STM32WL variants incorrectly define HAL_DAC_MODULE_ENABLED causing DAC-related build warnings

[anwfeb]

Describe the bug

STM32WL variants define HAL_DAC_MODULE_ENABLED even though STM32WL devices do not provide a DAC peripheral.

As a result, DAC-related code paths in wiring_analog.c and wiring_digital.c are compiled, causing the following warnings during build:

warning: implicit declaration of function 'dac_write_value'
warning: implicit declaration of function 'dac_stop'

The warnings originate from:

dac_write_value(...)
dac_stop(...)

which are compiled because HAL_DAC_MODULE_ENABLED is defined in STM32WL variant files.

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To Reproduce

Create a minimal Arduino project for STM32WL55.

platformio.ini

[env:wl55]
platform = ststm32
board = nucleo_wl55jc
framework = arduino

src/main.cpp

#include <Arduino.h>

void setup() {}
void loop() {}

Build the project.

Build output contains warnings similar to:

wiring_digital.c:40:9: warning: implicit declaration of function 'dac_stop'
wiring_analog.c:225:7: warning: implicit declaration of function 'dac_write_value'

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Expected behavior

STM32WL devices do not have a DAC peripheral, therefore DAC support should not be enabled for STM32WL variants and the project should build without DAC-related warnings.

---

Desktop

• OS: macOS
• PlatformIO Core: latest
• STM32 core version: 2.12.0
• Toolchain: GCC 12.3.1
• Upload method: ST-Link

---

Board

• Name: NUCLEO-WL55JC1
• MCU: STM32WL55JC

---

Additional context

The issue appears to come from STM32WL variant definitions enabling DAC support:

Examples:

variants/STM32WLxx/WL54JCI_WL55JCI_WLE4J(8-B-C)I_WLE5J(8-B-C)I/variant_generic.h
#define HAL_DAC_MODULE_ENABLED

variants/STM32WLxx/WL54JCI_WL55JCI_WLE4J(8-B-C)I_WLE5J(8-B-C)I/variant_NUCLEO_WL55JC1.h
#define HAL_DAC_MODULE_ENABLED

I verified that commenting out:

#define HAL_DAC_MODULE_ENABLED

in the STM32WL variant file removes the DAC-related warnings completely and the project builds cleanly.

Since STM32WL devices do not include a DAC peripheral, it seems that HAL_DAC_MODULE_ENABLED should not be defined for STM32WL variants.

[fpistm]

Hi @anwfeb
The STM32WL has a DAC:

Don't know why you get those warnings with pio. With Arduino I don't think they appears.

[fpistm]

I've tested to build with Arduino IDE and there is no warning.
I've also build an empty project with pio and no warning displayed.

PLATFORM: ST STM32 (19.6.0) > ST Nucleo WL55JC
HARDWARE: STM32WL55JC 48MHz, 64KB RAM, 256KB Flash
DEBUG: Current (stlink) On-board (stlink) External (cmsis-dap, jlink)
PACKAGES: 
 - framework-arduinoststm32 @ 4.21200.0 (2.12.0) 
 - framework-cmsis @ 2.60300.0 (6.3.0) 
 - framework-cmsis-dsp @ 1.16.2 
 - toolchain-gccarmnoneeabi @ 1.120301.0 (12.3.1)