Combine trace output with the code coverage report

[sema]

Create one single HTML report with code coverage, trace output, and links associating the two with each other.

The trace output should either provide links to the code they refer to, or allow for quick expansion of the code inline.

[BenSpencer]

I have been working on some HTML output of the traces as a step towards this. Currently there is no link to the coverage report. A couple of questions:

What do you think the best way to link the trace and the code/coverage report is? It could be by line/column number or by bytecode. I think bytecode seems more robust, but I am not clear whether we can identify each one, or ideally a range from a function call to return. What do you think?

Secondly, what options should we have to enable this HTML report. Is adding this as an extra option to --path-trace-report too clunky (so you would write something like "--path-trace-report click html")? Should this combine with the coverage report option ready for when they are linked?

[sema]

I would also prefer to do this on a bytecode level, this will give us a much more detailed picture later on.

So if we want to link from trace to code coverage, we could link each function call to the beginning of the function in the source code (where it is declared). I would think that the "first" bytecode handled after each function call could be used to identify it.