-Wshadow warnings

[wrgallo]

Platform

ESP32

IDE / Tooling

pioarduino

What happened?

Compiling the library esp32async/ESPAsyncWebServer @ 3.12.1 with the build_flags -Wshadow results in lots of warnings that requires attention, specially the declaration of 'i' shadows a previous local.

WebRequest.cpp

• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 47, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 55, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 63, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 70, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 78, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 86, Col 30]
• declaration of 'i' shadows a previous local [-Wshadow] [Ln 191, Col 18]
• declaration of 'i' shadows a previous local [-Wshadow] [Ln 204, Col 20]
• declaration of 'i' shadows a previous local [-Wshadow] [Ln 221, Col 18]

Stack Trace

Does not apply

Minimal Reproductible Example (MRE)

Compile the library esp32async/ESPAsyncWebServer @ 3.12.1 with the build flag -Wshadow.

I confirm that:

• I have read the documentation.
• I have searched for similar discussions.
• I have searched for similar issues.
• I have looked at the examples.
• I have upgraded to the lasted version of ESPAsyncWebServer (and AsyncTCP for ESP32).

[mathieucarbou]

@wrgallo : how this is an issue ?

[mathieucarbou]

• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 47, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 55, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 63, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 70, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 78, Col 30]
• declaration of 'AsyncClient* c' shadows a parameter [-Wshadow] [Ln 86, Col 30]

For these, if you look carefully at the code you'll see that these are false warnings. There is no shadowing in reality because the lambdas are not capturing anything.

[mathieucarbou]

@wrgallo : feel free to open a PR to clean that if you want / need. There is also some occurences in AsyncWebSocket.cpp.

The shadowing here, although not desirable, is controlled and this is a purely readability / cosmetic change to fix these warning.

There is no bug whatsoever.

[wrgallo]

@wrgallo : feel free to open a PR to clean that if you want / need. There is also some occurences in AsyncWebSocket.cpp.

The shadowing here, although not desirable, is controlled and this is a purely readability / cosmetic change to fix these warning.

There is no bug whatsoever.

The shadow warnings for the lambdas are usually not a problem indeed, but the declaration of 'i' shadows a previous local can be a very critical issue and will always require atention to make sure it isn't. So even if in this case it is a purely comestic change, it is recommended a fix, as it may be seen as poor coding quality.

I've openned this as a issue because I usually add build flags to treat warnings as errors. Also sometimes the "compile without any warnings" is a condition for any commits, so I decided to report.

I will be creating a pull-request to fix this later. Could you show me a snippet that would trigger the shadowing inside AsyncWebSocket.cpp too?

[mathieucarbou]

I think in AsyncWebSocket.cpp this was a false positive also. Some class variable names if I remember.

[mathieucarbou]

Thanks in advance for the PR ! Any improvement is more than welcomed :-)

[mathieucarbou]

@wrgallo : I have opened the PR #487