improve process to prevent warnings

[bmcdonnell-ionx]

Description

The number of compiler warnings has grown over time. Please consider implementing one or both of the following:

• Improve documentation to encourage contributors to check for and resolve any compiler warnings before merge.
• Add CI tests to enforce no compiler warnings allowed. (Preferred, I think.)

Related: #7885, #6305

Issue request type

[ ] Question
[X] Enhancement
[ ] Bug

[mattbrown015]

Also related, mbed should be compilable with "-Werror" #7312
[Mirrored to Jira]

[0xc0170]

Improve documentation to encourage contributors to check for and resolve any compiler warnings before merge.

This should be covered by docs, we will review (cc @AnotherButler)

Add CI tests to enforce no compiler warnings allowed. (Preferred, I think.)

This is definitely needed. We already discussed this. The referenced PR above by @mattbrown015 . There is this comment: #7312 (comment). believe we should put something in place soon and keep it under control and fix one by one.

cc @OPpuolitaival
[Mirrored to Jira]

[bmcdonnell-ionx]

I don't quite understand #7312 (comment). What is the part about +15 warnings?
[Mirrored to Jira]

[0xc0170]

My proposal is to start monitoring warnings (each PR would be checked against master and get the total number of warnings in the PR and comparison against master - how many it adds/removes - so +/- count. I believe just the latter should be sufficient). An example Total: 352 warnings (+10 warnings) -any positive number in the compared count to master (like that +10) would turn PR red.
[Mirrored to Jira]

[bmcdonnell-ionx]

any positive number in the compared count to master (like that +10) would turn PR red.

Sounds good to me.

The examples numbers you're using (352, +10, +15) suggested to me that you're not concerned with single warnings. I think you are, but to be clear: the goal should be Total: 0 warnings (+0 warnings).
[Mirrored to Jira]

[adbridge]

Internal Jira reference: https://jira.arm.com/browse/MBEDOSTEST-165