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Issue #5914: Add new C-API function PyOS_string_to_double, to complement 

PyOS_double_to_string, and deprecate PyOS_ascii_strtod and PyOS_ascii_atof.
This commit is contained in:
Mark Dickinson 2009-05-03 20:33:40 +00:00
parent 75930f85df
commit 725bfd8489
10 changed files with 253 additions and 96 deletions
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40
Doc/c-api/conversion.rst
View File

@ -62,6 +62,43 @@ The following functions provide locale-independent string to number conversions.
See the Unix man page :manpage:`strtod(2)` for details.
.. deprecated:: 3.1
Use :cfunc:`PyOS_string_to_double` instead.
.. cfunction:: double PyOS_string_to_double(const char *s, char **endptr, PyObject *overflow_exception)
Convert a string ``s`` to a :ctype:`double`, raising a Python
exception on failure. The set of accepted strings corresponds to
the set of strings accepted by Python's :func:`float` constructor,
except that ``s`` must not have leading or trailing whitespace.
The conversion is independent of the current locale.
If ``endptr`` is ``NULL``, convert the whole string. Raise
ValueError and return ``-1.0`` if the string is not a valid
representation of a floating-point number.
If endptr is not ``NULL``, convert as much of the string as
possible and set ``*endptr`` to point to the first unconverted
character. If no initial segment of the string is the valid
representation of a floating-point number, set ``*endptr`` to point
to the beginning of the string, raise ValueError, and return
``-1.0``.
If ``s`` represents a value that is too large to store in a float
(for example, ``"1e500"`` is such a string on many platforms) then
if ``overflow_exception`` is ``NULL`` return ``Py_HUGE_VAL`` (with
an appropriate sign) and don't set any exception. Otherwise,
``overflow_exception`` must point to a Python exception object;
raise that exception and return ``-1.0``. In both cases, set
``*endptr`` to point to the first character after the converted value.
If any other error occurs during the conversion (for example an
out-of-memory error), set the appropriate Python exception and
return ``-1.0``.
.. versionadded:: 3.1
.. cfunction:: char* PyOS_ascii_formatd(char *buffer, size_t buf_len, const char *format, double d)
@ -117,6 +154,9 @@ The following functions provide locale-independent string to number conversions.
See the Unix man page :manpage:`atof(2)` for details.
.. deprecated:: 3.1
Use PyOS_string_to_double instead.
.. cfunction:: char* PyOS_stricmp(char *s1, char *s2)

3
Include/pystrtod.h
View File

@ -9,6 +9,9 @@ extern "C" {
PyAPI_FUNC(double) PyOS_ascii_strtod(const char *str, char **ptr);
PyAPI_FUNC(double) PyOS_ascii_atof(const char *str);
PyAPI_FUNC(char *) PyOS_ascii_formatd(char *buffer, size_t buf_len, const char *format, double d);
PyAPI_FUNC(double) PyOS_string_to_double(const char *str,
char **endptr,
PyObject *overflow_exception);
/* The caller is responsible for calling PyMem_Free to free the buffer
that's is returned. */

12
Modules/_pickle.c
View File

@ -2971,15 +2971,15 @@ load_float(UnpicklerObject *self)
return bad_readline();
errno = 0;
d = PyOS_ascii_strtod(s, &endptr);
if ((errno == ERANGE && !(fabs(d) <= 1.0)) ||
(endptr[0] != '\n') || (endptr[1] != '\0')) {
d = PyOS_string_to_double(s, &endptr, PyExc_OverflowError);
if (d == -1.0 && PyErr_Occurred())
return -1;
if ((endptr[0] != '\n') || (endptr[1] != '\0')) {
PyErr_SetString(PyExc_ValueError, "could not convert string to float");
return -1;
}
if ((value = PyFloat_FromDouble(d)) == NULL)
value = PyFloat_FromDouble(d);
if (value == NULL)
return -1;
PDATA_PUSH(self->stack, value, -1);

49
Modules/_testcapimodule.c
View File

@ -1045,6 +1045,54 @@ test_with_docstring(PyObject *self)
Py_RETURN_NONE;
}
/* Test PyOS_string_to_double. */
static PyObject *
test_string_to_double(PyObject *self) {
double result;
char *msg;
#define CHECK_STRING(STR, expected) \
result = PyOS_string_to_double(STR, NULL, NULL); \
if (result == -1.0 && PyErr_Occurred()) \
return NULL; \
if (result != expected) { \
msg = "conversion of " STR " to float failed"; \
goto fail; \
}
#define CHECK_INVALID(STR) \
result = PyOS_string_to_double(STR, NULL, NULL); \
if (result == -1.0 && PyErr_Occurred()) { \
if (PyErr_ExceptionMatches(PyExc_ValueError)) \
PyErr_Clear(); \
else \
return NULL; \
} \
else { \
msg = "conversion of " STR " didn't raise ValueError"; \
goto fail; \
}
CHECK_STRING("0.1", 0.1);
CHECK_STRING("1.234", 1.234);
CHECK_STRING("-1.35", -1.35);
CHECK_STRING(".1e01", 1.0);
CHECK_STRING("2.e-2", 0.02);
CHECK_INVALID(" 0.1");
CHECK_INVALID("\t\n-3");
CHECK_INVALID(".123 ");
CHECK_INVALID("3\n");
CHECK_INVALID("123abc");
Py_RETURN_NONE;
fail:
return raiseTestError("test_string_to_double", msg);
#undef CHECK_STRING
#undef CHECK_INVALID
}
#ifdef HAVE_GETTIMEOFDAY
/* Profiling of integer performance */
static void print_delta(int test, struct timeval *s, struct timeval *e)
@ -1223,6 +1271,7 @@ static PyMethodDef TestMethods[] = {
{"test_empty_argparse", (PyCFunction)test_empty_argparse,METH_NOARGS},
{"test_null_strings", (PyCFunction)test_null_strings, METH_NOARGS},
{"test_string_from_format", (PyCFunction)test_string_from_format, METH_NOARGS},
{"test_string_to_double", (PyCFunction)test_string_to_double, METH_NOARGS},
{"test_with_docstring", (PyCFunction)test_with_docstring, METH_NOARGS,
PyDoc_STR("This is a pretty normal docstring.")},

32
Objects/complexobject.c
View File

@ -799,25 +799,26 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
*/
/* first look for forms starting with <float> */
errno = 0;
z = PyOS_ascii_strtod(s, &end);
if (end == s && errno == ENOMEM)
return PyErr_NoMemory();
if (errno == ERANGE && fabs(z) >= 1.0)
goto overflow;
z = PyOS_string_to_double(s, &end, PyExc_OverflowError);
if (z == -1.0 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_ValueError))
PyErr_Clear();
else
return NULL;
}
if (end != s) {
/* all 4 forms starting with <float> land here */
s = end;
if (*s == '+' || *s == '-') {
/* <float><signed-float>j | <float><sign>j */
x = z;
errno = 0;
y = PyOS_ascii_strtod(s, &end);
if (end == s && errno == ENOMEM)
return PyErr_NoMemory();
if (errno == ERANGE && fabs(y) >= 1.0)
goto overflow;
y = PyOS_string_to_double(s, &end, PyExc_OverflowError);
if (y == -1.0 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_ValueError))
PyErr_Clear();
else
return NULL;
}
if (end != s)
/* <float><signed-float>j */
s = end;
@ -877,11 +878,6 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
PyErr_SetString(PyExc_ValueError,
"complex() arg is a malformed string");
return NULL;
overflow:
PyErr_SetString(PyExc_OverflowError,
"complex() arg overflow");
return NULL;
}
static PyObject *

28
Objects/floatobject.c
View File

@ -193,36 +193,20 @@ PyFloat_FromString(PyObject *v)
/* We don't care about overflow or underflow. If the platform
* supports them, infinities and signed zeroes (on underflow) are
* fine. */
errno = 0;
PyFPE_START_PROTECT("strtod", goto error)
x = PyOS_ascii_strtod(s, (char **)&end);
PyFPE_END_PROTECT(x)
if (end == s) {
if (errno == ENOMEM)
PyErr_NoMemory();
else {
PyOS_snprintf(buffer, sizeof(buffer),
"invalid literal for float(): %.200s", s);
PyErr_SetString(PyExc_ValueError, buffer);
}
x = PyOS_string_to_double(s, (char **)&end, NULL);
if (x == -1.0 && PyErr_Occurred())
goto error;
}
/* Since end != s, the platform made *some* kind of sense out
of the input. Trust it. */
while (*end && isspace(Py_CHARMASK(*end)))
end++;
if (end != last) {
if (*end == '\0')
PyErr_SetString(PyExc_ValueError,
"null byte in argument for float()");
if (end == last)
result = PyFloat_FromDouble(x);
else {
PyOS_snprintf(buffer, sizeof(buffer),
"invalid literal for float(): %.200s", s);
PyErr_SetString(PyExc_ValueError, buffer);
result = NULL;
}
goto error;
}
result = PyFloat_FromDouble(x);
error:
if (s_buffer)
PyMem_FREE(s_buffer);

12
Python/ast.c
View File

@ -3162,17 +3162,17 @@ parsenumber(struct compiling *c, const char *s)
#ifndef WITHOUT_COMPLEX
if (imflag) {
compl.real = 0.;
PyFPE_START_PROTECT("atof", return 0)
compl.imag = PyOS_ascii_atof(s);
PyFPE_END_PROTECT(c)
compl.imag = PyOS_string_to_double(s, (char **)&end, NULL);
if (compl.imag == -1.0 && PyErr_Occurred())
return NULL;
return PyComplex_FromCComplex(compl);
}
else
#endif
{
PyFPE_START_PROTECT("atof", return 0)
dx = PyOS_ascii_atof(s);
PyFPE_END_PROTECT(dx)
dx = PyOS_string_to_double(s, NULL, NULL);
if (dx == -1.0 && PyErr_Occurred())
return NULL;
return PyFloat_FromDouble(dx);
}
}

5
Python/dtoa.c
View File

@ -61,6 +61,9 @@
* that hasn't been MALLOC'ed, private_mem should only be used when k <=
* Kmax.
*
* 7. _Py_dg_strtod has been modified so that it doesn't accept strings with
* leading whitespace.
*
***************************************************************/
/* Please send bug reports for the original dtoa.c code to David M. Gay (dmg
@ -1355,6 +1358,7 @@ _Py_dg_strtod(const char *s00, char **se)
/* no break */
case 0:
goto ret0;
/* modify original dtoa.c so that it doesn't accept leading whitespace
case '\t':
case '\n':
case '\v':
@ -1362,6 +1366,7 @@ _Py_dg_strtod(const char *s00, char **se)
case '\r':
case ' ':
continue;
*/
default:
goto break2;
}

25
Python/marshal.c
View File

@ -670,18 +670,17 @@ r_object(RFILE *p)
{
char buf[256];
double dx;
retval = NULL;
n = r_byte(p);
if (n == EOF || r_string(buf, (int)n, p) != n) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
retval = NULL;
break;
}
buf[n] = '\0';
retval = NULL;
PyFPE_START_PROTECT("atof", break)
dx = PyOS_ascii_atof(buf);
PyFPE_END_PROTECT(dx)
dx = PyOS_string_to_double(buf, NULL, NULL);
if (dx == -1.0 && PyErr_Occurred())
break;
retval = PyFloat_FromDouble(dx);
break;
}
@ -710,29 +709,27 @@ r_object(RFILE *p)
{
char buf[256];
Py_complex c;
retval = NULL;
n = r_byte(p);
if (n == EOF || r_string(buf, (int)n, p) != n) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
retval = NULL;
break;
}
buf[n] = '\0';
retval = NULL;
PyFPE_START_PROTECT("atof", break;)
c.real = PyOS_ascii_atof(buf);
PyFPE_END_PROTECT(c)
c.real = PyOS_string_to_double(buf, NULL, NULL);
if (c.real == -1.0 && PyErr_Occurred())
break;
n = r_byte(p);
if (n == EOF || r_string(buf, (int)n, p) != n) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
retval = NULL;
break;
}
buf[n] = '\0';
PyFPE_START_PROTECT("atof", break)
c.imag = PyOS_ascii_atof(buf);
PyFPE_END_PROTECT(c)
c.imag = PyOS_string_to_double(buf, NULL, NULL);
if (c.imag == -1.0 && PyErr_Occurred())
break;
retval = PyComplex_FromCComplex(c);
break;
}

111
Python/pystrtod.c
View File

@ -35,7 +35,7 @@
#ifndef PY_NO_SHORT_FLOAT_REPR
double
PyOS_ascii_strtod(const char *nptr, char **endptr)
_PyOS_ascii_strtod(const char *nptr, char **endptr)
{
double result;
_Py_SET_53BIT_PRECISION_HEADER;
@ -64,7 +64,7 @@ PyOS_ascii_strtod(const char *nptr, char **endptr)
*/
double
PyOS_ascii_strtod(const char *nptr, char **endptr)
_PyOS_ascii_strtod(const char *nptr, char **endptr)
{
char *fail_pos;
double val = -1.0;
@ -92,15 +92,10 @@ PyOS_ascii_strtod(const char *nptr, char **endptr)
and underflows */
errno = 0;
/* We process any leading whitespace and the optional sign manually,
then pass the remainder to the system strtod. This ensures that
the result of an underflow has the correct sign. (bug #1725) */
/* We process the optional sign manually, then pass the remainder to
the system strtod. This ensures that the result of an underflow
has the correct sign. (bug #1725) */
p = nptr;
/* Skip leading space */
while (Py_ISSPACE(*p))
p++;
/* Process leading sign, if present */
if (*p == '-') {
negate = 1;
@ -185,7 +180,6 @@ PyOS_ascii_strtod(const char *nptr, char **endptr)
copy = (char *)PyMem_MALLOC(end - digits_pos +
1 + decimal_point_len);
if (copy == NULL) {
if (endptr)
*endptr = (char *)nptr;
errno = ENOMEM;
return val;
@ -227,14 +221,11 @@ PyOS_ascii_strtod(const char *nptr, char **endptr)
got_val:
if (negate && fail_pos != nptr)
val = -val;
if (endptr)
*endptr = fail_pos;
return val;
invalid_string:
if (endptr)
*endptr = (char*)nptr;
errno = EINVAL;
return -1.0;
@ -242,12 +233,104 @@ PyOS_ascii_strtod(const char *nptr, char **endptr)
#endif
/* PyOS_ascii_strtod is DEPRECATED in Python 3.1 */
double
PyOS_ascii_strtod(const char *nptr, char **endptr)
{
char *fail_pos;
const char *p;
double x;
if (PyErr_WarnEx(PyExc_DeprecationWarning,
"PyOS_ascii_strtod and PyOS_ascii_atof are "
"deprecated. Use PyOS_string_to_double "
"instead.", 1) < 0)
return -1.0;
/* _PyOS_ascii_strtod already does everything that we want,
except that it doesn't parse leading whitespace */
p = nptr;
while (Py_ISSPACE(*p))
p++;
x = _PyOS_ascii_strtod(p, &fail_pos);
if (fail_pos == p)
fail_pos = (char *)nptr;
if (endptr)
*endptr = (char *)fail_pos;
return x;
}
/* PyOS_ascii_strtod is DEPRECATED in Python 3.1 */
double
PyOS_ascii_atof(const char *nptr)
{
return PyOS_ascii_strtod(nptr, NULL);
}
/* PyOS_string_to_double is the recommended replacement for the deprecated
PyOS_ascii_strtod and PyOS_ascii_atof functions. It converts a
null-terminated byte string s (interpreted as a string of ASCII characters)
to a float. The string should not have leading or trailing whitespace (in
contrast, PyOS_ascii_strtod allows leading whitespace but not trailing
whitespace). The conversion is independent of the current locale.
If endptr is NULL, try to convert the whole string. Raise ValueError and
return -1.0 if the string is not a valid representation of a floating-point
number.
If endptr is non-NULL, try to convert as much of the string as possible.
If no initial segment of the string is the valid representation of a
floating-point number then *endptr is set to point to the beginning of the
string, -1.0 is returned and again ValueError is raised.
On overflow (e.g., when trying to convert '1e500' on an IEEE 754 machine),
if overflow_exception is NULL then +-Py_HUGE_VAL is returned, and no Python
exception is raised. Otherwise, overflow_exception should point to a
a Python exception, this exception will be raised, -1.0 will be returned,
and *endptr will point just past the end of the converted value.
If any other failure occurs (for example lack of memory), -1.0 is returned
and the appropriate Python exception will have been set.
*/
double
PyOS_string_to_double(const char *s,
char **endptr,
PyObject *overflow_exception)
{
double x, result=-1.0;
char *fail_pos;
errno = 0;
PyFPE_START_PROTECT("PyOS_string_to_double", return -1.0)
x = _PyOS_ascii_strtod(s, &fail_pos);
PyFPE_END_PROTECT(x)
if (errno == ENOMEM) {
PyErr_NoMemory();
fail_pos = (char *)s;
}
else if (!endptr && (fail_pos == s || *fail_pos != '\0'))
PyErr_Format(PyExc_ValueError,
"could not convert string to float: "
"%.200s", s);
else if (fail_pos == s)
PyErr_Format(PyExc_ValueError,
"could not convert string to float: "
"%.200s", s);
else if (errno == ERANGE && fabs(x) >= 1.0 && overflow_exception)
PyErr_Format(overflow_exception,
"value too large to convert to float: "
"%.200s", s);
else
result = x;
if (endptr != NULL)
*endptr = fail_pos;
return result;
}
/* Given a string that may have a decimal point in the current
locale, change it back to a dot. Since the string cannot get