Damien George 9883d8e818 py/persistentcode: Maintain root ptr list of imported native .mpy code.
On ports where normal heap memory can contain executable code (eg ARM-based
ports such as stm32), native code loaded from an .mpy file may be reclaimed
by the GC because there's no reference to the very start of the native
machine code block that is reachable from root pointers (only pointers to
internal parts of the machine code block are reachable, but that doesn't
help the GC find the memory).

This commit fixes this issue by maintaining an explicit list of root
pointers pointing to native code that is loaded from an .mpy file.  This
is not needed for all ports so is selectable by the new configuration
option MICROPY_PERSISTENT_CODE_TRACK_RELOC_CODE.  It's enabled by default
if a port does not specify any special functions to allocate or commit
executable memory.

A test is included to test that native code loaded from an .mpy file does
not get reclaimed by the GC.

Fixes #6045.

Signed-off-by: Damien George <damien@micropython.org>
2020-08-02 22:34:09 +10:00
..

This directory contains tests for various functionality areas of MicroPython.
To run all stable tests, run "run-tests" script in this directory.

Tests of capabilities not supported on all platforms should be written
to check for the capability being present. If it is not, the test
should merely output 'SKIP' followed by the line terminator, and call
sys.exit() to raise SystemExit, instead of attempting to test the
missing capability. The testing framework (run-tests in this
directory, test_main.c in qemu_arm) recognizes this as a skipped test.

There are a few features for which this mechanism cannot be used to
condition a test. The run-tests script uses small scripts in the
feature_check directory to check whether each such feature is present,
and skips the relevant tests if not.

Tests are generally verified by running the test both in MicroPython and
in CPython and comparing the outputs. If the output differs the test fails
and the outputs are saved in a .out and a .exp file respectively.
For tests that cannot be run in CPython, for example because they use
the machine module, a .exp file can be provided next to the test's .py
file. A convenient way to generate that is to run the test, let it fail
(because CPython cannot run it) and then copy the .out file (but not
before checking it manually!)

When creating new tests, anything that relies on float support should go in the
float/ subdirectory.  Anything that relies on import x, where x is not a built-in
module, should go in the import/ subdirectory.