Refactor to remove duplicated nan/inf parsing code in
pystrtod.c, floatobject.c and dtoa.c.
diff --git a/Python/pystrtod.c b/Python/pystrtod.c
index d36f931..95c0ff6 100644
--- a/Python/pystrtod.c
+++ b/Python/pystrtod.c
@@ -3,6 +3,57 @@
#include <Python.h>
#include <locale.h>
+/* _Py_parse_inf_or_nan: Attempt to parse a string of the form "nan", "inf" or
+ "infinity", with an optional leading sign of "+" or "-". On success,
+ return the NaN or Infinity as a double and set *endptr to point just beyond
+ the successfully parsed portion of the string. On failure, return -1.0 and
+ set *endptr to point to the start of the string. */
+
+static int
+case_insensitive_match(const char *s, const char *t)
+{
+ while(*t && Py_TOLOWER(*s) == *t) {
+ s++;
+ t++;
+ }
+ return *t ? 0 : 1;
+}
+
+double
+_Py_parse_inf_or_nan(const char *p, char **endptr)
+{
+ double retval;
+ const char *s;
+ int negate = 0;
+
+ s = p;
+ if (*s == '-') {
+ negate = 1;
+ s++;
+ }
+ else if (*s == '+') {
+ s++;
+ }
+ if (case_insensitive_match(s, "inf")) {
+ s += 3;
+ if (case_insensitive_match(s, "inity"))
+ s += 5;
+ retval = negate ? -Py_HUGE_VAL : Py_HUGE_VAL;
+ }
+#ifdef Py_NAN
+ else if (case_insensitive_match(s, "nan")) {
+ s += 3;
+ retval = negate ? -Py_NAN : Py_NAN;
+ }
+#endif
+ else {
+ s = p;
+ retval = -1.0;
+ }
+ *endptr = (char *)s;
+ return retval;
+}
+
/**
* PyOS_ascii_strtod:
* @nptr: the string to convert to a numeric value.
@@ -49,6 +100,10 @@
result = _Py_dg_strtod(nptr, endptr);
_Py_SET_53BIT_PRECISION_END;
+ if (*endptr == nptr)
+ /* string might represent and inf or nan */
+ result = _Py_parse_inf_or_nan(nptr, endptr);
+
return result;
}
@@ -63,19 +118,6 @@
correctly rounded results.
*/
-/* Case-insensitive string match used for nan and inf detection; t should be
- lower-case. Returns 1 for a successful match, 0 otherwise. */
-
-static int
-case_insensitive_match(const char *s, const char *t)
-{
- while(*t && Py_TOLOWER(*s) == *t) {
- s++;
- t++;
- }
- return *t ? 0 : 1;
-}
-
double
_PyOS_ascii_strtod(const char *nptr, char **endptr)
{
@@ -101,6 +143,11 @@
decimal_point_pos = NULL;
+ /* Parse infinities and nans */
+ val = _Py_parse_inf_or_nan(nptr, endptr);
+ if (*endptr != nptr)
+ return val;
+
/* Set errno to zero, so that we can distinguish zero results
and underflows */
errno = 0;
@@ -118,31 +165,6 @@
p++;
}
- /* Parse infinities and nans */
- if (*p == 'i' || *p == 'I') {
- if (case_insensitive_match(p+1, "nf")) {
- val = Py_HUGE_VAL;
- if (case_insensitive_match(p+3, "inity"))
- fail_pos = (char *)p+8;
- else
- fail_pos = (char *)p+3;
- goto got_val;
- }
- else
- goto invalid_string;
- }
-#ifdef Py_NAN
- if (*p == 'n' || *p == 'N') {
- if (case_insensitive_match(p+1, "an")) {
- val = Py_NAN;
- fail_pos = (char *)p+3;
- goto got_val;
- }
- else
- goto invalid_string;
- }
-#endif
-
/* Some platform strtods accept hex floats; Python shouldn't (at the
moment), so we check explicitly for strings starting with '0x'. */
if (*p == '0' && (*(p+1) == 'x' || *(p+1) == 'X'))
@@ -231,7 +253,6 @@
if (fail_pos == digits_pos)
goto invalid_string;
- got_val:
if (negate && fail_pos != nptr)
val = -val;
*endptr = fail_pos;