[llvm-dev] Clang API: any way to use a virtual filesystem ?

[Jacob Carlborg via llvm-dev]

On 2020-10-05 09:44, Jean-Michaël Celerier via llvm-dev wrote:

> My question is: is it possible to hook something in clang to allow it to 
> go look for files inside a virtual file system à la 
> https://github.com/yevgeniy-logachev/vfspp for instance ? This way I 
> would only download the zip, not extract it, and it'd be just opened in 
> ram when needed.
> Or does it necessarily go through fopen() for includes right now ?

I have a tool where I use libclang (the C API). For the internal 
headers, I've embedded those inside the executable, to avoid the need to 
ship them separately or have the users to install them.

What I do is for each header file I create a `CXUnsavedFile` [1].  Then 
I can pass that to `clang_parseTranslationUnit` when parsing the source 
files.

`CXUnsavedFile` expects the filename and the content of the file. If you 
can get that, you should be able to use the same approach.

If you're using the C++ API, you can have a look at the implementation 
of `clang_parseTranslationUnit` to see how to do the same using the C++ API.

[1] https://clang.llvm.org/doxygen/structCXUnsavedFile.html
[2] 
https://clang.llvm.org/doxygen/group__CINDEX__TRANSLATION__UNIT.html#ga2baf83f8c3299788234c8bce55e4472e

-- 
/Jacob Carlborg