Skip to content

C++20 compatibility: a lot of warnings #8916

Open
@MacDada

Description

@MacDada

Basic Infos

  • This issue complies with the issue POLICY doc.
  • I have read the documentation at readthedocs and the issue is not addressed there.
  • I have tested that the issue is present in current master branch (aka latest git).
  • I have searched the issue tracker for a similar issue.
  • If there is a stack dump, I have decoded it.
  • I have filled out all fields below.

Platform

  • Hardware: [ESP-8266]
  • Core Version: [v3.0.2]
  • Development Env: [Platformio]
  • Operating System: [MacOS]

Settings in IDE

  • Module: [nodemcuv2]

Problem Description

I've set a flag to compile with the latest (available) standard: -std=gnu++20.

It works, but it produces a lot of warnings, for example:

.platformio/packages/framework-arduinoespressif8266/cores/esp8266/core_esp8266_si2c.cpp:576:33: warning: '++' expression of 'volatile'-qualified type is deprecated [-Wvolatile]
  576 |         twi_data = twi_txBuffer[twi_txBufferIndex++];
      |                                 ^~~~~~~~~~~~~~~~~
.platformio/packages/framework-arduinoespressif8266/cores/esp8266/core_esp8266_si2c.cpp:579:9: warning: '--' expression of 'volatile'-qualified type is deprecated [-Wvolatile]
  579 |         bitCount--;
      |         ^~~~~~~~
.platformio/packages/framework-arduinoespressif8266/cores/esp8266/core_esp8266_si2c.cpp:588:18: warning: compound assignment with 'volatile'-qualified left operand is deprecated [-Wvolatile]
  588 |         twi_data <<= 1;
      |         ~~~~~~~~~^~~~~
.platformio/packages/framework-arduinoespressif8266/cores/esp8266/core_esp8266_si2c.

They are all connected to the fact that starting with C++20, some of the volatile operations are deprecated: https://blog.feabhas.com/2021/05/modern-embedded-c-deprecation-of-volatile/

  1. Is there a plan for better support of C++20?
  2. Are you open for PRs in this matter?

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions