Re: [RFC stage 1] Proposed new warning: -Wmisleading-indentation

[Mike Stump <mikestump at comcast dot net>]

On Apr 16, 2015, at 8:01 AM, David Malcolm <dmalcolm@redhat.com> wrote:
> Attached is a work-in-progress patch for a new
>  -Wmisleading-indentation
> warning I've been experimenting with, for GCC 6.

Seems like a nice idea in general.

Does it also handle:

if (cone);
  stmt;

?  Would be good to add that to the test suite, as that is another hard to spot common error that should be caught.

I do think that it is reasonable to warn for things like:

  stmt;
    stmt;

one of those two lines is likely misindented, though, maybe you want to start with the high payback things first.

> An issue here is how to determine (i), or if it's OK to default to 8

Yes, 8 is the proper value to default it to.

> and have a command-line option (param?) to override it? (though what about,
> say, each header file?)

I’ll abstain from this.  The purist in me says no option for other than 8, life goes on.  20 years ago, someone was confused over hard v soft tabbing and what exactly the editor key TAB does.  That confusion is over, the 8 people have won.  Catering to other than 8 gives the impression that the people that lost still have a chance at winning.  :-)

> Thoughts on this, and on the patch?

Would be nice to have a stricter version that warns about all wildly inconsistently or wrongly indented lines.

{
  stmt;
    stmt;  // must be same as above
}

{
stmt; // must be indented at least 1
}

if (cond)
stmt;  // must be indented at least 1