https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110827
--- Comment #6 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #5)
> (In reply to Iain Sandoe from comment #2)
> > (In reply to Richard Biener from comment #1)
> > > I'm seeing all code properly instrumented. The coverage I see is
> > <snip>
> > > 1: 27:task foo() {
> > > -: 28: std::cout << "Running..." << std::endl;
> > > -: 29: co_return;
> > > 2: 30:}
> > <snip>
> > >
> > > I have no idea why for example line 28 isn't marked executed.
> >
> > So we are recognising that the ramp function has run:
> > foo () {
> > .... compiler-generated code with no line numbers
> > }
> >
> > but execution of the the outlined body (which is the 'actor' function) is
> > not, apparently recorded.
> >
> > The actor is essentially:
> >
> > foo.actor()
> > .. compiler-generated code no line numbers
> > {
> > std::cout << "Running..." << std::endl;
> > co_return;
> > }
> > .. compiler-generated code no line numbers
> >
> > co_return expands to some compiler-generated code too - so it's possible the
> > line numbers get confusing there - but the cout line ought to be
> > uncontroversial.
>
> Hmm, OK. I see both 'task foo' and _Z3fooPZ3foovE13_Z3foov.Frame.actor
> printed as functions "foo" in the IL dump.
We have to do that or debug and things like __PRETTY_FUNCTION__ get confused
(which led to other Pas).
> Maybe coverage is somehow confused here.
Perhaps, I do not know much about how the coverage stuff is supposed to
operate.
coroutine 'helper' functions are marked as such in the function struct - so it
is possible to special-case them.
> Maybe coverage doesn't work with nested functions (or C++ lambda) either?
the coroutine helpers are not (formally) nested i.e. they do _not_ use the
nested.cc machinery or a STATIC_CHAIN. (actually, AFAIU lambdas are the same).
However, they are both probably 'artificial' and/or anonymous?
> As said, there are edge counters present so it must be either a bug on
> the receiving side (in gcov) or the data is not appropriately attributed.
The basic shape of the coroutine helper functions is 'normal' (other than
being
artificial) - most of the work is already complete before gimplification - the
idea being that they should look as normal as possible to the middle end to
allow maximum opportunity for optimisation.
