This was missed in 692d36d779. It's not
strictly necessary as the GC will clean it anyway, but it's good to
pre-emptively gc_free() all the blocks used in lexing/parsing.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This also tweaks the repr for unicode strings to only escape a few
utf-8 code points. This makes emoji show in os.listdir() for
example.
Also, enable exfat support on full builds.
Fixes#5146
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>
This leaves much more space on SAMD21 builds that aren't "full builds".
These are new APIs that we don't need to add to old boards.
Also, tweak two Arduino boards to save space on them.
* The new nonstandard '%S' format takes a pointer to compressed_string_t
and prints it
* The new mp_cprintf and mp_vcprintf take a format string that is a
compressed_string_t
By storing "count of words by length", the long `wends` table can be
replaced with a short `wlencount` table. This saves flash storage space.
Extend the range of string lengths that can be in the dictionary.
Originally it was to 2 to 9; at one point it was changed to 3 to 9.
Putting the lower bound back at 2 has a positive impact on the French
translation (a bunch of them, such as "ch", "\r\n", "%q", are used).
Increasing the maximum length gets 'mpossible', ' doit être ',
and 'CircuitPyth' at the long end. This adds a bit of processing time
to makeqstrdata. The specific 2/11 values are again empirical based on
the French translation on the adafruit_proxlight_trinkey_m0.
Commit 4173950658 removed automatic building
of mpy-cross, which rebuilt it whenever any of its dependent source files
changed.
But needing to build mpy-cross, and not knowing how, is a frequent issue.
This commit aims to help by automatically building mpy-cross only if it
doesn't exist. For Makefiles it uses an order-only prerequisite, while
for CMake it uses a custom command.
If MICROPY_MPYCROSS (which is what makemanifest.py uses to locate the
mpy-cross executable) is defined in the environment then automatic build
will not be attempted, allowing a way to prevent this auto-build if needed.
Thanks to Trammell Hudson aka @osresearch for the original idea; see #5760.
Signed-off-by: Damien George <damien@micropython.org>
Optionally enabled via MICROPY_PY_UJSON_SEPARATORS. Enabled by default.
For dump, make sure mp_get_stream_raise is called after
mod_ujson_separators since CPython does it in this order (if both
separators and stream are invalid, separators will raise an exception
first).
Add separators argument in the docs as well.
Signed-off-by: Peter Züger <zueger.peter@icloud.com>
Signed-off-by: Damien George <damien@micropython.org>
Commit e33bc597 ("py: Remove calls to file reader functions when these
are disabled.") changed the condition for one caller of
do_execute_raw_code() from
MICROPY_PERSISTENT_CODE_LOAD
to
MICROPY_HAS_FILE_READER && MICROPY_PERSISTENT_CODE_LOAD
The condition that enables compiling the function itself needs to be
changed to match.
Signed-off-by: David Lechner <david@pybricks.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.
This adds #if MICROPY_PY_USELECT_SELECT around the uselect.select()
function. According to the docs, this function is only for CPython
compatibility and should not normally be used. So we can disable it
and save a few bytes of flash space where possible.
Signed-off-by: David Lechner <david@pybricks.com>
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>
I was puzzled by why the dictionary words were sorted by length.
It was because TextSplitter sorted its parameter, instead of a copy.
This doesn't affect encoding size, but does affect the encoding NUMBER
of the found words. We'll deliberately restore sorting by length next,
for other reasons, but not by spooky action.
Try to accurately measure the costs of including a word in the dictionary
vs the gains from using it in messages.
This saves about 160 bytes on trinket_m0 ja, the fullest translation
for that board. Other translations on the same board all have savings,
ranging from 24 to 228 bytes.
```
Translation Before After Savings
ja 1164 1324 160
de_DE 1260 1396 136
fr 1424 1652 228
zh_Latn_pinyin 1448 1520 72
pt_BR 1584 1736 152
pl 1592 1640 48
es 1724 1816 92
ko 1724 1816 92
fil 1764 1800 36
it_IT 1896 2040 144
nl 1956 2136 180
ID 2072 2180 108
cs 2124 2148 24
sv 2340 2448 108
en_x_pirate 2644 2740 96
en_GB 2652 2752 100
el 2656 2768 112
en_US 2656 2768 112
hi 2656 2768 112
```
By comparing the address of the initial 'name' field instead of the
addresses of the objects themselves, a small amount of type safety is
added back, vs just casting to void.
In the event that some other kind of object is passed in as 't',
which happens to have a 'name' field of the right type, the construct
would be (undesirably) accepted but it would almost certainly evaluate
to false at runtime.
This adds the --tags argument to the git describe command that is used
to define the MICROPY_GIT_TAG macro. This makes it match non-annotated
tags. This is useful for MicroPython derivatives that don't use
annotated tags.
Signed-off-by: David Lechner <david@pybricks.com>
Only include .c and .cpp files explicitly in the list of files passed to
the preprocessor for QSTR extraction. All relevant .h files will be
included in this process by "#include" from the .c(pp) files. In
particular for moduledefs.h, this is included by py/objmodule.c (and
doesn't actually contain any extractable MP_QSTR_xxx, but rather defines
macros with MP_QSTR_xxx's in them which are then part of py/objmodule.c).
The main reason for this change is to simplify the preprocessing step on
the javascript port, which tries to compile .h files as C++ precompiled
headers if they are passed with -E to clang.
Signed-off-by: Damien George <damien@micropython.org>
Fixes the following (the line numbers match commit 0e87459e2b):
../../extmod/crypto-algorithms/sha256.c:49:19: runtime error: left shif...
../../extmod/moduasyncio.c:106:35: runtime error: member access within ...
../../py/binary.c:210:13: runtime error: left shift of negative value -...
../../py/mpz.c:744:16: runtime error: negation of -9223372036854775808 ...
../../py/objint.c:109:22: runtime error: left shift of 1 by 31 places c...
../../py/objint_mpz.c:374:9: runtime error: left shift of 4611686018427...
../../py/objint_mpz.c:374:9: runtime error: left shift of negative valu...
../../py/parsenum.c:106:14: runtime error: left shift of 46116860184273...
../../py/runtime.c:395:33: runtime error: left shift of negative value ...
../../py/showbc.c:177:28: runtime error: left shift of negative value -...
../../py/vm.c:321:36: runtime error: left shift of negative value -1```
Testing was done on an amd64 Debian Buster system using gcc-8.3 and these
settings:
CFLAGS += -g3 -Og -fsanitize=undefined
LDFLAGS += -fsanitize=undefined
The introduced TASK_PAIRHEAP macro's conditional (x ? &x->i : NULL)
assembles (under amd64 gcc 8.3 -Os) to the same as &x->i, since i is the
initial field of the struct. However, for the purposes of undefined
behavior analysis the conditional is needed.
Signed-off-by: Jeff Epler <jepler@gmail.com>
This introduces a new macro to get the main thread and uses it to ensure
that asynchronous exceptions such as KeyboardInterrupt (CTRL+C) are only
scheduled on the main thread. This is more deterministic than being
scheduled on a random thread and is more in line with CPython that only
allow signal handlers to run on the main thread.
Fixes issue #7026.
Signed-off-by: David Lechner <david@pybricks.com>
This moves mp_pending_exception from mp_state_vm_t to mp_state_thread_t.
This allows exceptions to be scheduled on a specific thread.
Signed-off-by: David Lechner <david@pybricks.com>
Prior to this commit, cache flushing for ARM native code was done only in
the assembler code asm_thumb_end_pass()/asm_arm_end_pass(), at the last
pass of the assembler. But this misses flushing the cache when loading
native code from an .mpy file, ie in persistentcode.c.
The change here makes sure the cache is always flushed/cleaned/invalidated
when assigning native code on ARM architectures.
This problem was found running tests/micropython/import_mpy_native_gc.py on
the mimxrt port.
Signed-off-by: Damien George <damien@micropython.org>
asan considers that memcmp(p, q, N) is permitted to access N bytes at each
of p and q, even for values of p and q that have a difference earlier.
Accessing additional values is frequently done in practice, reading 4 or
more bytes from each input at a time for efficiency, so when completing
"non_exist<TAB>" in the repl, this causes a diagnostic:
==16938==ERROR: AddressSanitizer: global-buffer-overflow on
address 0x555555cd8dc8 at pc 0x7ffff726457b bp 0x7fffffffda20 sp 0x7fff
READ of size 9 at 0x555555cd8dc8 thread T0
#0 0x7ffff726457a (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xb857a)
#1 0x555555b0e82a in mp_repl_autocomplete ../../py/repl.c:301
#2 0x555555c89585 in readline_process_char ../../lib/mp-readline/re
#3 0x555555c8ac6e in readline ../../lib/mp-readline/readline.c:513
#4 0x555555b8dcbd in do_repl /home/jepler/src/micropython/ports/uni
#5 0x555555b90859 in main_ /home/jepler/src/micropython/ports/unix/
#6 0x555555b90a3a in main /home/jepler/src/micropython/ports/unix/m
#7 0x7ffff619a09a in __libc_start_main ../csu/libc-start.c:308
#8 0x55555595fd69 in _start (/home/jepler/src/micropython/ports/uni
0x555555cd8dc8 is located 0 bytes to the right of global variable
'import_str' defined in '../../py/repl.c:285:23' (0x555555cd8dc0) of
size 8
'import_str' is ascii string 'import '
Signed-off-by: Jeff Epler <jepler@gmail.com>
The proper way to do this is to test for __APPLE__ and __MACH__, where
__APPLE__ tests for an Apple OS and __MACH__ tests that it is based on CMU
Mach. Using both tests ensures that just Darwin (Apple's open source base
for MacOS, iOS, etc.) is recognized. __APPLE__ by itself will test for any
Apple OS, which can include older OS 7-9 and any future Apple OS. __MACH__
tests for any OS based on CMU Mach, including Darwin and GNU Hurd.
Fixes#7232.
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 caused an error when building on macos:
```
../../py/modmath.c:247:36: error: pragma diagnostic pop could not pop, no matching push [-Werror,-Wunknown-pragmas]
#pragma GCC diagnostic pop
^
1 error generated.
```
The pragma was half-removed during the merge of micropython.
This commit makes gc_lock_depth have one counter per thread, instead of one
global counter. This makes threads properly independent with respect to
the GC, in particular threads can now independently lock the GC for
themselves without locking it for other threads. It also means a given
thread can run a hard IRQ without temporarily locking the GC for all other
threads and potentially making them have MemoryError exceptions at random
locations (this really only occurs on MCUs with multiple cores and no GIL,
eg on the rp2 port).
The commit also removes protection of the GC lock/unlock functions, which
is no longer needed when the counter is per thread (and this also fixes the
cas where a hard IRQ calling gc_lock() may stall waiting for the mutex).
It also puts the check for `gc_lock_depth > 0` outside the GC mutex in
gc_alloc, gc_realloc and gc_free, to potentially prevent a hard IRQ from
waiting on a mutex if it does attempt to allocate heap memory (and putting
the check outside the GC mutex is now safe now that there is a
gc_lock_depth per thread).
Signed-off-by: Damien George <damien@micropython.org>
* modframebuf: _mp_framebuf_p_t is not "really" a protocol, but the
QSTR assignment caused problems when building as a dynamic module
* modure: str_index_to_ptr is not in the natmod API, disable URE match
spans when dynamic. mp_obj_len() is a bugfix, we should throw here
if the object is not string-like
* moduzlib: Correct paths to uzlib headers & sources. this relative
path (from moduzlib.c to the referenced file) works in all cases,
the other only worked from ports/PORTNAME.
* dynruntime: Handle 2-arg m_malloc, assert_native_inited, add a
micropythonish mp_arg_check_num_mp, fix mp_raise_msg to use dumb
strings, add mp_raise_arg1
* nativeglue: ad assert_native_inited
* translate: MP_ERROR_TEXT evaluates to its argument for DYNRUNTIME
* mpy-tool: A straggling magic number change
* mpy_ld: Have to renumber manually after dynruntime change
* import_mpy_native_gc.py: Update copy of features0 baked into this test
Doing "import <tab>" will now complete/list built-in modules.
Originally at adafruit#4548 and adafruit#4608
Signed-off-by: Artyom Skrobov <tyomitch@gmail.com>
Anything beginning with "_" will now only be tab-completed if there is
already a partial match for such an entry. In other words, entering
foo.<tab> will no longer complete/list anything beginning with "_".
Originally at adafruit#1850
Signed-off-by: Kathryn Lingel <kathryn@lingel.net>
After discussing with danh, I noticed that `a/**/b` would not match `a/b`.
After correcting this and re-running "pre-commit run --all", additional
files were reindented, including the codeformat script itself.
These commented-out lines of code have been unused for a long time, so
remove them to avoid confusion as to why they are there.
mp_obj_dict_free() never existed, this line was converted from
mp_map_deinit() and commented out as soon as it was added. The call to
mp_map_deinit(mp_loaded_modules_map) was commented in
1a1d11fa32.
Fixes issue #3507.
Signed-off-by: Damien George <damien@micropython.org>
This helper is added to properly set a pending exception, to mirror
mp_sched_schedule(), which schedules a function.
Signed-off-by: Damien George <damien@micropython.org>
If MICROPY_ENABLE_SCHEDULER is enabled then MP_STATE_VM(sched_state) must
be updated after handling the pending exception, which is done by the
mp_handle_pending() function.
Signed-off-by: Damien George <damien@micropython.org>
This introduces a new option, MICROPY_ERROR_REPORTING_NONE, which
completely disables all error messages. To be used in cases where
MicroPython needs to fit in very limited systems.
Signed-off-by: Damien George <damien@micropython.org>
Unify USB-related makefile var and C def as CIRCUITPY_USB.
Always define it as 0 or 1, same as all other settings.
USB_AVAILABLE was conditionally defined in supervisor.mk,
but never actually used to #ifdef USB-related code.
Loosely related to #4546
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>
This allows configuring the pre-allocated size of sys.modules dict, in
order to prevent unwanted reallocations at run-time (3 sys-modules is
really not quite enough for a larger project).
When building with STATIC undefined (e.g., -DSTATIC=), there are two
instances of mp_type_code that collide at link time: in profile.c and in
builtinevex.c. This patch resolves the collision by renaming one of them.
This allows the compiler to merge strings: e.g. "update",
"difference_update" and "symmetric_difference_update"
will all point to the same memory.
Shaves ~1KB off the image size, and potentially allows
bigger savings if qstr attrs are initialized in qstr_init(),
and not stored in the image.
The parts that are generic are added to py/ so they can be used by other
ports that use CMake.
py/usermod.cmake:
* Creates a usermod target to hang user C/CXX modules from.
* Gathers sources from user C/CXX modules and libs for QSTR scan.
ports/rp2/CMakeLists.txt:
* Includes py/usermod.cmake.
* Links the resulting usermod library to the MicroPython target.
py/mkrules.cmake:
Add cxxflags to qstr.i.last custom command for CXX modules:
* MICROPY_CPP_FLAGS so CXX modules will find includes.
* -DNO_QSTR to fix fatal error missing "genhdr/qstrdefs.generated.h".
Usage:
The rp2 port can be linked against user C modules by running:
make USER_C_MODULES=/path/to/module/micropython.cmake
CMake will print a list of included modules.
Co-authored-by: Graham Sanderson <graham.sanderson@raspberrypi.org>
Co-authored-by: Michael O'Cleirigh <michael.ocleirigh@rivulet.ca>
Signed-off-by: Phil Howard <phil@pimoroni.com>
mp_printf should be used to print the prefix because it's also used in
mp_bytecode_print2 (otherwise, depending on the system, different output
streams may be used).
Also print the current thread state when threading is enabled to easily see
which thread executes what opcode.
Signed-off-by: Damien George <damien@micropython.org>
This adds some additional code in mkfs which doesn't seem necessary, and
Disabling it saves 172 bytes flash.
Testing performed: Using a Feather M0 Adalogger, checked that
* an sdcard could still be mounted (using adafruit_sdcard)
* os.listdir() of "/" and "/sd" worked
* CIRCUITPY still mounted
This also adds a bit of code everywhere we DISPATCH(), but the net is
+232 bytes free on Feather M0 Adalogger.
Key assumption: All of the offsets in mp_execute_bytecode fit in 16 bits;
it is not clear whether the compiler will verify this assumption (e.g.,
by warning that a constant will be truncated)
* Always clear the peripheral interrupt so we don't hang when full
* Store the ringbuf in the object so it gets collected when we're alive
* Make UART objects have a finaliser so they are deinit when their
memory is freed
* Copy bytes into the ringbuf from the FIFO after we read to ensure
the interrupt is enabled ASAP
* Copy bytes into the ringbuf from the FIFO before measuring our
rx available because the interrupt is based on a threshold (not
> 0). For example, a single byte won't trigger an interrupt.
This allows a port to specify a custom qstrdefsport.h file, the same as the
QSTR_DEFS variable in a Makefile.
Signed-off-by: Damien George <damien@micropython.org>
The core cmake rules use custom commands to invoke qstr processing
scripts. For the zephyr port, it's possible that list arguments to these
commands may contain generator expressions, therefore we need to expand
them properly.
Signed-off-by: Maureen Helm <maureen.helm@nxp.com>
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>
The "word" referred to by BYTES_PER_WORD is actually the size of mp_obj_t
which is not always the same as the size of a pointer on the target
architecture. So rename this config value to better reflect what it
measures, and also prefix it with MP_.
For uses of BYTES_PER_WORD in setting the stack limit this has been
changed to sizeof(void *), because the stack usually grows with
machine-word sized values (eg an nlr_buf_t has many machine words in it).
Signed-off-by: Damien George <damien@micropython.org>
It's only used in one location, to test if << or >> will overflow when
shifting mp_uint_t. For such a test it's clearer to use sizeof(lhs_val),
which will be valid even if the type of lhs_val changes.
Signed-off-by: Damien George <damien@micropython.org>
This environment variable, if defined during the build process,
indicates a fixed time that should be used in place of "now" when
such a time is explicitely referenced.
This allows for reproducible builds of micropython.
See https://reproducible-builds.org/specs/source-date-epoch/
Signed-off-by: iTitou <moiandme@gmail.com>
This should be enabled when the mp_raw_code_save_file function is needed.
It is enabled for mpy-cross, and a check for defined(__APPLE__) is added to
cover Mac M1 systems.
It practically does the same as qstr_from_str and was only used in one
place, which should actually use the compile-time MP_QSTR_XXX form for
consistency; qstr_from_str is for runtime strings only.
Adds a new compile-time option MICROPY_EMIT_THUMB_ARMV7M which is enabled
by default (to get existing behaviour) and which should be disabled (set to
0) when building native emitter support (@micropython.native) on ARMv6M
targets.
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 RP2040 is new microcontroller from Raspberry Pi that features
two Cortex M0s and eight PIO state machines that are good for
crunching lots of data. It has 264k RAM and a built in UF2
bootloader too.
Datasheet: https://pico.raspberrypi.org/files/rp2040_datasheet.pdf
Several issues have been found in the implementation. While they're
unresolved, it may be better to disable the built-in module. (This
means that to work on fixing the module, it'll be necessary to
revert this commit)
* Better messaging when code is stopped by an auto-reload.
* Auto-reload works during sleeps on ESP32-S2. Ticks wake up the
main task each time.
* Made internal naming consistent. CamelCase Python names are NOT
separated by an underscore.
As a general pattern, required positional arguments that are not named do
not need to be parsed using mp_arg_parse_all().
Signed-off-by: Damien George <damien@micropython.org>
This changes lots of files to unify `board.h` across ports. It adds
`board_deinit` when CIRCUITPY_ALARM is set. `main.c` uses it to
deinit the board before deep sleeping (even when pretending.)
Deep sleep is now a two step process for the port. First, the
port should prepare to deep sleep based on the given alarms. It
should set alarms for both deep and pretend sleep. In particular,
the pretend versions should be set immediately so that we don't
miss an alarm as we shutdown. These alarms should also wake from
`port_idle_until_interrupt` which is used when pretending to deep
sleep.
Second, when real deep sleeping, `alarm_enter_deep_sleep` is called.
The port should set any alarms it didn't during prepare based on
data it saved internally during prepare.
ESP32-S2 sleep is a bit reorganized to locate more logic with
TimeAlarm. This will help it scale to more alarm types.
Fixes#3786
Two issues are tackled:
1. The calculation of the correct length to print is fixed to treat the
precision as a maximum length instead as the exact length.
This is done for both qstr (%q) and for regular str (%s).
2. Fix the incorrect use of mp_printf("%.*s") to mp_print_strn().
Because of the fix of above issue, some testcases that would print
an embedded null-byte (^@ in test-output) would now fail.
The bug here is that "%s" was used to print null-bytes. Instead,
mp_print_strn is used to make sure all bytes are outputted and the
exact length is respected.
Test-cases are added for both %s and %q with a combination of precision
and padding specifiers.
This allows calls to `allocate_memory()` while the VM is running, it will then allocate from the GC heap (unless there is a suitable hole among the supervisor allocations), and when the VM exits and the GC heap is freed, the allocation will be moved to the bottom of the former GC heap and transformed into a proper supervisor allocation. Existing movable allocations will also be moved to defragment the supervisor heap and ensure that the next VM run gets as much memory as possible for the GC heap.
By itself this breaks terminalio because it violates the assumption that supervisor_display_move_memory() still has access to an undisturbed heap to copy the tilegrid from. It will work in many cases, but if you're unlucky you will get garbled terminal contents after exiting from the vm run that created the display. This will be fixed in the following commit, which is separate to simplify review.
