Florian Westphal --- diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c index df395bac..61828eb9 100644 --- a/src/netlink_linearize.c +++ b/src/netlink_linearize.c @@ -711,14 +711,13 @@ static void netlink_gen_bitwise(struct netlink_linearize_ctx *ctx, while (left->etype == EXPR_BINOP && left->left != NULL && (left->op == OP_AND || left->op == OP_OR || left->op == OP_XOR)) binops[n++] = left = left->left; - n--; - netlink_gen_expr(ctx, binops[n--], dreg); + netlink_gen_expr(ctx, binops[--n], dreg); mpz_bitmask(mask, expr->len); mpz_set_ui(xor, 0); - for (; n >= 0; n--) { - i = binops[n]; + while (n > 0) { + i = binops[--n]; mpz_set(val, i->right->value); switch (i->op) {