Ghc的配置文件和代码覆盖范围选项有冲突吗？

Question

For GHC, if I add the -fhpc option while the -prof -fprof-auto options are enabled, GHC does not add any cost centers to the code, and the profiling report shows only CAFs. However, if I remove -fhpc profiling works fine. Is there a reason for this? Is there a way to enable both of these features?

Answer 1

There is no deep reason behind this - the simple truth of the matter is that GHC's "Coverage" pass is only run once (at maximum), and only ever generates one kind of annotation.

I think at this point it would mainly be a question of somebody putting in a bit of time to implement a fix and properly check that mixtures of annotations don't cause bad side-effects. Opening a GHC ticket for this particular issue might be a good idea - especially if you have a good use-case.