[cfe-dev] Using libclang to determine the location of a completion result

[Peter Geoghegan]

Hello,

I'm a user of clang_complete, a vim plugin that uses libclang's python
bindings to provide really nice code-completion for users of the vim
text editor:

https://github.com/Rip-Rip/clang_complete

As great as this is, it is functionally inferior to Omnicppcomplete in
one area: The lack of information about completion results.
Omnicppcomplete optionally provides information about the filename
that the declaration of the just-completed/highlighted for completion
symbol came from. As far as I can tell, it is impossible for
clang_complete to support this, due to the lack of upstream support. I
refer specifically to this comment within the CXCompletionResult
struct:

04031    * \todo In the future, we would like to provide a full cursor, to allow
04032    * the client to extract additional information from declaration.
04033    */

So, with completion implemented essentially by calling
clang_codeCompleteAt(), I can see no way of working backwards to
obtain some basic information pertaining to the
just-completed/previewed token. However, I have an idea that other
text editors do support something along the same lines. I wonder, do
they employ some trickery like immediately obtaining a CXCursor for
the symbol under the text editor's cursor after completion is
finished? It would be tricky to get that to work while traversing a
visual list of possible completions (for each completion), so I hope
the actual trick is much cleverer than that. Also, I don't suppose
that someone has plans to take the time to complete this todo item?

Thanks
-- 
Peter Geoghegan       http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training and Services