If a module has a future statement enabling nested scopes, they are
also enable for the exec statement and the functions compile() and
execfile() if they occur in the module.
If Python is run with the -i option, which enters interactive mode
after executing a script, and the script it runs enables nested
scopes, they are also enabled in interactive mode.
XXX The use of -i with -c "from __future__ import nested_scopes" is
not supported. What's the point?
To support these changes, many function variants have been added to
pythonrun.c. All the variants names end with Flags and they take an
extra PyCompilerFlags * argument. It is possible that this complexity
will be eliminated in a future version of the interpreter in which
nested scopes are not optional.
frees. Note there doesn't seem to be any way to test LocalsToFast(),
because the instructions that trigger it are illegal in nested scopes
with free variables.
Fix allocation strategy for cells that are also formal parameters.
Instead of emitting LOAD_FAST / STORE_DEREF pairs for each parameter,
have the argument handling code in eval_code2() do the right thing.
A side-effect of this change is that cell variables that are also
arguments are listed at the front of co_cellvars in the order they
appear in the argument list.
with free variables. Thanks to Martin v. Loewis for finding two of
the problems. This fixes SF buf 405583.
There is also a C API change: PyFrame_New() is reverting to its
pre-2.1 signature. The change introduced by nested scopes was a
mistake. XXX Is this okay between beta releases?
cell_clear(), the GC helper, must decref its reference to break
cycles.
frame_dealloc() must dealloc all cell vars and free vars in addition
to locals.
eval_code2() setup code must INCREF cells it copies out of the
closure.
The STORE_DEREF opcode implementation must DECREF the object it passes
to PyCell_Set().
create an empty dictionary if it is called without keyword args. Just
pass NULL.
XXX I had believed that this caused weird errors, but the test suite
runs cleanly.
discussion on python-dev. 'from mod import *' is still banned except
at the module level.
Fix value for special NOOPT entry in symtable. Initialze to 0 instead
of None, so that later uses of PyInt_AS_LONG() are valid. (Bug
reported by Donn Cave.)
replace local REPR macros with PyObject_REPR in object.h
This change eliminates an extra malloc/free when a frame with free
variables is created. Any cell vars or free vars are stored in
f_localsplus after the locals and before the stack.
eval_code2() fills in the appropriate values after handling
initialization of locals.
To track the size the frame has an f_size member that tracks the total
size of f_localsplus. It used to be implicitly f_nlocals + f_stacksize.
The majority of the changes are in the compiler. The mainloop changes
primarily to implement the new opcodes and to pass a function's
closure to eval_code2(). Frames and functions got new slots to hold
the closure.
Include/compile.h
Add co_freevars and co_cellvars slots to code objects.
Update PyCode_New() to take freevars and cellvars as arguments
Include/funcobject.h
Add func_closure slot to function objects.
Add GetClosure()/SetClosure() functions (and corresponding
macros) for getting at the closure.
Include/frameobject.h
PyFrame_New() now takes a closure.
Include/opcode.h
Add four new opcodes: MAKE_CLOSURE, LOAD_CLOSURE, LOAD_DEREF,
STORE_DEREF.
Remove comment about old requirement for opcodes to fit in 7
bits.
compile.c
Implement changes to code objects for co_freevars and co_cellvars.
Modify symbol table to use st_cur_name (string object for the name
of the current scope) and st_cur_children (list of nested blocks).
Also define st_nested, which might more properly be called
st_cur_nested. Add several DEF_XXX flags to track def-use
information for free variables.
New or modified functions of note:
com_make_closure(struct compiling *, PyCodeObject *)
Emit LOAD_CLOSURE opcodes as needed to pass cells for free
variables into nested scope.
com_addop_varname(struct compiling *, int, char *)
Emits opcodes for LOAD_DEREF and STORE_DEREF.
get_ref_type(struct compiling *, char *name)
Return NAME_CLOSURE if ref type is FREE or CELL
symtable_load_symbols(struct compiling *)
Decides what variables are cell or free based on def-use info.
Can now raise SyntaxError if nested scopes are mixed with
exec or from blah import *.
make_scope_info(PyObject *, PyObject *, int, int)
Helper functions for symtable scope stack.
symtable_update_free_vars(struct symtable *)
After a code block has been analyzed, it must check each of
its children for free variables that are not defined in the
block. If a variable is free in a child and not defined in
the parent, then it is defined by block the enclosing the
current one or it is a global. This does the right logic.
symtable_add_use() is now a macro for symtable_add_def()
symtable_assign(struct symtable *, node *)
Use goto instead of for (;;)
Fixed bug in symtable where name of keyword argument in function
call was treated as assignment in the scope of the call site. Ex:
def f():
g(a=2) # a was considered a local of f
ceval.c
eval_code2() now take one more argument, a closure.
Implement LOAD_CLOSURE, LOAD_DEREF, STORE_DEREF, MAKE_CLOSURE>
Also: When name error occurs for global variable, report that the
name was global in the error mesage.
Objects/frameobject.c
Initialize f_closure to be a tuple containing space for cellvars
and freevars. f_closure is NULL if neither are present.
Objects/funcobject.c
Add support for func_closure.
Python/import.c
Change the magic number.
Python/marshal.c
Track changes to code objects.
- Use PyObject_RichCompare*() where possible: when comparing
keyword arguments, in _PyEval_SliceIndex(), and of course in
cmp_outcome().
Unrelated stuff:
- Removed all trailing whitespace.
- Folded some long lines.
message, and tries to make the messages more consistent and helpful when
the wrong number of arguments or duplicate keyword arguments are supplied.
Comes with more tests for test_extcall.py and and an update to an error
message in test/output/test_pyexpat.
1) "from M import X" now works even if M is not a real module; it's
basically a getattr() operation with AttributeError exceptions
changed into ImportError.
2) "from M import *" now looks for M.__all__ to decide which names to
import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
filters out names starting with '_' as before. Whether or not
__all__ exists, there's no restriction on the type of M.
an empty keywords dictionary (via apply() or the extended call syntax),
the keywords dict should be ignored. If the keywords dict is not empty,
TypeError should be raised. (Between the restructuring of the call
machinery and this patch, an empty dict in this situation would trigger
a SystemError via PyErr_BadInternalCall().)
Added regression tests to detect errors for this.
More revision still needed.
Much of the code that was in the mainloop was moved to a series of
helper functions. PyEval_CallObjectWithKeywords was split into two
parts. The first part now only does argument handling. The second
part is now named call_object and delegates the call to a
call_(function,method,etc.) helper.
XXX The call_XXX helper functions should be replaced with tp_call
functions for the respective types.
The CALL_FUNCTION implementation contains three kinds of optimization:
1. fast_cfunction and fast_function are called when the arguments on
the stack can be passed directly to eval_code2() without copying
them into a tuple.
2. PyCFunction objects are dispatched immediately, because they are
presumed to occur more often than anything else.
3. Bound methods are dispatched inline. The method object contains a
pointer to the function object that will be called. The function
is called from within the mainloop, which may allow optimization #1
to be used, too.
The extened call implementation -- f(*args) and f(**kw) -- are
implemented as a separate case in the mainloop. This allows the
common case of normal function calls to execute without wasting time
on checks for extended calls, although it does introduce a small
amount of code duplication.
Also, the unused final argument of eval_code2() was removed. This is
probably the last trace of the access statement :-).
When a method is called with no regular arguments and * args, defer
the first arg is subclass check until after the * args have been
expanded.
N.B. The CALL_FUNCTION implementation is getting really hairy; should
review it to see if it can be simplified.
by making the DUP_TOPX code utterly straightforward. This also gets rid
of all normal-case internal DUP_TOPX if/branches, and allows replacing one
POP() with TOP() in each case, so is a good idea regardless.
Add definitions of INT_MAX and LONG_MAX to pyport.h.
Remove includes of limits.h and conditional definitions of INT_MAX
and LONG_MAX elsewhere.
This closes SourceForge patch #101659 and bug #115323.
which implements the automatic conversion from Unicode to a string
object using the default encoding.
The new API is then put to use to have eval() and exec accept
Unicode objects as code parameter. This closes bugs #110924
and #113890.
As side-effect, the traditional C APIs PyString_Size() and
PyString_AsString() will also accept Unicode objects as
parameters.
ceval.c:
define recurion_limit (static), default value is 2500
define Py_GetRecursionLimit and Py_SetRecursionLimit
raise RuntimeError if limit is exceeded
PC/config.h:
remove plat-specific definition
sysmodule.c:
add sys.(get|set)recursionlimit
how 'import' was called with a compiletime mechanism: create either a tuple
of the import arguments, or None (in the case of a normal import), add it to
the code-block constants, and load it onto the stack before calling
IMPORT_NAME.
Add the EXTENDED_ARG opcode to the virtual machine, allowing 32-bit
arguments to opcodes instead of being forced to stick to the 16-bit
limit. This is especially useful for machine-generated code, which
can be too long for the SET_LINENO parameter to fit into 16 bits.
This closes the implementation portion of SourceForge patch #100893.
eval_code2(): Implement new bytecodes PRINT_ITEM_TO and
PRINT_NEWLINE_TO, as per accepted SF patch #100970.
Also update graminit.c based on related Grammar/Grammar changes.
trying hard enough to find out what the arguments to an import were. There
is no test-case for this bug, yet, but this is what it looked like:
from encodings import cp1006, cp1026
ImportError: cannot import name cp1026
'__import__' was called with only the first name in the 'arguments' list.
name as n'. By doing some twists and turns, "as" is not a reserved word.
There is a slight change in semantics for 'from module import name' (it will
now honour the 'global' keyword) but only in cases that are explicitly
undocumented.
did the same anyway.
I'm not sure what to do with Tools/compiler/compiler/* -- that isn't part of
distutils, is it ? Should it try to be compatible with old bytecode version ?
Jeremy Hylton
Guido van Rossum
Thomas Wouters
Tim Peters
Ka-Ping Yee
Moshe Zadka
Charles G. Waldman
Fred Drake
Marc-André Lemburg
Vladimir Marangozov
Paul Prescod
Barry Warsaw