[llvm-cov] issues about merging llvm-cov output to generate coverage html report

[cyrilhuang]

In our practice to generate coverage report, we utilize all workers to run coverage jobs parallelly. Currently, each worker will use llvm-profdata to merge profraw, then use llvm-cov export to generate lcov files. After that, we'll merge all lcov files in a single machine, then we can create a final coverage report using genhtml.

However, since llvm provides more coverage metrics than lcov, like MC/DC, so I try to use llvm-cov show -format=html to directly generate html report. It seems that llvm-cov show doesn't support merge the html reports, or even the json reports. The only way to generate one report is to run all jobs in one machine.

So my question is, is there any llvm tools that can help merge all reports from llvm-cov, and output a final html report. Or do I have other options to generate coverage html reports in my previous way, and able to visualize all coverage metrics that llvm provides?

[evodius96]

So my question is, is there any llvm tools that can help merge all reports from llvm-cov, and output a final html report. Or do I have other options to generate coverage html reports in my previous way, and able to visualize all coverage metrics that llvm provides?

Hello! I implemented MC/DC and branch coverage. Presently there is no tool that can merge visualization html reports, although if you use llvm-cov export to dump a JSON, you could write a script to merge that data. Otherwise you have to merge the profile data using the llvm-profdata tool before visualization.