This implements (most of) the PEP-498 spec for f-strings and is based on
https://github.com/micropython/micropython/pull/4998 by @klardotsh.
It is implemented in the lexer as a syntax translation to `str.format`:
f"{a}" --> "{}".format(a)
It also supports:
f"{a=}" --> "a={}".format(a)
This is done by extracting the arguments into a temporary vstr buffer,
then after the string has been tokenized, the lexer input queue is saved
and the contents of the temporary vstr buffer are injected into the lexer
instead.
There are four main limitations:
- raw f-strings (`fr` or `rf` prefixes) are not supported and will raise
`SyntaxError: raw f-strings are not supported`.
- literal concatenation of f-strings with adjacent strings will fail
"{}" f"{a}" --> "{}{}".format(a) (str.format will incorrectly use
the braces from the non-f-string)
f"{a}" f"{a}" --> "{}".format(a) "{}".format(a) (cannot concatenate)
- PEP-498 requires the full parser to understand the interpolated
argument, however because this entirely runs in the lexer it cannot
resolve nested braces in expressions like
f"{'}'}"
- The !r, !s, and !a conversions are not supported.
Includes tests and cpydiffs.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Previously a subclass of a type that didn't implement unary_op, or didn't
handle MP_UNARY_OP_BOOL, would raise TypeError on bool conversion.
Fixes#5677.
The MP_OBJ_STOP_ITERATION optimisation is a shortcut for creating a
StopIteration() exception object, and means that heap memory does not need
to be allocated for the exception (in cases where it can be used). This
commit allows this optimised object to take an optional argument (before,
it could only have no argument).
The commit also adds some new tests to cover corner cases with
StopIteration and generators that previously did not work.
Signed-off-by: Damien George <damien@micropython.org>
Array equality is defined as each element being equal but to keep
code size down MicroPython implements a binary comparison. This
can only be used correctly for elements with the same binary layout
though so turn it into an NotImplementedError when comparing types
for which the binary comparison yielded incorrect results: types
with different sizes, and floating point numbers because nan != nan.
This commit adds the errno attribute to exceptions, so code can retrieve
errno codes from an OSError using exc.errno.
The implementation here simply lets `errno` (and the existing `value`)
attributes work on any exception instance (they both alias args[0]). This
is for efficiency and to keep code size down. The pros and cons of this
are:
Pros:
- more compatible with CPython, less difference to document and learn
- OSError().errno will correctly return None, whereas the current way of
doing it via OSError().args[0] will raise an IndexError
- it reduces code size on most bare-metal ports (because they already have
the errno qstr)
- for Python code that uses exc.errno the generated bytecode is 2 bytes
smaller and more efficient to execute (compared with exc.args[0]); so
bytecode loaded to RAM saves 2 bytes RAM for each use of this attribute,
and bytecode that is frozen saves 2 bytes flash/ROM for each use
- it's easier/shorter to type, and saves 2 bytes of space in .py files that
use it (for each use)
Cons:
- increases code size by 4-8 bytes on minimal ports that don't already have
the `errno` qstr
- all exceptions now have .errno and .value attributes (a cpydiff test is
added to address this)
See also #2407.
Signed-off-by: Damien George <damien@micropython.org>
For certain operands to mpn_div, the existing code path for
`DIG_SIZE == MPZ_DBL_DIG_SIZE / 2` had a bug in it where borrow could still
overflow in the `(x >= *n || *n - x <= borrow)` branch, ie
`borrow + x - (mpz_dbl_dig_t)*n` overflows the borrow variable. In such
cases the subsequent right-shift of borrow would not bring in the overflow
bit, leading to an error in the result. An example division that had
overflow when MPZ_DIG_SIZE = 16 is `(2 ** 48 - 1) ** 2 // (2 ** 48 - 1)`.
This is fixed in this commit by simplifying the code and handling the low
digits of borrow first, and then the upper bits (to shift down) separately.
There is no longer a distinction between `DIG_SIZE < MPZ_DBL_DIG_SIZE / 2`
and `DIG_SIZE == MPZ_DBL_DIG_SIZE / 2`.
This commit also simplifies the second part of the calculation so that
borrow does not need to be negated (instead the code just works knowing
that borrow is negative and using + instead of - in calculations involving
borrow).
Fixes#6777.
Signed-off-by: Damien George <damien@micropython.org>
This returns a reference to the globals dict associated with the function,
ie the global scope that the function was defined in. This attribute is
read-only but the dict itself is modifiable, per CPython behaviour.
Signed-off-by: Damien George <damien@micropython.org>
The use of -S ensures that only the CPython standard library is accessible,
which makes tests run the same regardless of any site-packages that are
installed. It also improves start-up time of CPython, reducing the overall
time spent running the test suite.
tests/basics/containment.py is updated to work around issue with old Python
versions not being able to str-format a dict-keys object, which becomes
apparent when -S is used.
Signed-off-by: Damien George <damien@micropython.org>
And enable this feature on unix, the coverage variant. The .exp test file
is needed so the test can run on CPython versions prior to "@=" operator
support.
Signed-off-by: Damien George <damien@micropython.org>
This is consistent with the other 'micro' modules and allows implementing
additional features in Python via e.g. micropython-lib's sys.
Note this is a breaking change (not backwards compatible) for ports which
do not enable weak links, as "import sys" must now be replaced with
"import usys".
As per CPython behaviour, compile(stmt, "file", "single") should create
code which prints to stdout (via __repl_print__) the results of any
expressions in stmt.
Signed-off-by: Damien George <damien@micropython.org>
MicroPython's original implementation of __aiter__ was correct for an
earlier (provisional) version of PEP492 (CPython 3.5), where __aiter__ was
an async-def function. But that changed in the final version of PEP492 (in
CPython 3.5.2) where the function was changed to a normal one. See
https://www.python.org/dev/peps/pep-0492/#why-aiter-does-not-return-an-awaitable
See also the note at the end of this subsection in the docs:
https://docs.python.org/3.5/reference/datamodel.html#asynchronous-iterators
And for completeness the BPO: https://bugs.python.org/issue27243
To be consistent with the Python spec as it stands today (and now that
PEP492 is final) this commit changes MicroPython's behaviour to match
CPython: __aiter__ should return an async-iterable object, but is not
itself awaitable.
The relevant tests are updated to match.
See #6267.
Because the argument arrays may overlap, as show by the new tests in this
commit.
Also remove the debugging comments for these macros, add a new comment
about overlapping regions, and separate the macros by blank lines to make
them easier to read.
Fixes issue #6244.
Signed-off-by: Damien George <damien@micropython.org>
This commit fixes lookups of class members to make it so that built-in
functions that are used as methods/functions of a class work correctly.
The mp_convert_member_lookup() function is pretty much completely changed
by this commit, but for the most part it's just reorganised and the
indenting changed. The functional changes are:
- staticmethod and classmethod checks moved to later in the if-logic,
because they are less common and so should be checked after the more
common cases.
- The explicit mp_obj_is_type(member, &mp_type_type) check is removed
because it's now subsumed by other, more general tests in this function.
- MP_TYPE_FLAG_BINDS_SELF and MP_TYPE_FLAG_BUILTIN_FUN type flags added to
make the checks in this function much simpler (now they just test this
bit in type->flags).
- An extra check is made for mp_obj_is_instance_type(type) to fix lookup of
built-in functions.
Fixes#1326 and #6198.
Signed-off-by: Damien George <damien@micropython.org>
An OrderedDict can now be used for the locals when creating a type
explicitly via type(name, bases, locals).
Signed-off-by: Damien George <damien@micropython.org>
The behavior mirrors the instance object dict attribute where a copy of the
local attributes are provided (unless the dict is read-only, then that dict
itself is returned, as an optimisation). MicroPython does not support
modifying this dict because the changes will not be reflected in the class.
The feature is only enabled if MICROPY_CPYTHON_COMPAT is set, the same as
the instance version.
Constant expression like "2 ** 3" will now be folded, and the special form
"X = const(2 ** 3)" will now compile because the argument to the const is
now a constant.
Fixes issue #5865.
Only the "==" operator was tested by the test suite in for such arguments.
Other comparison operators like "<" take a different path in the code so
need to be tested separately.
This commit implements a more complete replication of CPython's behaviour
for equality and inequality testing of objects. This addresses the issues
discussed in #5382 and a few other inconsistencies. Improvements over the
old code include:
- Support for returning non-boolean results from comparisons (as used by
numpy and others).
- Support for non-reflexive equality tests.
- Preferential use of __ne__ methods and MP_BINARY_OP_NOT_EQUAL binary
operators for inequality tests, when available.
- Fallback to op2 == op1 or op2 != op1 when op1 does not implement the
(in)equality operators.
The scheme here makes use of a new flag, MP_TYPE_FLAG_NEEDS_FULL_EQ_TEST,
in the flags word of mp_obj_type_t to indicate if various shortcuts can or
cannot be used when performing equality and inequality tests. Currently
four built-in classes have the flag set: float and complex are
non-reflexive (since nan != nan) while bytearray and frozenszet instances
can equal other builtin class instances (bytes and set respectively). The
flag is also set for any new class defined by the user.
This commit also includes a more comprehensive set of tests for the
behaviour of (in)equality operators implemented in special methods.
This commit adds a generator test for throwing into a nested exception, and
one when using yield-from with a pending exception cleanup. Both these
tests currently fail on the native emitter, and are simplified versions of
native test failures from uasyncio in #5332.
Instances of the slice class are passed to __getitem__() on objects when
the user indexes them with a slice. In practice the majority of the time
(other than passing it on untouched) is to work out what the slice means in
the context of an array dimension of a particular length. Since Python 2.3
there has been a method on the slice class, indices(), that takes a
dimension length and returns the real start, stop and step, accounting for
missing or negative values in the slice spec. This commit implements such
a indices() method on the slice class.
It is configurable at compile-time via MICROPY_PY_BUILTINS_SLICE_INDICES,
disabled by default, enabled on unix, stm32 and esp32 ports.
This commit also adds new tests for slice indices and for slicing unicode
strings.
Allows assigning attributes on class instances that implement their own
__setattr__. Both object.__setattr__ and super(A, b).__setattr__ will work
with this commit.
Because CPython 3.8.0 now produces different output:
- basics/parser.py: CPython does not allow '\\\n' as input.
- import/import_override: CPython imports _io.
This commit adds a sys.implementation.mpy entry when the system supports
importing .mpy files. This entry is a 16-bit integer which encodes two
bytes of information from the header of .mpy files that are supported by
the system being run: the second and third bytes, .mpy version, and flags
and native architecture. This allows determining the supported .mpy file
dynamically by code, and also for the user to find it out by inspecting
this value. It's further possible to dynamically detect if the system
supports importing .mpy files by `hasattr(sys.implementation, 'mpy')`.
Replace the is_running field with a tri-state variable to indicate
running/not-running/pending-exception.
Update tests to cover the various cases.
This allows cancellation in uasyncio even if the coroutine hasn't been
executed yet. Fixes#5242
Prior to this commit, when unwinding through an active finally the stack
was not being correctly popped/folded, which resulting in the VM crashing
for complicated unwinding of nested finallys.
This should be fixed with this commit, and more tests for return/break/
continue within a finally have been added to exercise this.
Prior to this patch mp_opcode_format would calculate the incorrect size of
the MP_BC_UNWIND_JUMP opcode, missing the additional byte. But, because
opcodes below 0x10 are unused and treated as bytes in the .mpy load/save
and freezing code, this bug did not show any symptoms, since nested unwind
jumps would rarely (if ever) reach a depth of 16 (so the extra byte of this
opcode would be between 0x01 and 0x0f and be correctly loaded/saved/frozen
simply as an undefined opcode).
This patch fixes this bug by correctly accounting for the additional byte.
.
With this patch alignment is done relative to the start of the buffer that
is being unpacked, not the raw pointer value, as per CPython.
Fixes issue #3314.
Prior to this patch the amount of free space in an array (including
bytearray) was not being maintained correctly for the case of slice
assignment which changed the size of the array. Under certain cases (as
encoded in the new test) it was possible that the array could grow beyond
its allocated memory block and corrupt the heap.
Fixes issue #4127.
Reuse the implementation for bytes since it works the same way regardless
of the underlying type. This method gets added for CPython compatibility
of bytearray, but to keep the code simple and small array.array now also
has a working decode method, which is non-standard but doesn't hurt.
This allows figuring out the number of bytes in the memoryview object as
len(memview) * memview.itemsize.
The feature is enabled via MICROPY_PY_BUILTINS_MEMORYVIEW_ITEMSIZE and is
disabled by default.
This patch fixes a bug in the VM when breaking within a try-finally. The
bug has to do with executing a break within the finally block of a
try-finally statement. For example:
def f():
for x in (1,):
print('a', x)
try:
raise Exception
finally:
print(1)
break
print('b', x)
f()
Currently in uPy the above code will print:
a 1
1
1
segmentation fault (core dumped) micropython
Not only is there a seg fault, but the "1" in the finally block is printed
twice. This is because when the VM executes a finally block it doesn't
really know if that block was executed due to a fall-through of the try (no
exception raised), or because an exception is active. In particular, for
nested finallys the VM has no idea which of the nested ones have active
exceptions and which are just fall-throughs. So when a break (or continue)
is executed it tries to unwind all of the finallys, when in fact only some
may be active.
It's questionable whether break (or return or continue) should be allowed
within a finally block, because they implicitly swallow any active
exception, but nevertheless it's allowed by CPython (although almost never
used in the standard library). And uPy should at least not crash in such a
case.
The solution here relies on the fact that exception and finally handlers
always appear in the bytecode after the try body.
Note: there was a similar bug with a return in a finally block, but that
was previously fixed in b735208403
All exceptions that unwind through the async-with must be caught and
BaseException is the top-level class, which includes Exception and others.
Fixes issue #4552.
Instead of assuming that the method is a bytecode object, and only
supporting load of __name__, make the operation generic by delegating the
load to the method object itself. Saves a bit of code size and fixes the
case of attempting to load __name__ on a native method, see issue #4028.
This ensures that implicit variables are only converted to implicit
closed-over variables (nonlocals) at the very end of the function scope.
If variables are closed-over when first used (read from, as was done prior
to this commit) then this can be incorrect because the variable may be
assigned to later on in the function which means they are just a plain
local, not closed over.
Fixes issue #4272.
Part of this test was trying to test some functionality of __getattribute__
but this method name was misspelt so it wasn't doing anything useful.
Fixing the typo in this name makes the test fail because MicroPython
doesn't support user defined __getattribute__ methods. So this part of the
test is removed. The remaining tests are modified slightly to make it
clearer what they are testing.
This makes these special methods have the same calling behaviour as other
methods in a class instance (mp_convert_member_lookup() is already called
by mp_obj_class_lookup()).
mp_make_raise_obj must be used to convert a possible exception type to an
instance object, otherwise the VM may raise a non-exception object.
An existing test is adjusted to test this case, with the original test
already moved to generator_throw.py.
This commit implements PEP479 which disallows raising StopIteration inside
a generator to signal that it should be finished. Instead, the generator
should simply return when it is complete.
See https://www.python.org/dev/peps/pep-0479/ for details.
If bytearray is constructed from str, a second argument of encoding is
required (in CPython), and third arg of Unicode error handling is allowed,
e.g.:
bytearray("str", "utf-8", "strict")
This is similar to bytes:
bytes("str", "utf-8", "strict")
This patch just allows to pass 2nd/3rd arguments to bytearray, but
doesn't try to validate them to not impact code size. (This is also
similar to how bytes constructor is handled, though it does a bit
more validation, e.g. check that in case of str arg, encoding argument
is passed.)
The native emitter keeps the current exception in a slot in its C stack
(instead of on its Python value stack), so when it catches an exception it
must explicitly clear that slot so the same exception is not reraised later
on.
Back in 8047340d75 basic support was added in
the VM to handle return statements within a finally block. But it didn't
cover all cases, in particular when some finally's were active and others
inactive when the "return" was executed.
This patch adds further support for return-within-finally by correctly
managing the currently_in_except_block flag, and should fix all cases. The
main point is that finally handlers remain on the exception stack even if
they are active (currently being executed), and the unwind return code
should only execute those finally's which are inactive.
New tests are added for the cases which now pass.
