In order to keep "import umodule" working, the existing mechanism is
replaced with a simple fallback to drop the "u".
This makes importing of built-ins no longer touch the filesystem, which
makes a typical built-in import take ~0.15ms rather than 3-5ms.
(Weak links were added in c14a81662c)
This work was funded through GitHub Sponsors.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Prior to this commit, importing a module that exists but has a syntax error
or some other problem that happens at import time would result in a
potentially-incomplete module object getting added to sys.modules.
Subsequent imports would use that object, resulting in confusing error
messages that hide the root cause of the problem.
This commit fixes that issue by removing the failed module from sys.modules
using the new NLR callback mechanism.
Note that it is still important to add the module to sys.modules while the
import is happening so that we can support circular imports just like
CPython does.
Fixes issue #967.
Signed-off-by: David Grayson <davidegrayson@gmail.com>
The changed functions now use less stack, and don't have any issues with
local variables needing to be declared volatile.
Testing on a PYBv1.0, imports (of .py, .mpy and frozen code) now use 64
less bytes of C stack per import depth.
Signed-off-by: Damien George <damien@micropython.org>
To use this:
- Create a built-in module, and add the module object as a member of the
parent module's globals dict.
- The submodule can set its `__name__` to either `QSTR_foo_dot_bar` or
`QSTR_bar`. The former requires using qstrdefs(port).h to make the qstr.
Because `bar` is a member of `foo`'s globals, it is possible to write
`import foo` and then immediately use `foo.bar` without importing it
explicitly. This means that if `bar` has an `__init__`, it will not be
called in this situation, and for that reason, sub-modules should not have
`__init__` methods. If this is required, then all initalisation for
sub-modules should be done by the top-level module's (i.e. `foo`'s)
`__init__` method.
This work was funded through GitHub Sponsors.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This makes it so that sub-packages are resolved relative to their parent's
`__path__`, rather than re-resolving each parent's filesystem path.
The previous behavior was that `import foo.bar` would first re-search
`sys.path` for `foo`, then use the resulting path to find `bar`.
For already-loaded and u-prefixed modules, because we no longer need to
build the path from level to level, we no longer unnecessarily search
the filesystem. This should improve startup time.
Explicitly makes the resolving process clear:
- Loaded modules are returned immediately without touching the filesystem.
- Exact-match of builtins are also returned immediately.
- Then the filesystem search happens.
- If that fails, then the weak-link handling is applied.
This maintains the existing behavior: if a user writes `import time` they
will get time.py if it exits, otherwise the built-in utime. Whereas `import
utime` will always return the built-in.
This also fixes a regression from a7fa18c203
where we search the filesystem for built-ins. It is now only possible to
override u-prefixed builtins. This will remove a lot of filesystem stats
at startup, as micropython-specific modules (e.g. `pyb`) will no longer
attempt to look at the filesystem.
Added several improvements to the comments and some minor renaming and
refactoring to make it clearer how the import mechanism works. Overall
code size diff is +56 bytes on STM32.
This work was funded through GitHub Sponsors.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
If sys.path is enabled, but empty, this will now no longer search the
filesystem. Previously an empty sys.path was equivalent to having
`sys.path=[""]`. This is a breaking change, but this behavior now matches
CPython.
This also provides an alternative mechanism to the u-prefix to force an
import of a builtin module:
```
import sys
_path = sys.path[:]
sys.path.clear()
import foo # Forces the built-in foo.
sys.path.extend(_path)
del _path
```
Code size diff is -32 bytes on PYBV11.
This work was funded through GitHub Sponsors.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Without this, building the unix port variants gives:
ports/unix/main.c:667: undefined reference to `mp_obj_is_package',
when MICROPY_ENABLE_EXTERNAL_IMPORT is 0.
Signed-off-by: Laurens Valk <laurens@pybricks.com>
This change makes it so the compiler and persistent code loader take a
mp_compiled_module_t* as their last argument, instead of returning this
struct. This eliminates a duplicate context variable for all callers of
these functions (because the context is now stored in the
mp_compiled_module_t by the caller), and also eliminates any confusion
about which context to use after the mp_compile_to_raw_code or
mp_raw_code_load function returns (because there is now only one context,
that stored in mp_compiled_module_t.context).
Reduces code size by 16 bytes on ARM Cortex-based ports.
Signed-off-by: Damien George <damien@micropython.org>
There are two calls to mp_builtin___import__():
1. ports/unix/main.c:main_() which provides a str in args[0]
2. py/runtime.c:mp_import_name() which provides a qstr in args[0]
The default implementation of mp_builtin___import__() is
mp_builtin___import___default() which has a different implementation based
on MICROPY_ENABLE_EXTERNAL_IMPORT.
If MICROPY_ENABLE_EXTERNAL_IMPORT is disabled then the handling of weak
links assumes that args[0] is a `const char *`, when it is either a str or
qstr object.
Use the existing qstr of the module name instead, and also use a vstr
instead of strcpy() to ensure no overflow occurs.
This allows ports to override mp_builtin___import__.
This can be useful in MicroPython applications where
MICROPY_ENABLE_EXTERNAL_IMPORT has to be disabled due to its impact on
build size (2% to 2.5% of the minimal port). By overriding the otherwise
very minimal mp_builtin___import__, ports can still allow limited forms
of application-specific imports.
Signed-off-by: Laurens Valk <laurens@pybricks.com>
The sys module should always be available (if it's compiled in), eg to
change sys.path for importing. So provide an explicit alias from "sys" to
"usys" so that "import sys" can always work.
Signed-off-by: Damien George <damien@micropython.org>
Background: .mpy files are precompiled .py files, built using mpy-cross,
that contain compiled bytecode functions (and can also contain machine
code). The benefit of using an .mpy file over a .py file is that they are
faster to import and take less memory when importing. They are also
smaller on disk.
But the real benefit of .mpy files comes when they are frozen into the
firmware. This is done by loading the .mpy file during compilation of the
firmware and turning it into a set of big C data structures (the job of
mpy-tool.py), which are then compiled and downloaded into the ROM of a
device. These C data structures can be executed in-place, ie directly from
ROM. This makes importing even faster because there is very little to do,
and also means such frozen modules take up much less RAM (because their
bytecode stays in ROM).
The downside of frozen code is that it requires recompiling and reflashing
the entire firmware. This can be a big barrier to entry, slows down
development time, and makes it harder to do OTA updates of frozen code
(because the whole firmware must be updated).
This commit attempts to solve this problem by providing a solution that
sits between loading .mpy files into RAM and freezing them into the
firmware. The .mpy file format has been reworked so that it consists of
data and bytecode which is mostly static and ready to run in-place. If
these new .mpy files are located in flash/ROM which is memory addressable,
the .mpy file can be executed (mostly) in-place.
With this approach there is still a small amount of unpacking and linking
of the .mpy file that needs to be done when it's imported, but it's still
much better than loading an .mpy from disk into RAM (although not as good
as freezing .mpy files into the firmware).
The main trick to make static .mpy files is to adjust the bytecode so any
qstrs that it references now go through a lookup table to convert from
local qstr number in the module to global qstr number in the firmware.
That means the bytecode does not need linking/rewriting of qstrs when it's
loaded. Instead only a small qstr table needs to be built (and put in RAM)
at import time. This means the bytecode itself is static/constant and can
be used directly if it's in addressable memory. Also the qstr string data
in the .mpy file, and some constant object data, can be used directly.
Note that the qstr table is global to the module (ie not per function).
In more detail, in the VM what used to be (schematically):
qst = DECODE_QSTR_VALUE;
is now (schematically):
idx = DECODE_QSTR_INDEX;
qst = qstr_table[idx];
That allows the bytecode to be fixed at compile time and not need
relinking/rewriting of the qstr values. Only qstr_table needs to be linked
when the .mpy is loaded.
Incidentally, this helps to reduce the size of bytecode because what used
to be 2-byte qstr values in the bytecode are now (mostly) 1-byte indices.
If the module uses the same qstr more than two times then the bytecode is
smaller than before.
The following changes are measured for this commit compared to the
previous (the baseline):
- average 7%-9% reduction in size of .mpy files
- frozen code size is reduced by about 5%-7%
- importing .py files uses about 5% less RAM in total
- importing .mpy files uses about 4% less RAM in total
- importing .py and .mpy files takes about the same time as before
The qstr indirection in the bytecode has only a small impact on VM
performance. For stm32 on PYBv1.0 the performance change of this commit
is:
diff of scores (higher is better)
N=100 M=100 baseline -> this-commit diff diff% (error%)
bm_chaos.py 371.07 -> 357.39 : -13.68 = -3.687% (+/-0.02%)
bm_fannkuch.py 78.72 -> 77.49 : -1.23 = -1.563% (+/-0.01%)
bm_fft.py 2591.73 -> 2539.28 : -52.45 = -2.024% (+/-0.00%)
bm_float.py 6034.93 -> 5908.30 : -126.63 = -2.098% (+/-0.01%)
bm_hexiom.py 48.96 -> 47.93 : -1.03 = -2.104% (+/-0.00%)
bm_nqueens.py 4510.63 -> 4459.94 : -50.69 = -1.124% (+/-0.00%)
bm_pidigits.py 650.28 -> 644.96 : -5.32 = -0.818% (+/-0.23%)
core_import_mpy_multi.py 564.77 -> 581.49 : +16.72 = +2.960% (+/-0.01%)
core_import_mpy_single.py 68.67 -> 67.16 : -1.51 = -2.199% (+/-0.01%)
core_qstr.py 64.16 -> 64.12 : -0.04 = -0.062% (+/-0.00%)
core_yield_from.py 362.58 -> 354.50 : -8.08 = -2.228% (+/-0.00%)
misc_aes.py 429.69 -> 405.59 : -24.10 = -5.609% (+/-0.01%)
misc_mandel.py 3485.13 -> 3416.51 : -68.62 = -1.969% (+/-0.00%)
misc_pystone.py 2496.53 -> 2405.56 : -90.97 = -3.644% (+/-0.01%)
misc_raytrace.py 381.47 -> 374.01 : -7.46 = -1.956% (+/-0.01%)
viper_call0.py 576.73 -> 572.49 : -4.24 = -0.735% (+/-0.04%)
viper_call1a.py 550.37 -> 546.21 : -4.16 = -0.756% (+/-0.09%)
viper_call1b.py 438.23 -> 435.68 : -2.55 = -0.582% (+/-0.06%)
viper_call1c.py 442.84 -> 440.04 : -2.80 = -0.632% (+/-0.08%)
viper_call2a.py 536.31 -> 532.35 : -3.96 = -0.738% (+/-0.06%)
viper_call2b.py 382.34 -> 377.07 : -5.27 = -1.378% (+/-0.03%)
And for unix on x64:
diff of scores (higher is better)
N=2000 M=2000 baseline -> this-commit diff diff% (error%)
bm_chaos.py 13594.20 -> 13073.84 : -520.36 = -3.828% (+/-5.44%)
bm_fannkuch.py 60.63 -> 59.58 : -1.05 = -1.732% (+/-3.01%)
bm_fft.py 112009.15 -> 111603.32 : -405.83 = -0.362% (+/-4.03%)
bm_float.py 246202.55 -> 247923.81 : +1721.26 = +0.699% (+/-2.79%)
bm_hexiom.py 615.65 -> 617.21 : +1.56 = +0.253% (+/-1.64%)
bm_nqueens.py 215807.95 -> 215600.96 : -206.99 = -0.096% (+/-3.52%)
bm_pidigits.py 8246.74 -> 8422.82 : +176.08 = +2.135% (+/-3.64%)
misc_aes.py 16133.00 -> 16452.74 : +319.74 = +1.982% (+/-1.50%)
misc_mandel.py 128146.69 -> 130796.43 : +2649.74 = +2.068% (+/-3.18%)
misc_pystone.py 83811.49 -> 83124.85 : -686.64 = -0.819% (+/-1.03%)
misc_raytrace.py 21688.02 -> 21385.10 : -302.92 = -1.397% (+/-3.20%)
The code size change is (firmware with a lot of frozen code benefits the
most):
bare-arm: +396 +0.697%
minimal x86: +1595 +0.979% [incl +32(data)]
unix x64: +2408 +0.470% [incl +800(data)]
unix nanbox: +1396 +0.309% [incl -96(data)]
stm32: -1256 -0.318% PYBV10
cc3200: +288 +0.157%
esp8266: -260 -0.037% GENERIC
esp32: -216 -0.014% GENERIC[incl -1072(data)]
nrf: +116 +0.067% pca10040
rp2: -664 -0.135% PICO
samd: +844 +0.607% ADAFRUIT_ITSYBITSY_M4_EXPRESS
As part of this change the .mpy file format version is bumped to version 6.
And mpy-tool.py has been improved to provide a good visualisation of the
contents of .mpy files.
In summary: this commit changes the bytecode to use qstr indirection, and
reworks the .mpy file format to be simpler and allow .mpy files to be
executed in-place. Performance is not impacted too much. Eventually it
will be possible to store such .mpy files in a linear, read-only, memory-
mappable filesystem so they can be executed from flash/ROM. This will
essentially be able to replace frozen code for most applications.
Signed-off-by: Damien George <damien@micropython.org>
This changes makemanifest.py & mpy-tool.py to merge string and mpy names
into the same list (now mp_frozen_names).
The various paths for loading a frozen module (mp_find_frozen_module) and
checking existence of a frozen module (mp_frozen_stat) use a common
function that searches this list.
In addition, the frozen lookup will now only take place if the path starts
with ".frozen", which needs to be added to sys.path.
This fixes issues #1804, #2322, #3509, #6419.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
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>
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>
Note: the uncrustify configuration is explicitly set to 'add' instead of
'force' in order not to alter the comments which use extra spaces after //
as a means of indenting text for clarity.
Now that error string compression is supported it's more important to have
consistent error string formatting (eg all lowercase English words,
consistent contractions). This commit cleans up some of the strings to
make them more consistent.
Instead of compiler-level if-logic. This is necessary to know what error
strings are included in the build at the preprocessor stage, so that string
compression can be implemented.
This commit implements automatic module weak links for all built-in
modules, by searching for "ufoo" in the built-in module list if "foo"
cannot be found. This means that all modules named "ufoo" are always
available as "foo". Also, a port can no longer add any other weak links,
which makes strict the definition of a weak link.
It saves some code size (about 100-200 bytes) on ports that previously had
lots of weak links.
Some changes from the previous behaviour:
- It doesn't intern the non-u module names (eg "foo" is not interned),
which saves code size, but will mean that "import foo" creates a new qstr
(namely "foo") in RAM (unless the importing module is frozen).
- help('modules') no longer lists non-u module names, only the u-variants;
this reduces duplication in the help listing.
Weak links are effectively the same as having a set of symbolic links on
the filesystem that is searched last. So an "import foo" will search
built-in modules first, then all paths in sys.path, then weak links last,
importing "ufoo" if it exists. Thus a file called "foo.py" somewhere in
sys.path will still have precedence over the weak link of "foo" to "ufoo".
See issues: #1740, #4449, #5229, #5241.
If MICROPY_PERSISTENT_CODE_LOAD or MICROPY_ENABLE_COMPILER are enabled then
code gets enabled that calls file reading functions which may be disabled
if no readers have been implemented.
To fix this, introduce a MICROPY_HAS_FILE_READER variable, which is
automatically set if MICROPY_READER_POSIX or MICROPY_READER_VFS is set but
can also be manually set if a custom reader is being implemented. Then
disable the file reading calls if this is not set.
The new option is MICROPY_ENABLE_EXTERNAL_IMPORT and is enabled by default
so that the default behaviour is the same as before. With it disabled
import is only supported for built-in modules, not for external files nor
frozen modules. This allows to support targets that have no filesystem of
any kind and that only have access to pre-supplied built-in modules
implemented natively.
This is a bit of a clumsy way of doing it but solves the issue of __init__
not running when a module is imported via its weak-link name. Ideally a
better solution would be found.
This patch simplifies the str creation API to favour the common case of
creating a str object that is not forced to be interned. To force
interning of a new str the new mp_obj_new_str_via_qstr function is added,
and should only be used if warranted.
Apart from simplifying the mp_obj_new_str function (and making it have the
same signature as mp_obj_new_bytes), this patch also reduces code size by a
bit (-16 bytes for bare-arm and roughly -40 bytes on the bare-metal archs).
Header files that are considered internal to the py core and should not
normally be included directly are:
py/nlr.h - internal nlr configuration and declarations
py/bc0.h - contains bytecode macro definitions
py/runtime0.h - contains basic runtime enums
Instead, the top-level header files to include are one of:
py/obj.h - includes runtime0.h and defines everything to use the
mp_obj_t type
py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
and defines everything to use the general runtime support functions
Additional, specific headers (eg py/objlist.h) can be included if needed.
The while-loop that calls chop_component will guarantee that level==-1 at
the end of the loop. Hence the code following it is unnecessary.
The check for p==this_name will catch imports that are beyond the
top-level, and also covers the case of new_mod_q==MP_QSTR_ (equivalent to
new_mod_l==0) so that check is removed.
There is also a new check at the start for level>=0 to guard against
__import__ being called with bad level values.
This patch changes mp_uint_t to size_t for the len argument of the
following public facing C functions:
mp_obj_tuple_get
mp_obj_list_get
mp_obj_get_array
These functions take a pointer to the len argument (to be filled in by the
function) and callers of these functions should update their code so the
type of len is changed to size_t. For ports that don't use nan-boxing
there should be no change in generate code because the size of the type
remains the same (word sized), and in a lot of cases there won't even be a
compiler warning if the type remains as mp_uint_t.
The reason for this change is to standardise on the use of size_t for
variables that count memory (or memory related) sizes/lengths. It helps
builds that use nan-boxing.
This patch refactors the error handling in the lexer, to simplify it (ie
reduce code size).
A long time ago, when the lexer/parser/compiler were first written, the
lexer and parser were designed so they didn't use exceptions (ie nlr) to
report errors but rather returned an error code. Over time that has
gradually changed, the parser in particular has more and more ways of
raising exceptions. Also, the lexer never really handled all errors without
raising, eg there were some memory errors which could raise an exception
(and in these rare cases one would get a fatal nlr-not-handled fault).
This patch accepts the fact that the lexer can raise exceptions in some
cases and allows it to raise exceptions to handle all its errors, which are
for the most part just out-of-memory errors during construction of the
lexer. This makes the lexer a bit simpler, and also the persistent code
stuff is simplified.
What this means for users of the lexer is that calls to it must be wrapped
in a nlr handler. But all uses of the lexer already have such an nlr
handler for the parser (and compiler) so that doesn't put any extra burden
on the callers.
Jim Mussared
David Grayson
Damien George
Laurens Valk
Simon Arlott
Angus Gratton
stijn
David Lechner
Damien George
Léa Saviot
Paul m. p. P
Sean Burton
Stefan Naumann
Alexander Steffen
Tom Collins
Ville Skyttä
Paul Sokolovsky