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

[Simon Glass]

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 <s...@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