cxxtest: optional stream test

[cuiziwei1]

Summary

skip the locale related test if libc doesn't enable CONFIG_CXX_LOCALIZATION.

Impact

cxxtest

Testing

ci

[nuttxpr]

[Experimental Bot, please feedback here]

I need the content of the PR to assess if it meets the requirements. Please provide the following:

• The actual changes made in the PR: A link to the PR or a description of the code modifications.
• The PR description: This usually contains information about the purpose and details of the changes.

With this information, I can then evaluate the PR against the NuttX requirements and provide you with a concise answer.

[cederom]

This is CPP test, you cannot remove C++ specific calls here, rejecting.

PR without description will be rejected, see https://github.com/apache/nuttx/blob/master/CONTRIBUTING.md.

If you think otherwise please reopen and explain the concept in detail.

[xiaoxiang781216]

This is CPP test, you cannot remove C++ specific calls here, rejecting.

why? locale is an optional feature in nuttx libc, so c++ test code should skip locale related test if libc close this feature.
BTW, the test case still keep and run if you enable CONFIG_CXX_LOCALIZATION, so I don't see any reason to reject this patch.

PR without description will be rejected, see https://github.com/apache/nuttx/blob/master/CONTRIBUTING.md.

If you think otherwise please reopen and explain the concept in detail.

Update.

[cederom]

Thanks @xiaoxiang781216 :-)

It is reaaaallly important to write good description of the PR, there was none. Contributing Guidelines were updated to provide examples, there is a reference at top of PR report, we even created PR AI BOT to suggest how the description can be improved to help in quick/good assessment. We have a lot of PR to analyze so we need the description why change is necessary, what it fixes/adds, what is the testing result before and after, so PR dont break more than it fixes. We cannot blindly accept undocumented PRs because things start falling apart :-)

C++ NuttX maintainers would be the best person to ask for a review here, I don't work with C++ sorry, if they give a GO you have my GO too. I have requested a review support on dev@ mailing list :-)

What I don't like here is replacing std::cout (C++ way) with printf (C way) and there is no explanation why this is necessary. I know C++ folks don't like this kind of stuff. It was here before for a reason right? :-)

[xiaoxiang781216]

Thanks @xiaoxiang781216 :-)

It is reaaaallly important to write good description of the PR, there was none. Contributing Guidelines were updated to provide examples, there is a reference at top of PR report, we even created PR AI BOT to suggest how the description can be improved to help in quick/good assessment. We have a lot of PR to analyze so we need the description why change is necessary, what it fixes/adds, what is the testing result before and after, so PR dont break more than it fixes. We cannot blindly accept undocumented PRs because things start falling apart :-)

Yes, it always good to request the contributor to add the detailed description.

C++ NuttX maintainers would be the best person to ask for a review here, I don't work with C++ sorry, if they give a GO you have my GO too :-)

Most C++ change in NuttX contributes by my team, so I am a good candidate to review the related change.

What I don't like here is replacing std::cout (C++ way) with printf (C way) and there is no explanation why this is necessary.

Because cin/cout depends on locale to pass the build, that's why to replace the code which call cin/cout unconditionally, the conditional part still keep as before:
https://github.com/apache/nuttx-apps/pull/2722/files#diff-9d02d89b087be466dd6bbdf41f260690b28365e09a162260f69e20ce7a4e2896R110
https://github.com/apache/nuttx-apps/pull/2722/files#diff-9d02d89b087be466dd6bbdf41f260690b28365e09a162260f69e20ce7a4e2896R141

I know C++ folks don't like this kind of stuff. It was here before for a reason right? :-)

cout/cin is very code size consumption:
https://github.com/apache/nuttx-apps/blob/master/testing/cxxsize/README.md
it's good to avoid iostream in embedded space.

here is the patch to reduce libcxx code size:
apache/nuttx#13721
apache/nuttx#14244
apache/nuttx#14250

[cederom]

Thank you @xiaoxiang781216 for the detailed explanation, now all clear :-)

• C++ code wrapped conditionally and executed properly when enabled.
• printf in place of std:: to reduce embedded code size where possible.

You see two sentences of explanation and things look totally different :-) :-)

[xiaoxiang781216]

Yes, @cuiziwei1 please update the pr, it's always important to describe the change clearly.