Most modern systems have EWOULDBLOCK aliased to EAGAIN, ie they have the
same value. But some systems use different values for these errnos and if
a uPy port is using the system errno values (ie not the internal uPy
values) then it's important to be able to distinguish EWOULDBLOCK from
EAGAIN. Eg if a system call returned EWOULDBLOCK it must be possible to
check for this return value, and this patch makes this now possible.
Instead of emitnative.c having configuration code for each supported
architecture, and then compiling this file multiple times with different
macros defined, this patch adds a file per architecture with the necessary
code to configure the native emitter. These files then #include the
emitnative.c file.
This simplifies emitnative.c (which is already very large), and simplifies
the build system because emitnative.c no longer needs special handling for
compilation and qstr extraction.
This patch moves the implementation of stream closure from a dedicated
method to the ioctl of the stream protocol, for each type that implements
closing. The benefits of this are:
1. Rounds out the stream ioctl function, which already includes flush,
seek and poll (among other things).
2. Makes calling mp_stream_close() on an object slightly more efficient
because it now no longer needs to lookup the close method and call it,
rather it just delegates straight to the ioctl function (if it exists).
3. Reduces code size and allows future types that implement the stream
protocol to be smaller because they don't need a dedicated close method.
Code size reduction is around 200 bytes smaller for x86 archs and around
30 bytes smaller for the bare-metal archs.
The LHS passed to mp_obj_int_binary_op() will always be an integer, either
a small int or a big int, so the test for this type doesn't need to include
an "other, unsupported type" case.
Without the compiler enabled the mp_optimise_value is unused, and the
micropython.opt_level() function is not useful, so exclude these from the
build to save RAM and code size.
When pystack is enabled mp_obj_fun_bc_prepare_codestate() will always
return a valid pointer, and if there is no more pystack available then it
will raise an exception (a RuntimeError). So having pystack enabled with
stackless enabled automatically gives strict stackless mode. There is
therefore no need to have code for strict stackless mode when pystack is
enabled, and this patch optimises the VM for such a case.
The VM expects that, if mp_resume() returns MP_VM_RETURN_EXCEPTION, then
the returned value is an exception instance (eg to add a traceback to it).
It's possible that a value passed to a generator's throw() is not an
exception so must be explicitly checked for if the thrown value is not
intercepted by the generator.
Thanks to @jepler for finding the bug.
Prior to this patch the code would crash if a key in a ** dict was anything
other than a str or qstr. This is because mp_setup_code_state() assumes
that keys in kwargs are qstrs (for efficiency).
Thanks to @jepler for finding the bug.
By using pre-compiled regexs, using startswith(), and explicitly checking
for empty lines (of which around 30% of the input lines are), automatic
qstr extraction is speed up by about 10%.
All callers of mp_obj_int_formatted() are expected to pass in a valid int
object, and they do:
- mp_obj_int_print() should always pass through an int object because it is
the print special method for int instances.
- mp_print_mp_int() checks that the argument is an int, and if not converts
it to a small int.
This patch saves around 20-50 bytes of code space.
Prior to this patch, some architectures (eg unix x86) could render floats
with "negative" digits, like ")". For example, '%.23e' % 1e-80 would come
out as "1.0000000000000000/)/(,*0e-80". This patch fixes the known cases.
Prior to this patch, some architectures (eg unix x86) could render floats
with a ":" character in them, eg 1e+39 would come out as ":e+38" (":" is
just after "9" in ASCII so this is like 10e+38). This patch fixes some of
these cases.
Prior to this patch the %f formatting of some FP values could be off by up
to 1, eg '%.0f' % 123 would return "122" (unix x64). Depending on the FP
precision (single vs double) certain numbers would format correctly, but
others wolud not. This patch should fix all cases of rounding for %f.
There's no need to have MP_OBJ_NULL a special case, the code can re-use
the MP_OBJ_STOP_ITERATION value to signal the special case and the VM can
detect this with only one check (for MP_OBJ_STOP_ITERATION).
This patch concerns the handling of an NLR-raised StopIteration, raised
during a call to mp_resume() which is handling the yield from opcode.
Previously, commit 6738c1dded introduced code
to handle this case, along with a test. It seems that it was lucky that
the test worked because the code did not correctly handle the stack pointer
(sp).
Furthermore, commit 79d996a57b improved the
way mp_resume() propagated certain exceptions: it changed raising an NLR
value to returning MP_VM_RETURN_EXCEPTION. This change meant that the
test introduced in gen_yield_from_ducktype.py was no longer hitting the
code introduced in 6738c1dded.
The patch here does two things:
1. Fixes the handling of sp in the VM for the case that yield from is
interrupted by a StopIteration raised via NLR.
2. Introduces a new test to check this handling of sp and re-covers the
code in the VM.
This path for src->deg==NULL is never used because mpz_clone() is always
called with an argument that has a non-zero integer value, and hence has
some digits allocated to it (mpz_clone() is a static function private to
mpz.c all callers of this function first check if the integer value is zero
and if so take a special-case path, bypassing the call to mpz_clone()).
There is some unused and commented-out functions that may actually pass a
zero-valued mpz to mpz_clone(), so some TODOs are added to these function
in case they are needed in the future.
All callers of the asm entry function guarantee that num_locals>=0, so no
need to add an explicit check for it. Use an assertion instead.
Also, the signature of asm_x86_entry is changed to match the other asm
entry functions.
If a port only needs the core files then it can now use the $(PY_CORE_O)
variable instead of $(PY_O). $(PY_EXTMOD_O) contains the list of extmod
files (including some files from lib/). $(PY_O) retains its original
definition as the list of all object file (including those for frozen code)
and is a convenience variable for ports that want everything.
Saves a few bytes of code space, and is more efficient because with
MICROPY_GC_CONSERVATIVE_CLEAR enabled by default all memory is already
cleared when allocated.
Otherwise passing -1 as maxlen will lead to a zero allocation and
subsequent unbound buffer overflow in deque.append() because i_put is
allowed to grow without bound.
So far, implements just append() and popleft() methods, required for
a normal queue. Constructor doesn't accept an arbitarry sequence to
initialize from (am empty deque is always created), so an empty tuple
must be passed as such. Only fixed-size deques are supported, so 2nd
argument (size) is required.
There's also an extension to CPython - if True is passed as 3rd argument,
append(), instead of silently overwriting the oldest item on queue
overflow, will throw IndexError. This behavior is desired in many
cases, where queues should store information reliably, instead of
silently losing some items.
The micropython.stack_use() function is useful to query the current C stack
usage, and it's inclusion in the micropython module doesn't need to be tied
to the inclusion of mem_info()/qstr_info() because it doesn't rely on any
of the code from these functions. So this patch introduces the config
option MICROPY_PY_MICROPYTHON_STACK_USE which can be used to independently
control the inclusion of stack_use(). By default it is enabled if
MICROPY_PY_MICROPYTHON_MEM_INFO is enabled (thus not changing any of the
existing ports).
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.
Prior to this patch uPy (on a 32-bit arch) would have severe issues when
calling bytes(-1): such a call would call vstr_init_len(vstr, -1) which
would then +1 on the len and call vstr_init(vstr, 0), which would then
round this up and allocate a small amount of memory for the vstr. The
bytes constructor would then attempt to zero out all this memory, thinking
it had allocated 2^32-1 bytes.
This patch changes the way REPL autocomplete finds matches. It now probes
the target object for all qstrs via mp_load_method_maybe to look for a
match with the given input string. Similar to how the builtin dir()
function works, this new algorithm now find all methods and instances of
user-defined classes including attributes of their parent classes. This
helps a lot at the REPL prompt for user-discovery and to autocomplete names
even for classes that are derived.
The downside is that this new algorithm is slower than the previous one,
and in particular will be slower the more qstrs there are in the system.
But because REPL autocomplete is primarily used in an interactive way it is
not that important to make it fast, as long as it is "fast enough" compared
to human reaction.
On a slow microcontroller (CPU running at 16MHz) the autocomplete time for
a list of 35 names in the outer namespace (pressing tab at a bare prompt)
takes about 160ms with this algorithm, compared to about 40ms for the
previous implementation (this time includes the actual printing of the
names as well). This time of 160ms is very reasonable especially given the
new functionality of listing all the names.
This patch also decreases code size by:
bare-arm: +0
minimal x86: -128
unix x64: -128
unix nanbox: -224
stm32: -88
cc3200: -80
esp8266: -92
esp32: -84
This patch improves the builtin dir() function by probing the target object
with all possible qstrs via mp_load_method_maybe. This is very simple (in
terms of implementation), doesn't require recursion, and allows to list all
methods of user-defined classes (without duplicates) even if they have
multiple inheritance with a common parent. The downside is that it can be
slow because it has to iterate through all the qstrs in the system, but
the "dir()" function is anyway mostly used for testing frameworks and user
introspection of types, so speed is not considered a priority.
In addition to providing a more complete implementation of dir(), this
patch is simpler than the previous implementation and saves some code
space:
bare-arm: -80
minimal x86: -80
unix x64: -56
unix nanbox: -48
stm32: -80
cc3200: -80
esp8266: -104
esp32: -64
This macro is written out explicitly in the two locations that it is used
and then the code is optimised, opening possibilities for further
optimisations and reducing code size:
unix: -48
minimal CROSS=1: -32
stm32: -32
Using the message "maximum recursion depth exceeded" for when the pystack
runs out of memory can be misleading because the pystack can run out for
reasons other than deep recursion (although in most cases pystack
exhaustion is probably indirectly related to deep recursion). And it's
important to give the user more precise feedback as to the reason for the
error: if they know precisely that the pystack was exhausted then they have
a chance to increase the amount of memory available to the pystack (as
opposed to not knowing if it was the C stack or pystack that ran out).
Also, C stack exhaustion is more serious than pystack exhaustion because it
could have been that the C stack overflowed and overwrote/corrupted some
data and so the system must be restarted. The pystack can never corrupt
data in this way so pystack exhaustion does not require a system restart.
Knowing the difference between these two cases is therefore important.
The actual exception type for pystack exhaustion remains as RuntimeError so
that programatically it behaves the same as a C stack exhaustion.
By adding __builtin_unreachable() at the end of nlr_push, we're
essentially telling the compiler that this function will never return.
When GCC LTO is in use, this means that any time nlr_push() is called
(which is often), the compiler thinks this function will never return
and thus eliminates all code following the call.
Note: I've added a 'return 0' for older GCC versions like 4.6 which
complain about not returning anything (which doesn't make sense in a
naked function). Newer GCC versions (tested 4.8, 5.4 and some others)
don't complain about this.
This constant exception instance was once used by m_malloc_fail() to raise
a MemoryError without allocating memory, but it was made obsolete long ago
by 3556e45711. The functionality is now
replaced by the use of mp_emergency_exception_obj which lives in the global
uPy state, and which can handle any exception type, not just MemoryError.
This feature is not often used so is guarded by the config option
MICROPY_PY_BUILTINS_RANGE_BINOP which is disabled by default. With this
option disabled MicroPython will always return false when comparing two
range objects for equality (unless they are exactly the same object
instance). This does not match CPython so if (in)equality between range
objects is needed then this option should be enabled.
Enabling this option costs between 100 and 200 bytes of code space
depending on the machine architecture.
This patch provides inline versions of the utf8 helper functions for the
case when unicode is disabled (MICROPY_PY_BUILTINS_STR_UNICODE set to 0).
This saves code size.
The unichar_charlen function is also renamed to utf8_charlen to match the
other utf8 helper functions, and the signature of this function is adjusted
for consistency (const char* -> const byte*, mp_uint_t -> size_t).
Prior to this patch, a float literal that was close to subnormal would
have a loss of precision when parsed. The worst case was something like
float('10000000000000000000e-326') which returned 0.0.
This patch simplifies how sentinel values are stored on the stack when
doing an unwind return or jump. Instead of storing two values on the stack
for an unwind jump it now stores only one: a negative small integer means
unwind-return and a non-negative small integer means unwind-jump with the
value being the number of exceptions to unwind. The savings in code size
are:
bare-arm: -56
minimal x86: -68
unix x64: -80
unix nanbox: -4
stm32: -56
cc3200: -64
esp8266: -76
esp32: -156
The array should be of type unsigned byte because that is the type of the
values being stored. And changing to uint8_t helps to prevent warnings
from some static analysers.
Note that the check for elem!=NULL is removed for the
MP_MAP_LOOKUP_ADD_IF_NOT_FOUND case because mp_map_lookup will always
return non-NULL for such a case.
This patch combines the compiler optimisation code for double and triple
tuple-to-tuple assignment, taking it from two separate if-blocks to one
combined if-block. This can be done because the code for both of these
optimisations has a lot in common. Combining them together reduces code
size for ports that have the triple-tuple optimisation enabled (and doesn't
change code size for ports that have it disabled).
The number of registers used should be 10, not 12, to match the assembly
code in nlrx64.c. With this change the 64bit mingw builds don't need to
use the setjmp implementation, and this fixes miscellaneous crashes and
assertion failures as reported in #1751 for instance.
To avoid mistakes in the future where something gcc-related for Windows
only gets fixed for one particular compiler/environment combination,
make use of a MICROPY_NLR_OS_WINDOWS macro.
To make sure everything nlr-related is now ok when built with gcc this
has been verified with:
- unix port built with gcc on Cygwin (i686-pc-cygwin-gcc and
x86_64-pc-cygwin-gcc, version 6.4.0)
- windows port built with mingw-w64's gcc from Cygwin
(i686-w64-mingw32-gcc and x86_64-w64-mingw32-gcc, version 6.4.0)
and MSYS2 (like the ones on Cygwin but version 7.2.0)
There are two checks that are always false so can be converted to (negated)
assertions to save code space and execution time. They are:
1. The check of the str parameter, which is required to be non-NULL as per
the original comment that it has enough space in it as calculated by
mp_int_format_size. And for all uses of this function str is indeed
non-NULL.
2. The check of the base parameter, which is already required to be between
2 and 16 (inclusive) via the assertion in mp_int_format_size.
The motivation behind this patch is to remove unreachable code in mpn_div.
This unreachable code was added some time ago in
9a21d2e070, when a loop in mpn_div was copied
and adjusted to work when mpz_dig_t was exactly half of the size of
mpz_dbl_dig_t (a common case). The loop was copied correctly but it wasn't
noticed at the time that the final part of the calculation of num-quo*den
could be optimised, and hence unreachable code was left for a case that
never occurred.
The observation for the optimisation is that the initial value of quo in
mpn_div is either exact or too large (never too small), and therefore the
subtraction of quo*den from num may subtract exactly enough or too much
(but never too little). Using this observation the part of the algorithm
that handles the borrow value can be simplified, and most importantly this
eliminates the unreachable code.
The new code has been tested with DIG_SIZE=3 and DIG_SIZE=4 by dividing all
possible combinations of non-negative integers with between 0 and 3
(inclusive) mpz digits.
Empty __VA_ARGS__ are not allowed in the C preprocessor so adjust the rule
arg offset calculation to not use them. Also, some compilers (eg MSVC)
require an extra layer of macro expansion.
This is the sixth and final patch in a series of patches to the parser that
aims to reduce code size by compressing the data corresponding to the rules
of the grammar.
Prior to this set of patches the rules were stored as rule_t structs with
rule_id, act and arg members. And then there was a big table of pointers
which allowed to lookup the address of a rule_t struct given the id of that
rule.
The changes that have been made are:
- Breaking up of the rule_t struct into individual components, with each
component in a separate array.
- Removal of the rule_id part of the struct because it's not needed.
- Put all the rule arg data in a big array.
- Change the table of pointers to rules to a table of offsets within the
array of rule arg data.
The last point is what is done in this patch here and brings about the
biggest decreases in code size, because an array of pointers is now an
array of bytes.
Code size changes for the six patches combined is:
bare-arm: -644
minimal x86: -1856
unix x64: -5408
unix nanbox: -2080
stm32: -720
esp8266: -812
cc3200: -712
For the change in parser performance: it was measured on pyboard that these
six patches combined gave an increase in script parse time of about 0.4%.
This is due to the slightly more complicated way of looking up the data for
a rule (since the 9th bit of the offset into the rule arg data table is
calculated with an if statement). This is an acceptable increase in parse
time considering that parsing is only done once per script (if compiled on
the target).
Instead of each rule being stored in ROM as a struct with rule_id, act and
arg, the act and arg parts are now in separate arrays and the rule_id part
is removed because it's not needed. This reduces code size, by roughly one
byte per grammar rule, around 150 bytes.
The rule name is only used for debugging, and this patch makes things a bit
cleaner by completely separating out the rule name from the rest of the
rule data.
Each NLR implementation (Thumb, x86, x64, xtensa, setjmp) duplicates a lot
of the NLR code, specifically that dealing with pushing and popping the NLR
pointer to maintain the linked-list of NLR buffers. This patch factors all
of that code out of the specific implementations into generic functions in
nlr.c, along with a helper macro in nlr.h. This eliminates duplicated
code.
If MICROPY_NLR_SETJMP is not enabled and the machine is auto-detected then
nlr.h now defines some convenience macros for the individual NLR
implementations to use (eg MICROPY_NLR_THUMB). This keeps nlr.h and the
implementation in sync, and also makes the nlr_buf_t struct easier to read.
A function with a naked attribute must only contain basic inline asm
statements and no C code.
For nlr_push this means removing the "return 0" statement. But for some
gcc versions this induces a compiler warning so the __builtin_unreachable()
line needs to be added.
For nlr_jump, this function contains a combination of C code and inline asm
so cannot be naked.
This reverts commit 6a3a742a6c.
The above commit has number of faults starting from the motivation down
to the actual implementation.
1. Faulty implementation.
The original code contained functions like:
NORETURN void nlr_jump(void *val) {
nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
nlr_buf_t *top = *top_ptr;
...
__asm volatile (
"mov %0, %%edx \n" // %edx points to nlr_buf
"mov 28(%%edx), %%esi \n" // load saved %esi
"mov 24(%%edx), %%edi \n" // load saved %edi
"mov 20(%%edx), %%ebx \n" // load saved %ebx
"mov 16(%%edx), %%esp \n" // load saved %esp
"mov 12(%%edx), %%ebp \n" // load saved %ebp
"mov 8(%%edx), %%eax \n" // load saved %eip
"mov %%eax, (%%esp) \n" // store saved %eip to stack
"xor %%eax, %%eax \n" // clear return register
"inc %%al \n" // increase to make 1, non-local return
"ret \n" // return
: // output operands
: "r"(top) // input operands
: // clobbered registers
);
}
Which clearly stated that C-level variable should be a parameter of the
assembly, whcih then moved it into correct register.
Whereas now it's:
NORETURN void nlr_jump_tail(nlr_buf_t *top) {
(void)top;
__asm volatile (
"mov 28(%edx), %esi \n" // load saved %esi
"mov 24(%edx), %edi \n" // load saved %edi
"mov 20(%edx), %ebx \n" // load saved %ebx
"mov 16(%edx), %esp \n" // load saved %esp
"mov 12(%edx), %ebp \n" // load saved %ebp
"mov 8(%edx), %eax \n" // load saved %eip
"mov %eax, (%esp) \n" // store saved %eip to stack
"xor %eax, %eax \n" // clear return register
"inc %al \n" // increase to make 1, non-local return
"ret \n" // return
);
for (;;); // needed to silence compiler warning
}
Which just tries to perform operations on a completely random register (edx
in this case). The outcome is the expected: saving the pure random luck of
the compiler putting the right value in the random register above, there's
a crash.
2. Non-critical assessment.
The original commit message says "There is a small overhead introduced
(typically 1 machine instruction)". That machine instruction is a call
if a compiler doesn't perform tail optimization (happens regularly), and
it's 1 instruction only with the broken code shown above, fixing it
requires adding more. With inefficiencies already presented in the NLR
code, the overhead becomes "considerable" (several times more than 1%),
not "small".
The commit message also says "This eliminates duplicated code.". An
obvious way to eliminate duplication would be to factor out common code
to macros, not introduce overhead and breakage like above.
3. Faulty motivation.
All this started with a report of warnings/errors happening for a niche
compiler. It could have been solved in one the direct ways: a) fixing it
just for affected compiler(s); b) rewriting it in proper assembly (like
it was before BTW); c) by not doing anything at all, MICROPY_NLR_SETJMP
exists exactly to address minor-impact cases like thar (where a) or b) are
not applicable). Instead, a backwards "solution" was put forward, leading
to all the issues above.
The best action thus appears to be revert and rework, not trying to work
around what went haywire in the first place.
Each NLR implementation (Thumb, x86, x64, xtensa, setjmp) duplicates a lot
of the NLR code, specifically that dealing with pushing and popping the NLR
pointer to maintain the linked-list of NLR buffers. This patch factors all
of that code out of the specific implementations into generic functions in
nlr.c. This eliminates duplicated code.
The factoring also allows to make the machine-specific NLR code pure
assembler code, thus allowing nlrthumb.c to use naked function attributes
in the correct way (naked functions can only have basic inline assembler
code in them).
There is a small overhead introduced (typically 1 machine instruction)
because now the generic nlr_jump() must call nlr_jump_tail() rather than
them being one combined function.
set_equal is called only from set_binary_op, and this guarantees that the
second arg to set_equal is always a set or frozenset. So there is no need
to do a further check.
This implements .pend_throw(exc) method, which sets up an exception to be
triggered on the next call to generator's .__next__() or .send() method.
This is unlike .throw(), which immediately starts to execute the generator
to process the exception. This effectively adds Future-like capabilities
to generator protocol (exception will be raised in the future).
The need for such a method arised to implement uasyncio wait_for() function
efficiently (its behavior is clearly "Future" like, and normally would
require to introduce an expensive Future wrapper around all native
couroutines, like upstream asyncio does).
py/objgenerator: pend_throw: Return previous pended value.
This effectively allows to store an additional value (not necessary an
exception) in a coroutine while it's not being executed. uasyncio has
exactly this usecase: to mark a coro waiting in I/O queue (and thus
not executed in the normal scheduling queue), for the purpose of
implementing wait_for() function (cancellation of such waiting coro
by a timeout).
Some compilers can treat enum types as signed, in which case 3 bits is not
enough to encode all mp_raw_code_kind_t values. So change the type to
mp_uint_t.
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.
Before this patch, if a user defined the __new__() function for a class
then two instances of that class would be created: once before __new__ is
called and once during the __new__ call (assuming the user creates some
instance, eg using super().__new__, which is most of the time). The first
one was then discarded. This refactor makes it so that a new instance is
only created if the user __new__ function doesn't exist.
This patch cleans up and generalises part of the code which handles
overriding and calling a native base-class's __init__ method. It defers
the call to the native make_new() function until after the user (Python)
__init__() method has run. That user method now has the chance to call the
native __init__/make_new and pass it different arguments. If the user
doesn't call the super().__init__ method then it will be called
automatically after the user code finishes, to finalise construction of the
instance.
The nan-boxing representation has an extra 16-bits of space to store
small-int values, and making use of it allows to create and manipulate full
32-bit positive integers (ie up to 0xffffffff) without using the heap.
This patch introduces the MICROPY_ENABLE_PYSTACK option (disabled by
default) which enables a "Python stack" that allows to allocate and free
memory in a scoped, or Last-In-First-Out (LIFO) way, similar to alloca().
A new memory allocation API is introduced along with this Py-stack. It
includes both "local" and "nonlocal" LIFO allocation. Local allocation is
intended to be equivalent to using alloca(), whereby the same function must
free the memory. Nonlocal allocation is where another function may free
the memory, so long as it's still LIFO.
Follow-up patches will convert all uses of alloca() and VLA to the new
scoped allocation API. The old behaviour (using alloca()) will still be
available, but when MICROPY_ENABLE_PYSTACK is enabled then alloca() is no
longer required or used.
The benefits of enabling this option are (or will be once subsequent
patches are made to convert alloca()/VLA):
- Toolchains without alloca() can use this feature to obtain correct and
efficient scoped memory allocation (compared to using the heap instead
of alloca(), which is slower).
- Even if alloca() is available, enabling the Py-stack gives slightly more
efficient use of stack space when calling nested Python functions, due to
the way that compilers implement alloca().
- Enabling the Py-stack with the stackless mode allows for even more
efficient stack usage, as well as retaining high performance (because the
heap is no longer used to build and destroy stackless code states).
- With Py-stack and stackless enabled, Python-calling-Python is no longer
recursive in the C mp_execute_bytecode function.
The micropython.pystack_use() function is included to measure usage of the
Python stack.
This function was implemented as an experiment, and was enabled only in
unix port. To remind, it allows to access arbitrary files frozen as
source modules (vs bytecode).
However, further experimentation showed that the same functionality can
be implemented with frozen bytecode. The process requires more steps, but
with suitable toolset it doesn't matter patch. This process is:
1. Convert binary files into "Python resource module" with
tools/mpy_bin2res.py.
2. Freeze as the bytecode.
3. Use micropython-lib's pkg_resources.resource_stream() to access it.
In other words, the extra step is using tools/mpy_bin2res.py (because
there would be wrapper for uio.resource_stream() anyway).
Going frozen bytecode route allows more flexibility, and same/additional
efficiency:
1. Frozen source support can be disabled altogether for additional code
savings.
2. Resources could be also accessed as a buffer, not just as a stream.
There're few caveats too:
1. It wasn't actually profiled the overhead of storing a resource in
"Python resource module" vs storing it directly, but it's assumed that
overhead is small.
2. The "efficiency" claim above applies to the case when resource
file is frozen as the bytecode. If it's not, it actually will take a
lot of RAM on loading. But in this case, the resource file should not
be used (i.e. generated) in the first place, and micropython-lib's
pkg_resources.resource_stream() implementation has the appropriate
fallback to read the raw files instead. This still poses some distribution
issues, e.g. to deployable to baremetal ports (which almost certainly
would require freezeing as the bytecode), a distribution package should
include the resource module. But for non-freezing deployment, presense
of resource module will lead to memory inefficiency.
All the discussion above reminds why uio.resource_stream() was implemented
in the first place - to address some of the issues above. However, since
then, frozen bytecode approach seems to prevail, so, while there're still
some issues to address with it, this change is being made.
This change saves 488 bytes for the unix x86_64 port.
This target removes any stray files (i.e. something not committed to git)
from scripts/ and modules/ dirs (or whatever FROZEN_DIR and FROZEN_MPY_DIR
is set to).
The expected workflow is:
1. make clean-frozen
2. micropython -m upip -p modules <packages_to_freeze>
3. make
As it can be expected that people may drop random thing in those dirs which
they can miss later, the content is actually backed up before cleaning.
This is second part of fun_bc_call() vs mp_obj_fun_bc_prepare_codestate()
common code refactor. This factors out code to initialize codestate
object. After this patch, mp_obj_fun_bc_prepare_codestate() is effectively
DECODE_CODESTATE_SIZE() followed by allocation followed by
INIT_CODESTATE(), and fun_bc_call() starts with that too.
fun_bc_call() starts with almost the same code as
mp_obj_fun_bc_prepare_codestate(), the only difference is a way to
allocate the codestate object (heap vs stack with heap fallback).
Still, would be nice to avoid code duplication to make further
refactoring easier.
So, this commit factors out the common code before the allocation -
decoding and calculating codestate size. It produces two values,
so structured as a macro which writes to 2 variables passed as
arguments.
The assembler back-end for most architectures needs to know if a jump is
backwards in order to emit optimised machine code, and they do this by
checking if the destination label has been set or not. So always reset
label offsets to -1 (this reverts partially the previous commit, with some
minor optimisation for the if-logic with the pass variable).
Clearing the labels to -1 is purely a debugging measure. For release
builds there is no need to do it as the label offset table should always
have the correct value assigned.
Accessing them will crash immediately instead still working for some time,
until overwritten by some other data, leading to much less deterministic
crashes.
This is mostly a workaround for forceful rebuilding of mpy-cross on every
codebase change. If this file has debug logging enabled (by patching),
mpy-cross build failed.
Before that, the output was truncated to 32 bits. Only "%x" format is
handled, because a typical use is for addresses.
This refactor actually decreased x86_64 code size by 30 bytes.
This allows the function to raise an exception when unknown keyword args
are passed in. This patch also reduces code size by (in bytes):
bare-arm: -24
minimal x86: -76
unix x64: -56
unix nanbox: -84
stm32: -40
esp8266: -68
cc3200: -48
Furthermore, this patch adds space (" ") to the set of ROM qstrs which
means it doesn't need to be put in RAM if it's ever used.
Return the result of called function. If exception happened, return
MP_OBJ_NULL. Allows to use mp_call_function_*_protected() with callbacks
returning values, etc.
This commit essentially reverts aa9dbb1b03
where this if-condition was added. It seems that even when that commit
was made the code was never reached by any tests, nor reachable by
analysis (see below). The same is true with the code as it currently
stands: no test triggers this if-condition, nor any uasyncio examples.
Analysing the flow of the program also shows that it's not reachable:
==START==
-> to trigger this if condition mp_execute_bytecode() must return
MP_VM_RETURN_YIELD with *sp==MP_OBJ_STOP_ITERATION
-> mp_execute_bytecode() can only return MP_VM_RETURN_YIELD from the
MP_BC_YIELD_VALUE bytecode, which can happen in 2 ways:
-> 1) from a "yield <x>" in bytecode, but <x> must always be a proper
object, never MP_OBJ_STOP_ITERATION; ==END1==
-> 2) via yield from, via mp_resume() which must return
MP_VM_RETURN_YIELD with ret_value==MP_OBJ_STOP_ITERATION, which
can happen in 3 ways:
-> 1) it delegates to mp_obj_gen_resume(); go back to ==START==
-> 2) it returns MP_VM_RETURN_YIELD directly but with a guard that
ret_val!=MP_OBJ_STOP_ITERATION; ==END2==
-> 3) it returns MP_VM_RETURN_YIELD with ret_val set from
mp_call_method_n_kw(), but mp_call_method_n_kw() must return a
proper object, never MP_OBJ_STOP_ITERATION; ==END3==
The above shows there is no way to trigger the if-condition and it can be
removed.
These checks are assumed to be true in all cases where gc_realloc is
called with a valid pointer, so no need to waste code space and time
checking them in a non-debug build.
So long as the input qstr identifier is valid (below the maximum number of
qstrs) the function will always return a valid pointer. This patch
eliminates the "return 0" dead-code.
This patch improves parsing of floating point numbers by converting all the
digits (integer and fractional) together into a number 1 or greater, and
then applying the correct power of 10 at the very end. In particular the
multiple "multiply by 0.1" operations to build a fraction are now combined
together and applied at the same time as the exponent, at the very end.
This helps to retain precision during parsing of floats, and also includes
a check that the number doesn't overflow during the parsing. One benefit
is that a float will have the same value no matter where the decimal point
is located, eg 1.23 == 123e-2.
Before this patch MP_BINARY_OP_IN had two meanings: coming from bytecode it
meant that the args needed to be swapped, but coming from within the
runtime meant that the args were already in the correct order. This lead
to some confusion in the code and comments stating how args were reversed.
It also lead to 2 bugs: 1) containment for a subclass of a native type
didn't work; 2) the expression "{True} in True" would illegally succeed and
return True. In both of these cases it was because the args to
MP_BINARY_OP_IN ended up being reversed twice.
To fix these things this patch introduces MP_BINARY_OP_CONTAINS which
corresponds exactly to the __contains__ special method, and this is the
operator that built-in types should implement. MP_BINARY_OP_IN is now only
emitted by the compiler and is converted to MP_BINARY_OP_CONTAINS by
swapping the arguments.
In mp_binary_op, there is no need to explicitly check for type->getiter
being non-null and raising an exception because this is handled exactly by
mp_getiter(). So just call the latter unconditionally.
This patch introduces a new compile-time config option to disable multiple
inheritance at the Python level: MICROPY_MULTIPLE_INHERITANCE. It is
enabled by default.
Disabling multiple inheritance eliminates a lot of recursion in the call
graph (which is important for some embedded systems), and can be used to
reduce code size for ports that are really constrained (by around 200 bytes
for Thumb2 archs).
With multiple inheritance disabled all tests in the test-suite pass except
those that explicitly test for multiple inheritance.
The function mp_obj_new_str_of_type is a general str object constructor
used in many places in the code to create either a str or bytes object.
When creating a str it should first check if the string data already exists
as an interned qstr, and if so then return the qstr object. This patch
makes the function have such behaviour, which helps to reduce heap usage by
reusing existing interned data where possible.
The old behaviour of mp_obj_new_str_of_type (which didn't check for
existing interned data) is made available through the function
mp_obj_new_str_copy, but should only be used in very special cases.
One consequence of this patch is that the following expression is now True:
'abc' is ' abc '.split()[0]
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).
Rationale:
* Calling Python build tool scripts from makefiles should be done
consistently using `python </path/to/script>`, instead of relying on the
correct she-bang line in the script [1] and the executable bit on the
script being set. This is more platform-independent.
* The name/path of the Python executable should always be used via the
makefile variable `PYTHON` set in `py/mkenv.mk`. This way it can be
easily overwritten by the user with `make PYTHON=/path/to/my/python`.
* The Python executable name should be part of the value of the makefile
variable, which stands for the build tool command (e.g. `MAKE_FROZEN` and
`MPY_TOOL`), not part of the command line where it is used. If a Python
tool is substituted by another (non-python) program, no change to the
Makefiles is necessary, except in `py/mkenv.mk`.
* This also solves #3369 and #1616.
[1] There are systems, where even the assumption that `/usr/bin/env` always
exists, doesn't hold true, for example on Android (where otherwise the unix
port compiles perfectly well).
All the asm macro names that convert a particular architecture to a generic
interface now follow the convention whereby the "destination" (usually a
register) is specified first.
Macros to convert big-endian values to host byte order and vice-versa.
These were defined in adhoc way for some ports (e.g. esp8266), allow
reuse, provide default implementations, while allow ports to override.
The technique of using alloca is how dotted import names are composed in
mp_import_from and mp_builtin___import__, so use the same technique in the
compiler. This puts less pressure on the heap (only the stack is used if
the qstr already exists, and if it doesn't exist then the standard qstr
block memory is used for the new qstr rather than a separate chunk of the
heap) and reduces overall code size.
This reverts commit 3289b9b7a7.
The commit broke building on MINGW because the filename became
micropython.exe.exe. A proper solution to support more Windows build
environments requires more thought and testing.
Per the comment found here
https://github.com/micropython/micropython-esp32/issues/209#issuecomment-339855157,
this patch adds finaliser code to prevent memory leaks from ussl objects,
which is especially useful when memory for a ussl context is allocated
outside the uPy heap. This patch is in-line with the finaliser code found
in many modsocket implementations for various ports.
This feature is configured via MICROPY_PY_USSL_FINALISER and is disabled by
default because there may be issues using it when the ussl state *is*
allocated on the uPy heap, rather than externally.
This allows to configure support for inplace special methods separately,
similar to "normal" and reverse special methods. This is useful, because
inplace methods are "the most optional" ones, for example, if inplace
methods aren't defined, the operation will be executed using normal
methods instead.
As a caveat, __iadd__ and __isub__ are implemented even if
MICROPY_PY_ALL_INPLACE_SPECIAL_METHODS isn't defined. This is similar
to the state of affairs before binary operations refactor, and allows
to run existing tests even if MICROPY_PY_ALL_INPLACE_SPECIAL_METHODS
isn't defined.
If MICROPY_PY_ALL_SPECIAL_METHODS is defined, actually define all special
methods (still subject to gating by e.g. MICROPY_PY_REVERSE_SPECIAL_METHODS).
This adds quite a number of qstr's, so should be used sparingly.
Update makeqstrdata.py to sort strings starting with "__" to the beginning
of qstr list, so they get low qstr id's, guaranteedly fitting in 8 bits.
Then use this property to further compact op_id => qstr mapping arrays.
Per https://docs.python.org/3/library/sys.html#sys.getsizeof:
getsizeof() calls the object’s __sizeof__ method. Previously, "getsizeof"
was used mostly to save on new qstr, as we don't really support calling
this method on arbitrary objects (so it was used only for reporting).
However, normalize it all now.
Not all compilers/analysers are smart enough to realise that this function
is never called if MICROPY_ERROR_REPORTING is not TERSE, because the logic
in the code uses if statements rather than #if to select whether to call
this function or not (MSC in debug mode is an example of this, but there
are others). So just unconditionally compile this helper function. The
code-base anyway relies on the linker to remove unused functions.
