gh-91731: Replace Py_BUILD_ASSERT() with static_assert() (#91730)

Python 3.11 now uses C11 standard which adds static_assert()
to <assert.h>.

* In pytime.c, replace Py_BUILD_ASSERT() with preprocessor checks on
  SIZEOF_TIME_T with #error.
* On macOS, py_mach_timebase_info() now accepts timebase members with
  the same size than _PyTime_t.
* py_get_monotonic_clock() now saturates GetTickCount64() to
  _PyTime_MAX: GetTickCount64() is unsigned, whereas _PyTime_t is
  signed.
This commit is contained in:
Victor Stinner 2022-04-20 19:26:40 +02:00 committed by GitHub
parent ad3ca17ff5
commit 7cdaf87ec5
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
10 changed files with 68 additions and 38 deletions

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@ -6637,19 +6637,19 @@ _datetime_exec(PyObject *module)
/* A 4-year cycle has an extra leap day over what we'd get from
* pasting together 4 single years.
*/
Py_BUILD_ASSERT(DI4Y == 4 * 365 + 1);
static_assert(DI4Y == 4 * 365 + 1, "DI4Y");
assert(DI4Y == days_before_year(4+1));
/* Similarly, a 400-year cycle has an extra leap day over what we'd
* get from pasting together 4 100-year cycles.
*/
Py_BUILD_ASSERT(DI400Y == 4 * DI100Y + 1);
static_assert(DI400Y == 4 * DI100Y + 1, "DI400Y");
assert(DI400Y == days_before_year(400+1));
/* OTOH, a 100-year cycle has one fewer leap day than we'd get from
* pasting together 25 4-year cycles.
*/
Py_BUILD_ASSERT(DI100Y == 25 * DI4Y - 1);
static_assert(DI100Y == 25 * DI4Y - 1, "DI100Y");
assert(DI100Y == days_before_year(100+1));
us_per_ms = PyLong_FromLong(1000);

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@ -964,7 +964,7 @@ _write_size64(char *out, size_t value)
{
size_t i;
Py_BUILD_ASSERT(sizeof(size_t) <= 8);
static_assert(sizeof(size_t) <= 8, "size_t is larger than 64-bit");
for (i = 0; i < sizeof(size_t); i++) {
out[i] = (unsigned char)((value >> (8 * i)) & 0xff);

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@ -5157,7 +5157,8 @@ dict_get_version(PyObject *self, PyObject *args)
version = dict->ma_version_tag;
Py_BUILD_ASSERT(sizeof(unsigned long long) >= sizeof(version));
static_assert(sizeof(unsigned long long) >= sizeof(version),
"version is larger than unsigned long long");
return PyLong_FromUnsignedLongLong((unsigned long long)version);
}

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@ -2381,7 +2381,8 @@ _pystat_fromstructstat(PyObject *module, STRUCT_STAT *st)
return NULL;
PyStructSequence_SET_ITEM(v, 0, PyLong_FromLong((long)st->st_mode));
Py_BUILD_ASSERT(sizeof(unsigned long long) >= sizeof(st->st_ino));
static_assert(sizeof(unsigned long long) >= sizeof(st->st_ino),
"stat.st_ino is larger than unsigned long long");
PyStructSequence_SET_ITEM(v, 1, PyLong_FromUnsignedLongLong(st->st_ino));
#ifdef MS_WINDOWS
PyStructSequence_SET_ITEM(v, 2, PyLong_FromUnsignedLong(st->st_dev));
@ -2396,7 +2397,8 @@ _pystat_fromstructstat(PyObject *module, STRUCT_STAT *st)
PyStructSequence_SET_ITEM(v, 4, _PyLong_FromUid(st->st_uid));
PyStructSequence_SET_ITEM(v, 5, _PyLong_FromGid(st->st_gid));
#endif
Py_BUILD_ASSERT(sizeof(long long) >= sizeof(st->st_size));
static_assert(sizeof(long long) >= sizeof(st->st_size),
"stat.st_size is larger than long long");
PyStructSequence_SET_ITEM(v, 6, PyLong_FromLongLong(st->st_size));
#if defined(HAVE_STAT_TV_NSEC)
@ -13761,10 +13763,12 @@ _Py_COMP_DIAG_POP
self->win32_file_index = stat.st_ino;
self->got_file_index = 1;
}
Py_BUILD_ASSERT(sizeof(unsigned long long) >= sizeof(self->win32_file_index));
static_assert(sizeof(unsigned long long) >= sizeof(self->win32_file_index),
"DirEntry.win32_file_index is larger than unsigned long long");
return PyLong_FromUnsignedLongLong(self->win32_file_index);
#else /* POSIX */
Py_BUILD_ASSERT(sizeof(unsigned long long) >= sizeof(self->d_ino));
static_assert(sizeof(unsigned long long) >= sizeof(self->d_ino),
"DirEntry.d_ino is larger than unsigned long long");
return PyLong_FromUnsignedLongLong(self->d_ino);
#endif
}

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@ -745,6 +745,8 @@ pyexpat_xmlparser_Parse_impl(xmlparseobject *self, PyTypeObject *cls,
slen = view.len;
}
static_assert(MAX_CHUNK_SIZE <= INT_MAX,
"MAX_CHUNK_SIZE is larger than INT_MAX");
while (slen > MAX_CHUNK_SIZE) {
rc = XML_Parse(self->itself, s, MAX_CHUNK_SIZE, 0);
if (!rc)
@ -752,7 +754,7 @@ pyexpat_xmlparser_Parse_impl(xmlparseobject *self, PyTypeObject *cls,
s += MAX_CHUNK_SIZE;
slen -= MAX_CHUNK_SIZE;
}
Py_BUILD_ASSERT(MAX_CHUNK_SIZE <= INT_MAX);
assert(slen <= INT_MAX);
rc = XML_Parse(self->itself, s, (int)slen, isfinal);

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@ -771,7 +771,10 @@ _PyLong_Sign(PyObject *vv)
static int
bit_length_digit(digit x)
{
Py_BUILD_ASSERT(PyLong_SHIFT <= sizeof(unsigned long) * 8);
// digit can be larger than unsigned long, but only PyLong_SHIFT bits
// of it will be ever used.
static_assert(PyLong_SHIFT <= sizeof(unsigned long) * 8,
"digit is larger than unsigned long");
return _Py_bit_length((unsigned long)x);
}
@ -5647,7 +5650,7 @@ popcount_digit(digit d)
{
// digit can be larger than uint32_t, but only PyLong_SHIFT bits
// of it will be ever used.
Py_BUILD_ASSERT(PyLong_SHIFT <= 32);
static_assert(PyLong_SHIFT <= 32, "digit is larger than uint32_t");
return _Py_popcount32((uint32_t)d);
}

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@ -206,7 +206,8 @@ PySlice_Unpack(PyObject *_r,
PySliceObject *r = (PySliceObject*)_r;
/* this is harder to get right than you might think */
Py_BUILD_ASSERT(PY_SSIZE_T_MIN + 1 <= -PY_SSIZE_T_MAX);
static_assert(PY_SSIZE_T_MIN + 1 <= -PY_SSIZE_T_MAX,
"-PY_SSIZE_T_MAX < PY_SSIZE_T_MIN + 1");
if (r->step == Py_None) {
*step = 1;

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@ -956,7 +956,7 @@ static wchar_t *
_Py_ConvertWCharForm(const wchar_t *source, Py_ssize_t size,
const char *tocode, const char *fromcode)
{
Py_BUILD_ASSERT(sizeof(wchar_t) == 4);
static_assert(sizeof(wchar_t) == 4, "wchar_t must be 32-bit");
/* Ensure we won't overflow the size. */
if (size > (PY_SSIZE_T_MAX / (Py_ssize_t)sizeof(wchar_t))) {

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@ -1507,9 +1507,11 @@ config_get_xoption_value(const PyConfig *config, wchar_t *name)
static PyStatus
config_init_hash_seed(PyConfig *config)
{
static_assert(sizeof(_Py_HashSecret_t) == sizeof(_Py_HashSecret.uc),
"_Py_HashSecret_t has wrong size");
const char *seed_text = config_get_env(config, "PYTHONHASHSEED");
Py_BUILD_ASSERT(sizeof(_Py_HashSecret_t) == sizeof(_Py_HashSecret.uc));
/* Convert a text seed to a numeric one */
if (seed_text && strcmp(seed_text, "random") != 0) {
const char *endptr = seed_text;

View file

@ -162,12 +162,11 @@ time_t
_PyLong_AsTime_t(PyObject *obj)
{
#if SIZEOF_TIME_T == SIZEOF_LONG_LONG
long long val;
val = PyLong_AsLongLong(obj);
long long val = PyLong_AsLongLong(obj);
#elif SIZEOF_TIME_T <= SIZEOF_LONG
long val = PyLong_AsLong(obj);
#else
long val;
Py_BUILD_ASSERT(sizeof(time_t) <= sizeof(long));
val = PyLong_AsLong(obj);
# error "unsupported time_t size"
#endif
if (val == -1 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
@ -184,9 +183,10 @@ _PyLong_FromTime_t(time_t t)
{
#if SIZEOF_TIME_T == SIZEOF_LONG_LONG
return PyLong_FromLongLong((long long)t);
#else
Py_BUILD_ASSERT(sizeof(time_t) <= sizeof(long));
#elif SIZEOF_TIME_T <= SIZEOF_LONG
return PyLong_FromLong((long)t);
#else
# error "unsupported time_t size"
#endif
}
@ -386,10 +386,10 @@ _PyTime_t
_PyTime_FromSeconds(int seconds)
{
/* ensure that integer overflow cannot happen, int type should have 32
bits, whereas _PyTime_t type has at least 64 bits (SEC_TO_MS takes 30
bits, whereas _PyTime_t type has at least 64 bits (SEC_TO_NS takes 30
bits). */
Py_BUILD_ASSERT(INT_MAX <= _PyTime_MAX / SEC_TO_NS);
Py_BUILD_ASSERT(INT_MIN >= _PyTime_MIN / SEC_TO_NS);
static_assert(INT_MAX <= _PyTime_MAX / SEC_TO_NS, "_PyTime_t overflow");
static_assert(INT_MIN >= _PyTime_MIN / SEC_TO_NS, "_PyTime_t underflow");
_PyTime_t t = (_PyTime_t)seconds;
assert((t >= 0 && t <= _PyTime_MAX / SEC_TO_NS)
@ -416,7 +416,8 @@ _PyTime_FromNanosecondsObject(_PyTime_t *tp, PyObject *obj)
return -1;
}
Py_BUILD_ASSERT(sizeof(long long) == sizeof(_PyTime_t));
static_assert(sizeof(long long) == sizeof(_PyTime_t),
"_PyTime_t is not long long");
long long nsec = PyLong_AsLongLong(obj);
if (nsec == -1 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
@ -437,7 +438,8 @@ pytime_fromtimespec(_PyTime_t *tp, struct timespec *ts, int raise_exc)
{
_PyTime_t t, tv_nsec;
Py_BUILD_ASSERT(sizeof(ts->tv_sec) <= sizeof(_PyTime_t));
static_assert(sizeof(ts->tv_sec) <= sizeof(_PyTime_t),
"timespec.tv_sec is larger than _PyTime_t");
t = (_PyTime_t)ts->tv_sec;
int res1 = pytime_mul(&t, SEC_TO_NS);
@ -466,7 +468,8 @@ _PyTime_FromTimespec(_PyTime_t *tp, struct timespec *ts)
static int
pytime_fromtimeval(_PyTime_t *tp, struct timeval *tv, int raise_exc)
{
Py_BUILD_ASSERT(sizeof(tv->tv_sec) <= sizeof(_PyTime_t));
static_assert(sizeof(tv->tv_sec) <= sizeof(_PyTime_t),
"timeval.tv_sec is larger than _PyTime_t");
_PyTime_t t = (_PyTime_t)tv->tv_sec;
int res1 = pytime_mul(&t, SEC_TO_NS);
@ -537,7 +540,8 @@ pytime_from_object(_PyTime_t *tp, PyObject *obj, _PyTime_round_t round,
return -1;
}
Py_BUILD_ASSERT(sizeof(long long) <= sizeof(_PyTime_t));
static_assert(sizeof(long long) <= sizeof(_PyTime_t),
"_PyTime_t is smaller than long long");
_PyTime_t ns = (_PyTime_t)sec;
if (pytime_mul(&ns, unit_to_ns) < 0) {
pytime_overflow();
@ -589,7 +593,8 @@ PyObject *
_PyTime_AsNanosecondsObject(_PyTime_t t)
{
_PyTime_t ns = pytime_as_nanoseconds(t);
Py_BUILD_ASSERT(sizeof(long long) >= sizeof(_PyTime_t));
static_assert(sizeof(long long) >= sizeof(_PyTime_t),
"_PyTime_t is larger than long long");
return PyLong_FromLongLong((long long)ns);
}
@ -984,15 +989,17 @@ py_mach_timebase_info(_PyTime_t *pnumer, _PyTime_t *pdenom, int raise)
_PyTime_t. In practice, timebase uses uint32_t, so casting cannot
overflow. At the end, only make sure that the type is uint32_t
(_PyTime_t is 64-bit long). */
Py_BUILD_ASSERT(sizeof(timebase.numer) < sizeof(_PyTime_t));
Py_BUILD_ASSERT(sizeof(timebase.denom) < sizeof(_PyTime_t));
static_assert(sizeof(timebase.numer) <= sizeof(_PyTime_t),
"timebase.numer is larger than _PyTime_t");
static_assert(sizeof(timebase.denom) <= sizeof(_PyTime_t),
"timebase.denom is larger than _PyTime_t");
/* Make sure that (ticks * timebase.numer) cannot overflow in
_PyTime_MulDiv(), with ticks < timebase.denom.
/* Make sure that _PyTime_MulDiv(ticks, timebase_numer, timebase_denom)
cannot overflow.
Known time bases:
* always (1, 1) on Intel
* (1, 1) on Intel
* (1000000000, 33333335) or (1000000000, 25000000) on PowerPC
None of these time bases can overflow with 64-bit _PyTime_t, but
@ -1019,8 +1026,17 @@ py_get_monotonic_clock(_PyTime_t *tp, _Py_clock_info_t *info, int raise_exc)
#if defined(MS_WINDOWS)
ULONGLONG ticks = GetTickCount64();
Py_BUILD_ASSERT(sizeof(ticks) <= sizeof(_PyTime_t));
_PyTime_t t = (_PyTime_t)ticks;
static_assert(sizeof(ticks) <= sizeof(_PyTime_t),
"ULONGLONG is larger than _PyTime_t");
_PyTime_t t;
if (ticks <= (ULONGLONG)_PyTime_MAX) {
t = (_PyTime_t)ticks;
}
else {
// GetTickCount64() maximum is larger than _PyTime_t maximum:
// ULONGLONG is unsigned, whereas _PyTime_t is signed.
t = _PyTime_MAX;
}
int res = pytime_mul(&t, MS_TO_NS);
*tp = t;
@ -1211,7 +1227,8 @@ py_get_win_perf_counter(_PyTime_t *tp, _Py_clock_info_t *info, int raise_exc)
/* Make sure that casting LONGLONG to _PyTime_t cannot overflow,
both types are signed */
_PyTime_t ticks;
Py_BUILD_ASSERT(sizeof(ticksll) <= sizeof(ticks));
static_assert(sizeof(ticksll) <= sizeof(ticks),
"LONGLONG is larger than _PyTime_t");
ticks = (_PyTime_t)ticksll;
_PyTime_t ns = _PyTime_MulDiv(ticks, SEC_TO_NS, (_PyTime_t)frequency);