1 files changed, 52 insertions, 0 deletions
diff --git a/usr.bin/xlint/lint1/msg_378.c b/usr.bin/xlint/lint1/msg_378.c
new file mode 100644
index 000000000000..4698e99a9e9e
--- /dev/null
+++ b/usr.bin/xlint/lint1/msg_378.c
@@ -0,0 +1,52 @@
+/*	$NetBSD: msg_378.c,v 1.3 2024/08/31 06:57:32 rillig Exp $	*/
+# 3 "msg_378.c"
+
+// Test for message: conversion '%.*s' is unreachable by input value [378]
+
+/*
+ * The typical use case of snprintb is to have a format that is specifically
+ * tailored to a particular input value.  Often, a format is only used in a
+ * single place.  Therefore, bits that are unreachable are redundant and may
+ * hint at typos.
+ */
+
+/* lint1-extra-flags: -X 351 */
+
+typedef typeof(sizeof(0)) size_t;
+typedef unsigned long long uint64_t;
+
+int snprintb(char *, size_t, const char *, uint64_t);
+
+void
+example(unsigned u32, uint64_t u64)
+{
+	char buf[64];
+
+	/* expect+5: warning: conversion '\040bit32' is unreachable by input value [378] */
+	snprintb(buf, sizeof(buf),
+	    "\020"
+	    "\037bit31"
+	    "\040bit32",
+	    u32 >> 1);
+
+	/* expect+5: warning: conversion 'b\075bit61\0' is unreachable by input value [378] */
+	snprintb(buf, sizeof(buf),
+	    "\177\020"
+	    "b\074bit60\0"
+	    "b\075bit61\0",
+	    u64 >> 3);
+
+	/* expect+12: warning: conversion 'b\000bit0\0' is unreachable by input value [378] */
+	/* expect+11: warning: conversion 'b\011bit9\0' is unreachable by input value [378] */
+	/* expect+10: warning: conversion 'f\017\002bits15-16\0' is unreachable by input value [378] */
+	/* expect+9: warning: conversion 'f\050\030bits40-63\0' is unreachable by input value [378] */
+	snprintb(buf, sizeof(buf),
+	    "\177\020"
+	    "b\000bit0\0"
+	    "b\010bit8\0"
+	    "b\011bit9\0"
+	    "f\012\002bits10-11\0"
+	    "f\017\002bits15-16\0"
+	    "f\050\030bits40-63\0",
+	    (u32 & 0xaa55aa55) << 8);
+}