system: support gcov output to stdout

[Gary-Hobson]

Summary

system: support gcov output to stdout

For detailed description, please refer to apache/nuttx#14838

Impact

Testing

qemu

[nuttxpr]

[Experimental Bot, please feedback here]

No, this PR does not fully meet the NuttX requirements as described. While it provides a link to a more detailed description, the PR summary itself lacks crucial information. It doesn't explain why this change is necessary, how it works, or what functional part of the code is changed within the PR description itself. Relying solely on an external link is discouraged.

The Impact section is entirely empty. This is a significant omission. At a minimum, it needs to address all the listed points, even if the answer is "NO" for most.

The Testing section is also insufficient. It simply states "qemu." It needs to specify the host operating system, compiler details, the specific qemu target architecture/board/configuration, and, crucially, the actual testing logs before and after the change. Simply stating "qemu" offers no evidence of testing efficacy.

Therefore, to meet the requirements, the PR needs to:

1. Expand the Summary: Explain the rationale for supporting gcov output to stdout, describe the code changes made to achieve this (e.g., which files were modified and how), and explicitly state the functional area affected (e.g., system/build system/debugging tools). While linking to the full PR is helpful, the core information should be present within the description itself.

2. Complete the Impact section: Address each point, even if the answer is "NO." Justify each answer. For example, if there's no user impact, explain why.

3. Provide detailed testing information: Specify the build host OS, CPU, compiler (including version), the target architecture, board, and configuration used with qemu. Most importantly, include the actual before and after testing logs demonstrating the change's effect.

[cederom]

Build errors come from dependency on apache/nuttx#14838 (review) right?

[Gary-Hobson]

Build errors come from dependency on apache/nuttx#14838 (review) right?

This is because the sim environment does not support __gcov_info_to_gcda, which causes compilation errors. It has been fixed.

[cederom]

@cederom: Build errors come from dependency on apache/nuttx#14838 (review) right?

@Gary-Hobson: This is because the sim environment does not support __gcov_info_to_gcda, which causes compilation errors. It has been fixed.

Hmm.. is it possible to make it work also on Sim? That sounds like a perfect candidate for experimentation because no real hardware is involved it can be build on any available build host and it could be part of CI..? :-)

[Gary-Hobson]

Hmm.. is it possible to make it work also on Sim? That sounds like a perfect candidate for experimentation because no real hardware is involved it can be build on any available build host and it could be part of CI..? :-)

In fact, it is easier to use the tools provided by the toolchain in the sim.
This mini version is to solve the problem of using it on some devices without storage media.

You can view the code coverage report directly in the simulator by following the steps below

./tools/configure.sh sim:nsh
make -j

+CONFIG_COVERAGE_ALL=y
+CONFIG_COVERAGE_TOOLCHAIN=y
+CONFIG_HAVE_CXXINITIALIZE=y
+CONFIG_SYSTEM_GCOV=y

bash> ./nuttx/nuttx
nsh>  gcov -d /tmp   #  "/"  can be any existing path
bash> ./nuttx/gcov.sh gcov-13
bash> microsoft-edge ./gcov/result/index.html

These two different methods will output the same result

[cederom]

Thank you @Gary-Hobson this is great utility! :-)

Could you please also update documentation in a free moment? Descrption of what this tool does, what are the use cases, and examples would be perfect to have.. for not it is empty https://nuttx.apache.org/docs/latest/applications/system/gcov/index.html :-)