mirror of https://github.com/python/cpython
Issue #4393: fix 3 classes of potential portability problems in longobject.c:
- fix some places where counters into ob_digit were declared as int instead of Py_ssize_t - add (twodigit) casts where necessary - fix code in _PyLong_AsByteArray that uses << on negative values
This commit is contained in:
Mark Dickinson
parent
0dfcfc8b59
commit
ff84aa87b4
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@ -513,7 +513,7 @@ _PyLong_FromByteArray(const unsigned char* bytes, size_t n,
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/* Because we're going LSB to MSB, thisbyte is
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more significant than what's already in accum,
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so needs to be prepended to accum. */
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accum |= thisbyte << accumbits;
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accum |= (twodigits)thisbyte << accumbits;
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accumbits += 8;
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if (accumbits >= PyLong_SHIFT) {
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/* There's enough to fill a Python digit. */
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@ -542,7 +542,7 @@ _PyLong_AsByteArray(PyLongObject* v,
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unsigned char* bytes, size_t n,
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int little_endian, int is_signed)
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{
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int i; /* index into v->ob_digit */
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Py_ssize_t i; /* index into v->ob_digit */
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Py_ssize_t ndigits; /* |v->ob_size| */
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twodigits accum; /* sliding register */
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unsigned int accumbits; /* # bits in accum */
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@ -587,7 +587,7 @@ _PyLong_AsByteArray(PyLongObject* v,
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accumbits = 0;
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carry = do_twos_comp ? 1 : 0;
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for (i = 0; i < ndigits; ++i) {
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twodigits thisdigit = v->ob_digit[i];
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digit thisdigit = v->ob_digit[i];
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if (do_twos_comp) {
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thisdigit = (thisdigit ^ PyLong_MASK) + carry;
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carry = thisdigit >> PyLong_SHIFT;
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@ -596,26 +596,23 @@ _PyLong_AsByteArray(PyLongObject* v,
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/* Because we're going LSB to MSB, thisdigit is more
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significant than what's already in accum, so needs to be
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prepended to accum. */
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accum |= thisdigit << accumbits;
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accumbits += PyLong_SHIFT;
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accum |= (twodigits)thisdigit << accumbits;
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/* The most-significant digit may be (probably is) at least
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partly empty. */
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if (i == ndigits - 1) {
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/* Count # of sign bits -- they needn't be stored,
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* although for signed conversion we need later to
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* make sure at least one sign bit gets stored.
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* First shift conceptual sign bit to real sign bit.
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*/
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stwodigits s = (stwodigits)(thisdigit <<
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(8*sizeof(stwodigits) - PyLong_SHIFT));
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unsigned int nsignbits = 0;
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while ((s < 0) == do_twos_comp && nsignbits < PyLong_SHIFT) {
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++nsignbits;
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s <<= 1;
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* make sure at least one sign bit gets stored. */
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digit s = do_twos_comp ? thisdigit ^ PyLong_MASK :
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thisdigit;
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while (s != 0) {
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s >>= 1;
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accumbits++;
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}
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accumbits -= nsignbits;
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}
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else
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accumbits += PyLong_SHIFT;
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/* Store as many bytes as possible. */
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while (accumbits >= 8) {
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@ -1079,7 +1076,7 @@ convert_binop(PyObject *v, PyObject *w, PyLongObject **a, PyLongObject **b) {
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static digit
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v_iadd(digit *x, Py_ssize_t m, digit *y, Py_ssize_t n)
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{
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int i;
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Py_ssize_t i;
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digit carry = 0;
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assert(m >= n);
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@ -1105,7 +1102,7 @@ v_iadd(digit *x, Py_ssize_t m, digit *y, Py_ssize_t n)
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static digit
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v_isub(digit *x, Py_ssize_t m, digit *y, Py_ssize_t n)
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{
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int i;
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Py_ssize_t i;
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digit borrow = 0;
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assert(m >= n);
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@ -1171,7 +1168,7 @@ inplace_divrem1(digit *pout, digit *pin, Py_ssize_t size, digit n)
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digit hi;
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rem = (rem << PyLong_SHIFT) + *--pin;
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*--pout = hi = (digit)(rem / n);
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rem -= hi * n;
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rem -= (twodigits)hi * n;
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}
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return (digit)rem;
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}
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@ -1436,11 +1433,11 @@ long_from_binary_base(char **str, int base)
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while (--p >= start) {
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int k = _PyLong_DigitValue[Py_CHARMASK(*p)];
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assert(k >= 0 && k < base);
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accum |= (twodigits)(k << bits_in_accum);
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accum |= (twodigits)k << bits_in_accum;
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bits_in_accum += bits_per_char;
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if (bits_in_accum >= PyLong_SHIFT) {
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*pdigit++ = (digit)(accum & PyLong_MASK);
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assert(pdigit - z->ob_digit <= (int)n);
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assert(pdigit - z->ob_digit <= n);
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accum >>= PyLong_SHIFT;
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bits_in_accum -= PyLong_SHIFT;
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assert(bits_in_accum < PyLong_SHIFT);
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@ -1449,7 +1446,7 @@ long_from_binary_base(char **str, int base)
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if (bits_in_accum) {
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assert(bits_in_accum <= PyLong_SHIFT);
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*pdigit++ = (digit)accum;
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assert(pdigit - z->ob_digit <= (int)n);
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assert(pdigit - z->ob_digit <= n);
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}
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while (pdigit - z->ob_digit < n)
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*pdigit++ = 0;
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@ -1846,7 +1843,7 @@ x_divrem(PyLongObject *v1, PyLongObject *w1, PyLongObject **prem)
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digit vj = (j >= size_v) ? 0 : v->ob_digit[j];
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twodigits q;
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stwodigits carry = 0;
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int i;
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Py_ssize_t i;
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SIGCHECK({
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Py_DECREF(a);
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@ -2008,7 +2005,7 @@ x_add(PyLongObject *a, PyLongObject *b)
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{
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Py_ssize_t size_a = ABS(Py_SIZE(a)), size_b = ABS(Py_SIZE(b));
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PyLongObject *z;
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int i;
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Py_ssize_t i;
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digit carry = 0;
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/* Ensure a is the larger of the two: */
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