[PATCH 6/6] lib: Provide a signed version of simple_itoa()

[Heinrich Schuchardt]

Am 19. März 2025 12:59:08 MEZ schrieb Simon Glass <sjg at chromium.org>:
>In some cases we want to show a signed value to the user without needing
>to use the full printf() implementation. Add a new version of the
>simple_itoa() function to handle this.

Where will this be used?
Why can't printf be used?
Why would this fit into this series which is about test improvements and not about functional changes?

Best regards

Heinrich 


>
>Update the existing function to use ulong instead of long, to avoid
>confusion about which it actually uses.
>
>Signed-off-by: Simon Glass <sjg at chromium.org>
>---
>
> include/vsprintf.h | 14 ++++++++++++++
> lib/vsprintf.c     | 29 +++++++++++++++++++++++++----
> test/lib/str.c     | 17 ++++++++++++++++-
> 3 files changed, 55 insertions(+), 5 deletions(-)
>
>diff --git a/include/vsprintf.h b/include/vsprintf.h
>index 9da6ce7cc4d..cd079684572 100644
>--- a/include/vsprintf.h
>+++ b/include/vsprintf.h
>@@ -219,6 +219,20 @@ int vsprintf(char *buf, const char *fmt, va_list args);
>  */
> char *simple_itoa(ulong val);
> 
>+/**
>+ * simple_itoa_signed() - convert a signed integer to a string
>+ *
>+ * This returns a static string containing the decimal representation of the
>+ * given value. The returned value may be overwritten by other calls to other
>+ * simple... functions, so should be used immediately
>+ *
>+ * If the value is negative, a minus sign ('-') is prepended
>+ *
>+ * @val: Value to convert
>+ * Return: string containing the signed decimal representation of @val
>+ */
>+char *simple_itoa_signed(long i);
>+
> /**
>  * simple_xtoa() - convert an unsigned integer to a hex string
>  *
>diff --git a/lib/vsprintf.c b/lib/vsprintf.c
>index c7340a047b2..478d445a569 100644
>--- a/lib/vsprintf.c
>+++ b/lib/vsprintf.c
>@@ -845,21 +845,42 @@ int vprintf(const char *fmt, va_list args)
> }
> #endif
> 
>-static char local_toa[22];
>+static char local_toa[23];
> 
>-char *simple_itoa(ulong i)
>+char *simple_itoa_(ulong i, bool use_signed)
> {
>-	/* 21 digits plus null terminator, good for 64-bit or smaller ints */
>-	char *p = &local_toa[21];
>+	/*
>+	 * 21 digits plus sign and null terminator, good for 64-bit or smaller
>+	 * ints
>+	 */
>+	char *p = &local_toa[22];
>+	bool neg = false;
> 
>+	if (use_signed && (long)i < 0) {
>+		i = -i;
>+		neg = true;
>+	}
> 	*p-- = '\0';
> 	do {
> 		*p-- = '0' + i % 10;
> 		i /= 10;
> 	} while (i > 0);
>+
>+	if (neg)
>+		*p-- = '-';
> 	return p + 1;
> }
> 
>+char *simple_itoa(ulong i)
>+{
>+	return simple_itoa_(i, false);
>+}
>+
>+char *simple_itoa_signed(long i)
>+{
>+	return simple_itoa_(i, true);
>+}
>+
> char *simple_xtoa(ulong num)
> {
> 	/* 16 digits plus nul terminator, good for 64-bit or smaller ints */
>diff --git a/test/lib/str.c b/test/lib/str.c
>index e62045318c0..d6d29bbf3eb 100644
>--- a/test/lib/str.c
>+++ b/test/lib/str.c
>@@ -221,14 +221,29 @@ static int str_itoa(struct unit_test_state *uts)
> 	ut_asserteq_str("123", simple_itoa(123));
> 	ut_asserteq_str("0", simple_itoa(0));
> 	ut_asserteq_str("2147483647", simple_itoa(0x7fffffff));
>-	ut_asserteq_str("4294967295", simple_itoa(0xffffffff));
>+	ut_asserteq_str("2147483647", simple_itoa_signed(0x7fffffff));
>+	ut_asserteq_str("2147483648", simple_itoa(0x80000000));
>+	if (IS_ENABLED(CONFIG_PHYS_64BIT)) {
>+		ut_asserteq_str("2147483648", simple_itoa_signed(0x80000000));
>+		ut_asserteq_str("4294967295", simple_itoa_signed(0xffffffff));
>+	} else {
>+		ut_asserteq_str("-2147483648", simple_itoa_signed(0x80000000));
>+		ut_asserteq_str("-1", simple_itoa_signed(0xffffffff));
>+	}
> 
> 	/* Use #ifdef here to avoid a compiler warning on 32-bit machines */
> #ifdef CONFIG_PHYS_64BIT
> 	if (sizeof(ulong) == 8) {
> 		ut_asserteq_str("9223372036854775807",
> 				simple_itoa((1UL << 63) - 1));
>+		ut_asserteq_str("9223372036854775807",
>+				simple_itoa_signed((1UL << 63) - 1));
>+		ut_asserteq_str("9223372036854775808",
>+				simple_itoa((1UL << 63)));
>+		ut_asserteq_str("-9223372036854775808",
>+				simple_itoa_signed((1UL << 63)));
> 		ut_asserteq_str("18446744073709551615", simple_itoa(-1));
>+		ut_asserteq_str("-1", simple_itoa_signed(-1));
> 	}
> #endif /* CONFIG_PHYS_64BIT */
>