[cfe-dev] AST XML dump

[Douglas Gregor]

On May 13, 2009, at 3:43 AM, Olaf Krzikalla wrote:

> Hi @clang-community,
>
> I've recently started a C(++)-source-to-source translation project.  
> The
> project is open-source and thus all the components involved needs to  
> be
> open-source too.
> The goal of the project is to semi-automatically rewrite and optimize
> parts of C(++) sources (C++ instead of C is a 'very-nice-to-have  
> feature').
> Currently I'm still in the evaluation phase. Obvisiously the first  
> thing
> I need is a parser. Beside gcc I found clang, sparse and the Ravi C
> parser as open source projects. Are there any others out there?

If C++ is important to you, GCC and Clang are the only two that are  
likely to handle the whole C++ language in the "near" future.

> From among these three projects clang seems to be the most promising
> project for my needs as it is already able to deal with some C++ (and
> according to cfe-commits the community is very active in this area).

Clang C++ is very active and support for C++ is improving rapidly.  
That said, we're still not to the point where we can handle even small  
applications (because we can't parse the C++ standard library headers  
yet). We're working on it!

> However one thing I badly need is a better AST dump. I'm now going to
> implement my own XML dump in clang since the current AST dump is  
> hard to
> parse. Any objections? (of course I can do what I want to do anyway,  
> but
> in the end I naturally want to contribute my additions to the clang
> project - so I better ask).


A good XML dump for Clang's representation would be a great addition  
to Clang. You might consider looking at GCC-XML's output format, since  
it is a decent representation of the C++ language in XML. GCC-XML is  
here:

	http://www.gccxml.org/HTML/Index.html

Matching the GCC-XML format means that other tools meant to work with  
GCC-XML (e.g., Pyste) could also work with Clang as a front end.

Since you mentioned source-to-source translation... Clang has a  
rewriter that allows you to replace certain parts of the source code  
(based on, e.g., a source range) with other code, without disturbing  
comments or formatting. If you're doing small, targeted rewrites in  
your source-to-source translation, it's something else to look at (and  
you won't need XML output to do it). Check out the Objective-C  
rewriter in the Clang source tree for an example (tools/clang-cc/ 
RewriterObjC.cpp).

	- Doug