[PATCH 08/15] lib: Move common digit-parsing code into a function

Simon Glass
2021-07-20T13:31:27Z

The code to convert a character into a digit is repeated twice in this
file. Factor it out into a separate function. This also makes the code a
little easier to read.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

lib/strto.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/lib/strto.c b/lib/strto.c
index ab6867a963f..c3f0f8e8c6c 100644
--- a/lib/strto.c
+++ b/lib/strto.c
@@ -30,16 +30,33 @@ static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
return s;
}

+/**
+ * decode_digit() - Decode a single character into its numeric digit value
+ *
+ * This ignore case
+ *
+ * @ch: Character to convert (expects '0'..'9', 'a'..'f' or 'A'..'F')
+ * @return value of digit (0..0xf) or 255 if the character is invalid
+ */
+static uint decode_digit(int ch)
+{
+ if (!isxdigit(ch))
+ return 256;
+
+ ch = tolower(ch);
+
+ return ch <= '9' ? ch - '0' : ch - 'a' + 0xa;
+}
+
ulong simple_strtoul(const char *cp, char **endp, uint base)
{
ulong result = 0;
- ulong value;
+ uint value;

cp = _parse_integer_fixup_radix(cp, &base);

- while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
- ? toupper(*cp) : *cp)-'A'+10) < base) {
- result = result*base + value;
+ while (value = decode_digit(*cp), value < base) {
+ result = result * base + value;
cp++;
}

@@ -136,12 +153,12 @@ unsigned long long ustrtoull(const char *cp, char **endp, unsigned int base)
unsigned long long simple_strtoull(const char *cp, char **endp,
unsigned int base)
{
- unsigned long long result = 0, value;
+ unsigned long long result = 0;
+ uint value;

cp = _parse_integer_fixup_radix(cp, &base);

- while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp - '0'
- : (islower(*cp) ? toupper(*cp) : *cp) - 'A' + 10) < base) {
+ while (value = decode_digit(*cp), value < base) {
result = result * base + value;
cp++;
}
--
2.32.0.402.g57bb445576-goog