[Bug c/69415] -Wmisleading-indentation warns on "if (__b < __a) return __b; return __a;"

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69415

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #3)
> (In reply to David Malcolm from comment #1)
> > Jonathan: do you have a sense of how likely we are to see the above
> > construct in copies of the STL lurking in 3rd-party codebases?  (or, indeed,
> 
> I'd be surprised if many such things exist.
> 
> > people compiling their own STL implementations with gcc 6)
> 
> I don't think this has anything to do with the STL, or the C++ standard
> library in general, IMHO it's just as likely to occur in any C++ code (the
> resipMin example is nothing to do with the standard library).
> 
> The author of the old libstdc++ code obviously wanted to keep the function
> body to a single line, which isn't something unique to std::lib writers :-)
> That case is different to the resipMin one though, the old libstdc++ code
> has the braces on the same line, which doesn't cause any warning.

Although the history you show reveals that for a while we did have the layout
that triggers the warning.

> Also, when the entire function body is on a single line (except possibly the
> braces) it's debatable whether there is any "indentation" at all, let alone
> misleading indentation :-)

Thinking further about this, the warning would be reasonable for:

void foo(int a, int b)
{
  if (cond1)
  {
    if (cond2) return a; return b;
  }

  // more code here ...
}

In that case the fact you have "return return" doesn't stop it being
misleading, so maybe the right heuristic here is to continue warning except for
one-liners where the entire function body (modulo opening and closing braces)
is a single line.