Introduce a new builtin exception, UnboundLocalError, raised when ceval.c
tries to retrieve or delete a local name that isn't bound to a value.
Currently raises NameError, which makes this behavior a FAQ since the same
error is raised for "missing" global names too: when the user has a global
of the same name as the unbound local, NameError makes no sense to them.
Even in the absence of shadowing, knowing whether a bogus name is local or
global is a real aid to quick understanding.
Example:
D:\src\PCbuild>type local.py
x = 42
def f():
print x
x = 13
return x
f()
D:\src\PCbuild>python local.py
Traceback (innermost last):
File "local.py", line 8, in ?
f()
File "local.py", line 4, in f
print x
UnboundLocalError: x
D:\src\PCbuild>
Note that UnboundLocalError is a subclass of NameError, for compatibility
with existing class-exception code that may be trying to catch this as a
NameError. Unfortunately, I see no way to make this wholly compatible
with -X (see comments in bltinmodule.c): under -X, [UnboundLocalError
is an alias for NameError --GvR].
[The ceval.c patch differs slightly from the second version that Tim
submitted; I decided not to raise UnboundLocalError for DELETE_NAME,
only for DELETE_LOCAL. DELETE_NAME is only generated at the module
level, and since at that level a NameError is raised for referencing
an undefined name, it should also be raised for deleting one.]
ExtensionClasses in isinstance() and issubclass().
- abstract instance and class protocols are used *only* in those
cases that would generate errors before the patch. That is, there's
no penalty for the normal case.
- instance protocol: an object smells like an instance if it
has a __class__ attribute that smells like a class.
- class protocol: an object smells like a class if it has a
__bases__ attribute that is a tuple with elements that
smell like classes (although not all elements may actually get
sniffed ;).
xrange(), especially for platforms where int and long are different
sizes (so sys.maxint isn't actually the theoretical limit for the
length of a list, but the largest C int is -- sys.maxint is the
largest Python int, which is actually a C long).
test for classes with a __complex__() method. The attribute is pulled
out of the instance with PyObject_GetAttr() but this transfers
ownership and the function object was never DECREF'd.
initialization of class exceptions. Specifically:
init_class_exc(): This function now returns an integer status of the
class exception initialization. No fatal errors in this method now.
Also, use PySys_WriteStderr() when writing error messages. When an
error occurs in this function, 0 is returned, but the partial creation
of the exception classes is not undone (this happens elsewhere).
Things that could trigger the fallback:
- exceptions.py fails to be imported (due to syntax error, etc.)
- one of the exception classes is missing (e.g. due to library
version mismatch)
- exception class can't be inserted into __builtin__'s dictionary
- MemoryError instance can't be pre-allocated
- some other PyErr_Occurred
newstdexception(): Changed the error message. This is still a fatal
error because if the string based exceptions can't be created, we
really can't continue.
initerrors(): Be sure to xdecref the .exc field, which might be
non-NULL if class exceptions init was aborted.
_PyBuiltin_Init_2(): If class exception init fails, print a warning
message and reinstate the string based exceptions.
OSError. The EnvironmentError serves primarily as the (common
implementation) base class for IOError and OSError. OSError is used
by posixmodule.c
Also added tuple definition of EnvironmentError when using string
based exceptions.
(1) If a sequence S is shorter than len(S) indicated, don't fail --
just use the shorter size. (I.e, len(S) is just a hint.)
(2) Implement the special case map(None, S) as list(S) -- it's faster.
the code here becomes much simpler. In particular: abs(), divmod(),
pow(), int(), long(), float(), len(), tuple(), list().
Also make sure that no use of a function pointer gotten from a
tp_as_sequence or tp_as_mapping structure is made without checking it
for NULL first.
A few other cosmetic things, such as properly reindenting slice().
but annoying memory leak. This was introduced when PyExc_Exception
was added; the loop above populating the PyExc_StandardError exception
tuple started at index 1 in bltin_exc, but PyExc_Exception was added
at index 0, so PyExc_StandardError was getting inserted in itself!
How else can a tuple include itself?!
Change the loop to start at index 2.
This was a *fun* one! :-)
This doesn't yet support "import a.b.c" or "from a.b.c import x", but
it does recognize directories. When importing a directory, it
initializes __path__ to a list containing the directory name, and
loads the __init__ module if found.
The (internal) find_module() and load_module() functions are
restructured so that they both also handle built-in and frozen modules
and Mac resources (and directories of course). The imp module's
find_module() and (new) load_module() also have this functionality.
Moreover, imp unconditionally defines constants for all module types,
and has two more new functions: find_module_in_package() and
find_module_in_directory().
There's also a new API function, PyImport_ImportModuleEx(), which
takes all four __import__ arguments (name, globals, locals, fromlist).
The last three may be NULL. This is currently the same as
PyImport_ImportModule() but in the future it will be able to do
relative dotted-path imports.
Other changes:
- bltinmodule.c: in __import__, call PyImport_ImportModuleEx().
- ceval.c: always pass the fromlist to __import__, even if it is a C
function, so PyImport_ImportModuleEx() is useful.
- getmtime.c: the function has a second argument, the FILE*, on which
it applies fstat(). According to Sjoerd this is much faster. The
first (pathname) argument is ignored, but remains for backward
compatibility (so the Mac version still works without changes).
By cleverly combining the new imp functionality, the full support for
dotted names in Python (mini.py, not checked in) is now about 7K,
lavishly commented (vs. 14K for ni plus 11K for ihooks, also lavishly
commented).
Good night!
Added PyErr_MemoryErrorInst to hold the pre-instantiated instance when
using class based exceptions.
Simplified the creation of all built-in exceptions, both class based
and string based. Actually, for class based exceptions, the string
ones are still created just in case there's a problem creating the
class based ones (so you still get *some* exception handling!). Now
the init and fini functions run through a list of structure elements,
creating the strings (and optionally classes) for every entry.
initerrors(): the new base class exceptions StandardError,
LookupError, and NumberError are initialized when using string
exceptions, to tuples containing the list of derived string
exceptions. This GvR trick enables forward compatibility! One bit of
nastiness is that the C code has to know the inheritance tree embodied
in exceptions.py.
Added the two phase init and fini functions.
classes as their second arguments. The former takes a class as the
first argument and returns true iff first is second, or is a subclass
of second.
The latter takes any object as the first argument and returns true iff
first is an instance of the second, or any subclass of second.
Also, change all occurances of pointer compares against
PyExc_IndexError with PyErr_ExceptionMatches() calls.
2. Fix two bugs in complex():
- Memory leak when using complex(classinstance) -- r was never
DECREF'ed.
- Conversion of the second argument, if not complex, was done using
the type vector of the 1st.
be Ellipsis!).
Bumped the API version because a linker-visible symbol is affected.
Old C code will still compile -- there's a b/w compat macro.
Similarly, old Python code will still run, builtin exports both
Ellipses and Ellipsis.
bltinmodule.c: fixed coerce() nightmare in ternary pow().
modsupport.c (initmodule2): pass METH_FREENAME flag to newmethodobject().
pythonrun.c: move flushline() into and around print_error().
global: Py_MakePendingCalls. Also guard against recursive calls
* Include/classobject.h, Objects/classobject.c,
Python/{ceval.c,bltinmodule.c}: entirely redone operator
overloading. The rules for class instances are now much more
relaxed than for other built-in types
(whose coerce must still return two objects of the same type)
* funcobject.c (func_repr): don't call getstringvalue(None) for anonymous
functions.
* bltinmodule.c: removed lambda (which is now a built-in function);
removed implied lambda for string arg to filter/map/reduce.
* Grammar, graminit.[ch], compile.[ch]: replaced lambda as built-in
function by lambda as grammar entity: instead of "lambda('x: x+1')" you
write "lambda x: x+1".
* Xtmodule.c (checkargdict): return 0, not NULL, for error.
* object.[ch], bltinmodule.c, fileobject.c: changed str() to call
strobject() which calls an object's __str__ method if it has one.
strobject() is also called by writeobject() when PRINT_RAW is passed.
* ceval.c: rationalize code for PRINT_ITEM (no change in function!)
* funcobject.c, codeobject.c: added compare and hash functionality.
Functions with identical code objects and the same global dictionary are
equal. Code objects are equal when their code, constants list and names
list are identical (i.e. the filename and code name don't count).
(hash doesn't work yet since the constants are in a list and lists can't
be hashed -- suppose this should really be done with a tuple now we have
resizetuple!)
careful about these.
* arraymodule.c: added 8 byte swap; added 'i' format character; added
reverse() method; rename read/write to fromfile/tofile.
* config.c: Set version to 0.9.9++.
* rotormodule.c (r_rand): declare k1..k5 as unsigned longs so the shifts
will have a well-defined effect independent of word size.
* bltinmodule.c: renamed bagof() to filter().
setlistslice() can be used to cut the unused part out of a freshly made
slice (as done by bagof()). [needed by the next mod!]
* structural changes to bagof(), map() etc.
* PROTO.h, mymalloc.h: added #ifdefs for TURBOC and GNUC.
* allobjects.h: added #include "rangeobject.h"
* Grammar: added lambda_input; relaxed syntax for exec.
* bltinmodule.c: added bagof, map, reduce, lambda, xrange.
* tupleobject.[ch]: added resizetuple().
* rangeobject.[ch]: new object type to speed up range operations (not
convinced this is needed!!!)
function vs. exec statement
* bltinmodule.c: renamed the module to __builtin__.
* posixmodule.c (posix_execv): renamed exec --> execv since it is now a
reserved word.
* Grammar: add exec statement; allow testlist in expr statement.
* ceval.c, compile.c, opcode.h: support exec statement;
avoid optimizing locals when it is used
* fileobject.{c,h}: add getfilename() internal function.
Added $(SYSDEF) to its build rule in Makefile.
* cgensupport.[ch], modsupport.[ch]: removed some old stuff. Also
changed files that still used it... And made several things static
that weren't but should have been... And other minor cleanups...
* listobject.[ch]: add external interfaces {set,get}listslice
* socketmodule.c: fix bugs in new send() argument parsing.
* sunaudiodevmodule.c: added flush() and close().
yet). The class is now passed to eval_code and stored in the current
frame. It is also stored in instance method objects. An "unbound"
instance method is now returned when a function is retrieved through
"classname.funcname", which when called passes the class to eval_code.
(1) dictionaries/mappings now have attributes values() and items() as
well as keys(); at the C level, use the new function mappinggetnext()
to iterate over a dictionary.
(2) "class C(): ..." is now illegal; you must write "class C: ...".
(3) Class objects now know their own name (finally!); and minor
improvements to the way how classes, functions and methods are
represented as strings.
(4) Added an "access" statement and semantics. (This is still
experimental -- as long as you don't use the keyword 'access' nothing
should be changed.)
f_fastlocals in a traceback object (this is a core dump hazard
if there are <nil> entries), but instead eval_code() merges the fast
locals back into the locals dictionary if it looks like the local
variables will be retained. Also, the merge routines save
exceptions since this is sometimes needed (alas!).
* Added id() to bltinmodule.c, which returns an object's address
(identity). Useful to walk arbitrary data structures containing
cycles.
* Added compile() to bltinmodule.c and compile_string() to
pythonrun.[ch]: support to exec/eval arbitrary code objects. The
code that defaults globals and locals is moved from run_node in
pythonrun.c (which is now identical to eval_node) to eval_code in
ceval.c. [XXX For elegance a clean-up session is necessary.]
* Stubs for faster implementation of local variables (not yet finished)
* Added function name to code object. Print it for code and function
objects. THIS MAKES THE .PYC FILE FORMAT INCOMPATIBLE (the version
number has changed accordingly)
* Print address of self for built-in methods
* New internal functions getattro and setattro (getattr/setattr with
string object arg)
* Replaced "dictobject" with more powerful "mappingobject"
* New per-type functio tp_hash to implement arbitrary object hashing,
and hashobject() to interface to it
* Added built-in functions hash(v) and hasattr(v, 'name')
* classobject: made some functions static that accidentally weren't;
added __hash__ special instance method to implement hash()
* Added proper comparison for built-in methods and functions
* Fixcprt.py: added [-y file] option, do only files younger than file.
* modsupport.[ch]: added vmkvalue().
* intobject.c: use mkvalue().
* stringobject.c: added "formatstring"; renamed string* to string_*;
ceval.c: call formatstring for string % value.
* longobject.c: close memory leak in divmod.
* parsetok.c: set result node to NULL when returning an error.
* flmodule.c: added {do,check}_only_forms to fl's list of functions;
and don't print a message when an unknown object is returned.
* pythonrun.c: catch SIGHUP and SIGTERM to do essential cleanup.
* Made jpegmodule.c smaller by using getargs() and mkvalue() consistently.
* Increased parser stack size to 500 in parser.h.
* Implemented custom allocation of stack frames to frameobject.c and
added dynamic stack overflow checks (value stack only) to ceval.c.
(There seems to be a bug left: sometimes stack traces don't make sense.)
sys.stderr or sys.stdin, and to work with any object as long as it has
a write() (respectively readline()) methods. Some functions that took
a FILE* argument now take an object* argument.
coercion is now completely generic.
* ceval.c: for instances, don't coerce for + and *; * reverses
arguments if left one is non-instance numeric and right one sequence.
* socketmodule.c: get rid of makepair(); fix makesocketaddr to fix
broken recvfrom()
* socketmodule: get rid of getStrarg()
* ceval.h: move eval_code() to new file eval.h, so compile.h is no
longer needed.
* ceval.c: move thread comments to ceval.h; always make save/restore
thread functions available (for dynloaded modules)
* cdmodule.c, listobject.c: don't include compile.h
* flmodule.c: include ceval.h
* import.c: include eval.h instead of ceval.h
* cgen.py: add forground(); noport(); winopen(""); to initgl().
* bltinmodule.c, socketmodule.c, fileobject.c, posixmodule.c,
selectmodule.c:
adapt to threads (add BGN/END SAVE macros)
* stdwinmodule.c: adapt to threads and use a special stdwin lock.
* pythonmain.c: don't include getpythonpath().
* pythonrun.c: use BGN/END SAVE instead of direct calls; also more
BGN/END SAVE calls etc.
* thread.c: bigger stack size for sun; change exit() to _exit()
* threadmodule.c: use BGN/END SAVE macros where possible
* timemodule.c: adapt better to threads; use BGN/END SAVE; add
longsleep internal function if BSD_TIME; cosmetics
Guido van Rossum
Barry Warsaw
Sjoerd Mullender