Add `warnings` and warn about displayio changes

Follow up to #8493

locale/circuitpython.pot

@@ -175,19 +175,23 @@ msgstr ""
 msgid "%q length must be >= %d"
 msgstr ""
 
+#: py/objmodule.c py/runtime.c
+msgid "%q moved from %q to %q"
+msgstr ""
+
 #: py/argcheck.c
 msgid "%q must be %d"
 msgstr ""
 
-#: py/argcheck.c shared-bindings/displayio/Bitmap.c
+#: py/argcheck.c shared-bindings/busdisplay/BusDisplay.c
-#: shared-bindings/displayio/Display.c
+#: shared-bindings/displayio/Bitmap.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 #: shared-bindings/is31fl3741/FrameBuffer.c
 #: shared-bindings/rgbmatrix/RGBMatrix.c
 msgid "%q must be %d-%d"
 msgstr ""
 
-#: shared-bindings/displayio/Display.c
+#: shared-bindings/busdisplay/BusDisplay.c
 msgid "%q must be 1 when %q is True"
 msgstr ""
 
@@ -212,6 +216,10 @@ msgstr ""
 msgid "%q must be a bytearray or array of type 'h', 'H', 'b', or 'B'"
 msgstr ""
 
+#: shared-bindings/warnings/__init__.c
+msgid "%q must be a subclass of %q"
+msgstr ""
+
 #: ports/espressif/common-hal/analogbufio/BufferedIn.c
 msgid "%q must be array of type 'H'"
 msgstr ""
@@ -247,6 +255,10 @@ msgstr ""
 msgid "%q out of range"
 msgstr ""
 
+#: py/objmodule.c py/runtime.c
+msgid "%q renamed %q"
+msgstr ""
+
 #: py/objrange.c py/objslice.c shared-bindings/random/__init__.c
 msgid "%q step cannot be zero"
 msgstr ""
@@ -434,8 +446,8 @@ msgstr ""
 msgid ", in %q\n"
 msgstr ""
 
-#: shared-bindings/displayio/Display.c
+#: shared-bindings/busdisplay/BusDisplay.c
-#: shared-bindings/displayio/EPaperDisplay.c
+#: shared-bindings/epaperdisplay/EPaperDisplay.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 msgid ".show(x) removed. Use .root_group = x"
 msgstr ""
@@ -625,7 +637,7 @@ msgstr ""
 msgid "Baudrate not supported by peripheral"
 msgstr ""
 
-#: shared-module/displayio/Display.c
+#: shared-module/busdisplay/BusDisplay.c
 #: shared-module/framebufferio/FramebufferDisplay.c
 msgid "Below minimum frame rate"
 msgstr ""
@@ -658,7 +670,7 @@ msgstr ""
 msgid "Both pins must support hardware interrupts"
 msgstr ""
 
-#: shared-bindings/displayio/Display.c
+#: shared-bindings/busdisplay/BusDisplay.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 msgid "Brightness not adjustable"
 msgstr ""
@@ -695,7 +707,8 @@ msgstr ""
 msgid "Buffer too short by %d bytes"
 msgstr ""
 
-#: ports/cxd56/common-hal/camera/Camera.c shared-bindings/displayio/Display.c
+#: ports/cxd56/common-hal/camera/Camera.c
+#: shared-bindings/busdisplay/BusDisplay.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 #: shared-bindings/struct/__init__.c shared-module/struct/__init__.c
 msgid "Buffer too small"
@@ -705,10 +718,10 @@ msgstr ""
 msgid "Buffers must be same size"
 msgstr ""
 
-#: ports/atmel-samd/common-hal/paralleldisplay/ParallelBus.c
+#: ports/atmel-samd/common-hal/paralleldisplaybus/ParallelBus.c
-#: ports/espressif/common-hal/paralleldisplay/ParallelBus.c
+#: ports/espressif/common-hal/paralleldisplaybus/ParallelBus.c
-#: ports/nrf/common-hal/paralleldisplay/ParallelBus.c
+#: ports/nrf/common-hal/paralleldisplaybus/ParallelBus.c
-#: ports/raspberrypi/common-hal/paralleldisplay/ParallelBus.c
+#: ports/raspberrypi/common-hal/paralleldisplaybus/ParallelBus.c
 #, c-format
 msgid "Bus pin %d is already in use"
 msgstr ""
@@ -893,8 +906,8 @@ msgstr ""
 msgid "DAC already in use"
 msgstr ""
 
-#: ports/atmel-samd/common-hal/paralleldisplay/ParallelBus.c
+#: ports/atmel-samd/common-hal/paralleldisplaybus/ParallelBus.c
-#: ports/nrf/common-hal/paralleldisplay/ParallelBus.c
+#: ports/nrf/common-hal/paralleldisplaybus/ParallelBus.c
 msgid "Data 0 pin must be byte aligned"
 msgstr ""
 
@@ -924,13 +937,13 @@ msgstr ""
 msgid "Device in use"
 msgstr ""
 
-#: shared-bindings/displayio/Display.c
+#: shared-bindings/busdisplay/BusDisplay.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 msgid "Display must have a 16 bit colorspace."
 msgstr ""
 
-#: shared-bindings/displayio/Display.c
+#: shared-bindings/busdisplay/BusDisplay.c
-#: shared-bindings/displayio/EPaperDisplay.c
+#: shared-bindings/epaperdisplay/EPaperDisplay.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 msgid "Display rotation must be in 90 degree increments"
 msgstr ""
@@ -1104,7 +1117,7 @@ msgid "Generic Failure"
 msgstr ""
 
 #: shared-bindings/framebufferio/FramebufferDisplay.c
-#: shared-module/displayio/Display.c
+#: shared-module/busdisplay/BusDisplay.c
 #: shared-module/framebufferio/FramebufferDisplay.c
 msgid "Group already used"
 msgstr ""
@@ -1202,7 +1215,7 @@ msgstr ""
 msgid "Internal define error"
 msgstr ""
 
-#: ports/espressif/common-hal/paralleldisplay/ParallelBus.c
+#: ports/espressif/common-hal/paralleldisplaybus/ParallelBus.c
 #: shared-module/os/getenv.c
 msgid "Internal error"
 msgstr ""
@@ -1225,7 +1238,7 @@ msgstr ""
 #: ports/raspberrypi/bindings/picodvi/Framebuffer.c
 #: ports/raspberrypi/common-hal/picodvi/Framebuffer.c py/argcheck.c
 #: shared-bindings/digitalio/DigitalInOut.c
-#: shared-bindings/displayio/EPaperDisplay.c
+#: shared-bindings/epaperdisplay/EPaperDisplay.c
 msgid "Invalid %q"
 msgstr ""
 
@@ -1428,9 +1441,10 @@ msgstr ""
 #: ports/mimxrt10xx/common-hal/busio/SPI.c
 #: ports/mimxrt10xx/common-hal/busio/UART.c ports/nrf/common-hal/busio/UART.c
 #: ports/raspberrypi/common-hal/busio/UART.c ports/stm/common-hal/busio/SPI.c
-#: ports/stm/common-hal/busio/UART.c shared-bindings/displayio/FourWire.c
+#: ports/stm/common-hal/busio/UART.c shared-bindings/fourwire/FourWire.c
-#: shared-bindings/displayio/I2CDisplay.c
+#: shared-bindings/i2cdisplaybus/I2CDisplayBus.c
-#: shared-bindings/paralleldisplay/ParallelBus.c shared-module/bitbangio/SPI.c
+#: shared-bindings/paralleldisplaybus/ParallelBus.c
+#: shared-module/bitbangio/SPI.c
 msgid "No %q pin"
 msgstr ""
 
@@ -1562,7 +1576,7 @@ msgstr ""
 msgid "Not playing"
 msgstr ""
 
-#: ports/espressif/common-hal/paralleldisplay/ParallelBus.c
+#: ports/espressif/common-hal/paralleldisplaybus/ParallelBus.c
 #, c-format
 msgid "Number of data_pins must be 8 or 16, not %d"
 msgstr ""
@@ -1852,7 +1866,7 @@ msgstr ""
 msgid "Reconnecting"
 msgstr ""
 
-#: shared-bindings/displayio/EPaperDisplay.c
+#: shared-bindings/epaperdisplay/EPaperDisplay.c
 msgid "Refresh too soon"
 msgstr ""
 
@@ -1953,7 +1967,7 @@ msgstr ""
 msgid "Source and destination buffers must be the same length"
 msgstr ""
 
-#: shared-bindings/paralleldisplay/ParallelBus.c
+#: shared-bindings/paralleldisplaybus/ParallelBus.c
 msgid "Specify exactly one of data0 or data_pins"
 msgstr ""
 
@@ -2013,7 +2027,7 @@ msgstr ""
 msgid "This microcontroller does not support continuous capture."
 msgstr ""
 
-#: shared-module/paralleldisplay/ParallelBus.c
+#: shared-module/paralleldisplaybus/ParallelBus.c
 msgid ""
 "This microcontroller only supports data0=, not data_pins=, because it "
 "requires contiguous pins."
@@ -2148,7 +2162,8 @@ msgstr ""
 msgid "Unable to create lock"
 msgstr ""
 
-#: shared-module/displayio/I2CDisplay.c shared-module/is31fl3741/IS31FL3741.c
+#: shared-module/i2cdisplaybus/I2CDisplayBus.c
+#: shared-module/is31fl3741/IS31FL3741.c
 #, c-format
 msgid "Unable to find I2C Display at %x"
 msgstr ""
@@ -2258,7 +2273,7 @@ msgstr ""
 msgid "Unsupported colorspace"
 msgstr ""
 
-#: shared-module/displayio/display_core.c
+#: shared-module/displayio/bus_core.c
 msgid "Unsupported display bus type"
 msgstr ""
 

py/circuitpy_defns.mk

@@ -395,6 +395,9 @@ endif
 ifeq ($(CIRCUITPY_VIDEOCORE),1)
 SRC_PATTERNS += videocore/%
 endif
+ifeq ($(CIRCUITPY_WARNINGS),1)
+SRC_PATTERNS += warnings/%
+endif
 ifeq ($(CIRCUITPY_WATCHDOG),1)
 SRC_PATTERNS += watchdog/%
 endif
@@ -680,13 +683,14 @@ SRC_SHARED_MODULE_ALL = \
 	usb/core/__init__.c \
 	usb/core/Device.c \
 	ustack/__init__.c \
-	watchdog/__init__.c \
-	zlib/__init__.c \
 	vectorio/Circle.c \
 	vectorio/Polygon.c \
 	vectorio/Rectangle.c \
 	vectorio/VectorShape.c \
 	vectorio/__init__.c \
+	warnings/__init__.c \
+	watchdog/__init__.c \
+	zlib/__init__.c \
 
 # All possible sources are listed here, and are filtered by SRC_PATTERNS.
 SRC_SHARED_MODULE = $(filter $(SRC_PATTERNS), $(SRC_SHARED_MODULE_ALL))

py/circuitpy_mpconfig.mk

@@ -589,6 +589,9 @@ CIRCUITPY_ULAB_OPTIMIZE_SIZE ?= 0
 CIRCUITPY_VIDEOCORE ?= 0
 CFLAGS += -DCIRCUITPY_VIDEOCORE=$(CIRCUITPY_VIDEOCORE)
 
+CIRCUITPY_WARNINGS ?= 1
+CFLAGS += -DCIRCUITPY_WARNINGS=$(CIRCUITPY_WARNINGS)
+
 # watchdog hardware support
 CIRCUITPY_WATCHDOG ?= 0
 CFLAGS += -DCIRCUITPY_WATCHDOG=$(CIRCUITPY_WATCHDOG)

py/modbuiltins.c

@@ -785,6 +785,10 @@ STATIC const mp_rom_map_elem_t mp_module_builtins_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_ViperTypeError), MP_ROM_PTR(&mp_type_ViperTypeError) },
     #endif
     { MP_ROM_QSTR(MP_QSTR_ZeroDivisionError), MP_ROM_PTR(&mp_type_ZeroDivisionError) },
+    #if CIRCUITPY_WARNINGS
+    { MP_ROM_QSTR(MP_QSTR_Warning), MP_ROM_PTR(&mp_type_Warning) },
+    { MP_ROM_QSTR(MP_QSTR_FutureWarning), MP_ROM_PTR(&mp_type_FutureWarning) },
+    #endif
 
     // Extra builtins as defined by a port
     MICROPY_PORT_BUILTINS

py/mpstate.h

@@ -36,6 +36,10 @@
 #include "py/objlist.h"
 #include "py/objexcept.h"
 
+#if CIRCUITPY_WARNINGS
+#include "shared-bindings/warnings/__init__.h"
+#endif
+
 // #if CIRCUITPY
 // #error CIRCUITPY is TRUE in mpstate.h.
 // #else
@@ -311,6 +315,10 @@ typedef struct _mp_state_thread_t {
     bool prof_callback_is_executing;
     struct _mp_code_state_t *current_code_state;
     #endif
+
+    #if CIRCUITPY_WARNINGS
+    warnings_action_t warnings_action;
+    #endif
 } mp_state_thread_t;
 
 // This structure combines the above 3 structures.

py/obj.h

@@ -916,6 +916,10 @@ extern const mp_obj_type_t mp_type_ZeroDivisionError;
 #if CIRCUITPY_ALARM
 extern const mp_obj_type_t mp_type_DeepSleepRequest;
 #endif
+#if CIRCUITPY_WARNINGS
+extern const mp_obj_type_t mp_type_Warning;
+extern const mp_obj_type_t mp_type_FutureWarning;
+#endif
 
 
 // Constant objects, globally accessible: None, False, True

py/objexcept.c

@@ -452,14 +452,16 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
 #if CIRCUITPY_ALARM
 MP_DEFINE_EXCEPTION(DeepSleepRequest, BaseException)
 #endif
-/*
+#if CIRCUITPY_WARNINGS
   MP_DEFINE_EXCEPTION(Warning, Exception)
+    MP_DEFINE_EXCEPTION(FutureWarning, Warning)
+#endif
+/*
     MP_DEFINE_EXCEPTION(DeprecationWarning, Warning)
     MP_DEFINE_EXCEPTION(PendingDeprecationWarning, Warning)
     MP_DEFINE_EXCEPTION(RuntimeWarning, Warning)
     MP_DEFINE_EXCEPTION(SyntaxWarning, Warning)
     MP_DEFINE_EXCEPTION(UserWarning, Warning)
-    MP_DEFINE_EXCEPTION(FutureWarning, Warning)
     MP_DEFINE_EXCEPTION(ImportWarning, Warning)
     MP_DEFINE_EXCEPTION(UnicodeWarning, Warning)
     MP_DEFINE_EXCEPTION(BytesWarning, Warning)

py/objmodule.c

@@ -34,6 +34,10 @@
 #include "py/runtime.h"
 #include "py/builtin.h"
 
+#if CIRCUITPY_WARNINGS
+#include "shared-module/warnings/__init__.h"
+#endif
+
 STATIC void module_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     (void)kind;
     mp_obj_module_t *self = MP_OBJ_TO_PTR(self_in);
@@ -62,6 +66,32 @@ STATIC void module_attr_try_delegation(mp_obj_t self_in, qstr attr, mp_obj_t *de
 STATIC void module_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
     mp_obj_module_t *self = MP_OBJ_TO_PTR(self_in);
     if (dest[0] == MP_OBJ_NULL) {
+        #if CIRCUITPY_DISPLAYIO && CIRCUITPY_WARNINGS
+        if (self == &displayio_module) {
+            #if CIRCUITPY_BUSDISPLAY
+            if (attr == MP_QSTR_Display) {
+                warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_Display, MP_QSTR_displayio, MP_QSTR_busdisplay);
+                warnings_warn(&mp_type_FutureWarning, translate("%q renamed %q"), MP_QSTR_Display, MP_QSTR_BusDisplay);
+            }
+            #endif
+            #if CIRCUITPY_EPAPERDISPLAY
+            if (attr == MP_QSTR_EPaperDisplay) {
+                warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_EPaperDisplay, MP_QSTR_displayio, MP_QSTR_epaperdisplay);
+            }
+            #endif
+            #if CIRCUITPY_FOURWIRE
+            if (attr == MP_QSTR_FourWire) {
+                warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_FourWire, MP_QSTR_displayio, MP_QSTR_fourwire);
+            }
+            #endif
+            #if CIRCUITPY_I2CDISPLAYBUS
+            if (attr == MP_QSTR_I2CDisplay) {
+                warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_I2CDisplay, MP_QSTR_displayio, MP_QSTR_i2cdisplaybus);
+                warnings_warn(&mp_type_FutureWarning, translate("%q renamed %q"), MP_QSTR_I2CDisplay, MP_QSTR_I2CDisplayBus);
+            }
+            #endif
+        }
+        #endif
         // load attribute
         mp_map_elem_t *elem = mp_map_lookup(&self->globals->map, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP);
         if (elem != NULL) {
@@ -173,6 +203,11 @@ STATIC const mp_module_delegation_entry_t mp_builtin_module_delegation_table[] =
 // Attempts to find (and initialise) a built-in, otherwise returns
 // MP_OBJ_NULL.
 mp_obj_t mp_module_get_builtin(qstr module_name, bool extensible) {
+    #if CIRCUITPY_PARALLELDISPLAYBUS && CIRCUITPY_WARNINGS
+    if (module_name == MP_QSTR_paralleldisplay) {
+        warnings_warn(&mp_type_FutureWarning, translate("%q renamed %q"), MP_QSTR_paralleldisplay, MP_QSTR_paralleldisplaybus);
+    }
+    #endif
     mp_map_elem_t *elem = mp_map_lookup((mp_map_t *)(extensible ? &mp_builtin_extensible_module_map : &mp_builtin_module_map), MP_OBJ_NEW_QSTR(module_name), MP_MAP_LOOKUP);
     if (!elem) {
         #if MICROPY_PY_SYS

py/runtime.c

@@ -47,6 +47,10 @@
 #include "py/stream.h"
 #include "py/gc.h"
 
+#if CIRCUITPY_WARNINGS
+#include "shared-module/warnings/__init__.h"
+#endif
+
 #if MICROPY_DEBUG_VERBOSE // print debugging info
 #define DEBUG_PRINT (1)
 #define DEBUG_printf DEBUG_printf
@@ -1659,6 +1663,25 @@ mp_obj_t __attribute__((noinline, )) mp_import_from(mp_obj_t module, qstr name)
 void mp_import_all(mp_obj_t module) {
     DEBUG_printf("import all %p\n", module);
 
+    #if CIRCUITPY_DISPLAYIO && CIRCUITPY_WARNINGS
+    if (module == &displayio_module) {
+        #if CIRCUITPY_BUSDISPLAY
+        warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_Display, MP_QSTR_displayio, MP_QSTR_busdisplay);
+        warnings_warn(&mp_type_FutureWarning, translate("%q renamed %q"), MP_QSTR_Display, MP_QSTR_BusDisplay);
+        #endif
+        #if CIRCUITPY_EPAPERDISPLAY
+        warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_EPaperDisplay, MP_QSTR_displayio, MP_QSTR_epaperdisplay);
+        #endif
+        #if CIRCUITPY_FOURWIRE
+        warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_FourWire, MP_QSTR_displayio, MP_QSTR_fourwire);
+        #endif
+        #if CIRCUITPY_I2CDISPLAYBUS
+        warnings_warn(&mp_type_FutureWarning, translate("%q moved from %q to %q"), MP_QSTR_I2CDisplay, MP_QSTR_displayio, MP_QSTR_i2cdisplaybus);
+        warnings_warn(&mp_type_FutureWarning, translate("%q renamed %q"), MP_QSTR_I2CDisplay, MP_QSTR_I2CDisplayBus);
+        #endif
+    }
+    #endif
+
     // TODO: Support __all__
     mp_map_t *map = &mp_obj_module_get_globals(module)->map;
     for (size_t i = 0; i < map->alloc; i++) {

shared-bindings/warnings/__init__.c

@@ -0,0 +1,112 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2023 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "py/mpstate.h"
+#include "py/obj.h"
+#include "py/objstr.h"
+#include "py/runtime.h"
+#include "shared-bindings/warnings/__init__.h"
+
+//| """Warn about potential code issues.
+//|
+//| This is a slimmed down version of the full CPython module. It defaults to
+//| the "always" action instead of "default", which prints once per occurrence.
+//| Only "error" and "ignore" are also supported. No filtering on category is
+//| available.
+//|
+//| |see_cpython_module| :mod:`cpython:warnings`.
+//|
+//| """
+//|
+//| import typing
+//|
+
+//| def warn(message: str, category: type = Warning) -> None:
+//|     """Issue a warning with an optional category. Use `simplefilter()` to
+//|     set if warnings are ignored, printed or raise an exception.
+//|
+//|     """
+//|     ...
+//|
+STATIC mp_obj_t warnings_warn(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_message, ARG_category };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_message, MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_category,  MP_ARG_OBJ, {.u_obj = MP_OBJ_FROM_PTR(&mp_type_Warning)} },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    mp_obj_t category_obj = args[ARG_category].u_obj;
+    if (!mp_obj_is_type(category_obj, &mp_type_type) ||
+        !mp_obj_is_subclass_fast(category_obj, MP_OBJ_FROM_PTR(&mp_type_Warning))) {
+        mp_raise_TypeError_varg(translate("%q must be a subclass of %q"), MP_QSTR_category, MP_QSTR_Warning);
+    }
+
+    common_hal_warnings_warn(mp_obj_str_get_str(args[ARG_message].u_obj), MP_OBJ_TO_PTR(category_obj));
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(warnings_warn_obj, 1, warnings_warn);
+
+//| def simplefilter(action: str) -> None:
+//|     """Set the action to take on all warnings. This is a subset of the CPython
+//|     behavior because it allows for per-category changes."""
+//|     ...
+//|
+STATIC mp_obj_t warnings_simplefilter(mp_obj_t action_in) {
+    const char *action_str = mp_obj_str_get_str(action_in);
+    warnings_action_t action;
+    if (strcmp(action_str, "error") == 0) {
+        action = WARNINGS_ERROR;
+    } else if (strcmp(action_str, "ignore") == 0) {
+        action = WARNINGS_IGNORE;
+    } else if (strcmp(action_str, "always") == 0) {
+        action = WARNINGS_ALWAYS;
+    } else {
+        mp_raise_ValueError(NULL);
+    }
+    common_hal_warnings_simplefilter(action);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(warnings_simplefilter_obj, warnings_simplefilter);
+
+STATIC const mp_rom_map_elem_t warnings_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_warnings) },
+
+    { MP_ROM_QSTR(MP_QSTR_warn), MP_ROM_PTR(&warnings_warn_obj) },
+    { MP_ROM_QSTR(MP_QSTR_simplefilter), MP_ROM_PTR(&warnings_simplefilter_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(warnings_module_globals, warnings_module_globals_table);
+
+const mp_obj_module_t warnings_module = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t *)&warnings_module_globals,
+};
+
+MP_REGISTER_MODULE(MP_QSTR_warnings, warnings_module);

shared-bindings/warnings/__init__.h

@@ -0,0 +1,39 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2023 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+typedef enum {
+    WARNINGS_DEFAULT,
+    WARNINGS_ERROR,
+    WARNINGS_IGNORE,
+    WARNINGS_ALWAYS,
+    WARNINGS_MODULE,
+    WARNINGS_ONCE
+} warnings_action_t;
+
+void common_hal_warnings_warn(const char *message, const mp_obj_type_t *category);
+void common_hal_warnings_simplefilter(warnings_action_t action);

shared-module/warnings/__init__.c

@@ -0,0 +1,73 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George
+ * Copyright (c) 2015 Josef Gajdusek
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdarg.h>
+
+#include "py/mpprint.h"
+#include "py/mpstate.h"
+#include "py/runtime.h"
+#include "shared-bindings/warnings/__init__.h"
+#include "shared-module/warnings/__init__.h"
+
+void common_hal_warnings_warn(const char *message, const mp_obj_type_t *category) {
+    warnings_action_t action = MP_STATE_THREAD(warnings_action);
+    if (action == WARNINGS_IGNORE) {
+        return;
+    }
+    if (action == WARNINGS_ERROR) {
+        mp_raise_msg_str(category, message);
+        // Doesn't get here
+        return;
+    }
+    mp_printf(MICROPY_ERROR_PRINTER, "%q: %s\n", category->name, message);
+}
+
+void warnings_warn(const mp_obj_type_t *category, const compressed_string_t *message, ...) {
+    warnings_action_t action = MP_STATE_THREAD(warnings_action);
+    if (action == WARNINGS_IGNORE) {
+        return;
+    }
+    va_list argptr;
+    va_start(argptr, message);
+    if (action == WARNINGS_ERROR) {
+        mp_raise_msg_vlist(category, message, argptr);
+        va_end(argptr);
+        // Doesn't get here
+        return;
+    }
+
+    mp_printf(MICROPY_ERROR_PRINTER, "%q: ", category->name);
+    mp_vcprintf(MICROPY_ERROR_PRINTER, message, argptr);
+    mp_print_str(MICROPY_ERROR_PRINTER, "\n");
+    va_end(argptr);
+}
+
+void common_hal_warnings_simplefilter(warnings_action_t action) {
+    MP_STATE_THREAD(warnings_action) = action;
+}

shared-module/warnings/__init__.h

@@ -0,0 +1,29 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+void warnings_warn(const mp_obj_type_t *category, const compressed_string_t *message, ...);