which can be reviewed via
http://coding.derkeiler.com/Archive/Python/comp.lang.python/2003-12/1011.html
Duncan Booth investigated, and discovered that an "optimisation" was
in fact a pessimisation for small numbers of elements in a source list,
compared to not having the optimisation, although with large numbers
of elements in the source list the optimisation was quite beneficial.
He posted his change to comp.lang.python (but not to SF).
Further research has confirmed his assessment that the optimisation only
becomes a net win when the source list has more than 100 elements.
I also found that the optimisation could apply to tuples as well,
but the gains only arrive with source tuples larger than about 320
elements and are nowhere near as significant as the gains with lists,
(~95% gain @ 10000 elements for lists, ~20% gain @ 10000 elements for
tuples) so I haven't proceeded with this.
The code as it was applied the optimisation to list subclasses as
well, and this also appears to be a net loss for all reasonable sized
sources (~80-100% for up to 100 elements, ~20% for more than 500
elements; I tested up to 10000 elements).
Duncan also suggested special casing empty lists, which I've extended
to all empty sequences.
On the basis that list_fill() is only ever called with a list for the
result argument, testing for the source being the destination has
now happens before testing source types.
bit by checking the value of UCHAR_MAX in Include/Python.h. There was a
check in Objects/stringobject.c. Remove that. (Note that we don't define
UCHAR_MAX if it's not defined as the old test did.)
and left shifts. (Thanks to Kalle Svensson for SF patch 849227.)
This addresses most of the remaining semantic changes promised by
PEP 237, except for repr() of a long, which still shows the trailing
'L'. The PEP appears to promise warnings for operations that
changed semantics compared to Python 2.3, but this is not
implemented; we've suffered through enough warnings related to
hex/oct literals and I think it's best to be silent now.
* Add more tests
* Refactor and neaten the code a bit.
* Rename union_update() to update().
* Improve the algorithms (making them a closer to sets.py).
function.
* Add a better test for deepcopying.
* Add tests to show the __init__() function works like it does for list
and tuple. Add related test.
* Have shallow copies of frozensets return self. Add related test.
* Have frozenset(f) return f if f is already a frozenset. Add related test.
* Beefed-up some existing tests.
by the function object or by the method object, the function
object's attribute usually wins. Christian Tismer pointed out that
that this is really a mistake, because this only happens for special
methods (like __reduce__) where the method object's version is
really more appropriate than the function's attribute. So from now
on, all method attributes will have precedence over function
attributes with the same name.
* Improve the hash function to increase the chance that distinct sets will
have distinct xor'd hash totals.
* Use PyDict_Merge where possible (it is faster than an equivalent iter/set
pair).
* Don't rebuild dictionaries where the input already has one.
Also SF patch 843455.
This is a critical bugfix.
I'll backport to 2.3 maint, but not beyond that. The bugs this fixes
have been there since weakrefs were introduced.
* Install the unittests, docs, newsitem, include file, and makefile update.
* Exercise the new functions whereever sets.py was being used.
Includes the docs for libfuncs.tex. Separate docs for the types are
forthcoming.
subtype_dealloc(): This left the dying object exposed to gc, so that
if cyclic gc triggered during the weakref callback, gc tried to delete
the dying object a second time. That's a disaster. subtype_dealloc()
had a (I hope!) unique problem here, as every normal dealloc routine
untracks the object (from gc) before fiddling with weakrefs etc. But
subtype_dealloc has obscure technical reasons for re-registering the
dying object with gc (already explained in a large comment block at
the bottom of the function).
The fix amounts to simply refraining from reregistering the dying object
with gc until after the weakref callback (if any) has been called.
This is a critical bug (hard to predict, and causes seemingly random
memory corruption when it occurs). I'll backport it to 2.3 later.
charmaptranslate_makespace() allocated more memory than required for the
next replacement but didn't remember that fact, so memory size was growing
exponentially every time a replacement string is longer that one character.
This fixes SF bug #828737.
key provides C support for the decorate-sort-undecorate pattern.
reverse provide a stable sort of the list with the comparisions reversed.
* Amended the docs to guarantee sort stability.
If a length-1 Unicode string was in the freelist and it was
uninitialized or pointed to a very large (magnitude) negative number,
the check
unicode_latin1[unicode->str[0]] == unicode
could cause a segmentation violation, e.g. unicode->str[0] is 0xcbcbcbcb.
Fix this in two ways:
1. Change guard befor unicode_latin1[] to test against 256U. If I
understand correctly, the unsigned long used to store UCS4 on my
box was getting converted to a signed long to compare with the
signed constant 256.
2. Change _PyUnicode_New() to make sure the first element of str is
always initialized to zero. There are several places in the code
where the caller can exit with an error before initializing any
of str, which would leave junk in str[0].
Also, silence a compiler warning on pointer vs. int arithmetic.
Bug fix candidate.
The unicode_resize() family only returns -1 or 0 so simply checking
for != 0 is sufficient, but somewhat unclear. Many Python API
functions return < 0 on error, reserving the right to return 0 or 1 on
success. Change the call sites for consistency with these calls.
file_truncate(): C doesn't define what fflush(fp) does if fp is open
for update, and the preceding I/O operation on fp was input. On Windows,
fflush() actually changes the current file position then. Because
Windows doesn't support ftruncate() directly, this not only caused
Python's file.truncate() to change the file position (contra our docs),
it also caused the file not to change size.
Repaired by getting the initial file position at the start, restoring
it at the end, and tossing all the complicated micro-efficiency checks
trying to avoid "provably unnecessary" seeks. file.truncate() can't
be a frequent operation, and seeking to the current file position has
got to be cheap anyway.
Bugfix candidate.
[ 784825 ] fix obscure crash in descriptor handling
Should be applied to release23-maint and in all likelyhood
release22-maint, too.
Certainly doesn't apply to release21-maint.
number. This accounts for the 2 refcount leaks per test_complex run
Michael Hudson discovered (I figured only I would have the stomach to
look for leaks in floating-point code <wink>).
when an encoding error occurs and the callback name is unknown,
i.e. when the callback has to be called. The problem was that
the fact that the callback has already been looked up was only
recorded in a local variable in charmap_encoding_error(), because
charmap_encoding_error() got it's own copy of the errorHandler
pointer instead of a pointer to the pointer in
PyUnicode_EncodeCharmap().
Now test_descr only appears to leak two references & I think this
are in fact illusory (it's to do with things getting resurrected in
__del__ methods & it's easy to be believe confusion occurs when that
happens <wink>). Woohoo!
Sure looks like it to me! <wink>
When I run the leak2.py script I posted to python-dev, I only see
three reference leaks in all of test_descr. When I run
test_descr.test_main, I still see 46 leaks. This clearly demands
posting a yelp to python-dev :-)
This certainly should be applied to release23-maint, and in all
likelyhood release22-maint as well.
The !PyType_Check(base) check snuck in as part of rev 2.215, but was
unrelated to the SF patch that is mentioned in the checkin comment.
The test is currently unnecessary because base is set to the return
value of best_bases(), which returns a type or NULL.
float_pow(): Don't let the platform pow() raise -1.0 to an integer power
anymore; at least glibc gets it wrong in some cases. Note that
math.pow() will continue to deliver wrong (but platform-native) results
in such cases.
tp_free is NULL or PyObject_Del at the end. Because it's a base type
it must call tp_free in its dealloc function, and because it's gc'able
it must not call PyObject_Del.
inherit_slots(): Don't inherit tp_free unless the type and its base
agree about whether they're gc'able. If the type is gc'able and the
base is not, and the base uses the default PyObject_Del for its
tp_free, give the type PyObject_GC_Del for its tp_free (the appropriate
default for a gc'able type).
cPickle.c: The Pickler and Unpickler types claim to be base classes
and gc'able, but their dealloc functions didn't call tp_free.
Repaired that. Also call PyType_Ready() on these typeobjects, so
that the correct (PyObject_GC_Del) default memory-freeing function
gets plugged into these types' tp_free slots.
Reverted a Py2.3b1 change to iterator in subclasses of list and tuple.
They had been changed to use __getitem__ whenever it had been overriden
in the subclass.
This caused some usabilty and performance problems. Also, it was
inconsistent with the rest of python where many container methods
access the underlying object directly without first checking for
an overridden getter. Users needing a change in iterator behavior
should override it directly.
* Increase dictionary growth rate resulting in more sparse dictionaries,
fewer lookup collisions, increased memory use, and better cache
performance. For dicts with over 50k entries, keep the current
growth rate in case an application is suffering from tight memory
constraints.
* Set the most common case (no resize) to fall-through the test.
Some version of gcc in the "RTEMS port running on the Coldfire (m5200)
processor" generates bad code for a loop in long_from_binary_base(),
comparing the wrong half of an int to a short. The patch changes the
decl of the short temp to be an int temp instead. This "simplifies"
the code enough that gcc no longer blows it.
As a side issue on this bug, it was noted that list and tuple iterators
used macros to directly access containers and would not recognize
__getitem__ overrides. If the method is overridden, the patch returns
a generic sequence iterator which calls the __getitem__ method; otherwise,
it returns a high custom iterator with direct access to container elements.
raising an exception. This is consistent with calling the
constructors for the other builtin types -- called without argument
they all return the false value of that type. (SF patch #724135)
Thanks to Alex Martelli.
I'm finding some pretty baffling output, like reprs consisting entirely
of three left parens. At least this will let us know what type the object
is (it's not str -- there's no quote character in the repr).
New tool combinerefs.py, to combine the two output blocks produced via
PYTHONDUMPREFS.
new line.
New pvt API function _Py_PrintReferenceAddresses(): Prints only the
addresses and refcnts of the live objects. This is always safe to call,
because it has no dependence on Python's C API.
Py_Finalize(): If envar PYTHONDUMPREFS is set, call (the new)
_Py_PrintReferenceAddresses() right before dumping final pymalloc stats.
We can't print the reprs of the objects here because too much of the
interpreter has been shut down. You need to correlate the addresses
displayed here with the object reprs printed by the earlier
PYTHONDUMPREFS call to _Py_PrintReferences().
New functions:
unsigned long PyInt_AsUnsignedLongMask(PyObject *);
unsigned PY_LONG_LONG) PyInt_AsUnsignedLongLongMask(PyObject *);
unsigned long PyLong_AsUnsignedLongMask(PyObject *);
unsigned PY_LONG_LONG) PyLong_AsUnsignedLongLongMask(PyObject *);
New and changed format codes:
b unsigned char 0..UCHAR_MAX
B unsigned char none **
h unsigned short 0..USHRT_MAX
H unsigned short none **
i int INT_MIN..INT_MAX
I * unsigned int 0..UINT_MAX
l long LONG_MIN..LONG_MAX
k * unsigned long none
L long long LLONG_MIN..LLONG_MAX
K * unsigned long long none
Notes:
* New format codes.
** Changed from previous "range-and-a-half" to "none"; the
range-and-a-half checking wasn't particularly useful.
New test test_getargs2.py, to verify all this.
even farther down, to just before the call to
_PyObject_DebugMallocStats(). This required the following changes:
- pystate.c, PyThreadState_GetDict(): changed not to raise an
exception or issue a fatal error when no current thread state is
available, but simply return NULL without raising an exception
(ever).
- object.c, Py_ReprEnter(): when PyThreadState_GetDict() returns NULL,
don't raise an exception but return 0. This means that when
printing a container that's recursive, printing will go on and on
and on. But that shouldn't happen in the case we care about (see
first bullet).
- Updated Misc/NEWS and Doc/api/init.tex to reflect changes to
PyThreadState_GetDict() definition.
interpreted by slicing, so negative values count from the end of the
list. This was the only place where such an interpretation was not
placed on a list index.
* Doc - add doc for when functions were added
* UserString
* string object methods
* string module functions
'chars' is used for the last parameter everywhere.
These changes will be backported, since part of the changes
have already been made, but they were inconsistent.
If a class was defined inside a function, used a static or class
method, and used super() inside the method body, it would be caught in
an uncollectable cycle. (Simplified version: The static/class method
object would point to a function object with a closure that referred
to the class.)
Bugfix candidate.
Arranged that all the objects exposed by __builtin__ appear in the list
of all objects. I basically peed away two days tracking down a mystery
leak in sys.gettotalrefcount() in a ZODB app (== tons of code), because
the object leaking the references didn't appear in the sys.getobjects(0)
list. The object happened to be False. Now False is in the list, along
with other popular & previously missing leak candidates (like None).
Alas, we still don't have a choke point covering *all* Python objects,
so the list of all objects may still be incomplete.
_Py_AddToAllObjects() that simply inserts an object at the front of
the doubly-linked list of all objects. Changed PyType_Ready() (the
closest thing we've got to a choke point for type objects) to call
that.
a doubly-linked list, exposed by sys.getobjects(). Unfortunately, it's not
really all live objects, and it seems my fate to bump into programs where
sys.gettotalrefcount() keeps going up but where the reference leaks aren't
accounted for by anything in the list of all objects.
This patch helps a little: if COUNT_ALLOCS is also defined, from now on
type objects will also appear in this list, provided at least one object
of a type has been allocated.
constructor, when passed a single complex argument, returns the
argument unchanged. This should be done only for the complex base
class; a complex subclass should of course cast the value to the
subclass in this case.
The fix also revealed a segfault in complex_getnewargs(): the argument
for the Py_BuildValue() format code "D" is the *address* of a
Py_complex struct, not the value. (This corroborated by the API
documentation.)
I expect this needs to be backported to 2.2.3.
This still falls back to helpers in copy_reg for:
- pickle protocols < 2
- calculating the list of slot names (done only once per class)
- the __newobj__ function (which is used as a token but never called)
the PyInt_AsLong function, and this returns a long, the value is first
retrieved with PyLong_AsLong, but afterwards overwritten by a call to
PyInt_AS_LONG.
Fixes SF #690253.
Don't access tp_descr_{get,set} of a descriptor without checking the
flag bits of the descriptor's type. While we know that the main type
(the type of the object whose attribute is being accessed) has all the
right flag bits (or else PyObject_Generic{Get,Set}Attr wouldn't be
called), we don't know that for its class attributes!
Will backport to 2.2.
using super() for an instance in a metaclass situation. Because the
class was a metaclass, the instance was a class, and hence the
PyType_Check() branch was taken. But this branch didn't apply. Make
it so that if this branch doesn't apply, the other branch is still
tried. All tests pass.
the optional proto 2 slot state.
pickle.py, load_build(): CAUTION: Noted that cPickle's
load_build and pickle's load_build really don't do the same
things with the state, and didn't before this patch either.
cPickle never tries to do .update(), and has no backoff if
instance.__dict__ can't be retrieved. There are no tests
that can tell the difference, and part of what cPickle's
load_build() did looked accidental to me, so I don't know
what the true intent is here.
pickletester.py, test_pickle.py: Got rid of the hack for
exempting cPickle from running some of the proto 2 tests.
dictobject.c, PyDict_Next(): documented intended use.
This changes the default __new__ to refuse arguments iff tp_init is the
default __init__ implementation -- thus making it a TypeError when you
try to pass arguments to a constructor if the class doesn't override at
least __init__ or __new__.
folded; this will change in Python 2.4. On a 32-bit machine, this
happens for 0x80000000 through 0xffffffff, and for octal constants in
the same value range. No warning is issued if an explicit base is
given, *or* if the string contains a sign (since in those cases no
sign folding ever happens).
descr_check(); it wasn't useful. Change the type argument of the
various _get() methods to PyObject * because the call signature of
tp_descr_get doesn't guarantee its type.
when Python code calls a descriptor's __get__ method. It should
translate None to NULL in both argument positions, and insist that at
least one of the argument positions is not NULL after this
transformation.
For the case where the current globals match the previous frame's
globals, eliminates three tests in two if statements. For the case
where we just get __builtins__ from a module, eliminate a couple of
tests.
wasn't used outside the assert (and hence caused a compiler warning
about an unused variable in NDEBUG mode). The assert wasn't very
useful any more.
_PyLong_NumBits(): moved the calculation of ndigits after asserting
that v != NULL.
Assorted code cleanups; e.g., sizeof(char) is 1 by definition, so there's
no need to do things like multiply by sizeof(char) in hairy malloc
arguments. Fixed an undetected-overflow bug in readline_file().
longobject.c: Fixed a really stupid bug in the new _PyLong_NumBits.
pickle.py: Fixed stupid bug in save_long(): When proto is 2, it
wrote LONG1 or LONG4, but forgot to return then -- it went on to
append the proto 1 LONG opcode too.
Fixed equally stupid cancelling bugs in load_long1() and
load_long4(): they *returned* the unpickled long instead of pushing
it on the stack. The return values were ignored. Tests passed
before only because save_long() pickled the long twice.
Fixed bugs in encode_long().
Noted that decode_long() is quadratic-time despite our hopes,
because long(string, 16) is still quadratic-time in len(string).
It's hex() that's linear-time. I don't know a way to make decode_long()
linear-time in Python, short of maybe transforming the 256's-complement
bytes into marshal's funky internal format, and letting marshal decode
that. It would be more valuable to make long(string, 16) linear time.
pickletester.py: Added a global "protocols" vector so tests can try
all the protocols in a sane way. Changed test_ints() and test_unicode()
to do so. Added a new test_long(), but the tail end of it is disabled
because it "takes forever" under pickle.py (but runs very quickly under
cPickle: cPickle proto 2 for longs is linear-time).
__module__ is the string name of the module the function was defined
in, just like __module__ of classes. In some cases, particularly for
C functions, the __module__ may be None.
Change PyCFunction_New() from a function to a macro, but keep an
unused copy of the function around so that we don't change the binary
API.
Change pickle's save_global() to use whichmodule() if __module__ is
None, but add the __module__ logic to whichmodule() since it might be
used outside of pickle.
error handers in the Unicode codecs: Negative
positions are treated as being relative to the end of
the input and out of bounds positions result in an
IndexError.
Also update the PEP and include an explanation of
this in the documentation for codecs.register_error.
Fixes a small bug in iconv_codecs: if the position
from the callback is negative *add* it to the size
instead of substracting it.
From SF patch #677429.
needs of pickling longs. Backed off to a definition that's much easier
to understand. The pickler will have to work a little harder, but other
uses are more likely to be correct <0.5 wink>.
_PyLong_Sign(): New teensy function to characterize a long, as to <0, ==0,
or >0.
types. The special handling for these can now be removed from save_newobj().
Add some testing for this.
Also add support for setting the 'fast' flag on the Python Pickler class,
which suppresses use of the memo.
start for the C implemention of new pickle LONG1 and LONG4 opcodes (the
linear-time way to pickle a long is to call _PyLong_AsByteArray, but
the caller has no idea how big an array to allocate, and correct
calculation is a bit subtle).
was broken because new-in-2.3 code added a tp_as_mapping slot to tuples.
Repaired that.
Added basic docs to check_recursion().
The code that intended to exempt tuples and strings was also broken here,
and in 2.2: these should use PyXYZ_CheckExact(), not PyXYZ_Check() -- we
can't know whether subclass instances are immutable. This part (and this
part alone) is a bugfix candidate.
Christian Tismer pointed out the high cost of the loop overhead and
function call overhead for 'c' * n where n is large. Accordingly,
the new code only makes lg2(n) loops.
Interestingly, 'c' * 1000 * 1000 ran a bit faster with old code. At some
point, the loop and function call overhead became cheaper than invalidating
the cache with lengthy memcpys. But for more typical sizes of n, the new
code runs much faster and for larger values of n it runs only a bit slower.
Refactor code in PyCFunction_Call giving a modest (tiny) speed boost,
a slight improvement in semantics (now detects invalid flag combinations),
and (arguably) improved clarity (making it blindingly clear which flag
combinations are allowed). All this comes at a cost of a few lines of
code duplication.
* Folded test for METH_KEYWORDS into the switch/case.
* Deferred testing for an empty dictionary until when and where needed.
* Make a similar deferral for filling the "size" variable.
* Inverted the dictionary test so that the common case falls though
instead of making a jump.
645404). I'm not 100% sure this is the right fix, so I'll keep the
bug report open for Samuele, but this fixes the index error and passes
the test suite (and I can't see why it *shouldn't* be the right fix
:-).
Initialize the small integers and __builtins__ in startup.
This removes some if conditions.
Change XDECREF to DECREF for values which shouldn't be NULL.
andsq_inplace_repeat. This fixes a number of corner case bugs (see #624807).
Consolidate the int and long sequence repeat code. Before the change, integers
checked for integer overflow but longs did not.
Obtain cleaner coding and a system wide
performance boost by using the fast, pre-parsed
PyArg_Unpack function instead of PyArg_ParseTuple
function which is driven by a format string.
[ 643835 ] Set Next Statement for Python debuggers
with a few tweaks by me: adding an unsigned or two, mentioning that
not all jumps are allowed in the doc for pdb, adding a NEWS item and
a note to whatsnew, and AuCTeX doing something cosmetic to libpdb.tex.
[#521782] unreliable file.read() error handling
* Objects/fileobject.c
(file_read): Clear errors before leaving the loop in all situations,
and also check if some data was read before exiting the loop with an
EWOULDBLOCK exception.
* Doc/lib/libstdtypes.tex
* Objects/fileobject.c
Document that sometimes a read() operation can return less data than
what the user asked, if running in non-blocking mode.
* Misc/NEWS
Document the fix.
containing class objects) are allowed as the second argument.
This makes issubclass() more similar to isinstance() where recursive
tuples are allowed too.
supported as the second argument. This has the same meaning as
for isinstance(), i.e. issubclass(X, (A, B)) is equivalent
to issubclass(X, A) or issubclass(X, B). Compared to isinstance(),
this patch does not search the tuple recursively for classes, i.e.
any entry in the tuple that is not a class, will result in a
TypeError.
This closes SF patch #649608.
Most of these patches are from Thomas Heller, with long lines folded
by Tim. The change to test_descr.py is from Guido. See the bug report.
Not a bugfix candidate -- METH_CLASS is new in 2.3.
Just van Rossum showed a weird, but clever way for pure python code to
trigger the BadInternalCall. The C code had assumed that calling a class
constructor would return an instance of that class; however, classes that
abuse __new__ can invalidate that assumption.
see problems with my code that I didn't see before the checkin, but:
When a subtype .mro() fails, we need to reset the type whose __bases__
are being changed, too. Fix + test.
[ 635933 ] make some type attrs writable
Plus a couple of extra tests beyond what's up there.
It hasn't been as carefully reviewed as it perhaps should, so all readers
are encouraged, nay exhorted, to give this a close reading.
There are still a couple of oddities related to assigning to __name__,
but I intend to solicit python-dev's opinions on these.
messages about MRO conflicts. (The tweaks include correcting spelling
errors, some refactoring to get the name of classic classes, and a
style nit or two.)
long but the double is too big to fit in a long. Prevent that. This
closes some recent bug or patch on SF, but SF is down now so I can't
say which.
Bugfix candidate.
Py_Init crash". refchain cannot be cleared because objects can live across
Py_Finalize() and Py_Initialize() if they are kept alive by circular
references.
619475; also closing SF bug 618704). I tweaked his code a bit for
style.
This raises TypeError for MRO order disagreements, which is an
improvement (previously these went undetected) but also a degradation:
what if the order disagreement doesn't affect any method lookups?
I don't think I care.
When mwh added extended slicing, strings and unicode became mappings.
Thus, dict was set which prevented an error when doing:
newstr = 'format without a percent' % string_value
This fix raises an exception again when there are no formats
and % with a string value.
Armin Rigo's Draconian but effective fix for
SF bug 453523: list.sort crasher
slightly fiddled to catch more cases of list mutation. The dreaded
internal "immutable list type" is gone! OTOH, if you look at a list
*while* it's being sorted now, it will appear to be empty. Better
than a core dump.
/* this is harder to get right than you might think */
angered some God somewhere. After noticing
>>> range(5000000)[slice(96360, None, 439)]
[]
I found that my cute test for the slice being empty failed due to
overflow. Fixed, and added simple test (not the above!).
classes was called with three arguments. This makes no sense, there's
no way to pass in the "modulo" 3rd argument as for __pow__, and
classic classes don't do this. [SF bug 620179]
I don't want to backport this to 2.2.2, because it could break
existing code that has developed a work-around. Code in 2.2.2 that
wants to use __ipow__ and wants to be forward compatible with 2.3
should be written like this:
def __ipow__(self, exponent, modulo=None):
...
macros. The 'op' argument is then the result from PyObject_MALLOC,
and that can of course be NULL. In that case, PyObject_Init[Var]
would raise a SystemError with "NULL object passed to
PyObject_Init[Var]". But there's nothing the caller of the macro can
do about this. So PyObject_Init[Var] should call just PyErr_NoMemory.
Will backport.
'%2147483647d' % -123 segfaults. This was because an integer overflow
in a comparison caused the string resize to be skipped. After fixing
the overflow, this could call _PyString_Resize() with a negative size,
so I (1) test for that and raise MemoryError instead; (2) also added a
test for negative newsize to _PyString_Resize(), raising SystemError
as for all bad arguments.
An identical bug existed in unicodeobject.c, of course.
Will backport to 2.2.2.
Also fixed an error message -- %s argument has non-string str()
doesn't make sense for %r, so the error message now differentiates
between %s and %r.
because PyObject_Repr() and PyObject_Str() ensure that this can never
happen. Added a helpful comment instead.
sees a Unicode argument. Unfortunately this test was also executed
for %r, because %s and %r share almost all of their code. This meant
that, if u is a unicode object while repr(u) is an 8-bit string
containing ASCII characters, '%r' % u is a *unicode* string containing
only ASCII characters!
Fixed by executing the test only for %s.
Also fixed an error message -- %s argument has non-string str()
doesn't make sense for %r, so the error message now differentiates
between %s and %r.
but returns r->len which is a long. This doesn't even cause a warning
on 32-bit platforms, but can return bogus values on 64-bit platforms
(and should cause a compiler warning). Fix this by inserting a range
check when LONG_MAX != INT_MAX, and adding an explicit cast to (int)
when the test passes. When r->len is out of range, PySequence_Size()
and hence len() will report an error (but an iterator will still
work).
Unicode strings (with arbitrary length) are allowed
as entries in the unicode.translate mapping.
Add a test case for multicharacter replacements.
(Multicharacter replacements were enabled by the
PEP 293 patch)
globals, _Py_Ticker and _Py_CheckInterval. This also implements Jeremy's
shortcut in Py_AddPendingCall that zeroes out _Py_Ticker. This allows the
test in the main loop to only test a single value.
The gory details are at
http://python.org/sf/602191
of PyString_DecodeEscape(). This prevents a call to
_PyString_Resize() for the empty string, which would
result in a PyErr_BadInternalCall(), because the
empty string has more than one reference.
This closes SF bug http://www.python.org/sf/603937
possible. This always called PyUnicode_Check() and PyString_Check(),
at least one of which would call PyType_IsSubtype(). Also, this would
call PyString_Size() on known string objects.
wrong thing for a unicode subclass when there were zero string
replacements. The example given in the SF bug report was only one way
to trigger this; replacing a string of length >= 2 that's not found is
another. The code would actually write outside allocated memory if
replacement string was longer than the search string.
(I wonder how many more of these are lurking? The unicode code base
is full of wonders.)
Bugfix candidate; this same bug is present in 2.2.1.
SHIFT and MASK, and widen digit. One problem is that code of the form
digit << small_integer
implicitly assumes that the result fits in an int or unsigned int
(platform-dependent, but "int sized" in any case), since digit is
promoted "just" to int or unsigned via the usual integer promotions.
But if digit is typedef'ed as unsigned int, this loses information.
The cure for this is just to cast digit to twodigits first.
interning. I modified Oren's patch significantly, but the basic idea
and most of the implementation is unchanged. Interned strings created
with PyString_InternInPlace() are now mortal, and you must keep a
reference to the resulting string around; use the new function
PyString_InternImmortal() to create immortal interned strings.
comments everywhere that bugged me: /* Foo is inlined */ instead of
/* Inline Foo */. Somehow the "is inlined" phrase always confused me
for half a second (thinking, "No it isn't" until I added the missing
"here"). The new phrase is hopefully unambiguous.
expensive and overly general PyObject_IsInstance(), call
PyObject_TypeCheck() which is a macro that often avoids a call, and if
it does make a call, calls the much more efficient PyType_IsSubtype().
This saved 6% on a benchmark for slot lookups.
-- replace then with slightly faster PyObject_Call(o,a,NULL). (The
difference is that the latter requires a to be a tuple; the former
allows other values and wraps them in a tuple if necessary; it
involves two more levels of C function calls to accomplish all that.)
rigorous instead of hoping for testing not to turn up counterexamples.
Call me heretical, but despite that I'm wholly confident in the proof,
and have done it two different ways now, I still put more faith in
testing ...
[ 587993 ] SET_LINENO killer
Remove SET_LINENO. Tracing is now supported by inspecting co_lnotab.
Many sundry changes to document and adapt to this change.
ah*bh and al*bl. This is much easier than explaining why that's true
for (ah+al)*(bh+bl), and follows directly from the simple part of the
(ah+al)*(bh+bl) explanation.
space is no longer needed, so removed the code. It was only possible when
a degenerate (ah->ob_size == 0) split happened, but after that fix went
in I added k_lopsided_mul(), which saves the body of k_mul() from seeing
a degenerate split. So this removes code, and adds a honking long comment
block explaining why spilling out of bounds isn't possible anymore. Note:
ff we end up spilling out of bounds anyway <wink>, an assert in v_iadd()
is certain to trigger.
(rev. 2.86). The other type is only disqualified from sq_repeat when
it has the CHECKTYPES flag. This means that for extension types that
only support "old-style" numeric ops, such as Zope 2's ExtensionClass,
sq_repeat still trumps nb_multiply.
k_mul() when inputs have vastly different sizes, and a little more
efficient when they're close to a factor of 2 out of whack.
I consider this done now, although I'll set up some more correctness
tests to run overnight.
cases, overflow the allocated result object by 1 bit. In such cases,
it would have been brought back into range if we subtracted al*bl and
ah*bh from it first, but I don't want to do that because it hurts cache
behavior. Instead we just ignore the excess bit when it appears -- in
effect, this is forcing unsigned mod BASE**(asize + bsize) arithmetic
in a case where that doesn't happen all by itself.
1. You can now have __dict__ and/or __weakref__ in your __slots__
(before only __weakref__ was supported). This is treated
differently than before: it merely sets a flag that the object
should support the corresponding magic.
2. Dynamic types now always have descriptors __dict__ and __weakref__
thrust upon them. If the type in fact does not support one or the
other, that descriptor's __get__ method will raise AttributeError.
3. (This is the reason for all this; it fixes SF bug 575229, reported
by Cesar Douady.) Given this code:
class A(object): __slots__ = []
class B(object): pass
class C(A, B): __slots__ = []
the class object for C was broken; its size was less than that of
B, and some descriptors on B could cause a segfault. C now
correctly inherits __weakrefs__ and __dict__ from B, even though A
is the "primary" base (C.__base__ is A).
4. Some code cleanup, and a few comments added.
algorithm. MSVC 6 wasn't impressed <wink>.
Something odd: the x_mul algorithm appears to get substantially worse
than quadratic time as the inputs grow larger:
bits in each input x_mul time k_mul time
------------------ ---------- ----------
15360 0.01 0.00
30720 0.04 0.01
61440 0.16 0.04
122880 0.64 0.14
245760 2.56 0.40
491520 10.76 1.23
983040 71.28 3.69
1966080 459.31 11.07
That is, x_mul is perfectly quadratic-time until a little burp at
2.56->10.76, and after that goes to hell in a hurry. Under Karatsuba,
doubling the input size "should take" 3 times longer instead of 4, and
that remains the case throughout this range. I conclude that my "be nice
to the cache" reworkings of k_mul() are paying.
Andrew MacIntyre
Hye-Shik Chang
Skip Montanaro
Raymond Hettinger
Michael W. Hudson
Guido van Rossum
Tim Peters
Jack Jansen
Jeremy Hylton
Armin Rigo
Walter Dörwald
Fred Drake
Martin v. Löwis
Neal Norwitz
Neil Schemenauer
Mark Hammond
Brett Cannon
Jim Fulton
Thomas Heller
Andrew M. Kuchling
Greg Ward
Marc-André Lemburg
Gustavo Niemeyer
Just van Rossum