Changeset 31a566b in mainline

Timestamp:

2019-05-27T16:17:24Z (6 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

0260034

Parents:

af5037d

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2019-02-25 16:35:41)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2019-05-27 16:17:24)

Message:

Generalize and fix strtol() and friends

Added the option to recognize prefixes used by str_uint() (unused atm).
Allow the error variable be something else than errno.
Fix behavior of strtoul()/strtoull() on unsigned input. The standard
doesn't consider negative input "out of range", the expected behavior
is to just negate the unsigned input value (wraparound).

File:

• uspace/lib/c/generic/strtol.c (modified) (9 diffs)

uspace/lib/c/generic/strtol.c

@@ -69 +69 @@
 }
 
+static inline int _prefixbase(const char *restrict *nptrptr, bool nonstandard_prefixes)
+{
+        const char *nptr = *nptrptr;
+
+        if (nptr[0] != '0')
+                return 10;
+
+        if (nptr[1] == 'x' || nptr[1] == 'X') {
+                *nptrptr += 2;
+                return 16;
+        }
+
+        if (nonstandard_prefixes) {
+                switch (nptr[1]) {
+                case 'b':
+                case 'B':
+                        *nptrptr += 2;
+                        return 2;
+                case 'o':
+                case 'O':
+                        *nptrptr += 2;
+                        return 8;
+                case 'd':
+                case 'D':
+                case 't':
+                case 'T':
+                        *nptrptr += 2;
+                        return 10;
+                }
+        }
+
+        return 8;
+}
+
 static inline uintmax_t _strtoumax(
     const char *restrict nptr, char **restrict endptr, int base,
-    bool *restrict sgn)
+    bool *restrict sgn, errno_t *err, bool nonstandard_prefixes)
 {
         assert(nptr != NULL);
@@ -96 +130 @@
         /* Figure out the base. */
 
-        if (base == 0) {
-                if (*nptr == '0') {
-                        if (tolower(nptr[1]) == 'x') {
-                                /* 0x... is hex. */
-                                base = 16;
-                                nptr += 2;
-                        } else {
-                                /* 0... is octal. */
-                                base = 8;
-                        }
-                } else {
-                        /* Anything else is decimal by default. */
-                        base = 10;
-                }
-        } else if (base == 16) {
-                /* Allow hex number to be prefixed with "0x". */
-                if (nptr[0] == '0' && tolower(nptr[1]) == 'x') {
+        if (base == 0)
+                base = _prefixbase(&nptr, nonstandard_prefixes);
+
+        if (base == 16 && !nonstandard_prefixes) {
+                /*
+                 * Standard strto* functions allow hexadecimal prefix to be
+                 * present when base is explicitly set to 16.
+                 * Our nonstandard str_* functions don't allow it.
+                 */
+
+                if (nptr[0] == '0' && (nptr[1] == 'x' || nptr[1] == 'X'))
                         nptr += 2;
-                }
-        } else if (base < 0 || base == 1 || base > 36) {
-                errno = EINVAL;
+        }
+
+        if (base < 2 || base > 36) {
+                *err = EINVAL;
                 return 0;
         }
@@ -127 +156 @@
 
         while (digit = _digit_value(*nptr), digit < base) {
-
                 if (result > max ||
                     __builtin_add_overflow(result * base, digit, &result)) {
 
-                        errno = ERANGE;
+                        *err = ERANGE;
                         result = UINTMAX_MAX;
                         break;
@@ -145 +173 @@
                  * Move the pointer to the end of the number,
                  * in case it isn't there already.
+                 * This can happen when the number has legal formatting,
+                 * but is out of range of the target type.
                  */
                 while (_digit_value(*nptr) < base) {
@@ -157 +187 @@
 
 static inline intmax_t _strtosigned(const char *nptr, char **endptr, int base,
-    intmax_t min, intmax_t max)
+    intmax_t min, intmax_t max, errno_t *err, bool nonstandard_prefixes)
 {
         bool sgn = false;
-        uintmax_t number = _strtoumax(nptr, endptr, base, &sgn);
+        uintmax_t number = _strtoumax(nptr, endptr, base, &sgn, err,
+            nonstandard_prefixes);
 
         if (number > (uintmax_t) max) {
@@ -167 +198 @@
                 }
 
-                errno = ERANGE;
+                *err = ERANGE;
                 return (sgn ? min : max);
         }
@@ -175 +206 @@
 
 static inline uintmax_t _strtounsigned(const char *nptr, char **endptr, int base,
-    uintmax_t max)
+    uintmax_t max, errno_t *err, bool nonstandard_prefixes)
 {
         bool sgn = false;
-        uintmax_t number = _strtoumax(nptr, endptr, base, &sgn);
-
-        if (sgn) {
-                if (number == 0) {
-                        return 0;
-                } else {
-                        errno = ERANGE;
-                        return max;
-                }
-        }
+        uintmax_t number = _strtoumax(nptr, endptr, base, &sgn, err,
+            nonstandard_prefixes);
 
         if (number > max) {
-                errno = ERANGE;
+                *err = ERANGE;
                 return max;
         }
 
-        return number;
+        return (sgn ? -number : number);
 }
 
@@ -212 +235 @@
 long strtol(const char *nptr, char **endptr, int base)
 {
-        return _strtosigned(nptr, endptr, base, LONG_MIN, LONG_MAX);
+        return _strtosigned(nptr, endptr, base, LONG_MIN, LONG_MAX, &errno, false);
 }
 
@@ -230 +253 @@
 unsigned long strtoul(const char *nptr, char **endptr, int base)
 {
-        return _strtounsigned(nptr, endptr, base, ULONG_MAX);
+        return _strtounsigned(nptr, endptr, base, ULONG_MAX, &errno, false);
 }
 
 long long strtoll(const char *nptr, char **endptr, int base)
 {
-        return _strtosigned(nptr, endptr, base, LLONG_MIN, LLONG_MAX);
+        return _strtosigned(nptr, endptr, base, LLONG_MIN, LLONG_MAX, &errno, false);
 }
 
 unsigned long long strtoull(const char *nptr, char **endptr, int base)
 {
-        return _strtounsigned(nptr, endptr, base, ULLONG_MAX);
+        return _strtounsigned(nptr, endptr, base, ULLONG_MAX, &errno, false);
 }
 
 intmax_t strtoimax(const char *nptr, char **endptr, int base)
 {
-        return _strtosigned(nptr, endptr, base, INTMAX_MIN, INTMAX_MAX);
+        return _strtosigned(nptr, endptr, base, INTMAX_MIN, INTMAX_MAX, &errno, false);
 }
 
 uintmax_t strtoumax(const char *nptr, char **endptr, int base)
 {
-        return _strtounsigned(nptr, endptr, base, UINTMAX_MAX);
+        return _strtounsigned(nptr, endptr, base, UINTMAX_MAX, &errno, false);
 }