The clang warning -Wshorten-64-to-32 can be useful to catch
inadvertent truncation. In some instances this truncation can lead to
changing the sign of a result, for example, truncation to return an
int to fit a sort routine. Silence the warning by making the implicit
truncation explicit.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/api/fs/fs.c | 4 ++--
 tools/lib/bitmap.c    | 2 +-
 tools/lib/string.c    | 6 +++---
 tools/lib/vsprintf.c  | 6 +++---
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index edec23406dbc..2c4677901de9 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -349,7 +349,7 @@ int filename__read_str(const char *filename, char **buf, size_t *sizep)
 {
 	struct io io;
 	char bf[128];
-	int err;
+	ssize_t err;
 
 	io.fd = open(filename, O_RDONLY);
 	if (io.fd < 0)
@@ -363,7 +363,7 @@ int filename__read_str(const char *filename, char **buf, size_t *sizep)
 	} else
 		err = 0;
 	close(io.fd);
-	return err;
+	return (int)err;
 }
 
 int filename__write_int(const char *filename, int value)
diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
index 2178862bb114..87bd15e3968e 100644
--- a/tools/lib/bitmap.c
+++ b/tools/lib/bitmap.c
@@ -32,7 +32,7 @@ size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
 			char *buf, size_t size)
 {
 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
-	unsigned int cur, rbot, rtop;
+	size_t cur, rbot, rtop;
 	bool first = true;
 	size_t ret = 0;
 
diff --git a/tools/lib/string.c b/tools/lib/string.c
index 3126d2cff716..638e75b63538 100644
--- a/tools/lib/string.c
+++ b/tools/lib/string.c
@@ -182,7 +182,7 @@ char *strreplace(char *s, char old, char new)
 	return s;
 }
 
-static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
+static void *check_bytes8(const u8 *start, u8 value, size_t bytes)
 {
 	while (bytes) {
 		if (*start != value)
@@ -206,7 +206,7 @@ void *memchr_inv(const void *start, int c, size_t bytes)
 {
 	u8 value = c;
 	u64 value64;
-	unsigned int words, prefix;
+	size_t words, prefix;
 
 	if (bytes <= 16)
 		return check_bytes8(start, value, bytes);
@@ -216,7 +216,7 @@ void *memchr_inv(const void *start, int c, size_t bytes)
 	value64 |= value64 << 16;
 	value64 |= value64 << 32;
 
-	prefix = (unsigned long)start % 8;
+	prefix = (size_t)start % 8;
 	if (prefix) {
 		u8 *r;
 
diff --git a/tools/lib/vsprintf.c b/tools/lib/vsprintf.c
index 8780b4cdab21..62028a5eea7e 100644
--- a/tools/lib/vsprintf.c
+++ b/tools/lib/vsprintf.c
@@ -8,7 +8,7 @@ int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
        int i = vsnprintf(buf, size, fmt, args);
        ssize_t ssize = size;
 
-       return (i >= ssize) ? (ssize - 1) : i;
+       return (i >= ssize) ? (int)(ssize - 1) : i;
 }
 
 int scnprintf(char * buf, size_t size, const char * fmt, ...)
@@ -21,7 +21,7 @@ int scnprintf(char * buf, size_t size, const char * fmt, ...)
        i = vsnprintf(buf, size, fmt, args);
        va_end(args);
 
-       return (i >= ssize) ? (ssize - 1) : i;
+       return (i >= ssize) ? (int)(ssize - 1) : i;
 }
 
 int scnprintf_pad(char * buf, size_t size, const char * fmt, ...)
@@ -40,5 +40,5 @@ int scnprintf_pad(char * buf, size_t size, const char * fmt, ...)
 		buf[i] = 0x0;
 	}
 
-	return (i >= ssize) ? (ssize - 1) : i;
+	return (i >= ssize) ? (int)(ssize - 1) : i;
 }
-- 
2.49.0.504.g3bcea36a83-goog

On Tue, Apr 01, 2025 at 11:23:03AM -0700, Ian Rogers wrote:
> The clang warning -Wshorten-64-to-32 can be useful to catch
> inadvertent truncation. In some instances this truncation can lead to
> changing the sign of a result, for example, truncation to return an
> int to fit a sort routine. Silence the warning by making the implicit
> truncation explicit.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---

...

> diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
> index 2178862bb114..87bd15e3968e 100644
> --- a/tools/lib/bitmap.c
> +++ b/tools/lib/bitmap.c
> @@ -32,7 +32,7 @@ size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
>  			char *buf, size_t size)
>  {
>  	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
> -	unsigned int cur, rbot, rtop;
> +	size_t cur, rbot, rtop;
>  	bool first = true;
>  	size_t ret = 0;

Maybe instead typecast find_next_bit()? We don't expect any of those
to overflow the 'unsigned int'.

Thanks,
Yury