[cfe-dev] [PATCH] Fixit for incorrect includes

[Aaron Ballman]

On Tue, Jul 17, 2012 at 12:10 PM, David Blaikie <dblaikie at gmail.com> wrote:
> On Tue, Jul 17, 2012 at 9:14 AM, Aaron Ballman <aaron at aaronballman.com> wrote:
>> This patch creates a fixit for include directives where the file could
>> not be found when using angle brackets, but can be found when using
>> quotes.  The converse is not needed since quoted includes will search
>> angle bracket locations by default.
>>
>> Eg)
>> #include <header.h>  // can be found via #include "header.h" instead
>>
>> Thoughts?
>
> Seems like a neat idea to me - but I'm not an authoritative sign-off.
>
> You used NULL as null constants for 2 of the conditional operators,
> then 0 for the third - that seems inconsistent. You might want to
> check what the prevailing style is in this file & stick to that
> (generally in LLVM, '0' seems to be winning as the authoritative null
> pointer constant, I believe).

Easy enough to rectify (I'll standardize on 0) -- this was a copy from
above, so I'll fix up there as well.

> Did you consider adding this case to the existing fixit testing files?
> They're already a grab-bag of things that can be fixed (this helps
> keep the test suite fast by not adding more separate test file
> executions) & this seems like it'd be at home there.

I thought about it, but it strikes me as different enough to warrant
its own test case.  Specifically, the fixit behavior is kind of
tricky.  Because the fixit writes out a separate file, but in a
different directory, I have to be a bit sneaky otherwise the header
file isn't available.  This is because the temp file goes to the
Output directory, but the header file remains in the FixIt directory.
To work around this, I copy the testcase to a temp file, modify the
testcase file directly with the fixit, then copy the temp back
(restoring the original contents).

> [& this makes me wonder: how scary (would it even be
> possible/practical?) would it be to do typo correction on #includes?
> Though we should check if it's worthwhile first - I wonder how often
> people make typos there]

I was wondering the same thing.  For instance, one (perhaps) simple
extension would be to try a case insensitive search for the file and
suggest the proper casing if the file cannot be found.  This is
especially interesting to x-platform developers where OS X and *nix
are generally case sensitive files, and Windows is generally case
insensitive.

~Aaron