ament_clang_tidy - Fix Reporting when WarningsAsErrors is specified in config

[mwcondino]

Issue Summary

When WarningsAsErrors is specified in .clang-tidy, this can lead to some failures in result reporting. Specifically, the following test program (src/factorial.cpp):

int Factorial(int n) {
    int result = 1;
    int fake = 1;
    for (int i = 1; i <= n; i++) {
        result *= i;
    }
    return result;
}

fails with this output:

The invocation of "clang-tidy" failed with error code 1: Command '['/usr/bin/clang-tidy', '-p', 'path/test_examples_cmake', '--header-filter', 'include/test_examples_cmake/.*', 'path']' returned non-zero exit status 1.

when running ament_clang_tidy.

After applying this fix, I get the following output, which is expected

src/factorial.cpp:36:9: error: unused variable 'fake' [clang-diagnostic-unused-variable,-warnings-as-errors]
    int fake = 1;
        ^

Relevant section of .clang-tidy, for reference:

Checks:
    'bugprone*,
     clang-analyzer*,
     cert*,
     performance*,
     portability*,
     readability*,
     hicpp*,
     -hicpp-signed-bitwise,
     google-readability-todo,
    '
FormatStyle:     file
WarningsAsErrors: '*'

Fix

By trying to access the output attribute of the raised exception, we can populate the output in cases where exceptions were raised and there was valid output.

[mwcondino]

hey @mjeronimo, could you take a look when you get a chance?

[mhidalgo-bdai]

This looks like a small enough fix and I happen to have been hit by #411 too. @marcoag @clalancette do you think we could get this in any time soon?

[clalancette]

This looks like a small enough fix and I happen to have been hit by #411 too. @marcoag @clalancette do you think we could get this in any time soon?

Yeah, this looks reasonable enough. I'm going to rebase it and then run CI on it.

[clalancette]

CI:

• Linux
• Linux-aarch64
• Windows

[mwcondino]

Thanks for the bump @mhidalgo-bdai , and thanks for merging @clalancette!

[mhidalgo-bdai]

@clalancette thank you! Could we also ask the Mergify bot for a Humble backport?

[clalancette]

@Mergifyio backport humble iron jazzy

[mergify]

backport humble iron jazzy

✅ Backports have been created

• #488 ament_clang_tidy - Fix Reporting when WarningsAsErrors is specified in config (backport #397) has been created for branch humble
• #489 ament_clang_tidy - Fix Reporting when WarningsAsErrors is specified in config (backport #397) has been created for branch iron
• #490 ament_clang_tidy - Fix Reporting when WarningsAsErrors is specified in config (backport #397) has been created for branch jazzy