525557738c
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 a7fa18c203a241f670f12ab507aa8b349fcd45a1 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>
The Unix version
The "unix" port requires a standard Unix-like environment with gcc and GNU make. This includes Linux, BSD, macOS, and Windows Subsystem for Linux. The x86 and x64 architectures are supported (i.e. x86 32- and 64-bit), as well as ARM and MIPS. Making a full-featured port to another architecture requires writing some assembly code for the exception handling and garbage collection. Alternatively, a fallback implementation based on setjmp/longjmp can be used.
To build (see section below for required dependencies):
$ cd ports/unix
$ make submodules
$ make
Then to give it a try:
$ ./build-standard/micropython
>>> list(5 * x + y for x in range(10) for y in [4, 2, 1])
Use CTRL-D (i.e. EOF) to exit the shell.
Learn about command-line options (in particular, how to increase heap size which may be needed for larger applications):
$ ./build-standard/micropython -h
To run the complete testsuite, use:
$ make test
The Unix port comes with a built-in package manager called mip, e.g.:
$ ./build-standard/micropython -m mip install hmac
or
$ ./build-standard/micropython
>>> import mip
>>> mip.install("hmac")
Browse available modules at [micropython-lib]
(https://github.com/micropython/micropython-lib). See
Package management
for more information about mip.
External dependencies
The libffi library and pkg-config tool are required. On Debian/Ubuntu/Mint
derivative Linux distros, install build-essential(includes toolchain and
make), libffi-dev, and pkg-config packages.
Other dependencies can be built together with MicroPython. This may be required to enable extra features or capabilities, and in recent versions of MicroPython, these may be enabled by default. To build these additional dependencies, in the unix port directory first execute:
$ make submodules
This will fetch all the relevant git submodules (sub repositories) that the port needs. Use the same command to get the latest versions of submodules as they are updated from time to time. After that execute:
$ make deplibs
This will build all available dependencies (regardless whether they are used
or not). If you intend to build MicroPython with additional options
(like cross-compiling), the same set of options should be passed to make deplibs. To actually enable/disable use of dependencies, edit the
ports/unix/mpconfigport.mk file, which has inline descriptions of the
options. For example, to build the SSL module, MICROPY_PY_USSL should be
set to 1.