examples: Mark asm, pio, etc. as noqa: F821 (undefined-name).

These files all use decorators (@asm_thumb, @asm_pio) that add names to the
function scope, that the linter cannot see.

It's useful to clear them in the file not in pyproject.toml as example code
will be copied and adapted elsewhere, and those developers may also use
Ruff (we hope!)

Signed-off-by: Angus Gratton <angus@redyak.com.au>

13 files changed, 31 insertions, 0 deletions

diff --git a/examples/asmled.py b/examples/asmled.py
index 09a06c184a..4ff35dfdf8 100644
--- a/examples/asmled.py
+++ b/examples/asmled.py
@@ -1,5 +1,9 @@
 # flash LED #1 using inline assembler
 # this version is overly verbose and uses word stores
+#
+# ruff: noqa: F821 - @asm_thumb decorator adds names to function scope
+
+
 @micropython.asm_thumb
 def flash_led(r0):
     movw(r1, (stm.GPIOA + stm.GPIO_BSRRL) & 0xFFFF)
diff --git a/examples/asmsum.py b/examples/asmsum.py
index f2c7f285ba..2d8c2b2c99 100644
--- a/examples/asmsum.py
+++ b/examples/asmsum.py
@@ -1,3 +1,6 @@
+# ruff: noqa: F821 - @asm_thumb decorator adds names to function scope
+
+
 @micropython.asm_thumb
 def asm_sum_words(r0, r1):
     # r0 = len
diff --git a/examples/natmod/btree/btree_py.py b/examples/natmod/btree/btree_py.py
index bd53c084a1..461b045c98 100644
--- a/examples/natmod/btree/btree_py.py
+++ b/examples/natmod/btree/btree_py.py
@@ -1,3 +1,7 @@
 # Implemented in Python to support keyword arguments
+
+# ruff: noqa: F821 - this file is evaluated with C-defined names in scope
+
+
 def open(stream, *, flags=0, cachesize=0, pagesize=0, minkeypage=0):
     return _open(stream, flags, cachesize, pagesize, minkeypage)
diff --git a/examples/natmod/features2/test.py b/examples/natmod/features2/test.py
index 5ac80120d7..af79b9692c 100644
--- a/examples/natmod/features2/test.py
+++ b/examples/natmod/features2/test.py
@@ -1,5 +1,7 @@
 # This Python code will be merged with the C code in main.c
 
+# ruff: noqa: F821 - this file is evaluated with C-defined names in scope
+
 import array
 
 
diff --git a/examples/rp2/pio_1hz.py b/examples/rp2/pio_1hz.py
index 84d761fa14..3ffab79d56 100644
--- a/examples/rp2/pio_1hz.py
+++ b/examples/rp2/pio_1hz.py
@@ -1,6 +1,8 @@
 # Example using PIO to blink an LED and raise an IRQ at 1Hz.
 # Note: this does not work on Pico W because it uses Pin(25) for LED output.
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 import time
 from machine import Pin
 import rp2
diff --git a/examples/rp2/pio_exec.py b/examples/rp2/pio_exec.py
index ce39f2df84..3bea51f8dd 100644
--- a/examples/rp2/pio_exec.py
+++ b/examples/rp2/pio_exec.py
@@ -5,6 +5,8 @@
 #   - using set_init and set_base
 #   - using StateMachine.exec
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 import time
 from machine import Pin
 import rp2
diff --git a/examples/rp2/pio_pinchange.py b/examples/rp2/pio_pinchange.py
index 767c8e78c2..4a210e7f39 100644
--- a/examples/rp2/pio_pinchange.py
+++ b/examples/rp2/pio_pinchange.py
@@ -8,6 +8,8 @@
 #   - setting an irq handler for a StateMachine
 #   - instantiating 2x StateMachine's with the same program and different pins
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 import time
 from machine import Pin
 import rp2
diff --git a/examples/rp2/pio_pwm.py b/examples/rp2/pio_pwm.py
index 176a238091..24fd6b85a3 100644
--- a/examples/rp2/pio_pwm.py
+++ b/examples/rp2/pio_pwm.py
@@ -1,5 +1,7 @@
 # Example of using PIO for PWM, and fading the brightness of an LED
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 from machine import Pin
 from rp2 import PIO, StateMachine, asm_pio
 from time import sleep
diff --git a/examples/rp2/pio_uart_rx.py b/examples/rp2/pio_uart_rx.py
index 080b6bd639..f46aaa6a5e 100644
--- a/examples/rp2/pio_uart_rx.py
+++ b/examples/rp2/pio_uart_rx.py
@@ -8,6 +8,8 @@
 #   - PIO irq handler
 #   - using the second core via _thread
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 import _thread
 from machine import Pin, UART
 from rp2 import PIO, StateMachine, asm_pio
diff --git a/examples/rp2/pio_uart_tx.py b/examples/rp2/pio_uart_tx.py
index 5e4af8f6cc..04abf2d0d1 100644
--- a/examples/rp2/pio_uart_tx.py
+++ b/examples/rp2/pio_uart_tx.py
@@ -1,5 +1,7 @@
 # Example using PIO to create a UART TX interface
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 from machine import Pin
 from rp2 import PIO, StateMachine, asm_pio
 
diff --git a/examples/rp2/pio_ws2812.py b/examples/rp2/pio_ws2812.py
index dd021a9d56..6de21ab8b7 100644
--- a/examples/rp2/pio_ws2812.py
+++ b/examples/rp2/pio_ws2812.py
@@ -1,5 +1,7 @@
 # Example using PIO to drive a set of WS2812 LEDs.
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 import array, time
 from machine import Pin
 import rp2
diff --git a/examples/rp2/pwm_fade.py b/examples/rp2/pwm_fade.py
index 5b7089c6b1..6672f3443f 100644
--- a/examples/rp2/pwm_fade.py
+++ b/examples/rp2/pwm_fade.py
@@ -1,6 +1,8 @@
 # Example using PWM to fade an LED.
 # Note: this does not work on Pico W because it uses Pin(25) for LED output.
 
+# ruff: noqa: F821 - @asm_pio decorator adds names to function scope
+
 import time
 from machine import Pin, PWM
 
diff --git a/ports/qemu-arm/test-frzmpy/frozen_asm.py b/ports/qemu-arm/test-frzmpy/frozen_asm.py
index 2c7f5c92cd..ba43264b38 100644
--- a/ports/qemu-arm/test-frzmpy/frozen_asm.py
+++ b/ports/qemu-arm/test-frzmpy/frozen_asm.py
@@ -1,5 +1,7 @@
 # Test freezing inline-asm code.
 
+# ruff: noqa: F821 - @asm_thumb decorator adds names to function scope
+
 import micropython