In this unusual case, (len + 1) is zero, the allocation in vstr_init
succeeds (allocating 1 byte), and then the caller is likely to erroneously
access outside the allocated region, for instance with a memset().
This could be triggered with os.urandom(-1) after it was converted to use
mp_obj_new_bytes_of_zeros.
PacketBuffer facilitates packet oriented BLE protocols such as BLE
MIDI and the Apple Media Service.
This also adds PHY, MTU and connection event extension negotiation
to speed up data transfer when possible.
By having an order-only dependency on the directory itself, the directory
is sure to be created before the rule to create a .mo file is.
This fixes a low-freqency error on github actions such as
> msgfmt: error while opening "build/genhdr/en_US.mo" for writing: No such file or directory
These s16-s21 registers are used by gcc so need to be saved. Future
versions of gcc (beyond v9.1.0), or other compilers, may eventually need
additional registers saved/restored.
See issue #4844.
Recent versions of gcc perform optimisations which can lead to the
following code from the MP_NLR_JUMP_HEAD macro being omitted:
top->ret_val = val; \
MP_NLR_RESTORE_PYSTACK(top); \
*_top_ptr = top->prev; \
This is noticeable (at least) in the unix coverage on x86-64 built with gcc
9.1.0. This is because the nlr_jump function is marked as no-return, so
gcc deduces that the above code has no effect.
Adding MP_UNREACHABLE tells the compiler that the asm code may branch
elsewhere, and so it cannot optimise away the code.
Protocols are nice, but there is no way for C code to verify whether
a type's "protocol" structure actually implements some particular
protocol. As a result, you can pass an object that implements the
"vfs" protocol to one that expects the "stream" protocol, and the
opposite of awesomeness ensues.
This patch adds an OPTIONAL (but enabled by default) protocol identifier
as the first member of any protocol structure. This identifier is
simply a unique QSTR chosen by the protocol designer and used by each
protocol implementer. When checking for protocol support, instead of
just checking whether the object's type has a non-NULL protocol field,
use `mp_proto_get` which implements the protocol check when possible.
The existing protocols are now named:
protocol_framebuf
protocol_i2c
protocol_pin
protocol_stream
protocol_spi
protocol_vfs
(most of these are unused in CP and are just inherited from MP; vfs and
stream are definitely used though)
I did not find any crashing examples, but here's one to give a flavor of what
is improved, using `micropython_coverage`. Before the change,
the vfs "ioctl" protocol is invoked, and the result is not intelligible
as json (but it could have resulted in a hard fault, potentially):
>>> import uos, ujson
>>> u = uos.VfsPosix('/tmp')
>>> ujson.load(u)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: syntax error in JSON
After the change, the vfs object is correctly detected as not supporting
the stream protocol:
>>> ujson.load(p)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OSError: stream operation not supported
If a translation only has unicode code points 255 and below, the "values"
array can be 8 bits instead of 16 bits. This reclaims some code size,
e.g., in a local build, trinket_m0 / en_US reclaimed 112 bytes and de_DE
reclaimed 104 bytes. However, languages like zh_Latn_pinyin, which use
code points above 255, did not benefit.
