[cfe-dev] Is Clang what I need?

[David Blaikie]

On Mon, Jan 7, 2013 at 1:29 PM, Pedro Delgado Perez
<pedro.delgadoperez at mail.uca.es> wrote:
> Thank you very much David.
>
> Which interface would you recommend me to use for my purpose? I don't
> understand really well what are the difference among them (LibClang,
> Plugins, LibTooling or Clang Tools) and i would need to know the best option
> for me. What I want is to create a tool reusing Clang only to analyze C++
> programs. If you need more information to give me an answer, please tell me
> what you would need to know.

If you're trying to do AST-matched source code transformations what
you probably want is to use libTooling (to write a "Clang Tool") along
with the AST matchers.


[The one thing still pending that blocks truly streamlined refactoring
tools using this infrastructure is the ability to automatically format
the modified code so it's still legible (eg: re-wrapping lines when
changing an identifier makes it shorter/longer), there's currently
work underway (in the form of "clang-format") to support this. Once
this functionality is combined with tooling and AST matchers we should
have the ability to write fairly ad-hoc C++ refactoring tools that
Just Work]

[+Manuel to this thread in case he has anything to add]

- David

>
> Thanks,
>
> Pedro D.
>
> El dia 07 ene 2013 17:29, David Blaikie <dblaikie at gmail.com> escribió:
>
> On Mon, Jan 7, 2013 at 2:44 AM, Pedro Delgado Perez
> <pedro.delgadoperez at mail.uca.es> wrote:
>
> Hello,
> I've just known Clang looking for a soution to the task i need to perform.
> Well, what I need is to parser a C++ program in order to get some
> information about the code and, after that, to change the code regarding
> that information collected.For instance, I would need to know if a certain
> program contains some arithmetic operators., obtaining a record with the
> line where the operator is located and which operator is. I've been reading
> about Clang and now I know you can go through the AST, but i'm not totally
> sure if it's what I'm looking for because apart from the example I've
> commented above, I would need a lot of kinds of information:- What are the
> global and the local variables.- If there is an overriden member when a
> class inherits from another.- If a method of a class is overloaded.-...I
> need that information because I have to change the original program once I
> have the record with the information. For instance, if in the code there is
> a reference to an overriden member, I have to turn that reference into the
> hidden member.
>
>
>
> The other question I have is: is it worth the effort and the time to learn
> how to use clang? I need an opinion to know how easy or tough is to learn
> how to use it.
>
> I hope you could lend me a hand. Thanks in advance.
>
> It depends a little on what alternatives you're considering. Clang
> isn't necessarily going to be easy to get started with, especially
> making source modifications, avoiding conflicts, etc, but it's
> probably the easiest thing available to do this job well.
>
> The tooling infrastructure ( http://clang.llvm.org/docs/Tooling.html )
> and AST Matchers ( http://clang.llvm.org/docs/LibASTMatchers.html )
> are designed to make this sort of task as easy & painless as possible.
>
> - David