Partial coverage reported on exception lines (MacOS, clang, DWARF-4)

[gl3n91]

Hi,

I’m quite new to both kcov and C++, so this may be due to misuse on my end. However, I’ve noticed that coverage reports show only partial coverage on lines containing exceptions, with the containing methods trailing bracket always reported as completely uncovered. Is this a limitation of kcov's binary inspection form of coverage, a potential issue, or simply misuse?

Environment:

• macOS
• clang (compiled with -gdwarf-4 to work around #485)

Please let me know if additional details would help.

Thanks!

[SimonKagstrom]

Yes, unfortunately it's how it works. Kcov really knows nothing about the high-level code, and only parses the DWARF information. Sometimes, multiple addresses map to the same line, and you'll get these partial hits. Depending on how the code looks, you can also find them for if-statements and so on. As for the uncovered bracket line, it's probably possible to figure out the path through disassembling the function, but kcov will try to instrument it anyway.

These days I mainly (almost exclusively!) use it with the coverage-gutters vscode plugin, which doesn't show partial lines anyway, so I don't see this that much.

Thanks for the -gdwarf-4 hint!