cpython/Python/modsupport.c
Victor Stinner 2d854c8e7b Issue #20024: Py_BuildValue() now saves/restores the current exception before
building an item if the build of a previous item failed.
2014-01-21 20:52:17 +01:00

572 lines
14 KiB
C

/* Module support implementation */
#include "Python.h"
#define FLAG_SIZE_T 1
typedef double va_double;
static PyObject *va_build_value(const char *, va_list, int);
/* Package context -- the full module name for package imports */
char *_Py_PackageContext = NULL;
/* Helper for mkvalue() to scan the length of a format */
static int
countformat(const char *format, int endchar)
{
int count = 0;
int level = 0;
while (level > 0 || *format != endchar) {
switch (*format) {
case '\0':
/* Premature end */
PyErr_SetString(PyExc_SystemError,
"unmatched paren in format");
return -1;
case '(':
case '[':
case '{':
if (level == 0)
count++;
level++;
break;
case ')':
case ']':
case '}':
level--;
break;
case '#':
case '&':
case ',':
case ':':
case ' ':
case '\t':
break;
default:
if (level == 0)
count++;
}
format++;
}
return count;
}
/* Generic function to create a value -- the inverse of getargs() */
/* After an original idea and first implementation by Steven Miale */
static PyObject *do_mktuple(const char**, va_list *, int, int, int);
static PyObject *do_mklist(const char**, va_list *, int, int, int);
static PyObject *do_mkdict(const char**, va_list *, int, int, int);
static PyObject *do_mkvalue(const char**, va_list *, int);
static PyObject *
do_mkdict(const char **p_format, va_list *p_va, int endchar, int n, int flags)
{
PyObject *d;
int i;
int itemfailed = 0;
if (n < 0)
return NULL;
if ((d = PyDict_New()) == NULL)
return NULL;
/* Note that we can't bail immediately on error as this will leak
refcounts on any 'N' arguments. */
for (i = 0; i < n; i+= 2) {
PyObject *k, *v;
int err;
k = do_mkvalue(p_format, p_va, flags);
if (k == NULL) {
itemfailed = 1;
Py_INCREF(Py_None);
k = Py_None;
}
v = do_mkvalue(p_format, p_va, flags);
if (v == NULL) {
itemfailed = 1;
Py_INCREF(Py_None);
v = Py_None;
}
err = PyDict_SetItem(d, k, v);
Py_DECREF(k);
Py_DECREF(v);
if (err < 0 || itemfailed) {
Py_DECREF(d);
return NULL;
}
}
if (d != NULL && **p_format != endchar) {
Py_DECREF(d);
d = NULL;
PyErr_SetString(PyExc_SystemError,
"Unmatched paren in format");
}
else if (endchar)
++*p_format;
return d;
}
static PyObject *
do_mklist(const char **p_format, va_list *p_va, int endchar, int n, int flags)
{
PyObject *v;
int i;
int itemfailed = 0;
if (n < 0)
return NULL;
v = PyList_New(n);
if (v == NULL)
return NULL;
/* Note that we can't bail immediately on error as this will leak
refcounts on any 'N' arguments. */
for (i = 0; i < n; i++) {
PyObject *w = do_mkvalue(p_format, p_va, flags);
if (w == NULL) {
itemfailed = 1;
Py_INCREF(Py_None);
w = Py_None;
}
PyList_SET_ITEM(v, i, w);
}
if (itemfailed) {
/* do_mkvalue() should have already set an error */
Py_DECREF(v);
return NULL;
}
if (**p_format != endchar) {
Py_DECREF(v);
PyErr_SetString(PyExc_SystemError,
"Unmatched paren in format");
return NULL;
}
if (endchar)
++*p_format;
return v;
}
static PyObject *
do_mktuple(const char **p_format, va_list *p_va, int endchar, int n, int flags)
{
PyObject *v;
int i;
int itemfailed = 0;
if (n < 0)
return NULL;
if ((v = PyTuple_New(n)) == NULL)
return NULL;
/* Note that we can't bail immediately on error as this will leak
refcounts on any 'N' arguments. */
for (i = 0; i < n; i++) {
PyObject *w;
if (itemfailed) {
PyObject *exception, *value, *tb;
PyErr_Fetch(&exception, &value, &tb);
w = do_mkvalue(p_format, p_va, flags);
PyErr_Restore(exception, value, tb);
}
else {
w = do_mkvalue(p_format, p_va, flags);
}
if (w == NULL) {
itemfailed = 1;
Py_INCREF(Py_None);
w = Py_None;
}
PyTuple_SET_ITEM(v, i, w);
}
if (itemfailed) {
/* do_mkvalue() should have already set an error */
Py_DECREF(v);
return NULL;
}
if (**p_format != endchar) {
Py_DECREF(v);
PyErr_SetString(PyExc_SystemError,
"Unmatched paren in format");
return NULL;
}
if (endchar)
++*p_format;
return v;
}
static PyObject *
do_mkvalue(const char **p_format, va_list *p_va, int flags)
{
for (;;) {
switch (*(*p_format)++) {
case '(':
return do_mktuple(p_format, p_va, ')',
countformat(*p_format, ')'), flags);
case '[':
return do_mklist(p_format, p_va, ']',
countformat(*p_format, ']'), flags);
case '{':
return do_mkdict(p_format, p_va, '}',
countformat(*p_format, '}'), flags);
case 'b':
case 'B':
case 'h':
case 'i':
return PyLong_FromLong((long)va_arg(*p_va, int));
case 'H':
return PyLong_FromLong((long)va_arg(*p_va, unsigned int));
case 'I':
{
unsigned int n;
n = va_arg(*p_va, unsigned int);
return PyLong_FromUnsignedLong(n);
}
case 'n':
#if SIZEOF_SIZE_T!=SIZEOF_LONG
return PyLong_FromSsize_t(va_arg(*p_va, Py_ssize_t));
#endif
/* Fall through from 'n' to 'l' if Py_ssize_t is long */
case 'l':
return PyLong_FromLong(va_arg(*p_va, long));
case 'k':
{
unsigned long n;
n = va_arg(*p_va, unsigned long);
return PyLong_FromUnsignedLong(n);
}
#ifdef HAVE_LONG_LONG
case 'L':
return PyLong_FromLongLong((PY_LONG_LONG)va_arg(*p_va, PY_LONG_LONG));
case 'K':
return PyLong_FromUnsignedLongLong((PY_LONG_LONG)va_arg(*p_va, unsigned PY_LONG_LONG));
#endif
case 'u':
{
PyObject *v;
Py_UNICODE *u = va_arg(*p_va, Py_UNICODE *);
Py_ssize_t n;
if (**p_format == '#') {
++*p_format;
if (flags & FLAG_SIZE_T)
n = va_arg(*p_va, Py_ssize_t);
else
n = va_arg(*p_va, int);
}
else
n = -1;
if (u == NULL) {
v = Py_None;
Py_INCREF(v);
}
else {
if (n < 0)
n = Py_UNICODE_strlen(u);
v = PyUnicode_FromUnicode(u, n);
}
return v;
}
case 'f':
case 'd':
return PyFloat_FromDouble(
(double)va_arg(*p_va, va_double));
case 'D':
return PyComplex_FromCComplex(
*((Py_complex *)va_arg(*p_va, Py_complex *)));
case 'c':
{
char p[1];
p[0] = (char)va_arg(*p_va, int);
return PyBytes_FromStringAndSize(p, 1);
}
case 'C':
{
int i = va_arg(*p_va, int);
return PyUnicode_FromOrdinal(i);
}
case 's':
case 'z':
case 'U': /* XXX deprecated alias */
{
PyObject *v;
char *str = va_arg(*p_va, char *);
Py_ssize_t n;
if (**p_format == '#') {
++*p_format;
if (flags & FLAG_SIZE_T)
n = va_arg(*p_va, Py_ssize_t);
else
n = va_arg(*p_va, int);
}
else
n = -1;
if (str == NULL) {
v = Py_None;
Py_INCREF(v);
}
else {
if (n < 0) {
size_t m = strlen(str);
if (m > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_OverflowError,
"string too long for Python string");
return NULL;
}
n = (Py_ssize_t)m;
}
v = PyUnicode_FromStringAndSize(str, n);
}
return v;
}
case 'y':
{
PyObject *v;
char *str = va_arg(*p_va, char *);
Py_ssize_t n;
if (**p_format == '#') {
++*p_format;
if (flags & FLAG_SIZE_T)
n = va_arg(*p_va, Py_ssize_t);
else
n = va_arg(*p_va, int);
}
else
n = -1;
if (str == NULL) {
v = Py_None;
Py_INCREF(v);
}
else {
if (n < 0) {
size_t m = strlen(str);
if (m > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_OverflowError,
"string too long for Python bytes");
return NULL;
}
n = (Py_ssize_t)m;
}
v = PyBytes_FromStringAndSize(str, n);
}
return v;
}
case 'N':
case 'S':
case 'O':
if (**p_format == '&') {
typedef PyObject *(*converter)(void *);
converter func = va_arg(*p_va, converter);
void *arg = va_arg(*p_va, void *);
++*p_format;
return (*func)(arg);
}
else {
PyObject *v;
v = va_arg(*p_va, PyObject *);
if (v != NULL) {
if (*(*p_format - 1) != 'N')
Py_INCREF(v);
}
else if (!PyErr_Occurred())
/* If a NULL was passed
* because a call that should
* have constructed a value
* failed, that's OK, and we
* pass the error on; but if
* no error occurred it's not
* clear that the caller knew
* what she was doing. */
PyErr_SetString(PyExc_SystemError,
"NULL object passed to Py_BuildValue");
return v;
}
case ':':
case ',':
case ' ':
case '\t':
break;
default:
PyErr_SetString(PyExc_SystemError,
"bad format char passed to Py_BuildValue");
return NULL;
}
}
}
PyObject *
Py_BuildValue(const char *format, ...)
{
va_list va;
PyObject* retval;
va_start(va, format);
retval = va_build_value(format, va, 0);
va_end(va);
return retval;
}
PyObject *
_Py_BuildValue_SizeT(const char *format, ...)
{
va_list va;
PyObject* retval;
va_start(va, format);
retval = va_build_value(format, va, FLAG_SIZE_T);
va_end(va);
return retval;
}
PyObject *
Py_VaBuildValue(const char *format, va_list va)
{
return va_build_value(format, va, 0);
}
PyObject *
_Py_VaBuildValue_SizeT(const char *format, va_list va)
{
return va_build_value(format, va, FLAG_SIZE_T);
}
static PyObject *
va_build_value(const char *format, va_list va, int flags)
{
const char *f = format;
int n = countformat(f, '\0');
va_list lva;
Py_VA_COPY(lva, va);
if (n < 0)
return NULL;
if (n == 0) {
Py_INCREF(Py_None);
return Py_None;
}
if (n == 1)
return do_mkvalue(&f, &lva, flags);
return do_mktuple(&f, &lva, '\0', n, flags);
}
PyObject *
PyEval_CallFunction(PyObject *obj, const char *format, ...)
{
va_list vargs;
PyObject *args;
PyObject *res;
va_start(vargs, format);
args = Py_VaBuildValue(format, vargs);
va_end(vargs);
if (args == NULL)
return NULL;
res = PyEval_CallObject(obj, args);
Py_DECREF(args);
return res;
}
PyObject *
PyEval_CallMethod(PyObject *obj, const char *methodname, const char *format, ...)
{
va_list vargs;
PyObject *meth;
PyObject *args;
PyObject *res;
meth = PyObject_GetAttrString(obj, methodname);
if (meth == NULL)
return NULL;
va_start(vargs, format);
args = Py_VaBuildValue(format, vargs);
va_end(vargs);
if (args == NULL) {
Py_DECREF(meth);
return NULL;
}
res = PyEval_CallObject(meth, args);
Py_DECREF(meth);
Py_DECREF(args);
return res;
}
int
PyModule_AddObject(PyObject *m, const char *name, PyObject *o)
{
PyObject *dict;
if (!PyModule_Check(m)) {
PyErr_SetString(PyExc_TypeError,
"PyModule_AddObject() needs module as first arg");
return -1;
}
if (!o) {
if (!PyErr_Occurred())
PyErr_SetString(PyExc_TypeError,
"PyModule_AddObject() needs non-NULL value");
return -1;
}
dict = PyModule_GetDict(m);
if (dict == NULL) {
/* Internal error -- modules must have a dict! */
PyErr_Format(PyExc_SystemError, "module '%s' has no __dict__",
PyModule_GetName(m));
return -1;
}
if (PyDict_SetItemString(dict, name, o))
return -1;
Py_DECREF(o);
return 0;
}
int
PyModule_AddIntConstant(PyObject *m, const char *name, long value)
{
PyObject *o = PyLong_FromLong(value);
if (!o)
return -1;
if (PyModule_AddObject(m, name, o) == 0)
return 0;
Py_DECREF(o);
return -1;
}
int
PyModule_AddStringConstant(PyObject *m, const char *name, const char *value)
{
PyObject *o = PyUnicode_FromString(value);
if (!o)
return -1;
if (PyModule_AddObject(m, name, o) == 0)
return 0;
Py_DECREF(o);
return -1;
}