[cfe-dev] Tips for optimising libclang

[Tobias Grosser]

On 04/04/2013 07:20 AM, Miguel Guedes wrote:
> On Wed, 2013-04-03 at 14:30 -0400, Sean Silva wrote:
>> Can you suggest a specific improvement to the documentation that would
>> help avoid this issue in the future?
>>
>
> Well, I find that a difficult question to answer because my mother
> tongue isn't English and so you could argue that the documentation is
> clear enough and it was I who failed to understand it.
>
> However, my personal opinion is that indeed it could do with some
> improvements designed to remove (what I think are) ambiguities and to
> make it easier for users who lack in-depth knowledge of clang, libclang
> or compiler technologies in general, as is my case, to use (lib)clang
> and develop. My personal opinion is the clearer the documentation is the
> less noise (like this very thread) the core cfe-devs would (perhaps) get
> in this mailing list; noise, which I'm sure is annoying - it took me
> awhile before I finally convinced myself I should post here.
>
> As requested, here's a few suggestions based on my (most) limited
> knowledge of libclang:
>
> * Creation of precompiled preamble
>
>    There's no mention in the documentation about the issue that Tobias
> raised in this thread; that the preamble is only created after the TU is
> parsed a second time. IOW, the documentation should make it clear that
> one must issue clang_parseTranslationUnit, followed by
> clang_reparseTranslationUnit to ensure the preamble is created.
>
>    BTW, no one has commented on whether this is a bug or a feature. I
> take it it's the former?

For me this looks like a bug or a behavior that is so surprising that it 
should be mentioned in the documentation. It would be really good if 
some clang autocompletion expert could comment on this.

Tobi