Options for tagging function in source

Clang Frontend
1

Hi,

I'm investigating possible solutions for tagging one or more functions of interest within C / C++ source code. By using clang I'd like to get the name of the tagged function. I "only" have two requirements:

- Not much more code required for tagging (best case is a one-liner)
- Implementation should be a clang plugin

So far there are three ideas how to achieve this:

1. Use #pragma tag <NameOfTag>. This would be the preferred solution, but as far as I have seen clang does not support #pragma plugins. Or is this information wrong and plugins for pragmas can be done somewhow?

2. Use __attribute__. Here I'm not sure whether, e.g.

     void foo(args) __attribute__((tag <NameOfTag>))

is usable within clang, since I wasn't able to implement this for instance by using hasAttr() within a ASTConsumer, the return value is always false.

3. Use a label, e.g. tag_<NameOfTag>:. Right now this is the solution I'm using, but here I have to ensure that no one re-uses this label which is rather hard to achieve, although I assume that no one uses labels within C / C++ these days, but you never know.

So, maybe I'm missing something (or my assumptions are wrong) and it would be nice to get some feedback regarding this.

Thanks,
Sebastian

2

Hi, Sebastian. I'd suggest using the [[annotate]] attribute, then checking each declaration afterwards to see if it has the tag. That requires no changes to the existing code, just an ASTConsumer in your plugin.

void test(int) __attribute__((annotate("NameOfTag")));

Best,
Jordy

3

Hi Jordy,

thanks. This works as expected.

Cheers,
Sebastian

4

So, maybe I'm missing something (or my assumptions are wrong) and it
would be nice to get some feedback regarding this.

clang already supports "annotate" attribute. See e.g.
http://llvm.org/devmtg/2011-11/Gregor_ExtendingClang.pdf for more
information