Module Name: src
Committed By: rillig
Date: Fri Mar 1 19:40:45 UTC 2024
Added Files:
src/usr.bin/xlint/lint1: cksnprintb.c
Log Message:
lint: test format strings from snprintb calls
The functions snprintb and snprintb_m are specific to NetBSD, and their
format strings are tricky to get correct. Provide some assistance in
catching the most common mistakes.
To generate a diff of this commit:
cvs rdiff -u -r0 -r1.1 src/usr.bin/xlint/lint1/cksnprintb.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Added files:
Index: src/usr.bin/xlint/lint1/cksnprintb.c
diff -u /dev/null src/usr.bin/xlint/lint1/cksnprintb.c:1.1
--- /dev/null Fri Mar 1 19:40:45 2024
+++ src/usr.bin/xlint/lint1/cksnprintb.c Fri Mar 1 19:40:45 2024
@@ -0,0 +1,290 @@
+/* $NetBSD: cksnprintb.c,v 1.1 2024/03/01 19:40:45 rillig Exp $ */
+
+/*-
+ * Copyright (c) 2024 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Roland Illig <ril...@netbsd.org>.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if HAVE_NBTOOL_CONFIG_H
+#include "nbtool_config.h"
+#endif
+
+#include <sys/cdefs.h>
+#if defined(__RCSID)
+__RCSID("$NetBSD: cksnprintb.c,v 1.1 2024/03/01 19:40:45 rillig Exp $");
+#endif
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "lint1.h"
+
+static bool
+match_string_literal(const tnode_t *tn, const buffer **str)
+{
+ while (tn->tn_op == CVT)
+ tn = tn_ck_left(tn);
+ return tn->tn_op == ADDR
+ && tn->tn_left->tn_op == STRING
+ && (*str = tn->tn_left->tn_string, (*str)->data != NULL);
+}
+
+static bool
+match_snprintb_call(const function_call *call,
+ const buffer **out_fmt, const tnode_t **out_val)
+{
+ const char *func;
+ const tnode_t *val;
+ const buffer *str;
+
+ if (call->func->tn_op == ADDR
+ && call->func->tn_left->tn_op == NAME
+ && (func = call->func->tn_left->tn_sym->s_name, true)
+ && ((strcmp(func, "snprintb") == 0 && call->args_len == 4)
+ || (strcmp(func, "snprintb_m") == 0 && call->args_len == 5))
+ && match_string_literal(call->args[2], &str)
+ && (val = call->args[3], true)) {
+ *out_fmt = str;
+ *out_val = val;
+ return true;
+ }
+ return false;
+}
+
+static int
+len(quoted_iterator it)
+{
+ return (int)(it.i - it.start);
+}
+
+static int
+range(quoted_iterator start, quoted_iterator end)
+{
+ return (int)(end.i - start.start);
+}
+
+static const char *
+start(quoted_iterator it, const buffer *buf)
+{
+ return buf->data + it.start;
+}
+
+static uintmax_t
+val(quoted_iterator it)
+{
+ return it.value;
+}
+
+static void
+check_hex_escape(const buffer *buf, quoted_iterator it)
+{
+ if (it.hex_digits > 1) {
+ bool upper = false;
+ bool lower = false;
+ for (size_t i = it.start + 2; i < it.i; i++) {
+ if (isupper((unsigned char)buf->data[i]))
+ upper = true;
+ if (islower((unsigned char)buf->data[i]))
+ lower = true;
+ }
+ if (upper && lower)
+ /* hex escape '%.*s' mixes uppercase and lower... */
+ warning(357, len(it), start(it, buf));
+ }
+ if (it.hex_digits > 2)
+ /* hex escape '%.*s' has more than 2 digits */
+ warning(358, len(it), start(it, buf));
+}
+
+static bool
+check_directive(const buffer *fmt, quoted_iterator *it, bool new_style,
+ uint64_t *prev_field_width)
+{
+
+ if (!quoted_next(fmt, it))
+ return false;
+ quoted_iterator dir = *it;
+
+ bool has_bit = !new_style
+ || dir.value == 'b' || dir.value == 'f' || dir.value == 'F';
+ if (has_bit && new_style && !quoted_next(fmt, it)) {
+ /* missing bit position after '%.*s' */
+ warning(364, len(dir), start(dir, fmt));
+ return false;
+ }
+ /* LINTED 86 "automatic 'bit' hides external declaration" */
+ quoted_iterator bit = *it;
+
+ bool has_width = new_style
+ && (dir.value == 'f' || dir.value == 'F');
+ if (has_width && !quoted_next(fmt, it)) {
+ /* missing field width after '%.*s' */
+ warning(365, range(dir, bit), start(dir, fmt));
+ return false;
+ }
+ quoted_iterator width = *it;
+
+ bool has_cmp = new_style
+ && (dir.value == '=' || dir.value == ':');
+ if (has_cmp && !quoted_next(fmt, it)) {
+ /* missing comparison value after directive '%.*s' */
+ warning(368, range(dir, bit), start(dir, fmt));
+ return false;
+ }
+ quoted_iterator cmp = *it;
+
+ bool has_default = new_style && dir.value == '*';
+ if (has_default && !quoted_next(fmt, it)) {
+ /* missing '\0' at the end of '%.*s' */
+ warning(366, range(dir, *it), start(dir, fmt));
+ return false;
+ }
+
+ if (!has_bit && !has_cmp && !has_default) {
+ /* unknown directive '%.*s' */
+ warning(374, len(dir), start(dir, fmt));
+ return false;
+ }
+
+ if (!quoted_next(fmt, it)) {
+ if (new_style && dir.value != '*')
+ /* missing '\0' at the end of '%.*s' */
+ warning(366, range(dir, *it), start(dir, fmt));
+ else
+ /* empty description in '%.*s' */
+ warning(367, range(dir, *it), start(dir, fmt));
+ return false;
+ }
+ quoted_iterator descr = *it;
+
+ quoted_iterator prev = *it;
+ for (;;) {
+ if (new_style && it->value == 0)
+ break;
+ if (!new_style && it->value == 0)
+ /* old-style format contains '\0' */
+ warning(362);
+ if (!new_style && it->value <= 32) {
+ *it = prev;
+ break;
+ }
+ if (it->escaped && !isprint((unsigned char)it->value)) {
+ /* non-printing character '%.*s' in description ... */
+ warning(363,
+ len(*it), start(*it, fmt),
+ range(descr, *it), start(descr, fmt));
+ }
+ prev = *it;
+ if (!quoted_next(fmt, it)) {
+ if (new_style) {
+ /* missing '\0' at the end of '%.*s' */
+ warning(366, range(dir, prev),
+ start(dir, fmt));
+ }
+ break;
+ }
+ }
+
+ if (has_bit)
+ check_hex_escape(fmt, bit);
+ if (has_width)
+ check_hex_escape(fmt, width);
+ if (has_bit && bit.octal_digits == 0 && bit.hex_digits == 0) {
+ /* bit position '%.*s' in '%.*s' should be escaped as ... */
+ warning(369, len(bit), start(bit, fmt),
+ range(dir, *it), start(dir, fmt));
+ }
+ if (has_width && width.octal_digits == 0 && width.hex_digits == 0) {
+ /* field width '%.*s' in '%.*s' should be escaped as ... */
+ warning(370, len(width), start(width, fmt),
+ range(dir, *it), start(dir, fmt));
+ }
+ if (has_bit && (new_style ? bit.value > 63 : bit.value - 1 > 31)) {
+ /* bit position '%.*s' (%ju) in '%.*s' out of range %u..%u */
+ warning(371,
+ len(bit), start(bit, fmt), val(bit),
+ range(dir, *it), start(dir, fmt),
+ new_style ? 0 : 1, new_style ? 63 : 32);
+ }
+ if (has_width && width.value > (new_style ? 64 : 32)) {
+ /* field width '%.*s' (%ju) in '%.*s' out of range 0..%u */
+ warning(372,
+ len(width), start(width, fmt), val(width),
+ range(dir, *it), start(dir, fmt),
+ new_style ? 64 : 32);
+ }
+ if (has_width && bit.value + width.value > 64) {
+ /* bit field end %ju in '%.*s' out of range 0..64 */
+ warning(373, val(bit) + val(width),
+ range(dir, *it), start(dir, fmt));
+ }
+ if (has_cmp && *prev_field_width < 64
+ && cmp.value & ~(uint64_t)0 << *prev_field_width) {
+ /* comparison value '%.*s' (%ju) exceeds field width %ju */
+ warning(375, len(cmp), start(cmp, fmt), val(cmp),
+ *prev_field_width);
+ }
+ if (descr.i == prev.i && dir.value != 'F') {
+ /* empty description in '%.*s' */
+ warning(367, range(dir, *it), start(dir, fmt));
+ }
+
+ if (has_width)
+ *prev_field_width = width.value;
+ return true;
+}
+
+void
+check_snprintb(const tnode_t *expr)
+{
+ const buffer *fmt;
+ const tnode_t *value;
+ if (!match_snprintb_call(expr->tn_call, &fmt, &value))
+ return;
+
+ quoted_iterator it = { .start = 0 };
+ if (!quoted_next(fmt, &it)) {
+ /* missing new-style '\177' or old-style number base */
+ warning(359);
+ return;
+ }
+ bool new_style = it.value == '\177';
+ if (new_style && !quoted_next(fmt, &it)) {
+ /* missing new-style number base after '\177' */
+ warning(360);
+ return;
+ }
+ if (it.value != 8 && it.value != 10 && it.value != 16) {
+ /* number base '%.*s' is %ju, should be 8, 10 or 16 */
+ warning(361, len(it), start(it, fmt), val(it));
+ return;
+ }
+
+ uint64_t prev_field_width = 64;
+ while (check_directive(fmt, &it, new_style, &prev_field_width))
+ continue;
+}
