UART1 can be used even if the switch is enabled. The schematics for this
board make I2C1 available on PB8/PB9, even though it can also be mapped
to PB6/PB7.
See #2396 and #2427.
The vstr.had_error flag was a relic from the very early days which assumed
that the malloc functions (eg m_new, m_renew) returned NULL if they failed
to allocate. But that's no longer the case: these functions will raise an
exception if they fail.
Since it was impossible for had_error to be set, this patch introduces no
change in behaviour.
An alternative option would be to change the malloc calls to the _maybe
variants, which return NULL instead of raising, but then a lot of code
will need to explicitly check if the vstr had an error and raise if it
did.
The code-size savings for this patch are, in bytes: bare-arm:188,
minimal:456, unix(NDEBUG,x86-64):368, stmhal:228, esp8266:360.
With the previous patch combining 3 emit functions into 1, it now makes
sense to also combine the corresponding VM opcodes, which is what this
patch does. This eliminates 2 opcodes which simplifies the VM and reduces
code size, in bytes: bare-arm:44, minimal:64, unix(NDEBUG,x86-64):272,
stmhal:92, esp8266:200. Profiling (with a simple script that creates many
list/dict/set comprehensions) shows no measurable change in performance.
The 3 kinds of comprehensions are similar enough that merging their emit
functions reduces code size. Decreases in code size in bytes are:
bare-arm:24, minimal:96, unix(NDEBUG,x86-64):328, stmhal:80, esp8266:76.
bool(None) has a fast path in mp_obj_is_true so doesn't need to be
handled in none_unary_op. The only caveat is that subclassing may
bypass the mp_obj_is_true function, but actually you aren't allowed to
subclass classes that have singleton instances like NoneType (see
https://mail.python.org/pipermail/python-dev/2002-March/020822.html for
reference on this point).
This is actually long overdue: the README in the windows directory has been
updated once to indicate mingw32 is abandoned and not ok to use with uPy,
but we forgot travis builds were still using it.
As a bonus the travis build will succeed again since moduerrno.c now compiles.
(see https://github.com/micropython/micropython/pull/2399)
Paul Sokolovsky
Damien George
juhasch
Dave Hylands
Renato Aguiar
stijn