all: Rename "sys" module to "usys".

This is consistent with the other 'micro' modules and allows implementing
additional features in Python via e.g. micropython-lib's sys.

Note this is a breaking change (not backwards compatible) for ports which
do not enable weak links, as "import sys" must now be replaced with
"import usys".

Author: stinos

docs/library/index.rst

@@ -77,7 +77,6 @@ it will fallback to loading the built-in ``ujson`` module.
    cmath.rst
    gc.rst
    math.rst
-   sys.rst
    uarray.rst
    uasyncio.rst
    ubinascii.rst
@@ -93,6 +92,7 @@ it will fallback to loading the built-in ``ujson`` module.
    usocket.rst
    ussl.rst
    ustruct.rst
+   usys.rst
    utime.rst
    uzlib.rst
    _thread.rst

docs/library/sys.rst renamed to docs/library/usys.rst

@@ -1,7 +1,7 @@
-:mod:`sys` -- system specific functions
-=======================================
+:mod:`usys` -- system specific functions
+========================================
 
-.. module:: sys
+.. module:: usys
    :synopsis: system specific functions
 
 |see_cpython_module| :mod:`python:sys`.
@@ -28,10 +28,10 @@ Functions
       This function is a MicroPython extension intended to provide similar
       functionality to the :mod:`atexit` module in CPython.
 
-.. function:: print_exception(exc, file=sys.stdout, /)
+.. function:: print_exception(exc, file=usys.stdout, /)
 
    Print exception with a traceback to a file-like object *file* (or
-   `sys.stdout` by default).
+   `usys.stdout` by default).
 
    .. admonition:: Difference to CPython
       :class: attention
@@ -84,7 +84,7 @@ Constants
    value directly, but instead count number of bits in it::
 
     bits = 0
-    v = sys.maxsize
+    v = usys.maxsize
     while v:
         bits += 1
         v >>= 1
@@ -113,7 +113,7 @@ Constants
    is an identifier of a board, e.g. ``"pyboard"`` for the original MicroPython
    reference board. It thus can be used to distinguish one board from another.
    If you need to check whether your program runs on MicroPython (vs other
-   Python implementation), use `sys.implementation` instead.
+   Python implementation), use `usys.implementation` instead.
 
 .. data:: stderr
 

drivers/nrf24l01/nrf24l01test.py

@@ -1,6 +1,6 @@
 """Test for nrf24l01 module.  Portable between MicroPython targets."""
 
-import sys
+import usys
 import ustruct as struct
 import utime
 from machine import Pin, SPI
@@ -14,14 +14,14 @@
 # master may be a slow device. Value tested with Pyboard, ESP32 and ESP8266.
 _SLAVE_SEND_DELAY = const(10)
 
-if sys.platform == "pyboard":
+if usys.platform == "pyboard":
     cfg = {"spi": 2, "miso": "Y7", "mosi": "Y8", "sck": "Y6", "csn": "Y5", "ce": "Y4"}
-elif sys.platform == "esp8266":  # Hardware SPI
+elif usys.platform == "esp8266":  # Hardware SPI
     cfg = {"spi": 1, "miso": 12, "mosi": 13, "sck": 14, "csn": 4, "ce": 5}
-elif sys.platform == "esp32":  # Software SPI
+elif usys.platform == "esp32":  # Software SPI
     cfg = {"spi": -1, "miso": 32, "mosi": 33, "sck": 25, "csn": 26, "ce": 27}
 else:
-    raise ValueError("Unsupported platform {}".format(sys.platform))
+    raise ValueError("Unsupported platform {}".format(usys.platform))
 
 # Addresses are in little-endian format. They correspond to big-endian
 # 0xf0f0f0f0e1, 0xf0f0f0f0d2

extmod/webrepl/websocket_helper.py

@@ -1,4 +1,7 @@
-import sys
+try:
+    import usys as sys
+except ImportError:
+    import sys
 
 try:
     import ubinascii as binascii

py/objmodule.c

@@ -159,7 +159,7 @@ STATIC const mp_rom_map_elem_t mp_builtin_module_table[] = {
     #endif
     #endif
     #if MICROPY_PY_SYS
-    { MP_ROM_QSTR(MP_QSTR_sys), MP_ROM_PTR(&mp_module_sys) },
+    { MP_ROM_QSTR(MP_QSTR_usys), MP_ROM_PTR(&mp_module_sys) },
     #endif
     #if MICROPY_PY_GC && MICROPY_ENABLE_GC
     { MP_ROM_QSTR(MP_QSTR_gc), MP_ROM_PTR(&mp_module_gc) },

tests/basics/async_await2.py

@@ -1,6 +1,9 @@
 # test await expression
 
-import sys
+try:
+    import usys as sys
+except ImportError:
+    import sys
 if sys.implementation.name == 'micropython':
     # uPy allows normal generators to be awaitables
     coroutine = lambda f: f

tests/basics/async_for2.py

@@ -1,6 +1,9 @@
 # test waiting within "async for" __anext__ function
 
-import sys
+try:
+    import usys as sys
+except ImportError:
+    import sys
 if sys.implementation.name == 'micropython':
     # uPy allows normal generators to be awaitables
     coroutine = lambda f: f

tests/basics/async_with2.py

@@ -1,6 +1,9 @@
 # test waiting within async with enter/exit functions
 
-import sys
+try:
+    import usys as sys
+except ImportError:
+    import sys
 if sys.implementation.name == 'micropython':
     # uPy allows normal generators to be awaitables
     coroutine = lambda f: f

tests/basics/attrtuple1.py

@@ -1,7 +1,10 @@
 # test attrtuple
 # we can't test this type directly so we use sys.implementation object
 
-import sys
+try:
+    import usys as sys
+except ImportError:
+    import sys
 t = sys.implementation
 
 # It can be just a normal tuple on small ports

tests/basics/builtin_callable.py

@@ -7,7 +7,10 @@
 print(callable("dfsd"))
 
 # modules should not be callabe
-import sys
+try:
+    import usys as sys
+except ImportError:
+    import sys
 print(callable(sys))
 
 # builtins should be callable